Pilot valve assembly and electromagnetic valve

Abstract

The utility model relates to a pilot valve assembly and an electromagnetic valve. The pilot valve assembly comprises a pilot valve element, a pilot valve seat and a pilot spring. The pilot valve seat comprises an upper valve seat and a lower valve seat, an oil liquid cavity is formed in the upper valve seat, the lower valve seat is arranged on the oil liquid cavity, a first oil hole is formed in the lower valve seat, and the upper valve seat and the lower valve seat are assembled to form the pilot valve seat; the pilot valve element is provided with an adjusting column and a second oil hole, and the adjusting column can axially move along with the pilot valve element; a guide cavity is formed between the adjusting column and the oil liquid cavity and communicates with the oil liquid cavity and the second oil hole. The pilot valve assembly and the electromagnetic valve have the advantages that due to the split design of the upper valve seat and the lower valve seat, the key size is small, and parts are easy to machine; meanwhile, the sizes and the number of the first oil holes can be adjusted by replacing the lower valve seat provided with the first oil holes of different specifications, or the first oil holes can be further machined by taking down the lower valve seat; and the oil liquid cavity can be directly communicated, so that the machining is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of solenoid valves, in particular to a pilot valve assembly and a solenoid valve. Background Art

[0002] A shock absorber is an important part of an automobile suspension system. It is used to suppress the oscillation when the shock-absorbing spring rebounds after vibration and the impact from the road surface, and plays a role in attenuating the vibration of the vehicle frame and the vehicle body, so as to improve the ride comfort and handling stability of the automobile. The shock absorber includes a solenoid valve, and the solenoid valve is used to control the flow rate of the oil in the chamber of the shock absorber, so as to realize the adjustment of the damping of the shock absorber and achieve the shock absorption function of the automobile. In the existing solenoid valve, the pressure of the pilot valve chamber is controlled by adjusting the magnitude of the input current, and then the opening degree of the main spool is controlled, so as to realize the adjustment of the damping magnitude of the shock absorber.

[0003] In the prior art, reference can be made to the Chinese patent with the publication number CN220930047U, which provides a flow regulating mechanism and a solenoid valve for a shock absorber, including a pilot spool, a pilot spring and a pilot valve seat. The pilot spring is located between the pilot spool and the pilot valve seat; an oil chamber is provided on the pilot valve seat, and the oil chamber communicates with both sides of the pilot valve seat; an adjusting column cooperating with the oil chamber is provided on the pilot spool, and the adjusting column can axially move along with the pilot spool to change the cross-section of the oil flow in the oil chamber. However, the structure of its pilot valve seat is complex. On the one hand, both the first oil hole and the second oil hole are on the side, which is not easy to process. On the other hand, the internal chamber is complex and the processing difficulty is high, which increases the production cost. Summary of the Utility Model

[0004] An object of the present application is to provide a pilot valve assembly and a solenoid valve, which can reduce the processing difficulty.

[0005] The technical solution adopted by the present application is as follows: A pilot valve assembly includes a pilot spool, a pilot valve seat and a pilot spring. The pilot spring is located between the pilot spool and the pilot valve seat; the pilot valve seat includes an upper valve seat and a lower valve seat. An oil chamber is provided on the upper valve seat, the lower valve seat is arranged on the oil chamber, and a first oil hole is provided on the lower valve seat. The upper valve seat and the lower valve seat are assembled to form the pilot valve seat; an adjusting column and a second oil hole are provided on the pilot spool. The adjusting column can axially move along with the pilot spool to change the cross-section of the oil flow in the oil chamber; a guide chamber is provided between the adjusting column and the oil chamber, and the guide chamber communicates with the oil chamber and the second oil hole respectively; the first oil hole communicates with the oil chamber.

[0006] Compared with the prior art, the advantages of the present application lie in the split design of the upper valve seat and the lower valve seat. Compared with the integral structure, after splitting, there are fewer key dimensions to be controlled, the parts are easy to process, the cost is reduced. At the same time, the lower valve seat can be disassembled and replaced, so that when the first oil hole is blocked, only the lower valve seat needs to be replaced, reducing the maintenance cost. At the same time, by replacing the lower valve seat with different specifications of the first oil hole, the size and quantity of the first oil hole can be adjusted, or the first oil hole can be further processed by removing the lower valve seat. There are no side holes, and the oil fluid cavity can be directly penetrated, which is convenient for processing. When the oil fluid enters from the oil fluid cavity, it will first collide with the adjusting column. The blocked oil fluid diffuses outward and enters the guiding cavity, and the guiding cavity guides the oil fluid to move towards the pilot valve core, and then flows out from the second oil hole. There are fewer bends in the oil fluid flow process, making the oil fluid flow stable and smooth.

[0007] In some embodiments of the present application, there are at least two first oil holes.

[0008] Further, the first oil holes are evenly distributed around the center of the lower valve seat.

[0009] In some embodiments of the present application, the oil fluid cavity sequentially includes a round hole section and a tapered hole section from top to bottom. The bottom of the round hole section is arc-transitionally connected to the top of the tapered hole section, and the cross-sectional area of the tapered hole section gradually increases from top to bottom.

[0010] Further, the diameter of the round hole section is not greater than the top diameter of the tapered hole section.

[0011] Further, an installation section is provided below the tapered hole section, and the installation section is used for installing the lower valve seat.

[0012] Further, a limiting surface for limiting the installation of the lower valve seat is provided between the installation section and the tapered hole section.

[0013] Further, the projection of the first oil hole on the horizontal plane is arranged inside the projection of the bottom edge of the tapered hole section on the horizontal plane.

[0014] In some embodiments of the present application, the upper valve seat includes a first ring member, a second ring member and a third ring member. The inner diameter of the first ring member is greater than the outer diameter of the third ring member. The second ring member is arranged between the first ring member and the third ring member, and the lower part of the first ring member is connected to the upper part of the third ring member through the second ring member.

[0015] Further, the oil fluid cavity is arranged on the third ring member.

[0016] Further, the top surface of the third ring member is higher than the top surface of the second ring member.

[0017] Further, the top surface of the third ring member is lower than the top surface of the first ring member.

[0018] Further, the outer diameter surface of the first ring member and the top surface of the first ring member are transitioned through a chamfer.

[0019] Further, a first convex ring extending downward is provided on the bottom surface of the first ring member, and the top surface of the first convex ring is connected and flush with the bottom surface of the second ring member.

[0020] Further, a second convex ring extending upward is provided on the top surface of the first ring member, and the inner diameter of the second convex ring is the same as the inner diameter of the first ring member.

[0021] Further, a first annular groove recessed toward the center is provided on the outer diameter surface of the second convex ring.

[0022] Further, the lower side wall of the first annular groove is connected to the top surface of the first ring member.

[0023] Further, the upper side wall of the first annular groove is an inclined surface; the bottom surface of the first annular groove is an arc surface.

[0024] In some embodiments of the present application, the pilot spool valve includes an upper spool valve and a lower spool valve. The lower spool valve has at least two groove platforms, and a first oil passage is formed between adjacent groove platforms.

[0025] Further, the upper spool valve includes a fourth ring member and a fifth ring member from bottom to top, and the top of the fourth ring member is connected to the bottom of the fifth ring member.

[0026] Further, the outer diameter of the fourth ring member is greater than the outer diameter of the fifth ring member.

[0027] Further, the inner diameter of the fourth ring member is the same as the inner diameter of the fifth ring member.

[0028] Further, the lower spool valve includes a support seat. A groove is provided on the bottom surface of the support seat, and the upper end of the adjustment column is connected to the bottom surface of the groove.

[0029] Further, the second oil hole is provided on the support seat.

[0030] Further, the second oil hole is.

[0031] Further, the adjustment column is provided at the center of the support seat.

[0032] Further, a buffer groove recessed inward is provided on the bottom surface of the adjustment column.

[0033] Further, the buffer groove is coaxial with the oil chamber.

[0034] Further, the buffer groove and the bottom surface of the adjustment column are transitioned through a chamfer.

[0035] Further, the second oil holes are evenly distributed around the center of the support seat.

[0036] Further, the projection of the second oil hole on the horizontal plane partially coincides with the projection of the fourth ring member on the horizontal plane.

[0037] Further, the area of the overlapping part of the projections of the second oil hole and the fourth ring member on the horizontal plane is greater than half of the projection area of the second oil hole on the horizontal plane.

[0038] Further, the side wall of the groove is stepped, and the diameter of the lower end of the groove is greater than the diameter of the upper end of the groove.

[0039] Further, a chamfer is provided for transition between the groove and the bottom surface of the support seat.

[0040] Further, an inclined surface is provided for transition between adjacent steps on the side wall of the groove.

[0041] Further, a second annular groove is provided on the bottom surface of the groove, and the outer side wall of the second annular groove is connected to the side wall of the groove.

[0042] Further, the inner side wall of the second annular groove is an inclined surface.

[0043] Further, the bottom surface of the second annular groove is an arc surface.

[0044] Further, the groove platform is connected to the lower valve core.

[0045] Further, the groove platform is in the shape of a wedge with a higher outer side and a lower inner side.

[0046] Further, the projection of the upper valve core on the horizontal plane completely covers the projection of the groove platform on the horizontal plane.

[0047] A solenoid valve obtained by the present utility model includes the above-mentioned pilot valve assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a schematic structural diagram of Embodiment 1 of the present utility model;

[0049] Figure 2 is a cross-sectional view of the pilot valve seat of Embodiment 1 of the present utility model;

[0050] Figure 3 is a schematic structural diagram of the pilot valve seat of Embodiment 1 of the present utility model Figure 1 ;

[0051] Figure 4 is a schematic structural diagram of the pilot valve seat of Embodiment 1 of the present utility model Figure 2 ;

[0052] Figure 5 is a schematic structural diagram of the pilot valve core of Embodiment 1 of the present utility model;

[0053] Figure 6 It is a cross-sectional view of the pilot valve core of Embodiment 1 of the present utility model;

[0054] Figure 7 It is a schematic structural diagram of the lower valve core of Embodiment 1 of the present utility model.

[0055] In the figure: 1. Pilot valve core; 11. Upper valve core; 111. Fourth ring member; 112. Fifth ring member; 12. Lower valve core; 121. Grooved platform; 122. First oil passage; 123. Support seat; 124. Adjusting column; 125. Groove; 1251. Second annular groove; 126. Second oil hole; 127. Buffer groove; 2. Pilot valve seat; 21. Upper valve seat; 211. First ring member; 2111. First convex ring; 2112. Second convex ring; 2113. First annular groove; 212. Second ring member; 213. Third ring member; 22. Lower valve seat; 221. First oil hole; 23. Oil chamber; 231. Circular hole section; 232. Tapered hole section; 233. Installation section; 234. Limiting surface; 24. Guide cavity; 3. Electric drive assembly; 31. Push rod; 4. Pilot spring. Detailed implementation manners

[0056] To further elaborate on the technical means and effects adopted by the present utility model to achieve the predetermined utility model purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and their effects of the present utility model as follows.

[0057] Embodiment 1:

[0058] A pilot valve assembly provided in this embodiment, as shown in Figure 1 , Figure 2 , includes a pilot valve core 1, a pilot valve seat 2 and a pilot spring 4. The pilot spring 4 is located between the pilot valve core 1 and the pilot valve seat 2. Specifically, the upper end of the pilot spring 4 abuts against the pilot valve core 1, and the lower end of the pilot spring 4 abuts against the pilot valve seat 2. When the pilot valve core 1 is subjected to the acting force of the push rod 31 on the electric drive assembly 3, the pilot valve core 1 moves downward to compress the pilot spring 4, so that the pilot spring 4 generates a reaction force. When the acting force applied by the push rod 31 to the pilot valve core 1 disappears, under the action of the pilot spring 4, the pilot valve core 1 moves upward to reset, so that the pilot valve core 1 can move up and down axially relative to the pilot valve seat 2. And the pilot spring 4 has the functions of vibration absorption and buffering, which can make the push rod 31 move smoothly when pushing the pilot valve core 1 downward.

[0059] The pilot valve seat 2 includes an upper valve seat 21 and a lower valve seat 22. An oil chamber 23 is provided on the upper valve seat 21. The lower valve seat 22 is disposed on the oil chamber 23. A first oil hole 221 is provided on the lower valve seat 22. The upper valve seat 21 and the lower valve seat 22 are detachably connected. The split design of the upper valve seat 21 and the lower valve seat 22, compared with the integral structure, has fewer key dimensions to be controlled after splitting, the parts are easy to machine, and the cost is reduced. At the same time, the lower valve seat 22 can be disassembled and replaced. When the first oil hole 221 is blocked, only the lower valve seat 22 needs to be replaced, reducing the maintenance cost. At the same time, by replacing the lower valve seat 22 provided with different specifications of the first oil hole 221, the size and quantity of the first oil hole 221 can be adjusted, or the first oil hole 221 can be further processed by removing the lower valve seat 22.

[0060] An adjustment column 124 and a second oil hole 126 are provided on the pilot valve core 1. The adjustment column 124 can axially move along with the pilot valve core 1 to change the flow rate of the oil chamber 23. A guide chamber 24 is provided between the adjustment column 124 and the oil chamber 23. The guide chamber 24 is respectively communicated with the oil chamber 23 and the second oil hole 126. The first oil hole 221 is communicated with the oil chamber 23. The adjustment column 124 is directly above the oil chamber 23. The adjustment column 124 is coaxial with the oil chamber 23. When the oil enters from the oil chamber 23, it will first collide with the adjustment column 124. The blocked oil diffuses outward and enters the guide chamber 24. The guide chamber 24 guides the oil to move towards the pilot valve core 1 and then flows out from the second oil hole 126. There are few bends in the oil flow process, making the oil flow stable and smooth.

[0061] For reliable oil inlet, as Figure 4 shown, the first oil hole 221 is; the first oil holes 221 are evenly distributed around the center of the lower valve seat 22. In this embodiment, there are three first oil holes 221.

[0062] For reliable oil inlet, the oil chamber 23 sequentially includes a round hole section 231 and a tapered hole section 232 from top to bottom. The bottom of the round hole section 231 is arc-transitionally connected to the top of the tapered hole section 232. The cross-sectional area of the tapered hole section 232 gradually increases from top to bottom. The diameter of the round hole section 231 is not greater than the top diameter of the tapered hole section 232. The tapered hole section 232 can facilitate the concentration of oil, and the gradually decreasing hole diameter can increase the oil flow rate.

[0063] For reliable installation of the lower valve seat 22, an installation section 233 is provided below the tapered hole section 232. The installation section 233 is used for the installation of the lower valve seat 22. A limiting surface 234 for blocking the lower valve seat 22 is provided between the installation section 233 and the tapered hole section 232. The lower valve seat 22 cooperates with the installation section 233. In this embodiment, the lower valve seat 22 is cylindrical, and the installation section 233 is in the shape of a round hole; the bottom surface of the lower valve seat 22 is flush with the bottom surface of the third ring member 213, reducing the step, and the oil flow is more stable.

[0064] To ensure reliable oil inlet, the projection of the first oil hole 221 on the horizontal plane is arranged inside the projection of the bottom edge of the conical hole section 232 on the horizontal plane. The outermost part of the oil flowing into the first oil hole 221 can flow upward along the conical hole section 232 without impacting the installation section 233, ensuring the stability of oil flow.

[0065] To ensure the reliable structure of the upper valve seat 21, as Figure 3 shown, the upper valve seat 21 includes a first ring member 211, a second ring member 212, and a third ring member 213. The inner diameter of the first ring member 211 is larger than the outer diameter of the third ring member 213. The second ring member 212 is arranged between the first ring member 211 and the third ring member 213. The lower part of the first ring member 211 is connected to the upper part of the third ring member 213 through the second ring member 212; the oil chamber 23 is arranged on the third ring member 213. Specifically, the inner diameter surface of the first ring member 211 is connected to the outer diameter surface of the second ring member 212, and the inner diameter surface of the second ring member 212 is connected to the outer diameter surface of the third ring member 213; the inner diameter of the first ring member 211 is larger than the diameter of the adjusting column 124. The first ring member 211 is used for the installation of the upper valve seat 21 and the outside; the guiding chamber 24 is formed by connecting the first ring member 211 and the third ring member 213 through the second ring member 212.

[0066] To ensure the reliable structure of the upper valve seat 21, the top surface of the third ring member 213 is higher than the top surface of the second ring member 212, which can make the connection strength between the two higher; the top surface of the third ring member 213 is lower than the top surface of the first ring member 211. The oil flowing out of the oil chamber 23 will be blocked by the adjusting column 124, so that the oil flows outward. And the top surface of the first ring member 211 is high, which can make the oil flow outward and then flow upward along the inner diameter surface of the first ring member 211, ensuring the guiding of oil flow; the outer diameter surface of the first ring member 211 and the top surface of the first ring member 211 are transitioned by a chamfer, and the chamfer transition can facilitate the installation of the first ring member 211 and the outside.

[0067] To improve the strength, a first convex ring 2111 extending downward is provided on the bottom surface of the first ring member 211. The top surface of the first convex ring 2111 is connected to and flush with the bottom surface of the second ring member 212. The design of the first convex ring 2111 enhances the connection strength between the first ring member 211 and the second ring member 212; the top surface of the first convex ring 2111 and the bottom surface of the second ring member 212 can reduce the step surface and reduce the resistance of oil flow.

[0068] To improve the directivity, a second convex ring 2112 extending upward is provided on the top surface of the first ring member 211. The inner diameter of the second convex ring 2112 is the same as that of the first ring member 211. A first annular groove 2113 recessed toward the center is provided on the outer diameter surface of the second convex ring 2112. The lower side wall of the first annular groove 2113 is connected to the top surface of the first ring member 211. The upper side wall of the first annular groove 2113 is an inclined surface. The bottom surface of the first annular groove 2113 is an arc surface. The outer diameter of the first convex ring 2111 is greater than that of the second convex ring 2112. The design of the second convex ring 2112 extends the guiding distance of the oil fluid. After the oil fluid flows along the inner diameter surface of the first ring member 211, it will then flow along the inner diameter surface of the second convex ring 2112, ensuring the stable flow of the oil fluid. The same inner diameter of the second convex ring 2112 and the first ring member 211 can reduce the stepped surface and improve the stability of the oil fluid flow. The design of the first annular groove 2113 facilitates the installation of the pilot spring 4. The top surface of the second convex ring 2112 is higher than the bottom surface of the adjusting column 124.

[0069] To make the oil fluid flow more stably, the oil inlet and outlet directions on the upper and lower sides of the pilot valve seat 2 are axial. That is, the oil inlet direction on the lower valve seat 22 is axial, the through direction of the first oil hole 221 is axial, the oil outlet direction on the upper valve seat 21 is axial, and no holes are provided in the circumferential direction of the first ring member 211. The oil fluid flows out axially along the inner wall surface of the first ring member 211. No oil holes need to be provided in the circumferential direction of the pilot valve seat 2, making the processing of the pilot valve seat 2 simpler. For a pilot valve seat with circumferential holes, the oil fluid needs to turn upward first after entering and also needs to turn from axial to radial when discharging oil. The oil path has many bends and large resistance, resulting in unstable oil fluid flow. After adopting axial oil inlet and outlet, the oil fluid can directly contact the pilot valve core 1 without turning after entering. After flowing through the pilot valve core 1, it can directly flow out axially. The oil path has fewer bends and the oil fluid flows more stably.

[0070] To make the pilot valve core 1 reliable, as Figure 5 shown, the pilot valve core 1 includes an upper valve core 11 and a lower valve core 12. At least two groove platforms 121 are provided between the upper valve core 11 and the lower valve core 12. A first oil path channel 122 is formed between adjacent groove platforms 121. In this embodiment, eight groove platforms 121 are provided. The first oil path channel 122 can communicate the inner side and the outer side of the pilot valve core 1. Here, the inner side and the outer side of the pilot valve core 1 are relative to the groove platforms 121. The upper valve core 11 is used to connect with the electric drive assembly 3, which increases the distance between the lower valve core 12 and the electric drive assembly 3, thereby adjusting the height of the lower valve core 12. The distance between the lower valve core 12 and the pilot valve seat 2 is reduced, causing the pilot spring 4 between the lower valve core 12 and the pilot valve seat 2 to be compressed, realizing the adjustment of the pre-tightening force of the pilot spring 4. The design of the first oil path channel 122 enables the oil fluid to flow through the first oil path channel 122 when the lower valve core 12 is not affected by the acting force of the ejector rod 31 on the electric drive assembly 3, improving the stability.

[0071] To ensure the reliable structure of the upper spool 11, as Figure 6 shown, the upper spool 11 includes a fourth ring member 111 and a fifth ring member 112 from bottom to top. The top of the fourth ring member 111 is connected to the bottom of the fifth ring member 112. The outer diameter of the fourth ring member 111 is greater than that of the fifth ring member 112. The inner diameters of the fourth ring member 111 and the fifth ring member 112 are the same. The fourth ring member 111 is used to increase the distance between the lower spool 12 and the electric drive assembly 3 and can also be used for limiting, so that the fifth ring member 112 can be pressed in place. The fifth ring member 112 is used for fitting and installing with the electric drive assembly 3.

[0072] To ensure the reliable structure of the lower spool 12, as Figure 7 shown, the lower spool 12 includes a support seat 123. A groove 125 is provided on the bottom surface of the support seat 123. The upper end of the adjusting column 124 is connected to the bottom surface of the groove 125. The second oil hole 126 is provided on the support seat 123. There are at least two second oil holes 126. The support seat 123 is integrally cylindrical. The adjusting column 124 is integrally cylindrical. The adjusting column 124 and the support seat 123 are coaxially arranged. In this embodiment, six second oil holes 126 are provided. The groove 125 can play a guiding role for the oil fluid, facilitating the guiding of the oil fluid to the second oil hole 126.

[0073] To buffer the impact of the oil fluid, the adjusting column 124 is arranged at the center of the support seat 123. An inwardly concave buffer groove 127 is provided on the bottom surface of the adjusting column 124. The buffer groove 127 is coaxial with the oil fluid chamber 23. A chamfer is provided between the buffer groove 127 and the bottom surface of the adjusting column 124. The design of the buffer groove 127 enables the oil fluid coming from the oil fluid chamber 23 to first enter the buffer groove 127, playing a role in buffering the impact of the oil fluid.

[0074] To ensure balanced oil discharge, the second oil holes 126 are evenly distributed around the center of the support seat 123. The projection of the second oil holes 126 on the horizontal plane partially coincides with the projection of the fourth ring member 111 on the horizontal plane. The even distribution of the second oil holes 126 can make the oil discharge balanced and stable. The partial coincidence of the second oil holes 126 and the fourth ring member 111 enables some of the oil fluid flowing out of the second oil holes 126 to collide with the bottom surface of the fourth ring member 111, and the remaining oil fluid will directly pass through the fourth ring member 111, preventing excessive impact force and making the oil fluid flow more stable.

[0075] To ensure stable oil discharge, the area of the overlapping part of the projections of the second oil holes 126 and the fourth ring member 111 on the horizontal plane is greater than half of the projection area of the second oil holes 126 on the horizontal plane. The large overlapping area of the projections of the second oil holes 126 and the fourth ring member 111 enables most of the oil fluid flowing out of the second oil holes 126 to directly collide with the bottom surface of the fourth ring member 111 and then flow outwards, and only a small part will pass through the fourth ring member 111, ensuring the stable flow of the oil fluid.

[0076] To ensure the reliability of the groove 125, the side wall of the groove 125 is stepped, and the diameter of the lower end of the groove 125 is larger than that of the upper end of the groove 125; a chamfer is provided for transition between the bottom surface of the groove 125 and the support seat 123; an inclined surface is provided for transition between adjacent steps on the side wall of the groove 125. The stepped side wall of the groove 125 with a larger lower part and a smaller upper part facilitates the flow of the oil towards the second oil hole 126 and also facilitates the placement of the pilot spring 4.

[0077] To ensure the stable flow of the oil, a second annular groove 1251 is provided on the bottom surface of the groove 125, and the outer side wall of the second annular groove 1251 is connected to the side wall of the groove 125; the inner side wall of the second annular groove 1251 is an inclined surface; the bottom surface of the second annular groove 1251 is an arc surface. The design of the second annular groove 1251 can play a buffering role. Compared with the impact on a vertical surface, the oil on the bottom surface of the groove 125 flows along the second annular groove 1251 to the side wall of the groove 125 with less impact, improving the stability of the oil flow and ensuring the overall stability of the valve core.

[0078] To ensure the reliable structure of the groove platform 121, the groove platform 121 is connected to the lower valve core 12; the groove platform 121 is in a wedge shape with a higher outer side and a lower inner side; the projection of the upper valve core 11 on the horizontal plane completely covers the projection of the groove platform 121 on the horizontal plane. In this embodiment, the outer surface of the groove platform 121 and the outer surface of the lower valve core 12 are on the same arc surface. The wedge-shaped structure has less resistance to the oil flow, ensuring the stable flow of the oil.

[0079] Embodiment 2:

[0080] A solenoid valve provided in this embodiment includes a pilot valve assembly as described in Embodiment 1.

[0081] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes, but as long as the technical content of the present invention is not departed from, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A pilot valve assembly, characterized in that, It includes a pilot valve spool (1), a pilot valve seat (2) and a pilot spring (4), and the pilot spring (4) is located between the pilot valve spool (1) and the pilot valve seat (2); the pilot valve seat (2) includes an upper valve seat (21) and a lower valve seat (22), an oil chamber (23) is provided on the upper valve seat (21), the lower valve seat (22) is arranged on the oil chamber (23), a first oil hole (221) is provided on the lower valve seat (22), and the upper valve seat (21) and the lower valve seat (22) are assembled to form the pilot valve seat; an adjusting column (124) and a second oil hole (126) are provided on the pilot valve spool (1), and the adjusting column (124) can axially move along with the pilot valve spool (1) to change the cross-section of the oil flow in the oil chamber (23); a guide chamber (24) is provided between the adjusting column (124) and the oil chamber (23), and the guide chamber (24) is respectively communicated with the oil chamber (23) and the second oil hole (126); the first oil hole (221) is communicated with the oil chamber (23).

2. The pilot valve assembly according to claim 1, wherein: There are at least two of the first oil holes (221); the first oil holes (221) are evenly distributed around the center of the lower valve seat (22); the oil chamber (23) includes a round hole section (231) and a tapered hole section (232), and the bottom of the round hole section (231) is connected with the top of the tapered hole section (232) by an arc transition connection, and the cross-sectional area of the tapered hole section (232) gradually increases from top to bottom; the diameter of the round hole section (231) is not greater than the top diameter of the tapered hole section (232).

3. The pilot valve assembly according to claim 2, characterized in that: An installation section (233) is provided below the tapered hole section (232), and the installation section (233) is used for the installation of the lower valve seat (22); a limiting surface (234) for limiting the installation of the lower valve seat (22) is provided between the installation section (233) and the tapered hole section (232).

4. A pilot valve assembly according to claim 1, characterized in that: The upper valve seat (21) includes a first ring part (211), a second ring part (212) and a third ring part (213), the inner diameter of the first ring part (211) is greater than the outer diameter of the third ring part (213), the second ring part (212) is arranged between the first ring part (211) and the third ring part (213), and the lower part of the first ring part (211) is connected with the upper part of the third ring part (213) through the second ring part (212); the oil chamber (23) is provided on the third ring part (213).

5. The pilot valve assembly according to claim 1, characterized in that: The pilot valve spool (1) includes an upper valve spool (11) and a lower valve spool (12), and the lower valve spool (12) has at least two groove platforms (121), and a first oil passage (122) is formed between adjacent groove platforms (121).

6. The pilot valve assembly according to claim 5, characterized in that: The upper valve spool (11) includes a fourth ring part (111) and a fifth ring part (112) from bottom to top, and the top of the fourth ring part (111) is connected with the bottom of the fifth ring part (112); the outer diameter of the fourth ring part (111) is greater than the outer diameter of the fifth ring part (112); the inner diameters of the fourth ring part (111) and the fifth ring part (112) are the same.

7. The pilot valve assembly according to claim 6, characterized in that: The lower spool (12) includes a support seat (123). A groove (125) is provided on the bottom surface of the support seat (123). The upper end of the adjusting column (124) is connected to the bottom surface of the groove (125). The second oil hole (126) is provided on the support seat (123). There are at least two second oil holes (126).

8. A pilot valve assembly according to claim 7, characterized in that: The adjusting column (124) is arranged at the center of the support seat (123). A buffer groove (127) recessed inward is provided on the bottom surface of the adjusting column (124). The buffer groove (127) is coaxial with the oil chamber (23). A chamfer is provided between the buffer groove (127) and the bottom surface of the adjusting column (124).

9. The pilot valve assembly according to claim 5, characterized in that: The groove platform (121) is connected to the lower spool (12). The groove platform (121) is in a wedge shape with a higher outer side and a lower inner side. The projection of the upper spool (11) on the horizontal plane completely covers the projection of the groove platform (121) on the horizontal plane.

10. A solenoid valve, characterized in that, It includes a pilot valve assembly according to any one of claims 1-9.

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