Multifunctional sealing detection device for membrane box for end face sealing and its vacuum helium mass spectrometry leak detection, positive pressure helium mass spectrometry leak detection and airtightness inspection method

Abstract

The present application relates to a kind of sealing detection device of tubular elastic sensitive element and its detection method, specifically, a kind of multifunctional sealing detection device of end face sealing diaphragm box and its vacuum helium mass spectroscopy leak detection, positive pressure helium mass spectroscopy leak detection, air tightness inspection method;It is to solve the problem that the sealing detection method of existing end face sealing diaphragm box exists narrow detection range, high cost, operation is complicated or influence diaphragm box itself size and precision problem.The present application includes shell, gas detection core coaxially arranged in one end of shell, positioning mandrel coaxially arranged in the other end of shell, output end is arranged on the side wall of shell and is connected with the inside of shell The mouth of pipe and the helium detection adapter connected with the input end of the mouth of pipe;The inside wall of shell is set as stepped test cavity;Gas detection core includes head and tail portion coaxially connected with each other;The two ends of positioning mandrel are adapted with positioning hole, and rigid fixed sleeve is arranged between the two first sealing members outside end face sealing diaphragm box.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of sealing detection device of tubular elastic sensitive element and its detection method, specifically, a kind of multifunctional sealing detection device of end face sealing diaphragm box and its vacuum helium mass spectroscopy leak detection, positive pressure helium mass spectroscopy leak detection, air tightness inspection method. BACKGROUND

[0002] End face sealing device is a kind of device for dynamic sealing between rotating shaft and base, which keeps a pair of friction pairs to be attached and relatively slides under the cooperation of fluid pressure and elastic force of compensation mechanism and auxiliary sealing, forms friction pair sealing surface, to prevent fluid leakage. The mode of end face sealing can be divided into bellows type end face sealing and spring type end face sealing according to the type of elastic element. Spring type end face sealing is limited by its own structural characteristics, and cannot withstand high temperature, and can only be used for normal temperature working condition. Bellows type end face sealing has good high temperature resistance and followability, and can buffer the runout of shaft. The bellows in bellows type end face sealing can seal medium and play the role of elastic compensation, and can be suitable for low temperature or high temperature working condition.

[0003] Based on the above characteristics, bellows type end face sealing is widely used in turbine pump end face sealing of space liquid rocket engine. The bellows used in bellows type end face sealing generally includes hydraulic expansion bellows and end face sealing diaphragm box in the form of welding. The structural diagram of end face sealing diaphragm box is shown in Figure 1 It is a tubular element made of multiple pairs of wave-shaped diaphragms 11, which are alternately welded along the inner and outer edges by using precision welding technology. It has the characteristics of precision, thin wall, good elasticity and high compression rate. It usually adopts argon arc welding, micro-beam plasma welding and other welding methods. The total number of welds is more than ten, including inner weld 12 and outer weld 13.

[0004] The working environment of space liquid rocket engine is usually harsh, with the main characteristics of high speed (the maximum speed can reach more than 40000 rpm), harsh environmental temperature (the minimum temperature can reach-183 ℃, and the maximum temperature can reach more than 650 ℃), high medium pressure (the medium pressure is about 0.5-5.0 MPa) and large dynamic load. Due to the harsh working environment, there are high requirements for the production quality and reliability of diaphragm box. If the diaphragm box fails during engine operation, it may cause leakage of sealing medium, abnormal operation of engine, or even engine accident, resulting in huge loss.

[0005] At present, most diaphragm box manufacturers adopt helium mass spectroscopy leak detection method to check the sealing after completing the welding of diaphragm box. Or the diaphragm box is assembled with two end machine parts, and then positive pressure helium mass spectroscopy leak detection or air tightness inspection under specified pressure is carried out. Although the existing method can meet the production delivery requirements of products, it has the following shortcomings:

[0006] 1) Currently, after the diaphragm is welded, most leak tests are performed using only vacuum helium mass spectrometry. This involves sealing the diaphragms at the upper and lower ends of the diaphragm with rubber rings and gaskets, then evacuating the interior and spraying helium from the outside for inspection. This inspection method can only verify the sealability of the diaphragm weld under a pressure differential of 1 atmosphere (approximately 0.1 MPa). However, the actual operating pressures experienced by diaphragms can typically reach 1.5 MPa to 5.0 MPa, or even higher. This helium inspection method clearly fails to fully cover the operating conditions of the diaphragm, resulting in a narrow detection range.

[0007] 2) Since the membrane box is an elastic component that is not easy to seal, and the membrane material is thin and easily damaged, if you want to perform positive pressure helium mass spectrometry leak detection or pressurized air tightness inspection, the current process is basically as follows:

[0008] a. Perform stress relief heat treatment or aging strengthening treatment on the membrane box;

[0009] b. Combine and weld the diaphragm box with the parts to be welded at both ends (most of the parts currently welded to the ends of the diaphragm box contain non-metallic materials and the diaphragm box is made of dissimilar metal materials, which is not suitable for the process of welding first and then heat treating);

[0010] c. After welding, seal the parts at both ends and perform positive pressure helium mass spectrometry leak detection or air tightness inspection under the specified pressure.

[0011] The disadvantage of this method is that if leakage is found in the diaphragm box weld, it cannot be remedied by rework welding (rework welding is not allowed after the diaphragm box has been heat treated). It also causes waste of welded parts at both ends and increases production costs.

[0012] 3) The existing membrane box air tightness inspection tooling and helium mass spectrometry leak detection tooling do not have a membrane box height limit function. The membrane box is prone to tensile or compressive deformation when subjected to pressure or vacuum during the inspection process, affecting the free height size of the membrane box and the accuracy of the parallelism of the two end faces.

[0013] 4) Currently, three sets of devices are required to perform vacuum helium mass spectrometry leak detection, positive pressure helium mass spectrometry leak detection and air tightness inspection of the membrane box respectively, which has poor integration and high cost; the operation is cumbersome, and the membrane box is easily damaged due to repeated disassembly and assembly. Summary of the Invention

[0014] The purpose of the present invention is to solve the problems of existing end face sealing membrane box sealing detection methods such as narrow detection range, high cost, cumbersome operation or impact on the size and accuracy of the membrane box itself, and to provide a multifunctional sealing detection device for end face sealing membrane box and its vacuum helium mass spectrometry leak detection, positive pressure helium mass spectrometry leak detection, and airtightness inspection methods.

[0015] To achieve the above objectives, the technical solutions provided by the present invention are:

[0016] A multifunctional sealing detection device for bellows for end face sealing is used for vacuum helium mass spectrometric leak detection, positive pressure helium mass spectrometric leak detection or air tightness check of the bellows for end face sealing, the bellows for end face sealing is a bellows, which comprises a plurality of annular diaphragms in wave shape arranged in layers, and the inner sides of the plurality of diaphragms are welded to form inner welds, and the two diaphragms corresponding to each inner weld are welded with the adjacent diaphragms of the adjacent inner welds to form outer welds; the special feature is that:

[0017] The device comprises a shell, a gas detection core coaxially arranged in one end of the shell, a positioning core shaft coaxially arranged in the other end of the shell, a connector nozzle arranged on the side wall of the shell and communicating with the inside of the shell, and a helium detection adapter connected with the input end of the connector nozzle.

[0018] The inner side wall of the shell is arranged as a stepped test cavity, and a positioning hole is arranged in the middle of the end face of the small diameter end of the test cavity.

[0019] The gas detection core comprises a head portion and a tail portion coaxially connected with each other, the head portion is a stepped column body with a stepped surface, the step of the stepped column body is matched with the stepped surface of the test cavity, the tail portion is a first cylindrical body, one end of the tail portion is connected with the large end of the head portion, a circular groove is arranged at the end of the small end of the head portion, and a first through hole communicated with the end face of the other end of the tail portion is arranged at the center of the circular groove in the axial direction.

[0020] The two ends of the positioning core shaft are matched with the positioning hole, a fourth sealing member is arranged on the side wall of one end of the positioning core shaft, and a protruding ring is arranged on the positioning core shaft close to the end.

[0021] A second sealing member is arranged between the inner side surface of the small end of the test cavity and the outer side surface of the small end of the stepped column body, a fastener and a third sealing member for sealing between the fastener and the end of the first through hole are arranged at one end of the tail portion of the gas detection core.

[0022] The output end of the connector nozzle is arranged on the side surface of the small end of the test cavity, the input end of the connector nozzle is connected with the helium mass spectrometric leak detector through the helium detection adapter, or the input end of the connector nozzle is connected with the helium cylinder.

[0023] The small end of the test cavity and the end face of the small end of the stepped column body are used for placing the bellows for end face sealing, the first sealing members are arranged on the end faces of the small end of the test cavity and the small end of the gas detection core in opposition, for sealing the bellows for end face sealing, and a rigid fixing sleeve for supporting the bellows for end face sealing is arranged between the two first sealing members outside the bellows for end face sealing.

[0024] Further, the rigid fixing sleeve is a circular ring composed of two semicircular rings, and a plurality of air holes are uniformly distributed on the circular ring in the circumferential direction.

[0025] Further, the connection mode between the shell and the gas detection core, the helium detection adapter and the connecting nozzle is all threaded connection; the fifth sealing element is arranged between the input end of the connecting nozzle and the output end of the helium detection adapter.

[0026] Further, the first sealing element, the second sealing element, the third sealing element and the fourth sealing element are all rubber rings; the fifth sealing element is a rubber gasket; the material of the rigid fixing sleeve is copper; the material of the positioning mandrel is fluoroplastic; and the fastener is an internal hexagonal screw.

[0027] Further, the diameter of the positioning hole is the diameter of the membrane box hole for end face sealing + (0.03-0.05) mm.

[0028] Further, the single-sided fitting gap between the one end of the positioning mandrel without the fourth sealing element and the positioning hole is 0.02-0.04 mm; the single-sided fitting gap between the outer side of the one end of the positioning mandrel provided with the fourth sealing element and the inner side of the positioning hole is 0.15-0.20 mm; the fitting gap between the inner side of the shell and the outer side of the gas detection core is 0.15-0.20 mm; the axial compression amount of the fourth sealing element is 8%-10% when the one end of the positioning mandrel provided with the fourth sealing element is installed in the shell; and the axial compression amount of the second sealing element is 8%-10% when the gas detection core is installed in the shell.

[0029] Further, the number of the air holes is 6-8, and the diameter of each air hole is 3-5 mm.

[0030] Meanwhile, the application also provides a vacuum helium mass spectrum leak detection method of a multifunctional sealing detection device of the end face sealing membrane box, which is characterized by comprising the following steps:

[0031] Step 1, prepare a helium bottle, a helium mass spectrum leak detector and an end face sealing membrane box to be detected; define the area between the rigid fixing sleeve and the inner end face of the small end of the test cavity as a first inner cavity, and define the communication area formed by the inner cavity of the circular groove, the inner cavity of the positioning hole and the inner cavity of the end face sealing membrane box as a second inner cavity;

[0032] Step 2, install the one end of the positioning mandrel without the fourth sealing element in the positioning hole, and then install the end face sealing membrane box to be detected in the preset position according to the positioning of the one end of the positioning mandrel, and set the weld preset leakage L1;

[0033] Step 3, remove the positioning mandrel, and then connect the helium bottle with the outer end of the positioning hole;

[0034] Step 4, connect the input end of the helium detection adapter with the leak detection port of the helium mass spectrum leak detector, and open the helium mass spectrum leak detector to perform vacuumizing operation on the first inner cavity.

[0035] Step 5, open the helium bottle to spray helium on the second inner cavity, while using the helium mass spectrometer leak detector to detect the helium leakage L2 of the first inner cavity per unit time, and compare L2 with L1 set in step 2, if L2≤L1, the vacuum helium mass spectrometer leak of the detected end face sealing diaphragm is qualified; if L2>L1, the vacuum helium mass spectrometer leak of the detected end face sealing diaphragm is unqualified.

[0036] And the application also provides a positive pressure helium mass spectrometer leak detection method of the multifunctional sealing detection device for the end face sealing diaphragm, which is characterized by comprising the following steps:

[0037] Step 1, prepare a helium bottle, a helium mass spectrometer leak detector and an end face sealing diaphragm to be detected; define the area between the rigid fixed sleeve and the inner side of the small end of the first column as the first inner cavity, and define the communication area composed of the inner cavity of the circular groove, the inner cavity of the positioning hole and the inner cavity of the end face sealing diaphragm as the second inner cavity;

[0038] Step 2, install the end of the positioning mandrel without the fourth sealing element in the positioning hole, and then install the end face sealing diaphragm to be detected in the preset position according to the positioning of the end of the positioning mandrel, and set the weld preset leakage L3;

[0039] Step 3, remove the positioning mandrel, and insert the end of the positioning mandrel with the fourth sealing element into the positioning hole;

[0040] Step 4, remove the helium detection adapter, the fastener and the third sealing element, connect the input end of the pipe mouth with the output end of the helium bottle, connect the outer end of the first through hole on the gas detection core with the leak detection port of the helium mass spectrometer leak detector, and then start the helium mass spectrometer leak detector to perform vacuumizing operation on the second inner cavity;

[0041] Step 5, open the helium bottle to spray helium on the first inner cavity, while the helium mass spectrometer leak detector detects the helium leakage L4 of the second inner cavity per unit time, and compares L4 with L3 set in step 2, if L4≤L3, the positive pressure helium mass spectrometer leak of the detected end face sealing diaphragm is qualified; if L4>L3, the positive pressure helium mass spectrometer leak of the detected end face sealing diaphragm is unqualified.

[0042] In addition, the application also provides an air tightness checking method of the multifunctional sealing detection device for the end face sealing diaphragm, which is characterized by comprising the following steps:

[0043] Step 1, prepare an end face sealing diaphragm to be detected and a compressed air bottle; define the area between the rigid fixed sleeve and the inner side of the small end of the first column as the first inner cavity, and define the communication area composed of the inner cavity of the circular groove, the inner cavity of the positioning hole and the inner cavity of the end face sealing diaphragm as the second inner cavity;

[0044] Step 2, install the positioning mandrel at the end without the fourth sealing element in the positioning hole, and then install the end face sealing diaphragm to be detected into the preset position according to the positioning of the positioning mandrel end to the end face sealing diaphragm,

[0045] Step 3, remove the positioning mandrel and the helium detection adapter, and make the outer end opening of the positioning hole vertically upward;

[0046] Step 4, connect the input end of the connector nozzle with the output end of the compressed air bottle, open the compressed air bottle, spray compressed air into the first inner cavity, and when the pressure of the sprayed compressed air is stable, inject a preset amount of leak detection liquid into the second inner cavity from the outer end opening of the positioning hole; wherein the leak detection liquid is pure water or anhydrous ethanol, and the injection amount of the leak detection liquid is 2mm-5mm higher than the top inner weld of the end face sealing diaphragm;

[0047] Step 5, observe whether there are bubbles in the leak detection liquid, if there are no bubbles, the air tightness check of the detected end face sealing diaphragm is qualified; otherwise, the air tightness check is unqualified.

[0048] Compared with the prior art, the beneficial effects of the present application are:

[0049] 1. The multifunctional sealing detection device for the end face sealing diaphragm provided by the present application includes three detection modes: vacuum helium mass spectrometry leak detection, positive pressure helium mass spectrometry leak detection and air tightness check of the end face sealing diaphragm, and has strong integration, which can reduce the preparation process and reduce the production energy consumption;

[0050] 2. The multifunctional sealing detection device for the end face sealing diaphragm provided by the present application does not need to be repeatedly assembled when switching the detection mode, only needs to simply replace a plurality of components, and the operation is quick and convenient; meanwhile, the assembly positioning accuracy and the consistency of the assembly position can be guaranteed;

[0051] 3. The multifunctional sealing detection device for the end face sealing diaphragm provided by the present application realizes the support of the diaphragm by using the rigid fixing sleeve composed of two semicircular rings, so that the diaphragm becomes a rigid part, the sealing detection of the diaphragm under high pressure can be realized after clamping and sealing, and the phenomenon that the diaphragm is excessively elongated after air detection or positive pressure leak detection can be effectively prevented. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 It is a structural schematic view of the existing end face sealing diaphragm;

[0053] Figure 2 It is a structural schematic view of the multifunctional sealing detection device for the end face sealing diaphragm of the embodiment of the present application;

[0054] Figure 3This is a schematic structural diagram of an embodiment of a multifunctional sealing detection device for an end-face sealing membrane box according to the present invention when performing vacuum helium mass spectrometry leak detection;

[0055] Figure 4 This is a schematic structural diagram of an embodiment of a multifunctional sealing detection device for an end-face sealing membrane box according to the present invention when performing positive pressure helium mass spectrometry leak detection;

[0056] Figure 5 This is a schematic structural diagram of an embodiment of a multifunctional sealing detection device for an end face sealing membrane box according to the present invention during an airtightness inspection;

[0057] Description of reference numerals:

[0058] 11. Diaphragm; 12. Inner weld; 13. Outer weld; 21. Shell; 22. Gas inspection core; 2201. First through hole; 2202. Circular groove; 23. Positioning mandrel; 2301. Raised ring; 24. Rigid fixing ferrule; 25. Take-off nozzle; 26. Helium inspection adapter; 27. Fastener; 28. First seal; 29. ​​Second seal; 210. Third seal; 211. Fourth seal; 212. Fifth seal; J. First inner cavity; K. Second inner cavity. DETAILED DESCRIPTION

[0059] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0060] A multifunctional sealing detection device for membrane box with end face sealing, see Figure 2 , used for performing vacuum helium mass spectrometry leak detection, positive pressure helium mass spectrometry leak detection or air tightness inspection on the end face sealing membrane box, the end face sealing membrane box is a bellows, including a plurality of wave-shaped annular membranes 11 stacked, the inner sides of the plurality of membranes 11 are welded in pairs to form inner welds 12, and the two membranes 11 corresponding to each inner weld 12 are respectively welded to the adjacent membranes 11 adjacent to the inner weld 12 to form outer welds 13;

[0061] It includes a housing 21, a gas detection core 22 coaxially arranged in one end of the housing 21, a positioning core shaft 23 coaxially arranged in the other end of the housing 21, a nozzle 25 whose output end is arranged on the side wall of the housing 21 and communicates with the interior of the housing 21, and a helium detection adapter 26 connected to the input end of the nozzle 25;

[0062] The inner side wall of the housing 21 is provided as a stepped test cavity, and a positioning hole 201 is provided in the middle of the end surface of the small diameter end;

[0063] The gas detection core 22 comprises a head and a tail which are coaxially connected, the head is a stepped cylinder with a stepped surface, the stepped surface of the stepped cylinder is matched with the stepped surface of the test cavity, the tail is a first cylinder, one end of the tail is connected with the large end of the head, the small end of the head is provided with a circular groove 2202, the center of the circular groove 2202 is provided with a first through hole 2201 which is communicated with the other end surface of the tail in the axial direction;

[0064] The two ends of the positioning mandrel 23 are matched with the positioning holes 201, the sidewall of one end of the positioning mandrel 23 is provided with a fourth sealing member 211, and the positioning mandrel 23 is provided with a protruding ring 2301 at a position close to the end;

[0065] The second sealing member 29 is arranged between the inner surface of the small end of the test cavity and the outer surface of the small end of the stepped cylinder, the first through hole 2201 located at one end of the tail of the gas detection core 22 is provided with a fastener 27 and a third sealing member 210 for sealing between the fastener 27 and the end of the first through hole 2201;

[0066] The output end of the adapter nozzle 25 is arranged on the side surface of the small end of the test cavity, the input end of the adapter nozzle 25 is connected with the helium mass spectrometer through the helium detection adapter 26, or the input end of the adapter nozzle 25 is connected with a helium cylinder;

[0067] The small end of the test cavity and the small end of the stepped cylinder are used for placing a membrane box for end face sealing, the bottom of the small end of the test cavity and the end surface of the small end of the gas detection core 22 are provided with first sealing members 28 in opposite positions, for sealing the membrane box for end face sealing, the rigid fixing sleeve 24 for supporting the membrane box for end face sealing is arranged between the two first sealing members 28 and outside the membrane box for end face sealing.

[0068] The rigid fixing sleeve 24 is used for supporting the membrane box for end face sealing, so that the membrane box for end face sealing becomes a rigid member, the material of the rigid fixing sleeve 24 is copper, in order to facilitate installation, the rigid fixing sleeve 24 comprises a circular ring composed of two semicircular rings, the circular ring is uniformly provided with 6-8 air holes with a diameter of 3-5 mm in the circumferential direction, so as to facilitate the entry and exit of the leakage detection gas helium, the diameter of the air hole can be determined according to the height of the rigid fixing sleeve 24, and generally 3-5 mm is enough. The material of the positioning mandrel 23 is fluoroplastic, and the strength is high.

[0069] The connection modes between the shell 21 and the gas detection core 22, the helium detection adapter 26 and the adapter nozzle 25 are all screw connections; the fifth sealing member 212 is arranged between the input end of the adapter nozzle 25 and the output end of the helium detection adapter 26.

[0070] In the embodiment, the first seal 28, the second seal 29, the third seal 210, and the fourth seal 211 are all rubber rings; the fifth seal 212 is a rubber gasket; and the fastener 27 is an inner hexagonal screw for easy disassembly. During processing, the single-sided fitting gap between the one end of the positioning mandrel 23 provided with the fourth seal 211 and the inner side of the positioning hole 201 is 0.02-0.04 mm; the single-sided fitting gap between the outer side of the one end of the positioning mandrel 23 provided with the fourth seal 211 and the inner side of the positioning hole 201 is 0.15-0.20 mm; and the fitting gap between the inner side of the shell 21 and the outer side of the gas detection core 22 is 0.15-0.20 mm.

[0071] When the one end of the positioning mandrel 23 provided with the fourth seal 211 is fitted into the shell 21, the axial compression amount of the fourth seal 211 is 8%-10%; and when the gas detection core 22 is fitted into the shell 21, the axial compression amount of the second seal 29 is 8%-10%.

[0072] Meanwhile, the embodiment also provides a vacuum helium mass spectrometry leak detection method of the multifunctional sealing property detection device for the end face sealing diaphragm pump, which is described below with reference to Figure 3 , and includes the following steps.

[0073] Step 1, prepare a helium bottle, a helium mass spectrometry leak detector, and an end face sealing diaphragm pump to be detected; define the area between the rigid fixed sleeve 24 and the inner end face of the small end of the test cavity as a first inner cavity J, and define the communication area formed by the inner cavity of the circular groove 2202, the inner cavity of the positioning hole 201, and the inner cavity of the end face sealing diaphragm pump as a second inner cavity K.

[0074] Step 2, install the one end of the positioning mandrel 23 without the fourth seal 211 in the positioning hole 201, and then fit the end face sealing diaphragm pump to be detected into a preset position according to the positioning of the one end of the positioning mandrel 23, and set a weld preset leakage amount L1.

[0075] Step 3, remove the positioning mandrel 23, and then connect the helium bottle to the outer end of the positioning hole 201.

[0076] Step 4, connect the input end of the helium detection adapter 26 to the leak detection port of the helium mass spectrometry leak detector, and open the helium mass spectrometry leak detector to perform vacuumization operation on the first inner cavity J.

[0077] Step 5, open the helium bottle to spray helium into the second inner cavity K, simultaneously detect the helium leakage amount L2 of the first inner cavity J per unit time by using the helium mass spectrometry leak detector, and compare L2 with L1 set in step 2; if L2≤L1, the vacuum helium mass spectrometry leak detection of the detected end face sealing diaphragm pump is qualified; and if L2>L1, the vacuum helium mass spectrometry leak detection of the detected end face sealing diaphragm pump is unqualified.

[0078] Moreover, the embodiment also provides the positive pressure helium mass spectrometric leak detection method of the multifunctional sealing property detection device of the end face sealing diaphragm box, see Figure 4 , comprising the following steps:

[0079] Step 1, prepare a helium cylinder, a helium mass spectrometric leak detector and an end face sealing diaphragm box to be detected; define the area between the rigid fixed sleeve 24 and the inner side surface of the small end of the first column as a first inner cavity J, and define the communication area composed of the inner cavity of the circular groove 2202, the inner cavity of the positioning hole 201 and the inner cavity of the end face sealing diaphragm box as a second inner cavity K;

[0080] Step 2, install the end of the positioning mandrel 23 without the fourth sealing element 211 in the positioning hole 201, and then according to the positioning of the one end of the positioning mandrel 23 to the end face sealing diaphragm box to be detected, install the end face sealing diaphragm box to be detected into a preset position, and set the weld preset leakage L3;

[0081] Step 3, remove the positioning mandrel 23, and insert the end of the positioning mandrel 23 with the fourth sealing element 211 into the positioning hole 201;

[0082] Step 4, remove the helium detection adapter 26, the fastener 27 and the third sealing element 210, connect the input end of the pipe mouth 25 with the output end of the helium cylinder, connect the outer end of the first through hole 2201 of the gas detection core 22 with the leak detection port of the helium mass spectrometric leak detector, and then start the helium mass spectrometric leak detector to perform vacuumizing operation on the second inner cavity K;

[0083] Step 5, open the helium cylinder, spray helium into the first inner cavity J, simultaneously the helium mass spectrometric leak detector detects the helium leakage L4 of the second inner cavity K per unit time, and compares L4 with L3 set in step 2, if L4≤L3, the positive pressure helium mass spectrometric leak detection of the end face sealing diaphragm box to be detected is qualified; if L4>L3, the positive pressure helium mass spectrometric leak detection of the end face sealing diaphragm box to be detected is unqualified.

[0084] In addition, the embodiment also provides the air tightness checking method of the multifunctional sealing property detection device of the end face sealing diaphragm box, see Figure 5 , comprising the following steps:

[0085] Step 1, prepare an end face sealing diaphragm box to be detected and a compressed air cylinder; define the area between the rigid fixed sleeve 24 and the inner side surface of the small end of the first column as a first inner cavity J, and define the communication area composed of the inner cavity of the circular groove 2202, the inner cavity of the positioning hole 201 and the inner cavity of the end face sealing diaphragm box as a second inner cavity K;

[0086] Step 2, install the end of the positioning mandrel 23 without the fourth sealing element 211 in the positioning hole 201, and then according to the positioning of the one end of the positioning mandrel 23 to the end face sealing diaphragm box to be detected, install the end face sealing diaphragm box to be detected into a preset position,

[0087] Step 3, remove the positioning mandrel 23 and helium detection adapter 26, and make the outer end opening of the positioning hole 201 vertically upward;

[0088] Step 4, connect the input end of the connector nozzle 25 with the output end of the compressed air bottle, open the compressed air bottle, spray compressed air into the first inner cavity J, and when the pressure of the sprayed compressed air is stable, inject a preset amount of leak detection liquid from the outer end opening of the positioning hole 201 into the second inner cavity K; wherein the leak detection liquid is pure water or anhydrous ethanol, and the injection amount of the leak detection liquid when injected is higher than the top inner weld 12 of the end face sealing diaphragm, and the height is 2mm-5mm higher;

[0089] Step 5, observe whether there are bubbles in the leak detection liquid, if there are no bubbles, the air tightness check of the detected end face sealing diaphragm is qualified; otherwise, the air tightness check is unqualified.

[0090] The above three detection methods are selected according to actual needs, and there is no sequence.

Claims

1. A multifunctional sealing detection device for an end face sealing membrane box, used for performing vacuum helium mass spectrometry leak detection, positive pressure helium mass spectrometry leak detection or airtightness inspection on the end face sealing membrane box, wherein the end face sealing membrane box is a bellows, comprising a plurality of wave-shaped annular membranes (11) stacked and arranged, wherein the inner sides of the plurality of membranes (11) are welded in pairs to form inner welds (12), and the two membranes (11) corresponding to each inner weld (12) are respectively welded to the adjacent membranes (11) of the adjacent inner weld (12) to form outer welds (13); characterized in that: The invention comprises a housing (21), a gas detection core (22) coaxially arranged in one end of the housing (21), a positioning core shaft (23) coaxially arranged in the other end of the housing (21), a nozzle (25) whose output end is arranged on the side wall of the housing (21) and communicates with the interior of the housing (21), and a helium detection adapter (26) connected to the input end of the nozzle (25); The inner side wall of the housing (21) is configured as a stepped test cavity, and a positioning hole (201) is provided in the middle of the end surface of the small-diameter end; The gas test core (22) comprises a head and a tail coaxially connected to each other, the head being a stepped column on the side, the steps of the stepped column matching the stepped surface of the test cavity, the tail being a first cylindrical body, one end of the tail being connected to the large end of the head, the small end of the head being provided with a circular groove (2202), the center of the circular groove (2202) being axially provided with a first through hole (2201) communicating with the other end face of the tail; Both ends of the positioning core shaft (23) are adapted to the positioning hole (201), a fourth sealing member (211) is provided on the side wall of one end thereof, and a raised ring (2301) is provided on the positioning core shaft (23) near the end thereof; A second sealing member (29) is provided between the inner side surface of the small end of the test cavity and the outer side surface of the small end of the stepped column; a fastener (27) and a third sealing member (210) for sealing between the fastener (27) and the end of the first through hole (2201) are provided at one end of the first through hole (2201) located at the tail of the gas inspection core (22); The output end of the take-over nozzle (25) is arranged on the side of the small end of the test cavity, and the input end of the take-over nozzle (25) is connected to a helium mass spectrometer leak detector through a helium detection adapter (26), or the input end of the take-over nozzle (25) is connected to a helium gas cylinder; A membrane box for end face sealing is placed between the small end of the test cavity and the end face of the small end of the stepped column. First sealing members (28) are arranged opposite to each other at the bottom of the small end of the test cavity and the end face of the small end of the air inspection core (22) for sealing the membrane box for end face sealing. A rigid fixing sleeve (24) for supporting the membrane box for end face sealing is arranged between the two first sealing members (28) and located outside the membrane box for end face sealing.

2. The multifunctional sealing detection device for an end face sealing membrane box according to claim 1, characterized in that: The rigid fixing sleeve (24) is a circular ring composed of two semicircular rings, and a plurality of vent holes are evenly distributed on the circular ring in the circumferential direction.

3. The multifunctional sealing detection device for an end face sealing membrane box according to claim 2, characterized in that: The connection between the housing (21) and the gas detection core (22), and between the helium detection adapter (26) and the nozzle (25) are all threaded connections; a fifth sealing member (212) is provided between the input end of the nozzle (25) and the output end of the helium detection adapter (26).

4. The multifunctional sealing detection device for an end face sealing membrane box according to claim 3, characterized in that: The first sealing member (28), the second sealing member (29), the third sealing member (210), and the fourth sealing member (211) are all rubber rings; the fifth sealing member (212) is a rubber gasket; the rigid fixing sleeve (24) is made of copper; the positioning core shaft (23) is made of fluoroplastic; and the fastener (27) is a hexagon socket screw.

5. The multifunctional sealing detection device for an end face sealing membrane box according to claim 4, characterized in that: The diameter of the positioning hole (201) is the diameter of the inner hole of the membrane box for end face sealing + (0.03-0.05) mm.

6. The multifunctional sealing detection device for an end face sealing membrane box according to claim 5, characterized in that: The unilateral fitting clearance between the end of the positioning core shaft (23) not provided with the fourth sealing member (211) and the positioning hole (201) is 0.02 to 0.04 mm; the unilateral fitting clearance between the outer side surface of the end of the positioning core shaft (23) provided with the fourth sealing member (211) and the inner side surface of the positioning hole (201) is 0.15 to 0.20 mm; the fitting clearance between the inner side surface of the housing (21) and the outer side surface of the gas detection core (22) is 0.15 to 0.20 mm; When one end of the positioning core shaft (23) provided with the fourth sealing member (211) is installed in the housing (21), the axial compression amount of the fourth sealing member (211) is 8% to 10%; when the air detection core (22) is installed in the housing (21), the axial compression amount of the second sealing member (29) is 8% to 10%.

7. The multifunctional sealing detection device for an end face sealing membrane box according to claim 6, characterized in that: The number of the ventilation holes is 6 to 8, and the diameter of each ventilation hole is 3 to 5 mm.

8. A vacuum helium mass spectrometry leak detection method for a multifunctional sealing detection device for an end face sealing membrane cartridge according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: prepare a helium gas cylinder, a helium mass spectrometer leak detector, and an end face sealing membrane box to be tested; define the area between the rigid fixing sleeve (24) and the inner end face of the small end of the test cavity as the first inner cavity (J), and define the communicating area formed by the inner cavity of the circular groove (2202), the inner cavity of the positioning hole (201), and the inner cavity of the end face sealing membrane box as the second inner cavity (K); Step 2: Install the end of the positioning core shaft (23) without the fourth sealing member (211) in the positioning hole (201), and then install the membrane box for the end face seal to be tested into a preset position according to the positioning of the end of the positioning core shaft (23), and set the preset leakage amount L1 of the weld; Step 3: Remove the positioning mandrel (23), and then connect the helium bottle to the outer end of the positioning hole (201); Step 4: Connect the input end of the helium detection adapter (26) to the leak detection port of the helium mass spectrometer leak detector, and start the helium mass spectrometer leak detector to perform a vacuum operation on the first inner cavity (J); Step 5. Open the helium cylinder to spray helium into the second inner cavity (K). At the same time, use a helium mass spectrometer leak detector to detect the helium leakage rate L2 per unit time of the first inner cavity (J), and compare L2 with L1 set in step 2. If L2 ≤ L1, the vacuum helium mass spectrometer leak test of the membrane box for end face sealing under test is qualified; if L2 > L1, the vacuum helium mass spectrometer leak test of the membrane box for end face sealing under test is unqualified.

9. A positive pressure helium mass spectrometry leak detection method for a multifunctional sealing detection device for an end face sealing membrane cartridge according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: prepare a helium gas cylinder, a helium mass spectrometer leak detector, and an end face sealing membrane box to be tested; define the area between the rigid fixing sleeve (24) and the inner side surface of the small end of the first cylinder as the first inner cavity (J), and define the communicating area formed by the inner cavity of the circular groove (2202), the inner cavity of the positioning hole (201), and the inner cavity of the end face sealing membrane box as the second inner cavity (K); Step 2: Install the end of the positioning core shaft (23) without the fourth sealing member (211) in the positioning hole (201), and then install the end face sealing membrane box to be tested into a preset position according to the positioning of the end of the positioning core shaft (23), and set the preset leakage amount L3 of the weld; Step 3: Remove the positioning core shaft (23), and insert the end of the positioning core shaft (23) with the fourth sealing member (211) into the positioning hole (201); Step 4: Remove the helium detection adapter (26), the fastener (27) and the third sealing member (210), connect the input end of the nozzle (25) to the output end of the helium cylinder, connect the outer end of the first through hole (2201) on the gas detection core (22) to the leak detection port of the helium mass spectrometer leak detector, and then start the helium mass spectrometer leak detector to evacuate the second inner cavity (K); Step 5. Open the helium cylinder and spray helium into the first inner cavity (J). At the same time, the helium mass spectrometer leak detector detects the helium leakage per unit time L4 of the second inner cavity (K), and compares L4 with L3 set in step 2. If L4≤L3, the positive pressure helium mass spectrometer leak test of the membrane box for the tested end face seal is qualified; if L4>L3, the positive pressure helium mass spectrometer leak test of the membrane box for the tested end face seal is unqualified.

10. A method for inspecting airtightness of a multifunctional sealing detection device for an end face sealing membrane box according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Prepare the end face sealing membrane box and the compressed air bottle to be tested; define the area between the rigid fixing sleeve (24) and the inner side surface of the small end of the first cylinder as the first inner cavity (J), and define the communicating area formed by the inner cavity of the circular groove (2202), the inner cavity of the positioning hole (201) and the inner cavity of the end face sealing membrane box as the second inner cavity (K); Step 2: Install the end of the positioning core shaft (23) without the fourth sealing member (211) into the positioning hole (201), and then install the end face sealing membrane box to be tested into the preset position according to the positioning of the end of the positioning core shaft (23). Step 3: Remove the positioning core shaft (23) and the helium detection adapter (26), and make the outer end opening of the positioning hole (201) face vertically upward; Step 4, connect the input end of the nozzle (25) to the output end of the compressed air bottle, open the compressed air bottle, spray compressed air into the first inner cavity (J), and when the pressure of the sprayed compressed air stabilizes, inject a preset amount of leakage-indicating liquid from the outer end opening of the positioning hole (201) into the second inner cavity (K); wherein the leakage-indicating liquid is pure water or anhydrous ethanol, and the injection amount of the leakage-indicating liquid is 2 mm to 5 mm higher than the inner weld (12) at the top of the membrane box for end face sealing; Step 5: Observe whether there are bubbles in the leakage-indicating liquid. If there are no bubbles, the airtightness test of the membrane box for sealing the inspected end face is qualified; otherwise, the airtightness test is unqualified.

Images