A pilot head assembly and a solenoid valve

Abstract

This invention discloses a pilot head assembly and a solenoid valve, relating to the field of solenoid valve technology. The pilot head assembly includes a housing sleeve. A first fixed iron core is fixedly connected to the upper inner cavity of the housing sleeve, and a first electromagnetic coil is sleeved on the outer wall of the housing sleeve corresponding to the position of the first fixed iron core. A second fixed iron core is fixedly connected to the lower inner cavity of the housing sleeve, and a second electromagnetic coil is sleeved on the outer wall of the housing sleeve corresponding to the position of the second fixed iron core. A moving iron core piston seat is movably inserted into the bottom of the housing sleeve. By setting a dual electromagnetic coil structure (first and second electromagnetic coils), and through the coordinated control of the dual electromagnetic coil structure and the rotating ratchet mechanism, stepless switching between normally open and normally closed states of the solenoid valve is achieved. The travel of the sealing plug can be precisely positioned by the limiting groove of the ratchet sleeve under different electromagnetic fields, completing mode switching without external mechanical devices, thus solving the pain point of traditional solenoid valves requiring complex external devices for switching.

Description

Technical Field

[0001] This invention relates to the field of solenoid valve technology, specifically to a pilot head assembly and a solenoid valve. Background Technology

[0002] Solenoid valves are electromagnetically controlled industrial devices, fundamental components of automation systems used to control fluids. They are actuators, not limited to hydraulic or pneumatic systems, and are used in industrial control systems to adjust the direction, flow rate, speed, and other parameters of the medium. Solenoid valves can be used with different circuits to achieve the desired control, ensuring both precision and flexibility.

[0003] Pilot-operated solenoid valves are a type of solenoid valve widely used in various industries. The structure of pilot-operated solenoid valves varies depending on the application. The pilot head assembly is a crucial component of the solenoid valve, typically including a sleeve, a moving iron core movably housed within the sleeve, a fixed iron core fixed within the sleeve, and an electromagnetic coil mounted on the outer wall of the sleeve. Its working principle is as follows: when the electromagnetic coil is energized, the fixed iron core attracts the moving iron core to move axially along the sleeve, thereby opening or closing the valve.

[0004] In the current field of industrial automation, solenoid valves are a key control component, and their performance directly affects the stability and reliability of the entire system. However, a common problem is that most existing pilot designs cannot effectively support the free switching function of solenoid valves between normally open and normally closed states. This leads to operational limitations for engineers in practical applications, often requiring additional components or complex configurations to meet this basic requirement. This design deficiency not only increases system complexity but may also introduce potential failure points, affecting the long-term operating efficiency and safety of the equipment. To address this, we propose a pilot assembly and a solenoid valve. Summary of the Invention

[0005] The purpose of this invention is to provide a pilot head assembly and a solenoid valve in order to effectively address the problem of smooth switching between the normally open state and the normally closed state of a solenoid valve.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0007] A pilot head assembly includes an outer sleeve. A first fixed iron core is fixedly connected to the upper inner cavity of the outer sleeve, and a first electromagnetic coil is sleeved on the outer wall of the outer sleeve corresponding to the position of the first fixed iron core. A second fixed iron core is fixedly connected to the lower inner cavity of the outer sleeve, and a second electromagnetic coil is sleeved on the outer wall of the outer sleeve corresponding to the position of the second fixed iron core. A movable iron core piston seat is movably inserted into the bottom of the outer sleeve, and a movable iron core push rod is fixedly connected to the center of the upper end of the movable iron core piston seat. The outer wall of the movable iron core push rod corresponds to the space between the second fixed iron core and the movable iron core piston seat. A section is fitted with a moving iron core return spring, and the upper end of the moving iron core push rod is movably inserted through the center of the second fixed iron core. The upper end of the moving iron core push rod is fixedly connected to a connecting guide tube, and the upper end of the connecting guide tube is fixedly connected to a first adsorption block of the moving iron core. The bottom of the moving iron core piston seat is provided with a piston groove, and a sealing plug is movably inserted into the piston groove. The upper end of the sealing plug is provided with a rotating ratchet mechanism. The side wall of the connecting guide tube is slidably inserted with a second adsorption block of the moving iron core, and the second adsorption block of the moving iron core is fixedly connected to the drive end of the rotating ratchet mechanism.

[0008] The rotating ratchet mechanism includes a switching push rod, which is fixedly connected to the upper center of the sealing plug. A locking sleeve is rotatably connected to the upper end of the switching push rod. A compression spring is sleeved between the outer wall of the sealing plug and the bottom of the movable slot at the upper end of the moving iron core push rod, corresponding to the locking sleeve. A ratchet sleeve is fixedly connected to the upper end of the movable slot of the moving iron core push rod. A switching pressure rod is slidably connected inside the ratchet sleeve. Multiple limiting slots are staggered along the lower edge of the ratchet sleeve. Multiple inclined claws are staggered on the upper outer wall of the locking sleeve, and the multiple inclined claws match the limiting slots. Multiple serrations are provided at the bottom of the switching pressure rod. When the multiple serrations contact the upper inclined surface of the inclined claws and move downward, a radial force is generated to drive the rotation. The upper end of the locking sleeve is movably inserted into the bottom of the switching pressure rod, and the upper end of the switching pressure rod passes through the ratchet sleeve and is fixedly connected to the lower center of the second adsorption block of the moving iron core.

[0009] The outer wall of the switching pressure rod is provided with multiple guide protrusions at equal intervals, and the bottom of the inner wall of the ratchet sleeve is provided with radial guide grooves corresponding to the multiple guide protrusions.

[0010] The upper end of the switching push rod is rotatably connected to the bottom of the locking sleeve via a self-lubricating graphite copper sleeve.

[0011] The bottom of the first adsorption block of the moving iron core is fixedly connected to a magnetic shielding pad, and the upper end of the connecting guide tube passes through the magnetic shielding pad and is fixedly connected to the first adsorption block of the moving iron core. The bottom of the connecting guide tube is threadedly connected to the upper end of the top rod of the moving iron core.

[0012] An electromagnetic valve includes the aforementioned pilot head assembly and valve body. The valve body has a pilot cavity at its upper end, and the lower end of the outer casing is threadedly connected to the upper end of the pilot cavity. Multiple limiting contact posts are fixedly connected to the bottom outer ring of the moving iron core piston seat at the bottom of the pilot cavity. A fluid channel is provided at the lower end of the valve body, and a main valve seat is provided in the middle of the fluid channel. A main valve core is provided at the upper end of the main valve seat, and a conical valve core spring is provided between the upper end of the main valve core and the inner wall of the valve body. The pilot cavity communicates with the inner cavities on both sides of the main valve seat in the fluid channel through a balance channel and a pressure relief channel, respectively. The pilot cavity also communicates with the inner cavity of the main valve core through a valve core communication hole. A conical pilot valve port is provided at the center of the bottom of the pilot cavity, and the pressure relief channel communicates with the inner cavity of the pilot cavity through the conical pilot valve port. The conical pilot valve port is a conical structure with the small end facing upwards, and the upper end of the conical pilot valve port is inserted into the bottom piston groove of the moving iron core piston seat, abutting against the bottom of the sealing plug.

[0013] Furthermore, a spiral connector is fixedly connected to the bottom of the outer wall of the outer casing, and a threaded step is provided at the upper end of the pilot cavity corresponding to the spiral connector. An O-ring is fitted on the bottom threaded end of the spiral connector.

[0014] Furthermore, the sidewall of the sealing plug is provided with multiple pressure balance holes at equal intervals corresponding to the bottom of the piston groove.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention achieves stepless switching between normally open and normally closed states of a solenoid valve by setting up a dual-electromagnetic coil structure with a first and a second electromagnetic coil, and through the coordinated control of the dual-electromagnetic coil structure and the rotating ratchet mechanism. Utilizing the sawtooth meshing design of the switching lever and the inclined pawl, combined with the elastic drive of the moving iron core return spring, the travel of the sealing plug can be precisely positioned through the limiting groove of the ratchet sleeve under different electromagnetic fields. Mode switching is completed without external mechanical devices, solving the pain point of traditional solenoid valves requiring complex external devices for switching. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of the pilot head of the present invention;

[0018] Figure 2 This is the present invention. Figure 1 Enlarged view of point A in the middle;

[0019] Figure 3 This is a partial structural diagram of the rotating ratchet mechanism of the present invention;

[0020] Figure 4 This is a perspective view of the ratchet sleeve of the present invention;

[0021] Figure 5 This is a schematic cross-sectional view of the core switching section of the present invention;

[0022] Figure 6 This is a diagram of the internal structure of the solenoid valve of the present invention.

[0023] Reference numerals: 1. Outer casing sleeve; 2. First fixed iron core; 3. First electromagnetic coil; 4. Second fixed iron core; 5. Second electromagnetic coil; 6. Moving iron core piston seat; 7. Moving iron core push rod; 8. Connecting guide cylinder; 9. First adsorption block of moving iron core; 10. Magnetic isolation pad; 11. Second adsorption block of moving iron core; 12. Sealing plug; 13. Switching push rod; 14. Locking rotating sleeve; 15. Switching pressure rod; 16. Ratchet sleeve; 17. Pressure... 18. Tightening spring; 19. Moving iron core return spring; 20. Valve body; 21. Pilot chamber; 22. Main valve seat; 23. Spiral connector; 24. Main valve core; 25. Conical valve core spring; 26. Balance channel; 27. Valve core connecting hole; 28. Pressure relief channel; 29. ​​Conical pilot valve port; 30. Guide protrusion; 31. Serrated edge; 32. Angled claw; 33. Limiting groove; 34. Pressure balance hole; 35. Limiting contact post. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0025] Please see Figures 1-5 This invention provides a pilot head assembly, including a housing sleeve 1. A first fixed iron core 2 is fixedly connected to the upper inner cavity of the housing sleeve 1, and a first electromagnetic coil 3 is sleeved on the outer wall of the housing sleeve 1 corresponding to the position of the first fixed iron core 2. A second fixed iron core 4 is fixedly connected to the lower inner cavity of the housing sleeve 1, and a second electromagnetic coil 5 is sleeved on the outer wall of the housing sleeve 1 corresponding to the position of the second fixed iron core 4. A movable iron core piston seat 6 is movably inserted into the bottom of the housing sleeve 1, and a movable iron core push rod 7 is fixedly connected to the center of the upper end of the movable iron core piston seat 6. The outer wall of the movable iron core push rod 7 corresponds to the position of the second fixed iron core 4 and the movable iron core piston seat. A moving iron core return spring 18 is sleeved between 6, and the upper end of the moving iron core push rod 7 is inserted into the center of the second fixed iron core 4. The upper end of the moving iron core push rod 7 is fixedly connected to the connecting guide tube 8, and the upper end of the connecting guide tube 8 is fixedly connected to the first adsorption block 9 of the moving iron core. The bottom of the moving iron core piston seat 6 is provided with a piston groove, and a sealing plug 12 is movably inserted into the piston groove. A rotating ratchet mechanism is provided at the upper end of the sealing plug 12. The second adsorption block 11 of the moving iron core is slidably inserted into the side wall of the connecting guide tube 8, and the second adsorption block 11 of the moving iron core is fixedly connected to the drive end of the rotating ratchet mechanism.

[0026] In this embodiment, preferably, the rotating ratchet mechanism includes a switching push rod 13, which is fixedly connected to the upper center of the sealing plug 12. A locking sleeve 14 is rotatably connected to the upper end of the switching push rod 13. A compression spring 17 is sleeved between the outer wall of the sealing plug 12 and the bottom of the movable slot at the upper end of the moving iron core push rod 7, corresponding to the locking sleeve 14. A ratchet sleeve 16 is fixedly connected to the upper end of the movable slot of the moving iron core push rod 7. A switching pressure rod 15 is slidably connected inside the ratchet sleeve 16, and the lower edge of the ratchet sleeve 16 is staggered. There are multiple limiting slots 32, and multiple inclined claws 31 are staggered on the upper outer wall of the locking rotating sleeve 14. The multiple inclined claws 31 match the limiting slots 32. The bottom of the switching pressure rod 15 is provided with multiple serrations 30. When the multiple serrations 30 contact the upper inclined surface of the inclined claws 31 and move downward, they generate radial force to drive rotation. The upper end of the locking rotating sleeve 14 is movably inserted into the bottom of the switching pressure rod 15, and the upper end of the switching pressure rod 15 passes through the ratchet sleeve 16 and is fixedly connected to the lower center of the second adsorption block 11 of the moving iron core. The rotating ratchet mechanism, employing the same principle as the press-and-release mechanism of a ballpoint pen's push-button, allows the switching lever 15 to slide within the ratchet sleeve 16 during solenoid valve operation. The up-and-down movement of the second adsorption block 11 on the moving iron core drives the ratchet sleeve 14 to rotate and lock within the ratchet sleeve 16. This, in turn, utilizes the engagement of the serrated teeth 30 and the inclined pawl 31 to effectively switch the solenoid valve between open and closed states, improving its efficiency and stability. Simultaneously, the clamping spring 17 ensures a tight fit between the locking sleeve 14 and the ratchet sleeve 16, preventing loosening from affecting the normal operation of the solenoid valve. Furthermore, this rotating ratchet mechanism is simple in structure, easy to manufacture and maintain, reducing the production and operating costs of the solenoid valve.

[0027] In this embodiment, preferably, the outer wall of the switching lever 15 is provided with multiple guide protrusions 29 at equal intervals, and the bottom of the inner wall of the ratchet sleeve 16 is provided with radial guide grooves corresponding to the multiple guide protrusions 29. The cooperative design of the guide protrusions 29 and the radial guide grooves ensures the stable sliding of the switching lever 15 within the ratchet sleeve 16, avoiding possible offset or jamming during the switching process. This design further improves the accuracy and smoothness of the solenoid valve switching action, ensuring the efficiency and reliability of the solenoid valve switching between different working states. At the same time, the structure of the guide protrusions 29 and the radial guide grooves is simple and easy to manufacture, without adding extra burden to the overall structural complexity of the solenoid valve, which is in line with the design intention of this invention to simplify the structure and improve the performance of the solenoid valve.

[0028] In this embodiment, preferably, the upper end of the switching push rod 13 and the bottom of the locking sleeve 14 are rotatably connected by a self-lubricating graphite copper sleeve. This connection method not only ensures flexible rotation between the switching push rod 13 and the locking sleeve 14, but also effectively reduces friction between them and extends service life through the characteristics of the self-lubricating graphite copper sleeve. The self-lubricating graphite copper sleeve has good self-lubricating properties and can maintain a low coefficient of friction under unlubricated conditions, thereby reducing heat and wear generated by friction and ensuring the long-term stable operation of the solenoid valve. In addition, this connection method is also convenient for installation and disassembly, which is beneficial for the maintenance and upkeep of the solenoid valve, further improving the practicality and reliability of the solenoid valve.

[0029] In this embodiment, preferably, a magnetic shielding pad 10 is fixedly connected to the bottom of the first adsorption block 9 of the moving iron core, and the upper end of the connecting guide tube 8 passes through the magnetic shielding pad 10 and is fixedly connected to the first adsorption block 9 of the moving iron core. The bottom of the connecting guide tube 8 is threadedly connected to the upper end of the moving iron core push rod 7. The magnetic shielding pad 10 effectively isolates the first adsorption block 9 of the moving iron core from direct contact with the surrounding magnetic materials, preventing unnecessary transmission and interference of magnetic force, and ensuring the stability and accuracy of the solenoid valve during operation. The design of the connecting guide tube 8 passing through the magnetic shielding pad 10 and being fixedly connected to the first adsorption block 9 of the moving iron core not only enhances the structural stability but also makes the connection between the moving iron core push rod 7 and the first adsorption block 9 of the moving iron core more reliable. Through the threaded connection, the bottom of the connecting guide tube 8 and the upper end of the moving iron core push rod 7 fit tightly, which is convenient for installation and adjustment and can effectively prevent loosening and falling off, further improving the working efficiency and safety of the solenoid valve.

[0030] Please see Figure 6 A solenoid valve includes the aforementioned pilot head assembly and valve body 19. A pilot cavity 20 is formed at the upper end of the valve body 19, and the lower end of the outer casing 1 is threadedly connected to the upper end of the pilot cavity 20. Multiple limiting contact pins 34 are fixedly connected to the bottom of the pilot cavity 20 corresponding to the bottom outer ring position of the moving iron core piston seat 6. A fluid channel is provided at the lower end of the valve body 19, and a main valve seat 21 is provided in the middle of the fluid channel. A main valve core 23 is provided at the upper end of the sealing plug 12, and a conical valve core spring 24 is provided between the upper end of the main valve core 23 and the inner wall of the valve body 19. The pilot chamber 20 is connected to the inner cavities on both sides of the main valve seat 21 in the fluid channel through the balance channel 25 and the pressure relief channel 27 respectively. The pilot chamber 20 is also connected to the inner cavity of the main valve core 23 through the valve core connecting hole 26. A conical pilot valve port 28 is provided at the bottom center of the pilot chamber 20. The pressure relief channel 27 is connected to the inner cavity of the pilot chamber 20 through the conical pilot valve port 28. The conical pilot valve port 28 is a conical structure with the small end facing upward. The upper end of the conical pilot valve port 28 is inserted into the bottom piston groove of the moving iron core piston seat 6 and abuts against the bottom of the sealing plug 12.

[0031] In this embodiment, preferably, a spiral connector 22 is fixedly connected to the bottom of the outer wall of the outer sleeve 1, and a threaded step is formed at the upper end of the pilot cavity 20 corresponding to the spiral connector 22. An O-ring is fitted on the bottom threaded end of the spiral connector 22. This design makes the connection between the outer sleeve 1 and the valve body 19 tighter, effectively preventing fluid leakage and enhancing the sealing performance of the solenoid valve. As a common sealing element, the O-ring has good elasticity and wear resistance, and can maintain a stable sealing effect during long-term use. In addition, the use of the spiral connector 22 not only facilitates the installation and disassembly of the outer sleeve 1 and the valve body 19, but also improves the overall structural strength of the solenoid valve, making it more durable.

[0032] In this embodiment, preferably, the sidewall of the sealing plug 12 is provided with multiple pressure balancing holes 33 at equal intervals corresponding to the bottom of the piston groove. The design of the pressure balancing holes 33 is to balance the pressure on both sides of the sealing plug 12, preventing the sealing plug 12 from being obstructed due to excessive pressure difference, thereby affecting its operation. During the operation of the solenoid valve, when the fluid flows through the main valve seat 21, a certain pressure change may occur around the main valve core 23 and the sealing plug 12. By providing pressure balancing holes 33, the pressure on both sides of the sealing plug 12 can be effectively balanced, thereby reducing the lateral force on the sealing plug 12 due to pressure difference, and improving its sealing stability and service life.

[0033] The lower edge of the inner wall of the piston groove at the bottom of the moving iron core piston seat 6 is also provided with a limiting protrusion ring, which limits the downward movement end position of the sealing plug 12 to prevent the sealing plug 12 from slipping off.

[0034] Working principle and usage process of this invention:

[0035] When the solenoid valve is in the normally closed state, the rotating ratchet mechanism switches the sealing plug 12 to its lowest position, the solenoid coil is de-energized, the moving iron core return spring 18 pushes the moving iron core piston seat 6 downward, causing the sealing plug 12 to press against the conical pilot valve port 28, closing the pressure relief channel 27. In the main valve state, the main valve core 23 is kept closed by the action of the conical valve core spring 24, and the fluid passage is cut off. When it is necessary to open the solenoid valve, the first solenoid coil 3 is energized, generating a magnetic field to attract the first adsorption block 9 of the moving iron core, which drives the connecting guide cylinder 8 and the moving iron core push rod 7 to move upward. The moving iron core return spring 18 is compressed, the moving iron core piston seat 6 moves upward accordingly, the sealing plug 12 disengages from the conical pilot valve port 28, the pressure relief channel 27 opens, the fluid enters the pilot chamber 20 through the balance channel 25, and is discharged through the pressure relief channel 27. The pressure difference on both sides of the main valve core 23 disappears, the conical valve core spring 24 pushes the main valve core 23 to open, and the fluid passage is opened.

[0036] When the solenoid valve is in the normally open state, the rotary ratchet mechanism switches to the upward retraction of the sealing plug 12. At this time, the moving iron core return spring 18 pushes the moving iron core piston seat 6 downward to abut against the limit contact post 34, thus leaving a gap between the sealing plug 12 and the conical pilot valve port 28. The pressure relief channel 27 opens, and the fluid enters the pilot chamber 20 through the balance channel 25 and is discharged through the pressure relief channel 27. The pressure difference on both sides of the main valve core 23 disappears, and the conical valve core spring 24 pushes the main valve core 23 to open, thus opening the fluid passage. When it is necessary to close the solenoid valve, the second solenoid coil 5 is energized, generating a magnetic field to attract the moving iron. The second adsorption block 11 of the core moves downward, pushing the rotating ratchet mechanism to rotate and push the sealing plug 12 downward. Since the conical pilot valve port 28 is inserted into the piston groove, the downward stroke of the sealing plug 12 is limited and cannot meet the distance requirement of the locking sleeve 14 rotation misalignment. At this time, the sealing plug 12 is pressed against the conical pilot valve port 28 under the dual action of the downward pushing force of the rotating ratchet mechanism and the adsorption force of the second adsorption block 11 of the moving iron core being energized by the second electromagnetic coil 5, closing the pressure relief channel 27. The main valve core 23 is kept closed by the action of the conical valve core spring 24, and the fluid channel is cut off.

[0037] When in mode switching mode, the first electromagnetic coil 3 is energized first, generating a magnetic field that attracts the first adsorption block 9 of the moving iron core, causing the connecting guide cylinder 8 and the moving iron core push rod 7 to move upward, thereby lifting the moving iron core piston seat 6. Then, the second electromagnetic coil 5 is energized. Due to the effect of the magnetic shielding block 10, the attraction of the second electromagnetic coil 5 to the second adsorption block 11 of the moving iron core is much greater than that of the first electromagnetic coil 3 to the second adsorption block 11 of the moving iron core. At this time, the second adsorption block 11 of the moving iron core moves downward, and the bottom sawtooth 30 of the switching pressure rod 15 contacts the inclined claw 31 of the locking rotating sleeve 14, generating a radial rotational force. As the moving iron core piston seat 6 is lifted, the bottom of the sealing plug 12 has enough space to move downward, so that the inclined claw 31 of the locking rotating sleeve 14 can rotate and move to the next limit slot 32. By switching different limit slots 32, the position of the sealing plug 12 is adjusted to adapt to different fluid control requirements.

[0038] By setting up a dual electromagnetic coil structure with a first electromagnetic coil 3 and a second electromagnetic coil 5, and through the coordinated control of the dual electromagnetic coil structure and the rotating ratchet mechanism, stepless switching between the normally open and normally closed states of the solenoid valve is achieved. Utilizing the sawtooth meshing design of the switching lever 15 and the inclined pawl 31, combined with the elastic drive of the moving iron core return spring 18, the stroke of the sealing plug 12 can be precisely positioned through the limiting groove 32 of the ratchet sleeve 16 under different electromagnetic fields. Mode switching is completed without the need for external mechanical devices, solving the pain point of traditional solenoid valves requiring complex external devices for switching.

[0039] The design employs a combination of split fixed iron cores (first fixed iron core 2 and second fixed iron core 4) and magnetic isolation pads 10 to achieve magnetic field isolation between the upper and lower electromagnetic fields, avoiding magnetic circuit interference when both coils operate simultaneously. The first adsorption block 9 and the second adsorption block 11 of the moving iron core form an independent magnetic circuit through the connecting guide tube 8. Combined with the sealing structure of the spiral connector 22, this ensures magnetic adsorption force while reducing magnetic leakage loss, thereby improving the movement accuracy of the moving iron core piston seat 6 by more than 40%, significantly enhancing the stability and response speed of the valve action.

[0040] The innovative conical pilot valve port 28 and piston groove insertion design, combined with the rotating ratchet drive mechanism of the sealing plug 12, form a double seal in the closed state: mechanical locking is achieved through the downward pressure of the rotating ratchet mechanism, while the elasticity of the conical valve core spring 24 enhances the sealing surface fit. Actual test data shows that this structure reduces the leakage rate to below 0.01 mL / min and increases the pressure resistance to the 25 MPa level, making it particularly suitable for high-pressure fluid control scenarios.

[0041] The moving iron core push rod 7 and the connecting guide cylinder 8 are connected by threads. Together with the replaceable locking sleeve 14 and switching pressure rod 15 module, the key wear parts can be quickly replaced. By adjusting the distribution density of the limit slots 32, it can adapt to working conditions with different stroke requirements. Actual tests have proven that it can cover the precision stroke adjustment requirements of 0.5-3mm, meeting the differentiated control needs of multiple industries such as chemical and hydraulic industries.

[0042] This invention features a compact structure, simple operation, and superior sealing performance. Through an innovative conical pilot valve port design, combined with precise control of a rotary ratchet mechanism, stepless switching between normally open and normally closed states of the solenoid valve is achieved, significantly improving the flexibility and accuracy of fluid control. Simultaneously, the combination of a split-type fixed iron core and a magnetic shielding pad effectively avoids magnetic circuit interference when two coils operate simultaneously, further enhancing the stability and response speed of valve action. Furthermore, this pilot head assembly and solenoid valve also possess significant advantages such as high pressure resistance and low leakage rate, making them particularly suitable for high-pressure fluid control scenarios, providing an efficient and reliable solution for fluid control in industries such as chemical and hydraulic systems.

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pilot head assembly, characterized in that: The system includes an outer casing (1), with a first fixed iron core (2) fixedly connected to the upper inner cavity of the outer casing (1), and a first electromagnetic coil (3) sleeved on the outer wall of the outer casing (1) corresponding to the position of the first fixed iron core (2). A second fixed iron core (4) is fixedly connected to the lower inner cavity of the outer casing (1), and a second electromagnetic coil (5) sleeved on the outer wall of the outer casing (1) corresponding to the position of the second fixed iron core (4). A movable iron core piston seat (6) is movably inserted into the bottom of the outer casing (1), and a movable iron core push rod (7) is fixedly connected to the center of the upper end of the movable iron core piston seat (6). The outer wall of the movable iron core push rod (7) corresponds to the position of the second fixed iron core (4) and the movable iron core piston seat (6). A moving iron core reset spring (18) is sleeved in a section, and the upper end of the moving iron core push rod (7) is inserted into the center of the second fixed iron core (4) with its upper end facing upward. The upper end of the moving iron core push rod (7) is fixedly connected to a connecting guide cylinder (8), and the upper end of the connecting guide cylinder (8) is fixedly connected to a moving iron core first adsorption block (9). The bottom of the moving iron core piston seat (6) is provided with a piston groove, and a sealing plug (12) is movably inserted into the piston groove. A rotating ratchet mechanism is provided at the upper end of the sealing plug (12). The side wall of the connecting guide cylinder (8) is slidably inserted with a moving iron core second adsorption block (11), and the moving iron core second adsorption block (11) is fixedly connected to the drive end of the rotating ratchet mechanism. The rotating ratchet mechanism includes a switching push rod (13), which is fixedly connected to the upper center of the sealing plug (12). A locking sleeve (14) is rotatably connected to the upper end of the switching push rod (13). A compression spring (17) is sleeved between the outer wall of the sealing plug (12) and the bottom of the movable slot at the upper end of the moving iron core push rod (7). A ratchet sleeve (16) is fixedly connected to the upper end of the movable slot of the moving iron core push rod (7). A switching pressure rod (15) is slidably connected inside the ratchet sleeve (16). Multiple ratchet sleeves (16) are staggered at intervals along the lower edge of the ratchet sleeve (16). The upper outer wall of the locking sleeve (14) is provided with a plurality of inclined claws (31) and the plurality of inclined claws (31) match the limiting slot (32). The bottom of the switching rod (15) is provided with a plurality of serrations (30). When the plurality of serrations (30) contact the upper inclined surface of the inclined claws (31) and move downward, a radial force is generated to drive the rotation. The upper end of the locking sleeve (14) is movably inserted into the bottom of the switching rod (15). The upper end of the switching rod (15) passes through the ratchet sleeve (16) and is fixedly connected to the lower center of the second adsorption block (11) of the moving iron core. The outer wall of the switching pressure rod (15) is provided with multiple guide protrusions (29) at equal intervals, and the bottom of the inner wall of the ratchet sleeve (16) is provided with radial guide grooves corresponding to the multiple guide protrusions (29); The upper end of the switching push rod (13) is rotatably connected to the bottom of the locking rotating sleeve (14) through a self-lubricating graphite copper sleeve; The bottom of the first adsorption block (9) of the moving iron core is fixedly connected to a magnetic shielding pad (10), and the upper end of the connecting guide cylinder (8) passes through the magnetic shielding pad (10) and is fixedly connected to the first adsorption block (9) of the moving iron core. The bottom of the connecting guide cylinder (8) is threadedly connected to the upper end of the top rod (7) of the moving iron core.

2. A solenoid valve, characterized in that: The valve body (19) includes the pilot head assembly and valve body (19) as described in any one of claims 1. The upper end of the valve body (19) is provided with a pilot cavity (20), and the lower end of the outer casing (1) is threadedly connected to the upper end of the pilot cavity (20). A plurality of limiting contact pins (34) are fixedly connected to the bottom of the pilot cavity (20) corresponding to the bottom outer ring position of the moving iron core piston seat (6). The lower end of the valve body (19) is provided with a fluid channel, and the middle part of the fluid channel is provided with a main valve seat (21). The upper end of the main valve seat (21) is provided with a main valve core (23), and a conical valve core spring (24) is provided between the upper end of the main valve core (23) and the inner wall of the valve body (19). The pilot cavity (20) is connected to the inner cavity on both sides of the main valve seat (21) in the fluid channel through the balance channel (25) and the pressure relief channel (27), and the pilot cavity (20) is connected to the inner cavity of the main valve core (23) through the valve core connecting hole (26). A conical pilot valve port (28) is provided at the bottom center of the pilot cavity (20), and the pressure relief channel (27) is connected to the inner cavity of the pilot cavity (20) through the conical pilot valve port (28). The conical pilot valve port (28) is a conical structure with the small end facing upward, and the upper end of the conical pilot valve port (28) is inserted into the bottom piston groove of the moving iron core piston seat (6) and abuts against the bottom of the sealing plug (12).

3. A solenoid valve according to claim 2, characterized in that: The outer wall of the outer casing (1) is fixedly connected to a spiral connector (22), and the upper end of the pilot cavity (20) is provided with a threaded step corresponding to the spiral connector (22). An O-ring is fitted on the bottom threaded end of the spiral connector (22).

4. A solenoid valve according to claim 2, characterized in that: The sidewall of the sealing plug (12) is provided with multiple pressure balance holes (33) at equal intervals corresponding to the bottom of the piston groove.

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