Multi-purpose leak detection tool for verifying sealing performance of static sealing part

Abstract

The invention relates to the technical field of vacuum pumps, and discloses a multipurpose leak detection tool for verifying the sealing performance of static sealing parts, which comprises a base and a cover plate, the base comprises a pedestal which is in lap joint with the bottom of the cover plate, a column base is integrally arranged at the center of the bottom of the pedestal, and a base is integrally and coaxially arranged at the bottom of the column base; the cover plate and the pedestal are correspondingly provided with eight groups of group pressing holes which are formed in a surrounding manner by taking the center point of the column base as an axis in a penetrating manner, each group of group pressing holes is internally provided with a leak detection pressing bolt assembly, and the top of the cover plate is provided with a heating plate. The multipurpose leak detection tool for verifying the sealing performance of the static sealing part solves the problems that an existing leak detection tool for verifying the sealing performance of the static sealing part of a vacuum pump is relatively single in function, can only realize leak detection of a certain sealing form, and does not have other leak detection verification as a reference, so that the verification sufficiency is not enough; and the accuracy of the sealing performance verification of the static sealing part is influenced.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum pumps, and in particular to a leak detection tool for verifying the sealing performance of multi-purpose static sealing parts. Background Art

[0002] There are many ways to statically seal a dry vacuum pump, such as: O-ring sealing, rubber gasket sealing, structural sealant sealing and flat sealant sealing, etc.; due to the current difficulty in troubleshooting problems with some sealing methods during leak detection, and high-temperature leak detection is also a problem, the current practice is to place the installed simple tooling (together with the part to be tested) in a high-temperature box for a period of time, then take it out and cool it to room temperature before leak detection. However, this does not reflect the actual sealing performance of the parts under high temperature conditions; therefore, in order to reduce project development risks, it is necessary to verify the sealing availability of parts in the early stages of project development, and it is best to use a simple and practical leak detection tooling.

[0003] However, the current leak detection tooling for verifying the sealing performance of static sealing parts of vacuum pumps has relatively simple functions and can only perform simple sealing leak detection (O-rings and sealants) at room temperature. It cannot simultaneously perform sealing leak detection for different compression ratio requirements, leak detection for sealing forms of rubber rings (gaskets) and sealants, and sealing leak detection directly at high temperatures. Some leak detection tooling can only perform leak detection for a certain sealing form, and there is no other leak detection verification as a reference, resulting in insufficient verification adequacy, affecting the accuracy of the sealing verification of static sealing parts, causing the sealing performance of static sealing parts to be lower than expected, and easily resulting in the failure to replace static sealing parts in time. Therefore, there will be losses for dry vacuum pump users. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the invention provides a multi-purpose leak detection tool for verifying the sealing performance of static sealing parts, which solves the problems mentioned in the above background.

[0005] The invention provides the following technical solutions: a leak detection tool for verifying the sealing performance of a multi-purpose static sealing part, comprising: a base and a cover; The base includes a pedestal overlapped on the bottom of the cover plate, a column seat is integrally provided at the center of the bottom of the pedestal, and a base is integrally coaxially provided at the bottom of the column seat; The cover plate and the pedestal are connected and correspondingly provided with eight groups of pressure holes centered around the center point of the column base. A leak detection pressure plug assembly is installed inside each group of pressure holes. A heating plate is provided on the top of the cover plate, and the heating plate is mounted on the cover plate through a fixed frame. An air flow channel is provided at the center of the base, which passes through the base from top to bottom. A lower pressure chamber is provided at the opening at the top of the air flow channel. An upper pressure chamber is provided at the center of the bottom of the cover. The position and size of the upper pressure chamber correspond to those of the lower pressure chamber. The lower pressure chamber and the upper pressure chamber are closed to form a vacuum chamber. A piece to be tested is sandwiched between the base and the cover. The piece to be tested surrounds the outer edges of the lower pressure chamber and the upper pressure chamber. A temperature sensor is installed on the base, and the top of the temperature sensor passes through the base and is located at the outer edge of the test piece. A terminal is provided on the top of the heating plate. Both the terminal and the temperature sensor are installed on the control box with wires. The leak detection pressure bolt assembly is composed of a bolt, a flat washer, an adjusting gasket, an elastic locking washer, a locking nut and the like from top to bottom.

[0006] Preferably, a helium leak detector bottom plate is provided at the bottom of the base, a regular rubber ring is sandwiched between the helium leak detector bottom plate and the base, and the opening of the air flow channel at the bottom of the base is located at the center of the regular rubber ring, and the position of the vent on the helium leak detector bottom plate corresponds to the position of the bottom of the air flow channel.

[0007] Preferably, a cross-shaped embedding groove is provided at the center of the top of the cover plate, the shape of the heating plate corresponds to the shape of the embedding groove, and the bottom of the heating plate is embedded in the embedding groove.

[0008] Preferably, the flat washer is pressed onto the top of the cover plate via a bolt, the adjusting gasket is located between the base and the cover plate, the elastic locking washer is sleeved on the bolt passing through the pressure group hole and located at the bottom of the base, and the elastic locking washer is pressed between the locking nut and the base.

[0009] Preferably, a test object mark is provided on the top of the base, the test object mark surrounds the periphery of the lower pressure cavity, and the test object is overlapped on the test object mark.

[0010] Preferably, the test piece includes a first sealant, the first sealant is in an overall ring shape, and the cross section of the first sealant is a flat oval.

[0011] Preferably, the test piece includes an O-shaped rubber ring, the O-shaped rubber ring is in an annular shape as a whole, and the cross section of the O-shaped rubber ring is circular.

[0012] Preferably, a second sealant is integrally assembled on the O-shaped rubber ring, and the thickness of the O-shaped rubber ring corresponds to the thickness of the second sealant.

[0013] Preferably, the test piece includes a rubber sealing pad, the rubber sealing pad is in the shape of a square frame as a whole, and the cross section of the rubber sealing pad is a square.

[0014] Preferably, a third sealant is integrally provided on the rubber sealing pad, and the thickness of the third sealant corresponds to the thickness of the rubber sealing pad.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. This multi-purpose leak detection tool for verifying the sealing performance of static sealing parts is equipped with a base, a cover, a heating plate and a leak detection pressure bolt assembly, and then the part to be tested is placed between the base and the cover for testing. It adopts a simple structural design to form a device that can perform leak detection on parts such as O-rings, sealing gaskets, structural sealants and flat sealants at room temperature. The leak detection tool can detect leaks of different sealing parts under different conditions, and can then perform multiple leak detection verifications as a reference, so that the leak detection results are sufficiently accurate, and the expected service life of the static sealing parts is improved, so that dry vacuum pump users can more accurately judge the cycle of replacing static sealing parts according to the specific use environment, and avoid the situation where static sealing parts are damaged prematurely and cause losses to users.

[0016] 2. This multi-purpose leak detection tool for verifying the sealing performance of static sealing parts provides a location for the placement of the test object by setting a test object mark, and does not restrict the shape of the test object. The leak detection tool can simultaneously perform leak detection on combined sealing structures, such as O-rings and flat sealants, or sealing gaskets and flat sealants. Therefore, when leaking, only one tool can be used to detect leaks in multiple sealing forms, greatly reducing the number of leak detection tools required for leak detection of different seals, while improving leak detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the invention; Figure 2 This is a schematic diagram of the connection structure between the base and the bottom plate of the helium leak detector; Figure 3 It is a schematic diagram of the structure of the invention; Figure 4 It is a side view structural diagram of the invention; Figure 5 For invention Figure 4 Schematic diagram of the cross-section structure along the A direction; Figure 6 This is a schematic diagram of the top view of the cover plate of the invention; Figure 7 This is a schematic diagram of the invention pedestal structure from a bird's-eye view; Figure 8 This is a schematic structural diagram of the first embodiment of the invention; Figure 9 This is a schematic structural diagram of the second embodiment of the invention; Figure 10 This is a schematic structural diagram of the third embodiment of the invention; Figure 11 This is a schematic structural diagram of the fourth embodiment of the invention; Figure 12 This is a schematic structural diagram of the fifth embodiment of the invention; Figure 13 This is a schematic structural diagram of the sixth embodiment of the invention; Figure 14 This is a structural diagram of the seventh embodiment of the invention.

[0018] In the figure: 1. Column base; 2. Base; 3. Stand; 4. Cover; 5. Heating plate; 6. Terminal; 7. Pressure group hole; 8. Fixing frame; 9. Helium leak detector bottom plate; 10. Standing rubber ring; 11. Temperature sensor; 12. Leak detection pressure plug assembly; 13. Air flow channel; 14. Lower pressure chamber; 15. Upper pressure chamber; 16. Part to be tested; 161. First sealant; 162. O-ring; 163. Rubber sealing gasket; 17. Embedding groove; 18. Test object mark; 19. Second sealant; 20. Third sealant. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] See also Figure 1-14 , a multi-purpose leak detection tool for verifying the sealing performance of static sealing parts, comprising: a base and a cover plate 4; The base includes a pedestal 3 overlapped on the bottom of the cover plate 4, a column base 1 is integrally provided at the center of the bottom of the pedestal 3, and a base 2 is coaxially integrally provided at the bottom of the column base 1; The cover plate 4 and the base 3 are provided with eight groups of pressure holes 7 extending around the center point of the column base 1. A leak detection plug assembly 12 is installed inside each group of pressure holes 7. A heating plate 5 is provided on the top of the cover plate 4. The heating plate 5 is mounted on the cover plate 4 via a fixing frame 8. An air flow channel 13 is provided at the center of the base, which runs through the base from top to bottom. A lower pressure chamber 14 is provided at the opening at the top of the air flow channel 13, which expands outward. An upper pressure chamber 15 is provided at the center of the bottom of the cover plate 4. The position and size of the upper pressure chamber 15 correspond to those of the lower pressure chamber 14. The lower pressure chamber 14 and the upper pressure chamber 15 are closed to form a vacuum chamber. A test piece 16 is sandwiched between the base 3 and the cover plate 4, and the test piece 16 surrounds the outer edges of the lower pressure chamber 14 and the upper pressure chamber 15. A temperature sensor 11 is mounted on the pedestal 3, and the top of the temperature sensor 11 passes through the pedestal 3 and is located at the outer edge of the test piece 16. A terminal 6 is provided on the top of the heating plate 5. The terminal 6 and the temperature sensor 11 are both mounted on the control box with wires. The control box can use a common device with heating and temperature measurement capabilities on the market, such as an instrument intelligent temperature control cabinet, and the temperature sensor 11 also uses a common sensor device on the market, such as an NTC104-F-3950 thermistor sensor, to ensure that the temperature measurement range is maintained within the ambient temperature range that the static sealing parts in the vacuum pump can encounter. When the static sealing parts are leak tested, the ambient temperature during the testing process is under the control of the leak tester at any time, thereby being able to more accurately grasp the leak test verification results of the static sealing parts, thereby improving the accuracy of the sealing verification of the static sealing parts. The leak detection pressure bolt assembly 12 is composed of a bolt, a flat washer, an adjusting washer, an elastic locking washer, and a locking nut structure from top to bottom.

[0021] Among them, a helium leak detector base plate 9 is provided at the bottom of the base 2, and a regular rubber ring 10 is sandwiched between the helium leak detector base plate 9 and the base 2, and the opening of the air flow channel 13 at the bottom of the base 2 is located at the center of the regular rubber ring 10. The position of the vent on the helium leak detector base plate 9 corresponds to the position of the bottom of the air flow channel 13. The helium leak detector base plate 9 is a structure commonly found on helium leak detectors on the market. When the leak detection tool is testing static sealing parts, its bottom can be docked with the helium leak detector, so that the leak detection tool can complete the vacuum leak detection of static sealing parts under the control of the helium leak detector.

[0022] Among them, a cross-shaped embedded groove 17 is opened at the center of the top of the cover plate 4, the shape of the heating plate 5 corresponds to the shape of the embedded groove 17, and the bottom of the heating plate 5 is embedded in the embedded groove 17, as shown in FIG. Figure 6 As shown, by providing an embedding groove 17 to embed the heating plate 5, not only the stability of the heating plate 5 is improved and the movement of the heating plate 5 is avoided, but also the outer edge of the bottom heating surface of the heating plate 5 is semi-wrapped, thereby improving the heating effect of the heating plate 5 and avoiding some heat from being lost from the gap on the outer edge of the heating plate 5.

[0023] Among them, the flat washer is pressed on the top of the cover plate 4 through the bolt, the adjustment gasket is located between the base 3 and the cover plate 4, the elastic locking washer is set on the bolt passing through the pressure group hole 7 and located at the bottom of the base 3, and the elastic locking washer is pressed between the locking nut and the base 3. The O-ring with a cross-sectional diameter of 3.5mm and a compression amount of 20% has a gasket thickness of 3.5*(1-20%)=2.8mm; the flat sealant can be 0-0 fitted without a gasket. If the adhesive layer is required to be 0.1mm thick, use a 0.1mm thick gasket. Select an adjustment gasket of appropriate thickness according to actual needs.

[0024] Among them, Figure 7 As shown, a detection object mark 18 is provided on the top of the base 3, and the detection object mark 18 surrounds the outer periphery of the lower pressure chamber 14. The test piece 16 is overlapped on the detection object mark 18. The test piece 16 can be adjusted according to actual conditions, and PTFE sealing rings, metal sealing rings (soft metal materials, such as aluminum alloy) and other sealing rings can be used for leak detection, so that the leak detection tool can verify the sealing of a variety of different sealing rings, thereby increasing the application range of the leak detection tool.

[0025] Example 1, as Figure 8 As shown, the test piece 16 includes a first sealant 161. The first sealant 161 is in the shape of a circular ring as a whole, and the cross-section of the first sealant 161 is a flat oval. When performing leak detection verification on the first sealant 161, the first sealant 161 is directly set as a first-connected ring along the position of the inspection object mark 18, and then the thickness of the gasket is replaced and adjusted according to the thickness required for leak detection of the first sealant 161 to achieve leak detection of the static sealing part under the required compression rate.

[0026] Example 2, as Figure 9 As shown, the part to be tested 16 includes an O-type rubber ring 162. The O-type rubber ring 162 is annular in shape and has a circular cross-section. When performing leak detection verification on the O-type rubber ring 162, the part to be leak-tested is directly placed on the position of the inspection object mark 18. After the O-type rubber ring 162 is completely flattened, the adjustment gasket of the corresponding thickness in the leak detection pressure bolt assembly 12 is replaced, and then the cover plate 4 is pressed down to make the O-type rubber ring 162 subject to the corresponding pressure. Then, according to the leak detection requirements, the helium leak detector and the control box are turned on and off to perform leak detection verification under various temperature environments.

[0027] The second sealant 19 is integrally assembled on the O-shaped rubber ring 162 , and the thickness of the O-shaped rubber ring 162 corresponds to the thickness of the second sealant 19 ; Example 3, as Figure 10 As shown, when the O-ring 162 and the second sealant 19 are combined for leak detection, a section is cut off from the O-ring 162 and filled with the second sealant 19. When the cover plate 4 is pressed down for leak detection, the O-ring 162 and the second sealant 19 are kept at the same thickness and pressure, and then the O-ring 162 and the second sealant 19 are combined for leak detection.

[0028] Example 4, as Figure 11 As shown, when the O-ring 162 and the second sealant 19 are combined for leak detection, multiple sections are cut from the O-ring 162 and filled with the second sealant 19, which corresponds to the third embodiment. The effect of leak detection in multiple sealing forms can be achieved with only one tool, thereby reducing the development cost of the tool.

[0029] Example 5, as Figure 12 As shown, the test piece 16 includes a rubber sealing gasket 163. The rubber sealing gasket 163 is in the shape of a square frame as a whole and has a square cross-section. When performing leak detection verification on the rubber sealing gasket 163, the rubber sealing gasket 163 is placed on the position of the test object mark 18. After the rubber sealing gasket 163 is completely flattened, the adjustment gasket of the corresponding thickness in the leak detection pressure bolt assembly 12 is replaced so that the rubber sealing gasket 163 can create a corresponding environment according to the leak detection requirements. Then, the helium leak detector and the control box are turned on and off to perform leak detection verification under various temperature environments.

[0030] The rubber sealing pad 163 is integrally provided with a third sealant 20 , and the thickness of the third sealant 20 corresponds to the thickness of the rubber sealing pad 163 ; Example 6: Figure 13 As shown, when the rubber sealing gasket 163 and the third sealant 20 are combined for leak detection, a section is cut off from the rubber sealing gasket 163 and filled with the third sealant 20. When the cover plate 4 is pressed down for leak detection, the rubber sealing gasket 163 and the third sealant 20 are kept at the same thickness and pressure to complete the combined leak detection of the rubber sealing gasket 163 and the third sealant 20.

[0031] Example 7, as Figure 14 As shown, when the rubber sealing gasket 163 and the third sealant 20 are combined for leak detection, multiple sections are cut from the rubber sealing gasket 163 and filled with the third sealant 20, corresponding to Example 6, to form a leak detection verification reference and improve the accuracy of the leak detection verification.

[0032] Working principle: When using the leak detection tool to perform leak detection on parts at room temperature: assemble the parts and the leak detection tool according to the component composition, then select the appropriate adjustment gasket according to the designed compression amount, start the leak detector, and the gas is continuously extracted from the vacuum chamber formed by the lower pressure chamber 14 and the upper pressure chamber 15 through the air flow channel 13. When the gas in the vacuum chamber reaches a certain vacuum degree (for example, 1.5Pa) and enters the fine inspection area, helium is sprayed at the leak detection pressure plug assembly 12 (the working safety air pressure is selected as appropriate, for example, 0.15MPa). If the leakage rate meets the design requirements (for example, <9.99X10-8Pa·m3 / s), the part is considered qualified, otherwise it is considered unqualified.

[0033] When using the leak detection fixture to test the sealing performance of parts at high temperature: assemble the parts and the leak detection fixture according to the component composition, then select the appropriate adjustment gasket according to the designed compression amount, turn on the power of the control box, set the experimental temperature, and use the heating plate 5 to heat. The temperature continues to rise. After reaching the set temperature and stabilizing for 10 minutes, start the leak detector. The gas is continuously extracted from the vacuum chamber through the air flow channel 13. When the gas in the vacuum chamber reaches a certain vacuum degree (for example, 1.5Pa) and enters the fine inspection area, helium is sprayed at the leak detection pressure plug assembly 12 (the working safety air pressure is selected as appropriate, for example, 0.15MPa). If the leak rate meets the design requirement (<9.99X10-8Pa·m3 / s), the part is considered qualified; otherwise, it is considered unqualified.

[0034] While embodiments of the invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and alterations may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-purpose leak detection tool for verifying the sealing performance of static sealing parts, characterized in that: include: Base and cover (4); The base comprises a pedestal (3) overlapped on the bottom of the cover plate (4), a column seat (1) is integrally provided at the center of the bottom of the pedestal (3), and a base (2) is integrally coaxially provided at the bottom of the column seat (1); The cover plate (4) and the pedestal (3) are connected and correspondingly provided with eight groups of pressure holes (7) opened around the center point of the column seat (1) as the axis, and a leak detection pressure bolt assembly (12) is installed inside each group of the pressure holes (7). A heating plate (5) is provided on the top of the cover plate (4), and the heating plate (5) is installed on the cover plate (4) through a fixed frame (8); An air flow channel (13) is provided at the center of the base, which passes through the base from top to bottom. A lower pressure chamber (14) is provided at the opening at the top of the air flow channel (13). An upper pressure chamber (15) is provided at the center of the bottom of the cover plate (4). The position and size of the upper pressure chamber (15) correspond to the position and size of the lower pressure chamber (14). The lower pressure chamber (14) and the upper pressure chamber (15) are closed to form a vacuum chamber. A test piece (16) is sandwiched between the base (3) and the cover plate (4). The test piece (16) surrounds the outer edges of the lower pressure chamber (14) and the upper pressure chamber (15). A temperature sensor (11) is mounted on the pedestal (3), and the top of the temperature sensor (11) passes through the pedestal (3) and is located at the outer edge of the test piece (16). A terminal (6) is provided on the top of the heating plate (5), and both the terminal (6) and the temperature sensor (11) are mounted on the control box using wires. The leak detection pressure bolt assembly (12) is composed of a bolt, a flat washer, an adjustment washer, an elastic locking washer, and a locking nut structure from top to bottom.

2. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 1, characterized in that: A helium leak detector base plate (9) is provided at the bottom of the base (2), a regular rubber ring (10) is sandwiched between the helium leak detector base plate (9) and the base (2), and the opening of the air flow channel (13) at the bottom of the base (2) is located at the center of the regular rubber ring (10), and the position of the vent on the helium leak detector base plate (9) corresponds to the position of the bottom of the air flow channel (13).

3. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 1, characterized in that: A cross-shaped embedding groove (17) is provided at the center of the top of the cover plate (4); the shape of the heating plate (5) corresponds to the shape of the embedding groove (17), and the bottom of the heating plate (5) is embedded in the embedding groove (17).

4. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 1, characterized in that: The flat washer is pressed onto the top of the cover plate (4) via a bolt, the adjustment gasket is located between the pedestal (3) and the cover plate (4), the elastic locking washer is sleeved on the bolt passing through the group pressure hole (7) and located at the bottom of the pedestal (3), and the elastic locking washer is pressed between the locking nut and the pedestal (3).

5. The leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 1, characterized in that: The top of the pedestal (3) is provided with an inspection object mark (18), the inspection object mark (18) surrounds the periphery of the lower pressure cavity (14), and the object to be tested (16) is overlapped on the inspection object mark (18).

6. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 5, characterized in that: The test piece (16) comprises a first sealant (161), the first sealant (161) is in the shape of a circular ring as a whole, and the cross section of the first sealant (161) is in the shape of a flat ellipse.

7. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 5, characterized in that: The test piece (16) comprises an O-shaped rubber ring (162), the O-shaped rubber ring (162) is in an annular shape as a whole, and the cross section of the O-shaped rubber ring (162) is circular.

8. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 7, characterized in that: The O-shaped rubber ring (162) is integrally assembled with a second sealant (19), and the thickness of the O-shaped rubber ring (162) corresponds to the thickness of the second sealant (19).

9. The leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 5, characterized in that: The test piece (16) comprises a rubber sealing pad (163), the rubber sealing pad (163) is in the shape of a square frame as a whole, and the cross section of the rubber sealing pad (163) is square.

10. A leak detection tool for verifying the sealing performance of a multi-purpose static sealing part according to claim 9, characterized in that: A third sealant (20) is integrally assembled on the rubber sealing pad (163), and the thickness of the third sealant (20) corresponds to the thickness of the rubber sealing pad (163).

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