Air tightness inspection device and method for product with exhaust valve
By designing an air tightness inspection device for products with exhaust valves and using high-pressure nitrogen and a multi-stage pressure reducing valve system to detect product air tightness, the problem that existing methods cannot detect is solved, and a simple and safe air tightness detection effect is achieved.
Patent Information
- Application Number
- CN202510823035.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-19
- Publication Date
- 2025-09-12
AI Technical Summary
Existing air tightness inspection methods cannot effectively detect the air tightness of products with exhaust valves. Common methods are not applicable or the detection effect is poor.
Design an air tightness inspection device for products with exhaust valves, including gas control tooling and sealing tooling. Through high-pressure nitrogen input and a multi-stage pressure reducing valve system, combined with a pressure gauge, the air tightness of the product is detected, and bolts and flange connections are used to ensure sealing.
It realizes stable and reliable air tightness testing of products with exhaust valves. It is easy to operate, meets the use requirements and ensures the safety of testing.
Smart Images
Figure CN120628474A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of air tightness detection, and in particular relates to an air tightness inspection device and an inspection method for a product with an exhaust valve. Background Art
[0002] At present, there are three common methods for checking air tightness. The first is the pressure difference method, which is often used to check the air tightness of a closed system. By applying different pressures inside and outside the system and then measuring the pressure difference, the sealing performance of the system is judged. If the system is well sealed, the pressure difference should be maintained at a stable level. If the pressure difference is unstable, it may mean that there is a leak in the system; the second is the bubble method, which is usually used to check smaller seals, such as pipes, valves, etc. The test piece is immersed in a pool of water or liquid, and pressure is applied to observe whether bubbles are generated. If bubbles are observed, it means that there is a gas leak and repair is needed; the third is the smoke method, which is an intuitive method suitable for detecting relatively small leaks. By injecting air into the system A certain amount of smoke or special detection smoke agent is injected into the system, and the movement of the smoke can be observed to determine whether there is a leak in the system. The above three airtightness detection methods cannot be used for airtightness inspection of products with exhaust valves. The product includes an exhaust valve, a high-pressure nitrogen cylinder, a precision optical system, a pneumatic control cabin, a disposable thermal battery, a control tracking circuit system, and a radio fuse system. Due to the exhaust valve, when the air pressure in the cabin reaches a certain level, the gas is discharged to the outside of the cabin through the exhaust valve, and the first method cannot be used; the product is a cylindrical product with a length of 2 meters and a diameter of 0.2 meters. It is not suitable for the second method of detecting small parts. The internal structure of the product is very complex, and smoke may affect the product status, and it is not suitable for the third method. Summary of the Invention
[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to design an inspection device and method for products with exhaust valves, so as to solve the problem mentioned in the background technology that the current common air tightness inspection method cannot detect products with exhaust valves.
[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solution: an air tightness inspection device for a product with an exhaust valve, comprising a gas control tooling and a sealing tooling, wherein the air inlet of the gas control tooling is connected to a gas source, and the high-pressure nitrogen output by the gas source is regulated by the gas control tooling and then connected to the sealing tooling through the output end of the gas control tooling, and the sealing tooling is connected to the bottom of the product with an exhaust valve, and a certain pressure of nitrogen is input into the cabin of the product with the exhaust valve to detect the air tightness of the product with the exhaust valve.
[0005] The sealing tooling includes a main body, a flange part and an inlet and outlet gas joint. The main body is a cylindrical structure with an open end. A flange part connected to it is provided at the edge of the end with the opening of the main body. The flange part is connected to the bottom of the product with an exhaust valve by bolts. The center of the outer end face of the main body is provided with an inlet and outlet gas joint. The inlet and outlet gas joint is connected to the output end of the gas control tooling. An annular rib is provided at the connection between the flange part and the main body, and an annular sealing ring is provided on the annular rib.
[0006] The gas control tooling is a rectangular box structure as a whole, and an input gas path, a first output gas path and a second output gas path are provided in the box, and the input gas path, the first output gas path and the second output gas path are connected by a tee.
[0007] The input gas circuit includes an air inlet, a switch A, a filter, a pressure gauge A, a first-level pressure reducing valve and a pressure gauge B. The air inlet is connected to the air source. The high-pressure nitrogen provided by the air source enters the filter after passing through the switch A. The nitrogen after passing through the filter enters the first-level pressure reducing valve, and then enters the air inlet of the three-way valve after passing through the first-level pressure reducing valve. The pressure gauge A is set between the first-level pressure reducing valve and the filter, and the pressure gauge B is set between the first-level pressure reducing valve and the three-way valve.
[0008] The first output gas circuit includes a secondary pressure reducing valve A, a safety valve A, a pressure gauge C, a switch B, a three-way switch A and an output end A. The nitrogen discharged from the three-way outlet enters the secondary pressure reducing valve A, passes through the secondary pressure reducing valve A, and then passes through the switch B and the three-way switch A in sequence. The nitrogen after passing through the three-way switch A is discharged from the output end A. A safety valve A and a pressure gauge C are provided between the secondary pressure reducing valve A and the switch B.
[0009] The second output gas circuit includes a secondary pressure reducing valve B, a safety valve B, a pressure gauge D, a switch C, a three-way switch B and an output end B. The nitrogen discharged from the three-way outlet enters the secondary pressure reducing valve B, passes through the secondary pressure reducing valve B, and then passes through the switch C and the three-way switch B in sequence. The nitrogen after passing through the three-way switch B is discharged from the output end B. A safety valve B and a pressure gauge D are provided between the secondary pressure reducing valve B and the switch C.
[0010] The present invention also provides an inspection method based on the air tightness inspection device of the product with an exhaust valve, comprising the following steps: Step 1: Use bolts to match the flange part and install the sealing tool on the bottom of the product with exhaust valve; Step 2: Connect the air inlet of the gas control tooling to the air source, and connect the output ends of the first output air path and the second output air path to the air inlet and outlet joints of the sealing tooling respectively; Step 3: Open switch A on the gas control tooling, switch B of the first output gas line, and switch C of the second output gas line, and slowly supply gas into the product chamber. When the exhaust valve of the product is exhausted, close switches B and C. Use the values of pressure gauges C and D to determine whether the connected product with an exhaust valve is leaking. Step 4: After completing the inspection process, remove the sealing tooling connected to the product, store the bolts and hoses in the box of the gas control tooling, and turn off the gas source.
[0011] The beneficial effects of the present invention are as follows: from the perspective of on-site use effects, the test performance is stable, the operation is simple, the detection work is safe and reliable, and the use requirements are met. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 Schematic diagram of the gas circuit of the gas control tooling of the present invention.
[0013] Figure 2 This is a schematic diagram of the interior of the sealing tooling of the present invention.
[0014] Figure 3 This is an external schematic diagram of the sealing tool of the present invention.
[0015] Figure 4 Schematic diagram of the control panel of the gas control tooling of the present invention.
[0016] In the figure: 1. Sealing tooling, 101. Flange part, 102. Inlet and outlet gas interfaces, 2. Gas control tooling, 3. Air inlet, 4. Switch A, 5. Pressure gauge A, 6. Primary pressure reducing valve, 7. Pressure gauge B, 8. Secondary pressure reducing valve A, 9. Pressure gauge C, 10. Switch B, 11. Three-way switch A, 12. Switch C, 13. Three-way switch B, 14. Pressure gauge D, 15. Secondary pressure reducing valve B, 16. Output end A, 17. Output end B, 18. Safety valve A, 19. Safety valve B, 20. Filter, 21. Tee. DETAILED DESCRIPTION
[0017] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings of this specification. It should be noted that the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0018] See also Figures 1-4A device for checking the air tightness of a product with an exhaust valve comprises a gas control tool 2 and a sealing tool 1. The air inlet 3 of the gas control tool 2 is connected to a gas source. The high-pressure nitrogen output by the gas source is regulated by the gas control tool 2 and then connected to the sealing tool 1 through the output end of the gas control tool 2. The sealing tool 1 is connected to the bottom of the product with an exhaust valve. A certain pressure of nitrogen is input into the cabin of the product with an exhaust valve to test the air tightness of the product with an exhaust valve. The gas control tool 2 is an overall rectangular box structure, and an input gas path, a first output gas path, and a second output gas path are provided within the box. The input gas path, the first output gas path, and the second output gas path are connected by a tee 21. The input gas circuit includes an air inlet 3, a switch A4, a filter 20, a pressure gauge A5, a first-level pressure reducing valve 6 and a pressure gauge B7. The air inlet 3 is connected to the air source. The high-pressure nitrogen provided by the air source enters the filter 20 after passing through the switch A4. The nitrogen after passing through the filter 20 enters the first-level pressure reducing valve 6, and then enters the air inlet of the tee 21 after passing through the first-level pressure reducing valve 6. A pressure gauge A5 is set between the first-level pressure reducing valve 6 and the filter 20, and a pressure gauge B7 is set between the first-level pressure reducing valve 6 and the tee 21. The first output gas path includes a secondary pressure reducing valve A8, a safety valve A18, a pressure gauge C9, a switch B10, a three-way switch A11, and an output terminal A16. Nitrogen discharged from the outlet of the three-way switch 21 enters the secondary pressure reducing valve A8, passes through the secondary pressure reducing valve A8, and then sequentially passes through the switch B10 and the three-way switch A11. The nitrogen after passing through the three-way switch A11 is discharged from the output terminal A16. A safety valve A18 and a pressure gauge C9 are provided between the secondary pressure reducing valve A8 and the switch B10. The second output gas path includes a secondary pressure reducing valve B15, a safety valve B19, a pressure gauge D14, a switch C12, a three-way switch B13, and an output port B17. Nitrogen discharged from the outlet of the three-way switch 21 enters the secondary pressure reducing valve B15, passes through the secondary pressure reducing valve B15, and then passes through the switch C12 and the three-way switch B13. The nitrogen after passing through the three-way switch B13 is discharged from the output port B17. The safety valve B19 and the pressure gauge D14 are provided between the secondary pressure reducing valve B15 and the switch C12. The sealing tool 1 includes a main body, a flange portion 101, and an inlet and outlet gas connector 102. The main body is a cylindrical structure with one end open. The flange portion 101 is integrally connected to the edge of the end with the opening. The flange portion 101 is bolted to the bottom of the product with the exhaust valve. The inlet and outlet gas connector 102 is provided at the center of the outer end surface of the main body. The flange portion 101 is provided with an annular rib at the connection with the main body, and the annular rib is provided with an annular sealing ring. The three-way switch A11 and the three-way switch B13 are connected to multiple output ends according to needs. The number of the sealing tooling 1 matches the number of the output ends, and multiple products with exhaust valves can be detected at the same time.
[0019] When the present invention is used: Step 1: Use bolts to match the flange part and install the sealing tool on the bottom of the product with exhaust valve. When installing, pay attention to whether the annular sealing ring and the connection at the bottom of the product are tightly matched; Step 2: Connect the air inlet of the gas control tooling to the air source, and connect the output ends of the first output air path and the second output air path to the air inlet and outlet joints of each sealing tooling through hoses respectively; Step 3: Open switch A on the gas control tooling, switch B on the first output gas line, and switch C on the second output gas line. Under the action of the pressure reducing valves at each level, the pressurized nitrogen provided by the gas source is slowly supplied to the product chamber through the sealing tooling. The opening pressure of safety valve A and safety valve B is set according to the parameters of the exhaust valve. When the exhaust valve of the product starts to exhaust, close switch B and switch C. Use the values of pressure gauges C and D to determine whether the connected product with an exhaust valve is leaking; Step 4: When the product is detected to be leak-free, proceed to the next step; When a leak is detected: first use a leak detector to check if there is any leak at the sealing ring of the head. If there is a leak at the sealing ring, replace the sealing ring and repeat the above steps to test again. Secondly, check whether there is air leakage at the screw. If there is air leakage, remove the screw and replace it. Apply medium-strength anaerobic glue and one-component room temperature vulcanized silicone rubber to the thread to fix and seal it. Repeat the above steps and test again. Check the fuze antenna for leaks again. If there are leaks, disassemble the product, send the fuze to the fuze cabin for repair, remove the fuze shell, replace the sealing ring at the fuze antenna, and repeat the above steps to test again after assembly. Finally, use a leak detection liquid to check whether the umbilical cable socket of the product is leaking. If there is leakage at the umbilical cable socket, use a bamboo stick and silicone rubber to seal the gap between the umbilical cable socket and the shell. Then use a plastic scraper to clean the excess silicone rubber at the joint of the umbilical cable socket and the shell. After standing for 24 hours, repeat the above steps and test again until there is no leakage and proceed to the next step. Step 5: After completing the inspection process, remove the sealing tooling connected to the product, store the bolts and hoses in the box of the gas control tooling, and turn off the gas source.
[0020] During testing, please note that the high-pressure (0MPa~20MPa) nitrogen gas from the gas source passes through switch A4, is sent to the first-stage pressure reducing valve 6 via filter 20, and is reduced to 1MPa~2MPa. It is then split into two paths through tee 21. One path is reduced to 0.035MPa by the second-stage pressure reducing valve A8 and is output to the product sealing tool 1. The other path is used to test the product packaging boxes. If the number of products to be tested is large, more branches can be opened through the three-way switches on each branch for simultaneous testing. Secondly, determine the opening pressure of the exhaust valve of the product. Contact the exhaust valve manufacturer and confirm that the opening pressure of the exhaust valve is 0.025MPa~0.035MPa. Prepare 10 products to be tested, install the sealing tool 1 to the rear end of each product in turn, connect the output end of the gas control tool 2 to the inlet and outlet gas joints 102 of each sealing tool 1 respectively, use the gas control tool 2 to supply gas into the product, and calculate the opening pressure of the exhaust valve of the 10 products. The opening pressure of the exhaust valve of the 10 products is within the range of 0.029MPa~0.032MPa, and most of the pressures are within the middle value of 0.03MPa provided by the exhaust valve manufacturer. The next step is to determine the tooling parameters. In order to prevent excessive pressure in the product cabin from damaging product components, combined with the technical indicators of the exhaust valve and the actual opening pressure of the exhaust valve, while ensuring that the exhaust valve should be in the open state during the test, the output pressure of the secondary pressure reducing valve A8 and the secondary pressure reducing valve B15 is set to 0.035 MPa, and the opening pressure of the safety valve A18 and the safety valve B19 is set to 0.07 MPa.
[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
[0022] The parts not described in detail in this invention are prior art.
Claims
1. An air tightness inspection device for a product with an exhaust valve, comprising a gas control tool (2) and a sealing tool (1), characterized in that: The air inlet (3) of the gas control tooling (2) is connected to the gas source, and the high-pressure nitrogen output by the gas source is regulated by the gas control tooling (2) and then connected to the sealing tooling (1) through the output end of the gas control tooling (2). The sealing tooling (1) is connected to the bottom of the product with the exhaust valve, and a certain pressure of nitrogen is input into the cabin of the product with the exhaust valve to detect the air tightness of the product with the exhaust valve.
2. The air tightness inspection device for a product with an exhaust valve according to claim 1, characterized in that: The sealing tool (1) comprises a main body, a flange portion (101) and an air inlet and outlet joint (102). The main body is a cylindrical structure with an opening at one end. A flange portion (101) connected to the main body is provided at the edge of the end with the opening. The flange portion (101) is connected to the bottom of the product with the exhaust valve by bolts. The air inlet and outlet joint (102) is provided at the center of the outer end surface of the main body. An annular rib is provided at the connection between the flange portion (101) and the main body, and an annular sealing ring is provided on the annular rib.
3. The air tightness inspection device for a product with an exhaust valve according to claim 1, characterized in that: The gas control tooling (2) is a rectangular box structure as a whole, and an input gas path, a first output gas path and a second output gas path are provided in the box, and the input gas path, the first output gas path and the second output gas path are connected via a tee (21).
4. The air tightness inspection device for a product with an exhaust valve according to claim 3, characterized in that: The input gas circuit includes an air inlet (3), a switch A (4), a filter (20), a pressure gauge A (5), a first-stage pressure reducing valve (6) and a pressure gauge B (7). The air inlet (3) is connected to an air source. The high-pressure nitrogen provided by the air source enters the filter (20) after passing through the switch A (4). The nitrogen after passing through the filter (20) enters the first-stage pressure reducing valve (6). After passing through the first-stage pressure reducing valve (6), the nitrogen enters the air inlet of the three-way valve (21). The pressure gauge A (5) is provided between the first-stage pressure reducing valve (6) and the filter (20), and the pressure gauge B (7) is provided between the first-stage pressure reducing valve (6) and the three-way valve (21).
5. The air tightness inspection device for a product with an exhaust valve according to claim 3, characterized in that: The first output gas path comprises a secondary pressure reducing valve A (8), a safety valve A (18), a pressure gauge C (9), a switch B (10), a three-way switch A (11) and an output terminal A (16). Nitrogen gas discharged from the gas outlet of the three-way switch (21) enters the secondary pressure reducing valve A (8), passes through the secondary pressure reducing valve A (8), and then sequentially passes through the switch B (10) and the three-way switch A (11). The nitrogen gas after passing through the three-way switch A (11) is discharged from the output terminal A (16). A safety valve A (18) and a pressure gauge C (9) are provided between the secondary pressure reducing valve A (8) and the switch B (10).
6. The air tightness inspection device for a product with an exhaust valve according to claim 3, characterized in that: The second output gas path comprises a secondary pressure reducing valve B (15), a safety valve B (19), a pressure gauge D (14), a switch C (12), a three-way switch B (13) and an output terminal B (17). Nitrogen gas discharged from the other gas outlet of the three-way switch (21) enters the secondary pressure reducing valve B (15), passes through the secondary pressure reducing valve B (15), and then passes through the switch C (12) and the three-way switch B (13) in sequence. The nitrogen gas after passing through the three-way switch B (13) is discharged from the output terminal B (17). A safety valve B (19) and a pressure gauge D (14) are provided between the secondary pressure reducing valve B (15) and the switch C (12).
7. The method for inspecting the air tightness of a product with an exhaust valve according to any one of claims 1 to 6, comprising the following steps: Step 1: Use bolts to fit the flange part (101) and install the sealing tool (1) on the bottom of the product with the exhaust valve; Step 2: Connect the air inlet (3) of the gas control tooling (2) to the air source, and connect the output ends of the first output air path and the second output air path to the air inlet and outlet joints (102) of the sealing tooling (1) respectively; Step 3: Open the switch A (4) on the gas control tooling (2), the switch B (10) of the first output gas line, and the switch C (12) of the second output gas line. Under the action of the first pressure reducing valve (6), the second pressure reducing valve A (8), and the second pressure reducing valve B (15), the pressurized gas output by the gas source is slowly supplied to the product chamber. The opening pressure of the safety valve A (18) and the safety valve B (19) are set according to the parameters of the exhaust valve. When the exhaust valve of the product is exhausted, close the switch B (10) and the switch C (12). The values of the pressure gauge C (9) and the pressure gauge D (14) are used to determine whether the connected product with the exhaust valve is leaking. Step 4: After completing the inspection process, remove the sealing tool (1) connected to the product, store the bolts and hoses in the box of the gas control tool (2), and turn off the gas source.
8. The method for inspecting the air tightness of a product with an exhaust valve according to claim 7, wherein: The first-stage pressure reducing valve (6) reduces the pressure to 1 MPa to 2 MPa, the second-stage pressure reducing valve A (8) and the second-stage pressure reducing valve B (15) reduce the pressure of the first output gas path and the second output gas path to 0.035 MPa, and the opening pressure of the safety valve A (18) and the safety valve B (19) is set to 0.07 MPa.