An air tightness test fixture

Abstract

The utility model provides a kind of airtightness test tool, for opening and closing explosion-proof valve, explosion-proof valve includes valve body, valve body is set up valve groove, valve groove is movably connected valve assembly, valve assembly includes valve cover and valve core, tool includes movable nut, pedestal, piston and sealing cover, sealing cover is set in pedestal, piston is set in sealing cover, one end of piston is screwed movable nut, piston includes piston head, piston rod and suction cup, piston head is slidably connected in second placing cavity, piston head connects piston rod, piston rod connects suction cup, suction cup is used to adsorb valve cover, the outer side wall of piston rod is set with several evenly distributed flow guide grooves, connector is set on sealing cover, the avoiding slot that is adapted to connector is set on pedestal, to make connector connect gas holder. By adopting the above structure, the valve assembly can be directly separated from the valve body, allowing gas to enter the battery pack from the separation point, completing the rapid increase of the pressure inside the battery pack, saving the inflation time and improving the efficiency of the airtightness test.

Description

Technical Field

[0001] This utility model relates to the field of automobile manufacturing technology, and in particular to an airtightness testing fixture. Background Technology

[0002] Electric vehicle battery packs are typically equipped with explosion-proof valves. Inside the explosion-proof valves are movable valve cores and breathable membranes. Under normal pressure differential, the battery pack exchanges gas with the outside through the breathable membrane, thereby maintaining the air pressure inside the battery pack close to that of the external environment. At the same time, the breathable membrane can prevent external liquids and particles from entering the battery pack.

[0003] When thermal runaway occurs in the cells within the battery pack, leading to a rapid increase in internal pressure, the explosion-proof valve will open, allowing the gas inside the battery pack to be quickly released to the outside, preventing the battery pack casing from exploding. The battery pack also requires a tight seal to prevent external dust and liquids from entering.

[0004] Typically, the airtightness of a battery pack is detected and identified through an airtightness test. The airtightness test of a battery pack involves installing an inflation fixture on the explosion-proof valve, which requires injecting gas into the battery pack to raise the pressure inside the battery pack to the target value. However, when the valve core of the explosion-proof valve is not open, gas enters the battery pack through the venting membrane. Since the venting membrane has a low permeability rate, inflation takes a long time, resulting in low test efficiency. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this utility model is to provide an airtightness testing fixture, which aims to solve the technical problem in existing technologies where, when conducting airtightness testing on battery packs, the pressure inside the battery pack needs to be increased to the target value, but gas enters the battery pack through the breathable membrane, requiring a long inflation time and affecting testing efficiency.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] An airtightness testing fixture is used to open and close an explosion-proof valve. The explosion-proof valve includes a valve body with a valve groove on one side. Several perforated slots are formed through the bottom of the valve groove. A valve assembly is movably connected within the valve groove. The valve assembly includes a valve cover and a valve core. The valve cover covers the valve core, and the valve core covers the perforated slots. The airtightness testing fixture includes a movable nut, a base, a piston, and a sealing cap. One side of the movable nut is recessed to form a threaded groove, and an air outlet is formed on the movable nut communicating with the threaded groove. The base includes a first seat body and a second seat body connected to each other. The second seat is connected to the explosion-proof valve. The side of the first seat facing away from the second seat is recessed to form a first receiving cavity. The side of the second seat facing away from the first seat is recessed to form a second receiving cavity communicating with the first receiving cavity. The sealing cover includes a first cover and a second cover. The second cover is located in the second receiving cavity. One end of the first cover is connected to the second cover, and the other end of the first cover passes through the first receiving cavity and is screwed into the screw groove. The side of the second cover facing away from the first cover is recessed to form a first placement cavity. The side of the first cover facing the second cover... A second placement cavity is formed by an inwardly recessed surface, communicating with the first placement cavity. A one-way valve communicating with the second placement cavity is provided on the side of the first cover facing away from the second cover, allowing gas in the second placement cavity to enter the threaded groove. The piston includes a piston head, a piston rod, and a suction cup. The piston head is slidably connected within the second placement cavity. A sealing cap is provided within the first placement cavity to close the second placement cavity. The sealing cap has a through hole. A limiting spring is provided within the second placement cavity, located between the piston head and the top of the second placement cavity. The piston head faces... One side of the sealing cap is connected to the piston rod. The end of the piston rod facing away from the piston head passes through the through hole and is connected to the suction cup. The suction cup is used to adsorb the valve cover. Several evenly spaced guide grooves are formed around the outer side wall of the piston rod. The guide grooves are located at the end of the piston rod facing the suction cup. An air hole communicating with the first receiving cavity is formed on the side wall of the first cover body. The air hole is located between the piston head and the sealing cap. A connector is provided on the air hole. An avoidance groove communicating with the first receiving cavity is formed on the side wall of the first seat body so that the connector can be connected to the gas storage tank.

[0008] Compared to related technologies, the advantages of this utility model are as follows: When it is necessary to increase the pressure inside the battery pack, the second seat is connected to the explosion-proof valve. By rotating the movable nut in the forward direction, with the connector limited by the clearance groove, the sealing cover moves axially downward, thereby driving the suction cup to move and adhere to the valve cover until the end of the second cover facing away from the first cover abuts against the top of the valve body, so that the valve body and the sealing cover form a sealed space; air is introduced into the second placement cavity through the connector, and the gas enters between the piston head and the sealing cover. Because the one-way valve is set on the top of the first cover, Under pressure, the piston head compresses the air between the piston head and the top of the second placement chamber. The air is discharged from the one-way valve to the screw groove and then discharged through the air outlet on the movable nut. At this time, the piston head moves upward axially, driving the valve cover and the valve core to move upward synchronously, opening the perforated groove. As the piston head moves further upward, the guide groove on the piston rod enters between the piston head and the sealing cover. The gas enters the first placement chamber through the perforated groove and then enters the battery pack through the perforated groove, completing the rapid increase of the internal pressure of the battery pack, which saves the inflation time and improves the efficiency of the airtightness test.

[0009] Furthermore, the first cover has several vent holes on the side facing away from the second cover that communicate with the second placement cavity, and the one-way valve cover is disposed on several of the vent holes.

[0010] Furthermore, a sealing ring is fitted onto the outer wall of the piston head, and the side of the sealing ring facing away from the piston head abuts against the inner wall of the first cover.

[0011] Furthermore, a first sealing ring is provided on the side of the second cover facing the explosion-proof valve.

[0012] Furthermore, the side of the first cover facing away from the second cover has an insertion hole communicating with the second placement cavity. The side of the one-way valve facing the first cover is connected to an insertion rod. The end of the insertion rod facing away from the one-way valve passes through the insertion hole and is connected to an abutment block.

[0013] Furthermore, a second sealing ring is provided at the bottom of the valve core, and the end of the second sealing ring facing away from the valve core abuts against the bottom of the valve groove.

[0014] Furthermore, the inner wall of the second receiving cavity is provided with a claw, and the outer wall of the valve body is recessed to form a groove that matches the claw.

[0015] Furthermore, an annular boss is provided on the outer wall of the movable nut. The annular boss is located at the end of the movable nut facing the base. An annular buckle is provided on the side of the annular boss facing away from the base. A sleeve interface is provided on the annular buckle. The movable nut is rotatably connected to the sleeve interface. The end of the annular buckle facing away from the movable nut bends downward and extends to connect to the outer wall of the first base.

[0016] Furthermore, the outer diameter of the second cover is greater than the diameter of the valve groove, and the outer diameter of the second cover is smaller than the outer diameter of the valve body, and the diameter of the suction cup is less than or equal to the diameter of the valve cover.

[0017] Furthermore, a venting groove penetrating the valve body is provided at the bottom of the valve groove, and an air-receiving groove is formed by the inward concavity of one side of the valve core. The air-receiving groove is connected to the venting groove, and a breathable membrane is provided at the bottom of the air-receiving groove. Several air channels communicating with the air-receiving groove are provided between the valve cover and the valve core. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the airtightness testing fixture connected to the explosion-proof valve in an embodiment of this utility model;

[0019] Figure 2 This is a partial internal structure diagram of the airtightness testing fixture connected to the explosion-proof valve in an embodiment of this utility model;

[0020] Figure 3 This is a schematic diagram of the disassembly structure of the sealing cap in the airtightness testing fixture in this embodiment of the utility model;

[0021] Figure 4 This is a schematic diagram of the internal structure of the sealing cap in the airtightness testing fixture in this embodiment of the utility model;

[0022] Figure 5 This is a schematic diagram of the explosion-proof valve in the airtightness testing fixture in this embodiment of the utility model;

[0023] Figure 6 This is a schematic diagram of the disassembly structure of the explosion-proof valve in the airtightness testing fixture in this utility model embodiment;

[0024] Figure 7 This is a schematic diagram showing the disassembled structure of the valve assembly in the explosion-proof valve of the airtightness testing fixture in this embodiment of the present invention;

[0025] Figure 8 This is a cross-sectional view of the airtightness testing fixture connected to the explosion-proof valve in the first working state in this embodiment of the present invention.

[0026] Figure 9This is a cross-sectional view of the airtightness testing fixture connected to the explosion-proof valve in the second working state in this embodiment of the present invention.

[0027] Figure 10 This is a cross-sectional view of the airtightness testing fixture connected to the explosion-proof valve in the third working state in this embodiment of the present invention.

[0028] Figure 11 This is a schematic diagram of the connection structure between the airtightness testing fixture, the explosion-proof valve, and the battery pack in an embodiment of this utility model;

[0029] Explanation of key component symbols:

[0030] 10. Movable nut; 110. Threaded groove; 120. Vent hole; 130. Annular boss; 20. Base; 210. First seat body; 211. First receiving cavity; 212. Clearance groove; 220. Second seat body; 221. Second receiving cavity; 222. Claw; 30. Piston; 310. Piston head; 311. Sealing ring; 320. Piston rod; 321. Guide groove; 330. Suction cup; 40. Sealing cap; 410. First cap body; 411. Second placement cavity; 412. Vent hole ; 420, Second cover; 421, First placement cavity; 430, One-way valve; 440, Limiting spring; 50, Explosion-proof valve; 510, Valve body; 511, Slot; 512, Support seat; 513, Return spring; 520, Valve groove; 530, Hollowed-out groove; 540, Valve assembly; 541, Valve cover; 542, Valve core; 5421, Air-containing groove; 5422, Breathable membrane; 5423, Air passage; 60, Sealing cap; 70, Connector; 80, First sealing ring; 100, Ring buckle.

[0031] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0032] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0033] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0034] Unless otherwise defined, 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 invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Please see Figures 1 to 11 The airtightness testing fixture in this embodiment of the present invention is used to open and close an explosion-proof valve 50. The explosion-proof valve 50 includes a valve body 510. A valve groove 520 is formed on one side of the valve body 510. A venting groove and several hollow grooves 530 are formed at the bottom of the valve groove 520, penetrating the valve body 510. The several hollow grooves 530 are evenly distributed around the venting groove. A valve assembly 540 is movably connected in the valve groove 520. The valve assembly 540 includes a valve cover 541 and a valve core 542. The valve cover 541 is used to cover the valve core 542. One side of the valve core 542 is recessed to form an air-containing groove 5421. The air-containing groove 5421 communicates with the venting groove. A breathable membrane 5422 is provided at the bottom of the air-containing groove 5421. Several air channels 5423 communicating with the air-containing groove 5421 are provided between the valve cover 541 and the valve core 542. The explosion-proof valve 50 is installed on the battery pack. During a routine airtightness test, air enters the air chamber 5421 through the air channel 5423 and then enters the ventilation channel through the breathable membrane 5422, thereby increasing the pressure inside the battery pack. However, the micropores on the breathable membrane 5422 only allow gas to pass through at a very low rate. Therefore, this inflation method takes a long time.

[0036] The airtightness testing fixture includes a movable nut 10, a base 20, a piston 30, and a sealing cap 40. One side of the movable nut 10 is recessed to form a threaded groove 110, and an air vent 120 communicating with the threaded groove 110 is provided on the movable nut 10. The air vent is used to connect the threaded groove 110 to the outside. The base 20 includes a first seat body 210 and a second seat body 220 connected to each other. The second seat body 220 is connected to the explosion-proof valve 50. One side of the first seat body 210 facing away from the second seat body 220... The first receiving cavity 211 is formed by the concave surface of the second seat 220. The second receiving cavity 221, which communicates with the first receiving cavity 211, is formed by the concave surface of the second seat 220 facing away from the first seat 210. Understandably, the inner sidewall of the second receiving cavity 221 is provided with a claw 222. The outer sidewall of the valve body 510 is concave to form a groove 511 that is adapted to the claw 222. When an airtightness test is required, the airtightness test fixture is assembled onto the explosion-proof valve 50 by the cooperation of the claw 222 and the groove 511.

[0037] The base 20 has a side opening for side mounting onto the explosion-proof valve 50.

[0038] The sealing cover 40 includes a first cover body 410 and a second cover body 420. The second cover body 420 is located in the second receiving cavity 221. One end of the first cover body 410 is connected to the second cover body 420, and the other end of the first cover body 410 passes through the first receiving cavity 211 and is screwed into the threaded groove 110. Understandably, the outer side wall of the end of the first cover body 410 facing away from the second cover body 420 has an external thread, and the threaded groove 110 is provided with an internal thread that matches the external thread to complete the screwing work between the two. An annular protrusion 130 is provided on the outer wall of the movable nut 10. The annular protrusion 130 is located at the end of the movable nut 10 facing the base 20. An annular buckle 100 is provided on the side of the annular protrusion 130 facing away from the base 20. A sleeve interface is provided on the annular buckle 100, and the movable nut 10 is rotatably connected to the sleeve interface. The end of the annular buckle 100 facing away from the movable nut 10 bends downward and extends to connect to the outer wall of the first seat 210. By providing the annular buckle 100, the distance between the movable nut 10 and the base 20 can be limited, preventing them from separating and causing the suction cup 330 to be unable to contact the valve cover 541. The sleeve interface on the annular buckle 10 can ensure the rotation function of the movable nut 10 under limited positioning. In this embodiment, the outer wall of the movable nut 10 is provided with knurling or temperature adjustment to increase the surface friction coefficient of the movable nut 10, making it convenient to rotate the movable nut 10 during testing to adjust the vertical position of the sealing cover 40.

[0039] The second cover 420 has a recessed side facing away from the first cover 410 to form a first placement cavity 421. The first cover 410 has a recessed side facing the second cover 420 to form a second placement cavity 411 communicating with the first placement cavity 421. A one-way valve 430 communicating with the second placement cavity 411 is provided on the side of the first cover 410 facing away from the second cover 420, so as to allow gas in the second placement cavity 411 to enter the screw groove 110. Understandably, the one-way valve 430 is also used to restrict air in the screw groove 110 from entering the second placement cavity 411. In this embodiment, the one-way valve 430 is an umbrella valve. In some embodiments, the one-way valve 430 is a ball valve or other types of valve body 510. The first cover 410 has several vent holes 412 on its side facing away from the second cover 420, which communicate with the second placement cavity 411. The one-way valve 430 is disposed on the vent holes 412. Air in the second placement cavity 411 enters the screw groove 110 through the vent holes 412 and the one-way valve 430. The first cover 410 has a plug hole on its side facing away from the second cover 420, which communicates with the second placement cavity 411. The one-way valve 430 is connected to a plug rod on its side facing the first cover 410. One end of the plug rod facing away from the one-way valve 430 passes through the plug hole and is connected to an abutment block. Understandably, the abutment block is used to abut against the top wall of the second placement cavity 411, thereby preventing the one-way valve 430 from detaching from the first cover 410.

[0040] The piston 30 includes a piston head 310, a piston rod 320, and a suction cup 330. The piston head 310 is slidably connected within the second placement cavity 411. A sealing cover 60 is disposed within the first placement cavity 421. One end of the sealing cover 60 is screwed or snapped into the first placement cavity 421. The sealing cover 60 is used to close the second placement cavity 411. A through hole is formed on the sealing cover 60. The piston rod 320 is connected to the side of the piston head 310 facing the sealing cover 60. In this embodiment, the piston rod 320 is made of rubber. The end of the piston rod 320 facing away from the piston head 310 passes through the through hole and is connected to the suction cup 330. The suction cup 330 is used to adsorb the valve cover 541. The side wall of the first cover 410 has an opening... The first receiving cavity 211 is connected to an air hole, which is located between the piston head 310 and the sealing cap 60. A connector 70 is provided on the air hole. The side wall of the first seat 210 is provided with a relief groove 212 that communicates with the first receiving cavity 211 so that the connector 70 can be connected to an air storage tank. Understandably, by filling the air hole with air through the air storage tank, air can enter between the piston head 310 and the sealing cap 60. A limiting spring 440 is provided in the second placement cavity 411. The limiting spring 440 is located between the piston head 310 and the top of the second placement cavity 411, that is, one end of the limiting spring 440 is connected to the piston head 310, and the other end of the limiting spring 440 is connected to the top of the second placement cavity 411. By setting the limiting spring 440, the piston head 310 can be prevented from moving down excessively under the action of gravity, causing air to fill between the piston head 310 and the top of the second receiving cavity 221, which would result in the piston 30 being unable to move and the test fixture failing. Furthermore, by setting the limiting spring 440, the piston 30 can be reset after the gas tank stops filling.

[0041] A sealing ring 311 is fitted onto the outer wall of the piston head 310. The side of the sealing ring 311 facing away from the piston head 310 abuts against the inner wall of the first cover 410. By setting the sealing ring 311, the sliding ability of the piston head 310 within the second placement cavity 411 can be ensured, while the sealing performance of the space between the piston head 310 and the sealing cover 60 can be improved. During use, the mobility of the piston head 310 can be improved by dripping grease onto the sealing ring 311.

[0042] A plurality of evenly spaced guide grooves 321 are formed on the outer wall of the piston rod 320. These guide grooves 321 are located at the end of the piston rod 320 facing the suction cup 330. When it is necessary to increase the pressure inside the battery pack, the second seat 220 is connected to the explosion-proof valve 50. By rotating the movable nut 10 in the forward direction, with the connector 70 limited by the clearance groove 212, the sealing cover 40 moves axially downward, thereby causing the suction cup 330 to move axially downward, pressing against and adsorbing the valve cover 541, until the end of the second cover 420 facing away from the first cover 410 abuts against the top of the valve body 510, forming a sealed space between the valve body 510 and the sealing cover 40. Gas is then introduced into the second placement cavity 411 through the connector 70, entering between the piston head 310 and the sealing cover 60. The one-way valve 430 is provided on the top of the first cover 410. Under pressure, the piston head 310 squeezes the air between the piston head 310 and the top of the second placement cavity 411. The air is discharged from the one-way valve 430 to the screw groove 110 and discharged through the air outlet 120 on the movable nut 10. At this time, the piston head 310 moves upward axially and drives the valve cover 541 and the valve core 542 to move upward synchronously, opening the hollow groove 530. As the piston head 310 moves further upward, the guide groove 321 on the piston rod 320 enters between the piston head 310 and the sealing cover 60. The gas enters the first placement cavity 421 through the hollow groove 530 and enters the battery pack through the hollow groove 530, completing the rapid increase of the pressure inside the battery pack, which saves the inflation time and improves the efficiency of the airtightness test.

[0043] Understandably, a gap is formed between the outer wall of the valve core 542 and the inner wall of the valve body 510, allowing gas to enter the hollowed-out groove 530 through this gap. The outer diameter of the second cover 420 is larger than the diameter of the valve groove 520, and the outer diameter of the second cover 420 is smaller than the outer diameter of the valve body 510, preventing the second cover 420 from blocking the gap and preventing gas flow. The diameter of the suction cup 330 is smaller than or equal to the diameter of the valve cover 541, preventing the suction cup 330 from blocking the gap and preventing gas flow. Furthermore, to ensure that a sealed space is formed between the second cover 420 and the valve body 510 after the sealing cover 40 moves down, a first sealing ring 80 is provided on the side of the second cover 420 facing the explosion-proof valve 50. After the second cover 420 moves down and abuts against the valve body 510, the first sealing ring 80 further seals, forming a completely sealed environment with the second placement cavity 411, the gap, and part of the valve groove 520.

[0044] The bottom of the valve body 510 is connected to a support base 512. A return spring 513 is provided between the support base 512 and the valve core 542 so that the valve core 542 covers a plurality of the hollow grooves 530. Preferably, a second sealing ring is provided at the bottom of the valve core 542. The end of the second sealing ring facing away from the valve core 542 abuts against the bottom of the valve groove 520. When no test is performed, under the traction force of the return spring 513, the valve core 542 presses the bottom of the valve groove 520, so that the second sealing ring seals the space of the hollow grooves 530 and the vent groove, preventing liquid from entering the battery pack through the hollow grooves 530 or the vent groove. Furthermore, after inflation is completed, the gas tank continues to inflate the space between the piston head 310 and the sealing cap 60. The movable nut 10 is rotated to disengage the second cover 420 from the valve body 510. At this time, the suction cup moves upward along the axial direction, and the return spring 513 continuously applies a return force to the valve core 542. When the return force exceeds the suction force of the suction cup, the suction cup disengages from the valve cover 541, and the valve core 542 resets under the action of the return spring 513, re-abutting against and sealing the hollow groove 530. After inflation stops, the limiting spring 440 drives the piston head 310 to reset.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An airtightness testing fixture for opening and closing explosion-proof valves, characterized in that: The explosion-proof valve includes a valve body with a valve groove on one side and several perforated slots penetrating the valve body at the bottom of the valve groove. A valve assembly is movably connected within the valve groove. The valve assembly includes a valve cover and a valve core. The valve cover covers the valve core, and the valve core covers the several perforated slots. The airtightness testing fixture includes a movable nut, a base, a piston, and a sealing cap. One side of the movable nut is recessed to form a threaded groove, and the movable nut is provided with an air vent that communicates with the threaded groove. The base includes a first base body and a second base body connected to each other. The second base body is connected to the explosion-proof valve. The side of the first base body facing away from the second base body is recessed to form a first receiving cavity. The side of the second base body facing away from the first base body is recessed to form a second receiving cavity that communicates with the first receiving cavity. The sealing cap includes a first cap and a second cap. The second cap is located in the second receiving cavity. One end of the first cap is connected to the second cap, and the other end of the first cap passes through the first receiving cavity and is screwed into the screw groove. The side of the second cap facing away from the first cap is recessed to form a first placement cavity. The side of the first cap facing the second cap is recessed to form a second placement cavity that communicates with the first placement cavity. A one-way valve that communicates with the second placement cavity is provided on the side of the first cap facing away from the second cap, so that gas in the second placement cavity can enter the screw groove. The piston includes a piston head, a piston rod, and a suction cup. The piston head is slidably connected to the second placement cavity. A sealing cover is provided in the first placement cavity to close the second placement cavity. The sealing cover has a through hole. A limiting spring is provided in the second placement cavity, located between the piston head and the top of the second placement cavity. The piston rod is connected to the side of the piston head facing the sealing cover. The end of the piston rod facing away from the piston head passes through the through hole and is connected to the suction cup, which is used to adsorb the valve cover. Several evenly spaced guide grooves are formed around the outer wall of the piston rod, located at the end of the piston rod facing the suction cup. An air hole communicating with the first receiving cavity is formed on the side wall of the first cover, located between the piston head and the sealing cover. A connector is provided on the air hole. An avoidance groove communicating with the first receiving cavity is formed on the side wall of the first seat to allow the connector to connect to the gas storage tank.

2. The airtightness testing fixture according to claim 1, characterized in that, The first cover has several vent holes on the side facing away from the second cover, which communicate with the second placement cavity, and the one-way valve cover is disposed on several of the vent holes.

3. The airtightness testing fixture according to claim 1, characterized in that, A sealing ring is fitted onto the outer wall of the piston head, and the side of the sealing ring facing away from the piston head abuts against the inner wall of the first cover.

4. The airtightness testing fixture according to claim 1, characterized in that, A first sealing ring is provided on the side of the second cover facing the explosion-proof valve.

5. The airtightness testing fixture according to claim 1, characterized in that, The first cover has a plug hole on the side facing away from the second cover that communicates with the second placement cavity. The side of the one-way valve facing the first cover is connected to a plug rod. The end of the plug rod facing away from the one-way valve passes through the plug hole and is connected to an abutment block.

6. The airtightness testing fixture according to claim 1, characterized in that, A second sealing ring is provided at the bottom of the valve core, and the end of the second sealing ring facing away from the valve core abuts against the bottom of the valve groove.

7. The airtightness testing fixture according to claim 1, characterized in that, The inner wall of the second receiving cavity is provided with a claw, and the outer wall of the valve body is recessed to form a groove that matches the claw.

8. The airtightness testing fixture according to claim 1, characterized in that, The outer wall of the movable nut is provided with an annular boss, which is located at the end of the movable nut facing the base. The side of the annular boss facing away from the base is provided with a ring buckle, which has a sleeve interface. The movable nut is rotatably connected to the sleeve interface. The end of the ring buckle facing away from the movable nut bends downward and extends to connect to the outer wall of the first base.

9. The airtightness testing fixture according to claim 1, characterized in that, The outer diameter of the second cover is greater than the diameter of the valve groove, and the outer diameter of the second cover is less than the outer diameter of the valve body. The diameter of the suction cup is less than or equal to the diameter of the valve cover.

10. The airtightness testing fixture according to claim 1, characterized in that, The bottom of the valve groove is also provided with a venting groove that penetrates the valve body. One side of the valve core is recessed to form an air-containing groove. The air-containing groove is connected to the venting groove. A breathable membrane is provided at the bottom of the air-containing groove. Several air channels connected to the air-containing groove are provided between the valve cover and the valve core.

Images