阅读说明：本技术 一种车架结构 (Vehicle frame structure ) 是由 秦初荣 张东锋 冯炜 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种车架结构,属于车辆技术领域。所述车架结构包括：两个变截面纵梁相对设置；变截面纵梁的顶部下凹形成低断面部分、第一高断面部分及第二高断面部分,低断面部分设置在第一高断面部分及第二高断面部分之间,低断面部分的高度小于第一高断面部分及第二高断面部分的高度。本发明车架结构可以增加车身布置所需的空间,同时可以减轻自重,将车身安装在车架上,使车架车身组合成一个刚性结构,共同承载,弥补车架单独承载强度不足问题。(The invention discloses a frame structure, and belongs to the technical field of vehicles. The frame structure includes: the two variable cross-section longitudinal beams are oppositely arranged; the top of the variable cross-section longitudinal beam is recessed to form a low-profile portion, a first high-profile portion and a second high-profile portion, the low-profile portion is arranged between the first high-profile portion and the second high-profile portion, and the height of the low-profile portion is smaller than the height of the first high-profile portion and the height of the second high-profile portion. The frame structure can increase the space required by the arrangement of the vehicle body, can reduce the dead weight, and can install the vehicle body on the frame, so that the vehicle body of the frame is combined into a rigid structure to bear together, thereby making up the problem of insufficient single bearing strength of the frame.)

1. A frame structure, comprising: the device comprises a headstock cross beam device, a suspension upper cross beam, a first bridge cross beam, two second bridge cross beams and two variable cross-section longitudinal beams;

the two variable cross-section longitudinal beams are oppositely arranged;

the top of the variable cross-section longitudinal beam is recessed to form a low-section part, a first high-section part and a second high-section part, the low-section part is arranged between the first high-section part and the second high-section part, and the height of the low-section part is smaller than that of the first high-section part and that of the second high-section part;

the end part of the first high-section part, which is far away from the second high-section part, is fixedly provided with a front end beam, and the front cross beam device is fixedly connected with the front end beam;

the first bridge cross beam is fixedly connected with the first high-section parts of the two variable cross-section longitudinal beams;

the two second bridge cross beams and the suspension upper cross beam are fixedly connected with the second high-section parts of the two variable-section longitudinal beams.

2. The frame structure of claim 1, wherein:

the first end of the low-profile portion is fixedly connected with the first high-profile portion through a first variable cross-section transition surface, and the second end of the low-profile portion is fixedly connected with the second high-profile portion through a second variable cross-section transition surface;

the height of the front end beam is less than the height of the first high-profile portion;

the front end beam is fixedly connected with the first high-section part through a third variable cross-section transition surface.

3. The frame structure of claim 2, wherein:

the first variable cross-section transition surface, the second variable cross-section transition surface and the third variable cross-section transition surface are of plane bevel structures.

4. The frame structure of claim 1, wherein:

and an auxiliary beam reinforcing device is fixedly arranged between the two variable cross-section longitudinal beams and is arranged at the low-section part.

5. The frame structure according to claim 4, characterized in that the auxiliary beam reinforcement means includes: two auxiliary beams;

the two auxiliary beams are fixedly arranged between the two variable cross-section longitudinal beams, and the auxiliary beams are fixedly connected with the inner sides of the corresponding variable cross-section longitudinal beams.

6. The frame structure according to claim 5, characterized in that the auxiliary beam includes: the web plate, the first flanging and the second flanging are arranged on the frame;

the top of the web plate is fixedly connected with the first flanging, the bottom of the web plate is fixedly connected with the second flanging, and the direction of the first flanging is the same as that of the second flanging;

the variable cross-section stringer includes: the main beam plate, the third flanging and the fourth flanging are arranged on the main beam plate;

the top of the main beam plate is fixedly connected with the third flanging, the bottom of the main beam plate is fixedly connected with the fourth flanging, the orientation of the third flanging is opposite to that of the fourth flanging, and the orientation of the fourth flanging is the same as that of the second flanging;

the web plate is attached to the main beam plate, the web plate is fixedly connected with the main beam plate, and the second flanging is attached to the fourth flanging.

7. The frame structure of claim 5, wherein:

and a plurality of first reinforcing cross beams are fixedly arranged between the two auxiliary beams.

8. The frame structure of claim 1, wherein:

and a plurality of second reinforcing cross beams are fixedly arranged between the two variable cross-section longitudinal beams.

9. A frame structure according to claim 1, characterized in that said bow cross member means comprises: the device comprises a headstock beam, a connecting pipe, a third reinforcing beam and two reinforcing longitudinal beams;

the first end of the connecting pipe is fixedly connected with the middle part of the headstock cross beam, the second end of the connecting pipe is fixedly connected with the middle part of the third reinforcing cross beam, and the two ends of the third reinforcing cross beam are respectively and fixedly connected with the inner sides of the two reinforcing longitudinal beams;

the outer sides of the two reinforcing longitudinal beams are fixedly connected with the corresponding front end beams, and the two ends of each reinforcing longitudinal beam are respectively fixedly connected with the head cross beam and the first bridge cross beam;

the headstock beam and the first bridge beam are fixedly arranged between the two front end beams.

10. The frame structure of claim 1, further comprising: a plurality of fourth reinforcing cross beams, a plurality of fifth reinforcing cross beams and a plurality of sixth reinforcing cross beams;

the plurality of fourth reinforcing cross beams are detachably arranged between the two variable cross-section longitudinal beams, and the plurality of fourth reinforcing cross beams are arranged between the first bridge cross beam and the low-section part;

the fifth reinforcing cross beams are detachably arranged between the two variable cross-section longitudinal beams, and the fifth reinforcing cross beams are arranged between the low-section part and the two second bridge cross beams;

the plurality of sixth reinforcing cross beams are detachably arranged between the two variable cross-section longitudinal beams, and the plurality of sixth reinforcing cross beams are arranged between the two second bridge cross beams.

Technical Field

The invention relates to the technical field of vehicles, in particular to a frame structure.

Background

The cross-country vehicle generally adopts a non-bearing type vehicle body structure, is provided with an independent frame assembly, has left and right longitudinal beams which are arranged in parallel and run through from front to back, and is connected with the longitudinal beams through a plurality of cross beams to form a frame structure with strong rigidity.

The cross-sectional structure of traditional frame longeron changes less, mostly only designs into local variable cross-section structure for the index requirement that adapts to vehicle approach angle and departure angle in front overhang and rear overhang department, and some motorcycle types are higher with frame middle part design in addition, and the position section that is close to both ends is lower to adapt to whole car intensity requirement. However, as the vehicle load-bearing requirements increase, the frame weight further increases due to the fact that the thickness of the side member plate is generally increased or the frame side member is reinforced by adopting a double-plate structure.

In the prior art, the frame and the body are independent in function, and the structure which is designed and developed independently is needed, so that the size of the whole vehicle is ultrahigh, the dead weight is increased, and the requirements of superior technical indexes cannot be met.

Disclosure of Invention

The invention provides a frame structure, which solves or partially solves the technical problems that in the prior art, the functions of a frame and a vehicle body are independent, and the structure needs to be independently designed and developed, so that the size of the whole vehicle is ultrahigh, and the self weight is increased.

In order to solve the above technical problem, the present invention provides a frame structure comprising: the device comprises a headstock cross beam device, a suspension upper cross beam, a first bridge cross beam, two second bridge cross beams and two variable cross-section longitudinal beams; the two variable cross-section longitudinal beams are oppositely arranged; the top of the variable cross-section longitudinal beam is recessed to form a low-section part, a first high-section part and a second high-section part, the low-section part is arranged between the first high-section part and the second high-section part, and the height of the low-section part is smaller than that of the first high-section part and that of the second high-section part; the end part of the first high-section part, which is far away from the second high-section part, is fixedly provided with a front end beam, and the front cross beam device is fixedly connected with the front end beam; the first bridge cross beam is fixedly connected with the first high-section parts of the two variable cross-section longitudinal beams; the first bridge cross beam is fixedly connected with the first high-section parts of the two variable cross-section longitudinal beams; the two second bridge cross beams and the suspension upper cross beam are fixedly connected with the second high-section parts of the two variable-section longitudinal beams.

Further, a first end of the low-profile portion is fixedly connected with the first high-profile portion through a first variable cross-section transition surface, and a second end of the low-profile portion is fixedly connected with the second high-profile portion through a second variable cross-section transition surface; the height of the front end beam is less than the height of the first high-profile portion; the front end beam is fixedly connected with the first high-section part through a third variable cross-section transition surface.

Further, the first variable cross-section transition surface, the second variable cross-section transition surface and the third variable cross-section transition surface are planar bevel structures.

Furthermore, an auxiliary beam reinforcing device is fixedly arranged between the two variable cross-section longitudinal beams, and the auxiliary beam reinforcing device is arranged at the low-section part.

Further, the auxiliary beam reinforcing apparatus includes: two auxiliary beams; the two auxiliary beams are fixedly arranged between the two variable cross-section longitudinal beams, and the auxiliary beams are fixedly connected with the inner sides of the corresponding variable cross-section longitudinal beams.

Further, the auxiliary beam includes: the web plate, the first flanging and the second flanging are arranged on the frame; the top of the web plate is fixedly connected with the first flanging, the bottom of the web plate is fixedly connected with the second flanging, and the direction of the first flanging is the same as that of the second flanging; the variable cross-section stringer includes: the main beam plate, the third flanging and the fourth flanging are arranged on the main beam plate; the top of the main beam plate is fixedly connected with the third flanging, the bottom of the main beam plate is fixedly connected with the fourth flanging, the orientation of the third flanging is opposite to that of the fourth flanging, and the orientation of the fourth flanging is the same as that of the second flanging; the web plate is attached to the main beam plate, the web plate is fixedly connected with the main beam plate, and the second flanging is attached to the fourth flanging.

Furthermore, a plurality of first reinforcing cross beams are fixedly arranged between the two auxiliary beams.

Furthermore, a plurality of second reinforcing cross beams are fixedly arranged between the two variable cross-section longitudinal beams.

Further, the head cross member device includes: the device comprises a headstock beam, a connecting pipe, a third reinforcing beam and two reinforcing longitudinal beams; the first end of the connecting pipe is fixedly connected with the middle part of the headstock cross beam, the second end of the connecting pipe is fixedly connected with the middle part of the third reinforcing cross beam, and the two ends of the third reinforcing cross beam are respectively and fixedly connected with the inner sides of the two reinforcing longitudinal beams; the outer sides of the two reinforcing longitudinal beams are fixedly connected with the corresponding front end beams, and the two ends of each reinforcing longitudinal beam are respectively fixedly connected with the head cross beam and the first bridge cross beam; the headstock beam and the first bridge beam are fixedly arranged between the two front end beams.

Further, the frame structure further includes: a plurality of fourth reinforcing cross beams, a plurality of fifth reinforcing cross beams and a plurality of sixth reinforcing cross beams; the plurality of fourth reinforcing cross beams are detachably arranged between the two variable cross-section longitudinal beams, and the plurality of fourth reinforcing cross beams are arranged between the first bridge cross beam and the low-section part; the fifth reinforcing cross beams are detachably arranged between the two variable cross-section longitudinal beams, and the fifth reinforcing cross beams are arranged between the low-section part and the two second bridge cross beams; the plurality of sixth reinforcing cross beams are detachably arranged between the two variable cross-section longitudinal beams, and the plurality of sixth reinforcing cross beams are arranged between the two second bridge cross beams.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

because the two variable cross-section longitudinal beams are oppositely arranged, the top of each variable cross-section longitudinal beam is recessed to form a low-section part, a first high-section part and a second high-section part, the low-section part is arranged between the first high-section part and the second high-section part, and the height of the low-section part is smaller than that of the first high-section part and the second high-section part, therefore, the low-section part passes through the mounting surface and the connecting surface required by the vehicle body, meanwhile, the side surfaces of the two variable cross-section longitudinal beams can provide mounting interfaces of a suspension device, the side surfaces and the upper planes of other variable cross-section longitudinal beams are welded and connected with the vehicle body framework and can be used as a whole to bear various loads of an upper loader and a chassis, the dead weight can be reduced, the vehicle body is mounted on the low-section part, the vehicle frame and the vehicle body, the front end of the variable cross-section longitudinal beam is fixedly connected with the front end beam device through the front end beam, the front end of the variable cross-section longitudinal beam can be used as a reinforcing device of a variable cross-section part at the front end of the variable cross-section longitudinal beam to ensure the strength of the variable cross-section longitudinal beam, the first cross-section part of the variable cross-section longitudinal beam is fixedly connected with the first high-section parts of the two variable cross-section longitudinal beams through the first cross-bridge beam, the first cross-bridge beam can be used as a reinforcing device of the first high-section part to ensure the strength of the variable cross-section longitudinal beam, and the two second cross-bridge beams and the upper suspension cross beam are fixedly connected with the second high-section parts of the two variable cross-section longitudinal beams, so the second high-section part of the variable cross-section longitudinal beam is connected into a whole through the two second cross-bridge beams and the upper suspension cross beam The rigid frame body, the two second bridge cross beams and the suspension upper cross beam can be used as a reinforcing device of the second high-section part, and the strength of the variable-section longitudinal beam is guaranteed.

Drawings

FIG. 1 is a schematic structural view of a vehicle frame structure provided in an embodiment of the present invention;

FIG. 2 is a schematic structural view of a variable cross-section rail of the frame structure of FIG. 1;

FIG. 3 is a schematic view of the structure of the auxiliary beam reinforcement of the frame structure of FIG. 1;

FIG. 4 is a schematic view of the installation of the reinforcing apparatus of the auxiliary beam of FIG. 3;

FIG. 5 is a schematic structural view of a third first reinforcing crossmember of the auxiliary beam reinforcing apparatus of FIG. 3;

FIG. 6 is a schematic structural view of a bow cross member assembly of the frame structure of FIG. 1;

FIG. 7 is a structural schematic view of a fourth reinforcing cross member of the frame structure of FIG. 1;

fig. 8 is a schematic structural view of a fifth reinforcing cross member of the frame structure of fig. 1.

Detailed Description

Referring to fig. 1-2, a frame structure provided in an embodiment of the present invention includes: the front cross beam device comprises a headstock cross beam device 1, a suspension upper cross beam 2, a first bridge cross beam 3, two second bridge cross beams 4 and two variable cross-section longitudinal beams 5.

The two variable cross-section longitudinal beams 5 are oppositely arranged.

The variable cross-section longitudinal beam 5 is concave at the top to form a low-profile portion 5-1, a first high-profile portion 5-2 and a second high-profile portion 5-3, the low-profile portion 5-1 is arranged between the first high-profile portion 5-2 and the second high-profile portion 5-3, and the height of the low-profile portion 5-1 is smaller than the height of the first high-profile portion 5-2 and the height of the second high-profile portion 5-3.

The end part of the first high-section part 5-2 departing from the second high-section part 5-3 is fixedly provided with a front end beam 6, and the vehicle head cross beam device 1 is fixedly connected with the front end beam 6.

The first bridge girder 3 is fixedly connected with the first high-section parts 5-2 of the two variable cross-section longitudinal girders 5.

The two second bridge cross beams 4 and the suspension upper cross beam 2 are fixedly connected with second high-section parts 5-3 of the two variable cross-section longitudinal beams 5.

In the embodiment of the application, because the two variable cross-section longitudinal beams 5 are oppositely arranged, the tops of the variable cross-section longitudinal beams 5 are concave downwards to form a low-section part 5-1, a first high-section part 5-2 and a second high-section part 5-3, the low-section part 5-1 is arranged between the first high-section part 5-2 and the second high-section part 5-3, the height of the low-section part 5-1 is less than that of the first high-section part 5-2 and the second high-section part 5-3, therefore, the low-section part 5-1 passes through the mounting surface and the connecting surface required by a vehicle body, meanwhile, the side surfaces of the two variable cross-section longitudinal beams 5 can provide mounting interfaces of a suspension device, the side surfaces and the upper plane of other variable cross-section longitudinal beams 5 are welded with the vehicle body framework and can integrally bear various loads of a top, the dead weight can be reduced, the vehicle body is arranged on the low-section part 5-1, the vehicle frame and the vehicle body are combined into a rigid structure to bear together, the problem of insufficient single bearing strength of the vehicle frame is solved, the whole vehicle is prevented from being ultrahigh in size, because the end part of the first high-section part 5-2, which is far away from the second high-section part 5-3, is fixedly provided with the front end beam 6, and the front cross beam device 1 is fixedly connected with the front end beam 6, the front end of the variable-section longitudinal beam 5 is connected with the front cross beam device 1 into a rigid frame body through the front end beam 6, the front cross beam device 1 can be used as a reinforcing device of the variable-section part at the front end of the variable-section longitudinal beam 5 to ensure the strength of the variable-section longitudinal beam 5, because the first bridge cross beam 3 is fixedly connected with the first high-section parts 5-2 of the two variable-section longitudinal beams 5, the first high-section parts 5, the first bridge cross beam 3 can be used as a reinforcing device of the first high-section part 5-2 to ensure the strength of the variable-section longitudinal beam 5, as the two second bridge cross beams 4 and the suspension upper cross beam 2 are fixedly connected with the second high-section parts 5-3 of the two variable-section longitudinal beams 5, the second high-section part 5-3 of the variable-section longitudinal beam 5 is connected into a rigid frame body through the two second bridge cross beams 4 and the suspension upper cross beam 2, and the two second bridge cross beams 4 and the suspension upper cross beam 2 can be used as a reinforcing device of the second high-section part 5-3 to ensure the strength of the variable-section longitudinal beam 5.

Specifically, a first end of the low-profile portion 5-1 is fixedly coupled to the first high-profile portion 5-2 via a first variable cross-section transition surface 5-4, and a second end of the low-profile portion 5-1 is fixedly coupled to the second high-profile portion 5-3 via a second variable cross-section transition surface 5-5. The height of the front end beam 6 is less than the height of the first high-profile portion 5-2; the front end beam 6 is fixedly connected with the first high-section part 5-2 through a third variable cross-section transition surface 5-6.

The first variable cross-section transition surface 5-4 and the second variable cross-section transition surface 5-5 are both plane bevel angle structures, and the first variable cross-section transition surface 5-4, the second variable cross-section transition surface 5-5 and the third variable cross-section transition surface 5-6 enable a longitudinal bending-resistant interface of the variable cross-section longitudinal beam 2 to present a part of buffer area, so that local stress concentration is avoided.

Referring to fig. 3 to 4, in particular, an auxiliary beam reinforcing device 7 is fixedly arranged between the two variable cross-section longitudinal beams 5, and the auxiliary beam reinforcing device 7 is arranged at the low-section part 5-1, so that the strength of the low-section part 5-1 of the variable cross-section longitudinal beam 5 can be ensured.

The auxiliary beam reinforcing device 7 includes: two auxiliary beams 7-1.

The two auxiliary beams 7-1 are fixedly arranged between the two variable cross-section longitudinal beams 5, and the auxiliary beams 7-1 are fixedly connected with the inner sides of the corresponding variable cross-section longitudinal beams. The low-section part 5-1 of the variable-section longitudinal beam 5 is connected with two auxiliary beams 7-1 to form a rigid frame body, and the two auxiliary beams 7-1 can be used as reinforcing devices of the low-section part 5-1 of the variable-section longitudinal beam 5.

The auxiliary beam 7-1 includes: a web 7-11, a first flange 7-12 and a second flange 7-13.

The auxiliary beam 7-1 is C-shaped.

The top of the web 7-11 is fixedly connected with the first flanging 7-12, and the bottom of the web 7-11 is fixedly connected with the second flanging 7-13. In the embodiment, the web 7-11, the first flanging 7-12 and the second flanging 7-13 can be integrally formed, so that the strength of the auxiliary beam 7-1 is ensured. The first cuff 7-12 is oriented in the same direction as the second cuff 7-13. The first flanging 7-12 is parallel to the second flanging 7-13.

The variable cross-section longitudinal beam 5 includes: 5-7 parts of main beam plates, 5-8 parts of third flanges and 5-9 parts of fourth flanges.

The variable cross-section stringer 5 is Z-shaped.

The top of the main beam plate 5-7 is fixedly connected with the third flanging 5-8, and the bottom of the main beam plate 5-7 is fixedly connected with the fourth flanging 5-9. In the embodiment, the main beam plate 5-7, the third flanging 5-8 and the fourth flanging 5-9 can be integrally formed, so that the strength of the variable cross-section longitudinal beam 5 is ensured. The third flanging 5-8 faces opposite to the fourth flanging 5-9, and the fourth flanging 5-9 faces the same direction as the second flanging 7-13.

The web plates 7-11 are attached to the main beam plates 5-7. In the embodiment, the web 7-11 is obliquely attached to the main beam plate 5-7, so that the local stress concentration of the variable cross-section longitudinal beam caused by the sudden change of the cross section is avoided. The web plates 7-11 are fixedly connected with the main beam plates 5-7. Specifically, in the present embodiment, the webs 7 to 11 may be fixedly connected to the main beam plates 5 to 7 by rivets or bolts, so as to facilitate assembly and disassembly. The second flanging 7-13 is attached to the fourth flanging 5-9, so that the main beam plate 5-7 can support the web plate 7-11 to a certain extent, and the fourth flanging 5-9 can support the second flanging 7-13 to a certain extent.

The auxiliary beam 7-1 ensures that the mechanical property of the variable cross-section longitudinal beam 5 is increased and the lateral rigidity of the variable cross-section longitudinal beam 5 is increased under the condition that the height of the low-section part 5-1 of the main beam plate 5-7 is not increased.

A plurality of first reinforcing cross beams 8 are fixedly arranged between the two auxiliary beams 7-1 and are used for ensuring the connection strength between the two auxiliary beams 7-1.

Referring to fig. 5, in the present embodiment, the number of the first reinforcing beams 8 is three, specifically, a first reinforcing beam 8-1, a second reinforcing beam 8-2, and a third reinforcing beam 8-3.

The first reinforcing beam 8-1 adopts a cast support and steel pipe beam assembly welding structure, so that the structure is simple, the welding amount is reduced, and the space is saved.

The second first reinforcing beam 8-2 is designed into a semi-closed metal plate tailor-welded structure, so that certain flexibility can be kept on the premise of meeting the strength requirement, and the defect of overlarge rigidity of a fully-closed box type structure is avoided.

The third first reinforcing beam 8-3 is designed into a back-to-back groove-shaped beam and two wing plates in a threaded connection assembly structure, so that the assembly manufacturability can be improved, various assembly schemes can be adopted conveniently, and the assembly flexibility is improved. Wherein, the third first strengthening beam 8-3 is a split type beam, and the third first strengthening beam 8-3 comprises: a trough-shaped cross beam 8-31 and two wings 8-32. The two wing plates 8-32 can be fixedly connected with the variable cross-section longitudinal beam 5 through bolts, the top of the groove-shaped cross beam 8-31 can be fixedly connected with one of the two wing plates 8-32 through bolts, and the bottom of the groove-shaped cross beam 8-31 can be fixedly connected with the other of the two wing plates 8-32 through bolts.

Specifically, a plurality of second reinforcing cross beams 9 are fixedly arranged between the two variable cross-section longitudinal beams 5, and specifically, a plurality of second reinforcing cross beams 9 are fixedly arranged between the two variable cross-section longitudinal beams 5 through bolts, so that the two variable cross-section longitudinal beams 5 are convenient to disassemble and assemble, and the strength of the two variable cross-section longitudinal beams 5 is ensured.

Referring to fig. 6, specifically, the bow cross member device 1 includes: the device comprises a headstock beam 1-1, a connecting pipe 1-2, a third reinforcing beam 1-3 and two reinforcing longitudinal beams 1-4.

The first end of the connecting pipe 1-2 is fixedly connected with the middle part of the headstock beam 1-1, the second end of the connecting pipe 1-2 is fixedly connected with the middle part of the third reinforced beam 1-3, the connecting pipe 1-2 is a front towing hook connecting pipe, and the connecting pipe 1-2 connects the headstock beam 1-1 and the third reinforced beam 1-3 into a whole to be used as a middle force transmission structure, so that the third reinforced beam 1-3 can share the force of the headstock beam 1-1, wherein the third reinforced beam 1-3 is a groove-shaped beam. Two ends of the third reinforcing cross beam 1-3 are respectively fixedly connected with the inner sides of the two reinforcing longitudinal beams 1-4. In the embodiment, two ends of a third reinforced transverse beam 1-3 are respectively welded with the inner sides of two reinforced longitudinal beams 1-4, and the third reinforced transverse beam 1-3 connects the two reinforced longitudinal beams 1-4 into a whole to be used as a middle force transmission structure, so that the two reinforced longitudinal beams 1-4 can share the force of the vehicle head transverse beam 1-1.

The outer sides of the two reinforcing longitudinal beams 1-4 are fixedly connected with the corresponding front end beam 6, in the embodiment, the outer sides of the two reinforcing longitudinal beams 1-4 can be fixedly connected with the corresponding front end beam 6 through welding, and the connection firmness is ensured. The two ends of the reinforcing longitudinal beams 1-4 are respectively and fixedly connected with the headstock cross beams 1-1 and the first bridge cross beam 3, in the embodiment, the two ends of the reinforcing longitudinal beams 1-4 can be respectively and fixedly connected with the headstock cross beams 1-1 and the first bridge cross beam 3 through welding, and the connection firmness is ensured. The nose beam 1-1 and the first axle beam 3 are fixedly arranged between the two front end beams 6, and in the embodiment, the nose beam 1-1 and the first axle beam 3 can be fixedly arranged between the two front end beams 6 by welding, so that the connection firmness is ensured.

The front cross beam 1-1, the first bridge cross beam 3, the two reinforcing longitudinal beams 1-4 and the two variable cross-section longitudinal beams 5 are connected into a rigid frame body which can be used as a reinforcing device at the variable cross-section part at the front end of the variable cross-section longitudinal beam 5 to ensure the strength of the variable cross-section longitudinal beam 5.

Specifically, referring to fig. 7-8, the frame structure further includes: a plurality of fourth reinforcing beams 10, a plurality of fifth reinforcing beams 11 and a plurality of sixth reinforcing beams 12.

A plurality of fourth reinforcing cross beams 10 are detachably arranged between the two variable cross-section longitudinal beams 5. In the present embodiment, a plurality of fourth reinforcing cross members 10 may be detachably disposed between the two variable cross-section side members 5 through the first brackets 13. A number of fourth reinforcing cross members 10 are arranged between the first bridge cross member 3 and the low-profile portion 5-1.

A plurality of fifth reinforcing cross beams 11 are detachably arranged between the two variable cross-section longitudinal beams 5. In the present embodiment, a plurality of fifth reinforcing cross beams 11 may be detachably disposed between the two variable cross-section longitudinal beams 5 through the second brackets 14. A plurality of fifth reinforcing cross members 11 are provided between the low-profile portion 5-1 and the two second bridge cross members 4.

A plurality of sixth reinforcing cross beams 12 are detachably arranged between the two variable cross-section longitudinal beams 5. In the present embodiment, a plurality of sixth reinforcing cross members 12 may be detachably disposed between the two variable-section side members 5 through third brackets. A number of sixth reinforcing cross members 12 are arranged between two second bridge cross members 4.

The fourth reinforcing beams 10 may be groove-shaped beams, and the fifth reinforcing beams 11 and the sixth reinforcing beams 12 may be concave beams, so that the overall arrangement is facilitated.

Specifically, the bottom of first bridge crossbeam 3 is fixed and is provided with first end backplate 15, and backplate 16 at the bottom of the equal fixed second that is provided with in bottom of two second bridge crossbeams 4, backplate 16 can strengthen the intensity of two variable cross section longerons 5 at the bottom of first end backplate 15 and the second, simultaneously, backplate 16 can with suspension support fixed connection at the bottom of through backplate 15 at the bottom of first end and the second. The first bridge cross beam 3 and the first bottom protection plate 15 are connected into a rigid frame body, and the first bridge cross beam 3 and the first bottom protection plate 15 can be used as a reinforcing device at the bottom of the first high-section part 5-2 of the variable-section longitudinal beam 5 to ensure the strength of the variable-section longitudinal beam 5. The two second bridge girders 4 are connected to a second bottom shell 16 by a rigid frame body, which serves as a reinforcement for the bottom of the second high-profile section 5-3 of the variable-profile longitudinal beam 5.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.