Lower vehicle body structure and vehicle

Abstract

The invention provides a lower vehicle body structure and a vehicle. The lower vehicle body structure comprises a lower vehicle body framework, a rear auxiliary frame and a battery pack. The lower vehicle body framework comprises rear floor longitudinal beams arranged on the left side and the right side respectively and a rear floor middle cross beam connected between the two rear floor longitudinal beams, the battery pack comprises a battery pack frame and a battery pack body, the rear end of the battery pack frame extends to the position below the rear floor middle cross beam, and the rear auxiliary frame is provided with a rear auxiliary frame front cross beam close to the battery pack. The left end and the right end of the rear auxiliary frame front cross beam are connected with the battery pack frame and the rear floor middle cross beam, the rear floor middle cross beam and the rear auxiliary frame front cross beam are connected to form a first annular structure, and the rear floor middle cross beam and the battery pack are connected to form a second annular structure. According to the lower vehicle body structure, the local rigidity and the overall rigidity of the vehicle can be improved, a force transmission channel between the battery pack frame and the rear auxiliary frame can be additionally arranged on each of the left side and the right side of the vehicle body, and the crashworthiness of the vehicle can be well improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to an underbody structure. The present invention also relates to a vehicle provided with the underbody structure. Background Art

[0002] With the increasing popularity of electric vehicles, people are paying more and more attention to their safety. In particular, the battery pack is mounted on the vehicle body structure, which places higher demands on the vehicle body structure's load-bearing capacity and ability to absorb collision forces.

[0003] The lower body frame and rear subframe are the primary transmission structures for collision forces. The strength of the connection and the effectiveness of the force transmission between them directly impact the safety of the vehicle and battery pack. In existing technologies, the layout of the rear portion of the lower body frame and the front subframe is irrational, resulting in poor transmission of collision forces in the vehicle's fore-aft direction. This not only compromises the safety of the battery pack but also affects the safety of the vehicle's occupants. Therefore, optimizing the front body's force transmission structure to improve force transmission performance is crucial. Summary of the Invention

[0004] In view of this, the present invention aims to provide an underbody structure to improve the crashworthiness of a vehicle.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A lower body structure includes a lower body frame, and a rear subframe and a battery pack arranged below the lower body frame; the lower body frame includes rear floor longitudinal beams arranged on left and right sides, and a rear floor middle cross beam connected between the rear floor longitudinal beams on both sides; the battery pack includes a battery pack frame and a battery pack body arranged in the battery pack frame, and the rear end of the battery pack frame extends to below the rear floor middle cross beam, and the rear subframe has a rear subframe front cross beam close to the battery pack; the left and right ends of the rear subframe front cross beam are connected to the battery pack frame and the rear floor middle cross beam, and the rear floor middle cross beam and the rear subframe front cross beam are connected to form a first ring structure, and the rear floor middle cross beam and the battery pack are connected to form a second ring structure.

[0007] Furthermore, the lower vehicle body frame includes rocker beams arranged on the left and right sides, the battery pack frame includes a rear side beam, side beams arranged on the left and right sides of the rear side beam, and an oblique beam connected between the rear side beam and the side beams on the corresponding side; the rocker beam is connected to the outer side of the rear floor longitudinal beam on the corresponding side, the side beam is connected to the bottom of the rocker beam on the corresponding side, the oblique beam is connected to the front cross beam of the rear subframe and the middle cross beam of the rear floor, and forms a third annular structure with the rear floor longitudinal beam and the rocker beam.

[0008] Furthermore, the side beam extends from the front end of the door sill beam to the rear end of the door sill beam; and / or, the height of the side beam is the same as the height of the battery pack body.

[0009] Furthermore, a threaded sleeve is provided on the rear floor longitudinal beam; the rear side beam and the front cross beam of the rear subframe are threadedly connected to the threaded sleeve through bolts.

[0010] Furthermore, a reinforcing plate is provided in the rear floor longitudinal beam, and the reinforcing plate is connected between the left and right side walls of the rear floor longitudinal beam; the reinforcing plate is box-shaped and forms a cavity with the rear floor longitudinal beam, and the threaded sleeve passes through the reinforcing plate.

[0011] Furthermore, the cross-sections of various parts of the battery pack frame are the same; the battery pack frame has a plurality of force transmission channels inside, and each of the force transmission channels is annular and arranged along the circumference of the battery pack frame.

[0012] Furthermore, the rear subframe includes a rear subframe rear cross beam spaced apart from the rear subframe front cross beam, and a rear subframe longitudinal beam connected between the rear subframe front cross beam and the left and right sides of the rear subframe rear cross beam; the left and right sides of the rear subframe rear cross beam are respectively connected to the rear floor longitudinal beams on the corresponding sides, and a fourth annular structure is formed between the rear subframe front cross beam, the rear subframe rear cross beam, the rear subframe longitudinal beam and the rear floor longitudinal beam.

[0013] Furthermore, the lower vehicle body frame includes a rear floor rear cross beam connected between the rear floor longitudinal beams on both sides, and the left and right sides of the rear subframe rear cross beam are arranged below the rear floor rear cross beam and are connected to the rear floor rear cross beam and the rear floor longitudinal beam at the same time.

[0014] Furthermore, the lower vehicle body frame includes a floor beam connected between the door sill beams on both sides, and the battery pack body includes a battery pack beam connected between the left and right sides of the battery pack frame; the battery pack beam and the floor beam are arranged correspondingly above and below and connected together.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The lower vehicle body structure described in the present invention is configured such that both left and right ends of the front cross beam of the rear subframe are connected to the battery pack frame and the rear floor middle cross beam, and the rear floor middle cross beam and the front cross beam of the rear subframe are connected to form a first ring structure, and the rear floor middle cross beam and the battery pack are connected to form a second ring structure, which can improve the local and overall rigidity of the vehicle, and a force transmission channel between the battery pack frame and the rear subframe can be added on the left and right sides of the vehicle body respectively, which can greatly improve the vehicle's crash resistance.

[0017] Furthermore, the side rails are connected below the corresponding side sills. The diagonal beams are connected to the front crossmember of the rear subframe and the center crossmember of the rear floor. Together with the rear floor longitudinal beams and sills, they form a third ring structure. This strengthens the connection between the rear floor frame and the sills and improves the vehicle's torsional rigidity. The third ring structure also further enhances the transmission and dispersion of collision forces. The side rails extend from the front to the rear of the sills and are the same height as the battery pack. This improves the overall horizontal and vertical dimensions of the battery pack, enhancing its crashworthiness and ensuring greater safety for the battery cells. The rear rails and the front crossmember of the rear subframe are connected via bolts and threaded sleeves, resulting in a simple connection structure and strong connection strength.

[0018] In addition, a box-shaped reinforcement plate is installed within the rear floor longitudinal beam, and the reinforcement plate and the rear floor longitudinal beam form a cavity, which can enhance the structural strength of the rear floor longitudinal beam and improve the rigidity and crashworthiness of the entire vehicle. The cross-section of each part of the battery pack frame is uniform, and the battery pack frame has multiple annular force transmission channels, which can provide the battery pack frame with excellent structural strength and force transmission performance, thereby improving its crashworthiness. The fourth ring structure formed by the front cross member of the rear subframe, the rear cross member of the rear subframe, the rear subframe longitudinal beam, and the rear floor longitudinal beam further enhances the strength and rigidity of the vehicle, while also forming a force transmission ring, which helps to disperse collision energy and compressive force on the vehicle, thereby improving the vehicle's crashworthiness.

[0019] Furthermore, the rear subframe's rear crossmember is connected to the rear floor's rear crossmember and rear floor longitudinal members, further enhancing the vehicle's strength and rigidity. The battery pack crossmember is positioned vertically above and connected to the floor crossmembers, enhancing the battery pack's mounting strength. This also transfers external forces from the battery pack to the floor crossmembers, distributing them and reducing damage to the battery pack while protecting the cells within.

[0020] In addition, another object of the present invention is to provide a vehicle provided with the above-mentioned lower vehicle body structure.

[0021] The vehicle of the present invention, by providing the lower body structure as described above, can improve the transmission effect of collision force, thereby helping to improve the collision safety of the vehicle and the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1A schematic structural diagram of a lower vehicle body structure according to an embodiment of the present invention from one viewing angle;

[0024] Figure 2 for Figure 1 Schematic diagram of the structure of the hidden rear floor;

[0025] Figure 3 A schematic structural diagram of the lower vehicle body structure according to an embodiment of the present invention from another perspective;

[0026] Figure 4 This is a partial structural diagram of the rear floor according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic structural diagram of a rear subframe according to an embodiment of the present invention;

[0028] Figure 6 is a schematic diagram of a first ring structure according to an embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of a second ring structure according to an embodiment of the present invention;

[0030] Figure 8 This is a partial structural diagram of the lower vehicle body frame according to an embodiment of the present invention;

[0031] Figure 9 A schematic structural diagram of a battery pack according to an embodiment of the present invention;

[0032] Figure 10 This is a schematic structural diagram of a battery pack frame according to an embodiment of the present invention;

[0033] Figure 11 is a schematic diagram of a third ring structure according to an embodiment of the present invention;

[0034] Figure 12 is a schematic diagram of a fourth ring structure according to an embodiment of the present invention;

[0035] Figure 13 This is a schematic structural diagram of the rear floor and the rear floor front crossbeam according to an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] 100, lower body frame; 200, battery pack;

[0038] A, first ring structure; B, second ring structure; C, third ring structure; D, fourth ring structure;

[0039] 1. Door sill beam; 2. Battery pack body; 3. Battery pack frame; 7. Rear subframe; 8. Rear floor;

[0040] 301, side beam; 302, front beam; 303, rear beam; 304, oblique beam; 305, battery pack cross beam; 306, battery pack rear cross beam; 307, bulge; 308, partition; 309, compartment;

[0041] 701, front cross member of rear subframe; 702, rear cross member of rear subframe; 703, longitudinal member of rear subframe;

[0042] 801. Front cross member of rear floor; 802. Middle cross member of rear floor; 803. Rear cross member of rear floor; 804. Longitudinal member of rear floor; 8041. Reinforcement plate; 8042. Reinforcement rib; 8043. Threaded sleeve; 805. Front flange. DETAILED DESCRIPTION

[0043] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0044] In describing the present invention, it should be noted that the directional terms used in this embodiment, such as "up, down, left, right, front, and rear," are defined with reference to the up-down, left-right, and front-to-back directions of the vehicle. The up-down direction of the vehicle is also the vehicle's height direction (Z direction), the front-to-back direction of the vehicle is also the vehicle's length direction (X direction), and the left-to-right direction of the vehicle is also the vehicle's width direction (Y direction). Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] Furthermore, in the description of the present invention, unless otherwise expressly defined, the terms "mounted," "connected," "connect," and "connector" should be interpreted broadly. For example, these terms may refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will appreciate the specific meanings of these terms in the present invention based on the specific circumstances.

[0046] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0047] This embodiment relates to an underbody structure comprising an underbody frame 100, a rear subframe 7 disposed below the underbody frame 100, and a battery pack 200. The underbody frame 100 includes left and right rear floor longitudinal beams 804 and a rear floor center cross member 802 connecting the two rear floor longitudinal beams 804. The battery pack 200 includes a battery pack frame 3 and a battery pack body 2 disposed within the battery pack frame 3.

[0048] The rear end of the battery pack frame 3 extends below the rear floor center cross member 802. The rear subframe 7 has a rear subframe front cross member 701 located near the battery pack 200. The left and right ends of the rear subframe front cross member 701 are connected to the battery pack frame 3 and the rear floor center cross member 802. The rear floor center cross member 802 and the rear subframe front cross member 701 are connected to form a first ring structure A, and the rear floor center cross member 802 and the battery pack 200 are connected to form a second ring structure B.

[0049] The lower vehicle body structure described in this embodiment is provided with the left and right ends of the front cross beam 701 of the rear subframe connected to the battery pack frame 3 and the rear floor middle cross beam 802, and the rear floor middle cross beam 802 and the front cross beam 701 of the rear subframe are connected to form a first ring structure A, and the rear floor middle cross beam 802 and the battery pack 200 are connected to form a second ring structure B, which can improve the local and overall rigidity of the vehicle, and a force transmission channel between the battery pack frame 3 and the rear subframe 7 can be added on the left and right sides of the vehicle body, which can better improve the collision resistance of the vehicle.

[0050] Based on the above overall introduction, an exemplary structure of the lower vehicle body structure in this embodiment is as follows: Figures 1 to 3 As shown in the figure, the rear floor 8, viewed from front to back, comprises a front portion at the front end, a rear portion at the rear end, and a middle portion connecting the front and rear portions. The front portion is lower than the rear portion in the vertical direction of the vehicle, and the middle portion is tilted in the longitudinal direction of the vehicle. The rear subframe front cross member 701 and the rear end of the battery pack frame 3 are both located below the middle portion. Rear floor longitudinal beams 804 follow the shape of the rear floor 8 and are located below the left and right sides.

[0051] like Figure 2 As shown in FIG, corresponding to the front portion of the rear floor 8, the outer front end of the rear floor longitudinal beam 804 is connected to the inner rear end of the rocker beam 1. The two beams overlap along the length of the vehicle, enhancing the connection strength between them and, consequently, the continuous transmission of collision forces. In this embodiment, each rear floor longitudinal beam 804 has a "U"-shaped cross-section with an upward-facing opening. Connected to the bottom of the rear floor 8, the opening is sealed by the rear floor 8, and a longitudinal beam cavity is formed within each rear floor longitudinal beam 804, thereby enhancing the structural strength and force transmission of the rear floor longitudinal beams 804. The spacing between the two rear floor longitudinal beams 804 gradually decreases from front to rear to accommodate the specifications of the rear subframe 7, thereby facilitating the connection between the rear end of the rear subframe 7 and the rear floor longitudinal beams 804.

[0052] Still refer to Figure 2 and Figure 4As shown in FIG, a bulge 307 is provided at the top of the rear end of the battery pack 200. The rear floor middle crossbeam 802 corresponds to the upper portion of the rear end of the battery pack frame 3 and is connected between the inner sides of the rear floor longitudinal beams 804 on both sides. The front side of the rear floor middle crossbeam 802 is connected to the rear side of the bulge 307. The cross section of the rear floor middle crossbeam 802 is a "U" shape with the opening facing upward. The opening is blocked by the middle portion of the rear floor 8, forming a crossbeam cavity between the rear floor middle crossbeam 802 and the middle portion of the rear floor 8, thereby improving the structural strength and force transmission effect of the rear floor middle crossbeam 802. In addition, the left and right sides of the bulge 307 are respectively connected to the inner sides of the rear floor longitudinal beams 804 on the same side, which helps to improve the connection strength between the battery pack 200 and the rear floor 8.

[0053] like Figure 5 As shown in the figure, the two ends of the front cross beam 701 of the rear subframe are arranged tilted outward in the front-to-back direction of the vehicle, so that the distance between the two ends of the front cross beam 701 of the rear subframe gradually decreases from the front to the rear. This arrangement is beneficial to the connection between the front cross beam 701 of the rear subframe and the battery pack frame 3 and the rear floor middle cross beam 802.

[0054] As a preferred embodiment, a threaded sleeve 8043 is provided on the rear floor longitudinal beam 804, and the rear side beam 303 and the rear subframe front crossbeam 701 are screwed together with the threaded sleeve 8043 via bolts. Here, the rear side beam 303 and the rear subframe front crossbeam 701 are screwed together with the threaded sleeve 8043 via bolts, which not only facilitates the connection between the rear floor center crossbeam 802 and the rear side beam 303 and the rear subframe front crossbeam 701, but also simplifies the connection structure and provides good connection strength.

[0055] In terms of detailed structure, Figure 6 As shown in FIG, to facilitate the placement of the threaded sleeve 8043, a reinforcement plate 8041 is provided within the rear floor longitudinal beam 804. The reinforcement plate 8041 is connected to the left and right sidewalls of the rear floor longitudinal beam 804. The reinforcement plate 8041 is box-shaped and forms a cavity with the rear floor longitudinal beam 804. The threaded sleeve 8043 passes through the reinforcement plate 8041. The box-shaped reinforcement plate 8041 within the rear floor longitudinal beam 804 and the cavity formed by the reinforcement plate 8041 and the rear floor longitudinal beam 804 enhance the structural strength of the rear floor longitudinal beam 804, thereby improving the rigidity and crashworthiness of the entire vehicle.

[0056] In this embodiment, the reinforcing plates 8041 are provided corresponding to the two ends of the rear floor center cross beam 802. The four sides of the reinforcing plates 8041 are connected to the inner walls of the rear floor longitudinal beams 804, and the above-mentioned cavity is formed between the bottom of the reinforcing plates 8041 and the rear floor longitudinal beams 804. This is conducive to improving the connection strength, thereby improving the installation strength of the threaded sleeve 8043, and also helping to improve the connection strength between the rear floor center cross beam 802 and the floor longitudinal beams.

[0057] In addition, if Figure 6 As shown in the figure, the reinforcing plate 8041 is provided with multiple reinforcing ribs 8042 arranged radially along the circumference of the threaded sleeve 8043 to further enhance the installation strength and connection reliability of the threaded sleeve 8043 on the reinforcing plate 8041. Bolts pass from bottom to top through the battery pack frame 3, the rear subframe front crossbeam 701, and are threadedly connected to the threaded sleeve 8043, thereby achieving a reliable connection between the rear side rail 303 and the rear subframe front crossbeam 701.

[0058] In this embodiment, the rear floor middle cross member 802 can be connected to the rear subframe front cross member 701 and the rear side member 303 through the rear floor longitudinal member 804 by screwing the bolts and the threaded sleeve 8043, thereby forming Figure 6 and Figure 7 The first ring structure A and the second ring structure B in the vehicle are arranged up and down in the height direction of the vehicle, which is beneficial to improving the dispersion and transmission effect of the collision force between the rear floor middle crossbeam 802, the battery pack frame 3 and the rear subframe front crossbeam 701, thereby improving the collision safety of the rear part of the lower body frame 100 and the battery pack 200.

[0059] Furthermore, the two side walls of the rear floor longitudinal beam 804 for installing the reinforcing plate 8041 are convex in the left and right directions of the vehicle, which is conducive to increasing the installation space of the reinforcing plate 8041, and then helping to improve the specifications and strength of the reinforcing plate 8041, thereby helping to improve the reliability of the reinforcing plate 8041 in the connected state, and then helping to ensure the connection stability between the bolt and the threaded sleeve 8043.

[0060] As a preferred Figures 8 to 11 As shown in , the lower vehicle body frame 100 in this embodiment includes rocker beams 1 disposed on both sides. The battery pack frame 3 includes a rear side beam 303, side beams 301 disposed on both sides of the rear side beam 303, and a diagonal beam 304 connecting the rear side beam 303 and the corresponding side beam 301. As shown above, the rocker beam 1 is connected to the outside of the corresponding rear floor longitudinal beam 804, the side beam 301 is connected to the bottom of the corresponding rocker beam 1, and the diagonal beam 304 is connected to the rear subframe front crossbeam 701 and the rear floor middle crossbeam 802. Together with the rear floor longitudinal beam 804 and the rocker beam 1, it forms a third annular structure C.

[0061] Here, the side beam 301 is connected to the bottom of the corresponding side rocker beam 1, the oblique beam 304 is connected to the front crossbeam 701 of the rear subframe and the middle crossbeam 802 of the rear floor, and is formed together with the rear floor longitudinal beam 804 and the rocker beam 1 to form a third ring structure C, which can make the connection structure between the rear floor 8 frame and the rocker beam 1 more stable and help improve the torsional stiffness of the vehicle. The setting of the third ring structure C is also conducive to further improving the transmission and dispersion of collision forces.

[0062] The third annular structure C in this embodiment is arranged on the left and right sides of the first annular structure A and the second annular structure B, and can cooperate with the first annular structure A and the stacked annular structure to improve the connection strength between the rear subframe 7 and the battery pack frame 3 and the rocker beam 1, and enhance the dispersion and transmission of collision force in the front-to-rear direction and the left-to-right direction of the vehicle.

[0063] As a preferred embodiment, Figure 3 As shown in the figure, the side rails 301 extend from the front end of the rocker beam 1 to the rear end. Here, the length of the side rails 301 is made equal to that of the rocker beam 1, which helps increase the size of the battery pack 200 in the vehicle's fore-aft direction. This not only further increases the capacity of the battery pack 200, but also improves the rigidity and crashworthiness of the lower body structure. Furthermore, the height of the side rails 301 is the same as that of the battery pack body 2. This arrangement helps increase the overall size of the battery pack 200 in the vehicle's fore-aft direction, thereby improving its crashworthiness and making the battery cells safer.

[0064] Furthermore, the battery pack frame 3 has a uniform cross-section across all parts, and has multiple force transmission channels within it. Each of these channels is annular and arranged along the circumference of the battery pack frame 3. This uniform cross-section across all parts of the battery pack frame 3 and the presence of multiple annular force transmission channels within the frame give the battery pack frame 3 superior structural strength and force transmission performance, improving its crashworthiness.

[0065] Specifically, the side beams 301, front beams 302, rear beams 303, and diagonal beams 304 each contain multiple cavities arranged sequentially along their widths, each extending along the length of the beam. Furthermore, each cavity is provided with multiple partitions 308 arranged in a staggered pattern, dividing the cavity into multiple stacked sub-cavities 309. The multiple cavities within the beams, and the partitions 308 dividing the cavity into stacked sub-cavities 309, provide the battery pack frame 3 with superior structural strength and force transmission performance, improving its crashworthiness.

[0066] It should be noted that the identical cross-sections of the various parts of the battery pack frame 3 refer to the following: the cross-sectional shapes of the side beams 301, the front beams 302, the rear beams 303, and the diagonal beams 304 are identical, and the sub-cavities 309 within the side beams 301, the front beams 302, the rear beams 303, and the diagonal beams 304 can be connected, thereby forming a plurality of the aforementioned annular force transmission channels. The multiple annular force transmission channels are arranged in the width and height directions of the battery pack frame 3. They are arranged along the circumference of the battery pack frame 3, which can greatly enhance the structural strength and collision resistance of the battery pack frame 3. At the same time, the collision energy is absorbed by the multiple force transmission channels, which helps to reduce the collision force transmitted to the battery pack body 2, thereby improving the safety of the battery cells in the battery pack 200.

[0067] As a preferred embodiment, Figure 7 and Figure 12 As shown in FIG, the rear subframe 7 includes a rear subframe rear cross member 702 spaced apart from the rear subframe front cross member 701, and longitudinal members of the rear subframe 7 connected between the rear subframe front cross member 701 and the left and right sides of the rear subframe rear cross member 702. The left and right sides of the rear subframe rear cross member 702 are respectively connected to the rear floor longitudinal members 804 on the corresponding sides, forming a fourth annular structure D between the rear subframe front cross member 701, the rear subframe rear cross member 702, the longitudinal members of the rear subframe 7, and the rear floor longitudinal members 804.

[0068] In this embodiment, a fourth annular structure D is formed between the front cross member 701 of the rear subframe, the rear cross member 702 of the rear subframe, the longitudinal beams of the rear subframe, and the longitudinal beams 804 of the rear floor. This structure can further enhance the strength and rigidity of the vehicle and form a force transmission ring, thereby dispersing collision energy and squeezing force on the vehicle, thereby improving the crashworthiness of the vehicle.

[0069] Furthermore, a fifth annular structure, formed by the rear floor center cross member 802, rear floor longitudinal members 804, and rear floor rear cross member 803, is located above the fourth annular structure D. The fourth and fifth annular structures, working together, enhance force transmission between the rear floor 8 and the rear subframe 7.

[0070] like Figure 12As shown in FIG, in the left-right direction of the vehicle, the longitudinal beams of the rear subframe 7 are located inboard of the rear floor longitudinal beam 804 on the same side. In the front-to-back direction of the vehicle, the front crossbeam 701 of the rear subframe is located behind the middle crossbeam 802 of the rear floor. The ends of the rear crossbeam 702 of the rear subframe are also tilted outward, so that the distance between the ends of the rear crossbeam 702 gradually increases from front to back. This facilitates the connection between the rear crossbeam 702 and the rear floor rear crossbeam 803 described below. Furthermore, the middle portion of the longitudinal beams of the rear subframe 7 is arched upward, leveraging the higher structural strength of the arched structure to further enhance the strength and force transmission performance of the longitudinal beams of the rear subframe 7.

[0071] The aforementioned fourth annular structures D are located on either side of the fifth annular structure. These multiple annular structures work together to further block the dispersion and transmission of collision forces in the left-right and front-back directions of the vehicle, resulting in improved collision safety. Furthermore, these multiple annular structures enhance both local and overall vehicle rigidity.

[0072] In order to improve the transmission effect of the rear subframe 7 on the collision force, Figure 7 As shown in FIG, the spacing between the front ends of the two rear subframe longitudinal beams 703 is gradually reduced from front to rear. This facilitates receiving collision forces transmitted from the front and guiding the collision forces to be absorbed by the rear subframe 7 and then dispersed and transmitted rearward, thereby improving the safety of the rear subframe 7. Furthermore, the spacing between the rear ends of the two rear subframe longitudinal beams 703 is gradually increased from front to rear. This facilitates guiding the collision forces rearward while dispersing them, achieving a better dispersion effect.

[0073] Furthermore, the lower vehicle body frame 100 includes a rear floor rear cross member 803 connected between two rear floor longitudinal members 804. The left and right sides of the rear subframe rear cross member 702 are disposed below the rear floor rear cross member 803 and are connected to both the rear floor rear cross member 803 and the rear floor longitudinal members 804. The simultaneous connection of the rear subframe rear cross member 702 with the rear floor rear cross member 803 and the rear floor longitudinal members 804 further enhances the strength and rigidity of the vehicle.

[0074] In terms of detailed structure, Figure 3 As shown in the figure, the rear floor rear cross member 803 is located at the rear of the rear floor 8, and a cavity is formed between the rear floor rear cross member 803 and the rear floor 8 to improve force transmission. In the left-right direction of the vehicle, both ends of the rear floor rear cross member 803 extend outward to the bottom of the rear floor longitudinal member 804 on the same side, where they are connected to the rear floor longitudinal member 804. This arrangement helps to improve the structural strength of the rear floor 8 and its ability to withstand collision forces.

[0075] To facilitate the connection between the rear floor rear cross member 803 and the rear subframe 7. Figure 3 As shown in FIG, the rear end of the longitudinal beam of the rear subframe 7 is connected to a connecting sleeve. Bolts pass through the connecting sleeve and the bottom of the rear floor rear cross member 803 and are then connected to nuts. This connects the rear end of the longitudinal beam of the rear subframe 7 to the bottom of the rear floor rear cross member 803. The rear subframe rear cross member 702 is connected to the rear floor rear cross member 803 via the longitudinal beam of the rear subframe 7.

[0076] As a preferred embodiment, Figure 8 and Figure 10 As shown in the figure, the lower body frame 100 includes a floor crossbeam connected between the door sill beams 1 on both sides, and the battery pack body 2 includes a battery pack crossbeam 305 connected between the left and right sides of the battery pack frame 3. The battery pack crossbeam 305 is arranged corresponding to the floor crossbeam above and below and is connected together.

[0077] The battery pack crossbeam 305 is arranged correspondingly to the floor crossbeam above and below and connected together, which can improve the installation strength of the battery pack 200. At the same time, the external force borne by the battery pack 200 can also be transmitted to the floor crossbeam, and they are jointly decomposed and consumed, which can reduce damage to the battery pack 200 and help protect the internal battery cells.

[0078] In terms of detailed structure, the floor cross beams in this embodiment are two spaced apart and connected in the middle between the door sill beams 1 on both sides along the front-to-back direction of the vehicle, and the battery pack cross beam 305 is arranged in a one-to-one correspondence with each floor cross beam. Figure 8 As shown in , for the convenience of distinguishing descriptions, the floor cross member arranged at the front is referred to as the front floor cross member, and the floor cross member arranged at the rear is referred to as the rear floor cross member.

[0079] The front floor beam is provided with a mounting structure for mounting the front seats, and the rear floor beam is provided with a mounting structure for mounting the rear seats. The floor beams in this embodiment are preferably formed by roller pressing, which helps to improve the structural strength and force transmission effect of the rear floor beam 8.

[0080] Preferably, the battery pack crossbeam 305 is detachably connected to the floor crossbeam to facilitate loading and unloading of the battery pack 200. For example, the battery pack crossbeam 305 is bolted to the floor crossbeam. Alternatively, other easily removable connection structures may be employed. Bolts can pass through the battery pack crossbeam 305 and the corresponding floor crossbeam and then be screwed together with nuts, thereby connecting the battery pack crossbeam 305 to the floor crossbeam.

[0081] As a preferred embodiment, Figure 10 As shown in the figure, the structure of the battery pack cross beam 305 in this embodiment is roughly the same as that of the side beam 301, and two cavities are also provided therein. Each cavity is provided with two partitions 308 arranged at intervals along the upper and lower directions of the vehicle, so that each cavity has three sub-cavities 309.

[0082] The high structural strength of the cavity structure and the effective force transmission of the stacked sub-cavities 309 further enhance the structural strength and torsional rigidity of the battery pack cross member 305, thereby improving the collision performance of the side battery pack cross member 305 and the safety of the battery pack 200. Furthermore, the provision of sub-cavities 309 within the battery pack cross member 305 also helps reduce the weight of the battery pack 200, thereby contributing to the lightweight design of the lower body structure.

[0083] In addition, if Figure 2 and Figure 13 As shown in the figure, a rear floor front cross beam 801 is provided below the front end of the rear floor 8, and both ends of the rear floor front cross beam 801 are respectively connected to the front end of the rear floor longitudinal beam 804. The cross section of the rear floor front cross beam 801 is "L"-shaped, and has a horizontal portion connected to the top surface of the battery pack body 2, and a vertical portion connected to the front side wall of the bulge 307. The front end of the rear floor 8 is also provided with a downwardly folded front flange 805, and the front end of the rear floor 8 can also form a cross beam cavity with the rear floor front cross beam 801 through the front flange 805. The provision of the rear floor front cross beam 801 here can increase the force transmission path strength in the left and right directions of the entire vehicle, thereby helping to improve the force transmission effect of the collision force at the rear of the vehicle body.

[0084] In this embodiment, the front and rear sides of the bulge 307 are respectively connected to the front crossbeam 801 and the middle crossbeam 802 of the rear floor, and the left and right sides are respectively connected to the longitudinal beam 804 of the rear floor, which is conducive to further improving the connection strength between the bulge 307 and the rear floor 8, thereby improving the connection reliability between the battery pack 200 and the rear floor 8 during the force transmission process.

[0085] Further, such as Figure 10 As shown, the battery pack rear cross member 306, located below the rear floor front cross member 801, is connected between the side beams 301 on both sides. The battery pack rear cross member 306 is connected to the rear floor front cross member 801 by bolts and nuts passing through the battery pack rear cross member 306 and the rear floor front cross member 801. This arrangement further enhances the connection between the rear portion of the battery pack 200 and the rear floor 8.

[0086] In this embodiment, the underbody structure absorbs, distributes, and transmits collision forces backward to the rear floor 8 and the rear portion of the battery pack 200 via the first, second, and third annular structures A, B, and C, mitigating the impact force. Furthermore, the fourth and fifth annular structures D and D, along with the rear floor longitudinal beams 804, rear floor rear cross beams 803, and rear floor front cross beams 801, disperse and transmit collision forces simultaneously in the fore-aft, left-right, and up-and-down directions of the vehicle. This enhances the structural strength of the rear underbody structure and, in turn, improves the safety of the battery pack 200 and the vehicle as a whole.

[0087] In addition, this embodiment also relates to a vehicle, which is provided with the above-mentioned lower body structure. The vehicle in this embodiment, by providing the above-mentioned lower body structure, is conducive to improving the safety of the battery pack 200 and the vehicle.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lower vehicle body structure, characterized in that: It comprises a lower vehicle body frame (100), and a rear sub-frame (7) and a battery pack (200) arranged below the lower vehicle body frame (100); The lower vehicle body frame (100) includes rear floor longitudinal beams (804) disposed on the left and right sides, and a rear floor middle cross beam (802) connected between the rear floor longitudinal beams (804) on both sides; the battery pack (200) includes a battery pack frame (3) and a battery pack body (2) disposed within the battery pack frame (3); and the rear end of the battery pack frame (3) extends below the rear floor middle cross beam (802); and the rear subframe (7) has a rear subframe front cross beam (701) adjacent to the battery pack (200); The left and right ends of the front cross beam (701) of the rear subframe are both connected to the battery pack frame (3) and the rear floor middle cross beam (802), and the rear floor middle cross beam (802) and the front cross beam (701) of the rear subframe are connected to form a first annular structure (A), and the rear floor middle cross beam (802) and the battery pack (200) are connected to form a second annular structure (B).

2. The lower vehicle body structure according to claim 1, characterized in that: The lower vehicle body frame (100) includes door sill beams (1) disposed on the left and right sides, and the battery pack frame (3) includes a rear side beam (303), side beams (301) disposed on the left and right sides of the rear side beam (303), and an oblique beam (304) connected between the rear side beam (303) and the side beams (301) on the corresponding side. The threshold beam (1) is connected to the outside of the rear floor longitudinal beam (804) on the corresponding side, the side beam (301) is connected below the threshold beam (1) on the corresponding side, the oblique beam (304) is connected to the front cross beam (701) of the rear subframe and the middle cross beam (802) of the rear floor, and is formed with the rear floor longitudinal beam (804) and the threshold beam (1) to form a third annular structure (C).

3. The lower vehicle body structure according to claim 2, wherein: The side beam (301) extends from the front end of the door sill beam (1) to the rear end of the door sill beam (1); and / or, The height of the side beam (301) is the same as the height of the battery pack body (2).

4. The lower vehicle body structure according to claim 2, wherein: A threaded sleeve (8043) is provided on the rear floor longitudinal beam (804); The rear side beam (303) and the rear subframe front cross beam (701) are screwed to the threaded sleeve (8043) via bolts.

5. The lower vehicle body structure according to claim 4, characterized in that: A reinforcing plate (8041) is provided in the rear floor longitudinal beam (804), and the reinforcing plate (8041) is connected between the left and right side walls of the rear floor longitudinal beam (804); The reinforcing plate (8041) is box-shaped and forms a cavity with the rear floor longitudinal beam (804), and the threaded sleeve (8043) passes through the reinforcing plate (8041).

6. The lower vehicle body structure according to claim 1, characterized in that: The cross-sections of various parts of the battery pack frame (3) are the same; The battery pack frame (3) has a plurality of force transmission channels inside, and each of the force transmission channels is annular and arranged along the circumference of the battery pack frame (3).

7. The lower vehicle body structure according to claim 1, characterized in that: The rear subframe (7) comprises a rear subframe rear crossbeam (702) spaced apart from the rear subframe front crossbeam (701), and a rear subframe longitudinal beam (703) connected between the rear subframe front crossbeam (701) and the left and right sides of the rear subframe rear crossbeam (702); The left and right sides of the rear subframe rear cross beam (702) are respectively connected to the rear floor longitudinal beam (804) on the corresponding sides, and a fourth annular structure (D) is formed between the rear subframe front cross beam (701), the rear subframe rear cross beam (702), the rear subframe longitudinal beam (703) and the rear floor longitudinal beam (804).

8. The lower vehicle body structure according to claim 7, characterized in that: The lower vehicle body frame (100) includes a rear floor rear cross beam (803) connected between the rear floor longitudinal beams (804) on both sides. The left and right sides of the rear subframe rear cross beam (702) are arranged below the rear floor rear cross beam (803) and are connected to the rear floor rear cross beam (803) and the rear floor longitudinal beam (804) at the same time.

9. The lower vehicle body structure according to any one of claims 2 to 5, characterized in that: The lower vehicle body frame (100) includes a floor crossbeam connected between the door sill beams (1) on both sides, and the battery pack body (2) includes a battery pack crossbeam (305) connected between the left and right sides of the battery pack frame (3); The battery pack crossbeam (305) and the floor crossbeam are arranged correspondingly up and down and connected together.

10. A vehicle, characterized in that: The vehicle is provided with the lower vehicle body structure according to any one of claims 1 to 9.

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