Molding structure of power battery pack upper cover based on continuous fiber thermoplastic reinforced composite material

Abstract

The utility model relates to a forming structure of a power battery pack upper cover based on a continuous fiber thermoplastic reinforced composite material, the battery pack upper cover is provided with an arch platform part and a platform part which is connected with four bottom edges of the arch platform part and is flattened towards the periphery, and the battery pack upper cover is divided into a main body block and four vertex angle blocks, the main body block comprises an arch abutment part lacking four corners and a platform part lacking four corners, the main body block is provided with first lap joint areas along two edges of notches of the four unfilled corners, the vertex angle block comprises unfilled corners of the arch abutment part and unfilled corners of the platform part in the main body block, and the vertex angle block is provided with second lap joint areas along two edges spliced with the notches of the main body block. According to the scheme, the partitioned structural design is adopted, the battery pack upper cover is divided into the main body block and the four vertex angle blocks, and redundant fibers are removed by arranging the plane unfolding structure, so that the problems of disorder and accumulation of the fibers in the vertex angle blocks are solved. Through the structural design of the lap joint area, the connection strength of the vertex angle block and the main body block is improved, and the overall mechanical property of the battery pack upper cover is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery shell manufacturing, in particular to a molding structure of a power battery pack upper cover based on a continuous fiber thermoplastic reinforced composite material. Background Art

[0002] With the continuous breakthroughs in new energy vehicle battery technology, the development of power battery technology has become one of the key driving forces for the clean energy revolution. Applications such as electric vehicles, energy storage systems, and renewable energy power generation devices all rely on high-performance battery technology. The battery PACK (i.e., battery pack) is a crucial component in the battery module, and its main task is to protect the battery cell and ensure its normal operation.

[0003] Similar to the principle of reinforced concrete, resin-based fiber-reinforced composite materials refer to a high-strength, high-rigidity, low-density material system formed by compounding glass fiber or carbon fiber as a reinforcing material with resin as the matrix. The battery PACK cover formed by composite materials can reduce the weight by 20%-30% compared to the metal-formed cover, which can effectively improve the overall energy density of the battery pack.

[0004] The composite materials used in the battery PACK cover can be divided into two categories: thermosetting matrix and thermoplastic matrix, and the reinforcing fibers can be divided into two categories: continuous fiber and discontinuous fiber. Among them, the thermosetting resin composite material system is the most widely used in the current production of the cover. The commonly used thermosetting resin system mainly has the following problems: complex process, high cost, stable chemical properties after curing, not easy to degrade, not easy to recycle, and high recycling cost. With the continuous improvement of domestic and foreign requirements for battery costs and environmental protection, thermoplastic resin-based composite materials have attracted more and more attention from all walks of life due to their simple molding process, low manufacturing cost and recyclable characteristics.

[0005] As a reinforcing material for the resin matrix, the continuity of the fiber and the directionality of the fiber arrangement in the matrix will determine the mechanical properties after being composited with the matrix, thereby affecting the product performance. Therefore, the performance of continuous fiber reinforced thermoplastic composites is far superior to that of discontinuously reinforced composites.

[0006] However, due to the presence of continuous fibers in continuous fiber reinforced thermoplastic composite sheets, the prefabricated sheets have poor ductility after softening. Therefore, after the sheet is placed in the mold, during the process of heating and pressurizing the sheet to fit the mold surface, fiber disorder or fiber accumulation is easily formed at the top corner of the upper cover, thereby affecting the mechanical properties.

[0007] In order to overcome the above shortcomings, we invented a molding structure for the upper cover of a power battery pack based on continuous fiber thermoplastic reinforced composite materials. Utility Model Content

[0008] The purpose of the invention of the utility model is to solve the problem that the existing continuous fiber reinforced thermoplastic composite material sheet has poor ductility after softening, and when the sheet is placed in the mold, it is easy to form fiber disorder or fiber accumulation at the top corner of the product cover during the process of heating and pressurizing the sheet to fit the mold surface, thereby affecting its mechanical properties. The specific solution is as follows:

[0009] Based on the molding structure of the upper cover of the power battery pack of continuous fiber thermoplastic reinforced composite materials, the upper cover of the battery pack is provided with an arch portion and a platform portion which is flattened toward all sides and connected to the four bottom edges of the arch portion. The upper cover of the battery pack is divided into a main body block and four corner blocks. The main body block includes an arch portion which is missing four corners and a platform portion which is missing four corners. The main body block is provided with a first overlap zone along both edges of the notches of the four missing corners. The corner block includes the missing corners of the arch portion and the platform portion in the main body block. The corner block is provided with a second overlap zone along both edges which are spliced ​​with the notches of the main body block.

[0010] Furthermore, the main body block is flattened into a cross-shaped main body area and four L-shaped first overlapping areas.

[0011] Furthermore, the thickness of the first overlapping area is half of the thickness of the main body area.

[0012] Furthermore, the width of the first overlapping area is ≥20 mm.

[0013] Option 1: The top corner block is flattened along the diagonal line into a triangle and a pointed hat shape connected to the triangle with a point on the diagonal line of the upper cover corner as the origin. The pointed hat shape includes the second overlapping area, and the thickness of the second overlapping area is half of the thickness of the area outside the second overlapping area. The width of the second overlapping area is ≥20mm.

[0014] Option 2: The corner block is located on the line connecting the other two diagonals that are not on the diagonal line of the corner of the upper cover as the origin. The origin is located on the platform part. It is flattened along the long side and short side of the upper cover into a right triangle and a bent shape connected to the right triangle. The right triangle and the bent shape each contain a part of the second overlap area. The thickness of the second overlap area is half the thickness of the area outside the second overlap area. The width of the second overlap area is ≥20mm.

[0015] In summary, the technical solution of the utility model has the following beneficial effects:

[0016] This solution solves the problem that existing continuous fiber reinforced thermoplastic composite sheets have poor ductility after softening. After the sheet is placed in the mold, it is easy to form fiber disorder or fiber accumulation at the top corners of the product cover during the process of heating and pressurizing the sheet to fit the mold surface, thereby affecting its mechanical properties. This solution adopts a special block structure design, which divides the battery pack cover into a main block and four top corner blocks. By setting a reasonable plane expansion structure, the excess fibers are removed, thereby eliminating the fiber disorder and accumulation problems in the top corner areas. The overlap area (including the first overlap area and the second overlap area) structural design is then used to improve the connection strength between the top corner block and the main block, reduce the impact of the block on the overall strength of the battery pack cover, and thus improve the overall mechanical properties of the battery pack cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the embodiment of the utility model, the following is a brief introduction to the drawings required for the description of the embodiment of the utility model. Obviously, the drawings described below are only part of the embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0018] Figure 1 This is a product diagram of the molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material of the utility model;

[0019] Figure 2 It is a block schematic diagram of the molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material of the utility model;

[0020] Figure 3 A flattened view of the main body of the battery pack cover of the present invention;

[0021] Figure 4 It is a structural diagram of the top corner block of the battery pack cover of the utility model;

[0022] Figure 5 A flattened view of the top corner block of the battery pack cover of Example 1 of the utility model;

[0023] Figure 6 A flattened view of the top corner block of the battery pack cover of Example 2 of the utility model;

[0024] Figure 7 A flattened view of the top corner block of the battery pack cover of Example 3 of the utility model;

[0025] Figure 8 This is a flattened view of the top corner block of the battery pack cover of Example 4 of the utility model.

[0026] Description of reference numerals:

[0027] 10-battery pack cover, 11-arch portion, 12-platform portion, 13-main body block, 14-vertex block, 15-first overlapping area, 16-second overlapping area, 131-main body area, 141-first triangle, 142-first pointed hat shape, 143-second triangle, 144-second pointed hat shape, 145-first right-angled triangle, 146-first bent shape, 147-second right-angled triangle, 148-second bent shape. DETAILED DESCRIPTION

[0028] 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, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] like Figures 1 to 4 As shown, based on the molding structure of the upper cover of the power battery pack of the continuous fiber thermoplastic reinforced composite material, the upper cover 10 of the battery pack is provided with an arch portion 11 and a platform portion 12 which is flattened to the four sides and connected to the four bottom sides of the arch portion 11. The upper cover 10 of the battery pack is divided into a main body block 13 and four corner blocks 14. The main body block 13 includes the arch portion 11 which is missing four corners and the platform portion 12 which is missing four corners. The main body block 13 is provided with a first overlap area 15 along the two edges of the notches of the four notches. The corner block 14 includes the notches of the arch portion 11 and the platform portion 12 in the main body block 13. The corner block 14 is provided with a second overlap area 16 along the two edges spliced ​​with the notches of the main body block 13.

[0030] Specifically, the main body block 13 is flattened into a cross-shaped main body area 131 and four L-shaped first overlapping areas 15. The thickness of the first overlapping area 15 is half of the thickness of the main body area. The width of the first overlapping area 15 is ≥20 mm.

[0031] Embodiment 1:

[0032] like Figures 1 to 5As shown, on the basis of the above specific implementation, the top corner block 14 takes a point A on the diagonal line AB of the upper cover angle (the upper cover angle refers to the angle in the top corner block that constitutes the upper cover) as the origin A. The origin A of this embodiment 1 is located at a point on the platform portion 12, and is flattened along the diagonal line AB into a triangle (such as the first triangle 141 in this embodiment 1, the first triangle 141 is a right triangle), and a pointed hat shape connected to the triangle (such as the first pointed hat shape 142 in this embodiment 1, the first pointed hat shape 142 is composed of a straight bottom edge and two arc outer edges). The pointed hat shape includes a second overlap area 16, and the thickness of the second overlap area 16 is half the thickness of the area outside the second overlap area. The width of the second overlap area 16 is ≥20mm.

[0033] Embodiment 2:

[0034] like Figure 6 As shown, based on Example 1, the difference from Example 1 is that the top corner block 14 of Example 2 takes a point B on the diagonal line AB of the upper corner as the origin B, and the origin B of Example 2 is located at a point on the abutment portion 11, and is flattened along the diagonal line AB into a triangle (such as the second triangle 143 in Example 2, the second triangle 143 is composed of a straight bottom side and two arc outer sides), and a pointed hat shape connected to the triangle (such as the second pointed hat shape 144 in Example 2, the tip of the second pointed hat shape 144 is a right angle). The rest of the content is the same as Example 1, and will not be repeated here.

[0035] Embodiment 3:

[0036] like Figure 1 , 2 As shown in , 3, 4, and 7, on the basis of the above specific implementation, the vertex block 14 takes a point C on the other two diagonal lines CD that are not on the diagonal line AB of the upper cover corner as the origin C, and the origin C is located on the platform portion 12 and is the midpoint of the left half of the diagonal line CD. It is flattened along the long and short sides of the upper cover (referring to the battery pack upper cover 10 as a rectangle) into a right triangle (such as the first right triangle 145 of this embodiment 3) and a bent shape connected to the right triangle (such as the first bent shape 146 of this embodiment 3), and the right triangle and the bent shape each contain a part of the second overlap area 16. The thickness of the second overlap area 16 is half of the thickness of the area outside the second overlap area 16. The width of the second overlap area 16 is ≥20mm.

[0037] Embodiment 4:

[0038] like Figure 8As shown, based on Example 3, the difference from Example 3 is that the vertex block 14 of Example 4 takes a point D on the diagonal line CD as the origin D, and the origin D is located above the platform portion 12 and is at the midpoint of the right half of the diagonal line CD. It is flattened along the long and short sides of the upper cover into a right triangle (such as the second right triangle 147 of Example 4) and a bent shape connected to the right triangle (such as the second bent shape 148 of Example 4). The rest of the content is the same as Example 3 and will not be repeated here.

[0039] The inventive idea of ​​this scheme is to divide the battery pack cover 10 (the material is a continuous fiber thermoplastic reinforced composite material plate) into a main body block 13 and a top corner block 14, and design a flat sheet of material of a specific shape according to the geometric characteristics of the top corner block 14 (that is, the flat structure of the top corner block 14), which can effectively reduce the fiber accumulation and fiber disorder problems of the material at the top corner during the mold-painting process. In the connection part of the main body block 13 and the top corner block 14, an overlapping area (i.e., a first overlapping area 15 and a second overlapping area 16) is set, and the thickness of the overlapping area is half of the thickness of the non-overlapping area. The thickness of the two areas after overlapping is the same as the thickness of the non-overlapping area. The connection strength of the main body block 13 and the top corner block 14 can be ensured by overlapping, and the battery pack cover 10 can be ensured to meet the strength requirements. The flat sheet of material of a specific shape can be processed and formed by CNC (CNC is the abbreviation of Computerized Numerical Control in English, and computer digital control in Chinese), which is conducive to the continuous and automated production of the battery pack cover 10.

[0040] This solution is based on the continuous fiber thermoplastic reinforced composite power battery pack cover molding structure into the battery pack cover production process is briefly described as follows:

[0041] 1) Material selection: According to the thickness d of the battery pack cover, environmental requirements and mechanical performance requirements, suitable continuous fiber thermoplastic reinforced composite material sheets are required. The sheet thickness should be ≥1.2d, and the fiber directions should be symmetrically laid in alternating layers of 0°, 90°, 45°, and -45°;

[0042] 2) Block design: The battery pack cover is divided into a plane area (i.e., the main body block 13), a corner area (i.e., the corner block 14), and an overlap area (i.e., the first overlap area 15 and the second overlap area 16). The thickness of the plane area and the corner area is 1.2d, and the thickness of the overlap area is 0.6d. The plane area and the corner area are flattened;

[0043] 3) CNC processing: According to the requirements of the development drawing, compile the CNC processing program and use CNC processing to shape the plate;

[0044] 4) Heating and softening: preheat the processed plate to soften it, the preheating temperature is 80℃-100℃, and the preheating time is 30min-60min;

[0045] 5) Material laying: first transfer the flat plate to the mold, lay it flat, then transfer the flat plate with a specific shape in the corner area to the mold, lay the corner area flat, and align and flatten the overlapping area;

[0046] 6) Pressurization and curing: close the mold and pressurize, the pressure is 6t-10t, and the pressure holding time is 15min-20min;

[0047] 7) Demolding: After the mold is opened, take the product (battery pack cover) out of the mold;

[0048] 8) Trimming and drilling: After the product has cooled, trimming and drilling are performed according to the shape requirements.

[0049] The embodiments 1-4 provided in this solution are not intended to limit this solution, and can be selected and used in combination with specific product conditions. In addition, other origins can be found on the top corner block 14 according to the above-mentioned flattening principle to carry out flattening structure design, which all fall within the scope of protection of this solution.

[0050] In summary, the technical solution of the utility model has the following beneficial effects:

[0051] This solution solves the problem that existing continuous fiber reinforced thermoplastic composite sheets have poor ductility after softening. After the sheet is placed in the mold, it is easy to form fiber disorder or fiber accumulation at the top corners of the product cover during the process of heating and pressurizing the sheet to fit the mold surface, thereby affecting its mechanical properties. This solution adopts a special block structure design, which divides the battery pack cover into a main block and four top corner blocks. By setting a reasonable plane expansion structure, the excess fibers are removed, thereby eliminating the fiber disorder and accumulation problems in the top corner areas. The overlap area (including the first overlap area and the second overlap area) structural design is then used to improve the connection strength between the top corner block and the main block, reduce the impact of the block on the overall strength of the battery pack cover, and thus improve the overall mechanical properties of the battery pack cover.

[0052] The above-mentioned implementation modes do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-mentioned implementation modes shall be included in the protection scope of the technical solution.

Claims

1. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material is characterized by: The battery pack cover is provided with an arch portion and a platform portion which is flattened toward all sides and connected to the four bottom edges of the arch portion. The battery pack cover is divided into a main body block and four corner blocks. The main body block includes an arch portion which is missing four corners and a platform portion which is missing four corners. The main body block is provided with a first overlap zone along the two edges of the notches of the four corners. The corner blocks include the missing corners of the arch portion and the platform portion in the main body block. The corner blocks are provided with a second overlap zone along the two edges which are spliced ​​with the notches of the main body block.

2. According to claim 1, the molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material is characterized in that: The main body block is flattened into a cross-shaped main body area and four L-shaped first overlapping areas.

3. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 2 is characterized in that: The thickness of the first overlapping region is half of the thickness of the main body region.

4. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 3 is characterized in that: The width of the first overlapping area is ≥20 mm.

5. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 1 is characterized in that: The top corner block is flattened along the diagonal line to form a triangle and a pointed hat shape connected to the triangle, with a point on the diagonal line of the upper cover corner as the origin.

6. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 5 is characterized in that: The pointed hat shape includes the second overlapping area, and the thickness of the second overlapping area is half of the thickness of the area outside the second overlapping area.

7. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 6 is characterized in that: The width of the second overlapping area is ≥20 mm.

8. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 1 is characterized in that: The top corner block takes a point on the line connecting the other two diagonals which are not on the diagonal line of the corner of the upper cover as its origin, and the origin is located above the platform portion, and is flattened along the long and short sides of the upper cover into a right triangle and a bent shape connected to the right triangle, and the right triangle and the bent shape respectively contain a portion of the second overlapping area.

9. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 8 is characterized in that: The thickness of the second overlapping area is half of the thickness of the area outside the second overlapping area.

10. The molding structure of the upper cover of the power battery pack based on the continuous fiber thermoplastic reinforced composite material according to claim 9, characterized in that: The width of the second overlapping area is ≥20 mm.

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