A high pressure on-off valve

Abstract

This invention relates to fluid machinery control elements, specifically to a high-pressure switching valve. The high-pressure switching valve includes a valve body and a valve core. The valve core is slidably mounted within the valve body cavity. The valve body cavity is divided into a sliding section and a socket section from back to front. The valve core is divided into a guide section and a plug-in section from back to front. The plug-in section has a radial gap from the inner wall of the sliding section. The socket section allows the plug-in section to be inserted, forming a closed annular buffer cavity with the valve body cavity wall. The valve body has a pressure relief channel for connecting the valve body cavity to the external atmosphere or low-pressure equipment. When the plug-in section is inserted into the socket section, the annular buffer cavity and the pressure relief channel are isolated from each other. When the plug-in section separates from the socket section, the portion of the valve body cavity in front of the valve core is connected to the pressure relief channel. During multiple reciprocating movements, the high-pressure fluid in the portion of the valve body cavity in front of the valve core is gradually discharged. The rebound force on the valve core gradually decreases until, after the rebound movement, the plug-in section of the valve core will no longer disengage from the socket section, shortening the oscillation time of the valve core.

Description

Technical Field

[0001] This invention relates to fluid machinery control components, and more specifically to a high-pressure switching valve. Background Technology

[0002] High-pressure on / off valves are used to control the flow of fluid in pipelines or on equipment. A typical high-pressure on / off valve consists of a valve body and a valve core. The valve body has a straight channel, with its two ends forming the valve body's inlet and control port, respectively. The inlet is connected to a high-pressure fluid source. An outlet perpendicular to the straight channel is located on the side wall of the valve body. The valve core slides within the straight channel. When the valve core is blocked at the outlet, the pressure on both sides of the valve core is the same, i.e., the pressure on the valve body's inlet side is the same as the pressure on the valve body's control port side; at this time, the high-pressure on / off valve is in the closed state. When the high-pressure on / off valve vents air through the control port, a pressure difference is created between the valve body's inlet side and the valve body's control port side, allowing the valve core to slide within the straight channel, thus connecting the inlet and outlet; at this time, the high-pressure on / off valve is in the open state.

[0003] The pressure difference across the valve core of a high-pressure on / off valve directly affects the valve core's movement speed, while the opening speed of the control port determines the pressure difference change between the inlet and the control port. If the high-pressure on / off valve uses a low-speed opening of the control port, the pressure drop on the control port side of the valve body is slower, resulting in a smaller pressure difference across the valve core within the set time. This leads to a lower initial velocity and acceleration of the valve core, a lower velocity when the valve core reaches the end of the valve body, and relatively less impact kinetic energy between the valve core and the valve body. However, due to the slower valve core speed, the time it takes for the valve core to fully emerge from the opening is longer, resulting in a smaller flow rate through the high-pressure on / off valve within the set time, which cannot meet the usage requirements.

[0004] When the control port is opened rapidly, the pressure on the control port side of the valve body drops quickly, resulting in a large pressure difference across the valve core within the set time. This causes the valve core to have a significant acceleration and velocity. If the valve does not have a buffer structure, a large impact will occur between the valve core and the valve body when the valve core reaches the end of the valve body. This strong impact will cause significant vibration and noise, thereby reducing the service life of the valve itself and other equipment. This is especially true for high-pressure, large-diameter on / off valves, because the valve core diameter is large, the pressure-bearing area of ​​the valve core is large, and the force exerted by the high-pressure fluid on the valve core is greater, resulting in a greater acceleration and velocity of the valve core and a greater impact with the valve body.

[0005] To address the impact issue during rapid valve opening, a buffer spring is typically installed at the end of the valve body cavity to cushion the rapidly moving valve core. While the buffer spring effectively cushions the valve core through compression, its return to its original shape exerts a rebound force, causing the valve core to move in the opposite direction. This reverse-moving valve core is then subjected to the force of the high-pressure fluid at the valve inlet, causing it to oscillate back and forth between the buffer spring and the valve body inlet. However, the valve core dissipates its kinetic energy to zero solely through friction with other parts during this movement, resulting in prolonged oscillations. This prolonged oscillation reduces the lifespan of the high-pressure switching valve and other equipment. Summary of the Invention

[0006] The purpose of this invention is to provide a high-pressure switching valve to solve the technical problem that the valve core of the existing high-pressure switching valve will oscillate back and forth for a long time after being subjected to the rebound force of the buffer spring, which reduces the service life of the high-pressure switching valve itself and other equipment.

[0007] To achieve the above objectives, the technical solution of the high-pressure switching valve of the present invention is as follows:

[0008] The high-pressure switching valve includes a valve body and a valve core. The valve core is slidably installed inside the valve body cavity. The direction of the valve core's forward movement is defined as the opening direction of the high-pressure switching valve. The valve body cavity is divided into a sliding section and a socket section from back to front. The valve core is divided into a guide section and a plug section from back to front. The sliding section and the guide section are in sliding sealing fit. The plug section and the inner wall of the sliding section are radially spaced. The socket section is for the plug section to be inserted so that the plug section and the inner wall of the valve body form a closed annular buffer cavity. The valve body is provided with a pressure relief channel for connecting the valve body cavity to the outside atmosphere or low-pressure equipment. When the plug section is inserted into the socket section, the annular buffer cavity and the pressure relief channel are isolated from each other. When the plug section and the socket section are separated, the part of the valve body cavity in front of the valve core is connected to the pressure relief channel.

[0009] The beneficial effects are as follows: In the high-pressure switching valve of the present invention, when the high-pressure switching valve is open and the plug section of the valve core is not inserted into the socket section of the valve body, a portion of the high-pressure fluid in the front part of the valve core's internal cavity is discharged through the pressure relief channel. After the valve core moves forward, the plug section is inserted into the socket section of the valve body. The radial distance between the plug section and the inner wall of the sliding section forms a closed annular buffer cavity. The continuing movement of the valve core compresses the fluid in the annular buffer cavity, causing the fluid in the annular buffer cavity to exert a rebound force on the valve core, thus buffering the valve core until its speed is zero. Then, the valve core moves backward under the action of the rebound force. When the plug section disengages from the socket section, the annular buffer cavity is no longer closed. A portion of the high-pressure fluid in the front part of the valve core's internal cavity is discharged again through the pressure relief channel. Under the action of the high-pressure fluid at the rear end of the valve core, the valve core gradually decelerates to zero and then moves forward again. Since a portion of the high-pressure fluid in the front part of the valve core's internal cavity was discharged during the previous movement, the fluid pressure in the compressed annular piston cavity decreases, and the rebound force of the fluid on the valve core decreases. After multiple reciprocating movements, the rebound force on the valve core gradually decreases until the insertion section of the valve core no longer disengages from the insertion hole after the rebound movement, and the back-and-forth oscillation of the valve core gradually weakens until it disappears. This design can shorten the time of back-and-forth oscillation of the valve core.

[0010] Further improvements include the installation of coaxially distributed drain pipes within the insertion section, forming an annular space between the drain pipes and the insertion section. The valve core is equipped with a central blind hole extending in the front-rear direction, with the opening of the central blind hole facing forward. The central blind hole allows the drain pipe to be inserted when the insertion section is inserted into the annular space, and the pressure relief channel is formed by the drain pipe. When the insertion section separates from the insertion section, the central blind hole detaches from the drain pipe.

[0011] The beneficial effects are as follows: With this design, when the plug section is inserted into the annular space, the high-pressure fluid in the central blind hole can be discharged to the outside through the drain pipe. Since the diameter of the drain pipe is smaller than the diameter of the central blind hole of the valve core, the fluid flows from the valve core to the drain pipe, which generates a certain damping effect, further buffering the rapidly sliding valve core and improving the buffering effect. When the plug section moves backward and disengages from the plug section, the space enclosed by the central blind hole and the drain pipe gradually increases, causing the pressure in the central blind hole to gradually decrease, thereby reducing the rebound force of the high-pressure fluid in the central blind hole on the valve core.

[0012] A further improvement is made by providing a step at the opening of the central blind hole. The inner hole of the step is smaller than the rest of the central blind hole, and the step is used to fit against the outer wall of the drain pipe inserted into the central blind hole.

[0013] The beneficial effect is that this design guides the drain pipe only through the step, making the diameter of other parts of the central blind hole larger than the inner hole of the step, increasing the diameter difference between the central blind hole and the central hole of the drain pipe, and improving the damping effect.

[0014] Further improvements include aligning the rear end of the drain pipe with the rear end of the insertion hole section, with the drain pipe extending rearward beyond the insertion hole section.

[0015] The beneficial effect is that, with this design, before the valve core's insertion section is inserted into the valve body's insertion hole section, the step at the opening of the blind hole in the center of the valve core fits against the outer wall of the drain pipe, thus preventing the fluid in the annular space from flowing into the drain pipe in advance and forming a blocked annular space, thereby improving the damping effect.

[0016] Further improvements include a pressure relief channel that extends straight forward and backward.

[0017] The beneficial effect is that this design allows high-pressure fluid inside the valve body to be discharged through a straight channel, increasing the pressure relief speed.

[0018] Further improvements include the installation of a buffer spring within the insertion section, which is fitted around the outer periphery of the drain pipe.

[0019] The beneficial effect is that this design ensures that the buffer spring and the drain pipe do not interfere with each other, simplifying the structure of the high-pressure switching valve.

[0020] Further improvements include the addition of a buffer piston within the insertion section. The buffer piston is fitted around the outer periphery of the drain pipe and abuts against the rear end of the buffer spring. A damping hole is provided on the front bottom wall of the insertion section.

[0021] The beneficial effect is that, with this design, the forward-moving valve core pushes the buffer piston to compress the gas in the insertion section, causing the gas to be discharged from the damping hole. The buffer piston, damping hole, and insertion section together constitute a piston cylinder, which can produce a certain buffering effect on the valve core.

[0022] In a further improvement, the buffer piston includes a support seat and a plug body. The support seat forms a support end face for the buffer piston to abut against the buffer spring. The plug body is fixed inside the support seat, and there is a radial gap between the inner hole of the support seat and the pressure relief pipe.

[0023] The beneficial effect is that, with this design, when the valve core strikes the plug, the buffer piston that moves forward transmits the force evenly to the buffer spring through the support end face, making the buffer spring stable under force.

[0024] Further improvements include a two-stage buffer structure within the socket section. The annular buffer chamber provides primary buffering for the valve core, while the secondary buffer structure provides secondary buffering for the valve core after the insertion section is inserted into the socket section.

[0025] The beneficial effect is that this design first uses the high-pressure fluid in the annular buffer chamber to buffer the valve core at a high speed, and then uses the secondary buffer structure to buffer the valve core after it has decelerated, so as to reduce the rebound force of the secondary buffer structure on the valve core. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the high-pressure switch valve of the present invention in the closed state;

[0027] Figure 2 for Figure 1 Enlarged view of part A in the image;

[0028] Figure 3 for Figure 1 A schematic diagram of the structure of the high-pressure switching valve when it has just formed a closed annular buffer chamber;

[0029] Figure 4 for Figure 3 A schematic diagram of the structure when the valve core just squeezes the buffer piston;

[0030] Figure 5 for Figure 4 A schematic diagram of the structure when the valve core velocity is zero;

[0031] Figure 6 for Figure 5 A schematic diagram of the structure when the valve core is disengaged from the insertion hole section in the reverse direction.

[0032] In the diagram: 11. Valve body; 12. Valve core; 13. Insertion section; 14. Drain pipe; 15. Buffer piston; 16. Buffer spring; 17. Pressure relief channel; 18. Control port; 19. Fluid inlet; 20. Fluid outlet; 21. Central blind hole; 22. Plug body; 23. Support seat; 24. Damping hole; 25. Insertion section; 26. Annular buffer chamber; 27. Guide section; 28. Sliding section. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0035] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the process or method that includes said element.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "provided with" should be interpreted broadly. For example, the object "provided with" can be a part of the main body, or it can be separately arranged from the main body and connected to the main body. This connection can be a detachable connection or a non-detachable connection. Those skilled in the art can understand the specific meaning of the above terms in this invention through specific circumstances.

[0038] The present invention will be further described in detail below with reference to embodiments.

[0039] Embodiment 1 of the high-pressure switching valve of the present invention:

[0040] The high-pressure switching valve of the present invention is used to be installed on pipelines or equipment to control the flow of fluid within the pipelines or equipment.

[0041] like Figure 1As shown, the high-pressure switching valve includes a valve body 11 and a valve core 12. The valve core 12 is slidably installed inside the valve body 11 and is sealed to the valve body 11. The valve body 11 has a fluid inlet 19, a fluid outlet 20, and a control port 18. The fluid inlet 19, fluid outlet 20, and control port 18 are all connected to the inner cavity of the valve body 11. The fluid inlet 19 and control port 18 are located at opposite ends of the inner cavity of the valve body 11 in the sliding direction of the valve core 12, respectively. The fluid outlet 20 is perpendicular to the sliding direction of the valve core 12. The fluid inlet 19 is connected to a high-pressure fluid source. To close the high-pressure switching valve, high-pressure fluid is introduced into the inner cavity of the valve body 11 through the control port 18, so that the pressure on the inlet side and the outlet side of the valve body 11 is balanced, thereby allowing the valve core 12 to stably seal at the fluid outlet 20. When the high-pressure switching valve is opened, the control port 18 is opened to discharge the high-pressure gas on the valve control port 18 side, causing the valve core 12 to slide forward and expose the fluid outlet 20. The forward movement direction of valve core 12 is defined as the opening action direction of the high-pressure switching valve.

[0042] like Figure 3 As shown, the inner cavity of the valve body 11 is divided into a sliding section 28 and a socket section 25 from back to front. The inner diameter of the socket section 25 is smaller than that of the sliding section 28. The valve core 12 is divided into a guide section 27 and a plug section 13 from back to front. The guide section 27 and the sliding section 28 are in a sliding sealing fit. The outer periphery of the plug section 13 is spaced from the inner wall of the sliding section 28. When the plug section 13 is inserted into the socket section 25, the plug section 13 and the inner wall of the sliding section 28 form a closed annular buffer cavity 26. After the valve core 12 compresses the annular buffer cavity 26 forward, the high-pressure fluid compressed in the annular buffer cavity 26 can provide a first-stage buffer for the valve core 12, reducing the speed of the valve core 12.

[0043] A drain pipe 14 is coaxially distributed within the insertion section 25, forming an annular space between the drain pipe 14 and the insertion section 25. The rear end of the drain pipe 14 corresponds to the rear end of the insertion section 25, and the drain pipe 14 extends rearward beyond the insertion section 25. When the insertion section 13 separates from the insertion section 25, the drain pipe 14 connects the inner cavity of the sliding section 28 to the outside atmosphere, allowing the high-pressure gas in the inner cavity of the sliding section 28 to be discharged through the drain pipe 14. The central hole of the drain pipe 14 extends in the front-rear direction, and the front opening of the central hole is the control port 18 of the valve body 11. In this embodiment, the drain pipe 14 forms a pressure relief channel 17.

[0044] like Figure 4As shown, the valve core 12 has a central blind hole 21 extending forward and backward. The opening of the central blind hole 21 faces forward, and a step is provided at the opening of the central blind hole 21. The inner diameter of the step is smaller than the inner diameter of other positions of the central blind hole 21. When the plug section 13 is inserted into the annular space of the plug section 25, the drain pipe 14 is inserted into the central blind hole 21. The inner wall of the step fits against the outer wall of the drain pipe 14. The central blind hole 21 is connected to the pressure relief channel 17. The high-pressure fluid in the central blind hole 21 is discharged through the pressure relief channel 17. Since the inner diameter of the central blind hole 21 is larger than the inner diameter of the pressure relief channel 17, the pressure relief channel 17 produces a certain damping effect on the fluid when the fluid flows through the pressure relief channel 17, so as to further buffer the valve core 12.

[0045] like Figure 1 and Figure 2 As shown, a two-stage buffer structure is provided within the insertion section 25. This structure includes a buffer piston 15 and a buffer spring 16, both of which are fitted around the outer periphery of the drain pipe 14. The buffer piston 15 includes a plug body 22 and a support seat 23. The support seat 23 has a U-shaped cross-section, and the plug body 22 is installed within the opening of the support seat 23. A certain radial distance exists between the inner hole of the support seat 23 and the outer wall of the drain pipe 14, allowing the buffer piston 15 to slide smoothly in the front-back direction. The support seat 23 forms a support end face for the buffer piston 15 to abut against the buffer spring 16, enabling the buffer piston 15 to evenly transmit force to the buffer spring 16 through this support end face. A damping hole 24 extending front-back is provided on the front side wall of the insertion section 25. The buffer piston 15, the damping hole 24, and the insertion section 25 together constitute a piston cylinder. When the moving valve core 12 strikes the buffer piston 15, the buffer piston 15 and the buffer spring 16 move forward. The compressed buffer spring 16 provides secondary buffering for the valve core 12. At the same time, the volume of the piston cylinder decreases, and the gas in the piston cylinder is discharged outward through the smaller damping orifice 24, so as to buffer the valve core 12.

[0046] When the high-pressure switch valve of the present invention is first opened, the front end face of the plug section 13 is a certain distance away from the stepped end face between the sliding section 28 and the socket section 25. At this time, if... Figure 1 As shown, the inner cavity of the valve body 11 is connected to the outside atmosphere. The high-pressure gas in the inner cavity of the valve body 11 flows out through the pressure relief channel 17 and the control port 18. After the valve core 12 moves a certain distance, the front end face of the insertion section 13 is just flush with the step end face between the sliding section 28 and the insertion hole section 25. Figure 3As shown, at this time, the insertion section 13 is aligned with the insertion hole section 25, and the drain pipe 14 is inserted into the central blind hole 21 of the valve core 12. The insertion section 13 and the inner cavity of the valve body 11 together form a closed annular buffer cavity 26. After the valve core 12 continues to move forward, the valve core 12 compresses the high-pressure fluid in the annular buffer cavity 26, so that the compressed high-pressure fluid exerts a rebound force on the valve core 12 to provide a first-level buffer for the moving valve core 12. At the same time, the high-pressure fluid in the central blind hole 21 is discharged through the pressure relief channel 17. Figure 4 As shown, the continuously moving valve core 12 impacts the buffer piston 15, pushing the buffer piston 15 and buffer spring 16 forward. The buffer piston 15 compresses the gas in the insertion section 25 and discharges it through the damping hole 24. The compressed buffer spring 16 applies a rebound force to the valve core 12, providing secondary buffering for the valve core 12, causing the valve core 12 to decelerate again until it reaches zero. Figure 5 As shown, at this time, the high-pressure fluid in the annular buffer chamber 26 and the rebound force of the secondary buffer structure on the valve core 12 push the valve core 12 to begin moving backward. After a period of time, the insertion section 13 disengages from the insertion hole section 25, as shown. Figure 6 As shown, the inner cavity of the sliding section 28 is connected to the pressure relief channel 17. A portion of the high-pressure fluid in the inner cavity of the sliding section 28, located at the front end of the valve core 12, is discharged outwards again through the pressure relief channel 17. Under the action of the high-pressure fluid at the inlet side of the valve body 11, the valve core 12 gradually decelerates to zero and moves forward again. Because some of the high-pressure fluid in the inner cavity of the sliding section 28 was discharged from the front end of the valve core 12 during the previous movement, the pressure in the newly formed annular piston cavity decreases, and the rebound force of the fluid in the compressed annular piston cavity on the valve body 11 decreases. After multiple movements, the pressure of the high-pressure fluid in the annular piston cavity decreases further until the rebound force on the valve core 12 decreases to the point where the insertion section 13 of the valve core 12 will no longer disengage from the insertion hole section 25 after the rebound movement. The back-and-forth oscillation of the valve core 12 gradually weakens until it disappears.

[0047] Embodiment 2 of the high-pressure switching valve of the present invention:

[0048] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the high-pressure switching valve further includes a drain pipe 14, which forms a pressure relief channel 17. In this embodiment, the drain pipe 14 is omitted, and the valve body 11 is provided with a pressure relief channel 17 communicating with the side wall of the insertion section 25. In other embodiments, a pressure relief hole can be provided on the front bottom wall of the insertion section 25, allowing the high-pressure fluid inside the valve body 11 at the front end of the valve core 12 to flow out through the pressure relief hole, thus forming a pressure relief channel.

Claims

1. A high-pressure switching valve, comprising a valve body (11) and a valve core (12), wherein the valve core (12) is slidably mounted within the inner cavity of the valve body (11), characterized in that, The direction of the forward movement of the valve core (12) is defined as the opening direction of the high-pressure switch valve. The inner cavity of the valve body (11) is divided into a sliding section (28) and a socket section (25) from back to front. The valve core (12) is divided into a guide section (27) and a plug section (13) from back to front. The sliding section (28) and the guide section (27) are in sliding sealing fit. The inner walls of the plug section (13) and the sliding section (28) are radially spaced. The socket section (25) is for the plug section (13) to be inserted so that the plug section (13) can be inserted. 13) A closed annular buffer cavity (26) is formed by the inner wall of the valve body (11). The valve body (11) is provided with a pressure relief channel (17) for connecting the inner cavity of the valve body (11) with the outside atmosphere or low-pressure equipment. When the plug section (13) is inserted into the socket section (25), the annular buffer cavity (26) and the pressure relief channel (17) are isolated from each other. When the plug section (13) and the socket section (25) are separated, the inner cavity of the valve body (11) in front of the valve core (12) is connected to the pressure relief channel (17).

2. The high-pressure switching valve according to claim 1, characterized in that, The insertion section (25) is provided with a coaxially distributed drain pipe (14), and an annular space is formed between the drain pipe (14) and the insertion section (25). The valve core (12) is provided with a central blind hole (21) extending in the front-back direction. The opening of the central blind hole (21) faces forward. The central blind hole (21) is used for the drain pipe (14) to be inserted when the insertion section (13) is inserted into the annular space. The pressure relief channel (17) is formed by the drain pipe (14). When the insertion section (13) and the insertion section (25) are separated, the central blind hole (21) and the drain pipe (14) are separated from each other.

3. The high-pressure switching valve according to claim 2, characterized in that, The opening of the central blind hole (21) is provided with a step, the inner hole of the step is smaller than the other parts of the central blind hole (21), and the step is used to fit against the outer wall of the drain pipe (14) inserted into the central blind hole (21).

4. The high-pressure switching valve according to claim 3, characterized in that, The rear end of the drain pipe (14) corresponds to the rear end of the insertion hole section (25), and the drain pipe (14) extends rearward out of the insertion hole section (25).

5. The high-pressure switching valve according to any one of claims 1 to 4, characterized in that, The pressure relief channel (17) is a straight channel extending forward and backward.

6. The high-pressure switching valve according to claim 2, 3, or 4, characterized in that, A buffer spring (16) is provided inside the insertion hole section (25), and the buffer spring (16) is sleeved on the outer periphery of the drain pipe (14).

7. The high-pressure switching valve according to claim 6, characterized in that, The insertion section (25) is also provided with a buffer piston (15), which is sleeved on the outer periphery of the drain pipe (14) and abuts against the rear end of the buffer spring (16). A damping hole (24) is provided on the front bottom wall of the insertion section (25).

8. The high-pressure switching valve according to claim 7, characterized in that, The buffer piston (15) includes a support seat (23) and a plug body (22). The support seat (23) forms a support end face for the buffer piston (15) to abut against the buffer spring (16). The plug body (22) is fixed inside the support seat (23). There is a radial gap between the inner hole of the support seat (23) and the pressure relief pipe.

9. The high-pressure switching valve according to any one of claims 1 to 4, characterized in that, The insertion section (25) is provided with a two-stage buffer structure. The annular buffer cavity (26) is used to provide a first-stage buffer for the valve core (12), and the second-stage buffer structure is used to provide a second-stage buffer for the valve core (12) after the insertion section (13) is inserted into the insertion section (25).

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