Cap assembly and cylindrical battery

Abstract

The cap assembly comprises an anti-explosion piece, a top cover plate, an inner rubber ring and a lower end plate, the anti-explosion piece comprises a first outer wall and a second outer wall, and the first outer wall and the second outer wall are located on the two opposite sides of the anti-explosion piece in the height direction of the anti-explosion piece respectively; the top cover plate is arranged on one side of the second outer wall, and the inner rubber ring is arranged on one side of the first outer wall. By arranging the sinking table and the welding protrusion welded to the sinking table, when welding treatment is conducted between the anti-explosion piece and the lower end plate, the sinking table and the welding protrusion are attached and welded, welding treatment between the anti-explosion piece and the lower end plate can be completed, the welding flatness is guaranteed, meanwhile, the welding area is reduced, and the welding quality of the anti-explosion piece and the lower end plate is improved. And the flatness is easier to control, so that the explosion-proof sheet is not easy to have the problems of explosion points, pseudo soldering and the like in the welding process, meanwhile, the welding reject ratio is reduced, and the battery manufacturing cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery cap assembly technical field especially, relate to a cap assembly and cylindrical battery. BACKGROUND

[0002] The battery cap assembly is an indispensable part of the battery device, mainly used for protecting the battery, ensuring its safety and stability during use. The battery cap is usually made of plastic or metal material, with certain strength, heat resistance and sealing property, to prevent external substances from entering the battery interior, and prevent the leakage of electrolyte

[0003] The utility model with publication number CN215070164U proposes a cap assembly for cylindrical battery and cylindrical battery, the cap assembly for cylindrical battery includes: current collector disc, current collector disc is equipped with through hole that penetrates current collector disc;Pole, pole is connected with current collector disc, and the first end of pole is fixed in through hole, and the first end of pole is equipped with electric connection part, and at least part of electric connection part is exposed in through hole to abut with the pole lug of the pole core of cylindrical battery;Cover plate, cover plate is located in one side of current collector disc and is set on pole, and cover plate is used for closing the opening of the shell of cylindrical battery. However, for the cap assembly of conventional 21 series cylindrical battery, when welding between the explosion-proof sheet and the lower end plate, the middle area of the explosion-proof sheet is usually directly welded with the upward protrusion of the lower end plate. Since the middle area of the explosion-proof sheet is large, the welding area is large, it is difficult to control the flatness of the welding, and the explosion point, false welding and other situations are prone to occur during welding, which leads to the increase of poor welding rate. Therefore, the present application proposes a cap assembly and cylindrical battery to solve the above problems. Utility model content

[0004] Therefore, the utility model provides a cap assembly and cylindrical battery to solve the technical problems that the middle welding area of the explosion-proof sheet is large when welding between the explosion-proof sheet and the lower end plate, it is difficult to control the flatness of the welding, and the explosion point and false welding are prone to occur during welding.

[0005] The technical scheme of the utility model is as follows: the utility model provides a cap assembly, which comprises an explosion-proof sheet, a top cover plate, an inner rubber ring and a lower end plate, wherein,

[0006] The explosion-proof sheet comprises a first outer wall and a second outer wall, and the first outer wall and the second outer wall are located on opposite sides of the explosion-proof sheet in the height direction of the explosion-proof sheet;

[0007] The top cover plate is arranged on one side of the second outer wall, and the inner rubber ring is arranged on one side of the first outer wall;

[0008] The first outer wall is provided with a sunken platform, and the sunken platform is located at the middle part of the explosion-proof sheet.

[0009] On the basis of the above technical scheme, preferably, the distance between the two ends of the first welding wall in the length direction of the explosion-proof sheet is W1, the distance between the two ends of the explosion-proof sheet is W0, and 8%≤W1 / W0≤18%.

[0010] On the basis of the above technical scheme, preferably, the distance between the first welding wall and the second outer wall in the height direction of the explosion-proof sheet is H40, the distance between the first welding wall and the first outer wall in the height direction of the explosion-proof sheet is H43, and 32%≤H43 / H40≤48%.

[0011] On the basis of the above technical scheme, preferably, the second outer wall is provided with a center groove and an outer peripheral groove, the center groove is located inside the outer peripheral groove and at the center of the explosion-proof sheet, the depth of the center groove is H10, and 12%≤H10 / H40≤26%.

[0012] On the basis of the above technical scheme, preferably, the depth of the outer peripheral groove is H11, and 50%≤H10 / H11≤70%.

[0013] On the basis of the above technical scheme, preferably, the distance between the center groove and the outer peripheral groove in the length direction of the explosion-proof sheet is W31, and the distance between the center groove and the end wall of the explosion-proof sheet in the length direction of the explosion-proof sheet is W30, and 39%≤W31 / W30≤59%.

[0014] On the basis of the above technical scheme, preferably, the included angles between the two side walls of the sunken platform in the length direction of the explosion-proof sheet and the first outer wall are α and β respectively, 120°≤α≤150°, and 120°≤β≤150°.

[0015] On the basis of the above technical scheme, preferably, the distance between the two ends of the second welding wall in the length direction of the explosion-proof sheet is W11, and 76%≤W1 / W11≤96%.

[0016] On the basis of the above technical scheme, preferably, the distance between the first outer wall and the second outer wall is H42, and 0.2mm≤H42≤0.4mm.

[0017] The utility model also proposes a cylindrical battery which comprises the cap assembly.

[0018] The cap assembly and the cylindrical battery have the following beneficial effects compared with the prior art:

[0019] By arranging the sinking platform on the explosion-proof sheet and the welding protrusion welded with the sinking platform on the lower end plate, the sinking platform and the welding protrusion are attached and welded when welding the explosion-proof sheet and the lower end plate, so that the welding process between the explosion-proof sheet and the lower end plate is completed, the welding flatness is ensured, the welding area is reduced, the flatness is more easily controlled, the explosion-proof sheet is not prone to problems such as explosion and false welding during welding, the welding failure rate is reduced, and the battery manufacturing cost is reduced. At the same time, the sinking platform can be used as a reinforcing rib to increase the strength of the slotted center position of the explosion-proof sheet, prevent the explosion-proof sheet from being deformed when the top cover plate and the explosion-proof sheet are pressed into the outer insulating ring, prevent the explosion-proof sheet from being deformed to cause early valve opening or valve closing, and ensure the stability of the explosion-proof sheet valve opening. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed in the embodiment or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0021] Figure 1 It is a sectional view of the cap assembly of the present application;

[0022] Figure 2 It is a connection mode schematic view of the explosion-proof sheet and the lower end plate of the cap assembly of the present application;

[0023] Figure 3 It is a sectional view of the cap assembly of the present application; Figure 2 It is an enlarged schematic view of A shown in the drawing;

[0024] Figure 4 It is a sectional view of the explosion-proof sheet of the cap assembly of the present application;

[0025] Figure 5 It is a sectional view of the cap assembly of the present application; Figure 4 It is an enlarged schematic view of B shown in the drawing;

[0026] Figure 6 It is a sectional view of the cap assembly of the present application; Figure 4 It is an enlarged schematic view of C shown in the drawing.

[0027] In the diagram: 1. Explosion-proof sheet; 11. First outer wall; 12. Second outer wall; 13. Lower platform; 131. First welded wall; 14. Upper protrusion; 15. Aircraft side; 16. Center groove; 17. Outer peripheral groove; 2. Top cover plate; 3. Inner rubber ring; 4. Lower end plate; 41. Welding protrusion; 411. Second welded wall; 5. Outer insulating ring. Detailed Implementation

[0028] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0029] like Figures 1-6 As shown, the cap assembly of this utility model includes an explosion-proof sheet 1, a top cover plate 2, an inner rubber ring 3, and a lower end plate 4. The explosion-proof sheet 1 includes a first outer wall 11 and a second outer wall 12, which are located on opposite sides of the explosion-proof sheet 1 in the height direction. The top cover plate 2 is disposed on one side of the second outer wall 12, and the inner rubber ring 3 is disposed on one side of the first outer wall 11. A recessed platform 13 is provided on the first outer wall 11. The recessed platform 13 is a frustum-shaped platform and is located in the middle of the explosion-proof sheet 1. The lower end plate 4 is disposed on the side of the inner rubber ring 3 away from the first outer wall 11. A welding protrusion 41 is formed in the middle of the lower end plate 4. The recessed platform 13 includes a first welding wall 131, and the welding protrusion 41 includes a second welding wall 411. The first welding wall 131 and the second welding wall 411 are attached and welded together.

[0030] Figure 1 The X-direction represents the length of the explosion-proof sheet 1, and the Z-direction represents the height of the explosion-proof sheet 1.

[0031] In specific implementation, the second outer wall 12 is provided with an upper protrusion 14, which is an annular protrusion that is inserted into the inner side of the top cover plate 2 and is sealed and fitted with the top cover plate 2. The first outer wall 11 is provided with an aircraft edge 15, which is located on the periphery of the inner rubber ring 3 and is sealed and fitted with the inner rubber ring 3. It also includes an outer insulating ring 5, and the top cover plate 2 and the explosion-proof sheet 1 are both located inside the outer insulating ring 5 and are sealed and fitted with the outer insulating ring 5.

[0032] By providing a recessed platform 13 on the explosion-proof sheet 1 and a welding protrusion 41 on the lower end plate 4 that is welded to the recessed platform 13, the welding process between the explosion-proof sheet 1 and the lower end plate 4 can be completed by attaching and welding the recessed platform 13 and the welding protrusion 41 together.

[0033] In this way, when the explosion-proof sheet 1 is welded with the lower end plate 4, the explosion-proof sheet 1 can be in full contact with the welding protrusion 41, and the welding flatness is ensured by welding the sunken platform 13 with the welding protrusion 41, and the welding area is reduced, and the flatness is easier to control, so that the explosion-proof sheet 1 is not easy to explode, false welding and other problems during welding, and the welding failure rate is reduced, and the battery manufacturing cost is reduced.

[0034] At the same time, when assembling the explosion-proof sheet 1 and the outer insulation ring 5, the top cover plate 2 is extruded, and since the outer insulation ring 5 is made of plastic material, it will spread to the shaft center due to deformation, which may extrude the explosion-proof sheet 1 and the lower end plate 4 and other components, affecting the overall sealing of the battery. By setting the sunken platform 13 in the middle of the explosion-proof sheet 1, the sunken platform 13 can be used as a reinforcing rib to increase the strength of the slot at the center of the explosion-proof sheet 1. In this way, the structural strength of the explosion-proof sheet 1 is greatly increased, so that when the top cover plate 2 and the explosion-proof sheet 1 are pressed into the outer insulation ring 5 using a larger force, the explosion-proof sheet 1 will not be deformed, thereby preventing the explosion-proof sheet 1 from opening the valve too early or not opening the valve due to deformation, and ensuring the stability of the explosion-proof sheet 1 opening the valve.

[0035] As a preferred embodiment, the distance between the two ends of the first welding wall 131 in the length direction of the explosion-proof sheet 1 is W1, and the distance between the two ends of the explosion-proof sheet 1 is W0, 8%≤W1 / W0≤18%.

[0036] In this way, the main purpose is to ensure the strength and reliability of the welding interface, while taking into account the actual needs in the manufacturing and assembly process. By setting a reasonable ratio of W1 / W0, the strength of the welding area can be optimized to avoid insufficient strength due to too small welding area, and also to prevent area waste due to too large welding area. At the same time, a proper W1 / W0 ratio can effectively disperse mechanical stress, avoid material fatigue or fracture caused by concentrated stress during use, and improve the reliability of the overall structure.

[0037] As a preferred embodiment, the distance between the first welding wall 131 and the second outer wall 12 in the height direction of the explosion-proof sheet 1 is H40, and the distance between the first welding wall 131 and the first outer wall 11 in the height direction of the explosion-proof sheet 1 is H43, 32%≤H43 / H40≤48%.

[0038] In this way, the optimized structural design, safety and functionality of the battery cap assembly are achieved. By setting a reasonable ratio of H43 / H40, uniform stress distribution is achieved, avoiding local stress concentration at the welding site under high temperature and high pressure, which may cause fatigue or fracture. At the same time, the appropriate height difference can ensure that the inner rubber ring 3 and the welding site form a good seal, which helps to prevent electrolyte leakage and gas penetration, and improves the overall sealing performance of the assembly. If H43 / H40 is too large, more thermal stress and deformation may occur during welding, affecting the assembly accuracy and the consistency of the overall structure.

[0039] As a preferred embodiment, the second outer wall 12 is provided with a central groove 16 and an outer peripheral groove 17. The central groove 16 is located inside the outer peripheral groove 17 and at the center of the rupture disc 1. The depth of the central groove 16 is H10, and 12%≤H10 / H40≤26%.

[0040] By setting the central groove 16 and the outer peripheral groove 17, the pressure or stress applied inside the rupture disc 1 can be effectively dispersed, making the material more resistant during operation or use. At the same time, the central groove 16 and the outer peripheral groove 17 can provide a positioning reference to help better align and position other components during assembly, ensuring assembly accuracy and reducing errors during production.

[0041] As a preferred embodiment, the depth of the outer peripheral groove 17 is H11, and 50%≤H10 / H11≤70%.

[0042] This design is mainly to ensure the structural strength, sealing and safety of the battery cap assembly.

[0043] By setting a reasonable ratio of H10 / H40, the depth of the groove can be ensured to maintain the strength of the welding wall without excessive material consumption, ensuring the strength and reliability of the overall structure. A suitable depth ratio helps to avoid stress concentration due to excessive depth to some extent, thereby reducing the risk of potential structural failure.

[0044] By setting a reasonable ratio of H10 / H11, the depth difference between the central groove 16 and the outer peripheral groove 17 can be ensured to achieve better sealing effect, avoid liquid or gas leakage, and improve the overall safety of the assembly. If the value of H10 / H11 is too large, the control difficulty in the production process will increase, affecting the assembly accuracy.

[0045] As a preferred embodiment, the distance between the central groove 16 and the outer peripheral groove 17 on the length square of the rupture disc 1 is W31, and the distance between the central groove 16 and the end wall of the rupture disc 1 on the length square of the rupture disc 1 is W30, and 39%≤W31 / W30≤59%.

[0046] In this way, a reasonable W31 / W30 ratio can help effectively disperse the stress applied during the use of the battery cover cap, thereby preventing local stress concentration, reducing the risk of material fatigue and fracture, and improving the overall strength and reliability of the assembly. A better spacing design can increase the heat dissipation space around the assembly, which helps effectively dissipate heat under high temperature working conditions and improves the performance and life of the battery.

[0047] As a preferred embodiment, the angles between the two side walls of the sinking platform 13 on the length direction of the explosion-proof sheet 1 and the first outer wall 11 are α and β respectively, 120°≤α≤150°, 120°≤β≤150°.

[0048] The angles of α and β are set to cooperate with the settings of the above embodiments, in order to ensure the welding strength between the sinking platform 13 and the welding protrusion 41 while ensuring the stability of the electrical connection between the sinking platform 13 and the welding protrusion 41.

[0049] As a preferred embodiment, the spacing between the two ends of the second welding wall 411 on the length direction of the explosion-proof sheet 1 is W11, 76%≤W1 / W11≤96%.

[0050] In this way, in order to ensure the strength of the welding structure, thereby improving the overall carrying capacity of the assembly. A reasonable W1 / W11 ratio helps to evenly disperse mechanical stress during use, reducing the risk of fatigue, cracking or failure caused by stress concentration. At the same time, a reasonable ratio increases the tolerance in production, improving manufacturing precision. If W1 / W11 is too large, a wide welding surface may cause imperfect bonding between components, affecting the sealing effect and increasing the risk of leakage. If W1 / W11 is too small, the welding surface may not be able to provide sufficient strength to withstand the pressure and stress that may be encountered during battery use, which may cause welding failure.

[0051] The application also provides a cylindrical battery comprising the above-mentioned cover cap assembly.

[0052] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A cap assembly, characterized by: The explosion-proof sheet (1), the top cover plate (2), the inner rubber ring (3) and the lower end plate (4) are included, wherein The explosion-proof sheet (1) includes a first outer wall (11) and a second outer wall (12), and the first outer wall (11) and the second outer wall (12) are respectively located on opposite sides of the explosion-proof sheet (1) in the height direction of the explosion-proof sheet (1); The top cover plate (2) is arranged on one side of the second outer wall (12), and the inner rubber ring (3) is arranged on one side of the first outer wall (11); The first outer wall (11) is provided with a sunken platform (13), and the sunken platform (13) is located in the middle of the explosion-proof sheet (1), the lower end plate (4) is arranged on the side of the inner rubber ring (3) away from the first outer wall (11), the middle of the lower end plate (4) is formed with a welding protrusion (41), the sunken platform (13) includes a first welding wall (131), the welding protrusion (41) includes a second welding wall (411), and the first welding wall (131) is attached to and welded with the second welding wall (411).

2. The cap assembly of claim 1, wherein: The distance between the first welding wall (131) and the second welding wall (411) in the length direction of the explosion-proof sheet (1) is W1, the distance between the two ends of the explosion-proof sheet (1) is W0, and 8%≤W1 / W0≤18%.

3. The cap assembly of claim 1, wherein: The distance between the first welding wall (131) and the second outer wall (12) in the height direction of the explosion-proof sheet (1) is H40, the distance between the first welding wall (131) and the first outer wall (11) in the height direction of the explosion-proof sheet (1) is H43, and 32%≤H43 / H40≤48%.

4. The cap assembly of claim 3, wherein: The second outer wall (12) is provided with a central groove (16) and a peripheral groove (17), the central groove (16) is located inside the peripheral groove (17) and at the center of the explosion-proof sheet (1), the depth of the central groove (16) is H10, and 12%≤H10 / H40≤26%.

5. The cap assembly of claim 4, wherein: The depth of the peripheral groove (17) is H11, and 50%≤H10 / H11≤70%.

6. The cap assembly of claim 4, wherein: The distance between the central groove (16) and the peripheral groove (17) in the length direction of the explosion-proof sheet (1) is W31, the distance between the central groove (16) and the end wall of the explosion-proof sheet (1) in the length direction of the explosion-proof sheet (1) is W30, and 39%≤W31 / W30≤59%.

7. The cap assembly of claim 1, wherein: The angles between the two side walls of the sunken platform (13) in the length direction of the explosion-proof sheet (1) and the first outer wall (11) are α and β respectively, 120°≤α≤150°, and 120°≤β≤150°.

8. The cap assembly of claim 2, wherein: The distance between the two ends of the second welding wall (411) in the length direction of the explosion-proof sheet (1) is W11, and 76%≤W1 / W11≤96%.

9. The cap assembly of claim 1, wherein: The distance between the first outer wall (11) and the second outer wall (12) is H42, and 0.2mm≤H42≤0.4mm.

10. A cylindrical battery characterized by: The cap assembly includes the cap assembly according to any one of claims 1 to 9. The cap assembly includes the cap assembly according to any one of claims 1 to 9.

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