An ultra-low temperature switching valve

Abstract

This application relates to the technical field of gas control, and in particular to a cryogenic switching valve, which includes a columnar valve body with a normally closed inlet channel, a normally open inlet channel, and an outlet channel on its side wall. The valve body contains a normally closed inlet chamber, a normally open inlet chamber, and a connecting chamber, with the outlet channel connected to the connecting chamber. It also includes a valve core containing a control component, a reset component, a normally closed valve, and a normally open valve. The normally closed and normally open valves are connected by a connecting component. The reset component drives the normally closed valve to seal with the connecting chamber, and the control component drives the normally open valve to seal with the connecting chamber and disengages the normally closed valve. Specific structural details are provided for the connecting component, valve frame, lead seal, reset component, and control component. This application achieves the technical effect of stably switching fluid channels in cryogenic environments.

Description

Technical Field

[0001] This application relates to the technical field of gas control, and in particular to a cryogenic switching valve. Background Technology

[0002] In the industrial sector, valves, as key components controlling fluid flow, are crucial for the normal operation of the entire system. With continuous technological advancements, various industries are placing increasingly higher demands on valve performance, especially in extreme environments such as cryogenic environments, which present even more stringent challenges to valve performance and reliability. Valves used in cryogenic environments have wide applications, spanning aerospace, cryogenic refrigeration, superconducting technology, and many other fields. The development of these fields relies on the stable operation of valves in cryogenic environments to ensure the efficiency and safety of the systems.

[0003] In related technologies, valves with an integrated stem structure are typically used to achieve the switching function. In this type of valve, the integrated stem connects two valves to control the opening and closing of different channels. However, in actual use, to achieve a tight seal between the valve and the seat, high concentricity is required on both sides of the seat, usually achieved through high-precision machining. Furthermore, after undergoing extensive vibration testing, the valve's performance is significantly affected, making it unable to maintain a stable operating state. Utility Model Content

[0004] To overcome the above-mentioned technical problems, this application provides an ultra-low temperature switching valve.

[0005] The cryogenic switching valve provided in this application adopts the following technical solution: A cryogenic switching valve includes a valve body with a columnar structure. The valve body has a normally closed inlet channel, a normally open inlet channel, and an outlet channel on its sidewall. The valve body contains a normally closed inlet chamber communicating with the normally closed inlet channel, a normally open inlet chamber communicating with the normally open inlet channel, and a connecting cavity connecting the normally closed and normally open inlet chambers. The inner diameter of the connecting cavity is smaller than that of the normally closed and normally open inlet chambers. The outlet channel is connected to the connecting cavity. A valve core includes a control component, a reset component, a normally closed valve, and a normally open valve coaxially arranged with the valve body. The normally closed valve is located in the normally closed inlet chamber and is capable of reciprocating along its own axis. Connected to the valve body, the normally open valve is located in the normally open intake chamber and is reciprocating along its own axis. The normally closed valve and the normally open valve are connected by a connecting assembly, the length of which is greater than the length of the communicating chamber. The reset assembly is driven to the normally closed valve to seal the normally closed valve with the end of the communicating chamber near the normally closed intake chamber. The control assembly is driven to the normally open valve to seal the normally open valve with the end of the communicating chamber near the normally open intake chamber, and simultaneously drives the normally closed valve to overcome the effect of the reset assembly and lose contact with the end of the communicating chamber near the normally closed intake chamber.

[0006] By adopting the above technical solution, when the cryogenic switching valve is working, in the initial state, the reset component drives the normally closed valve to seal with the end of the connecting chamber near the normally closed inlet chamber, allowing gas from the normally open inlet channel to flow out through the normally open inlet chamber, the connecting chamber, and the outlet channel. When the control component is working, it drives the normally open valve to seal with the end of the connecting chamber near the normally open inlet chamber, while simultaneously driving the normally closed valve to overcome the effect of the reset component and lose contact with the end of the connecting chamber near the normally closed inlet chamber. At this time, gas from the normally closed inlet channel can flow out through the normally closed inlet chamber, the connecting chamber, and the outlet channel, thus achieving the switching of the inlet channel.

[0007] Optionally, the connecting assembly includes a connecting rod, a mounting block, a rod seat, and a ball seat. One end of the connecting rod mates with the rod seat, and the other end of the connecting rod has a ball head that mates with the ball seat. The connecting rod has a limiting ring for mates with the end of the rod seat. There are two mounting blocks, each with a mounting side and a connecting side. The connecting side of the mounting block is integrally formed with the ends of the rod seat and the ball seat away from the connecting rod. The rod seat is fixedly connected to either the normally closed valve or the normally open valve via the mounting block, and the ball seat is fixedly connected to the other of the normally closed valve or the normally open valve via the mounting block.

[0008] By adopting the above technical solution, the ball head and ball seat reference universal joint reduces the coaxiality requirements of the normally closed and normally open valves of the valve core on both sides of the valve body, solves the problem of sealing difficulties caused by insufficient concentricity, and reduces processing costs and assembly difficulty.

[0009] Optionally, both the normally closed valve and the normally open valve include a valve skeleton. The valve skeleton includes a sealing seat. One end of the sealing seat is provided with a guide rod, and the other end is provided with a mounting groove for cooperating with the mounting block. The mounting groove is provided with a plurality of first threaded holes, which are equidistant from the guide rod. The mounting side of the mounting block is provided with a second threaded hole that mates with the first threaded holes.

[0010] By adopting the above technical solution, the first threaded hole in the mounting groove on the valve skeleton sealing seat matches the second threaded hole on the mounting block, which facilitates the installation of the valve skeleton and the mounting block. During installation, the screws are tightened with torque after applying thread sealant. After the thread sealant has fully solidified, the joint is finished by cold rolling. This makes the connection between the valve skeleton and the mounting block more stable and ensures that its performance remains unaffected after undergoing a large-scale (44.3g) vibration test.

[0011] Optionally, the valve skeleton further includes a sealing ring, and the mounting groove at the end away from the guide rod is provided with a sealing groove for installing the sealing ring. The side wall of the mounting block is provided with a flange that mates with the sealing ring. Both ends of the communicating cavity, the sealing groove and the flange are provided with bosses and sealing spikes that mate with the sealing ring.

[0012] By adopting the above technical solution, the sealing ring is installed in the sealing groove, and the flange on the side wall of the mounting block and the boss sealing spikes at both ends of the connecting cavity and the sealing groove are used to enhance the sealing performance of the valve skeleton and further reduce the possibility of valve leakage.

[0013] Optionally, the ball seat is provided with a lead seal for fixing the ball head.

[0014] By adopting the above technical solution, the lead seal can restrict the ball head to be in the ball seat, ensuring the stability of the ball head and ball seat fit, thereby maintaining the reliability of the connection between normally closed and normally open valves and reducing the valve performance degradation caused by ball head loosening.

[0015] Optionally, the valve body has a normally closed end cap at one end near the normally closed intake chamber. The reset assembly includes an elastic element and a reset guide sleeve coaxially arranged with the valve body and fixedly connected to the normally closed end cap. The guide rod of the normally closed valve is slidably connected to the reset guide sleeve. The elastic element is sleeved outside the reset guide sleeve. One end of the elastic element abuts against the normally closed end cap, and the other end abuts against the normally closed valve.

[0016] By adopting the above technical solution, when the cryogenic switching valve is in operation, if the control component does not drive the normally open valve, one end of the elastic element of the reset component abuts against the normally closed end cap, and the other end abuts against the normally closed valve, so that the normally closed valve and the end of the connecting cavity near the normally closed inlet cavity are sealed together. At this time, gas enters the normally open inlet cavity from the normally open inlet channel, passes through the connecting cavity, and finally leaves the cryogenic switching valve from the outlet channel.

[0017] Optionally, the valve body has a normally open end cap near the normally open intake chamber. The control assembly includes a bellows and a control guide sleeve coaxially arranged with the valve body and fixedly connected to the normally open end cap. The guide rod of the normally open valve is slidably connected to the control guide sleeve. The bellows is sleeved outside the control guide sleeve. One end of the bellows is fixedly connected to the normally closed end cap, and the other end is fixedly connected to the normally closed valve. The normally open end cap has an air core interface at the end away from the normally open intake chamber. The air core interface is connected to the reset guide sleeve.

[0018] By adopting the above technical solution, during switching, the gas core interface is vented, and the gas enters the control guide sleeve through the gas core interface. This causes the guide rod of the normally open valve to slide within the control guide sleeve, which in turn drives the normally closed valve to move against the action of the reset component through the connecting assembly. This causes the normally closed valve to lose its engagement with the end of the connecting cavity near the normally closed inlet chamber, while the normally open valve maintains a sealing engagement with the end of the connecting cavity near the normally open inlet chamber, thus realizing the valve switching function. At this time, the gas enters the normally closed inlet chamber from the normally closed inlet channel, passes through the connecting cavity, and finally leaves the cryogenic switching valve from the outlet channel.

[0019] Optionally, the control guide sleeve sidewall is provided with a communication hole near the normally open end cap.

[0020] By adopting the above technical solution, the communication hole can realize the connection between the inside of the control guide sleeve and the inner cavity of the bellows, which helps to balance the pressure, ensure the stable operation of the control components, and thus ensure the stable operation of the cryogenic switching valve.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. It can reduce the leakage of the valve seat seal in ultra-low temperature (liquid nitrogen temperature range) environment, and its performance can still be maintained without being affected after undergoing a large-scale (44.3g) vibration test; 2. The bellows cavity has been simplified, reducing the number of forced cylinder parts and related sealing gaskets, thus lowering the possibility of valve leakage; 3. By replacing the traditional one-piece valve stem with a connecting rod, and using a ball head and ball seat reference to a universal joint, the concentricity of the valve seat on both sides is reduced, solving the problem of sealing difficulties caused by insufficient concentricity, and reducing processing costs and assembly difficulty. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the cryogenic switching valve provided in the embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the internal structure of the cryogenic switching valve provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the valve skeleton provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the mounting block and the ball seat provided in the embodiment of this application.

[0024] Explanation of reference numerals in the attached drawings: 1-Valve body; 101-Normally closed air inlet channel; 102-Normally closed air inlet chamber; 103-Normally open air inlet channel; 104-Normally open air inlet chamber; 105-Air outlet channel; 106-Connecting cavity; 1061-First boss sealing spike; 2-Valve frame; 201-Sealing seat; 202-Guide rod; 203-Mounting groove; 204-First threaded hole; 205-Sealing groove; 206-Second boss sealing spike; 3-Normally open valve; 4-Normally closed 5-Connecting rod; 501-Ball head; 502-Limiting ring; 6-Mounting block; 601-Second threaded hole; 602-Flange; 603-Third boss sealing spike; 7-Rod seat; 8-Ball seat; 9-Sealing ring; 10-Lead seal; 11-Normally closed end cap; 1101-Reset guide sleeve; 12-Elastic element; 13-Normally open end cap; 1301-Control guide sleeve; 1302-Air core interface; 1303-Communication hole; 14-Bellwall. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0026] This application discloses an ultra-low temperature switching valve.

[0027] like Figure 1 and Figure 2As shown, the cryogenic switching valve includes a valve body 1, which has a columnar structure. The side wall of the valve body 1 has a normally closed inlet channel 101, a normally open inlet channel 103, and an outlet channel 105. The valve body 1 has a normally closed inlet chamber 102 communicating with the normally closed inlet channel 101, a normally open inlet chamber 104 communicating with the normally open inlet channel 103, and a connecting chamber 106 connecting the normally closed inlet chamber 102 and the normally open inlet chamber 104. The inner diameter of the connecting chamber 106 is smaller than that of the normally closed inlet chamber 102 and the normally open inlet chamber 104. The outlet channel 105 is connected to the connecting chamber 106. The valve core includes a control component, a reset component, a normally closed valve 4 and a normally open valve 3 coaxially arranged with the valve body 1. The normally closed valve 4 is located in the normally closed inlet chamber. 102, and is connected to valve body 1 by reciprocating along its own axis. Normally open valve 3 is located in normally open intake chamber 104 and is connected to valve body 1 by reciprocating along its own axis. Normally closed valve 4 and normally open valve 3 are connected by a connecting assembly. The length of the connecting assembly is greater than the length of the connecting chamber 106. The reset assembly is driven to connect normally closed valve 4 to drive normally closed valve 4 to seal with the end of connecting chamber 106 near normally closed intake chamber 102. The control assembly is driven to connect normally open valve 3 to drive normally open valve 3 to seal with the end of connecting chamber 106 near normally open intake chamber 104. At the same time, it drives normally closed valve 4 to overcome the effect of the reset assembly and lose contact with the end of connecting chamber 106 near normally closed intake chamber 102.

[0028] When the cryogenic switching valve operates in its initial state, the reset assembly drives the normally closed valve 4 to form a sealed fit with the end of the connecting chamber 106 near the normally closed intake chamber 102. At this time, the gas in the normally open intake channel 103 flows to the outlet channel 105 through the normally open intake chamber 104 and the connecting chamber 106. When the control assembly is activated, it drives the normally open valve 3 to form a sealed fit with the end of the connecting chamber 106 near the normally open intake chamber 104, and simultaneously drives the normally closed valve 4 to overcome the action of the reset assembly, releasing the sealed fit with the end of the connecting chamber 106 near the normally closed intake chamber 102. At this time, the gas in the normally closed intake channel 101 flows to the outlet channel 105 through the normally closed intake chamber 102 and the connecting chamber 106, thereby realizing the switching of the intake channel.

[0029] like Figure 2As shown, the connecting assembly includes a connecting rod 5, a mounting block 6, a rod seat 7, and a ball seat 8. One end of the connecting rod 5 mates with the rod seat 7, and the other end of the connecting rod 5 is provided with a ball head 501 that mates with the ball seat 8. A lead seal 10 for fixing the ball head 501 is provided at the ball seat 8. A limiting ring 502 for mates with the end of the rod seat 7 is provided on the connecting rod 5. There are two mounting blocks 6, each with a mounting side and a connecting side. The connecting side of the mounting block 6 is integrally formed with the ends of the rod seat 7 and the ball seat 8 away from the connecting rod 5. The rod seat 7 is fixedly connected to either the normally closed valve 4 or the normally open valve 3 via the mounting block 6. The ball seat 8 is fixedly connected to the other of the normally closed valve 4 and the normally open valve 3 via the mounting block 6. The lead seal 10 can restrict the ball head 501 to be in the ball seat 8, ensuring the stability of the fit between the ball head 501 and the ball seat 8, thereby maintaining the reliability of the connection between the normally closed valve 4 and the normally open valve 3, and reducing the valve performance degradation caused by the loosening of the ball head 501.

[0030] In this embodiment, the ball seat 8 is fixedly connected to the normally closed valve 4 via its mounting block 6, and the rod seat 7 is fixedly connected to the normally open valve 3 via its mounting block 6.

[0031] The ball head 501 and ball seat 8 adopt the structure of a universal joint, which relaxes the coaxiality requirements of the normally closed valve 4 and normally open valve 3 of the valve core on both sides of the valve body 1. The cooperation between the connecting rod 5 and the rod seat 7 relaxes the coaxiality requirements of the normally closed valve 4 and normally open valve 3 of the valve core on both sides of the valve body 1, effectively solving the sealing difficulties caused by insufficient concentricity and coaxiality, while significantly reducing processing costs and assembly difficulty.

[0032] like Figures 2-4 As shown, both the normally closed valve 4 and the normally open valve 3 include a valve frame 2. The valve frame 2 includes a sealing seat 201. One end of the sealing seat 201 is provided with a guide rod 202, and the other end is provided with a mounting groove 203 for cooperating with the mounting block 6. The mounting groove 203 is provided with a plurality of first threaded holes 204. The first threaded holes 204 are equidistantly arranged around the guide rod 202. The mounting side of the mounting block 6 is provided with a second threaded hole 601 that mates with the first threaded holes 204.

[0033] The first threaded hole 204 in the mounting groove 203 on the sealing seat 201 of the valve skeleton 2 mates with the second threaded hole 601 on the mounting block 6, which facilitates the installation of the valve skeleton 2 and the mounting block 6. During installation, the screws are tightened with torque after applying thread sealant. After the thread sealant has fully solidified, the joints are finished by cold rolling. This makes the connection between the valve skeleton 2 and the mounting block 6 more stable and ensures that its performance remains unaffected after undergoing a large-scale (44.3g) vibration test.

[0034] like Figure 2 and Figure 3As shown, the valve frame 2 also includes a sealing ring 9. The mounting groove 203 is provided with a sealing groove 205 for mounting the sealing ring 9 on the circumferential direction at one end away from the guide rod 202. The side wall of the mounting block 6 is provided with a flange 602 that mates with the sealing ring 9.

[0035] like Figures 2-4 As shown, in order to further improve the sealing performance, the two ends of the connecting cavity 106 can be provided with a first boss sealing spike 1061, the sealing groove 205 can be provided with a second boss sealing spike 206, and the flange 602 can be provided with a third boss sealing spike 603. The first boss sealing spike 1061, the second boss sealing spike 206 and the third boss sealing spike 603 are all used to cooperate with the sealing ring 9.

[0036] By installing the sealing ring 9 in the sealing groove 205, and cooperating with the flange 602 on the side wall of the mounting block 6 and the boss sealing spikes at both ends of the connecting cavity 106 and the sealing groove 205, the sealing performance of the valve skeleton 2 is enhanced, and the possibility of valve leakage is further reduced.

[0037] like Figure 2 As shown, the valve body 1 has a normally closed end cap 11 at one end near the normally closed intake chamber 102. The reset assembly includes an elastic element 12 and a reset guide sleeve 1101 that is coaxially arranged with the valve body 1 and fixedly connected to the normally closed end cap 11. The guide rod 202 of the normally closed valve 4 is slidably connected to the reset guide sleeve 1101. The elastic element 12 is sleeved on the outside of the reset guide sleeve 1101. One end of the elastic element 12 abuts against the normally closed end cap 11, and the other end abuts against the normally closed valve 4.

[0038] When the cryogenic switching valve is in operation, if the control component does not drive the normally open valve 3, one end of the elastic element 12 of the reset component abuts against the normally closed end cap 11, and the other end abuts against the normally closed valve 4, so that the normally closed valve 4 is sealed to the end of the connecting cavity 106 near the normally closed inlet cavity 102. At this time, gas enters the normally open inlet cavity 104 from the normally open inlet channel 103, passes through the connecting cavity 106, and finally leaves the cryogenic switching valve from the outlet channel 105.

[0039] like Figure 1 and Figure 2As shown, the valve body 1 has a normally open end cap 13 at one end near the normally open intake chamber 104. The control assembly includes a bellows 14 and a control guide sleeve 1301 that is coaxially arranged with the valve body 1 and fixedly connected to the normally open end cap 13. The guide rod 202 of the normally open valve 3 is slidably connected to the control guide sleeve 1301. The bellows 14 is sleeved on the outside of the control guide sleeve 1301. One end of the bellows 14 is fixedly connected to the normally closed end cap 11, and the other end is fixedly connected to the normally closed valve 4. The normally closed end cap 11, the bellows 14 and the normally closed valve 4 form a closed inner cavity. The normally open end cap 13 has an air core interface 1302 at one end away from the normally open intake chamber 104. The air core interface 1302 is connected to the reset guide sleeve 1101.

[0040] During switching, gas is introduced through the gas core interface 1302, and gas enters the control guide sleeve 1301. This causes the guide rod 202 of the normally open valve 3 to slide within the control guide sleeve 1301. This, in turn, drives the normally closed valve 4 to move against the reset component via the connecting assembly. This causes the normally closed valve 4 to lose its engagement with the end of the connecting cavity 106 near the normally closed inlet chamber 102, while simultaneously sealing the end of the normally open valve 3 with the end of the connecting cavity 106 near the normally open inlet chamber 104, thus achieving the valve switching function. At this time, gas enters the normally closed inlet chamber 102 from the normally closed inlet channel 101, passes through the connecting cavity 106, and finally exits the cryogenic switching valve from the outlet channel 105.

[0041] To balance the pressure, a communication hole 1303 is provided on the side wall of the control guide sleeve 1301 near the normally open end cap 13. The communication hole 1303 enables communication between the inside of the control guide sleeve 1301 and the inner cavity of the bellows 14, ensuring the stable operation of the control components and thus guaranteeing the stable operation of the cryogenic switching valve.

[0042] The implementation principle of an ultra-low temperature switching valve according to an embodiment of this application is as follows: In the initial state, the elastic element 12 of the reset assembly applies a pre-tightening force by abutting against the normally closed end cap 11 and the normally closed valve 4, driving the sealing seat 201 of the normally closed valve 4 to tightly engage with the end of the connecting cavity 106 near the normally closed air inlet cavity 102, forming a reliable seal. At this time, gas enters the normally open air inlet cavity 104 through the normally open air inlet channel 103, and flows to the air outlet channel 105 through the connecting cavity 106, realizing gas flow in the normally open state. When an external control signal inputs compressed gas through the gas core interface 1302, the gas enters the control guide sleeve 1301 through the gas core interface 1302, pushing the guide rod 202 of the normally open valve 3 to slide axially along the control guide sleeve 1301. The movement of the normally open valve 3 is transmitted to the normally closed valve 4 through the connecting assembly, causing the normally closed valve 4 to overcome the resistance of the elastic element 12 of the reset assembly and release its sealing engagement with the connecting cavity 106. Simultaneously, the sealing seat 201 of the normally open valve 3 forms a sealing fit with the end of the connecting cavity 106 near the normally open intake cavity 104. At this time, the gas switches to enter the normally closed intake cavity 102 from the normally closed intake channel 101, and flows to the outlet channel 105 through the connecting cavity 106. During this process, the communication hole 1303 on the side wall of the control guide sleeve 1301 balances the pressure of the inner cavity of the bellows 14 and the control guide sleeve 1301, ensuring that the guide rod 202 slides smoothly; the universal joint structure of the ball head 501 and the ball seat 8 compensates for possible coaxiality deviations on both sides of the valve body 1, avoiding sealing failure; the sealing ring 9, in conjunction with the boss sealing spike, maintains elasticity at ultra-low temperatures, effectively reducing the risk of leakage.

[0043] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A cryogenic switching valve, characterized in that, include: The valve body (1) has a columnar structure. The side wall of the valve body (1) has a normally closed air intake channel (101), a normally open air intake channel (103), and an air outlet channel (105). The valve body (1) is provided with a normally closed air intake chamber (102) communicating with the normally closed air intake channel (101), a normally open air intake chamber (104) communicating with the normally open air intake channel (103), and a connecting chamber (106) connecting the normally closed air intake chamber (102) and the normally open air intake chamber (104). The inner diameter of the connecting chamber (106) is smaller than that of the normally closed air intake chamber (102) and the normally open air intake chamber (104). The air outlet channel (105) is connected to the connecting chamber (106). The valve core includes a control component, a reset component, a normally closed valve (4) and a normally open valve (3) coaxially arranged with the valve body (1). The normally closed valve (4) is located in the normally closed intake chamber (102) and is connected to the valve body (1) by reciprocating movement along its own axis. The normally open valve (3) is located in the normally open intake chamber (104) and is connected to the valve body (1) by reciprocating movement along its own axis. The normally closed valve (4) and the normally open valve (3) are connected by a connecting component, the length of which is greater than the length of the communicating cavity (106). The reset component is driven to connect with the normally closed valve (4) to drive the normally closed valve (4) to seal with the end of the communication cavity (106) near the normally closed intake cavity (102). The control component is driven to connect with the normally open valve (3) to drive the normally open valve (3) to seal with the end of the communication cavity (106) near the normally open intake cavity (104). At the same time, the normally closed valve (4) is driven to overcome the effect of the reset component and lose contact with the end of the communication cavity (106) near the normally closed intake cavity (102).

2. The cryogenic switching valve according to claim 1, characterized in that, The connecting assembly includes a connecting rod (5), a mounting block (6), a rod seat (7), and a ball seat (8). One end of the connecting rod (5) engages with the rod seat (7), and the other end of the connecting rod (5) is provided with a ball head (501) that engages with the ball seat (8). The connecting rod (5) is provided with a limiting ring (502) for engaging with the end of the rod seat (7). There are two mounting blocks (6). Each mounting block (6) has a mounting side and a connecting side. The connecting side of the mounting block (6) is integrally formed with the ends of the rod seat (7) and the ball seat (8) away from the connecting rod (5). The rod seat (7) is fixedly connected to either the normally closed valve (4) or the normally open valve (3) through the mounting block (6). The ball seat (8) is fixedly connected to the other of the normally closed valve (4) or the normally open valve (3) through the mounting block (6).

3. The cryogenic switching valve according to claim 2, characterized in that, Both the normally closed valve (4) and the normally open valve (3) include a valve frame (2). The valve frame (2) includes a sealing seat (201). One end of the sealing seat (201) is provided with a guide rod (202), and the other end is provided with a mounting groove (203) for cooperating with the mounting block (6). The mounting groove (203) is provided with a plurality of first threaded holes (204). The first threaded holes (204) are equidistantly arranged around the guide rod (202). The mounting side of the mounting block (6) is provided with a second threaded hole (601) that cooperates with the first threaded holes (204).

4. The cryogenic switching valve according to claim 3, characterized in that, The valve frame (2) also includes a sealing ring (9). The mounting groove (203) is provided with a sealing groove (205) for installing the sealing ring (9) at one end away from the guide rod (202). The side wall of the mounting block (6) is provided with a flange (602) that mates with the sealing ring (9). Both ends of the connecting cavity (106), the sealing groove (205) and the flange (602) are provided with boss sealing spikes that mate with the sealing ring (9).

5. The cryogenic switching valve according to claim 2, characterized in that, The ball seat (8) is provided with a lead seal (10) for fixing the ball head (501).

6. The cryogenic switching valve according to claim 2, characterized in that, The valve body (1) is provided with a normally closed end cap (11) at one end near the normally closed air inlet chamber (102). The reset assembly includes an elastic element (12) and a reset guide sleeve (1101) coaxially arranged with the valve body (1) and fixedly connected to the normally closed end cap (11). The guide rod (202) of the normally closed valve (4) is slidably connected to the reset guide sleeve (1101). The elastic element (12) is sleeved on the reset guide sleeve (1101). One end of the elastic element (12) abuts against the normally closed end cap (11), and the other end abuts against the normally closed valve (4).

7. The cryogenic switching valve according to claim 6, characterized in that, The valve body (1) has a normally open end cap (13) at one end near the normally open air intake chamber (104). The control assembly includes a bellows (14) and a control guide sleeve (1301) coaxially arranged with the valve body (1) and fixedly connected to the normally open end cap (13). The guide rod (202) of the normally open valve (3) is slidably connected to the control guide sleeve (1301). The bellows (14) is sleeved outside the control guide sleeve (1301). One end of the bellows (14) is fixedly connected to the normally closed end cap (11), and the other end is fixedly connected to the normally closed valve (4). The normally open end cap (13) has an air core interface (1302) at one end away from the normally open air intake chamber (104). The air core interface (1302) is connected to the reset guide sleeve (1101).

8. The cryogenic switching valve according to claim 7, characterized in that, The control guide sleeve (1301) has a communication hole (1303) on its side wall near the normally open end cap (13).

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