Composite bottom guard plate, battery and electric device

Abstract

A composite bottom guard plate, a battery and an electric device. The composite bottom guard plate comprises a first plate (1), a second plate (2) and metal plates (4), wherein the first plate (1) and the second plate (2) enclose a first accommodating cavity (10), and the first accommodating cavity (10) is filled with the metal plates (4); or the composite bottom guard plate further comprises a third plate (3) and honeycomb plates (5), wherein the second plate (2) and the third plate (3) enclose a second accommodating cavity (30), one of the metal plates (4) and the honeycomb plates (5) is accommodated in the first accommodating cavity (10), and the other of the metal plates (4) and the honeycomb plates (5) is accommodated in the second accommodating cavity (30).

Description

Composite bottom guard plate, battery and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 21, 2024, with application number 202420564643.8. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a composite bottom guard plate, a battery and an electrical device. Background Art

[0003] As the most important structural support component of the battery pack, the battery underbody guard has a significant impact on the safety, lightweighting, and corrosion resistance of the battery system. In related technologies, the main materials used for battery underbody guards are steel guards or composite steel guards, which have excellent processing and welding properties. When the battery is installed on the chassis of a vehicle (such as an electric vehicle), the battery is easily affected by scraping or supporting the bottom of the vehicle under actual driving conditions. Steel guards or composite steel guards can provide protection for the battery.

[0004] However, steel guard plates or composite steel guard plates are heavy and have poor rigidity. They are easily squeezed and deformed when scraping or supporting the bottom, causing damage to the battery pack or even causing a fire, reducing the safety of the battery. Technical Solutions

[0005] In a first aspect, the present application provides a composite underbody guard plate, comprising a stacked first plate, a second plate, and a metal plate, wherein the upper surfaces of the first plate and the second plate enclose a first accommodating cavity;

[0006] There is a cavity in the metal plate, and the metal plate is filled and installed in the first accommodating cavity; or, the composite bottom guard plate also includes a third plate and a honeycomb plate, the lower surface of the second plate and the third plate form a second accommodating cavity, one of the metal plate and the honeycomb plate is filled and installed in the first accommodating cavity, and the other of the metal plate and the honeycomb plate is filled and installed in the second accommodating cavity.

[0007] In a second aspect, the present application provides a battery, including a battery pack and a composite bottom guard plate provided in the present application, wherein the first plate of the composite bottom guard plate is installed at the bottom of the battery pack.

[0008] On the third aspect, the present application provides an electrical device, including an electrical user and a battery provided by the present application, and the battery supplies power to the electrical user. Beneficial effects

[0009] The beneficial effects of the present application are as follows: when the composite bottom guard plate includes five layers of plates, namely, a first plate, a second plate, a third plate, a metal plate and a honeycomb plate, by filling and installing one of the metal plate and the honeycomb plate in the first accommodating cavity and the other in the second accommodating cavity, the composite bottom guard plate forms a five-layer plate structure, and the metal plate improves the structural strength of the composite bottom guard plate, thereby improving the anti-extrusion ability of the composite bottom guard plate when the battery scrapes or supports the bottom; at the same time, the honeycomb plate has a good buffering effect and can form a buffer space inside the composite bottom guard plate to absorb the extrusion energy and collision energy when the battery scrapes or supports the bottom, reduce the deformation of the composite bottom guard plate, avoid deformation of the battery pack, and improve the protection of the battery pack; when the composite bottom guard plate includes the first plate, the second plate and When the battery is a metal plate, the composite bottom guard plate forms a three-layer plate structure, and a buffer space is formed between the first plate and the second plate, so that the metal plate absorbs the extrusion energy and collision energy when the battery scrapes or bottoms out, reduces the deformation of the composite bottom guard plate, and has a better buffering effect, thereby avoiding deformation of the battery pack and improving the protection of the battery pack; the battery and electrical equipment proposed in this application include a composite bottom guard plate, which improves the structural strength of the composite bottom guard plate, thereby improving the anti-extrusion ability of the composite bottom guard plate when the battery scrapes or bottoms out; at the same time, a buffer space is formed inside the composite bottom guard plate to absorb the extrusion energy and collision energy when the battery scrapes or bottoms out, reduces the deformation of the composite bottom guard plate, avoids deformation of the battery pack, and improves the protection of the battery pack and the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a schematic diagram of the structural decomposition of a composite bottom guard plate provided in one embodiment of the present application;

[0011] FIG2 is a partial longitudinal cross-sectional view of a composite bottom guard plate provided in one embodiment of the present application;

[0012] FIG3 is a partial enlarged view of point A in FIG1 ;

[0013] FIG4 is a partial enlarged view of point B in FIG1 ;

[0014] FIG5 is a top view of a second plate provided in another embodiment of the present application;

[0015] FIG6 is a schematic diagram of the structural decomposition of a composite bottom guard plate provided in another embodiment of the present application;

[0016] FIG7 is a partial longitudinal cross-sectional view of a composite bottom guard plate provided in another embodiment of the present application;

[0017] FIG8 is a partial enlarged view of point C in FIG6;

[0018] FIG9 is a partial enlarged view of point D in FIG6;

[0019] FIG10 is a cross-sectional view of a second plate provided in one embodiment of the present application;

[0020] FIG11 is a schematic diagram of the structure of a composite bottom guard plate provided in another embodiment of the present application;

[0021] FIG12 is a partial enlarged view of point E in FIG11;

[0022] FIG13 is a schematic structural diagram of a fiber provided in one embodiment of the present application;

[0023] FIG14 is a schematic diagram of the three-dimensional structure of a battery provided in one embodiment of the present application;

[0024] FIG15 is a schematic diagram of the three-dimensional structure of an electrical device provided in one embodiment of the present application.

[0025] The names and numbers of the components in the figure are as follows:

[0026] 1. First plate; 10. First accommodating cavity; 11. Third hole; 121. Warp fiber bundle; 122. Weft fiber bundle; 2. Second plate; 21. First limiting groove; 211. First side surface; 212. Second side surface; 22. Second hole; 23. Second limiting groove; 3. Third plate; 30. Second accommodating cavity; 31. Split plate; 32. First hole; 4. Metal plate; 41. Cavity; 5. Honeycomb plate; 100. Battery; 200. Electrical equipment. Modes for Carrying Out the Invention

[0027] One embodiment of this application provides a battery comprising a battery pack and a composite underbody shield mounted on the bottom of the battery pack to protect it. The battery of this embodiment can be installed on the chassis of a new energy vehicle as a power battery. Of course, the battery can also be used in other electrical devices, without specific limitation here.

[0028] The main materials used for the bottom guard plates in related technologies are steel guard plates or composite steel guard plates. When the vehicle is driving on actual road conditions, the battery is easily affected by scraping or supporting the bottom. Since the steel guard plates or composite steel guard plates are heavy and have poor rigidity, they are easily squeezed and deformed when scraping or supporting the bottom, causing damage to the battery pack or even causing a fire, reducing the safety of the battery.

[0029] Based on this, as shown in Figures 1 and 2, this embodiment also proposes a composite bottom guard plate, which includes a stacked first plate 1, a second plate 2, a third plate 3, a metal plate 4, and a honeycomb plate 5. The upper surfaces of the first plate 1 and the second plate 2 form a first accommodating cavity 10, and the lower surfaces of the third plate 3 and the second plate 2 form a second accommodating cavity 30. One of the metal plate 4 and the honeycomb plate 5 is filled and installed in the first accommodating cavity 10, and the other of the metal plate 4 and the honeycomb plate 5 is filled and installed in the second accommodating cavity 30. By filling and installing one of the metal plate 4 and the honeycomb plate 5 in the first accommodating cavity 10 and the other in the second accommodating cavity 30, the composite bottom guard plate forms a five-layer plate structure. The metal plate 4 improves the structural strength of the composite bottom guard plate, thereby improving the composite bottom guard plate's ability to resist extrusion when the battery is scraped or supported. At the same time, the honeycomb panel 5 has a good buffering effect and can form a buffer space inside the composite bottom guard plate to absorb the extrusion energy and collision energy when the battery scrapes or supports the bottom, reduce the deformation of the composite bottom guard plate, avoid deformation of the battery pack, and improve the protection of the battery pack.

[0030] As shown in Figure 1, the metal plate 4 of this embodiment is installed in the first accommodating cavity 10, closer to the bottom of the battery pack. The honeycomb panel 5 is installed in the second accommodating cavity 30 and located below the metal plate 4. In other embodiments, the installation positions of the metal plate 4 and the honeycomb panel 5 can be interchanged, that is, the honeycomb panel 5 is installed in the first accommodating cavity 10, closer to the bottom of the battery pack, and the metal plate 4 is installed in the second accommodating cavity 30 and located below the honeycomb panel 5.

[0031] Specifically, in this embodiment, the first plate 1, second plate 2, third plate 3, metal plate 4, and honeycomb plate 5 are bonded together using a hot pressing process. This improves the structural strength of the composite underbody panel. Furthermore, the hot pressing process increases the production efficiency of the composite underbody panel. In other embodiments, the first plate 1, second plate 2, third plate 3, metal plate 4, and honeycomb plate 5 are bonded together to enhance the structural strength of the composite underbody panel. Furthermore, this bonding assembly method is simple and easy, reducing the cost of the composite underbody panel and improving production efficiency.

[0032] As shown in Figures 1, 2, and 10, the upper surface of the second plate 2 is provided with a first retaining groove 21, and the lower surface of the second plate 2 is also provided with a corresponding second retaining groove 23. The first plate 1 is attached to the circumferential edge of the upper surface of the second plate 2 and, together with the first retaining groove 21, forms a first accommodating cavity 10. The third plate 3 is attached to the circumferential edge of the lower surface of the second plate 2 and, together with the second retaining groove 23, forms a second accommodating cavity 30. A metal plate 4 is installed in the first retaining groove 21, and a honeycomb panel 5 is installed in the second retaining groove 23 to respectively retain and secure the metal plate 4 and honeycomb panel 5, ensuring stable assembly of the metal plate 4 and honeycomb panel 5. When the battery is scraped or supported, the third plate 3 is subjected to compression and impact, and the honeycomb panel 5 deforms and absorbs most of the compression and collision energy, reducing deformation of the composite underbody. The metal plate 4 enhances the structural strength of the composite underbody, ensuring that the first plate 1, which is closer to the battery pack, does not deform or only slightly deforms, greatly improving the safety of the battery pack.

[0033] As shown in Figures 3, 4, 11 and 12, the third plate 3 is provided with a first hole 32, the second plate 2 is provided with a second hole 22, and the second hole 22 is coaxially arranged with the first hole 32. The first plate 1 is provided with a third hole 11, and the third hole 11 is coaxially arranged with the first hole 32. Fasteners can be sequentially inserted into the first hole 32, the second hole 22 and the third hole 11 to lock the third plate 3, the second plate 2 and the first plate 1 to the bottom of the battery pack. The fasteners of this embodiment can be bolts or pins, etc., so that the first plate 1, the second plate 2 and the third plate 3 are fixedly assembled with the battery pack by bolt connection or riveting, thereby improving the connection strength and stability between the composite bottom guard plate and the battery pack. In other embodiments, the first plate 1 can also be bonded to the bottom of the battery pack. The bonding assembly method is simple and easy, reduces costs and improves production efficiency.

[0034] It should be noted that the middle beam of the battery pack includes an X-direction crossbeam and a Y-direction crossbeam arranged in a cross shape, and the fixed positions of the X-direction crossbeam and the Y-direction crossbeam can be moved along the X direction or the Y direction according to the arrangement of the battery cells. As shown in Figures 5 and 10, the upper surface of the second plate 2 of this embodiment is provided with four first limiting grooves 21 arranged in an array along the X direction and the Y direction, and the lower surface of the second plate 2 is provided with four second limiting grooves 23 arranged in an array along the X direction and the Y direction. The third plate 3 includes four split plates 31, and the four split plates 31 are respectively arranged with the corresponding second limiting grooves 23 to form a second accommodating cavity 30. The four split plates 31 form a cross-shaped groove (i.e., the installation area of ​​the middle beam) that is compatible with the middle beam to facilitate the assembly of the second plate 2 and the middle beam. There are four honeycomb panels 5, and the four honeycomb panels 5 are respectively installed in the corresponding second limiting grooves 23. In other embodiments, if the battery pack's center beam eliminates the Y-direction crossbeam, the upper surface of the second plate 2 is provided with two first retaining grooves 21 spaced apart along the Y direction, and the lower surface of the second plate 2 is provided with two second retaining grooves 23 spaced apart along the Y direction. The third plate 3 comprises two split plates 31, each of which, along with the corresponding second retaining grooves 23, encloses a second accommodating cavity 30. A straight groove (i.e., the mounting area for the center beam) is formed between the two split plates 31, facilitating assembly of the second plate 2 with the center beam. Two honeycomb panels 5 are provided, each mounted within a corresponding second retaining groove 23.

[0035] As shown in Figure 5, the first limiting groove 21 has two first side surfaces 211 arranged opposite each other along the X direction and two second side surfaces 212 arranged opposite each other along the Y direction. The spacing d2 between the first side surface 211 and the outer side surface of the adjacent second plate 2 along the Y direction is 20 mm to 300 mm. The spacing d1 between the second side surface 212 and the outer side surface of the adjacent second plate 2 along the X direction is 20 mm to 100 mm. The spacing d3 between two adjacent second side surfaces 212 of two first limiting grooves 21 spaced apart along the Y direction is 20 mm to 50 mm. Specifically, d1 can be 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm, etc. d2 can be 20 mm, 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, or 300 mm, etc. d3 can be 20 mm, 30 mm, 40 mm, or 50 mm, etc. By setting the sizes of d1, d2, and d3, the first limiting groove 21 and the second limiting groove 23 have sufficient areas to increase the usable area of ​​the honeycomb panel 5 and the metal plate 4. While ensuring the structural strength of the composite bottom guard plate, the area of ​​the composite bottom guard plate's buffer space is increased, so that the honeycomb panel 5 can absorb as much extrusion energy and collision energy as possible when the battery scrapes or supports the bottom, reducing the deformation of the composite bottom guard plate. If d1, d2, and d3 are too small, the difficulty of assembling the first plate 1, the second plate 2, and the third plate 3, as well as the difficulty of assembling the composite bottom guard plate and the battery pack, increases the amount of metal plate 4 used, and increases the weight of the composite bottom guard plate. If d1, d2, and d3 are too large, the amount of honeycomb panel 5 used is reduced, the area of ​​the composite bottom guard plate's buffer space is reduced, and it is not conducive to reducing the deformation of the composite bottom guard plate.

[0036] It should be noted that the material of the honeycomb panel 5 is one of polypropylene, polyethylene, polycarbonate, polyphenylene ether or polystyrene. The honeycomb panel 5 prepared from these materials has a high structural strength, avoids breakage after being squeezed, and has a good buffering effect. At the same time, it is convenient for the processing and manufacturing of the honeycomb panel 5, improves the manufacturing efficiency of the honeycomb panel 5, and reduces the production cost. Specifically, the honeycomb panel 5 includes a skin and a honeycomb core, and a plurality of honeycomb cores are covered on one surface of the skin to improve the buffering effect of the honeycomb panel 5. The honeycomb core can be polygonal or circular, etc., and the specific structure and processing process of the honeycomb panel 5 will not be described in detail. In other embodiments, the honeycomb panel 5 can also be made of other materials, as long as it has a good buffering effect.

[0037] Specifically, the thickness of the honeycomb panel 5 is 5 mm to 10 mm. The thickness of the honeycomb panel 5 can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm, etc. The thickness of the honeycomb panel 5 is set to 5 mm to 10 mm to ensure that the honeycomb panel 5 has sufficient structural strength, while ensuring that it is light in weight and occupies a small volume, thereby reducing the total weight of the composite bottom guard plate. When the thickness of the honeycomb panel 5 is too small, the structural strength of the honeycomb panel 5 is low, the buffering effect is poor, and it is difficult to meet the use requirements of the composite bottom guard plate. When the thickness of the honeycomb panel 5 is too large, the weight of the honeycomb panel 5 is heavy, which makes the total weight and occupied volume of the composite bottom guard plate larger.

[0038] The metal plate 4 of this embodiment is a solid steel plate or a solid aluminum plate. When the metal plate 4 is a solid steel plate, it is desirable to use galvanized or tinned steel to improve the steel's corrosion resistance. Of course, the surface of the solid steel plate can also be treated with a coating or powder coating to ensure corrosion resistance. When the metal plate 4 is a solid aluminum plate, an aluminum profile can be used. Aluminum profiles are lighter and offer better corrosion resistance, reducing the weight of the composite underbody and providing a certain cushioning effect.

[0039] Specifically, the thickness of the metal plate 4 is 0.6mm to 1.5mm. The thickness of the metal plate 4 of this embodiment can be 0.6mm, 0.8mm, 1mm, 1.2mm or 1.5mm, etc. Setting the thickness of the metal plate 4 to 0.6mm to 1.5mm can ensure that the metal plate 4 has sufficient structural strength while ensuring that the weight is light, thereby reducing the total weight of the composite bottom guard plate. When the thickness of the metal plate 4 is too small, the structural strength of the metal plate 4 is low, and it is difficult to meet the use requirements of the composite bottom guard plate. When the thickness of the metal plate 4 is too large, the total weight and occupied volume of the composite bottom guard plate are both large, thereby increasing the total volume of the battery.

[0040] When the battery is scraped or bottomed out, the third plate 3 is subjected to the most severe squeezing and collision. Therefore, the thickness of the third plate 3 is greater than that of the first plate 1 and the second plate 2, respectively, so that the structural strength of the third plate 3 is higher, and serious damage to the third plate 3 is avoided, thereby improving the safety of the battery. Specifically, the thickness of the first plate 1 and the second plate 2 are both 0.4mm to 1mm, and the thickness of the third plate 3 is 0.6mm to 1.5mm. In this embodiment, the thickness of the first plate 1 and the second plate 2 are equal, and can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, etc. The thickness of the third plate 3 can be 0.6mm, 0.8mm, 1mm, 1.2mm or 1.5mm, etc. The thickness of the first plate 1 and the second plate 2 is set to 0.4mm to 1mm, and the thickness of the third plate 3 is set to 0.6mm to 1.5mm to ensure that the first plate 1, the second plate 2, and the third plate 3 have sufficient structural strength while ensuring a low weight, thereby reducing the total weight of the composite bottom guard plate. If the thickness of the first plate 1, the second plate 2, and the third plate 3 is too small, the structural strength of the composite bottom guard plate is low and it is difficult to meet the requirements of use. If the thickness of the first plate 1, the second plate 2, and the third plate 3 is too large, the total weight and occupied volume of the composite bottom guard plate are both large.

[0041] The first, second, and third panels 3 of this embodiment are each made of one of glass fiber, carbon fiber, boron fiber, ultra-high molecular weight polyethylene fiber, polypropylene, polyethylene, polycarbonate, polyphenylene ether, and polystyrene. The composite material of the first, second, and third panels 1, 2, and 3 improves the overall structural strength of the composite underbody panel.

[0042] As shown in Figure 13, when the first plate 1, second plate 2, and third plate 3 are all made of one of glass fiber, carbon fiber, boron fiber, and ultra-high molecular weight polyethylene fiber, the fibers include warp fiber bundles 121 and weft fiber bundles 122, and the warp fiber bundles 121 and weft fiber bundles 122 are arranged in a cross-staggered arrangement. The cross-staggered arrangement of the warp fiber bundles 121 and weft fiber bundles 122 improves the structural strength of the fibers, resulting in higher overall strength for the first plate 1, second plate 2, and third plate 3, which are formed by combining one of the fibers, and reduces deformation of the composite bottom guard plate when scraping or supporting the bottom.

[0043] As shown in Figures 14 and 15, this embodiment also proposes an electrical device 200, including an electrical subject and a battery 100. The first plate 1 of the composite bottom guard plate is installed at the bottom of the battery pack, and the battery 100 supplies power to the electrical subject. The electrical subject can be a new energy vehicle. The composite bottom guard plate forms a five-layer plate structure, and the metal plate 4 improves the structural strength of the composite bottom guard plate, thereby improving the composite bottom guard plate's ability to resist extrusion when the battery scrapes or supports the bottom. At the same time, the honeycomb plate 5 has a good buffering effect and can form a buffer space inside the composite bottom guard plate to absorb extrusion energy and collision energy when the battery scrapes or supports the bottom, reduce the deformation of the composite bottom guard plate, avoid deformation of the battery pack, and improve the protection of the battery pack and the safety of the battery.

[0044] In another embodiment of the present application, as shown in FIG6 , this embodiment proposes a composite bottom guard plate, which has basically the same structure as the composite bottom guard plates of other embodiments, with the main difference being that the composite bottom guard plate of this embodiment has only a three-layer structure, and the composite bottom guard plate only includes a stacked first plate 1, a second plate 2, and a metal plate 4, and the upper surfaces of the first plate 1 and the second plate 2 form a first accommodating cavity 10. The metal plate 4 has a cavity 41 therein, and the first accommodating cavity 10 is filled and installed with the metal plate 4. It should be noted that the first plate 1 and the second plate 2 are both composite resin plates, which improve the structural strength of the composite bottom guard plate, thereby improving the composite bottom guard plate's ability to resist extrusion when the battery is scraped or supported. At the same time, by arranging a metal plate 4 with a cavity 21 between the first plate 1 and the second plate 2, the composite bottom guard plate forms a three-layer plate structure, and a buffer space is formed between the first plate 1 and the second plate 2, so that the metal plate 4 absorbs the extrusion energy and collision energy when the battery scrapes or supports the bottom, reducing the deformation of the composite bottom guard plate, achieving a better buffering effect, avoiding deformation of the battery pack, and improving the protection of the battery pack.

[0045] Specifically, in this embodiment, the first plate 1, the second plate 2, and the metal plate 4 are combined into one body through a hot pressing process, thereby enhancing the structural strength of the composite underbody panel. Furthermore, the hot pressing process improves the production efficiency of the composite underbody panel. In other embodiments, the first plate 1, the second plate 2, and the metal plate 4 can also be bonded together to further enhance the structural strength of the composite underbody panel. Furthermore, the bonding assembly method is simple and easy, reducing the cost of the composite underbody panel and improving production efficiency.

[0046] As shown in Figures 6 and 7, the upper surface of the second plate 2 is provided with a first retaining groove 21. The first plate 1 is attached to the circumferential edge of the second plate 2 and, together with the first retaining groove 21, forms a first accommodating cavity 10. The first retaining groove 21 is filled with a metal plate 4, which secures the metal plate 4 in place. The inner side surface of the second plate 2 (the side facing the first plate 1) has the first retaining groove 21, and the outer side surface of the second plate 2 forms a corresponding boss structure. When the battery is scraped or supported, the second plate 2 is subjected to an extrusion impact. The metal plate 4 deforms and absorbs most of the extrusion and collision energy, reducing deformation of the composite underbody guard. The first plate 1, which is closer to the battery pack, does not deform or only slightly deforms, greatly protecting the battery pack's safety. It should be noted that because the circumferential edge of the second plate 2 overlaps the circumferential edge of the first plate 1, there is no need for an additional reinforced resin frame between the circumferential edges of the second and first plates 2, simplifying the structure of the composite underbody guard and reducing costs.

[0047] As shown in Figures 8 and 9, the second plate 2 is provided with a second hole 22, and the first plate 1 is coaxially provided with a corresponding third hole 11. Fasteners can be sequentially inserted through the second hole 22 and the third hole 11, thereby securing the second plate 2 and the first plate 1 to the bottom of the battery pack. The fasteners in this embodiment can be bolts or pins, allowing the second plate 2 and the first plate 1 to be fixedly assembled to the battery pack via bolting or riveting, thereby improving the strength and stability of the connection between the composite underbody guard and the battery pack. In other embodiments, the first plate 1 can also be adhesively bonded to the bottom of the battery pack. This simple and easy adhesive assembly method reduces battery costs and improves production efficiency.

[0048] The middle beam of the battery pack in this embodiment includes an X-direction crossbeam and a Y-direction crossbeam arranged in a cross shape, and the fixed positions of the X-direction crossbeam and the Y-direction crossbeam can be moved along the X direction or the Y direction according to the arrangement position of the battery cells. The inner side surface of the second plate 2 in this embodiment has four first limiting grooves 21 arranged in an array along the X direction and the Y direction, so that the outer side surface of the second plate 2 has four bosses arranged in an array along the X direction and the Y direction, and the four bosses form a cross-shaped groove that is compatible with the middle beam to facilitate the assembly of the composite bottom guard plate and the middle beam. There are four metal plates 4, and the four metal plates 4 are respectively installed in the corresponding first limiting grooves 21. In other embodiments, if the middle beam of the battery pack cancels the Y-direction crossbeam, the inner side surface of the second plate 2 correspondingly has two first limiting grooves 21 spaced apart along the Y direction. There are two metal plates 4, and the two metal plates 4 are respectively installed in the corresponding first limiting grooves 21.

[0049] In this embodiment, the metal plate 4 is an aluminum profile. Aluminum profiles have high structural strength, preventing fracture under compression and providing a good cushioning effect. Compared to steel plates, aluminum profiles are lighter, reducing the weight of the composite underbody guard, and they also offer better corrosion resistance. Furthermore, aluminum profiles can be purchased directly without the need for design or processing, resulting in lower costs. In other embodiments, the metal plate 4 can be made of other materials, as long as it includes the cavity 21 to provide a good cushioning effect.

[0050] Among them, the aluminum profile plate is extruded in one piece to form at least one cavity 21 that is arranged to pass through the aluminum profile plate in the length direction or the width direction. The production efficiency and structural strength of the aluminum profile plate are improved by the one-piece extrusion molding method. The longitudinal section of the cavity 21 of this embodiment is rectangular. It can be understood that the longitudinal cross-section of the cavity 21 can also be circular, triangular or other polygonal, which is not specifically limited here. In other embodiments, the metal plate 4 can also be formed by welding a plurality of aluminum profile plates. Specifically, the metal plate 4 includes a plurality of aluminum profile plates, and the plurality of aluminum profile plates are welded together to form at least one cavity 21.

[0051] Specifically, the thickness of the aluminum profile plate is 8mm to 16mm, and the wall thickness of the aluminum profile plate is 1.5mm to 4mm. The thickness of the aluminum profile plate can be 8mm, 10mm, 12mm, 14mm or 16mm, etc. The wall thickness of the aluminum profile plate can be 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm or 4mm, etc. The thickness and wall thickness of the aluminum profile plate are set to 8mm to 16mm to ensure that the aluminum profile plate has sufficient structural strength, while ensuring that it is light in weight and occupies a small volume, thereby reducing the total weight of the composite bottom guard plate. When the thickness and wall thickness of the aluminum profile plate are too small, the structural strength of the aluminum profile plate is low, the buffering effect is poor, and it is difficult to meet the use requirements of the composite bottom guard plate. When the thickness and wall thickness of the aluminum profile plate are too large, the weight of the aluminum profile plate is heavy, making the total weight and occupied volume of the composite bottom guard plate larger.

[0052] When the battery is scraped and supported, the second plate 2 is squeezed and collided the most severely. Therefore, the thickness of the first plate 1 is less than that of the second plate 2, so that the structural strength of the second plate 2 is higher, serious damage to the second plate 2 is avoided, and the safety of the battery is improved. Specifically, the thickness of the first plate 1 is 0.4mm to 1mm, and the thickness of the second plate 2 is 0.6mm to 1.5mm. The thickness of the first plate 1 of this embodiment can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, etc. The thickness of the second plate 2 can be 0.6mm, 0.8mm, 1mm, 1.2mm or 1.5mm, etc. The thickness of the first plate 1 is set to 0.4mm to 1mm, and the thickness of the second plate 2 is set to 0.6mm to 1.5mm to ensure that the first plate 1 and the second plate 2 have sufficient structural strength, while ensuring that the weight is light, thereby reducing the total weight of the composite bottom guard plate. When the thickness of the first plate 1 and the second plate 2 is too small, the structural strength of the first plate 1 and the second plate 2 is low, and it is difficult to meet the use requirements of the composite bottom guard plate. When the thickness of the first plate 1 and the second plate 2 is too large, the total weight and occupied volume of the composite bottom guard plate are both large.

Claims

1. A composite bottom guard plate, comprising a first plate (1), a second plate (2), and a metal plate (4) stacked together, wherein the upper surfaces of the first plate (1) and the second plate (2) enclose a first accommodating cavity (10); The metal plate (4) has a cavity (41) therein, and the metal plate (4) is filled and installed in the first accommodating cavity (10); or, the composite bottom guard plate further includes a third plate (3) and a honeycomb plate (5), the lower surface of the second plate (2) and the third plate (3) enclose a second accommodating cavity (30), one of the metal plate (4) and the honeycomb plate (5) is filled and installed in the first accommodating cavity (10), and the other of the metal plate (4) and the honeycomb plate (5) is filled and installed in the second accommodating cavity (30).

2. The composite underbody according to claim 1, wherein: The first plate (1), the second plate (2) and the metal plate (4) are bonded together or composited into one piece through a hot pressing process; Alternatively, the first plate (1), the second plate (2), the third plate (3), the metal plate (4) and the honeycomb plate (5) are bonded together or composited into one body through a hot pressing process.

3. The composite underbody according to claim 1, wherein: When the composite bottom guard plate does not include the third plate (3) and the honeycomb plate (5), the metal plate (4) is an aluminum profile plate.

4. The composite underbody according to claim 3, wherein: The aluminum profile plate is integrally extruded to form at least one cavity (21) penetrating along the length direction or the width direction in the aluminum profile plate; Alternatively, the metal plate (4) comprises a plurality of the aluminum profile plates, and the plurality of the aluminum profile plates are welded together to enclose at least one cavity (21).

5. The composite bottom guard plate according to claim 3, wherein: The thickness of the aluminum profile plate is 8 mm to 16 mm, and the wall thickness of the aluminum profile plate is 1.5 mm to 4 mm.

6. The composite underbody panel according to claim 1, wherein: The material of the honeycomb panel (5) is one of polypropylene, polyethylene, polycarbonate, polyphenylene ether or polystyrene.

7. The composite underbody according to claim 1, wherein: The thickness of the honeycomb panel (5) is 5 mm to 10 mm.

8. The composite underbody according to claim 1, wherein: When the composite bottom guard plate includes the third plate (3) and the honeycomb plate (5), the metal plate (4) is a solid steel plate or a solid aluminum plate.

9. The composite underbody panel according to claim 8, wherein: The thickness of the metal plate (4) is 0.6 mm to 1.5 mm.

10. The composite underbody according to any one of claims 1 to 9, wherein: When the metal plate (4) does not include the third plate (3) and the honeycomb plate (5), the upper surface of the second plate (2) is provided with a first limiting groove (21), and the first plate (1) is attached to the circumferential edge of the upper surface of the second plate (2) and encloses the first accommodating cavity (10) with the first limiting groove (21); When the composite bottom guard plate further includes the third plate (3) and the honeycomb plate (5), a second limiting groove (23) is correspondingly provided on the lower surface of the second plate (2), and the third plate (3) is attached to the circumferential edge of the lower surface of the second plate (2) and encloses the second accommodating cavity (30) with the second limiting groove (23).

11. The composite underbody according to claim 10, wherein: When the composite bottom guard plate does not include the third plate (3) and the honeycomb plate (5), the upper surface of the second plate (2) is provided with two first limiting grooves (21) spaced apart along the Y direction, or the upper surface of the second plate (2) is provided with four first limiting grooves (21) arranged in an array along the X direction and the Y direction; When the composite bottom guard plate further includes the third plate (3) and the honeycomb plate (5), the lower surface of the second plate (2) is further provided with two second limiting grooves (23) spaced apart along the Y direction; the third plate (3) includes two split plates (31), and the two split plates (31) are respectively arranged with the corresponding second limiting grooves (23) to form the second accommodating cavity (30); or the lower surface of the second plate (2) is provided with four second limiting grooves (23) arranged in an array along the X direction and the Y direction; the third plate (3) includes four split plates (31), and the four split plates (31) are respectively arranged with the corresponding second limiting grooves (23) to form the second accommodating cavity (30).

12. The composite underbody panel according to claim 11, wherein: The first limiting groove (21) has two first side surfaces (211) arranged opposite to each other along the X direction and two second side surfaces (212) arranged opposite to each other along the Y direction, the spacing between the first side surface (211) and the outer side surface of the adjacent second plate (2) along the Y direction is 20 mm to 300 mm; the spacing between the second side surface and the outer side surface of the adjacent second plate (2) along the X direction is 20 mm to 100 mm; and the spacing between two adjacent second side surfaces (212) of the two first limiting grooves (21) arranged at intervals along the Y direction is 20 mm to 50 mm.

13. The composite underbody according to any one of claims 1 to 9, wherein: When the composite bottom guard plate does not include the third plate (3) and the honeycomb plate (5), the second plate (2) is coaxially provided with a second hole (22), and the first plate (1) is coaxially provided with a third hole (11), and a fastener can be sequentially passed through the second hole (22) and the third hole (11), and the first plate (1) and the second plate (2) are both locked to the bottom of the battery pack; When the composite bottom guard plate further includes the third plate (3) and the honeycomb plate (5), the third plate (3) is further provided with a first hole (32), and the fastener can be sequentially passed through the first hole (32), the second hole (22), and the third hole (11) to lock the third plate (3), the second plate (2), and the first plate (1) to the bottom of the battery pack.

14. The composite underbody according to any one of claims 1 to 9, wherein: The first plate (1) can be bonded to the bottom of the battery pack.

15. The composite underbody according to any one of claims 1 to 9, wherein: When the composite bottom guard plate does not include the third plate (3) and the honeycomb plate (5), the thickness of the second plate (2) is greater than the thickness of the first plate (1); the thickness of the first plate (1) is 0.4 mm to 1 mm, and the thickness of the second plate (2) is 0.6 mm to 1.5 mm; Alternatively, when the composite bottom guard plate includes the third plate (3) and the honeycomb plate (5), the thickness of the third plate (3) is greater than the thickness of the first plate (1) and the second plate (2); the thickness of the first plate (1) and the second plate (2) are both 0.4 mm to 1 mm, and the thickness of the third plate (3) is 0.6 mm to 1.5 mm.

16. The composite underbody according to any one of claims 1 to 9, wherein: The materials of the first plate (1), the second plate (2) and the third plate (3) are all one of glass fiber, carbon fiber, boron fiber, ultra-high molecular weight polyethylene fiber, polypropylene, polyethylene, polycarbonate, polyphenylene ether and polystyrene.

17. The composite underbody panel according to claim 16, wherein: When the materials of the first plate (1), the second plate (2) and the third plate (3) are all one of the glass fiber, the carbon fiber, the boron fiber and the ultra-high molecular weight polyethylene fiber, the fibers include warp fiber bundles (121) and weft fiber bundles (122), and the warp fiber bundles (121) and the weft fiber bundles (122) are arranged in a cross-staggered manner.

18. A battery comprising a battery pack and the composite bottom guard plate according to any one of claims 1 to 17, wherein the first plate (1) of the composite bottom guard plate is mounted on the bottom of the battery pack.

19. An electric device comprising an electric main body and the battery according to claim 18, wherein the battery supplies power to the electric main body.

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