Explosion-proof valve and top cover assembly

Abstract

The utility model belongs to the technical field of battery structures, and discloses an anti-explosion valve and a top cover assembly. The anti-explosion valve comprises an anti-explosion valve body, a deformation part and a welding part, the deformation part is provided with a nick and connected between the welding part and the anti-explosion valve body, the deformation part is provided with a first-stage groove and a second-stage groove, the nick is formed in the bottom wall of the first-stage groove, the first-stage groove is formed in the bottom wall of the second-stage groove, and the second-stage groove is formed in the bottom wall of the second-stage groove. And the first-stage groove and the second-stage groove are used for limiting the thickness of the deformation part. In the process of welding and installing the anti-explosion valve, deformation generated by welding heat is changed from being concentrated at the nick position to being generated at the nick position and the deformation part, so that the deformation degree of the nick position is greatly reduced, the phenomenon that deep nicks meeting the preset bursting pressure value are subjected to concentrated stress in the normal welding process is avoided, and the welding quality of the anti-explosion valve is improved. Therefore, it is guaranteed that the explosion-proof valve can have an intact structure after welding, the explosion-proof valve can be normally broken when the preset explosion pressure value is reached, the preset explosion-proof effect is achieved, and welding damage is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of battery structures, in particular to an explosion-proof valve and a top cover assembly. Background Art

[0002] The battery generally includes a shell, a top cover assembly, and a cell, wherein the cell is placed inside the shell, and the top cover assembly and the shell form a sealed structure to protect the cell. The positive and negative pins of the cell are connected to the top cover assembly, and the external circuit is connected to the top cover assembly to realize power supply. The top cover assembly includes a top cover sheet and an explosion-proof valve, which is welded and installed on the top cover sheet and can rupture when the pressure reaches a preset bursting pressure value, thereby connecting the inside of the battery with the outside, releasing the pressure, and avoiding a high-intensity explosion.

[0003] In order to meet the requirement of exploding only when the preset bursting pressure value is reached or exceeded, the explosion-proof valve is generally made of high-strength materials such as steel, and the depth of the notch where the rupture occurs is strictly controlled. The deeper the notch, the smaller the residual thickness of the notch, and the weaker the structural strength between the two sides of the notch, the easier it is to rupture at the notch. However, after the explosion-proof valve is welded and installed, deformation and cracking often occur at the notch, resulting in the explosion-proof valve not being able to rupture normally when the preset bursting pressure value is reached after welding, and even rupture occurs after welding and installation, resulting in welding damage.

[0004] Based on the above, there is an urgent need for an explosion-proof valve and a top cover assembly to solve the above technical problems. Utility Model Content

[0005] One purpose of the utility model is to provide an explosion-proof valve, which can rupture when subjected to a preset explosion pressure value to connect the inside and outside of a battery, quickly reduce the high pressure in the battery, and is not prone to welding damage during welding installation.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] An explosion-proof valve, comprising an explosion-proof valve body, a deformation portion and a welding portion, wherein the welding portion is used for welding and connecting a top cover sheet, the deformation portion is provided with notches and connected between the welding portion and the explosion-proof valve body, the deformation portion can rupture when subjected to a preset explosion pressure value, and,

[0008] The deformation part is provided with a first-level groove and a second-level groove, the notch is provided on the bottom wall of the first-level groove, the first-level groove is provided on the bottom wall of the second-level groove, and the bottom wall width of the second-level groove is greater than the notch width of the first-level groove, and the first-level groove and the second-level groove are used to limit the thickness of the deformation part.

[0009] Preferably, the notch is arranged in the middle of the bottom wall of the first-stage groove; and / or,

[0010] The first-stage groove is arranged at the middle part of the bottom wall of the second-stage groove.

[0011] Preferably, the side wall of the first-stage groove is inclined, and the notch width of the first-stage groove is greater than the bottom wall width of the first-stage groove; and / or,

[0012] The side wall of the second-stage groove is inclined, and the notch width of the second-stage groove is greater than the bottom wall width of the second-stage groove.

[0013] Preferably, the side wall of the first-stage groove is arranged perpendicular to the bottom wall of the first-stage groove; and / or,

[0014] The side wall of the second-stage groove is vertically arranged to the bottom wall of the second-stage groove.

[0015] Preferably, the depth h from the top surface of the explosion-proof valve body to the bottom wall of the second-stage groove is not greater than half of the thickness d of the explosion-proof valve body.

[0016] Preferably, the deformation portion is further provided with a third-level groove, and the second-level groove is arranged on the bottom wall of the third-level groove.

[0017] Preferably, the explosion-proof valve also includes a connecting portion, which is connected between the explosion-proof valve body and the welding portion, and the thickness of the connecting portion is greater than the thickness of the deformation portion, so that the connecting portion is connected between the explosion-proof valve body and the welding portion when subjected to the preset bursting pressure value.

[0018] Preferably, the explosion-proof valve is an integral structure made by stamping.

[0019] Another object of the utility model is to provide a top cover assembly, which can connect the inside and outside of the battery when subjected to a preset bursting pressure value, quickly reduce the high pressure in the battery, and is not prone to welding damage during welding installation.

[0020] To achieve this purpose, the utility model adopts the following technical solutions:

[0021] The top cover assembly comprises a top cover sheet and the explosion-proof valve, wherein the top cover sheet has a pressure relief hole, the explosion-proof valve is sealed in the pressure relief hole, and the welding part of the explosion-proof valve is welded to the top cover sheet.

[0022] The beneficial effects of the utility model are as follows: compared with the explosion-proof valve in the prior art, a deformation part is connected and arranged between the welding part and the explosion-proof valve body, and when the thickness of the deformation part can be less than the thickness of the explosion-proof valve body, in the process of welding and installing the explosion-proof valve, the deformation caused by the welding heat will change from being concentrated at the notch to occurring at the notch and the deformation part, especially at the connection between the first-level groove and the second-level groove, thereby greatly reducing the degree of deformation at the notch during the welding process, avoiding the phenomenon that deeper notches that meet the preset bursting pressure value are subjected to concentrated stress during normal welding, thereby ensuring that the explosion-proof valve can have a sound structure after welding, and can rupture normally when the preset bursting pressure value is reached, achieving the preset explosion-proof effect, and preventing welding damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a top view of the explosion-proof valve provided by the utility model;

[0024] Figure 2 It is a side view of the explosion-proof valve provided by the utility model;

[0025] Figure 3 is along Figure 1 Cross-sectional view of explosion-proof valve from the perspective of medium BB;

[0026] Figure 4 yes Figure 1 A partial enlarged view of the middle A;

[0027] Figure 5 yes Figure 3 A partial enlarged view of point C in the middle.

[0028] In the figure:

[0029] 1. Explosion-proof valve body;

[0030] 2. deformation part; 20. notch; 21. first-level groove; 22. second-level groove;

[0031] 3. Welding part;

[0032] 4. Connection part. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0034] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0037] The following is based on the attached Figure 1 To Attachment Figure 5 The utility model introduces an explosion-proof valve and a top cover assembly.

[0038] refer to Figures 1 to 3As shown, the existing explosion-proof valve and the explosion-proof valve provided by the utility model both include an explosion-proof valve body 1 and a welding part 3. Among them, the welding part 3 is arranged around the outside of the explosion-proof valve body 1 and is detachably connected to the explosion-proof valve body 1. The welding part 3 is used to weld and connect the top cover sheet to weld and install the explosion-proof valve on the top cover sheet. A notch 20 is provided between the explosion-proof valve body 1 and the welding part 3, and the notch 20 is used to limit the thickness of the connection between the explosion-proof valve body 1 and the welding part 3. When the explosion-proof valve is subjected to a preset bursting pressure value, the connection is broken, so that the explosion-proof valve body 1 and the welding part 3 can be separated. After separation, the high pressure on one side of the explosion-proof valve can be released through the opening caused by the break between the explosion-proof valve body 1 and the welding part 3. Specifically in the battery, the high-pressure gas and electrolyte inside the battery can be discharged to the outside of the battery through the opening caused by the break between the explosion-proof valve body 1 and the welding part 3, thereby avoiding the pressure inside the battery from being kept increasing, resulting in strong explosion consequences and causing safety risks.

[0039] In the explosion-proof valve provided by the utility model, Figures 3 to 5 As shown, a deformation part 2 is connected and arranged between the welding part 3 and the explosion-proof valve body 1, and a notch 20 is arranged on the deformation part 2. Compared with the explosion-proof valve in the prior art, in the explosion-proof valve provided by the utility model, a first-level groove 21 and a second-level groove 22 are further arranged on the deformation part 2. The notch 20 is arranged on the bottom wall of the first-level groove 21, and the first-level groove 21 is arranged on the bottom wall of the second-level groove 22, and the bottom wall width of the second-level groove 22 is greater than the notch width of the first-level groove 21, so that the first-level groove 21 and the second-level groove 22 form a stepped groove along the thickness direction of the explosion-proof valve and from top to bottom. The first-level groove 21 and the second-level groove 22 are used to limit the thickness of the deformation part 2, so that the thickness of the deformation part 2 can be less than the thickness of the explosion-proof valve body 1.

[0040] When the thickness of the deformation portion 2 can be less than the thickness of the explosion-proof valve body 1, during the process of welding and installing the explosion-proof valve, the deformation caused by the welding heat will change from being concentrated at the notch 20 to occurring at the notch 20 and the deformation portion 2, especially the connection between the first-level groove 21 and the second-level groove 22, thereby greatly reducing the degree of deformation at the notch 20 during the welding process, avoiding the phenomenon that the deeper notch 20 that meets the preset bursting pressure value is subjected to concentrated stress during normal welding, thereby ensuring that the explosion-proof valve can have a sound structure after welding, and can rupture normally when the preset bursting pressure value is reached, achieving the preset explosion-proof effect, and preventing welding damage.

[0041] plan Residual thickness after notch (mm) Burst pressure value (MPa) Existing explosion-proof valve 0.022 0.478 The first explosion-proof valve after improvement 0.022 0.417 Improved second explosion-proof valve 0.026 0.441 Improved third explosion-proof valve 0.03 0.474

[0042] Table 1 Correspondence between the residual thickness of the notch and the bursting pressure value before and after improvement

[0043] As shown in Table 1, for the same residual thickness of the notch 20, the bursting pressure value of the improved structure provided by the utility model is significantly smaller, and when reaching a similar bursting pressure value, the residual thickness of the notch 20 provided by the improved structure provided by the utility model is larger, and it is less likely to be damaged during welding. For example, if the required bursting pressure value is 0.9MPa, the residual thickness of the notch 20 of the existing explosion-proof valve is about 0.045mm, and after the improvement, the residual thickness of the notch 20 can be set to about 0.06mm, and the thickness is increased by about 33%, which can greatly reduce the deformation effect on the notch 20 during welding.

[0044] Preferably, in this embodiment, if Figure 4 , Figure 5 As shown, the notch 20 is arranged in the middle of the bottom wall of the first-level groove 21. During the welding process, affected by the welding heat, the welding portion 3 will generate an extrusion force on the notch 20 at a high temperature, and generate a pulling force on the notch 20 after cooling down. When subjected to the pulling force, the notch 20 will be in a state of being easy to break. In the utility model, the thickness of the deformation part 2 is limited by the first-level groove 21 and the second-level groove 22, so that the deformation part 2 can be deformed to share part of the pulling force, thereby reducing the pulling force borne by the notch 20. In addition, when the notch 20 is arranged in the middle of the bottom wall of the first-level groove 21, the forces on both sides of the notch 20 can be made symmetrical. Symmetrical stress can make the notch 20 deform evenly, avoiding the local concentration of stress at the notch 20, resulting in the bursting pressure value that the notch 20 can withstand being less than the preset bursting pressure value, thereby reducing the change in the performance of the explosion-proof valve due to welding heat during the welding process and improving the consistency of the performance of the explosion-proof valve after the welding process.

[0045] Further, continue to refer to Figure 4 , Figure 5 As shown, in this embodiment, the first-stage groove 21 can also be arranged in the middle of the bottom wall of the second-stage groove 22. Similar to the arrangement of the notch 20 in the middle of the bottom wall of the first-stage groove 21, the arrangement of the first-stage groove 21 in the middle of the bottom wall of the second-stage groove 22 can make the local forces on both sides of the notch 20 symmetrical and the deformation degrees similar, so that the notch 20 is uniformly deformed, avoiding the stress concentration in the local area of ​​the notch 20, thereby reducing the influence of the welding installation process on the bursting pressure value of the explosion-proof valve.

[0046] Optionally, in the present embodiment, the explosion-proof valve adopts an integrated structure made by stamping, such as a stamped stainless steel integrated part. The integrated structure made by stamping makes the overall structure of the explosion-proof valve more solid and stable. This structure can effectively resist external impact and pressure, ensuring that the explosion-proof valve can still maintain good working performance under harsh working conditions. In addition, the integrated structure helps to improve its safety performance. Since there are no welds or seams between the welding portion 3 and the explosion-proof valve body 1, the risk of leakage and failure is reduced. At the same time, the integrated structure can also enhance the pressure resistance of the explosion-proof valve, ensuring that it can work safely and reliably under high pressure environments.

[0047] Further optionally, in the present embodiment, the side wall of the first-stage groove 21 is inclined, and the notch width of the first-stage groove 21 is greater than the bottom wall width of the first-stage groove 21. In the process of stamping manufacturing, since the side wall of the first-stage groove 21 is inclined, and the notch width of the first-stage groove 21 is greater than the bottom wall width of the first-stage groove 21, it is convenient for the stamping die to quickly withdraw from the first-stage groove 21 after forming the first-stage groove 21, which greatly simplifies the structure of the stamping die and the stamping process, and avoids the phenomenon of the stamping die being embedded in the explosion-proof valve during the stamping process, resulting in alarm interruption in the continuous production process, affecting the production progress, and even causing a large number of explosion-proof valves to be produced poorly.

[0048] Similarly, in some embodiments, the second-stage groove 22 may also adopt a similar structural setting, that is, the side wall of the second-stage groove 22 is inclined, and the notch width of the second-stage groove 22 is greater than the bottom wall width of the second-stage groove 22. The stamping die quickly withdraws from the second-stage groove 22 after forming the second-stage groove 22, which can also greatly simplify the structure of the stamping die and the stamping process, and avoid the phenomenon of the stamping die being embedded in the explosion-proof valve during the stamping process.

[0049] Optionally, in some other embodiments, the side wall of the first-stage groove 21 may be vertically arranged with respect to the bottom wall of the first-stage groove 21. The closer the angle between the side wall of the first-stage groove 21 and the bottom wall of the first-stage groove 21 is to 90°, the more likely the connection between the side wall of the first-stage groove 21 and the bottom wall of the first-stage groove 21 will be to have stress concentration, and the stress on the notch 20 can be shared to a greater extent, thereby achieving a better buffering effect and preventing the notch 20 from being damaged by welding.

[0050] Similarly, the side wall of the second-stage groove 22 and the bottom wall of the second-stage groove 22 may also be arranged vertically to further enhance the buffering and protection effect of the entire deformation portion 2 on the notch 20 .

[0051] Of course, in some other embodiments, a third-level groove can be set in the deformation portion 2, and the second-level groove 22 can be set on the bottom wall of the third-level groove, so as to further increase the width of the deformation portion 2, and form more structures that are prone to stress concentration on both sides of the notch 20 to protect the notch 20 and prevent the notch 20 from being damaged during the welding process.

[0052] It should be noted that the number of grooves provided on the deformation portion 2 is not specifically limited in the present invention, and can be as follows: Figure 4 , Figure 5 The first-level groove 21 and the second-level groove 22 shown may also be provided with a third-level groove or even a fourth-level groove, as long as they can protect the notch 20 and maintain the normal performance of the explosion-proof valve. Similarly, the specific structure of the first-level groove 21 and the second-level groove 22 is not limited in the utility model. The first-level groove 21 may adopt a method in which the side wall and the bottom wall are inclined, and the second-level groove 22 may adopt a method in which the side wall and the bottom wall are perpendicular, or the first-level groove 21 may adopt a method in which the side wall and the bottom wall are perpendicular, and the second-level groove 22 may adopt a method in which the side wall and the bottom wall are inclined, which also fall within the scope of protection of the utility model.

[0053] Preferably, in this embodiment, the depth h from the top surface of the explosion-proof valve body to the bottom wall of the second-stage groove 22 is not greater than half of the thickness d of the explosion-proof valve body. Specifically in this embodiment, the depth h of the second-stage groove 22 is not greater than half of the thickness d of the explosion-proof valve body, so as to avoid the distance between the first-stage groove 21 and the bottom surface of the explosion-proof valve body being too small, resulting in easy fracture at the first-stage groove 21.

[0054] like Figure 1 As shown, the explosion-proof valve further includes a connecting portion 4, which is connected and arranged between the explosion-proof valve body 1 and the welding portion 3, and the connecting portion 4 is not provided with a notch 20, so that its average thickness is greater than the average thickness of the deformation portion 2. When the connecting portion 4 is subjected to a preset bursting pressure value, it can remain connected between the explosion-proof valve body 1 and the welding portion 3, avoiding the explosion-proof valve body 1 and the welding portion 3 from being separated, moving at a high speed under the action of airflow, and causing damage to surrounding structures or personnel.

[0055] The utility model also provides a top cover assembly, comprising a top cover sheet and the above explosion-proof valve. The top cover sheet has a pressure relief hole, the explosion-proof valve is sealed and arranged in the pressure relief hole, and the welding part 3 of the explosion-proof valve is welded and connected to the top cover sheet.

[0056] Compared with the explosion-proof valve in the prior art, a deformation portion 2 is connected and arranged between the welding portion 3 and the explosion-proof valve body 1, and when the thickness of the deformation portion 2 can be less than the thickness of the explosion-proof valve body 1, during the process of welding and installing the explosion-proof valve, the deformation caused by the welding heat will change from being concentrated at the notch 20 to occurring at the notch 20 and the deformation portion 2, especially at the connection between the first-level groove 21 and the second-level groove 22, thereby greatly reducing the degree of deformation at the notch 20 during the welding process, avoiding the phenomenon that the deeper notch 20 that meets the preset bursting pressure value is subjected to concentrated stress during normal welding, thereby ensuring that the explosion-proof valve can have a sound structure after welding, and can rupture normally when the preset bursting pressure value is reached, thereby achieving the preset explosion-proof effect and preventing welding damage.

[0057] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. Explosion-proof valve, characterized in that: The explosion-proof valve comprises an explosion-proof valve body (1), a deformation portion (2) and a welding portion (3), wherein the welding portion (3) is used for welding and connecting a top cover sheet, the deformation portion (2) is provided with a notch (20) and is connected between the welding portion (3) and the explosion-proof valve body (1), the deformation portion (2) can rupture when subjected to a preset explosion pressure value, and, The deformable portion (2) is provided with a first-level groove (21) and a second-level groove (22); the notch (20) is provided on the bottom wall of the first-level groove (21); the first-level groove (21) is provided on the bottom wall of the second-level groove (22); the bottom wall width of the second-level groove (22) is greater than the notch width of the first-level groove (21); the first-level groove (21) and the second-level groove (22) are used to limit the thickness of the deformable portion (2).

2. The explosion-proof valve according to claim 1, characterized in that: The notch (20) is arranged in the middle of the bottom wall of the first-stage groove (21); and / or, The first-stage groove (21) is arranged in the middle of the bottom wall of the second-stage groove (22).

3. The explosion-proof valve according to claim 1, characterized in that: The side wall of the first-stage groove (21) is arranged obliquely, and the notch width of the first-stage groove (21) is greater than the bottom wall width of the first-stage groove (21); and / or, The side wall of the second-stage groove (22) is arranged obliquely, and the notch width of the second-stage groove (22) is greater than the bottom wall width of the second-stage groove (22).

4. The explosion-proof valve according to claim 1, characterized in that: The side wall of the first-stage groove (21) is arranged perpendicular to the bottom wall of the first-stage groove (21).

5. The explosion-proof valve according to claim 1, characterized in that: The side wall of the second-stage groove (22) is arranged perpendicular to the bottom wall of the second-stage groove (22).

6. The explosion-proof valve according to claim 1, characterized in that: The depth h from the top surface of the explosion-proof valve body (1) to the bottom wall of the second-stage groove (22) is no greater than half the thickness d of the explosion-proof valve body (1).

7. The explosion-proof valve according to claim 1, characterized in that: The deformation portion (2) is also provided with a third-level groove, and the second-level groove (22) is arranged on the bottom wall of the third-level groove.

8. The explosion-proof valve according to claim 1, characterized in that: The explosion-proof valve further comprises a connecting portion (4), wherein the connecting portion (4) is connected between the explosion-proof valve body (1) and the welding portion (3), and the thickness of the connecting portion (4) is greater than the thickness of the deformation portion (2), so that the connecting portion (4) is connected between the explosion-proof valve body (1) and the welding portion (3) when subjected to the preset explosion pressure value.

9. The explosion-proof valve according to any one of claims 1 to 8, characterized in that: The explosion-proof valve is an integrated structure made by stamping.

10. A top cover assembly, characterized in that: It comprises a top cover sheet and an explosion-proof valve according to any one of claims 1 to 9, wherein the top cover sheet has a pressure relief hole, the explosion-proof valve is sealed in the pressure relief hole, and a welding portion (3) of the explosion-proof valve is welded to the top cover sheet.

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