阅读说明：本技术 车身下部结构 (Vehicle body lower structure ) 是由 露崎匠 今村壮吾 森荣茂树 吉永圭太 小泽裕之 新田贵志 山田誉 芝田泰之 于 2018-05-18 设计创作，主要内容包括：车身下部结构具备：下边梁载荷传递构件(52、56),其设于下边梁(14、15)的内部；地板横梁(35),其设于在所述下边梁(14、15)之间架设的地板(16)的上表面(16a)和下表面(16b)中的一方,具有朝向所述下边梁载荷传递构件(52、56)的上部(56a)延伸的延出部(108)；地板下方搭载部件(28),其设于所述地板(16)的下方,具备地板下方横梁(131)；地板下方框架(29、30),其安装于所述地板下方搭载部件(28)及所述下边梁(14、15)的下部；地板下方载荷传递构件(152),其设于所述地板下方框架(29、30),与所述地板下方横梁(131)对置,所述地板下方载荷传递构件(152)具有：与所述下边梁载荷传递构件(52、56)的下部(56b)对置的上半部(152a)；以及固定于所述地板下方框架(29、30)中的安装于所述下边梁(14、15)的下部的部位的下半部(152b)。(The vehicle body lower portion structure includes: rocker load transmission members (52, 56) provided inside the rocker (14, 15); a floor cross member (35) that is provided on one of the upper surface (16a) and the lower surface (16b) of a floor (16) that is laid between the rocker beams (14, 15), and that has an extension section (108) that extends toward the upper section (56a) of the rocker load transmission members (52, 56); a underfloor mounting member (28) provided below the floor (16) and including an underfloor cross member (131); underfloor frames (29, 30) attached to the underfloor mounting member (28) and the lower portions of the rocker beams (14, 15); a underfloor load transmission member (152) provided to the underfloor frames (29, 30) and facing the underfloor cross member (131), the underfloor load transmission member (152) comprising: an upper half (152a) that faces a lower portion (56b) of the rocker load transmitting member (52, 56); and a lower half section (152b) fixed to a portion of the underfloor frames (29, 30) that is attached to the lower portion of the rocker beams (14, 15).)

1. A vehicle body lower portion structure is characterized in that,

the vehicle body lower portion structure includes:

a rocker load transmitting member provided inside the rocker;

a floor cross member provided on one of an upper surface and a lower surface of a floor panel that is erected between the rocker beams, and having an extension portion that extends toward an upper portion of the rocker load transmission member;

a underfloor mounting member provided below the floor and including an underfloor cross member;

a underfloor frame attached to the underfloor mounting member and a lower portion of the lower side beam; and

a underfloor load transfer member provided to the underfloor frame and opposed to the underfloor cross member,

the underfloor load transfer member includes:

an upper half portion that faces a lower portion of the rocker load transmitting member;

and the lower half part is fixed at the part, arranged at the lower part of the lower edge beam, in the under-floor frame.

2. The vehicle body lower structure according to claim 1,

the under-floor cross member has left and right side members disposed on the left and right sides in the vehicle width direction and a center member disposed substantially at the center in the vehicle width direction,

the left and right side members and the center member are formed in a substantially hat-shaped cross-sectional shape in cross section,

an upper surface of the center beam is formed lower than upper surfaces of the left and right side beams,

a recessed portion communicating in the front-rear direction of the vehicle body is formed by the upper surface of the center rail and the vehicle-widthwise inner ends of the left and right side rails,

the left and right side members are coupled to the floor cross member above, and are coupled to the center member in the vicinity below a coupling portion coupled to the floor cross member.

3. The vehicle body lower structure according to claim 1,

the underfloor cross member is formed in an inverted T-shaped cross section, and has: a beam main body portion that rises upward and whose upper portion is coupled to the floor cross member via a fastening member; a front extension base extending forward from a lower edge of the beam main body; and a rear extension base extending rearward from a lower edge of the beam main body,

the front extension seat and the rear extension seat are combined on the bottom wall of the storage battery shell.

4. The vehicle body lower structure according to claim 1,

the vehicle body lower portion structure further includes a frame portion disposed outside the under-floor mounting member and opposed to the inner corner portion,

the under-floor mounting member includes the under-floor cross member opposed to the frame portion,

the frame portion includes:

an engaging portion opposed to the inner corner; and

and an inclined portion extending obliquely upward from a lower surface side of the underfloor mounting component toward a lower end portion of the rocker flange so that an imaginary extension line intersects the rocker flange.

5. The vehicle body lower structure according to claim 1,

the floor beam is arranged on the upper surface of the floor,

the extension part extends to the lower edge beam with a descending slope,

a gusset plate is provided between the lower surface of the floor panel and the inner wall of the rocker, the gusset plate being erected at a distance from the extension.

6. The vehicle body lower structure according to claim 1 or 5,

the upper half portion of the underfloor load transmitting member is disposed at the same height as the rocker load transmitting member,

the lower half portion of the underfloor load transfer member is disposed at the same height as a portion of the underfloor frame that is attached to a lower portion of the rocker,

the upper half part and the lower half part are fixed on the frame below the floor.

7. The vehicle body lower portion structure according to any one of claims 1, 5, and 6,

the underfloor frame has:

a frame inner wall portion facing the underfloor mounting member; and

a frame extension portion extending from the frame inner wall portion along a bottom portion of the underfloor mounting member,

the under-floor cross member is disposed inside the under-floor mounting member,

the underfloor cross member is formed of a pillar portion and a seat portion,

the column part stands from a bottom part of the underfloor loading component, and an end part of the column part, which is opposed to the upper half part of the underfloor load transmitting member, is fixed to a side wall of the underfloor loading component,

the seat portion extends from the pillar portion along the bottom portion, and is fixed to the frame extension portion via the bottom portion.

8. The vehicle body lower structure according to claim 7,

the underfloor mounting member includes a cross member extending along the seat portion in a state of being fixed to an outer surface of the bottom portion, and having a rib bulging toward the bottom portion,

the seat portion is fixed in a state of being overlapped with the bottom portion of the underfloor mounting component and the cross member.

9. The vehicle body lower structure according to claim 8,

the underfloor frame has:

a mounting top mounted to a lower portion of the lower sill;

a mounting outer wall portion extending downward from the mounting top portion;

a mounting base portion extending on the same plane relative to the frame extension from the mounting outer wall portion to the frame extension; and

a connecting portion that is offset downward from the attachment bottom portion and is fixed to the frame extension portion,

the underfloor frame is formed in a U-shaped section by the mounting top, the mounting outer wall portion, and the mounting bottom.

10. The vehicle body lower structure according to claim 8 or 9,

the under-floor frame is erected on the left and right side walls of the carrying component under the floor,

the seat section is provided continuously in the vehicle width direction between the left and right underfloor frames,

the cross member is provided so as to extend in the vehicle width direction on the left and right sides with a space therebetween at the center in the vehicle width direction,

the vehicle body lower portion structure includes side members that are disposed between the left and right side cross members, extend in the vehicle body front-rear direction, and are fixed to the bottom portion of the under-floor mounting member.

11. The vehicle body lower structure according to claim 2,

the left and right side members are provided with a pair of partition wall members fixed to at least three surfaces of a front wall, an upper wall and a rear wall of the side members,

the pair of partition wall members are provided at front and rear positions of a joint portion with the floor cross member in the extending direction of the side member.

12. The vehicle body lower structure according to claim 11,

the center beam is coupled to the left and right side beams at a lower region of the partition wall member.

13. The vehicle body lower structure according to claim 12,

stud bolts fastened to the upper walls of the side members are used at the joints where the left and right side members are joined to the floor cross member,

the pair of partition wall members are provided in front and rear of positions where the stud bolts protrude in the extending direction of the side member.

14. The vehicle body lower structure according to claim 13,

a battery and the underfloor cross member are disposed inside the battery case,

the battery case includes a case body having an upper side opening and a case cover for closing the opening of the case body,

the stud bolt has a threaded portion protruding upward of the housing cover and is fastened and fixed to the floor cross-member side by the threaded portion,

the bolt body of the stud bolt is held in the through hole of the housing cover by an elastic seal member.

15. The vehicle body lower structure according to claim 14,

a bracket having a through hole is installed in the floor cross member, and a work hole facing the through hole is provided in an upper wall of the floor cross member,

and fastening and fixing a nut to the screw portion of the stud bolt protruding upward from the through hole through the working hole.

16. The vehicle body lower structure according to any one of claims 2, 11 to 15,

an auxiliary partition member that substantially closes a gap between a lower surface of the side member and an upper surface of the center member is coupled to the center member and the vehicle width direction inner end edges of the left and right side members.

17. The vehicle body lower structure according to any one of claims 2, 11 to 16,

the underfloor cross member includes a forward projecting seat projecting forward from a lower edge of the front wall and a rearward projecting seat projecting rearward from a lower edge of the rear wall,

the front extension seat and the rear extension seat are disposed on the upper surface side of the bottom wall of the battery case, and the lower surface reinforcing member is disposed on the lower surface side of the bottom wall,

the front protruding seat and the rear protruding seat are combined with the lower surface reinforcing member in a state of sandwiching the bottom wall therebetween.

18. The vehicle body lower structure according to claim 17,

the lower surface reinforcing member is joined to the lower surface of the bottom wall so as to extend substantially in the vehicle width direction,

a further lower surface reinforcing member extending substantially in the front-rear direction of the vehicle body is joined to the lower surface of the bottom wall.

19. The vehicle body lower structure according to any one of claims 2, 11 to 18,

the vehicle body lower portion structure further includes a load transmission plate that is erected on the upper surfaces of the left and right side members.

20. The vehicle body lower structure according to claim 3,

the front extension seat and the rear extension seat are arranged on the upper surface side of the bottom wall of the storage battery shell,

a lower surface reinforcing member is disposed on a lower surface side of the bottom wall,

the front protruding seat and the rear protruding seat are combined with the lower surface reinforcing member in a state of sandwiching the bottom wall therebetween.

21. The vehicle body lower structure according to claim 20,

the lower surface reinforcing member is formed of a plate-like member having a substantially wave-shaped cross section extending substantially in the vehicle width direction.

22. The vehicle body lower structure according to claim 20,

the battery case has case side walls rising upward from left and right end portions of the bottom wall,

a housing frame extending substantially in the front-rear direction of the vehicle body is coupled to the outer side of the housing side wall,

the case frame has an extension piece disposed on a lower surface of the bottom wall of the battery case to constitute the lower surface reinforcing member,

the front extension seat and the rear extension seat are combined with the extension piece in a state of clamping the bottom wall therebetween.

23. The vehicle body lower structure according to any one of claims 3 and 20 to 22,

the beam main body portion of the under-floor cross beam has an upper wall, a front wall extending downward from a front portion of the upper wall, and a rear wall extending downward from a rear portion of the upper wall,

a partition member that restricts three surfaces of the upper wall, the front wall, and the rear wall of the beam body is coupled to the beam body in the vicinity of a fixing portion of the fastening member.

24. The vehicle body lower structure according to any one of claims 3 and 20 to 23,

the floor panel is disposed above the battery case,

the floor cross member is provided with:

a cross plate joined to an upper surface of the floor panel and having a substantially hat-shaped cross section, the cross plate forming a closed cross section extending substantially in a vehicle width direction with the floor panel, and both ends in the vehicle width direction being bridged to the pair of rocker beams; and

a gusset inclined portion having a substantially hat-shaped cross section, which is provided so as to bridge between a lower surface of an end region of the floor panel in the vehicle width direction and a side surface of the rocker, and which forms a closed cross section extending substantially in the vehicle width direction with the floor panel,

the gusset inclined portion and the gusset inclined portion are formed so as to be inclined downward toward the outside in the vehicle width direction,

a bracket serving also as a cross-sectional reinforcement portion is attached to the inside of the center region of the cross plate in the vehicle width direction,

the bracket is coupled to the beam main body portion of the under-floor cross beam by the fastening member.

25. The vehicle body lower structure according to claim 24,

a battery and the underfloor cross member are disposed inside the battery case,

the battery case includes a case body having an upper side opening and a case cover for closing the opening of the case body,

the fastening member is a stud bolt having both end portions fastened to the bracket and the underfloor cross member,

the bolt body of the stud bolt is held in the through hole of the housing cover by an elastic seal member.

26. The vehicle body lower structure according to claim 22,

a mounting frame for coupling the case frame to a lower surface of the lower side sill is coupled to the case frame,

a frame extension piece overlapped with the lower surface of the extension piece of the shell frame is extended and arranged on the mounting frame,

the frame extension piece is combined with the extension piece to the bottom wall of the battery case.

27. The vehicle body lower structure according to any one of claims 3 and 20 to 26,

the beam main body portion of the under-floor cross beam includes an upper wall, a front wall extending downward from a front portion of the upper wall, and a rear wall extending downward from a rear portion of the upper wall,

a reinforcing plate having a substantially コ -shaped cross section and joined to the upper wall, the front wall, and the rear wall is disposed inside the beam body.

28. The vehicle body lower structure according to any one of claims 3 and 20 to 27, wherein,

the front and rear protruding seats include a base portion that bulges upward, has a lower surface that communicates with the internal space of the beam main body, and has a substantially flat upper surface.

29. The vehicle body lower structure according to claim 4,

the frame portion is provided on an outer peripheral wall of the underfloor mounting member, and is formed into an L-shaped closed cross section with the inclined portion by the engaging portion.

30. The vehicle body lower structure according to claim 4 or 29,

the rocker is provided with:

a lower side member outer member on the outer side in the vehicle width direction;

a rocker inner member joined to the rocker outer member from a vehicle width direction inner side to form a closed cross section together with the rocker outer member; and

a first energy-absorbing member disposed at the closed cross section and attached to the rocker outer member.

31. The vehicle body lower portion structure according to any one of claims 4, 29, and 30,

the frame portion includes a second energy-absorbing member disposed inside.

32. The vehicle body lower structure according to any one of claims 4 and 29 to 31, wherein,

an upper portion of the underfloor cross member is disposed so as to face a central portion in a vertical direction of the rocker.

33. The vehicle body lower structure according to any one of claims 4 and 29 to 32,

the underfloor cross member includes:

a fragile portion formed in an outer region on the outer side in the vehicle width direction; and

and a fastening portion formed in an inner region on the inner side in the vehicle width direction.

34. The vehicle body lower structure according to any one of claims 4 and 29 to 33,

the under-floor cross member is formed in a hollow shape, and includes a partition wall provided at a center in a vertical direction and vertically partitioning the under-floor cross member.

35. The vehicle body lower structure according to any one of claims 4 and 29 to 34, wherein,

the vehicle body lower portion structure further includes a first floor cross member and a second floor cross member extending in the vehicle width direction along the upper surface of the floor panel and spaced apart in the vehicle body front-rear direction,

the first floor cross member and the second floor cross member are formed in a hat shape in cross section by a top portion, a pair of wall portions, a front flange and a rear flange,

the front flange and the rear flange are joined to an upper surface of the floor panel,

a seat is supported by the first floor beam and the second floor beam,

the first floor cross member has a first recess recessed upward in a wall portion opposed to the second floor cross member,

the second floor cross member has a second recess recessed upward in a wall portion opposed to the first floor cross member,

the floor panel has a raised portion that rises upward along the first recessed portion and the second recessed portion.

36. The vehicle body lower structure according to claim 35,

the floor lower cross member is connected to the floor below the first floor cross member and the second floor cross member.

37. The vehicle body lower structure according to any one of claims 4 and 29 to 36,

the under-floor cross member has a recess formed with a downward recess at the center in the vehicle width direction,

the vehicle body lower portion structure includes a pipe housing portion that is attached to the recess so as to extend in the vehicle body front-rear direction, and that houses at least one of a pipe and a hose.

Technical Field

The present invention relates to a vehicle body lower portion structure.

The present application claims priority based on the Japanese application laid-open in Japanese patent application No. 2017-100755, published in Japanese application laid-open in Japanese patent application No. 2017-106655, published in Japanese application laid-open in Japanese patent application No. 2017-106656, published in Japanese patent application No. 2017-05-30, and published in Japanese application laid-open in Japanese patent application No. 2017-100110330, published in Japanese patent application No. 2017-06-02, and the contents thereof are incorporated herein by reference.

Background

As a vehicle body lower portion structure, for example, the following structure is known: a floor panel is provided between the left and right side sills, a floor cross member is provided on the upper surface of the floor panel, and a battery pack is mounted below the floor panel. A battery is housed inside the battery package. The battery in the battery package needs to be protected from a load input from the side of the vehicle.

Therefore, the height of the rocker is increased and the energy absorbing member is provided inside the rocker. And, a floor cross member is provided toward the energy-absorbing member. Therefore, the energy absorbing member is crushed by the impact load input from the side of the vehicle, and the impact load can be absorbed by the energy absorbing member.

This can suppress deformation of the side wall of the battery case, and protect the battery in the battery package (i.e., the underfloor mounting member) (see, for example, patent document 1).

As a lower structure of a vehicle, the following structure is known: a battery case for housing a plurality of batteries is provided between the left and right side sills of the vehicle body (see, for example, patent documents 2 and 3).

In the lower structure of the vehicle described in patent document 2, the battery case disposed below the floor panel is mounted on the left and right side sills. A battery cross member extending in the vehicle width direction is coupled to the inside of the battery case. The battery cross member extends substantially in the vehicle width direction and is joined to the peripheral wall and the bottom wall of the battery case. The storage battery beam has the following functions: when an impact load is input to the rocker from a side, a space is secured on the inside in the vehicle width direction, and the input load is transmitted to the inside in the vehicle width direction. The battery cross member is formed to have a substantially constant cross section in the vehicle width direction.

However, in a vehicle in which a battery cross member is erected in a battery case, it is desirable to provide a recess for allowing a member such as a wiring cable to pass through the recess in an upper portion of the battery cross member. Patent document 3 describes a lower structure of a vehicle that can respond to such a desire.

In the lower structure of the vehicle described in patent document 3, the battery cross member includes a lower cross member that is bridged between the left and right side walls of the battery case, and an upper cross member that is coupled to an upper portion of the lower cross member. The upper cross member is divided into two blocks in a central region in the vehicle width direction, and the two blocks are coupled to an upper portion of the lower cross member in a state of being separated in the left-right direction. Thus, a recess through which a wiring cable or the like can be inserted is formed between the two blocks of the upper cross member.

In the lower structure of the vehicle described in patent document 3, the battery case disposed below the floor panel is mounted on the left and right side sills. A battery cross member extending in the vehicle width direction is coupled to the inside of the battery case. The battery cross member has a vertically long rectangular cross section extending substantially in the vehicle width direction and is joined to the peripheral wall and the bottom wall of the battery case. The storage battery beam has the following functions: when an impact load is input to the rocker from a side, a space portion is defined at the inside in the vehicle width direction, and the input load is transmitted to the inside in the vehicle width direction.

In the lower structure of the vehicle described in patent document 3, a vehicle-body-side cross member extending substantially in the vehicle width direction on the floor is disposed above the battery cross member. Both ends in the vehicle width direction of the vehicle body side cross member are bridged to the left and right rocker members, and the center region in the vehicle width direction is connected to the battery cross member below via a fastening member. A seat belt anchor for supporting a seat belt of a seat belt apparatus is fixed to the vehicle body side cross member.

Further, as a vehicle body lower portion structure, there is known a structure including: for example, an energy absorbing member is provided inside the rocker, a battery pack is provided below the floor panel, and a battery cross member is provided inside the battery pack. The battery package accommodates a battery.

According to the vehicle body lower portion structure, the impact load input from the side of the vehicle can be absorbed by the energy absorbing member, and the excess load can be supported by the battery cross member. This can protect the battery pack (i.e., the battery) from an impact load input from the side of the vehicle.

However, in a passenger car (sedan) of a vehicle type, a lower end portion of a rocker is disposed at a height substantially equal to a minimum ground height dimension. Therefore, the lower surface (i.e., the bottom portion) of the battery package is disposed at substantially the same height as the lower end portion of the rocker.

Since the lower surface of the battery package is disposed at substantially the same height as the lower end of the rocker, the battery package can be hidden from view from the outside of the vehicle.

Further, since the lower surface of the battery pack is disposed at substantially the same height as the lower end of the rocker, the energy absorbing member inside the rocker absorbs the impact load input from the side of the vehicle, and then the battery cross member can support the remaining load. This can protect the battery pack (i.e., the battery) from an impact load input from the side of the vehicle (see, for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

However, the height of the rocker of the vehicle body lower portion structure of patent document 1 increases. Thus, the upper portion of the rocker is located above the floor. Therefore, the rocker becomes an obstacle when the passenger gets on or off the vehicle, and it is difficult to ensure good getting-on/off performance of the passenger.

In addition, the height of the rocker is increased, which hinders suppression of the weight of the rocker (i.e., the vehicle body weight).

Accordingly, an object of the present invention is to provide a vehicle body lower portion structure that can protect underfloor mounting components from an impact load input from a side of a vehicle while ensuring good boarding and alighting performance of passengers.

In the lower structural body described in patent document 3, since the upper cross member and the lower cross member are formed of extruded metal having a large thickness, sufficient rigidity for receiving an impact load from the side of the vehicle body can be relatively easily secured. However, when the main part of the battery cross member is formed of an extruded member as in the lower structure described in patent document 3, there is a concern that the manufacturing cost will increase.

Accordingly, an object of the present invention is to provide a vehicle lower structure in which a recessed portion communicating in the front-rear direction is formed in a substantially central region of a battery cross member in the vehicle width direction, and sufficient rigidity in the vehicle width direction is secured without causing an increase in manufacturing cost.

In the lower structure of the vehicle described in patent document 3, the battery cross member is formed in a vertically long rectangular cross-sectional shape, and the lower end thereof is welded and fixed to the upper surface of the bottom wall of the battery case. Therefore, there is a fear that: when a large load in the front-rear direction is input to the vehicle body side cross member by the seat belt anchor and the load is transmitted to the upper portion of the battery cross member via the fastening member, the battery cross member collapses in the front-rear direction due to a moment acting on the battery cross member.

Therefore, an object of the present invention is to provide a lower structure of a vehicle that can suppress collapse of a battery cross member in the front-rear direction and maintain high support rigidity of a vehicle body side cross member when a load in the front-rear direction is input from the vehicle body side cross member to the battery cross member.

However, as a vehicle model of a vehicle, suv (sports vehicle) is known. The lower side rail of the SUV is provided at a higher position than the vehicle of the passenger car. Therefore, when the battery pack is mounted on the SUV, the lower surface of the battery pack can be disposed below the rocker. The battery package can be made large by disposing the lower surface of the battery package below the rocker.

However, when the lower surface of the battery pack is disposed below the rocker, the lower portion of the battery cross member is disposed below the rocker. Therefore, it is difficult to transmit the impact load input from the side of the vehicle to the lower portion of the battery cross member. Therefore, it is difficult to support the impact load by the lower portion of the battery cross member, and a design for protecting the battery pack (i.e., the underfloor mounting component) from the impact load is desired.

Therefore, an object of the present invention is to provide a vehicle body lower portion structure that can protect underfloor mounting components from an impact load input from the side of a vehicle in a state where the lower surface of a battery package is disposed below a rocker.

Means for solving the problems

As a means for solving the above problems, the present invention has the following configuration.

(1) The vehicle body lower portion structure according to the aspect of the present invention includes: a rocker load transmitting member provided inside the rocker; a floor cross member provided on one of an upper surface and a lower surface of a floor panel that is erected between the rocker beams, and having an extension portion that extends toward an upper portion of the rocker load transmission member; a underfloor mounting member provided below the floor and including an underfloor cross member; a underfloor frame attached to the underfloor mounting member and a lower portion of the lower side beam; a underfloor load transmission member provided to the underfloor frame and opposed to the underfloor cross member, the underfloor load transmission member including: an upper half portion that faces a lower portion of the rocker load transmitting member; and the lower half part is fixed at the part, arranged at the lower part of the lower edge beam, in the under-floor frame.

According to the vehicle body lower portion structure of the present invention described in the above (1), the rocker load transmitting member is provided inside the rocker. The extended portion of the floor cross member is extended toward the upper portion of the rocker load transmitting member. Further, the underfloor load transfer member is opposed to the underfloor cross member. The upper half of the underfloor load transmitting member is opposed to the lower portion of the rocker load transmitting member. The lower half of the underfloor load transfer member is connected to the lower portion of the rocker via the underfloor frame.

Therefore, when an impact load is input from the side of the vehicle, a part of the impact load is transmitted to the floor cross member through the upper portion of the rocker load transmitting member via the first load path. Further, the remaining part of the impact load is transmitted to the underfloor cross member through the lower portion of the rocker load transmitting member and the upper half portion of the underfloor load transmitting member via the second load path.

The remainder of the impact load is transmitted to the underfloor cross member through the lower portion of the rocker, the underfloor frame, and the lower half portion of the underfloor load transmitting member via the third load path.

In this way, the impact load input from the side of the vehicle can be transmitted in a distributed manner via the transmission paths of the first load path, the second load path, and the third load path. Therefore, the floor cross member and the underfloor cross member can support the impact load. This can suppress collapse and deformation of the side wall of the underfloor mounting component, and can protect the underfloor mounting component from the impact load.

Further, the impact load inputted from the side of the vehicle is transmitted while being dispersed in the first to third load paths, so that it is not necessary to increase the height of the rocker and a rocker load transmission member is provided inside the rocker. This prevents the rocker from interfering with the boarding and alighting of the passenger, and enables the boarding and alighting performance of the passenger to be ensured satisfactorily.

In addition, the increase in the weight of the rocker (i.e., the vehicle body weight) can be suppressed without increasing the height of the rocker.

(2) In the vehicle body lower portion structure recited in the above (1), the under-floor cross member may include left and right side members disposed on left and right sides in a vehicle width direction, and a center member disposed at a substantially center in the vehicle width direction, the left and right side members and the center member may have a substantially hat-shaped cross section, an upper surface of the center member may be formed lower than upper surfaces of the left and right side members, a recess communicating in a front-rear direction of the vehicle body may be formed by an upper surface of the center member and vehicle width direction inner ends of the left and right side members, and the left and right side members may be coupled to the upper floor cross member, and may be coupled to the center member in a vicinity below a coupling portion coupled to the floor cross member.

According to the vehicle body lower portion structure of the present invention described in (2) above, the battery cross member is configured with the left and right side members and the center member, which are relatively simple to form, as main elements. Therefore, the left and right side members and the center member can be easily formed by press molding or the like. Further, since the recess is formed by the upper surface of the center beam and the end portions of the left and right side beams, the recess can be used as a through groove for a distribution cable or the like.

Further, since the left and right side members are coupled to the center member in the vicinity of the lower portion of the coupling portion coupled to the floor cross member, when an impact load is input to the side members through the rocker member from the side of the vehicle body, the input load can be supported while being dispersed between the floor cross member and the center member. Therefore, when this structure is adopted, it is possible to suppress bending of the battery cross member in the central region when an impact load is input from the rocker, while using the battery cross member that can be manufactured at low cost.

(3) In the vehicle body lower portion structure described in (1) above, the underfloor cross member may be formed in an inverted T-shaped cross-sectional shape, and may include: a beam main body portion that rises upward and whose upper portion is coupled to the floor cross member via a fastening member; a front extension base extending forward from a lower edge of the beam main body; and a rear extension base extending rearward from a lower edge of the beam main body, the front extension base and the rear extension base being coupled to a bottom wall of the battery case.

According to the vehicle body lower portion structure of the present invention described in (3), when a load in the front-rear direction is input to the vehicle body side cross member, the load is input to the upper portion of the beam main body portion of the battery cross member via the fastening member. Thus, a moment in a direction of tilting forward and backward acts on the beam main body, but a forward projecting seat and a backward projecting seat are provided extending forward and backward of the beam main body, and these projecting seats are coupled to the bottom wall of the battery case. Therefore, the collapse of the beam main body portion is suppressed by the forward projecting seat and the rearward projecting seat. As a result, the vehicle-body-side cross member is supported with high rigidity by the beam main body portion and the fastening member.

(4) In the vehicle body lower portion structure of the above (1), the vehicle body lower portion structure may further include a frame portion that is disposed outside the underfloor mounting member and that faces an inner corner, the underfloor mounting member may include the underfloor cross member that faces the frame portion, and the frame portion may include: an engaging portion opposed to the inner corner; and an inclined portion extending obliquely upward from a lower surface side of the underfloor mounting component toward a lower end portion of the rocker flange so that an imaginary extension line intersects the rocker flange.

According to the vehicle body lower portion structure of the present invention described in (4) above, the rocker flange of the rocker extends downward from the vehicle width direction outer side of the inner corner portion. The inclined portion of the frame portion extends from the lower surface side of the underfloor mounting member toward the lower end portion of the rocker flange in an upwardly inclined manner, and an imaginary extension line of the inclined portion intersects with the rocker flange. Therefore, the hidden by the rocker flange can be made so that the inclined portion is difficult to see from the outside of the vehicle. Thus, the large underfloor mounting member can be disposed below the rocker on the lower surface of the vehicle underfloor mounting member without affecting the appearance of the vehicle.

Further, by forming the inclined portion in the frame portion, a part of the impact load input from the side of the vehicle to the rocker can be transmitted as a so-called offset load to the lower portion of the underfloor cross member via the frame portion.

The upper portion of the underfloor cross member faces the rocker. That is, a part of the impact load input from the side of the vehicle to the rocker can be transmitted to the upper portion of the underfloor cross member.

Therefore, the impact load input from the side of the vehicle to the rocker can be transmitted while being dispersed between the upper portion and the lower portion of the under-floor cross member. This enables the underfloor cross member to support the impact load. As a result, the large underfloor mounting component disposed below the rocker on the lower surface of the underfloor mounting component can be protected from the impact load.

(5) In the vehicle body lower portion structure of the above (1), the floor cross member may be provided on an upper surface of the floor panel, the extension portion may extend to the rocker with a downward gradient, and a gusset plate may be provided between a lower surface of the floor panel and an inner wall of the rocker, the gusset plate being erected with a gap from the extension portion.

According to the vehicle body lower portion structure of the invention described in the above (5), the extension portion of the floor cross member is extended to the rocker with a descending gradient. A gusset plate is provided between the lower surface of the floor panel and the inner wall of the rocker panel, and the gusset plate is provided at a distance from the extended portion. Therefore, the extending portion and the gusset plate can form a cross section substantially identical to the cross section of the floor cross member. The cross section formed by the extended portion and the gusset plate can be substantially the same size as the floor cross member.

This makes it possible to favorably transmit the impact load input from the side of the vehicle to the floor cross member via the extension portion and the gusset, and to secure the first load path.

Further, by providing the floor cross member on the upper surface of the floor, the floor cross member can be removed from below the floor. This can increase the capacity of the mounting member provided below the floor panel.

(6) In the vehicle body lower portion structure of the above (1) or (5), the upper half portion of the underfloor load transmission member may be disposed at the same height as the rocker load transmission member, the lower half portion of the underfloor load transmission member may be disposed at the same height as a portion of the underfloor frame that is attached to a lower portion of the rocker, and the upper half portion and the lower half portion may be fixed to the underfloor frame.

According to the vehicle body lower portion structure of the present invention described in (6) above, the upper half portion of the underfloor load transmitting member is fixed, and the upper half portion is disposed at the same height as the rocker load transmitting member. Therefore, the second load path for transmitting the impact load from the rocker load transmitting member to the upper half portion of the underfloor load transmitting member can be ensured.

Further, the lower half portion of the underfloor load transfer member is fixed, and the lower half portion is disposed at the same height as a portion of the lower portion of the rocker beam attached to the underfloor frame. Therefore, a third load path for transmitting the impact load from a portion of the lower portion of the rocker beam mounted on the underfloor frame to the lower half of the underfloor load transmitting member can be ensured.

This makes it possible to reliably disperse the impact load input from the side of the vehicle to the underfloor cross member via the second load path and the third load path.

(7) In the vehicle body lower portion structure according to any one of the above (1), (5), and (6), the underfloor frame may include: a frame inner wall portion facing the underfloor mounting member; and a frame extension portion that extends from the frame inner wall portion along a bottom portion of the underfloor mounting member, wherein the underfloor cross member is disposed inside the underfloor mounting member, the underfloor cross member is formed of a pillar portion that stands from the bottom portion of the underfloor mounting member, an end portion that faces the upper half portion of the underfloor load transmission member is fixed to a side wall of the underfloor mounting member, and a seat portion that extends from the pillar portion along the bottom portion and is fixed to the frame extension portion via the bottom portion.

According to the vehicle body lower portion structure of the present invention described in the above (7), the end portion of the pillar portion of the underfloor cross member is fixed to the side wall of the underfloor mounting member. Therefore, the second load path for transmitting the impact load from the upper half portion of the underfloor load transmitting member to the pillar portion of the underfloor cross member can be ensured.

Further, the seat portion of the underfloor cross member is fixed to the frame extension portion via the bottom portion. Therefore, a third load path for transmitting the impact load from the frame extension portion (i.e., the underfloor frame) to the seat portion of the underfloor cross member can be ensured. This makes it possible to reliably disperse the impact load input from the side of the vehicle to the underfloor cross member via the second load path and the third load path.

(8) In the vehicle body lower portion structure of the above (7), the underfloor mounting member may include a cross member that extends along the seat portion in a state of being fixed to an outer surface of the bottom portion and that has a bead bulging toward the bottom portion, and the seat portion may be fixed in a state of being overlapped with the bottom portion of the underfloor mounting member and the cross member.

According to the vehicle body lower portion structure of the present invention described in (8) above, the seat portion of the underfloor cross member is fixed in a state of being overlapped with the bottom portion of the underfloor mounting member and the cross member. In addition, ribs are formed on the cross beam. The cross-sectional strength of the beam can be improved by the ribs. Therefore, the seat portion of the underfloor cross member can be firmly reinforced with the cross member. This can improve the transmission efficiency of the impact load in the third load path.

(9) In the vehicle body lower portion structure of the above (8), the underfloor frame may include: a mounting top mounted to a lower portion of the lower sill; a mounting outer wall portion extending downward from the mounting top portion; a mounting base portion extending on the same plane relative to the frame extension from the mounting outer wall portion to the frame extension; and a coupling portion that is offset downward from the mounting bottom portion and is fixed to the frame extension portion, wherein the underfloor frame is formed in a U-shaped cross section by the mounting top portion, the mounting outer wall portion, and the mounting bottom portion.

According to the vehicle body lower portion structure of the present invention as recited in the above (9), the mounting bottom portion of the underfloor frame extends on the same plane as the frame extension portion. Therefore, the attachment bottom portion and the extension portion of the underfloor frame extend linearly. This makes it possible to transmit the impact load linearly from the mounting bottom portion to the frame extension portion, and to improve the transmission efficiency of the third load path.

(10) In the vehicle body lower portion structure of the above (8) or (9), the under-floor frames may be mounted on left and right side walls of the under-floor mounting member, the seat portions may be provided continuously in the vehicle width direction between the left and right under-floor frames, the cross members may be provided so as to extend in the vehicle width direction on left and right sides with a space therebetween at a center in the vehicle width direction, and the vehicle body lower portion structure may include side members that are disposed between the left and right cross members, extend in the vehicle body front-rear direction, and are fixed to a bottom portion of the under-floor mounting member.

According to the vehicle body lower portion structure of the present invention described in (10) above, the seat portion (i.e., the underfloor cross member) and the cross member are provided at the bottom portion of the underfloor mounting member. Thus, the impact load input from the side of the vehicle can be supported by the seat portion (underfloor cross member) and the cross member.

In addition, the bottom of the underfloor mounting member is provided with a side member. This enables the side member to support the impact load input in the front-rear direction of the vehicle.

Further, the strength of the underfloor mounting member can be increased by providing the cross member and the side member at the bottom of the underfloor mounting member. This makes it possible to increase the size of the underfloor mounting member. For example, when the battery pack is applied as the underfloor mounting member, the battery storage capacity can be increased by enlarging the battery pack.

(11) In the vehicle body lower portion structure of the above (2), the left and right side members may be provided with a pair of partition wall members fixed to at least three surfaces of a front wall, an upper wall, and a rear wall of the substantially hat-shaped cross section of the side members, and the pair of partition wall members may be provided at front and rear positions of a joint portion with the floor cross member in an extending direction of the side members.

According to the vehicle body lower portion structure of the present invention described in (11) above, since the cross section at the front-rear position of the joint portion where each side member and the floor cross member are joined can be firmly reinforced by the partition wall member, it is possible to suppress the cross section of the side member from collapsing in the vicinity of the joint portion where the side member and the floor cross member are joined when an impact load is input from the vehicle body side direction to the side member.

(12) In the vehicle body lower portion structure of the above (11), the center rail may be coupled to the left and right side rails in a region below the partition wall member.

According to the vehicle body lower portion structure of the present invention described in (12) above, the inside of the closed cross section formed by joining the center member and the left and right side members can be reinforced by the partition wall members, and therefore, the crushing of the cross section of the side members can be more effectively suppressed.

(13) In the vehicle body lower portion structure of the above (12), stud bolts fastened to the upper walls of the side members may be used at the coupling portions where the left and right side members are coupled to the floor cross member, and the pair of partition wall members may be provided in front and rear of the projecting positions of the stud bolts in the extending direction of the side members.

According to the vehicle body lower portion structure of the present invention described in (13) above, the floor cross member separated in the up-down direction and the left and right side members can be easily coupled by the stud bolts. In addition, the closed cross section formed by the center beam and the side beams and the partition wall member can suppress crushing of the cross section at the fastening portion of the stud bolt of the left and right side beams.

(14) In the vehicle body lower portion structure of the above (13), the battery and the under-floor cross member may be disposed inside a battery case, the battery case may include a case main body having an upper side opening and a case cover closing an opening of the case main body, the stud bolt may have a threaded portion that protrudes upward of the case cover and is fastened and fixed to the under-floor cross member side by the threaded portion, and a bolt portion of the stud bolt may be held in a through hole of the case cover by an elastic sealing member.

According to the vehicle body lower portion structure of the present invention described in (14) above, since the plug portion of the stud bolt is held in the through hole of the housing cover by the elastic sealing member, it is possible to finely adjust the position and direction of the screw portion projecting upward of the housing cover when the floor cross member is fastened to the stud bolt. Therefore, when this structure is adopted, the floor cross member can be made to have good fastening workability to the stud bolts. Further, the elastic sealing member can prevent water from entering the battery case through the through hole of the case cover.

(15) In the vehicle body lower portion structure of the above (14), a bracket having a through-hole may be attached to the floor cross member, a work hole may be provided in an upper wall of the floor cross member so as to face the through-hole, and a nut may be fastened and fixed to the screw portion of the stud bolt protruding upward from the through-hole through the work hole.

According to the vehicle body lower portion structure of the present invention described in (15), the rigidity of the floor cross member can be improved by the bracket. Further, since the floor cross member is provided with the working hole facing the through hole of the bracket, the screwing operation of the nut to the screw portion of the stud bolt can be easily performed through the working hole.

(16) In the vehicle body lower portion structure of any one of the above (2) and (11) to (15), an auxiliary partition member that substantially closes a gap between a lower surface of the side member and an upper surface of the center member may be coupled to the center member at the vehicle width direction inner end edges of the left and right side members.

According to the vehicle body lower portion structure of the present invention described in (16), the auxiliary partitioning wall member can suppress the crushing of the cross section of the vehicle transverse direction inner end edges of the left and right side members, and the rigidity of the battery cross member can be further improved. Further, since the gap between the vehicle width direction inner end edges of the left and right side members and the center member is substantially closed by the auxiliary partition member, it is possible to suppress entry of foreign matter into the side members from the vehicle width direction inner end portions of the left and right side members.

(17) In the vehicle body lower portion structure recited in any one of the above (2) and (11) to (16), the under-floor cross member may include a front protruding seat protruding forward from a lower edge of the front wall and a rear protruding seat protruding rearward from a lower edge of the rear wall, the front protruding seat and the rear protruding seat may be disposed on an upper surface side of a bottom wall of the battery case, a lower surface reinforcing member may be disposed on a lower surface side of the bottom wall, and the front protruding seat and the rear protruding seat may be coupled to the lower surface reinforcing member with the bottom wall interposed therebetween.

According to the vehicle body lower portion structure of the present invention described in (17) above, the front protruding seat and the rear protruding seat of the battery cross member are coupled to the lower surface reinforcing member with the bottom wall of the battery case interposed therebetween, and therefore, the lower ends of the battery cross member in the front and rear direction can be supported by the battery case with high rigidity.

(18) In the vehicle body lower portion structure of the above (17), the lower surface reinforcing member may be joined to a lower surface of the bottom wall so as to extend substantially in the vehicle width direction, and a separate lower surface reinforcing member extending substantially in the front-rear direction of the vehicle body may be further joined to the lower surface of the bottom wall.

According to the vehicle body lower portion structure of the present invention described in (18) above, the bottom wall of the battery case is reinforced by the lower surface reinforcing member extending substantially in the vehicle width direction and the other lower surface reinforcing member extending substantially in the front-rear direction of the vehicle body, and therefore, the rigidity of the entire bottom wall of the battery case can be improved.

(19) In the vehicle body lower portion structure of any one of the above (2) and (11) to (18), the vehicle body lower portion structure may further include a load transmission plate that is bridged over upper surfaces of the left and right side members.

According to the vehicle body lower portion structure of the present invention described in (19), the bending rigidity of the battery cross member in the vehicle width direction central region can be effectively improved by the load transmission plate. Further, since the bending rigidity of the battery cross member can be effectively improved only by installing the load transmission plates on the upper surfaces of the left and right side members, it is possible to suppress an increase in manufacturing cost for reinforcing the members.

(20) In the vehicle body lower portion structure of the above (3), the front extension socket and the rear extension socket may be disposed on an upper surface side of a bottom wall of the battery case, a lower surface reinforcing member may be disposed on a lower surface side of the bottom wall, and the front extension socket and the rear extension socket may be coupled to the lower surface reinforcing member with the bottom wall interposed therebetween.

According to the vehicle body lower portion structure of the present invention described in (20) above, the front protruding seat and the rear protruding seat of the battery cross member are integrated with the bottom wall of the battery case together with the lower surface reinforcing member, and therefore, the collapse of the beam main body portion of the battery cross member in the front-rear direction can be more firmly suppressed. In addition, in the case of this structure, the members to be joined can be formed by press-formed members that can be manufactured at low cost, and the members can be welded and fixed to each other.

(21) In the vehicle body lower portion structure of the above (20), the lower surface reinforcing member may be formed of a plate-like member having a substantially wave-shaped cross section extending substantially in the vehicle width direction.

According to the vehicle body lower portion structure of the present invention described in (21), since the substantially wave-shaped cross section of the plate-shaped member as the lower surface reinforcing member extends substantially in the vehicle width direction on the lower surface side of the bottom wall of the battery case, the rigidity of the bottom wall of the battery case can be effectively improved by the plate-shaped lower surface reinforcing member.

(22) In the vehicle body lower portion structure of the above (20), the battery case may have case side walls rising upward from left and right end portions of the bottom wall, a case frame extending substantially in the vehicle body front-rear direction may be coupled to an outer side of the case side walls, the case frame may have an extension piece disposed on a lower surface of the bottom wall of the battery case to constitute the lower surface reinforcing member, and the front extension seat and the rear extension seat may be coupled to the extension piece with the bottom wall interposed therebetween.

According to the vehicle body lower portion structure of the present invention as recited in the above (22), the extension piece provided to the case frame is disposed on the lower surface of the bottom wall of the battery case, and the front extension seat and the rear extension seat of the battery cross member are integrated with the bottom wall and the extension piece of the battery case. This can more firmly suppress the collapse of the beam main body portion of the battery cross beam in the front-rear direction.

(23) In the vehicle body lower portion structure of any one of the above (3), (20) and (22), the beam main body portion of the under-floor cross member may have an upper wall, a front wall extending downward from a front portion of the upper wall, and a rear wall extending downward from a rear portion of the upper wall, and a partition member that restricts three surfaces of the upper wall, the front wall, and the rear wall of the beam main body portion may be coupled to the beam main body portion in the vicinity of a fixing portion of the fastening member.

According to the vehicle body lower portion structure of the present invention described in (23) above, since the cross-sectional rigidity in the vicinity of the fixing portion of the fastening member of the beam main body portion is increased by the partition member, the cross-sectional deformation in the vicinity of the fixing portion of the fastening member can be effectively suppressed. Therefore, even when the thickness of the beam main body portion has to be reduced in order to reduce the weight, the inclination movement and sinking of the fastening member can be suppressed, and the floor cross member can be supported with high rigidity by the battery cross member.

(24) In the vehicle body lower portion structure of any one of the above (3) and (20) to (23), the floor panel may be disposed above the battery case, and the floor cross member may include: a cross plate joined to an upper surface of the floor panel and having a substantially hat-shaped cross section, the cross plate forming a closed cross section extending substantially in a vehicle width direction with the floor panel, and both ends in the vehicle width direction being bridged to the pair of rocker beams; and a gusset inclined portion having a substantially hat-shaped cross section, which is provided so as to extend between a lower surface of an end region in the vehicle width direction of the floor panel and a side surface of the rocker, and which forms a closed cross section extending substantially in the vehicle width direction between the gusset inclined portion and the floor panel, wherein the end region in the vehicle width direction of the gusset inclined portion and the gusset inclined portion are formed so as to be inclined downward toward the outside in the vehicle width direction, a bracket serving also as a cross-sectional reinforcement portion is attached to an inner portion of a central region in the vehicle width direction of the cross panel, and the bracket is coupled to the beam main body portion of the underfloor cross beam by the fastening member.

According to the vehicle body lower portion structure of the present invention as recited in the above (24), since the end regions of the lateral plate in the vehicle width direction and the gusset plates are formed so as to be inclined downward toward the outside in the vehicle width direction, the closed cross section of the central region formed by the floor panel and the lateral plate and the inclined closed cross section of the end regions formed by the lateral plate and the gusset plates are continuous. Therefore, the left and right rocker members can be connected by the substantially constant continuous closed cross section of the vehicle-side cross member while the central region of the vehicle-side cross member is formed in a shape raised upward with respect to the rocker members. In addition, in the case of this configuration, since the center region of the vehicle-body side cross member is formed in a shape that is raised upward with respect to the rocker, the battery case disposed below the center region of the vehicle-body side cross member can be positioned on the upper side. Therefore, the ground height below the battery case can be easily ensured. The cross section of the center region of the cross plate is reinforced by a bracket serving also as a cross-section reinforcement portion, and the bracket is coupled to the battery cross member by a fastening member. Therefore, when a load is input to the vehicle-body side cross member, the input load can be supported by the battery cross member while suppressing the cross-sectional deformation of the cross plate.

(25) In the vehicle body lower portion structure of (24), the battery and the under-floor cross member may be disposed inside the battery case, the battery case may include a case main body having an upper side opening and a case cover closing the opening of the case main body, the fastening member may be a stud bolt having both end portions fastened to the bracket and the under-floor cross member, and a bolt portion of the stud bolt may be held in a through hole of the case cover by an elastic sealing member.

According to the vehicle body lower portion structure of the present invention described in (25) above, since the bolt portion of the stud bolt is held in the through hole of the housing cover by the elastic sealing member, it is possible to finely adjust the position and direction of the screw portion projecting upward of the housing cover when fastening and fixing the stud bolt to the vehicle body side cross member. Therefore, when this structure is adopted, the workability of fastening the vehicle body side cross member to the stud bolt is good. Further, since the through hole of the case cover is closed by the elastic sealing member, the penetration of water into the battery case through the through hole can be prevented. In this case, the vibration of the housing cover can also be suppressed by the elastic sealing member.

In addition, when the upper surface of the elastic sealing member is brought into contact with the circumferential region lower surface of the through hole of the floor panel, it is possible to prevent water that has passed through the through hole of the floor panel and enters the vehicle interior. In this case, the elastic sealing member can suppress vibration of the floor.

(26) In the vehicle body lower portion structure of the above (22), a mounting frame that connects the case frame to a lower surface of the rocker may be coupled to the case frame, a frame extension piece that overlaps a lower surface of the extension piece of the case frame may be extended from the mounting frame, and the frame extension piece may be coupled to the bottom wall of the battery case together with the extension piece.

According to the vehicle body lower portion structure of the present invention as set forth in the above (26), since the frame extension piece of the mounting frame and the extension wall of the case frame are joined to the bottom wall of the battery case so as to overlap three, it is possible to enhance the rigidity of the bottom wall of the battery case as well as to fasten the mounting frame to the case frame.

(27) In the vehicle body lower portion structure of any one of the above (3), (20) and (26), the beam main body portion of the under-floor cross member may have an upper wall, a front wall extending downward from a front portion of the upper wall, and a rear wall extending downward from a rear portion of the upper wall, and a reinforcing plate having a substantially コ -shaped cross section joined to the upper wall, the front wall, and the rear wall may be disposed inside the beam main body portion.

According to the vehicle body lower portion structure of the present invention described in (27) above, the rigidity of the beam main body portion to which the fastening member is fixed can be easily increased with a simple structure. In addition, the reinforcing plate can be formed of a press-formed member that can be manufactured at low cost. Therefore, the product cost can be reduced.

(28) In the vehicle body lower portion structure of any one of the above (3), (20) and (27), the front protruding seat and the rear protruding seat may include a base portion that bulges upward, has a lower surface that communicates with the internal space of the beam main body portion, and has a substantially flat upper surface.

According to the vehicle body lower portion structure of the present invention described in (28), the upper surface of each of the base portions provided on the front protruding seat and the rear protruding seat can be used as the battery support portion and the like. Further, the lower surfaces of the front and rear overhang seats can be widely communicated with the internal space of the beam body by the base portion rising upward, and therefore, the electrodeposition coating liquid for rust prevention can be easily spread to each corner of the inside of the battery beam during manufacturing.

(29) In the vehicle body lower portion structure of the above (4), the framework portion may be provided on an outer peripheral wall of the underfloor mounting member, and may be formed into an L-shaped closed cross section by the engagement portion and the inclined portion.

According to the vehicle body lower portion structure of the present invention as set forth in the above (29), the engagement portion faces the inner corner portion. The frame portion is formed into an L-shaped closed cross section by the engaging portion and the inclined portion. Therefore, the engaging portion is firmly formed in the frame portion. That is, the inner corner portion (i.e., the rocker) can be reliably received by the frame portion formed with the engaging portion. This enables the impact load input to the rocker to be reliably transmitted to the underfloor cross member via the frame portion. As a result, the transmitted impact load can be supported by the underfloor cross member.

(30) In the vehicle body lower portion structure of the above (4) or (29), the rocker may include: a lower side member outer member on the outer side in the vehicle width direction; a rocker inner member joined to the rocker outer member from a vehicle width direction inner side to form a closed cross section together with the rocker outer member; and a first energy-absorbing member disposed on the closed cross section and attached to the rocker outer member.

According to the vehicle body lower portion structure of the invention described in (30) above, the first energy-absorbing member is attached to the rocker outer member. Therefore, the degree of freedom in the shape of the rocker inner can be increased, and the inner corner portion can be easily formed in the rocker inner. By forming the inner corner portion in a right-angled shape, the inner corner portion can be favorably engaged with the engagement portion when an impact load is input from the side of the vehicle.

As a result, a part of the impact load input from the side of the vehicle to the rocker can be transmitted as a so-called offset load to the lower portion of the underfloor cross member via the frame portion.

(31) In the vehicle body lower portion structure of any one of the above (4), (29), and (30), the frame portion may include a second energy-absorbing member disposed inside.

According to the vehicle body lower portion structure of the present invention as set forth in the above (31), the second energy absorbing member is provided inside the frame portion. Therefore, the second energy-absorbing member can be crushed by the impact load input from the side of the vehicle. By crushing the second energy-absorbing member by the impact load, the inner corner portion of the rocker can be engaged well by the frame portion.

This makes it possible to more reliably transmit a part of the impact load input from the side of the vehicle to the rocker as a so-called offset load to the lower portion of the under-floor cross member via the frame portion.

(32) In the vehicle body lower portion structure of any one of the above (4), (29) to (31), an upper portion of the under-floor cross member may be disposed so as to face a central portion in a vertical direction of the rocker.

According to the vehicle body lower portion structure of the present invention as recited in the above (32), the upper portion of the under-floor cross member is opposed to the center portion of the rocker. This allows a part of the impact load input from the side of the vehicle to the rocker to be transmitted as a so-called horizontal load to the upper portion of the under-floor cross member.

Therefore, the impact load input from the side of the vehicle to the rocker can be transmitted while being dispersed between the upper portion and the lower portion of the under-floor cross member. This enables the underfloor cross member to support the impact load.

(33) In the vehicle body lower portion structure of any one of the above (4), (29) and (32), the under-floor cross member may include a weak portion formed in an outer region on an outer side in the vehicle width direction and a strong portion formed in an inner region on an inner side in the vehicle width direction.

According to the vehicle body lower portion structure of the invention described in (33), the weak portion is formed in the outer region of the underfloor cross member. Therefore, the fragile portion is crushed to absorb the impact load inputted from the side of the vehicle.

On the other hand, a fastening portion is formed in an inner region of the underfloor cross member. Therefore, the load absorbed by the fragile portion can be supported by the strong portion.

This can divide the floor panel into an energy absorption region on the outer side in the vehicle width direction and a protection region on the inner side in the vehicle width direction.

(34) In the vehicle body lower portion structure of any one of the above (4), (29) and (33), the under-floor cross member may be formed in a hollow shape and may include a partition wall provided at a center in a vertical direction and partitioning the under-floor cross member in a vertical direction.

According to the vehicle body lower portion structure of the invention as recited in the above (34), the hollow underfloor cross member is partitioned vertically by the partition wall. The cross member under the floor can be divided into a cross member upper portion and a cross member lower portion by a partition wall.

This allows a part of the impact load input from the side of the vehicle to the rocker to be transmitted to the upper portion of the cross member as a so-called horizontal load. Further, a part of the impact load input from the side of the vehicle to the rocker can be transmitted to the lower portion of the cross member as a so-called offset load.

In this way, a part of the impact load input from the side of the vehicle to the rocker can be transmitted in two paths, i.e., the upper beam portion and the lower beam portion. As a result, a part of the impact load can be supported satisfactorily by the beam upper portion and the beam lower portion.

(35) In the vehicle body lower portion structure according to any one of the above (4), (29) to (34), the vehicle body lower portion structure may further include a floor panel extending in the vehicle width direction along an upper surface of the floor panel, a first floor cross member and a second floor cross member spaced apart in a vehicle body longitudinal direction, the first floor cross member and the second floor cross member being formed in a hat-shaped cross section by a top portion, a pair of wall portions, a front flange and a rear flange, the front flange and the rear flange are joined to an upper surface of the floor panel, a seat is supported by the first floor cross member and the second floor cross member, the first floor cross member has a first recess recessed upward in a wall portion opposed to the second floor cross member, the second floor cross member has a second recess recessed upward in a wall portion opposed to the first floor cross member, the floor panel has a raised portion that is raised upward along the first recessed portion and the second recessed portion.

According to the vehicle body lower portion structure of the present invention as set forth in the above (35), the seat is supported by the first floor cross member and the second floor cross member. That is, the first floor cross member and the second floor cross member are reinforced by the seat. Therefore, the first recessed portion and the second recessed portion can be formed while the strength of the first floor cross member and the second floor cross member is ensured.

The raised portion of the floor panel is raised upward along the first recessed portion and the second recessed portion. Therefore, the space under the floor can be secured large, and the capacity of the under-floor mounting member disposed under the floor can be increased.

Here, the raised portion of the floor is formed between the first floor cross member and the second floor cross member. Therefore, the bulge is located below the seat. For example, the bulging portion is disposed at a position further toward the rear side of the vehicle body than the feet of the passenger seated in the seat (the periphery of the portion where the feet are placed by the passenger). This prevents the bulge from being an obstacle when a foot of a passenger seated in the seat is placed.

(36) In the vehicle body lower portion structure of the above (35), the under-floor cross member may be coupled to the floor below the first floor cross member and the second floor cross member.

According to the vehicle body lower portion structure of the invention described in (36) above, the underfloor cross member is connected to the floor below the first floor cross member via the connecting member. Thus, the floor below the first floor cross member is reinforced by the under-floor cross member.

Further, a floor cross member is connected to the floor below the second floor cross member. Thus, the floor below the second floor cross member is reinforced by the underfloor cross member.

Therefore, the rigidity of the floor below the first floor cross member can be increased, and the rigidity of the floor below the second floor cross member can be increased. Thus, even if the floor cross member or the underfloor cross member has the weak portion in part, the resistance to the impact load input from the side of the vehicle can be improved.

(37) In the vehicle body lower portion structure of any one of the above (4), (29) and (36), the under-floor cross member may have a recess formed with a downward recess at a center in the vehicle width direction, and the recess may have a pipe storage portion attached so as to extend in the vehicle body longitudinal direction, the pipe storage portion storing at least one of a pipe and a hose.

According to the vehicle body lower portion structure of the present invention described in (37) above, the tube housing portion can be provided in the recess portion by forming the recess portion in the underfloor cross member. The pipe housing portion houses a pipe, a hose, and the like.

Further, by providing the tube housing portion in the recess of the underfloor cross member, the recess can be reinforced by the tube housing portion. Therefore, when a load is transmitted from the side of the vehicle to the underfloor cross member, the transmitted load can be supported by the pipe housing portion. This prevents the recess from being bent by the transmitted load, and the transmitted load can be supported by the underfloor cross member.

Effects of the invention

According to the aspect of the invention, the extended portion of the floor cross member is extended toward the upper portion of the rocker load transmitting member. Further, the upper half of the underfloor load transmitting member is opposed to the lower portion of the rocker load transmitting member. The lower half portion of the underfloor load transfer member is fixed to a portion of the lower portion of the rocker attached to the underfloor frame.

Therefore, the impact load input from the side of the vehicle can be transmitted through the transmission paths of the first load path, the second load path, and the third load path. This can suppress collapse and deformation of the side wall of the underfloor mounting component, and can protect the underfloor mounting component from the impact load.

Further, by transmitting the impact load input from the side of the vehicle through the first to third load paths, it is not necessary to increase the height of the rocker and to provide the rocker load transmitting member inside the rocker. This prevents the rocker from interfering with the boarding and alighting of the passenger, and enables the boarding and alighting performance of the passenger to be ensured satisfactorily.

The battery cross member has left and right side members and a center member having a substantially hat-shaped cross section, an upper surface of the center member is formed lower than upper surfaces of the left and right side members, and a recess is formed by the upper surface of the center member and vehicle-width-direction inner ends of the left and right side members. Therefore, the concave portion can be used as a through groove for a wiring cable or the like, and the main portion of the battery cross member can be formed of a press-formed product or the like that can be manufactured at low cost.

The left and right side members of the battery cross member are coupled to the upper floor cross member, and are coupled to the center member in the vicinity of the lower portion of each coupling portion. Therefore, sufficient rigidity in the vehicle width direction can be ensured while employing a configuration having a recessed portion communicating with the front-rear direction in a substantially central region in the vehicle width direction.

In addition, a front extension seat and a rear extension seat are extended from the lower edge of the beam main body of the battery cross beam, and are coupled to the bottom wall of the battery case. Therefore, when a load in the front-rear direction is input to the battery cross member from the vehicle body side cross member through the fastening member, the battery cross member can be suppressed from collapsing in the front-rear direction. Therefore, the support rigidity with respect to the vehicle-body side cross member can be improved.

The frame portion is formed with an inclined portion. Therefore, a part of the impact load input from the side of the vehicle to the rocker can be transmitted as a so-called offset load to the lower portion of the underfloor cross member via the frame portion. Further, the upper portion of the underfloor cross member is opposed to the rocker. Therefore, a part of the impact load input from the side of the vehicle to the rocker can be transmitted to the upper portion of the underfloor cross member.

Thus, the underfloor mounting components can be protected from the impact load input from the side of the vehicle in a state in which the lower surface of the battery package is disposed below the rocker.

Drawings

Fig. 1 is a perspective view showing a vehicle body lower portion structure according to a first embodiment of the present invention.

Fig. 2 is a plan view showing a vehicle body lower portion structure according to a first embodiment of the present invention.

Fig. 3 is a perspective view showing a state in which the battery pack of the vehicle body lower portion structure according to the first embodiment of the present invention is viewed from the rear lower side.

Fig. 4 is a perspective view showing a state in which a seat is removed from the vehicle body lower portion structure of the first embodiment of the present invention.

Fig. 5 is a cross-sectional view of the vehicle body lower portion structure according to the first embodiment of the present invention taken along line V-V of fig. 2.

Fig. 6 is an enlarged cross-sectional view showing a VI portion of fig. 5 in the vehicle body lower portion structure according to the first embodiment of the present invention.

Fig. 7 is a perspective view showing an outer partition wall and an inner partition wall of a vehicle body lower portion structure according to a first embodiment of the present invention.

Fig. 8 is an exploded perspective view showing an outer partition wall and an inner partition wall of a vehicle body lower portion structure according to a first embodiment of the present invention.

Fig. 9 is a perspective view showing a gusset of the vehicle body lower portion structure according to the first embodiment of the present invention.

Fig. 10 is a perspective view showing a state in which the battery pack of the vehicle body lower portion structure according to the first embodiment of the present invention is viewed from the rear upper side.

Fig. 11 is a cross-sectional view of the vehicle body lower portion structure of the first embodiment of the present invention taken along line XI-XI of fig. 10.

Fig. 12 is a perspective view of a battery pack frame of the vehicle body lower portion structure according to the first embodiment of the present invention, taken obliquely from above.

Fig. 13 is a perspective view of the battery pack frame and the battery case of the vehicle body lower portion structure according to the first embodiment of the present invention, taken obliquely from below.

Fig. 14 is a perspective view showing a left partition wall of the vehicle body lower portion structure according to the first embodiment of the present invention.

Fig. 15 is a side view showing a left partition wall of the vehicle body lower portion structure according to the first embodiment of the present invention.

Fig. 16 is a cross-sectional view illustrating an example in which an impact load is input from the vehicle-side direction to the vehicle body lower portion structure of the first embodiment of the present invention.

Fig. 17 is a cross-sectional view illustrating an example in which the vehicle body lower portion structure of the first embodiment of the present invention is used to protect the battery from an impact load input from the side of the vehicle.

Fig. 18 is a perspective view showing a vehicle body lower portion structure according to a second embodiment of the present invention.

Fig. 19 is a plan view of a part of a vehicle body lower portion structure of the second embodiment of the present invention removed.

Fig. 20 is a cross-sectional view of the vehicle body lower portion structure according to the second embodiment of the present invention taken along the line III-III in fig. 19.

Fig. 21 is an enlarged cross-sectional view of a portion IV of fig. 20 showing a vehicle body lower portion structure according to a second embodiment of the present invention.

Fig. 22 is a perspective view of a vehicle body lower portion structure according to a second embodiment of the present invention, partially cut along a line V-V in fig. 20.

Fig. 23 is a perspective view of a vehicle body lower portion structure according to a second embodiment of the present invention, partially cut away along the line VI-VI in fig. 20.

Fig. 24 is a perspective view of the vehicle body lower portion structure according to the second embodiment of the present invention, partially cut along line VII-VII in fig. 20.

Fig. 25 is a perspective view of a part of a vehicle body lower portion structure according to a second embodiment of the present invention.

Fig. 26 is an enlarged cross-sectional view showing the same portion of the vehicle body lower portion structure of the second embodiment of the present invention as the portion IX of fig. 23.

Fig. 27 is a perspective view of a vehicle body lower portion structure according to a second embodiment of the present invention.

Fig. 28 is a sectional view of a vehicle body lower portion structure according to another second embodiment of the present invention.

Fig. 29 is a perspective view showing a vehicle body lower portion structure according to a third embodiment of the present invention.

Fig. 30 is a plan view of a part of a vehicle body lower portion structure of a third embodiment of the present invention removed.

Fig. 31 is a cross-sectional view of the vehicle body lower portion structure of the third embodiment of the invention taken along the line III-III in fig. 30.

Fig. 32 is a cross-sectional view of the vehicle body lower portion structure of the third embodiment of the present invention taken along the line IV-IV in fig. 31.

Fig. 33 is a perspective view of a vehicle body lower portion structure according to a third embodiment of the present invention, partially cut along the line V-V in fig. 31.

Fig. 34 is a perspective view of a part of a vehicle body lower portion structure according to a third embodiment of the present invention.

Fig. 35 is a perspective view of the vehicle body lower portion structure according to the third embodiment of the present invention, partially cut along line VII-VII in fig. 30.

Fig. 36 is a perspective view of the vehicle body lower portion structure according to the third embodiment of the present invention, partially cut along line VII-VII in fig. 30.

Fig. 37 is a perspective view showing a vehicle body lower portion structure according to a fourth embodiment of the present invention.

Fig. 38 is a perspective view showing a state in which a seat is removed from a vehicle body lower portion structure according to a fourth embodiment of the present invention.

Fig. 39 is a sectional view of the fourth embodiment of the present invention taken along the line III-III of fig. 38.

Fig. 40 is an enlarged cross-sectional view of the portion IV of fig. 39 showing a fourth embodiment of the present invention.

Fig. 41 is a perspective view showing a fourth embodiment of the present invention, taken along the line V-V in fig. 40.

Fig. 42 is a perspective view showing a fourth embodiment of the present invention, taken along line VI-VI in fig. 38.

Fig. 43 is an enlarged perspective view of a VII portion of fig. 42 showing a fourth embodiment of the present invention.

Fig. 44 is a perspective view showing a battery pack and a battery pack frame unit according to a fourth embodiment of the present invention.

Fig. 45 is a perspective view showing a coupled state of a floor cross member and a battery cross member in the fourth embodiment of the present invention.

Fig. 46 is a cross-sectional view taken along line X-X of fig. 38 of the fourth embodiment of the present invention.

Fig. 47 is a cross-sectional view showing a state in which the left frame portion is exploded from the vehicle body lower portion structure of the fourth embodiment of the present invention.

Fig. 48 is a perspective view showing a fourth embodiment of the present invention, taken along line XII-XII in fig. 40.

Fig. 49 is a cross-sectional view illustrating an example in which the battery is protected by the underbody structure when an impact load is input from the side of the vehicle in the fourth embodiment of the present invention.

Fig. 50 is a sectional view showing a vehicle body lower portion structure according to another fourth embodiment of the present invention.

Fig. 51 is a cross-sectional view showing a left frame portion of a vehicle body lower portion structure according to another fourth embodiment of the present invention.

Fig. 52 is a cross-sectional view of a battery cross member showing a vehicle body lower portion structure according to another fourth embodiment of the present invention.

Detailed Description

A first embodiment of the present invention is explained based on the drawings. In the drawings, an arrow FR indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow LH indicates the left side of the vehicle.

As shown in fig. 1 and 2, the vehicle body 10 includes a vehicle underbody structure 12 that constitutes a lower portion of the vehicle body 10. The vehicle body lower portion structure 12 includes a left rocker 14, a right rocker 15, a floor 16, a floor cross member unit 17, a left outer partition wall unit 18, a left inner partition wall unit 19, a right outer partition wall unit 21, a right inner partition wall unit 22, a left gusset unit 24, a right gusset unit 25, a driver seat 31, and a passenger seat 32.

As shown in fig. 3, the vehicle body lower portion structure 12 includes a battery pack (underfloor mounting component, vehicle-mounted component) 28, a left battery pack frame (underfloor frame) 29, a right battery pack frame (underfloor frame) 30, a left partition wall (underfloor load transmitting member) 152 (see fig. 13), and a right partition wall (underfloor load transmitting member) (not shown).

Since the vehicle body lower portion structure 12 is formed of substantially bilaterally symmetrical members, the left-side constituent members will be described below, and the right-side constituent members will not be described.

Returning to fig. 1 and 2, the left rocker 14 is provided at the left side portion 10a of the two side portions of the vehicle body 10 and extends in the vehicle body front-rear direction. The right rocker 15 is provided at the right side portion 10b of the both side portions of the vehicle body 10 and extends in the vehicle body front-rear direction.

A floor 16 is disposed between the left rocker 14 and the right rocker 15. The floor 16 is erected on the left and right rocker beams 14 and 15. A floor cross member unit 17 is attached to an upper surface 16a of the floor panel 16. The floor cross member unit 17 includes a first floor cross member 34, a second floor cross member 35, and a third floor cross member 36.

The first floor cross member 34 is disposed on the vehicle body front side in the vehicle compartment 38. The first floor cross member 34 is erected in the vehicle width direction on the left and right side sills 14, 15.

The second floor cross member 35 is disposed on the vehicle body rear side of the first floor cross member 34. The second floor cross member 35 spans the left and right rocker members 14, 15 in the vehicle width direction, and extends parallel to the first floor cross member 34.

The third floor cross member 36 is disposed on the vehicle body rear side of the second floor cross member 35. The third floor cross member 36 spans the left and right rocker members 14, 15 in the vehicle width direction, and extends parallel to the second floor cross member 35.

The first floor cross member 34, the second floor cross member 35, and the third floor cross member 36 are provided at intervals in the vehicle body longitudinal direction. The driver seat 31 is attached to the right halves of the first floor cross member 34 and the second floor cross member 35 by fastening members such as bolts 37 and nuts. The passenger seat 32 is attached to the left half portions of the first floor cross member 34 and the second floor cross member 35 by fastening members such as bolts 41 and nuts 42 (see fig. 5). In addition, a rear seat 43 is provided on the third floor cross member 36.

In this way, the driver seat 31 is attached to the right halves of the first floor cross member 34 and the second floor cross member 35. Further, the passenger seat 32 is mounted on the left half portions of the first floor cross member 34 and the second floor cross member 35. The first floor cross member 34 and the second floor cross member 35 are respectively erected on the left rocker 14 and the right rocker 15.

The first floor cross member 34, the second floor cross member 35, and the third floor cross member 36 are similar members. Therefore, the second floor cross member 35 will be described in detail below, and the detailed description of the first floor cross member 34 and the third floor cross member 36 will be omitted. Hereinafter, the second floor cross member 35 will be simply referred to as "floor cross member 35".

The left outer partition wall unit 18 includes a first outer partition wall 51, a second outer partition wall 52, and a third outer partition wall 53.

The first outer partition wall 51 is disposed on an extension line of the first floor cross member 34. The second partition wall 52 is disposed on an extension line of the second floor cross member 35. The third outer partition wall 53 is disposed on an extension line of the third floor cross member 36.

The first outer partitioning wall 51, the second outer partitioning wall 52, and the third outer partitioning wall 53 are rocker load transmitting members that are attached to the left rocker 14 and can transmit load.

The first outer partition wall 51, the second outer partition wall 52, and the third outer partition wall 53 are similar members, and the second outer partition wall 52 will be described in detail as the "outer partition wall 52" below, and the detailed description of the first outer partition wall 51 and the third outer partition wall 53 will be omitted.

As shown in fig. 4, the left inner partition wall unit 19 includes a first inner partition wall 55, a second inner partition wall 56, and a third inner partition wall 57.

The first inner partition wall 55 is disposed on an extension line of the first floor cross member 34. The second inner partition wall 56 is disposed on an extension line of the second floor cross member 35. The third inner partition wall 57 is disposed on an extension line of the third floor cross member 36.

The first inner partition wall 55, the second inner partition wall 56, and the third inner partition wall 57 are rocker load transmitting members that are attached to the left rocker 14 and can transmit load.

The first inner partition wall 55, the second inner partition wall 56, and the third inner partition wall 57 are similar members, and hereinafter, the second inner partition wall 56 will be described in detail as the "inner partition wall 56", and the detailed description of the first inner partition wall 55 and the third inner partition wall 57 will be omitted.

Returning to fig. 2, the gusset unit 24 on the left side includes a first gusset 61, a second gusset 62, and a third gusset 63.

The first gusset 61 is disposed below the inclined portion 99 at the left end portion side of the first floor cross member 34. The second gusset 62 is disposed below the inclined portion 107 (see also fig. 5) on the left end portion side of the second floor cross member 35. The third gusset 63 is disposed below the inclined portion 109 at the left end portion side of the third floor cross member 36.

The first gusset plate 61, the second gusset plate 62, and the third gusset plate 63 are similar members, and the second gusset plate 62 will be described in detail below as the "gusset plate 62", and the detailed description of the first gusset plate 61 and the third gusset plate 63 will be omitted.

As shown in fig. 5 and 6, the left rocker 14 includes a rocker outer 65, a rocker inner 66, and a reinforcement plate 67.

The rocker outer 65 is disposed on the vehicle width direction outer side. The rocker outer 65 has an outer bulge 71, an upper flange 72, and a lower flange 73. The outer bulging portion 71 bulges outward in the vehicle width direction from the upper flange 72 and the lower flange 73. A reinforcing member 74 is mounted to the inner surface of the outer bulge 71. The upper flange 72 extends upward from the upper end of the outer bulge 71. The lower flange 73 extends downward from the lower end of the outer bulge portion 71.

The rocker inner 66 is provided on the vehicle width direction inner side of the rocker outer 65. The rocker inner member 66 has an inner bulge 76, an upper flange 77, and a lower flange 78. The inner bulging portion 76 bulges inward in the vehicle width direction from the upper flange 77 and the lower flange 78. The inner bulging portion 76 is formed in a U-shaped cross section by an inner wall 81, an upper portion 82 and a lower portion 83. A reinforcing member 79 is attached to the inner surface of the inner bulging portion 76. The upper flange 77 extends upward from the outer end of the upper portion 82. The lower flange 78 extends downwardly from the outer end of the lower portion 83.

The reinforcing plate 67 is interposed between the rocker outer member 65 and the rocker inner member 66. The reinforcing plate 67 is formed in a flat plate shape and interposed between the rocker outer member 65 and the rocker inner member 66. Specifically, the upper edge portion 67a of the reinforcement plate 67 is joined in a sandwiched state between the upper flange 72 of the rocker outer 65 and the upper flange 77 of the rocker inner 66. Further, the lower edge portion 67b of the reinforcement plate 67 is joined in a sandwiched state between the lower flange 73 of the rocker outer 65 and the lower flange 78 of the rocker inner 66. That is, the reinforcing plate 67 is sandwiched between the rocker outer 65 and the rocker inner 66.

The left rocker 14 is formed in the outer shape of a rectangular frame by a rocker outer member 65 and a rocker inner member 66. The upper edge portion 67a of the reinforcing plate 67 is interposed between the upper flanges 72, 77, and the lower edge portion 67b of the reinforcing plate 67 is interposed between the lower flanges 73, 78, whereby the reinforcing plate 67 is disposed so as to face in the vertical direction.

An outer space 88 is formed between the rocker outer 65 and the reinforcing plate 67. Further, an inner space 89 is formed between the rocker inner 66 and the reinforcement plate 67.

As shown in fig. 7 and 8, the outer partition wall 52 is disposed in an outer space (interior) 88 between the rocker outer 65 and the reinforcing plate 67. The outer partition wall 52 has a side wall 84, a bottom 85 and an engagement flange 86. The side wall 84 has a front side wall 84a, a rear side wall 84b, an upper side wall 84c, and a lower side wall 84 d. The side wall 84 is formed in a rectangular frame shape by a front side wall 84a, a rear side wall 84b, an upper side wall 84c, and a lower side wall 84 d.

An end portion of the side wall 84 (an end portion on a side away from the reinforcing plate 67) is closed by a bottom portion 85. The bottom 85 is formed in a rectangular shape. At the other end portion (end portion on the reinforcing plate 67 side) of the side wall 84, an opening 87 is opened in a rectangular shape (see also fig. 6). An engagement flange 86 is formed at the other end of the side wall 84.

The joining flange 86 has a front joining flange 86a, a rear joining flange 86b, an upper joining flange 86c, and a lower joining flange 86 d.

The front joining flange 86a projects from the other end portion of the front side wall 84a toward the vehicle body front along the outer surface 67c of the reinforcement plate 67. The rear joining flange 86b projects from the other end portion of the rear side wall 84b toward the vehicle body rear along the outer surface 67c of the reinforcement plate 67. The upper joining flange 86c projects upward from the other end portion of the upper side wall 84c along the outer surface 67c of the reinforcing plate 67. The lower joining flange 86d extends downward from the other end portion of the lower side wall 84d along the outer surface 67c of the reinforcing plate 67.

That is, the other end portion of the joining flange 86 on the opening 87 side of the side wall 84 is provided over the entire circumference of the opening 87. The front joining flange 86a, the rear joining flange 86b, the upper joining flange 86c, and the lower joining flange 86d constituting the joining flange 86 are arranged in a state of being in contact with the outer surface 67c of the reinforcing plate 67.

In this way, the outer partition wall 52 is formed in a box shape (hereinafter referred to as a box shape) having a polygonal cross section (specifically, a rectangular cross section) in which the opening 87 is opened on the reinforcing plate 67 side.

An inner partition wall 56 is disposed in an inner space (interior) 89 between the rocker inner 66 and the reinforcement plate 67. The inner partition wall 56 has a side wall 91, a bottom 92, and a joining flange 93, similarly to the outer partition wall 52. The side wall 91 has a front side wall 91a, a rear side wall 91b, an upper side wall 91c, and a lower side wall 91 d. The side wall 91 is formed in a rectangular frame shape by a front side wall 91a, a rear side wall 91b, an upper side wall 91c, and a lower side wall 91 d.

One end portion (end portion on the side away from the reinforcing plate 67) of the side wall 91 is closed by a bottom portion 92. The bottom 92 is formed in a rectangular shape. An opening 94 is opened at the other end (end on the reinforcing plate 67 side) of the side wall 91. The opening 94 of the inner partition wall 56 has a rectangular shape having the same shape as the opening 87 of the outer partition wall 52.

A joining flange 93 is formed at the other end of the side wall 91.

The joining flange 93 has a front joining flange 93a, a rear joining flange 93b, an upper joining flange 93c, and a lower joining flange 93 d. The front joining flange 93a extends from the other end portion of the front side wall 91a toward the vehicle body front side along the inner surface 67d of the reinforcement plate 67. The rear joining flange 93b projects from the other end portion of the rear side wall 91b toward the vehicle body rear along the inner surface 67d of the reinforcement plate 67. The upper joining flange 93c extends upward from the other end portion of the upper side wall 91c along the inner surface 67d of the reinforcing plate 67. The lower joining flange 93d extends downward from the other end portion of the lower side wall 91d along the inner surface 67d of the reinforcing plate 67.

That is, the other end portion of the joining flange 93 on the opening 94 side of the side wall 91 is provided over the entire circumference of the opening 94. The front joining flange 93a, the rear joining flange 93b, the upper joining flange 93c, and the lower joining flange 93d constituting the joining flange 93 are arranged in a state of being in contact with the inner surface 67d of the reinforcing plate 67.

The inner partition wall 56 has an opening 94 on the reinforcing plate 67 side, the opening 94 has a rectangular shape having the same shape as the opening 87 of the outer partition wall 52, and the inner partition wall 56 has a box shape with a polygonal cross section (a rectangular cross section in the first embodiment).

In a state where the joining flange 86 of the outer partition wall 52 is in contact with the outer surface 67c of the reinforcement plate 67 and the joining flange 93 of the inner partition wall 56 is in contact with the inner surface 67d of the reinforcement plate 67, the joining flange 86 and the joining flange 93 overlap with each other across the reinforcement plate 67. The overlapped joining flange 86 and the joining flange 93 are joined to each other via the reinforcing plate 67.

Thus, the outer partition wall 52 and the inner partition wall 56 are attached to the reinforcement panel 67 in a state of being overlapped in the vehicle width direction. The outer partition wall 52 and the inner partition wall 56 are provided so as to overlap the floor cross member 35 in the vehicle width direction.

In this state, the side wall 84 of the outer partition wall 52 extends from the reinforcement panel 67 in a direction away toward the vehicle width direction outer side. Further, one end portion of the side wall 84 of the outer partition wall 52 on the side away from the reinforcement plate 67 is closed by a bottom portion 85. The side wall 91 of the inner partition wall 56 extends from the reinforcement plate 67 in a direction away toward the inside in the vehicle width direction. Further, one end portion of the side wall 91 of the inner partition wall 56 on the side away from the reinforcement plate 67 is closed by a bottom portion 92.

As shown in fig. 2 and 6, the outer partition wall 52 and the inner partition wall 56 are provided so as to overlap the floor cross member 35 in the vehicle width direction. Therefore, when the impact load F1 is input from the side of the vehicle Ve, the outer partition wall 52 and the inner partition wall 56 can be crushed by the impact load F1. Further, the floor cross member 35 can satisfactorily support the load F2 that has passed through the outer partition wall 52 and the inner partition wall 56.

In this way, the impact load F1 input from the side of the vehicle Ve can crush the outer partition wall 52 and the inner partition wall 56, thereby absorbing the impact energy.

A part of the remaining load absorbed by the outer partition wall 52 and the inner partition wall 56 is transmitted to the floor cross member 35 as a load F2. That is, the outer partition wall 52 and the inner partition wall 56 are rocker load transmitting members.

The floor cross member (i.e., the second floor cross member) 35 can support the remaining load F2 absorbed by the outer partition wall 52 and the inner partition wall 56. Similarly, the first floor cross member 34 can support the remaining load F2 absorbed by the first outer partition wall 51 and the first inner partition wall 55.

This can suppress deformation of the vehicle body side portion such as the left rocker 14 to the passenger seat 32. In addition, the vehicle body side portion of the right rocker 15 and the like can be suppressed from being deformed to the driver seat 31.

That is, the passenger of the passenger seat 32 and the driver seat 31 can be protected from the impact load F1.

Returning to fig. 8, the reinforcing plate 67 has a hole portion 96. The holes 96 are formed at positions corresponding to the openings 87, 94 of the outer partition wall 52 and the inner partition wall 56. By forming the hole portion 96 in the reinforcing plate 67, when performing electrodeposition coating on the inside of the left rocker 14, the electrodeposition coating material can be guided well to the inside of the left rocker 14 by the hole portion 96. This makes it possible to easily adhere the electrodeposition paint to the inside of the left rocker 14.

Further, by forming the hole portion 96 in the reinforcing plate 67, the reinforcing plate 67 can be reduced in weight, and the vehicle body 10 can be reduced in weight.

As shown in fig. 5 and 7, the left side portion 16c of the floor panel 16 is attached to an upper portion (upper surface) 82 of the inner bulging portion 76 of the rocker inner member 66. The upper portion 82 of the inner bulging portion 76 is a portion that becomes the upper portion of the left rocker 14. Hereinafter, the upper portion of the left rocker 14 is referred to as "rocker upper portion 82".

The floor 16 is formed flat. The floor panel 16 is disposed at the same height as the rocker upper portion 82. This prevents the left rocker 14 from interfering with the boarding of the passenger, and ensures good boarding and alighting performance of the passenger.

A floor cross member 35 is provided on the upper surface 16a of the floor panel 16. The floor cross member 35 has a beam upper portion 101, a beam front wall portion 102, a beam rear wall portion 103, a beam front flange 104, and a beam rear flange 105.

A beam front wall portion 102 extends downward from the front edge of the beam upper portion 101 toward the floor 16. A beam rear wall portion 103 extends downward from the rear edge of the beam upper portion 101 toward the floor 16. The floor cross member 35 is formed in a U-shaped cross section by a beam upper portion 101, a beam front wall portion 102, and a beam rear wall portion 103.

The beam front flange 104 extends from the lower edge of the beam front wall portion 102 along the upper surface 16a of the floor panel 16 toward the front of the vehicle body. The beam rear flange 105 extends rearward of the vehicle body from the lower edge of the beam rear wall portion 103 along the upper surface 16a of the floor panel 16.

The floor cross member 35 is attached to the upper surface 16a of the floor panel 16 by joining the beam front flange 104 and the beam rear flange 105 to the upper surface 16a of the floor panel 16. In this state, the upper portion 101 of the floor cross member 35 is positioned above the lower side member upper portion 82.

The floor cross member 35 has an inclined portion 107 on the left rocker 14 side. The beam upper portion 101 has an extension 108 near the left end.

The extending portion 108 is a portion forming an upper portion of the inclined portion 107. The extending portion 108 extends to the rocker upper portion 82 with a downward gradient toward the vehicle width direction outer side. In other words, the extension portion 108 extends with a downward slope toward the upper portion 56a of the inner partition wall 56.

The outer end 108a of the extension 108 is located at the rocker upper portion 82. An end 104a of the beam front flange 104 and an end 105a of the beam rear flange 105 are joined to the rocker upper 82 via the left side portion 16c of the floor panel 16. Therefore, the end portion 107a of the inclined portion 107 is joined to the rocker upper portion 82 via the left side portion 16c of the floor panel 16.

As shown in fig. 6 and 9, a gusset 62 is bridged between the inner wall 81 of the inner bulging portion 76 of the rocker inner member 66 and the lower surface 16b of the floor panel 16. Hereinafter, the inner wall 81 of the inner bulging portion 76 is referred to as "rocker inner wall (rocker inner wall) 81".

The gusset 62 has a gusset inclined portion 111, a gusset front wall portion 112, a gusset rear wall portion 113, and gusset flanges 114 to 118. The gusset inclined portion 111 is formed in a rectangular shape in plan view. The gusset inclined portion 111 extends from the lower surface 16b of the floor panel 16 to the rocker inner wall 81 with a downward gradient toward the vehicle width direction outer side with a space from the extending portion 108. That is, the gusset 62 extends downward from the lower surface 16b of the floor panel 16 toward the outside in the vehicle width direction to the rocker inner wall 81.

An angled gusset front wall portion 112 extends from the front edge of the gusset inclined portion 111 toward the floor panel 16. An angled gusset rear wall portion 113 extends from the rear edge of the gusset inclined portion 111 toward the floor panel 16. The gusset 62 is formed in a U-shaped cross section by a gusset inclined portion 111, a gusset front wall portion 112, and a gusset rear wall portion 113.

An angled gusset flange 114 extends from the lower edge of the angled portion 111 of the gusset. Angled gusset flanges 115, 116 extend from the side edges 112a and the upper edge 112b, respectively, of the gusset front wall portion 112. Angled gusset flanges 117, 118 extend from the side edges 113a and upper edges 113b, respectively, of the gusset rear wall portion 113.

A gusset flange 114 extending from the lower edge of the gusset inclined portion 111 is joined to a portion 81a of the rocker inner wall 81 that faces the inner partition wall 56.

Gusset flanges 115 extending from the sides 112a of the gusset front wall portion 112 are joined to the sill inner wall 81. A gusset flange 117 extending from the side 113a of the gusset rear wall portion 113 is joined to the rocker inner wall 81.

Gusset flange 116, which extends from upper edge 112b of gusset front wall portion 112, is joined to lower surface 16b of floor panel 16. A gusset flange 118 extending from the upper edge 113b of the gusset rear wall portion 113 is joined to the lower surface 16b of the floor panel 16.

Thus, the inclined portion 107 is formed in the floor cross member 35, and the extending portion 108 of the inclined portion 107 extends downward toward the outside in the vehicle width direction to the rocker upper portion 82. The gusset inclined portion 111 extends downward from the lower surface 16b of the floor panel 16 toward the outside in the vehicle width direction to the rocker inner wall 81.

The inclined portion 107 and the gusset 62 form a cross section. In addition, the straight portion 35a in the floor cross member 35 is formed in a cross section.

Therefore, the strength of the inclined portion 107 is secured similarly to the linear portion 35a in the floor cross member 35. Thus, when the impact load F1 is input from the side of the vehicle Ve, the load F3 can be transmitted from the inner partition wall 56 to the gusset 62 via the rocker inner wall 81.

Thus, the remaining part of the impact load F1 absorbed by the outer partition wall 52 and the inner partition wall 56 is transmitted to the floor cross member 35 as the load F2 via the inclined portion 107 and the gusset 62, and the first load path can be ensured.

The load F3 transmitted to the floor cross member 35 is supported by the floor cross member 35.

Further, by providing the floor cross member 35 on the upper surface 16a of the floor panel 16, the floor cross member can be removed from below the floor panel 16. Therefore, the space 119 below the floor panel 16 can be increased.

This can increase the capacity of the battery package 28 provided below the floor panel 16. As a result, the capacity of the battery 123 housed in the battery package 28 can be increased, and the cruising distance of the vehicle Ve can be increased.

Returning to fig. 3 and 5, a battery package 28 is provided between the left and right side sills 14 and 15 and below the floor panel 16. The battery pack 28 is attached to the vehicle body lower portion structure 12 by a pair of front support brackets 46, a pair of rear support brackets 47, the left battery pack frame 29, the right battery pack frame 30, and a plurality of fastening members 133 (see also fig. 10).

The battery pack 28 includes a battery case 121 and a cover 122. The battery case 121 includes a case wall 124, a case bottom (bottom of the underfloor mounting member) 125, a case flange 126, a battery cross member unit (underfloor cross member) 131 (see fig. 10), a cross member unit 171, and a side member 172.

The housing wall 124 has a front wall, a rear wall, a left side wall 124a, and a right side wall 124 b. The case wall 124 is formed in a rectangular frame shape by a front wall, a rear wall, a left side wall 124a, and a right side wall 124b (see fig. 10).

The lower end of the case wall 124 is closed by a case bottom 125, and the upper end of the case wall 124 is formed with an opening 127. The case flange 126 extends outward from the entire periphery of the opening 127 of the case wall 124 toward the battery case 121.

As shown in fig. 10, a battery beam unit 131 is provided inside the battery case 121 (i.e., inside 129 of the battery package 28 (see fig. 5)). The battery beam unit 131 includes a first battery beam 131A, a second battery beam 131B, and a third battery beam 131C.

First battery cross member 131A, second battery cross member 131B, and third battery cross member 131C are underfloor cross members provided below floor panel 16 and inside battery case 121.

The first battery cross member 131A is provided at the front of the battery case 121 and extends in the vehicle width direction. The second battery cross member 131B is provided at a distance in the vehicle rear direction of the first battery cross member 131A and extends in the vehicle width direction. The third battery cross member 131C is provided at a distance in the vehicle rear direction of the second battery cross member 131B and extends in the vehicle width direction.

The first battery beam 131A, the second battery beam 131B, and the third battery beam 131C are similar members. Hereinafter, the second battery cross member 131B will be described as the battery cross member 131, and detailed description of the first battery cross member 131A and the third battery cross member 131C will be omitted.

The battery cross member 131 extends in the vehicle width direction in the interior 129 of the battery package 28. The left end 131a of the battery cross member 131 is joined to the left side wall 124a of the case wall portion 124. The right end 131b of the battery beam 131 is joined to the right side wall 124b of the case wall 124.

Returning to fig. 11 and 12, the battery cross member 131 includes a support column 175, a front seat 176 and a rear seat 177. The battery cross member 131 is formed in a T-shaped cross section by the column part 175, the front seat part 176, and the rear seat part 177.

The support portion 175 stands from the case bottom 125 of the battery case 121. The end of the stay portion 175 that faces the upper half 152a of the left partition wall 152 is fixed to the left side wall 124a of the battery case 121. Hereinafter, the upper half 152a of the left partition wall 152 is referred to as "partition wall upper half 152 a".

The pillar portion 175 has a pillar top 181, a pillar front wall portion 182, and a pillar rear wall portion 183.

The pillar top 181 is located above the case bottom 125 of the battery case 121, and extends in the vehicle width direction along the case bottom 125.

A post front wall portion 182 extends from the front edge of the post top 181 toward the housing bottom 125. The post rear wall portion 183 extends from the rear edge of the post top 181 toward the housing bottom 125.

The pillar portion 175 is formed in a U-shaped cross section by a pillar top portion 181, a pillar front wall portion 182, and a pillar rear wall portion 183.

A front joint piece (an end portion facing the upper half portion of the underfloor load transmitting member) 184 protrudes from the left end portion of the pillar front wall portion 182 toward the vehicle body front. A rear joint piece (an end portion facing the upper half portion of the underfloor load transmitting member) 185 extends from the left end portion of the pillar rear wall portion 183 toward the vehicle body front. The front joining piece 184 and the rear joining piece 185 form "an end portion of the pillar portion 175 that faces the partition wall upper half portion 152 a".

The front engaging piece 184 and the rear engaging piece 185 are engaged with the left side wall 124a of the battery case 121. In this state, front joint piece 184 and rear joint piece 185 are disposed at positions facing partition wall upper half 152 a. Therefore, a second load path through which the impact load F4 is transmitted from the partition wall upper half portion 152a to the pillar portion 175 of the battery cross member 131 can be ensured.

A front seat portion 176 is formed on the lower side of the pillar front wall portion 182. A rear seat portion 177 is formed below the pillar rear wall portion 183.

The front seat portion 176 extends from the lower edge of the pillar front wall portion 182 toward the front of the vehicle body along the case bottom portion 125. The front seat 176 is engaged (fixed) to the housing bottom 125.

The rear seat portion 177 extends from the lower edge of the pillar rear wall portion 183 toward the rear of the vehicle body along the case bottom portion 125. The rear seat portion 177 is engaged (fixed) to the housing bottom portion 125.

The front seat section 176 and the rear seat section 177 are provided between the left battery pack frame 29 and the right battery pack frame 30 (see fig. 3) in a state of being continuous in the vehicle width direction. In other words, the front seat portion 176 and the rear seat portion 177 are provided between the left side wall 124a and the right side wall 124b (see fig. 10) of the housing wall portion 124 in a state of being continuous in the vehicle width direction.

As shown in fig. 5, the lower attachment portions 133a of the plurality of fastening members 133 (see also fig. 10) are attached to the battery cross member 131 by bolts 187 and nuts 188 (see fig. 5) at intervals in the vehicle width direction.

A battery 123 is housed inside the battery case 121. The battery case 121 is covered with a cover 122. In this state, the battery pack 28 is attached to the vehicle body lower portion structure 12 by the plurality of fastening members 133.

As shown in fig. 3 and 13, a beam unit 171 is provided on an outer surface 125a of the case bottom 125 of the battery case 121. The beam unit 171 includes a first beam 191A, a second beam 191B, and a third beam 191C.

The first cross member 191A is provided at the front portion of the battery case 121 and extends in the vehicle width direction. The second cross member 191B is provided at a distance rearward of the first cross member 191A in the vehicle body, and extends in the vehicle width direction. The third cross member 191C is provided at a distance rearward of the second cross member 191B in the vehicle body, and extends in the vehicle width direction.

The first beam 191A, the second beam 191B, and the third beam 191C are similar members. Hereinafter, the second beam 191B will be described as the beam 191, and the detailed description of the first beam 19lA and the third beam 191C will be omitted.

The cross member 191 includes a left cross member 192 and a right cross member 193. The left cross member 192 and the right cross member 193 are provided on the left and right sides at a distance from each other at the center in the vehicle width direction.

The left and right beams 192 and 193 are bilaterally symmetrical members, and hereinafter, the left beam 192 will be described, and detailed description of the right beam 193 will be omitted.

As shown in fig. 11 and 13, the left cross member 192 extends along the front seat portion 176 and the rear seat portion 177 in a state of being joined (fixed) to the outer surface 125a of the housing bottom portion 125. The left cross member 192 has ribs 195. The rib 195 extends in the vehicle body longitudinal direction along the left cross member 192, and is formed so as to bulge toward the case bottom 125.

For example, in the embodiment, the example in which the plurality of ribs 195 are formed has been described, but the present invention is not limited thereto. As another example, a rib 195 may be formed.

By forming the rib 195 in the left cross member 192, the sectional strength of the left cross member 192 can be improved. Specifically, the sectional strength can be improved against the load in the longitudinal direction of the left cross member 192.

The front seat section 176 is joined (fixed) to the housing bottom section 125 and the left cross member 192 in a state of being overlapped with each other. The rear seat portion 177 is joined (fixed) to the case bottom 125 and the left cross member 192 in a state of being overlapped with each other.

Thus, the front seat portion 176 and the rear seat portion 177 are joined in a state of being overlapped with the case bottom portion 125 and the left cross member 192. Therefore, a third load path for transmitting the load F5 (see also fig. 12) from the frame extension 151 of the left battery pack frame 29 to the front seat portion 176 and the rear seat portion 177 of the battery cross member 131 can be ensured.

In particular, the front seat portion 176 and the rear seat portion 177 are firmly reinforced by the left cross member 192. This can improve the transmission efficiency of the load F5 in the third load path.

Front joint piece 184 and rear joint piece 185 are disposed at positions facing partition wall upper half 152 a. Therefore, a second load path through which the load F4 is transmitted from the partition wall upper half portion 152a to the pillar portion 175 of the battery cross member 131 can be ensured.

This makes it possible to reliably disperse the impact load F1 input from the side of the vehicle Ve to the battery cross member 131 via the second load path and the third load path.

As shown in fig. 3, the side member 172 is disposed between the left cross member 192 and the right cross member 193. The side member 172 extends in the vehicle body front-rear direction. In this state, the side member 172 is fixed to the outer surface 125a of the case bottom 125. Thus, the side member 172 can support the impact load F6 input from the front-rear direction of the vehicle.

As shown in fig. 3 and 11, the battery case 121 includes a front seat 176, a rear seat 177 (i.e., a battery cross member 131), and a left cross member 192 at the case bottom 125. Thus, the impact load F1 input from the side of the vehicle Ve can be supported by the front seat portion 176 and the rear seat portion 177 (i.e., the battery cross member 131) and the left cross member 192.

The case bottom 125 is provided with a side member 172. Thus, the impact load F6 input from the front-rear direction of the vehicle Ve can be supported by the side member 172.

Further, by providing the left cross member 192 and the side member 172 on the case bottom 125, the strength of the battery case 121 (i.e., the battery package 28) can be improved. This can increase the size of the battery pack 28. By making the battery package 28 large, the capacity of the battery 123 (see fig. 5) can be increased.

Returning to fig. 5, opening 127 of battery case 121 is closed from above by lid cover 122. The cover 122 has a cover wall portion 135, a cover top 136, and a cover flange 137.

The cover wall portion 135 has a front wall, a rear wall, a left side wall 135a, and a right side wall. The cover wall portion 135 is formed in a rectangular frame shape by a front wall, a rear wall, a left side wall 135a, and a right side wall. That is, the cover wall portion 135 is formed in the same manner as the case wall portion 124.

The cover wall 135 has an upper end closed by the cover top 136 and a lower end formed with an opening 138. A cover flange 137 extends outward of the cover 122 from the entire periphery of the opening 138 of the cover wall portion 135.

By overlapping the cover flange 137 with the housing flange 126 from above, the space between the cover flange 137 and the housing flange 126 is sealed by the sealing member. Thus, the opening 127 of the battery case 121 is closed by the cover 122. The battery 123 is housed in the battery package 28 at an inner portion 129. In a state where the opening 127 of the battery case 121 is closed by the cover 122, the upper portion 133b of the fastening member 133 protrudes upward from the opening of the cover top 136.

The projecting upper portion 133b is fastened to the bracket 141 of the floor cross member 35 by a bolt or a nut. Thereby, the battery pack 28 is fastened to the bracket 141 of the floor cross member 35 by the plurality of fastening members 133.

As shown in fig. 6 and 12, the battery package 28 is disposed on the vehicle width direction inner side of the left rocker 14. The battery package 28 is provided at a predetermined interval L1 with respect to the rocker inner wall 81.

Left battery pack frame 29 is attached to left side wall 124a of case wall 124. The right battery pack frame 30 (see fig. 3) is attached to the right side wall 124b of the case wall portion 124.

The left battery pack frame 29 and the right battery pack frame 30 are bilaterally symmetrical members, and hereinafter, the left battery pack frame 29 will be described as the battery pack frame 29, and detailed description of the right battery pack frame 30 will be omitted.

The battery pack frame 29 is formed in an L-shaped cross section. The battery pack frame 29 includes a fixing portion 143 and a frame body 144.

The fixing portion 143 is attached to the lower portion 83 of the inner bulging portion 76. The lower portion 83 of the inner bulging portion 76 is a portion that becomes the lower portion of the left rocker 14. Hereinafter, the lower portion of the left rocker 14 is referred to as a "rocker lower portion 83".

The frame body 144 stands from the fixing portion 143 toward the rocker inner wall 81, and is disposed so as to face the inner partition wall 56 with the rocker inner wall 81 interposed therebetween.

Frame body 144 has frame inner wall portion 146, frame outer wall portion 147, frame top portion 148, frame bottom portion 149, and frame extension 151. The frame main body 144 is formed into a rectangular frame shape in cross section by a frame inner wall portion 146, a frame outer wall portion 147, a frame top portion 148, and a frame bottom portion 149.

The frame inner wall portion 146 of the frame body 144 faces the left side wall 124a of the case wall portion 124, and is joined along the left side wall 124 a.

Further, the frame inner wall portion 146 is also joined to the front joining piece 184 and the rear joining piece 185 of the battery cross member 131 via the left side wall 124 a. That is, the frame body 144 is joined to the battery cross member 131.

The frame extension 151 extends along the case bottom 125 of the battery case 121 and is coupled to the case bottom 125.

The left end of the front seat portion 176 of the battery cross member 131 is joined (fixed) to the frame extension 151 via the case bottom portion 125.

The left end of the rear seat portion 177 of the battery cross member 131 is joined (fixed) to the frame extension portion 151 via the case bottom portion 125.

A left partition wall 152 is attached to the inside 145 of the frame main body 144.

The fixing portion 143 has a mounting top portion 154, a mounting outer wall portion 155, a mounting bottom portion 156, a bent portion 157, an upper coupling portion 158, and a lower coupling portion (coupling portion) 159. The fixing portion 143 is formed in a U-shape in cross section by a mounting top portion 154, a mounting outer wall portion 155, and a mounting bottom portion 156.

A mounting outer wall portion 155 extends downward from the outer end of the mounting top portion 154. The mounting bottom portion 156 extends on the same plane with respect to the frame extension 151 from the lower end of the mounting outer wall portion 155 to the frame extension 151. The lower connection portion 159 is biased downward from an end of the attachment bottom portion 156 via a bent portion 157. The lower coupling portion 159 is fixed along the frame extension 151 of the frame body 144.

Thus, the mounting bottom portion 156 and the frame extension portion 151 linearly extend. This makes it possible to linearly transmit the load F5 from the mounting bottom 156 to the frame extension 151, and to improve the transmission efficiency of the third load path.

The upper coupling portion 158 is engaged along the frame outer wall portion 147 of the frame body 144.

A sleeve 162 is interposed in the fixing portion 143, and a bolt 163 is inserted through the sleeve 162. The fixing portion 143 is attached to the rocker lower portion 83 by a bolt 163 and a nut 164. In other words, the attachment top portion 154 of the fixing portion 143 is attached in a state of abutting against the rocker lower portion 83 by the bolt 163 and the nut 164.

Thus, the fixing portion 143 is attached to the rocker lower portion 83, and the frame body 144 of the battery pack frame 29 rises toward the rocker inner wall 81. The frame body 144 faces the inner partition wall 56 via the rocker inner wall 81. Further, the frame main body 144 is joined to the front joining piece 184 and the rear joining piece 185 of the battery cross member 131.

A left partition wall 152 is provided in the interior 145 of the frame body 144. The left partition wall 152 is provided along the left side wall (side wall) 124a of the battery case 121. The left partition wall 152 is a battery load transmission member (underfloor load transmission member) disposed so as to face the left end portion 131a of the battery cross member 131.

As shown in fig. 14 and 15, the left partition wall 152 includes a partition wall front wall portion 201, a partition wall rear wall portion 202, a partition wall side wall portion 203, and a partition wall top portion 204.

The partition front wall portion 201 is arranged upright from the frame bottom portion 149 of the frame main body 144 in the vehicle width direction, and is formed substantially rectangular. A first joining piece 206 is formed at the upper portion and a second joining piece 207 is formed at the lower portion of the outer edge of the partition wall front wall portion 201. Further, a third joining piece 208 is formed on the lower side of the partition wall front wall portion 201.

The partition rear wall portion 202 is formed in a substantially rectangular shape similarly to the partition front wall portion 201. The partition rear wall portion 202 is disposed behind the partition front wall portion 201 in the vehicle body so as to face the partition front wall portion 201. A fourth joining piece 301 is formed at the upper portion and a fifth joining piece 302 is formed at the lower portion of the outer edge of the partition wall rear wall portion 202. Further, a sixth joining piece 303 is formed on the lower side of the partition wall rear wall portion 202.

A partition wall side wall portion 203 is connected to an inner edge of the partition wall front wall portion 201 and an inner edge of the partition wall rear wall portion 202. The partition wall side wall portion 203 is formed substantially rectangular. The partition wall side wall portion 203 is arranged in a state of standing from the frame bottom portion 149 of the frame main body 144 in the vehicle body front-rear direction.

A partition top portion 204 is connected to an upper edge of the partition front wall portion 201, an upper edge of the partition rear wall portion 202, and an upper edge of the partition side wall portion 203. The partition top portion 204 is formed in a substantially rectangular shape.

The first joining piece 206, the second joining piece 207, the fourth joining piece 301, and the fifth joining piece 302 are joined to the frame outer wall portion 147 of the frame main body 144 by spot welding or the like. The third joining piece 208 and the sixth joining piece 303 are joined to the frame bottom 149 of the frame main body 144 by spot welding or the like.

In this state, the left partition wall 152 is formed into a box shape having a polygonal cross section (a rectangular cross section in the first embodiment) by the partition wall front wall portion 201, the partition wall rear wall portion 202, the partition wall side wall portion 203, and the partition wall top portion 204.

For example, the left partition wall 152 is formed by bending a single steel plate. Since the left partitioning wall 152 is formed in a box shape having a rectangular cross section, when an impact load F1 is input from the side of the vehicle Ve, the left partitioning wall 152 can be crushed to absorb impact energy. That is, the left partition wall 152 is a battery load transmission member (underfloor load transmission member) that is attached to the battery package 28 and is capable of transmitting a load.

The left partition wall 152 has an upper partition wall half (upper half) 152a and a lower partition wall half (lower half) 152 b.

The first joining piece 206 and the fourth joining piece 301 of the partition upper half 152a are joined to the frame outer wall portion 147 of the frame main body 144. Thereby, the partition upper half 152a is fixed to the frame body 144 (i.e., the battery pack frame 29).

The second joining piece 207 and the fifth joining piece 302 of the partition lower half 152b are joined to the frame outer wall portion 147 of the frame main body 144. In addition, the third joint piece 208 and the sixth joint piece 303 of the partition lower half 152b are joined to the frame bottom 149 of the frame main body 144. Thereby, the partition lower half 152b is fixed to the frame main body 144 (i.e., the battery pack frame 29).

As shown in fig. 6, the partition wall upper half 152a is disposed so as to face the lower portion 56b of the inner partition wall 56. The partition wall upper half 152a is disposed at the same height as the lower portion 56b of the inner partition wall 56. The partition upper half 152a is fixed to the frame body 144 (i.e., the battery pack frame 29). Therefore, a second load path for transmitting the load F4 from the lower portion 56b of the inner partition wall 56 to the partition wall upper half 152a can be ensured.

The partition lower half 152b is disposed at the same height as the mounting portion 29a of the battery pack frame 29 to the rocker lower portion 83. The partition lower half 152b is fixed to the frame body 144 (i.e., the battery pack frame 29). That is, the partition lower half 152b is fixed at the same height as the mounting portion 29a of the battery pack frame 29 (the portion of the underfloor frame that is mounted to the lower portion of the rocker).

Therefore, a third load path for transmitting the load F5 from the attachment point 29a of the battery pack frame 29 to the partition lower half 152b of the left partition 152 can be ensured.

This makes it possible to reliably disperse the impact load F1 input from the side of the vehicle Ve to the battery cross member 131 via the second load path and the third load path.

As described above, according to the vehicle body lower portion structure 12, the outer partition wall 52 and the inner partition wall 56 are provided inside the left rocker 14. The extension portion 108 of the floor cross member 35 extends toward the upper portion 56a of the inner partition wall 56. Further, left partition wall 152 faces battery cross member 131. The partition upper half 152a faces the lower portion 56b of the inner partition 56. The lower partition wall half 152b of the left partition wall 152 is connected to the rocker lower portion 83 via the battery pack frame 29.

Therefore, when the impact load F1 is input from the side of the vehicle Ve, a part of the impact load F1 can be transmitted to the floor cross member 35 via the upper portion 56a of the inner partition wall 56 through the first load path. The remaining part of the impact load F1 can be transmitted to the battery cross member 131 via the lower portion 56b of the inner partition wall 56 and the partition wall upper half portion 152a through the second load path.

The remaining portion of the impact load F1 can be transmitted to the battery cross member 131 through the rocker lower portion 83, the battery pack frame 29, and the partition lower half portion 152b of the left partition 152, and through the third load path.

In this way, the impact load F1 input from the side of the vehicle Ve can be transmitted dispersedly via the transmission paths of the first load path, the second load path, and the third load path. Therefore, the impact load F1 can be supported by the floor cross member 35 and the battery cross member 131. This can suppress the collapse deformation of the left side wall 124a of the battery package 28, and protect the battery package 28 (i.e., the battery 123) from the impact load F1.

Further, by transmitting the impact load F1 input from the side of the vehicle Ve so as to be dispersed in the first to third load paths, it is not necessary to increase the height of the left rocker 14 and to provide a partition wall inside the left rocker 14 as a rocker load transmitting member. Thus, the left rocker 14 does not interfere with the passenger getting on and off the vehicle, and the passenger getting on and off performance can be ensured satisfactorily.

In addition, the increase in the weight of the left rocker 14 (i.e., the vehicle body weight) can be suppressed without increasing the height of the left rocker 14.

Next, an example in which the battery 123 is protected by the vehicle underbody structure 12 when an impact load F6 is input from the side of the vehicle Ve will be described with reference to fig. 16 and 17.

As shown in fig. 16, the obstacle 350 collides from the side of the vehicle Ve. Therefore, the impact load F6 is input from the side direction of the vehicle Ve to the left rocker 14. The outer bulging portion 71 of the rocker outer 65 of the left rocker 14 deforms inward in the vehicle width direction due to the impact load F6 input to the left rocker 14. The outer bulge portion 71 deforms and comes into contact with the bottom portion 85 of the outer partition wall 52.

The respective joining flanges 86, 93 of the outer partition wall 52 and the inner partition wall 56 are joined to each other via the reinforcing plate 67. Therefore, the box-like shape of the outer partition wall 52 is restrained by the joining flange 86. In addition, the box-like shape of the inner partition wall 56 is restrained by the joining flange 93.

Thus, the impact load F6 is transmitted to the entire region (i.e., the entire circumference) of the side wall 84 of the outer bulkhead 52 when the outer bulge portion 71 abuts against the bottom portion 85 of the outer bulkhead 52. Further, the impact load F6 is transmitted to the entire area (i.e., the entire circumference) of the side wall 91 of the inner partition wall 56.

The impact load F6 causes the entire periphery of the side wall 84 of the outer partition wall 52 and the entire periphery of the side wall 91 of the inner partition wall 56 to collapse due to the impact load F6, thereby absorbing the impact energy.

As shown in fig. 17, a part of the remaining load absorbed by the outer partition wall 52 and the inner partition wall 56 can be transmitted as a load F7 to the floor cross member 35 via the inclined portion 107 and the gusset 62 through a first load path.

A part of the remaining load can be transmitted as load F8 to battery cross member 131 (more specifically, stay portion 175) via partition wall upper half portion 152a, and can be transmitted as a second load path.

A part of the remaining load can be transmitted as a load F9 to the battery cross member 131 (specifically, the front seat section 176 and the rear seat section 177) via the frame extension section 151 of the left battery pack frame 29 and to the third load path.

Load F7 is supported by floor beam 35. Further, load F8 and load F9 are supported by battery cross member 131. Therefore, the outer partition wall 52 and the inner partition wall 56 can be sufficiently crushed, and the impact energy due to the impact load F6 can be favorably absorbed by the outer partition wall 52 and the inner partition wall 56.

By supporting the load F8 and the load F9 by the battery cross member 131, the left partition wall 152 can be crushed. Therefore, the load F8 and the load F9 can be favorably absorbed by the battery pack frame 29.

This can protect battery 123 housed inside 129 of battery package 28 from impact load F6.

The technical scope of the present invention is not limited to the first embodiment described above, and various modifications can be made without departing from the scope of the present invention.

For example, in the first embodiment, the floor cross member 35 is provided on the upper surface 16a of the floor panel 16, but the present invention is not limited thereto. As another example, the floor cross member 35 may be provided on the lower surface 16b of the floor panel 16.

In the first embodiment, the battery package 28 as the vehicle-mounted component is exemplified as the underfloor mounting component, but the present invention is not limited thereto. As other vehicle-mounted components, the present invention can also be applied to other components such as a fuel tank and a fuel cell stack (fuel cell stack).

A second embodiment of the present invention is explained based on the drawings. In the drawings, an arrow FR indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow LH indicates the left side of the vehicle.

Fig. 18 is a diagram of a skeleton portion of the vehicle body 10 of the present embodiment as viewed obliquely from the rear and from the left and above, and fig. 19 is a diagram of the vehicle body lower portion structure 12 of the vehicle body 10 as viewed from above. Fig. 20 is a view of the vehicle body lower portion structure 12 taken along the line III-III in fig. 19.

The vehicle body lower portion structure 12 is a lower portion side structure positioned on the vehicle body 10, and is a structure including a pair of rocker beams 140 arranged on the left and right side portions on the vehicle body lower end side and extending in the substantially front-rear direction of the vehicle body.

The vehicle body lower portion structure 12 includes a pair of rocker beams 140, a floor panel 16 in which both ends in the vehicle width direction are bridged to the left and right rocker beams 140, a plurality of floor cross members 340, 350, 360 (vehicle body side cross members) disposed on the upper surface side of the floor panel 16, a battery case 280 (see fig. 20) in which the left and right rocker beams 140 are side-bridged below the floor panel 16, and a plurality of battery cross members (underfloor cross members) 450 provided inside the battery case 280. In the present embodiment, the front and rear installation portions of the driver seat 31 and the passenger seat 32 installed in the vehicle compartment are attached to the first two floor cross members 340 and 350.

The floor cross members 340, 350, and 360 extend substantially in the vehicle width direction, and both end portions in the extending direction are coupled to the left and right rocker members 140. The floor cross members 340, 350, 360 are disposed apart from each other in the vehicle body front-rear direction.

Fig. 27 is a front left oblique lower view of battery case 280 and peripheral components attached to the outside of battery case 280.

As shown in fig. 20 and 27, battery case 280 includes case body 280A having an upper side opened, and case cover 280B closing an upper opening of case body 280A. The case body 280A includes a substantially rectangular bottom wall 280Aa in plan view, and a peripheral wall 280Ab rising upward from a peripheral region of the bottom wall 280 Aa. Hereinafter, a portion of the peripheral wall 280Ab that rises upward from the left and right side end portions is referred to as a housing side wall 500.

A plurality of batteries 510 (see fig. 23 and 24) and a plurality of battery cross members 450 extending substantially in the vehicle width direction so as to partition the interior of the battery case 280 in the front-rear direction are disposed inside the battery case 280. In the present embodiment, three battery beams 450 are provided. Each battery cross member 450 is disposed on the floor 16 at a position directly below the floor cross members 340, 350, and 360. The three floor beams 340, 350, 360 are arranged substantially parallel to the battery beam 450.

The respective cross sections (cross sections substantially orthogonal to the front-rear direction of the vehicle body) including the respective floor cross members 340, 350, and 360 and the battery cross member 450 corresponding thereto are formed to have substantially the same structure. Therefore, the cross-sectional structure of the vehicle body lower portion structure 12 will be described below, with a cross section of the floor cross member 350 including the center in the front-rear direction and the battery cross member 450 therebelow being representative.

As shown in fig. 20 and 27, a rectangular tubular case frame 520 extending substantially in the vehicle body longitudinal direction is coupled to the outer surface of the case side wall 500 of the case main body 280A. The lower end of the inner side wall 520A of the case frame 520, which is joined to the case side wall 500 of the case main body 280A, is bent inward in the vehicle width direction, and an extension piece 520b is provided at the tip of the bent portion. The extension piece 520b overlaps the lower surface of the bottom wall 280Aa of the case main body 280A and is joined to the lower surface of the bottom wall 280 Aa.

Further, a mounting frame 530 bulging outward in the vehicle width direction from a lower region of the casing frame 520 is coupled to the vehicle width direction outer side of the casing frame 520. The mounting frame 530 forms a horizontally long rectangular cross-section together with the outer side wall of the case frame 520 in a state of being coupled with the case frame 520. The rectangular cross section extends substantially in the front-rear direction of the vehicle body. The mounting frame 530 is overlapped with inner lower surfaces of the left and right side sills 140, and is coupled to the lower surface of the side sill 140 by a fastening member 540.

Further, a lower wall of the mounting frame 530 is joined to a lower surface of the case frame 520, and a frame extension piece 530A extending to extend to a lower surface side of the bottom wall 280Aa of the case main body 280A is provided at a front end portion of the lower wall. The frame extension piece 530A overlaps the lower surface of the extension piece 520b of the housing frame 520, and is joined to the lower surface of the bottom wall 280Aa of the housing main body 280A together with the extension piece 520 b. The frame extension pieces 530a and 520b and the bottom wall 280Aa are joined by welding in a state where three pieces are overlapped, for example.

For convenience, the detailed shape of the housing frame 520 in fig. 27 is not shown.

Fig. 21 is an enlarged view of the IV portion of fig. 20. Fig. 22 is a perspective view of the vehicle body lower portion structure 12 including a cross section along the line V-V of fig. 20. Fig. 23 is a perspective view of the vehicle body lower portion structure 12 including a cross section along the line VI-VI in fig. 20. Fig. 24 is a perspective view of the vehicle body lower portion structure 12 including a cross section along line VII-VII of fig. 20. Fig. 25 is a view of a portion of the battery case 280 of the vehicle body lower portion structure 12 as viewed from the obliquely upper right side of the rear portion. Fig. 26 is an enlarged sectional view of the same portion as the IX portion of fig. 23.

As shown in fig. 20 and 21, the battery cross member 450 includes left and right side members 450S arranged on the left and right sides in the vehicle width direction, and a center member 450C arranged at the center in the vehicle width direction. The left and right side members 450S are formed in the same shape. Each of the side member 450S and the center member 450C has a substantially hat-shaped cross section in a cross section perpendicular to the vehicle width direction. Wherein the height of the upper surface of the center beam 450C is set lower than the height of the upper surface of the side beam 450S.

As shown in fig. 22 and 23, the side member 450S includes: a beam body 370 having a substantially コ -shaped cross section and rising upward, and including a front wall 370f, an upper wall 370u, and a rear wall 370 r; a front projecting seat 380 projecting forward from a lower edge of the front wall 370 f; and a rear projecting seat 390 projecting rearward from a lower edge of the rear wall 370 r. Similarly, as shown in fig. 23 and 24, the center beam 450C includes: a beam body 400 having a substantially コ -shaped cross section and rising upward, the beam body having a front wall 400f, an upper wall 400u, and a rear wall 400 r; a front extension base 410 extending forward from a lower edge of the front wall 40 f; and a rear projecting seat 420 projecting rearward from a lower edge of the rear wall 400 r. As shown in fig. 20, 23, and 25, the center member 450C is inserted into the left and right side members 450S at the end edges on both sides in the vehicle width direction, and is welded and fixed to the left and right side members 450S in a state of being overlapped by a predetermined amount in the vehicle width direction.

Specifically, the left and right edges of the center beam 450C are welded and fixed to the inner surfaces of the front wall 370f and the rear wall 370r of the side beam 450S corresponding to the front surface of the front wall 400f and the rear surface of the rear wall 400 r. The upper wall 400u is separated from the upper wall 370u of the corresponding side beam 450S by a prescribed distance. The front extension seat 410 and the rear extension seat 420 at the left and right end edges of the center beam 450C are partially cut away in the front and rear direction, respectively, to form engagement pieces 410a and 420a shown in fig. 23. The upper surfaces of these engagement pieces 410a, 420a are fixed by welding to the lower surfaces on the root sides of the forward projecting seat 380 and the rearward projecting seat 390 of the left and right side beams 450S.

The center beam 450C is overlapped with the left and right side beams 450S only at the left and right end edges, and the center region is not overlapped with the side beams 450S. Therefore, between the left and right side members 450S, a recess 430 communicating in the front-rear direction of the vehicle body is formed by the upper surface of the center member 450C and the vehicle width direction inner end surfaces of the left and right side members 450S. As shown in fig. 20 and 24, a member spanning the battery cross member 450 in the front-rear direction, such as the distribution cable 440, is disposed in the recess 430.

A plurality of portions of the upper portion of the battery cross member 450 separated in the vehicle width direction are coupled to the corresponding floor cross member 350 above by a plurality of stud bolts 460. Specifically, the upper walls 370u of the left and right side members 450S are each coupled to the left and right halves of the floor cross member 350 by two stud bolts 460.

As shown in fig. 23 and 26, the stud bolt 460 includes: a substantially cylindrical central plug body portion 460 a; a lower screw part 460b projecting downward from the lower surface of the plug part 460 a; and an upper screw part 460c upwardly protruding from the upper surface of the bolt part 460 a.

The lower end of the stud bolt 460 is coupled to the vehicle width direction outer portion and inner portion of the upper wall 370u of the beam main body portion 370 of each of the left and right side members 450S. As shown in fig. 23 and 26, each stud bolt 460 is fixed to the side member 450S by screwing a nut 470 into a threaded portion 460b that penetrates the upper wall 370u of the member body 370 from above to below. Further, the threaded portion 460c of each stud bolt 460 penetrating the floor 16 from below to above penetrates the bracket 480 of the floor cross member 350 further to above, and the nut 490 is screwed to the threaded portion 460 c. The upper portion of the stud 460 is thereby secured to the floor cross member 350.

The bracket 480 is a metal member having a substantially hat-shaped cross section which also serves as a cross-sectional reinforcement portion of the floor cross member 350, and a portion corresponding to a hat-shaped brim portion is joined to a lower surface of an upper wall of the floor cross member 350, and a through hole 480a into which the screw portion 460c of the stud bolt 460 is inserted is formed in a portion corresponding to a top portion of the hat-shaped brim portion. The stud bolt 460 is welded to the upper wall of the floor cross member 350 with the top of the hat shape facing downward. A working hole 550 for screwing a nut 490 into a screw portion 460c protruding upward from the through-hole 480a is formed in a portion of the upper wall of the floor cross member 350, the portion facing the through-hole 480a of the bracket 480.

As shown in fig. 23 and 26, a support flange 460aA and a small-diameter shaft portion 460aB projecting upward from the support flange 460aA are provided in a bolt body portion 460a of the stud bolt 460. A thick cylindrical elastic seal member 560 is fitted to the shaft portion 460 aB. A support groove 560a is provided on the outer peripheral surface of the elastic sealing member 560. The support groove 560a is partially locked to the peripheral edge of the through hole 570 of the housing cover 280B. The bolt body 460a of the stud bolt 460 is held in the through hole 570 of the housing cover 280B by the elastic seal member 560. Further, the lower surface of the elastic sealing member 560 abuts against the upper surface of the support flange 460aA, and the upper surface of the elastic sealing member 560 abuts against the lower surface of the floor panel 16.

Here, the portions of the left and right side members 450S that are provided with the stud bolts 460 on the vehicle width direction inner sides (the joint portions with the floor cross member 350) are disposed above the joint regions between the center member 450C and the side members 450S. In other words, the side beam 450S is coupled to the center beam 450C in the vicinity below the installation portion of the stud bolt 460 (the coupling portion coupled to the floor cross member 350).

As shown in fig. 20, 21, 25, and the like, a first partition wall member (partition wall member) 580 and a second partition wall member (partition wall member) 590 are provided inside the left and right side beams 450S in the front and rear of the installation portion of each stud bolt 460 in the extending direction of the side beam 450S. Each of the first bulkhead member 580 and the second bulkhead member 590 has flanges 580a, 590a (see fig. 25) for joining, and is fixed to at least three surfaces of the front wall 370f, the upper wall 370u, and the rear wall 370r of the side member 450S by welding or the like.

The first bulkhead member 580 and the second bulkhead member 590 of the side member 450S, which are disposed inward in the vehicle width direction, are disposed above the joint area between the side member 450S and the center member 450C. That is, the center beam 450C is coupled to the left and right side beams 450S in the lower region of the first bulkhead member 580 and the second bulkhead member 590. Therefore, the closed cross-section interior formed by the center beam 450C and the left and right side beams 450S being joined is reinforced by the first partition wall member 58 and the second partition wall member 59.

An auxiliary partition member 600 that substantially closes the gap between the left and right side members 450S facing the recessed portion 430 is coupled to the center member 450C at the vehicle width direction inner end portions of the side members. The auxiliary bulkhead member 600 has a flange 600a for joining, and is joined by welding or the like to the inner surfaces of the front wall 370f and the rear wall 370r of the side beam 450S and the upper surface of the upper wall 400u of the center beam 450C.

As shown in fig. 22, a reinforcing plate 200 having a substantially コ -shaped cross section, which is joined to the upper wall 370u, the front wall 370f, and the rear wall 370r of the beam body 370, is disposed inside the beam body 370 of the left and right side beams 450S. That is, the walls of the beam main body 370 are double-walled by the metal reinforcing plate 200, and the above-described members are coupled to the walls reinforced by the reinforcing plate 200.

As shown in fig. 24 and 25, a metal reinforcing plate 210 is bridged between the front surfaces of the front walls 370f and the rear surfaces of the rear walls 370r of the left and right side members 450S, respectively. The reinforcing plate 210 is formed of a rectangular metal plate extending in the vehicle width direction, and the edge portions on both sides in the vehicle width direction are joined to the front walls 370f of the left and right side members 450S and the rear walls 370r of the left and right side members 450S by welding or the like.

As described above, the left and right side members 450S and the center member 450C of the battery cross member 450 have the front projecting seats 380 and 410 projecting forward from the lower edges of the front walls 370f and 400f of the beam main bodies 370 and 400, and the rear projecting seats 390 and 420 projecting rearward from the lower edges of the rear walls 370r and 400r of the beam main bodies 370 and 400. That is, the side beams 450S and the center beam 450C are formed in an inverted T-shaped cross section.

The battery cross member 450 is disposed so that the front protruding seats 380 and 410 and the rear protruding seats 390 and 420 face the upper surface of the bottom wall 280Aa of the battery case 280. On the other hand, the lower surface reinforcing member 610 is disposed at a position directly below the installation portion of the battery cross member 450 in the lower surface of the bottom wall 280Aa of the battery case 280.

The lower surface reinforcing member 610 is formed of a metal plate-like member having a substantially wave-shaped cross section extending substantially in the vehicle width direction. The front projecting seats 380 and 410 and the rear projecting seats 390 and 420 of the battery cross member 450 are coupled to the lower surface reinforcing member 610 with the bottom wall 280Aa of the battery case 280 interposed therebetween. For example, the flat flanges of the front projecting seats 380 and 410 and the rear projecting seats 390 and 420 and the flat flange of the lower surface reinforcing member 610 are overlapped on the upper and lower surfaces of the bottom wall 280Aa, and in this state, the members are welded to each other so as to be overlapped three by three. Thus, the battery cross member 450 is integrated with the lower surface reinforcing member 610 on the lower surface so that the front protruding seats 380 and 410 protruding forward and backward from the beam main bodies 370 and 400 and the rear protruding seats 390 and 420 sandwich the bottom wall 280 Aa.

As shown in fig. 27, another lower surface reinforcing member 620 extending substantially in the front-rear direction of the vehicle body is coupled to the lower surface of the bottom wall 280Aa of the battery case 280. Thus, the bottom wall 280Aa of the battery case 280 is strongly reinforced on the lower surface side in the vehicle body front-rear direction and the vehicle width direction.

As shown in fig. 22 to 24, a base portion 230 having a flat upper surface and bulging upward with respect to a joint surface with the bottom wall 280Aa of the peripheral edge is provided at a part of the base side (side connected to the beam main bodies 370 and 400) of the front projecting seats 380 and 410 and the rear projecting seats 390 and 420 of the battery cross beam 450. As shown in fig. 23, the base 230 can mount the battery 510 on its upper surface. Further, the lower surface side of the base part 230 communicates with the internal space of the beam main body part 370.

As described above, in the vehicle body lower portion structure 12 of the present embodiment, the battery cross member 450 includes the left and right side members 450S and the center member 450C having a substantially hat-shaped cross section, the upper surface of the center member 450C is formed lower than the upper surfaces of the left and right side members 450S, and the recess 430 communicating with the front-rear direction is formed by the upper surface of the center member 450C and the vehicle width direction inner side end portions of the left and right side members 450S. Therefore, the concave portion 430 provided in the battery cross member 450 can be used as a through groove for a wiring cable or the like, and the main portion of the battery cross member 450 can be formed by a press-formed member or the like which can be manufactured at low cost.

In the vehicle body lower portion structure 12 of the present embodiment, the left and right side members 450S are coupled to the upper floor cross member 350, and the side members 450S are coupled to the center member 450C in the vicinity below the coupling portions (fastening portions of the stud bolts 460). Therefore, as shown in fig. 21, when an impact load F is input to the side member 450S of the battery cross member 450 from the vehicle body side through the rocker 140, the input load F can be supported so as to be dispersed to the floor cross member 350 and the center beam 450C. Therefore, it is possible to suppress bending of the battery cross member 450 in the central region when the impact load F is input from the rocker 140 while adopting the structure of the battery cross member 450 that can be manufactured at low cost.

Therefore, in the vehicle body lower portion structure 12 of the present embodiment, the concave portion 430 communicating with the front-rear direction can be formed in the substantially central region of the battery cross member 450 in the vehicle width direction, and sufficient rigidity in the vehicle width direction can be secured without causing an increase in manufacturing cost.

In the vehicle body lower portion structure 12 of the present embodiment, the first partition wall member 580 and the second partition wall member 590 are provided at positions in front and rear of the coupling portion (the fastening portion of the stud bolt 460) to the floor cross member 350 in the extending direction of the left and right side members 450S, and the first partition wall member 580 and the second partition wall member 590 are fixed to at least three surfaces of the front wall 370f, the upper wall 370u, and the rear wall 370r of the side members 450S. Therefore, the cross section at the front-rear position of the joint portion where the left and right side members 450S and the floor cross member 350 are joined is firmly reinforced by the first bulkhead member 580 and the second bulkhead member 590. Therefore, in the case where the vehicle body lower portion structure 12 of the present embodiment is employed, when an impact load is input from the vehicle body side direction side member 450S, the cross section of the side member 450S can be suppressed from being crushed in the vicinity of the joint portion with the floor cross member 350.

In particular, in the vehicle body lower portion structure 12 of the present embodiment, the center sill 450C is joined to the left and right side sills 450S in the lower region of the first bulkhead member 580 and the second bulkhead member 590, and therefore the inside of the closed cross section formed by joining the center sill 450C and the side sills 450S is reinforced by the first bulkhead member 580 and the second bulkhead member 590. Therefore, by adopting this structure, the crushing of the cross section of the side member 450S can be more effectively suppressed.

In the vehicle body lower portion structure 12 of the present embodiment, the stud bolts 460 fastened to the upper walls 370u of the side members 450S are used at the coupling portions where the left and right side members 450S and the floor cross member 350 are coupled, and the first partition wall member 580 and the second partition wall member 590 are provided in front and rear of the projecting positions of the stud bolts 460 in the extending direction of the left and right side members 450S. Therefore, the floor cross member 350 separated in the vertical direction can be easily coupled to the left and right side members 450S by the stud bolts 460. Further, the closed cross section formed by the center beam 450C and the side beams 450S, and the first bulkhead member 580 and the second bulkhead member 590 can suppress collapse of the cross section at the fastening portions of the stud bolts 460 of the left and right side beams 450S when an impact load is inputted from the side.

In the vehicle body lower portion structure 12 of the present embodiment, the threaded portion 460c of the stud bolt 460 is projected above the case cover 280B of the battery case 280, and the stud bolt 460 is fastened and fixed to the floor cross member 350 by the threaded portion 460 c. The plug body 460a of the stud bolt 460 is held in the through hole 570 of the housing cover 280B by the elastic seal member 560. Therefore, the plug body 460a of the stud bolt 460 is held in the through hole 570 of the housing cover 280B by the elastic seal member 560. Therefore, when the floor cross member 350 is fastened to the stud bolts 460, the position and direction of the threaded portion 460c protruding above the housing cover 280B can be finely adjusted. Therefore, when this structure is adopted, the floor cross member 350 can be fastened to the stud bolts 460 with good workability.

In the vehicle body lower portion structure 12 of the present embodiment, the through hole 570 of the case cover 280B can be closed by the elastic seal member 560. Therefore, the elastic sealing member 560 can prevent water from entering the battery case 280 through the through hole 570 of the case cover 280B.

In the vehicle body lower portion structure 12 of the present embodiment, the auxiliary bulkhead member 600 that substantially closes the gap between the lower surface of the side member 450S and the upper surface of the center member 450C is coupled to the center member 450C at the vehicle width direction inner side end edges of the left and right side members 450S. Therefore, the auxiliary partition member 600 can suppress the crushing of the cross section of the vehicle width direction inner end edges of the left and right side members 450S, and the rigidity of the battery cross member 450 can be further improved. Further, the gap between the vehicle width direction inner end edges of the left and right side members 450S and the center member 450C is substantially closed by the auxiliary bulkhead member 600. Therefore, it is possible to suppress the entry of foreign matter into the side member 450S from the vehicle width direction inner end portion of each of the left and right side members 450S.

In the vehicle body lower portion structure 12 of the present embodiment, the battery cross member 450 includes the front projecting seats 380 and 410 projecting forward from the lower edges of the front walls 370f and 400f, and the rear projecting seats 390 and 420 projecting rearward from the lower edges of the rear walls 370r and 400 r. The front projecting seats 380 and 410 and the rear projecting seats 390 and 420 are disposed on the upper surface side of the bottom wall 280Aa of the battery case 280. A lower surface reinforcing member 610 is disposed on the lower surface side of the bottom wall 280 Aa. The front projecting seats 380 and 410 and the rear projecting seats 390 and 420 are coupled to the lower surface reinforcing member 610 with the bottom wall 280Aa interposed therebetween.

In the vehicle body lower portion structure 12 of the present embodiment, with this structure, the front projecting seats 380 and 410 and the rear projecting seats 390 and 420 are integrated with the bottom wall 280Aa of the battery case 280 together with the lower surface reinforcing member 610. Therefore, when a load in the front-rear direction is input to the battery cross member 450 from the floor cross member 350 side via the stud bolts 460, the battery cross member 450 can be suppressed from collapsing in the front-rear direction. Therefore, the vehicle body lower portion structure 12 can support the lower front and rear ends of the battery cross member 450 to the battery case 280 with high rigidity.

In particular, when the lower surface reinforcing member 610 is formed of a plate-shaped portion seat having a substantially wave-shaped cross section extending substantially in the vehicle width direction as in the present embodiment, the rigidity of the bottom wall 280Aa of the battery case 280 can be effectively improved while suppressing an increase in the weight of the vehicle body.

In the vehicle body lower portion structure 12 of the present embodiment, not only the lower surface reinforcing member 610 extending substantially in the vehicle width direction but also another lower surface reinforcing member 620 extending substantially in the vehicle front-rear direction are coupled to the lower surface of the bottom wall 280Aa of the battery case 280. Therefore, the vehicle body lower portion structure 12 of the present embodiment can improve the rigidity of the entire bottom wall 280Aa of the battery case 280.

Fig. 28 is a sectional view showing a vehicle body lower portion structure 1120 according to another embodiment. Fig. 28 shows a case main body 280A of the battery case 280 and a cross section orthogonal to the vehicle body longitudinal direction inside thereof. In fig. 28, the same reference numerals are given to the same components as those of the above-described embodiment.

The basic structure of the vehicle body lower portion structure 1120 of the other embodiment is substantially the same as that of the above-described embodiment, but a load transmission plate 630 is provided on the upper surface of the left and right side members 450S having a higher upper surface height than the center member 450C. The load transfer plates 630 are formed of metal plates having substantially the same width as the side beams 450S.

In the vehicle body lower portion structure 1120 of the other embodiment described above, the bending rigidity of the vehicle width direction central region of the battery cross member 450 can be effectively increased by the load transmission plate 630. In addition, in this vehicle body lower portion structure 1120, the bending rigidity of the battery cross member 450 can be effectively improved only by installing the load transmission plates 630 on the upper surfaces of the left and right side members 450S. Therefore, the increase in manufacturing cost for reinforcing the battery cross member 450 can be suppressed.

The present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the scope of the invention.

A third embodiment of the present invention is explained based on the drawings. In the drawings, an arrow FR indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow LH indicates the left side of the vehicle.

Fig. 29 is a diagram of a skeleton portion of the vehicle body 10 of the present embodiment as viewed obliquely from the rear and from the left and above, and fig. 30 is a diagram of the vehicle body lower portion structure 12 of the vehicle body 10 as viewed from above. Fig. 31 is a view of the vehicle body lower portion structure 12 taken along the line III-III in fig. 30.

The vehicle body lower portion structure 12 is a structure located on the lower portion side of the vehicle body 10, and includes a pair of rocker beams 140 that are arranged on the left and right side portions on the vehicle body lower end side and extend in the substantially front-rear direction of the vehicle body.

The vehicle body lower portion structure 12 includes: a pair of lower edge beams 140; a floor panel 16 having both ends in the vehicle width direction erected on left and right side sills 140; a plurality of floor cross members 340, 350, 360 (vehicle body side cross members) arranged on the upper surface side of the floor panel 16; battery cases 280 (see fig. 31) provided on the left and right side sills 140 and side-supported below the floor panel 16; and a plurality of battery beams (underfloor beams) 450 provided inside the battery case 280. In the case of the present embodiment, the front two floor cross members 340, 350 are attached with the respective front and rear installation portions of the driver seat 31 and the passenger seat 32 installed in the vehicle interior.

The floor cross members 340, 350, and 360 extend substantially in the vehicle width direction, and both end portions in the extending direction are coupled to the left and right rocker members 140. The floor cross members 340, 350, 360 are disposed apart from each other in the vehicle body front-rear direction.

Fig. 35 and 36 are perspective views partially cut along line VII-VII in fig. 30. Fig. 35 is a view of the cross-sectional portion viewed from obliquely right above the rear portion, and fig. 36 is a view of the cross-sectional portion viewed from obliquely right below the rear portion.

As shown in fig. 31, 35, and 36, battery case 280 includes case body 280A that opens on the upper side, and case cover 280B that closes the opening in the upper portion of case body 280A. The case body 280A includes a substantially rectangular bottom wall 280Aa in plan view, and a peripheral wall 280Ab rising upward from a peripheral region of the bottom wall 280 Aa. Hereinafter, a portion of the peripheral wall 280Ab that rises upward from the left and right side end portions is referred to as a housing side wall 500.

A plurality of batteries 510 (see fig. 32) and a plurality of battery cross members 450 extending substantially in the vehicle width direction so as to partition the inside of the battery case 280 in the front-rear direction are disposed inside the battery case 280. In the present embodiment, three battery beams 450 are provided. Each battery cross member 450 is disposed on the floor 16 at a position directly below the floor cross members 340, 350, and 360. The three floor beams 340, 350, 360 are arranged substantially parallel to the battery beam 450.

The respective cross sections (cross sections substantially orthogonal to the front-rear direction of the vehicle body) including the respective floor cross members 340, 350, and 360 and the battery cross member 450 corresponding thereto are formed to have substantially the same configuration. Therefore, the cross-sectional structure of the vehicle body lower portion structure 12 will be described below, with a cross section of the floor cross member 350 including the center in the front-rear direction and the battery cross member 450 therebelow being representative.

As shown in fig. 31, 35, and 36, a rectangular tubular case frame 520 extending substantially in the vehicle body longitudinal direction is coupled to the outer surface of the case side wall 500 of the case main body 280A. The lower end of the inner side wall 520A of the case frame 520, which is joined to the case side wall 500 of the case main body 280A, is bent inward in the vehicle width direction, and an extension piece 520b is provided at the tip of the bent portion. The extension piece 520b overlaps the lower surface of the bottom wall 280Aa of the case main body 280A and is joined to the lower surface of the bottom wall 280 Aa.

Further, a mounting frame 530 bulging outward in the vehicle width direction from a lower region of the casing frame 520 is coupled to the vehicle width direction outer side of the casing frame 520. The mounting frame 530 forms a horizontally long rectangular cross-section together with the outer side wall of the case frame 520 in a state of being coupled with the case frame 520. The rectangular cross section extends substantially in the front-rear direction of the vehicle body. The mounting frame 530 is overlapped with inner lower surfaces of the left and right rocker beams 140, and is coupled to the lower surfaces of the rocker beams 140 by fastening members 540.

Further, a lower wall of the mounting frame 530 is joined to a lower surface of the case frame 520, and a frame extension piece 530A extending to extend to a lower surface side of the bottom wall 280Aa of the case main body 280A is provided at a front end portion of the lower wall. The frame extension piece 530A overlaps the lower surface of the extension piece 520b of the housing frame 520, and is joined to the lower surface of the bottom wall 280Aa of the housing main body 280A together with the extension piece 520 b. The frame extension piece 530a, the extension piece 520b, and the bottom wall 280Aa are joined by welding, for example, in a state where three pieces are overlapped.

Fig. 32 is a view showing a cross section along the line IV-IV in fig. 31, and fig. 33 is a perspective view of the vehicle body lower portion structure 12 including a cross section along the line V-V in fig. 31. Fig. 34 is a view of a part of the battery case 280 of the vehicle body lower portion structure 12 as viewed from the rear obliquely upward right side.

As shown in fig. 32 and 33, the battery cross member 450 includes: a beam body 370 having a substantially コ -shaped cross section and rising upward, and including a front wall 370f, an upper wall 370u, and a rear wall 370 r; a front projecting seat 380 projecting forward from a lower edge of the front wall 370 f; and a rear projecting seat 390 projecting rearward from a lower edge of the rear wall 370 r.

A plurality of portions of the upper portion of the battery cross member 450, which are separated in the vehicle width direction, are coupled to the corresponding floor cross member 350 above by a plurality of stud bolts 460 as fastening members. Specifically, upper wall 370u of beam body 370 of battery cross beam 450 is coupled to the left and right halves of floor cross beam 350 by four stud bolts 460.

As shown in fig. 32, the stud bolt 460 includes a substantially cylindrical central bolt portion 460a, a lower threaded portion 460b projecting downward from the lower surface of the bolt portion 460a, and an upper threaded portion 460c projecting upward from the upper surface of the bolt portion 460 a.

The lower end of the stud bolt 460 is coupled to the upper wall 370u of the beam main body portion 370 of the battery cross member 450. As shown in fig. 32, the stud bolt 460 is fixed to the battery cross member 450 by screwing a nut 470 into a screw portion 460b that penetrates the upper wall 370u of the member main body portion 370 from above to below. Further, the threaded portion 460c of each stud bolt 460 penetrating the floor 16 from below to above penetrates the bracket 480 of the floor cross member 350 further to above, and the nut 490 is screwed to the threaded portion 460 c. The upper portion of the stud 460 is thereby secured to the floor cross member 350.

The bracket 480 is a metal member having a substantially hat-shaped cross section that also serves as a cross-sectional reinforcement portion of the floor cross member 350 (a cross plate 650 described later). A portion of the bracket 480 corresponding to the hat brim of the hat shape is joined to the lower surface of the upper wall of the floor cross member 350 (cross plate 650), and a through hole 480a into which the screw portion 460c of the stud bolt 460 is inserted is formed in a portion corresponding to the top of the hat shape. The stud bolt 460 is welded to the upper wall of the floor cross member 350 with the top of the hat shape facing downward. A working hole 550 for screwing a nut 490 into a screw portion 460c protruding upward from the through-hole 480a is formed in a portion of the upper wall of the floor cross member 350, the portion facing the through-hole 480a of the bracket 480.

As shown in fig. 32, a support flange 460aA and a small-diameter shaft 460aB projecting upward from the support flange 460aA are provided in a bolt body portion 460a of the stud bolt 460. A thick cylindrical elastic seal member 560 is fitted to the shaft portion 460 aB. A support groove 560a is provided on the outer peripheral surface of the elastic sealing member 560. The support groove 560a is partially locked to the peripheral edge of the through hole 570 of the housing cover 280B. The bolt body 460a of the stud bolt 460 is held in the through hole 570 of the housing cover 280B by the elastic seal member 560. Further, the lower surface of the elastic sealing member 560 abuts against the upper surface of the support flange 460aA, and the upper surface of the elastic sealing member 560 abuts against the lower surface of the floor panel 16.

As shown in fig. 31, 35, and the like, a first partition wall member (partition wall member) 580 and a second partition wall member (partition wall member) 590 are provided inside the battery cross member 450 in the front and rear of the installation portion of each stud bolt 460 in the extending direction of the battery cross member 450. Each of first partition member 580 and second partition member 590 has flanges 580a and 590a (see fig. 34) for joining, and is fixed to at least three surfaces of front wall 370f, upper wall 370u, and rear wall 370r of battery cross member 450 by welding or the like.

As shown in fig. 33, a reinforcing plate 200 having a substantially コ -shaped cross section, which is joined to the upper wall 370u, the front wall 370f, and the rear wall 370r of the beam body 370, is disposed inside the beam body 370 of the battery cross member 450. That is, the walls of the beam main body 370 are double-walled by the metal reinforcing plate 200, and the above-described members are coupled to the walls reinforced by the reinforcing plate 200.

As described above, the battery cross member 450 includes the forward projecting seat 380 that projects forward from the lower edge of the front wall 370f of the beam body 370, and the rearward projecting seat 390 that projects rearward from the lower edge of the rear wall 370r of the beam body 370. That is, battery cross member 450 has an inverted T-shaped cross section.

The battery cross member 450 is disposed such that the front extension seat 380 and the rear extension seat 390 face the upper surface of the bottom wall 280Aa of the battery case 280. On the other hand, the lower surface reinforcing member 610 is disposed at a position directly below the installation portion of the battery beam 450 on the lower surface of the bottom wall 280Aa of the battery case 280.

The lower surface reinforcing member 610 is formed of a metal plate-like member having a substantially wave-shaped cross section extending substantially in the vehicle width direction. The front projecting seat 380 and the rear projecting seat 390 of the battery cross member 450 are coupled to the lower surface reinforcing member 610 with the bottom wall 280Aa of the battery case 280 interposed therebetween. For example, the flat flanges of the front extension seat 380 and the rear extension seat 390 and the flat flange of the lower surface reinforcing member 610 are overlapped on the upper and lower surfaces of the bottom wall 280Aa, and in this state, the members are welded so as to be overlapped three by three. The battery cross member 450 is thus integrated with the lower surface reinforcing member 610 on the lower surface such that the front extension seat 380 and the rear extension seat 390, which extend forward and rearward from the beam body portion 370, sandwich the bottom wall 280 Aa.

As shown in fig. 35 and 36, the extension piece 520b of the case frame 520 is joined to the lower surface of the bottom wall 280Aa of the battery case 280 at the end region of the battery cross member 450 in the vehicle width direction. The extension piece 520b constitutes a lower surface reinforcing member. The front projecting seat 380 and the rear projecting seat 390 are coupled to each other with the bottom wall 280Aa interposed therebetween, similarly to the lower surface reinforcing member 610 described above.

As shown in fig. 32 and 33, a pedestal portion 230 having a flat upper surface and bulging upward with respect to a joint surface with the bottom wall 280Aa of the peripheral edge is provided at a part of the base side (side connected to the beam main body portion 370) of the front extension seat 380 and the rear extension seat 390 of the battery cross member 450. As shown in fig. 32, the base 230 can mount the battery 510 on its upper surface. Further, the lower surface side of the base part 230 communicates with the internal space of the beam main body part 370.

As shown in fig. 31, the floor cross member 350 includes: a cross plate 650 joined to an upper surface of the floor panel 16 and forming a closed cross section extending substantially in the vehicle width direction with the floor panel 16; and a gusset inclined portion 111 that is provided so as to bridge between the lower surface of the end region of the floor panel 16 in the vehicle width direction and the inner surface of the rocker 14 and forms a closed cross section extending substantially in the vehicle width direction with respect to the floor panel 16. The cross plate 650 has a substantially hat-shaped cross section, and both ends in the vehicle width direction are joined to the upper surfaces of the left and right rocker members 140. The gusset inclined portion 111 is formed in a substantially hat-shaped cross section, and both ends in the vehicle width direction are joined to the lower surface of the floor panel 16 and the inner side surface of the rocker 140. In the present embodiment, the horizontal plate 650 is formed by joining a plurality of plate members.

The upper wall of the vehicle width direction end region of the lateral plate 650 is inclined downward toward the vehicle width direction outer side. Thus, the opening area of the inner portion of the closed cross section formed by the cross plate 650 and the upper surface of the floor panel 16 gradually narrows toward the vehicle width direction outer side. Similarly, the lower wall of the gusset inclined portion 111 is inclined downward toward the outside in the vehicle width direction. Thus, the opening area of the inside of the closed cross section formed by the gusset inclined portion 111 and the lower surface of the floor panel 16 gradually increases toward the outside in the vehicle width direction.

The floor cross member 350 is formed in a shape in which a central region in the vehicle width direction rises upward with respect to the rocker 140. However, in the floor cross member 350, with the above-described configuration, the closed cross section of the central region formed by the floor panel 16 and the lateral plate 650 and the inclined closed cross section of the end region formed by the lateral plate 650 and the gusset inclined portion 111 are continuous so as to have substantially constant cross-sectional areas.

As described above, in the vehicle body lower portion structure 12 of the present embodiment, the front projecting seat 380 and the rear projecting seat 390 are provided to extend from the lower edge of the beam main body portion 370 of the battery cross member 450, and the front projecting seat 380 and the rear projecting seat 390 are coupled to the bottom wall 280Aa of the battery case 280. When a load in the front-rear direction is input from the seat belt to the vehicle body side cross member, for example, when an impact load is input, the load is input to the upper portion of the beam main body portion 370 of the battery cross member 450 via the stud bolt 460 as a fastening member. At this time, a moment in the direction of tilting forward and backward acts on the beam main body 370 by the stud bolt 460, but the moment is received by the forward projecting seat 380 and the rearward projecting seat 390 projecting forward and backward from the lower edge of the beam main body 370 and the respective coupling portions coupled to the battery case 28. Therefore, when a load in the front-rear direction is input from the floor cross member 350 (vehicle body side cross member) to the battery cross member 450, the collapse of the battery cross member 450 in the front-rear direction can be suppressed with high rigidity.

Therefore, by adopting the vehicle body lower portion structure 12 of the present embodiment, the support rigidity of the floor cross member 350 can be maintained high.

In the vehicle body lower portion structure 12 of the present embodiment, the front extension socket 380 and the rear extension socket 390 are disposed on the upper surface side of the bottom wall 280Aa of the battery case 280, the lower surface reinforcing member 610 is disposed on the lower surface side of the bottom wall 280Aa, and the front extension socket 380 and the rear extension socket 390 are coupled to the lower surface reinforcing member 610 with the bottom wall 280Aa interposed therebetween. The front extension seat 380 and the rear extension seat 390 of the battery cross member 450 are integrated with the bottom wall 280Aa of the battery case 280 together with the lower surface reinforcing member 610. Therefore, with this structure, the front-rear collapse of beam main body 370 of battery cross member 450 can be more firmly suppressed.

In addition, in the case of this structure, the members to be coupled to the battery cross member 450 can be formed by press-molding that can be manufactured at low cost, and the members can be welded and fixed to each other.

In particular, in the present embodiment, since the substantially wave-shaped cross section of the lower surface reinforcing member is formed by the plate-shaped member extending substantially in the vehicle width direction, the rigidity of the bottom wall 280Aa of the battery case 280 can be effectively increased by the plate-shaped lower surface reinforcing member 610.

In the vehicle body lower portion structure 12 of the present embodiment, the case frame 520 is coupled to the outside of the case side wall 500 of the battery case 280, the extension piece 520b extending from the case frame 520 overlaps the lower surface of the bottom wall 280Aa of the battery case 280, and the front extension piece 380 and the rear extension piece 390 of the battery cross member 450 are coupled to the extension piece 520b with the bottom wall 280Aa interposed therebetween. Therefore, in the end region of the battery cross member 450 in the vehicle width direction, the front projecting seat 380 and the rear projecting seat 390 are integrated with the extension piece 520b with the bottom wall 280Aa of the battery case 280 interposed therebetween. Therefore, with this structure, the front-rear collapse of the beam main body portion 370 of the battery cross member 450 can be more firmly restricted.

In the vehicle body lower portion structure 12 of the present embodiment, the first partition wall member 580 and the second partition wall member 590 that restrain three surfaces, i.e., the upper wall 370u, the front wall 370f, and the rear wall 370r of the beam main body portion 370 are coupled to the beam main body portion 370 of the battery cross member 450 in the vicinity of the fastening portion of the stud bolt 460. As a result, the first partition wall member 580 and the second partition wall member 590 can increase the rigidity of the cross section in the vicinity of the fastening portion of the stud bolt 460 of the beam body portion, and therefore, the deformation of the cross section in the vicinity of the fastening portion of the stud bolt 460 can be effectively suppressed. Therefore, even when this structure is adopted, if only the thickness of the beam main body 370 can be reduced for weight reduction, tilting and sinking of the stud bolts 460 can be suppressed, and the floor cross member 350 can be supported with high rigidity by the battery cross member 450.

In addition, in the vehicle body lower portion structure 12 of the present embodiment, the floor cross member (vehicle body side cross member) 350 includes: a cross plate 650 having both ends in the vehicle width direction erected on the rocker 140 and having a substantially hat-shaped cross section; and a gusset inclined portion 111 that is formed in a substantially hat-shaped cross section and extends between a lower surface of an end region in the vehicle width direction of the floor panel 16 and a side surface of the rocker 140, wherein the end region in the vehicle width direction of the lateral plate 650 and the gusset inclined portion 111 are formed so as to be inclined downward toward the outside in the vehicle width direction. Further, a bracket 480 also serving as a cross-sectional reinforcement portion is mounted inside the lateral plate 650 in a region near the center in the vehicle width direction, and the bracket 480 is coupled to the beam main body portion 370 of the battery cross member 450 by a stud bolt 460. Therefore, the left and right rocker beams 140 can be connected by a substantially constant continuous closed cross section of the floor cross member 350 while the central region of the floor cross member 350 is formed in a shape rising upward with respect to the rocker beams 140.

In the case of the above-described configuration, since the central region of the floor cross member 350 is formed in a shape rising upward with respect to the rocker 140, the battery case 280 disposed below the central region of the floor cross member 350 can be positioned on the upper side. Therefore, the ground height below the battery case 280 can be easily ensured.

In the case of the above-described structure, the cross section of the central region of the horizontal plate 650 is reinforced by the bracket 480 serving also as a cross-sectional reinforcing portion, and the bracket 480 is coupled to the battery cross member 450 by the stud bolt 460. Therefore, when a load is input to the floor cross member 350, the battery cross member 450 can support the input load while suppressing the deformation of the cross section of the lateral plate 650.

In the present embodiment, the bolt portion 460a of the stud bolt 460 that couples the battery cross member 450 and the floor cross member 350 is held in the through hole 570 of the case cover 280B via the elastic seal member 560. Therefore, when fastening and fixing the stud bolt 460 to the floor cross member 350, the position and direction of the threaded portion 460c protruding above the housing cover 280B can be finely adjusted. Therefore, when this structure is adopted, the floor cross member 350 can be fastened to the stud bolts 460 with good workability.

In addition, in the case of this configuration, since the through-hole 570 of the case cover 280B is closed by the elastic sealing member 560, the penetration of water into the battery case 280 through the through-hole 570 can be prevented. In the case of the present embodiment, since the elastic sealing member 560 is interposed between the stud bolt 460 and the housing cover 280B, the elastic sealing member 560 can suppress vibration of the housing cover 280B.

In the above configuration, when the upper surface of the elastic sealing member 560 is brought into contact with the lower surface of the circumferential region of the through hole 570 of the floor panel 16, the elastic sealing member 560 can prevent water from entering the vehicle interior through the through hole 570 of the floor panel 16. In this case, the elastic sealing member 560 can also suppress vibration of the floor panel 16.

In the vehicle body lower portion structure 12 of the present embodiment, the attachment frame 530 that connects the case frame 520 and the lower surface of the rocker 140 is coupled to the case frame 520. A frame extension piece 530a extending from the mounting frame 530 overlaps the lower surface of the extension piece 520b of the case frame 520, and the frame extension piece 530a is joined to the bottom wall 280Aa of the battery case 280 together with the extension piece 520 b. Therefore, the attachment of the attachment frame 530 to the case frame 520 can be made stronger, and the rigidity of the bottom wall 280Aa of the battery case 280 can be improved.

In the vehicle body lower portion structure 12 of the present embodiment, a reinforcing plate 200 having a substantially コ -shaped cross section, which is joined to the upper wall 370u, the front wall 370f, and the rear wall 370r of the beam main body 370, is disposed inside the beam main body 370 of the battery cross member 450. Therefore, the rigidity of the beam main body 370 to which the stud bolt 460 is fastened can be easily increased with a simple structure. Further, since the reinforcing plate 200 can be formed by a press-formed member that can be manufactured at low cost, the product cost can be reduced.

In the vehicle body lower portion structure 12 of the present embodiment, the base portion 230, which has a lower surface bulging upward and communicates with the internal space of the beam main body portion 370 and an upper surface that is substantially flat, is provided on the forward projecting seat 380 and the rearward projecting seat 390. Therefore, the upper surface of the base portion 230 provided on the front extension seat 380 and the rear extension seat 390 can be used as a battery support portion or the like. In addition, in the case of this configuration, since the lower surfaces of the front projection seat 380 and the rear projection seat 390 can be made to communicate with the internal space of the beam main body 370 with a wide opening area by the base part 230 rising upward, the electrodeposition coating liquid for rust prevention can be easily spread to each corner of the inside of the battery beam 450 at the time of manufacture.

The present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the scope of the invention.

A fourth embodiment of the present invention is explained based on the drawings. In the drawings, an arrow FR indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow LH indicates the left side of the vehicle.

(first embodiment)

As shown in fig. 37 and 38, the vehicle body 10 includes a vehicle body lower portion structure 12 that constitutes a lower portion of the vehicle body 10. The vehicle body lower portion structure 12 includes a left rocker (rocker) 14, a right rocker (rocker) 15, a floor panel 16, a floor cross member unit 180, a battery pack 2000 (see fig. 39), a battery pack frame unit 2200 (see fig. 39), a driver seat (seat) 2400, and a passenger seat (seat) 2600.

Since the vehicle body lower portion structure 12 is configured by substantially bilaterally symmetrical members, the left-side constituent members will be described below, and the right-side constituent members will not be described.

As shown in fig. 38 and 39, the left rocker 14 is provided at the left side portion (outer side) 10a of the vehicle body 10 and extends in the vehicle body longitudinal direction. The right rocker 15 is provided at the right side portion (outer side) 10b of the vehicle body 10 and extends in the vehicle body front-rear direction.

A floor 16 is disposed between the left rocker 14 and the right rocker 15. The floor 16 is erected on the left and right rocker beams 14 and 15. A floor cross member unit 180 is attached to the upper surface 16a of the floor panel 16. The floor cross member unit 180 includes a first floor cross member 3100, a second floor cross member 3200, and a third floor cross member 3300.

The first floor cross member 3100 is disposed on the vehicle body front side in the vehicle compartment 3500. The first floor cross member 3100 includes a left first floor cross member 3100A and a right first floor cross member 3100B.

The left first floor cross member 3100A is erected in the vehicle width direction between the left rocker 14 and the floor tunnel 3700. The right first floor cross member 3100B is erected over the right rocker 15 and the floor tunnel 3700 in the vehicle width direction.

The left first floor cross member 3100A and the right first floor cross member 3100B are linearly arranged in the vehicle width direction.

The floor tunnel 3700 is a portion that bulges upward at the center of the floor panel 16 in the vehicle width direction.

The left first floor cross member 3100A is a member substantially bilaterally symmetrical to the right first floor cross member 3100B. Therefore, in the following description, the left first floor cross member 3100A will be referred to as "first floor cross member 3100", and the right first floor cross member 3100B will not be described.

The first floor cross member 3100 is erected over the left and right side sills 14, 15 in the vehicle width direction.

The second floor cross member 3200 is disposed on the vehicle body rear side of the first floor cross member 3100. The second floor cross member 3200 is erected on the left and right side sills 14, 15 in the vehicle width direction, and extends in parallel with the first floor cross member 3100.

The third floor cross member 3300 is disposed on the vehicle body rear side of the second floor cross member 3200. The third floor cross member 3300 is erected on the left and right side sills 14, 15 in the vehicle width direction, and extends in parallel with the second floor cross member 3200.

The first floor cross member 3100, the second floor cross member 3200, and the third floor cross member 3300 are provided at intervals in the vehicle body longitudinal direction.

A driver seat 2400 (see fig. 37) is attached to the right half portions of the right first floor cross member 3100B and the second floor cross member 3200 by fastening members such as bolts and nuts, for example. For example, a passenger seat 2600 (see fig. 37) is attached to the left half portions of the first floor cross member 3100 and the second floor cross member 3200 by fastening members such as bolts and nuts. In addition, a rear seat is provided in the third floor cross member 3300.

As shown in fig. 40 and 41, the left rocker 14 includes a rocker outer member 4100, a rocker inner member 4200, a reinforcing plate 4300, and a first energy absorbing member 4400.

The rocker outer 4100 is provided on the vehicle width direction outer side. The rocker outer member 4100 has an outer bulging portion 4600, an upper outer flange 4700, and a lower outer flange 4800. The outer expanded portion 4600 is expanded outward in the vehicle width direction from the upper outer flange 4700 and the lower outer flange 4800. A reinforcing member is mounted to an inner surface of the outer swelling portion 4600. The upper outer flange 4700 extends upward from the upper end of the outer expanded portion 4600. The lower outer flange 4800 extends downward from the lower end of the outer expanded portion 4600.

The rocker inner member 4200 is joined to the rocker outer member 4100 from the vehicle width direction inner side, and is provided on the vehicle width direction inner side of the rocker outer member 4100. The rocker inner member 4200 has an inner bulge 5200, an upper inner flange 5300, and a lower inner flange 5400. The inner bulging portion 5200 bulges inward in the vehicle width direction from the upper inner flange 5300 and the lower inner flange 5400.

The inner bulged portion 5200 has an inner upper portion 5600, a first inner wall 5700, an inner central portion 5800, a second inner wall 5900, and an inner lower portion 6100. The inner upper portion 5600 extends inward in the vehicle width direction from the lower end of the upper inner flange 5300. A first inner wall 5700 extends downwardly from the inner end of the inner upper portion 56. The inner center portion 5800 extends from the lower end of the first inner wall 5700 with a downward gradient toward the inside in the vehicle width direction. The second inner wall 5900 extends downward from the lower end of the inner central portion 5800. The inner lower portion 6100 protrudes outward in the vehicle width direction from the lower end of the second inner wall 5900. Lower inner flange 5400 extends downward from the lower end of inner lower portion 6100.

Inner lower portion 6100 extends orthogonally to second inner wall 5900. The inner corner 6400 is formed to be orthogonal to the inner lower portion 6100 and the second inner wall 5900. The inner corner portion 6400 is formed at a lower portion of the left rocker 14 on the vehicle width direction inner side.

The reinforcing plate 4300 is interposed between the rocker outer member 4100 and the rocker inner member 4200. The reinforcing plate 4300 is formed in a flat plate shape. Specifically, the upper reinforcement panel flange 4300b is sandwiched between the upper outer flange 4700 of the rocker outer member 4100 and the upper inner flange 5300 of the rocker inner member 4200, and joined thereto. Further, the lower gusset flange 4300a of the gusset 4300 is sandwiched between the lower outer flange 4800 of the rocker outer member 4100 and the lower inner flange 5400 of the rocker inner member 4200, and joined together.

The lower outer flange 4800, the lower gusset flange 4300a, and the lower inner flange 5400 are joined to form a rocker flange 6600 from each of the flanges 4800, 4300a, 5400. The rocker flange 6600 extends downward from an outer end 6400a of the inner corner 6400 on the vehicle width direction outer side, and a lower end 6600a extends inward in the vehicle width direction.

The left rocker 14 is formed in the outer shape of a rectangular frame (i.e., a closed cross section) by the rocker outer member 4100 and the rocker inner member 4200. The upper reinforcing plate flange 4300b of the reinforcing plate 4300 is sandwiched between the upper outer flange 4700 and the upper inner flange 5300. Additionally, the lower reinforcing plate flange 4300a of the reinforcing plate 4300 is sandwiched between the lower outer flange 4800 and the lower inner flange 5400. Thus, the reinforcing plate 4300 is disposed in the vertical direction.

A rocker space 6800 is formed between the rocker outer member 4100 and the rocker inner member 4200.

A first energy absorbing member 4400 is disposed in the rocker space 6800 (i.e., a closed cross section). The first energy absorbing member 4400 is attached to the rocker outer member 4100, and bulges out toward the rocker inner member 4200 side through the opening 4300c of the reinforcing plate 4300.

The first energy absorbing member 4400 has a first front wall 7100, a first rear wall 7200, a first side wall 7300, a first front flange 7400, and a first rear flange 7500.

A first front flange 7400 projects from the base end of the first front wall 7100 toward the front of the vehicle body. The first rear wall 7200 is disposed at a distance from the first front wall 7100 on the vehicle body rear side. A first rear flange 7500 projects from a base end of the first rear wall 7200 toward the rear of the vehicle body. The front end of the first front wall 7100 and the front end of the first rear wall 7200 are connected by a first side wall 7300.

The first energy-absorbing member 4400 is formed in a U-shaped cross section by the first front wall 7100, the first rear wall 7200, and the first side wall 7300. The first front flange 7400 is joined to the rocker outer member 4100. The first rear flange 7500 is joined to the rocker outer member 4100. Thus, the first energy absorbing member 4400 is attached to the rocker outer member 4100, and bulges out toward the rocker inner member 4200 side through the opening 4300c of the reinforcing plate 4300.

Therefore, when the impact load F1 is input from the side of the vehicle Ve, the first energy-absorbing member 4400 can be crushed by the impact load F1.

In this way, the first energy absorbing member 4400 is attached to the rocker outer member 4100. Therefore, the degree of freedom in the shape of the rocker inner member 4200 can be increased, and the inner corner 6400 can be easily formed in the rocker inner member 4200. By forming the inner corner portion 6400 in a right-angled shape, the inner corner portion 6400 can be favorably engaged with a frame engagement portion 2080 (described later) when an impact load F1 is input from the side of the vehicle Ve.

As shown in fig. 42 and 43, the left side portion 16b of the floor panel 16 is attached to the inner center portion 5800 of the rocker inner 4200. The first floor cross member 3100 and the second floor cross member 3200 extend in the vehicle width direction along the upper surface 16a of the floor panel 16. The first floor cross member 3100 and the second floor cross member 3200 are provided at intervals in the vehicle body longitudinal direction.

First floor cross member 3100 has a first beam top portion (top portion) 8100, a first beam front wall portion 8200, a first beam rear wall portion 8300, a first beam front flange (front flange) 8400, and a first beam rear flange (rear flange) 8500.

A first beam front wall portion 8200 projects downwardly from a front edge of the first beam top portion 8100 toward the floor panel 16. The first beam rear wall portion 8300 extends downward from the rear edge of the first beam top portion 8100 toward the floor panel 16. The first floor cross member 3100 is formed in a U-shaped cross section by a first beam top portion 8100, a first beam front wall portion 8200, and a first beam rear wall portion 8300.

The first floor cross member 3100 is formed in a hat-shaped cross section by a first beam top portion 8100, a first beam front wall portion 8200, a first beam rear wall portion 8300, a first beam front flange 8400, and a first beam rear flange 8500.

The first beam front flange 8400 extends from the lower edge of the first beam front wall portion 8200 toward the front of the vehicle body along the upper surface 16a of the floor panel 16. The first beam rear flange 8500 extends rearward of the vehicle body from the lower edge of the first beam rear wall portion 8300 along the upper surface 16a of the floor panel 16.

The first floor cross member 3100 is attached to the upper surface 16a of the floor panel 16 by joining the first beam front flange 8400 and the first beam rear flange 8500 to the upper surface 16a of the floor panel 16. The first floor cross member 3100 and the floor panel 16 form a closed cross section.

In this state, the left flange 8600 of the first girder top portion 8100 is joined to the upper portion of the left rocker 14 (specifically, the inner upper portion 5600 of the left rocker 14). Therefore, the first beam top portion 8100 of the first floor cross member 3100 is disposed on the same plane as the inner upper portion 5600 of the left lower side beam 14.

Further, the first floor cross member 3100 has a first recessed portion 8800 recessed upward at a first member rear wall portion 8300 facing the second floor cross member 3200 (see also fig. 40).

The second floor cross member 3200 has a second beam top portion (top portion) 9100, a second beam front wall portion 9200, a second beam rear wall portion 9300, a second beam front flange (front flange) 9400, and a second beam rear flange (rear flange) 9500.

The second beam front wall portion 9200 extends downward from the front edge of the second beam top portion 9100 toward the floor panel 16. The second beam rear wall portion 9300 projects downward from the rear edge of the second beam top portion 9100 toward the floor panel 16. The second floor cross member 3200 is formed in a U-shaped cross section by the second beam top portion 9100, the second beam front wall portion 9200, and the second beam rear wall portion 9300.

The second floor cross member 3200 is formed in a hat shape in cross section by the second beam top portion 9100, the second beam front wall portion 9200, the second beam rear wall portion 9300, the second beam front flange 9400, and the second beam rear flange 9500.

The second beam front flange 9400 extends forward of the vehicle body from the lower edge of the second beam front wall portion 9200 along the upper surface 16a of the floor panel 16. The second beam rear flange 9500 extends rearward of the vehicle body from the lower edge of the second beam rear wall portion 9300 along the upper surface 16a of the floor panel 16.

The second floor cross member 3200 is attached to the upper surface 16a of the floor panel 16 by joining the second beam front flange 9400 and the second beam rear flange 9500 to the upper surface 16a of the floor panel 16. A closed cross section is formed by the second floor beam 3200 and the floor 16.

In this state, the flange 9600 of the second beam top portion 9100 is joined to the upper portion of the left rocker 14 (specifically, the inner upper portion 5600 of the left rocker 14). Therefore, the second beam top portion 9100 of the second floor beam 3200 is arranged on the same plane as the inner upper portion 5600 of the left rocker 14.

In addition, the second floor cross member 3200 has a second recessed portion 9700 recessed upward at a second beam front wall portion 9200 opposed to the first floor cross member 3100.

The passenger seat 2600 is supported by the left half portions of the first floor cross member 3100 and the second floor cross member 3200 (see fig. 37). That is, the first floor cross member 3100 and the second floor cross member 3200 are reinforced by the passenger seats 2600. Therefore, the first concave portion 8800 and the second concave portion 9700 can be formed while the strength of the first floor cross member 3100 and the second floor cross member 3200 is ensured.

Therefore, the impact load F1 input from the side direction of the vehicle Ve to the left rocker 14 can be transmitted as the load F2 to the first floor cross member 3100 and the second floor cross member 3200 through the first load path.

The first concave portion 8800 and the second concave portion 9700 are joined along the raised portion 3800 (see fig. 42) of the floor 16. That is, the floor panel 16 has a raised portion 3800 raised upward along the first concave portion 8800 and the second concave portion 9700.

Since the raised portion 3800 of the floor panel 16 is raised upward along the first concave portion 8800 and the second concave portion 9700, a large space 9800 below the floor panel 16 can be ensured. This can increase the capacity of the battery package 2000 (i.e., the battery 99) disposed below the floor panel.

A bulge 3800 of floor 16 is formed between first floor beam 3100 and second floor beam 3200. Therefore, the bulge 3800 is located below the passenger seat 2600. For example, the swollen portions 3800 are disposed at positions on the vehicle body rear side of the feet of the passenger seated in the passenger seat 2600 (the periphery of the portion where the passenger places the feet). This can prevent the bulging portion 3800 from interfering with the placement of the feet of the passenger seated in the passenger seat 2600.

As shown in fig. 43 and 44, a battery package 2000 (underfloor mounting member) is provided between the left rocker 14 and the right rocker 15 (see fig. 38) and below the floor panel 16. The battery package 2000 includes a battery case 1020, a plurality of battery beams (underfloor beams) 1040, and a tube receiving portion 1060.

Battery case 1020 has case wall portion (outer peripheral wall) 1070, case bottom portion (lower surface) 1080, and case flange 1090.

Housing wall portion 1070 has a housing front wall 1070a, a housing rear wall 1070b, a housing left side wall 1070c, and a housing right side wall 1070 d. Case wall portion 1070 is formed in a rectangular frame shape by case front wall 1070a, case rear wall 1070b, case left side wall 1070c, and case right side wall 1070 d.

Case wall portion 1070 has a lower end closed by case bottom portion 1080 and an upper end formed with case opening portion 1110. Case flange 1090 extends outward from the entire circumference of case opening 1110 toward battery case 1020.

A plurality of battery beams 1040 are provided in an interior 1125 of the battery case 1020. Battery cross member 1040 extends in the vehicle width direction in an inner portion 1125 of battery case 1020.

Battery beam 1040 has a battery beam top (upper surface) 1140, a battery beam front wall 1150, a battery beam rear wall 1160, a battery beam front flange 1170, a battery beam rear flange 1180, a battery beam left end flange 1190, a battery beam right end flange 1210, and a battery beam bulkhead (bulkhead) 1220.

Battery beam top 1140 is disposed above case bottom 1080 (specifically, at the same height as case opening 1110), and extends in the vehicle width direction along case bottom 1080.

Battery beam front wall section 1150 extends from the front edge of battery beam top section 1140 toward housing bottom section 1080. Battery beam rear wall 1160 extends from the rear edge of battery beam top 1140 toward housing bottom 1080.

The battery beam front flange 1170 projects from the lower edge of the battery beam front wall portion 1150 toward the front of the vehicle body. Battery beam rear flange 1180 projects toward the vehicle body rear from the lower edge of battery beam rear wall 1160.

A battery beam left end flange 1190 projects toward the vehicle body front from the left end portion of the battery beam front wall portion 1150. Battery beam right end flange 1210 projects from the left end portion of battery beam rear wall 1160 toward the front of the vehicle body.

Battery beam 1040 is formed in a U-shape in cross section by battery beam top 1140, battery beam front wall 1150, and battery beam rear wall 1160.

Battery beam 1040 is formed in a hat-shaped cross-section by battery beam top 1140, battery beam front wall 1150, battery beam rear wall 1160, battery beam front flange 1170, and battery beam rear flange 1180.

Battery beam front flange 1170 and battery beam rear flange 1180 are joined to housing bottom 1080.

Therefore, battery beam 1040 is formed in a hollow shape (i.e., a closed cross section) by battery beam top portion 1140, battery beam front wall portion 1150, battery beam rear wall portion 1160, and case bottom portion 1080.

The battery beam partition 1220 is provided at the center in the vertical direction of the battery beam 1040. Specifically, front flange 1120a of battery beam partition 1220 is joined to battery beam front wall portion 1150, and rear flange 1120b of battery beam partition 1220 is joined to battery beam rear wall portion 1160. Thus, a battery beam partition wall 1220 is provided at the center in the vertical direction of the battery beam 1040.

That is, the battery beam 1040 is partitioned vertically by the battery beam partition wall 1220. Therefore, the battery beam 1040 is divided into a beam upper portion (upper portion) 1040a and a beam lower portion (lower portion) 1040b by the battery beam partition wall 1220.

As a result, a part of the impact load F1 input from the side direction of the vehicle Ve to the left rocker 14 can be transmitted as a so-called horizontal load F3 to the beam upper portion 1040a through the second load path. Further, a part of the impact load F1 input from the left rocker 14 in the lateral direction of the vehicle Ve can be transmitted to the cross member lower portion 1040b through a path of the third load path as a so-called offset load F4.

In this way, a part of the impact load F1 input from the vehicle Ve toward the left rocker 14 can be transmitted through two paths, i.e., the beam upper portion 1040a and the beam lower portion 1040 b. As a result, a part of the impact load F1 can be supported satisfactorily by the beam upper portion 1040a and the beam lower portion 1040 b.

In addition, the battery beam left end flange 1190 is joined to the case left side wall 1070c of the battery case 1020. Battery beam right end flange 1210 is joined to case right side wall 1070d of battery case 1020.

In this state, the battery beam 1040 is disposed so that the battery beam top portion (upper surface) 1140 faces (faces) the rocker center portion (center portion) 14a (see fig. 40) in the vertical direction of the left rocker 14. Therefore, a part of the impact load F1 input from the side direction left rocker 14 of the vehicle Ve can be reliably transmitted to the beam upper portion 1040a through the path of the second load path as a so-called horizontal load.

As shown in fig. 39, battery beam 1040 is formed in a hollow shape and includes weak portion 1240 and strong portion 1250.

The fragile portion 1240 is formed in the outer region E1 on the vehicle width direction outer side. The fastening portion 1250 is formed in the inner region E2 on the vehicle width direction inner side.

Thus, a fragile portion 1240 is formed in the outer region E1 of the battery beam 1040. Therefore, the fragile portion 1240 can be crushed to absorb the impact load F1 input from the side of the vehicle Ve.

On the other hand, a fastening portion 1250 is formed in the inner region E2 of the battery cross member 1040. Therefore, the excessive load absorbed by the fragile portion 1240 can be supported by the strong portion 1250.

Thus, the floor (i.e., vehicle body floor) 16 can be divided into an energy absorption region (i.e., outer region) E1 on the vehicle width direction outer side and a protection region (i.e., inner region) E2 on the vehicle width direction inner side.

As shown in fig. 45 and 46, of the plurality of battery beams 1040, the battery beam 1040 in the 2 nd row from the front of the vehicle body is disposed below the first floor beam 3100.

Further, of the plurality of battery beams 1040, the battery beam 1040 in the 4 th row from the front of the vehicle body is disposed below the second floor beam 3200.

Hereinafter, in fig. 45 and 46, for convenience, the battery beam 1040 in the 2 nd row will be described as a battery beam (underfloor beam) 1040A. The battery beam 1040 in the 3 rd row will be described as a battery beam (underfloor beam) 1040B.

A mounting bracket 1260 is provided on the floor 16 below the outer end side of the second floor beam 3200. Battery cross member 104B of row 3 is connected to outer mounting bracket 1260 via outer connecting member 1270.

Outer coupling member 1270 includes sleeve 1310, bolt 1320, and nut 1330. The sleeve 1310 is disposed to extend in the vertical direction between the floor 16 below the second floor beam 3200 and the housing bottom portion 1080. Sleeve 1310 is disposed so as to penetrate through inner portion 1040c of battery beam 1040B. Bolt 1320 is inserted into sleeve 1310 from below housing bottom 1080 through housing bottom 1080, and threaded portion 1320a protrudes upward from floor 16 and outer mounting bracket 1260. A nut 1330 is screwed into the screw portion 1320 a.

An inner mounting bracket 1350 is provided at the floor 16 below the inner end side of the second floor beam 3200. Battery cross member 1040B is connected to inner mounting bracket 1350 via inner connecting member 1360.

Inner connecting structure 1360 includes sleeve 1370, bolt 1380 and nut 1390. The sleeve 1370 is disposed to extend in the vertical direction between the floor 16 below the second floor beam 3200 and the housing bottom 1080. Sleeve 1370 is disposed to penetrate through inner portion 1040c of battery beam 1040B. Bolt 1380 is inserted into sleeve 1370 from below housing bottom 1080 through housing bottom 1080, and screw portion 1380a protrudes upward from inner mounting bracket 1350. A nut 1390 is screwed to the threaded portion 1380 a.

The battery beam 1040B is coupled to the floor panel 16 below the outer end side of the second floor beam 3200 via an outer mounting bracket 1260 by an outer coupling member 1270. Further, a battery beam 1040B is connected to the floor 16 below the inner end side of the second floor beam 3200 via an inner mounting bracket 1350 via an inner connecting member 1360. Therefore, the floor panel 16 below the second floor beam 3200 is reinforced by the battery beam 1040B.

That is, the rigidity of the floor panel 16 below the first floor cross member 3100 can be improved. Accordingly, even if second floor beam 3200 or battery beam 1040B has weak portion 1240 in a local portion, the resistance to impact load F1 input from the side of vehicle Ve can be improved.

The floor 16 of the first floor cross member 3100 is provided with an outer mounting bracket 1410 and an inner mounting bracket 1420. Battery cross member 1040A of row 2 is connected to outer mounting bracket 1410 and inner mounting bracket 1420 via outer connecting member 1440 and inner connecting member 1360.

The structure for connecting the battery beam 1040A in the 2 nd row to the floor panel 16 of the first floor beam 3100 is the same as the structure for connecting the battery beam 1040B in the 3 rd row to the floor panel 16 of the second floor beam 3200. Therefore, detailed description of the structure for connecting the battery cross member 1040A of the 2 nd row to the floor panel 16 of the first floor cross member 3100 is omitted.

By coupling the battery cross member 1040A of the 2 nd row to the floor panel 16 of the first floor cross member 3100, the rigidity of the floor panel 16 below the second floor cross member 3200 can be improved. Thus, even if first floor cross member 3100 and battery cross member 1040A have weak portions 1240 in part, the resistance to an impact load input from the side of vehicle Ve can be improved.

As shown in fig. 44 and 46, the battery cross member 1040 has a battery cross member recess (concave portion) 1480 at the center in the vehicle width direction. The battery beam recess 1480 is formed so as to be recessed downward.

A tube housing portion 1060 is attached to the battery beam recess 148 so as to extend in the vehicle body longitudinal direction. The tube receiving portion 1060 has a tube portion 1510, a left flange 1520, and a right flange 1530.

The tube portion 1510 is formed in a hollow closed cross section. Inside the pipe portion 1510, a pipe 1540, a hose 1550, and the like are housed. The left flange 1520 extends leftward in the vehicle width direction from the left side of the pipe 1510. The left flange 1520 mounts to a left side portion 1140a of the battery beam recess 1480 in the battery beam top portion 1140.

The right flange 1530 extends rightward in the vehicle width direction from the right side portion of the pipe portion 1510. The right flange 1530 is mounted to the right side portion 1140b of the battery beam recess 1480 in the battery beam top 1140.

That is, the tube housing 1060 is bridged over the left side portion 1140a and the right side portion 1140b of the battery beam recess 1480.

By forming the battery beam recess 1480 in the battery beam 1040, the tube receiving portion 1060 can be provided in the battery beam recess 1480. The pipe receiving portion 1060 receives a pipe 1540, a hose 1550, and the like.

Further, by bridging tube receiving portion 1060 on battery beam recess 1480 of battery beam 1040, battery beam recess 1480 is reinforced by tube receiving portion 1060. Therefore, when a load is transmitted from the side of the vehicle Ve to the battery cross member 1040, the transmitted load can be supported by the pipe receiving portion 1060. This prevents the battery beam recess 1480 from being bent by the transmitted load, and the transmitted load can be supported by the battery beam 1040.

As shown in fig. 44 and 47, a battery pack frame unit 2200 is attached to the battery pack 2000. The battery pack frame unit 2200 includes a left frame portion (frame portion) 1610, a right frame portion (frame portion) 1620, and a front frame portion (frame portion) 1630.

The left frame portion 1610 is provided on the case left side wall 1070c of the battery case 1020 from the outside of the battery case 1020. The right frame portion 1620 is provided on the case right side wall 1070d of the battery case 1020 from the outside of the battery case 1020. The front frame portion 1630 is provided on the case front wall 1070a of the battery case 1020 from the outside of the battery case 1020.

The left frame portion 1610, the right frame portion 1620, and the front frame portion 1630 are similarly configured. Therefore, the left frame portion 1610 will be described below, and the description of the right frame portion 1620 and the front frame portion 1630 will be omitted.

The left frame portion 1610 is provided with a first frame portion 1650, a second frame portion 1660, a first frame energy-absorbing member (second energy-absorbing member) 1670, and a second frame energy-absorbing member (second energy-absorbing member) 1680. The left frame portion 1610 is formed in an L-shaped section.

First frame portion 1650 has a first frame inner wall portion 1710, a first frame outer wall portion 1720, a first frame top portion 1730, a first frame engagement portion 1740, and a first frame bottom portion 1750.

The first frame inner wall portion 1710 has an inner wall lower half 1710a and an inner wall upper half 1710 b. The inner wall lower half portion 1710a stands substantially vertically. The inner wall upper half portion 1710b extends obliquely upward and outward in the vehicle width direction from the upper end of the inner wall lower half portion 1710a to the first frame top portion 1730.

The first frame outer wall 1720 has an outer wall center portion 1720a, an outer wall upper portion 1720b, and an outer wall lower portion 1720 c. The outer wall center portion 1720a is disposed on the vehicle width direction outer side with respect to the first frame inner wall portion 1710, and stands substantially vertically. The outer wall upper portion 1720b extends obliquely upward and inward in the vehicle width direction from the upper end of the outer wall center portion 1720a to the first frame top 1730. The outer wall lower portion 1720c extends obliquely downward and inward in the vehicle width direction from the lower end of the outer wall center portion 1720a to the first frame bottom portion 1750.

The first frame top 1730 communicates with the upper end of the inner wall upper half 1710b and the upper end of the outer wall upper portion 1720 b.

The first frame joint portion 1740 extends from the lower end of the inner wall lower half portion 1710a toward the vehicle width direction inner side (specifically, the housing bottom portion 1080).

The first frame bottom 1750 extends from the lower end of the outer wall lower 1720c toward the vehicle width direction inner side (specifically, the housing bottom 1080) along the lower surface of the first frame joint 1740.

The first frame portion 1650 is formed in a closed cross section by the first frame inner wall portion 1710, the first frame outer wall portion 1720, the first frame top portion 1730, and the first frame bottom portion 1750.

The inner wall upper half 1710b of the first frame member 1650 is joined to the case left side wall 1070c of the battery case 1020 and the battery beam left end flange 1190. Inner end 1740a of first frame joint 1740 and inner end 1750a of first frame bottom 1750 are joined to case bottom 1080 of battery case 1020.

A first frame energy absorbing member 1670 is housed in the interior 1780 (i.e., closed cross section) of the first frame portion 1650.

Second frame portion 1660 has a second frame top 1810, a second frame outer wall portion 1820, a second frame beveled portion (ramp) 1830, and a second frame flange 1840.

The second frame outer wall portion 1820 is disposed on the vehicle width direction outer side of the first frame portion 1650, and stands substantially vertically.

The second frame top 1810 extends horizontally from the upper end of the second frame outer wall portion 1820 toward the vehicle width direction inner side to the outer wall center portion 1720a of the first frame outer wall portion 1720.

A second frame flange 1840 extends upward from the inner end of the second frame top 1810 along the outer surface of the outer wall center portion 1720 a. The second frame flange 1840 is joined to the outer wall central portion 1720 a.

The second frame inclined portion 1830 extends downward with a downward gradient from the lower end of the second frame outer wall portion 1820 toward the vehicle width direction inner side to the outer wall lower portion 1720c of the first frame outer wall portion 1720. The lower portion 1830a of the second frame inclined portion 1830 is arranged along the lower surface of the outer wall lower portion 1720 c. A lower portion 1830a of the second frame inclined portion 1830 is engaged with the outer wall lower portion 1720 c.

The second frame flange 1840 is joined to the outer wall central portion 1720a, and the lower portion 1830a of the second frame inclined portion 1830 is joined to the outer wall lower portion 1720c, whereby the first frame portion 1650 is mounted on the second frame portion 1660.

The second frame inclined portion 1830 extends obliquely upward from the case bottom portion (lower surface) 1080 side of the battery case 1020 toward the lower end portion 6600a of the rocker flange 6600 so that the imaginary extension 1860 intersects the rocker flange 6600.

As shown in fig. 40, the rocker flange 6600 of the left rocker 14 extends downward from the outer end 6400a of the inner corner 6400 on the vehicle transverse direction outer side. The second frame inclined portion 1830 is extended in an upward inclined manner from the case bottom portion 1080 side toward the lower end portion 6600a of the rocker flange 6600 so that a virtual extension 1860 of the second frame inclined portion 1830 intersects with the rocker flange 6600.

Therefore, the second frame inclined portion 183 can be hidden by the rocker flange 6600 so as to be difficult to see from the outside of the vehicle Ve. Thus, the case bottom portion 1080 of the battery package 2000 mounted on the vehicle Ve can be arranged on the large-sized battery package 2000 below the left rocker 14 without affecting the appearance of the vehicle Ve.

In addition, a second frame inclined portion 1830 is formed in the second frame portion 1660. Thus, a part of the impact load F1 input from the vehicle Ve in the lateral direction to the left rocker 14 can be transmitted as a so-called offset load F4 to the lower portion (i.e., the beam lower portion) 1040b of the battery beam 1040 via the left frame portion 1610.

An upper portion 1040a of the battery cross member 1040 (i.e., a cross member upper portion) faces the lower half portion of the left rocker 14. That is, a part of the impact load F1 input from the left rocker 14 in the lateral direction of the vehicle Ve can be transmitted to the beam upper portion 1040a as the so-called horizontal load F3.

Therefore, the impact load F1 input from the vehicle Ve in the lateral direction to the left rocker 14 can be transmitted while being dispersed between the beam upper portion 1040a and the beam lower portion 1040 b. Thereby, the impact load F1 can be supported by the battery cross member 1040. As a result, large battery package 2000 having case bottom 1080 disposed below left rocker 14 of battery package 2000 can be protected from impact load F1.

As shown in fig. 47, the second frame portion 1660 is formed in a closed cross section by the second frame top 1810, the second frame outer wall portion 1820, the second frame inclined portion 1830, and the outer wall central portion 1720a of the first frame portion 1650.

A second frame energy-absorbing member (i.e., a second energy-absorbing member) 1680 is housed inside 1870 (i.e., a closed cross-section) of the second frame portion 1660.

That is, a first frame energy-absorbing member 1670 and a second frame energy-absorbing member 1680 (i.e., a second energy-absorbing member) are provided inside the left frame portion 1610.

As shown in fig. 47 and 48, the first frame energy-absorbing member 1670 is housed in the inner portion 1780 of the first frame portion 1650. First frame energy absorbing member 1670 has second front wall 1910, second rear wall 1920, second side wall 1930, second front flange 1940, and second rear flange 1950.

A second front flange 1940 protrudes from a base end of the second front wall 1910 toward the front of the vehicle body. The second rear wall 1920 is disposed at a distance from the second front wall 1910 toward the rear of the vehicle body. A second rear flange 1950 projects from a base end of the second rear wall 1920 toward the rear of the vehicle body. The front end of the second front wall 1910 and the front end of the second rear wall 1920 are joined by a second side wall 1930.

First frame energy-absorbing member 1670 is formed in a cross-sectional U shape by second front wall 1910, second rear wall 1920, and second side wall 1930. The second front flange 1940 is joined to the first frame inner wall portion 1710. The second rear flange 1950 is joined to the first frame inner wall portion 1710. Thus, first frame energy absorbing member 1670 is mounted to first frame interior wall portion 1710.

The second frame energy absorbing member 1680 is received within the interior 1870 of the second frame portion 1660. The second frame energy-absorbing member 1680 has a third front wall 2010, a third rear wall 2020, a third side wall 2030, a third front flange 2040, and a third rear flange 2050.

The third front flange 2040 protrudes from the base end of the third front wall 2010 toward the front of the vehicle body. The third rear wall 2020 is disposed at a distance from the third front wall 2010 on the vehicle rear side. The third rear flange 2050 extends rearward of the vehicle body from the base end of the third rear wall 2020. The front end of the third front wall 2010 and the front end of the third rear wall 2020 are joined by a third side wall 2030.

The second frame energy-absorbing member 1680 is formed in a U-shape in section by the third front wall 2010, the third rear wall 2020, and the third side wall 2030. The third front flange 2040 is coupled to the second frame inclined portion 1830. The third rear flange 205 is joined to the second frame inclined part 183. Thereby, the second frame energy absorbing member 1680 is attached to the second frame inclined portion 1830.

As shown in fig. 40 and 47, the first frame energy-absorbing member 1670 and the second frame energy-absorbing member 1680 can be crushed by the impact load F1 input from the side of the vehicle Ve. The first frame energy-absorbing member 1670 and the second frame energy-absorbing member 1680 are crushed by the impact load F1, and thus the inner corner 6400 of the left rocker 14 can be engaged well by the left frame portion 1610.

Thus, a part of the impact load F1 input from the vehicle Ve in the lateral direction to the left rocker 14 can be reliably transmitted as a so-called offset load F4 to the beam lower portion 1040b of the battery beam 1040 via the left frame portion 1610.

The left frame portion 1610 has a frame engaging portion (engaging portion) 2080. The frame engagement portion 2080 is disposed so that the outer wall center portion 1720a of the first frame outer wall portion 1720 intersects (specifically, is orthogonal to) the second frame top 1810, and is formed of the outer wall center portion 1720a and the second frame top 1810. In other words, the frame engaging portion 2080 is formed in an L-shaped cross section by the upper portion 1720b of the outer wall center portion 1720a and the second frame top portion 1810.

Thus, the left frame portion 1610 has a frame engaging portion 2080 and a second frame inclined portion 1830. The left frame portion 1610 is formed into an L-shaped closed cross section by a frame engaging portion 2080, a second frame inclined portion 1830, and the like.

In a state where the second frame top 1810 of the second frame section 1660 contacts the inner lower portion 6100 of the left rocker 14 from below, the second frame section 1660 is attached to the inner lower portion 6100 by bolts 2110, nuts 2120 (see fig. 40), and the like.

In this state, the frame engaging portion 2080 faces (opposes) the inner corner 6400 of the left rocker 14 (see fig. 40). The left frame portion 1610 is formed into an L-shaped closed cross section by a frame engaging portion 2080, a second frame inclined portion 1830, and the like.

Therefore, the frame engaging portion 2080 is firmly formed at the left frame portion 1610. That is, the inner corner portion 6400 (i.e., the left rocker 14) can be reliably received by the left frame portion 1610 formed with the frame engaging portion 2080. Thus, when an impact load F1 is input from the side of the vehicle Ve, the impact load F1 input to the left rocker 14 can be reliably transmitted to the left frame portion 1610.

The left frame portion 1610 is joined to the battery beam left end flange 1190 via the case left side wall 1070c of the battery case 1020. Therefore, the battery cross member 1040 is disposed to face the left frame portion 1610. This enables the load transmitted to the left frame portion 1610 to be transmitted to the battery cross member 1040, and the transmitted load can be supported by the battery cross member 1040.

Next, an example of protecting the battery 99 by the vehicle body lower portion structure 12 when the impact load F5 is input from the side of the vehicle Ve will be described with reference to fig. 49.

For ease of description, an example will be described in which the impact load F5 is input to the first floor cross member 3100.

As shown in fig. 49, the obstacle 220 collides from the side of the vehicle Ve. Therefore, the impact load F5 is input from the side direction of the vehicle Ve to the left rocker 14. The outer expanded portion 4600 of the rocker outer member 4100 of the left rocker 14 deforms inward in the vehicle width direction due to the impact load F5 input to the left rocker 14. The outer bulging portions 4600 deform, so that the first energy-absorbing member 4400 is crushed by the impact load F5 to absorb the impact energy.

A part of the remaining load absorbed by the first energy-absorbing member 4400 can be transmitted to the first floor cross member 3100 through a path of the first load path as the load F6.

In this state, the inner corner 6400 of the left rocker 14 is reliably blocked by the frame engagement portion 2080 of the left frame portion 1610. Therefore, the excessive load is transmitted to the left frame portion 1610 through the inner corner portion 6400 and the frame engagement portion 2080 of the left rocker 14.

By transmitting the load F7 to the left frame portion 1610, the second frame energy-absorbing member 1680 and the first frame energy-absorbing member 1670 of the left frame portion 1610 are crushed by buckling under the load F7 to absorb the impact energy.

The left frame portion 1610 is joined to the battery beam left end flange 1190 via the case left side wall 1070c of the battery case 1020. Therefore, the battery cross member 1040 is disposed to face the left frame portion 1610. This allows the load F7 transmitted to the left frame portion 1610 to be transmitted to the battery cross member 1040, and the transmitted load to be supported by the battery cross member 1040.

The upper portion 1040a of the battery cross member 104 faces the lower half of the left lower side member 14. Therefore, a part of the load transmitted to the left frame portion 1610 can be transmitted to the beam upper portion 1040a through a path of the second load path as a so-called horizontal load F8.

The second frame inclined portion 1830 is formed on the second frame 1660. Therefore, the excessive load transmitted to the left frame portion 1610 can be transmitted to the beam lower portion 1040b via the left frame portion 1610 through a third load path as a so-called offset load F9.

In this way, the impact load F5 input from the side of the vehicle Ve can be favorably absorbed by the first energy-absorbing member 4400, the first frame energy-absorbing member 1670, and the second frame energy-absorbing member 1680. Further, the impact load F5 input from the side of the vehicle Ve can be dispersed to the paths of the first to third load paths.

Therefore, the loads F6, F8, and F9 distributed in the paths of the first to third load paths can be supported satisfactorily by the first floor cross member 3100 and the battery cross member 1040. This can protect battery 99 housed in interior 1125 of battery case 1020 from impact load F5.

Next, a vehicle body lower portion structure 300 according to a second embodiment will be described with reference to fig. 50 to 52. The same reference numerals are given to similar components in the vehicle body lower portion structure 300 of the second embodiment that are the same as those in the vehicle body lower portion structure 12 of the first embodiment, and detailed description is omitted. Similarly to the vehicle body lower portion structure 12 of the first embodiment, the vehicle body lower portion structure 300 of the second embodiment has a substantially bilaterally symmetrical structure. Therefore, the left side structure of the vehicle body lower portion structure 300 will be described below, and the right side structure will not be described.

(second embodiment)

As shown in fig. 50, the left rocker (rocker) 3020, floor cross member 3040, battery cross member 3060, and left frame (framework) 3080 of the vehicle body lower structure 300 are formed of an aluminum alloy. The other structure of the vehicle body lower portion structure 300 is the same as the vehicle body lower portion structure 12 of the first embodiment.

The left rocker 3020, the floor cross member 3040, the battery cross member 3060, and the left frame portion 3080 are formed of an aluminum alloy, and thus the vehicle body lower portion structure 300 can be reduced in weight. Further, by reducing the weight of the vehicle body lower portion structure 300, the fuel consumption can be improved.

The left rocker 3020 is an extruded member made of an aluminum alloy. The left rocker 3020 has a rocker outer side wall 3110, a rocker inner side wall 3120, a rocker top 3130, a rocker bottom 3140, a rocker flange 3150, and a first energy-absorbing member 3160.

The left rocker 3020 is formed as a rectangular closed cross-section by a rocker outer side wall 3110, a rocker inner side wall 3120, a rocker top 3130 and a rocker bottom 3140.

The first energy-absorbing member 3160 is housed inside the rectangular closed cross section of the left rocker 3020. The impact load F10 input from the side of the vehicle Ve can be absorbed by the first energy-absorbing member 3160.

The rocker inner side wall 3120 has a rocker lower half 3120a that forms a lower half in the up-down direction. The rocker bottom 3140 has a rocker inner half 3140a that forms an inner half in the vehicle width direction. The rocker lower half 3120a and the rocker inner half 3140a are formed so as to intersect (specifically, orthogonally intersect). The rocker lower half 3120a and the rocker inner half 3140a form an inner corner 3180. The rocker flange 3150 extends downward from an outer end 3140b of the inner corner 3180 on the vehicle width direction outer side.

That is, the left rocker 3020 is formed by extrusion molding of an aluminum alloy in the same manner as the left rocker 14 of the first embodiment.

The floor cross member 3040 is formed by extrusion molding of an aluminum alloy in the same manner as the first floor cross member 3100 and the second floor cross member 3200 of the first embodiment. A part of the remaining load after being absorbed by the first energy-absorbing member 3160 is transmitted to the floor cross member 3040 through the path of the first load path as the load F11.

As shown in fig. 51, the left frame portion 3080 is formed by extrusion molding of an aluminum alloy in the same manner as the left frame portion 1610 of the first embodiment.

The left frame portion 3080 includes a first frame portion 3210, a second frame portion 3220, a first frame energy-absorbing member (second energy-absorbing member) 3230, and a second frame energy-absorbing member (second energy-absorbing member) 3240. The left frame portion 3080 is formed in an L-shaped cross section.

The first frame portion 3210 has a first frame inner wall portion 3260, a first frame outer wall portion 3270, a first frame top portion 3280, and a first frame bottom portion 3290. Inner end portion 3290a of first frame bottom portion 3290 is joined to case bottom portion 1080 of battery case 1020 from below. The first frame outer wall portion 3270 has an outer wall lower portion 3270 a. The outer wall lower portion 3270a extends to the first frame bottom portion 3290 with a downward gradient toward the inside in the vehicle width direction.

The second frame portion 3220 has a second frame top portion 3310, a second frame outer wall portion 3320, and a second frame inclined portion (inclined portion) 3330.

The second frame inclined portion 3330 extends from the lower end of the second frame outer wall portion 3320 to the upper end of the outer wall lower portion 3270a with a downward gradient toward the inside in the vehicle width direction.

The second frame inclined portion 3330 extends obliquely upward from the case bottom portion (lower surface) 1080 side of the battery case 1020 toward the lower end portion 3150a of the rocker flange 3150 so that the imaginary extension line 3360 intersects the rocker flange 3150.

Therefore, the hiding with the rocker flange 3150 can be performed so that the second frame inclined portion 3330 is difficult to be visually recognized from the outside of the vehicle Ve. Thus, the case bottom portion 1080 of the battery pack can be disposed on the large-sized battery case 1020 (i.e., the battery pack) below the left side sill 3020 without affecting the appearance of the vehicle Ve.

The left frame portion 3080 has a frame engaging portion (engaging portion) 3380. The frame engaging portion 3380 is formed by the outer wall upper portion 3270b of the first frame outer wall portion 3270 and the second frame top portion 3310 by being disposed so as to intersect (be orthogonal to) the outer wall upper portion 3270b and the second frame top portion 3310. In other words, the frame engaging portion 3380 is formed in an L-shaped cross section by the outer wall upper portion 3270b and the second frame top portion 3310.

The left frame portion 3080 is formed into an L-shaped closed cross section by the frame engaging portion 3380, the second frame inclined portion 3330, the outer wall lower portion 3270a, and the like. The frame engaging portion 3380 faces (faces) the inner corner 3180 of the left rocker 3020.

Therefore, the inner corner portion 3180 (i.e., the left rocker 3020) can be reliably received by the left frame portion 3080 in which the frame engaging portion 3380 is formed. When an impact load F10 is input from the side of the vehicle Ve, the impact load F10 input to the left rocker 3020 can be reliably transmitted to the left frame portion 3080.

The left frame portion 3080 has a first closed cross section and a second closed cross section. The first closed section is formed by a first frame portion 3210. The second closed cross section is formed by the second frame portion 3220 and the first frame outer wall portion 3270.

The first frame energy absorbing member 3230 is received in the first closed section. A second frame energy absorbing member 3240 is received in the second closed section.

As shown in fig. 52, the battery cross member 3060 is formed by extrusion molding of an aluminum alloy in the same manner as the battery cross member 1040 of the first embodiment.

The battery beam 3060 has a battery beam top 3410, a battery beam front wall 3420, a battery beam rear wall 3430, a battery beam bottom 3440, and a battery beam bulkhead 3450.

The battery beam 3060 is divided up and down by a battery beam partition 3450. Therefore, the battery beam 3060 is divided into a beam upper part 3060a and a beam lower part 3060b by the battery beam partition wall 3450.

Returning to fig. 50, the battery beam 3060 is divided into a beam upper part 3060a and a beam lower part 3060 b. A part of the impact load F10 input from the left rocker 3020 in the lateral direction of the vehicle Ve can be transmitted to the beam upper portion 3060a through a path of the second load path as a so-called horizontal load F12. Further, a part of the impact load F10 input from the left rocker 3020 in the lateral direction of the vehicle Ve can be transmitted to the lateral beam lower part 3060b through a path of the third load path as a so-called offset load F13.

A part of the impact load F10 input from the side direction of the vehicle Ve to the left rocker 3020 can be transmitted through two paths, i.e., the beam upper portion 3060a and the beam lower portion 3060 b. As a result, a part of the impact load F10 can be supported well by the beam upper part 3060a and the beam lower part 3060 b.

As shown in fig. 51, according to the vehicle body lower portion structure 300 of the second embodiment, similarly to the vehicle body lower portion structure 12 of the first embodiment, the battery 99 housed in the interior 1125 of the battery case 1020 can be protected from the impact load F10 input from the side of the vehicle Ve.

Specifically, the vehicle body lower portion structure 300 can satisfactorily absorb the impact load F10 input from the side of the vehicle Ve by the first energy-absorbing member 3160, the first frame energy-absorbing member 3230, and the second frame energy-absorbing member 3240. Further, the impact load F10 input from the side of the vehicle Ve can be dispersed as loads F11, F12, and F13 on the first to third load paths.

Therefore, the loads F11, F12, and F13 distributed in the paths of the first to third load paths can be supported satisfactorily by the floor cross member 3040 and the battery cross member 3060. This can protect battery 99 housed in interior 1125 of battery case 1020 from impact load F10.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the battery package 2000 as the vehicle-mounted component is exemplified as the underfloor mounting component, but the present invention is not limited thereto. As other vehicle-mounted components, the present invention can also be applied to other components such as a fuel tank and a fuel cell stack (fuel cell stack).

In the above embodiment, the example in which the lower end portion 6600a of the rocker flange 6600 projects inward in the vehicle width direction has been described, but the present invention is not limited to this. As another example, the lower end portion 6600a of the rocker flange 6600 may be extended vertically downward. Alternatively, the lower end portion 6600a of the rocker flange 6600 may be extended outward in the vehicle width direction.

Description of the reference numerals

10 vehicle body

12. 1120 vehicle body lower part structure

10a left side (outer side)

10b right side (outer side)

14. 302 left lower side beam

14a center part (center part) of the lower side member

15 right lower side beam

16 floor

Upper surface of 16a floor

16b lower surface of floor

28. 2000 accumulator packaging body (carrying parts under floor)

29 left accumulator packaging body frame (floor lower frame)

29a mounting part of the frame of the battery pack (part of the under-floor frame mounted on the lower part of the lower side beam)

30 right accumulator packaging body frame (floor lower frame)

34 first floor beam

35 second floor beam

36 third floor Cross Member

51 first outer partition wall (lower side load transmission member)

52 second outer partition wall (lower side beam load transfer component)

53 third outer bulkhead (lower side beam load transfer component)

55 first inner partition wall (lower side beam load transmission component)

56 second inner partition wall (lower side beam load transmission component)

56a inner partition wall

56b inner partition wall lower portion

57 third inner partition wall (lower side beam load transmission member)

61 first gusset plate

62 second gusset

63 third angle brace

81 lower edge beam inner wall (inner wall of lower edge beam)

83 lower part of lower edge beam (lower part of lower edge beam)

108 extending part

Inclined portion of 111 gusset

124 housing wall

124a left side wall

124b right side wall

125 bottom of the shell (bottom of the carrying component under the floor)

125a outer surface of the bottom of the housing

Inside of 129 accumulator package

131 accumulator beam (floor lower beam)

131A first accumulator beam (floor lower beam)

131B second accumulator beam (floor lower beam)

131C third accumulator beam (floor lower beam)

140 lower side beam

146 inner wall of frame

151 frame extension

152 left bulkhead (Battery load transfer component, underfloor load transfer component)

152a partition wall upper half (Upper half of underfloor load transfer member)

152b lower half of bulkhead (lower half of underfloor load transfer member)

154 mounting top

155 mounting an outer wall part

156 mounting base

157 bending part

159 lower connecting part (connecting part)

172 longitudinal beam

175 strut section

176 front seat part

177 backseat

184 front joint piece (end opposite to the upper half of the load transmission component under the floor)

185 rear joint piece (end opposite to the upper half of the load transmission component under the floor)

191 crossbeam

191A first beam

191B second beam

191C third beam

192 left beam

193 Right cross member

195 rib

200 reinforcing plate

230 base part

280. 1020 accumulator casing

280A casing body

280Aa bottom wall

280B casing cover

350 floor beam

370. 400 beam body portion

370f front wall

370u upper wall

370r rear wall

380. 410 front extension seat

390. 420 rear extension seat

430 concave part

450 accumulator beam (floor lower beam)

450C center beam

450S side beam

460 stud (fastening component)

460a bolt body part

460c screw part

480 bracket

480a through hole

490 nut

500 side wall of housing

510 storage battery

520 casing frame

520b extension piece

530 mounting frame

530a frame extension piece

550 working hole

560 elastic sealing member

570 through hole

580 first bulkhead component (bulkhead component)

590 second bulkhead component (bulkhead component)

600 auxiliary bulkhead member

610 lower surface reinforcing member

620 additional lower surface reinforcing members

630 load transfer plate

650 horizontal plate

1040. 1040A, 1040B accumulator beam (under floor beam)

1040a Beam Upper portion (Upper portion)

1040b lower beam (lower part)

1060 tube accommodation part

1070 wall of case (outer peripheral wall)

1080 case bottom (lower surface)

1140 accumulator beam top (Upper surface)

1220 accumulator beam bulkhead (bulkhead)

1240 frangible portion

1250 firm part

1480 accumulator Beam Recessed portion (Recessed portion)

1540 piping

1550 flexible pipe

1610 left frame part (frame part)

1620 right frame part (frame part)

1630 front frame part (frame part)

1650 first frame section

1660 second frame part

1670. 3230 first frame energy absorbing Member (second energy absorbing Member)

1680. 3240 second frame energy absorbing Member (second energy absorbing Member)

1780 interior of the first frame part

1830. 3330 second frame inclined part (inclined part)

1860. 3360 imaginary extension line

1870 inside of the second frame part

2080. 3380 engaging part of frame (engaging part)

2400 driver's seat (armchair)

2600 passenger seats (chairs)

3100. 3100A, 3100B first floor crossbeam

3150. 6600 lower edge beam flange

3150a, 6600a lower end of the lower edge beam flange

3200 second floor beam

3800 bulge

4100 outer member of lower edge beam

4200 lower boundary beam inner member

4400. 3160 first energy absorbing Member

6400. 3180 the inner corner

8100 first Beam Top (Top)

8200. 8300 front wall of the first beam, rear wall of the first beam (a pair of walls)

8400. 8500 first Beam front Flange, first Beam rear Flange (front Flange, rear Flange)

8800 first concave part

9100 second beam top (Top)

9200. 9300 front wall part of the second beam, rear wall part of the second beam (a pair of wall parts)

9400. 9500 second Beam front Flange, second Beam rear Flange (front Flange, rear Flange)

9700 second concave part

Outer region of E1

Inner region of E2

F1, F5, F10 impact load

Ve vehicle.