A lower vehicle body structure and a vehicle capable of improving mounting point dynamic stiffness of a trailing arm

Abstract

This utility model provides a lower body structure and automobile for improving the dynamic stiffness of trailing arm mounting. The lower body structure includes: a lower body frame and a pair of trailing arm mounting assemblies, which are mounted on the front of the lower body frame. The lower body frame includes: a pair of longitudinal beams, a front crossbeam, a rear crossbeam, and a rear side beam of the battery pack. The pair of trailing arm mounting assemblies are respectively mounted on the front of the pair of longitudinal beams; the front crossbeam is connected to the front of the pair of longitudinal beams, and both ends of the front crossbeam gradually widen from the inside to the outside of the lower body frame; the rear crossbeam is connected to the middle of the pair of longitudinal beams; the rear side beam of the battery pack is connected to the upper surface of the front crossbeam. The gradually widening structure at both ends of the front crossbeam forms a "diffusion" force transmission path at both ends of the front crossbeam under collision or trailing arm load, reducing stress concentration and improving the overall stiffness of the trailing arm mounting position.

Description

Technical Field

[0001] This utility model belongs to the field of bicycle technology, and more specifically, relates to a lower body structure and automobile that improves the dynamic stiffness of the trailing arm mounting point. Background Technology

[0002] With the rapid development of new energy vehicles, especially pure electric vehicles, the noise level of vehicle powertrain systems has been significantly reduced, and the noise and vibration problems related to traditional internal combustion engines are no longer the main issue. Instead, noise and vibration caused by road surface excitation have gradually become one of the core challenges affecting the overall NVH performance of vehicles.

[0003] In pure electric vehicles, due to the lack of engine noise masking effect, vibrations and noises transmitted from the road surface to the vehicle body via the tires and suspension system are more easily perceived by the driver and passengers, especially on rough roads or at high speeds, where road noise is particularly prominent. Research indicates that the connection point between the trailing arm and the vehicle body in the rear suspension system is one of the key paths for the transmission of road vibrations into the vehicle interior. The dynamic stiffness of this connection point directly determines the efficiency of the transmission of road vibrations to the vehicle body, thus affecting the vibration level inside the vehicle and structural radiated noise. Insufficient dynamic stiffness at the trailing arm connection point can cause road vibrations to be transmitted to the vehicle body via the tire-suspension or subframe, resulting in steering wheel vibration, seat vibration, and a rumbling sound inside the vehicle, especially exacerbated on rough roads or at high speeds. Therefore, increasing the dynamic stiffness of the trailing arm connection point can effectively reduce the transmission of road vibrations into the vehicle interior, thereby reducing the risk of vibration-radiated noise from body panels, improving the comfort of the driver and rear passengers, and enhancing the vehicle's NVH performance.

[0004] Traditional methods for improving the dynamic stiffness of the trailing arm mounting point mainly include: increasing the thickness of the local structure or the number of reinforcing components; using high-strength steel or castings; and optimizing the force transmission path near the mounting point to form a "ring" or "closed cavity" structure to enhance local stiffness. However, in the skateboard platform architecture, the upper and lower bodies are usually decoupled and modularly assembled by bolting. While this structural form is beneficial for platformization and battery pack placement, it also brings new challenges: the lower body structure has limited space, making it difficult to arrange a traditional "ring" closed force transmission structure; the structural rigidity near the mounting point is insufficient, making it difficult to effectively resist dynamic loads from the trailing arm; and the connection point between the upper and lower bodies is far from the trailing arm mounting area, making it impossible to form effective overall stiffness support.

[0005] Therefore, under the skateboard platform architecture, there is an urgent need for a new type of lower body longitudinal arm mounting structure that adapts to the characteristics of modular structure and takes into account lightweight and manufacturing feasibility, so as to effectively improve the dynamic stiffness of the mounting point, block the transmission path of road vibration, thereby improving the NVH performance of the whole vehicle and enhancing ride comfort. Utility Model Content

[0006] The purpose of this invention is to provide a lower body structure and automobile that improves the dynamic stiffness of the trailing arm mounting point, thereby solving the problem of mismatch between traditional lower body structures and skateboard platform architecture.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting, comprising: a lower vehicle body frame and a pair of trailing arm mounting assemblies, wherein the pair of trailing arm mounting assemblies are mounted on the front of the lower vehicle body frame.

[0008] The lower vehicle frame includes:

[0009] A pair of longitudinal beams and a pair of said longitudinal arm mounting assemblies are respectively mounted on the front of the pair of said longitudinal beams;

[0010] A front crossbeam, which is connected to the front of a pair of longitudinal beams, and the two ends of the front crossbeam gradually widen from the inside to the outside of the lower body frame;

[0011] A rear crossbeam, which is connected to the middle of a pair of longitudinal beams.

[0012] Optionally, the lower body structure also includes:

[0013] The rear beam of the battery pack is connected to the upper surface of the front crossbeam.

[0014] Optionally, a cavity is formed inside the longitudinal beam;

[0015] The trailing arm mounting assembly includes a support portion and a mounting portion. The support portion is fixedly disposed within the cavity, and the outer periphery of the support portion contacts the inner periphery of the longitudinal beam. The mounting portion is fixedly disposed on the upper surface of the longitudinal beam, and the mounting portion is positioned corresponding to the support portion. The mounting portion is provided with a trailing arm mounting hole.

[0016] Optionally, the lower body structure also includes:

[0017] The first reinforcing plate has its upper part connected to one side surface of the mounting part and its lower part connected to the longitudinal beam.

[0018] The second reinforcing plate has its upper part connected to the other side surface of the mounting part, and its lower part connected to the longitudinal beam.

[0019] Optionally, the lower body structure further includes a third reinforcing plate, the upper part of which is connected to the second reinforcing plate, and the lower part of which is connected to the longitudinal beam.

[0020] Optionally, the width of the mounting part is smaller than the width of the front part of the longitudinal beam, one side surface of the mounting part is flush with one side surface of the longitudinal beam, the other side surface of the mounting part forms a stepped shape with the other side surface of the longitudinal beam, the second reinforcing plate is L-shaped, and the third reinforcing plate is stepped.

[0021] Optionally, the front crossbeam is a hollow structure, comprising a left section, a middle section, and a right section connected in sequence, wherein the wall thickness of the left section and the right section is greater than the wall thickness of the middle section.

[0022] Optionally, the mounting part is shaped like a winnowing basket.

[0023] Optionally, both ends of the front crossbeam are triangular.

[0024] Optionally, the longitudinal beam includes a base plate and a cover plate, the cover plate has an inverted U-shaped cross-section, the base plate is connected below the cover plate, and the cavity is formed between the base plate and the cover plate.

[0025] Secondly, this utility model provides an automobile, including the lower body structure described in the first aspect for improving the dynamic stiffness of the trailing arm mounting point.

[0026] The beneficial effects of this utility model are as follows: It provides a lower vehicle body structure that improves the dynamic stiffness of the trailing arm mounting, comprising: a lower vehicle frame and a pair of trailing arm mounting assemblies, the pair of trailing arm mounting assemblies being mounted on the front of the lower vehicle frame. The lower vehicle frame includes: a pair of longitudinal beams, a front crossbeam, a rear crossbeam, and a rear side beam of the battery pack. The pair of trailing arm mounting assemblies are respectively mounted on the front of the pair of longitudinal beams; the front crossbeam is connected to the front of the pair of longitudinal beams, and the two ends of the front crossbeam gradually widen from the inside to the outside of the lower vehicle frame; the rear crossbeam is connected to the middle of the pair of longitudinal beams; the rear side beam of the battery pack is connected to the upper surface of the front crossbeam. The gradually widening structure at both ends of the front crossbeam forms a "diffusion" force transmission path at both ends of the front crossbeam under collision or trailing arm load, reducing stress concentration and improving the overall stiffness of the trailing arm mounting position.

[0027] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0028] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally represent like parts.

[0029] Figure 1 The diagram shows a schematic structural diagram of the lower vehicle body structure of Embodiment 1 of this utility model, excluding the dynamic stiffness of the lifting longitudinal arm mounting point of the rear side beam of the battery pack.

[0030] Figure 2 The diagram shows a schematic structural diagram of the lower vehicle body structure of Embodiment 1 of the present invention, including the lifting longitudinal arm mounting point dynamic stiffness of the rear side beam of the battery pack.

[0031] Figure 3 A schematic structural diagram of the rear beam of the battery pack according to Embodiment 1 of this utility model is shown.

[0032] Figure 4 A schematic structural diagram of the longitudinal beam of Embodiment 1 of this utility model is shown.

[0033] Figure 5 A schematic structural diagram of the cover plate of Embodiment 1 of this utility model is shown.

[0034] Figure 6 A schematic structural diagram of the base plate of Embodiment 1 of this utility model is shown.

[0035] Figure 7 A schematic structural diagram of the support portion of Embodiment 1 of this utility model is shown, showing the support portion mounted on the base plate.

[0036] Figure 8 A schematic structural diagram of the front support plate of Embodiment 1 of this utility model is shown.

[0037] Figure 9 A schematic structural diagram of the rear support plate of Embodiment 1 of this utility model is shown.

[0038] Figure 10 One of the schematic structural diagrams of the mounting part, the first reinforcing plate and the second reinforcing plate of Embodiment 1 of the present invention is shown.

[0039] Figure 11 The second schematic structural diagram shows the mounting part, the first reinforcing plate and the second reinforcing plate of Embodiment 1 of this utility model mounted on the longitudinal beam.

[0040] Figure 12 A schematic structural diagram of the mounting portion of Embodiment 1 of this utility model is shown.

[0041] Figure 13 A schematic structural diagram of the first reinforcing plate of Embodiment 1 of this utility model is shown.

[0042] Figure 14 A schematic structural diagram of the second reinforcing plate of Embodiment 1 of this utility model is shown.

[0043] Figure 15 A schematic structural diagram of the mounting part, first reinforcing plate, second reinforcing plate and third reinforcing plate of Embodiment 1 of the present invention is shown.

[0044] Figure 16A schematic structural diagram of the third reinforcing plate of Embodiment 1 of this utility model is shown.

[0045] Explanation of reference numerals in the attached figures:

[0046] 1. Lower body frame; 11. Longitudinal beam; 11a. Floor plate; 11b. Cover plate; 12. Front crossbeam; 12a. Left section; 12b. Middle section; 12c. Right section; 13. Rear crossbeam;

[0047] 2. Trailing arm mounting assembly; 21. Support section; 21a. Front support plate; 21b. Rear support plate; 22. Mounting section; 23. First reinforcing plate; 24. Second reinforcing plate; 25. Third reinforcing plate;

[0048] 3. Rear beam of battery pack. Detailed Implementation

[0049] Preferred embodiments of the present invention will now be described in more detail. While preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0050] Example 1

[0051] like Figure 1 As shown, this embodiment provides a lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting, including: a lower vehicle body frame 1 and a pair of trailing arm mounting assemblies 2, wherein the pair of trailing arm mounting assemblies 2 are mounted on the front of the lower vehicle body frame 1;

[0052] The lower body frame 1 includes:

[0053] A pair of longitudinal beams 11 and a pair of longitudinal arm mounting assemblies 2 are respectively installed at the front of the pair of longitudinal beams 11;

[0054] The front crossbeam 12 is connected to the front of a pair of longitudinal beams 11. The two ends of the front crossbeam 12 gradually widen from the inside to the outside of the lower body frame 1.

[0055] The rear crossbeam 13 is connected to the middle of a pair of longitudinal beams 11;

[0056] In this embodiment, both ends of the front crossbeam 12 are triangular, and the crossbeam is wide V-shaped.

[0057] Specifically, the gradually widening structure at both ends of the front crossbeam 12 forms a "diffusion" force transmission path at both ends of the front crossbeam 12 under collision or trailing arm load, reducing stress concentration and improving the overall rigidity of the trailing arm installation position.

[0058] Optionally, such asFigure 2 and 3 As shown, the lower body structure also includes a rear side beam 3 of the battery pack, which is connected to the upper surface of the front crossbeam 12.

[0059] In this embodiment, the rear beam 3 of the battery pack and the crossbeam are arranged according to the shape, and the rear beam 3 of the battery pack is also wide V-shaped. The rear beam 3 of the battery pack is connected to the front crossbeam 12 by bolts.

[0060] Specifically, the rear side beam 3 of the battery pack is connected to the upper surface of the front crossbeam 12, and the overall rigidity of the longitudinal arm mounting position is further improved by means of the rear side beam 3 of the battery pack.

[0061] Optionally, such as Figures 4-6 As shown, a cavity is formed inside the longitudinal beam 11; preferably, the longitudinal beam 11 includes a bottom plate 11a and a cover plate 11b, the cover plate 11b has an inverted U-shaped cross section, the bottom plate 11a is connected to the bottom of the cover plate 11b, and a cavity is formed between the bottom plate 11a and the cover plate 11b.

[0062] like Figures 7-12 As shown, the longitudinal arm mounting assembly 2 includes a support part 21 and a mounting part 22. The support part 21 is fixedly disposed in the cavity, and the outer periphery of the support part 21 contacts the inner periphery of the longitudinal beam 11. The mounting part 22 is fixedly disposed on the upper surface of the longitudinal beam 11, and the mounting part 22 is positioned corresponding to the support part 21. The mounting part 22 is provided with a longitudinal arm mounting hole.

[0063] Specifically, the support 21 is embedded inside the cavity of the longitudinal beam 11, effectively distributing the longitudinal arm load to the entire longitudinal beam 11, rather than relying solely on local welding or bolt connections. This reduces local stress concentration and improves the three-dimensional dynamic stiffness of the longitudinal arm mounting point in the X, Y, and Z directions. The inverted U-shaped cover plate 11b and the base plate 11a form a closed cavity, allowing for flexible arrangement of reinforcing structures within the cavity. Compared to the traditional one-piece longitudinal beam 11, it is easier to achieve precise positioning and welding of the internal support 21, reducing manufacturing difficulty and cost while maintaining high rigidity.

[0064] In this embodiment, the support part 21 includes a front support plate 21a and a rear support plate 21b. The rear support plate 21b has an inverted "V" shaped flange on one side that is screwed to the bottom surface of the rear longitudinal beam 11, and the flange on the other side is welded to the front support plate 21a. The front support plate 21a is welded to the longitudinal beam 11 on three sides.

[0065] Optionally, such as Figure 10 , 11 As shown in 13 and 14, the lower body structure also includes:

[0066] The first reinforcing plate 23 has its upper part connected to one side surface of the mounting part 22, and its lower part connected to the longitudinal beam 11.

[0067] The upper part of the second reinforcing plate 24 is connected to the other side surface of the mounting part 22, and the lower part of the second reinforcing plate 24 is connected to the longitudinal beam 11.

[0068] Specifically, the first reinforcing plate 23 and the second reinforcing plate 24 are arranged opposite to each other on both sides of the mounting part 22 to effectively resist the lateral and torsional loads brought by the trailing arm, further improve the overall dynamic stiffness of the trailing arm mounting position, thereby achieving vibration isolation from road surface excitation and improving the ride comfort inside the vehicle.

[0069] In this embodiment, the first reinforcing plate 23 is designed with local longitudinal reinforcing ribs and is partially wrapped around the mounting part 22 and the longitudinal beam 11 by welding; the second reinforcing plate 24 is L-shaped, with its vertical surface welded to the mounting part 22 and its flange welded to the longitudinal beam 11 and connected by two-point screws.

[0070] Optionally, such as Figure 15 and 16 As shown, the lower body structure also includes a third reinforcing plate 25, the upper part of which is connected to the second reinforcing plate 24, and the lower part of which is connected to the longitudinal beam 11.

[0071] Specifically, the third reinforcing plate 25 further transfers the load to the bottom plate 11a of the longitudinal beam 11, forming a three-level force transmission path, which significantly improves the local stiffness.

[0072] Optionally, the width of the mounting part 22 is smaller than the width of the front part of the longitudinal beam 11, one side surface of the mounting part 22 is flush with one side surface of the longitudinal beam 11, and the other side surface of the mounting part 22 forms a stepped shape with the other side surface of the longitudinal beam 11. The second reinforcing plate 24 is L-shaped and the third reinforcing plate 25 is stepped.

[0073] Specifically, the combination of the L-shaped second reinforcing plate 24 and the stepped third reinforcing plate 25 balances spatial arrangement and structural efficiency, avoids interference with surrounding components, and achieves both lightweight and high rigidity. The width of the mounting section 22 is less than the width of the longitudinal beam 11, forming a step that provides an overlap step for the third reinforcing plate 25, avoiding stress abrupt changes caused by traditional reinforcing plates, achieving continuous stiffness transition, and reducing the risk of weld fatigue.

[0074] In this embodiment, the third reinforcing plate 25 is a box-shaped structure. The vertical surface of the third reinforcing plate 25 is attached to the vertical surface of the second reinforcing plate 24 and connected by welding points, which further improves the dynamic stiffness of the longitudinal arm installation position.

[0075] Optionally, such as Figure 1 As shown, the front crossbeam 12 is a hollow structure. The front crossbeam 12 includes a left section 12a, a middle section 12b, and a right section 12c connected in sequence. The wall thickness of the left section 12a and the right section 12c is greater than the wall thickness of the middle section 12b.

[0076] Specifically, the design achieves a strength gradient design, reducing weight in non-critical areas and strengthening in critical connection areas, thus balancing lightweight and stiffness.

[0077] Optionally, the mounting part 22 is shaped like a winnowing basket.

[0078] Specifically, the mounting section 22 is shaped like a scoop, forming a "semi-enclosed" box structure, which improves local torsional stiffness and facilitates positioning and error prevention during the installation of the longitudinal arm, thereby improving assembly efficiency.

[0079] Example 2

[0080] This embodiment provides a car, including:

[0081] Example 1: Lower vehicle body structure with improved dynamic stiffness at the mounting point of the longitudinal arm.

[0082] Specifically, the front crossbeam 12 of the vehicle's lower body structure has a gradually widening structure at both ends. Under collision or trailing arm load, the two ends of the front crossbeam 12 form a "diffusion" force transmission path, reducing stress concentration and improving the overall rigidity of the trailing arm mounting position. The rear side beam 3 of the battery pack is connected to the upper surface of the front crossbeam 12. The rear side beam 3 of the battery pack further improves the overall rigidity of the trailing arm mounting position. The structural design is simple and highly universal, and subsequent passenger vehicles can refer to this structure for platform development.

[0083] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting, characterized in that, include: The lower body frame (1) and a pair of trailing arm mounting assemblies (2) are mounted on the front of the lower body frame (1); The lower vehicle frame (1) includes: A pair of longitudinal beams (11) and a pair of longitudinal arm mounting assemblies (2) are respectively mounted on the front of the pair of longitudinal beams (11); A front crossbeam (12) is connected to the front of a pair of longitudinal beams (11), and the two ends of the front crossbeam (12) gradually widen from the inside to the outside of the lower body frame (1). The rear crossbeam (13) is connected to the middle of a pair of longitudinal beams (11).

2. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 1, characterized in that, Also includes: The rear side beam (3) of the battery pack is connected to the upper surface of the front crossbeam (12).

3. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 1, characterized in that, The longitudinal beam (11) has a cavity inside; The longitudinal arm mounting assembly (2) includes a support part (21) and a mounting part (22). The support part (21) is fixedly disposed in the cavity. The outer periphery of the support part (21) contacts the inner periphery of the longitudinal beam (11). The mounting part (22) is fixedly disposed on the upper surface of the longitudinal beam (11). The mounting part (22) is positioned opposite to the support part (21). The mounting part (22) is provided with a longitudinal arm mounting hole.

4. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 3, characterized in that, Also includes: The first reinforcing plate (23) has its upper part connected to one side surface of the mounting part (22) and its lower part connected to the longitudinal beam (11). The upper part of the second reinforcing plate (24) is connected to the other side surface of the mounting part (22), and the lower part of the second reinforcing plate (24) is connected to the longitudinal beam (11). The upper part of the third reinforcing plate (25) is connected to the second reinforcing plate (24), and the lower part of the third reinforcing plate (25) is connected to the longitudinal beam (11).

5. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 4, characterized in that, The width of the mounting part (22) is smaller than the width of the front part of the longitudinal beam (11). One side surface of the mounting part (22) is flush with one side surface of the longitudinal beam (11). The other side surface of the mounting part (22) forms a stepped shape with the other side surface of the longitudinal beam (11). The second reinforcing plate (24) is L-shaped and the third reinforcing plate (25) is stepped.

6. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 1, characterized in that, The front crossbeam (12) is a hollow structure. The front crossbeam (12) includes a left section (12a), a middle section (12b) and a right section (12c) connected in sequence. The wall thickness of the left section (12a) and the right section (12c) is greater than the wall thickness of the middle section (12b).

7. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 3, characterized in that, The mounting part (22) is shaped like a winnowing basket.

8. The lower vehicle body structure for improving the jogging stiffness of the trailing arm mounting according to claim 1, characterized in that, Both ends of the front crossbeam (12) are triangular.

9. The lower vehicle body structure for improving the dynamic stiffness of the trailing arm mounting according to claim 3, characterized in that, The longitudinal beam (11) includes a bottom plate (11a) and a cover plate (11b). The cover plate (11b) has an inverted U-shaped cross section. The bottom plate (11a) is connected to the bottom of the cover plate (11b), and the cavity is formed between the bottom plate (11a) and the cover plate (11b).

10. A car, characterized in that, include: The underbody structure for improving the dynamic stiffness of the trailing arm mounting point as described in any one of claims 1-9.

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