阅读说明：本技术 功率控制单元的密封结构 (Sealing structure of power control unit ) 是由 国井洋 于 2020-02-20 设计创作，主要内容包括：本发明提供一种能够使连接导体的热量效率良好地向外部放出,能够抑制导体外壳、密封构件的耐久性的降低的功率控制单元的密封结构。功率控制单元具备功率模块、水套以及供电连接模块。水套具有从水套的一侧面朝向水套的另一侧面贯通的贯通孔。供电连接模块具有：连接导体,其将贯通孔贯通并将内部供电通路与外部供电通路连接；以及导体外壳,其抱持连接导体的外部供电通路侧的至少一部分的周围。在水套与导体外壳之间夹装有将贯通孔的周围密闭的密封构件。(The invention provides a sealing structure of a power control unit, which can effectively release heat of a connecting conductor to the outside and can inhibit the reduction of the durability of a conductor housing and a sealing member. The power control unit includes a power module, a water jacket, and a power supply connection module. The water jacket has a through hole that penetrates from one side surface of the water jacket toward the other side surface of the water jacket. The power supply connection module has: a connection conductor which penetrates the through hole and connects the internal power supply path and the external power supply path; and a conductor housing that surrounds at least a part of the connection conductor on the external power supply path side. A sealing member for sealing the periphery of the through hole is interposed between the water jacket and the conductor housing.)

1. A sealing structure for a power control unit, the power control unit comprising:

a power module;

a water jacket in which the power module is disposed on one side surface side of the water jacket, and the power module is cooled by cooling water flowing inside the water jacket; and

a power supply connection module which is attached to the other side surface side of the water jacket and connects an internal power supply passage of the power module with an external power supply passage of a motor unit,

the sealing structure of the power control unit is characterized in that,

the water jacket has a through hole penetrating from one side surface of the water jacket toward the other side surface of the water jacket,

the power supply connection module has:

a connection conductor penetrating the through hole and connecting the internal power supply path and the external power supply path; and

a conductor housing that embraces at least a part of the periphery of the external power supply path side of the connection conductor,

a seal member for sealing the periphery of the through hole is interposed between the water jacket and the conductor housing.

2. The sealing structure of a power control unit according to claim 1,

three connecting conductors are arranged corresponding to each of the three-phase alternating currents,

three of the connection conductors are held by the common conductor housing.

3. The sealing structure of a power control unit according to claim 1,

a cylindrical wall protruding from the other side surface of the water jacket and communicating with the through hole,

the conductor housing is provided with a projection portion inserted into the interior of the cylindrical wall,

the sealing member is disposed between an outer peripheral surface of the protruding portion and an inner peripheral surface of the cylindrical wall.

4. The sealing structure of a power control unit according to claim 1,

the conductor housing has a base wall abutting the other side surface of the water jacket,

the seal member is disposed between the peripheral edge of the through hole in the other side surface of the water jacket and the base wall.

5. A sealing structure of a power control unit according to any one of claims 1 to 4,

the connection conductor has:

a module-side bus bar connected to the internal power supply path;

a motor-side bus connected to the external power supply path; and

a braided wire connecting the module-side bus bar and the motor-side bus bar,

at least a portion of the braided wire is located within the through-hole.

Technical Field

The present invention relates to a sealing structure of a power control unit connected to a motor unit.

Background

A known structure is one in which a power control unit is directly connected to a motor unit mounted on a vehicle. The power control unit incorporates therein a power module having functions of an inverter, a boost converter, and the like for driving and regenerating the motor. A power supply connection module that connects a power supply path of three phases on the motor unit side and a power supply path of three phases on the power module side is provided between the motor unit and the power control unit (for example, refer to japanese patent laid-open No. 2016-.

Such a power supply connection module includes a connection conductor such as a bus bar for connecting a power supply path (hereinafter referred to as an "external power supply path") of each phase on the motor unit side to a power supply path (hereinafter referred to as an "internal power supply path") of a corresponding phase on the power module side, and a resin conductor case for holding the connection conductor. The conductor case is fixed to the motor unit side, for example, and when the power control unit is attached to the motor unit, a part of the conductor case is disposed inside the lower case through the through hole of the lower case of the power control unit. The end of the connection conductor held by the conductor housing is connected to the internal power supply path inside the lower housing.

In the power control unit using the above-described power feeding connection module, a through hole is formed in the wall of the lower case so that a part of the conductor housing of the power feeding connection module and the connection conductor are inserted into the lower case. Further, if there is a gap between the through hole and the conductor housing, there is a possibility that dust or dirt may enter the block of the power control unit, and therefore a seal member is interposed between the conductor housing and the peripheral region portion of the through hole of the lower case.

In the above-described conventional power control unit sealing structure, a sealing member is interposed between a conductor housing that holds a connection conductor and an outer wall of a power control unit (lower case). Therefore, when the connection conductor through which a high-voltage current flows generates heat, the heat is easily transferred to the sealing member through the conductor housing. Further, there is a fear that the sealing member is deteriorated if the high heat is continuously transmitted to the sealing member for a long period of time. Further, when the connection conductor generates heat, the heat is transferred to the conductor case made of resin, and therefore the conductor case has to be made of expensive resin having high heat resistance, which is likely to cause an increase in product cost.

Disclosure of Invention

The present invention has been made in view of such circumstances, and an object thereof is to provide a sealing structure of a power control unit, which can efficiently release heat of a connection conductor to the outside and suppress a decrease in durability of a conductor housing and a sealing member.

In order to solve the above problems and achieve the above object, the present invention adopts the following aspects.

(1) In a sealing structure of a power control unit according to an aspect of the present invention, the power control unit includes: a power module; a water jacket in which the power module is disposed on one side surface side of the water jacket, and the power module is cooled by cooling water flowing inside the water jacket; and a power supply connection module that is attached to the other side surface side of the water jacket and connects an internal power supply passage of the power module and an external power supply passage of the motor unit, wherein the water jacket has a through hole that penetrates from one side surface of the water jacket toward the other side surface of the water jacket, the power supply connection module including: a connection conductor penetrating the through hole and connecting the internal power supply path and the external power supply path; and a conductor housing that surrounds at least a part of the connection conductor on the external power supply path side, wherein a sealing member that seals the periphery of the through hole is interposed between the water jacket and the conductor housing.

According to the above aspect (1), when the connection conductor generates heat due to the high-voltage current flowing in the connection conductor, the heat is transferred to the water jacket through the conductor housing and the seal member. The heat transferred to the water jacket is released to the outside by the cooling water flowing inside the water jacket. Thus, heat generated by the connection conductor is efficiently released to the outside through the water jacket, and the reduction in durability of the conductor housing and the sealing member due to heat is suppressed.

(2) In the above aspect (1), three connection conductors may be provided corresponding to each of the three-phase alternating currents, and the three connection conductors may be held by the common conductor housing.

According to the above aspect (2), the heat generated from the three connection conductors can be transferred to the water jacket through the common conductor housing and the seal member. Therefore, when this configuration is adopted, the number of components can be reduced, and the number of assembly steps of the components can be reduced.

(3) In addition to the above-described means (1) or (2), a cylindrical wall that communicates with the through hole may be provided to protrude from the other side surface of the water jacket, a protruding portion that is inserted into the cylindrical wall may be provided on the conductor housing, and the sealing member may be disposed between an outer peripheral surface of the protruding portion and an inner peripheral surface of the cylindrical wall.

According to the above aspect (3), the sealing member is in contact with the cylindrical wall on the water jacket side and the protruding portion on the conductor housing side over a wide contact surface. Therefore, it is possible to more favorably prevent the entry of dust and dirt into the power control unit and to improve the heat transfer from the conductor housing to the water jacket via the seal member.

(4) In addition to the above-described means (1) or (2), the conductor housing may have a base wall that abuts against the other side surface of the water jacket, and the seal member may be disposed between a peripheral portion of the through hole in the other side surface of the water jacket and the base wall.

According to the above aspect (4), since the sealing member can be compressed with a large force when the conductor housing is assembled to the water jacket, it is possible to more favorably prevent the entry of dust or dirt into the power control unit with a relatively simple structure.

(5) In addition to any one of the above aspects (1) to (4), the connection conductor may include: a module-side bus bar connected to the internal power supply path; a motor-side bus connected to the external power supply path; and a braided wire connecting the module-side bus bar and the motor-side bus bar, at least a part of the braided wire being positioned in the through hole.

According to the above aspect (5), the braided wire interposed between the motor-side bus bar and the module-side bus bar can suppress the absorption of errors in the connection portion and the generation of stress accompanying vehicle vibration. In addition, the heat generated by the braided wire portion is efficiently transmitted to the water jacket through the inner wall of the through hole. Therefore, in the case of this configuration, the heat of the braided wire portion which is likely to generate heat can be efficiently released to the outside.

According to the aspect of the present invention, heat generated by the connection conductor can be efficiently transferred to the water jacket through the conductor housing and the seal member, and can be released to the outside through the cooling water flowing inside the water jacket, so that the reduction in durability of the conductor housing and the seal member due to heat can be suppressed.

Drawings

Fig. 1 is a plan view showing the arrangement of devices in an engine room of a vehicle according to an embodiment.

Fig. 2 is a schematic side view of the vehicle according to the embodiment, which corresponds to the view from direction II in fig. 1.

Fig. 3 is a side view of a power control unit of an embodiment.

Fig. 4 is a side view of an upper portion of the motor unit of the embodiment.

Fig. 5 is a front view of the power supply connection module of the embodiment.

Fig. 6 is an exploded perspective view of the power supply connection module of the embodiment.

Fig. 7 is a sectional view of the power control unit of the embodiment taken along line VII-VII of fig. 3.

Fig. 8 is a sectional view of the power control unit of the embodiment taken along line VIII-VIII of fig. 7.

Fig. 9 is a plan view of the water jacket of the embodiment.

Fig. 10 is a perspective view of an engine room of a power control unit according to the embodiment.

Fig. 11 is the same sectional view as fig. 7 of a power control unit of another embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that, in some of the drawings, an arrow FR pointing to the front of the vehicle, an arrow UP pointing to the upper side of the vehicle, and an arrow LH pointing to the left side of the vehicle are labeled.

Fig. 1 is a view of an engine room 1 of a vehicle as viewed from above, and fig. 2 is a schematic side view corresponding to a view from direction II of fig. 1.

An engine 2 and a motor unit 3 for driving a vehicle are mounted in an engine room 1 of the vehicle. The motor unit 3 drives the vehicle and regeneratively generates power according to the running condition of the vehicle. The motor unit 3 is integrally coupled with a side portion of the engine 2. A power control unit 4 is connected to an upper portion of the motor unit 3, and the power control unit 4 converts electric power of a high-voltage battery, not shown, into ac power and outputs the ac power to the motor unit 3, and conversely, outputs electric power regenerated and generated by the motor unit 3 to the high-voltage battery. In the figure, reference numeral 5 denotes a high-voltage cable that connects a high-voltage battery, not shown, to the power control unit 4, reference numeral 6 denotes a radiator, and reference numeral 7 denotes an air cleaner that filters outside air and introduces the filtered outside air into the engine 2.

Fig. 3 is a diagram of power control unit 4 viewed from the left side of the vehicle.

The power control unit 4 includes: a power module 10 having functions of an inverter, a boost converter, and the like; a water jacket 11 located below the power module 10 and supporting the power module 10; an upper case 12 attached to the upper surface side of the water jacket 11 and covering the upper and periphery of the power module 10; and a lower case 13 attached to the lower surface side of the water jacket 11 and covering a reactor or the like, not shown, disposed below the water jacket 11.

The power module 10 receives a control signal from a control device, not shown, converts the direct current of the high-voltage battery into three-phase alternating current and outputs the three-phase alternating current to the motor main body of the motor unit 3, and converts the three-phase alternating current generated by the motor main body into direct current and outputs the direct current to the high-voltage battery at the time of regenerative power generation. The power module 10 and the motor unit 3 are electrically connected by two power supply connection modules 14 (power supply connection portions). The two power supply connection modules 14 are a power supply connection module for driving the motor and a power supply connection module for regeneration. The two power supply connection modules 14 have the same structure.

The two power supply connection modules 14 are separately mounted to the upper portion of the motor block 3a (fixed block) of the motor unit 3 in the vehicle front-rear direction. Each power supply connection module 14 is detachably attached to the upper portion of the motor block 3 a.

The water jacket 11 is made of a metal material having excellent thermal conductivity, and cools the mounted equipment by circulating cooling water inside. The water jacket 11 is provided with an inlet 11i and an outlet 11o (see fig. 9) for cooling water. The inlet 11i and the outlet 11o are connected to a cooling water circulation circuit, not shown.

Further, the power module 10 is mounted on the upper surface side of the water jacket 11 via a module holding member 17. In the present embodiment, the module holding member 17 and the water jacket 11 constitute a support block that supports the power module 10 on the lower side of the power module 10.

The main portion of the upper case 12 is integrally formed of an aluminum alloy, a heat-resistant resin, or the like. The upper case 12 mainly includes an upper wall 12u that covers the upper side of the power module 10, a side wall 12s that extends from each of front, rear, left, and right end portions of the upper wall 12u so as to be bent in the water jacket 11 direction, and a peripheral flange 12f that projects outward from a lower end of the side wall 12 s. The peripheral flange 12f overlaps the upper surface of the water jacket 11 and is fastened by bolts to the peripheral edge of the water jacket 11.

The lower case 13 is integrally formed of a metal plate material. The lower housing 13 includes a peripheral edge flange 13f (see fig. 7) that is bolt-fastened to the lower surface of the water jacket 11, and a bulging portion 13a that bulges downward from the peripheral edge flange 13 f. The bulging portion 13a covers the outside of a housing member such as a reactor, not shown, attached to the lower surface side of the water jacket 11.

Fig. 4 is a diagram showing a state in which two power supply connection modules 14 are mounted on the upper portion of the motor block 3 a. Fig. 5 is a front view of the power supply connection module 14, and fig. 6 is an exploded perspective view of the power supply connection module 14. In addition, fig. 7 is a sectional view taken along line VII-VII of fig. 3, and fig. 8 is a sectional view taken along line VIII-VIII of fig. 7. It should be noted that the two power supply connection modules 14 are connected to the inside of the power control unit 4 in substantially the same manner. The configuration of the connection portion in the power control unit 4 corresponding to each power supply connection module 14 is also the same.

As shown in fig. 7 and 8, the module holding member 17 holding the power module 10 is provided with an internal power feeding path 20 connected to each power feeding connection module 14. Three internal power supply paths 20 are provided corresponding to the power supply connection modules 14. Similarly, three external power supply paths, not shown, are provided on the motor block 3a side of the motor unit 3 corresponding to the power supply connection blocks 14.

As shown in fig. 4 and 5, the power supply connection module 14 includes three module-side bus bars 21 connected to the internal power supply path 20 on the power module 10 side, three motor-side bus bars 22 connected to the external power supply path on the motor unit 3 side, three braided wires 23 connecting the module-side bus bars 21 of the corresponding phases to the motor-side bus bars 22, and an insulating resin-made bus bar case 24 (conductor case) holding the three motor-side bus bars 22.

The module-side bus bar 21 and the motor-side bus bar 22 are formed of conductive metal plates having a predetermined thickness.

The braided wire 23 is formed by, for example, braiding a plurality of copper wires. The braided wire 23 can easily deform the module-side bus bar 21 and the motor-side bus bar 22 in various directions, and can efficiently dissipate heat generated by energization to the outside.

In the present embodiment, the module-side bus bar 21, the braided wire 23, and the motor-side bus bar 22 constitute a connection conductor that connects the internal power supply path 20 on the power module 10 side and the external power supply path on the motor unit 3 side.

As shown in fig. 5 and 6, the bus bar case 24 includes a plate-shaped base wall 24b that is overlapped with and fastened by bolts to the upper surface (see fig. 4) of the motor block 3a, a lower protruding portion 241 that protrudes downward from the base wall 24b, and an upper protruding portion 24u (protruding portion) that protrudes upward from the base wall 24 b. The three motor-side bus bars 22 are held in a state of being separated from each other by the lower protruding portion 241, the base wall 24b, and the upper protruding portion 24 u. The three motor-side bus bars 22 are held by the bus bar case 24 such that the longitudinal direction thereof is oriented in the vertical direction and the motor-side bus bars are aligned in a row with each being aligned in the lateral direction. The lower end of each motor-side bus bar 22 is exposed to the outside from the side surface of the lower protruding portion 241 near the lower end. A connection fixing portion 22a that is fastened by a bolt to an external power supply passage in the motor unit 3 is provided at a lower end portion of the motor-side bus bar 22. In the present embodiment, the connection fixing portion is constituted by the bolt insertion hole 22a-1 and the weld nut 22 a-2.

An annular holding groove 25 having a vertical width larger than a dimension in the depth direction is formed in the outer peripheral surface of the bus bar case 24 on the base side of the upper protruding portion 24 u. A seal ring 26 (seal member) having a substantially elliptical shape with a vertically long cross section is fitted to the holding groove 25. The seal ring 26 seals the space between the bus bar case 24 and the water jacket 11 as described later. An annular groove 27 is formed in the lower surface of the base wall 24b, and a seal ring 28 for sealing between the lower surface of the base wall 24b and the upper surface of the motor block 3a is attached to the annular groove 27.

Three cylindrical portions 29 that individually cover the peripheries of the upper end sides of the three motor-side bus bars 22 are provided on the upper end side of the upper protruding portion 24u of the bus bar case 24. An integral insulating cover member 30 made of an insulating resin material is detachably attached to the three cylindrical portions 29. The insulating cover member 30 constitutes the power supply connection module 14 together with the module-side bus bar 21, the motor-side bus bar 22, the braided wire 23, the bus bar case 24, and the like.

The insulating cover member 30 includes a lower block 30a fitted to the three cylindrical portions 29 of the bus bar case 24 from above, and three cylindrical portions 30b projecting upward from the upper portion of the lower block 30 a. The lower block 30a and each tube 30b are formed with a continuous insertion hole 31 penetrating in the vertical direction. The lower ends of the insertion holes 31 disposed in the lower block 30a are fitted to the cylindrical portions 29 of the bus bar case 24. The braided wires 23 of the corresponding phase and a part of the lower side of the module-side bus bar 21 are arranged in the respective tube portions 30b in the inserted state.

As shown in fig. 7, when the insulating cover member 30 is assembled to the upper portion of the bus bar housing 24, the periphery of the connection portion between the upper portion of the motor-side bus bar 22 of each phase and the braided wire 23 is directly covered by each cylindrical portion 29 of the bus bar housing 24. At this time, the periphery of the connection portion between the braided wire 23 of each phase and the lower portion of the module-side bus bar 21 is directly covered by the peripheral wall of the corresponding insertion hole 31 of the insulating cover member 30. Therefore, the lower side of the braided wire 23 is covered with the insulating cover member 30 via the cylindrical portion 29 of the bus bar case 24, and the upper side of the braided wire 23 is directly covered with the insulating cover member 30. As shown in fig. 7, the insulating cover member 30 and each cylindrical portion 29 surround the braided wire 23 and the module-side bus bar 21 with a gap d therebetween.

In the present embodiment, the wall of each cylindrical portion 30b of the insulating cover member 30 constitutes a partition wall that partitions between adjacent braided wires 23.

The upper end of each cylindrical portion 30b of the insulating cover member 30 assembled to the bus bar housing 24 extends at least to a position facing a part of the module-side bus bar 21. Therefore, the insulating cover member 30 can reliably restrict the inclination of the module-side bus bar 21 due to the deformation of the braided wire 23 by the respective tube portions 30 b.

However, the insulating cover member 30 can restrict the inclination of the module-side bus bar 21 to some extent if it is configured to surround the periphery of the braided wire 23 even if it does not reach the height of the position facing the module-side bus bar 21.

As shown in fig. 6 and the like, a tongue piece 32 capable of bending deformation is formed by a notch in a wall of a lower edge of the lower block 30a of the insulating cover member 30. The tongue piece 32 is formed with a locking hole 33 penetrating in the plate thickness direction. On the other hand, a protrusion 34 capable of being fitted into the locking hole 33 is provided on the outer surface of the cylindrical portion 29 of the bus bar case 24. When the insulating cover member 30 is fitted to the cylindrical portion 29 of the bus bar case 24, the protrusion 34 bends the tongue piece 32 and fits into the locking hole 33. This prevents the insulating cover member 30 from coming off the bus bar housing 24.

As shown in fig. 5 and 8, the upper surfaces of the adjacent cylindrical portion 30b and the lower block 30a of the insulating cover member 30 of the present embodiment are formed with a recess 35 that opens upward.

The recess 35 separates the surrounding portions of the adjacent module-side bus bars 21, and allows insertion of the displacement restricting portion 36 protruding from the module holding member 17 when the power supply connection module 14 is assembled to the power control unit 4. The displacement restricting portion 36 restricts displacement of the insulating cover member 30 by being inserted into the recess 35 of the insulating cover member 30.

Fig. 9 is a view of the water jacket 11 as viewed from above.

The water jacket 11 is formed in a substantially rectangular shape in plan view, and an inlet 11i for cooling water is disposed on a front surface near one end in the longitudinal direction, and an outlet 11o for cooling water is disposed on a side surface near the other end in the longitudinal direction. A cooling passage 11a is formed in the water jacket 11 so as to flow from the inlet 11i to the outlet 11 o. A pair of through holes 38 that penetrate the water jacket 11 from above to below are formed in one side portion of the water jacket 11 at a position close to the cooling passage 11 a. Each through hole 38 is formed in an elongated hole shape along the longitudinal direction of the water jacket 11.

As shown in fig. 7, a cylindrical wall 39 projecting downward is provided to project from a lower edge of each through hole 38 of the water jacket 11. The inner peripheral surface of the cylindrical wall 39 is continuous with the through hole 38. Part of the power supply connection module 14 is inserted into the cylindrical wall 39 and the through hole 38 from below. Specifically, a portion of the bus bar case 24 above the base wall 24b, the insulating cover member 30 assembled to the bus bar case 24, and an upper region of the three-phase connection conductors (the module-side bus bar 21, the braided wire 23, and the motor-side bus bar 22) held by these members are inserted into the cylindrical wall 39 and the through hole 38. At this time, the seal ring 26 attached to the upper protruding portion 24u of the busbar housing 24 is elastically deformed and brought into close contact with the inner peripheral surface of the cylindrical wall 39. The seal ring 26 abuts against the inner peripheral surface of the cylindrical wall 39 and the inner wall of the holding groove 25 of the upper protruding portion 24u, and seals therebetween. As a result, the periphery of the water jacket 11 on the lower side of the through hole 38 is closed by the seal ring 26. The seal ring 26 transfers heat to the main body side of the water jacket 11 through the cylindrical wall 39. Therefore, the heat transferred from the three-phase connection conductors to the seal ring 26 is released to the water jacket 11.

The base wall 24b of the bus bar housing 24 is fixed to the lower surface of the water jacket 11 by bolt fastening or the like. The braided wires 23 of the respective phases are arranged inside the through-holes 38.

As described above, when a part of the power supply connection module 14 is inserted into the cylindrical wall 39 and the through hole 38, the inclination of the module-side bus bar 21 due to the deflection of the braided wire 23 is restricted by the insulating cover member 30. As described above, when the power feed connection block 14 is assembled to the water jacket 11, the connection fixing portions 21a at the upper ends of the block-side bus bars 21 of the power feed connection block 14 are disposed at positions facing the corresponding internal power feed passages 20 of the block holding member 17. As shown in fig. 7, the connection fixing portion 21a of each module-side bus bar 21 is connected to the corresponding internal power supply path 20 by fastening with a bolt 40. Fastening of the connection fixing portion 21a by the bolt 40 (fastening member) is performed by an operation tool through the opening 41 not provided in the upper case 12. The opening 41 is disposed at a position diagonally above the side of the upper case 12, where the connection fixing portion 21a of the module-side bus bar 21 faces.

Fig. 10 is a diagram of power control unit 4 disposed in engine room 1 as viewed from the obliquely upper left side of the rear portion.

As shown in fig. 10, two recesses 42 are formed in the side 12a of the upper case 12, which is sandwiched between the upper wall 12u and the side wall 12s (the side wall facing the outside in the vehicle width direction) of the upper case 12 and has a substantially right-angled cross-sectional shape, so that the corners of the side 12a are cut away. The bottom wall of the recess 42 is formed by an inclined wall 43 inclined downward from the center of the upper wall 12u toward the side wall 12 s. The opening 41 is formed in the inclined wall 43, which is used for fastening the connection fixing portion 21 a. The inclined wall 43 is formed at a position diagonally opposite to the connection fixing portion 21a from the side.

The opening 41 is formed in a shape and a size such that the head of the bolt 40 as the fastening member or the connection fixing portion 21a can be visually recognized in a front view orthogonal to the inclined wall 43. The opening 41 is used for attaching and detaching the bolt 40 as a fastening member, and is formed in a size into which the bolt 40 and the distal end portion of the operation tool can be inserted.

Further, as shown in fig. 7, since the through hole 38 of the water jacket 11 is disposed below the opening 41 of the upper case 12, it is necessary to avoid the bolt 40 from falling off from the through hole 38 when the bolt 40 is attached and detached. In the present embodiment, since the insulating cover member 30 is disposed so as to fill the gap between the through hole 38 and the connection conductor (the module-side bus bar 21, the braided wire 23), the bolt 40 can be prevented from coming off the through hole 38.

As shown in fig. 7, the opening 41 provided in each inclined wall 43 is normally closed by a lid member 44. The cover member 44 is detachably attached to the corresponding inclined wall 43 by a fastening screw or the like, and is removed from the inclined wall 43 when necessary for maintenance or the like.

As shown in fig. 10, a high-voltage cable 5 connected to a high-voltage circuit including a capacitor in the upper case 12 is drawn out from the upper portion of the upper case 12. The high-voltage cable 5 is disposed on the upper wall 12u of the upper case 12 at a position bypassing each inclined wall 43.

As described above, the sealing structure of the power control unit according to the present embodiment can transmit the heat generated by the connection conductor in the power supply connection module 14 to the water jacket 11 through the bus bar housing 24 and the seal ring 26. Therefore, the heat of the connection conductor can be efficiently released to the outside by the cooling water flowing through the water jacket 11. Therefore, when the seal structure of the present embodiment is used, the reduction in durability due to heat of the bus bar case 24 and the seal ring 26 can be suppressed.

In the seal structure of the present embodiment, the bus bar case 24 sandwiches the three connection conductors, and the bus bar case 24 that sandwiches the three connection conductors is in contact with the water jacket 11 via one seal ring 26. Therefore, in the case of this configuration, the performance of the seal structure can be improved by the small number of components, and the number of assembling steps of the components can be reduced.

In the seal structure of the present embodiment, a cylindrical wall 39 is provided so as to protrude from the lower surface of the water jacket 11, and an upper protruding portion 24u that is inserted into the cylindrical wall 39 is provided so as to protrude from the upper portion of the bus bar case 24. Further, a seal ring 26 is disposed between the outer peripheral surface of the upper protruding portion 24u and the inner peripheral surface of the cylindrical wall 39. Therefore, the seal ring 26 that transmits heat in the power feeding connection module 14 is in contact with the cylindrical wall 39 over a wide area between the upper protruding portion 24u and the cylindrical wall 39. Therefore, when this configuration is employed, it is possible to more favorably prevent the entry of dust and dirt into the power control unit 4 and to improve the heat transfer from the bus bar case 24 to the water jacket 11 by the seal ring 26.

In the power supply connection module 14 of the present embodiment, the module-side bus bar 21 and the motor-side bus bar 22 are connected by the braided wire 23 to constitute a connection conductor. Therefore, the braided wire 23 can suppress absorption of an error in the connection portion of the power supply connection module 14 and generation of stress accompanying vehicle vibration. In the present embodiment, at least a part of the braided wire 23, which is likely to generate heat when energized, is disposed inside the through hole 38 of the water jacket 11. Therefore, high heat generated in the braided wire 23 can be efficiently released to the water jacket 11 through the inner wall of the through hole 38.

Fig. 11 is a sectional view of another embodiment similar to fig. 7 of the above embodiment. In fig. 11, the same reference numerals are given to the same portions as those of the above-described embodiment. In addition, reference numeral 104 in fig. 11 is a power control unit, and reference numeral 114 is a power supply connection module.

The basic structure of the seal structure of the present embodiment is the same as that of the above embodiment, but no cylindrical wall is provided on the lower surface of the water jacket, and a seal ring 51 (seal member) is interposed between the upper surface of the base wall 24b of the bus bar housing 24 and the lower surface of the water jacket 111. The seal ring 51 is retained in an annular groove 50 formed in the upper surface of the base wall 24 b.

In the seal structure of the present embodiment, when the bus bar case 24 is assembled to the water jacket 111 by bolt fastening or the like, the seal ring 51 can be compressed with a large force. Therefore, the structure is relatively simple, and entry of dust and garbage into the power control unit 104 can be more favorably prevented.

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 present invention.