CN219224077U

CN219224077U - Air tightness detection system

Info

Publication number: CN219224077U
Application number: CN202320927376.1U
Authority: CN
Inventors: 吴凯; 李勇盛; 王建祥; 陈有军
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-04-23
Filing date: 2023-04-23
Publication date: 2023-06-20
Anticipated expiration: 2033-04-23

Abstract

The application belongs to airtight detection field, proposes an airtight detecting system, include: the vacuum box is internally provided with at least one cavity, each cavity is used for accommodating at least one workpiece, and the vacuum box is used for being connected with the leak detector; the first vacuumizing device is connected with the vacuum box and is used for vacuumizing the vacuum box; a pressure detection assembly for detecting the gas pressure within the vacuum box and/or the workpiece; the second vacuumizing device is used for vacuumizing the workpiece; and the inflation device is used for inflating detection gas into the workpiece. The air tightness detection system provided by the embodiment of the application can sequentially perform large leakage detection and micro leakage detection on the workpiece, reduces the use amount of detection gas, and reduces the detection cost.

Description

Air tightness detection system

Technical Field

The application belongs to airtight detection field, especially relates to an airtight detecting system.

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry, and electric vehicles become an important component of sustainable development of the automobile industry due to the energy conservation and environmental protection advantages of the electric vehicles. For electric vehicles, battery technology is an important factor in the development of the electric vehicles.

Air tightness is an important index affecting the safety performance of the battery. In the actual production process, it is generally necessary to perform leak detection on the battery case to determine whether the air tightness of the battery case meets the requirement. However, how to realize leakage detection of a battery case based on lower cost has been a problem.

Disclosure of Invention

In view of this, the embodiments of the present application provide an air tightness detection system capable of reducing the cost of air tightness detection.

The embodiment of the application provides an air tightness detection system, which comprises:

the vacuum box is internally provided with at least one cavity, each cavity is used for accommodating at least one workpiece, and the vacuum box is used for being connected with the leak detector;

the first vacuumizing device is connected with the vacuum box and is used for vacuumizing the vacuum box;

a pressure detection assembly for detecting a gas pressure within the vacuum box and/or the workpiece;

the second vacuumizing device is used for vacuumizing the workpiece;

and the inflation device is used for inflating detection gas into the workpiece.

The air tightness detection system comprises a vacuum box, a first vacuumizing device, a second vacuumizing device, a pressure detection assembly and an air charging device, wherein the air tightness detection system can utilize the first vacuumizing device and the pressure detection piece to carry out large leakage detection on a workpiece, and utilizes the second vacuumizing device and the air charging device to carry out micro leakage detection on the workpiece, and the air tightness detection system can simultaneously detect the air tightness of a plurality of workpieces and has higher detection efficiency; in addition, when the workpiece has the problem of large leakage, micro leakage detection is not needed, waste of detection gas is reduced, and cost of air tightness detection is effectively reduced.

In some embodiments, the gas tightness detection system further comprises a plugging mechanism comprising a seal and a plugging drive assembly; the sealing driving assembly is used for driving the sealing element to move, so that the sealing element enters the inner cavity of the workpiece and is sealed at the end part of the workpiece, and the sealing element and the notch area of the workpiece are arranged at intervals.

By adopting the technical scheme, the sealing piece and the notch area are arranged at intervals, and the plugging mechanism can realize the sealing of the inner cavity of the workpiece under the working condition of not interfering the notch area.

In some embodiments, the seal is 6mm to 12mm from the scored area of the workpiece.

Through adopting above-mentioned technical scheme, gas tightness detecting system is applicable to the detection cylinder casing work piece, and the shutoff mechanism is difficult for interfering the nick area of casing, reduces the unusual probability of electric core blasting.

In some embodiments, the plugging driving assembly comprises a first driving member, a mounting member and a second driving member, wherein the second driving member is arranged on the mounting member, the sealing member is connected with the second driving member, the first driving member is in driving connection with the mounting member, and the first driving member is used for driving the mounting member to move towards a direction approaching or away from the workpiece so as to enable the sealing member to enter the inner cavity of the workpiece; the second driving piece is used for driving the sealing piece to expand so that the sealing piece is in interference fit with the inner cavity of the workpiece.

Through adopting above-mentioned technical scheme, shutoff drive assembly can drive the sealing member and get into in the work piece and drive the sealing member inflation for the sealing member can seal the work piece, so that detect the gas tightness of work piece, avoid causing detection error because of the poor seal.

In some embodiments, the mounting member is provided with a plurality of second driving members, the number of the cavities is plural, each cavity is used for accommodating one workpiece, and the second driving members are arranged in one-to-one correspondence with the cavities.

Through adopting above-mentioned technical scheme, the mounting can drive a plurality of second driving pieces and sealing member simultaneously and remove, and shutoff driving assembly can seal a plurality of work pieces simultaneously, has promoted detection efficiency.

In some embodiments, the second driving member includes a cylinder body, a piston rod movably connected to the cylinder body, and an ejector member disposed at an end of the piston rod, wherein the sealing member is sleeved on the piston rod and is located between the cylinder body and the ejector member, and the cylinder body is used for driving the piston rod to stretch and retract, so that the sealing member expands between the ejector member and the cylinder body.

By adopting the technical scheme, the sealing mechanism can conveniently put the sealing element before expansion into the workpiece, and the sealing element is driven to expand through the second driving element, so that the sealing effect is better.

In some embodiments, the seal is an annular rubber member.

By adopting the technical scheme, the sealing element is annular so as to be sleeved on the piston rod conveniently; and the sealing element is a rubber element, has better elasticity and is convenient to deform and recover.

In some embodiments, the gas tightness detection system further comprises a gas recovery device in communication with the workpiece and for recovering the detection gas within the workpiece.

By adopting the technical scheme, the gas recovery device can recover the detection gas, so that the detection cost is reduced.

In some embodiments, the gas recovery device comprises an evacuation pump, a first tank, and a first solenoid valve, a first end of the first solenoid valve being configured to connect to the workpiece and a second end of the first solenoid valve being configured to connect to the evacuation pump; opening the first solenoid valve causes the evacuation pump to pump the detection gas within the workpiece into the first canister.

By adopting the technical scheme, the recovery detection gas can be controlled by controlling the first electromagnetic valve, and the control mode of the gas recovery device is simpler.

In some embodiments, the gas recovery device further comprises a second tank for supplying gas to the vacuum box, a compressor, a second solenoid valve, and a third solenoid valve, the gas pressure in the second tank being greater than the gas pressure in the first tank, a first end of the second solenoid valve being connected to the first tank and the evacuation pump, and a second end of the second solenoid valve being connected to the compressor, a first end of the third solenoid valve being connected to the compressor and a second end of the third solenoid valve being connected to the second tank; the first electromagnetic valve is closed, the second electromagnetic valve and the third electromagnetic valve are opened, so that the detection gas in the first tank body can be compressed into the second tank body.

Through adopting above-mentioned technical scheme, under the control of a plurality of solenoid valves, the compressor can compress the internal gas of first jar to the internal second jar to follow-up use of convenience.

In some embodiments, the gas recovery device further comprises a fourth electromagnetic valve, one end of the fourth electromagnetic valve is connected with the second tank body, the other end of the fourth electromagnetic valve is connected with a gas supply branch, and the fourth electromagnetic valve is opened to enable the detection gas in the second tank body to be introduced into the gas filling device through the gas supply branch.

Through adopting above-mentioned technical scheme, gas recovery unit not only can retrieve the detection gas, can also regard as the air supply to detect the use for the detection gas obtains the cyclic utilization, has saved the detection cost.

In some embodiments, the gas recovery device further comprises a concentration meter for detecting the concentration of the detected gas in the gas supply branch, a high pressure gas cylinder, and a fifth solenoid valve connected between the high pressure gas cylinder and the first tank.

Through adopting above-mentioned technical scheme, the concentration of gaseous concentration meter monitoring detection is used to gas recovery unit to and utilize high-pressure gas cylinder and fifth solenoid valve to supplement the detection gas in to the air feed branch road, make the concentration of gas recovery unit air feed qualified, avoid influencing the accuracy of detection.

In some embodiments, the vacuum box includes a base within which the cavity is provided and a lid for closing the base to seal the base.

By adopting the technical scheme, the cover piece can move relative to the base, so that the cover piece can be arranged on the base in a covering way to seal the base; the cover member may also open the opening of the base to facilitate access to and release of the work piece.

In some embodiments, the inflator is provided on the cover; the number of the air charging devices is multiple, and the air charging devices are respectively arranged in one-to-one correspondence with the cavities.

Through setting up a plurality of aerating device, the gas tightness detecting system that this application embodiment provided can aerify the work piece simultaneously to carry out the microleakage and detect.

In some embodiments, the gas tightness detection system comprises a plurality of the vacuum boxes, and the plurality of vacuum boxes are each used to connect the leak detector.

Because a plurality of vacuum boxes are all connected in the leak detector, the leak detector can detect the work piece in a plurality of vacuum boxes simultaneously, has promoted detection efficiency.

In some embodiments, the number of vacuum boxes is four, and three vacuum boxes are used to connect the leak detectors simultaneously.

By adopting the technical scheme, three-box linkage is realized, and the detection efficiency is further improved.

In some embodiments, the air tightness detection system further comprises a conveying mechanism and an up-down robot, wherein the conveying mechanism is used for conveying the workpiece, and the up-down robot is used for grabbing the workpiece on the conveying mechanism into the cavity.

Through setting up transport mechanism and last unloading robot, gas tightness detecting system can realize automatic conveying work piece and automatic unloading, and degree of automation is higher, has further promoted detection efficiency and has reduced detection cost.

In some embodiments, the air tightness detection system further comprises a plasma wind sweeping device, wherein the plasma wind sweeping device is arranged on one side of the conveying mechanism and is used for sweeping the workpiece through plasma wind.

The air tightness detection system provided by the embodiment has the plasma air sweeping function, static electricity and dust on a workpiece can be removed, cleanliness of the workpiece after detection is improved, and possibility of leakage of the battery cell due to dust corrosion is reduced.

The foregoing description is only an overview of the technical solutions of the present application, and may be implemented according to the content of the specification in order to make the technical means of the present application more clearly understood, and in order to make the above-mentioned and other objects, features and advantages of the present application more clearly understood, the following detailed description of the present application will be given.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the description of the embodiments or the conventional technology will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic illustration of a structure of a workpiece provided in some embodiments of the present application;

FIG. 2 is one of the schematic diagrams of the tightness detection system provided in some embodiments of the present application;

FIG. 3 is a schematic diagram of a second embodiment of an airtight detection system according to the present invention;

FIG. 4 is a schematic diagram of a vacuum box and an inflator in an airtight inspection system according to some embodiments of the present disclosure;

FIG. 5 is a schematic structural view of a plugging mechanism provided in some embodiments of the present application;

FIG. 6 is a schematic diagram of a gas recovery device in a gas tightness detection system according to some embodiments of the present application;

fig. 7 is a schematic structural diagram of a plurality of vacuum boxes and a loading and unloading robot in an airtight detection system according to some embodiments of the present application;

Fig. 8 is a schematic structural diagram of an air tightness detection system according to some embodiments of the present application.

The meaning of the labels in the figures is:

100. an air tightness detection system; 200. a workpiece; 210. an inner cavity; 220. a scored area;

10. a vacuum box; 11. a cavity; 12. a base; 13. a cover member;

21. a first vacuumizing device; 22. a second vacuumizing device;

30. a pressure detection assembly; 31. a pressure detecting member; 32. a vacuum gauge;

40. an inflator;

50. a leak detector;

60. a plugging mechanism; 61. a seal; 62. a plugging drive assembly; 621. a first driving member; 622. a mounting member; 623. a second driving member; 6231. a cylinder body; 6233. a push member;

70. a gas recovery device; 71. an evacuation pump; 72. a first tank; 73. a second tank; 74. a compressor; 75. a gas supply branch; 76. a concentration meter; 77. a high pressure gas cylinder; v1, a first electromagnetic valve; v2, a second electromagnetic valve; v3, a third electromagnetic valve; v4, a fourth electromagnetic valve; v5, a fifth electromagnetic valve; v6, a sixth electromagnetic valve;

81. a conveying mechanism; 82. feeding and discharging robots; 83. and a plasma air sweeping device.

Detailed Description

Embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical solutions of the present application, and thus are only examples, and are not intended to limit the scope of protection of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first," "second," etc. are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, which means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural sheets" refers to two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are orientation or positional relationship based on the drawings, and are merely for convenience of describing the embodiments of the present application and simplifying the description, and are not intended to indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.

It has been found that the existing air tightness detection system generally detects the air tightness of the workpiece by introducing helium into the workpiece and detecting the leakage value of the helium, however, the detection system easily causes a great deal of waste of the helium and has high detection cost.

In view of this, the present application provides an air tightness detection system, including a vacuum box, a first vacuumizing device, a pressure detection assembly, a second vacuumizing device and an inflating device. At least one cavity is arranged in the vacuum box, each cavity is used for accommodating at least one workpiece, and the vacuum box is used for being connected with the leak detector; the first vacuumizing device is connected with the vacuum box and is used for vacuumizing the vacuum box; the pressure detection component is used for detecting the gas pressure in the vacuum box and/or the workpiece; the second vacuumizing device is used for vacuumizing the workpiece; the inflator is used for filling the detection gas into the workpiece. The air tightness detection system provided by the embodiment of the application can sequentially perform large leakage detection and micro leakage detection on the workpiece, so that waste of detection gas is avoided, the use amount of the detection gas is reduced, and the detection cost is reduced.

The air tightness detection device provided in the embodiment of the application is used for detecting air tightness of a workpiece, and in the embodiment, the workpiece is taken as a battery shell for illustration. It will be appreciated that the workpiece to be measured may also be a battery or other workpiece, etc. Referring to fig. 1, an inner cavity 210 is disposed in the workpiece 200, and openings communicating with the inner cavity 210 are disposed at two ends of the workpiece 200. In this embodiment, the workpiece 200 is a cylindrical battery case, and the outer peripheral surface of the workpiece 200 is provided with a scored area 220.

The margin of the cylindrical battery monomer group is extremely high, no effective exhaust channel is provided for the uncontrolled gas to reach the end part for pressure relief, the instantaneous pressure relief is extremely easy to be realized in a shell bursting mode, the shell bursting leads high-temperature uncontrolled substances to directly contact adjacent battery monomers, and the thermal spread among the battery monomers is easy to be initiated. The workpiece 200 shown in fig. 1 employs a cylindrical aluminum shell large face scoring technique, and the uncontrolled cell can be depressurized through pressure relief Kong Zhengchang of the scored area 220.

Referring to fig. 2 to 4, the air tightness detection system 100 includes a vacuum box 10, a first vacuumizing device 21, a pressure detection assembly 30, a second vacuumizing device 22 and an inflating device 40. At least one cavity 11 is provided within the vacuum box 10, each cavity 11 being adapted to receive at least one workpiece 200, the vacuum box 10 being adapted to be connected to a leak detector 50; the first vacuumizing device 21 is connected with the vacuum box 10 and is used for vacuumizing the vacuum box 10; the pressure detection assembly 30 is used to detect the gas pressure within the vacuum box 10 and/or the workpiece 200; the second vacuumizing device 22 is used for vacuumizing the workpiece 200; the inflator 40 is used to inflate the workpiece 200 with a detection gas.

The vacuum box 10 can be made of aluminum, and the inner surface of the vacuum box is polished and cleaned after being processed, so that good background and little gas storage are ensured, and the pumping speed of the vacuum box 10 is improved. It will be appreciated that the vacuum box 10 may be of other materials.

Referring to fig. 4 and 5, at least one cavity 11 is disposed in the vacuum box 10, each cavity 11 is configured to accommodate at least one workpiece 200, and the vacuum box 10 and the cavity 11 can be sealed, such that the cavity 11 can be used as the vacuum cavity 11 for detection. In order to improve the detection efficiency, a plurality of boxes are arranged in the vacuum box 10, for example, 10 cavities 11 are arranged in the vacuum box 10, and the 10 cavities 11 can be arranged in 2 parallel rows, and each cavity 11 is used for accommodating one workpiece 200. It will be appreciated that in other embodiments, the number of cavities 11 may be 1, 5, 8, etc.; multiple workpieces 200 may also be housed simultaneously within each chamber 11.

The first vacuumizing device 21 is used for vacuumizing the vacuum box 10, the second vacuumizing device 22 is used for vacuumizing the workpiece 200, and the first vacuumizing device 21 and the second vacuumizing device 22 can be matched with control valves for use. Optionally, the first vacuumizing device 21 and the second vacuumizing device 22 each include a vacuum pump, an electromagnetic valve, a pressure sensor, a pipeline, and the like, and can perform vacuumizing operation within a set time.

If a plurality of cavities 11 are disposed in the vacuum box 10, the cavities 11 are all communicated with the interior of the vacuum box 10, the first vacuum pumping device 21 may be communicated with the vacuum box 10 to simultaneously pump vacuum to the cavities 11, that is, the first vacuum pumping device 21 may pump vacuum to the vacuum box 10 (including the cavities 11 in the vacuum box 10). In some embodiments, each cavity 11 may be used with a control valve, in which case the first evacuating device 21 may selectively evacuate one or more cavities 11. In addition, the first evacuating device 21 does not evacuate the workpiece 200 so that the workpiece 200 has a different gas pressure from the chamber 11.

The second evacuating device 22 is used to evacuate the workpiece 200. It will be appreciated that the workpiece 200 itself may be a sealed workpiece, such as where the workpiece 200 is a packaged battery, or where the workpiece 200 is sealed, the second vacuuming means 22 may be activated to vacuumize the workpiece 200.

The pressure sensing assembly 30 is used to sense the gas pressure within the vacuum box 10 and/or the workpiece 200 to detect if a large leak exists in the workpiece 200. "large leakage" refers to the presence of a significant leak in the workpiece 200, and "micro leakage" refers to the presence of a small leak in the workpiece 200. The large leakage detection is to perform primary detection on the air tightness of the workpiece 200; after the large leak detection is qualified, the workpiece 200 is subjected to micro leak detection to determine whether the air tightness of the workpiece 200 is qualified.

The pressure sensing assembly 30 may include one or more gas pressure sensing elements 31. The pressure detection assembly 30 is used to detect the presence of a large leak in the workpiece 200 by measuring the differential pressure. Specifically, during the process of vacuumizing the vacuum box 10 by the first vacuumizing device 21, the pressure detecting assembly 30 may detect a pressure change of the vacuum box 10 or detect a pressure change of the workpiece 200, so as to determine whether the workpiece 200 has a large leakage problem. For example, while the vacuum box 10 is being evacuated, the pressure detecting assembly 30 detects the pressure change of the workpiece 200 and holds the pressure for several seconds, and the pressure can be maintained if the workpiece 200 is not greatly leaked. In some embodiments, the pressure detection assembly 30 may also detect the pressure of the workpiece 200 and the vacuum box 10 by a plurality of gas pressure detectors 31, respectively, to detect large leakage problems.

The inflator 40 is used to communicate with the workpiece 200 and to inflate the workpiece 200 with a detection gas, such as helium, or other gases.

Leak detector 50 may include a mass spectrometer leak detector for detecting the constituents of the analyte test gas, control valves, calibration sections, and the like. The leak detector 50 is used to detect the amount of detected gas in the vacuum box 10, and the second evacuating device 22, the inflator 40 and the leak detector 50 are used together to detect whether a micro leak exists in the workpiece 200. When the detection gas is helium, the mass spectrometer leak detector is a helium mass spectrometer leak detector.

The detection process of the airtight detecting system 100 includes large leak detection and micro leak detection.

The large leakage detection process comprises the following steps: the workpiece 200 is placed in the cavity 11 of the vacuum box 10, the first vacuumizing device 21 is started to vacuumize the vacuum box 10, and the pressure of the gas in the vacuum box 10 or the workpiece 200 is detected by the pressure detection assembly 30 to detect whether the workpiece 200 has a large leak. If a plurality of workpieces 200 are disposed in the vacuum box 10, the plurality of workpieces 200 can be simultaneously subjected to large leak detection. The method of judging the large leakage may be various, for example, the pressure detecting assembly 30 detects the pressure change of the work 200 while evacuating the vacuum box 10, and holds the pressure for several seconds, and there is no large leakage if the pressure of the work 200 can be maintained.

The micro leakage detection process comprises the following steps: if the workpiece 200 has no problem of large leakage, the second vacuumizing device 22 is started to vacuumize the cavity 11, the inflating device 40 is used for inflating detection gas into the workpiece 200 (only the detection gas is needed in the micro-leakage detection process), and the leak detector 50 detects whether the workpiece 200 has micro-leakage by detecting the content of the detection gas in the vacuum box 10. If the leak detector 50 detects that the detected gas in the vacuum box 10 exceeds the preset content, the workpiece 200 is judged to have micro leakage; otherwise, it is determined that the workpiece 200 is not subject to micro-leakage.

If a plurality of workpieces 200 are disposed in the vacuum box 10, the plurality of workpieces 200 can be subjected to micro-leak detection at the same time. For example, when the leak detector 50 determines that the detected gas exceeds the preset level, the five workpieces 200 may be divided into two groups, one group including three workpieces 200 and one group including two workpieces 200, and the two groups of workpieces 200 may be subjected to the leak detection, respectively, and the leak detection process may be repeated until the workpieces 200 having the leak are detected.

As can be seen from the above description, if the workpiece 200 has a problem of large leakage, the micro leakage detection is not required, that is, the detection gas is not required to be filled into the workpiece 200, so that the waste of the detection gas is avoided.

The air tightness detection system 100 provided by the embodiment of the application comprises a vacuum box 10, a first vacuumizing device 21, a second vacuumizing device 22, a pressure detection assembly 30 and an air charging device 40, wherein the air tightness detection system 100 can utilize the first vacuumizing device 21 and the pressure detection piece 31 to perform large leakage detection on a workpiece 200, and utilize the second vacuumizing device 22 and the air charging device 40 to perform micro leakage detection on the workpiece 200, and the air tightness detection system 100 can simultaneously detect the air tightness of a plurality of workpieces 200 and has higher detection efficiency; in addition, when the workpiece 200 has the problem of large leakage, micro leakage detection is not needed, so that waste of detection gas is reduced, and the detection cost is effectively reduced.

Alternatively, the pressure detecting assembly 30 includes a plurality of pressure detecting members 31 for detecting the gas pressure in one workpiece 200, and vacuum gauges 32 for detecting the gas pressure in the vacuum box 10.

Referring to fig. 1, 3 and 5, the air tightness detection system 100 further includes a plugging mechanism 60, where the plugging mechanism 60 includes a sealing member 61 and a plugging driving assembly 62; the closure drive assembly 62 is used to drive the seal 61 to move such that the seal 61 enters the interior cavity 210 of the workpiece 200 and closes off the end of the workpiece 200 and such that the seal 61 is spaced from the scored area 220 of the workpiece 200.

In inspecting the workpiece 200, it is necessary to first seal the workpiece 200 with the sealing mechanism 60 so that the workpiece 200 is sealed by the sealing member 61, and then vacuum-pumping or the like may be performed.

The workpiece 200 in this embodiment is a cylindrical shell with an inner cavity 210, at least one end of the cylindrical shell is provided with an opening, and the plugging mechanism 60 is used for plugging the opening of the workpiece 200. It will be appreciated that two ends of the workpiece 200 are provided with openings, and that two blocking mechanisms 60 are used to block two openings of the workpiece 200, respectively. The closure drive assembly 62 is used to drive the seal 61 from the opening of the workpiece 200 into the interior cavity 210 of the workpiece 200 and cause the seal 61 to be closed at the end of the workpiece 200.

Since the workpiece 200 is provided with the score region 220, the seal 61 needs to be spaced apart from the score region 220 in order to avoid interference of the seal 61 with the score region 220.

By adopting the above technical scheme, the sealing member 61 is arranged at intervals with the scoring area 220, and the blocking mechanism 60 can realize the sealing of the inner cavity 210 of the workpiece 200 under the working condition of not interfering with the scoring area 220.

In other embodiments, the capping mechanism 60 may be omitted if the workpiece 200 itself is a hermetic workpiece 200.

In some embodiments, the seal 61 is 6mm to 12mm from the scored area 220 of the workpiece 200.

The spacing between seal 61 and scored area 220 refers to the minimum spacing between seal 61 and scored area 220. In this embodiment, the workpiece 200 is a cylindrical housing and the seal 61 is required to enter the interior cavity 210 of the workpiece 200 to seal the workpiece 200. The spacing between the seal 61 and the workpiece 200 at the scored area 220 is 6mm to 12mm, e.g., 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, etc. If the gap is less than 6mm, it may cause the seal 61 to interfere with the scored area 220; if the clearance is larger than 12mm, insufficient distance between the sealing member 61 and the opening may be caused.

By adopting the above technical scheme, the air tightness detection system 100 is suitable for detecting the cylindrical shell workpiece 200, the plugging mechanism 60 is not easy to interfere with the notch area 220 of the shell, and the probability of abnormal explosion of the battery cell is reduced.

It will be appreciated that the spacing between the seal 61 and the scored area 220 of the workpiece 200 may be other ranges, and may be specifically set depending on the size of the workpiece 200.

As shown in fig. 5, in some embodiments, the occlusion drive assembly 62 includes a first drive element 621, a mounting element 622, and a second drive element 623, the second drive element 623 being disposed on the mounting element 622 and the seal 61 being coupled to the second drive element 623, the first drive element 621 being drivingly coupled to the mounting element 622, the first drive element 621 being configured to drive the mounting element 622 in a direction toward or away from the workpiece 200 to move the seal 61 into the interior cavity 210 of the workpiece 200; the second driver 623 is configured to expand the seal 61 to provide an interference fit between the seal 61 and the interior cavity 210 of the workpiece 200.

The first driving piece 621 is used for driving the mounting piece 622 to linearly move so as to make the mounting piece 622 move in a direction approaching or moving away from the workpiece 200; the first driving piece 621 may be a cylinder, an oil cylinder, a ball screw structure, or the like.

The mounting member 622 is used for mounting the second driving member 623 such that the first driving member 621 moves the second driving member 623 and the sealing member 61 via the mounting member 622. The mounting member 622 may be a plate body or the like, and the shape of the mounting member 622 is not limited in this application.

The seal 61 is made of elastic material such as rubber, and can be inflated to seal the work 200; the second driving member 623 is used for connecting the sealing member 61 and expanding the sealing member 61 so that the expanded sealing member 61 is in interference fit with the inner cavity 210 of the workpiece 200, and thus the expanded sealing member 61 can seal the workpiece 200. The second driving element 623 may apply force to push the sealing element 61 to expand and deform, or may drive the sealing element 61 to expand by blowing air into the sealing element 61.

When it is desired to seal the workpiece 200, the first driving piece 621 drives the mounting piece 622 to move toward the direction approaching the workpiece 200, so that the sealing piece 61 enters the inner cavity 210 of the workpiece 200; the second driver 623 then expands the seal 61 to provide an interference fit between the seal 61 and the interior cavity 210 of the workpiece 200, such that the seal 61 may be sealed at the opening of the workpiece 200. After the detection is completed, the second driving member 623 brings the sealing member 61 into shrinkage deformation, and then the first driving member 621 drives the mounting member 622, the second driving member 623, and the sealing member 61 to move in a direction away from the workpiece 200.

Through adopting above-mentioned technical scheme, shutoff drive assembly 62 can drive seal 61 get into in the work piece 200 and drive seal 61 inflation for seal 61 can seal work piece 200, so that detect the gas tightness of work piece 200, avoid causing detection error because of the poor seal.

In some embodiments, the mounting member 622 is provided with a plurality of second driving members 623, the number of the cavities 11 is plural, and each cavity 11 is configured to receive one workpiece 200, and the second driving members 623 are disposed in a one-to-one correspondence with the cavities 11.

The plurality of cavities 11 are arranged in parallel and arranged in a row, the plurality of second driving members 623 are simultaneously installed on the installation member 622, and each second driving member 623 is used for being connected with one sealing member 61, so that the installation member 622 can simultaneously drive the plurality of second driving members 623 and the sealing members 61 to move, the plugging driving assembly 62 can simultaneously seal the plurality of workpieces 200, and the detection efficiency is improved.

When the two ends of the workpiece 200 are provided with openings, the two sealing driving assemblies 62 are respectively arranged on two opposite sides of the workpiece 200, so that the two sealing driving assemblies 62 can simultaneously seal the two ends of the workpiece 200.

In some embodiments, the second driving member 623 includes a cylinder body 6231, a piston rod (not shown) movably connected to the cylinder body 6231, and a push member 6233 provided at an end of the piston rod, the sealing member 61 is sleeved on the piston rod and located between the cylinder body 6231 and the push member 6233, and the cylinder body 6231 is configured to drive the piston rod to expand and contract so that the sealing member 61 expands between the push member 6233 and the cylinder body 6231.

The radial width of the ejector 6233 is greater than the radial width of the piston rod, and the radial width of the ejector 6233 is less than the radial width of the post-expansion seal 61.

In use, the seal 61 is sleeved on the piston rod and is located between the cylinder body 6231 and the ejector 6233; driven by the first driving piece 621, the ejector piece 6233 and the seal 61 enter the inner cavity 210 of the work 200; next, the cylinder body 6231 drives the piston rod back, and the ejector 6233 moves toward the cylinder body 6231 to apply pressure to the seal 61, expanding the seal 61 between the ejector and the cylinder body 6231 so that the seal 61 can interference fit with the inner wall of the workpiece 200 and seal the workpiece 200.

By adopting the above technical scheme, the plugging mechanism 60 can conveniently put the sealing element 61 before expansion into the workpiece 200, and the second driving element 623 drives the sealing element 61 to expand, so that the sealing effect is better.

In some embodiments, the seal 61 is a ring-shaped rubber member.

The sealing element 61 is annular so as to be sleeved on the piston rod; moreover, the sealing element 61 is a rubber element, has good elasticity and is convenient to deform and recover.

In other embodiments, the sealing member 61 may be made of other elastic materials.

Referring to fig. 2 and 3, in some embodiments, the gas tightness detection system 100 further includes a gas recovery device 70, and the gas recovery device 70 is in communication with the workpiece 200 and is used for recovering the detection gas in the workpiece 200.

At the time of micro-leak detection, the inflator 40 fills the work 200 with a detection gas; after the detection, the gas recovery device 70 recovers the detection gas in the workpiece 200, for example, recovers the detection gas into a storage tank. In some embodiments, the gas recovery device 70 and the gas source of the inflator device 40 may be integrated in one device and the recovered test gas may be reused. In some embodiments, the recovery of the detection gas by the gas recovery device 70 may be up to 85%.

By adopting the above technical scheme, the gas recovery device 70 can recover the detection gas, thereby reducing the detection cost.

Referring to fig. 6, in some embodiments, the gas recovery device 70 includes an evacuation pump 71, a first tank 72, and a first solenoid valve V1, a first end of the first solenoid valve V1 is connected to the workpiece 200 and a second end of the first solenoid valve V1 is connected to the evacuation pump 71, and the evacuation pump 71 is connected to the first tank 72; opening the first solenoid valve V1 causes the evacuation pump 71 to pump the inspection gas in the workpiece 200 into the first tank 72.

The first tank 72 is used for storing recovered detection gas; when the first solenoid valve V1 is opened, the evacuation pump 71 can recover the detection gas in the workpiece 200 into the first tank.

The first end of the first solenoid valve V1 may be directly connected to the workpiece 200 in order for the evacuation pump to pump the detection gas; in some embodiments, the first end of the first solenoid valve V1 may also be connected to the vacuum box 10, and after the inspection is completed, the inner cavity 210 of the workpiece 200 is communicated with the vacuum box 10, and the evacuation pump may also pump out the inspection gas in the workpiece 200.

By adopting the above technical scheme, the recovery detection gas can be controlled by controlling the first electromagnetic valve V1, and the control mode of the gas recovery device 70 is simpler.

With continued reference to fig. 6, the gas recovery device 70 further includes a second tank 73 for supplying gas to the vacuum box 10, a compressor 74, a second electromagnetic valve V2, and a third electromagnetic valve V3, wherein the gas pressure in the second tank 73 is greater than the gas pressure in the first tank 72, a first end of the second electromagnetic valve V2 is connected to the first tank 72 and the evacuation pump 71, a second end of the second electromagnetic valve V2 is connected to the compressor 74, a first end of the third electromagnetic valve V3 is connected to the compressor 74, and a second end of the third electromagnetic valve V3 is connected to the second tank 73; the first solenoid valve V1 is closed, the second solenoid valve V2 and the third solenoid valve V3 are opened, and the detection gas in the first tank 72 can be compressed into the second tank 73.

Specifically, the first tank 72 is a low-pressure tank storing low-pressure gas, the second tank 73 is a high-pressure tank storing high-pressure gas, and the compressor (compressor) is a driven fluid machine lifting the low-pressure gas to high-pressure gas.

After the pump 71 pumps the detection gas into the first tank 72, the first electromagnetic valve V1 is closed, the second electromagnetic valve V2 and the third electromagnetic valve V3 are opened, and the compressor 74 is started, so that the detection gas in the first tank 72 is transferred into the second tank through the compressor 74 to store the detection gas in the second tank 73, and the detection gas in the second tank 73 can be refilled into the workpiece 200.

By adopting the above technical scheme, under the control of a plurality of electromagnetic valves, the compressor 74 can compress the gas in the first tank 72 into the second tank 73 for subsequent use.

Referring to fig. 2 and 6, in some embodiments, the gas recycling device 70 further includes a fourth electromagnetic valve V4, one end of the fourth electromagnetic valve V4 is connected to the second tank 73, and the other end is connected to the gas supply branch 75, and the fourth electromagnetic valve V4 is opened to enable the detection gas in the second tank 73 to be introduced into the inflator 40 through the gas supply branch 75.

The fourth solenoid valve V4 is used for controlling inflation, and both ends of the air supply branch 75 are respectively connected to the fourth solenoid valve V4 and the inflator 40, so that after the fourth solenoid valve is opened, the detection gas in the second tank 73 can be inflated into the workpiece 200 through the inflator 40.

It will be appreciated that the gas supply branch is capable of supplying gas to a plurality of workpieces 200, and that in order to control the supply of gas to a particular workpiece 200, the present embodiment further provides a sixth solenoid valve V6, the first end of the sixth solenoid valve V6 being connected to the gas supply branch 75 and the second end being connected to the workpiece 200.

Thus, the gas recovery device 70 not only can recover the detection gas, but also can be used as a gas source for detection, so that the detection gas can be recycled, and the detection cost is saved.

With continued reference to fig. 6, in some embodiments, the gas recovery device 70 further includes a concentration meter 76, a high-pressure gas cylinder 77, and a fifth electromagnetic valve V5, wherein the concentration meter 76 is used for detecting the concentration of the detected gas in the gas supply branch 75, and the fifth electromagnetic valve V5 is connected between the high-pressure gas cylinder 77 and the first tank 72.

The concentration meter 76 is used for detecting the concentration of the detection gas in the gas supply branch so as to make the concentration of the detection gas filled in the workpiece 200 qualified; the high pressure gas cylinder 77 is used to store a high pressure detection gas (e.g., helium). If the concentration meter 76 detects that the concentration of the detected gas in the gas supply branch 75 is insufficient, the fifth electromagnetic valve may be opened to transfer the detected gas in the high-pressure gas cylinder 77 into the first tank 72, so as to increase the concentration of the detected gas in the first tank 72, and further increase the concentrations of the detected gas in the second tank 73 and the gas supply branch 75.

By adopting the above technical scheme, the gas recovery device 70 can monitor the concentration of the detected gas by using the concentration meter 76, and supplement the detected gas to the gas supply branch 75 by using the high-pressure gas cylinder 77 and the fifth electromagnetic valve V5, so that the concentration of the gas supplied by the gas recovery device 70 is qualified, and the influence on the accuracy of detection is avoided.

Referring to fig. 4, the vacuum box 10 includes a base 12 and a cover 13, the cavity 11 is disposed in the base 12, and the cover 13 is used for covering the base 12 to seal the base 12.

The cavity 11 is arranged in the base 12, and the number of the cavities 11 can be one or more; the cover 13 is movable relative to the base 12 so that the cover 13 can be placed over the base 12 to seal the base 12; the cover 13 may also open the opening of the base 12 to facilitate access to the work piece 200.

The vacuum box 10 may further comprise a sliding table mechanism for moving the base 12 or the cover 13. For example, the cover 13 is disposed above the support, and the sliding mechanism is connected to the base 12 and is used to drive the base 12 to move under the support. The vacuum box 10 may also include a jacking mechanism for jacking the base 12.

By adopting the technical scheme, the cover piece 13 can seal the base 12, so that the vacuum box 10 is formed into a closed cavity 11 for vacuumizing operation.

In some embodiments, the inflator 40 is provided on the cover 13; the number of the inflators 40 is plural, and the inflators 40 are disposed in one-to-one correspondence with the chambers 11.

One end of the inflator 40 is connected to a gas source, and the other end is in communication with the workpiece 200, and the inflator 40 may include a control valve, an inflation nozzle, etc., which is configured to communicate with the interior cavity 210 of the workpiece 200, and the control valve is configured to control inflation time. The inflator 40 may have other structures as long as the workpiece 200 can be inflated with the detection gas.

By providing a plurality of inflators 40, the air tightness detection system 100 provided in the embodiment of the present application can simultaneously inflate the workpiece 200 to perform micro leakage detection.

Referring to FIG. 2, in some embodiments, the air tightness detection system 100 includes a plurality of vacuum boxes 10, and the plurality of vacuum boxes 10 are each used to connect to the leak detector 50.

The air tightness detection system 100 illustrated in fig. 2 comprises a plurality of vacuum boxes 10, only one vacuum box 10 being illustrated in the air tightness detection system 100 of fig. 3, it being understood that the air tightness detection system 100 illustrated in fig. 3 may also comprise a plurality of vacuum boxes 10.

Specifically, each vacuum box 10 is connected to a first evacuating device 21, a second evacuating device 22, an inflating device 40, a leak detector 50, and a gas recovery device 70. The air tightness detection system 100 further comprises a plurality of control valves for controlling the detection steps, i.e. the first evacuating device 21, the second evacuating device 22, the inflating device 40, the leak detector 50 and the gas recovery device 70 can be connected to the corresponding vacuum boxes 10 through the control valves.

Because the vacuum boxes 10 are connected to the leak detector 50, the leak detector 50 can detect the workpieces 200 in the vacuum boxes 10 at the same time, thereby improving the detection efficiency.

Referring to fig. 2 and 7, in some embodiments, the number of vacuum boxes 10 is four, and three vacuum boxes 10 are used to connect leak detectors 50 simultaneously.

Specifically, four vacuum boxes 10 are disposed adjacently, and after the second evacuating device 22 is evacuated, the leak detector 50 can be used to detect the leaking detection gas in three vacuum boxes 10 simultaneously, and the fourth vacuum box 10 serves as a spare box. When a defective product appears in one vacuum box 10, the vacuum box 10 is rechecked to find out the defective workpiece 200, and the standby box and other boxes form three-box linkage, so that the detection beat is ensured.

For example, 8 workpieces 200 are provided in each vacuum box 10, the detection time of the leak detector 50 on a single vacuum box 10 is 48S, and the detection time can reach 16S/box through three-box linkage.

It will be appreciated that in other embodiments, a multi-box linkage may be provided, not limited to a three-box linkage.

Referring to fig. 5, 7 and 8, in some embodiments, the air tightness detection system 100 further includes a conveying mechanism 81 and an loading and unloading robot 82, the conveying mechanism 81 is used for conveying the workpiece 200, and the loading and unloading robot 82 is used for grabbing the workpiece 200 on the conveying mechanism 81 into the cavity 11.

The type of transfer mechanism 81 may be various, for example, the transfer mechanism 81 includes a conveyor line for conveying the workpieces 200 in the tray, the transfer mechanism being capable of transferring the workpieces 200 to the vacuum box 10.

The loading and unloading robot 82 is used for grabbing the workpiece 200 on the conveying mechanism 81 into the cavity 11, and the loading and unloading robot 82 can also automatically unload, namely grabbing the workpiece 200 detected in the cavity 11 onto the conveying mechanism, the defective product temporary storage line and the like. When the vacuum boxes 10 are plural, the plural vacuum boxes 10 may be disposed corresponding to one loading/unloading robot 82, so that loading/unloading is performed on the plural vacuum boxes 10 by using the loading/unloading robot 82. It is understood that the number of the loading and unloading robots 82 may be plural.

Through setting up transport mechanism 81 and last unloading robot 82, gas tightness detecting system 100 can realize automatic conveying work piece 200 and automatic unloading, and degree of automation is higher, has further promoted detection efficiency and has reduced detection cost.

Referring to fig. 3 and 8, in some embodiments, the air tightness detection system 100 further includes a plasma wind blowing device 83, where the plasma wind blowing device 83 is disposed on one side of the conveying mechanism 81, and is used for blowing the workpiece 200 by plasma wind.

After the air tightness of the workpiece 200 is detected, the workpiece 200 can be cleaned by the plasma air blowing device 83 in an on-line plasma air, and static electricity and dust on the surface of the workpiece 200 are removed by blowing the workpiece 200. Optionally, the plasma wind purge device 83 has a dust box, and the plasma wind purge device 83 can blow and suck to collect dust.

The air tightness detection system 100 of the embodiment has a plasma air blowing function, can remove static electricity and dust on the workpiece 200, improves the cleanliness of the workpiece 200 after detection, and reduces the possibility of leakage of the battery cell due to dust corrosion.

Referring to fig. 1 to 8, in some embodiments, the air tightness detection system 100 includes a vacuum box 10, a first vacuumizing device 21, a pressure detection assembly 30, a second vacuumizing device 22, an inflating device 40, a gas recovery device 70, and a plugging mechanism 60, wherein a cavity 11 in the vacuum box 10 is used for accommodating a workpiece 200, the plugging mechanism 60 is used for sealing the workpiece 200, the first vacuumizing device 21 and the pressure detection assembly 30 cooperate to perform large leakage detection on the workpiece 200, and the second vacuumizing device 22, the inflating device 40, and the gas recovery device 70 cooperate to perform small leakage detection on the workpiece 200; optionally, the detection gas is helium.

The detection method of the air tightness detection system 100 is as follows:

first, the workpiece 200 is placed in the vacuum box 10.

Specifically, the loading and unloading robot 82 grabs the workpiece 200 and places the workpiece 200 into the cavity 11 of the vacuum box 10, and the vacuum box 10 is covered and sealed.

Subsequently, the workpiece 200 is subjected to large leak detection.

Specifically, the first vacuumizing device 21 is opened to vacuumize the vacuum box 10, and at this time, the second vacuumizing device 22, the inflating device 40 and the gas recovery device 70 are all in the closed state. While the vacuum is being drawn, the pressure detection assembly 30 detects a change in the gas pressure within the vacuum box 10 or the workpiece 200 to detect whether a large leak exists in the workpiece 200. If the workpiece 200 has a large leakage, the air tightness detection system 100 can automatically send out an audible and visual alarm, and the system needs to be stopped and reset at the moment, so that the workpiece 200 is taken out.

If the workpiece 200 has no large leakage, then the micro-leakage detection is performed.

Specifically, the first vacuumizing device 21 and the second vacuumizing device 22 are started, the vacuum box 10 and the workpiece 200 are vacuumized at the same time, when the gas pressure in the vacuum box 10 and the workpiece 200 reaches a preset value, the leak detector 50 is automatically started, the helium background in the current vacuum box 10 is measured, and the helium background value is recorded; the second evacuating device 22 is then turned off, and the workpiece 200 is inflated with helium gas by the inflator 40, so that the workpiece 200 is inspected for micro-leaks. Optionally, the system automatically determines whether the workpiece 200 is acceptable and gives a prompt or audible and visual alarm. When the leak is detected, the system subtracts the helium background value from the detected leak rate value, and the display value is the actual leak rate of the workpiece 200.

After the detection is finished, automatically entering a discharging program, and deflating the vacuum box 10 and the workpiece 200 to prevent helium residues in the workpiece 200 from interfering with the next detection of the workpiece 200; after the deflation is completed, the loading and unloading robot 82 takes away the workpiece 200, and the leak detection is finished.

Optionally, after the detection is completed, the gas recovery device 70 automatically recovers helium.

Optionally, the air tightness detection system 100 further has a helium removal function, when the leak rate of the unqualified product is too high, the air tightness detection system 100 automatically fills high-purity nitrogen into the polluted vacuum box 10 and the public pipeline to remove helium background, so that false alarm generated by helium background pollution (namely, too high helium background) in the vacuum box 10 can not occur to the equipment.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims

1. A gas tightness detection system, comprising:

the second vacuumizing device is used for vacuumizing the workpiece;

2. The tightness detection system of claim 1 wherein said tightness detection system further comprises a plugging mechanism comprising a seal and a plugging drive assembly;

the sealing driving assembly is used for driving the sealing element to move, so that the sealing element enters the inner cavity of the workpiece and is sealed at the end part of the workpiece, and the sealing element and the notch area of the workpiece are arranged at intervals.

3. The air tightness detection system according to claim 2, wherein a distance between the seal and the scored area of the workpiece is 6mm to 12mm.

4. The gas tightness detection system of claim 2 wherein said closure drive assembly comprises a first drive member, a mounting member, and a second drive member, said second drive member being disposed on said mounting member and said seal member being connected to said second drive member, said first drive member being drivingly connected to said mounting member, said first drive member being adapted to drive said mounting member in a direction toward or away from said workpiece to cause said seal member to enter said interior cavity of said workpiece; the second driving piece is used for driving the sealing piece to expand so that the sealing piece is in interference fit with the inner cavity of the workpiece.

5. The air tightness detection system according to claim 4, wherein a plurality of second driving members are provided on the mounting member, the number of the cavities is plural, each of the cavities is used for accommodating one of the workpieces, and the second driving members are provided in one-to-one correspondence with the cavities.

6. The air tightness detection system according to claim 4, wherein the second driving member comprises a cylinder body, a piston rod movably connected to the cylinder body, and an ejector member provided at an end of the piston rod, the sealing member is sleeved on the piston rod and located between the cylinder body and the ejector member, and the cylinder body is configured to drive the piston rod to expand and contract so that the sealing member expands between the ejector member and the cylinder body.

7. The gas tightness detection system of claim 4 wherein said seal is a ring-like rubber member.

8. The gas tightness detection system of claim 1 further comprising a gas recovery device in communication with said workpiece and for recovering a detection gas within said workpiece.

9. The gas tightness detection system of claim 8 wherein said gas recovery device comprises an evacuation pump, a first tank, and a first solenoid valve, a first end of said first solenoid valve being for connection to said workpiece and a second end of said first solenoid valve being connected to said evacuation pump, said evacuation pump being connected to said first tank;

opening the first solenoid valve causes the evacuation pump to pump the detection gas within the workpiece into the first canister.

10. The air tightness detection system according to claim 9, wherein said air recovery device further comprises a second tank for supplying air to said vacuum box, a compressor, a second solenoid valve, and a third solenoid valve, the air pressure in said second tank being greater than the air pressure in said first tank, the first end of said second solenoid valve being connected to said first tank and said evacuation pump, and the second end of said second solenoid valve being connected to said compressor, the first end of said third solenoid valve being connected to said compressor and the second end of said third solenoid valve being connected to said second tank;

The first electromagnetic valve is closed, the second electromagnetic valve and the third electromagnetic valve are opened, so that the detection gas in the first tank body can be compressed into the second tank body.

11. The gas tightness detection system according to claim 10, wherein said gas recovery device further comprises a fourth solenoid valve, one end of said fourth solenoid valve is connected to said second tank and the other end is connected to a gas supply branch, and opening of said fourth solenoid valve allows the detection gas in said second tank to pass through said gas supply branch into said inflator.

12. The gas tightness detection system according to claim 11, wherein said gas recovery device further comprises a concentration meter for detecting a concentration of the detection gas in said gas supply branch, a high-pressure gas cylinder, and a fifth electromagnetic valve connected between said high-pressure gas cylinder and said first tank.

13. The air tightness detection system of any of claims 1-12 wherein the vacuum box comprises a base and a cover, the cavity being provided in the base, the cover being for covering the base to seal the base.

14. The air tightness detection system according to claim 13, wherein said inflating device is provided on said cover member; the number of the air charging devices is multiple, and the air charging devices are respectively arranged in one-to-one correspondence with the cavities.

15. The tightness detection system of any of claims 1-12 wherein said tightness detection system comprises a plurality of said vacuum boxes, and wherein a plurality of said vacuum boxes are each used in connection with said leak detector.

16. The air tightness detection system of claim 15 wherein said number of vacuum boxes is four and three of said vacuum boxes are used to connect said leak detectors simultaneously.

17. The air tightness detection system of any of claims 1-12 further comprising a transfer mechanism for transferring a workpiece and an up-down robot for gripping the workpiece on the transfer mechanism into the cavity.

18. The gas tightness detection system of claim 17 further comprising a plasma wind sweeping device provided on one side of said conveyor mechanism for sweeping the workpiece by a plasma wind.