Battery edge covering beam structure, battery pack and manufacturing method of battery edge covering beam structure

Abstract

The invention relates to the technical field of batteries, and discloses a battery edge covering beam structure, a battery pack and a manufacturing method of the battery edge covering beam structure, the battery edge covering beam structure comprises a first side plate, a second side plate and a bottom plate, the second side plate is arranged opposite to the first side plate; the bottom plate is respectively connected with the lower ends of the first side plate and the second side plate; the ends, away from the bottom plate, of the first side plate and the second side plate are each provided with a bent plate, the bent plates on the two sides are bent towards each other multiple times and extend in the direction of the bottom plate, the free end of the bent plate of the first side plate is welded to the inner wall of the first side plate, and the side, close to the second side plate, of the bent plate of the second side plate is welded to the inner wall of the second side plate. The ends, close to each other, of the bent plates on the two sides are welded. The bent plates are arranged at the ends, away from the bottom plate, of the first side plate and the second side plate respectively, the bent plates are bent towards each other for multiple times, extend towards the direction of the bottom plate and are welded, the extrusion resistance of the battery pack can be effectively improved, manufacturing is easy, and the use cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery pack side beam structure, a battery pack, and a method for manufacturing the battery pack side beam structure. Background Art

[0002] Battery packs are widely used in outdoor energy storage cabinets, vehicles, etc. The lower box of the battery pack is an important component, and its structural strength determines the safety performance of the battery pack.

[0003] At present, the side beam structure of the lower shell of the battery pack is generally made of aluminum alloy profiles that are easy to lighten, through welding, casting and other processes. However, the material properties of the aluminum alloy profiles determine that its structural strength is relatively low, which is difficult to meet the structural strength requirements of the lower box of the battery pack. Summary of the invention

[0004] In view of this, the present invention provides a battery pack side beam structure, a battery pack and a method for manufacturing a battery pack side beam structure to solve the problem that the battery pack side beam structure made of aluminum alloy profiles has low structural strength and is difficult to meet the strength requirements for use.

[0005] In a first aspect, the present invention provides a battery side beam structure, comprising:

[0006] first side panel;

[0007] a second side panel, arranged opposite to the first side panel;

[0008] A bottom plate, connected to the lower ends of the first side plate and the second side plate respectively;

[0009] The first side panel and the second side panel each have a bent plate at one end away from the bottom panel, the bent plates on both sides are bent toward each other for multiple times and extend toward the bottom panel, the free end of the bent plate of the first side panel is welded to the inner wall of the first side panel, the side of the bent plate of the second side panel close to the second side panel is welded to the inner wall of the second side panel, and the ends of the bent plates on both sides close to each other are welded.

[0010] Beneficial effects: The battery pack side beam structure of the present invention has a bending plate respectively arranged at one end of the first side plate and the second side plate away from the bottom plate, the bending plates are bent toward each other for many times and extend toward the bottom plate, the two bending plates are welded at the ends close to each other, and the two bending plates are respectively welded to the first side plate and the second side plate, so that the bottom plate, the first side plate, the second side plate and the two bending plates can support each other and disperse the extrusion force, the structural strength is high, it has good anti-extrusion ability, and can meet the use requirements of the battery pack. Moreover, the manufacturing process is simpler than traditional welding, casting, etc., and the use cost is lower. The shape of the side beam structure can be adjusted according to the type of battery pack, and it is flexible to use and widely used.

[0011] In an optional embodiment, a height H1 of the first side panel and a height H2 of the second side panel satisfy 1 / 2H2≤H1≤2 / 3H2, and H2≥30 mm.

[0012] Beneficial effect: The second side plate is used to abut against the electrode group. By limiting the height of the second side plate and the relative relationship between the first side plate and the second side plate, it is possible to ensure that the second side plate and the electrode group have a sufficiently large contact area, thereby improving the anti-extrusion ability of the battery pack.

[0013] In an optional embodiment, the bent plate of the second side panel and the second side panel form a first cavity, the bent plate of the second side panel and the bent plate of the first side panel form a second cavity located below the first cavity, the cross-section of the first cavity is triangular, and the cross-section of the second cavity is rectangular.

[0014] Beneficial effects: The bent plate of the second side panel and the second side panel form a first cavity with a triangular cross-section, which has strong structural stability, can save materials, and is easy to form and process. The bent plate of the second side panel and the bent plate of the first side panel form a second cavity with a rectangular cross-section located below the first cavity, which is easy to weld the two side panels.

[0015] In an optional embodiment, the triangular cross-section of the first cavity is bent at a corner to form an arc, and the radius of the arc R is ≥ 3 mm.

[0016] Beneficial effect: By bending the triangular cross-section of the first cavity to form an arc and limiting the radius of the arc, the stress concentration at the corner of the triangular cross-section can be reduced, the stress can be effectively dispersed, the risk of fracture of the second side panel and the bent plate of the second side panel can be reduced, the compressive resistance of the battery side beam structure can be improved, and it is easy to process.

[0017] In an optional embodiment, a height H2 of the second side plate and a height H3 of the first cavity satisfy 3 / 2H3≤H2≤2H3.

[0018] Beneficial effect: The bent plate of the second side plate is arranged at a middle position close to the second side plate, and the force is evenly distributed, which can effectively disperse the extrusion force.

[0019] In an optional embodiment, the bent plate of the first side plate and the first side plate enclose a third cavity, and the third cavity is provided with a hypotenuse welded to the corner of the triangular cross section of the first cavity.

[0020] Beneficial effect: The third cavity is provided with a hypotenuse welded to the corner of the triangular section of the first cavity, which facilitates welding of the two. The bent plate of the first side plate and the first side plate form the third cavity to further enhance the structural strength of the side beam structure.

[0021] In an optional embodiment, the bent plate of the first side panel, the bent plate of the second side panel and the bottom plate form a fourth cavity located below the third cavity and the second cavity, and the height H1 of the first side panel and the height H4 of the fourth cavity satisfy 3 / 2H4≤H1≤2H4.

[0022] Beneficial effect: After the first cavity, the second cavity and the third cavity are completed by rolling and welding, the bent plate of the first side plate, the bent plate of the second side plate and the bottom plate form a fourth cavity, which has a fast molding speed and does not require additional processing, and can effectively reduce manufacturing costs. By limiting the relationship between the height of the first side plate and the height of the fourth cavity, the bent plate of the first side plate can be welded in the middle position close to the second side plate, with uniform force, further dispersing the extrusion force and improving the structural strength.

[0023] In an optional embodiment, the width W1 of the bottom plate, the width W2 of the second cavity and the minimum width W3 of the third cavity satisfy 1 / 3W1≤W2=W3≤1 / 2W1.

[0024] Beneficial effect: By limiting the relationship between the width of the bottom plate, the width of the second cavity and the minimum width of the third cavity, the strength of the area where the battery side beam structure is prone to deformation can be enhanced, further reducing application concentration and improving the anti-extrusion ability of the battery side beam structure.

[0025] In a second aspect, the present invention further provides a battery pack, comprising: a housing and at least one electrode group, wherein at least one electrode group is installed in a receiving cavity of the housing, and the housing comprises:

[0026] Bottom shell;

[0027] The battery package side beam structure mentioned above is arranged around the four sides of the bottom shell and forms the accommodating cavity with the bottom shell.

[0028] Beneficial effect: Because the battery pack includes a battery pack side beam structure, it has the same effect as the battery pack side beam structure and will not be described in detail here.

[0029] In a third aspect, the present invention further provides a method for manufacturing a battery side beam structure, comprising:

[0030] Prepare edge beam profiles;

[0031] Rolling the side beam profile to form a bottom plate and a first side plate and a second side plate located on opposite sides of the bottom plate;

[0032] Rolling the two ends of the first side plate and the second side plate away from the bottom plate to form two bent plates that are bent toward each other and extend toward the bottom plate;

[0033] The free end of the bent plate of the first side plate and the inner wall of the first side plate, the side of the bent plate of the second side plate close to the second side plate and the inner wall of the second side plate, and the ends of the bent plates on both sides close to each other are welded respectively.

[0034] Beneficial effects: The manufacturing method of the battery pack side beam structure of the present invention uses a high-strength side beam profile as a base material, and uses a rolling and welding process to make the side beam profile into a bottom plate, a first side plate and a second side plate located on opposite sides of the bottom plate, and two end bent plates located at the first side plate and the second side plate away from the bottom plate. Compared with traditional welding and casting processes, the manufacturing method is simple and the use cost is low. Moreover, the bent plates are bent toward each other for many times and extend toward the bottom plate, and the ends of the two bent plates close to each other are welded, and the two bent plates are respectively welded to the first side plate and the second side plate, so that the bottom plate, the first side plate, the second side plate and the two bent plates can support each other and disperse the extrusion force. The structure has high strength and good anti-extrusion ability, which can meet the use requirements of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic structural diagram of a battery side beam structure according to an embodiment of the present invention;

[0037] Figure 2 A cross-sectional view of a battery side beam structure according to an embodiment of the present invention.

[0038] Description of reference numerals:

[0039] 1. First side plate; 2. Second side plate; 3. Bottom plate; 4. Bending plate; 5. First cavity; 6. Second cavity; 7. Third cavity; 8. Fourth cavity. DETAILED DESCRIPTION

[0040] 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.

[0041] Combine the following Figure 1 to Figure 2 , describing an embodiment of the present invention.

[0042] According to an embodiment of the present invention, on the one hand, Figure 1 As shown, a battery pack side beam structure is provided, which mainly includes: a first side plate 1, a second side plate 2 and a bottom plate 3. The second side plate 2 is arranged opposite to the first side plate 1. The bottom plate 3 is connected to the lower ends of the first side plate 1 and the second side plate 2, respectively. The first side plate 1 and the second side plate 2 have a bending plate 4 at one end away from the bottom plate 3, respectively. The bending plates 4 on both sides are bent toward each other for many times and extend toward the bottom plate 3. The free end of the bending plate 4 of the first side plate 1 is welded to the inner wall of the first side plate 1, and the side of the bending plate 4 of the second side plate 2 close to the second side plate 2 is welded to the inner wall of the second side plate 2, and the ends of the bending plates 4 on both sides are welded close to each other.

[0043] It can be seen that the battery pack side beam structure provided by the embodiment of the present invention has a bending plate 4 provided at one end of the first side plate 1 and the second side plate 2 away from the bottom plate 3, respectively. The bending plates 4 are bent toward each other for many times and extend toward the bottom plate 3. The two bending plates 4 are welded at the ends close to each other, and the two bending plates 4 are welded to the first side plate 1 and the second side plate 2, respectively, so that the bottom plate 3, the first side plate 1, the second side plate 2 and the two bending plates 4 can support each other and disperse the extrusion force. The structure has high strength and good anti-extrusion ability, and can meet the use requirements of the battery pack. Moreover, the manufacturing process is simpler than traditional welding, casting, etc., and the use cost is lower.

[0044] In order to improve the structural strength of the battery pack side beam structure made of traditional aluminum alloy materials, the size of the aluminum alloy is generally thickened, which takes up more space in the battery pack and increases the weight of the battery pack. The battery pack design is more difficult and its scope of use is limited.

[0045] The battery pack side beam structure of the embodiment of the present invention is made of a side beam profile. By rolling the opposite sides of the side beam profile, a first side panel 1 and a second side panel 2 that are oppositely arranged, and a bottom panel 3 connected to the lower ends of the first side panel 1 and the second side panel 2 can be formed. That is, the first side panel 1, the second side panel 2 and the bottom panel 3 can be formed in one piece. In addition, each bending portion of the two bending plates 4 can be achieved by rolling, and then welding is performed after the rolling is completed. The production is simple, the connection is firm, and the structure is stable. The side beam profile can be made of sheet metal, and the thickness can be less than 1.2 mm. There is no need to set a mold, which has lower use costs and lower processing difficulty. There is no need to increase the thickness of the material, so the space occupied is smaller, and the shape of the battery pack side beam structure can be adjusted according to the type of battery pack, which is flexible to use and widely used.

[0046] In one embodiment, Figure 2 As shown, the height H1 of the first side plate 1 and the height H2 of the second side plate 2 satisfy 1 / 2H2≤H1≤2 / 3H2, H2≥30mm. For example, H2 is 30mm and H1 is 20mm. Alternatively, H2 is 40mm and H1 is 20mm.

[0047] Taking the application of the battery pack in a vehicle as an example, the first side plate 1 is used to abut against the vehicle body, and the second side plate 2 is used to abut against the electrode group. By limiting the height of the second side plate 2 and the relative relationship between the first side plate 1 and the second side plate 2, it is possible to ensure that the second side plate 2 has a sufficiently large contact area with the electrode group, thereby improving the anti-extrusion ability of the battery pack.

[0048] In addition, the first side panel 1 and the second side panel 2 can be respectively perpendicular to the bottom panel 3 for easy use, and rounded corners are respectively provided at the connections between the first side panel 1 and the second side panel 2 and the bottom panel 3 to further reduce stress concentration, improve fatigue resistance, enhance impact resistance and seismic resistance, and at the same time improve the overall stability and durability of the battery pack edge beam structure.

[0049] The height direction of the embodiment of the present invention is as follows Figure 2 As shown by the arrow H in FIG. 1 , that is, the up and down directions.

[0050] Further, in one embodiment, if Figure 2 As shown, the bent plate 4 of the second side panel 2 and the second side panel 2 form a first cavity 5, and the bent plate 4 of the second side panel 2 and the bent plate 4 of the first side panel 1 form a second cavity 6 located below the first cavity 5. The cross-section of the first cavity 5 is triangular, and the cross-section of the second cavity 6 is rectangular.

[0051] The bent plate 4 of the second side panel 2 of the embodiment of the present invention and the second side panel 2 form a first cavity 5 with a triangular cross-section, which has strong structural stability, can save materials, and is easy to form and process. The bent plate 4 of the second side panel 2 and the bent plate 4 of the first side panel 1 form a second cavity 6 with a rectangular cross-section located below the first cavity 5, which is easy to weld the two side panels.

[0052] Furthermore, in one embodiment, if Figure 2 As shown, the triangular cross-section corners of the first cavity 5 are bent to form an arc, and the radius of the arc R ≥ 3mm. By bending the triangular cross-section corners of the first cavity 5 to form an arc and limiting the radius of the arc, it is possible to reduce stress concentration at the corners of the triangular cross-section, effectively disperse stress, reduce the risk of fracture of the second side plate 2 and the bent plate 4 of the second side plate 2, improve the compressive strength of the battery side beam structure, and facilitate processing.

[0053] Specifically, the cross section of the first cavity 5 is a right triangle, the second side plate 2 is a right angle side, and the connection between the bent plate 4 of the second side plate 2 and the second side plate 2 is bent to form an arc. In addition, each bent portion of the bent plate 4 of the second side plate 2 can form an arc.

[0054] In one embodiment, Figure 2 As shown, the height H2 of the second side plate 2 and the height H3 of the first cavity 5 satisfy 3 / 2H3≤H2≤2H3. For example, H2=2H3, or H2=3 / 2H3. The bending plate 4 of the second side plate 2 is arranged at a middle position close to the second side plate 2, and is evenly stressed, which can effectively disperse the extrusion force and improve the structural strength of the first cavity 5.

[0055] In one embodiment, Figure 2 As shown, the bent plate 4 of the first side panel 1 and the first side panel 1 enclose a third cavity 7, and the third cavity 7 is provided with a hypotenuse welded to the corner of the triangular cross section of the first cavity 5. The triangular cross section of the first cavity 5 is also tilted downward away from the corner of the second side panel 2 to form a welding surface. The hypotenuse of the third cavity 7 is welded and fixed to the welding surface. The third cavity 7 is provided with a hypotenuse welded to the corner of the triangular cross section of the first cavity 5 to facilitate welding of the two. The bent plate 4 of the first side panel 1 and the first side panel 1 enclose the third cavity 7 to further enhance the structural strength of the side beam structure.

[0056] Specifically, Figure 2As shown, the cross-section of the third cavity 7 is a pentagon with two relatively parallel sides, and the other side is a hypotenuse. The hypotenuse is welded to the corner of the triangular cross-section, and the welding length is L1, L1 ≥ 5mm. The side connected to the lower end of the hypotenuse is welded to the free end of the bent plate 4 of the second side panel 2, and the welding length is L2, L2 ≥ 5mm. The side of the rectangular cross-section of the second cavity 6 close to the second side panel 2 is welded to the inner wall of the second side panel 2, and the welding length is L3, L3 ≥ 5mm. The free end of the bent plate 4 of the first side panel 1 faces away from the third cavity 7 and extends toward the bottom plate 3, and is welded to the inner wall of the first side panel 1, and the welding length is L4, L4 ≥ 5mm. Each bend of the bent plate 4 of the first side panel 1 can also form an arc to further reduce stress concentration.

[0057] In one embodiment, Figure 2 As shown, the bent plate 4 of the first side panel 1, the bent plate 4 of the second side panel 2 and the bottom panel 3 form a fourth cavity 8 located below the third cavity 7 and the second cavity 6, and the height H1 of the first side panel 1 and the height H4 of the fourth cavity 8 satisfy 3 / 2H4≤H1≤2H4. For example, H1=2H4, or H1=3 / 2H4. After the first cavity 5, the second cavity 6 and the third cavity 7 are processed by rolling and welding, the bent plate 4 of the first side panel 1, the bent plate 4 of the second side panel 2 and the bottom panel 3 form a fourth cavity 8, with a fast molding speed and no need for additional processing, which can effectively reduce the manufacturing cost. By limiting the relationship between the height of the first side panel 1 and the height of the fourth cavity 8, the bent plate 4 of the first side panel 1 can be welded in the middle position close to the second side panel 2, with uniform force, further dispersing the extrusion force and improving the structural strength.

[0058] It should be noted that during the stress process of the first side plate 1 and the second side plate 2, the one-half, one-third, and two-thirds positions are usually the key positions for stress concentration or stress transmission. The top of the bent plate 4 of the first side plate 1 is parallel to the bottom plate 3, so that the force during extrusion is concentrated at the two-thirds position in the height direction of the second side plate 2. At the same time, the bent plates 4 are welded and fixed in the middle area of ​​the first side plate 1 and the second side plate 2, so as to strengthen the anti-extrusion ability of the battery side beam structure through the two bent plates 4 and improve the structural strength.

[0059] In one embodiment, Figure 2 As shown, the width W1 of the bottom plate 3, the width W2 of the second cavity 6, and the minimum width W3 of the third cavity 7 satisfy 1 / 3W1≤W2=W3≤1 / 2W1. By limiting the relationship between the width of the bottom plate 3, the width of the second cavity 6, and the minimum width of the third cavity 7, the strength of the area where the side beam structure is prone to deformation can be strengthened, the application concentration can be further reduced, and the anti-extrusion ability and structural strength of the side beam structure can be improved.

[0060] The width direction of the embodiment of the present invention is as follows Figure 2 As shown by the arrow W in .

[0061] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising: a shell and at least one pole group, wherein the at least one pole group is installed in a receiving cavity of the shell, and the shell comprises: a bottom shell and a battery pack side beam structure, wherein the battery pack side beam structure is arranged around the bottom shell and forms a receiving cavity with the bottom shell.

[0062] Because the battery pack includes a battery pack side beam structure, it has the same effect as the battery pack side beam structure and will not be described in detail here.

[0063] Taking the battery pack used in a vehicle as an example, the bottom shell is fixed under the vehicle floor, the first side plate abuts against the vehicle shell, and the second side plate abuts against the electrode group in the accommodating cavity.

[0064] In order to realize the basic functions of the battery pack, the battery pack in this embodiment may also include other necessary modules or components, such as a heat dissipation system, wires, etc. It should be noted that the other necessary modules or components included in the battery pack may be of any suitable existing structure. In order to clearly and briefly illustrate the technical solution provided by this embodiment, the above-mentioned parts will not be described in detail here, and the drawings in the specification are also simplified accordingly. However, it should be understood that the scope of the embodiments of the present invention is not limited by this.

[0065] According to an embodiment of the present invention, in another aspect, a method for manufacturing a battery side beam structure is provided, comprising:

[0066] S100. Prepare side beam profiles.

[0067] S200 , rolling the side beam profile to form a bottom plate 3 and a first side plate 1 and a second side plate 2 located on opposite sides of the bottom plate 3 .

[0068] S300 , rolling the two ends of the first side plate 1 and the second side plate 2 away from the bottom plate 3 to form two bent plates 4 that are bent toward each other and extend toward the bottom plate 3 .

[0069] S400, the free end of the bent plate 4 of the first side plate 1 and the inner wall of the first side plate 1, the side of the bent plate 4 of the second side plate 2 close to the second side plate 2 and the inner wall of the second side plate 2, and the ends of the bent plates 4 on both sides close to each other are welded respectively.

[0070] It can be seen that the method for manufacturing the battery pack side beam structure provided by the embodiment of the present invention uses a high-strength side beam profile as a base material, and manufactures the side beam profile into a bottom plate 3, a first side plate 1 and a second side plate 2 located on opposite sides of the bottom plate 3, and bent plates 4 at both ends of the first side plate 1 and the second side plate 2 away from the bottom plate 3 through rolling and welding processes. Compared with traditional processes such as welding and casting, the method is simple to manufacture and has a low cost. Moreover, the bent plates 4 are bent toward each other for many times and extend toward the bottom plate 3. The ends of the two bent plates 4 close to each other are welded, and the two bent plates 4 are respectively welded to the first side plate 1 and the second side plate 2, so that the bottom plate 3, the first side plate 1, the second side plate 2 and the two bent plates 4 can support each other and disperse the extrusion force. The structural strength is high, it has good anti-extrusion ability, and can meet the use requirements of the battery pack.

[0071] 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 battery side beam structure, characterized in that: include: first side panel; a second side panel, arranged opposite to the first side panel; A bottom plate, connected to the lower ends of the first side plate and the second side plate respectively; The first side panel and the second side panel each have a bent plate at one end away from the bottom panel, the bent plates on both sides are bent toward each other for multiple times and extend toward the bottom panel, the free end of the bent plate of the first side panel is welded to the inner wall of the first side panel, the side of the bent plate of the second side panel close to the second side panel is welded to the inner wall of the second side panel, and the ends of the bent plates on both sides close to each other are welded.

2. The battery pack side beam structure according to claim 1, characterized in that: A height H1 of the first side plate and a height H2 of the second side plate satisfy 1 / 2H2≤H1≤2 / 3H2, and H2≥30 mm.

3. The battery pack side beam structure according to claim 2, characterized in that: The bent plate of the second side panel and the second side panel form a first cavity, and the bent plate of the second side panel and the bent plate of the first side panel form a second cavity located below the first cavity. The cross-section of the first cavity is triangular, and the cross-section of the second cavity is rectangular.

4. The battery pack side beam structure according to claim 3, characterized in that: The triangular cross-section corners of the first cavity are bent to form arcs, and the radius of the arc is R≥3mm.

5. The battery pack side beam structure according to claim 3, characterized in that: A height H2 of the second side plate and a height H3 of the first cavity satisfy 3 / 2H3≤H2≤2H3.

6. The battery pack side beam structure according to claim 3, characterized in that: The bent plate of the first side plate and the first side plate form a third cavity, and the third cavity is provided with a hypotenuse welded to the corner of the triangular cross section of the first cavity.

7. The battery pack side beam structure according to claim 6, characterized in that: The bent plate of the first side plate, the bent plate of the second side plate and the bottom plate form a fourth cavity located below the third cavity and the second cavity, and a height H1 of the first side plate and a height H4 of the fourth cavity satisfy 3 / 2H4≤H1≤2H4.

8. The battery pack side beam structure according to claim 6, characterized in that: The width W1 of the bottom plate, the width W2 of the second cavity, and the minimum width W3 of the third cavity satisfy 1 / 3W1≤W2=W3≤1 / 2W1.

9. A battery pack, characterized in that: include: A housing and at least one pole group, wherein at least one pole group is installed in a receiving cavity of the housing, and the housing comprises: Bottom shell; The battery package side beam structure according to any one of claims 1 to 8, wherein the battery package side beam structure is arranged around the four sides of the bottom shell and forms the accommodating cavity with the bottom shell.

10. A method for manufacturing a battery side beam structure, characterized in that: include: Prepare edge beam profiles; Rolling the side beam profile to form a bottom plate and a first side plate and a second side plate located on opposite sides of the bottom plate; Rolling the two ends of the first side plate and the second side plate away from the bottom plate to form two bent plates that are bent toward each other and extend toward the bottom plate; The free end of the bent plate of the first side plate and the inner wall of the first side plate, the side of the bent plate of the second side plate close to the second side plate and the inner wall of the second side plate, and the ends of the bent plates on both sides close to each other are welded respectively.

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