Lower vehicle body structure and vehicle

Abstract

This application relates to a lower body structure and a vehicle. The lower body structure includes a sill beam, a seat crossbeam, and a battery pack. The first and second energy-absorbing zones of the sill beam can fully absorb collision energy, the bending zone provides reliable bending support, and the inclined structure of the load-bearing zone can effectively transfer the collision force to the seat crossbeam, avoiding insufficient performance caused by a single structure bearing all the collision force. The end of the seat crossbeam is fixedly connected to the sill beam and cooperates with the load-bearing zone, enhancing the connection stability between the seat crossbeam and the sill beam and effectively suppressing the upward flipping and bending tendency of the seat crossbeam during a side pole collision. The force of the bending zone can be transferred to the bottom guard plate assembly through the lower shell beam. The supporting functions of the lower shell beam and the bottom guard plate assembly, combined with the supporting function of the seat crossbeam, form a stable force transmission closed loop, improving the overall rigidity and strength of the lower body, preventing the bottom battery pack from being severely squeezed during a side pole collision, and ensuring the safety of the occupants and the battery pack.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a lower body structure and a vehicle. Background Technology

[0002] With the development of automotive manufacturing technology, cell-to-body (CTB) integration technology is gradually being applied to vehicle production, combined with... Figure 1 This technology uses the battery pack 300 cover as a vehicle chassis, optimizing the assembly process. The seat crossbeams 200, sill beams 100, and the bottom structure of the battery pack 300 form a force transmission path to resist collision energy and ensure safety.

[0003] However, CTB technology, which involves welding without a bottom plate, results in a weaker lower body structure compared to the traditional method of welding the seat crossbeams and lower floor together. (Refer to...) Figure 2 When a vehicle is subjected to a side impact, the bottom battery pack 300 is easily severely crushed, which is detrimental to the safety of the driver and passengers. Summary of the Invention

[0004] Therefore, it is necessary to provide a lower body structure and vehicle to address the problem that the bottom battery pack is easily severely crushed when a vehicle using CTB technology is subjected to a side impact.

[0005] This application provides a lower vehicle body structure, including: a sill beam having a first energy-absorbing area, a second energy-absorbing area, a bending-resistant area, and a load-bearing area; one side of the first energy-absorbing area is connected to the second energy-absorbing area and the load-bearing area; the load-bearing area is located above the second energy-absorbing area; the bending-resistant area is connected to the side of the second energy-absorbing area away from the first energy-absorbing area and the lower side of the load-bearing area; wherein the load-bearing area gradually slopes upward from the side connected to the first energy-absorbing area to the side away from the first energy-absorbing area; a seat crossbeam, the end of which is fixedly connected to the sill beam; a portion of the end of the seat crossbeam is located on the side of the load-bearing area away from the first energy-absorbing area, and a portion of the end of the seat crossbeam is located above the load-bearing area; and a battery pack including a lower housing beam and a bottom guard plate assembly; at least a portion of the lower housing beam is located on the side of the bending-resistant area away from the second energy-absorbing area and is connected to the bending-resistant area; and the bottom guard plate assembly is connected to the lower housing beam.

[0006] According to one embodiment of this application, a first horizontal step surface is formed on the upper side of the transfer zone, and a second horizontal step surface and a ramp surface are formed on the side of the transfer zone away from the first energy absorption zone, wherein the ramp surface connects the first horizontal step surface and the second horizontal step surface; the seat crossbeam is at least connected to the first horizontal step surface, the ramp surface and the second horizontal step surface of the transfer zone.

[0007] According to one embodiment of this application, the end of the seat crossbeam is provided with a first connecting portion, a second connecting portion and a third connecting portion; wherein, the first connecting portion and the second connecting portion are located on both sides of the seat crossbeam, and the first connecting portion and the second connecting portion are both fitted and fixed to the position of the ramp surface and the second horizontal step surface; the third connecting portion is located between the first connecting portion and the second connecting portion, and the third connecting portion is fitted and fixed to the position of at least the first horizontal step surface.

[0008] According to one embodiment of this application, the threshold beam includes vertical stiffeners separating the first energy-absorbing zone, the second energy-absorbing zone, and the bending-resistant zone, and transverse stiffeners located in the first energy-absorbing zone and the second energy-absorbing zone. The transverse stiffeners are fixedly connected to the vertical stiffeners on both sides. The transverse stiffeners located in the first energy-absorbing zone divide the first energy-absorbing zone into at least two filling cavities, and at least one of the filling cavities is provided with energy-absorbing material. The number of transverse stiffeners located in the second energy-absorbing zone is less than the number of transverse stiffeners located in the first energy-absorbing zone.

[0009] According to one embodiment of this application, the threshold beam includes at least two first inclined stiffeners located in the bending zone, the two sides of the first inclined stiffeners being fixedly connected to the two side walls of the bending zone, and an included angle being formed between adjacent first inclined stiffeners.

[0010] According to one embodiment of this application, the threshold beam includes a second inclined stiffener located in the load-bearing area, the second inclined stiffener gradually tilting upward from the side close to the first energy-absorbing area to the side away from the first energy-absorbing area.

[0011] According to one embodiment of this application, the threshold beam includes a cladding steel and an aluminum profile, at least a portion of the cladding steel wraps around the outside of the aluminum profile, and the portion of the cladding steel wrapping around the outside of the aluminum profile is conformally arranged along the outer wall of the aluminum profile.

[0012] According to one embodiment of this application, the seat crossbeam includes a front crossbeam and a rear crossbeam, both of which are connected to the sill beam. At least one of the front and rear crossbeams is configured to include: a top stamped steel plate; a bottom steel plate located below the top stamped steel plate and forming an inner cavity of the crossbeam with the top stamped steel plate; and an inner beam comprising an aluminum profile or a polyurethane pultruded composite material, the inner beam being located within the inner cavity of the crossbeam.

[0013] According to one embodiment of this application, the inner beam of the front crossbeam includes a plurality of surrounding plates, a third inclined stiffener, and an end cap. The plurality of surrounding plates are connected sequentially along the circumference of the inner beam. The third inclined stiffener forms an angle with the vertical plane and is fixedly connected to the upper and lower surrounding plates respectively. The end cap is fixedly connected to at least a portion of the ends of the surrounding plates and / or at least a portion of the ends of the third inclined stiffener.

[0014] According to one embodiment of this application, the bottom steel plate of the front crossbeam is a roll-formed steel plate structure, and the bottom circumference plate of the inner beam of the front crossbeam is arranged in a conformal manner with the bottom steel plate.

[0015] According to one embodiment of this application, the rear crossbeam forms a seat mounting area and a footrest recess area; the inner beam of the rear crossbeam includes a lower cavity, an upper cavity, and supporting ribs, the lower cavity being located in the seat mounting area and the footrest recess area, the upper cavity being located in the seat mounting area, and the supporting ribs forming an angle with the horizontal plane; wherein, the supporting ribs are disposed in the lower cavity and the upper cavity, the number of supporting ribs in the lower cavity is greater than the number of supporting ribs in the upper cavity, or, the supporting ribs are disposed only in the lower cavity.

[0016] According to one embodiment of this application, the lower shell beam includes: a lower shell frame beam located on the side of the bending resistance zone away from the second energy absorption zone and above the edge of the bottom guard plate assembly; and a lower shell hanging point beam located below the bending resistance zone and fixedly connected to the lower shell frame beam, wherein the lower shell hanging point beam is fixedly connected to the edge of the bottom guard plate assembly.

[0017] According to one embodiment of this application, the battery pack further includes a cooling plate, the edge of which is fixedly connected to the lower housing frame beam. The bottom guard plate assembly includes: a steel bottom guard plate located below the cooling plate and fixedly connected to the lower housing hanging point beam; and a composite material bottom plate including a layer plate and a shaped foam material. The layer plate is located between the cooling plate and the steel bottom guard plate and is bonded and fixed to the lower side of the cooling plate. The layer plate extends in a wavy shape, and the shaped foam material fills the space between the layer plate and the steel bottom guard plate.

[0018] According to one embodiment of this application, the shelf includes a plurality of veneers, one side of which is provided with a connecting mortise and the other side of which forms a connecting tenon; between each pair of adjacent veneers, the connecting tenon of one veneer is inserted into the connecting mortise of the other veneer.

[0019] According to one embodiment of this application, a first side plate and a second side plate are provided on one side of the single plate, the first side plate is disposed above the second side plate at a distance, the connecting mortise is formed between the first side plate and the second side plate, and the upper side of the first side plate is bonded and fixed to the cooling plate.

[0020] According to one embodiment of this application, a first limiting structure is provided at the bottom of the lower shell frame beam, the first limiting structure is located above the composite material base plate, and a second limiting structure is fixedly connected to the lower edge of the steel bottom guard plate, the second limiting structure being fixed to the lower shell hanging point beam.

[0021] According to one embodiment of this application, the edge of the cooling plate is riveted to the lower housing frame beam, and the edge of the cooling plate is bonded to the bottom surface of the lower housing frame beam. An overflow port is provided on the inner side of the bottom surface of the lower housing frame beam.

[0022] This application also provides a vehicle including the lower body structure of the above embodiments.

[0023] The aforementioned lower body structure and vehicle, including the sill beam, comprises a first energy-absorbing zone, a second energy-absorbing zone, a bending zone, and a load-bearing zone. The first and second energy-absorbing zones effectively absorb collision energy, the bending zone provides reliable bending support, and the inclined structure of the load-bearing zone effectively transfers the collision force to the seat crossbeam, avoiding insufficient performance due to a single structure bearing all the collision force. The end of the seat crossbeam is fixedly connected to the sill beam and precisely matches the position of the load-bearing zone, enhancing the connection stability between the seat crossbeam and the sill beam and effectively suppressing the upward flipping and bending tendency of the seat crossbeam during a side pillar collision. At least a portion of the lower housing beam of the battery pack is located on the side of the bending zone opposite to the second energy-absorbing zone and is connected to the bending zone. The bottom guard plate assembly is connected to the lower housing beam. The force of the bending zone can be transferred to the lower housing beam and the bottom guard plate assembly. The supporting effect of the lower housing beam and the bottom guard plate assembly, combined with the supporting effect of the seat crossbeam, forms a stable force transmission closed loop, improving the overall rigidity and strength of the lower body, preventing the bottom battery pack from being severely squeezed during a side pillar collision, and ensuring the safety of the occupants and the battery pack. Therefore, this application effectively solves the problem of weakened strength and rigidity caused by welding of the vehicle body without a bottom plate under CTB technology, and the problem of the battery pack being easily squeezed. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the battery pack installation structure in the prior art.

[0025] Figure 2 This is a diagram illustrating the impact of side impacts on the battery pack in existing technologies.

[0026] Figure 3 This is a half-sectional view of the lower vehicle body structure according to an embodiment of this application.

[0027] Figure 4 This is a partial cross-sectional view of the lower vehicle body structure according to an embodiment of this application.

[0028] Figure 5 This is a partial structural schematic diagram of the sill beam of the lower vehicle body structure according to an embodiment of this application.

[0029] Figure 6 This is a cross-sectional view of the front crossbeam of the lower vehicle body structure according to an embodiment of this application.

[0030] Figure 7 This is an exploded view of the inner beam in the front crossbeam of the lower vehicle body structure according to an embodiment of this application.

[0031] Figure 8 This is a sectional view of the rear crossbeam of the lower vehicle body structure according to an embodiment of this application.

[0032] Figure 9 This is an installation view of the bottom guard plate assembly in the lower vehicle body structure according to an embodiment of this application.

[0033] Figure 10 This is an enlarged view of the mounting structure of the bottom guard plate assembly in the lower vehicle body structure according to an embodiment of this application.

[0034] Figure 11 This is a schematic diagram of the composite material floor plate in the lower vehicle body structure according to an embodiment of this application.

[0035] Figure label:

[0036] 100. Threshold beam; 110. Steel cladding; 111. Extension; 120. Aluminum profile; 121. First energy-absorbing zone; 1211. Vertical stiffener; 1212. Horizontal stiffener; 122. Second energy-absorbing zone; 123. Bending zone; 1231. First inclined stiffener; 124. Load-bearing zone; 1241. First horizontal step surface; 1242. Second horizontal step surface; 1243. Sloping surface; 1244. Second inclined stiffener; 125. Energy-absorbing material;

[0037] 200. Seat crossbeam; 210. Front crossbeam; 211. Top stamped steel plate; 2111. Seat mounting nut; 212. Bottom steel plate; 213. Inner beam; 2131. Enclosure panel; 2132. Third inclined stiffener; 2133. End cap; 2134. Lower cavity; 2135. Upper cavity; 2136. Support stiffener; 214. First connecting part; 215. Second connecting part; 216. Third connecting part; 220. Rear crossbeam; 221. Seat mounting area; 222. Footrest recessed area;

[0038] 300. Battery pack; 310. Lower housing frame beam; 311. First limiting structure; 312. Glue overflow port; 320. Lower housing hanging point beam; 330. Bottom guard plate assembly; 331. Steel bottom guard plate; 3311. Second limiting structure; 332. Composite material bottom plate; 333. Sheet plate; 3331. Single plate; 3332. First side plate; 3333. Second side plate; 334. Shaped foam material; 340. Cooling plate. Detailed Implementation

[0039] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0040] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0041] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0044] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0045] Combination Figure 3 , Figure 4 and Figure 5 The lower vehicle body structure provided in one embodiment of this application includes a sill beam 100, a seat crossbeam 200, and a battery pack 300.

[0046] The sill beam 100 includes a first energy-absorbing zone 121, a second energy-absorbing zone 122, a bending-resistant zone 123, and a load-bearing zone 124. One side of the first energy-absorbing zone 121 is connected to the second energy-absorbing zone 122 and the load-bearing zone 124. The load-bearing zone 124 is located above the second energy-absorbing zone 122. The bending-resistant zone 123 is connected to the side of the second energy-absorbing zone 122 away from the first energy-absorbing zone 121 and the lower side of the load-bearing zone 124. The load-bearing zone 124 gradually slopes upwards from the side connected to the first energy-absorbing zone 121 to the side away from the first energy-absorbing zone 121. The end of the seat crossbeam 200 is fixedly connected to the sill beam 100. A portion of the end of the seat crossbeam 200 is located on the side of the load-bearing zone 124 away from the first energy-absorbing zone 121, and a portion of the end of the seat crossbeam 200 is located above the load-bearing zone 124. The battery pack 300 includes a lower housing beam and a bottom guard plate assembly 330. At least a portion of the lower housing beam is located on the side of the bending zone 123 opposite to the second energy absorption zone 122 and is connected to the bending zone 123. The bottom guard plate assembly 330 is connected to the lower housing beam.

[0047] The first energy-absorbing zone 121, located near the outer side of the vehicle, is the area where the impact force first acts. Its structure can collapse and deform upon impact, thus fully absorbing the initial impact energy. This energy absorption method effectively reduces the impact load on subsequent structures, preventing high-intensity impact forces from being directly transmitted to the vehicle body or battery pack 300. The second energy-absorbing zone 122 follows the first energy-absorbing zone 121, continuing the energy absorption process and further dissipating the impact energy that the first energy-absorbing zone 121 did not fully absorb, allowing the impact energy to gradually decay and preventing a sudden surge of energy into the subsequent bending structure, which could cause structural damage. The bending zone 123, located behind the second energy-absorbing zone 122, has strong bending resistance. When subjected to residual impact energy, it can maintain its basic structural shape, preventing excessive deformation that could cause the lower vehicle body to intrude into the passenger compartment or compress the battery pack 300, providing necessary protective space for the occupants and the battery pack 300. The load-bearing zone 124 is located above the second energy-absorbing zone 122. Its inclined structure forms a force transmission channel. After the first energy-absorbing zone 121 absorbs part of the energy, the remaining collision force will be transmitted upward along the inclined direction of the load-bearing zone 124 to achieve force diversion. This allows the seat beam 200 to participate in the force bearing and prevents the sill beam 100 from failing due to bearing all the load on its own.

[0048] The end of the seat crossbeam 200 is fixedly connected to the sill beam 100. Part of its end is located on the side of the load-bearing zone 124 opposite to the first energy-absorbing zone 121, and part is located on the upper side of the load-bearing zone 124. This positional relationship allows the impact force transmitted by the load-bearing zone 124 to directly act on the effective load-bearing parts of the seat crossbeam 200, enabling the seat crossbeam 200 to quickly respond to the impact force and perform its load-bearing function. The seat crossbeam 200 itself possesses a certain structural strength, and after bearing the impact force, it can resist bending deformation, effectively suppressing the upward flipping and bending tendency that easily occurs during side pillar collisions. Simultaneously, it further transmits some of the impact force to other stable structures of the vehicle body, achieving distributed load-bearing of the impact force and reducing the stress on a single structure.

[0049] The lower housing beam provides lateral support to the bending zone 123, enhancing its bending resistance and preventing it from deforming towards the battery pack 300 under impact force. It also provides a stable mounting base for the battery pack 300, preventing displacement or shaking during a collision.

[0050] When a vehicle encounters a side pillar collision, the collision force first acts on the first energy-absorbing zone 121 of the sill beam 100. The first energy-absorbing zone 121 absorbs a large amount of initial collision energy through crumpling deformation. The energy that is not completely absorbed is transferred to the second energy-absorbing zone 122 and the load-bearing zone 124. The inclined structure of the load-bearing zone 124 can transfer part of the force upward to the seat crossbeam 200. After the seat crossbeam 200 receives the force, it resists bending deformation through its own structural strength, while dispersing part of the force to other structures of the vehicle body. The second energy-absorbing zone 122 can continue to attenuate energy through deformation, and the residual energy is transferred to the bending zone 123. The bending zone 123 resists deformation with its own bending resistance. When the bending zone 123 deforms, it can be transferred to the bottom guard plate assembly 330 through the lower shell beam. During this process, the lower shell beam of the battery pack 300 provides support for the sill beam 100 from the side and bottom, ensuring that the sill beam 100 remains structurally stable during the collision. The entire force transmission process is continuous and orderly, forming a complete force transmission closed loop.

[0051] Understandably, common vehicle battery packs with thin steel plates have only slight stamping features and limited central support points. When facing a side pole impact, the thin steel plate has almost no rigidity along the vehicle width, making it prone to large-scale bending deformation at the bottom that could crush the battery cells. However, in this embodiment, due to the energy absorption effect of the first energy absorption zone 121 and the second energy absorption zone 122, as well as the supporting effect of the bending zone 123, the bearing zone 124, the seat crossbeam 200, and the lower housing beam, the force transmitted to the bottom guard plate assembly 330 is relatively small. Therefore, while avoiding side compression of the battery pack 300's interior, it also prevents the bottom guard plate assembly 330 from being subjected to large-scale bending deformation that could crush the battery cells, thus achieving further protection for the battery pack 300.

[0052] In summary, this embodiment effectively compensates for the reduced strength and stiffness caused by the lack of bottom plate welding in CTB technology. It can fully absorb collision energy and resist structural deformation during side pillar collisions, providing strong protection for the safety of passengers and protecting the integrity of the battery pack 300, thereby improving the vehicle's collision safety performance.

[0053] According to one embodiment of this application, the threshold beam 100 includes a steel cladding 110 and an aluminum profile 120. At least a portion of the steel cladding 110 wraps around the outside of the aluminum profile 120, and the portion of the steel cladding 110 wrapping around the outside of the aluminum profile 120 is conformally arranged along the outer wall of the aluminum profile 120.

[0054] The portion of the steel cladding 110 wraps around the outside of the aluminum profile 120 and fits tightly against it. This not only constrains and strengthens the aluminum profile 120, enhancing its overall structural stability and preventing it from breaking, shifting, or detaching from its original position during a collision, but also provides a stable connection for the seat crossbeam 200. Through a fixed connection with the end of the seat crossbeam 200, a reliable force transmission path is established between the sill beam 100 and the seat crossbeam 200, ensuring that the impact force can be smoothly transmitted from the sill beam 100 to the seat crossbeam 200, preventing the connection from loosening or breaking under the impact force. In addition, the steel cladding 110 also facilitates the welding and fixing of the sill beam 100 to other structures such as the A-pillar and B-pillar of the vehicle.

[0055] Optionally, the aluminum profile 120 forms a first energy-absorbing area 121, a second energy-absorbing area 122, a bending-resistant area 123, and a load-bearing area 124. Further, the covering steel 110 is wrapped around the outside of the first energy-absorbing area 121, the second energy-absorbing area 122, the bending-resistant area 123, and the load-bearing area 124.

[0056] Using aluminum profile 120 as the inner core helps reduce the overall weight of the vehicle and provides better deformation buffering capacity in the event of a collision. The combination of aluminum profile 120 and cladding steel 110 can simultaneously meet the requirements for collision buffering and structural strength.

[0057] According to one embodiment of this application, the lower shell beam includes a lower shell side frame beam 310 and a lower shell hanging point beam 320. The lower shell side frame beam 310 is located on the side of the bending resistance zone 123 opposite to the second energy absorption zone 122, and the lower shell hanging point beam 320 is located below the bending resistance zone 123 and is fixedly connected to the lower shell side frame beam 310 and the covering steel 110, respectively. The edge of the bottom guard plate assembly 330 is fixedly connected to the lower shell hanging point beam 320.

[0058] For example, the lower housing frame beam 310 is located on the side of the bending zone 123 away from the second energy-absorbing zone 122, and is closely fitted with the covering steel 110 at the location of the bending zone 123. It can provide lateral support for the bending zone 123, enhance the bending resistance of the bending zone 123, and prevent the bending zone 123 from deforming towards the battery pack 300 under the action of the impact force. The lower housing hanging point beam 320 is located below the bending zone 123 and is fixedly connected to the lower housing frame beam 310 to form a longitudinal support structure. This not only consolidates the connection reliability between the sill beam 100 and the battery pack 300, but also shares the longitudinal load borne by the bending zone 123, preventing the bending zone 123 from deforming excessively due to insufficient longitudinal support. At the same time, it provides a stable installation foundation for the battery pack 300, preventing the battery pack 300 from shifting or shaking during the collision.

[0059] When a vehicle encounters a side pillar collision, the impact force first acts on the first energy-absorbing zone 121 of the sill beam 100. The first energy-absorbing zone 121 absorbs a large amount of initial impact energy through crumpling deformation. The energy that is not completely absorbed is transferred to the second energy-absorbing zone 122 and the load-bearing zone 124: the inclined structure of the load-bearing zone 124 can transfer part of the force upward to the seat crossbeam 200. After the seat crossbeam 200 receives the force, it resists bending deformation through its own structural strength, while dispersing part of the force to other structures of the vehicle body; the second energy-absorbing zone 122 can continue to attenuate through deformation. Energy, including residual energy, is transferred to the bending-resistant zone 123. The bending-resistant zone 123 resists deformation due to its own bending resistance. When the bending-resistant zone 123 deforms, the energy is transferred to the bottom protective plate assembly 330 via the lower housing frame beam 310 and the lower housing mounting point beam 320. During this process, the lower housing frame beam 310 and the lower housing mounting point beam 320 of the battery pack 300 provide support to the sill beam 100 from the side and bottom, ensuring that the sill beam 100 remains structurally stable during a collision. The entire force transmission process is continuous and orderly, forming a complete closed-loop force transmission system. The structure of the lower housing frame beam 310 and the lower housing mounting point beam 320 effectively reduces the stress on the bottom protective plate assembly 330 and facilitates the installation and fixing of the bottom protective plate assembly 330.

[0060] According to one embodiment of this application, a first horizontal step surface 1241 is formed on the upper side of the transfer area 124, and a second horizontal step surface 1242 and a ramp surface 1243 are formed on the side of the transfer area 124 away from the first energy absorption area 121. The ramp surface 1243 connects the first horizontal step surface 1241 and the second horizontal step surface 1242. The seat crossbeam 200 is at least connected to the first horizontal step surface 1241, the ramp surface 1243 and the second horizontal step surface 1242 of the transfer area 124.

[0061] It should be noted that when the sill beam 100 includes a steel cladding 110 and an aluminum profile 120, the first horizontal step surface 1241, the ramp surface 1243, and the second horizontal step surface 1242 are located on the aluminum profile 120. The steel cladding 110 is in contact with the first horizontal step surface 1241, the ramp surface 1243, and the second horizontal step surface 1242. The connection between the seat crossbeam 200 and the first horizontal step surface 1241, the ramp surface 1243, and the second horizontal step surface 1242 of the load-bearing area 124 is achieved by connecting the steel cladding 110 to the positions corresponding to the first horizontal step surface 1241, the ramp surface 1243, and the second horizontal step surface 1242.

[0062] In some embodiments, the first horizontal step surface 1241 extends laterally along the upper side of the load-bearing area 124, and the covering steel 110 can be tightly fitted onto this plane to form a reliable contact base. One end of the ramp surface 1243 connects to the first horizontal step surface 1241, and the other end connects to the second horizontal step surface 1242, forming a smooth transition structure. The second horizontal step surface 1242 is arranged parallel to the first horizontal step surface 1241 and is located on the side of the load-bearing area 124 away from the first energy-absorbing area 121. The covering steel 110 adheres to the surfaces of the first horizontal step surface 1241, the ramp surface 1243, and the second horizontal step surface 1242, and is fixed by welding or bonding to ensure no relative sliding between them. The end of the seat beam 200 contacts the area of ​​the covering steel 110 that adheres to the above three surfaces, and is fixed by welding or riveting, so that the seat beam 200 can directly bear the force transmitted from the load-bearing area 124.

[0063] The corresponding connection between the seat crossbeam 200 and the sill beam 100 on three sides enables the seat crossbeam 200 to bear the impact force from all directions, enhancing the force transmission efficiency between the two and effectively suppressing the upward flipping and folding tendency of the seat crossbeam 200. By optimizing the shape of the contact surface and the connection method, the connection stability and force transmission reliability between the sill beam 100 and the seat crossbeam 200 are improved, further consolidating the overall rigidity of the lower body. In the event of a side pillar collision, the impact force can be more effectively dispersed, protecting the safety of the passenger compartment and the battery pack 300.

[0064] According to one embodiment of this application, the end of the seat crossbeam 200 is provided with a first connecting portion 214, a second connecting portion 215, and a third connecting portion 216; wherein, the first connecting portion 214 and the second connecting portion 215 are respectively placed on both sides of the seat crossbeam 200, and both the first connecting portion 214 and the second connecting portion 215 are fitted and fixed to the ramp surface 1243 and the second horizontal step surface 1242, specifically by fitting and fixing to the ramp surface 1243 and the second horizontal step surface 1242 in a position that is fitted and fixed to the covered steel 110; the third connecting portion 216 is located between the first connecting portion 214 and the second connecting portion 215, and the third connecting portion 216 is at least fitted and fixed to the first horizontal step surface 1241. Optionally, the cladding steel 110 is provided with an extension 111, which is located above the aluminum profile 120 and extends vertically. The third connecting part 216 is attached to the position of the first horizontal step surface 1241 of the cladding steel 110 and is fixed to the extension 111.

[0065] In some embodiments, the first connecting portion 214 and the second connecting portion 215 are located on the left and right sides of the end of the seat crossbeam 200, respectively, and are symmetrically distributed. Their shapes are adapted to the contours of the area where the covered steel 110 adheres to the slope surface 1243 and the second horizontal step surface 1242, allowing them to completely fit the surface of that area. The first connecting portion 214 and the second connecting portion 215 are fixed to the covered steel 110 by welding to ensure connection strength. The third connecting portion 216 is located at the middle position of the end of the seat crossbeam 200, between the first connecting portion 214 and the second connecting portion 215. The extension portion 111 of the covered steel 110 extends vertically from the top of the aluminum profile 120, forming a vertical support structure. The upper side of the third connecting portion 216 adheres to the extension portion 111, and the lower side adheres to the area where the covered steel 110 adheres to the first horizontal step surface 1241, achieving double fixation through welding.

[0066] The symmetrical distribution of the first connecting part 214 and the second connecting part 215 ensures uniform force distribution on both sides of the seat beam 200, preventing structural deformation caused by excessive force on one side and improving the anti-rollover capability of the seat beam 200. The fixation of both parts to the ramp surface 1243 and the second horizontal step surface 1242 enhances the stability of force transmission, ensuring that the impact force can be quickly transmitted to the seat beam 200. The third connecting part 216, located in the middle, fills the connection gap in the middle area of ​​the end of the seat beam 200. Its connection with the first horizontal step surface 1241 increases the longitudinal support force, effectively suppressing the upward arching tendency of the seat beam 200. The first connecting part 214, the second connecting part 215, and the third connecting part 216 form a multi-directional fixation between the seat beam 200 and the cladding steel 110, significantly improving the connection strength and preventing loosening or breakage of the connection points during a collision. The force transmission path has been further optimized, enabling the collision force to be transmitted evenly and stably from the sill beam 100 to the seat crossbeam 200, thereby improving the overall collision resistance performance of the lower body and providing more reliable safety protection for drivers and passengers.

[0067] According to one embodiment of this application, the sill beam 100 includes vertical stiffeners 1211 separating a first energy-absorbing zone 121, a second energy-absorbing zone 122, and a bending-resistant zone 123, and transverse stiffeners 1212 located in the first energy-absorbing zone 121 and the second energy-absorbing zone 122. The transverse stiffeners 1212 are fixedly connected to the vertical stiffeners 1211 on both sides. The transverse stiffeners 1212 located in the first energy-absorbing zone 121 divide the first energy-absorbing zone 121 into at least two filling cavities, and at least one filling cavity is provided with energy-absorbing material 125. The number of transverse stiffeners 1212 located in the second energy-absorbing zone 122 is less than the number of transverse stiffeners 1212 located in the first energy-absorbing zone 121. In some embodiments, the vertical stiffeners 1211 extend longitudinally along the sill beam 100, dividing the internal space of the sill beam 100 into independent first energy-absorbing zone 121, second energy-absorbing zone 122, and bending-resistant zone 123, so that each region can function independently. Horizontal stiffeners 1212 are laterally disposed inside the first energy-absorbing zone 121 and the second energy-absorbing zone 122, with their ends fixedly connected to the vertical stiffeners 1211 on both sides. The first energy-absorbing zone 121 has a larger number of horizontal stiffeners 1212, dividing it into multiple independent filling cavities. At least some of these cavities are filled with energy-absorbing material 125; optionally, all filling cavities are filled with energy-absorbing material 125. The energy-absorbing material 125 is tightly fitted to the horizontal stiffeners 1212 and the vertical stiffeners 1211 without gaps. The second energy-absorbing zone 122 has fewer horizontal stiffeners 1212 than the first energy-absorbing zone 121, resulting in a relatively larger volume of the resulting cavities.

[0068] When a collision occurs, the transverse stiffeners 1212 and the energy-absorbing material 125 of the first energy-absorbing zone 121 first come into contact with the collision force and absorb energy through the collapse deformation of the transverse stiffeners 1212 and the compression deformation of the energy-absorbing material 125. The unabsorbed energy is transferred to the second energy-absorbing zone 122, where the transverse stiffeners 1212 continue to absorb energy through collapse deformation. Finally, the remaining energy is transferred to the bending zone 123.

[0069] In this embodiment, the vertical stiffeners 1211 clearly define the functional boundaries of the three regions, avoiding mutual interference between different functional regions and ensuring that each region can specifically perform energy absorption or bending resistance. The first energy-absorbing region 121, with its numerous transverse stiffeners 1212 and filled with energy-absorbing material 125, increases the energy-absorbing area and capacity, enabling rapid absorption of a large amount of initial collision energy, reducing the stress on subsequent structures, and improving overall energy absorption efficiency. The second energy-absorbing region 122, with fewer transverse stiffeners 1212, reduces material usage while maintaining energy absorption effectiveness, achieving lightweighting. By rationally allocating the number of transverse stiffeners 1212 and the filling energy-absorbing material 125, a stepped absorption of collision energy is achieved, improving energy absorption while maintaining lightweighting, further optimizing the energy absorption performance of the sill beam 100, and providing more effective collision protection for the lower body.

[0070] Optionally, the energy-absorbing material 125 may be aluminum foam board, honeycomb aluminum board, or microporous foamed polypropylene, etc.

[0071] According to one embodiment of this application, the threshold beam 100 includes at least two first inclined stiffeners 1231 located in the bending zone 123. The two sides of the first inclined stiffeners 1231 are respectively fixedly connected to the two side walls of the bending zone 123, and an included angle is formed between adjacent first inclined stiffeners 1231.

[0072] Each first inclined stiffener 1231 is fixedly connected at both ends to the left and right side walls of the bending zone 123, forming a stable support structure. An angle is formed between two adjacent first inclined stiffeners 1231, and at least two first inclined stiffeners 1231 can divide the inner cavity of the bending zone 123 into multiple triangular or trapezoidal cavities.

[0073] The fixed connection between the first inclined stiffener 1231 and the two side walls of the bending zone 123 enhances the overall structural strength of the bending zone 123 and prevents lateral deformation under lateral pressure. The included angle structure formed by adjacent first inclined stiffeners 1231 utilizes the stability principle of triangles to improve the bending resistance of the bending zone 123, effectively resisting lateral pressure during a collision and preventing excessive indentation or fracture of the bending zone 123. The mesh support system allows forces to be evenly distributed within the bending zone 123, avoiding local stress concentration and further enhancing the load-bearing capacity of the bending zone 123. This structure enables the bending zone 123 to stably absorb residual collision energy, maintain its structural shape, provide reliable protection space for the passenger compartment and battery pack 300, prevent structural intrusion due to failure of the bending zone 123, and improve the side pillar collision safety performance of the vehicle.

[0074] According to one embodiment of this application, the threshold beam 100 includes a second inclined stiffener 1244 located in the bearing area 124. The second inclined stiffener 1244 gradually inclines upward from the side close to the first energy absorption area 121 to the side away from the first energy absorption area 121.

[0075] In some embodiments, the second inclined stiffener 1244 is located inside the load-bearing area 124, and its extension direction is consistent with or similar to the overall inclined direction of the load-bearing area 124. Starting from the side close to the first energy-absorbing area 121, it gradually inclines upward towards the side away from the first energy-absorbing area 121. The two ends of the second inclined stiffener 1244 are fixedly connected to the upper and lower walls of the load-bearing area 124, respectively, to form a longitudinal support structure. The number of such stiffeners can be set to one or more according to actual force requirements. After the collision force is transmitted to the load-bearing area 124, the second inclined stiffener 1244 bears the longitudinal pressure and guides the pressure to the upper seat crossbeam 200 by its own inclined structure, while bearing part of the pressure itself to prevent excessive deformation of the load-bearing area 124.

[0076] The design of the second inclined stiffener 1244, with its overall inclination direction aligned with or similar to that of the load-bearing area 124, optimizes the force transmission path. This allows the impact force to be transmitted more smoothly from the load-bearing area 124 to the seat crossbeam 200, reducing energy loss during force transmission and improving transmission efficiency. Furthermore, the second inclined stiffener 1244 enhances the structural strength of the load-bearing area 124, preventing local collapse or deformation during force transmission and ensuring stable force transmission. Therefore, by adding the second inclined stiffener 1244, both the structural strength of the load-bearing area 124 and the force transmission effect are improved, enabling the impact force to be transmitted more efficiently to the seat crossbeam 200. This achieves coordinated force distribution between the sill beam 100 and the seat crossbeam 200, further enhancing the collision resistance of the lower body.

[0077] It should be noted that when the threshold beam 100 includes the steel cladding 110 and the aluminum profile 120, the aforementioned vertical stiffener 1211, horizontal stiffener 1212, filling cavity, energy-absorbing material 125, first inclined stiffener 1231 and second inclined stiffener 1244 are all provided on the aluminum profile 120. For ease of reading, they will not be described again here.

[0078] Combination Figure 6 and Figure 8 According to one embodiment of this application, the seat crossbeam 200 includes a front crossbeam 210 and a rear crossbeam 220. Both the front crossbeam 210 and the rear crossbeam 220 are connected to the sill beam 100. Both the front crossbeam 210 and the rear crossbeam 220 are configured to include: a top stamped steel plate 211, a bottom steel plate 212, and an inner beam 213. The bottom steel plate 212 is located below the top stamped steel plate 211 and forms an inner cavity of the crossbeam with the top stamped steel plate 211. The inner beam 213 is made of aluminum or polyurethane pultruded composite material and is located in the inner cavity of the crossbeam and is fitted and fixed to the periphery of the inner cavity of the crossbeam.

[0079] In some embodiments, the top stamped steel plate 211 is located above the bottom steel plate 212, generally in a Z-shape, providing upper protection and support. The bottom steel plate 212 and the lower edge of the top stamped steel plate 211 are joined together to form the inner cavity of the crossbeam, and the joint can be fixed by welding. The shape of the inner beam 213 is adapted to the shape of the inner cavity of the crossbeam, filling the inner cavity of the crossbeam and closely fitting the inner walls of the top stamped steel plate 211 and the bottom steel plate 212, and can be fixed by means such as adhesive bonding. When aluminum is selected for the inner beam 213, it has the characteristics of lightweight and high strength; when polyurethane pultruded composite material is selected, it has good bending resistance and lightweight advantages. After the impact force is transmitted to the seat crossbeam 200, the top stamped steel plate 211 and the bottom steel plate 212 first bear the external pressure and resist deformation through their own structural strength, while simultaneously transmitting the force to the inner beam 213. The inner beam 213 further resists bending with its own strength, and the three work together to achieve the functions of anti-deformation and force transmission.

[0080] The top stamped steel plate 211 and the bottom steel plate 212 enhance the overall rigidity and bending resistance of the seat crossbeam 200, effectively resisting bending and torsional forces during a collision. The inner beam 213, filled within the crossbeam cavity, fits tightly with the outer crossbeam, forming a composite load-bearing structure that further strengthens the bending resistance of the seat crossbeam 200, preventing localized dents or fractures. The choice of aluminum or polyurethane pultruded composite materials ensures strength while achieving lightweighting of the seat crossbeam 200, reducing the overall weight of the lower body and improving vehicle economy and handling. The synergistic force distribution of these three components allows the collision force to be evenly distributed within the seat crossbeam 200, avoiding localized stress concentration, effectively suppressing the upward tilting and bending tendency of the seat crossbeam 200, and improving its impact resistance.

[0081] The front crossbeam 210 and rear crossbeam 220 of this embodiment combine strength, rigidity and lightweight, and can more effectively bear the collision force, providing reliable support for the overall force transmission closed loop of the lower body, and further ensuring the safety of the passenger compartment.

[0082] Optionally, the top stamped steel plate 211 is provided with a first connecting part 214, a second connecting part 215 and a third connecting part 216, and is welded to the cladding steel 110 through the first connecting part 214, the second connecting part 215 and the third connecting part 216. Part of the cladding steel 110 extends to the lower side of the bottom steel plate 212, and the lower side and end of the bottom steel plate 212 are welded to the cladding steel 110.

[0083] Combination Figure 7 According to one embodiment of this application, the inner beam 213 of the front crossbeam 210 includes a plurality of surrounding plates 2131, a third inclined stiffener 2132 and an end cap 2133. The plurality of surrounding plates 2131 are connected sequentially along the circumference of the inner beam 213. The third inclined stiffener 2132 forms an angle with the vertical plane and is fixedly connected to the upper surrounding plate 2131 and the lower surrounding plate 2131 respectively. The end cap 2133 is fixedly connected to at least a portion of the ends of the surrounding plates 2131 and / or at least a portion of the ends of the third inclined stiffener 2132.

[0084] In some embodiments, multiple surrounding panels 2131 are sequentially spliced ​​along the circumference of the inner beam 213 to form a closed frame structure. The number of surrounding panels 2131 is determined according to the cross-sectional shape of the inner beam 213 to ensure the integrity of the frame structure. A third inclined stiffener 2132 is disposed inside the frame formed by the surrounding panels 2131, forming a certain angle with the vertical plane, for example, an angle of 30° or 45° with the vertical plane. Its upper end is fixedly connected to the upper surrounding panel 2131, and its lower end is fixedly connected to the lower surrounding panel 2131 to form an inclined support structure. The end cap 2133 is flat and its size is adapted to the end size of the frame formed by the surrounding panels 2131. It covers both ends of the frame and is fixed to the ends of the surrounding panels 2131 and the third inclined stiffener 2132 by welding, thereby closing the ends of the inner beam 213. After the impact force is transmitted to the inner beam 213, the enclosure 2131 first bears the external force and resists deformation through its own structure. The third inclined stiffener 2132 converts the longitudinal force into the oblique force and disperses it. The end cap 2133 prevents the internal structure from loosening from the end. The three work together to improve the impact resistance of the inner beam 213.

[0085] The closed frame structure formed by the enclosure plate 2131 provides basic structural support for the inner beam 213, enhancing its overall rigidity and preventing overall deformation under impact forces. The oblique support of the third inclined stiffener 2132 utilizes the stability principle of a triangle to improve the bending and torsional resistance of the inner beam 213, effectively dispersing concentrated forces and reducing localized stress on the enclosure plate 2131, preventing damage due to excessive localized stress. The closed structure of the end cap 2133 prevents the end structure of the inner beam 213 from loosening during a collision, ensuring the overall integrity of the inner beam 213, while also enhancing the load-bearing capacity of the ends, allowing forces to be evenly transmitted from the ends to the entire inner beam 213. Overall, through the synergistic effect of the enclosure 2131, the third inclined stiffener 2132, and the end cap 2133, the strength and impact resistance of the inner beam 213 of the front crossbeam 210 are further improved, enabling the front crossbeam 210 to more effectively bear and disperse collision forces, providing a more reliable guarantee for the overall safety of the undercarriage.

[0086] Optionally, when there are two or more third inclined stiffeners 2132, an angle is formed between adjacent third inclined stiffeners 2132, thereby further improving the structural strength of the inner beam 213.

[0087] In some embodiments, the bottom steel plate 212 of the front crossbeam 210 is a roll-formed steel plate structure, and the bottom circumferential plate 2131 of the inner beam 213 of the front crossbeam 210 is conformally arranged to the bottom steel plate 212. For example, both the roll-formed steel plate structure and the bottom circumferential plate 2131 of the inner beam 213 of the front crossbeam 210 form multiple bent segments, which are generally Z-shaped and connected sequentially. The multiple bent segments of the roll-formed steel plate structure correspond one-to-one with the bent segments of the bottom circumferential plate 2131 of the inner beam 213 of the front crossbeam 210. Thus, on the one hand, the bending strength of the bottom steel plate 212 in the front crossbeam 210 can be further enhanced, and on the other hand, the connection stability between the bottom steel plate 212 and the inner beam 213 in the front crossbeam 210 can be increased.

[0088] Combination Figure 4 and Figure 8 According to one embodiment of this application, the rear crossbeam 220 forms a seat mounting area 221 and a footrest recess area 222; the inner beam 213 of the rear crossbeam 220 includes a lower cavity 2134, an upper cavity 2135 and a support rib 2136, the lower cavity 2134 is located in the seat mounting area 221 and the footrest recess area 222, the upper cavity 2135 is located in the seat mounting area 221, and the support rib 2136 forms an angle with the horizontal plane; wherein, the support rib 2136 is disposed in the lower cavity 2134 and the upper cavity 2135, the number of support rib 2136 in the lower cavity 2134 is greater than the number of support rib 2136 in the upper cavity 2135, or, the support rib 2136 is disposed only in the lower cavity 2134.

[0089] In some embodiments, the seat mounting area 221 of the rear crossbeam 220 is used to mount a seat, and the footrest recess area 222 provides space for the passenger's feet; both are distributed along the length of the rear crossbeam 220. The lower cavity 2134 of the inner beam 213 penetrates through the seat mounting area 221 and the footrest recess area 222, while the upper cavity 2135 is located only in the seat mounting area 221. The cross-sectional area of ​​the lower cavity 2134 is larger than that of the upper cavity 2135. The support ribs 2136 are inclinedly disposed inside the cavity, forming a certain angle with the horizontal plane. When both the lower cavity 2134 and the upper cavity 2135 are provided with support ribs 2136, the support ribs 2136 in the lower cavity 2134 are more densely arranged and more numerous. When the support ribs 2136 are only disposed in the lower cavity 2134, the support ribs 2136 are evenly distributed inside the lower cavity 2134 and fixedly connected to the inner wall of the lower cavity 2134. After the collision force is transmitted to the rear crossbeam 220, the lower cavity 2134, due to its wide coverage and numerous supporting ribs 2136, mainly bears and disperses most of the collision force. The upper cavity 2135 assists in bearing the force according to the force requirements of the seat installation area 221. The supporting ribs 2136 enhance the bending resistance of the cavity through oblique support.

[0090] The lower cavity 2134 covers the seat mounting area 221 and the footrest recess area 222, enhancing the overall structural strength and addressing the structural continuity issues caused by the footrest recess area 222, preventing deformation in this area due to insufficient strength. The upper cavity 2135 is only located in the seat mounting area 221, meeting the stress requirements of the seat mounting area 221 while reducing material usage in other areas, achieving lightweighting. The inclined arrangement of the support ribs 2136 improves the cavity's resistance to bending and torsion. The increased number of support ribs 2136 in the lower cavity 2134 further enhances its load-bearing capacity and force dispersion effect, ensuring stable force transmission of the rear crossbeam 220 during a collision. Based on the stress characteristics of different areas of the rear crossbeam 220, the cavities and support ribs 2136 are differentiated, achieving lightweighting while ensuring strength in key areas. This allows the rear crossbeam 220 to adapt to the stress requirements of different areas, improving its overall collision resistance and further solidifying the force transmission closed loop of the lower body.

[0091] According to one embodiment of this application, both the front crossbeam 210 and the rear crossbeam 220 are configured to include a seat mounting nut 2111. The top stamped steel plate 211 is provided with a mounting hole, and the inner beam 213 is provided with a clearance hole. The seat mounting nut 2111 is located in the mounting hole and the clearance hole. The seat mounting nut 2111 is welded and fixed to the top stamped steel plate 211 and has a clearance fit with the inner beam 213. The seat mounting nut 2111 is used to install and fix the seat.

[0092] The seat mounting nut 2111 is welded and fixed to the top stamped steel plate 211, which can ensure the stability of the seat installation. The seat mounting nut 2111 and the inner beam 213 are clearance-fitted. The force of the seat mounting nut 2111 is transmitted to the inner beam 213 through the top stamped steel plate 211 and the bottom steel plate 212, rather than directly to the inner beam 213, which helps to avoid local deformation of the inner beam 213.

[0093] Combination Figure 9 , Figure 10 and Figure 11 According to one embodiment of this application, the battery pack 300 further includes a cooling plate 340, the edge of which is fixedly connected to the lower housing frame beam 310. The bottom protective plate assembly 330 includes a steel bottom protective plate 331 and a composite material bottom plate 332. The steel bottom protective plate 331 is located below the cooling plate 340 and is fixedly connected to the lower housing hanging point beam 320. The composite material bottom plate 332 includes a layer 333 and a shaped foam material 334. The layer 333 is located between the cooling plate 340 and the steel bottom protective plate 331 and is bonded and fixed to the lower side of the cooling plate 340. The layer 333 extends in a wavy shape, and the shaped foam material 334 fills the space between the layer 333 and the steel bottom protective plate 331.

[0094] In some embodiments, the steel bottom guard plate 331 is located on the outermost side of the bottom guard plate assembly 330, is flat, covers the bottom of the battery pack 300, and its edge is fixed to the lower housing frame beam 310 by welding. The layer plate 333 of the composite material bottom plate 332 extends laterally in a wavy shape, and the wavy protrusions and depressions form a continuous structure. The shaped foam material 334 fills the gap between the layer plate 333 and the steel bottom guard plate 331, and fits tightly with both without gaps. The shaped foam material 334 can be partially or fully bonded to the layer plate 333 and / or the steel bottom guard plate 331. The cooling plate 340 is located on the upper side of the layer plate 333, and its lower surface is bonded to the layer plate 333. The edge of the cooling plate 340 is fixed to the lower housing frame beam 310 to ensure a firm connection.

[0095] Optionally, the laminate 333 of the composite material base plate 332 is made of polyurethane (PU) pultruded material or other composite materials with good flexural strength. The shaped foam material 334 is polypropylene microporous foam material or polyurethane foam material.

[0096] When the bottom is impacted, the steel bottom guard plate 331 first absorbs the impact force, the shaped foam material 334 absorbs energy through compression deformation, the corrugated layer plate 333 further absorbs energy through its own deformation, and the cooling plate 340 provides support for the layer plate 333, while transferring part of the force to the lower shell frame beam 310, so as to achieve the gradual absorption and dispersion of energy.

[0097] The steel bottom guard plate 331 can be flat overall, with bending features around its perimeter. The welding and fixing of the steel bottom guard plate 331 to the lower housing frame beam 310 provides basic structural support and protection for the bottom guard plate assembly 330, preventing external obstacles from directly intruding into the battery pack 300. The corrugated layer 333 increases its cross-sectional stiffness and energy absorption space. Compared to the flat layer 333, it can absorb more energy with the same amount of deformation, improving the energy absorption efficiency of the bottom guard plate assembly 330. The filling of the shaped foam material 334 fills the gap between the layer 333 and the steel bottom guard plate 331, enhancing the connection stability between the two. Simultaneously, its excellent buffering performance effectively absorbs impact energy, reducing the impact force transmitted to the cooling plate 340 and the battery cell. The bonding of the cooling plate 340 to the shelf 333 and the riveting of it to the lower housing frame beam 310 not only achieve the heat dissipation function, but also enhance the connection strength between the bottom guard plate assembly 330 and the battery pack 300, enabling the bottom guard plate assembly 330 to participate in force transmission more stably.

[0098] It is worth noting that the protective function of the bottom guard plate assembly 330 includes both bottom impact protection and side impact protection. The combination structure of the layer plate 333 and the shaped foam material 334 with the cooling plate 340, the lower shell frame beam 310 and the lower shell hanging point beam 320 can simultaneously meet the above two aspects of protection.

[0099] This embodiment significantly improves the impact resistance and energy absorption effect of the bottom of the battery pack 300 through the synergistic effect of the steel bottom guard plate 331, the corrugated layer plate 333 and the shaped foam material 334, effectively avoids the bottom deformation and squeezing of the battery cells, and ensures the safety of the battery pack 300. At the same time, the setting of the cooling plate 340 takes into account the heat dissipation requirements and improves the overall reliability of the battery pack 300.

[0100] According to one embodiment of this application, the shelf 333 includes a plurality of single plates 3331, one side of the single plate 3331 is provided with a connecting mortise, and the other side of the single plate 3331 forms a connecting tenon; between each pair of adjacent single plates 3331, the connecting tenon of one single plate 3331 is inserted into the connecting mortise of the other single plate 3331.

[0101] In some embodiments, each veneer 3331 is a long strip structure with a mortise formed on one side. The cross-sectional shape of the mortise is rectangular or trapezoidal, and the other side forms a tenon. The shape of the tenon matches the shape of the mortise, allowing it to be precisely inserted into the mortise. In two adjacent veneers 3331, the tenon of the preceding veneer 3331 is inserted into the mortise of the following veneer 3331, forming a tight interlocking fit. Multiple veneers 3331 are sequentially spliced ​​together using this mortise and tenon connection method to form a complete shelf 333. When the bottom is subjected to an impact force, the force borne by a single veneer 3331 is transferred to the adjacent veneers 3331 through the mortise and tenon connection, allowing the force to be distributed throughout the entire shelf 333, preventing a single veneer 3331 from deforming due to excessive force.

[0102] The mortise and tenon joint eliminates the need for additional fasteners, simplifying the assembly process of the shelf 333, reducing assembly costs, and avoiding the risk of fasteners loosening or failing during impacts. The precise fit between the tenon and mortise ensures a strong connection between adjacent panels 3331, preventing relative slippage and improving the overall structural stability of the shelf 333. The distributed force transmission within the shelf 333 ensures uniform stress distribution on each panel 3331, reducing localized stress concentration and improving the overall bending and deformation resistance of the shelf 333. The splicing design of multiple panels 3331 allows the shelf 333 to be flexibly adjusted in length according to the size of the battery pack 300, enhancing structural adaptability. Overall, this mortise and tenon joint shelf 333 structure improves connection stability and impact resistance while simplifying the assembly process, reducing costs, and further optimizing the performance of the bottom protective plate assembly 330, providing more reliable protection for the bottom of the battery pack 300.

[0103] According to one embodiment of this application, a first side plate 3332 and a second side plate 3333 are provided on one side of the single plate 3331. The first side plate 3332 is disposed above the second side plate 3333 at intervals. A connecting mortise is formed between the first side plate 3332 and the second side plate 3333. The upper side of the first side plate 3332 is bonded and fixed to the cooling plate 340.

[0104] In some embodiments, the first side plate 3332 and the second side plate 3333 are both vertically disposed on one side of the single plate 3331, and are parallel to each other. The height of the first side plate 3332 is higher than that of the second side plate 3333, forming a structure with vertical spacing. The space between the two forms a connecting mortise. The upper end face of the first side plate 3332 is higher and flatter than other positions of the single plate 3331. The upper end face of the first side plate 3332 is completely attached to the lower surface of the cooling plate 340 and is fixed by adhesive to ensure that there is no gap between the two. When adjacent single plates 3331 are connected, the tenon of one single plate 3331 is inserted into the connecting mortise of the other single plate 3331. The first side plate 3332 and the second side plate 3333 provide vertical and vertical limits for the tenon, while the first side plate 3332 is bonded and fixed to the cooling plate 340.

[0105] The mortise formed by the first side plate 3332 and the second side plate 3333 provides omnidirectional positioning for the tenons of adjacent single plates 3331, preventing the tenons from shifting vertically under impact force and improving the reliability and stability of the mortise and tenon connection. The bonding and fixing of the upper side of the first side plate 3332 to the cooling plate 340 enhances the connection strength between the layer plate 333 and the cooling plate 340, preventing relative sliding between them and improving the overall rigidity of the bottom guard plate assembly 330. This further optimizes the connection method of the layer plate 333 and its fit with the cooling plate 340, making the bottom guard plate assembly 330 more stable and efficient in force transmission. Furthermore, the area of ​​the layer plate 333 other than the bonding position between the upper side of the first side plate 3332 and the cooling plate 340 can form a gap with the cooling plate 340, allowing for slight deformation of the layer plate 333 and effectively reducing damage to the cooling plate 340 during bottom impact.

[0106] According to one embodiment of this application, a first limiting structure 311 is provided at the bottom of the lower shell frame beam 310. The first limiting structure 311 is located above the composite material base plate 332. A second limiting structure 3311 is fixedly connected to the lower edge of the steel bottom guard plate 331. The second limiting structure 3311 is welded and fixed to the lower shell hanging point beam 320.

[0107] In some embodiments, both the first limiting structure 311 and the second limiting structure 3311 are elongated structures. The first limiting structure 311 is located above the second limiting structure 3311, and the two are parallel to each other, forming a structure with vertical spacing. The space between the first limiting structure 311 and the second limiting structure 3311 can accommodate the edge of the bottom guard plate assembly 330, realizing the cooperation between the bottom guard plate assembly 330 and the lower shell side frame beam 310 and the lower shell hanging point beam 320. When the bottom is impacted, the force borne by the bottom guard plate assembly 330 is transmitted to the first limiting structure 311 and the second limiting structure 3311, and then to the lower shell side frame beam 310, realizing the force dispersion transmission. When the side is impacted, the bottom guard plate assembly 330 can also provide good support for the lower shell side frame beam 310 and the lower shell hanging point beam 320.

[0108] The above structure achieves a reliable connection between the bottom guard plate assembly 330 and the lower housing frame beam 310 through mortise and tenon joints, further consolidating the bottom structure of the battery pack 300, effectively preventing the bottom guard plate assembly 330 from failing in the event of a bottom collision, and ensuring the safety of the battery pack 300.

[0109] Furthermore, the second limiting structure 3311 is first fixed to the lower edge of the steel bottom guard plate 331, and then fixed to the lower shell hanging point beam 320 by welding, which facilitates installation while ensuring structural strength. Optionally, the second limiting structure 3311 is an aluminum layer disposed on the lower edge of the steel bottom guard plate 331, generated by methods such as chemical vapor deposition, with the edge of the aluminum layer flush with the edge of the steel plate, and the aluminum layer is welded to the inner side of the lower shell hanging point beam 320 by processes such as friction stir welding.

[0110] Furthermore, the connection and limiting of the first limiting structure 311 and the second limiting structure 3311 ensures the firm installation of the bottom guard plate assembly 330, thus eliminating the need for fixing by structures such as rivets and bolts, effectively reducing production costs. Moreover, in conventional bottom guard plate bolt installation, the side column impact and compression indirectly transmits the axial preload of the bolts to the bottom guard plate section, while this embodiment directly and comprehensively participates in the load-bearing through the section position, making the bending potential more thoroughly utilized than the former.

[0111] Optionally, the first limiting structure 311 has an L-shaped cross-section. One of its two vertical parts is fixed vertically to the bottom of the lower housing frame beam 310, and the other part is parallel to the upper edge of the bottom guard plate assembly 330. On the one hand, this can increase the contact area with the bottom guard plate assembly 330 and improve the ability to resist bottom impact. On the other hand, it can provide a small amount of deformation space for the edge of the bottom guard plate assembly 330 when bottom impact or side impact occurs, thus preventing stress concentration.

[0112] According to one embodiment of this application, the edge of the cooling plate 340 is riveted to the lower housing frame beam 310, and the edge of the cooling plate 340 is bonded to the bottom surface of the lower housing frame beam 310. An overflow port 312 is provided on the inner side of the bottom surface of the lower housing frame beam 310.

[0113] In some embodiments, the edge of the cooling plate 340 is fixed to the bottom of the lower housing frame beam 310 by riveting with a flow drill. The rivets are evenly distributed along the edge to ensure uniform connection. The edge of the cooling plate 340 is bonded to the bottom surface of the lower housing frame beam 310 with adhesive. The adhesive is evenly applied to the contact surface. An overflow port 312 is provided on the inner side of the bottom surface of the lower housing frame beam 310. The overflow port 312 is a long groove to accommodate excess adhesive. After the impact force is transmitted to the cooling plate 340, the riveting structure bears the main mechanical force, preventing the cooling plate 340 from separating from the lower housing frame beam 310. The adhesive structure enhances the sealing performance and provides auxiliary load-bearing capacity. Excess adhesive is discharged through the overflow port 312 to avoid adhesive accumulation that affects the bonding effect.

[0114] The dual fixing method of riveting and bonding significantly improves the connection strength and reliability between the cooling plate 340 and the lower housing frame beam 310 compared to a single fixing method. Riveting provides stable mechanical support, while bonding enhances the sealing and overall integrity of the connection, effectively preventing the cooling plate 340 from loosening during collisions. The overflow port 312 allows excess adhesive to drain, ensuring complete contact between the cooling plate 340 and the bottom surface of the lower housing frame beam 310, improving bonding quality and connection strength, while avoiding stress concentration caused by adhesive buildup. This dual fixing and overflow port 312 design ensures connection strength and improves sealing performance, preventing moisture or impurities from entering the battery pack 300 through gaps. It also allows the cooling plate 340 to participate in force transmission more stably, further enhancing the overall reliability and impact resistance of the battery pack 300.

[0115] Of course, in some embodiments, the edge of the cooling plate 340 and the bottom of the lower housing frame beam 310 can also be fixed by welding. In this case, a notch is provided at the bottom of the lower housing frame beam 310 to facilitate welding.

[0116] This application also provides a vehicle including the lower body structure of the above embodiments.

[0117] Since the vehicle in this embodiment includes all the features of the lower body structure described above, it also has the same technical effect, which will not be repeated here.

[0118] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A lower vehicle body structure characterized by comprising: The application relates to a vehicle body structure, comprising: a threshold beam having a first energy-absorbing area, a second energy-absorbing area, a bending-resistant area and a transition area, one side of the first energy-absorbing area being connected with the second energy-absorbing area and the transition area, the transition area being located on the upper side of the second energy-absorbing area, the bending-resistant area being connected with the side of the second energy-absorbing area away from the first energy-absorbing area and the lower side of the transition area, wherein the transition area gradually inclines upward from the side of the first energy-absorbing area to the side away from the first energy-absorbing area; a seat cross beam, the end of the seat cross beam being fixedly connected with the threshold beam, part of the end of the seat cross beam being located on the side of the transition area away from the first energy-absorbing area and part of the end of the seat cross beam being located on the upper side of the transition area; a battery pack comprising a lower shell beam and a bottom guard plate assembly, at least part of the lower shell beam being located on the side of the bending-resistant area away from the second energy-absorbing area and being connected with the bending-resistant area, the bottom guard plate assembly being connected with the lower shell beam.

2. The undercarriage structure according to claim 1, characterized by The upper side of the transition area forms a first water platform step surface, the side of the transition area away from the first energy-absorbing area forms a second water platform step surface and an inclined surface, and the inclined surface is connected with the first water platform step surface and the second water platform step surface. The seat cross beam is connected with at least the first water platform step surface, the inclined surface and the second water platform step surface of the transition area.

3. The undercarriage structure according to claim 2, characterized in that, The end of the seat cross beam is provided with a first connecting part, a second connecting part and a third connecting part. The first connecting part and the second connecting part are arranged on the two sides of the seat cross beam, and the first connecting part and the second connecting part are fixed with the inclined surface and the second water platform step surface. The third connecting part is located between the first connecting part and the second connecting part, and the third connecting part is fixed with at least the position of the first water platform step surface.

4. The undercarriage structure according to claim 1, characterized by The threshold beam comprises vertical rib plates separating the first energy-absorbing area, the second energy-absorbing area and the bending-resistant area and horizontal rib plates located in the first energy-absorbing area and the second energy-absorbing area, and the horizontal rib plates are fixedly connected with the vertical rib plates on the two sides. The horizontal rib plates located in the first energy-absorbing area separate the first energy-absorbing area into at least two filling cavities, and at least one of the filling cavities is provided with energy-absorbing material. The number of the horizontal rib plates located in the second energy-absorbing area is less than that of the horizontal rib plates located in the first energy-absorbing area.

5. The undercarriage structure according to claim 4, characterized in that, The threshold beam comprises at least two first inclined rib plates located in the bending-resistant area, the two sides of the first inclined rib plates are fixedly connected with the two side walls of the bending-resistant area respectively, and an included angle is formed between adjacent first inclined rib plates.

6. The undercarriage structure of claim 1, wherein The threshold beam comprises a second inclined rib plate located in the transition area, and the second inclined rib plate gradually inclines upward from the side close to the first energy-absorbing area to the side away from the first energy-absorbing area.

7. The undercarriage structure according to any one of claims 1 to 6, characterized in that, The threshold beam comprises a clad steel material and an aluminum profile, at least part of the clad steel material is wrapped outside the aluminum profile, and the part of the clad steel material wrapped outside the aluminum profile is arranged along the outer wall of the aluminum profile.

8. The undercarriage structure according to any one of claims 1 to 6, characterized in that, The seat crossbeam includes a front crossbeam and a rear crossbeam, both of which are connected to the sill beam. At least one of the front crossbeam and the rear crossbeam is configured to include: Top stamped steel plate; The bottom steel plate is located below the top stamped steel plate and together with the top stamped steel plate forms the inner cavity of the crossbeam; The inner beam is made of aluminum or polyurethane pultruded composite material and is located inside the crossbeam cavity.

9. The undercarriage structure according to claim 8, characterized in that, The inner beam of the front crossbeam includes multiple surrounding plates, a third inclined stiffener, and an end cap. The multiple surrounding plates are connected sequentially along the circumference of the inner beam. The third inclined stiffener forms an angle with the vertical plane and is fixedly connected to the upper and lower surrounding plates respectively. The end cap is fixedly connected to the ends of at least a portion of the surrounding plates and / or at least a portion of the ends of the third inclined stiffener.

10. The undercarriage structure of claim 9, wherein, The bottom steel plate of the front crossbeam is a roll-formed steel plate structure, and the inner beam of the front crossbeam has a bottom panel that is shaped to fit the bottom steel plate.

11. The undercarriage structure of claim 8, wherein, The rear crossbeam forms a seat mounting area and a footrest recess area; The inner beam of the rear crossbeam includes a lower cavity, an upper cavity, and a supporting rib. The lower cavity is located in the seat mounting area and the footrest recess area, the upper cavity is located in the seat mounting area, and the supporting rib forms an angle with the horizontal plane. The supporting ribs are provided in the lower cavity and the upper cavity, and the number of supporting ribs in the lower cavity is greater than the number of supporting ribs in the upper cavity, or the supporting ribs are only provided in the lower cavity.

12. The undercarriage structure according to any one of claims 1 to 6, characterized in that, The lower shell beam includes: The lower housing frame beam is located on the side of the bending resistance zone away from the second energy absorption zone, and is located above the edge of the bottom protective plate assembly; The lower housing hanging point beam is located below the bending resistance zone and is fixedly connected to the lower housing frame beam. The lower housing hanging point beam is fixedly connected to the edge of the bottom guard plate assembly.

13. The undercarriage structure of claim 12, wherein, The battery pack also includes a cooling plate, the edge of which is fixedly connected to the lower housing frame beam. The bottom protective plate assembly includes: A steel bottom guard plate is located below the cooling plate and is fixedly connected to the hanging point beam of the lower shell; A composite material base plate includes a layer and a shaped foam material. The layer is located between the cooling plate and the steel base plate and is bonded and fixed to the lower side of the cooling plate. The layer extends in a wavy shape, and the shaped foam material fills the space between the layer and the steel base plate.

14. The undercarriage structure of claim 13, wherein, The shelf comprises multiple veneers, one side of which is provided with a connecting mortise, and the other side of which is formed with a connecting tenon; Between each pair of adjacent veneers, the tenon of one veneer is inserted into the mortise of the other veneer.

15. The undercarriage structure of claim 14, wherein, The single board has a first side plate and a second side plate on one side. The first side plate is spaced above the second side plate. The connecting mortise is formed between the first side plate and the second side plate. The upper side of the first side plate is bonded and fixed to the cooling plate.

16. The undercarriage structure of claim 13, wherein The bottom of the lower shell frame beam is provided with a first limiting structure, which is located above the composite material base plate. The lower edge of the steel bottom guard plate is fixedly connected with a second limiting structure, which is fixed to the lower shell hanging point beam.

17. The undercarriage structure of claim 13, wherein, The edge of the cooling plate is riveted to the lower housing frame beam, and the edge of the cooling plate is bonded to the bottom surface of the lower housing frame beam. An overflow outlet is provided on the inner side of the bottom surface of the lower housing frame beam.

18. A vehicle characterized by comprising: Includes the lower vehicle body structure as described in any one of claims 1 to 17.

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