Ultra-vacuum electromagnetic valve and testing method thereof

Abstract

The invention provides an ultra-vacuum electromagnetic valve and a testing method thereof.The ultra-vacuum electromagnetic valve comprises a valve body and an iron core assembly, a vacuum opening, a volcano-shaped valve opening and a vacuumizing opening are formed in the valve body, and the vacuumizing opening communicates with the vacuum opening through the volcano-shaped valve opening; the iron core assembly comprises a movable iron core slidably installed on the upper side of the volcanic valve port and a valve port sealing piece, one end of the movable iron core is concaved inwards to form a sealing piece cavity, the outer side end of the sealing piece cavity is provided with an imbedding opening, the inner side end of the sealing piece cavity is expanded outwards to form an extrusion space, and the imbedding opening is expanded outwards to form an expansion absorption area; the valve port sealing piece is arranged in the sealing piece cavity from the placing opening in an extrusion mode, the expansion absorption area is used for absorbing the deformation amount of the valve port sealing piece, and therefore it is guaranteed that the sealing face of the valve port sealing piece is always flat. According to the ultra-vacuum electromagnetic valve and the testing method thereof, the defect that an existing vacuum electromagnetic valve is not suitable for an ultra-vacuum scene due to poor sealing performance is overcome.

Description

Technical Field

[0001] The invention relates to the field of solenoid valves, and in particular to an ultra-vacuum solenoid valve and a testing method thereof. Background Art

[0002] The vacuum solenoid valve generally includes a vacuum port, a vacuum pumping port, a valve port, a movable iron core and a spring. The vacuum pumping port is connected to the vacuum pump, and the vacuum port is connected to the container. When the electromagnetic coil is energized to generate a magnetic field, the movable iron core overcomes the spring force and moves upward to open the valve port, the vacuum solenoid valve is opened, the vacuum pump is turned on, and all pipelines are connected. At this time, the vacuum pump through the vacuum solenoid valve to the container is in a vacuum state. If there is any poor seal around the vacuum solenoid valve, the vacuum pump will always be in a working state and cannot be pumped to the required high vacuum state. When the electromagnetic coil is de-energized, the movable iron core moves downward under the action of the spring force and closes the valve port. At this time, the vacuum solenoid valve is in a closed state, the vacuum is cut off, the vacuum pump is turned off and the vacuum breaking valve of the vacuum pump is opened. At this time, the vacuum pumping port end is atmospheric pressure, and the vacuum port end is ultra-vacuum. At this time, if the valve port is not sealed well, the vacuum port and the container cannot maintain an ultra-vacuum state.

[0003] The existing vacuum solenoid valve has a poor external seal and / or internal seal, which limits its use to a vacuum range of only 10 -1 pa to 10 -4 pa. With the continuous development of science and technology and the emergence of new industries, such as photovoltaics, new energy, artificial intelligence, etc., higher requirements for vacuum solenoid valves are required for supporting applications, but the existing vacuum solenoid valves are not suitable for ultra-vacuum scenarios and need to be improved. Summary of the invention

[0004] 1. Technical problems to be solved

[0005] The problem to be solved by the present invention is to provide an ultra-vacuum solenoid valve and a testing method thereof, so as to overcome the defect that the existing vacuum solenoid valve is not suitable for ultra-vacuum scenarios due to poor sealing.

[0006] (2) Technical solution

[0007] In order to solve the technical problem, the present invention provides an ultra-vacuum solenoid valve, including.

[0008] The valve body is provided with a vacuum port, a volcano-shaped valve port and a vacuum extraction port, wherein the vacuum extraction port is connected with the vacuum port through the volcano-shaped valve port.

[0009] An iron core assembly includes a movable iron core slidably installed on the upper side of the volcano-shaped valve port and a valve port seal for opening and closing the volcano-shaped valve port; the movable iron core is concave at one end facing the volcano-shaped valve port to form a seal cavity, the outer end of the seal cavity is provided with an insertion port, the inner end thereof is expanded outward to form an extrusion space, and the insertion port is expanded outward to form a trumpet-shaped expansion absorption area; the valve port seal is loaded into the seal cavity from the insertion port by extrusion, the extrusion space is used to prevent the valve port seal from being squeezed and deformed, and the expansion absorption area is used to absorb the deformation of the valve port seal when the valve port seal is pressed against the volcano-shaped valve port, thereby ensuring that the sealing surface of the valve port seal is always flat.

[0010] In some embodiments, the valve mouth seal is provided with the sealing surface at one end facing the volcano-shaped valve mouth, and a plurality of arc-shaped buffer ribs are provided at equal intervals in a ring at the other end. The buffer ribs are convexly arranged and abut against the inner wall of the sealing cavity, and an elastic zone is formed between the sealing surface and the outer end surface of the buffer ribs.

[0011] In some embodiments, the side wall of the movable iron core is provided with an exhaust hole connected to the extrusion space, and the exhaust hole is used to discharge the gas in the sealing cavity when the valve mouth seal is installed; the outer circumferential wall of the movable iron core is wrapped with a plastic-coated wear-resistant ring, and the movable iron core is provided with an annular energy absorption cavity at a position close to the sealing cavity, and the annular energy absorption cavity is located inside the plastic-coated wear-resistant ring.

[0012] In some embodiments, it also includes a magnetic isolation tube assembly located on the upper side of the valve body, and the magnetic isolation tube assembly is sealed and connected to the valve body through a compression sealing assembly; the compression sealing assembly includes a spiral sleeve and a sealing ring, the valve body is provided with a threaded column extending toward the magnetic isolation tube assembly, the end of the threaded column is provided with an annular groove, and the sealing ring is installed in the annular groove; an annular pressure block corresponding to the sealing ring is provided on the magnetic isolation tube assembly, the spiral sleeve is sleeved on the magnetic isolation tube assembly and is threadedly connected to the threaded column, so that the annular pressure block presses the sealing ring.

[0013] In some embodiments, the magnetic isolation tube assembly includes a hollow magnetic isolation tube and a static iron core partially inserted in the magnetic isolation tube, and the annular pressure block is arranged on the magnetic isolation tube; a welding shoulder is arranged on the static iron core, and the welding shoulder is abutted against the end of the magnetic isolation tube and is welded and fixed to the magnetic isolation tube; a magnetic isolation tube sealing ring is installed on the outer circumferential wall of the static iron core extending part, and the end of the static iron core extending part is contracted to form a conical anti-scratch part.

[0014] In some embodiments, the movable iron core is slidably installed in the magnetic isolation tube, and the end of the static iron core facing the movable iron core has an attraction surface, the attraction surface is provided with an energy absorption groove, and an anti-collision plate is installed on the outside of the energy absorption groove.

[0015] In some embodiments, an iron core spring is installed between the movable iron core and the magnetic isolation tube assembly, and the iron core spring always makes the movable iron core tend to move toward the volcano-shaped valve port; an annular flange is provided at the lower end of the movable iron core, and a spring limiting groove is provided on the magnetic isolation tube assembly; one end of the iron core spring is abutted against the annular flange, and the other end thereof is abutted in the spring limiting groove.

[0016] In some embodiments, an electromagnetic coil is disposed on the magnetic isolation tube assembly, and the electromagnetic coil is fixedly connected to the magnetic isolation tube assembly via a fastening nut.

[0017] In some embodiments, the vacuum port and the vacuum extraction port are coaxially arranged, the volcano-shaped valve port, the core assembly and the magnetic isolation tube assembly are coaxially arranged, the axis of the vacuum port and the axis of the volcano-shaped valve port are perpendicular, and the valve port seal is T-shaped.

[0018] The present invention also provides a method for testing an ultra-vacuum solenoid valve, which is implemented based on the ultra-vacuum solenoid valve and includes the following steps.

[0019] A01, external leakage test; power on the ultra-vacuum solenoid valve and open it, connect its vacuum port to the vacuum pump, and connect its vacuum port to the container, so that the vacuum pump, the ultra-vacuum solenoid valve and the container are in an ultra-vacuum state; then, with the help of the helium detection method of the mass spectrometer, put the ultra-vacuum solenoid valve into the sealed cavity of the mass spectrometer and fill the sealed cavity with helium, calculate the leakage rate of the inspected part and judge whether it is qualified; if qualified, go to step A02, otherwise it is unqualified.

[0020] A02, internal leakage test; the ultra-vacuum solenoid valve is powered off and closed, and its vacuum port is connected to the vacuum pump. The vacuum pump is turned on, and the vacuum pump and the ultra-vacuum solenoid valve are in an ultra-vacuum state; then, with the help of the helium detection method of the mass spectrometer, the vacuum port of the ultra-vacuum solenoid valve is connected to the helium filling port of the mass spectrometer and filled with helium, the leakage rate of the inspected part is calculated and whether it is qualified; if it is qualified, it is a qualified product, otherwise it is a failed product.

[0021] The helium detection method comprises the following steps.

[0022] B01, calculate the system's effective minimum detectable leak rate Q emin ; Input the standard leak rate Q of the tested part into the mass spectrometer 标 Then, the mass spectrometer I n ,I1 ,I 0 , Q 0 and γ parameters, and calculate Q by the following formula emin。

[0023] ; Among them, I n —Noise floor value, Pa·m 3 / s;I 1 —Calibrated leak response value, Pa·m 3 / s;I 0 —System background value, Pa·m 3 / s;Q 0 —Leakage rate of calibrated leak, Pa·m 3 / s;γ—helium concentration, ppm.

[0024] Final judgment Q emin Is it less than Q 标 If yes, go to step B02, otherwise debug the mass spectrometer.

[0025] B02, apply nitrogen; close the calibration valve of the mass spectrometer, record the mass spectrometer reading by I 1 Down to I 0 +0.37(I 1 -I 0 ) The time t experienced is the reaction time of the leak detection system; then wait for the system background to return to I 0 After that, apply helium with a concentration of γ to the test piece for a period of not less than 3t, and record the reaction value I of the test piece. 2。

[0026] B03, calculate the leakage rate Q of the tested part; 2 ,I 1 ,I 0 , Q 0 Substitute the γ and γ parameters into the following formula to calculate Q.

[0027] ; Among them, I 2 —Test piece response value, Pa·m 3 / s.

[0028] Finally, determine whether Q is less than Q 标 If yes, it is qualified, otherwise it is unqualified.

[0029] (III) Beneficial effects.

[0030] An ultra-vacuum solenoid valve and a testing method thereof provided by the present invention have the following advantages compared with the prior art.

[0031] 1) After the valve port seal and the seal cavity are squeezed and installed, since there is an extrusion space (clearance fit) in the seal cavity, the valve port seal will not be deformed due to extrusion and affect the seal with the volcano-shaped valve port; an expansion absorption area is set. When the valve port seal and the volcano-shaped valve port are squeezed under the action of the iron core spring, the valve port seal will be deformed. At this time, the expansion absorption area can absorb the deformation, so that the sealing surface always remains flat, and the internal sealing effect is excellent.

[0032] 2) A sealing ring is provided between the magnetic isolation tube assembly and the valve body. When the spiral sleeve is rotated, the annular pressure block can smoothly press the sealing ring without causing damage to the sealing ring, and the sealing is reliable and stable. This breaks the previous design of pressing by rotation. The sealing ring will not be twisted, flipped or deformed due to rotation, which effectively improves the external sealing effect. To ensure absolute sealing, a magnetic isolation tube sealing ring is provided in the middle of the static iron core, which adds a guarantee for sealing and ensures the reliability of external sealing.

[0033] 3) The design of adding buffer ribs to the valve port seal increases the height of the elastic zone, making the overall elastic space larger. During the assembly and extrusion process, it can not only ensure strong elastic force, but also keep the sealing surface flat. At the same time, the air at the end of the valve port seal will flow out from the exhaust hole more smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 The figure is a schematic diagram of the structure of an ultra-vacuum solenoid valve of the present invention.

[0036] Figure 2 The present invention is a schematic structural diagram of an ultra-vacuum solenoid valve core assembly.

[0037] Figure 3 The present invention is a schematic structural diagram of a movable iron core of an ultra-vacuum solenoid valve.

[0038] Figure 4 The present invention is a structural schematic diagram of the connection between a movable iron core of an ultra-vacuum solenoid valve and a valve port sealing member.

[0039] Figure 5 It is a structural schematic diagram of a super vacuum solenoid valve port sealing member closing a volcano-shaped valve port according to the present invention.

[0040] Figure 6The present invention is a schematic structural diagram of a valve port sealing member of an ultra-vacuum solenoid valve.

[0041] Figure 7 This is a schematic diagram of the structure of a valve port seal of an ultra-vacuum solenoid valve of the present invention from a top view.

[0042] Figure 8 The present invention is a schematic structural diagram of a super vacuum solenoid valve compression sealing assembly.

[0043] Fig. 9 The present invention is a schematic structural diagram of a super vacuum solenoid valve magnetic isolation tube assembly.

[0044] The names of the components corresponding to the reference numerals in the figure are: 1. valve body; 101. vacuum port; 102. volcano-shaped valve port; 103. vacuum port; 104. threaded column; 105. annular groove; 2. core assembly; 21. movable core; 22. valve port seal; 23. plastic-coated wear-resistant ring; 211. seal cavity; 212. insertion port; 213. extrusion space; 214. expansion absorption zone; 215. exhaust hole; 216. annular energy absorption cavity; 217. Annular flange; 221, sealing surface; 222, buffer rib; 223, elastic area; 3, fastening nut; 4, magnetic isolation tube assembly; 41, magnetic isolation tube; 42, static iron core; 43, magnetic isolation tube sealing ring; 44, anti-collision plate; 401, annular pressure block; 402, spring limit groove; 421, welding shoulder; 422, conical anti-scratch part; 423, energy absorption groove; 5, compression sealing assembly; 51, spiral sleeve; 52, sealing ring; 6, iron core spring; 7, electromagnetic coil. DETAILED DESCRIPTION

[0045] The present application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0047] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0048] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show the components related to the present application rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0049] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the examples can be practiced without these specific details.

[0050] The technical solutions provided by various embodiments of the present application are described below in conjunction with the accompanying drawings.

[0051] See also Figures 1 to 9 The present invention provides an ultra-vacuum solenoid valve, including a valve body 1, an iron core assembly 2, a magnetic isolation tube assembly 4, a compression sealing assembly 5, an iron core spring 6 and an electromagnetic coil 7.

[0052] See also Figure 1 and Figure 2 The valve body 1 is provided with a vacuum port 101, a volcano-shaped valve port 102 and a vacuum port 103, and the vacuum port 103 is connected with the vacuum port 101 through the volcano-shaped valve port 102; wherein the vacuum port 101 and the vacuum port 103 are respectively located on both sides of the valve body 1, and the vacuum port 101 and the vacuum port 103 are arranged coaxially, and the axis of the vacuum port 101 is perpendicular to the axis of the volcano-shaped valve port 102. The core assembly 2 includes a movable core 21 slidably mounted on the upper side of the volcano-shaped valve port 102 and a valve port seal 22 for opening and closing the volcano-shaped valve port 102, the valve port seal 22 is located directly above the volcano-shaped valve port 102, and the valve port seal 22 can open or close the volcano-shaped valve port 102 under the drive of the movable core 21.

[0053] See also Figures 2 to 5The end of the movable iron core 21 facing the volcano-shaped valve port 102 is concave to form a sealing cavity 211, wherein the valve port sealing member 22 is T-shaped, and the shape of the sealing cavity 211 is similar to the outer contour of the valve port sealing member 22. An insertion port 212 is provided at the outer end of the sealing cavity 211, and an extrusion space 213 is formed by expanding the inner end of the sealing cavity 211, and the extrusion space 213 is connected to the sealing cavity 211. A trumpet-shaped expansion absorption area 214 is formed at the insertion port 212, and the expansion absorption area 214 is connected to the insertion port 212. The valve seal 22 is loaded into the seal cavity 211 from the insertion port 212 by extrusion. The extrusion space 213 is set so that after the valve seal 22 is loaded, there is a certain gap between the outer wall of the end of the valve seal 22 away from the sealing surface 221 and the inner wall of the seal cavity 211. On the one hand, the gap can prevent the valve seal 22 from being squeezed and deformed during loading. On the other hand, when the sealing surface 221 is pressed against the volcano-shaped valve port 102, the deformation of the valve seal 22 can be absorbed to ensure the flatness of the sealing surface 221, thereby improving the internal sealing performance. The expansion absorption area 214 is used to absorb the deformation of the valve seal 22 when the valve seal 22 is pressed against the volcano-shaped valve port 102, thereby ensuring that the sealing surface 221 of the valve seal 22 is always flat.

[0054] In the prior art, some vacuum solenoid valve manufacturers, in order to achieve a higher vacuum degree, use the method of increasing the core spring force to make the sealing surface and the valve port contact more closely (internal seal) to improve the sealing requirements, thereby achieving a better leakage value; but this often comes at a higher price. In order to overcome the spring force, the coil volume is made larger and the power is made higher, which not only increases the cost, but also fails to meet the leakage value requirements during actual application. The increased spring force has no effect at all under ultra-vacuum conditions.

[0055] Internal sealing is very important. In the present invention, after the valve port seal 22 and the seal cavity 211 are squeezed and installed, since the seal cavity 211 has an extrusion space (clearance fit), the valve port seal 22 will not be deformed due to extrusion and affect the seal with the volcano-shaped valve port 102. An expansion absorption area 214 is provided. When the valve port seal 22 and the volcano-shaped valve port 102 are squeezed under the action of the iron core spring 6, the valve port seal 22 will be deformed. At this time, the expansion absorption area 214 can absorb the deformation, so that the sealing surface 221 is always kept flat, and the internal sealing effect is excellent.

[0056] In some embodiments, Figures 4 to 7As shown, a sealing surface 221 is provided at one end of the valve seal 22 facing the volcano-shaped valve port 102, and the sealing surface 221 corresponds to the expansion absorption area 214. A plurality of arc-shaped buffer ribs 222 are provided at equal intervals in a ring shape at the other end of the valve seal 22. In this embodiment, there are four buffer ribs 222. The buffer ribs 222 are convexly arranged and abut against the inner wall of the seal cavity 211, and an elastic area 223 is formed between the sealing surface 221 and the outer end surface of the buffer ribs 222. In this structure, the design of adding buffer ribs 222 to the valve seal 22 increases the height of the elastic area 223, so that the overall elastic space is larger. During the assembly and extrusion process, not only a strong elastic force can be guaranteed, but also the flatness of the sealing surface 221 can be kept all the time. At the same time, the air at the end of the valve seal 22 will flow out from the exhaust hole 215 more smoothly.

[0057] In some embodiments, Figures 4 to 7 As shown, the side wall of the movable iron core 21 is provided with an exhaust hole 215 connected with the extrusion space 213, and the exhaust hole 215 is used to discharge the gas in the sealing cavity 211 when the valve port seal 22 is installed; the exhaust hole 215 is provided, and the gas in the sealing cavity 211 can be discharged when the valve port seal 22 is extruded and installed, so that the valve port seal 22 can be stably fitted in the sealing cavity 211. The outer circumferential wall of the movable iron core 21 is wrapped with a plastic-coated wear-resistant ring 23, and the movable iron core 21 is provided with an annular energy absorption cavity 216 at a position close to the sealing cavity 211, and the annular energy absorption cavity 216 is located inside the plastic-coated wear-resistant ring 23; the outer wall of the movable iron core 21 is wrapped with the plastic-coated wear-resistant ring 23, so that the movable iron core 21 moves up and down smoothly and the friction coefficient is reduced; in order to ensure that the plastic-coated wear-resistant ring 23 can fully wrap the movable iron core, an annular energy absorption cavity is provided on the surface to make the roundness and concentricity of the wrapping better.

[0058] In some embodiments, Figure 1 and Figure 8 As shown, the magnetic isolation tube assembly 4 is located on the upper side of the valve body 1, and the magnetic isolation tube assembly 4 is sealed and connected to the valve body 1 through a compression seal assembly 5. The compression seal assembly 5 includes a spiral sleeve 51 and a sealing ring 52. The valve body 1 is provided with a threaded column 104 extending toward the magnetic isolation tube assembly 4. The end of the threaded column 104 is provided with an annular groove 105, and the sealing ring 52 is installed in the annular groove 105. The magnetic isolation tube assembly 4 is provided with an annular pressing block 401 corresponding to the sealing ring 52, and the annular pressing block 401 is placed on the sealing ring 52. The spiral sleeve 51 is placed on the magnetic isolation tube assembly 4 and is threadedly connected to the threaded column 104, so that the annular pressing block 401 presses the sealing ring 52.

[0059] In an ultra-vacuum environment, in addition to the extremely high requirements for internal sealing, external sealing is also one of the key points. The external sealing mainly lies in the sealing between the magnetic isolation tube assembly 4 and the valve body 1 and the sealing of the magnetic isolation tube assembly 4 itself. In this structure, a sealing ring is provided between the magnetic isolation tube assembly and the valve body. When the spiral sleeve 51 is rotated, the annular pressing block 401 can smoothly press the sealing ring 52 without causing damage to the sealing ring, and the sealing is reliable and stable. The previous design of pressing by rotation is broken, and the sealing ring will not be twisted, flipped or deformed due to rotation, which effectively improves the sealing effect.

[0060] In some embodiments, Figure 1 and Fig. 9 As shown, the magnetic isolation tube assembly 4 includes a hollow magnetic isolation tube 41 and a static iron core 42 partially inserted into the magnetic isolation tube 41, and an annular pressure block 401 is arranged on the magnetic isolation tube 41; a welding shoulder 421 is arranged on the static iron core 42, and the welding shoulder 421 is placed against the end of the magnetic isolation tube 41 and is welded and fixed to the magnetic isolation tube 41; a magnetic isolation tube sealing ring 43 is installed on the outer circumferential wall of the inserted portion of the static iron core 42, and the end of the inserted portion of the static iron core 42 is contracted to form a conical anti-scratch portion 422. The movable iron core 21 is slidably installed in the magnetic isolation tube 41, and the end of the static iron core 42 facing the movable iron core 21 has an attraction surface, and an energy absorption groove 423 is arranged on the attraction surface, and an anti-collision plate 44 is installed on the outer side of the energy absorption groove 423.

[0061] Since tiny pores will be formed after welding, a magnetic isolation tube sealing ring 43 is provided in the middle of the static iron core 42 to ensure absolute sealing under ultra-vacuum conditions, which adds a layer of protection for sealing and ensures the reliability of external sealing. Since the static iron core 42 has a conical anti-scratch portion 422, when the static iron core 42 and the magnetic isolation tube 41 are interference-fitted, the metals will not be forcibly scratched to produce metal foam and iron filings under the action of the conical anti-scratch portion 422, which will affect the internal cleanliness of the solenoid valve. In addition, an anti-collision sheet is provided on the suction surface of the static iron core. Under the action of the energy absorption groove, even if there is continuous impact, the suction surface can be guaranteed to be flat without impact powder.

[0062] In some embodiments, Figure 1 and Figure 5 As shown, an iron core spring 6 is installed between the movable iron core 21 and the magnetic isolation tube assembly 4, and the iron core spring 6 always makes the movable iron core 21 tend to move toward the volcano-shaped valve port 102; an annular flange 217 is provided at the lower end of the movable iron core 21, and a spring limiting groove 402 is provided on the magnetic isolation tube assembly 4; one end of the iron core spring 6 abuts on the annular flange 217, and the other end thereof abuts in the spring limiting groove 402. An electromagnetic coil 7 is provided on the magnetic isolation tube assembly 4, and the electromagnetic coil 7 is fixedly connected to the magnetic isolation tube assembly 4 through a fastening nut 3.

[0063] The present invention also provides a method for testing an ultra-vacuum solenoid valve, which is implemented based on the ultra-vacuum solenoid valve and includes the following steps.

[0064] A01, external leakage test; turn on the ultra-vacuum solenoid valve and open it, connect its vacuum port 103 to the vacuum pump, and connect its vacuum port 101 to the container, so that the vacuum pump, the ultra-vacuum solenoid valve and the container are in an ultra-vacuum state; then, with the help of the helium detection method of the mass spectrometer, put the ultra-vacuum solenoid valve into the sealed chamber of the mass spectrometer and fill the sealed chamber with helium, calculate the leakage rate of the inspected part and judge whether it is qualified; if it is qualified, go to step A02, otherwise it is unqualified.

[0065] A02, internal leakage test; the ultra-vacuum solenoid valve is powered off and closed, its vacuum port 103 is connected to the vacuum pump, the vacuum pump is turned on, and the vacuum pump and the ultra-vacuum solenoid valve are in an ultra-vacuum state; then, with the help of the helium detection method of the mass spectrometer, the vacuum port 101 of the ultra-vacuum solenoid valve is connected to the helium filling port of the mass spectrometer and filled with helium, the leakage rate of the inspected part is calculated and whether it is qualified; if it is qualified, it is a qualified product, otherwise it is a failed product.

[0066] The helium detection method includes the following steps.

[0067] B01, calculate the system's effective minimum detectable leak rate Q emin ; Input the standard leak rate Q of the tested part into the mass spectrometer 标 Then, the mass spectrometer I n ,I 1 ,I 0 , Q 0 and γ parameters, and calculate Q by the following formula emin。

[0068] ; Among them, I n —Noise floor value, Pa·m 3 / s;I 1 —Calibrated leak response value, Pa·m 3 / s;I 0 —System background value, Pa·m 3 / s;Q 0 —Leakage rate of calibrated leak, Pa·m 3 / s;γ—helium concentration, ppm.

[0069] Final judgment Q emin Is it less than Q 标 If yes, go to step B02, otherwise debug the mass spectrometer.

[0070] B02, apply nitrogen; close the calibration valve of the mass spectrometer, record the mass spectrometer reading by I1 Down to I 0 +0.37(I 1 -I 0 ) The time t experienced is the reaction time of the leak detection system; then wait for the system background to return to I 0 After that, apply helium with a concentration of γ to the test piece for a period of not less than 3t, and record the reaction value I of the test piece. 2。

[0071] B03, calculate the leakage rate Q of the tested part; 2 ,I 1 ,I 0 , Q 0 Substitute the γ and γ parameters into the following formula to calculate Q.

[0072] ; Among them, I 2 —Test piece response value, Pa·m 3 / s.

[0073] Finally, determine whether Q is less than Q 标 If yes, it is qualified, otherwise it is unqualified.

[0074] The existing vacuum solenoid valve only tests internal leakage, and only uses air during the test, so the test results are not very realistic. Under ultra-vacuum requirements, when the vacuum degree reaches 10 -6 pa to 10 -7 When the electromagnetic valve is at an ultra-vacuum pressure of 1000 psi, it is already in an extreme vacuum, and simple detection methods are no longer sufficient for the detection of ultra-vacuum electromagnetic valves. The present invention adopts the helium detection method of the mass spectrometer to test both external leakage and internal leakage; when detecting external leakage, the electromagnetic valve is placed in a sealed cavity, and then helium is injected. At this time, the outside of the electromagnetic valve is completely surrounded by helium. When the inside of the electromagnetic valve is in an ultra-vacuum environment, the detection method of the present invention can perform a full range of detection on any part of the electromagnetic valve, and the detection result is true and effective. When detecting internal leakage, the electromagnetic valve is in a closed state, and the valve port seal and the volcano-shaped valve port seal are mainly detected. The helium injection method is used to detect changes in the vacuum degree, and the detection result is true and effective.

[0075] The same and similar parts between the various embodiments in this specification can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0076] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An ultra-vacuum solenoid valve, characterized in that: include: A valve body (1), wherein a vacuum port (101), a volcano-shaped valve port (102) and a vacuum extraction port (103) are provided therein, wherein the vacuum extraction port (103) is communicated with the vacuum port (101) through the volcano-shaped valve port (102); The core assembly (2) comprises a movable core (21) slidably mounted on the upper side of the volcano-shaped valve port (102) and a valve port seal (22) for opening and closing the volcano-shaped valve port (102); one end of the movable core (21) facing the volcano-shaped valve port (102) is concave to form a seal cavity (211); an outer end of the seal cavity (211) is provided with an insertion port (212); an inner end thereof is expanded outward to form an extrusion space (213); and a trumpet-shaped opening (213) is formed at the insertion port (212). Expansion absorption area (214); the valve port seal (22) is inserted into the seal cavity (211) from the insertion port (212) by extrusion, the extrusion space (213) is used to prevent the valve port seal (22) from being squeezed and deformed, and the expansion absorption area (214) is used to absorb the deformation of the valve port seal (22) when the valve port seal (22) is pressed against the volcano-shaped valve port (102), thereby ensuring that the sealing surface (221) of the valve port seal (22) is always flat.

2. The ultra-vacuum solenoid valve according to claim 1, characterized in that: The valve port seal (22) is provided with the sealing surface (221) at one end facing the volcano-shaped valve port (102), and a plurality of arc-shaped buffer ribs (222) are provided at equal intervals in a circular shape at the other end thereof, the buffer ribs (222) are provided outwardly convexly and abut against the inner wall of the sealing member cavity (211), and an elastic area (223) is formed between the sealing surface (221) and the outer end surface of the buffer ribs (222).

3. The ultra-vacuum solenoid valve according to claim 1, characterized in that: The side wall of the movable iron core (21) is provided with an exhaust hole (215) connected to the extrusion space (213), and the exhaust hole (215) is used to exhaust the gas in the sealing cavity (211) when the valve port sealing member (22) is installed; the outer circumferential wall of the movable iron core (21) is wrapped with a plastic-coated wear-resistant ring (23), and the movable iron core (21) is provided with an annular energy absorption cavity (216) at a position close to the sealing cavity (211), and the annular energy absorption cavity (216) is located inside the plastic-coated wear-resistant ring (23).

4. The ultra-vacuum solenoid valve according to claim 1, characterized in that: It also includes a magnetic isolation tube assembly (4) located on the upper side of the valve body (1), the magnetic isolation tube assembly (4) is sealed and connected to the valve body (1) through a compression sealing assembly (5); the compression sealing assembly (5) includes a spiral sleeve (51) and a sealing ring (52); the valve body (1) is provided with a threaded column (104) extending toward the magnetic isolation tube assembly (4), the end of the threaded column (104) is provided with an annular groove (105), and the sealing ring (52) is installed in the annular groove (105); the magnetic isolation tube assembly (4) is provided with an annular pressing block (401) corresponding to the sealing ring (52), the spiral sleeve (51) is sleeved on the magnetic isolation tube assembly (4) and is threadedly connected to the threaded column (104), so that the annular pressing block (401) presses the sealing ring (52).

5. The ultra-vacuum solenoid valve according to claim 4, characterized in that: The magnetic isolation tube assembly (4) comprises a hollow magnetic isolation tube (41) and a static iron core (42) partially inserted into the magnetic isolation tube (41); the annular pressure block (401) is arranged on the magnetic isolation tube (41); a welding shoulder (421) is arranged on the static iron core (42); the welding shoulder (421) is abutted against the end of the magnetic isolation tube (41) and is welded and fixed to the magnetic isolation tube (41); a magnetic isolation tube sealing ring (43) is installed on the outer circumferential wall of the extension portion of the static iron core (42); the end of the extension portion of the static iron core (42) is contracted to form a conical anti-scratch portion (422).

6. The ultra-vacuum solenoid valve according to claim 5, characterized in that: The movable iron core (21) is slidably mounted in the magnetic isolation tube (41); the static iron core (42) has an engaging surface at one end facing the movable iron core (21); an energy absorbing groove (423) is provided on the engaging surface; and an anti-collision sheet (44) is mounted on the outside of the energy absorbing groove (423).

7. The ultra-vacuum solenoid valve according to claim 4, characterized in that: An iron core spring (6) is installed between the movable iron core (21) and the magnetic isolation tube assembly (4), and the iron core spring (6) always makes the movable iron core (21) tend to move toward the volcano-shaped valve port (102); an annular flange (217) is provided at the lower end of the movable iron core (21), and a spring limiting groove (402) is provided on the magnetic isolation tube assembly (4); one end of the iron core spring (6) is abutted against the annular flange (217), and the other end thereof is abutted in the spring limiting groove (402).

8. The ultra-vacuum solenoid valve according to claim 4, characterized in that: An electromagnetic coil (7) is disposed on the outer sleeve of the magnetic isolation tube assembly (4), and the electromagnetic coil (7) is fixedly connected to the magnetic isolation tube assembly (4) via a fastening nut (3).

9. The ultra-vacuum solenoid valve according to claim 4, characterized in that: The vacuum port (101) and the vacuum extraction port (103) are coaxially arranged, the volcano-shaped valve port (102), the core assembly (2) and the magnetic isolation tube assembly (4) are coaxially arranged, the axis of the vacuum port (101) and the axis of the volcano-shaped valve port (102) are perpendicular, and the valve port seal (22) is T-shaped.

10. A method for testing an ultra-vacuum solenoid valve, implemented based on the ultra-vacuum solenoid valve according to any one of claims 1 to 9, characterized in that: The following steps are involved: A01, external leakage test; the ultra-vacuum solenoid valve is powered on and opened, and its vacuum port (103) is connected to a vacuum pump, and its vacuum port (101) is connected to a container, and the vacuum pump, the ultra-vacuum solenoid valve and the container are in an ultra-vacuum state; then, by means of a helium detection method of a mass spectrometer, the ultra-vacuum solenoid valve is placed in a sealed cavity of the mass spectrometer and helium is filled into the sealed cavity, the leakage rate of the inspected part is calculated and whether it is qualified; if it is qualified, step A02 is entered, otherwise it is a defective product; A02, internal leakage test; the ultra-vacuum solenoid valve is powered off and closed, its vacuum port (103) is connected to a vacuum pump, the vacuum pump is turned on, and an ultra-vacuum state is maintained between the vacuum pump and the ultra-vacuum solenoid valve; then, by means of a helium detection method of a mass spectrometer, the vacuum port (101) of the ultra-vacuum solenoid valve is connected to a helium filling port of the mass spectrometer and filled with helium, the leakage rate of the inspected part is calculated and whether it is qualified; if it is qualified, it is a qualified product, otherwise it is a failed product; The helium detection method comprises the following steps: B01, calculate the system's effective minimum detectable leak rate Q emin ; Input the standard leak rate Q of the tested part into the mass spectrometer 标 Then, the mass spectrometer I n , I1, I0, Q0 and γ parameters, and calculate Q by the following formula emin ; ； Among them, I n —Noise floor value, Pa·m 3 / s; I1—calibration leak response value, Pa·m 3 / s; I0—system background value, Pa·m 3 / s; Q0—leakage rate of calibrated leak, Pa·m 3 / s;γ—helium concentration, ppm; Final judgment Q emin Is it less than Q 标 If so, proceed to step B02, otherwise debug the mass spectrometer; B02, apply nitrogen; close the calibration valve of the mass spectrometer, record the time t taken for the mass spectrometer reading to drop from I1 to I0+0.37(I1-I0), where t is the reaction time of the leak detection system; then, after the system background returns to I0, apply helium with a concentration of γ to the test piece, the application time of helium is not less than 3t, and record the test piece reaction value I2; B03, calculate the leakage rate Q of the tested part; substitute I2, I1, I0, Q0 and γ parameters into the following formula to calculate Q; ； Where, I2—Test piece response value, Pa·m 3 / s; Finally, determine whether Q is less than Q 标 If yes, it is qualified, otherwise it is unqualified.

Images