Lower body frame structure

Abstract

The present invention belongs to the technical field of vehicle body structures and relates to a lower vehicle body frame structure. The lower vehicle body frame structure includes a rear floor cross member, a left rear longitudinal beam, a right rear longitudinal beam, a first diamond frame, a second diamond frame, and a rear panel. The rear floor cross member is fixedly connected between the front ends of the left rear longitudinal beam and the right rear longitudinal beam. The rear ends of the left rear longitudinal beam and the right rear longitudinal beam are fixedly connected to the rear panel. The first diamond frame is fixedly connected between the rear floor cross member, the left rear longitudinal beam, and the right rear longitudinal beam. The second diamond frame is fixedly connected between the rear panel, the left rear longitudinal beam, and the right rear longitudinal beam. The first diamond frame is fixedly connected to the second diamond frame. The lower vehicle body frame structure can effectively transmit collision forces, ensure collision safety, and at the same time improve the bending and torsional stiffness of the whole vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle body structures, and particularly relates to a lower vehicle body frame structure. Background Art

[0002] During the vehicle body development process, the performance of the lower vehicle body frame structure will affect the bending and torsion stiffness performance, collision performance, and NVH (Noise, Vibration, Harshness) performance of the whole vehicle. With the increasing emphasis of vehicle manufacturers on collision performance (especially rear collision and offset collision performance, etc.), higher requirements are also put forward for the lower vehicle body frame structure. Therefore, a lower vehicle body frame structure with good performance can greatly improve the key performances such as the bending and torsion performance and collision safety of the whole vehicle.

[0003] Currently, the lower vehicle body structures in the market are relatively traditional, adopting a form of simply assembling cross beams and longitudinal beams, locally forming a "mouth" - shaped structure, and achieving the purpose of meeting local performance requirements by reasonably adjusting the material thickness locally or changing the material grade of some parts. However, there are often phenomena such as uneven vehicle body stiffness and local stress concentration, resulting in an unstable lower vehicle body structure, poor collision energy absorption effect, and poor bending and torsion stiffness. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: aiming at the technical problem of poor collision energy absorption effect of the existing lower vehicle body structure, to provide a lower vehicle body frame structure.

[0005] To solve the above - mentioned technical problem, an embodiment of the present invention provides a lower vehicle body frame structure, including a rear floor cross beam, a left rear longitudinal beam, a right rear longitudinal beam, a first diamond - shaped frame, a second diamond - shaped frame, and a rear bulkhead. The rear floor cross beam is fixedly connected between the front ends of the left rear longitudinal beam and the right rear longitudinal beam. The rear ends of the left rear longitudinal beam and the right rear longitudinal beam are fixedly connected to the rear bulkhead. The first diamond - shaped frame is fixedly connected between the rear floor cross beam, the left rear longitudinal beam, and the right rear longitudinal beam. The second diamond - shaped frame is fixedly connected between the rear bulkhead, the left rear longitudinal beam, and the right rear longitudinal beam. The first diamond - shaped frame is fixedly connected to the second diamond - shaped frame, and the first diamond - shaped frame is located in front of the second diamond - shaped frame in the vehicle body length direction.

[0006] Optionally, the first diamond-shaped frame includes a first left inclined longitudinal beam, a second left inclined longitudinal beam, a first right inclined longitudinal beam, and a second right inclined longitudinal beam. The front ends of the first left inclined longitudinal beam and the first right inclined longitudinal beam are fixedly connected to the rear floor cross beam. The rear end of the first left inclined longitudinal beam and the front end of the second left inclined longitudinal beam are fixedly connected at a first position on the left rear longitudinal beam. The rear end of the first right inclined longitudinal beam and the front end of the second right inclined longitudinal beam are fixedly connected at a first position on the right rear longitudinal beam. The rear ends of the second left inclined longitudinal beam and the second right inclined longitudinal beam are fixedly connected to the second diamond-shaped frame.

[0007] Optionally, the front end of the first left inclined longitudinal beam is located on the left side of the front end of the first right inclined longitudinal beam in the vehicle body width direction.

[0008] Optionally, the first diamond-shaped frame further includes a first cross beam, which is fixedly connected between the rear ends of the second left inclined longitudinal beam and the second right inclined longitudinal beam, and the second diamond-shaped frame is fixedly connected to the first cross beam.

[0009] Optionally, the second diamond-shaped frame includes a third left inclined longitudinal beam, a fourth left inclined longitudinal beam, a third right inclined longitudinal beam, and a fourth right inclined longitudinal beam. The front ends of the third left inclined longitudinal beam and the third right inclined longitudinal beam are fixedly connected to the first cross beam. The rear end of the third left inclined longitudinal beam and the front end of the fourth left inclined longitudinal beam are fixedly connected at a second position on the left rear longitudinal beam. The rear end of the third right inclined longitudinal beam and the front end of the fourth right inclined longitudinal beam are fixedly connected at a second position on the right rear longitudinal beam. The rear ends of the fourth left inclined longitudinal beam and the fourth right inclined longitudinal beam are fixedly connected to the rear panel.

[0010] Optionally, the second diamond-shaped frame further includes a second cross beam, which is fixedly connected between the front ends of the third left inclined longitudinal beam and the third right inclined longitudinal beam, and the second cross beam is fixedly connected to the first cross beam.

[0011] Optionally, the lower vehicle body frame structure further includes a first longitudinal beam and a second longitudinal beam. The front ends of the first longitudinal beam and the second longitudinal beam are fixedly connected to the first cross beam. The rear ends of the first longitudinal beam and the second longitudinal beam are fixedly connected to the second cross beam. The first longitudinal beam is located on the left side of the second longitudinal beam in the vehicle body width direction.

[0012] Optionally, the lower body frame structure further includes a left sill beam, a left rear cross beam of the front seat, a right sill beam, and a right rear cross beam of the front seat. The rear end of the left sill beam is fixedly connected to the front end of the left rear longitudinal beam. The left rear cross beam of the front seat includes a first cross beam section and a first inclined section. The left end of the first cross beam section is fixedly connected to the left sill beam. The right end of the first cross beam section is fixedly connected to the front end of the first inclined section. The rear end of the first inclined section is fixedly connected to the rear floor cross beam. The front end of the first inclined section is located on the left side of the rear end of the first inclined section in the vehicle body width direction.

[0013] The rear end of the right sill beam is fixedly connected to the front end of the right rear longitudinal beam. The right rear cross beam of the front seat includes a second cross beam section and a second inclined section. The right end of the second cross beam section is fixedly connected to the right sill beam. The left end of the second cross beam section is fixedly connected to the front end of the second inclined section. The rear end of the second inclined section is fixedly connected to the rear floor cross beam. The front end of the second inclined section is located on the right side of the rear end of the second inclined section in the vehicle body width direction.

[0014] The left rear cross beam of the front seat is located on the left side of the right rear cross beam of the front seat in the vehicle body width direction.

[0015] Optionally, the lower body frame structure further includes a left front cross beam of the front seat, a right front cross beam of the front seat, a left middle channel longitudinal beam, a right middle channel longitudinal beam, a left front longitudinal beam, and a right front longitudinal beam. The front end of the left sill beam and the front end of the left middle channel longitudinal beam are fixedly connected to the left front longitudinal beam. The rear end of the left middle channel longitudinal beam is fixedly connected to the rear floor cross beam. The left front cross beam of the front seat is fixedly connected between the left sill beam, the left middle channel longitudinal beam, and the left front longitudinal beam. The front end of the right sill beam and the front end of the right middle channel longitudinal beam are fixedly connected to the right front longitudinal beam. The rear end of the right middle channel longitudinal beam is fixedly connected to the rear floor cross beam. The right front cross beam of the front seat is fixedly connected between the right sill beam, the right middle channel longitudinal beam, and the right front longitudinal beam.

[0016] Optionally, the rear end of the left middle channel longitudinal beam and the rear end of the first inclined section of the left rear cross beam of the front seat are fixedly connected to a first position on the rear floor cross beam. The rear end of the right middle channel longitudinal beam and the rear end of the second inclined section of the right rear cross beam of the front seat are fixedly connected to a second position on the rear floor cross beam.

[0017] According to the underbody frame structure of the embodiment of the present invention, the first diamond frame is fixedly connected between the rear floor cross member, the left rear longitudinal beam and the right rear longitudinal beam, the second diamond frame is fixedly connected between the rear panel, the left rear longitudinal beam and the right rear longitudinal beam, and the first diamond frame is fixedly connected to the front side of the second diamond frame, so that the underbody frame structure is alternately arranged with diamonds and triangles and is hierarchically matched, forming a structure similar to a "spring" as a whole, which can absorb energy well and effectively transmit the collision force during the processes of frontal collision, rear collision and side collision, ensuring collision safety and improving the bending and torsion stiffness of the whole vehicle. Brief Description of the Drawings

[0018] Figure 1 is a schematic diagram of the underbody frame structure provided by an embodiment of the present invention;

[0019] Figure 2 is Figure 1 the sectional view at A-A in

[0020] Figure 3 is Figure 1 the sectional view at B-B in

[0021] Figure 4 is Figure 1 the sectional view at C-C in

[0022] Figure 5 is a schematic diagram of the force transmission path when the underbody frame structure provided by an embodiment of the present invention undergoes a frontal collision or a rear collision;

[0023] Figure 6 is a schematic diagram of the force transmission path when the underbody frame structure provided by an embodiment of the present invention undergoes a side collision.

[0024] The reference numerals in the specification are as follows:

[0025] 1, rear floor cross member;

[0026] 2, left rear longitudinal beam;

[0027] 3, right rear longitudinal beam;

[0028] 4, first diamond frame; 41, first left inclined longitudinal beam; 42, second left inclined longitudinal beam; 43, first right inclined longitudinal beam; 44, second right inclined longitudinal beam; 45, first cross member;

[0029] 5, second diamond frame; 51, third left inclined longitudinal beam; 52, fourth left inclined longitudinal beam; 53, third right inclined longitudinal beam; 54, fourth right inclined longitudinal beam; 55, second cross member;

[0030] 6, rear panel;

[0031] 7. First longitudinal beam; 8. Second longitudinal beam; 9. Left sill beam;

[0032] 10. Left rear cross beam of front seat; 101. First cross beam section; 102. First inclined section;

[0033] 11. Right sill beam;

[0034] 12. Right rear cross beam of front seat; 121. Second cross beam section; 122. Second inclined section;

[0035] 13. Left front cross beam of front seat; 14. Right front cross beam of front seat;

[0036] 15. Left middle channel longitudinal beam; 16. Right middle channel longitudinal beam;

[0037] 17. Left front longitudinal beam; 18. Right front longitudinal beam. Detailed implementation manners

[0038] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] As Figures 1 to 4 shown, the lower body frame structure provided by the embodiment of the present invention includes a rear floor cross beam 1, a left rear longitudinal beam 2, a right rear longitudinal beam 3, a first diamond frame 4, a second diamond frame 5 and a rear panel 6. The rear floor cross beam 1 is fixedly connected between the front ends of the left rear longitudinal beam 2 and the right rear longitudinal beam 3. The rear ends of the left rear longitudinal beam 2 and the right rear longitudinal beam 3 are fixedly connected to the rear panel 6. The first diamond frame 4 is fixedly connected between the rear floor cross beam 1, the left rear longitudinal beam 2 and the right rear longitudinal beam 3. The second diamond frame 5 is fixedly connected between the rear panel 6, the left rear longitudinal beam 2 and the right rear longitudinal beam 3. The first diamond frame 4 is fixedly connected to the second diamond frame 5. The first diamond frame 4 is located in front of the second diamond frame 5 in the vehicle body length direction.

[0040] The underbody frame structure provided by the embodiment of the present invention fixes and connects the first diamond frame 4 between the rear floor crossbeam 1, the left rear longitudinal beam 2 and the right rear longitudinal beam 3, fixes and connects the second diamond frame 5 between the rear panel 6, the left rear longitudinal beam 2 and the right rear longitudinal beam 3, and fixes and connects the first diamond frame 4 to the front side of the second diamond frame 5, so that the underbody frame structure is arranged with diamonds and triangles alternately and is hierarchically matched, forming a structure similar to a "spring" as a whole. During the process of frontal collision, rear collision and side collision, it can absorb energy well and effectively transmit the collision force, ensuring collision safety and at the same time improving the bending and torsional stiffness of the whole vehicle.

[0041] In one embodiment, as Figure 1 shown, the first diamond frame 4 includes a first left inclined longitudinal beam 41, a second left inclined longitudinal beam 42, a first right inclined longitudinal beam 43 and a second right inclined longitudinal beam 44. The front ends of the first left inclined longitudinal beam 41 and the first right inclined longitudinal beam 43 are fixedly connected to the rear floor crossbeam 1. The rear end of the first left inclined longitudinal beam 41 and the front end of the second left inclined longitudinal beam 42 are fixedly connected to the left rear longitudinal beam 2. The rear end of the first right inclined longitudinal beam 43 and the front end of the second right inclined longitudinal beam 44 are fixedly connected to the right rear longitudinal beam 3. The rear ends of the second left inclined longitudinal beam 42 and the second right inclined longitudinal beam 44 are fixedly connected to the second diamond frame 5.

[0042] Through the fixed connection between the first left inclined longitudinal beam 41, the second left inclined longitudinal beam 42, the first right inclined longitudinal beam 43 and the second right inclined longitudinal beam 44, the first diamond frame 4 is fixed to the vehicle body, which can absorb energy well and effectively transmit the collision force during the process of frontal collision, rear collision and side collision, ensuring collision safety and at the same time improving the bending and torsional stiffness of the whole vehicle.

[0043] In one embodiment, as Figure 1 shown, the rear end of the first left inclined longitudinal beam 41 and the front end of the second left inclined longitudinal beam 42 are fixedly connected to the first position of the left rear longitudinal beam 2. The rear end of the first right inclined longitudinal beam 43 and the front end of the second right inclined longitudinal beam 44 are fixedly connected to the first position of the right rear longitudinal beam 3.

[0044] Integrating the rear end of the first left inclined longitudinal beam 41 and the front end of the second left inclined longitudinal beam 42 together, and integrating the rear end of the first right inclined longitudinal beam 43 and the front end of the second right inclined longitudinal beam 44 together effectively strengthens the joint strength of the connection position and greatly improves the torsional stiffness of the whole vehicle.

[0045] In one embodiment, as Figure 1As shown, the front end of the first left inclined longitudinal beam 41 is located on the left side of the front end of the first right inclined longitudinal beam 43 in the vehicle body width direction, so that the first diamond frame 4 is more stably fixedly connected between the rear floor cross beam 1, the left rear longitudinal beam 2 and the right rear longitudinal beam 3.

[0046] In one embodiment, as Figure 1 shown, the first diamond frame 4 further includes a first cross beam 45. The first cross beam 45 is fixedly connected between the rear end of the second left inclined longitudinal beam 42 and the rear end of the second right inclined longitudinal beam 44 to form the first diamond frame 4. The second diamond frame 5 is fixedly connected to the first cross beam 45 to realize the connection between the first diamond frame 4 and the second diamond frame 5.

[0047] In one embodiment, as Figure 1 shown, the second diamond frame 5 includes a third left inclined longitudinal beam 51, a fourth left inclined longitudinal beam 52, a third right inclined longitudinal beam 53 and a fourth right inclined longitudinal beam 54. The front ends of the third left inclined longitudinal beam 51 and the third right inclined longitudinal beam 53 are fixedly connected to the first cross beam 45. The rear end of the third left inclined longitudinal beam 51 and the front end of the fourth left inclined longitudinal beam 52 are fixedly connected to the left rear longitudinal beam 2. The rear end of the third right inclined longitudinal beam 53 and the front end of the fourth right inclined longitudinal beam 54 are fixedly connected to the right rear longitudinal beam 3. The rear ends of the fourth left inclined longitudinal beam 52 and the fourth right inclined longitudinal beam 54 are fixedly connected to the rear panel 6.

[0048] Through the fixed connection among the third left inclined longitudinal beam 51, the fourth left inclined longitudinal beam 52, the third right inclined longitudinal beam 53 and the fourth right inclined longitudinal beam 54, the second diamond frame 5 is fixed on the vehicle body, and can absorb energy well and effectively transmit the collision force during the frontal collision, rear collision and side collision, ensuring the collision safety and improving the bending and torsional stiffness of the whole vehicle at the same time.

[0049] In one embodiment, as Figure 1 shown, the rear end of the third left inclined longitudinal beam 51 and the front end of the fourth left inclined longitudinal beam 52 are fixedly connected to the second position of the left rear longitudinal beam 2, and the rear end of the third right inclined longitudinal beam 53 and the front end of the fourth right inclined longitudinal beam 54 are fixedly connected to the second position of the right rear longitudinal beam 3.

[0050] Integrating the rear end of the third left inclined longitudinal beam 51 and the front end of the fourth left inclined longitudinal beam 52 together, and integrating the rear end of the third right inclined longitudinal beam 53 and the front end of the fourth right inclined longitudinal beam 54 together effectively strengthens the joint strength of the connection position and greatly improves the torsional stiffness of the whole vehicle.

[0051] In one embodiment, as Figure 1As shown, the second diamond-shaped frame 5 further includes a second cross beam 55. The second cross beam 55 is fixedly connected between the front ends of the third left inclined longitudinal beam 51 and the third right inclined longitudinal beam 53 to form the second diamond-shaped frame 5. The second cross beam 55 is fixedly connected to the first cross beam 45 to realize the connection between the first diamond-shaped frame 4 and the second diamond-shaped frame 5.

[0052] In one embodiment, as Figure 1 shown, the lower body frame structure further includes a first longitudinal beam 7 and a second longitudinal beam 8. The front ends of the first longitudinal beam 7 and the second longitudinal beam 8 are fixedly connected to the first cross beam 45, and the rear ends of the first longitudinal beam 7 and the second longitudinal beam 8 are fixedly connected to the second cross beam 55. The first longitudinal beam 7 is located on the left side of the second longitudinal beam 8 in the width direction of the vehicle body to realize the connection between the first diamond-shaped frame 4 and the second diamond-shaped frame 5.

[0053] By fixedly connecting the first longitudinal beam 7 and the second longitudinal beam 8 between the first cross beam 45 and the second cross beam 55, the lower body frame structure integrally forms a structure similar to a "spring", which can absorb energy well and effectively transmit the collision force during frontal collision, rear collision and side collision, ensuring collision safety and improving the bending and torsional stiffness of the whole vehicle at the same time.

[0054] In one embodiment, as Figure 1 shown, the lower body frame structure further includes a left sill beam 9, a front seat left rear cross beam 10, a right sill beam 11 and a front seat right rear cross beam 12. The rear end of the left sill beam 9 is fixedly connected to the front end of the left rear longitudinal beam 2. The front seat left rear cross beam 10 includes a first cross beam section 101 and a first inclined section 102. The left end of the first cross beam section 101 is fixedly connected to the left sill beam 9, the right end of the first cross beam section 101 is fixedly connected to the front end of the first inclined section 102, and the rear end of the first inclined section 102 is fixedly connected to the rear floor cross beam 1. The front end of the first inclined section 102 is located on the left side of the rear end of the first inclined section 102 in the width direction of the vehicle body.

[0055] The rear end of the right sill beam 11 is fixedly connected to the front end of the right rear longitudinal beam 3. The front seat right rear cross beam 12 includes a second cross beam section 121 and a second inclined section 122. The right end of the second cross beam section 121 is fixedly connected to the right sill beam 11, the left end of the second cross beam section 121 is fixedly connected to the front end of the second inclined section 122, and the rear end of the second inclined section 122 is fixedly connected to the rear floor cross beam 1. The front end of the second inclined section 122 is located on the right side of the rear end of the second inclined section 122 in the width direction of the vehicle body.

[0056] The front seat left rear cross member 10 is located on the left side of the front seat right rear cross member 12 in the vehicle body width direction. The front seat left rear cross member 10 and the front seat right rear cross member 12 are designed to be curved so as to be connected to the rear floor cross member 1, and can effectively disperse the side impact force.

[0057] In one embodiment, as Figure 1 shown, the lower body frame structure further includes a front seat left front cross member 13, a front seat right front cross member 14, a left middle channel longitudinal beam 15, a right middle channel longitudinal beam 16, a left front longitudinal beam 17 and a right front longitudinal beam 18. The front end of the left sill beam 9 and the front end of the left middle channel longitudinal beam 15 are fixedly connected to the left front longitudinal beam 17. The rear end of the left middle channel longitudinal beam 15 is fixedly connected to the rear floor cross member 1. The front seat left front cross member 13 is fixedly connected between the left sill beam 9, the left middle channel longitudinal beam 15 and the left front longitudinal beam 17. The front end of the right sill beam 11 and the front end of the right middle channel longitudinal beam 16 are fixedly connected to the right front longitudinal beam 18. The rear end of the right middle channel longitudinal beam 16 is fixedly connected to the rear floor cross member 1. The front seat right front cross member 14 is fixedly connected between the right sill beam 11, the right middle channel longitudinal beam 16 and the right front longitudinal beam 18 to form a complete lower body frame structure.

[0058] In one embodiment, as Figure 1 shown, the rear end of the left middle channel longitudinal beam 15 and the rear end of the first inclined section 102 of the front seat left rear cross member 10 are fixedly connected to the first position of the rear floor cross member 1. The rear end of the right middle channel longitudinal beam 16 and the rear end of the second inclined section 122 of the front seat right rear cross member 12 are fixedly connected to the second position of the rear floor cross member 1.

[0059] Integrating the rear end of the left middle channel longitudinal beam 15 with the rear end of the first inclined section 102, and integrating the rear end of the right middle channel longitudinal beam 16 with the rear end of the second inclined section 122 effectively strengthens the joint strength of the connection position and greatly improves the torsional stiffness of the whole vehicle.

[0060] As Figures 2 to 4 shown, each part (rear floor cross member 1, left rear longitudinal beam 2, right rear longitudinal beam 3, first cross member 45, second cross member 55, rear panel 6, first longitudinal beam 7, second longitudinal beam 8, left sill beam 9, right sill beam 11, left middle channel longitudinal beam 15, right middle channel longitudinal beam 16, left front longitudinal beam 17 and right front longitudinal beam 18) in the lower body frame structure provided by the present invention is mainly in the form of a beam structure. The beam structure can be made of steel parts or aluminum parts. If the beam structure is made of steel parts, it is formed by stamping, and the beam structures are connected together by welding technology. If the beam structure is made of aluminum parts, it is formed by extrusion, and the beam structures are connected by riveting, screwing and gluing and other technologies.

[0061] When a frontal collision or a rear collision occurs to the lower body frame structure provided by the present invention, the force transmission path is as follows Figure 5 shown. Taking the frontal collision as an example, when a frontal collision occurs, a part of the collision force received by the left front longitudinal beam 17 is transmitted to the left sill beam 9, and another part is transmitted to the left middle channel longitudinal beam 15. A part of the force transmitted to the left sill beam 9 is transmitted to the left rear cross beam 10 of the front seat, and another part is transmitted to the left rear longitudinal beam 2. The force transmitted to the left middle channel longitudinal beam 15 and the left rear cross beam 10 of the front seat will be transmitted to the rear floor cross beam 1, and finally transmitted by the rear floor cross beam 1 to the first diamond frame 4 and the second diamond frame 5 to complete the effective transmission of the left side collision force.

[0062] And a part of the collision force received by the right front longitudinal beam 18 is transmitted to the right sill beam 11, and another part is transmitted to the right middle channel longitudinal beam 16. A part of the force transmitted to the right sill beam 11 is transmitted to the right rear cross beam 12 of the front seat, and another part is transmitted to the right rear longitudinal beam 3. The force transmitted to the right middle channel longitudinal beam 16 and the right rear cross beam 12 of the front seat will be transmitted to the rear floor cross beam 1, and finally transmitted by the rear floor cross beam 1 to the first diamond frame 4 and the second diamond frame 5 to complete the effective transmission of the right side collision force.

[0063] When a rear collision occurs, the force transmission direction is opposite to that of the above-mentioned frontal collision.

[0064] During either a frontal collision or a rear collision, the lower body frame structure can effectively transmit the collision force and will not overly crush the occupant compartment.

[0065] When a side collision occurs to the lower body frame structure provided by the present invention, the force transmission path is as follows Figure 6 shown. Taking the left side collision as an example, when a side collision occurs, a part of the collision force received by the left sill beam 9 is transmitted from the left front cross beam 13 of the front seat to the left middle channel longitudinal beam 15, and then transmitted from the left middle channel longitudinal beam 15 to the rear floor cross beam 1; another part is transmitted from the left rear cross beam 10 of the front seat to the rear floor cross beam 1. The force transmitted to the rear floor cross beam 1 will be sequentially transmitted to the first diamond frame 4 and the second diamond frame 5 to complete the force transmission and decomposition.

[0066] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lower body frame structure, characterized in that, It includes a rear floor crossbeam, a left rear longitudinal beam, a right rear longitudinal beam, a first diamond-shaped frame, a second diamond-shaped frame, and a rear panel. The rear floor crossbeam is fixedly connected between the front ends of the left rear longitudinal beam and the right rear longitudinal beam. The rear ends of the left rear longitudinal beam and the right rear longitudinal beam are fixedly connected to the rear panel. The first diamond-shaped frame is fixedly connected between the rear floor crossbeam, the left rear longitudinal beam, and the right rear longitudinal beam. The second diamond-shaped frame is fixedly connected between the rear panel, the left rear longitudinal beam, and the right rear longitudinal beam. The first diamond-shaped frame is fixedly connected to the second diamond-shaped frame. The first diamond-shaped frame is located on the front side of the second diamond-shaped frame in the vehicle body length direction.

2. The underbody frame structure according to claim 1, characterized in that, The first diamond-shaped frame includes a first left inclined longitudinal beam, a second left inclined longitudinal beam, a first right inclined longitudinal beam, and a second right inclined longitudinal beam. The front ends of the first left inclined longitudinal beam and the first right inclined longitudinal beam are fixedly connected to the rear floor crossbeam. The rear end of the first left inclined longitudinal beam and the front end of the second left inclined longitudinal beam are fixedly connected to the first position of the left rear longitudinal beam. The rear end of the first right inclined longitudinal beam and the front end of the second right inclined longitudinal beam are fixedly connected to the first position of the right rear longitudinal beam. The rear ends of the second left inclined longitudinal beam and the second right inclined longitudinal beam are fixedly connected to the second diamond-shaped frame.

3. The underbody frame structure according to claim 2, characterized in that, The front end of the first left inclined longitudinal beam is located on the left side of the front end of the first right inclined longitudinal beam in the vehicle body width direction.

4. The underbody frame structure according to claim 2, characterized in that, The first diamond-shaped frame further includes a first crossbeam, which is fixedly connected between the rear ends of the second left inclined longitudinal beam and the second right inclined longitudinal beam. The second diamond-shaped frame is fixedly connected to the first crossbeam.

5. The underbody frame structure according to claim 4, characterized in that, The second diamond-shaped frame includes a third left inclined longitudinal beam, a fourth left inclined longitudinal beam, a third right inclined longitudinal beam, and a fourth right inclined longitudinal beam. The front ends of the third left inclined longitudinal beam and the third right inclined longitudinal beam are fixedly connected to the first crossbeam. The rear end of the third left inclined longitudinal beam and the front end of the fourth left inclined longitudinal beam are fixedly connected to the second position of the left rear longitudinal beam. The rear end of the third right inclined longitudinal beam and the front end of the fourth right inclined longitudinal beam are fixedly connected to the second position of the right rear longitudinal beam. The rear ends of the fourth left inclined longitudinal beam and the fourth right inclined longitudinal beam are fixedly connected to the rear panel.

6. The underbody frame structure according to claim 5, characterized in that, The second diamond-shaped frame further includes a second crossbeam, which is fixedly connected between the front ends of the third left inclined longitudinal beam and the third right inclined longitudinal beam. The second crossbeam is fixedly connected to the first crossbeam.

7. The underbody frame structure according to claim 6, characterized in that, The underbody frame structure further includes a first longitudinal beam and a second longitudinal beam. The front ends of the first longitudinal beam and the second longitudinal beam are fixedly connected to the first crossbeam. The rear ends of the first longitudinal beam and the second longitudinal beam are fixedly connected to the second crossbeam. The first longitudinal beam is located on the left side of the second longitudinal beam in the vehicle body width direction.

8. The underbody frame structure according to claim 1, characterized in that, The lower vehicle body frame structure further includes a left sill beam, a left rear cross beam of the front seat, a right sill beam, and a right rear cross beam of the front seat. The rear end of the left sill beam is fixedly connected to the front end of the left rear longitudinal beam. The left rear cross beam of the front seat includes a first cross beam section and a first inclined section. The left end of the first cross beam section is fixedly connected to the left sill beam. The right end of the first cross beam section is fixedly connected to the front end of the first inclined section. The rear end of the first inclined section is fixedly connected to the rear floor cross beam. The front end of the first inclined section is located on the left side of the rear end of the first inclined section in the vehicle body width direction. The rear end of the right sill beam is fixedly connected to the front end of the right rear longitudinal beam. The right rear cross beam of the front seat includes a second cross beam section and a second inclined section. The right end of the second cross beam section is fixedly connected to the right sill beam. The left end of the second cross beam section is fixedly connected to the front end of the second inclined section. The rear end of the second inclined section is fixedly connected to the rear floor cross beam. The front end of the second inclined section is located on the right side of the rear end of the second inclined section in the vehicle body width direction. The left rear cross beam of the front seat is located on the left side of the right rear cross beam of the front seat in the vehicle body width direction.

9. The underbody frame structure according to claim 8, characterized in that, The lower vehicle body frame structure further includes a left front cross beam of the front seat, a right front cross beam of the front seat, a left middle channel longitudinal beam, a right middle channel longitudinal beam, a left front longitudinal beam, and a right front longitudinal beam. The front end of the left sill beam and the front end of the left middle channel longitudinal beam are fixedly connected to the left front longitudinal beam. The rear end of the left middle channel longitudinal beam is fixedly connected to the rear floor cross beam. The left front cross beam of the front seat is fixedly connected between the left sill beam, the left middle channel longitudinal beam, and the left front longitudinal beam. The front end of the right sill beam and the front end of the right middle channel longitudinal beam are fixedly connected to the right front longitudinal beam. The rear end of the right middle channel longitudinal beam is fixedly connected to the rear floor cross beam. The right front cross beam of the front seat is fixedly connected between the right sill beam, the right middle channel longitudinal beam, and the right front longitudinal beam.

10. The underbody frame structure according to claim 9, characterized in that, The rear end of the left middle channel longitudinal beam and the rear end of the first inclined section of the left rear cross beam of the front seat are fixedly connected to the first position of the rear floor cross beam. The rear end of the right middle channel longitudinal beam and the rear end of the second inclined section of the right rear cross beam of the front seat are fixedly connected to the second position of the rear floor cross beam.

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