A pilot-operated solenoid valve

Abstract

This application relates to the field of fluid control, and in particular to a pilot-operated solenoid valve. It includes a valve body, a valve cover, a valve core assembly, and an electromagnetic drive device. The valve body has an inlet channel, an outlet channel, and a main valve port between them; the valve core assembly includes a diaphragm and a drive rod, the diaphragm being axially movable within the guide hole, and having mutually isolated guide holes and balance holes on the diaphragm; the valve cover has a sealing element, forming a sealing cavity with the diaphragm; the guide holes communicate with the outlet channel and are opened and closed by the drive rod; the balance holes connect the sealing cavity and the inlet channel. This application achieves excellent anti-clogging performance, significantly reduces the stringent requirements for precision machining and assembly of components, and comprehensively improves the valve's operational reliability and service life.

Description

Technical Field

[0001] This application relates to the field of fluid control, and in particular to a pilot-operated solenoid valve. Background Technology

[0002] Solenoid valves, as core actuators in fluid control systems, are widely used in industrial automation, building HVAC, medical devices, and other fields. Pilot-operated solenoid valves, due to their characteristic of using low-power electromagnetic force to control the pilot circuit and then using the medium pressure to drive the main valve, have the advantages of large opening and closing force and low power consumption.

[0003] However, existing pilot-operated solenoid valves generally suffer from several technical defects. In the pilot control stage, traditional pilot channels are typically designed as single, tortuous, narrow channels, which are prone to blockage when the medium contains impurities. This leads to failure in establishing pilot pressure, rendering the main valve inoperable and resulting in severely compromised reliability. Regarding the motion mechanism, the fit between the piston or valve stem assembly and the guide components requires extremely high precision. Even minor machining or assembly errors can easily cause uneven wear and jamming, affecting service life and stability. Furthermore, the return spring is prone to fatigue, loosening, or breakage under long-term alternating loads, affecting sealing reliability and reset response; wear debris generated on the contact surfaces of the moving and stationary iron cores in the electromagnetic drive section under high-frequency operation can also contaminate the medium or hinder movement.

[0004] The aforementioned technologies have several drawbacks, including: poor pilot channel design leading to blockages; excessively high precision requirements for moving parts increasing manufacturing costs and failure rates; and insufficient durability of key components affecting the overall service life. Utility Model Content

[0005] To overcome the shortcomings of the prior art, this application provides a pilot-operated solenoid valve that can achieve excellent anti-clogging performance, significantly reduce the stringent requirements for precision machining and assembly of parts, and comprehensively improve the valve's operational reliability and service life.

[0006] This application is achieved through the following technical solution: A pilot-operated solenoid valve includes a valve body, a valve cover, a valve core assembly, and an electromagnetic drive device. The valve body has an inlet channel, an outlet channel, and a main valve port located between the two. The valve core assembly includes a diaphragm and a drive rod. The diaphragm is movably disposed at the main valve port for opening or closing the main valve port, and the diaphragm has a guide hole and a balance hole that are isolated from each other. The valve cover has a sealing element, and a sealing cavity is formed between the sealing element and the diaphragm. The guide hole can communicate with the outlet channel, and the drive rod is used to open and close the guide hole. The balance hole connects the sealing cavity and the inlet channel.

[0007] By adopting the above technical solution, this application integrates the opening and closing control of the main valve port and the pilot pressure control function into the same diaphragm component, and optimizes the guiding design of the valve cover. The valve cover has a guide hole arranged coaxially perpendicular to the direction of the main valve port. The diaphragm is axially movable within this guide hole, providing precise guidance for the opening and closing movement of the diaphragm, preventing skewing and jamming during movement, and reducing dependence on the coaxiality of the assembly between parts. The groove on the diaphragm cooperates with the sealing element on the valve cover to form a sealing cavity above the diaphragm. This structural design facilitates the installation and positioning of the sealing element and improves the reliability of the seal. The guide hole and balance hole on the diaphragm are physically isolated from each other in space and flow path. The guide hole, as a key outlet of the pilot control flow path, is directly controlled by the drive rod and connects the sealing cavity and the outlet channel; the balance hole, as a static pressure balancing channel, always connects the sealing cavity and the high-pressure inlet channel. This "one-petal, two-hole, functionally separated, and guide-optimized" design optimizes the fluid path and motion mechanism, reducing the risk of impurity deposition and clogging, making it particularly suitable for media environments with poor water quality or containing small particles. Simultaneously, the static pressure balance established through the balancing orifice ensures that the static pressure on both sides of the diaphragm is essentially equal when the solenoid valve is not in operation. At this point, the diaphragm, under the preload of the second spring, can reliably seal against the main valve port, avoiding creep or premature fatigue of the sealing element caused by continuous pressure on one side, thus improving the reliability and durability of the seal. The guide orifice design further enhances the consistency and lifespan of the valve's operation.

[0008] Optionally, a baffle is fixedly provided in the valve body, the baffle separating the water inlet channel from the water outlet channel, the main valve port being located at the baffle, and the diaphragm flap being separably attached to the axial end face of the baffle.

[0009] By adopting the above technical solution, a fixed baffle is integrated inside the valve body. This baffle acts as a structural skeleton, clearly dividing the valve body cavity into independent inlet and outlet water passage chambers. The main valve port is directly machined in the center of this baffle. This design makes the valve body structure more compact and integral, reducing additional connecting parts and potential leakage points. The diaphragm flap directly adheres to the flat axial end face of the baffle for sealing. The sealing path is very short, and the force-bearing surface is planar, which makes the sealing force transmission direct and effective. Compared with the design of placing the main valve port at a complex flow channel bend, this solution simplifies the geometric relationship of the sealing pair, not only reducing the machining difficulty of the diaphragm flap and valve port, but also improving the sealing consistency of the main valve port during frequent opening and closing. In addition, the baffle structure provides a stable and reliable installation reference surface for the diaphragm flap, which helps to ensure the movement trajectory of the diaphragm flap during operation and improves the response speed and accuracy of the main valve port opening and closing.

[0010] Optionally, a sealing ring is provided between the main valve port and the diaphragm flap.

[0011] By adopting the above technical solution, an elastic sealing ring is embedded at the edge of the main valve port of the diaphragm or at the corresponding contact surface of the diaphragm flap. This sealing ring constitutes the first line of defense for the main seal. When the diaphragm flap is pressed against the diaphragm under the action of the second spring, the sealing ring first undergoes elastic deformation, filling the microscopic unevenness between the diaphragm flap and the end face of the diaphragm, achieving an initial seal. As the system pressure builds up, the medium pressure further pushes the diaphragm flap against the diaphragm, increasing the compression and contact stress of the sealing ring, forming a self-tightening sealing effect. This dual sealing mechanism of "elastic pre-tightening + pressure assistance" significantly improves the sealing level and reliability of the main valve port under high-pressure conditions. The sealing ring material can be flexibly selected according to the characteristics of the medium, thereby broadening the applicable medium range of the solenoid valve. This design is a major improvement over the solution that relies solely on the elasticity of the diaphragm flap material for sealing, and is especially suitable for applications with high working pressure, stringent sealing requirements, or media with slight permeability.

[0012] Optionally, the electromagnetic drive device includes a coil assembly, a moving iron core axially movable within the coil assembly, and a fixed iron core fixedly connected to the coil assembly.

[0013] By adopting the above technical solution, a mature electromagnetic direct drive principle is employed. When the coil assembly is energized, it generates a magnetic field, driving the moving iron core to perform precise axial linear motion within a guide cavity composed of a fixed iron core and a coil frame. This driving method offers advantages such as fast response speed, precise control, and a good linear relationship between output force and current. The linear motion of the moving iron core is directly converted into the lifting and lowering of the drive rod via a mechanical connection, resulting in a short power transmission chain, high efficiency, and no lag or energy loss caused by intermediate conversion links. The entire electromagnetic drive device has a compact structure, facilitating modular design and production. The fixed connection between the fixed iron core and the coil assembly provides a stable magnetic circuit and motion reference for the moving iron core, ensuring the efficiency and stability of the electromagnetic force output. This solution is suitable for automated fluid control systems requiring rapid opening and closing, precise control, or frequent operations.

[0014] Optionally, the moving iron core is detachably connected to the drive rod.

[0015] By adopting the above technical solution, the connection between the moving iron core and the drive rod is designed to be detachable. This brings multiple conveniences in practical applications: First, in the assembly process, the valve body and valve cover can be assembled and tested separately from the electromagnetic drive module before final assembly, improving the assembly efficiency and flexibility of the production line. Second, in the maintenance process, if the electromagnetic drive part or the valve core part needs to be repaired or replaced, they can be easily separated for localized repairs, eliminating the need for complete scrapping or complex disassembly, thus reducing maintenance costs and time. Third, in terms of product serialization, by adapting drive rods of different lengths or specifications, electromagnetic drive modules of the same specification can be combined with valve body components of different diameters or connection methods to quickly form a product series, meeting diverse customer needs. This design reflects a design philosophy oriented towards manufacturing and assembly as well as ease of maintenance.

[0016] Optionally, the bottom end face of the moving iron core is provided with an axial blind hole, and the side wall of the blind hole is provided with a radially penetrating pin hole; one end of the drive rod is connected to the diaphragm flap, and the other end extends into the blind hole, and the side wall of the rod segment located in the blind hole is provided with a limiting groove; the pin hole and the limiting groove are radially corresponding, and a pin passes through the pin hole and is engaged in the limiting groove, so that the drive rod and the moving iron core are relatively fixed in the axial direction.

[0017] By adopting the above technical solution, a specific, efficient, and reliable interlocking mechanical connection implementation scheme is provided. The blind hole at the bottom of the moving iron core provides guiding and accommodating space for the upper end of the drive rod. After the drive rod is inserted into the blind hole, a radially inserted pin passes through both the pin hole of the moving iron core and the limiting groove of the drive rod, achieving axial fixation and circumferential limiting of both. The staggered arrangement of the pin hole and the blind hole ensures that the insertion path of the pin intersects with the axial movement direction of the drive rod, further enhancing the torsional resistance and overall stability of the connection structure. This connection method has the following outstanding advantages: the connection is firm and reliable, the pin withstands shear force, and it can effectively transmit electromagnetic driving force and return spring force; the centering requirement is relatively relaxed, the clearance between the blind hole and the drive rod can be appropriately enlarged, and the fit between the pin and the limiting groove can absorb minor centering errors. This significantly reduces the precision machining requirements for the extremely high coaxiality of the two key components, the moving iron core and the drive rod, thereby reducing manufacturing costs and scrap rate; the assembly process is simple, requiring only the insertion of the drive rod, alignment of the hole and groove, and driving in the pin, making it easy to achieve automated or semi-automated assembly and improving production efficiency. It is an optimal solution that cleverly balances precision, cost, and reliability while ensuring performance.

[0018] Optionally, the moving iron core has a mounting hole at one end near the fixed iron core, and a first spring is placed in the mounting hole, with one end of the first spring abutting against the bottom of the fixed iron core.

[0019] By adopting the above technical solution, a dedicated mounting hole is set inside the moving iron core to accommodate the first spring. This mounting hole provides precise radial positioning for the spring, preventing it from deflecting or jamming during operation. One end of the first spring abuts against the bottom of the fixed iron core, providing the moving iron core with a continuous, directional restoring force pointing towards the disengaged electromagnetic engagement position. Its core function is that when the electromagnetic coil is de-energized, the spring force can quickly and reliably push the moving iron core back to its initial position, thereby driving the drive rod to close the guide orifice. This is the key guarantee for the solenoid valve to achieve the "power-off shutdown" function. The selection of spring parameters directly affects the minimum operating differential pressure, response speed, and closing sealing performance of the solenoid valve. The design of embedding it within the moving iron core makes the structure more compact and avoids the additional space occupation and protection problems that may arise from an external spring.

[0020] Optionally, a second spring is fitted on the drive rod, with one end of the second spring abutting against the diaphragm flap and the other end abutting against the inner wall of the valve cover.

[0021] By adopting the above technical solution, a second spring is installed between the diaphragm flap and the inner wall of the valve cover. This second spring drives the diaphragm flap to abut against the main valve port, and its force always pushes the diaphragm flap in the direction of closing the main valve port. The second spring and the first spring together form a synergistic dual-spring reset system. The first spring mainly ensures the reset of the electromagnetic drive part, while the second spring directly provides the necessary initial sealing pressure to the diaphragm flap. Even under very low or even zero system pressure, the second spring can ensure sufficient clamping force between the diaphragm flap and the main valve port to achieve a reliable seal. When the system pressure is built up, the spring force and the fluid pressure work together to further enhance the sealing effect. This design decouples and optimizes the reset function and the sealing pre-tightening function separately, enabling the solenoid valve to maintain good sealing performance and response characteristics over a wide range from low to high pressure, improving the product's adaptability and reliability.

[0022] Optionally, the coil assembly includes an electromagnetic coil, a protective housing is fitted over the electromagnetic coil, and a power connection board is connected to the protective housing.

[0023] By adopting the above technical solution, the electromagnetic drive component has been integrated and designed with protection. The electromagnetic coil is the core electromagnetic conversion element, and it is encased in a protective shell. This shell is typically made of metal or high-strength engineering plastic, primarily serving as physical protection, environmental protection, and electromagnetic shielding. The power connection plate is fixed to the protective shell and integrates terminals or leads, providing a standard and reliable electrical interface for users to quickly and correctly connect the power cord. This modular, protected shell design allows the electromagnetic drive component to adapt to more complex industrial environments, improving the overall durability and ease of installation of the solenoid valve.

[0024] Optionally, a nut seat is provided at the end of the fixed iron core away from the electromagnetic coil, and the nut seat presses and fixes the electromagnetic coil inside the protective shell.

[0025] By adopting the above technical solution, a nut seat is installed at the tail end of the fixed iron core. During assembly, after placing the internal components such as the electromagnetic coil, moving iron core, and fixed iron core into the protective shell, the entire electromagnetic core assembly is firmly pressed and fixed within the protective shell by rotating the nut seat or tightening the mating nut with a tool. This fixing method has the advantages of simple structure, strong clamping force, and good shock resistance. It eliminates the need for multiple screws, pressure plates, or retaining rings that may be required in traditional solutions, simplifying the assembly process of the coil assembly, reducing the number of parts, and lowering costs. At the same time, this axial clamping method helps ensure the stability and consistency of the relative position between the electromagnetic coil and the fixed and moving iron cores, which is crucial for maintaining stable electromagnetic performance. The nut seat itself can also serve as an auxiliary structure for hoisting or installation, increasing the integration of the design.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. This application constructs an independent and optimized pilot control and pressure balance dual flow channel by opening mutually isolated guide holes and balance holes on the main valve diaphragm, thereby solving the technical problem of easy clogging of the single pilot flow channel of the traditional pilot-operated solenoid valve, and significantly enhancing the working reliability and durability of the valve under harsh media conditions. 2. This application reduces the reliance on precision machining of parts by adopting an interlocking mechanical connection (such as a pin limiting structure) between the moving iron core and the drive rod, thereby widening the manufacturing tolerance and improving production efficiency and product consistency; 3. This application forms a dual reset system that acts on the pilot valve and the main valve respectively by setting a first spring that is respectively housed in the central hole of the moving iron core and a second spring located in the sealing cavity. This effectively improves the valve shut-off response speed, sealing reliability and action consistency, and extends the service life of key moving parts. Attached Figure Description

[0027] Figure 1 This is a three-dimensional structural schematic diagram of a pilot-operated solenoid valve in the embodiment; Figure 2 This is a cross-sectional view of a pilot-operated solenoid valve in the embodiment; Figure 3 This is a magnified view of a portion of the membrane flap described in the embodiment; Figure 4 This is an assembly diagram of the drive rod and the moving iron core described in the embodiment.

[0028] In the diagram: 1. Valve body; 11. Inlet channel; 12. Outlet channel; 13. Main valve port; 131. Sealing ring; 14. Baffle plate; 2. Valve cover; 21. Guide hole; 3. Valve core assembly; 31. Diaphragm; 311. Flow guide hole; 312. Balance hole; 313. Groove; 32. Drive rod; 321. Limiting groove; 4. Sealing element; 5. Sealing cavity; 6. Electromagnetic drive device; 61. Coil assembly; 611. Electromagnetic coil; 612. Protective shell; 613. Power connection plate; 62. Moving iron core; 621. Blind hole; 622. Mounting hole; 623. Pin hole; 624. Pin; 63. Fixed iron core; 631. Nut seat; 7. First spring; 8. Second spring. Detailed Implementation

[0029] The following will be combined with the appendix Figures 1 to 4 The technical solutions of the various embodiments of this application have been clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0030] Example 1 Reference Figure 1 and Figure 2 This application discloses a pilot-operated solenoid valve, including a valve body 1, a valve cover 2, a valve core assembly 3, and an electromagnetic drive device 6. The valve body 1 has an inlet channel 11, an outlet channel 12, and a main valve port 13 located between the two. The valve core assembly 3 includes a diaphragm flap 31 and a drive rod 32. The valve cover 2 has a guide hole 21 arranged coaxially in a direction perpendicular to the main valve port 13, and the diaphragm flap 31 is axially movable and disposed in the guide hole 21. The diaphragm flap 31 has a groove 313. The valve cover 2 has a sealing element 4, and a sealing cavity 5 is formed between the sealing element 4 and the groove 313 above the diaphragm flap 31. The diaphragm flap 31 has a guide hole 311 and a balance hole 312 that are isolated from each other. The balance hole 312 connects the sealing cavity 5 and the inlet channel 11. The guide hole 311 connects the sealing cavity 5 and the outlet channel 12. The drive rod 32 can open or close the guide hole 311 under the drive of the electromagnetic drive device 6.

[0031] Specifically, refer to Figure 1 and Figure 2The valve body 1 is typically made of corrosion-resistant metals such as brass or stainless steel, and has independent inlet and outlet channels 11 and 12. A fixed baffle 14 is positioned between these two channels. This baffle 14 can be integrally formed with the valve body 1 or it can be a separate annular component fixed to the valve body 1 by interference fit or welding. The central opening of the baffle 14 forms the main valve port 13, and its end face facing the valve cover 2 is precision machined to form a flat sealing surface. The valve cover 2 is fixedly connected to the upper port of the valve body 1 by bolts, and a sealing gasket is placed between them to ensure a tight seal at the connection. To further enhance the sealing reliability of the main valve port 13, an elastic sealing ring 131 is provided between the main valve port 13 and the diaphragm valve 31. This sealing ring 131 is typically made of wear-resistant and corrosion-resistant elastic materials, such as nitrile rubber or fluororubber. Its function is to provide an additional elastic seal when the diaphragm valve 31 closes the main valve port 13, filling tiny gaps and ensuring effective blocking of the medium.

[0032] Reference Figure 2 and Figure 3 An annular sealing element 4 is installed on the inner side of the valve cover 2. Specifically, a guide hole 21 is machined inside the valve cover 2, coaxially arranged in a direction perpendicular to the main valve port 13. This guide hole 21 provides precise axial guidance for the movement of the valve core assembly 3. The valve core assembly 3 is the core for controlling fluid flow, including a diaphragm 31 and a drive rod 32. The diaphragm 31 is a circular elastic element, commonly made of oil-resistant, aging-resistant rubber or reinforced engineering plastic. The diaphragm 31 is axially movable within the guide hole 21, its position directly opposite the main valve port 13. A groove 313 is provided on the side of the diaphragm 31 facing the valve cover 2. This groove 313 cooperates with the sealing element 4 on the valve cover 2 to form a closed sealing cavity 5 above the diaphragm 31. The diaphragm 31 has two functionally independent and isolated holes: one located in or near the center, called the flow guide hole 311; the other located off-center, called the balance hole 312. The balance hole 312 is always connected to the water inlet channel 11 of the sealing cavity 5 and the valve body 1. The drive rod 32 is a metal rod, one end of which is connected to the central area of ​​the diaphragm flap 31. In the initial state, its lower end blocks the guide hole 311 of the diaphragm flap 31.

[0033] Reference Figures 2 to 4The electromagnetic drive device 6 provides the actuating power for the drive rod 32. It mainly includes a coil assembly 61, a movable iron core 62 that can move axially within the coil assembly 61, and a fixed iron core 63 fixedly connected thereto. The coil assembly 61 consists of an electromagnetic coil 611, a protective outer shell 612 surrounding it, and a power connection plate 613 for connecting to a power source. The movable iron core 62 is detachably connected to the upper end of the drive rod 32. In one specific embodiment, the bottom end face of the movable iron core 62 has an axial blind hole 621, and the side wall of the blind hole 621 has a radially penetrating pin hole 623, with the pin hole 623 and the blind hole 621 arranged alternately. The upper end of the drive rod 32 is inserted into the blind hole 621, and its rod section side wall has a limiting groove 321. During assembly, a pin 624 is inserted into the pin hole 623 and engaged in the limiting groove 321, thus achieving axial relative fixation between the drive rod 32 and the movable iron core 62. This staggered arrangement enhances the torsional stability of the connection structure. To ensure the electromagnetic coil 611 is securely installed, a nut seat 631 is provided at the end of the fixed iron core 63 away from the electromagnetic coil 611. By tightening the nut seat 631, the electromagnetic coil 611 can be pressed and fixed inside the protective housing 612.

[0034] Reference Figure 3 and Figure 4 The reset function of this solenoid valve is achieved by two springs working together. One is a first spring 7, which is housed in the mounting hole 622 at the upper end of the moving iron core 62, with its two ends abutting against the bottom of the fixed iron core 63 and the step in the mounting hole 622, respectively. It is responsible for pushing the moving iron core 62 and the drive rod 32 back to their original positions after power is cut off. The other is a second spring 8, which is located in the sealing cavity 5 formed by the groove 313 of the diaphragm flap 31 and the sealing element 4. Its two ends are compressed between the inner wall of the diaphragm flap 31 and the valve cover 2, and it is used to drive the diaphragm flap 31 to abut against the main valve port 13, providing the diaphragm flap 31 with the initial sealing pressure required to close the main valve port 13.

[0035] The implementation principle of this embodiment is as follows: In the initial power-off closed state, the electromagnetic drive device 6 generates no magnetic force. Under the action of the first spring 7, the moving iron core 62 and the drive rod 32 connected to it are in the upper position, and the lower end of the drive rod 32 blocks the guide hole 311 of the diaphragm flap 31. At the same time, under the pre-tightening force of the second spring 8, the diaphragm flap 31 is tightly attached to the sealing surface of the partition plate 14, closing the main valve port 13. At this time, the medium from the water inlet channel 11 slowly fills through the balance hole 312 on the diaphragm flap 31 and eventually makes the pressure in the sealing cavity 5 equal to the pressure in the water inlet channel 11. Under the combined action of this balanced pressure and the force of the second spring 8, the diaphragm flap 31 remains stably closed and sealed.

[0036] When the solenoid valve needs to be opened, the solenoid coil 611 is energized. The coil generates a magnetic field, attracting the moving iron core 62 to move downwards against the resistance of the first spring 7. The moving iron core 62, connected by the pin 624, drives the drive rod 32 to move downwards synchronously. The lower end of the drive rod 32 then leaves and opens the guide hole 311 of the diaphragm 31. Once the guide hole 311 is open, the medium in the sealing cavity 5 flows rapidly to the outlet channel 12 through this hole, causing a sharp drop in pressure in the sealing cavity 5. At this time, the medium pressure below the diaphragm 31 is significantly higher than the pressure above. Under this pressure difference, the diaphragm 31 bulges upwards against the force of the second spring 8, thus completely separating from the partition 14. The main valve port 13 is opened, and the medium can flow in large quantities from the inlet channel 11 to the outlet channel 12, and the solenoid valve enters the open flow state.

[0037] When the solenoid valve needs to be closed, the power supply to the solenoid coil 611 is cut off. The magnetic field disappears, and the moving iron core 62 immediately returns to its original position under the restoring force of the first spring 7, driving the drive rod 32 back to its original position and re-sealing the guide hole 311 of the diaphragm flap 31. After the guide hole 311 is closed, the medium in the inlet channel 11 slowly flows into the sealing cavity 5 again through the balance hole 312, causing the pressure in the sealing cavity 5 to gradually rise until it is balanced with the pressure in the inlet channel 11 again. As the pressure in the sealing cavity 5 recovers, the diaphragm flap 31 moves downward and re-fits tightly against the sealing surface of the partition 14 under the combined action of the pressure of the second spring 8 and the gradually balanced fluid pressure. The main valve port 13 is reliably closed, and the solenoid valve returns to its initial de-energized closed state. This dual-spring coordinated, pressure differential driven design ensures rapid and reliable valve opening and closing, as well as excellent sealing performance.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this application.

Claims

1. A pilot operated solenoid valve comprising a valve body (1), a valve cover (2), a spool assembly (3) and a solenoid drive (6), characterized in that The valve body (1) has an inlet channel (11), an outlet channel (12), and a main valve port (13) located between them. The valve core assembly (3) includes a diaphragm flap (31) and a drive rod (32). The valve cover (2) has a guide hole (21) arranged coaxially in a direction perpendicular to the main valve port (13), and the diaphragm flap (31) is axially movable within the guide hole (21). The diaphragm flap (31) has a groove (313). The valve cover (2) has a sealing element (4). A sealing cavity (5) is formed between the element (4) and the groove (313) above the membrane flap (31); the membrane flap (31) is provided with a guide hole (311) and a balance hole (312) that are isolated from each other; the balance hole (312) connects the sealing cavity (5) and the water inlet channel (11); the guide hole (311) connects the sealing cavity (5) and the water outlet channel (12); the drive rod (32) can open or close the guide hole (311) under the drive of the electromagnetic drive device (6).

2. A pilot operated solenoid valve according to claim 1, characterized in that The valve body (1) is fixedly provided with a partition (14), which separates the water inlet channel (11) from the water outlet channel (12). The main valve port (13) is located at the partition (14), and the diaphragm flap (31) is separably attached to the axial end face of the partition (14).

3. A pilot operated solenoid valve according to claim 2, wherein A sealing ring (131) is provided between the main valve port (13) and the diaphragm flap (31).

4. The pilot operated solenoid valve according to claim 1, wherein The electromagnetic drive device (6) includes a coil assembly (61), a moving iron core (62) axially movable within the coil assembly (61), and a fixed iron core (63) fixedly connected to the coil assembly (61).

5. A pilot-operated solenoid valve according to claim 4, characterized in that, The moving iron core (62) is detachably connected to the drive rod (32).

6. A pilot-operated solenoid valve according to claim 5, characterized in that, The bottom end face of the moving iron core (62) is provided with an axial blind hole (621), and the side wall of the blind hole (621) is provided with a radially penetrating pin hole (623); the pin hole (623) and the blind hole (621) are arranged alternately; the upper end of the drive rod (32) is inserted into the blind hole (621), and the side wall of the drive rod (32) is provided with a limiting groove (321); the pin (624) provided in the pin hole (623) is adapted to the limiting groove (321).

7. A pilot-operated solenoid valve according to claim 4, characterized in that, The moving iron core (62) has a mounting hole (622) at one end near the fixed iron core (63). A first spring (7) is placed in the mounting hole (622), and one end of the first spring (7) abuts against the bottom of the fixed iron core (63).

8. A pilot-operated solenoid valve according to claim 7, characterized in that, A second spring (8) is provided between the diaphragm flap (31) and the inner wall of the valve cover (2), and the second spring (8) is used to drive the diaphragm flap (31) to abut against the main valve port (13).

9. A pilot-operated solenoid valve according to claim 4, characterized in that, The coil assembly (61) includes an electromagnetic coil (611), a protective shell (612) is fitted on the electromagnetic coil (611), and a power connection plate (613) is connected to the protective shell (612).

10. A pilot-operated solenoid valve according to claim 9, characterized in that, The fixed iron core (63) is provided with a nut seat (631) at one end away from the electromagnetic coil (611), and the nut seat (631) presses and fixes the electromagnetic coil (611) inside the protective shell (612).

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