Performance test method for ultra-high vacuum elastic energy storage metal sealing ring

Abstract

The present invention discloses a performance testing method and device for an ultra-high vacuum elastic energy storage metal sealing ring. The method comprises the following steps: first applying a compression load through a compression instrument, obtaining a relationship curve between the compression load and the compression amount of the sealing ring and a minimum compression load, repeating the test at least three times, and obtaining a critical value of the compression load; then applying a torque through a sealing chain, obtaining a relationship curve between the torque value and the compression amount of the sealing ring and a minimum torque, and repeating the test at least three times to obtain a critical value of the torque; fitting the above curves, and obtaining an equivalent conversion value of the compression load and the torque value. In the device, a groove for placing the sealing ring is formed between the upper flange and the lower flange, the upper flange is detachably connected to a moving rod of the compression instrument through an upper fixing plate, the lower flange is connected to a fixed base of the compression instrument through a lower fixing plate, the groove is connected to a vacuum tube, an angle valve, and a leak detector, and the periphery of the connection between the upper flange and the lower flange is detachably connected to a sealing chain. The present invention has a simple principle and can assist in the structural design of an ultra-high vacuum metal sealing ring.

Description

Technical Field

[0001] The invention relates to the technical field of sealing ring performance testing, and in particular to a performance testing method for an ultra-high vacuum elastic energy storage metal sealing ring. Background Art

[0002] Ultra-high vacuum elastic energy storage metal seal is the key sealing element of the accelerator ultra-high vacuum system, which realizes the detachable end face seal of metal to metal. The accelerator ultra-high vacuum elastic energy storage metal seal is essentially a C-shaped spring energy storage seal, which is mainly composed of a metal jacket of aluminum, copper, silver, stainless steel or other metal materials and an energy storage spring. It is often used in equipment in the fields of ultra-high vacuum, nuclear devices, aerospace, petroleum, cryogenics, chemical industry, metallurgy, power machinery, steam containers, etc. Its energy storage and sealing principle is generally as follows: when the spring energy storage seal is installed in the sealing groove, the external load applied to the system causes the spring to be compressed, causing the sealing surface of its spring jacket to be close to the groove. After the spring jacket is stressed, plastic flow occurs, compensating for the concave and convex surface and artificial scratches formed by the processing of the sealing interface material to block the medium from passing through the sealing surface, thereby forming an effective mechanical seal. The external load applied to the equipment, the spring rebound force and the pressure difference of the sealing interface medium jointly form a contact stress required for the sealing interface, thereby achieving long-term effective sealing.

[0003] At present, in the domestic ultra-high vacuum systems such as the Beijing positron storage ring, spallation neutron source and high-energy synchrotron radiation source, ultra-high vacuum metal sealing rings have the advantages of 200°C high-temperature degassing baking, long-term radiation corrosion protection, and almost no penetration of small molecule gases during use. However, due to technological blockade, the above-mentioned ultra-high vacuum metal sealing ring products still rely mainly on foreign imports. In this field, there is very little research and development on such ultra-high vacuum metal sealing ring products. In order to better meet the needs of the domestic market and reduce product costs, it is extremely important to research and develop such ultra-high vacuum metal sealing ring products and their production processes, testing processes, etc. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a performance testing method for an ultra-high vacuum elastic energy storage metal sealing ring. The testing method is simple in principle, and the test results can provide a high reference value for the use of ultra-high vacuum metal sealing rings, assist in the structural design of ultra-high vacuum metal sealing rings, and avoid failure during use that affects the normal use of accelerator equipment.

[0005] Another object of the present invention is to provide a performance testing device for an ultra-high vacuum elastic energy storage metal sealing ring for realizing the above-mentioned performance testing method.

[0006] The technical solution of the present invention is: a performance testing method for an ultra-high vacuum elastic energy storage metal sealing ring, comprising the following steps:

[0007] (1) Place the sealing ring in the groove on the top surface of the lower flange. The upper flange is connected to the moving rod of the compressor through the upper fixing plate. The lower flange is connected to the fixed base of the compressor through the lower fixing plate. The groove between the upper flange and the lower flange is connected to the leak detector to form a vacuum system.

[0008] (2) The moving rod of the compression instrument applies a compressive load, driving the upper flange to move toward the lower flange, and monitoring and recording the movement process from the sealing ring contacting the upper flange to the compression amount generated to form an effective seal;

[0009] From the time when the sealing ring starts to contact the upper flange to the time when compression occurs, a leak detector is used to perform helium mass spectrometry leak detection on the groove in real time by using the helium spray leak detection method, and the leak rate value is recorded; the displacement change of the sealing ring during the compression movement is recorded by a displacement meter to obtain the change of the compression amount of the sealing ring; the compression load change of the sealing ring during the compression movement of the upper flange is recorded by a stress gauge; thereby obtaining the relationship curve between the compression load and the compression amount of the sealing ring, and obtaining the minimum compression load for effective sealing;

[0010] (3) Replace the new sealing ring and repeat steps (1) and (2) for a number of repetitions greater than or equal to 3 times, and obtain the average value between the minimum and maximum values ​​of the minimum compression loads during multiple effective seals as the critical value of the compression load when the sealing ring is sealed;

[0011] (4) Separate the upper fixed plate from the moving rod of the compression instrument, and fix the reflector of the laser interferometer on it; place a sealing ring in the groove on the top surface of the lower flange; and install a sealing chain on the outer periphery of the connection between the upper flange and the lower flange;

[0012] (5) The compression load is provided by gradually locking the two ends of the sealing chain, driving the upper flange to gradually approach the lower flange, so that the sealing ring contacts the upper flange from the beginning until the sealing ring is compressed to form an effective seal;

[0013] In the process from when the sealing ring starts to contact the upper flange to when the compression occurs, a leak detector is used to perform helium mass spectrometry leak detection on the groove in real time by using a helium spray leak detection method, and the leak rate value is recorded. The change in the compression of the sealing ring from when the upper flange contacts the sealing ring to when the sealing ring is compressed is recorded by using a reflector plate of a laser interferometer. The torque change of the sealing chain from when the upper flange contacts the sealing ring to when the sealing ring is compressed is recorded by using a torque wrench; thereby, a relationship curve between the torque value and the compression of the sealing ring is obtained, as well as the minimum torque of the sealing chain when effective sealing is obtained;

[0014] (6) Replace the new sealing ring and repeat steps (4) and (5) until the number of repetitions is greater than or equal to three times. Record and obtain the average value between the minimum value and the maximum value of each minimum torque during multiple effective sealings as the torque critical value of the sealing ring when sealing.

[0015] (7) In the same coordinate system, the relationship curves between the multiple compression loads obtained in step (3) and the compression amount of the sealing ring are fitted, with the horizontal axis being the compression amount of the sealing ring and the vertical axis being the compression load; at the same time, the relationship curves between the multiple torque values ​​obtained in step (6) and the compression amount of the sealing ring are also fitted, with the horizontal axis being the compression amount of the sealing ring and the vertical axis being the torque value; based on the value of the same sealing ring compression amount, the equivalent conversion value of the compression load of the compressor and the torque value of the sealing chain is obtained.

[0016] In the above step (2), during the movement of the upper flange, starting from the moment when the sealing ring contacts the upper flange, the leak detector performs a leak test on the groove every time the upper flange moves 0.3 mm relative to the lower flange;

[0017] In the above step (5), during the movement of the upper flange, the leak detector performs a leak test on the groove every time the upper flange moves 0.3 mm relative to the lower flange from the time the sealing ring contacts the upper flange.

[0018] In the above step (3), the test times of steps (1) and (2) are repeated three times, and three sealing rings of the same specifications are used for testing respectively;

[0019] In the above step (6), the test times of steps (4) and (5) are repeated three times, and three sealing rings of the same specifications are used for testing respectively.

[0020] In the above performance testing method, further, after obtaining the critical value of the compression load or the critical value of the torque, when the compression load of the sealing ring is at the minimum and maximum values ​​under the effective sealing state, the fatigue life test of the sealing ring is respectively performed, and the linear reciprocating motion vibration number of the upper flange relative to the lower flange is greater than 15,000 times. During the vibration process, the groove is leak tested in real time by a leak detector, and the leakage rate value is recorded until the leakage rate value is detected to be less than or equal to the design value of 1.0E-11Pa.l / s. The corresponding number of vibrations corresponds to the fatigue life of the sealing ring.

[0021] The leak detector performs a leak test at a frequency of one leak test for every 200 vibrations.

[0022] Through the above-mentioned performance test method of ultra-high vacuum metal sealing ring, parameters such as the critical value of compression load, critical value of torque, fatigue life, etc. of a certain specification of ultra-high vacuum elastic energy storage metal sealing ring during sealing can be obtained. These parameters can provide a reference for the use of the same type of ultra-high vacuum elastic energy storage metal sealing ring products in actual engineering, so as to quickly understand at what compression load or torque the same type of ultra-high vacuum elastic energy storage metal sealing ring products can achieve an ideal sealing effect, and also to quickly understand the fatigue life of the same type of ultra-high vacuum elastic energy storage metal sealing ring products, so as to replace or maintain them in time, so as to facilitate the application of ultra-high vacuum elastic energy storage metal sealing ring products in the ultra-high vacuum system of accelerators.

[0023] The present invention discloses a performance testing device for an ultra-high vacuum elastic energy storage metal sealing ring for realizing the above-mentioned performance testing method, comprising an upper flange, a lower flange, a sealing chain, a compressor, an angle valve and a leak detector, wherein a groove for placing the sealing ring is formed between the upper flange and the lower flange, an upper fixing plate is provided on the top of the upper flange, and the upper fixing plate is detachably connected to a moving rod of the compressor, a lower fixing plate is provided on the bottom of the lower flange, and the lower fixing plate is connected to a fixed base of the compressor, a vacuum tube is connected to the groove, and the vacuum tube is connected to the leak detector through an angle valve, and the periphery of the connection between the upper flange and the lower flange is detachably connected to the sealing chain. Among them, when it is necessary to test the critical value of the compression load when the sealing ring is sealed, there is no need to install and use the sealing chain, and the upper flange can be driven to be gradually pressed down by the moving rod of the compression instrument; when it is necessary to test the critical value of the torque when the sealing ring is sealed, the upper flange does not need a compression instrument, and the upper fixed plate and the moving rod of the compression instrument can be disassembled and separated, and the two ends of the sealing chain are gradually locked, and the torque generated is used to make the upper flange gradually approach the lower flange, thereby gradually compressing the sealing ring. At this time, it is necessary to connect an external laser interferometer and its reflector to the upper flange, and the change in the compression of the sealing ring from the upper flange contacting the sealing ring to the compression of the sealing ring is recorded by a torque wrench.

[0024] The bottom surface of the upper flange is a plane, and the top surface of the lower flange is provided with an annular groove, which serves as a groove for placing a sealing ring; or the bottom surface of the upper flange is provided with a first annular groove, and the top surface of the lower flange is provided with a second annular groove, and the first annular groove and the second annular groove cooperate to form a groove for placing a sealing ring.

[0025] The depth of the groove is smaller than the diameter of the sealing ring.

[0026] The bottom surface of the upper flange is provided with a plurality of first positioning pin holes, and the top surface of the lower flange is provided with a plurality of second positioning pin holes, and each first positioning pin hole is connected to a corresponding second positioning pin hole through a positioning pin. The number of positioning pin holes and positioning pins can be determined according to the actual size of the upper flange and the lower flange. The accurate positioning between the upper flange and the lower flange can be effectively ensured through the cooperation of the positioning pin holes and the positioning pins, the consistency of multiple tests of the sealing ring can be ensured, and the accuracy of the final test results can be improved.

[0027] The sealing chain includes a chain block and a chain link, and two adjacent chain links are connected by a chain block. When the sealing chain is installed on the outer periphery of the upper flange and the lower flange, the two chain blocks at both ends of the sealing chain are gradually locked by bolts; each chain block is provided with a wedge-shaped groove on one side facing the outer periphery of the upper flange and the lower flange, and one side of the outer periphery of the upper flange is an inclined surface, and one side of the outer periphery of the lower flange is also an inclined surface, and the inclined surfaces on both sides of the wedge-shaped groove match the inclined surfaces of the edges of the upper flange and the lower flange respectively. In this structure, the inclined surfaces on both sides of the wedge-shaped groove cooperate with the inclined surfaces of the edges of the upper flange and the lower flange. When the two chain blocks at both ends of the sealing chain are gradually locked by bolts, as the sealing chain tightens the upper flange and the lower flange, the inclined surfaces on both sides of the wedge-shaped groove force the upper flange and the lower flange to move closer to each other. Since the lower flange is generally fixedly installed on the fixed base of the compressor, the upper flange is generally forced to gradually approach the lower flange, thereby gradually compressing the sealing ring in the groove.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The performance test method and device of the ultra-high vacuum elastic energy storage metal sealing ring are simple in principle and easy to operate. The test results of the sealing ring's compression load critical value, torque critical value, fatigue life and other parameters can provide a high reference value for the use of the same type of ultra-high vacuum elastic energy storage metal sealing ring products, assist in the structural design of the sealing ring under different working conditions, and can be used for working condition prediction and regular maintenance to avoid the phenomenon of sealing failure of ultra-high vacuum metal sealing ring products during use, which may affect the normal use of accelerator equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of the performance testing device for the ultra-high vacuum elastic energy storage metal sealing ring (the compression instrument is not shown in the figure).

[0031] Figure 2 for Figure 1 The cross-sectional schematic diagram of the performance test device after removing the sealing chain is shown.

[0032] Figure 3 It is a schematic diagram of the status of the upper flange and the lower flange when both ends of the sealing chain are gradually locked.

[0033] Figure 4 for Figure 3 AA section view of the .

[0034] Figure 5 for Figure 4 A partial enlarged view of the middle groove and the sealing ring cross section.

[0035] In the above figures, the components indicated by the respective reference numerals are as follows: 1 is an upper flange, 2 is a lower flange, 3 is a sealing chain, 3-1 is a chain block, 3-2 is a chain link, 3-3 is a wedge-shaped groove, 4 is an angle valve, 5 is a leak detector, 6 is an upper fixed plate, 7 is a lower fixed plate, 8 is a sealing ring, 9 is a groove, 9-1 is a first annular groove, 9-2 is a second annular groove, 10 is a vacuum tube, 11 is the connection between the two ends of the sealing chain, 12 is a first positioning pin hole, 13 is a second positioning pin hole, and 14 is a positioning pin. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto. Example

[0037] This embodiment provides a performance testing device for an ultra-high vacuum elastic energy storage metal sealing ring, such as Figure 1 or Figure 2 As shown, it includes an upper flange 1, a lower flange 2, a sealing chain 3, a compressor (not shown in the figure), an angle valve 4 and a leak detector 5. A groove 9 for placing a sealing ring 8 is formed between the upper flange and the lower flange. The top of the upper flange is provided with an upper fixing plate 6, which is detachably connected to the moving rod of the compressor. The bottom of the lower flange is provided with a lower fixing plate 7, which is connected to the fixed base of the compressor. The groove is connected with a vacuum tube 10, which is connected to the leak detector through an angle valve. The periphery of the connection between the upper flange and the lower flange is detachably connected to the sealing chain. When it is necessary to test the critical value of the compression load when the sealing ring is sealed, it is not necessary to install and use the sealing chain, and the moving rod of the compressor can be used to drive the upper flange to be gradually pressed down; when it is necessary to test the critical value of the torque when the sealing ring is sealed, the upper flange does not need to be connected to the compressor, and the upper fixing plate can be disassembled and separated from the moving rod of the compressor, and the two ends of the sealing chain are gradually locked (such as Figure 3 As shown, this can be achieved by gradually tightening the bolts 11 at the connection points at both ends of the sealing chain), and using the torque generated by it to gradually bring the upper flange closer to the lower flange, thereby gradually compressing the sealing ring. At this time, it is necessary to connect an external laser interferometer and its reflector to the upper flange, and record the change in the compression of the sealing ring from the time the upper flange contacts the sealing ring to the time the sealing ring is compressed, and use a torque wrench to record the torque change of the sealing chain from the time the upper flange contacts the sealing ring to the time the sealing ring is compressed.

[0038] The groove structure has the following two forms:

[0039] (1) The bottom surface of the upper flange is flat, and the top surface of the lower flange is provided with an annular groove, which is used as a groove for placing the sealing ring;

[0040] (2) A first annular groove is provided on the bottom surface of the upper flange, and a second annular groove is provided on the top surface of the lower flange. The first annular groove and the second annular groove cooperate to form a groove for placing a sealing ring.

[0041] This embodiment adopts the second structural form mentioned above, specifically as follows Figure 4 or Figure 5 The depth of the groove (ie, the total depth of the first annular groove 9-1 and the second annular groove 9-2) is smaller than the diameter of the sealing ring.

[0042] In addition, if Figure 4 As shown, the bottom surface of the upper flange is provided with a plurality of first positioning pin holes 12, and the top surface of the lower flange is provided with a plurality of second positioning pin holes 13, and each first positioning pin hole is connected to a corresponding second positioning pin hole through a positioning pin 14. The number of positioning pin holes and positioning pins can be determined according to the actual size of the upper flange and the lower flange. The accurate positioning between the upper flange and the lower flange can be effectively ensured by the cooperation of the positioning pin holes and the positioning pins, the consistency of multiple tests of the sealing ring can be ensured, and the accuracy of the final test results can be improved.

[0043] like Figure 1 As shown, the sealing chain includes a chain block 3-1 and a chain link 3-2. Two adjacent chain links are connected by a chain block. When the sealing chain is installed on the outer periphery of the upper flange and the lower flange, the two chain blocks at both ends of the sealing chain are gradually locked by bolts; each chain block is provided with a wedge-shaped groove 3-3 (such as Figure 4 or Figure 5 As shown in the figure, one side of the outer peripheral edge of the upper flange is a bevel, and one side of the outer peripheral edge of the lower flange is also a bevel. The bevels on both sides of the wedge-shaped groove match the bevels of the upper flange and the lower flange edges respectively. In this structure, the bevels on both sides of the wedge-shaped groove cooperate with the bevels on the edges of the upper flange and the lower flange. When the two chain blocks at both ends of the sealing chain are gradually tightened by bolts, as the sealing chain tightens the upper flange and the lower flange, the bevels on both sides of the wedge-shaped groove force the upper flange and the lower flange to move closer to each other. Since the lower flange is generally fixedly installed on the fixed base of the compressor, the upper flange is generally forced to gradually approach the lower flange, thereby gradually compressing the sealing ring in the groove. Example

[0044] The present embodiment provides a performance testing method for an ultra-high vacuum elastic energy storage metal sealing ring, which is implemented by the performance testing device of embodiment 1, and specifically comprises the following steps:

[0045] (1) Place the sealing ring in the groove on the top surface of the lower flange. The upper flange is connected to the moving rod of the compressor through the upper fixing plate. The lower flange is connected to the fixed base of the compressor through the lower fixing plate. The groove between the upper flange and the lower flange is connected to the leak detector to form a vacuum system.

[0046] (2) The moving rod of the compression instrument applies a compressive load, driving the upper flange to move toward the lower flange, and monitoring and recording the movement process from the sealing ring contacting the upper flange to the compression amount generated to form an effective seal;

[0047] From the time when the sealing ring starts to contact the upper flange to the time when compression occurs, a leak detector is used to perform helium mass spectrometry leak detection on the groove in real time by using the helium spray leak detection method, and the leak rate value is recorded. During the movement of the upper flange, from the time when the sealing ring starts to contact the upper flange, the leak detector performs a leak detection test on the groove every time the upper flange moves 0.3mm relative to the lower flange; the displacement change of the sealing ring during the compression movement is recorded by the displacement meter to obtain the change of the compression amount of the sealing ring; the compression load change of the sealing ring during the compression movement of the upper flange is recorded by the stress meter; thus, the relationship curve between the compression load and the compression amount of the sealing ring is obtained, and the minimum compression load for effective sealing is obtained;

[0048] (3) Replace a new sealing ring and repeat steps (1) and (2). The number of repetitions is required to be greater than or equal to three times. The average value between the minimum value and the maximum value of each minimum compression load during multiple effective sealing is obtained as the critical value of the compression load when the sealing ring is sealed. In this embodiment, the test is repeated three times and three sealing rings of the same specifications are used for testing respectively.

[0049] (4) Separate the upper fixed plate from the moving rod of the compression instrument, and fix the reflector of the laser interferometer on it; place a sealing ring in the groove on the top surface of the lower flange; and install a sealing chain on the outer periphery of the connection between the upper flange and the lower flange;

[0050] (5) The compression load is provided by gradually locking the two ends of the sealing chain, driving the upper flange to gradually approach the lower flange, so that the sealing ring contacts the upper flange from the beginning until the sealing ring is compressed to form an effective seal;

[0051] During the process from when the sealing ring starts to contact the upper flange to when compression occurs, a leak detector is used to perform helium mass spectrometry leak detection on the groove in real time by using a helium spray leak detection method, and the leak rate value is recorded. During the movement of the upper flange, the leak detector performs a leak detection test on the groove every time the upper flange moves 0.3mm relative to the lower flange from the time the sealing ring starts to contact the upper flange. The change in the compression of the sealing ring during the process from when the upper flange contacts the sealing ring to when compression occurs is recorded by the reflector of the laser interferometer. The change in the torque of the sealing chain during the process from when the upper flange contacts the sealing ring to when compression occurs is recorded by a torque wrench. Thus, a curve of the relationship between the torque value and the compression of the sealing ring is obtained, as well as the minimum torque of the sealing chain when effective sealing is obtained.

[0052] (6) Replace the new sealing ring and repeat steps (4) and (5) until the number of repetitions is greater than or equal to three times, and record and obtain the average value between the minimum value and the maximum value of each minimum torque during multiple effective sealings as the torque critical value when the sealing ring is sealed; in this embodiment, the test is repeated three times and three sealing rings of the same specifications are used for testing respectively;

[0053] (7) In the same coordinate system, the relationship curves between the multiple compression loads obtained in step (3) and the compression amount of the sealing ring are fitted, with the horizontal axis being the compression amount of the sealing ring and the vertical axis being the compression load; at the same time, the relationship curves between the multiple torque values ​​obtained in step (6) and the compression amount of the sealing ring are also fitted, with the horizontal axis being the compression amount of the sealing ring and the vertical axis being the torque value; based on the value of the same sealing ring compression amount, the equivalent conversion value of the compression load of the compressor and the torque value of the sealing chain is obtained.

[0054] Through the above-mentioned performance test method of ultra-high vacuum metal sealing ring, the critical value of compression load and critical value of torque of a certain specification of ultra-high vacuum elastic energy storage metal sealing ring when sealing can be obtained. These parameters can provide a reference for the use of the same type of ultra-high vacuum elastic energy storage metal sealing ring products in actual engineering, so as to quickly understand the compression load or torque under which the same type of ultra-high vacuum elastic energy storage metal sealing ring products can achieve an ideal sealing effect, and facilitate the application of ultra-high vacuum elastic energy storage metal sealing ring products in the ultra-high vacuum system of accelerators. Example

[0055] The present embodiment is a performance test method for an ultra-high vacuum elastic energy storage metal sealing ring. Compared with the embodiment 2, the difference is that: on the basis of the above performance test method, further, after obtaining the critical value of the compression load or the critical value of the torque, when the compression load of the sealing ring is at the minimum value and the maximum value in the effective sealing state, the sealing ring is subjected to fatigue life test respectively, and the linear reciprocating motion vibration number of the upper flange relative to the lower flange is greater than 15,000 times. During the vibration process, the groove is leak tested in real time by a leak detector, and the leakage rate value is recorded until the leakage rate value is detected to be less than or equal to the design value of 1.0E-11Pa.l / s. The corresponding vibration number corresponds to the fatigue life of the sealing ring. Among them, the frequency of the leak test performed by the leak detector is one leak test for every 200 vibrations.

[0056] Through the above-mentioned performance test method of ultra-high vacuum metal sealing ring, parameters such as the critical value of compression load, critical value of torque, fatigue life, etc. of a certain specification of ultra-high vacuum elastic energy storage metal sealing ring during sealing can be obtained. These parameters can provide a reference for the use of the same type of ultra-high vacuum elastic energy storage metal sealing ring products in actual engineering, so as to quickly understand at what compression load or torque the same type of ultra-high vacuum elastic energy storage metal sealing ring products can achieve an ideal sealing effect, and also to quickly understand the fatigue life of the same type of ultra-high vacuum elastic energy storage metal sealing ring products, so as to replace or maintain them in time, so as to facilitate the application of ultra-high vacuum elastic energy storage metal sealing ring products in the ultra-high vacuum system of accelerators.

[0057] As described above, the present invention can be better implemented. The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made according to the content of the present invention are covered by the scope of protection required by the claims of the present invention.

Claims

1. The performance test method of ultra-high vacuum elastic energy storage metal sealing ring is characterized by: The following steps are involved: (1) Place the sealing ring in the groove on the top surface of the lower flange. The upper flange is connected to the moving rod of the compressor through the upper fixing plate. The lower flange is connected to the fixed base of the compressor through the lower fixing plate. The groove between the upper flange and the lower flange is connected to the leak detector to form a vacuum system. (2) The moving rod of the compression instrument applies a compressive load, driving the upper flange to move toward the lower flange, and monitoring and recording the movement process from the sealing ring contacting the upper flange to the compression amount generated to form an effective seal; From the time when the sealing ring starts to contact the upper flange to the time when compression occurs, a leak detector is used to perform helium mass spectrometry leak detection on the groove in real time by using the helium spray leak detection method, and the leak rate value is recorded; the displacement change of the sealing ring during the compression movement is recorded by a displacement meter to obtain the change of the sealing ring compression; the compression load change of the sealing ring during the compression movement of the upper flange is recorded by a stress gauge; Thus, the relationship curve between compression load and compression amount of sealing ring and the minimum compression load for effective sealing can be obtained; (3) Replace the new sealing ring and repeat steps (1) and (2) for three or more times. Obtain the average value between the minimum and maximum values ​​of the minimum compression loads during multiple effective seals as the critical value of the compression load during the sealing of the sealing ring. (4) Separate the upper fixed plate from the moving rod of the compression instrument, and fix the reflector of the laser interferometer on it; place a sealing ring in the groove on the top surface of the lower flange; and install a sealing chain on the outer periphery of the connection between the upper flange and the lower flange; (5) The compression load is provided by gradually locking the two ends of the sealing chain, driving the upper flange to gradually approach the lower flange, so that the sealing ring contacts the upper flange from the beginning until the sealing ring is compressed to form an effective seal; In the process from when the sealing ring starts to contact the upper flange to when compression occurs, a leak detector is used to perform helium mass spectrometry leak detection on the groove in real time by using a helium spray leak detection method, and the leak rate value is recorded. The change in the compression of the sealing ring from when the upper flange contacts the sealing ring to when compression occurs is recorded by using a reflector plate of a laser interferometer. The torque change of the sealing chain from when the upper flange contacts the sealing ring to when compression occurs is recorded by using a torque wrench. Thus, the relationship curve between torque value and compression of the sealing ring is obtained, as well as the minimum torque of the sealing chain when effective sealing is achieved; (6) Replace the new sealing ring and repeat steps (4) and (5) until the number of repetitions is greater than or equal to three times. Record and obtain the average value between the minimum value and the maximum value of each minimum torque during multiple effective sealings as the torque critical value of the sealing ring when sealing. (7) In the same coordinate system, the relationship curves between the multiple compression loads obtained in step (3) and the compression amount of the sealing ring are fitted, with the horizontal axis being the compression amount of the sealing ring and the vertical axis being the compression load; at the same time, the relationship curves between the multiple torque values ​​obtained in step (6) and the compression amount of the sealing ring are also fitted, with the horizontal axis being the compression amount of the sealing ring and the vertical axis being the torque value; according to the value of the same compression amount of the sealing ring, the equivalent conversion value of the compression load of the compression instrument and the torque value of the sealing chain is obtained; The performance testing device for the ultra-high vacuum elastic energy storage metal sealing ring for realizing the above-mentioned performance testing method comprises an upper flange, a lower flange, a sealing chain, a compressor, an angle valve and a leak detector. A groove for placing the sealing ring is formed between the upper flange and the lower flange. The top of the upper flange is provided with an upper fixing plate, which is detachably connected to the moving rod of the compressor. The bottom of the lower flange is provided with a lower fixing plate, which is connected to the fixed base of the compressor. The groove is connected with a vacuum tube, which is connected to the leak detector through an angle valve. The periphery of the connection between the upper flange and the lower flange is detachably connected to the sealing chain.

2. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: In step (2), during the movement of the upper flange, starting from the moment the sealing ring contacts the upper flange, the leak detector performs a leak test on the groove every time the upper flange moves 0.3 mm relative to the lower flange; In step (5), during the movement of the upper flange, the leak detector performs a leak test on the groove every time the upper flange moves 0.3 mm relative to the lower flange from the time the sealing ring contacts the upper flange.

3. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: In step (3), the test of steps (1) and (2) is repeated three times, and three sealing rings of the same specifications are used for testing respectively; In step (6), the test times of steps (4) and (5) are repeated three times, and three sealing rings of the same specifications are used for testing respectively.

4. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: After obtaining the critical value of the compression load or the critical value of the torque, when the compression load of the sealing ring is at the minimum and maximum values ​​under the effective sealing state, the sealing ring is subjected to fatigue life tests respectively, and the linear reciprocating motion vibration number of the upper flange relative to the lower flange is greater than 15,000 times. During the vibration process, the groove is subjected to a real-time leak test by a leak detector, and the leakage rate value is recorded until the leakage rate value is detected to be less than or equal to the design value of 1.0E-11Pa.l / s. The corresponding number of vibrations corresponds to the fatigue life of the sealing ring.

5. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 4 is characterized in that: The leak detector performs a leak test once every 200 vibrations.

6. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: The bottom surface of the upper flange is a plane, and the top surface of the lower flange is provided with an annular groove, which serves as a groove for placing a sealing ring; or the bottom surface of the upper flange is provided with a first annular groove, and the top surface of the lower flange is provided with a second annular groove, and the first annular groove and the second annular groove cooperate to form a groove for placing a sealing ring.

7. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: The depth of the groove is smaller than the diameter of the sealing ring.

8. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: A plurality of first positioning pin holes are distributed on the bottom surface of the upper flange, and a plurality of second positioning pin holes are distributed on the top surface of the lower flange. Each first positioning pin hole is connected to a corresponding second positioning pin hole via a positioning pin.

9. The performance testing method of the ultra-high vacuum elastic energy storage metal sealing ring according to claim 1 is characterized in that: The sealing chain includes a chain block and a chain link, and two adjacent chain links are connected by a chain block. When the sealing chain is installed on the outer periphery of the upper flange and the lower flange, the two chain blocks located at both ends of the sealing chain are gradually locked by bolts; each chain block is provided with a wedge-shaped groove on the side facing the outer periphery of the upper flange and the lower flange, one side of the outer periphery edge of the upper flange is an inclined surface, and one side of the outer periphery edge of the lower flange is also an inclined surface, and the inclined surfaces on both sides of the wedge-shaped groove respectively match the inclined surfaces of the edges of the upper flange and the lower flange.

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