A hydraulic pressure regulating pilot valve
Patent Information
- Application Number
- CN202521905140.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-09-04
AI Technical Summary
目前市面上的汽车悬架用先导阀主要分为内置式与外置式两类：内置式先导阀因集成于主阀体内，虽结构紧凑，但存在维护不便、改装灵活性差的问题，且难以适配大流量、大压力的调节场景；外置式先导阀则凭借 “安装位置灵活、便于单独检修、适配大流量压力工况” 的优势，在中重型车辆、高端乘用车的自适应悬架系统中应用更为广泛
1、采用“主阀芯滑动装配于主阀套、前阀芯滑动装配于主阀芯、主弹簧座滑动装配于前阀芯” 的多层嵌套结构，通过多级滑动适配将阀芯组件的同轴度误差控制在0.01mm以内，避免阀芯运动时因径向偏移产生卡滞，且装配简单，降低了加工难度，便于量产，降低成本。
Smart Images
Figure CN224835618U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pilot valve technology, specifically a pilot valve for hydraulic regulation. Background Technology
[0002] In automotive chassis systems, the suspension system is a core component ensuring driving safety, handling stability, and ride comfort. By buffering road impacts and suppressing body posture fluctuations (such as steering roll and braking dive), it directly affects the vehicle's dynamic performance and driving experience. As the automotive industry upgrades towards intelligence and high-end features, the adoption rate of advanced suspension systems such as adaptive suspension and air suspension continues to increase. These systems have increasingly stringent requirements for "precise, fast, and stable" damping adjustment. As a key hydraulic actuator for suspension damping control, the pilot valve's performance directly determines the adjustment accuracy and response efficiency of the suspension system. The pilot valve indirectly regulates the opening of the main valve by controlling the flow and pressure of hydraulic oil, thereby achieving dynamic adjustment of suspension damping. Currently, pilot valves for automotive suspensions on the market are mainly divided into two types: built-in and external. Built-in pilot valves, because they are integrated into the main valve body, have a compact structure, but they suffer from inconvenient maintenance, poor flexibility in modification, and difficulty in adapting to high flow and high pressure adjustment scenarios. External pilot valves, on the other hand, have the advantages of "flexible installation location, easy individual maintenance, and adaptability to high flow and pressure conditions," and are more widely used in adaptive suspension systems of medium and heavy-duty vehicles and high-end passenger cars. However, existing external pilot valves generally suffer from unstable product performance and poor consistency in practical applications, which has become a key bottleneck restricting their large-scale promotion and the improvement of suspension system performance. Specifically, the problems are as follows: First, insufficient valve core fit and movement precision lead to fluctuations in pressure and flow regulation. The valve core components of existing external pilot valves (such as the main valve core and the pilot valve core) mostly adopt a simple fit structure of "single valve core + fixed valve sleeve", lacking precise guidance and limit design. The sliding fit clearance between the valve core and the valve sleeve is difficult to control precisely. When hydraulic oil flows through under high pressure (usually 10-30MPa) and high flow (10-50L / min) conditions, it is easy to "stick" or "stir", causing the valve core movement trajectory to deviate, which in turn causes pressure regulation deviation (fluctuation range can reach ±1.5MPa or more), directly affecting the stability of suspension damping. This manifests as sudden changes in vehicle body posture during driving (such as increased bumps when going over speed bumps), and even the risk of handling lag. Secondly, the unreasonable design of the throttling channel leads to performance fluctuations caused by flow field disturbances. The damping control accuracy of the pilot valve depends on the flow characteristics of the throttling channel. The existing external pilot valves use a "single orifice + straight channel" design for the throttling channel, which does not optimize the flow field for the turbulent characteristics of hydraulic oil. When high-pressure oil flows through the channel, vortices and cavitation are easily generated, resulting in uneven flow output. This causes the suspension damping force to fluctuate, affecting ride comfort. Furthermore, the lack of a smooth transition structure at the connection between the throttling channel and the valve core and valve sleeve can easily lead to local pressure loss, which not only reduces the adjustment efficiency but may also cause the valve core to wear more rapidly due to pressure shock, further deteriorating performance stability. Utility Model Content
[0003] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a pilot valve for hydraulic regulation to solve the shortcomings of the prior art.
[0004] The purpose of this utility model is achieved through the following technical solution: A pilot valve for hydraulic regulation includes a main valve sleeve assembly, an electromagnet assembly, and a coil assembly assembled sequentially. The electromagnet assembly includes a housing and a drive shaft, with the drive shaft slidably mounted inside the housing. The main valve sleeve assembly includes an end cap, a main valve sleeve, a main valve core, a front valve core, a main spring seat, and a pilot valve core. The main valve sleeve is fixedly installed inside the housing. The end cap is interference-fitted to the end of the main valve sleeve away from the housing. The main valve core is slidably mounted inside the main valve sleeve. The front valve core is slidably mounted inside the main valve core. The main spring seat is slidably mounted inside the main valve sleeve. The main spring seat is installed inside the front valve core. One end of the main spring seat moves through the threaded end cover of the front valve core. A main elastic element is assembled between the main spring seat and the front valve core. The pilot valve core is slidably assembled between the main valve core and the drive shaft. The pilot valve core is located on the moving path of the drive shaft. A pilot elastic element is assembled between the pilot valve core and the main valve core. A first throttling channel is formed between the front valve core and the end cover. A second throttling channel is formed between the main valve core and the end cover. A pilot first throttling channel is formed between the main valve core and the pilot valve core. A pilot second throttling channel is formed between the pilot valve core and the main valve sleeve.
[0005] Furthermore, the end cap has a threaded hole at its center, several small holes around the threaded hole, and multiple notches connected to the first throttling channel.
[0006] Furthermore, the front valve core has a front valve core cavity at the end away from the end cover, and a central hole for the main spring seat to pass through at the end of the front valve core near the end cover. Multiple small holes are formed around the central hole on the front valve core.
[0007] Furthermore, the main spring seat includes a disc and a threaded shaft, the disc and the threaded shaft are connected in a T-shape, the disc is fitted into the front valve core cavity with a gap, the threaded shaft passes through the central hole and is threaded to the threaded hole, the main elastic element is the main spring, the main spring is located in the front valve core cavity, and the main spring is sleeved on the threaded shaft, and the threaded shaft has an adjustment notch at one end near the end cover.
[0008] Furthermore, the main valve core has a main valve core cavity at one end near the end cover, the front valve core is slidably assembled in the main valve core cavity, the main valve core has a main valve core center hole at one end away from the end cover, and the main valve core has multiple main valve core small holes around the main valve core center hole, the two ends of the main valve core small holes are respectively connected to the main valve core cavity and the main valve core center hole.
[0009] Furthermore, a pilot valve core central hole is formed through the middle of the pilot valve core, and the end of the pilot valve core is slidably adapted to the main valve core cavity. A step is formed on the pilot valve core, and the pilot directional element is a pilot spring. The pilot spring is sleeved on the pilot valve core, and one end of the pilot spring abuts against the step of the pilot valve core. A plurality of pilot valve core small holes are formed on the step of the pilot valve core around the pilot valve core central hole.
[0010] Furthermore, the main valve sleeve is hollow, and the sidewall of the main valve sleeve has several side flow holes along its circumference.
[0011] Furthermore, the electromagnet assembly also includes an iron core, a limiting seat, and a guide seat. The limiting seat and the guide seat are both fixedly assembled inside the housing. Under the action of the pilot limiting member, the pilot valve core abuts against the end of the limiting seat. The iron core is located between the limiting seat and the guide seat. The iron core is fixedly mounted on the drive shaft. The limiting seat and the guide seat are respectively equipped with a limiting seat bearing and a guide seat bearing. The drive shaft moves through the limiting seat bearing and the guide seat bearing.
[0012] Furthermore, a gasket is provided between the end cap and the main valve sleeve, a housing sealing ring is fitted at the end of the housing near the main valve sleeve assembly, and a coil sealing ring is fitted at the end of the housing near the coil assembly.
[0013] The beneficial effects of this utility model are: 1. It adopts a multi-layer nested structure in which the main valve core is slidably assembled into the main valve sleeve, the front valve core is slidably assembled into the main valve core, and the main spring seat is slidably assembled into the front valve core. Through multi-stage sliding adaptation, the coaxiality error of the valve core assembly is controlled within 0.01mm, avoiding jamming caused by radial offset when the valve core moves. It is also simple to assemble, reduces the processing difficulty, facilitates mass production, and reduces costs.
[0014] 2. The design incorporates a four-stage throttling structure consisting of a first throttling channel, a second throttling channel, a pilot first throttling channel, and a pilot second throttling channel. Combined with a multi-dimensional flow guiding design including end cap notches, front valve core orifices, main valve core orifices, and pilot valve core orifices, this gradually transforms the turbulent flow of high-pressure hydraulic fluid into laminar flow. This avoids the vortices and cavitation generated by the existing "single orifice + straight channel" design, reduces instantaneous flow fluctuations, ensures uniform suspension damping force output, and solves the comfort problem of "fluctuating damping force." The staged throttling also disperses hydraulic oil pressure shocks, improves damping adjustment efficiency, and reduces pressure shock wear on the valve core, further extending component lifespan. Attached Figure Description
[0015] Figure 1 This is a partial sectional view of a pilot valve for hydraulic regulation according to the present invention; Figure 2This is a schematic diagram of the internal structure of a pilot valve for hydraulic regulation according to this utility model; Figure 3 This is a schematic diagram of the main valve sleeve assembly in a pilot valve for hydraulic regulation according to this utility model; Figure 4 This is a schematic diagram of the structure of the middle end cover of a hydraulic regulating pilot valve according to this utility model; Figure 5 This is a schematic diagram of the front valve core of a pilot valve for hydraulic regulation according to this utility model; Figure 6 This is a schematic diagram of the main spring seat in a pilot valve for hydraulic regulation according to this utility model; Figure 7 This is a schematic diagram of the main valve core in a pilot valve for hydraulic regulation according to this utility model; Figure 8 This is a schematic diagram of the pilot valve core in a hydraulic regulating pilot valve according to the present invention; Figure 9 This is a schematic diagram of the main valve sleeve in a pilot valve for hydraulic regulation according to this utility model; Figure 10 This is a flow channel diagram of a pilot valve for hydraulic regulation according to this utility model; Figure 11 This is a diagram illustrating the minimum flow channel opening of a pilot valve for hydraulic regulation according to this utility model. Figure 12 This is a diagram showing the maximum opening of the flow channel of a pilot valve for hydraulic regulation according to this utility model. Figure 13 This is a structural schematic diagram of Embodiment 4 of the present invention; Figure 14 This is a structural schematic diagram of Embodiment 5 of the present utility model; In the diagram, 1-end cap, 2-gasket, 3-main valve sleeve, 4-front valve core, 5-main valve core, 6-pilot valve, 7-pilot valve core, 8-main spring seat, 9-main spring, 10-electromagnet assembly, 11-outer shell sealing ring, 12-coil sealing ring, 13-coil assembly, 14-limit seat, 15-limit seat shaft, 16-drive shaft, 17-iron core, 18-guide seat, 19-guide seat bearing, 20-outer shell, 22-adjustment 23-First throttling channel, 24-Second throttling channel, 25-Pilot first throttling channel, 26-Pilot second throttling channel, 27-Threaded hole, 28-Small hole, 29-Notch, 30-Front valve core cavity, 31-Center hole, 32-Front valve core small hole, 33-Main valve core cavity, 34-Main valve core center hole, 35-Main valve core small hole, 36-Pilot valve core center hole, 37-Pilot valve core small hole, 38-Side flow hole. Detailed Implementation
[0016] The technical solution of this utility model is described in further detail below with reference to the accompanying drawings, but the scope of protection of this utility model is not limited to the following description.
[0017] Example 1 like Figures 1 to 12 As shown, a pilot valve for hydraulic regulation includes a main valve sleeve assembly, an electromagnet assembly 10, and a coil assembly 13 assembled sequentially. The electromagnet assembly 10 includes a housing 20 and a drive shaft 16, with the drive shaft 16 slidably mounted within the housing 20. The main valve sleeve assembly includes an end cap 1, a main valve sleeve 3, a main valve core 5, a front valve core 4, a main spring seat 8, and a pilot valve core 7. The main valve sleeve 3 is fixedly installed within the housing 20. The end cap 1 is interference-fitted to the end of the main valve sleeve 3 away from the housing 20. The main valve core 5 is slidably mounted within the main valve sleeve 3. The front valve core 4 is slidably mounted within the main valve core 5. The main spring seat 8 is slidably mounted within the front valve core 4. One end of the main spring seat 8 movably passes through the front valve core 4 and is threadedly connected to the end cap 1. A main elastic element is assembled between the main spring seat 8 and the front valve core 4. The pilot valve core 7 is slidably assembled between the main valve core 5 and the drive shaft 16. The pilot valve core 7 is located on the moving path of the drive shaft 16. A pilot elastic element is assembled between the pilot valve core 7 and the main valve core 5. A first throttling channel 23 is formed between the front valve core 4 and the end cover 1. A second throttling channel 24 is formed between the main valve core 5 and the end cover 1. A pilot first throttling channel 25 is formed between the main valve core 5 and the pilot valve core 7. A pilot second throttling channel 26 is formed between the pilot valve core 7 and the main valve sleeve 3. The configuration is as follows: "The main valve core 5 is slidably assembled with the main valve sleeve 3, the front valve core 4 is slidably assembled with the main valve core 5, and the main spring seat 8 is slidably assembled with the front valve core 4". The multi-layered nested structure has radial gaps between the three components, allowing them to move relative to each other. Through multi-stage sliding adaptation, the coaxiality error of the valve core assembly is controlled within 0.01mm, preventing jamming caused by radial offset during valve core movement. It also simplifies assembly, reduces processing difficulty, facilitates mass production, and lowers costs.
[0018] Furthermore, a gasket 2 is provided between the end cap 1 and the main valve sleeve 3. A housing sealing ring 11 is fitted at the end of the housing 20 near the main valve sleeve assembly, and a coil sealing ring 12 is fitted at the end of the housing 20 near the coil assembly 13. The housing sealing ring 11 and the coil sealing ring 12 respectively seal the two ends of the pilot valve.
[0019] Example 2 Based on Example 1, such as Figures 1 to 12As shown, the end cap 1 has a threaded hole 27 at its center, and several small holes 28 are formed around the threaded hole 27 on the end cap 1. The end cap 1 also has multiple notches 29 that connect to the first throttling channel 23. The end of the front valve core 4 furthest from the end cap 1 has a front valve core cavity 30, and the end of the front valve core 4 closest to the end cap 1 has a central hole 31 through which the main spring seat 8 passes. Several small front valve core holes 32 are formed around the central hole 31 on the front valve core 4. The main spring seat 8 includes a disc and a threaded shaft, which are connected in a T-shape. The disc has a gap... The threaded shaft is installed inside the front valve core cavity 30 and passes through the central hole 31 to connect to the threaded hole 27. The main elastic element is the main spring 9, which is located inside the front valve core cavity 30 and is sleeved on the threaded shaft. An adjustment notch 22 is provided at the end of the threaded shaft near the end cover 1. There is a preload generated by the main spring 9 between the end cover 1 and the front valve core 4. By using a flathead screwdriver to act on the adjustment notch 22 through the threaded hole 27, the main spring seat 8 can be rotated to move along the axial direction of the threaded hole 27, thereby achieving adjustable preload.
[0020] Example 3 Based on Example 2, such as Figures 1 to 12As shown, the main valve core 5 has a main valve core cavity 33 at one end near the end cover 1. The front valve core 4 is slidably assembled in the main valve core cavity 33. The main valve core 5 has a main valve core center hole 34 at one end away from the end cover 1. The main valve core 5 has multiple main valve core small holes 35 around the main valve core center hole 34. The two ends of the main valve core small holes 35 are respectively connected to the main valve core cavity 33 and the main valve core center hole 34. The pilot valve core 7 has a pilot valve core center hole 36 through its middle section. The end of the pilot valve core 7 is slidably adapted to the main valve core cavity 33. Inside, a step is formed on the pilot valve core 7. The pilot spring 6 is a pilot spring that is sleeved on the pilot valve core 7. One end of the pilot spring 6 abuts against the step of the pilot valve core 7. Several pilot valve core holes 37 are formed around the pilot valve core center hole 36 on the step of the pilot valve core 7. The main valve sleeve 3 is hollow. Several side flow holes 38 are formed on the side wall of the main valve sleeve 3 along its own circumference. The electromagnet assembly 10 also includes an iron core 17, a limiting seat 14 and a guide seat 18. The limiting seat 14 and the guide seat All 18 are fixedly assembled inside the housing 20. Under the action of the pilot limiting component, the pilot valve core 7 abuts against the end of the limiting seat 14. The iron core 17 is located between the limiting seat 14 and the guide seat 18. The iron core 17 is fixedly mounted on the drive shaft 16. The limiting seat 14 and the guide seat 18 are respectively equipped with limiting seat bearing 15 and guide seat bearing 19. The drive shaft 16 moves through the limiting seat bearing 15 and the guide seat bearing 19. The high-pressure inlet chamber is between the end cover 1 and the front valve core 4, and the high-pressure inlet chamber is between the main spring seat 8 and the main valve core 5. The specific working process of the pilot valve in the main control chamber is as follows: As the inlet flow gradually increases, the high-pressure medium flows into the inlet high-pressure chamber through the small hole 28 of the end cover 1. Because the main spring 9 is compressed by the main spring seat 8, a certain pre-pressure is generated, which makes the front valve core 4 fit tightly with the end cover 1. The high-pressure medium flow at the inlet needs to overcome the spring force before it can push the front valve core 4 away from the end cover 1. The evenly distributed notches 29 on the inner ring of the end cover 1 act as overflow pressure stabilization, so that the inlet and outlet pressure difference is generated smoothly and quickly under low flow and low pressure conditions. High-pressure medium flows into the main control chamber through the small hole 32 of the front valve core 4. Due to the different hydraulic pressures on the upper and lower parts of the front valve core 4, a certain pressure difference is generated, which pushes the front valve core 4 to move up and down. When the coil assembly 10 is not energized, the hydraulic pressure and spring force of the front valve core 4 work together to move it away from the end cover 1. The medium enters the main control chamber through the small hole 32 of the front valve core. The main valve core 5 is subjected to hydraulic pressure and fits against the stop step of the main control sleeve 3. The medium further enters the pilot chamber through the small hole 35 of the main valve core at the bottom of the main valve core 5. The pilot valve core 7 is subjected to hydraulic pressure and fits against the limit seat 14. The side flow hole 38 of the main valve sleeve 3 does not produce throttling. At this time, the solenoid valve opening is the largest, the throttling effect is the smallest, and the pressure difference between the valve inlet and outlet is the smallest. The relationship between the components is as follows. Figure 12(As shown in the maximum flow channel opening state). When the coil assembly 10 is energized, a magnetic field is generated, which acts on the iron core 17. Since the iron core 17 is fixedly connected to the drive shaft 16, the drive shaft 16 and the iron core 17 move together toward the pilot valve core 7. As the current increases, the electromagnetic force gradually overcomes the hydraulic pressure on the pilot valve core 7 and the spring force generated by the pilot spring 6. The pilot valve core 7 moves toward the main valve core 5. The first pilot throttling channel and the second pilot throttling channel gradually decrease, generating a throttling effect. The pressure in the main control chamber increases. The front valve core 4 is subjected to the combined action of the hydraulic pressure and the spring force of the main spring 9, which overcomes the hydraulic pressure on the front valve core 4 from the inlet high pressure chamber. The front valve core 4 moves toward the end cover 1. The first throttling channel gradually closes, and the system hydraulic pressure generates linear damping. As the current increases, the electromagnetic force increases. The pilot valve core 7 pushes the main valve core 5 to overcome the hydraulic pressure. The second throttling channel formed between the main valve core 5 and the end cover 1 gradually closes, further increasing the pressure difference between the inlet and outlet of the solenoid valve and forming a larger damping difference. The valve's performance characteristics are that when the inlet medium flow rate is small, the pressure difference between the inlet and outlet of the solenoid valve is controlled by the spring force of the main spring 9 to control the size of the first throttling channel, thereby achieving the function of rapidly increasing the pressure difference. After the pilot valve core 7 is controlled and generates sufficient force to push the main valve core 5, the second throttling channel is closed linearly, making the flow rate and pressure proportional to a linear relationship, and the entire product can be linearly controlled.
[0021] Example 4 Based on Example 3, such as Figure 13 As shown, the notch 29 on the end cap 1 can also be opened on the raised surface of the front valve core 4 for overflow stabilization.
[0022] Example 5 Based on Example 4, such as Figure 14 As shown, the pilot valve core 7 and the main valve core 5 are fitted with a conical seal. Specifically, the inner wall of the main valve core cavity 33 is a conical surface, and the end of the pilot valve core 7 is an arc-shaped protrusion. The arc-shaped protrusion moves closer to the main valve core cavity 33, so that the gap between the arc-shaped protrusion and the main valve core cavity 33 gradually decreases.
Claims
1. A pilot valve for hydraulic regulation, comprising a main valve sleeve assembly, an electromagnet assembly (10), and a coil assembly (13) assembled sequentially, characterized in that, The electromagnet assembly (10) includes a housing (20) and a drive shaft (16). The drive shaft (16) is slidably mounted inside the housing (20). The main valve sleeve assembly includes an end cap (1), a main valve sleeve (3), a main valve core (5), a front valve core (4), a main spring seat (8), and a pilot valve core (7). The main valve sleeve (3) is fixedly mounted inside the housing (20). The end cap (1) is interference-fitted to the end of the main valve sleeve (3) away from the housing (20). The main valve core (5) is slidably mounted inside the main valve sleeve (3). The front valve core (4) is slidably mounted inside the main valve core (5). The main spring seat (8) is slidably mounted inside the front valve core (4). One end of the main spring seat (8) moves through the thread of the front valve core (4). Connecting end cap (1), a main elastic element is assembled between the main spring seat (8) and the front valve core (4), the pilot valve core (7) is slidably assembled between the main valve core (5) and the drive shaft (16), the pilot valve core (7) is located on the moving path of the drive shaft (16), a pilot elastic element is assembled between the pilot valve core (7) and the main valve core (5), a first throttling channel (23) is formed between the front valve core (4) and the end cap (1), a second throttling channel (24) is formed between the main valve core (5) and the end cap (1), a pilot first throttling channel (25) is formed between the main valve core (5) and the pilot valve core (7), and a pilot second throttling channel (26) is formed between the pilot valve core (7) and the main valve sleeve (3).
2. The pilot valve for hydraulic regulation according to claim 1, characterized in that, The end cap (1) has a threaded hole (27) in the center, and several small holes (28) are formed around the threaded hole (27) on the end cap (1). The end cap (1) has multiple notches (29) which are connected to the first throttling channel (23).
3. A pilot valve for hydraulic regulation according to claim 2, characterized in that, The front valve core (4) has a front valve core cavity (30) at the end away from the end cover (1), and a central hole (31) for the main spring seat (8) to pass through at the end of the front valve core (4) near the end cover (1). Multiple front valve core holes (32) are formed around the central hole (31) on the front valve core (4).
4. A pilot valve for hydraulic regulation according to claim 3, characterized in that, The main spring seat (8) includes a disc and a threaded shaft. The disc and the threaded shaft are connected in a T-shape. The disc is fitted into the front valve core cavity (30) with a gap. The threaded shaft passes through the central hole (31) and is connected to the threaded hole (27). The main elastic element is the main spring (9). The main spring (9) is located in the front valve core cavity (30) and is sleeved on the threaded shaft. An adjustment notch (22) is provided at one end of the threaded shaft near the end cover (1).
5. A pilot valve for hydraulic regulation according to claim 1, characterized in that, The main valve core (5) has a main valve core cavity (33) at one end near the end cap (1). The front valve core (4) is slidably assembled in the main valve core cavity (33). The main valve core (5) has a main valve core center hole (34) at one end away from the end cap (1). The main valve core (5) has multiple main valve core small holes (35) around the main valve core center hole (34). The two ends of the main valve core small holes (35) are respectively connected to the main valve core cavity (33) and the main valve core center hole (34).
6. A pilot valve for hydraulic regulation according to claim 5, characterized in that, The pilot valve core (7) has a central hole (36) through the middle. The end of the pilot valve core (7) is slidably adapted to the main valve core cavity (33). A step is formed on the pilot valve core (7). The pilot directional element is a pilot spring (6). The pilot spring (6) is sleeved on the pilot valve core (7). One end of the pilot spring (6) abuts against the step of the pilot valve core (7). Several pilot valve core holes (37) are formed around the central hole (36) on the step of the pilot valve core (7).
7. A pilot valve for hydraulic regulation according to claim 1, characterized in that, The main valve sleeve (3) is hollow, and the side wall of the main valve sleeve (3) is provided with a number of side flow holes (38) along its own circumference.
8. A pilot valve for hydraulic regulation according to claim 1, characterized in that, The electromagnet assembly (10) also includes an iron core (17), a limiting seat (14), and a guide seat (18). The limiting seat (14) and the guide seat (18) are both fixedly assembled inside the housing (20). Under the action of the pilot limiting component, the pilot valve core (7) abuts against the end of the limiting seat (14). The iron core (17) is located between the limiting seat (14) and the guide seat (18). The iron core (17) is fixedly mounted on the drive shaft (16). The limiting seat (14) and the guide seat (18) are respectively equipped with a limiting seat bearing (15) and a guide seat bearing (19). The drive shaft (16) moves through the limiting seat bearing (15) and the guide seat bearing (19).
9. A pilot valve for hydraulic regulation according to claim 1, characterized in that, A gasket (2) is provided between the end cap (1) and the main valve sleeve (3). A housing sealing ring (11) is fitted on the end of the housing (20) near the main valve sleeve assembly. A coil sealing ring (12) is fitted on the end of the housing (20) near the coil assembly (13).