Air tightness detection clamp for battery top cover

Abstract

The utility model relates to an air tightness detection clamp for a battery top cover, the battery top cover is provided with one or more detected parts, and the air tightness detection clamp comprises a first jig and a second jig; the first jig is provided with a first jig surface, and the first jig surface is provided with a first protruding part and a first airflow channel. The second jig is provided with a second jig surface, and the second jig surface is provided with a second protruding part and a second airflow channel. One of the first protruding part and the second protruding part on the two sides of the same detected part is an elastic sealing ring, the other one is a pressure applying part, and the pressure applying part abuts against and presses the elastic sealing ring. Each elastic sealing ring can be compressed, so that the air tightness of a sealing cavity between the elastic sealing ring and the battery top cover is ensured, the influence of the difference of the planeness of the top cover on the compression amount of the elastic sealing ring is reduced, and the accuracy of air tightness detection is improved; therefore, the leak rate of the top cover can be obtained more accurately, and the service life and the performance of the battery can be predicted better.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an airtightness detection fixture for a battery top cover. Background Art

[0002] The shell composed of the top cover and the aluminum shell is an important part of the battery and is a shell with good airtightness. The top cover composed of the pole for transmitting current, the explosion-proof valve for pressure relief and the top cover aluminum sheet is not an integrated molding, so there are inevitably leaks between the components. If the leaks are too large, it will affect whether the battery will leak electrolyte during its service life, affecting the battery performance and product safety performance. Therefore, the reliability of the airtightness test results of the battery top cover is very important. The size of these leaks needs to be tested by the mature helium mass spectrometer leak detector on the market with the aid of a helium detection fixture for leak rate detection.

[0003] In the prior art, the helium detection fixture is mainly composed of a lower mold that supports the top cover and is connected to the helium mass spectrometer leak detector, an O-ring placed between the large surface of the top cover aluminum sheet and the lower mold of the helium detection fixture, and an upper mold pressed on the other side of the top cover to compress the sealing ring in contact with the aluminum sheet. The lower mold and the aluminum sheet form a sealed cavity. The existing upper mold is generally pressed on the edges of the top cover. When the top cover is large or the aluminum sheet is deformed, the compression of the sealing ring will decrease. When the top cover is large or the aluminum sheet is deformed, the upper mold pressed on the edges of the aluminum sheet cannot make the sealing ring reach a sufficient amount of compression. When the top cover is helium-tested, helium passes through the leak between the sealing ring of the helium detection fixture and the aluminum sheet, causing the test to fail, resulting in a misjudgment of the top cover leakage rate, affecting the accuracy of the helium test. How to improve the accuracy of helium detection is a technical problem that needs to be solved in this field. Utility Model Content

[0004] To this end, the utility model provides a battery top cover airtightness detection fixture which improves the accuracy of helium detection.

[0005] In order to solve the above technical problems, the utility model provides an airtightness detection fixture for a battery top cover, wherein the battery top cover has one or more inspected parts, and the airtightness detection fixture comprises a first fixture and a second fixture for respectively clamping on both sides of the battery top cover in a thickness direction;

[0006] The first fixture has a first fixture surface facing the battery top cover, the first fixture surface is provided with a first protrusion around the inspected part, and the first fixture is also provided with a first airflow channel for conveying the inspection gas to one side of the inspected part;

[0007] The second fixture has a second fixture surface facing the battery top cover, the second fixture surface is provided with a second protrusion, and the second fixture is also provided with a second air flow channel for conveying the gas on the other side of the inspected part to the gas detection device;

[0008] Among the first protrusion and the second protrusion on both sides of the same inspected part, one is an elastic sealing ring and the other is a pressure-applying part, and the pressure-applying part contacts and presses the elastic sealing ring.

[0009] Furthermore, the first airflow channel corresponds one-to-one to the inspected part, and the first airflow channel is used to transport the detection gas to one side of the corresponding inspected part, and the second airflow channel corresponds one-to-one to the inspected part, and the second airflow channel is used to transport the gas on the other side of the corresponding inspected part to the gas detection device.

[0010] Furthermore, the first fixture is also provided with a main channel, and the main channel is connected to all the first airflow channels on the first fixture.

[0011] Furthermore, the first jig is also provided with a first sealing ring groove and / or the second jig is also provided with a second sealing ring groove, the first sealing ring groove is used to embed the elastic sealing ring on the first jig, and the second sealing ring groove is used to embed the elastic sealing ring on the second jig.

[0012] Furthermore, the pressure-applying portion and the first fixture are an integral structure and / or the pressure-applying portion and the second fixture are an integral structure.

[0013] Furthermore, the distance between the center of the same inspected part and the inner edge of the corresponding elastic sealing ring is greater than the distance between the center of the same inspected part and the inner edge of the corresponding pressure-applying part; the distance between the center of the same inspected part and the outer edge of the corresponding elastic sealing ring is less than the distance between the center of the same inspected part and the outer edge of the corresponding pressure-applying part.

[0014] Furthermore, the pressure applying portion is a pressure applying ring.

[0015] Further, the first jig is provided with a first avoidance groove and / or the second jig is provided with a second avoidance groove, the first avoidance groove is used to avoid the portion of the inspected part protruding from the first jig side, the first protrusion is provided on the outer circle of the groove of the first avoidance groove, the second avoidance groove is used to avoid the portion of the inspected part protruding from the second jig side, and the second protrusion is provided on the outer circle of the groove of the second avoidance groove.

[0016] Furthermore, the surface of the second fixture faces upward, the second fixture is provided with a top cover limiting groove, the top cover limiting groove is used to support the battery top cover and limit the horizontal movement of the battery top cover, and the second protrusion is arranged at the bottom of the top cover limiting groove.

[0017] Furthermore, the inspected part is the part where the explosion-proof valve is located and / or the part where the pole is located.

[0018] The above technical solution of the utility model has the following advantages compared with the prior art:

[0019] 1) In the battery top cover air tightness detection fixture of the utility model, elastic sealing rings and pressure parts for compressing the elastic sealing rings are respectively arranged on both sides of each inspected part, so that each elastic sealing ring can be compressed, thereby ensuring the air tightness of the sealing cavity between the elastic sealing ring and the battery top cover, reducing the influence of the difference in the flatness of the top cover itself on the compression amount of the elastic sealing ring, and improving the accuracy of air tightness detection; thereby more accurately obtaining the leakage rate of the top cover, and better predicting the service life and performance of the battery;

[0020] 2) The air tightness detection fixture of the battery top cover described in the utility model has a first air flow channel corresponding to the inspected part one by one, and a second air flow channel corresponding to the inspected part one by one, ensuring that there is a test gas on the air inlet side of each inspected part, and each inspected part is independently tested for air tightness, thereby ensuring the accuracy of the battery top cover air tightness detection;

[0021] 3) The air tightness detection fixture of the battery top cover described in the utility model has a main channel on the first fixture, and the detection gas is sent to each first air flow channel through a detection gas supply device and a main channel, so that the connection between the gas detection device and the air tightness detection fixture is simpler;

[0022] 4) The air tightness detection fixture of the battery top cover described in the utility model is provided with a first sealing ring slot and / or a second sealing ring slot for the elastic sealing ring, which is convenient for the installation of the elastic sealing ring on the one hand and for the replacement of the elastic sealing ring on the other hand;

[0023] 5) In the air tightness detection fixture of the battery top cover described in the utility model, the pressure-applying part and the first fixture are an integrated structure and / or the pressure-applying part and the second fixture are an integrated structure. The pressure-applying part is formed at the same time as the first fixture or the second fixture is formed, and there is no need to assemble the pressure-applying part later, so the air tightness detection fixture is easier to manufacture;

[0024] 6) In the air tightness detection fixture of the battery top cover described in the utility model, the width of the elastic sealing ring is smaller than the width of the pressure-applying part. On the one hand, if there is a slight offset between the two, it can also ensure that the pressure-applying part can compress the elastic sealing ring, and the installation position requirements of the elastic sealing ring and the pressure-applying part are reduced. On the other hand, the elastic sealing ring has a larger pressure area, and the compression effect of the elastic sealing ring is better;

[0025] 7) The air tightness detection fixture of the battery top cover described in the utility model, the pressure-applying part is a pressure-applying ring, which can ensure that all positions of the elastic sealing ring are compressed, and the compression effect of the elastic sealing ring is better;

[0026] 8) The air tightness detection fixture of the battery top cover described in the utility model, the first fixture is provided with a first avoidance groove and / or the second fixture is provided with a second avoidance groove, which can be applicable to the air tightness detection of the battery top cover with a protrusion;

[0027] 9) The battery top cover airtightness detection fixture of the utility model positions the battery top cover by setting the top cover limit groove to ensure that the first protrusions, the second protrusions and the inspected part meet the preset position relationship;

[0028] 10) The air tightness detection fixture of the battery top cover described in the utility model is used to detect the explosion-proof valve and / or the pole, and the installation position of the pole and the installation position of the explosion-proof valve can be used to detect the air tightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments of the utility model in combination with the accompanying drawings.

[0030] Figure 1 It is a structural schematic diagram of the air tightness detection fixture of the battery top cover in the utility model;

[0031] Figure 2 It is a structural schematic diagram of the first fixture in the utility model;

[0032] Figure 3 It is a structural schematic diagram of the second fixture in the utility model;

[0033] Figure 4 It is a working schematic diagram of the air tightness detection fixture of the battery top cover in the utility model;

[0034] Figure 5 It is a partial cross-sectional view of the airtightness detection fixture of the battery top cover in the utility model when working.

[0035] Explanation of the reference numerals in the drawings in the specification: 1. battery top cover; 11. inspected part; 2. first fixture; 21. first fixture surface; 22. pressure-applying part; 23. first air flow channel; 24. main channel; 3. second fixture; 31. second fixture surface; 32. elastic sealing ring; 33. second air flow channel; 34. second avoidance groove; 35. top cover limit groove. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0037] See also Figures 1 to 5 As shown, the utility model provides an air tightness detection fixture for a battery top cover.

[0038] The battery top cover 1 has one or more inspected parts 11, and the airtightness detection fixture comprises a first fixture 2 and a second fixture 3 for respectively clamping on both sides of the battery top cover 1 in the thickness direction;

[0039] The first fixture 2 has a first fixture surface 21 facing the battery top cover 1, and the first fixture surface 21 is provided with a first protrusion around the inspected part 11. The first fixture 2 is also provided with a first airflow channel 23 for conveying the inspection gas to one side of the inspected part 11;

[0040] The second fixture 3 has a second fixture surface 31 facing the battery top cover 1, the second fixture surface 31 is provided with a second protrusion, and the second fixture 3 is also provided with a second air flow channel 33 for conveying the gas on the other side of the inspected part 11 to the gas detection device;

[0041] Among the first protrusion and the second protrusion on both sides of the same inspected part 11, one is an elastic sealing ring 32 and the other is a pressure-applying part 22. The pressure-applying part 22 contacts and presses the elastic sealing ring 32, and the elastic sealing ring 32 can be compressed by the pressure-applying part 22, thereby playing a sealing role.

[0042] Each inspected portion 11 has an air inlet side surface and an air outlet side surface facing the first fixture 2 and the second fixture 3 respectively. The detection gas is delivered to the air inlet side of the inspected portion 11, and the gas on the air outlet side of the inspected portion 11 is delivered to the gas detection device. When the inspected portion 11 is not leaking, the gas on the air outlet side of the inspected portion 11 does not contain the detection gas. When the inspected portion 11 is leaking, the gas on the air outlet side of the inspected portion contains the detection gas.

[0043] The detection gas is usually an inert gas, such as helium. The first raised portion is convexly arranged relative to the first fixture surface 21, and the first raised portion corresponds to the air inlet side surface of the inspected portion 11 one by one. When the first fixture 2 contacts the battery top cover 1, the first raised portion contacts the edge of the corresponding air inlet side surface, and the first raised portion surrounds the corresponding air inlet side surface. The second raised portion is convexly arranged relative to the second fixture surface 31, and the second raised portion corresponds to the air outlet side surface one by one. When the second fixture 3 contacts the battery top cover 1, the second raised portion contacts the edge of the corresponding air outlet side surface, and the second raised portion surrounds the corresponding air outlet side surface. The elastic sealing ring 32 can be arranged on the first jig 2 or on the second jig 3, and the pressure-applying portion 22 can be arranged on the first jig 2 or on the second jig 3, as long as it can be ensured that one of the air inlet side surface and the air outlet side surface of each inspected part 11 is in contact with the elastic sealing ring 32 and the other is in contact with the pressure-applying portion 22.

[0044] The first airflow channel 23 is used to deliver the test gas to the air inlet side of each inspected part 11. The second airflow channel 33 is used to deliver the gas on the air outlet side of each inspected part 11 to the gas detection device, and the gas detection device detects whether the test gas content in the gas on the air outlet side of each inspected part 11 meets the requirements. If it meets the requirements, the air tightness of the inspected part 11 meets the standards. If it does not meet the requirements, the air tightness of the inspected part 11 does not meet the standards.

[0045] Through the above technical solution: an elastic sealing ring 32 and a pressure portion 22 for compressing the elastic sealing ring 32 are respectively arranged on both sides of each inspected part 11, so that each elastic sealing ring 32 can be compressed, thereby ensuring the airtightness of the sealing cavity between the elastic sealing ring 32 and the battery top cover, reducing the influence of the difference in the flatness of the top cover itself on the compression amount of the elastic sealing ring 32, and improving the accuracy of airtightness detection; thereby more accurately obtaining the leakage rate of the top cover, and better predicting the service life and performance of the battery.

[0046] In the preferred implementation mode of the present embodiment, the above-mentioned first airflow channel 23 corresponds one-to-one with the above-mentioned inspected part 11, and the above-mentioned first airflow channel 23 is used to transport the detection gas to one side of the corresponding above-mentioned inspected part 11, and the above-mentioned second airflow channel 33 corresponds one-to-one with the above-mentioned inspected part 11, and the above-mentioned second airflow channel 33 is used to transport the gas on the other side of the corresponding above-mentioned inspected part 11 to the above-mentioned gas detection device.

[0047] The first airflow channel 23 has an air inlet port and an air outlet port, the air outlet port of the first airflow channel 23 passes through the first fixture surface 21, and the air outlet port of the first airflow channel 23 faces the air inlet side surface of the corresponding inspected part 11, and the second airflow channel 33 has an air inlet port and an air outlet port, the air inlet port of the second airflow channel 33 passes through the second fixture surface 31, and the air inlet port of the second airflow channel 33 faces the air outlet side surface of the corresponding inspected part 11.

[0048] Through the above technical solution: the first air flow channel 23 corresponds to the inspected part 11 one by one, and the second air flow channel 33 corresponds to the inspected part 11 one by one, ensuring that there is detection gas on one side of each inspected part 11, and each inspected part 11 is subjected to independent air tightness detection, thereby ensuring the accuracy of the battery top cover air tightness detection.

[0049] In other embodiments, all first protrusions may be pressure-applying portions, all second protrusions may be elastic sealing rings, the first airflow channel may not face the inspected portion, the detection gas output by the first airflow channel may enter the inner side of the pressure-applying portion from the outer side of the pressure-applying portion, and the detection gas output by the first airflow channel may diffuse to the air inlet side surfaces of each inspected portion.

[0050] In a preferred implementation manner of the present embodiment, the first fixture 2 is further provided with a main channel 24 , and the main channel 24 is connected to all the first airflow channels 23 on the first fixture 2 .

[0051] The air inlet ports of all the first airflow channels 23 on the same first fixture 2 are connected to the above-mentioned main channel 24, and the above-mentioned main channel 24 is connected to the detection gas supply device. Specifically, the air inlet ports of the first airflow channels 23 are connected to the side wall of the above-mentioned main channel 24, and one end of the main channel 24 is connected to the detection gas supply device.

[0052] Through the above technical solution: a main channel 24 is provided on the first fixture 2, and the detection gas is sent to each first airflow channel 23 through a detection gas supply device and a main channel 24, making the connection between the detection gas supply device and the airtightness detection fixture simpler.

[0053] In other embodiments, the first fixture may not be provided with the main channel, and each first air flow channel is directly connected to the detection gas supply device.

[0054] In a preferred implementation manner of the present embodiment, the second fixture 3 is further provided with a second sealing ring groove, and the second sealing ring groove is used for embedding the elastic sealing ring 32 on the second fixture 3 .

[0055] In this embodiment, the first protrusions are all configured as pressure portions 22, the second protrusions are all configured as elastic sealing rings 32, the second fixture 3 is provided with second sealing ring grooves corresponding to the elastic sealing rings 32, and the elastic sealing rings 32 are embedded in the corresponding second sealing ring grooves.

[0056] According to the above technical solution, a second sealing ring groove is provided for the elastic sealing ring 32 , which is convenient for installing the elastic sealing ring 32 on the one hand, and for replacing the elastic sealing ring 32 on the other hand.

[0057] In other embodiments, the first protrusions are all configured as elastic sealing rings, the second protrusions are all configured as pressure-applying parts, the first jig is provided with sealing ring grooves corresponding one to one with the elastic sealing rings, or part of the first protrusions are elastic sealing rings, part of the first protrusions are pressure-applying parts, part of the second protrusions are elastic sealing rings, and part of the second protrusions are pressure-applying parts. In this case, the first jig and the second jig are both provided with sealing ring grooves corresponding one to one with the elastic sealing rings.

[0058] In a preferred implementation manner of this embodiment, the pressure applying portion 22 and the first fixture 2 are an integral structure.

[0059] In this embodiment, the first protrusions are all configured as pressure-applying portions 22 , and the second protrusions are all configured as elastic sealing rings 32 , that is, all the pressure-applying portions 22 are disposed on the first fixture 2 and are integrally formed.

[0060] Through the above technical solution: the pressure-applying part 22 and the first fixture 2 are an integrated structure, and the pressure-applying part 22 is formed while the first fixture 2 is formed. There is no need to assemble the pressure-applying part 22 later, and the airtightness detection fixture is easier to manufacture.

[0061] In other embodiments, the first raised portions are all configured as elastic sealing rings, and the second raised portions are all configured as pressure-applying portions, and the pressure-applying portions and the second fixture are an integral structure, or part of the first raised portions are elastic sealing rings, part of the first raised portions are pressure-applying portions, part of the second raised portions are elastic sealing rings, and part of the second raised portions are pressure-applying portions. In this case, part of the pressure-applying portions are integrally formed with the first fixture, and part of the pressure-applying portions are integrally formed with the second fixture.

[0062] In the preferred implementation mode of the present embodiment, the distance between the center of the same above-mentioned inspected part 11 and the inner edge of the corresponding above-mentioned elastic sealing ring 32 is greater than the distance between the inner edge of the corresponding above-mentioned pressure-applying part 22; the distance between the center of the same above-mentioned inspected part 11 and the outer edge of the corresponding above-mentioned elastic sealing ring 32 is less than the distance between the outer edge of the corresponding above-mentioned pressure-applying part 22.

[0063] Each inspected part 11 and the center of the corresponding elastic sealing ring 32 and the center of the corresponding pressure-applying part 22 are located on the same straight line, the elastic sealing ring 32 is arranged around the center, the elastic sealing ring 32 has an inner edge facing the center and an outer edge facing away from the center, the distance between the inner edge and the outer edge of the elastic sealing ring 32 is the width of the elastic sealing ring 32, and the distance between the inner edge and the center of the elastic sealing ring 32 is the inner diameter of the elastic sealing ring 32. The pressure-applying part 22 is arranged around the center, the pressure-applying part 22 has an inner edge facing the center and an outer edge facing away from the center, the distance between the inner edge and the outer edge of the pressure-applying part 22 is the width of the pressure-applying part 22, the distance between the inner edge and the center of the pressure-applying part 22 is the inner diameter of the pressure-applying part, the inner diameter of the pressure-applying part 22 is smaller than the inner diameter of the elastic sealing ring 32, and the width of the pressure-applying part 22 is larger than the width of the elastic sealing ring 32.

[0064] Through the above technical solution: the width of the elastic sealing ring 32 is smaller than the width of the pressure-applying portion 22. On the one hand, if there is a slight offset between the two, it can also ensure that the pressure-applying portion 22 can compress the elastic sealing ring 32, and the requirements for the installation positions of the elastic sealing ring 32 and the pressure-applying portion 22 are reduced. On the other hand, the force-bearing area of ​​the elastic sealing ring 32 is larger, and the compression effect of the elastic sealing ring 32 is better.

[0065] In other embodiments, the distance between the center of the same inspected part and the inner edge of the corresponding elastic sealing ring may be smaller than the distance between the center of the same inspected part 11 and the outer edge of the corresponding elastic sealing ring may be larger than the distance between the center of the same inspected part 11 and the outer edge of the corresponding elastic sealing ring, the inner diameter of the pressure-applying part may be larger than the inner diameter of the elastic sealing ring, and the width of the pressure-applying part may be larger than the width of the elastic sealing ring.

[0066] In a preferred implementation of this embodiment, the pressure applying portion 22 is a pressure applying ring.

[0067] The pressure applying portion 22 is an annular structure surrounding the center.

[0068] Through the above technical solution: the pressure-applying portion 22 is a pressure-applying ring, which can ensure that each position of the elastic sealing ring 32 is evenly compressed, and the compression effect of the elastic sealing ring 32 is better.

[0069] In other embodiments, the pressure-applying portion may be a plurality of pressure-applying points arranged at intervals along the circumferential direction, and the distances between the plurality of pressure-applying points cannot be too far to ensure that the pressure-applying portion can compress every part of the elastic sealing ring.

[0070] In a preferred implementation manner of the present embodiment, the second fixture 3 is provided with a second avoidance groove 34 for avoiding the portion of the inspected part 11 protruding from the second fixture side, and the second protrusion is provided on the outer circle of the notch of the second avoidance groove 34 .

[0071] In this embodiment, the protrusion height of the inspected part 11 toward the second jig side of the top cover is relatively high. At this time, a second avoidance groove 34 needs to be provided on the second jig 3 to prevent the problem that the battery top cover cannot contact the second protrusion due to the protrusion of the inspected part 11.

[0072] Through the above technical solution: the second fixture 3 is provided with a second avoidance groove 34, which can be suitable for the airtightness detection of the battery top cover with a protrusion.

[0073] In other embodiments, the first fixture may be provided with a first avoidance groove for avoiding a portion of the inspected part protruding from a side of the first fixture, and the first protrusion is provided on an outer circle of a notch of the first avoidance groove.

[0074] In the preferred implementation mode of the present embodiment, the second fixture surface 31 faces upward, the second fixture 3 is provided with a top cover limiting groove 35, the top cover limiting groove 35 is used to support the battery top cover 1 and limit the horizontal movement of the battery top cover 1, and the second protrusion is provided at the bottom of the top cover limiting groove 35.

[0075] In this embodiment, the second fixture surface 31 faces upward. When the battery top cover is tested for air tightness, the battery top cover is first placed in the top cover limiting groove 35 of the second fixture surface 31 so that the battery top cover remains in the set position, and then the first fixture 2 is pressed downward on the top of the battery top cover.

[0076] Through the above technical solution: by setting the top cover limiting groove 35, the battery top cover is positioned to ensure that the first protrusions, the second protrusions and the inspected part 11 meet the preset position relationship.

[0077] In other embodiments, the surface of the first fixture faces upward, the first fixture is provided with a top cover limiting groove, and the first protrusion is provided at the bottom of the top cover limiting groove.

[0078] In the preferred implementation mode of this embodiment, the inspected part 11 is the part where the explosion-proof valve is located and the part where the pole is located.

[0079] In this embodiment, the battery top cover 1 is provided with an explosion-proof valve and a pole, and the explosion-proof valve and the pole are not an integral structure with the battery top cover, because there may be leakage between the explosion-proof valve and the battery top cover, and there may also be leakage between the pole and the battery top cover.

[0080] Through the above technical solution: the inspected part 11 is the part where the explosion-proof valve is located and / or the part where the pole is located, and the air tightness detection can be performed on the installation position of the pole and the installation position of the explosion-proof valve.

[0081] In other embodiments, the inspected parts 11 may all be parts where explosion-proof valves are located, or parts where poles are located.

[0082] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention of the utility model.

Claims

1. A battery top cover airtightness testing fixture, the battery top cover (1) having one or more inspected parts (11), characterized in that: The airtightness detection fixture comprises a first fixture (2) and a second fixture (3) for respectively clamping two sides of the battery top cover (1) in the thickness direction; The first jig (2) has a first jig surface (21) facing the battery top cover (1), the first jig surface (21) is provided with a first protrusion around the inspected part (11), and the first jig (2) is further provided with a first air flow channel (23) for conveying a detection gas to one side of the inspected part (11); The second jig (3) has a second jig surface (31) facing the battery top cover (1), the second jig surface (31) is provided with a second protrusion, and the second jig (3) is also provided with a second air flow channel (33) for conveying the gas on the other side of the inspected part (11) to the gas detection device; One of the first protruding portion and the second protruding portion on both sides of the same inspected part (11) is an elastic sealing ring (32) and the other is a pressure-applying portion (22), and the pressure-applying portion (22) contacts and presses the elastic sealing ring (32).

2. The airtightness detection fixture according to claim 1, characterized in that: The first airflow channel (23) corresponds to the inspected part (11) on a one-to-one basis, and the first airflow channel (23) is used to transport the detection gas to one side of the corresponding inspected part (11), and the second airflow channel (33) corresponds to the inspected part (11) on a one-to-one basis, and the second airflow channel (33) is used to transport the gas on the other side of the corresponding inspected part (11) to the gas detection device.

3. The airtightness detection fixture according to claim 2, characterized in that: The first fixture (2) is also provided with a main channel (24), wherein the main channel (24) is connected to all first airflow channels (23) on the first fixture (2).

4. The airtightness detection fixture according to claim 1, characterized in that: The first jig (2) is further provided with a first sealing ring retaining groove and / or the second jig (3) is further provided with a second sealing ring retaining groove, the first sealing ring retaining groove being used for embedding the elastic sealing ring (32) on the first jig (2), and the second sealing ring retaining groove being used for embedding the elastic sealing ring (32) on the second jig (3).

5. The airtightness detection fixture according to claim 1, characterized in that: The pressure-applying portion (22) and the first fixture (2) are an integral structure and / or the pressure-applying portion (22) and the second fixture (3) are an integral structure.

6. The airtightness testing fixture according to claim 1, characterized in that: The distance between the center of the same inspected part (11) and the inner edge of the corresponding elastic sealing ring (32) is greater than the distance between the center of the same inspected part (11) and the inner edge of the corresponding pressure-applying part (22); and the distance between the center of the same inspected part (11) and the outer edge of the corresponding elastic sealing ring (32) is less than the distance between the center of the same inspected part (11) and the outer edge of the corresponding pressure-applying part (22).

7. The airtightness testing fixture according to claim 1, characterized in that: The pressure applying portion (22) is a pressure applying ring.

8. The airtightness testing fixture according to claim 1, characterized in that: The first jig (2) is provided with a first avoidance groove and / or the second jig (3) is provided with a second avoidance groove (34), the first avoidance groove is used to avoid the portion of the inspected part (11) protruding from the first jig side, the first protrusion is provided on the outer circle of the notch of the first avoidance groove, the second avoidance groove (34) is used to avoid the portion of the inspected part (11) protruding from the second jig side, and the second protrusion is provided on the outer circle of the notch of the second avoidance groove (34).

9. The airtightness testing fixture according to claim 1, characterized in that: The second fixture surface (31) faces upwards, the second fixture (3) is provided with a top cover limiting groove (35), the top cover limiting groove (35) is used to support the battery top cover (1) and limit the horizontal movement of the battery top cover (1), and the second protrusion is provided at the bottom of the top cover limiting groove (35).

10. The airtightness testing fixture according to claim 1, characterized in that: The inspected part (11) is the part where the explosion-proof valve is located and / or the part where the pole is located.

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