Bidirectional flow control pilot-operated type electromagnetic valve provided with reducing valve and adopting sealing piston ring structure
By introducing a diameter change valve and sealed piston ring structure into the pilot solenoid valve, the two-way flow of the piston is controlled by using the pilot pipe line and the solenoid valve, the problem of one-way flow of the conventional pilot solenoid valve and difficulty in pushing the piston is solved, and rapid And stable bidirectional circulation and longer service life.
Patent Information
- Application Number
- CN202420652476.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-29
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-03-29
AI Technical Summary
Conventional pilot solenoid valves can only flow in one direction, and it is difficult to open the piston when the fluid pressure difference is small, making it impossible to achieve fast and stable bidirectional flow in a fast and stable manner.
Bidirectional flow-controlled pilot solenoid valve adopts a sealed piston ring structure with a variable diameter valve. Through the design of the pilot pipe line and the variable diameter valve, the solenoid valve controls the on-off pilot pipe line, forming a pressure difference to push the piston to open and close , ensure two-way circulation.
The two-way flow of the pilot solenoid valve is realized, which improves the piston sliding speed and the service life of the device, avoids the problem of difficulty in pushing the piston. It is suitable for a variety of scenarios such as gas station oil depots.
Smart Images
Figure CN222229616U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of pilot-operated electromagnetic valves, in particular to a two-way flow-controlled pilot-operated electromagnetic valve with a reducing valve and a sealing piston ring structure. Background Art
[0002] A pilot solenoid valve refers to a valve that, when powered on, relies on electromagnetic force to lift the valve stem and open the pilot valve port. At this time, the upper chamber of the solenoid valve is depressurized through the pilot hole, forming a pressure difference around the main valve core with a lower top and a higher bottom. Under the action of the pressure difference, the fluid pressure pushes the main valve core upward to open the main valve port. When the power is off, under the action of the spring force and the gravity of the main valve core, the valve stem is reset, the pilot hole is closed, the main valve core moves downward, and the main valve port is closed. The pressure in the upper chamber of the solenoid valve increases, and the fluid pressure pressurizes the main valve core to achieve a sealing effect. Conventional pilot solenoid valves can only flow in one direction, and if the fluid pressure difference of conventional pilot solenoid valves is small, it may be difficult to open the piston. Therefore, it is necessary to provide a pilot solenoid valve that can flow quickly, stably, and in both directions. Utility Model Content
[0003] The utility model aims to provide a two-way flow control pilot electromagnetic valve with a reducing valve and a sealing piston ring structure, so as to provide a pilot electromagnetic valve capable of rapid and stable two-way flow.
[0004] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a two-way flow-controlled pilot solenoid valve with a sealing piston ring structure and a reducing valve, comprising a valve body, a solenoid valve part and a valve cover covered on the valve body, both ends of the valve body are through ports, a valve cavity connected to the through ports is opened in the valve body, a piston part is slidably arranged in the valve cavity, and both ends of the valve body are opened with pilot holes connected to the through ports on both sides respectively; a pilot line is arranged in the valve cover, and both ends of the pilot line are equipped with reducing valves, and the two reducing valves are connected to the pilot holes on both sides respectively. When the fluid passes through When the reducer on one side enters the pilot line, the cross-sectional area of the reducer on this side that can provide fluid flow becomes smaller. Conversely, when the fluid flows out of the pilot line through the reducer on the other side, the cross-sectional area of the reducer here that can provide fluid flow is larger than that at the inlet end. The reducer also includes two one-way flow parts connected to the pilot line and arranged on both sides of the valve cover. The one-way flow parts can allow the fluid in the pilot line to enter the valve cavity. A connecting hole is opened in the center of the valve cover to allow the fluid in the valve cavity to enter the pilot line. The solenoid valve part includes at least one solenoid valve that can control the on and off of the pilot line.
[0005] The principles and beneficial effects of this solution are:
[0006] The fluid enters the pilot hole through the opening on the left side (here it is assumed to be the left side). When the solenoid valve is started, the pilot hole on the left side is connected to the pilot line through the reducing valve. The solenoid valve starts to open the pilot line. When the fluid enters the pilot line through the reducing valve, the cross-sectional area of the reducing valve available for fluid circulation becomes smaller. At this time, the flow rate of the fluid entering the pilot line becomes faster and the pressure decreases, so that the fluid in the valve cavity can be drawn into the pilot line and flow out from the reducing valve on the right. Here, the cross-sectional area of the reducing valve available for fluid circulation is larger than the inlet end, so that the fluid entering the pilot line and the fluid in the valve cavity can flow out. At this time, in the pilot line, the fluid increment is less than the discharge amount, and the pressure difference between the pilot line and the valve cavity fluid can be maintained, so that the valve cavity fluid continues to flow out, and then the piston part is continuously driven to slide upward, so that the valve cavity is connected with the openings at both ends, and the fluid in the opening can flow directly through the valve cavity. While the fluid flows, the piston part is further lifted upward to further open the valve port.
[0007] When the valve needs to be closed, the solenoid valve closes the pilot line, and the fluid enters the pilot line through the reducing valve but cannot pass through the pilot line. The fluid enters the valve cavity above the piston part from the fluid in the pilot line through the one-way flow part on this side, thereby pushing the piston part to slide downward to close the valve port.
[0008] 1. Two pilot holes are provided in this technical solution, and both pilot holes can be connected through a pilot line. No matter which port the fluid enters from, a pilot circuit can be formed to drive the piston to open. This pilot solenoid valve can flow in both directions and is suitable for more usage scenarios, such as gas stations and oil depots that require output and input.
[0009] 2. When the fluid flow rate is fast, a large pulling force is required to pull the piston to flow, which places high requirements on the performance of the solenoid valve. Through the setting of the pilot line, a pressure difference is generated between the valve cavity and the valve body, and the pressure in the valve cavity is relieved at the same time. The fluid in the valve cavity is discharged through the pilot line and drives the piston to open, thereby increasing the sliding speed of the piston and enabling faster flow and extending the service life of the device. On the other hand, in the pilot line of the present technical solution, the fluid increment is less than the discharge amount, which can maintain the pressure difference between the pilot line and the valve cavity fluid, so that the valve cavity fluid continues to flow out, and then continuously drives the piston to slide upward, which can avoid the problem of insufficient pressure difference in the valve cavity above the piston that may occur in conventional pilot valves and makes it difficult to push the piston, thereby ensuring the reliability of the device.
[0010] Preferably, as an improvement, the variable valve includes a variable valve body, a variable valve core and a sliding tube, a first through hole is opened in the center of the variable valve body, the sliding tube is coaxial with the variable valve body and embedded in the variable valve body, the inner diameter of the sliding tube is larger than the first through hole, the variable valve core includes a flow limiting tube and a flow expansion part, the flow limiting tube is fixed on the side of the flow expansion part close to the first through hole, the flow expansion part can slide in the sliding tube, the outer diameter of the flow limiting tube is smaller than the diameter of the first through hole, and a plurality of flow channels are provided on the cross section of the flow expansion part.
[0011] The beneficial effect is as follows: through the above-mentioned arrangement, when the flow direction of the fluid is from the sliding tube to the first through hole, the variable diameter valve core is driven by the fluid to flow in the direction of the first through hole. When the variable diameter valve core slides to the end of the sliding tube, the outer diameter of the flow limiting tube is smaller than the diameter of the first through hole, and the flow limiting tube can be inserted into the first through hole. At this time, the fluid cannot enter the first through hole from the flow channel, but can only enter the first through hole from the flow limiting tube. The cross-sectional area through which the fluid can pass in the variable diameter valve is reduced, thereby changing the flow rate. When the flow direction of the fluid is from the first through hole to one side of the sliding tube, the variable diameter valve core is driven by the fluid to flow in the direction away from the first through hole. When the variable diameter valve core moves to a certain extent, the fluid can not only flow out of the flow limiting tube, but also flow through the flow channel set on the expansion part, thereby increasing the flow rate per unit time.
[0012] Preferably, as an improvement, the one-way flow portion includes a check valve body and a check piston. The check valve body is fixed on the valve cover and passes through the valve cover. A three-way hole is opened inside the check valve body. Two ends of the three-way hole are respectively connected to the pilot line, and the remaining end is covered with a check piston. A support spring for supporting the check piston is provided under the check piston.
[0013] The beneficial effect is: by setting the check nozzle body, when the fluid passes through the check piston, the pressure of the fluid overcomes the elastic force of the supporting spring so that the fluid passes through the piston and enters the valve cavity. When the valve cavity is filled with the fluid, the elastic force of the spring covers the check piston at the port to close it, thereby achieving one-way flow and preventing reverse flow, thereby enabling the device to realize a two-way solenoid valve.
[0014] Preferably, as an improvement, the piston part includes a guide pin and a pressure plate, a piston, and a nut that pass through the guide pin in sequence, a sealing annular groove is opened on the lower surface of the piston, the sealing annular groove is filled with sealing filler, the pressure plate is pressed on the sealing filler, the cross-section of the pressure plate is conical, the nut is threadedly connected to the guide pin, and two O-rings are sleeved on the outer circumference of the piston.
[0015] The beneficial effects are as follows: the sealing annular groove is filled with sealing filler, the pressure plate ensures the seal by pressing on the sealing filler, ensures the sealing of the piston part, ensures the reliability of the device, effectively prevents fluid leakage, and ensures the sealing performance of the system. The threaded connection between the nut and the guide pin can firmly connect the guide pin and the piston, extend the service life of the device, avoid loosening or falling off caused by fluid impact, and improve the operating stability of the system.
[0016] Preferably, as an improvement, a limit block is provided at the bottom of the through opening below the piston, and a sliding hole capable of accommodating the reciprocating sliding of the guide pin is opened on the limit block.
[0017] The beneficial effect is: through the above arrangement, when the piston is opened and reciprocated, the guide pin slides vertically up and down in the sliding hole, which can limit the piston to stable axial movement when opened or closed, prevent its sliding direction from deviating under the impact of fluid pressure, and avoid the weakening of sealing performance.
[0018] Preferably, as an improvement, the solenoid valve part includes two solenoid valves symmetrically arranged on the valve cover, and the solenoid valves each include a shell and a coil group, a return spring, and a moving iron core inside the shell. The coil group can drive the moving iron core to slide back and forth, and the moving iron core can control the on and off of the pilot line. The two ends of the return spring respectively resist the valve cover and the moving iron core.
[0019] The beneficial effect is that the return spring can ensure that the moving iron core can return quickly, thereby ensuring normal connection and disconnection between the two ports, further ensuring the reliable working state of the solenoid valve, and reducing the risk of system failure.
[0020] Preferably, as an improvement, the cross section of the flow expansion portion is annular, the flow limiting tube is fixed inside the flow expansion portion, and four flow channels are opened on the cross section of the flow expansion portion.
[0021] Preferably, as an improvement, two pilot ports are provided on the pilot conduit, and the two moving iron cores can block the pilot ports respectively, and the cross-section of the pilot ports is an inverted cone.
[0022] Preferably, as an improvement, it also includes a variable valve cover, which can cover the variable valve body, and a second annular groove is opened on the surface of the variable valve body close to the variable valve cover, and a sealing ring is embedded in the second annular groove; a limiting ring is provided on the side of the sliding tube away from the first channel. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a cross-sectional view of the pilot-operated solenoid valve of the utility model;
[0024] Figure 2 It is a cross-sectional view of the variable diameter valve of the utility model;
[0025] Figure 3 It is a side view of the variable diameter valve core of the utility model;
[0026] Figure 4 It is a cross-sectional view of the backflow prevention nozzle body of the utility model;
[0027] Figure 5 It is a cross-sectional view of the piston part of the utility model. DETAILED DESCRIPTION
[0028] The following is further described in detail through specific implementation methods:
[0029] The figure marks in the drawings of the specification include: valve body 1, valve cover 2, through port 3, pilot hole 4, pilot line 5, variable diameter valve body 6, sliding tube 7, return spring 8, first through hole 9, flow limiting tube 10, flow expansion part 11, flow channel 12, check nozzle body 13, check piston 14, support spring 15, guide pin 16, pressure plate 17, piston 18, nut 19, sealing packing 20, O-ring 21, limit block 22, variable diameter valve cover 23, moving iron core 24, pilot port 25, connecting hole 26.
[0030] Example
[0031] The embodiment is basically as follows Figure 1-Figure 5 As shown, Figure 1 The bidirectional flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure shown in FIG. 1 comprises a valve body 1, a solenoid valve portion and a valve cover 2 covering the valve body 1. Figure 1 As shown, both ends of the valve body 1 are ports 3 for receiving fluid, a valve cavity communicating with the port 3 is opened in the valve body 1, a piston portion is slidably arranged in the valve cavity, and both ends of the valve body 1 are symmetrically provided with pilot holes 4 communicating with the ports 3 on both sides respectively; Figure 1 As shown, a pilot line 5 is provided in the valve cover 2, and both ends of the pilot line 5 are installed with reducing valves, and the two reducing valves are respectively connected with the pilot holes 4 on both sides. When the fluid enters the pilot line 5 through the reducing valve on the left, the cross-sectional area of the reducing valve on this side that can provide the fluid for circulation becomes smaller. On the contrary, when the fluid flows out of the pilot line 5 through the reducing valve on the right, the cross-sectional area of the reducing valve that can provide the fluid for circulation is larger than the inlet end. It also includes two one-way flow parts connecting the pilot line 5 and arranged on both sides of the valve cover 2. The two one-way flow parts are symmetrically arranged on the valve cover 2. The one-way flow parts can allow the fluid in the pilot line 5 to enter the valve cavity in one direction. A connecting hole 26 is opened in the center of the valve cover 2 to allow the fluid in the valve cavity to enter the pilot line 5. The solenoid valve part includes at least one solenoid valve that can control the on and off of the pilot line 5. In this embodiment, two solenoid valves are included.
[0032] like Figure 2 and Figure 3As shown, the variable valve includes a variable valve body 6, a variable valve core and a sliding tube 7. The center of the variable valve body 6 is provided with a first through hole 9. The sliding tube 7 is coaxial with the variable valve body 6 and embedded in the variable valve body 6. The inner diameter of the sliding tube 7 is larger than the first through hole 9. The variable valve core includes a flow limiting tube 10 and a flow expansion part 11. The flow limiting tube 10 is fixed to the side of the flow expansion part 11 close to the first through hole 9. The flow expansion part 11 can slide in the sliding tube 7. The outer diameter of the flow limiting tube 10 is smaller than the diameter of the first through hole 9. Four flow channels 12 are provided on the cross section of the flow expansion part 11. The cross section of the flow expansion part 11 is annular. The flow limiting tube 10 is fixed inside the flow expansion part 11. Figure 1 As shown, two pilot ports 25 are provided on the pilot conduit 5, and two moving iron cores 24 can block the pilot ports 25 respectively, and the cross section of the pilot ports 25 is an inverted cone.
[0033] It also includes a variable valve cover 23, which can cover the variable valve body 6. The surface of the variable valve body 6 close to the variable valve cover 23 is provided with a second annular groove, and a sealing ring is embedded in the second annular groove; a limiting ring is provided on the side of the sliding tube 7 away from the first through hole 9. When the flow direction of the fluid is from the sliding tube 7 to the first through hole 9, the variable valve core is driven by the fluid to flow toward the first through hole 9. When the variable valve core slides to the end of the sliding tube 7, the outer diameter of the flow limiting tube 10 is smaller than the diameter of the first through hole 9, and the flow limiting tube 10 can be inserted into the first through hole 9. At this time, the fluid cannot enter the first through hole 9 from the flow channel 12, and can only enter the first through hole 9 from the flow limiting tube 10. The cross-sectional area through which the fluid can pass in the variable valve is reduced, thereby changing the flow rate; when the flow direction of the fluid is from the first through hole 9 to one side of the sliding tube 7, the variable valve core is driven by the fluid to flow away from the first through hole 9. When the variable valve core moves to a certain extent, the fluid can not only flow out from the flow limiting tube 10, but also flow through the flow channel 12 set on the expansion part 11, so that the flow rate per unit time increases.
[0034] The one-way flow portion in this embodiment includes Figure 4 The check nozzle body 13 and the check piston 14 shown are fixed to the valve cover 2 by bolts and penetrated into the valve cover 2. A three-way hole is opened inside the check nozzle body 13. The three-way hole is T-shaped. The horizontal ends of the three-way hole are respectively connected to the pilot line 5. A check piston 14 is provided at the vertical port of the three-way hole. A support spring 15 for supporting the check piston 14 is provided below the check piston 14. The check nozzle body 13 is provided. When the fluid flows from the check piston 14, the pressure of the fluid overcomes the elastic force of the support spring 15 so that the fluid passes through the support spring 15 and enters the valve cavity. When the fluid in the valve cavity is filled, the elastic force of the support spring 15 covers the check piston 14 at the port to make it closed to achieve the effect of one-way flow, prevent reverse flow, and thus enable the device to achieve a two-way flow pilot solenoid valve.
[0035] like Figure 1 and Figure 5 As shown, the piston part includes a guide pin 16 and a pressure plate 17, a piston 18, and a nut 19 that pass through the guide pin 16 in sequence. A sealing annular groove is provided on the lower surface of the piston 18, and a sealing filler 20 is filled in the sealing annular groove. The pressure plate 17 is pressed on the sealing filler 20. The cross section of the pressure plate 17 is conical. The nut 19 is threadedly connected to the guide pin 16. The outer peripheral surface of the piston 18 is covered with two O-rings 21 for sealing. A limit block 22 is provided at the bottom of the through port 3 below the piston 18, and a sliding hole that can accommodate the reciprocating sliding of the guide pin 16 is provided on the limit block 22. Through the above arrangement, when the piston 18 is opened and closed reciprocatingly, the guide pin 16 slides vertically up and down in the sliding hole, which can limit the piston 18 to a stable axial movement when it is opened or closed, preventing its sliding direction from being offset under the impact of fluid pressure, and avoiding the weakening of the sealing performance.
[0036] The solenoid valve part includes two solenoid valves symmetrically arranged on the valve cover 2. The solenoid valves include a housing and a coil group, a return spring 8, and a moving iron core 24 in the housing. The coil group can drive the moving iron core 24 to slide back and forth. The moving iron core 24 can control the on and off of the pilot line 5. The two ends of the return spring 8 respectively press against the valve cover 2 and the moving iron core 24. The sealing annular groove is filled with a sealing filler 20. The pressure plate 17 ensures the seal by pressing on the sealing filler 20, ensures the sealing of the piston part, ensures the reliability of the device, effectively prevents fluid leakage, and ensures the sealing performance of the system. The threaded connection between the nut 19 and the guide pin 16 can firmly connect the guide pin 16 and the piston 18, extend the service life of the device, avoid loosening or falling off caused by fluid impact, and improve the operating stability of the system.
[0037] The implementation method of the bidirectional flow control pilot solenoid valve with a reducing valve and a sealing piston ring structure is as follows:
[0038] The fluid enters the pilot hole 4 through the port 3 on the left. When the solenoid valve is started, the pilot hole 4 on the left is connected with the pilot line 5 through the reducer. The solenoid valve starts to open the pilot line 5. When the fluid enters the pilot line 5 through the reducer, the cross-sectional area of the reducer available for fluid circulation becomes smaller. At this time, the flow rate of the fluid entering the pilot line 5 becomes faster and the pressure decreases, so that the fluid in the valve cavity can be drawn into the pilot line 5 and flows out from the reducer on the right. The cross-sectional area of the reducer available for fluid circulation is larger than the inlet end, so that the fluid entering the pilot line 5 and the fluid in the valve cavity can flow out. At this time, in the pilot line 5, the fluid increment is less than the discharge amount, and the pressure difference between the pilot line 5 and the valve cavity fluid can be maintained, so that the valve cavity fluid continues to flow out, and then the piston part is continuously driven to slide upward, so that the valve cavity is connected with the ports 3 at both ends, and the fluid in the port 3 can flow directly through the valve cavity. While the fluid flows, the piston part is further lifted upward to further open the valve port.
[0039] When the valve needs to be closed, the solenoid valve closes the pilot line 5, and the fluid enters the pilot line 5 through the reducing valve but cannot pass through the pilot line 5. The fluid enters the valve cavity above the piston part from the fluid in the pilot line 5 through the one-way flow part on this side, and then pushes the piston part to slide downward to close the valve port.
[0040] 1. Two pilot holes 4 are provided in the technical solution, and both pilot holes 4 can be connected through the pilot line 5. No matter which port 3 the fluid enters from, a pilot circuit can be formed to drive the piston to open. The pilot solenoid valve can flow in both directions and can be applied to more usage scenarios, such as gas stations and oil depots that require output and input.
[0041] 2. When the fluid flow rate is fast, a large pulling force is required to pull the piston to flow, which places high requirements on the performance of the solenoid valve. Through the setting of the pilot line 5, a pressure difference is generated between the valve cavity and the port 3 of the valve body 1, and the pressure in the valve cavity is relieved at the same time. The fluid in the valve cavity is discharged through the pilot line and the piston is driven to open, thereby increasing the sliding speed of the piston, enabling faster flow and extending the service life of the device. On the other hand, in the pilot line 5 of the technical solution, the fluid increment is less than the discharge amount, which can maintain the pressure difference between the pilot line 5 and the valve cavity fluid, so that the valve cavity fluid continues to flow out, and then continuously drives the piston to slide upward, which can avoid the problem of insufficient pressure difference in the valve cavity above the piston part that may occur in conventional pilot valves and makes it difficult to push the piston 18, thereby ensuring the reliability of the device.
[0042] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.
Claims
1. A two-way flow control pilot solenoid valve with a reducing valve and a sealing piston ring structure, comprising a valve body, a solenoid valve part and a valve cover covering the valve body, with ports at both ends of the valve body, a valve cavity connected to the ports opened in the valve body, a piston part slidably arranged in the valve cavity, and pilot holes respectively connected to the ports on both sides opened at both ends of the valve body, characterized in that: A pilot line is provided in the valve cover, and both ends of the pilot line are equipped with reducing valves, which are respectively connected with the pilot holes on both sides. When the fluid enters the pilot line through the reducing valve on one side, the cross-sectional area of the reducing valve on this side that can provide the fluid for circulation becomes smaller, and conversely, when the fluid flows out of the pilot line through the reducing valve on the other side, the cross-sectional area of the reducing valve that can provide the fluid for circulation is larger than that at the inlet end. The valve cover also includes two one-way flow parts that connect the pilot line and are arranged on both sides of the valve cover. The one-way flow parts can allow the fluid in the pilot line to enter the valve cavity. A connecting hole is provided in the center of the valve cover for allowing the fluid in the valve cavity to enter the pilot line. The solenoid valve part includes at least one solenoid valve that can control the on and off of the pilot line.
2. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 1, characterized in that: The variable diameter valve includes a variable diameter valve body, a variable diameter valve core and a sliding tube. A first through hole is opened in the center of the variable diameter valve body. The sliding tube is coaxial with the variable diameter valve body and embedded in the variable diameter valve body. The inner diameter of the sliding tube is larger than the first through hole. The variable diameter valve core includes a flow limiting tube and a flow expansion part. The flow limiting tube is fixed on a side of the flow expansion part close to the first through hole. The flow expansion part can slide in the sliding tube. The outer diameter of the flow limiting tube is smaller than the diameter of the first through hole. A plurality of flow channels are arranged on the cross section of the flow expansion part.
3. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 2, characterized in that: The one-way flow part includes a check nozzle body and a check piston. The check nozzle body is fixed on the valve cover and penetrates into the valve cover. A three-way hole is opened inside the check nozzle body. Two ends of the three-way hole are respectively connected to the pilot line, and the remaining end is covered with a check piston. A support spring for supporting the check piston is provided under the check piston.
4. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 3, characterized in that: The piston part includes a guide pin and a pressure plate, a piston, and a nut that pass through the guide pin in sequence. A sealing annular groove is opened on the lower surface of the piston, and the sealing annular groove is filled with sealing filler. The pressure plate is pressed on the sealing filler. The cross-section of the pressure plate is conical. The nut is threadedly connected to the guide pin, and two O-rings are sleeved on the outer circumference of the piston.
5. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 4, characterized in that: A limit block is arranged at the bottom of the through opening below the piston, and a sliding hole capable of accommodating the reciprocating sliding of the guide pin is opened on the limit block.
6. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 5, characterized in that: The solenoid valve part includes two solenoid valves symmetrically arranged on the valve cover. The solenoid valves include a shell and a coil group, a return spring, and a moving iron core in the shell. The coil group can drive the moving iron core to slide back and forth. The moving iron core can control the on and off of the pilot line. The two ends of the return spring respectively resist the valve cover and the moving iron core.
7. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 6, characterized in that: The cross section of the flow expansion part is annular, the flow limiting tube is fixed inside the flow expansion part, and four flow channels are opened on the cross section of the flow expansion part.
8. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 7, characterized in that: Two pilot ports are arranged on the pilot conduit, and two moving iron cores can respectively block the pilot ports, and the cross-section of the pilot ports is an inverted cone.
9. The two-way flow control pilot solenoid valve with a variable diameter valve and a sealing piston ring structure according to claim 8, characterized in that: It also includes a variable valve cover, which can cover the variable valve body. The surface of the variable valve body close to the variable valve cover is provided with a second annular groove, in which a sealing ring is embedded. A limiting ring is provided on the side of the sliding tube away from the first channel.