Gas valve sealing performance detection device and detection method thereof

Abstract

The invention relates to the technical field of gas valve sealing performance detection devices, in particular to a gas valve sealing performance detection device and a detection method thereof.The gas valve sealing performance detection device comprises a machine shell and a machine cover arranged on the machine shell in a covering mode and further comprises a spring, a pressure sensor and a gas mass spectrometer, and a valve cavity is formed between the machine shell and the machine cover; a valve element matched with the valve cavity is arranged in the valve cavity in a sliding mode, the pressure of a gas source is controlled through a gas source mechanism, displacement or static movement of the valve element in the valve cavity is achieved, the gas leakage amount of dynamic sealing or static sealing of a to-be-tested sealing ring on the valve element is detected through a gas mass spectrometer, and meanwhile the gas leakage amount can be detected according to testing requirements. The material and the shape of the sealing ring to be tested, the roughness of the sealing groove on the valve core, the roughness of the inner wall on the valve cavity and the roughness processing technology are controlled independently or in a combined manner, the flexibility of the testing device is high, the friction force between the sealing ring to be tested and the metal surface in the sealing test can be measured, the structure is simple, the cost is low, the operation is simple and convenient, and the testing efficiency is high. And the test time is short.

Description

Technical Field

[0001] The present invention relates to the technical field of gas valve sealing performance detection devices, and in particular to a gas valve sealing performance detection device and a detection method thereof. Background Art

[0002] The sealing performance of valves is one of the most important performance requirements of valves. The main testing methods for valve sealing performance are static sealing test and dynamic sealing test. Both tests are generally carried out after the valve is assembled. If the sealing performance is not good, re-adjusting the assembly is not only very cumbersome, but also requires high time and material processing costs.

[0003] For gas valves, especially hydrogen valves, sealing is very difficult. Since the atomic radius of hydrogen is very small, not only does the sealing ring need to have good mechanical properties and hydrogen permeation resistance, but also there are strict requirements on the roughness of the metal surface in contact with it. At present, the metal surface roughness of the hydrogen valve seal is generally 0.2-0.3μm. The inner cavity structure of the valve is very complex and the size is relatively small. The cost to achieve such surface roughness is high. For the dynamic sealing performance of gas valves, there are many influencing factors, such as the material of the sealing ring, the shape of the sealing ring, the roughness of the metal surface, the roughness processing technology, the friction between the sealing ring and the metal surface, etc. If the valve is assembled and then the influence of different influencing factors on the sealing performance is studied, the time cost and material preparation cost are very huge.

[0004] In summary, the sealing ring material, sealing ring shape, metal surface roughness and roughness processing technology, and the friction between the sealing ring and the metal surface will affect the sealing performance and cost of the hydrogen valve. In the prior art, there is no test device that can test the sealing performance of the hydrogen valve simply, quickly, and at low cost while taking the above factors into consideration. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in order to solve the problem that the adjustment and assembly of the existing equipment for static sealing test and dynamic sealing test is not only very cumbersome, but also requires high time and material processing costs, a gas valve sealing performance detection device and a detection method are now provided.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a gas valve sealing performance detection device, including a casing and a cover arranged on the casing, and also including a spring, a pressure sensor and a gas mass spectrometer, the casing has a valve cavity, a valve core is slidably arranged in the casing, the valve core divides the valve cavity into a first cavity and a second cavity, a sealing groove is arranged on the valve core, a sealing ring to be tested is arranged in the sealing groove, the inner wall of the sealing groove and the contact surface of the sealing ring to be tested has a required surface roughness, the sealing ring to be tested is sealed with the inner wall of the casing, the inner wall of the casing in contact with the sealing ring to be tested has a required surface roughness, and the first A cavity is connected with an air source mechanism, the air source mechanism is used to deliver gas of required pressure into the first cavity and realize the displacement or stationary control of the valve core in the valve cavity, a strain gauge is arranged in the housing, the strain gauge is located within the contact surface range between the sealing ring to be tested and the inner wall of the housing, the spring is arranged in the second cavity, one end of the spring is against the inner bottom wall of the housing, and the other end of the spring is against the valve core, the pressure sensor is arranged in the second cavity, one end of the pressure sensor is against the inner bottom wall of the housing, and the other end of the pressure sensor is against the valve core, a displacement detection mechanism for detecting the displacement of the valve core is arranged on the housing, and the strain gauge is connected to the strain gauge;

[0007] The gas source mechanism includes a gas cylinder, a pneumatic power unit and an air compressor. The gas cylinder contains the required gas. The output end of the gas cylinder and the air compressor are respectively connected to the input end of the pneumatic power unit. The output end of the pneumatic power unit is connected to the first cavity. Compared with the prior art, this solution controls the pressure of the gas source through the gas source mechanism to achieve the displacement or stillness of the valve core in the valve cavity. The gas mass spectrometer detects the gas leakage of the dynamic seal or static seal of the sealing ring to be tested on the valve core. At the same time, according to the test requirements, the material, shape, roughness of the sealing groove on the valve core, roughness of the inner wall of the valve cavity and the roughness processing technology of the sealing ring to be tested can be controlled separately or in combination. The test device has greater flexibility and can measure the friction between the sealing ring to be tested and the metal surface in the sealing test. It has a simple structure, low cost, easy operation and short test time.

[0008] In order to facilitate observation of the output pressure of the pneumatic power unit, in some preferred embodiments, a pressure gauge is provided on the output end of the pneumatic power unit, through which the pressure input into the first chamber can be intuitively observed.

[0009] In order to facilitate the control of the input of the required gas, in some preferred embodiments, a valve is provided between the output end of the gas cylinder and the input end of the gas pressure power unit.

[0010] In order to realize the installation of the strain gauge on the casing, some preferred embodiments are that the upper end of the casing is provided with an annular installation groove, the strain gauge is arranged at the bottom of the annular installation groove, the strain gauge is fixed to the side of the annular installation groove close to the test seal ring, the annular installation groove is filled with a rigid filler, and the strain gauge is located below the rigid filler. By setting an annular installation groove on the casing, the strain gauge is arranged at the bottom of the annular installation groove, and the rigid filler is filled at the upper part of the annular installation groove, the rigid material is used to support the annular installation groove to prevent the annular groove from deformation.

[0011] Preferably in some embodiments, there is a gap between the strain gauge and a side of the annular mounting groove away from the test sealing ring.

[0012] In some preferred embodiments, the strain gauge is fixed to the inner wall of the annular mounting groove by gluing.

[0013] In order to ensure the sealing of the valve chamber during testing, some preferred embodiments are that the casing and the cover are statically sealed, the upper end of the casing is provided with a step that matches the cover, and the end face and side faces of the step that matches the casing and the cover are respectively provided with end face seals and radial seals.

[0014] In some preferred embodiments, a guide strip is provided on the contact surface between the valve core and the valve cavity, and the guide strip is used to guide the valve core when it is displaced.

[0015] A detection method using the gas valve sealing performance detection device as described above is characterized in that the specific operation steps are as follows:

[0016] S 1. Determine the material and shape of the seal ring to be tested, as well as the roughness value of the inner wall of the valve cavity and the inner wall of the seal groove on the casing;

[0017] S2. Install the guide belt on the valve core, and then install the sealing ring to be tested in the sealing groove of the valve core;

[0018] S3. Place the valve core into the valve cavity, and then place the cover on the casing;

[0019] S4, opening the valve, the air compressor and the air pressure power unit respectively, and filling the first chamber with gas, and monitoring the pressure with a pressure gauge;

[0020] S5. Fill the housing with gas of required pressure through the pneumatic power unit. With the help of the spring, the valve core can be moved. The displacement detection mechanism detects the moving distance of the valve core, and records the pressure value F of the strain gauge and the pressure value f of the pressure sensor. The friction coefficient of the seal ring to be tested can be calculated through μ=f / F, or the position of the valve core will not change, so the static sealing performance test can be realized. At the same time, the gas mass spectrometer detects the gas leakage of the seal.

[0021] S6. After the test is completed, the high-pressure gas in the casing is unloaded through the air pressure power unit.

[0022] In some preferred embodiments, the calculation steps for measuring the friction coefficient of the seal ring to be tested in step S5 are as follows:

[0023] S5.1. Measure the strain ε at the contact point between the sealing ring to be tested and the inner wall of the casing by means of a strain gauge;

[0024] S5.2. Calculation of stress σ

[0025] From the measured strain ε, the stress is calculated by σ = Eε, where E is the elastic modulus;

[0026] S5.3. Calculate the positive pressure F at the contact point between the tested sealing ring and the inner wall of the casing:

[0027] F=σA=EεA

[0028] Where A is the contact area between the strain gauge and the housing. The strain gauge is annular. A = 2πrh, where r is the radius of the annular mounting groove and h is the height of the strain gauge.

[0029] Therefore, F = Eε2πrh;

[0030] S5.4. The pulling force f required for the tested sealing ring to overcome the friction force is directly measured by the pressure sensor, and the friction coefficient is calculated according to the formula μ=f / F.

[0031] The beneficial effects of the present invention are as follows: when in use, a gas valve sealing performance detection device and a detection method thereof of the present invention control the pressure of the gas source through a gas source mechanism to realize the displacement or stationary state of the valve core in the valve cavity, and a gas mass spectrometer detects the gas leakage of the dynamic seal or static seal of the sealing ring to be tested on the valve core. At the same time, according to the test requirements, the material, shape, roughness of the sealing groove on the valve core, roughness of the inner wall of the valve cavity and the roughness processing technology of the sealing ring to be tested can be controlled separately or in combination. The test device has great flexibility and can measure the friction between the sealing ring to be tested and the metal surface in the sealing test. It has a simple structure, low cost, easy operation and short testing time, thus avoiding the problem that the existing equipment for static sealing test and dynamic sealing test is not only very cumbersome to adjust and assemble, but also requires high time and material processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0033] Figure 1 It is a schematic diagram of the structure of the present invention;

[0034] Figure 2 yes Figure 1 A partial enlarged view of middle A;

[0035] Figure 3 It is a schematic diagram of the structure in the annular installation groove of the present invention.

[0036] In the figure: 1, machine cover, 2, machine casing, 3, valve core, 4, gas mass spectrometer, 5, adapter, 6, spring, 7, pressure sensor, 8, plug, 9, displacement detection mechanism, 10, guide belt, 11, sealing ring to be tested, 12, strain gauge, 13, rigid packing, 14, O-ring, 15, air compressor, 16, gas cylinder, 17, pneumatic power unit, 18, valve, 19, pressure gauge, 21, valve chamber, 22, sealing groove, 23, first chamber, 24, second chamber, 25, annular mounting groove, 26, step. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with embodiments:

[0038] The present invention is not limited to the following specific embodiments. A person skilled in the art can implement the present invention in various other specific embodiments according to the contents disclosed in the present invention, or any simple changes or modifications made to the design structure and ideas of the present invention fall within the protection scope of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0041] like Figure 1-3 As shown, a gas valve sealing performance detection device includes a housing 2, a cover 1, a transfer tube 5, a spring 6, a pressure sensor 7 and a gas mass spectrometer 4. The cover 1 is arranged on the housing 2, a valve cavity 21 is arranged between the housing 2 and the cover 1, a valve core 3 is slidably arranged in the housing 2, and the valve core 3 divides the valve cavity 21 into two first cavities 23 and a second cavity 24. A sealing groove 22 is arranged on the valve core 3, and a sealing ring 11 to be tested is arranged in the sealing groove 22. The inner wall of the contact surface between the sealing groove 22 and the sealing ring 11 to be tested has a required surface roughness. The sealing ring 11 to be tested contacts the inner wall of the valve cavity 21 and forms a sealing surface. The inner wall of the valve cavity 21 in contact with the sealing ring 11 to be tested has a required surface roughness. In this embodiment, the metal surface roughness of the inner wall of the valve cavity 21 is generally 0.2-0. 3μm, the first cavity 23 is connected with the air source mechanism, the air source mechanism is used to deliver the gas of the required pressure into the first cavity 23 and realize the displacement or stillness of the control valve core 3 in the valve cavity 21, a strain gauge 12 is arranged in the casing 2, the strain gauge 12 is located in the contact surface range of the sealing ring 11 to be tested and the inner wall of the casing 2, the inner wall of the casing 2 is located between the sealing ring 11 to be tested and the strain gauge 12, the spring 6 is arranged in the second cavity 24, one end of the spring 6 is against the inner bottom wall of the casing 2, and the other end of the spring 6 is against the valve core 3, the pressure sensor 7 is arranged in the second cavity 24, one end of the pressure sensor 7 is against the inner bottom wall of the casing 2, and the other end of the pressure sensor 7 is against the valve core 3, the casing 2 is provided with a displacement detection mechanism 9 for detecting the displacement of the valve core 3, and the strain gauge 12 is connected to the strain gauge through a connecting line.

[0042] The gas source mechanism includes a gas cylinder 16, a pneumatic power unit 17 and an air compressor 15. The gas cylinder 16 is filled with required gas. The output end of the gas cylinder 16 and the air compressor 15 are respectively connected to the input end of the pneumatic power unit 17. The output end of the pneumatic power unit 17 is connected to the first chamber 23 through the transfer tube 5. A pressure gauge 19 is provided on the output end of the pneumatic power unit 17. A valve 18 is provided between the output end of the gas cylinder 16 and the input end of the pneumatic power unit 17. In this embodiment, the gas cylinder 16 is filled with a hydrogen cylinder 16 or helium to perform a comparative test on the sealing performance of hydrogen or helium. The pneumatic power unit 17 is mainly composed of a booster pump and related pipe valve parts. The air compressor 15 drives the pneumatic power unit 17 to work. The input of the pneumatic power unit 17 is connected to the gas cylinder 16 and the air compressor 15. The output of the pneumatic power unit 17 is connected to the first chamber 23. The pressure at the output end of the pneumatic power unit 17 is higher than the pressure of the gas cylinder 16.

[0043] An annular mounting groove 25 is opened at the upper end of the casing 2, and the strain gauge 12 is arranged at the bottom of the annular mounting groove 25. The strain gauge 12 is fixed to the side of the annular mounting groove 25 close to the test sealing ring 11 by glue. The annular mounting groove 25 is filled with a rigid filler 13. The strain gauge 12 is located below the rigid filler 13. There is a gap between the side of the annular mounting groove 25 away from the test sealing ring 11 and the strain gauge 12. The material of the rigid filler 13 is metal, such as iron.

[0044] There are two static seals between the casing 2 and the cover 1. A step 26 is provided on the cover 1. The step 26 matches the valve cavity 21. The step 26 is arranged in the valve cavity 21. A first sealing ring is provided between the step 26 and the valve cavity 21 to form a first seal. A second sealing ring is provided between the end face of the cover 1 and the end face of the casing 2 to form a second seal. The first sealing ring and the second sealing ring are both O-rings 14, so that the end face and side face of the step 26 that match the casing 2 and the cover 1 form an end face seal and a radial seal respectively.

[0045] A guide belt 10 is provided on the contact surface between the valve core 3 and the valve cavity 21. The guide belt 10 is used to guide the valve core 3 during displacement to ensure that the displacement of the valve core 3 is stable and reliable. A plug 8 is threadedly connected to the bottom of the casing 2. One end of the plug 8 is located in the second cavity 24 and is against the pressure sensor 7. The plug 8 needs to be installed on the casing 2 during testing. After the test, the plug 8 is removed, and the metal rod is inserted through the threaded hole to quickly push out the valve core 3 and the pressure sensor 7.

[0046] Example 2

[0047] Embodiment 2 is an application of Embodiment 1, specifically: a detection method using the gas valve sealing performance detection device as described above, and the specific operation steps are as follows:

[0048] S1, determine the material and shape of the sealing ring 11 to be tested, and the roughness values ​​of the inner wall of the valve cavity 21 and the inner wall of the sealing groove 22 on the housing 2;

[0049] S2, installing the guide belt 10 on the valve core 3, and then installing the sealing ring 11 to be tested in the sealing groove 22 of the valve core 3;

[0050] S3, put the valve core 3 into the valve chamber 21, and then cover the machine cover 1 on the machine housing 2;

[0051] S4, respectively opening the valve 18, the air compressor 15 and the air pressure power unit 17, and filling the first chamber 23 with gas, and monitoring the pressure with the pressure gauge 19;

[0052] S5. Fill the housing 2 with gas of the required pressure through the pneumatic power unit 17. With the help of the spring 6, the valve core 3 can be moved. The displacement detection mechanism 9 detects the moving distance of the valve core 3, and records the pressure value F of the strain gauge 12 and the pressure value f of the pressure sensor 7. The friction coefficient of the sealing ring 11 to be tested can be calculated through μ=f / F, or the position of the valve core 3 will not change, so the static sealing performance test can be realized. At the same time, the gas mass spectrometer 4 can detect the gas leakage of the dynamic and static sealing of the sealing ring 11 to be tested;

[0053] The calculation steps for measuring the friction coefficient of the seal ring 11 to be tested in step S5 are as follows:

[0054] S5.1. The strain ε at the contact point between the sealing ring 11 to be tested and the inner wall of the housing 2 is measured by a strain gauge. When the strain gauge 12 is compressed, its resistance decreases. When the strain gauge 12 is stretched, its resistance increases. The strain on the strain gauge 12 is determined by detecting the change in resistance through the strain gauge:

[0055]

[0056] Wherein, ΔR is the resistance change of the strain gauge 12 caused by the strain, R0 is the nominal resistance of the strain gauge 12, k is the strain coefficient of the strain gauge 12, and ε is the strain to be measured. In this embodiment, the strain ε is measured as 2.24×10 -6 ;

[0057] S5.2. Calculation of stress σ

[0058] The stress is calculated from the measured strain ε by σ=Eε, where E is the elastic modulus. The material of the housing 2 is 316L, and E is about 193 GPa.

[0059] S5.3. Calculate the positive pressure F at the contact point between the tested sealing ring 11 and the inner wall of the housing 2:

[0060] F=σA=EεA

[0061] Wherein, A is the contact area between the strain gauge 12 and the housing 2, the strain gauge 12 is annular, A=2πrrh, where r is the radius of the annular mounting groove 25, r=13mm, and h is the height of the strain gauge 12, h=9mm; therefore, F=Eε2πrh=319.92N;

[0062] S5.4. The pulling force f=25.6N required for the tested sealing ring 11 to overcome the friction force is directly measured by the pressure sensor 7. The friction coefficient is calculated according to the formula μ=f / F=0.08. That is, when the valve core 3 starts to move, the displacement of the displacement detection mechanism 9 will begin to change. At this time, the value of the pressure sensor 7 is f. The pressure sensor 7 is reset to zero before ventilation.

[0063] S6. After the detection is completed, the high-pressure gas in the casing 2 is unloaded through the air pressure power unit 17.

[0064] When the above-mentioned gas valve sealing performance detection device and detection method are in use, the present scheme has a simple structure. Before the test, the shape and material of the sealing ring 11 to be tested can be determined first, and the surface roughness of the sealing groove 22 on the required valve core 3 and the metal surface roughness of the inner wall of the valve cavity 21 on the shell can be determined. After the preliminary preparation work is done, the required sealing ring 11 to be tested is installed in the sealing groove 22 on the valve core 3, and the valve core 3 is installed in the valve cavity 21, and then the machine cover 1 is covered on the shell 2 to complete the assembly of the valve core 3. Then the next step of testing can be started. After the test is completed, the machine cover 1 is removed, and the plug 8 is loosened to push out the pressure sensor 7 and the valve core 3. The operation is convenient and quick, the testing efficiency is high, and the testing cost is low.

[0065] The above-mentioned ideal embodiments of the present invention are for inspiration. Through the above-mentioned description, relevant staff can make various changes and modifications without departing from the technical idea of ​​the present invention. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A gas valve sealing performance detection device, comprising a housing (2) and a cover (1) disposed on the housing (2), characterized in that: The device also comprises a spring (6), a pressure sensor (7) and a gas mass spectrometer (4); a valve cavity (21) is provided in the housing (2); a valve core (3) is slidably arranged in the housing (2); the valve core (3) divides the valve cavity (21) into a first cavity (23) and a second cavity (24); a sealing groove (22) is arranged on the valve core (3); a sealing ring (11) to be tested is arranged in the sealing groove (22); the inner wall of the contact surface between the sealing groove (22) and the sealing ring (11) to be tested has a required surface roughness; the sealing ring (11) to be tested is in sealing cooperation with the inner wall of the housing (2); the inner wall of the housing (2) in contact with the sealing ring (11) to be tested has a required surface roughness; the first cavity (23) is connected to an air source mechanism; the air source mechanism is used to supply air to the first cavity (23); The housing (2) is provided with a strain gauge (12), and the strain gauge (12) is located within the contact surface between the sealing ring (11) to be tested and the inner wall of the housing (2). The spring (6) is arranged in the second chamber (24), and one end of the spring (6) is abutted against the inner bottom wall of the housing (2), and the other end of the spring (6) is abutted against the valve core (3). The pressure sensor (7) is arranged in the second chamber (24), and one end of the pressure sensor (7) is abutted against the inner bottom wall of the housing (2), and the other end of the pressure sensor (7) is abutted against the valve core (3). The housing (2) is provided with a displacement detection mechanism (9) for detecting the displacement of the valve core (3), and the strain gauge (12) is connected to the strain gauge; The gas source mechanism comprises a gas cylinder (16), a pneumatic power unit (17) and an air compressor (15); the gas cylinder (16) contains required gas; the output end of the gas cylinder (16) and the air compressor (15) are respectively connected to the input end of the pneumatic power unit (17); and the output end of the pneumatic power unit (17) is connected to the first chamber (23).

2. A gas valve sealing performance detection device according to claim 1, characterized in that: A pressure gauge (19) is provided on the output end of the pneumatic power unit (17).

3. A gas valve sealing performance detection device according to claim 1 or 2, characterized in that: A valve (18) is provided between the output end of the gas cylinder (16) and the input end of the air pressure power unit (17).

4. A gas valve sealing performance detection device according to claim 1, characterized in that: An annular mounting groove (25) is provided at the upper end of the housing (2); the strain gauge (12) is arranged at the bottom of the annular mounting groove (25); the strain gauge (12) is fixed to a side of the annular mounting groove (25) close to the test sealing ring (11); a rigid filler (13) is filled in the annular mounting groove (25); and the strain gauge (12) is located below the rigid filler (13).

5. A gas valve sealing performance detection device according to claim 4, characterized in that: There is a gap between the side of the annular mounting groove (25) away from the test sealing ring (11) and the strain gauge (12).

6. A gas valve sealing performance detection device according to claim 5, characterized in that: The strain gauge (12) is fixed to the inner wall of the annular mounting groove (25) by gluing.

7. A gas valve sealing performance detection device according to claim 1, characterized in that: The upper end of the casing (2) is provided with a step (26) that matches the cover (1), and the end face and side face of the step (26) that matches the casing (2) and the cover (1) are respectively provided with an end face seal and a radial seal.

8. A gas valve sealing performance detection device according to claim 1, characterized in that: A guide strip (10) is provided on the contact surface between the valve core (3) and the valve cavity (21), and the guide strip (10) is used to guide the valve core (3) when it moves.

9. A detection method using the gas valve sealing performance detection device according to any one of claims 1 to 8, characterized in that: The specific steps are as follows: S1, determining the material and shape of the sealing ring (11) to be tested, and the roughness values ​​of the inner wall of the valve chamber (21) and the inner wall of the sealing groove (22) on the housing (2); S2, installing the guide belt (10) on the valve core (3), and then installing the sealing ring (11) to be tested in the sealing groove (22) of the valve core (3); S3, placing the valve core (3) into the valve chamber (21), and then placing the machine cover (1) on the machine housing (2); S4, respectively opening the valve (18), the air compressor (15) and the air pressure power unit (17), and filling the first chamber (23) with gas, and monitoring the pressure with the pressure gauge (19); S5. Fill the housing (2) with gas of the required pressure through the pneumatic power unit (17). With the help of the spring (6), the valve core (3) can be moved. The displacement detection mechanism (9) detects the moving distance of the valve core (3), and records the pressure value F of the strain gauge (12) and the pressure value f of the pressure sensor (7). The friction coefficient of the sealing ring (11) to be tested can be calculated through μ=f / F. Alternatively, the position of the valve core (3) will not change, so the static sealing performance test can be realized. At the same time, the gas mass spectrometer (4) detects the amount of gas leakage in the seal. S6. After the detection is completed, the high-pressure gas in the casing (2) is unloaded through the air pressure power unit (17).

10. The detection method of the gas valve sealing performance detection device according to claim 9, characterized in that: The calculation steps for measuring the friction coefficient of the seal ring to be tested in step S5 are as follows: S5.

1. measuring the strain ε at the contact point between the sealing ring (11) to be tested and the inner wall surface of the housing (2) by means of a strain gauge; S5.

2. Calculation of stress σ From the measured strain ε, the stress is calculated by σ = Eε, where E is the elastic modulus; S5.

3. Calculate the positive pressure F at the contact point between the seal ring (11) to be tested and the inner wall of the housing (2): F=σA=EεA Wherein, A is the contact area between the strain gauge (12) and the housing (2), the strain gauge (12) is annular, A=2πrh, where r is the radius of the annular mounting groove (25), and h is the height of the strain gauge (12); Therefore, F = Eε2πrh; S5.

4. The pulling force f required for the tested sealing ring (11) to overcome the friction force is directly measured by the pressure sensor (7), and the friction coefficient is calculated according to the formula μ=f / F.

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