Composite beam, battery pack lower shell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a composite beam, a battery pack lower shell and a battery pack. The composite beam comprises a main material made of a composite material and an auxiliary material made of a metal material. The main material is provided with at least one first cavity, and the first cavity penetrates through the main material in the length direction of the main material; the composite material is arranged in the first cavity, and the auxiliary material is fixedly connected with the main material. The composite material beam provided by the invention comprises the main material and the auxiliary material, the mode of combining the composite material and metal is adopted, the composite material beam not only has the advantages of light weight, low cost, high stability, good insulativity and good corrosion resistance of the composite material, but also has the strength of the metal material due to the fact that the auxiliary material made of the metal material is arranged in the first cavity of the main material; and the auxiliary material can make up the weft-wise strength of the pure composite beam, so that the composite beam has better comprehensive performance, and the product has higher competitiveness.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a composite beam, a battery pack lower shell and a battery pack. Background Art

[0002] With the rapid development of the new energy vehicle industry around the world, the demand for power battery packs, as one of the core components of electric vehicles, is also increasing.

[0003] The power battery pack is composed of battery modules, upper shell, lower shell, water cooling plate and other components. The lower shell includes a crossbeam. At present, most crossbeams are made of aluminum or steel materials. The product is heavy, has poor insulation, high cost, and it is difficult to achieve a uniform cross-section.

[0004] For this reason, the related art also proposes a technical solution of using composite materials for the crossbeam. Compared with metal, composite materials have advantages such as light weight, low cost, high stability and insulation. However, composite materials also have obvious shortcomings as crossbeams. They have high radial strength but low latitudinal strength and cannot withstand latitudinal impact force. Therefore, the comprehensive performance of the crossbeam in the related art needs to be improved. Summary of the invention

[0005] In view of this, the present invention provides a composite beam, a battery pack lower shell and a battery pack to solve the problem of poor comprehensive performance of the cross beam in the battery pack.

[0006] In a first aspect, the present invention provides a composite beam, comprising a main material made of a composite material and an auxiliary material made of a metal material. The main material has at least one first cavity, the first cavity penetrates the main material along the length direction of the main material; the auxiliary material is arranged in the first cavity, and the auxiliary material is fixedly connected to the main material.

[0007] Beneficial effects: The composite beam provided by the present invention includes a main material and an auxiliary material, and adopts a combination of composite materials and metals. It not only has the advantages of light weight, low cost, high stability, good insulation and good corrosion resistance of composite materials, but also because the auxiliary material of metal material is arranged in the first cavity of the main material, it has the strength of metal material. The auxiliary material can make up for the latitudinal strength of the pure composite beam, so that the composite beam has better comprehensive performance and the product is more competitive.

[0008] In an optional embodiment, the first cavity is arranged in the middle of the main material along the height direction of the main material.

[0009] In an optional embodiment, the auxiliary material has at least one second cavity, and the second cavity penetrates the auxiliary material along the length direction of the auxiliary material.

[0010] In an optional embodiment, the composite beam is a pultruded structure.

[0011] In an alternative embodiment, the cross-section of the auxiliary material is a symmetric structure.

[0012] In an alternative embodiment, the cross-section of the auxiliary material is in the shape of a Chinese character 'Ri', 'Tian', 'Hui' or 'Mi'.

[0013] In an alternative embodiment, the main material is made of a composite material composed of an injection molding material and glass fiber, and / or the auxiliary material is made of aluminum.

[0014] In an alternative embodiment, the injection molding material includes saturated resin, PP, unsaturated resin, epoxy resin or polyurethane.

[0015] In a second aspect, the present invention further provides a lower housing of a battery pack, including a frame and a bottom guard plate. Cross beams and longitudinal beams are connected inside the frame, and the cross beams and longitudinal beams divide the lower housing of the battery pack into multiple partitions for accommodating the battery cell module or electrical structure; the bottom guard plate is connected to the frame to form a semi-closed structure with an open top; the cross beam and / or the longitudinal beam adopts the composite beam in the above technical solution.

[0016] Beneficial effects: Since the battery pack includes a composite beam and has the same effects as the composite beam, they will not be elaborated here.

[0017] In a third aspect, the present invention further provides a battery pack, including a battery cell module, an upper housing and the lower housing of the battery pack in the above technical solution. The lower housing of the battery pack cooperates with the upper housing to form an accommodation cavity therebetween, and the battery cell module is encapsulated in the accommodation cavity.

[0018] Beneficial effects: Since the battery pack includes the lower housing of the battery pack and has the same effects as the lower housing of the battery pack, they will not be elaborated here. Description of the Drawings

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a cross-sectional view of a composite beam according to an embodiment of the present invention;

[0021] Figure 2 It is an exploded view of a lower housing of a battery pack according to an embodiment of the present invention.

[0022] Explanation of the reference numerals:

[0023] 1. Composite beam; 11. Main material; 111. First cavity; 12. Auxiliary material; 121. Second cavity; 2. Frame; 3. Bottom guard plate; 4. Cross beam; 5. Longitudinal beam; 6. Liquid cooling plate; 10. Lower shell of battery pack. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] Combine the following Figure 1 to Figure 2 , describing an embodiment of the present invention.

[0026] According to an embodiment of the present invention, in a first aspect, a composite beam 1 is provided, comprising a main material 11 made of a composite material and an auxiliary material 12 made of a metal material. The main material 11 has at least one first cavity 111, and the first cavity 111 penetrates the main material 11 along the length direction of the main material 11; the auxiliary material 12 is arranged in the first cavity 111, and the auxiliary material 12 is fixedly connected to the main material 11.

[0027] The composite beam 1 provided by the present invention includes a main material 11 and an auxiliary material 12, and adopts a combination of composite materials and metals. It not only has the advantages of light weight, low cost, high stability, good insulation and good corrosion resistance of composite materials, but also has the strength of metal materials because the auxiliary material 12 made of metal is arranged in the first cavity 111 of the main material 11. The auxiliary material 12 can make up for the latitudinal strength of the pure composite beam 1, so that the composite beam 1 has better comprehensive performance and the product is more competitive.

[0028] In addition, by providing the first cavity 111 , on the one hand, the weight of the composite beam 1 can be reduced, and on the other hand, connection with the auxiliary material 12 can be achieved.

[0029] In some embodiments, along the height direction of the main material 11 , the first cavity 111 is disposed in the middle of the main material 11 .

[0030] Specifically, the first cavity 111 is disposed in the middle of the main material 11 , which can effectively disperse stress concentration and avoid structural damage caused by excessive local stress.

[0031] In some embodiments, the auxiliary material 12 has at least one second cavity 121 , and the second cavity 121 penetrates the auxiliary material 12 along the length direction of the auxiliary material 12 .

[0032] By providing at least one second cavity 121 in the auxiliary material 12, it is possible to reduce the weight of the composite beam 1 as a whole while maintaining the structural strength, achieving lightweighting, reducing the amount of material used, and lowering costs.

[0033] In some embodiments, the composite beam 1 is a pultruded structure.

[0034] Specifically, the composite beam 1 is formed by pultrusion process, which endows the composite beam 1 with excellent tensile strength and bending stiffness. The main material 11 and the auxiliary material 12 can be highly bonded, with a stable structure, and continuous and automated production can be achieved, greatly improving production efficiency and being suitable for large-scale production.

[0035] In some embodiments, the cross-section of the auxiliary material 12 is a symmetric structure.

[0036] Specifically, designing the cross-section of the auxiliary material 12 as a symmetric structure can ensure uniform distribution of the load on the auxiliary material 12, avoid local stress concentration, thereby improving the overall strength and durability of the auxiliary material 12. At the same time, it can ensure uniform stiffness of the auxiliary material 12 in all directions, enhance the rigidity of the overall structure, and reduce flexure and vibration when受力. The composite beam 1 obtained in this way has better strength in both the warp and weft directions. In addition, the design of the symmetric structure is relatively simple, easy to calculate and analyze, reducing the design complexity. It is also easier to implement in the manufacturing process, facilitating molding and reducing the manufacturing cost.

[0037] In some embodiments, the cross-section of the auxiliary material 12 is in the shape of a Chinese character 'Ri', 'Tian', 'Hui', or 'Mi'.

[0038] In some embodiments, the main material 11 is made of a composite material composed of an injection molding material and glass fiber, and / or the auxiliary material 12 is made of aluminum.

[0039] Specifically, the main material 11 is made of a composite material composed of an injection molding material and glass fiber. The injection molding material and glass fiber have a low density, which can significantly reduce the weight of the main material 11 and is suitable for application scenarios requiring lightweight design. At the same time, glass fiber has high strength and stiffness, which can significantly improve the mechanical properties of the composite material.

[0040] The auxiliary material 12 is made of aluminum. Aluminum has a low density, which can significantly reduce the weight of the auxiliary material 12 and further reduce the weight of the entire composite beam 1. At the same time, aluminum alloy has relatively high strength and stiffness, which can enhance the local strength of the auxiliary material 12 and improve the strength of the overall structure.

[0041] In some embodiments, the injection molding material includes saturated resin, PP, unsaturated resin, epoxy resin, or polyurethane.

[0042] In this embodiment, the cross-sectional structure of the main material 11 of the composite beam 1 is in the shape of a letter "J", with a wall thickness of 2 mm to 5 mm, the main material 11 has three first cavities 111, and the auxiliary material 12 is arranged in the first cavity 111 in the middle of the main material 11. The auxiliary material 12 uses an aluminum profile, the cross-sectional structure of the auxiliary material 12 is in the shape of a letter "J", and the wall thickness of the product is 1.5 mm to 3 mm. The auxiliary material 12 is embedded in the pultrusion equipment and formed together with the main material 11.

[0043] The composite beam 1 formed in this way has higher latitudinal tensile strength than the pure composite beam 1 and can be applied to products with higher requirements to cope with various usage scenarios.

[0044] The following provides tests of comparative examples and examples, wherein comparative example 1 is a pultruded composite material, comparative example 2 is an aluminum profile, and example 1 is a composite beam 1 provided by the present invention. The test results are shown in Table 1.

[0045] Table 1:

[0046]

[0047] It can be seen from Table 1 that, compared with Comparative Example 1 or Comparative Example 2, the performance of Example 1 in four aspects, namely, tensile strength (latitudinal), tensile strength (radial), bending strength (latitudinal) and bending strength (radial), is significantly improved.

[0048] According to an embodiment of the present invention, in a second aspect, a battery pack lower shell 10 is further provided, comprising a frame 2 and a bottom guard plate 3. A crossbeam 4 and a longitudinal beam 5 are connected inside the frame 2, and the crossbeam 4 and the longitudinal beam 5 divide the battery pack lower shell 10 into a plurality of partitions for accommodating battery cell modules or electrical structures; the bottom guard plate 3 is connected to the frame 2 to form a semi-enclosed structure with an open top; the crossbeam 4 and / or the longitudinal beam 5 adopt the composite beam 1 in the above embodiment.

[0049] The battery pack lower shell 10 provided by the present invention includes the composite beam 1 in the above embodiment. The composite beam 1 is a combination of composite material and metal material through the main material 11 and the auxiliary material 12. It not only has the advantages of high thermal deformation temperature, electrolyte resistance, acid and alkali resistance, good weather resistance and good insulation of the composite material, but also has the strength of metal material, and has the advantages of low cost and light weight, etc., making the battery pack lower shell 10 more competitive.

[0050] Because the battery pack includes the composite beam 1, it has the same effect as the composite beam 1, and will not be described in detail here.

[0051] Specifically, in some embodiments, the battery pack lower shell 10 includes a liquid cooling plate 6, and the liquid cooling plate 6 is disposed between the bottom guard plate 3 and the frame 2. In the battery pack lower shell 10 provided in this embodiment, the cross beam 4 and / or the longitudinal beam 5 are composite beams 1, which are bonded to the liquid cooling plate 6 of the battery pack lower shell 10 by structural adhesive and fixed to each other by bolts.

[0052] According to an embodiment of the present invention, in a third aspect, a battery pack is also provided, comprising a battery cell module, an upper shell and the battery pack lower shell 10 in the above embodiment, the battery pack lower shell 10 and the upper shell cooperate to form a accommodating cavity therebetween, and the battery cell module is encapsulated in the accommodating cavity.

[0053] Because the battery pack includes the battery pack lower shell 10 , it has the same effect as the battery pack lower shell 10 , which will not be described in detail here.

[0054] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A composite beam, characterized in that: Comprising: A main material made of a composite material, the main material having at least one first cavity that penetrates the main material along the length direction of the main material; An auxiliary material made of a metal material, the auxiliary material being disposed in the first cavity, and the auxiliary material being fixedly connected to the main material.

2. The composite beam according to claim 1, characterized in that: Along the height direction of the main material, the first cavity is disposed in the middle of the main material.

3. The composite beam according to claim 1 or 2, characterized in that: The auxiliary material has at least one second cavity that penetrates the auxiliary material along the length direction of the auxiliary material.

4. The composite beam according to claim 1 or 2, characterized in that: The composite material beam is a pultruded structure.

5. The composite beam according to claim 1 or 2, characterized in that: The cross-section of the auxiliary material is a symmetric structure.

6. The composite beam according to claim 5, characterized in that: The cross-section of the auxiliary material is in the shape of a Chinese character 'Ri', 'Tian', 'Hui' or 'Mi'.

7. The composite beam according to claim 1 or 2, characterized in that: The main material is made of a composite material composed of an injection molding material and glass fiber, and / or the auxiliary material is made of aluminum.

8. The composite beam according to claim 7, characterized in that: The injection molding material includes saturated resin, PP, unsaturated resin, epoxy resin or polyurethane.

9. A battery pack lower shell, characterized in that: Comprising: A frame, a cross beam and a longitudinal beam are connected inside the frame, and the cross beam and the longitudinal beam divide the lower housing of the battery pack into multiple partitions for accommodating a battery cell module or an electrical structure; A bottom guard plate, the bottom guard plate being connected to the frame to form a semi-closed structure with an open top; The cross beam and / or the longitudinal beam adopt the composite material beam according to any one of claims 1 to 8.

10. A battery pack, characterized in that: Comprising: A battery cell module; An upper housing; The lower housing of the battery pack according to claim 9, the lower housing of the battery pack cooperating with the upper housing to form an accommodation cavity therebetween, and the battery cell module being encapsulated in the accommodation cavity.

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