Electric vehicle chassis and chassis production process

Abstract

The application discloses a kind of electric vehicle chassis and chassis production process in new energy electric vehicle technical field.Electric vehicle chassis includes main body and heat insulation plate body, the narrow surface of the storage cavity for storing battery pack on main body is provided with convex rib, and the recess of the surface of battery pack is embedded into convex rib.By the cooperation of convex rib and recess, the effective heat conduction contact area of battery pack and main body is increased, so that the heat generated by battery pack is more directly and quickly dissipated through main body.The bottom wall of the storage cavity for adhering battery pack is provided with not less than two heat dissipation fins, and the heat exchange area of main body to the outside is increased by heat dissipation fins, so that the heat of battery pack is dissipated through main body to the outside / cooling medium.The heat conduction plate of heat insulation plate body adheres to the side of battery pack away from the bottom wall of storage cavity, to form a new heat dissipation passage acting on battery pack.The chassis production process includes heat treatment, extrusion molding, CNC machining and turning.

Description

Technical Field

[0001] This invention belongs to the field of new energy electric vehicle technology, specifically relating to an electric vehicle chassis and chassis manufacturing process. Background Technology

[0002] In recent years, new energy electric vehicles have developed rapidly and have become an important direction for future transportation. Unlike fuel vehicles, electric chassis, in addition to their load-bearing function, integrate battery packs, drive-by-wire actuators, intelligent suspension, and domain controllers, forming a multi-functional integrated platform. The deep integration of the power battery and chassis structure into a single unit fully utilizes chassis space, achieving vehicle lightweighting and significantly lowering the vehicle's center of gravity to the chassis plane, thus significantly improving the electric vehicle's driving stability and anti-roll capability.

[0003] However, existing new energy electric vehicles typically use independently sealed battery packs, suspended or fixed to a battery mounting cavity under the vehicle chassis by bolts. During vehicle operation, the battery pack continuously generates heat. If heat dissipation is not timely, it will not only accelerate battery aging and shorten its lifespan, but may also induce serious safety hazards such as thermal runaway. Current conventional heat dissipation methods mainly rely on heat conduction between the battery pack casing and the chassis metal structure to dissipate heat, resulting in low heat exchange efficiency and high thermal resistance. With the continuous increase in the power density and fast charging rate requirements of new energy vehicles, battery heat generation has increased dramatically. Passive heat conduction alone is no longer sufficient to meet the heat dissipation needs under high-load conditions, and traditional heat dissipation methods are gradually becoming a bottleneck restricting further improvements in electric vehicle performance. Summary of the Invention

[0004] The purpose of this invention is to disclose an electric vehicle chassis and chassis manufacturing process, which can effectively dissipate the heat of the battery pack through the chassis, thereby preventing the problem of heat accumulation leading to reduced battery life and promoting further improvement in the performance of electric vehicles.

[0005] To achieve the above objectives, the present invention discloses an electric vehicle chassis comprising: The main body includes a storage cavity and heat dissipation fins. The storage cavity is used to store a battery pack. The side wall of the storage cavity is provided with a protruding ridge, which is used to embed into a groove on the surface of the battery pack. The bottom wall of the storage cavity, which is used to fit the battery pack, is provided with no less than two heat dissipation fins. A heat insulation plate is disposed on the side of the column away from the bottom wall of the storage cavity; the heat insulation plate includes a heat-conducting plate, which is attached to the side of the battery pack away from the bottom wall of the storage cavity.

[0006] As an optional implementation, the heat dissipation fins extend along the width direction of the main body, and a plurality of the heat dissipation fins are distributed along the length direction of the main body; the width of the main body is D, and the length of the fins along the width direction of the main body is d; the value of d is in the range of 0.8D-0.9D.

[0007] As an optional implementation, the heat-conducting plate includes a first side plate and a second side plate; the first side plate includes a first mating surface and a first through groove, the through groove being disposed on the first mating surface; the second side plate includes a second mating surface and a second through groove, the second through groove being disposed on the second mating surface; the first mating surface is fixedly connected to the second mating surface, and both the first through groove and the second through groove are used for transporting refrigerant.

[0008] As an optional implementation, the first through slot is parallel to the second through slot, and the first through slot and the second through slot are offset from each other along the width direction of the heat-conducting plate.

[0009] As an optional implementation, the heat-conducting plate further includes a thermally conductive adhesive layer disposed between the first bonding surface and the second bonding surface.

[0010] As an optional implementation, the heat insulation plate further includes a thermal insulation plate; the thermal insulation plate is disposed on the side of the heat-conducting plate away from the main body; the thermal insulation plate is used to isolate the heat-conducting plate from the cabin of the electric vehicle.

[0011] As an optional implementation, the electric vehicle chassis further includes side wings, which are provided on both opposite sides of the main body; the side wings are used to increase the width of the main body.

[0012] As an optional implementation, a connecting block is provided on the side of the wing near the main body, and a positioning groove is provided on the main body corresponding to the position of the connecting block; the positioning groove is used to cooperate with the connecting block.

[0013] As an optional implementation, the side wing includes a hollow inner cavity, the two sides of which are connected to the outside; the side wall of the storage cavity is provided with a through hole, the through hole connecting the storage cavity and the hollow inner cavity.

[0014] On the other hand, the present invention discloses a chassis manufacturing process for producing the aforementioned electric vehicle chassis, wherein the electric vehicle chassis includes a main body; the chassis manufacturing process includes the following steps: S1. Heat treatment: Heat the ingot to 560℃-580℃ and hold for 4h-12h; S2. Extrusion molding: Install the flow-dividing combination mold, put the heat-treated ingot into the extrusion cylinder, and start the extruder; S3, CNC machining: machining open openings or through holes in extruded hollow profiles; S4. Turning: Perform multiple turning operations along the length of the bottom wall on one side of the hollow profile to form heat dissipation fins.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The sidewall of the storage cavity on the main body is provided with protruding ridges, which are used to embed into the grooves on the surface of the battery pack. Through the cooperation of the protruding ridges and the grooves, the battery pack is tightly fitted and positioned against the sidewall of the storage cavity. This not only increases the stability of the battery pack's position within the storage cavity, but also significantly increases the effective thermally conductive contact area between the battery pack and the main body, reducing the thermal resistance at the interface between the two. This allows the heat generated by the battery pack to be dissipated more directly and quickly through the main body.

[0016] The bottom wall of the storage cavity, which is used to fit the battery pack, is equipped with no fewer than two heat dissipation fins. The heat dissipation fins increase the heat exchange area of ​​the main body to the outside, and accelerate the dissipation of the battery pack's heat to the outside of the vehicle / cooling medium through the main body.

[0017] The heat-conducting plate of the heat insulation plate is attached to the side of the battery pack away from the bottom wall of the storage cavity. The heat-conducting plate is attached to the other side of the battery pack, and actively disperses the heat on the other side of the battery to form a new heat dissipation path for the battery pack.

[0018] With the cooperation of protruding ribs, heat dissipation fins, and heat insulation plates, a comprehensive heat dissipation path is formed covering the circumferential sidewalls of the battery pack. This three-dimensional heat conduction effectively alleviates potential heat accumulation points in the battery pack, balances the temperature distribution between the center and edges, and between the top and bottom of the battery pack, significantly reduces the temperature difference between different areas of the battery pack, and prevents the risk of performance degradation or thermal runaway caused by localized overheating of the battery pack. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a first three-dimensional structural diagram of the chassis disclosed in this invention; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 This is an exploded view of the heat-conducting plate disclosed in this invention; Figure 4 yes Figure 3 Enlarged view of point B in the middle; Figure 5 This is a first cross-sectional view of the heat-conducting plate disclosed in this invention; Figure 6 This is a second cross-sectional view of the heat-conducting plate disclosed in this invention; Figure 7 This is an exploded view of the main body and the heat insulation panel disclosed in this invention; Figure 8 This is a second three-dimensional structural diagram of the chassis disclosed in this invention; Figure 9 This is an exploded view of the chassis disclosed in this invention; Figure 10 yes Figure 9 Enlarged view of point C in the middle; Figure 11 This is a three-dimensional cross-sectional view of the chassis disclosed in this invention; Figure 12 yes Figure 11 Enlarged view at point D; Figure 13 This is a schematic flowchart of the chassis manufacturing process disclosed in this invention.

[0021] Explanation of key figure labels: 1. Main body; 11. Storage cavity; 111. Protruding ridge; 112. Through hole; 12. Heat dissipation fins; 13. Positioning groove; 2. Insulation plate body; 21. Heat-conducting plate; 211. First side plate; 2111. First mating surface; 2112. First through groove; 212. Second side plate; 2121. Second mating surface; 2122. Second through groove; 213. Thermally conductive adhesive layer; 22. Thermal insulation plate; 3. Side wings; 31. Connecting block; 32. Hollow inner cavity. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0024] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0025] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0026] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0027] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0028] Please see Figures 1 to 2 As shown, one embodiment of this application discloses an electric vehicle chassis, including a main body 1 and a heat insulation plate 2. The main body 1 includes a storage cavity 11 and heat dissipation fins 12. The storage cavity 11 is used to store a battery pack. A protruding ridge 111 is provided on the side wall of the storage cavity 11, which is used to embed into a groove on the surface of the battery pack. Through the cooperation of the protruding ridge 111 and the groove, the battery pack is tightly fitted and positioned against the side wall of the storage cavity 11, which not only increases the stability of the battery pack's position within the storage cavity 11, but also significantly increases the effective thermal contact area between the battery pack and the main body 1, reducing the contact thermal resistance at the interface between the two, allowing the heat generated by the battery pack to be dissipated more directly and quickly through the main body 1. The bottom wall of the storage cavity 11, which is used to fit the battery pack, is provided with at least two heat dissipation fins 12. These fins increase the external heat exchange area of ​​the main body 1, accelerating the dissipation of heat from the battery pack to the outside of the vehicle / cooling medium through the main body 1.

[0029] The heat insulation plate 2 is located on the side of the column away from the bottom wall of the storage cavity 11. The heat insulation plate 2 includes a heat-conducting plate 21, which is attached to the side of the battery pack away from the bottom wall of the storage cavity 11. The heat-conducting plate 21 is attached to the other side of the battery pack, and actively disperses the heat on the other side of the battery to form a new heat dissipation path for the battery pack.

[0030] With the cooperation of the protruding ribs 111, the heat dissipation fins 12, and the heat insulation plate 2, a comprehensive heat dissipation path covering the circumferential sidewalls of the battery pack is formed. This three-dimensional heat conduction effectively alleviates potential heat accumulation points in the battery pack, balances the temperature distribution between the center and edges, and between the top and bottom of the battery pack, significantly reduces the temperature difference between different areas of the battery pack, and prevents the risk of performance degradation or thermal runaway caused by local overheating of the battery pack.

[0031] Please see Figure 1 As shown, in some embodiments, the heat dissipation fins 12 extend along the width direction of the main body 1, and multiple heat dissipation fins 12 are distributed along the length direction of the main body 1. The width of the main body 1 is D, and the length of the heat dissipation fins 12 along the width direction of the main body 1 is d, where the value of d ranges from 0.8D to 0.9D.

[0032] The heat dissipation fins 12 are configured to extend along the width direction of the main body 1, and multiple heat dissipation fins 12 are arranged at intervals along the length direction of the main body 1. This effectively suppresses the local accumulation of heat, allowing the high temperature generated in the central area of ​​the battery pack to be quickly conducted laterally and dissipated, thus maintaining extremely uniform temperature in all areas of the battery pack.

[0033] The value of d ranges from 0.8D to 0.9D. Within this width range, it can ensure that the heat dissipation fins 12 have a large effective heat exchange area within the limited chassis width, while maintaining the necessary edge safety distance to avoid the risk of scratches caused by the heat dissipation fins 12 being too large or insufficient heat dissipation caused by the heat dissipation fins being too small.

[0034] The length of the heat dissipation fins 12 is slightly less than the width of the main body 1, creating a guiding gap between the edge of the heat dissipation fins 12 and the edge of the main body 1. This ensures that airflow between different heat dissipation fins 12 can exchange with the outside through the guiding gap at the edge, thus constructing an efficient lateral ventilation and heat dissipation mechanism. When airflow impacts the heat dissipation fins 12, the guiding gap at the edge guides part of the airflow to laterally dart along a direction perpendicular to the heat dissipation fins 12, causing forced convection displacement between the high-temperature airflow between adjacent heat dissipation fins 12 and the fresh, cold outside air. This significantly reduces the surface temperature of the heat dissipation fins 12 and improves the overall heat exchange efficiency of the heat dissipation fins 12.

[0035] Under the intense thermal expansion and contraction caused by high-power charging and discharging of the battery pack, the gap at the edge of the heat dissipation fin 12 provides a deformation buffer space for the heat dissipation fin 12, preventing the fin from buckling or cracking due to thermal expansion obstruction, thus ensuring the long-term reliability of the heat dissipation fin 12 structure.

[0036] Please see Figures 3 to 6As shown, in some embodiments, the heat-conducting plate 21 includes a first side plate 211 and a second side plate 212. The first side plate 211 includes a first mating surface 2111 and a first through groove 2112, with the through groove disposed on the first mating surface 2111. The second side plate 212 includes a second mating surface 2121 and a second through groove 2122, with the second through groove 2122 disposed on the second mating surface 2121. The first mating surface 2111 is fixedly connected to the second mating surface 2121, and both the first through groove 2112 and the second through groove 2122 are used for transporting refrigerant.

[0037] By adopting a split assembly structure of a first side plate 211 and a second side plate 212 for the heat-conducting plate 21, and respectively setting corresponding first through grooves 2112 and second through grooves 2122 on the first mating surface 2111 and the second mating surface 2121, a closed refrigerant flow channel is formed inside the heat-conducting plate 21. The forced circulation of the refrigerant within the flow channel can quickly remove the heat accumulated in the battery pack.

[0038] In some embodiments, the first side plate 211 and the second side plate 212 constitute a split structure of the heat-conducting plate 21, which facilitates the processing of the direction, number, and cross-sectional shape of the refrigerant flow channels. The first through-slot 2112 and the second through-slot 2122 can be processed into curved shapes, or the first through-slot 2112 or the second through-slot 2122 can be centrally distributed according to the actual distribution of the battery pack to achieve precise temperature control in zones. Compared with external independent cooling pipes, this integrated heat-conducting plate 21 structure significantly reduces the number of external connectors, reduces the complexity and leakage risk of the active heat dissipation structure, and at the same time makes full and effective use of the internal space of the heat-conducting plate 21, improving the integration of the heat insulation plate 2.

[0039] Please see Figure 5 As shown, in this embodiment, the first through groove 2112 is parallel to the second through groove 2122, and the first through groove 2112 and the second through groove 2122 are staggered along the width direction of the heat-conducting plate 21. This significantly increases the number of refrigerant transport channels per unit length in the width direction of the heat-conducting plate 21.

[0040] Increasing the number of refrigerant channels per unit width significantly increases the contact area between the refrigerant and the inner wall of the heat-conducting plate 21, directly expanding the effective heat exchange area of ​​the heat-conducting plate 21. This allows the heat-conducting plate 21 to achieve higher heat exchange power with a smaller volume. The high-density refrigerant channels allow the refrigerant to be closer to heat sources on the surface of the battery pack, greatly shortening the straight-line distance of heat transfer from the battery surface to the refrigerant, effectively eliminating the lateral temperature gradient inside the heat-conducting plate 21, ensuring a highly uniform temperature field on the top surface of the battery pack, and preventing the generation of local hot spots in the battery pack.

[0041] Please see Figure 6As shown, in this embodiment, the first channel 2112 is parallel to the second channel 2122, and the first channel 2112 and the second channel 2122 together form the same channel for transporting refrigerant.

[0042] The flow channel formed by the splicing of the first channel 2112 and the second channel 2122 has a larger cross-sectional area, which significantly reduces the flow resistance of the refrigerant and allows a larger flow of refrigerant to pass through per unit time, thereby multiplying the heat absorption efficiency and response speed of the heat-conducting plate 21 and effectively coping with the severe thermal shock brought about by the surge in battery pack power.

[0043] The large cross-section refrigerant channel provides ample flow space, making it easier for trace amounts of welding residue, metal shavings, or oxide particles to be flushed away by the fluid rather than causing blockages or accumulations within the channel. In some low-temperature applications, when the refrigerant viscosity increases or tiny ice crystals form, the large cross-section channel effectively avoids "ice blockage" caused by narrow channels, ensuring the continuity of refrigerant circulation and improving the applicability of the heat-conducting plate 21 in different environments to guarantee the heat dissipation effect on the battery pack.

[0044] Please see Figures 5 to 6 As shown, in some embodiments, the heat-conducting plate 21 further includes a thermally conductive adhesive layer 213, which is disposed between the first bonding surface 2111 and the second bonding surface 2121.

[0045] The thermally conductive adhesive comprises a base resin, fillers (including flake alumina and a small amount of boron nitride), catalysts, coupling agents, etc. The adhesive strength of the thermally conductive adhesive enhances the bond strength between the first side plate 211 and the second side plate 212, compensating for potential defects such as incomplete or missed welds.

[0046] By eliminating the air gap between the interface of the first side plate 211 and the second side plate 212 through thermally conductive adhesive, the thermal resistance of air is blocked, and the thermal contact area between the first side plate 211 and the second side plate 212 is increased to nearly 100%, which significantly improves the heat conduction efficiency between the first side plate 211 and the second side plate 212, ensuring that the heat-conducting plate 21 can fully absorb the heat of the battery pack.

[0047] Under the assembly pressure of the first side plate 211 and the second side plate 212, the thermally conductive adhesive layer 213 is squeezed into a thin layer. The thermally conductive adhesive layer 213 completely fills the micro-valve and assembly gap between the outer mating surfaces of the first through groove 2112 and the second through groove 2122, preventing the refrigerant from penetrating outward along the radial direction of the first through groove 2112 or the second through groove 2122. This prevents some refrigerant from remaining in the gap between the first side plate 211 and the second side plate 212, thus preventing the formation of local dead zones and preventing the trapped refrigerant from hindering the heat transfer process between the first side plate 211 and the second side plate.

[0048] Please see Figure 7As shown, in some embodiments, the heat insulation plate 2 further includes a thermal insulation plate 22, which is disposed on the side of the heat-conducting plate 21 away from the main body 1. The thermal insulation plate 22 is used to isolate the heat-conducting plate 21 from the cabin of the electric vehicle.

[0049] During the process of absorbing heat from the top of the battery pack and cooling the refrigerant, the heat-conducting plate 21 may maintain a relatively high temperature. The thermal insulation plate 22, with its extremely low thermal conductivity, can reduce the heat transfer originating from the heat-conducting plate 21 by more than 90%, preventing the high-load heat generation of the battery pack from causing the temperature rise of the cabin floor, and ensuring the constant temperature comfort and air conditioning efficiency of the cabin environment.

[0050] The thermal insulation plate 22 typically also has damping and vibration reduction characteristics, which can effectively suppress the transmission of structural noise and vibration caused by the heat-conducting plate 21 and refrigerant flow to the cabin. At the same time, in extreme conditions such as refrigerant leakage or failure of the heat-conducting plate 21, this plate can act as a last physical firewall to prevent high temperature or refrigerant from directly contacting the cabin interior and ensure occupant safety.

[0051] Please see Figures 8 to 9 As shown, in some embodiments, the electric vehicle chassis also includes side wings 3, with side wings 3 provided on both opposite sides of the main body 1, and the side wings 3 are used to increase the width of the main body 1.

[0052] Side wings 3 increase the chassis's mass distribution width, directly improving the vehicle's roll center height and lateral moment of inertia. During high-speed lane changes or cornering, this effectively suppresses body roll, counteracts the yaw torque from the high-torque motor output, and significantly enhances tire contact patch and grip, thereby improving driving safety and handling smoothness.

[0053] The side wing 3, acting as a reinforcing rib, forms a box-shaped cross-section with the main storage cavity 11, significantly improving the torsional stiffness and bending mode of the chassis assembly. This structural reinforcement results in less deformation of the chassis when subjected to the enormous weight of the battery pack and complex road impacts, thereby ensuring the long-term structural integrity of the internal refrigerant channels and heat conduction interfaces, and preventing the chassis's heat dissipation efficiency from decreasing or refrigerant leakage due to deformation.

[0054] Please see Figures 10 to 12 As shown, in some embodiments, the side wing 3 is provided with a connecting block 31 on the side close to the main body 1, and the main body 1 is provided with a positioning groove 13 corresponding to the position of the connecting block 31. The positioning groove 13 is used to cooperate with the connecting block 31.

[0055] By setting a connecting block 31 on the side wing 3 and opening a corresponding positioning groove 13 on the main body 1, a mortise and tenon type interlocking positioning structure is formed, realizing high-precision assembly and collaborative load-bearing between the side wing 3 and the main body 1.

[0056] By combining the shape and surface fit of the block 31 and the positioning groove 13, the freedom of the side wing 3 in three-dimensional space is restricted before welding or fastening, effectively eliminating assembly misalignment caused by cumulative tolerances. This rigid positioning ensures that the heat dissipation fins 12 on the outer edge of the side wing 3 always maintain the designed safety clearance between the chassis guard plate and road obstacles, avoiding the risk of scratches caused by assembly deviations.

[0057] Please see Figure 11 and Figure 12 As shown, in some embodiments, the side wing 3 includes a hollow inner cavity 32, the two sides of which are connected to the outside. The side wall of the storage cavity 11 is provided with a through hole 112, which connects the storage cavity 11 and the hollow inner cavity 32.

[0058] The hollow inner cavity 32 is equivalent to adding a huge, concealed heat dissipation duct to the side of the chassis. The heat accumulated inside the battery pack in the storage cavity 11 can be directly carried away by the high-speed airflow flowing through the hollow inner cavity 32 in the form of thermal convection through the through hole 112. This results in an exponential improvement in the lateral heat dissipation efficiency of the battery pack, making it particularly suitable for instantaneous thermal shock management under high-power fast charging of the battery pack.

[0059] When the two sides of the hollow cavity 32 are connected to the outside, a continuous forced convection is formed within the hollow cavity 32 in conjunction with the oncoming wind generated by the vehicle's movement or the negative pressure at the rear of the chassis. Once the battery pack generates a large amount of high-temperature and high-pressure gas due to thermal runaway, the through hole 112 can quickly guide the gas into the hollow channel of the side wing 3, allowing it to be discharged to both sides of the vehicle along the shortest path, preventing high-temperature smoke from accumulating at the bottom of the chassis or flowing back into the cabin, thus significantly reducing the destructive intensity of a thermal runaway accident.

[0060] The hollow inner cavity 32 significantly reduces the amount of solid material used and lowers the weight of the chassis assembly while ensuring the bending stiffness of the side wings 3. At the same time, this cavity structure can serve as an energy-absorbing crumple zone in side collisions. When subjected to a side impact, it absorbs energy through deformation and protects the battery pack in the core storage cavity 11 from direct compression, thereby improving the overall vehicle's side collision safety level.

[0061] Please see Figure 13 As shown, in some embodiments, the present invention discloses a chassis manufacturing process for producing the aforementioned electric vehicle chassis. The electric vehicle chassis includes a main body 1, and the chassis manufacturing process includes the following steps: S1. Heat treatment: Heat the ingot to 560℃-580℃ and hold for 4h-12h; S2. Extrusion molding: Install the flow-dividing combination mold, put the heat-treated ingot into the extrusion cylinder, and start the extruder; S3, CNC machining: machining open openings or through holes in extruded hollow profiles; S4. Turning: Perform multiple turning operations along the length of the bottom wall on one side of the hollow profile to form heat dissipation fins 12.

[0062] In S1, the ingot is homogenized to effectively eliminate residual internal stress formed during the casting process, significantly improving the material's tendency for intergranular corrosion and fracture toughness. Simultaneously, the homogenized structure refines the recrystallized grains during subsequent extrusion, ensuring that the final formed body 1 has a dense metallographic structure and isotropic mechanical properties. This provides a solid material foundation for the chassis to withstand complex road impact loads and prevents brittle fracture during use.

[0063] In S2, a split-flow combined die is used to extrude hollow profiles, achieving one-time integral forming of the chassis body 1 (including storage cavity 11 and protruding ridge 111). This process metallurgically bonds the complex multi-chamber structure of the body 1 (such as storage cavity 11 and protruding ridge 111) under high pressure through a die welding line, avoiding cumbersome welding and assembly processes and significantly improving chassis production efficiency. Simultaneously, the work hardening effect generated by extrusion deformation significantly improves the yield strength and tensile strength of the body 1, and the hollow structure significantly reduces material usage while maintaining the same stiffness.

[0064] In step S3, precision CNC machining is performed on the extruded hollow profile to accurately remove closed walls in specific areas to form the opening of the storage cavity 11, or to machine key assembly features such as the positioning groove 13 and the through hole 112. This step ensures that the fit tolerance between the main body 1 and components such as the side wing 3 and the heat-conducting plate 21 reaches the micron level. In particular, the machining accuracy of the through hole 112 and the positioning groove 13 directly determines the sealing performance of the subsequent refrigerant channel and the positioning stability of the battery pack.

[0065] In S4, a gear-cutting machine is typically used to continuously machine along the length of the bottom wall of the hollow profile, directly cutting the integrally formed heat dissipation fins 12 onto the chassis body 1. Compared to traditional riveting or welding of additional fins, this process eliminates the interfacial thermal resistance between the fins and the body 1, achieving continuous heat conduction of the metal substrate and maximizing heat transfer efficiency. Simultaneously, the machining process ensures consistent pitch, height, and thickness of the heat dissipation fins 12, guaranteeing uniform airflow distribution among the fins and preventing eddy currents, thereby achieving optimal aerodynamic heat dissipation performance of the heat dissipation fins 12 within a limited space.

[0066] In some embodiments, the chassis manufacturing process also includes S5, namely, a stress-relief annealing process. Heat dissipation fins 12 are formed by cutting a hollow profile using a tooth-shaving machine. Residual processing stress exists between the fin roots and the hollow profile substrate. Over time, this processing stress gradually releases, easily leading to slight warping at the edges of the heat dissipation fins 12 and increased thermal resistance, thereby limiting the heat dissipation capacity of the heat dissipation fins 12. Therefore, it is necessary to perform stress-relief annealing on the machined heat dissipation fins 12 to eliminate the residual processing stress between the fin roots and the hollow profile substrate. The specific stress-relief annealing process includes an annealing temperature of 150℃~180℃, holding at that temperature for 2h~4h, followed by furnace cooling.

[0067] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. An electric vehicle chassis for use in electric vehicles, characterized in that, include: The main body (1) includes a storage cavity (11) and heat dissipation fins (12). The storage cavity (11) is used to store a battery pack. The side wall of the storage cavity (11) is provided with a protruding ridge (111), which is used to embed into the groove on the surface of the battery pack. The bottom wall of the storage cavity (11) is provided with no less than two heat dissipation fins (12) to fit against the battery pack. A heat insulation plate (2) is disposed on the side of the column away from the bottom wall of the storage cavity (11); the heat insulation plate (2) includes a heat-conducting plate (21), which is attached to the side of the battery pack away from the bottom wall of the storage cavity (11).

2. The electric vehicle chassis according to claim 1, characterized in that: The heat dissipation fins (12) extend along the width direction of the main body (1), and a plurality of the heat dissipation fins (12) are distributed along the length direction of the main body (1); the width of the main body (1) is D, and the length of the fins along the width direction of the main body (1) is d; the value range of d is 0.8D-0.9D.

3. The electric vehicle chassis according to claim 1, characterized in that: The heat-conducting plate (21) includes a first side plate (211) and a second side plate (212); the first side plate (211) includes a first mating surface (2111) and a first through groove (2112), the through groove being disposed on the first mating surface (2111); the second side plate (212) includes a second mating surface (2121) and a second through groove (2122), the second through groove (2122) being disposed on the second mating surface (2121); the first mating surface (2111) is fixedly connected to the second mating surface (2121), and both the first through groove (2112) and the second through groove (2122) are used for transporting refrigerant.

4. The electric vehicle chassis according to claim 3, characterized in that: The first through groove (2112) is parallel to the second through groove (2122), and the first through groove (2112) and the second through groove (2122) are offset from each other along the width direction of the heat-conducting plate (21).

5. The electric vehicle chassis according to claim 3, characterized in that: The heat-conducting plate (21) further includes a heat-conducting adhesive layer (213), which is disposed between the first bonding surface (2111) and the second bonding surface (2121).

6. The electric vehicle chassis according to claim 1, characterized in that: The heat insulation plate (2) also includes a thermal insulation plate (22); the thermal insulation plate (22) is located on the side of the heat-conducting plate (21) away from the main body (1); the thermal insulation plate (22) is used to isolate the heat-conducting plate (21) from the cabin of the electric vehicle.

7. The electric vehicle chassis according to any one of claims 1-6, characterized in that: The electric vehicle chassis also includes side wings (3), and the side wings (3) are provided on both sides of the main body (1); the side wings (3) are used to increase the width of the main body (1).

8. The electric vehicle chassis according to claim 7, characterized in that: The side wing (3) is provided with a connecting block (31) on the side close to the main body (1), and the main body (1) is provided with a positioning groove (13) corresponding to the position of the connecting block (31); the positioning groove (13) is used to cooperate with the connecting block (31).

9. The electric vehicle chassis according to claim 7, characterized in that: The side wing (3) includes a hollow inner cavity (32), the two sides of which are connected to the outside; the side wall of the storage cavity (11) is provided with a through hole (112), the through hole (112) connecting the storage cavity (11) and the hollow inner cavity (32).

10. A chassis manufacturing process for producing the electric vehicle chassis according to any one of claims 1-9, characterized in that: The electric vehicle chassis includes a main body (1); the chassis manufacturing process includes the following steps: S1. Heat treatment: Heat the ingot to 560℃-580℃ and hold for 4h-12h; S2, Extrusion molding: Install the flow-dividing combination mold, put the heat-treated ingot into the extrusion cylinder, and start the extruder; S3, CNC machining: machining open openings or through holes in extruded hollow profiles; S4. Turning: Perform multiple turning operations along the length of the bottom wall on one side of the hollow profile to form heat dissipation fins (12).

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