Protective structure and power battery pack

Abstract

The application provides a protection structure and a power battery pack, and relates to the technical field of the power battery pack. The protection structure provided by the application comprises a bottom protection plate, a liquid cooling plate and a buffer assembly. The buffer assembly comprises first support plates, first corrugated energy-absorbing plates and second support plates arranged in sequence. At least part of the first support plates abuts against the bottom of the liquid cooling plate, and the second support plates abut against the top of the bottom protection plate. A plurality of elastic members are arranged on the first corrugated energy-absorbing plates. The first ends of the elastic members are connected with the first support plates, and the second ends of the elastic members are connected with the second support plates. The first support plates, the first corrugated energy-absorbing plates and the second support plates form a layered support and energy-absorbing structure, and the plurality of elastic members on the first corrugated energy-absorbing plates are connected with the first support plates and the second support plates respectively. When the bottom of the power battery pack is impacted, the impact energy can be absorbed and dispersed in multiple stages, and the safety of the power battery pack is improved.

Description

Technical Field

[0001] This application relates to power battery pack technology, and more particularly to a protective structure and a power battery pack. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the safety of the power battery pack, as the core energy storage unit of the vehicle, has become a key technical indicator restricting the industry's development. During actual vehicle operation, the power battery pack is typically installed under the chassis and is constantly exposed to complex and changing road environments. During driving, the vehicle may encounter impacts from road debris, potholes, speed bumps, or other obstacles, or be involved in collisions due to insufficient clearance between the vehicle chassis and the ground. These external impacts can be transmitted to the bottom of the power battery pack, causing structural deformation, damage to internal cells, and even triggering serious safety accidents such as thermal runaway and fire.

[0003] In related technologies, the protective structure at the bottom of the power battery pack mainly includes a single-layer metal protective plate structure, which directly covers the bottom of the power battery pack with rigid material to resist external impact.

[0004] However, traditional protective structures lack sufficient buffering performance, cannot effectively absorb and disperse collision energy, and have poor safety. Summary of the Invention

[0005] In view of this, this application provides a protective structure and a power battery pack, wherein the protective structure can effectively absorb and disperse collision energy, thereby improving the safety of the power battery pack.

[0006] To achieve the above objectives, this application provides a protective structure and a power battery pack, which adopt the following technical solution:

[0007] In a first aspect, this application provides a protective structure, including a bottom protective plate and a liquid cooling plate, and further including a buffer assembly disposed between the bottom protective plate and the liquid cooling plate, the buffer assembly including a first support plate, a first corrugated energy-absorbing plate and a second support plate disposed sequentially;

[0008] At least a portion of the first support plate abuts against the bottom of the liquid cooling plate, and the second support plate abuts against the top of the bottom protective plate;

[0009] The first corrugated energy-absorbing plate is provided with a plurality of elastic elements, the first end of the elastic element being connected to the first support plate, and the second end of the elastic element being connected to the second support plate.

[0010] In one possible embodiment, the first corrugated energy-absorbing plate and the first support plate form a first receiving cavity, and the first corrugated energy-absorbing plate and the second support plate form a second receiving cavity; at least one of the first receiving cavity and the second receiving cavity is filled with foamed material.

[0011] In one possible embodiment, the first corrugated energy-absorbing plate has at least one connecting hole, which connects the first receiving cavity and the second receiving cavity;

[0012] The foamed material has a fluid state and a foamed state. In the fluid state, the foamed material can flow between the first accommodating cavity and the second accommodating cavity through the connecting hole.

[0013] The fluid state solidifies to form the foamed state.

[0014] In one possible embodiment, the liquid cooling plate is provided with a flow channel region and a non-flow channel region, the flow channel region protruding toward the buffer assembly from the non-flow channel region;

[0015] The flow channel area abuts against the first support plate, and a buffer gap is provided between the non-flow channel area and the first support plate.

[0016] In one possible embodiment, the buffer assembly is provided with a protrusion that extends toward the liquid cooling plate into the buffer gap and abuts against the non-flow channel region.

[0017] In one possible embodiment, the protrusion includes a support cover connected to the first support plate and abutting against the non-flow channel region;

[0018] The protrusion also includes a plurality of second corrugated energy-absorbing plates and a plurality of third support plates arranged alternately in sequence; a buffer cavity is formed between the support cover and the first support plate, and the second corrugated energy-absorbing plates and the third support plates are both disposed in the buffer cavity.

[0019] In one possible embodiment, the top surface of the liquid cooling plate is provided with a first protective coating;

[0020] The bottom surface of the liquid cooling plate, the top surface of the bottom protective plate, and the bottom surface of the bottom protective plate are all provided with a second protective coating.

[0021] In one possible embodiment, the first protective coating is an insulating coating.

[0022] In one possible embodiment, a honeycomb panel is further disposed between the first support plate and the second support plate.

[0023] The protective structure provided in this application, by setting a buffer component between the bottom protective plate and the liquid cooling plate, and forming a layered support and energy absorption structure by the first support plate, the first corrugated energy-absorbing plate and the second support plate arranged in sequence, and by connecting multiple elastic elements on the first corrugated energy-absorbing plate to the first support plate and the second support plate respectively, can absorb and disperse the impact energy in multiple stages when the bottom of the power battery pack is impacted, reduce local stress concentration and enhance the stability support capacity of the bottom structure, thereby improving the impact resistance of the protective structure, reducing the adverse effects on the liquid cooling plate and the internal components of the battery pack, and helping to balance the structural safety and thermal safety of the power battery pack.

[0024] Secondly, this application provides a power battery pack, including a cell module and a protective structure as described above, wherein the cell module is connected to the protective structure.

[0025] The power battery pack provided in this application can absorb and disperse impact energy in multiple stages when the bottom of the power battery pack is impacted, thereby improving the structural safety and thermal safety of the power battery pack.

[0026] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the technical solutions provided by this application, other technical features contained in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific embodiments. Attached Figure Description

[0027] The specific embodiments of this application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of this application, and this application is not limited to the specific embodiments described below.

[0028] Figure 1 This is a partial internal structure diagram of the protective structure provided in the embodiments of this application;

[0029] Figure 2 for Figure 1 A magnified structural diagram of part A in the middle;

[0030] Figure 3 for Figure 1 A schematic diagram of the exploded structure;

[0031] Figure 4 for Figure 1 Another structural diagram from another perspective;

[0032] Figure 5 This is a partial internal structure diagram of a protective structure provided in another embodiment of this application;

[0033] Figure 6 for Figure 5 A schematic diagram of the exploded structure;

[0034] Figure 7 for Figure 6 A partial structural diagram of the central protrusion;

[0035] Figure 8 A partial internal structure diagram of a buffer component provided in another embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 10. Foaming material; 20. Connecting hole; 100. Bottom protective plate; 200. Liquid cooling plate; 201. Flow channel area; 202. Non-flow channel area; 203. Buffer gap; 300. Buffer assembly; 301. First receiving cavity; 302. Second receiving cavity; 310. First support plate; 320. First corrugated energy-absorbing plate; 330. Second support plate; 340. Elastic element; 400. Protrusion; 410. Support cover; 420. Second corrugated energy-absorbing plate; 430. Third support plate; 500. First protective coating; 600. Second protective coating; 700. Honeycomb panel.

[0038] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0040] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0041] In the description of the embodiments of this application, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0042] In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise specified precisely.

[0043] The terms “first,” “second,” “third,” “fourth,” etc., used in the description of this application and in the above-mentioned figures are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0044] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0045] As mentioned in the background section, with the rapid development of the new energy vehicle industry, the safety of the power battery pack, as the core energy storage unit of the vehicle, has become a key technical indicator restricting the industry's development. The bottom protective structure of the power battery pack needs to withstand both impact and vibration loads from the bottom during daily driving, rapid acceleration and deceleration, driving over speed bumps, potholes, or scraping against road shoulders, and works in conjunction with a liquid cooling plate to manage the battery pack's heat dissipation.

[0046] To balance protective strength, structural weight, and thermal safety, the bottom structure typically employs a combination of a bottom protective plate, a liquid cooling plate, and transitional support components in between. This allows external impacts to be transmitted and dispersed step by step, while minimizing impact on the battery cell modules and cooling channels. Since power battery packs are highly sensitive to structural deformation and temperature rise, bottom protection scenarios require not only impact resistance but also good installation adaptability and continuous thermal management within a limited space.

[0047] Current power battery pack bottom protection solutions typically use a single-layer metal skid plate as the outermost protective component, with a liquid cooling plate positioned above it for battery thermal management. The two are separated by a fixed support structure. When the vehicle's bottom is impacted by gravel, a bottoming-out collision, or a road protrusion, the external load first acts on the skid plate, and then is directly transferred to the upper structure. While the single-layer rigid skid plate possesses some puncture resistance, it primarily relies on the material's inherent rigidity and limited elastic-plastic deformation to withstand the impact. The impact energy is difficult to effectively diffuse within the structure, often resulting in high stress concentrations in certain areas. This can lead to localized dents in the skid plate, instability in the support area, and even further transfer of the impact to the liquid cooling plate and battery cell modules.

[0048] Meanwhile, simply increasing the thickness of the protective plate to improve impact resistance can easily lead to increased vehicle weight, reduced installation space, and decreased range. On the other hand, relying solely on a thin and lightweight structure is insufficient to provide adequate protection under low-speed bottoming-out or medium-energy impacts, highlighting the significant conflict between protective strength and lightweight design. In existing structures, the liquid cooling plate primarily serves a heat dissipation function, typically focusing on flow channel arrangement and heat exchange efficiency, lacking coordinated design with bottom protection. Consequently, during impacts, the bottom load can easily be directly transferred to the liquid cooling plate, further amplifying the risk of localized damage and adversely affecting the structural stability and thermal safety of the battery pack.

[0049] Based on the aforementioned technical problems, this application provides a protective structure and a power battery pack. In this technical solution, a buffer assembly is proposed, disposed between the bottom protective plate and the liquid-cooled plate. The buffer assembly includes a first support plate, a first corrugated energy-absorbing plate, and a second support plate arranged sequentially. At least a portion of the first support plate abuts against the bottom of the liquid-cooled plate, and the second support plate abuts against the top of the bottom protective plate. The first corrugated energy-absorbing plate is provided with multiple elastic elements, with the first end of each elastic element connected to the first support plate and the second end connected to the second support plate. A transitional relationship with buffering and support functions is formed between the bottom protective plate, the liquid-cooled plate, and the buffer assembly, allowing external impacts to be gradually transmitted and absorbed through the multi-layered structure. This reduces the direct impact force on the liquid-cooled plate and the internal battery cell modules, improving the impact resistance, structural stability, and thermal safety of the bottom protective structure of the power battery pack under complex road conditions.

[0050] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0051] Reference Figure 1 , Figure 2 and Figure 3As shown in the embodiment of this application, a protective structure includes a bottom guard plate 100, a liquid cooling plate 200, and a buffer assembly 300 disposed between the bottom guard plate 100 and the liquid cooling plate 200. The bottom guard plate 100 is used to form the outer protective surface of the power battery pack facing the bottom of the vehicle. It is the first load-bearing component to withstand road impacts, bottoming collisions, gravel impacts, and vibration loads. Its function is to provide primary blocking of external mechanical loads and transfer the load to the inner structure.

[0052] In one possible embodiment, the bottom guard plate 100 can be made of steel plate, aluminum alloy plate or fiber reinforced composite plate. Alternatively, it can be made of high-strength thin plate combined with local reinforcing ribs according to the vehicle's lightweight requirements. The thickness of the bottom guard plate 100 is usually greater than the thickness of the internal support plate to ensure its outer protective capability. Its shape can be flat, shell-shaped with reinforced folds or partially convex and concave plate to adapt to the bottom contour of the battery pack and improve its bending and dent resistance.

[0053] The liquid cooling plate 200 is used to connect with the battery thermal management circuit to control the heat dissipation of the cell module. It is located inside the bottom guard plate 100 and faces the inside of the battery pack. At least part of the bottom of the liquid cooling plate 200 abuts against the first support plate 310 in the buffer assembly 300 to obtain structural support while maintaining the heat exchange interface. In one possible embodiment, the liquid cooling plate 200 can be an aluminum alloy liquid cooling plate 200, a copper-aluminum composite liquid cooling plate 200, or a stainless steel liquid cooling plate 200. Its flow channel can be arranged in a straight, serpentine, or parallel manner. The plate surface of the liquid cooling plate 200 can be provided with local reinforcement area and heat exchange area according to the thermal management requirements, and can be manufactured by integral die casting, brazing, or welding assembly.

[0054] The buffer assembly 300 is disposed between the bottom protective plate 100 and the liquid cooling plate 200 to form a transition layer with load-bearing, buffering and energy absorption functions between the two. It includes a first support plate 310, a first corrugated energy-absorbing plate 320 and a second support plate 330 arranged in sequence. The first support plate 310 is arranged close to the liquid cooling plate 200 and the second support plate 330 is arranged close to the bottom protective plate 100. The first corrugated energy-absorbing plate 320 is located between the two and forms a sandwich-type load-bearing relationship.

[0055] In one possible embodiment, the first support plate 310 and the second support plate 330 can be made of metal plate, composite plate or high-strength engineering plastic plate respectively, and both can be flat or partially stamped and reinforced plate; the first corrugated energy-absorbing plate 320 can be made of metal corrugated plate, aluminum alloy corrugated plate, galvanized steel corrugated plate or composite material corrugated plate, with its crests and troughs continuously distributed to form an energy-absorbing path that can buckle, fold and gradually collapse, and the wave height and wave pitch can be designed according to the expected impact level and installation space, and can be a single-layer corrugated, double-layer corrugated or locally variable wave pitch corrugated structure.

[0056] Combination Figure 4 As shown, a plurality of elastic elements 340 are provided on the first corrugated energy-absorbing plate 320. The first end of the elastic element 340 is connected to the first support plate 310, and the second end of the elastic element 340 is connected to the second support plate 330 to form a bidirectional constraint and elastic recovery channel in the vertical direction. In one possible embodiment, the elastic element 340 may be a rubber spring, a polyurethane elastic column, a metal spring, a spring sheet, a rubber column, an air elastomer, or a magnetoelastic element. The elastic element 340 may be arranged in a columnar, annular, sheet-like, or multi-cavity shape, and may be arrayed along the crest region, trough region, or their interval region of the first corrugated energy-absorbing plate 320 to achieve local enhancement or uniform distribution according to the load path.

[0057] Furthermore, the contact between the first support plate 310 and the liquid cooling plate 200 can be achieved through surface contact, partial contact, or transition contact via a thermally conductive pad, in order to balance load-bearing and heat conduction requirements; the contact between the second support plate 330 and the bottom protective plate 100 can be achieved through surface contact, reinforcing rib contact, or edge limiting contact.

[0058] The connection method between the bottom protective plate 100, the first support plate 310, the first corrugated energy-absorbing plate 320, and the second support plate 330 can be selected according to the manufacturing process, such as welding, riveting, bolting, snap-fitting, or gluing. The protective structure provided in this application embodiment combines the bottom protective plate 100, the first support plate 310, the first corrugated energy-absorbing plate 320, the second support plate 330, and multiple elastic elements 340 in a hierarchical manner. This allows the bottom protective plate 100 to initially bear the external impact and transmit it inward. Subsequently, the second support plate 330 guides the load into the interlayer area between the first corrugated energy-absorbing plate 320 and the first support plate 310. The impact energy is absorbed and dispersed step by step during the crest buckling, progressive folding, and compression rebound of the corrugated structure and the elastic elements 340. The load path no longer directly acts on the liquid cooling plate 200, but instead achieves buffering, limiting, and energy dissipation through the coordinated action of multiple components.

[0059] At the same time, the contact relationship between the first support plate 310 and the liquid cooling plate 200 enables the liquid cooling plate 200 to obtain the necessary structural support while bearing the thermal management function, avoiding excessive deformation when subjected to local impact, thereby improving the bottom protection capability without significantly increasing the overall thickness and structural weight, and maintaining the continuity and stability between the liquid cooling plate 200 and the internal thermal management system of the battery pack.

[0060] In one possible implementation, the first corrugated energy-absorbing plate 320 and the first support plate 310 form a first receiving cavity 301, and the first corrugated energy-absorbing plate 320 and the second support plate 330 form a second receiving cavity 302; at least one of the first receiving cavity 301 and the second receiving cavity 302 is filled with foam material 10.

[0061] In one possible embodiment, the first receiving cavity 301 and the second receiving cavity 302 are confined cavities defined by the first corrugated energy-absorbing plate 320 and the adjacent support plate. The first receiving cavity 301 is located between the first corrugated energy-absorbing plate 320 and the first support plate 310, and the second receiving cavity 302 is located between the first corrugated energy-absorbing plate 320 and the second support plate 330. The foaming material 10 is filled in at least one of the two receiving cavities to form a composite buffer space that can participate in energy absorption between the corrugated structure body and the support plate.

[0062] In this embodiment, the foamed material 10 is a buffer medium that can generate pore expansion, volume increase or compression deformation under pressure, heat or restricted expansion conditions. Its function is to use its compressibility, damping characteristics and energy dissipation ability to absorb the impact load transmitted through the bottom plate 100 for a second time, and fill the gaps inside the cavity, thereby reducing local stress concentration and improving the structure's resistance to collapse.

[0063] The arrangement of the first receiving cavity 301 and the second receiving cavity 302 allows the foamed material 10 to be confined within a limited space. Its expansion and deformation process is jointly restricted by the waveform profile of the first corrugated energy-absorbing plate 320 and the flat surface of the support plate. Therefore, it will not diffuse freely when subjected to external loads, but will gradually release strain energy through restricted deformation.

[0064] For example, the foaming material 10 may be any one of polyurethane foaming material 10, expanded silicone, EPP (Expanded Polypropylene) foaming material 10, EPDM (Ethylene Propylene Diene Monomer) foaming material 10, phenolic foam or metal foam, or a composite foaming material with similar compression resilience properties.

[0065] When the vehicle's bottom is subjected to impact from a bottoming out, gravel, or road protrusion, the load is transferred through the underbody protection plate 100 to the second support plate 330 and further acts on the first corrugated energy-absorbing plate 320. While the first corrugated energy-absorbing plate 320 undergoes local bending and corrugated compression, the foam material 10 in the cavity is simultaneously compressed and undergoes pore collapse, volume compression, or viscoelastic energy dissipation, thereby absorbing the impact energy in stages. After the impact is released, the foam material 10 and corrugated structure that have not suffered permanent damage can recover some deformation under elastic recovery, thereby maintaining the stability of the gap between the support plate and the corrugated energy-absorbing plate and reducing the transmission of impact to the liquid cooling plate 200.

[0066] At least one through hole 20 is provided on the first corrugated energy-absorbing plate 320, which connects the first receiving cavity 301 and the second receiving cavity 302. The foaming material 10 has a fluid state and a foamed state. When the foaming material 10 is in the fluid state, it can flow between the first receiving cavity 301 and the second receiving cavity 302 through the through hole 20. The fluid state of the foaming material 10 solidifies to form the foamed state.

[0067] In one possible embodiment, the connecting hole 20 is a through-type connecting channel disposed on the first corrugated energy-absorbing plate 320, which is essentially a transition channel for connecting the first receiving cavity 301 and the second receiving cavity 302. The function of the connecting hole 20 is to allow the foamed material 10 in a fluid state to cross the isolation area between the first receiving cavity 301 and the second receiving cavity 302, so as to achieve a balanced distribution of material and pressure connection in the two cavities, thereby forming a more continuous support and buffer structure in the subsequent foaming, expansion or curing process.

[0068] The connecting holes 20 can be positioned to avoid the main load-bearing rib areas and preferably placed in areas with shorter material flow paths and better cavity connectivity, so as to achieve mutual conduction between cavities without significantly weakening the overall load-bearing capacity of the plate. For example, the connecting holes 20 can be processed into round holes, elliptical holes, oblong holes, rectangular holes, slit holes, or multi-hole array structures.

[0069] The aperture or equivalent width of the connecting hole 20 should generally be smaller than the corrugated wave pitch to ensure that the plate still maintains the necessary corrugated load-bearing characteristics, while it should be larger than the maximum characteristic size of the liquid matrix, dispersed phase particles or bubbles in the foamed material 10 before formation to ensure smooth flow. When there are a large number of connecting holes 20, they can be evenly arranged along the corrugated wavelength direction, or they can be locally densified in areas of the bottom guard plate 100 with large impact loads to enhance the cross-cavity compensation capability of the foamed material 10 in that area.

[0070] In this embodiment, the foaming material 10 refers to a material that is in a fluid state upon injection, subsequently expands under specific conditions, and transforms into a foam with certain elasticity and support. Once in the foamed state, the material viscosity increases and it gradually expands and solidifies, thereby forming a more uniformly distributed elastic filler within the first receiving cavity 301 and the second receiving cavity 302. The flow process of the foaming material 10 in the fluid state can be completed before assembly or after the component assembly via a pre-reserved injection port. The connecting hole 20 serves as a pressure differential balance channel, allowing the material to first fill the lower resistance area during the initial injection phase, and then compensate the other cavity through the channel, thereby improving the overall continuity of the foamed layer and the consistency of energy dissipation.

[0071] The foamed material 10 first enters one of the cavities in the first accommodating cavity 301 or the second accommodating cavity 302 in a fluid state, and migrates to the other cavity through the connecting hole 20 on the first corrugated energy-absorbing plate 320 under the action of pressure difference, so that the material distribution in the two cavities gradually tends to be balanced. As the material temperature changes, chemical reaction or external activation conditions are met, the foamed material 10 gradually transforms into a foamed state and undergoes volume expansion. At this time, on the one hand, it forms a continuous buffer filling layer in the first accommodating cavity 301 and the second accommodating cavity 302, and on the other hand, it is confined by the connecting hole 20 in a cavity system that is interconnected but not completely isolated. Thus, when subjected to impact load from the direction of the bottom protective plate 100, the second support plate 330 and the first corrugated energy-absorbing plate 320 can first bear the load and absorb the energy through deformation. Then, the compression deformation, shear energy dissipation and local buckling around the pores of the foamed material 10 in the cavity can jointly disperse the load and gradually transfer the remaining impact to the bottom of the first support plate 310 and the liquid cooling plate 200.

[0072] Since the foamed material 10 can achieve cross-cavity flow and balanced filling through the connecting holes 20, it can reduce the stiffness abrupt change caused by excessive local voids or excessive material accumulation in a single cavity after molding, making the buffer response of the first receiving cavity 301 and the second receiving cavity 302 more consistent, thereby reducing the adverse effects of impact concentration on the liquid cooling plate 200 and the internal battery cell module, while maintaining the overall lightweight and thermal management continuity of the bottom protection structure.

[0073] Furthermore, the liquid cooling plate 200 is provided with a flow channel region 201 and a non-flow channel region 202. The flow channel region 201 protrudes from the non-flow channel region 202 toward the buffer assembly 300. The flow channel region 201 abuts against the first support plate 310, and a buffer gap 203 is provided between the non-flow channel region 202 and the first support plate 310.

[0074] In this embodiment, the flow channel region 201 and the non-flow channel region 202 are structural divisions of the functional zones at the bottom of the liquid cooling plate 200. The flow channel region 201 refers to the load-bearing area formed around the coolant channel, heat exchange ribs or locally enhanced heat transfer structure, while the non-flow channel region 202 refers to the area that does not directly form a coolant channel and mainly undertakes the functions of plate surface integrity and auxiliary support.

[0075] Because the flow channel region 201 protrudes towards the buffer assembly 300 from the non-flow channel region 202, it can first form a supporting fit with the first support plate 310 in the form of a protruding contact surface, preferentially bearing the load transmitted from the bottom guard plate 100 and the buffer assembly 300, and dispersing the load to the area inside the liquid cooling plate 200 with higher structural rigidity and stronger load-bearing capacity. At the same time, a buffer gap 203 is reserved between the non-flow channel region 202 and the first support plate 310, so that the non-flow channel region 202 does not directly contact the first support plate 310 under normal operating conditions. This reduces hard interference caused by the superposition of assembly tolerances, and leaves deformation space for local elastic deformation and displacement absorption when an impact occurs, thereby reducing the adverse effects of local stress concentration on the surface of the liquid cooling plate 200.

[0076] In one possible embodiment, the flow channel region 201 can be formed by stamping bosses, welding flow channel ribs, extrusion forming local ribs, or local bulges on the outer wall of the liquid cooling channel, so as to form a clear height difference relative to the non-flow channel region 202; the non-flow channel region 202 can be a flat plate surface, a shallow concave plate surface, or a plate surface that has been locally reinforced but has not formed obvious flow channel bulges.

[0077] During operation, the bottom guard plate 100 first withstands external impacts from road surface gravel, undercarriage scraping, or shoulder scraping, and transfers the load to the buffer assembly 300. Subsequently, the first support plate 310 undergoes controlled deformation under the synergistic action of the elastic element 340 and the corrugated energy-absorbing plate, dispersing the force to the liquid-cooled plate 200. Since the flow channel region 201 protrudes towards the buffer assembly 300 from the non-flow channel region 202, the first support plate 310 will preferentially contact the flow channel region 201, thereby concentrating the load-bearing path in the functional load-bearing area of ​​the liquid-cooled plate 200. The non-flow channel region 202, due to the buffer gap 203 reserved between it and the first support plate 310, will not be immediately subjected to top pressure in the initial impact stage, thus avoiding local buckling and secondary stress concentration caused by rigid collisions of a large area of ​​the plate surface. While ensuring that the flow channel region 201 continues to participate in the heat dissipation path and structural support, it can reduce the ineffective pressure on the non-flow channel region 202, reduce the impact of impact on the sealing performance, flatness and internal flow channel stability of the liquid cooling plate 200, and further reduce the risk of impact being transmitted to the cell module, thereby improving the impact resistance, structural stability and thermal safety of the bottom protective structure of the power battery pack.

[0078] In one possible implementation, refer to Figure 5 , Figure 6 and Figure 7 As shown, the buffer assembly 300 is provided with a protrusion 400, which extends toward the liquid cooling plate 200 into the buffer gap 203 and abuts against the non-flow channel region 202.

[0079] The protrusion 400 is a partial lifting structure formed on the buffer assembly 300. It extends into the buffer gap 203 formed between the bottom guard plate 100 and the liquid cooling plate 200 by the non-flow channel region 202, and establishes a pressure-bearing contact with the non-flow channel region 202. The function of the protrusion 400 is to provide local support and pre-compression for the non-flow channel region 202 of the liquid cooling plate 200, so that when the bottom impact load is transmitted to the liquid cooling plate 200, it is first partially received and dispersed by the protrusion 400, and then further transmitted to other load-bearing layers inside the buffer assembly 300. This reduces the possibility of local collapse, buckling or denting deformation of the non-flow channel region 202, and reduces the impact force acting directly on the liquid cooling plate 200 body and its surrounding connection area.

[0080] In a specific implementation, the protrusion 400 includes a support cover 410, which is connected to the first support plate 310 and abuts against the non-flow channel region 202. The protrusion 400 also includes a plurality of second corrugated energy-absorbing plates 420 and a plurality of third support plates 430 arranged alternately in sequence. A buffer cavity is formed between the support cover 410 and the first support plate 310, and the second corrugated energy-absorbing plates 420 and the third support plates 430 are both disposed in the buffer cavity. In this embodiment, the support cover 410 is a pressure-bearing cover disposed on the outside of the protrusion 400 and used to directly contact the non-flow channel area 202 of the liquid cooling plate 200. After the support cover 410 is connected to the first support plate 310, an enclosed buffer cavity structure is formed between the two. The support cover 410 is located on the side closer to the liquid cooling plate 200, and the first support plate 310 serves as the inner boundary of the buffer cavity and cooperates with the main support surface, so that the second corrugated energy-absorbing plate 420 and the third support plate 430 can undergo orderly deformation and stepwise force transmission within a limited space.

[0081] The second corrugated energy-absorbing plate 420 is used to generate controllable buckling and folding deformation under pressure, while the third support plate 430 is used to provide stable layered support and load distribution path between adjacent energy-absorbing layers. When the two are arranged alternately, they can form a stacked energy-absorbing channel, so that the impact energy is gradually dissipated in the buffer cavity through a multi-level structure.

[0082] For example, in one possible embodiment, the support cover 410 can be made into an arc-shaped cover, an arched cover, or a box-shaped cover, and can be made of one or more materials selected from aluminum alloy, magnesium alloy, steel, composite materials, or high-strength engineering plastics to take into account pressure resistance, quality control, and ease of forming; the second corrugated energy-absorbing plate 420 can be a fine corrugated plate, a trapezoidal corrugated plate, a honeycomb corrugated composite plate, or a folded sheet plate, preferably having a relatively uniform distribution of crests and troughs so that it buckles in a predetermined order when loaded; the third support plate 430 can be a flat plate, a stiffened plate, a locally bearing plate, or a spacer frame, and its material can be the same as that of the support cover 410, or it can be a high-strength metal plate or a composite plate to improve interlayer stability and local compressive strength.

[0083] When the structure is in operation, the external impact first acts on the support cover 410. After the support cover 410 undergoes slight elastic deformation, it transfers the load to the buffer cavity. Multiple second corrugated energy-absorbing plates 420 enter the compressive buckling state in sequence under the separation and support of the third support plate 430. The impact energy is gradually attenuated from the surface to the inside and from the local to the whole. The third support plate 430 forms a stable force transmission transition between adjacent energy-absorbing layers, suppressing load concentration and reducing the direct impact on the first support plate 310 and the non-flow channel region 202 of the liquid cooling plate 200 it supports.

[0084] Therefore, the protrusion 400 can improve the impact resistance and buffer energy absorption capacity of the local area without significantly increasing the structural thickness, reduce the peak load of the bottom impact propagating to the liquid cooling plate 200, and help maintain the structural integrity of the liquid cooling plate 200 and the overall stability of the battery pack.

[0085] Furthermore, the top surface of the liquid cooling plate 200 is provided with a first protective coating 500; the bottom surface of the liquid cooling plate 200, the top surface of the bottom protective plate 100, and the bottom surface of the bottom protective plate 100 are all provided with a second protective coating 600.

[0086] In one possible embodiment, the first protective coating 500 is a functional coating layer applied to the top surface of the liquid cooling plate 200 to improve its surface protection performance. Its main function is to provide moisture-proof, corrosion-proof and anti-micro-vibration wear protection to the side of the liquid cooling plate 200 facing the inside of the battery pack, so as to avoid damage to the surface of the liquid cooling plate 200 caused by condensation, slight leakage, assembly friction or local stress concentration inside the battery pack.

[0087] The second protective coating 600 is a functional coating layer that covers the bottom surface of the liquid cooling plate 200 and the top and bottom surfaces of the underbody protection plate 100. Its function is to provide synergistic protection for the upper and lower surfaces of the liquid cooling plate 200 and the underbody protection plate 100, so that when the bottom of the vehicle is subjected to impact from gravel, abrasion from sand and gravel, erosion from mud and water, and corrosion from salt spray, it can reduce the risk of surface erosion, coating peeling and substrate corrosion, while enhancing the wear resistance, impact resistance and electrical insulation performance of the local surface.

[0088] The first protective coating 500 and the second protective coating 600 do not necessarily have to be made of the same material. They can be adapted to different locations and stress environments. The first protective coating 500 can be any one or a combination of insulating varnish, impact-resistant polyurea, epoxy coating, or ceramic composite coating to balance electrical performance and surface damage resistance. The second protective coating 600 can be any one or a combination of PVC (Polyvinyl Chloride) varnish, polyurea elastic layer, polyurethane coating, rubberized coating, or wear-resistant and corrosion-resistant coating to improve the wear and corrosion resistance of the outer exposed surface under complex road conditions.

[0089] For example, the first protective coating 500 may adopt a multi-layer spraying structure, including a primer, an intermediate functional layer and a topcoat, to enhance the adhesion between the coating and the liquid cooling plate 200 substrate and improve the local stress release capability; the second protective coating 600 may adopt a composite system of a primer, a transition layer and a topcoat, so that it has a certain elasticity and energy dissipation capability while ensuring protective performance.

[0090] Through the above-mentioned configuration, the first protective coating 500 avoids scratches, corrosion or insulation failure during assembly, thermal expansion and contraction and long-term vibration; the second protective coating 600 is to cover the upper and lower sides of the bottom protection system as a whole, and improve the structure's comprehensive resistance to external impact, friction and environmental erosion.

[0091] Furthermore, the first protective coating 500 is an insulating coating, which is used to block unintended conduction paths of current between the liquid cooling plate 200 and adjacent conductive components. The function of this insulating coating is to provide a stable electrical isolation barrier on the top surface of the liquid cooling plate 200 when the liquid cooling plate 200 is located inside the power battery pack and is arranged adjacent to the cell module bracket, busbar mounting components, or other metal connectors, thereby reducing the risk of short circuits, leakage, and electrochemical corrosion caused by metal contact, cooling medium leakage, or localized damage to the coating.

[0092] In one possible embodiment, the insulating coating may be any one or a combination of PVC insulating varnish, epoxy insulating coating, polyimide coating, ceramic insulating coating or fluoroplastic coating. Exemplarily, it may also be formed by spraying, brushing, rolling, dipping or sintering to adapt to different materials and surface roughness conditions of the liquid cooling plate 200.

[0093] The insulating coating can also be an insulating film, insulating tape, insulating covering layer, ceramic spray coating or anodized layer. It can also be combined with the sealing layer to form a composite insulating protection structure, so that it can maintain stable electrical isolation performance under temperature cycling, vibration and shock and long-term immersion in coolant.

[0094] In one possible embodiment, such as Figure 8 As shown, a honeycomb panel 700 is also provided between the first support plate 310 and the second support plate 330.

[0095] The honeycomb panel 700 is a honeycomb-shaped load-bearing buffer component disposed between the first support plate 310 and the second support plate 330. Essentially, it utilizes regularly arranged honeycomb cells to form an intermediate load-bearing layer with high specific strength and superior crushing characteristics, so as to construct an additional load transfer and energy absorption path between the bottom protective plate 100 and the liquid cooling plate 200.

[0096] In one possible embodiment, the honeycomb panel 700 can be any of the following: aluminum honeycomb panel 700, paper-based honeycomb panel 700, composite material honeycomb panel 700, plastic honeycomb panel 700, or metal honeycomb core panel. The honeycomb cells can be regular hexagonal, square, circular, rhomboid, or mixed-type lattice. For example, it can also be a sandwich panel combining upper and lower skins and thin-walled honeycomb core, or a single honeycomb core embedded between support plates. Among them, the aluminum honeycomb panel 700 has a good balance between compressive strength and lightweight, the composite material honeycomb panel 700 can take into account both corrosion resistance and structural adaptability, the paper-based honeycomb panel 700 can be used in scenarios with higher weight requirements and moderate impact levels, while the metal honeycomb core panel is suitable for working conditions with higher requirements for load-bearing stability.

[0097] This application embodiment also provides a power battery pack, including a cell module (not shown in the figure) and the protective structure provided above, wherein the cell module is connected to the protective structure.

[0098] The protective structure serves as a bottom load-bearing and protective unit on the outside of the battery cell module, absorbing impact and vibration loads from the bottom during vehicle operation. Since the protective structure itself includes a bottom guard plate 100, a liquid cooling plate 200, and a buffer assembly 300 disposed between them, and the first support plate 310, the first corrugated energy-absorbing plate 320, the second support plate 330, and multiple elastic elements 340 in the buffer assembly 300 form a graded buffer path, external impacts are absorbed and dispersed step by step before being transmitted to the battery cell module, reducing localized stress concentration on the liquid cooling plate 200 and the battery cell module.

[0099] This approach helps maintain the stability of the battery cell module installation and avoids direct impact on the cooling channels and heat dissipation continuity, thus ensuring the impact resistance, structural reliability, and thermal safety of the power battery pack. Therefore, it is more suitable for complex working conditions under the chassis of new energy vehicles.

[0100] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein.

[0101] The embodiments in this application are intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed in this application. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0102] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A protective structure comprising a bottom protective plate (100) and a liquid cooling plate (200), characterized in that, It also includes a buffer assembly (300) disposed between the bottom protective plate (100) and the liquid cooling plate (200), the buffer assembly (300) including a first support plate (310), a first corrugated energy-absorbing plate (320) and a second support plate (330) disposed in sequence. At least part of the first support plate (310) abuts against the bottom of the liquid cooling plate (200), and the second support plate (330) abuts against the top of the bottom protective plate (100); The first corrugated energy-absorbing plate (320) is provided with a plurality of elastic elements (340), the first end of the elastic element (340) is connected to the first support plate (310), and the second end of the elastic element (340) is connected to the second support plate (330).

2. The protective structure according to claim 1, characterized in that, The first corrugated energy-absorbing plate (320) and the first support plate (310) form a first receiving cavity (301), and the first corrugated energy-absorbing plate (320) and the second support plate (330) form a second receiving cavity (302); at least one of the first receiving cavity (301) and the second receiving cavity (302) is filled with foam material (10).

3. The protective structure according to claim 2, characterized in that, The first corrugated energy-absorbing plate (320) has at least one connecting hole (20), which connects the first receiving cavity (301) and the second receiving cavity (302). The foamed material (10) has a fluid state and a foamed state. In the fluid state, the foamed material (10) can flow between the first receiving cavity (301) and the second receiving cavity (302) through the connecting hole (20). The fluid state solidifies to form the foamed state.

4. The protective structure according to claim 1, characterized in that, The liquid cooling plate (200) is provided with a flow channel region (201) and a non-flow channel region (202), and the flow channel region (201) protrudes from the non-flow channel region (202) toward the buffer assembly (300). The flow channel region (201) abuts against the first support plate (310), and a buffer gap (203) is provided between the non-flow channel region (202) and the first support plate (310).

5. The protective structure according to claim 4, characterized in that, The buffer assembly (300) is provided with a protrusion (400) that extends toward the liquid cooling plate (200) into the buffer gap (203) and abuts against the non-flow channel region (202).

6. The protective structure according to claim 5, characterized in that, The protrusion (400) includes a support cover (410), which is connected to the first support plate (310) and abuts against the non-flow channel region (202); The protrusion (400) also includes a plurality of second corrugated energy-absorbing plates (420) and a plurality of third support plates (430) arranged alternately in sequence; the support cover (410) and the first support plate (310) form a buffer cavity, and the second corrugated energy-absorbing plates (420) and the third support plates (430) are both arranged in the buffer cavity.

7. The protective structure according to any one of claims 1 to 6, characterized in that, The top surface of the liquid cooling plate (200) is provided with a first protective coating (500). The bottom surface of the liquid cooling plate (200), the top surface of the bottom protective plate (100), and the bottom surface of the bottom protective plate (100) are all provided with a second protective coating (600).

8. The protective structure according to claim 7, characterized in that, The first protective coating (500) is an insulating coating.

9. The protective structure according to any one of claims 1 to 6, characterized in that, A honeycomb panel (700) is also provided between the first support plate (310) and the second support plate (330).

10. A power battery pack, characterized in that, It includes a battery cell module and a protective structure as described in any one of claims 1 to 9, wherein the battery cell module is connected to the protective structure.

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