Differential pressure type air tightness detection device

Abstract

The utility model provides a differential pressure type air tightness detection device. The differential pressure type air tightness detection device comprises a valve plate, an air inlet valve, an exhaust valve, a pressure sensor and a differential pressure sensor, the valve plate is provided with an air inlet channel, a first air outlet channel and a second air outlet channel, and the air inlet valve is connected with the air inlet channel, the first air outlet channel and the second air outlet channel and used for controlling connection and disconnection of the air inlet channel, the first air outlet channel and the second air outlet channel. The exhaust valve is connected with the first air outlet channel and the second air outlet channel and used for controlling connection and disconnection between the first air outlet channel and the outside and between the second air outlet channel and the outside. The pressure sensor is connected to the first air outlet channel and used for detecting whether the pressure in the test cavity changes or not. The pressure difference sensor is connected to the first air outlet channel and the second air outlet channel and is used for detecting the pressure difference between the test cavity and the standard cavity; according to the utility model, different test modes can be selected according to the specific requirements of users, so as to meet the requirements of test efficiency or detection accuracy.

Description

Technical Field

[0001] This utility model relates to the technical field of airtightness testing equipment, specifically a differential pressure airtightness testing device. Background Technology

[0002] A sealing tester, also known as an airtightness tester, is mainly used for sealing tests of packaging bags, bottles, tubes, cans, boxes, battery packs, etc. in industries such as food, pharmaceuticals, medical devices, daily chemicals, automobiles, electronic components, stationery, and consumer electronics, to prevent damage and air leakage.

[0003] Existing sealing tests typically employ two methods: direct testing and differential pressure testing. Direct testing involves connecting a pressure sensor to the test line, placing the test product in the test chamber, injecting compressed gas, and observing any change in pressure on the sensor after it has settled. This method is simple and convenient, but if the test product experiences an extremely slow leak, it may not be detectable in a short time, making it suitable for products with moderate accuracy requirements. Differential pressure testing involves placing a differential pressure sensor between the test line and a standard line, placing the test product and a standard product in the test chamber and standard chamber respectively, injecting compressed gas, and observing any pressure difference on the differential pressure sensor. This method offers high accuracy and reliable results, making it suitable for products with high precision requirements, but the process is slightly more cumbersome. Therefore, designing a differential pressure airtightness testing device that allows users to select the testing method according to their needs is a pressing issue.

[0004] In addition, the air circuit of the existing air tightness testing device is controlled by solenoid valves. However, after prolonged use, solenoid valves are prone to overheating, which affects the stability of airflow and thus the accuracy of the test. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a device that allows for selection of airtightness detection methods according to needs.

[0006] The technical solution of this utility model is to provide a differential pressure airtightness detection device with the following structure:

[0007] The device includes a valve plate and an intake valve, an exhaust valve, a pressure sensor, and a differential pressure sensor mounted on the valve plate. The valve plate has an intake channel, a first exhaust channel, and a second exhaust channel. The intake valve is connected to the intake channel, the first exhaust channel, and the second exhaust channel to control the opening and closing of these channels. The exhaust valve is connected to the first exhaust channel and the second exhaust channel to control the opening and closing of these channels with the outside environment. The pressure sensor is connected to the first exhaust channel to detect changes in pressure within the test chamber. The differential pressure sensor is connected to the first exhaust channel and the second exhaust channel to detect the pressure difference between the test chamber and the standard chamber.

[0008] After adopting the above structure, the differential pressure airtightness detection device of this utility model has the following advantages compared with the prior art:

[0009] This invention features an air inlet channel, a first air outlet channel, and a second air outlet channel on a valve plate. The air inlet channel is connected to an external air source, while the first and second air outlet channels are connected to a test chamber and a standard chamber, respectively. A pressure sensor is connected to the first air outlet channel, and differential pressure sensors are connected to both. Users can choose between pressure sensor detection or differential pressure sensor detection as needed. When using the pressure sensor, the test product is placed in the test chamber, and the air inlet valve connects the air inlet channel to the first air outlet channel to inflate the test chamber. After inflating, the air inlet valve disconnects the connection between the air inlet channel and the first air outlet channel. The user then observes whether the pressure sensor on the first air outlet channel changes. If it does, it indicates that the test product is damaged. When using the differential pressure sensor, the user places the test product in the test chamber and a standard product in the standard chamber. The air inlet valve connects the air inlet channel to both the first and second air outlet channels to inflate the test chamber and the standard chamber. After inflating, the air inlet valve disconnects the connection between the air inlet channel and the first and second air outlet channels. The user then observes whether the differential pressure sensor displays a pressure difference value.

[0010] This invention features both a pressure sensor and a differential pressure sensor on the valve plate. Users can choose the appropriate sensor based on their specific needs. When testing products with low requirements, a pressure sensor can be selected to improve testing efficiency, while when testing products with high requirements, a differential pressure sensor can be selected to improve testing accuracy.

[0011] Preferably, the end of the air intake channel away from the air intake valve passes through one side wall of the valve plate and is connected to an air intake nozzle for connecting to an external air source; the ends of the first air outlet channel and the second air outlet channel away from the air intake valve pass through the other side wall of the valve plate and are both connected to an air outlet nozzle, with the two air outlet nozzles respectively used for connecting to the test chamber and the standard chamber.

[0012] Preferably, each of the two air outlets is equipped with a manual shut-off ball valve for opening or closing the corresponding air outlet. When pressure sensor detection is selected, the second air outlet channel can be closed using the manual shut-off ball valve.

[0013] Preferably, the connection points between the differential pressure sensor and the first and second air outlet channels are equipped with filter elements to filter the air entering the differential pressure sensor. This prevents dust, impurities, and other contaminants from entering the differential pressure sensor, thus avoiding affecting its detection accuracy and extending its service life.

[0014] Preferably, the intake valve includes a valve body, a piston plate, a sealing connector, and a sealing gasket. The valve body has an upper valve chamber and a lower valve chamber arranged coaxially and communicating with each other from top to bottom. The valve body has a first through hole and a second through hole, which communicate with the top and bottom of the upper valve chamber, respectively. The piston plate is slidably connected to the upper valve chamber, and its outer peripheral wall is sealed to the inner wall of the upper valve chamber. The sealing connector is slidably connected to the lower valve chamber, and its outer peripheral wall is sealed to the inner wall of the lower valve chamber. The upper end of the sealing connector extends into the upper valve chamber and connects to the bottom of the piston plate, while its lower end connects to the sealing gasket. The valve plate has a third, fourth, and fifth through hole, one end of which communicates with the lower end of the lower valve chamber, and the other end connects to the intake channel, the first outlet channel, and the second outlet channel, respectively. The sealing gasket moves up and down with the piston plate via the sealing connector, thereby opening or closing the fourth and fifth through holes.

[0015] Air is injected into the valve chamber through the first or second through hole, creating a pressure difference between the upper and lower parts of the piston plate. This pressure difference drives the piston plate to move up and down, which in turn moves the sealing gasket up and down through the sealing connector, causing the gasket to come into contact with or separate from the fourth or fifth through hole. When the gasket comes into contact with the fourth or fifth through hole, the connection between the air intake channel and the first and second air outlet channels is broken; when the gasket separates from the fourth or fifth through hole, the air intake channel connects with the first and second air outlet channels.

[0016] Preferably, a limiting hole is provided on the inner top wall of the upper valve chamber, and a limiting rod is provided on the top of the piston plate at a position corresponding to the limiting hole. The free end of the limiting rod slides axially and is circumferentially limited within the limiting hole. This can prevent circumferential rotation when the sealing gasket moves up and down, thereby avoiding misalignment of the sealing gasket with the fourth and fifth through holes, which could lead to poor sealing.

[0017] Preferably, both the piston plate and the sealing connector are provided with sealing rings on their outer peripheral walls to improve their sealing performance.

[0018] Preferably, the lower end of the sealing connector is provided with a connecting hole for the upper end of the sealing gasket to be inserted, the upper end of the inner wall of the connecting hole is provided with an annular groove, and the upper end of the outer peripheral wall of the sealing gasket is provided with a radially protruding snap ring, which snaps into the annular groove. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the valve plate in this utility model.

[0021] Figure 3 This is a cross-sectional view of the valve plate in this utility model.

[0022] Figure 4 This is a half-sectional view of the intake valve in this utility model.

[0023] Figure 5 for Figure 4 A magnified view of a portion of the image.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Valve plate; 11. Inlet channel; 12. First outlet channel; 13. Second outlet channel; 14. Inlet nozzle; 15. Outlet nozzle; 16. Manual shut-off ball valve; 17. Third through hole; 18. Fourth through hole; 19. Fifth through hole; 2. Inlet valve; 21. Valve body; 211. Upper valve chamber; 2111. Limiting hole; 212. Lower valve chamber; 213. First through hole; 214. Second through hole; 22. Piston plate; 221. Limiting rod; 23. Sealing connector; 231. Connecting hole; 232. Annular groove; 24. Sealing gasket; 241. Snap-fit ​​ring; 25. Sealing ring; 3. Exhaust valve; 4. Pressure sensor; 5. Differential pressure sensor; 6. Filter element. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. At the same time, the terms "first", "second", etc., are only used to distinguish the names of various components and do not have a primary or secondary relationship. Therefore, they should not be construed as limitations on this utility model.

[0028] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, this utility model discloses a differential pressure air tightness detection device, which includes a valve plate 1 and an intake valve 2, an exhaust valve 3, a pressure sensor 4 and a differential pressure sensor 5 disposed on the valve plate 1.

[0029] The valve plate 1 is provided with an air inlet channel 11, a first air outlet channel 12 and a second air outlet channel 13. The air inlet valve 2 is connected to the air inlet channel 11, the first air outlet channel 12 and the second air outlet channel 13 and is used to control the opening and closing of the air inlet channel 11 and the first air outlet channel 12 and the second air outlet channel 13. The exhaust valve 3 is connected to the first air outlet channel 12 and the second air outlet channel 13 and is used to control the opening and closing of the first air outlet channel 12 and the second air outlet channel 13 with the outside.

[0030] The end of the air intake channel 11 away from the air intake valve 2 passes through one side wall of the valve plate 1 and is connected to an air intake nozzle 14 for connecting to an external air source. The ends of the first air outlet channel 12 and the second air outlet channel 13 away from the air intake valve 2 pass through the other side wall of the valve plate 1 and are both connected to air outlet nozzles 15. The two air outlet nozzles 15 are used to connect to the test chamber and the standard chamber, respectively. Each of the two air outlet nozzles 15 is connected to a manual shut-off ball valve 16 for opening or closing the corresponding air outlet nozzle 15.

[0031] Pressure sensor 4 is connected to the first outlet channel 12 to detect whether the pressure inside the test chamber changes; differential pressure sensor 5 is connected to the first outlet channel 12 and the second outlet channel 13 to detect the pressure difference between the test chamber and the standard chamber.

[0032] This invention features an air inlet channel 11, a first air outlet channel 12, and a second air outlet channel 13 on a valve plate 1. The air inlet channel 11 is connected to an external air source via an air inlet nozzle 14. The first air outlet channel 12 and the second air outlet channel 13 are connected to the test chamber and the standard chamber, respectively, via air outlet nozzles 15. When testing products with low accuracy requirements, a pressure sensor 4 can be used. The test product is first placed in the test chamber, and the second air outlet channel 13 is closed by a manual shut-off ball valve 16. Then, the air inlet valve 2 connects the air inlet channel 11 to the first air outlet channel 12 to inflate the test chamber. After inflation, the air inlet valve 2 disconnects the connection between the air inlet channel 11 and the first air outlet channel 12. The pressure sensor 4 on the first air outlet channel 12 is then observed to check for changes. If a change occurs, it indicates that the test product is damaged. After the test, the first air outlet channel 12 is connected to the outside via an exhaust valve 3 to expel the air from the test chamber. When users test products requiring high accuracy, they can choose differential pressure sensor 5 for detection. First, the test product is placed in the test chamber, and the standard product is placed in the standard chamber. Then, the inlet valve 2 connects the inlet channel 11 with the first outlet channel 12 and the second outlet channel 13, inflating the test chamber and the standard chamber. After inflation, the inlet valve 2 disconnects the inlet channel 11 from the first outlet channel 12 and the second outlet channel 13. After the chamber comes to rest, the differential pressure sensor 5 is observed to determine if a pressure difference value is observed. After the test, the exhaust valve 3 connects the first outlet channel 12 and the second outlet channel 13 to the outside, thereby expelling the air from the test chamber and the standard chamber. The pressure sensor 4 and differential pressure sensor 5 mentioned above are existing technologies and will not be described in detail here.

[0033] This utility model simultaneously sets a pressure sensor 4 and a differential pressure sensor 5 on the valve plate 1. Users can choose according to specific needs. When testing products with low requirements, the pressure sensor 4 is selected to improve testing efficiency, and when testing products with high requirements, the differential pressure sensor 5 is selected to improve testing accuracy.

[0034] A filter element 6 is provided at the connection between the differential pressure sensor 5 and the first air outlet channel 12 and the second air outlet channel 13. This filter element is used to filter the air entering the differential pressure sensor 5, preventing dust, impurities, etc. from entering the differential pressure sensor 5, thereby ensuring the detection accuracy of the differential pressure sensor 5 and improving the service life of the differential pressure sensor 5.

[0035] For example Figure 4 and Figure 5As shown, the intake valve 2 includes a valve body 21, a piston plate 22, a sealing connector 23, and a sealing gasket 24. The valve body 21 has an upper valve chamber 211 and a lower valve chamber 212 arranged coaxially and communicating with each other from top to bottom. The valve body 21 has a first through hole 213 and a second through hole 214, which communicate with the top and bottom of the upper valve chamber 211, respectively. The piston plate 22 is slidably connected to the upper valve chamber 211, and its outer peripheral wall is sealed to the inner wall of the upper valve chamber 211. The sealing connector 23 is slidably connected to the lower valve chamber 212, and its outer peripheral wall is sealed to the inner wall of the lower valve chamber. 212 The inner wall is sealed; the upper end of the sealing connector 23 extends into the upper valve chamber 211 and is connected to the bottom of the piston plate 22, and the lower end of the sealing connector 23 is connected to the sealing gasket 24; the valve plate 1 is provided with a third through hole 17, a fourth through hole 18 and a fifth through hole 19, one end of the third through hole 17, the fourth through hole 18 and the fifth through hole 19 is connected to the lower end of the lower valve chamber 212, and the other end is connected to the air inlet channel 11, the first air outlet channel 12 and the second air outlet channel 13 respectively; the sealing gasket 24 moves up and down with the piston plate 22 through the sealing connector 23, thereby opening or closing the fourth through hole 18 and the fifth through hole 19.

[0036] Air is injected into the upper valve chamber 211 through the first through hole 213 or the second through hole 214, creating a pressure difference between the upper and lower parts of the piston plate 22. This drives the piston plate 22 to move up and down, which in turn drives the sealing gasket 24 to move up and down through the sealing connector 23, causing the sealing gasket 24 to come into contact with or separate from the fourth through hole 18 and the fifth through hole 19. When the sealing gasket 24 comes into contact with the fourth through hole 18 and the fifth through hole 19, the connection between the air intake channel 11 and the first air outlet channel 12 and the second air outlet channel 13 is broken; when the sealing gasket 24 separates from the fourth through hole 18 and the fifth through hole 19, the air intake channel 11 connects with the first air outlet channel 12 and the second air outlet channel 13. The air intake valve 2 is made of aluminum, which has good heat dissipation, and the sealing gasket 24 is far away from the driving part (i.e., the piston plate 22 in the upper valve chamber 211), so it is not easy for it to overheat, ensuring the stability of the airflow and thus ensuring the accuracy of the detection.

[0037] The upper valve chamber 211 has a limiting hole 2111 on its inner top wall. The piston plate 22 has a limiting rod 221 at the position corresponding to the limiting hole 2111 on its top. The free end of the limiting rod 221 slides axially and is circumferentially limited in the limiting hole 2111. This can prevent the sealing gasket 24 from rotating circumferentially when it moves up and down, thereby preventing the sealing gasket 24 from being misaligned with the fourth through hole 18 and the fifth through hole 19, which would result in poor sealing.

[0038] Both the piston plate 22 and the sealing connector 23 are provided with sealing rings 25 on their outer peripheral walls to improve their sealing performance.

[0039] The lower end of the sealing connector 23 is provided with a connecting hole 231 for the upper end of the sealing gasket 24 to be inserted. The upper end of the inner wall of the connecting hole 231 is provided with an annular groove 232. The upper end of the outer peripheral wall of the sealing gasket 24 is provided with a radially protruding snap ring 241. The snap ring 241 is snapped into the annular groove 232 to prevent it from falling off.

[0040] The exhaust valve 3 has the same structure as the intake valve 2. The valve plate 1 is also provided with a sixth through hole, a seventh through hole and an eighth through hole. One end of the sixth through hole, the seventh through hole and the eighth through hole are connected to the lower valve chamber of the exhaust valve 3, and the other end are connected to the outside, the first exhaust channel 12 and the second exhaust channel 13 respectively. The principle is the same as that of the intake valve 2. The connection or disconnection between the outside and the first exhaust channel 12 and the second exhaust channel 13 is realized by the up and down movement of the sealing gasket of the exhaust valve 3.

[0041] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A differential pressure airtightness testing device, characterized in that: The device includes a valve plate (1) and an intake valve (2), an exhaust valve (3), a pressure sensor (4), and a differential pressure sensor (5) disposed on the valve plate (1). The valve plate (1) is provided with an intake channel (11), a first exhaust channel (12), and a second exhaust channel (13). The intake valve (2) is connected to the intake channel (11), the first exhaust channel (12), and the second exhaust channel (13) to control the opening and closing of the intake channel (11) and the first exhaust channel (12) and the second exhaust channel (13). The exhaust valve (3) is connected to the first exhaust channel (12) and the second exhaust channel (13) to control the opening and closing of the first exhaust channel (12) and the second exhaust channel (13) with the outside. The pressure sensor (4) is connected to the first exhaust channel (12) to detect whether the pressure in the test chamber changes. The differential pressure sensor (5) is connected to the first exhaust channel (12) and the second exhaust channel (13) to detect the pressure difference between the test chamber and the standard chamber.

2. The differential pressure airtightness testing device according to claim 1, characterized in that: The end of the air intake channel (11) away from the air intake valve (2) passes through one side wall of the valve plate (1) and is connected to an air intake nozzle (14) for connecting to an external air source; the end of the first air outlet channel (12) and the second air outlet channel (13) away from the air intake valve (2) passes through the other side wall of the valve plate (1) and are both connected to an air outlet nozzle (15), and the two air outlet nozzles (15) are respectively used to connect to the test chamber and the standard chamber.

3. The differential pressure airtightness testing device according to claim 2, characterized in that: Both of the air outlets (15) are connected to a manual shut-off ball valve (16) for opening or closing the corresponding air outlet (15).

4. The differential pressure airtightness testing device according to claim 3, characterized in that: The differential pressure sensor (5) is provided with a filter element (6) at the connection between it and the first air outlet channel (12) and the second air outlet channel (13) to filter the air entering the differential pressure sensor (5).

5. The differential pressure airtightness testing device according to claim 4, characterized in that: The intake valve (2) includes a valve body (21), a piston plate (22), a sealing connector (23), and a sealing gasket (24). The valve body (21) has an upper valve chamber (211) and a lower valve chamber (212) arranged coaxially and communicating with each other from top to bottom. The valve body (21) has a first through hole (213) and a second through hole (214), which communicate with the top and bottom of the upper valve chamber (211), respectively. The piston plate (22) is slidably connected to the upper valve chamber (211), and the outer peripheral wall of the piston plate (22) is sealed to the inner wall of the upper valve chamber (211). The sealing connector (23) is slidably connected to the lower valve chamber (212), and the outer peripheral wall of the sealing connector (23) is sealed to the inner wall of the lower valve chamber (211). 212) Inner wall sealing fit; the upper end of the sealing connector (23) extends into the upper valve chamber (211) and is connected to the bottom of the piston plate (22), and the lower end of the sealing connector (23) is connected to the sealing gasket (24); the valve plate (1) is provided with a third through hole (17), a fourth through hole (18) and a fifth through hole (19), one end of the third through hole (17), the fourth through hole (18) and the fifth through hole (19) is connected to the lower end of the lower valve chamber (212), and the other end is connected to the air inlet channel (11), the first air outlet channel (12) and the second air outlet channel (13) respectively; the sealing gasket (24) moves up and down with the piston plate (22) through the sealing connector (23), thereby opening or closing the fourth through hole (18) and the fifth through hole (19).

6. The differential pressure airtightness testing device according to claim 5, characterized in that: The upper valve chamber (211) has a limiting hole (2111) on its inner top wall. The piston plate (22) has a limiting rod (221) at the position corresponding to the limiting hole (2111) on its top. The free end of the limiting rod (221) slides axially and is circumferentially limited in the limiting hole (2111).

7. The differential pressure airtightness testing device according to claim 5, characterized in that: Both the piston plate (22) and the sealing connector (23) are provided with sealing rings (25) on their outer peripheral walls to improve their sealing performance.

8. The differential pressure airtightness testing device according to claim 5, characterized in that: The lower end of the sealing connector (23) is provided with a connecting hole (231) for inserting the upper end of the sealing gasket (24). The upper end of the inner wall of the connecting hole (231) is provided with an annular groove (232). The upper end of the outer peripheral wall of the sealing gasket (24) is provided with a radially protruding snap ring (241). The snap ring (241) is snapped into the annular groove (232).

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