Airtightness detection system and method and battery manufacturing production line

Abstract

The invention relates to an airtightness detection system and method and a battery manufacturing production line. The air tightness detection system is used for detecting the air tightness of a to-be-detected product, the to-be-detected product is provided with an inner cavity, a first air hole and a third air hole, the first air hole and the third air hole are communicated with the inner cavity, the air tightness detection system has an inflation mode and a circulation mode, and the air tightness detection system comprises an air source assembly which comprises a tracing air source, and the tracing air source is communicated with the first air hole; the circulating assembly communicates with the first air hole and the third air hole; when the airtightness detection system is in an inflation mode, the tracer gas source inflates tracer gas into an inner cavity of the to-be-detected product, and the circulation assembly is closed; when the airtightness detection system is in a circulation mode, the circulation assembly is used for circulating gas output by the third gas hole into the inner cavity through the first gas hole. The combination of the inflation mode and the circulation mode can reduce the possibility that the gas in the inner cavity diffuses to the outside in the mixing process of the tracer gas and the air, and reduces the waste of the tracer gas.

Description

[0001] This application is a divisional application of the Chinese invention patent application entitled “Airtightness Detection System and Battery Manufacturing Production Line” filed by the applicant on October 18, 2023, with application number 202311348346.6. Technical Field

[0002] The present application relates to the field of airtightness detection technology, and in particular to an airtightness detection system, method and battery manufacturing production line. Background Art

[0003] In the manufacturing process of a product to be tested that has a high requirement for air tightness, it is necessary to conduct an air tightness test on the product to be tested before it leaves the factory to determine whether the air tightness of the product to be tested is qualified.

[0004] Before testing, it is necessary to fill the inner cavity of the product to be tested with tracer gas, and replace at least part of the air in the inner cavity of the product to be tested with the tracer gas. During testing, the amount of tracer gas leaking from the outer surface of the product to be tested is detected by the detection device, which can be used as a basis for judging the airtightness of the product to be tested. However, in the related art, there is a waste of tracer gas. Summary of the invention

[0005] In view of the above problems, the present application provides an airtightness detection system, method and battery manufacturing production line, which can alleviate the problem of waste in filling tracer gas.

[0006] In one aspect of the present application, an airtightness detection system is provided for detecting the airtightness of a product to be tested, wherein the product to be tested has an inner cavity and a first air hole and a third air hole both connected to the inner cavity, the airtightness detection system has an inflation mode and a circulation mode, and the airtightness detection system includes:

[0007] The gas source assembly includes a tracer gas source, the tracer gas source is connected to the first gas hole;

[0008] A circulation component, connecting the first air hole and the third air hole;

[0009] Among them, when the airtight detection system is in the inflation mode, the tracer gas source fills the inner cavity of the product to be tested with tracer gas, and the circulation component is closed; when the airtight detection system is in the circulation mode, the circulation component is used to circulate the gas output by the third air hole into the inner cavity through the first air hole.

[0010] In the present application, when in the inflation mode, the amount of tracer gas in the inner cavity can be increased during the process of filling the inner cavity with tracer gas. When the circulation component is started, the tracer gas and air circulate in the circulation component and the inner cavity only under the action of the circulation component, so that the tracer gas and the air can be fully mixed. Then, during the subsequent air tightness test, the gas overflowing to the surface of the product to be tested is evenly distributed with tracer gas and can be sensitively detected by the detection device. In addition, the setting of the circulation component can also reduce the possibility of the gas in the inner cavity diffusing to the outside during the mixing of the tracer gas and the air, thereby reducing the waste of tracer gas.

[0011] In some embodiments of the present application, when the gas pressure in the inner cavity reaches the inflation threshold, the tracer gas source stops inflating the inner cavity.

[0012] The inflation threshold refers to the pressure value at which the gas in the inner cavity has a reasonable leakage rate. When the air pressure in the inner cavity reaches the inflation threshold, the tracer gas source stops inflating the inner cavity, and the inner cavity of the product to be tested is tested for air tightness at this air pressure, and the tracer gas leaked to the surface of the product to be tested is captured by the detection device.

[0013] In some embodiments of the present application, the product to be tested further has a second air hole communicating with the inner cavity;

[0014] The gas source assembly also includes a pressure regulating valve, which includes a pressure regulating body and a pressure detection unit. The pressure regulating body is connected between the tracer gas source and the first air hole. The pressure detection unit is arranged on the pressure regulating body and connected with the second air hole.

[0015] When the airtight detection system is in the inflation mode, the pressure regulating body is opened, the air pressure detection unit detects the air pressure at the second air hole and feeds back to the pressure regulating body, and the pressure regulating body is configured to increase its own opening when the air pressure at the second air hole is less than or equal to a preset air pressure threshold, and to decrease its own opening when the air pressure at the second air hole is greater than the preset air pressure threshold; the preset air pressure threshold is less than the inflation threshold.

[0016] Since the air pressure detection unit is connected to the second air hole, and the air pressure of the second air hole is equal to the air pressure in the inner cavity, the air pressure at the second air hole detected by the air pressure detection unit can truly reflect the air pressure in the inner cavity. In this case, the pressure regulating body can accurately adjust its opening according to the air pressure at the second air hole, and increase the opening when the air pressure at the second air hole is less than or equal to the preset air pressure threshold, which is conducive to improving the charging efficiency and replacement efficiency of the tracer gas, and then the air tightness detection efficiency is also improved.

[0017] In some embodiments of the present application, the air pressure detection unit is disposed at the end of the product to be tested.

[0018] Since the air pressure detection unit is arranged at the end of the product to be tested, it is close to the product to be tested, which can facilitate improving the accuracy of the detection.

[0019] In some embodiments of the present application, the airtightness detection system further includes an air extraction component, which is connected to the third air hole;

[0020] When the airtightness detection system is in the negative pressure extraction mode, the air extraction component extracts part of the gas in the inner cavity of the product to be tested, and the circulation component is closed;

[0021] The airtight detection system can be in inflation mode and negative pressure extraction mode at the same time before the air pressure in the inner cavity reaches a preset air pressure threshold. When the air pressure in the inner cavity reaches the preset air pressure threshold, the extraction component stops working and the tracer air source inflates until the air pressure in the inner cavity reaches the inflation threshold.

[0022] When the airtightness detection system is in the inflation mode, before the air pressure in the inner cavity reaches the preset air pressure threshold, the air extraction component in the airtightness detection system works, so that the tracer gas in the tracer gas source can automatically flow into the inner cavity to increase the amount of tracer gas in the inner cavity, which is convenient for subsequent detection devices to capture. On the other hand, the operation of the air extraction component can also accelerate the speed and uniformity of the mixing of tracer gas and air. The more uniform the mixture of tracer gas and air, the more efficient and accurate the subsequent detection device will be in detecting airtightness.

[0023] When the air pressure in the inner cavity reaches the preset air pressure threshold, the suction assembly is turned off. At this time, the tracer gas source continues to fill the inner cavity with tracer gas to further increase the amount of tracer gas in the inner cavity until the air pressure in the inner cavity reaches the inflation threshold. It can be understood that when the air pressure in the inner cavity reaches the preset air pressure threshold, the suction assembly is turned off, which can reduce the discharge of gas in the inner cavity, so that the air pressure in the inner cavity can quickly rise to the inflation threshold, with a higher inflation efficiency.

[0024] In some embodiments of the present application, the airtight detection system further includes an adsorption component;

[0025] When the airtightness detection system is in the inflation mode and the negative pressure extraction mode at the same time, and the air pressure in the inner cavity is negative pressure, the adsorption component is used to adsorb the weak strength part of the product to be tested.

[0026] Since the mechanical strength of the weak part is relatively weak, when the inner cavity is under negative pressure, the weak part is easily deformed under the action of atmospheric pressure, causing the product to be unqualified. By setting up an adsorption component, when the inner cavity is under negative pressure, the adsorption force of the adsorption component can at least offset part of the force of atmospheric pressure, and the risk of deformation of the weak part is reduced. Afterwards, when the air pressure in the inner cavity rises to at least equal to the atmospheric pressure, the risk of deformation of the weak part due to atmospheric pressure drops sharply, and at this time, the adsorption component can be revoked. It can be seen that the setting of the adsorption component can reduce the risk of deformation of the product to be tested when the suction component is working, which is beneficial to improving the reliability of airtightness detection.

[0027] In some embodiments of the present application, the adsorption assembly includes a vacuum adsorption component, and the vacuum adsorption component is used to vacuum adsorb the weak strength part of the product to be tested.

[0028] The vacuum adsorption method is simple and corresponds to the negative pressure environment of the inner cavity, which is more conducive to suppressing the deformation of weak parts.

[0029] In some embodiments of the present application, the vacuum suction member includes a substrate and a vacuum suction cup, and the vacuum suction cup is disposed on one side of the substrate.

[0030] The vacuum suction cup not only has strong suction force, but also is not easy to damage the weak parts when it comes into contact with them.

[0031] In some embodiments of the present application, when there are multiple vacuum suction cups, all of the vacuum suction cups are used to jointly adsorb the same weak strength portion; or, each vacuum suction cup adsorbs its corresponding weak strength portion one by one.

[0032] Providing a plurality of vacuum suction cups can further increase the suction force.

[0033] In some embodiments of the present application, the airtightness detection system further includes a detection device, which is located outside the product to be tested and is used to detect the amount of tracer gas leaked from the surface of the product to be tested after the circulation mode.

[0034] Since the detection device is arranged outside the product to be detected and the detection is performed after the circulation mode, the detection accuracy is higher.

[0035] In another aspect of the present application, a battery manufacturing production line is provided, which includes any one of the above

[0036] An airtightness detection system of an embodiment.

[0037] Another aspect of the present application further provides an airtightness detection method for detecting the airtightness of a product to be tested, comprising:

[0038] Filling the inner cavity of the product to be tested with tracer gas through the first air hole of the product to be tested, and simultaneously extracting part of the gas in the inner cavity of the product to be tested through the third air hole of the product to be tested;

[0039] When the air pressure in the inner cavity reaches a preset air pressure threshold, the extraction of part of the gas is stopped;

[0040] When the air pressure in the inner cavity reaches the inflation threshold, the injection of the tracer gas is stopped, and the gas output from the third air hole is circulated into the inner cavity through the first air hole;

[0041] Detect the amount of tracer gas leaking from the surface of the product to be tested.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0044] FIG1 is a schematic diagram of the structure of an airtightness detection system in one or more embodiments of the present application.

[0045] FIG. 2 is an exploded view of an adsorption assembly and a product to be tested in one or more embodiments of the present application.

[0046] Figure Number:

[0047] 100. Airtightness detection system;

[0048] 10. Air source assembly; 20. Air extraction assembly; 30. Adsorption assembly; 40. Circulation assembly; 50. Pressure measuring piece; 60. Controller;

[0049] 11. Pressure regulating valve; 111. Pressure regulating body; 112. Air pressure detection unit; 12. Tracer gas source; 13. Tracer valve; 14. Tracer tube; 15. Air source; 16. Air tube; 17. Air valve; 18. Connecting tube; 19. Pressure measuring tube;

[0050] 21. Air pump; 22. Air pipe; 23. Air valve;

[0051] 31. substrate; 32. vacuum chuck;

[0052] 41. Circulation pump; 42. Circulation pipe; 43. Circulation valve;

[0053] 2000, product to be tested; 2100, first air hole; 2200, second air hole; 2300, third air hole; 2400, weak part; 2500, inner cavity. DETAILED DESCRIPTION

[0054] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0055] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0056] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0058] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0059] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0060] In the related art, an airtightness detection system is usually used to detect the airtightness of the product to be tested, so as to provide a basis for judging the airtightness of the product to be tested. In the actual detection process, it is necessary to introduce a tracer gas into the inner cavity of the product to be tested, and the tracer gas replaces at least part of the air in the inner cavity of the product to be tested. Then, the amount of the tracer gas leaked from the surface of the product to be tested is detected by the detection device, and the airtightness of the product to be tested can be judged. It can be understood that since the main component of the gas in the product to be tested is the tracer gas after the tracer gas replaces at least part of the air, the more the amount of tracer gas leaked, the worse the airtightness of the product to be tested, and vice versa, the better the airtightness of the product to be tested. However, in the related art, the charging efficiency of the tracer gas and the replacement efficiency of the air in the product to be tested are low, resulting in a decrease in the airtightness detection efficiency.

[0061] Among them, the main reason for the low charging efficiency and replacement efficiency of the tracer gas is that in the airtightness detection system, the pressure regulating valve arranged between the tracer gas source and the product to be tested is located at the end of the tracer gas source and is far away from the product to be tested, and the air pressure detection unit on the pressure regulating valve is located outside the product to be tested and is used to detect the air pressure on the input path of the tracer gas input into the product to be tested. As the tracer gas flows on the input path of the tracer gas, the air pressure of the tracer gas gradually decreases. Therefore, when the tracer gas in the inner cavity of the product to be tested does not reach the charging threshold, the air pressure on the input path of the tracer gas is usually greater than the air pressure in the inner cavity of the product to be tested.

[0062] It is not accurate for the air pressure detection unit to use the air pressure on the input path of the tracer gas as the air pressure in the product to be tested. When the air pressure detection unit feeds back the air pressure on the input path of the tracer gas detected to the pressure regulating body, and the air pressure reaches the preset air pressure threshold, the pressure regulating body mistakenly believes that the air pressure in the inner cavity of the product to be tested has also reached the preset air pressure threshold, and then reduces its own opening to reduce the air flow of the tracer gas input into the product to be tested. However, at this time, the air pressure in the inner cavity of the product to be tested is actually less than the preset air pressure threshold. In this case, the action of the pressure regulating body to reduce its own opening will lead to a reduction in the air flow of the tracer gas entering the inner cavity of the product to be tested, and the inflation efficiency of the tracer gas and the replacement efficiency of the replaced air will be reduced, and the air tightness detection efficiency will also decrease accordingly.

[0063] In order to alleviate the problem of low inflation efficiency and replacement efficiency of tracer gas, the present application provides a new airtight detection system, in which the product to be tested has an inner cavity and a first air hole and a second air hole both connected to the inner cavity, the pressure regulating body is connected between the tracer gas source and the first air hole, and the air pressure detection unit is connected to the second air hole.

[0064] In such an embodiment, the tracer gas of the tracer gas source passes through the pressure regulating body and the first air hole in sequence and enters the inner cavity of the product to be tested. The air pressure at the second air hole is consistent with the air pressure in the inner cavity of the product to be tested. Therefore, the air pressure at the second air hole detected by the air pressure detection unit is the air pressure in the inner cavity of the product to be tested, so that the air pressure detection unit can truly feedback the air pressure in the inner cavity of the product to be tested. When the air pressure at the second air hole fed back by the air pressure detection unit is greater than the preset air pressure threshold, the pressure regulating body can truly and accurately judge that the air pressure in the product to be tested has also reached the preset air pressure threshold, and then reduce its own opening to reduce the air flow of the tracer gas input.

[0065] It can be seen that under the design of the present application, the air pressure detection unit can truly feed back the air pressure in the inner cavity of the product to be tested to the pressure regulating body, so that the pressure regulating body can accurately reduce its own opening when the air pressure at the second air hole is greater than the preset air pressure threshold. In this way, the charging efficiency and replacement efficiency of the tracer gas are improved, and the detection efficiency of the airtight detection system is also improved.

[0066] Please refer to FIG. 1 , which is a schematic diagram of the structure of an airtightness detection system 100 in one or more embodiments of the present application.

[0067] In the first aspect, the embodiment of the present application provides an airtightness detection system 100, which is used to perform airtightness detection on a product 2000 to be tested. Among them, the product 2000 to be tested can be but is not limited to a battery. The product 2000 to be tested can also be a camera, a lamp, and other products that require airtightness. For the convenience of explanation, the following embodiments are all described by taking the product 2000 to be tested as a battery as an example. If the airtightness of the battery is low, external water vapor can easily enter the battery and affect the operation of the battery. If the airtightness of the battery is high, it is difficult for external water vapor to enter the battery, and the reliability of the battery operation is high.

[0068] The product to be tested 2000 has an inner cavity 2500 and a first air hole 2100 and a second air hole 2200 both connected to the inner cavity 2500. The airtight detection system 100 has an inflation mode. The airtight detection system 100 includes an air source assembly 10. The air source assembly 10 includes a pressure regulating valve 11 and a tracer air source 12. The pressure regulating valve 11 includes a pressure regulating body 111 and an air pressure detection unit 112. The pressure regulating body 111 is connected between the tracer air source 12 and the first air hole 2100. The air pressure detection unit 112 is arranged on the pressure regulating body 111 and is connected to the second air hole 2200. When the airtight detection system 100 is in the inflation mode, the pressure regulating body 111 is opened, the air pressure detection unit 112 detects the air pressure at the second air hole 2200 and feeds back to the pressure regulating body 111. The pressure regulating body 111 is configured to reduce its own opening when the air pressure at the second air hole 2200 is greater than a preset air pressure threshold.

[0069] The tracer gas source 12 can be a hydrogen source, a helium source, etc. When the tracer gas source 12 is a hydrogen source, the tracer gas is hydrogen. When the tracer gas source 12 is a helium source, the tracer gas is helium. A detection device capable of sensing the tracer gas is provided in the airtightness detection system 100. The detection device is located outside the product to be tested 2000, and is used to sense the amount of tracer gas overflowing from the product to be tested 2000 to the surface. If the amount of tracer gas sensed by the detection device is large, it means that the airtightness of the product to be tested 2000 is poor. Otherwise, it means that the airtightness of the product to be tested 2000 is excellent. The detection device and the way in which the detection device senses the amount of tracer gas are conventional technologies in the art, so they will not be described here.

[0070] The gas filling mode refers to a mode in which the tracer gas source 12 fills the inner cavity 2500 of the product to be tested 2000 with tracer gas. In the process of filling the inner cavity 2500 with tracer gas, the amount of tracer gas in the inner cavity 2500 can be increased, so that when the gas of the product to be tested 2000 leaks later, a large amount of tracer gas is carried in the gas and can be captured by the detection device. The more tracer gas the tracer gas source 12 fills into the inner cavity 2500, the greater the amount of tracer gas in the inner cavity 2500, and the higher the accuracy and sensitivity of the subsequent detection device.

[0071] Specifically, the tracer gas source 12 itself may have a pressure far greater than the air pressure in the inner cavity 2500, and the tracer gas source 12 may fill the inner cavity 2500 of the product 2000 to be tested with tracer gas under the action of its own pressure. Alternatively, an air pump may be provided in the gas source assembly 10, and the tracer gas may be filled into the inner cavity 2500 of the product 2000 to be tested under the action of the air pump. Alternatively, part of the gas in the inner cavity 2500 may be extracted to form a negative pressure in the inner cavity 2500, and then the tracer gas may flow into the inner cavity 2500 under the action of the negative pressure. Of course, the way in which the tracer gas source 12 fills the inner cavity 2500 with tracer gas is not limited to the above-mentioned ways, and may also be other ways, which are not specifically limited here.

[0072] The pressure regulating body 111 is opened, which means that the opening of the pressure regulating body 111 is greater than 0, and the pressure regulating body 111 is closed, which means that the opening of the pressure regulating body 111 is 0. When in the inflation mode, the pressure regulating body 111 is always kept open.

[0073] The internal space between the air pressure detection unit 112 and the pressure regulating body 111 is not connected, so the tracer gas will not affect the air pressure detected by the air pressure detection unit 112 when passing through the pressure regulating body 111. Specifically, the air pressure detection unit 112 is electrically connected to the pressure regulating body 111, and the air pressure detection unit 112 feeds back the air pressure at the second air hole 2200 to the pressure regulating body 111. The pressure regulating body 111 adjusts its opening according to the air pressure fed back by the air pressure detection unit 112 to change the gas flow rate of the input tracer gas.

[0074] The air pressure at the first air hole 2100 and the second air hole 2200 is consistent with the air pressure in the inner cavity 2500. The air pressure at the second air hole 2200 detected by the air pressure detection unit 112 is the air pressure in the inner cavity 2500. Before the detection device starts to detect, the air pressure in the inner cavity 2500 should be increased to the inflation threshold. The inflation threshold refers to the air pressure value at which the gas in the inner cavity 2500 has a reasonable leakage rate. When the air pressure in the inner cavity 2500 reaches the inflation threshold, the tracer gas source 12 stops inflating the inner cavity 2500, and the inner cavity 2500 of the product to be tested 2000 is tested for air tightness at this air pressure, and the tracer gas leaked to the surface of the product to be tested 2000 is captured by the detection device. The preset air pressure threshold refers to an air pressure value that is less than but close to the inflation threshold. The preset air pressure threshold and the inflation threshold are both greater than the atmospheric pressure.

[0075] In order to quickly increase the air pressure in the inner cavity 2500 to the inflation threshold, when the air pressure in the inner cavity 2500 is less than or equal to the preset air pressure threshold, the pressure regulating body 111 increases the opening and increases the gas flow rate of the charged tracer gas, so as to improve the inflation efficiency. When the air pressure in the inner cavity 2500 is greater than the preset air pressure threshold, the pressure regulating body 111 decreases the opening and reduces the gas flow rate of the charged tracer gas, so as to reduce the possibility of excessive pressure in the inner cavity 2500 caused by over-inflation.

[0076] Therefore, in actual operation, when the air pressure fed back to the pressure regulating body 111 by the air pressure detection unit 112 is less than or equal to the preset air pressure threshold, the pressure regulating body 111 increases its opening. When the air pressure fed back to the pressure regulating body 111 by the air pressure detection unit 112 is greater than the preset air pressure threshold, the pressure regulating body 111 decreases its opening.

[0077] In the related art, the product to be tested 2000 is only provided with the first air hole 2100, and the pressure regulating valve 11 is located on the input path of the tracer gas input into the product to be tested 2000 and is far away from the product to be tested 2000. As the tracer gas flows on the input path of the tracer gas, the pressure of the tracer gas gradually decreases. Therefore, when the tracer gas in the inner cavity 2500 of the product to be tested 2000 does not reach the inflation threshold, the pressure on the input path of the tracer gas is usually greater than the pressure in the inner cavity 2500 of the product to be tested 2000. Therefore, it is not accurate for the air pressure detection unit 112 to use the detected pressure on the input path of the tracer gas as the air pressure in the product to be tested 2000, which will cause the pressure regulating body 111 to mistakenly believe that the air pressure in the product to be tested 2000 is relatively large and has also reached the preset air pressure threshold, and then reduce its own opening. This will result in a reduction in the amount of tracer gas in the product 2000 to be tested, a reduction in both the charging efficiency and the replacement efficiency of the tracer gas, and a reduction in the efficiency of airtightness detection.

[0078] In the present application, since the air pressure detection unit 112 is connected to the second air hole 2200, and the air pressure of the second air hole 2200 is equal to the air pressure in the inner cavity 2500, the air pressure at the second air hole 2200 detected by the air pressure detection unit 112 can truly reflect the air pressure in the inner cavity 2500. In this case, the pressure regulating body 111 can accurately adjust its opening according to the air pressure at the second air hole 2200, and increase the opening when the air pressure at the second air hole 2200 is less than or equal to the preset air pressure threshold, which is conducive to improving the charging efficiency and replacement efficiency of the tracer gas, and then, the air tightness detection efficiency is also improved.

[0079] It can be understood that in the present application, the air pressure detection unit 112 should be arranged at the end of the product 2000 to be tested and close to the product 2000 to be tested, so as to improve the accuracy of the detection.

[0080] In one or more embodiments of the present application, the gas source assembly 10 also includes a tracer valve 13 and a tracer tube 14. The tracer tube 14 is connected between the tracer gas source 12 and the pressure regulating body 111, and the tracer valve 13 is connected to the tracer tube 14. When the airtight detection system 100 is in the inflation mode, the tracer valve 13 is opened.

[0081] The tracer valve 13 may be a mechanical valve or a solenoid valve, and may be specifically configured as required.

[0082] When in the inflation mode, the tracer valve 13 and the pressure regulating body 111 are both opened, and the tracer gas from the tracer gas source 12 enters the inner cavity 2500 of the product to be tested 2000 through the tracer tube 14, the pressure regulating body 111 and the first air hole 2100 to increase the gas volume of the tracer gas in the inner cavity 2500, making it convenient for the subsequent detection device to detect the air tightness of the product to be tested 2000.

[0083] By providing the tracer valve 13 and the tracer tube 14 , when the tracer valve 13 is opened, the tracer gas source 12 can conveniently input the tracer gas into the product to be tested 2000 through the tracer tube 14 , thereby improving the reliability of the air tightness detection.

[0084] Further, in one or more embodiments of the present application, the airtight detection system 100 also includes a replacement mode; the air source assembly 10 also includes an air source 15, an air pipe 16 and an air valve 17, one end of the air pipe 16 is connected to the tracer pipe 14 located between the tracer valve 13 and the pressure regulating body 111, the other end of the air pipe 16 is connected to the air source 15, and the air valve 17 is connected to the air pipe 16. When the airtight detection system 100 is in the replacement mode, the tracer valve 13 is closed, and the pressure regulating body 111 and the air valve 17 are both opened; when the airtight detection system 100 is in the inflation mode, the air valve 17 is closed.

[0085] The replacement mode refers to a mode in which the air source 15 introduces air into the inner cavity 2500 of the product to be tested 2000 so that the air replaces the tracer gas. After the replacement mode ends, the inner cavity 2500 of the product to be tested 2000 is mainly filled with air, and the product to be tested 2000 can be used normally.

[0086] When the airtight detection system 100 is in the inflation mode, the pressure regulating body 111 and the tracer valve 13 are both opened, and the air valve 17 is closed to reduce the possibility of the air source 15 inputting air into the inner cavity 2500; when the airtight detection system 100 is in the replacement mode, the pressure regulating body 111 and the air valve 17 are both opened, the tracer valve 13 is closed, and the air source 15 inputs air into the inner cavity 2500 of the product to be tested 2000 to replace the tracer gas in the inner cavity 2500.

[0087] By providing the air source 15, the air pipe 16 and the air valve 17, combined with the tracer valve 13 and the tracer tube 14, the airtightness detection system 100 can be freely switched between the inflation mode and the replacement mode, and the working reliability is high.

[0088] In one or more embodiments of the present application, the airtightness detection system 100 also has a negative pressure extraction mode, a third air hole 2300 connected to the inner cavity 2500 is opened on the product to be tested 2000, and the airtightness detection system 100 also includes an air extraction component 20, which is connected to the third air hole 2300; when the airtightness detection system 100 is in the negative pressure extraction mode or the inflation mode and the air pressure in the inner cavity 2500 reaches a preset air pressure threshold, the air extraction component 20 is used to extract part of the gas in the inner cavity 2500.

[0089] The negative pressure pumping mode refers to a mode in which the gas extraction component 20 extracts part of the gas in the inner cavity 2500 of the product to be tested 2000 to make the inner cavity 2500 present a negative pressure. In this mode, the gas pressure in the inner cavity 2500 is negative pressure, and the extracted gas is air. When the negative pressure pumping mode ends, the tracer gas switches to the inflation mode.

[0090] In the inflation mode, the tracer gas source 12 inputs the tracer gas into the inner cavity 2500, so that the air pressure in the inner cavity 2500 gradually increases. Initially, the air pressure in the inner cavity 2500 is still negative pressure, and as the input of the tracer gas increases, the air pressure in the inner cavity 2500 gradually increases. When the air pressure in the inner cavity 2500 is greater than 0, the negative pressure in the inner cavity 2500 is converted into positive pressure.

[0091] Then, the tracer gas source 12 continues to input the tracer gas into the inner cavity 2500, and the gas pressure in the inner cavity 2500 increases accordingly. When the gas pressure in the inner cavity 2500 reaches the preset gas pressure threshold, the gas extraction component 20 stops working, and the tracer gas source 12 continues to inflate until the gas pressure in the inner cavity 2500 reaches the inflation threshold.

[0092] It can be understood that when the vacuum assembly 20 is in the negative pressure pumping mode, the air pressure in the inner cavity 2500 is reduced so that the tracer gas source 12 can automatically flow to the inner cavity 2500. The vacuum assembly 20 is in the inflation mode to continue to exhaust the air in the inner cavity 2500 and mix the air and the tracer gas. In the negative pressure pumping mode, the air pressure in the inner cavity 2500 is less than the atmospheric pressure. In the inflation mode, the air pressure in the inner cavity 2500 is less than the atmospheric pressure, equal to the atmospheric pressure, and greater than the atmospheric pressure.

[0093] When the airtightness detection system 100 is in the inflation mode, before the air pressure in the inner cavity 2500 reaches the preset air pressure threshold, the air extraction component 20 in the airtightness detection system 100 works, so that the tracer gas in the tracer gas source 12 can automatically flow into the inner cavity 2500, so as to increase the gas volume of the tracer gas in the inner cavity 2500, which is convenient for subsequent detection devices to capture. On the other hand, the operation of the air extraction component 20 can also accelerate the speed and uniformity of the mixing of the tracer gas and the air. The more uniform the mixing of the tracer gas and the air, the higher the efficiency and more accurate the subsequent detection device is in detecting airtightness.

[0094] When the air pressure in the inner cavity 2500 reaches the preset air pressure threshold, the suction assembly is turned off. At this time, the tracer gas source 12 continues to fill the inner cavity 2500 with tracer gas to further increase the amount of tracer gas in the inner cavity 2500 until the air pressure in the inner cavity 2500 reaches the inflation threshold. It can be understood that when the air pressure in the inner cavity 2500 reaches the preset air pressure threshold, the suction assembly is turned off, which can reduce the discharge of gas in the inner cavity 2500, so that the air pressure in the inner cavity 2500 can quickly rise to the inflation threshold, with higher inflation efficiency.

[0095] It can be seen that the arrangement of the gas extraction assembly 20 facilitates the input of the tracer gas into the inner cavity 2500 and helps to achieve uniform mixing of the tracer gas and air.

[0096] Furthermore, in one or more embodiments of the present application, the vacuum assembly 20 includes a vacuum pump 21, a vacuum pipe 22 and a vacuum valve 23; the vacuum pipe 22 is connected between the third air hole 2300 and the vacuum pump 21, and the vacuum valve 23 is connected to the vacuum pipe 22; the airtightness detection system 100 is in a negative pressure mode or an inflation mode and before the air pressure in the inner cavity 2500 reaches the inflation threshold, the vacuum valve 23 and the vacuum pump 21 are both opened.

[0097] When the air extraction valve 23 and the air extraction pump 21 are both opened, the gas in the product 2000 to be tested can be discharged to the outside through the air extraction pipe 22 and the air extraction pump 21, thereby ensuring the reliability of the gas output. When the air extraction valve 23 and the air extraction pump 21 are closed, the gas in the inner cavity 2500 can be effectively prevented from being discharged, thereby reducing the leakage of the tracer gas in the inner cavity 2500.

[0098] Please refer to FIG. 1 again, and also refer to FIG. 2 at the same time. FIG. 2 is an exploded view of the adsorption component 30 and the product to be tested 2000 in one or more embodiments of the present application.

[0099] In one or more embodiments of the present application, the airtightness detection system 100 also includes an adsorption component 30; when the airtightness detection system 100 is in a negative pressure extraction mode and an inflation mode, and the air pressure in the inner cavity 2500 is a negative pressure, the adsorption component 30 is used to adsorb the weak strength part 2400 of the product 2000 to be tested.

[0100] The adsorption component 30 may be a magnetic adsorption component, a vacuum adsorption component or other adsorption components 30. Exemplarily, the adsorption component 30 includes a substrate 31 and a vacuum suction cup 32, and the vacuum suction cup 32 is disposed on one side of the substrate 31, and may be one or more. When there are multiple vacuum suction cups 32, all vacuum suction cups 32 may be used to jointly adsorb the same weak strength part 2400, or each vacuum suction cup 32 may also adsorb the corresponding weak strength part 2400 one by one.

[0101] Taking the product 2000 to be tested as a battery as an example, the battery includes a box body and a battery cell, the box body has an inner cavity 2500, and the battery cell is arranged in the inner cavity 2500. The box body is composed of a first part and a second part, the first part is a hollow structure with one end open and the other end closed, the second part can be a plate-shaped or a hollow structure with one end open and the other end closed, the second part covers the opening of the first part, and is surrounded by the first part to form the inner cavity 2500. When the battery is placed in the inner cavity 2500, the battery cell is supported on the first part. Generally, the mechanical strength of the first part is greater than that of the second part, and therefore, the second part is the weak part 2400 in the product 2000 to be tested. In this embodiment, the adsorption component 30 is located on the side of the second part facing away from the first part and adsorbs the first part.

[0102] Since the mechanical strength of the weak part 2400 is relatively weak, when the inner cavity 2500 is at a negative pressure, the weak part 2400 is easily deformed under the action of atmospheric pressure, causing the product 2000 to be unqualified. By setting the adsorption component 30, when the inner cavity 2500 is at a negative pressure, the adsorption force of the adsorption component 30 can at least offset part of the atmospheric pressure, and the risk of deformation of the weak part 2400 is reduced. Afterwards, when the air pressure in the inner cavity 2500 rises to at least equal to the atmospheric pressure, the risk of deformation of the weak part 2400 due to the atmospheric pressure drops sharply, and at this time, the adsorption component 30 can be revoked. It can be seen that the setting of the adsorption component 30 can reduce the risk of deformation of the product 2000 to be tested when the suction component is working, which is conducive to improving the reliability of airtightness detection.

[0103] In one or more embodiments of the present application, the airtight detection system 100 also has a circulation mode; the airtight detection system 100 also includes a circulation component 40; when the airtight detection system 100 is in the circulation mode, the circulation component 40 is used to circulate the gas output by the third air hole 2300 to the inner cavity 2500 through the first air hole 2100. When the airtight detection system 100 is in the inflation mode and the negative pressure extraction mode, the circulation component 40 is closed.

[0104] The circulation mode refers to a mode in which the circulation component 40 drives the gas in the inner cavity 2500 to circulate.

[0105] In the circulation mode, the circulation component 40 is started, and at the same time, the suction component is closed, so that the gas in the inner cavity 2500 circulates only in the inner cavity 2500 through the circulation component 40 and the product 2000 to be tested. In the inflation mode, the negative pressure pumping mode and the replacement mode, the circulation component 40 is closed.

[0106] By setting the circulation component 40, when the circulation component 40 is started, the tracer gas and air circulate in the circulation component 40 and the inner cavity 2500 only under the action of the circulation component 40, so that the tracer gas and the air can be fully mixed, and then, in the subsequent air tightness test, the gas overflowing to the surface of the product 2000 to be tested is evenly distributed with the tracer gas and can be sensitively detected by the detection device. In addition, the setting of the circulation component 40 can also reduce the possibility of the gas in the inner cavity 2500 diffusing to the outside during the mixing of the tracer gas and the air, thereby reducing the waste of the tracer gas.

[0107] In one or more embodiments of the present application, the circulation component 40 includes a circulation pump 41, a circulation valve 43 and a circulation pipe 42. The circulation pump 41 is connected to the first air hole 2100 and the third air hole 2300 through the circulation pipe 42, and the circulation valve 43 is connected to the circulation pipe 42. When the airtight detection system 100 is in the circulation mode, the circulation valve 43 and the circulation pump 41 are both opened. In the inflation mode and the negative pressure pumping mode, the circulation valve 43 and the circulation pump 41 are both closed.

[0108] The circulation assembly 40 includes two circulation pipes 42 and two circulation valves 43, which correspond to each other, and each circulation valve 43 is mounted on the corresponding circulation pipe 42. The air source assembly 10 also includes a connecting pipe 18, which is connected between the pressure regulating body 111 and the first air hole 2100, one of the circulation pipes 42 is connected between the circulation pump 41 and the connecting pipe 18, and the other circulation pipe 42 is connected between the circulation pump 41 and the air extraction pipe 22.

[0109] When the circulation pump 41 and the circulation valve 43 are both turned on, the gas in the inner cavity 2500 can circulate in the inner cavity 2500 of the product 2000 to be tested and in the circulation component 40 to achieve full mixing of the tracer gas and air.

[0110] The provision of the circulation pump 41 , the circulation pipe 42 and the circulation valve 43 improves the reliability of gas circulation when the circulation component 40 is working.

[0111] In some embodiments of the present application, the air source assembly 10 also includes a pressure measuring tube 19, which is connected between the air pressure detection unit 112 and the second air hole 2200; the airtight detection system 100 also includes an air pressure detection component, which is connected to the pressure measuring tube 19 and is always used to detect the air pressure in the pressure measuring tube 19.

[0112] When the pressure measuring tube 19 is connected between the air pressure detection unit 112 and the second air hole 2200, the air pressure in the test tube is consistent with the air pressure at the second air hole 2200, the air pressure in the inner cavity 2500 of the product 2000 to be tested, the air pressure detected by the air pressure detection unit 112, and the air pressure detected by the air pressure detection component.

[0113] The air pressure detection component can be a pressure gauge, a pressure sensor or other air pressure detection instruments.

[0114] The air pressure detection element is always used to monitor the air pressure in the product to be tested 2000. Always means from the time when the product to be tested 2000 is placed in the airtightness detection system 100 and assembled with the airtightness detection system 100 to the end of the airtightness detection.

[0115] It can be understood that the air pressure detection unit 112 of the pressure regulating valve 11 only measures pressure and feeds back to the pressure regulating body 111 when the pressure regulating body 111 of the pressure regulating valve 11 is opened. When the pressure regulating body 111 is closed, the pressure measuring function of the air pressure detection unit 112 fails. Specifically, in the airtight detection system 100, when the airtight detection system 100 is in the inflation state and the replacement state, the air pressure detection unit 112 measures pressure and feeds back to the pressure regulating body 111. When the airtight detection system 100 is in the negative pressure extraction state and the circulation state, the pressure measuring function of the air pressure detection unit 112 fails.

[0116] In the airtight detection system 100, when the airtight detection system 100 is in the inflation state, the replacement state, the negative pressure pumping state and the circulation state, the air pressure detection component can be used to detect the air pressure in the inner cavity 2500 of the product to be tested 2000. In this way, during the entire airtightness detection process, when the air pressure in the inner cavity 2500 is abnormal, the operator can know in time and take emergency measures. For example, if the air pressure detected by the air pressure detection component suddenly drops sharply, it means that the airtightness of the product to be tested 2000 is seriously unqualified, so it needs to be returned to the factory for re-testing and troubleshooting. If the air pressure detected by the air pressure detection component suddenly rises sharply, it means that the air source component 10 may be faulty, and the air source component 10 needs to be checked and repaired.

[0117] It can be seen that in the present application, by setting up an air pressure detection component, the air pressure detection component can detect the air pressure inside the product 2000 to be tested in real time, which is conducive to real-time monitoring of the air pressure inside the product 2000 to be tested.

[0118] In one or more embodiments of the present application, the airtight detection system 100 further includes a controller 60, a pressure regulating body 111, a tracer gas source 12, a tracer valve 13, an air source 15 and an air valve 17 in the air source assembly 10, an air pump 21 and an air valve 23 in the air extraction assembly 20, a circulation pump 41 and a circulation valve 43 in the circulation assembly 40, and an air pressure detection component are all electrically connected to the controller 60. The above components all work under the control of the controller 60 to realize the automation of airtight detection.

[0119] Next, the working process of the entire airtightness detection system 100 is described in detail.

[0120] Initially, the airtightness detection system 100 starts the negative pressure pumping mode. At this time, the controller 60 controls the air pump 23 and the air pump 21 to open, and the controller 60 controls the circulation valve 43, the pressure regulating body 111, the tracer valve 13 and the air valve 17 to be closed. Under the action of the air pump 21, part of the air in the inner cavity 2500 of the product 2000 to be tested is extracted, and the air pressure in the inner cavity 2500 is reduced to negative pressure.

[0121] Next, the airtightness detection system 100 starts the inflation mode, the controller 60 controls the air extraction valve 23 and the air extraction pump 21 to remain open, controls the pressure regulating body 111 and the tracer valve 13 to open, and controls the other circulation valves 43 and the air valve 17 to continue to remain closed, and the tracer gas in the tracer gas source 12 is input into the inner cavity 2500. At the same time, the gas mixed with the tracer gas and the air in the inner cavity 2500 continues to be discharged to the outside under the action of the air extraction component 20. In this way, while the intensity of the tracer gas and the air in the inner cavity 2500 can be increased, part of the air can be further discharged to increase the proportion of the tracer gas in the inner cavity 2500.

[0122] As the tracer gas is continuously input, the proportion of the tracer gas in the inner cavity 2500 increases, and the proportion of the air decreases, so as to gradually realize the replacement of the air by the tracer gas. In this process, the air pressure detection unit 112 detects the air pressure at the second air hole 2200 and feeds it back to the pressure regulating body 111. When the air pressure at the second air hole 2200 is less than or equal to the preset air pressure threshold, the pressure regulating body 111 increases its opening to realize efficient input of the tracer gas into the inner cavity 2500. When the air pressure at the second air hole 2200 is greater than the preset air pressure threshold, the air extraction valve 23 and the air extraction pump 21 are closed, and the pressure regulating body 111 decreases its opening, and the tracer gas source 12 continues to input the tracer gas until the air pressure in the inner cavity 2500 of the product 2000 to be tested rises to the inflation threshold.

[0123] Afterwards, the tracer valve 13 and the pressure regulating body 111 are closed, the air valve 17 and the air extraction valve 23 remain closed, the circulation valve 43 and the circulation pump 41 are opened, and the airtightness detection system 100 starts the circulation mode. Under the action of the circulation pump 41, the gas circulates in the inner cavity 2500 and the circulation component 40 to achieve full mixing of the tracer gas and the air. In this way, the gas overflowing from the product 2000 to be tested is mixed with a high concentration of tracer gas, and the detection sensitivity is high.

[0124] It is worth mentioning that when the inflation threshold in the inner cavity 2500 is equal to the pressure of the tracer gas source 12, in the circulation state, the tracer valve 13 and the pressure regulating body 111 can be closed or opened.

[0125] After the air tightness test step is completed, the air valve 17, the pressure regulating body 111 and the air extraction valve 23 are all opened, the tracer valve 13 and the circulation valve 43 are closed, and the air tightness test system 100 starts the replacement mode. Under the action of the air extraction pump 21, the air in the air source 15 is input into the inner cavity 2500 and mixed with the gas in the inner cavity 2500 and output. With the continuous action of the suction pump, the tracer gas in the inner cavity 2500 is eventually replaced by air, and the air tightness test is completed.

[0126] In a second aspect, the present application provides a battery manufacturing production line, which includes an airtightness detection system 100 as described in any one of the above embodiments.

[0127] The battery manufacturing production line in the present application has the effects described in any of the above embodiments, so they will not be repeated here.

[0128] According to Figures 1 and 2, the present application provides an airtightness detection system 100 for detecting the airtightness of a product to be tested 2000. The product to be tested 2000 has an inner cavity 2500 and a first air hole 2100 and a second air hole 2200 both connected to the inner cavity 2500. The airtightness detection system 100 has an inflation mode, and the airtightness detection system 100 includes an air source component 10. The air source assembly 10 includes a pressure regulating valve 11 and a tracer air source 12. The pressure regulating valve 11 includes a pressure regulating body 111 and an air pressure detection unit 112. The pressure regulating body 111 is connected between the tracer air source 12 and the first air hole 2100. The air pressure detection unit 112 is arranged on the pressure regulating body 111 and is connected with the second air hole 2200. When the airtight detection system 100 is in the inflation mode, the pressure regulating body 111 is opened, and the air pressure detection unit 112 detects the air pressure at the second air hole 2200 and feeds back to the pressure regulating body 111. The pressure regulating body 111 is configured to reduce its own opening when the air pressure at the second air hole 2200 is greater than a preset air pressure threshold.

[0129] In the airtightness detection system 100 of the present application, since the air pressure detection unit 112 is connected to the second air hole 2200, and the air pressure of the second air hole 2200 is equal to the air pressure in the inner cavity 2500, the air pressure at the second air hole 2200 detected by the air pressure detection unit 112 can truly reflect the air pressure in the inner cavity 2500. In this case, the pressure regulating body 111 can accurately adjust its opening according to the air pressure at the second air hole 2200, and increase the opening when the air pressure at the second air hole 2200 is less than or equal to the preset air pressure threshold, which is conducive to improving the charging efficiency and replacement efficiency of the tracer gas, and thus, the airtightness detection efficiency is also improved.

[0130] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0131] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An airtightness detection system for detecting the airtightness of a product to be tested (2000), characterized in that: The product to be tested (2000) has an inner cavity (2500) and a first air hole (2100) and a third air hole (2300) both of which are in communication with the inner cavity (2500). The airtightness detection system has an inflation mode and a circulation mode, and the airtightness detection system comprises: An air source assembly (10) comprising a tracer air source (12), wherein the tracer air source (12) is in communication with the first air hole (2100); A circulation component (40) connected to the first air hole (2100) and the third air hole (2300); Wherein, when the airtightness detection system is in the charging mode, the tracer gas source (12) charges the inner cavity (2500) of the product to be tested (2000) with tracer gas, and the circulation component (40) is closed; when the airtightness detection system is in the circulation mode, the circulation component (40) is used to circulate the gas output from the third air hole (2300) into the inner cavity (2500) through the first air hole (2100).

2. The airtightness detection system according to claim 1, characterized in that: When the gas pressure in the inner cavity (2500) reaches the inflation threshold, the tracer gas source (12) stops inflating the inner cavity (2500).

3. The airtightness detection system according to claim 2, characterized in that: The product to be tested (2000) further comprises a second air hole (2200) in communication with the inner cavity (2500); The gas source assembly (10) further comprises a pressure regulating valve (11), the pressure regulating valve (11) comprising a pressure regulating body (111) and an air pressure detection unit (112), the pressure regulating body (111) being connected between the tracer gas source (12) and the first air hole (2100), and the air pressure detection unit (112) being arranged on the pressure regulating body (111) and connected to the second air hole (2200); When the airtight detection system is in the inflation mode, the pressure regulating body (111) is opened, the air pressure detection unit (112) detects the air pressure at the second air hole (2200) and feeds back to the pressure regulating body (111), and the pressure regulating body (111) is configured to increase its own opening when the air pressure at the second air hole (2200) is less than or equal to a preset air pressure threshold, and to decrease its own opening when the air pressure at the second air hole (2200) is greater than the preset air pressure threshold; the preset air pressure threshold is less than the inflation threshold.

4. The airtightness detection system according to claim 3, characterized in that: The air pressure detection unit (112) is arranged at one end of the product to be tested (2000).

5. The airtightness detection system according to claim 2, characterized in that: The airtightness detection system further comprises an air extraction component (20), wherein the air extraction component (20) is in communication with the third air hole (2300); When the airtightness detection system is in a negative pressure extraction mode, the air extraction component (20) extracts part of the gas in the inner cavity (2500) of the product to be tested (2000), and the circulation component (40) is closed; The airtightness detection system can be in the inflation mode and the negative pressure extraction mode at the same time before the air pressure in the inner cavity (2500) reaches a preset air pressure threshold, and when the air pressure in the inner cavity (2500) reaches the preset air pressure threshold, the suction component (20) stops working and the tracer gas source (12) inflates until the air pressure in the inner cavity (2500) reaches the inflation threshold.

6. The airtightness detection system according to claim 5, characterized in that: The airtightness detection system further comprises an adsorption component (30); When the airtightness detection system is in the inflation mode and the negative pressure extraction mode at the same time, and the air pressure in the inner cavity (2500) is negative pressure, the adsorption component (30) is used to adsorb the weak part (2400) of the product to be tested (2000).

7. The airtightness detection system according to claim 6, characterized in that: The adsorption assembly (30) comprises a vacuum adsorption component, and the vacuum adsorption component is used to vacuum adsorb the weak strength portion (2400) of the product to be tested (2000).

8. The airtightness detection system according to claim 7, characterized in that: The vacuum suction component comprises a substrate (31) and a vacuum suction cup (32), wherein the vacuum suction cup (32) is arranged on one side of the substrate (31).

9. The airtightness detection system according to claim 8, characterized in that: When there are multiple vacuum suction cups (32), all of the vacuum suction cups (32) are used to jointly adsorb the same weak strength portion (2400); or, each of the vacuum suction cups (32) adsorbs the corresponding weak strength portion (2400) one by one.

10. The airtightness detection system according to claim 1, characterized in that: The airtightness detection system (100) further comprises a detection device, which is located outside the product to be tested (2000) and is used to detect the amount of the tracer gas leaked from the surface of the product to be tested (2000) after the circulation mode.

11. A battery manufacturing production line, characterized in that: The battery manufacturing production line comprises the airtightness detection system as described in any one of claims 1-10.

12. An airtightness detection method for detecting the airtightness of a product to be tested (2000), characterized in that: include: Filling the inner cavity (2500) of the product to be tested (2000) with tracer gas through the first air hole (2100) of the product to be tested (2000), and simultaneously extracting part of the gas in the inner cavity (2500) of the product to be tested (2000) through the third air hole (2300) of the product to be tested (2000); When the air pressure in the inner cavity (2500) reaches a preset air pressure threshold, stopping the extraction of part of the gas; When the gas pressure in the inner cavity (2500) reaches the filling threshold, the filling of the tracer gas is stopped, and the gas output from the third gas hole (2300) is circulated into the inner cavity (2500) through the first gas hole (2100); Detecting the amount of the tracer gas leaked from the surface of the product to be tested (2000).

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