Bottom protection plate assembly and battery pack

Abstract

The utility model provides a bottom guard plate subassembly and battery pack, said bottom guard plate subassembly includes cover plate, bottom plate and packing layer, said cover plate and said bottom plate are laminated, and said cover plate and said bottom plate have the accommodation cavity therebetween, said packing layer is provided in said accommodation cavity; wherein the bottom plate is provided with at least one exhaust hole, the exhaust hole is communicated with the containing cavity, and the hole diameter of the end, away from the containing cavity, of the exhaust hole is smaller than the hole diameter of the end, close to the containing cavity, of the exhaust hole. According to the bottom protection plate assembly and the battery pack provided by the utility model, gas in the accommodating cavity of the bottom protection plate assembly can be smoothly discharged, so that the accommodating cavity is uniformly filled with the filling material.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a bottom guard plate assembly and a battery pack. Background Art

[0002] The bottom guard plate in the battery pack structure is usually used to protect the bottom of the battery pack to prevent damage and destruction to the battery module due to collision, friction, water vapor, etc.

[0003] The interlayer cavity of the current sandwich bottom guard plate is usually filled with foam glue, but the exhaust holes of some current sandwich bottom guard plates are unreasonably designed, and the gas in the cavity is not easy to discharge or is discharged incompletely, which can easily lead to incomplete foaming in the cavity, the foam glue cannot be leveled, and the interlayer cavity cannot be filled, resulting in poor stability and poor quality of the bottom guard plate. Utility Model Content

[0004] The embodiments of the utility model provide a bottom guard plate assembly and a battery pack, which are conducive to the smooth discharge of gas in the accommodating cavity of the bottom guard plate assembly, so that the filling material is evenly filled in the accommodating cavity, so as to improve the stability and quality of the bottom guard plate.

[0005] In a first aspect, the utility model provides a bottom guard plate assembly, comprising a cover plate, a bottom plate and a filling layer, wherein the cover plate and the bottom plate are stacked, and a receiving cavity is provided between the cover plate and the bottom plate, and the filling layer is provided in the receiving cavity;

[0006] Wherein, at least one exhaust hole is provided on the bottom plate, the exhaust hole is communicated with the accommodating cavity, and the aperture of the exhaust hole at one end away from the accommodating cavity is smaller than the aperture of the exhaust hole at one end close to the accommodating cavity.

[0007] In one embodiment, the base plate includes a receiving portion and a connecting portion connected to an edge of the receiving portion, the receiving portion having a receiving groove configured to receive the filling layer, and the connecting portion is parallel to the cover plate and configured to be connected to the cover plate.

[0008] In one embodiment, the exhaust hole is disposed on the connecting portion.

[0009] In one embodiment, the accommodating portion includes a plurality of side edges, and the connecting portion connected to each side edge is provided with the exhaust hole.

[0010] In one embodiment, in a direction perpendicular to the cover plate, a height of the exhaust hole is less than or equal to 0.2 mm.

[0011] In one embodiment, at least one glue injection hole is provided on the cover plate, and the glue injection hole is communicated with the accommodating cavity.

[0012] In one embodiment, a projection of the glue injection hole on the bottom plate is located on the central axis of the accommodating portion.

[0013] In one embodiment, the cover plate and / or the bottom plate are made of steel or aluminum.

[0014] In one embodiment, the cover plate and / or the bottom plate are made of polypropylene resin.

[0015] In one embodiment, the material of the filling layer is foamed rubber or modified polyphenylene ether.

[0016] In a second aspect, the utility model provides a battery pack, including a box body and a battery module arranged in the box body, the box body includes a top cover and a bottom guard plate assembly as described above that are relatively arranged, and a side plate located between the top cover and the bottom guard plate assembly.

[0017] The utility model provides a bottom guard plate assembly and a battery pack, wherein exhaust holes are arranged on the bottom plate, and the aperture of the exhaust hole at one end away from the accommodating cavity is smaller than the aperture of the exhaust hole at one end close to the accommodating cavity, wherein the aperture close to the accommodating cavity is large, which is convenient for gas convergence in the cavity, and the aperture close to the outside is small, so that the apertures at both ends of the exhaust hole are differentiated, which is beneficial to forming a gas pressure difference between the inside and the outside, and is convenient for the smooth discharge of the gas in the cavity during filling, thereby facilitating the filling uniformity of the material in the accommodating cavity, so as to improve the stability and quality of the bottom guard plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a structural schematic diagram of a bottom guard plate assembly provided by an embodiment of the utility model;

[0020] Figure 2 It is a side view of a bottom guard plate assembly provided by an embodiment of the utility model;

[0021] Figure 3 It is a top view of a base plate provided by an embodiment of the utility model;

[0022] Figure 4 yes Figure 3 An enlarged schematic diagram of a part A of the midsole plate;

[0023] Figure 5 is a cross-sectional view of a bottom guard plate assembly provided by an embodiment of the utility model;

[0024] Figure 6 It is a structural schematic diagram of another bottom guard plate assembly provided by an embodiment of the utility model;

[0025] Figure 7 It is a cross-sectional view of another bottom guard plate assembly provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0027] like Figure 1-Figure 2 As shown, a bottom guard plate assembly provided by the utility model includes a cover plate 100, a bottom plate 200 and a filling layer 300, wherein the cover plate 100 and the bottom plate 200 are stacked, and a receiving cavity 210 is provided between the cover plate 100 and the bottom plate 200, and the filling layer 300 is arranged in the receiving cavity 210; wherein, at least one exhaust hole 201 is provided on the bottom plate 200, the exhaust hole 201 is connected with the receiving cavity 210, and the aperture of the exhaust hole 201 away from the receiving cavity 210 is smaller than the aperture of the exhaust hole 201 close to the receiving cavity 210.

[0028] During the assembly process of the bottom guard plate assembly, the cover plate 100 and the bottom plate 200 are usually assembled and connected first, and then the material of the filling layer 300 is injected into the receiving cavity 210 between the cover plate 100 and the bottom plate 200. Since the receiving cavity 210 is a closed space, there is air in the receiving cavity 210 when the material is not filled. When filling the receiving cavity 210 with material, the air in the receiving cavity 210 needs to be discharged at the same time so that the material of the filling layer 300 can be injected into the receiving cavity 210 and fill the receiving cavity 210. In the traditional bottom guard plate structure, the aperture of the exhaust hole 201 provided on the bottom guard plate is usually consistent, and the exhaust rate is slow and the exhaust effect is poor, which can easily lead to uneven filling in the receiving cavity 210, or the gas in the cavity cannot be completely discharged, and the material cannot fill the receiving cavity 210, which in turn leads to poor stability and poor quality of the bottom guard plate assembly. Therefore, the present application improves the structure of the exhaust hole 201, and differentiates the aperture of the exhaust hole 201 set on the base plate 200, so that the aperture of the exhaust hole 201 away from the accommodating cavity 210 is smaller than the aperture of the exhaust hole 201 close to the accommodating cavity 210, that is, the aperture of the exhaust hole 201 close to the accommodating cavity 210 is larger, which is convenient for the convergence of gas in the cavity, and the aperture of the exhaust hole 201 close to the outside is smaller, which is conducive to forming a gas pressure difference between the inside and the outside, and is convenient for the smooth discharge of the gas in the cavity when filling the material, which can improve the exhaust rate, and further improve the filling rate and filling uniformity.

[0029] In one embodiment, if Figure 3-Figure 4 As shown, the cross section of the exhaust hole 201 may be a trapezoid, the side close to the accommodating cavity 210 is the bottom side of the trapezoid, the side close to the outside is the top side b of the trapezoid, and the length a of the bottom side is greater than the length b of the top side. For example, the length a of the bottom side is 20 mm, and the length b of the top side is 10 mm.

[0030] In one embodiment, if Figure 5 As shown, the base plate 200 includes a receiving portion 220 and a connecting portion 230 connected to the edge of the receiving portion 220, the receiving portion 220 is a U-shaped receiving groove, configured to receive the filling layer 300, the connecting portion 230 surrounds the edge of the opening side of the receiving portion 220, and the connecting portion 230 is parallel to the cover plate 100 and is configured to be connected to the cover plate 100.

[0031] The receiving portion 220 and the connecting portion 230 may be an integrally formed structure, and the U-shaped receiving groove structure of the receiving portion 220 may be formed by stamping or die-molding a plate-shaped bottom guard plate material. The depth h of the U-shaped receiving groove of the receiving portion 220 may range from 6 mm to 8 mm, but is not limited thereto, and may be specifically designed according to actual process requirements.

[0032] When the cover plate 100 and the base plate 200 are assembled, the cover plate 100 is installed on the open side of the accommodating portion 220, and a closed accommodating cavity 210 is formed between the cover plate 100 and the accommodating portion 220. The surface of the connecting portion 230 in contact with the cover plate 100 is tightly fitted to avoid glue leakage during filling. At the same time, the base plate 200 is fixedly connected to the cover plate 100 through the connecting portion 230.

[0033] The connection part 230 and the cover plate 100 may be fixed by bonding with an adhesive, for example, by applying glue between the connection part 230 and the cover plate 100 and connecting them by hot pressing. The connection part 230 and the cover plate 100 may also be fixedly connected by fasteners, such as Figure 7 As shown, for example, corresponding through holes 101 may be provided on the connecting portion 230 and the cover plate 100 , and rivets or bolts 102 may be passed through the through holes 101 to fix the cover plate 100 to the base plate 200 .

[0034] In one embodiment, if Figure 3-Figure 4 As shown, the exhaust hole 201 can be arranged on the connecting portion 230. The exhaust hole 201 can be a through hole that penetrates the connecting portion 230, or a groove structure formed on the side of the connecting portion 230 facing the cover plate 100. When the cover plate 100 is attached to the connecting portion 230, the exhaust hole 201 is formed between the groove and the cover plate 100. When the exhaust hole 201 is arranged on the connecting portion 230, on the one hand, it can be avoided that when the exhaust hole 201 is arranged on the accommodating portion 220, the filling material blocks the exhaust hole 201 during the filling process, resulting in the air above the exhaust hole 201 being unable to be discharged, causing the problem of insufficient filling. On the other hand, when the exhaust hole 201 is filled with the filling material, it is easy to judge that the accommodating cavity 210 is filled with the filling material.

[0035] In one embodiment, if Figure 3As shown, the accommodating portion 220 includes a plurality of side edges, and the connecting portion 230 connected to each side edge is provided with the exhaust hole 201. For example, the bottom plate 200 may be a square structure with four side edges, and accordingly, the bottom plate 200 has four connecting portions 230 located around the accommodating portion 220, and at least one exhaust hole 201 may be provided on each connecting portion 230. Furthermore, the exhaust holes 201 on the connecting portions 230 on opposite sides may be centrally symmetrically arranged, which can ensure the exhaust uniformity of each side of the accommodating cavity 210 on one hand, and on the other hand, when the exhaust holes 201 on each side are filled with material, it indicates that the accommodating cavity 210 is fully filled with material, which can solve the problem of insufficient filling and uneven filling of the traditional bottom guard plate.

[0036] In one embodiment, if Figure 2 As shown, in the direction perpendicular to the cover plate, the height c of the exhaust hole 201 is less than or equal to 0.2 mm. For example, the height c of the exhaust hole 201 may be equal to 0.2 mm. Within this height range, the gas in the accommodating cavity 210 is easily discharged, while the filling material is not easily discharged.

[0037] In this application, if Figure 1 , Figure 5 As shown, at least one glue injection hole 110 is provided on the cover plate 100, and the glue injection hole 110 is connected to the accommodating cavity 210. After the cover plate 100 and the bottom plate 200 are assembled, the filling material can be injected into the accommodating cavity 210 from the glue injection hole 110 by using a glue injection device. When the accommodating cavity 210 is filled with the filling material, the filling material is solidified to form the filling layer 300.

[0038] In one embodiment, if Figure 1 , Figure 5 As shown, the projection of the injection hole 110 on the bottom plate 200 is located on the central axis of the receiving portion 220, that is, the injection hole 110 is arranged at the center of the cover plate 100. For example, a through hole with a diameter of 10 mm can be opened at the center of the cover plate 100 as the injection hole 110. The injection hole 110 is arranged at the center of the cover plate 100, which is conducive to the filling material flowing through the entire receiving cavity 210 in the shortest path, so as to ensure that the filling material is quickly leveled in the receiving cavity 210 and the filling is uniform.

[0039] In other embodiments, the cover plate 100 may be provided with a plurality of glue injection holes 110. Furthermore, the plurality of glue injection holes 110 may be provided on opposite sides of the cover plate 100 and may be symmetrically arranged. Figure 6-Figure 7As shown, the glue injection hole 110 can be arranged at a diagonally opposite corner of the cover plate 100 , and the projection of the glue injection hole 110 on the bottom plate 200 is located within the range of the accommodation portion 220 .

[0040] In the present application, the material of the cover plate 100 and / or the base plate 200 may be metal, such as steel or aluminum, but not limited thereto. The material of the cover plate 100 and / or the base plate 200 may also be polypropylene (PP) resin, such as continuous fiber reinforced polypropylene composite material, but not limited thereto. Metal materials have good strength and can protect the internal structure of the battery pack. Resin materials are light in weight, have good tensile strength, and have the characteristics of corrosion resistance, low noise, and low cost.

[0041] The material of the filling layer 300 can be an organic polymer material with good buffering performance. For example, the material of the filling layer 300 can be foam glue, such as two-component polyurethane foam glue. The foam glue has its own adhesiveness and can bond the filling layer 300 with the upper and lower layers of the cover plate 100 and the bottom plate 200. The foam glue has the characteristics of light weight and high strength, and has good impact resistance and buffering energy absorption. After being compounded with the cover plate 100 and the bottom plate 200, it can disperse local energy, so that the bottom guard plate assembly has a small deformation when it is bumped. For another example, the material of the filling layer 300 can also be modified polyphenylene ether (i.e., a blend of polyphenylene ether and polystyrene). Modified polyphenylene ether has low density, high compressive strength, and good buffering and energy absorption effects.

[0042] Furthermore, the thickness of the cover plate 100 and the bottom plate 200 is in the range of 0.8 mm to 2 mm. Within the above range, the basic strength of the cover plate 100 and the bottom plate 200 can be ensured, and the overall thickness of the bottom guard plate assembly will not be too thick.

[0043] In one embodiment, the cover plate 100 and the bottom plate 200 may both be made of metal. For example, the cover plate 100 may be a 1 mm steel plate, the bottom plate 200 may be a 1 mm aluminum plate, and the filling layer 300 may be a foam, such as a two-component polyurethane foam. In this structure, the cover plate side strength of the bottom guard plate assembly is greater than the bottom plate side strength, and the strength of the bottom guard plate assembly is designed to be strong inside and weak outside, so that the external damage is more serious before the internal damage, which is convenient for the driver to observe and judge whether the bottom guard plate assembly needs to be replaced.

[0044] In one embodiment, the material of the cover plate 100 may be metal, and the material of the base plate 200 may be resin. For example, the cover plate 100 may be a 1 mm steel plate, the base plate 200 may be a 1 mm continuous fiber reinforced PP resin, and the filling layer 300 may be a foam, such as a two-component polyurethane foam. In this structure, the cover plate 100 uses a high-strength steel plate to protect the internal structure of the battery pack, and the base plate 200 uses a continuous fiber reinforced PP resin. The fiber-reinforced PP resin material is light in weight, with a density of only 1 / 5 of that of metal, and a tensile strength consistent with that of high-strength steel, which maintains the plane strength of the base plate 200. When used as the material of the base plate 200, it is not easy to deform, and at the same time, it has strong weather resistance, waterproof and anti-corrosion properties, and the noise caused by being hit by gravel is small. In addition, the PP material has a low glass transition temperature, strong processability, and low mold cost. This composite bottom guard plate assembly has both the strength of a metal base plate and the rigidity and buffering energy absorption, and is more cost-effective. In addition, the steel plate and the continuous fiber reinforced PP resin plate can be connected by hot pressing with glue. The hot pressing process is close to the curing temperature of the foam and can be carried out simultaneously, which can shorten the manufacturing process and save costs.

[0045] In one embodiment, the cover plate 100 and the base plate 200 may both be made of resin. For example, the cover plate 100 may be made of 1 mm continuous fiber reinforced PP resin, the base plate 200 may be made of 1 mm continuous fiber reinforced PP resin, and the filling layer 300 may be modified polyphenylene ether. In this structure, the density of the continuous fiber reinforced PP resin is 1550 kg / m 3 The density of modified polyphenylene ether is only 200kg / m 3 The compressive strength of modified polyphenylene ether can reach 100MPa, which has a good buffering and energy absorption effect. Among them, the upper and lower layers of continuous fiber reinforced PP resin and modified polyphenylene ether can be bonded by glue hot pressing. Due to the good polarity of polymer materials, it is easy to bond and composite to ensure the stability of the bottom guard plate assembly structure. The composite bottom guard plate assembly has good strength and rigidity, and has the advantages of light weight and low cost.

[0046] The following is a method for manufacturing a bottom guard plate assembly to further illustrate the above bottom guard plate assembly. The method for manufacturing the bottom guard plate assembly comprises the following steps:

[0047] 1) Provide a cover plate and a bottom plate of preset sizes; wherein the cover plate can be a steel plate, and the bottom plate can be an aluminum plate, but is not limited thereto.

[0048] 2) Through holes are opened on the edges of the cover plate and the bottom plate to serve as rivet holes or bolt holes, and glue injection holes are also opened on the cover plate.

[0049] 3) The base plate is shaped by processing the plate by die stamping so that the base plate forms a receiving portion and a connecting portion that are connected to each other, wherein the receiving portion has a U-shaped receiving groove, wherein the depth of the receiving groove is 6 mm to 8 mm; in addition, a through hole is opened on the connecting portion as a rivet hole or a bolt hole, and an exhaust hole is opened on the connecting portion.

[0050] 4) The cover plate and the bottom plate are locked with rivets or bolts to form a closed accommodating cavity between the cover plate and the bottom plate.

[0051] 5) The volume of the accommodating cavity is calculated, and the mass of the foam glue required is converted according to the density of the foam glue. The glue is quickly injected from the injection hole at a certain rate by a glue injection device until the specified amount of glue is injected.

[0052] 6) After the injection is completed, a pressure-maintaining tool (with a built-in heating function) is used to press on the cover plate, and the heating temperature is controlled at 80-100°C for 2-4 hours to ensure that the foam glue is completely cured. The use of a pressure-maintaining tool can ensure that the foam glue will not cause the cover plate and the bottom plate to deform due to the expansion force.

[0053] 7) After the pressure-holding curing is completed, remove the pressure-holding tooling, clean up the overflowed residual glue, and conduct finished product inspection.

[0054] In a second aspect, the utility model provides a battery pack, including a box body and a battery module arranged in the box body, the box body includes a top cover and a bottom guard plate assembly as described above that are relatively arranged, and a side plate located between the top cover and the bottom guard plate assembly.

[0055] In summary, the utility model provides a bottom guard plate assembly and a battery pack, wherein exhaust holes are arranged on the bottom plate, and the aperture of the exhaust hole away from the end of the accommodating cavity is smaller than the aperture of the exhaust hole close to the end of the accommodating cavity, wherein the aperture close to the accommodating cavity is large, which is convenient for the gas convergence in the cavity, and the aperture close to the outside is small, which is conducive to forming a gas pressure difference between the inside and the outside, and is convenient for the smooth discharge of the gas in the cavity during filling, thereby helping to improve the filling uniformity of the material in the accommodating cavity, so as to improve the stability and quality of the bottom guard plate.

[0056] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A bottom guard plate assembly, characterized in that: It comprises a cover plate, a bottom plate and a filling layer, wherein the cover plate and the bottom plate are stacked, and a receiving cavity is provided between the cover plate and the bottom plate, and the filling layer is provided in the receiving cavity; Wherein, at least one exhaust hole is provided on the bottom plate, the exhaust hole is communicated with the accommodating cavity, and the aperture of the exhaust hole at one end away from the accommodating cavity is smaller than the aperture of the exhaust hole at one end close to the accommodating cavity.

2. The bottom guard plate assembly according to claim 1, characterized in that: The bottom plate includes a receiving portion and a connecting portion connected to an edge of the receiving portion, the receiving portion having a receiving groove configured to receive the filling layer, and the connecting portion is parallel to the cover plate and configured to be connected to the cover plate.

3. The bottom guard plate assembly according to claim 2, characterized in that: The exhaust hole is arranged on the connecting portion.

4. The bottom guard plate assembly according to claim 3, characterized in that: The accommodating portion includes a plurality of side edges, and the connecting portion connected to each side edge is provided with the exhaust hole.

5. The bottom guard plate assembly according to claim 1, characterized in that: In a direction perpendicular to the cover plate, a height of the exhaust hole is less than or equal to 0.2 mm.

6. The bottom guard plate assembly according to claim 2, characterized in that: At least one glue injection hole is arranged on the cover plate, and the glue injection hole is communicated with the accommodating cavity.

7. The bottom guard plate assembly according to claim 6, characterized in that: The projection of the glue injection hole on the bottom plate is located on the central axis of the accommodating portion.

8. The bottom guard plate assembly according to any one of claims 1 to 7, characterized in that: The cover plate and / or the bottom plate are made of steel or aluminum.

9. The bottom guard plate assembly according to any one of claims 1 to 7, characterized in that: The cover plate and / or the bottom plate are made of polypropylene resin.

10. The bottom guard plate assembly according to any one of claims 1 to 7, characterized in that: The material of the filling layer is foamed rubber or modified polyphenylene ether.

11. A battery pack, characterized in that: It comprises a box body and a battery module arranged in the box body, wherein the box body comprises a top cover arranged opposite to each other and a bottom guard plate assembly as described in any one of claims 1 to 10, and a side plate located between the top cover and the bottom guard plate assembly.

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