Pilot-operated type electromagnetic valve capable of increasing stroke of main valve element through flow limiting ring

Abstract

The utility model relates to the field of electromagnetic valves, and discloses a pilot-operated type electromagnetic valve using a flow limiting ring to increase the stroke of a main valve element, the pilot-operated type electromagnetic valve comprises an electromagnetic valve unit and a main valve unit, the main valve unit comprises a main valve body provided with a main valve cavity, a main valve closing piece is arranged in the main valve cavity in a sliding mode, and the main valve cavity is further provided with an inlet and an outlet which are communicated with the main valve cavity. The electromagnetic valve unit can control opening and closing of the first pilot hole, the first pilot hole communicated with the main valve cavity and the outlet is formed in the main valve body, the electromagnetic valve is characterized by further comprising a feedback part and a flow limiting ring arranged on the main valve closing piece in a sleeving mode, the main valve closing piece can slide relative to the flow limiting ring, and the feedback part comprises a magnetic switch arranged at the bottom of the main valve body. A magnet is fixed to the bottom of the main valve closing piece, the main valve closing piece comprises a main piston body, and a plurality of through grooves communicated with the inlet and the main valve cavity are formed in the flow limiting ring. The pilot-operated type electromagnetic valve can accurately feed back opening and closing signals of the electromagnetic valve.

Description

Technical Field

[0001] The utility model relates to the field of electromagnetic valves, in particular to a pilot electromagnetic valve which uses a flow limiting ring to increase the stroke of a main valve core. Background Art

[0002] As a valve body for controlling the flow of fluid, the solenoid valve has a valve core that opens and closes the flow path. The valve core drives the piston structure inside the valve body to control the opening and closing of the flow path. The valve body of the pilot solenoid valve is more complicated than that of the conventional solenoid valve. It is impossible to visually observe whether the piston is open and whether it is opened to the set position. It is also impossible to know whether the pilot valve and the main valve closing parts are all open normally, and it is difficult to accurately feedback the working status of the solenoid valve body to the control system. Therefore, in order to ensure the reliability and safety of system control, it is necessary to monitor the working status of the solenoid valve position. The traditional method of setting a pressure sensing component or opening at the bottom of the valve may cause the pressure resistance of the device to be weakened and the medium to leak out, which in turn reduces the durability of the device and makes it easy to damage and difficult to repair. Therefore, it is necessary to provide a pilot solenoid valve that can accurately and safely feedback the opening and closing signals of the solenoid valve. Utility Model Content

[0003] The utility model aims to provide a pilot-operated solenoid valve which uses a flow-limiting ring to increase the stroke of a main valve core, so as to provide a pilot-operated solenoid valve which can accurately and safely feed back the opening and closing signals of the solenoid valve.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a pilot solenoid valve that uses a limiting ring to increase the stroke of the main valve core, including a solenoid valve unit and a main valve unit, the main valve unit including a main valve body provided with a main valve cavity, a main valve closing member slidably provided in the main valve cavity, an inlet and an outlet are also provided on the main valve cavity and are both connected to the main valve cavity, the solenoid valve unit can control the opening and closing of the first pilot hole, the main valve body is provided with a first pilot hole connecting the main valve cavity and the outlet, and also includes a feedback part and a limiting ring sleeved on the main valve closing member, the main valve closing member can slide relative to the limiting ring, the feedback part includes a magnetic switch arranged at the bottom of the main valve body, a magnet is fixed at the bottom of the main valve closing member, the main valve closing member includes a main piston body, and the limiting ring is provided with a plurality of through grooves connecting the inlet and the main valve cavity.

[0005] The beneficial effects of this program are:

[0006] When the first pilot hole is opened, the medium in the upper chamber of the main piston body flows to the outlet, and then the pressure in the upper chamber is relieved, and the pressure in the lower chamber is greater than the pressure in the upper chamber, causing the main piston body to move upward and open to allow the fluid to pass. The technical solution is achieved by setting a flow limiting ring, which has a number of through grooves connecting the inlet and the main valve chamber. The solenoid valve unit opens the first pilot hole. When the fluid flows in from the inlet, the main piston body is in a closed state at this time, and the fluid is connected to the main valve chamber from the through groove. The fluid enters the pilot hole from the main valve chamber, causing the main valve chamber above the main piston body to be relieved of pressure, driving the main piston body to move upward. By setting a through groove on the flow limiting ring, during the opening process of the main piston body, the fluid medium can only flow to the outlet through the through groove, which can ensure that the travel distance of the main piston body is increased.

[0007] In order to meet the rear-end flow, the main piston body needs to move upward to a suitable height to meet the flow requirements. Therefore, a magnetic switch is set to sense the magnet. In actual use, the magnet must move a certain distance before the magnetic switch can accurately identify the distance moved by the main piston body through the feedback of the magnet, thereby achieving the effective conversion condition of the magnetic switch and switching to an open-circuit signal. Through the above-mentioned setting, it is possible to intuitively judge from the system whether the main piston body moves or not, and truly and effectively reflect the opening and closing status of the valve body. Compared with the traditional method of setting a pressure sensing component or opening at the bottom of the valve, the present technical solution is more stable and accurate, avoiding the situation where the pressure resistance of the device is weakened and the medium leaks due to the opening, causing safety hazards. By ensuring the correct stroke of the main piston body and the accurate identification of the magnetic switch, the possibility of misoperation and failure can be reduced, and the reliability and stability of the system are improved. The above-mentioned design scheme can effectively improve the performance of the solenoid valve, thereby improving the overall performance of the product.

[0008] Preferably, as an improvement, the flow limiting ring includes a fixedly connected ring body and a bottom ring with the same inner diameter as the piston cavity, the ring body is provided with three through grooves evenly distributed circumferentially, and the bottom ring is provided with two arc-shaped through holes on the side close to the inlet. When the main piston body is opened, the fluid enters from the arc-shaped through holes and flows from the through grooves to the outlet, and the bottom ring between the two arc-shaped through holes is a support plate.

[0009] The beneficial effects are as follows: through the above-mentioned arrangement, the stroke of the main piston body is H, the nominal diameter of the valve is d, and the sealing line is in the process of the main piston body moving to open. The fluid medium only flows from the through groove to the outlet. The number of through grooves is n, and the width of the through groove is D. At this time, the flow channel s1' in the valve is equal to nDH, ensuring that the inlet and outlet flow channel areas are the same. By setting the through grooves, the stroke of the main piston body can be increased. By setting three through grooves, the stability of the movement of the main piston body can be ensured. When the first pilot hole is opened, the fluid in the inlet can enter the main valve cavity through the arc-shaped through hole and the through groove and then communicate with the first pilot hole. By setting the arc-shaped through hole, a larger flow rate of fluid can be facilitated to flow through. By setting the reserved part of the bottom ring as a support plate, when the flow limiting ring is installed, the support plate and the valve wall of the main valve cavity can be abutted to achieve a positioning effect. At the same time, the support plate can support the position of the flow limiting ring so that it does not move, thereby ensuring the position stability of the flow limiting ring during fluid flow.

[0010] Preferably, as an improvement, the main valve closing member also includes a main sealing gasket, a piston nut and a guide pin fixedly connected to the main piston body, a slide groove is opened on the switch mounting seat, the switch mounting seat passes through the bottom of the main valve body and is fixed to the main valve body, the guide pin is slidably connected to the slide groove, the magnet is embedded in the guide pin bottom plate, the main sealing gasket passes through the guide pin and is embedded in the bottom of the main piston body, the piston nut is threadedly connected to the bottom of the main piston body and fixes the main sealing gasket to the main piston body, the guide pin is provided with a support plate for supporting the main sealing gasket, and the main piston body is also provided with a first sealing groove, and a sealing ring portion is embedded in the first sealing groove.

[0011] The beneficial effects are: through the above-mentioned setting, the main sealing gasket is fixed by the piston nut, ensuring the position accuracy of the main sealing gasket and ensuring that it will not fall off during long-term use. The threaded connection between the piston nut and the bottom of the main piston body can fix the main sealing gasket on the main piston body, thereby enhancing the stability and reliability of the seal and reducing the risk of failure caused by structural looseness. By setting the main sealing gasket, the sealing performance of the main valve closing part is ensured, thereby ensuring the stable operation of the solenoid valve.

[0012] Preferably, as an improvement, the solenoid valve unit includes a solenoid valve and a valve cover, the valve cover is fixedly connected to the main valve body, the solenoid valve includes a sealing shell, a coil group and a moving iron core that slides under the drive of electromagnetic force, a solenoid valve chamber is provided in the valve cover, a second piston is slidably provided in the solenoid valve chamber, a first connecting hole is opened in the center of the second piston, and a second pilot hole connecting the main valve chamber and the solenoid valve chamber is also opened on the second piston, and a second sealing gasket that can block the first connecting hole is embedded in the bottom of the moving iron core.

[0013] The beneficial effect is: by opening the moving iron core, the first connecting hole is opened, the second pilot hole is connected with the first connecting hole to form a pilot circuit, and the pressure is relieved to drive the second piston to open upward and then open the first pilot hole so that the inlet and outlet are connected to form another level of pilot circuit.

[0014] Preferably, as an improvement, the solenoid valve unit also includes a head and a non-magnetic tube, the non-magnetic tube is fixed at the bottom of the head, the moving iron core is located inside the non-magnetic tube and can slide relative to the non-magnetic tube, a connecting groove is opened on the valve cover, the bottom of the non-magnetic tube is threadedly connected to the connecting groove, and a sealing filler is provided at the bottom of the connecting groove.

[0015] The beneficial effects are: the valve cover is connected to the solenoid valve unit through a non-magnetic tube, the non-magnetic tube is threadedly connected to the connecting groove and a sealing filler is provided at the bottom of the connecting groove. When the non-magnetic tube is fixed, the sealing filler can be further fixed to improve the sealing of the device, thereby ensuring that the device can be used in a high-pressure environment in deep water.

[0016] Preferably, as an improvement, the solenoid valve unit is further provided with a return part, the return part includes a first spring, a limit ring and a second spring, the limit ring is provided with an opening for the moving iron core to slide, the cross-section of the limit ring is an inverted U-shape, and a clamping ring is provided at the end of the moving iron core, the two ends of the first spring are respectively abutted against the non-magnetic tube and the clamping ring, the two ends of the second spring are respectively abutted against the limit ring and the second piston, and the upper surface of the limit ring is abutted against the non-magnetic tube.

[0017] The beneficial effect is as follows: by setting a two-stage spring for return, when the moving iron core returns, the two ends of the first spring respectively abut against the non-magnetic tube and the retaining ring to provide a first-stage return elastic force to assist the moving iron core to return and close the first connecting hole, and the two ends of the second spring respectively abut against the limiting ring and the second piston to provide elastic force to ensure that the second piston returns to close the first pilot hole, and the above two-stage rebound force can make the second piston and the moving iron core respond quickly to ensure the timely closure of the first pilot hole; the upper surface of the limiting ring abuts against the non-magnetic tube, and by setting the limiting ring, it can be limited when connecting the non-magnetic tube and the valve cover, avoiding excessive installation of the non-magnetic tube and causing the spacing between the moving iron core and the second piston to not meet the requirements.

[0018] Preferably, as an improvement, a sealing shell cover is arranged outside the coil group, and the sealing shell includes a shell, an upper cover, a cover plate and a lower cover. The shell is in a circular tube shape, the cover plate is fixed inside the shell, the head is fixed to the cover plate by bolts, the upper cover and the lower cover are respectively covered on both ends of the shell and are threadedly connected to the shell, and sealing rings are provided at the connection between the upper cover and the lower cover.

[0019] The beneficial effect is that the sealing shell can be provided to ensure that the solenoid valve can meet the sealing requirements applicable to deep water environments.

[0020] Preferably, as an improvement, it also includes a flow limiting ring pressure ring installed in the main valve cavity, and the flow limiting ring pressure ring fixes the flow limiting ring at the bottom of the main valve cavity.

[0021] The beneficial effect is that the position of the position-limiting and current-limiting ring can be stabilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a schematic diagram of the structure of an embodiment of the utility model;

[0023] Figure 2 This is a schematic diagram of the structure of the second piston in an embodiment of the utility model;

[0024] Figure 3 This is a schematic diagram of the structure of the main valve closing member of the utility model embodiment;

[0025] Figure 4 This is a schematic diagram of the installation of the current limiting ring of the embodiment of the utility model;

[0026] Figure 5 It is a top cross-sectional view of a current limiting ring according to an embodiment of the utility model;

[0027] Figure 6 It is a cross-sectional view of the current limiting ring according to an embodiment 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: main valve body 1, first pilot hole 2, limiting ring 3, switch mounting seat 4, guide pin 5, magnet 6, through groove 7, bottom ring 8, ring body 9, support plate 10, main sealing gasket 11, piston nut 12, support plate 13, first sealing groove 14, coil part 15, valve cover 16, moving iron core 17, main piston body 18, second piston 19, first connecting hole 20, second pilot hole 21, second sealing gasket 22, second sealing groove 23, first return spring 24, head 25, non-magnetic tube 26, connecting groove 27, sealing packing 28, first spring 29, limiting ring 30, second spring 31, retaining ring 32, housing 33, upper cover 34, cover plate 35, lower cover 36, sealing ring 37, limiting ring pressure ring 38.

[0030] Example

[0031] The embodiment is basically as follows Figure 1-Figure 6 As shown, Figure 1The pilot solenoid valve shown in the figure uses a limiting ring to increase the stroke of the main valve core, including a solenoid valve unit and a main valve unit, the main valve unit including a main valve body 1 provided with a main valve cavity, a main valve closing member slidably provided in the main valve cavity, an inlet and an outlet are also provided on the main valve cavity and are both connected to the main valve cavity, the outlet and the main valve cavity are connected at the main valve port, and a first pilot hole 2 connecting the main valve cavity and the outlet is opened on the main valve body 1; the solenoid valve unit can control the opening and closing of the first pilot hole 2, and also includes a feedback part and a limiting ring 3 sleeved on the main valve closing member, the main valve closing member can slide relative to the limiting ring 3, the feedback part includes a magnetic switch and a switch mounting seat 4 for mounting the magnetic switch, the main valve closing member includes a main piston body 18 and a guide pin 5 fixed to the main piston body 18, a slide groove is opened on the switch mounting seat 4, the switch mounting seat 4 passes through the bottom of the main valve body 1 and is fixed to the main valve body 1, the guide pin 5 is slidably connected to the slide groove, and a magnet 6 is fixed at the bottom of the guide pin 5, and the magnet 6 in this embodiment is a permanent magnet, such as Figure 5 and Figure 6 As shown, the flow limiting ring 3 is provided with a plurality of through grooves 7 connecting the inlet and the main valve cavity. The flow limiting ring 3 in this embodiment comprises a bottom ring 8 and a ring body 9 which are fixedly connected. The outer diameter of the bottom ring 8 is the same as the inner diameter of the main valve cavity. The ring body 9 is provided with three through grooves 7. The existing piston stop valve has a designed piston stroke of h, a valve nominal diameter of d, and a cylindrical surface formed by the stop valve port sealing line during the piston movement and opening process is s1 (flow channel in the valve) = Πdh, and the inlet and outlet flow channel area s2 = Π(d / 2) 2 =Id 2 / 4, in order to ensure s1 = s2, then Πdh = Id 2 / 4, h=d / 4; In the technical solution, a flow limiting ring is provided and a through groove 7 is provided on the flow limiting ring, the stroke of the main piston body 18 is designed to be H, the nominal diameter of the valve is d, and the sealing line is in the process of the main piston body 18 moving and opening, and the fluid medium only flows from the through groove 7 to the outlet, the number of the through grooves 7 is n, and the width of the through groove is D. At this time, the flow channel s1' in the valve is =nDH. In order to ensure s1'=s2, nDH=Πd 2 / 4, setting the number n of the through grooves 7 to 3 can improve the stability of the movement of the main piston body 18, H = Πd 2 / (12D), the sliding stroke of the main piston body 18 is ensured by providing the through slots 7 and ensuring the width D and number of the through slots 7. In this embodiment, the sum of the cross-sectional areas of the three through slots 7 is equal to the inlet and outlet flow channel area. Figure 5 As shown, the bottom ring 8 has two arc-shaped through holes near the right side, and the remaining bottom ring 8 between the two arc-shaped through holes is a support plate 10, as shown in FIG. Figure 4 and Figure 5As shown, it also includes a flow limiting ring pressure ring 38 installed in the main valve cavity. The flow limiting ring pressure ring 38 fixes the flow limiting ring 3 at the bottom of the main valve cavity. When the fluid enters, the flow limiting ring 3 needs to withstand a large water flow pressure and is easy to shift. Therefore, the flow limiting ring pressure ring 38 is provided to ensure the stability of the flow limiting ring 3; when the first pilot hole 2 is opened, the fluid in the inlet can enter the main valve cavity through the arc-shaped through hole and the through groove 7 and then communicate with the first pilot hole 2. By providing the arc-shaped through hole, it is possible to facilitate the flow of a larger flow of fluid; by providing a reserved part of the bottom ring 8 as a support plate 10, when the flow limiting ring 3 is installed, the support plate 10 can be against the valve wall of the main valve cavity to achieve a positioning effect. At the same time, the support plate 10 can support the position of the flow limiting ring 3 so that it does not move, thereby ensuring the position stability of the flow limiting ring 3 during fluid flow. As shown Figure 3 As shown, the main valve closing member includes a main seal 11 and a piston nut 12. The main seal 11 passes through the guide pin 5 and is embedded in the bottom of the main piston body 18. The piston nut 12 is threadedly connected to the bottom of the main piston body 18 and fixes the main seal 11 on the main piston body 18. The guide pin 5 is provided with a support plate 13 for supporting the main seal 11. When the main piston body 18 slides downward along the main valve cavity, the main seal 11 blocks the main valve port. The main piston body 18 also has a first sealing groove 14, in which a sealing ring portion is embedded. The piston nut 12 fixes the main seal 11 to ensure the position accuracy of the main seal 11 and to ensure that it will not fall off during long-term use. The threaded connection between the piston nut 12 and the bottom of the main piston body 18 can fix the main seal 11 on the main piston body 18, thereby enhancing the stability and reliability of the seal. A first annular groove is formed on the upper surface of the main piston body 18 , and a first return spring 24 is provided between the valve cover 16 and the main valve body 1 , and the bottom of the first return spring 24 is embedded and installed in the first annular groove.

[0032] like Figure 1 and Figure 2As shown, the solenoid valve unit includes a solenoid valve and a valve cover 16, the valve cover 16 is fixedly connected to the main valve body 1, the solenoid valve includes a moving iron core 17 that slides under the drive of electromagnetic force, a solenoid valve cavity is provided in the valve cover 16, a second piston 19 is slidably provided in the solenoid valve cavity, a first connecting hole 20 is provided at the center of the second piston 19, a second pilot hole 21 connecting the main valve cavity and the solenoid valve cavity is also provided on the second piston 19, and a second sealing gasket 22 capable of blocking the first connecting hole 20 is embedded at the bottom of the moving iron core 17. The first connecting hole 20 is opened by opening the moving iron core 17, and the second pilot hole 21 is connected to the first connecting hole 20 to form a pilot circuit, and the pressure is relieved to drive the second piston 19 to open upward and then open the first pilot hole 2 so that the inlet and outlet are connected to form a second-stage pilot circuit. A second sealing groove 23 is provided on the upper side wall of the second piston 19, and a sealing ring portion is also embedded in the second seal. The sealing ring portion includes a first sealing ring located on the inner side and a second sealing ring located on the outer side. The first sealing ring is made of silicone and the second sealing ring is made of polytetrafluoroethylene. The second sealing ring contacts the inner wall of the valve cavity. The first sealing ring is made of silicone, which is elastic. When the second sealing ring is worn after being used for a period of time, the first sealing ring can push the second sealing ring outward to continuously ensure the sealing of the piston. The second sealing ring is made of polytetrafluoroethylene, which has excellent corrosion resistance and sealing properties, and can prevent the erosion of the second sealing ring by the fluid. At the same time, it has good high lubricity, non-stickiness and weather resistance. The high lubricity and non-stickiness make the piston slide more smoothly in the main valve cavity, and the weather resistance extends the service life of the device.

[0033] The solenoid valve unit also includes a head 25 and a non-magnetic tube 26. The non-magnetic tube 26 is fixed to the bottom of the head 25 by bolts. The moving iron core 17 is located inside the non-magnetic tube 26 and can slide relative to the non-magnetic tube 26. A connecting groove 27 is provided on the valve cover 16. The bottom of the non-magnetic tube 26 is threadedly connected to the connecting groove 27. A sealing filler 28 is provided at the bottom of the connecting groove 27. A return portion is also provided, which includes a first spring 29, a stop ring 30 and a second spring 31. The stop ring 30 has an opening for the moving iron core 17 to slide. The cross section of the stop ring 30 is an inverted U shape. A snap ring 32 is provided at the end of the moving iron core 17. The two ends of the first spring 29 are respectively in contact with the non-magnetic tube 26 and the snap ring 32. The two ends of the second spring 31 are respectively in contact with the stop ring 30 and the second piston 19. The upper surface of the stop ring 30 is in contact with the non-magnetic tube 26. By setting a two-stage spring for return, when the moving iron core 17 returns, the two ends of the first spring 29 respectively abut against the non-magnetic tube 26 and the retaining ring 32 to provide a first-level return elastic force to assist the moving iron core 17 to return and close the first connecting hole 20, and the two ends of the second spring 31 respectively abut against the limiting ring 30 and the second piston 19 to provide elastic force to ensure that the second piston 19 returns to close the first pilot hole 2. The above two-stage rebound force can make the second piston 19 and the moving iron core 17 respond quickly to ensure the timely closure of the first pilot hole 2; the upper surface of the limiting ring 30 abuts against the non-magnetic tube 26. By setting the limiting ring 30, it can be limited when connecting the non-magnetic tube 26 and the valve cover 16, so as to avoid the spacing between the moving iron core 17 and the second piston 19 not meeting the requirements due to excessive installation of the non-magnetic tube 26. The sealing shell is arranged outside the coil group, and the sealing shell includes a shell 33, an upper cover 34, a cover plate 35 and a lower cover 36. The shell 33 is a circular tube, and the cover plate 35 is fixed inside the shell 33. The head 25 is fixedly connected to the cover plate 35 by bolts. The upper cover 34 and the lower cover 36 are respectively covered at both ends of the shell 33 and are threadedly connected to the shell 33, and a sealing ring 37 is provided at the connection between the upper cover 34 and the lower cover 36.

[0034] The specific implementation process is as follows:

[0035] When the first pilot hole 2 is opened, the medium in the upper chamber of the main piston body 18 flows to the outlet, and then the pressure in the upper chamber is relieved, and the pressure in the lower chamber is greater than the pressure in the upper chamber, so that the main piston body 18 moves upward and opens to allow the fluid to pass. The technical solution is provided with a flow limiting ring 3, and a plurality of through grooves 7 connecting the inlet and the main valve chamber are opened on the flow limiting ring 3. The solenoid valve unit opens the first pilot hole 2. When the fluid flows in from the inlet, the main piston body 18 is in a closed state at this time, and the fluid is connected with the main valve chamber from the through groove 7. The fluid enters the pilot hole from the main valve chamber, so that the main valve chamber above the main piston body 18 is relieved, driving the main piston body 18 to move upward. By adjusting the number and width of the through grooves 7, it can be ensured that the main piston body 18 reaches a sufficient height.

[0036] In order to meet the rear-end flow, the main piston body 18 needs to move upward to a suitable height to meet the flow requirements. Therefore, a magnetic switch is set to sense the magnet 6. In actual use, when the magnet 6 moves, it must move a certain distance range before the magnetic switch can accurately identify the distance moved by the main piston body 18 through the feedback of the magnet 6, thereby achieving the effective switching conditions of the magnetic switch and switching to an open-circuit signal. Through the above-mentioned setting, it is possible to intuitively judge from the system whether the main piston body 18 moves or not, and truly and effectively reflect the opening and closing status of the valve. Compared with the traditional method of setting a pressure sensing component or an opening at the bottom of the valve, the present technical solution is more stable and accurate, and avoids the situation where the pressure resistance of the device is weakened and the medium leaks due to the opening, causing safety hazards.

[0037] By ensuring the correct stroke of the main piston body 18 and the accurate identification of the magnetic switch, the possibility of misoperation and failure can be reduced, and the reliability and stability of the system can be improved. The above design scheme can effectively improve the performance of the solenoid valve, including flow control, pressure loss and system stability, thereby improving the overall performance of the product.

[0038] 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 pilot solenoid valve using a flow limiting ring to increase the stroke of the main valve core comprises a solenoid valve unit and a main valve unit, wherein the main valve unit comprises a main valve body provided with a main valve cavity, a main valve closing member is slidably provided in the main valve cavity, an inlet and an outlet are provided on the main valve cavity and are both connected to the main valve cavity, the solenoid valve unit can control the opening and closing of a first pilot hole, and a first pilot hole connecting the main valve cavity and the outlet is provided on the main valve body, and the characteristics are as follows: It also includes a feedback part and a flow limiting ring sleeved on the main valve closing member. The main valve closing member can slide relative to the flow limiting ring. The feedback part includes a magnetic switch arranged at the bottom of the main valve body. A magnet is fixed to the bottom of the main valve closing member. The main valve closing member includes a main piston body. The flow limiting ring is provided with a plurality of through grooves connecting the inlet and the main valve cavity.

2. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 1, characterized in that: The flow limiting ring includes a fixedly connected ring body and a bottom ring with the same inner diameter as the piston cavity. The ring body is provided with three through grooves evenly distributed circumferentially. The bottom ring has two arc-shaped through holes on the side close to the inlet. When the main piston body is opened, the fluid enters from the arc-shaped through holes and flows from the through grooves to the outlet. The bottom ring between the two arc-shaped through holes is a support plate.

3. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 2, characterized in that: The main valve closing member also includes a main sealing gasket, a piston nut and a guide pin fixedly connected to the main piston body. A slide groove is opened on the switch mounting seat, the switch mounting seat passes through the bottom of the main valve body and is fixed to the main valve body, the guide pin is slidably connected to the slide groove, the magnet is embedded in the guide pin bottom plate, the main sealing gasket passes through the guide pin and is embedded in the bottom of the main piston body, the piston nut is threadedly connected to the bottom of the main piston body and fixes the main sealing gasket to the main piston body, the guide pin is provided with a support plate for supporting the main sealing gasket, and there is also a first sealing groove on the main piston body, and a sealing ring portion is embedded in the first sealing groove.

4. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 3, characterized in that: The solenoid valve unit includes a solenoid valve and a valve cover. The valve cover is fixedly connected to the main valve body. The solenoid valve includes a sealing shell, a coil group and a moving iron core that slides under the drive of electromagnetic force. A solenoid valve cavity is arranged in the valve cover. A second piston is slidably arranged in the solenoid valve cavity. A first connecting hole is opened in the center of the second piston. A second pilot hole connecting the main valve cavity and the solenoid valve cavity is also opened on the second piston. A second sealing gasket that can block the first connecting hole is embedded in the bottom of the moving iron core.

5. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 4, characterized in that: The solenoid valve unit also includes a head and a non-magnetic tube. The non-magnetic tube is fixed at the bottom of the head. The moving iron core is located inside the non-magnetic tube and can slide relative to the non-magnetic tube. A connecting groove is opened on the valve cover. The bottom of the non-magnetic tube is threadedly connected to the connecting groove. A sealing filler is provided at the bottom of the connecting groove.

6. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 5, characterized in that: The solenoid valve unit is also provided with a return part, which includes a first spring, a limit ring and a second spring. The limit ring is provided with an opening for the moving iron core to slide. The cross-section of the limit ring is an inverted U-shape. A clamping ring is provided at the end of the moving iron core. The two ends of the first spring are respectively abutted against the non-magnetic tube and the clamping ring, and the two ends of the second spring are respectively abutted against the limit ring and the second piston, and the upper surface of the limit ring is abutted against the non-magnetic tube.

7. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 6, characterized in that: The sealing shell cover is arranged outside the coil group. The sealing shell includes a shell, an upper cover, a cover plate and a lower cover. The shell is in a circular tube shape. The cover plate is fixed inside the shell. The head is fixedly connected to the cover plate by bolts. The upper cover and the lower cover are respectively covered at both ends of the shell and are threadedly connected to the shell, and sealing rings are provided at the connection between the upper cover and the lower cover.

8. The pilot-operated solenoid valve using a flow limiting ring to increase the main valve core stroke according to claim 7, characterized in that: It also includes a flow-limiting ring pressure ring installed in the main valve cavity, and the flow-limiting ring pressure ring fixes the flow-limiting ring at the bottom of the main valve cavity.

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