Single-coil three-position four-way electromagnetic valve

Abstract

The application belongs to the technical field of electromagnetic valves, and is especially a single-coil three-position four-way electromagnetic valve, which comprises a valve group, the valve group comprises a valve sleeve and a valve core slidingly connected in the valve sleeve, a bidirectional electromagnet is installed on one side of the valve group, an armature in the bidirectional electromagnet is connected with a push rod, the bidirectional electromagnet drives the valve core through the push rod, and a centering mechanism for resetting is installed between the valve group and the bidirectional electromagnet; independent springs are adopted in the application, the springs are matched with the bosses in the shell through the gaskets at the two ends of the springs, the armature can be reset when the electromagnet loses magnetic force, the valve core is simultaneously reset, the valve core is ensured to be in the accurate center position, and the accuracy and the service life are higher and longer, respectively, compared with the common resetting mechanism in which two springs are arranged opposite to each other.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic valve technology, specifically relating to a single-coil three-position four-way electromagnetic valve. Background Technology

[0002] Solenoid valves are electromagnetically controlled industrial devices and are basic automated components 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, thus ensuring both control accuracy and flexibility. There are many types of solenoid valves, and different solenoid valves play different roles in different parts of the control system.

[0003] In existing solenoid valves, the stroke of the internal valve core is a fixed value set initially. The stroke corresponds to the open position of the valve core and cannot be adjusted. For three-position solenoid valves, a return spring is generally used to reset the valve core to the neutral position when the electromagnetic force is lost. The valve core and valve sleeve of the solenoid valve need to cooperate to achieve on / off switching, so the accuracy requirements are high. The traditional reset mechanism is two sets of symmetrically arranged springs. However, after long-term use, the springs are prone to deformation, resulting in uneven elastic force on both sides, which affects the reset and centering of the valve core.

[0004] To address the aforementioned issues, this application proposes a single-coil three-position four-way solenoid valve. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a single-coil three-position four-way solenoid valve, which features precise centering even after long-term use, rapid response, and adjustable valve core stroke.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a single-coil three-position four-way solenoid valve, comprising a valve assembly, the valve assembly comprising a valve sleeve and a valve core slidably connected in the valve sleeve, a bidirectional electromagnet mounted on one side of the valve assembly, an armature of the bidirectional electromagnet connected to a push rod, the bidirectional electromagnet driving the valve core through the push rod, a centering mechanism for reset being installed between the valve assembly and the bidirectional electromagnet, the centering mechanism comprising a guide seat, one end of the guide seat being inserted into and threadedly connected to the bidirectional electromagnet, a connecting sleeve being installed on the exposed end of the guide seat, the connecting sleeve being used to connect the valve sleeve and the guide seat, a reset spring being provided inside the guide seat and sleeved outside the push rod, the middle part of the push rod being a boss structure, one side of the reset spring being provided on the boss of the push rod, and the other side being provided with a hook connector abutting against the surface of the hook connector, the hook connector being connected to the valve core.

[0007] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, the guide seat has a channel in the middle that matches the boss of the push rod, and the boss of the push rod slides in the channel.

[0008] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, the centering mechanism includes a spring pad disposed on the surface of the hook connector. The spring pad is sleeved on the surface of the hook connector, one side of the spring pad abuts against one end of the return spring, and the inner edge of the other side engages with the boss of the hook connector. The valve sleeve has a stepped structure formed on the inner side of one end inside the connecting sleeve, and a limiting pad is engaged at the bottom of the stepped structure. The outer edge of the hook connector corresponds to the limiting pad, and the distance from the hook connector to the limiting pad is B. The connecting sleeve is sleeved on the surfaces of the guide seat and the valve sleeve, and a gap is provided between the guide seat and the valve sleeve. The spring pad is disposed at this gap, and its outer wall is in contact with the connecting sleeve. The distance from the spring pad to the end face of the guide seat is also B.

[0009] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, the end of the hook connector away from the return spring is integrally formed with the valve core, and the inner walls of the hook connector and the valve sleeve are provided with a slot, the end of the return spring is disposed in the slot, and the return spring abuts against both the hook connector and the inner wall of the valve sleeve.

[0010] As a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, the bidirectional electromagnet includes a housing, a coil wound inside the housing, an armature slidably connected inside the coil, a push rod installed in the middle of the armature, a plug installed on the top of the housing, a screw plug threadedly connected to the side of the housing, the screw plug extending to the inner side of the coil and symmetrically arranged with the guide seat, and two sets of permanent magnets symmetrically arranged in the middle of the inner side of the coil.

[0011] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, both ends of the return spring are provided with washers, which are made of metal and are used to increase the contact area of ​​the return spring.

[0012] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, both the middle part of the hook connector and the valve core are provided with pin holes, and the hook connector and the valve core are pin-connected.

[0013] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, the end face of the push rod is a frustum structure, and the hook connector is provided with a T-shaped through groove corresponding to the position of the push rod, and the hook connector and the push rod are engaged through the T-shaped through groove.

[0014] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, both the plug and the guide seat are made of soft magnetic material.

[0015] In a preferred embodiment of the single-coil three-position four-way solenoid valve of the present invention, the distance from the armature to the screw plug and the guide seat is ±A.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention employs an independent spring. Through the cooperation of washers at both ends of the spring and bosses inside the housing, when the electromagnet loses its magnetic force, the armature can be reset, simultaneously driving the valve core to reset, ensuring that the valve core is in an accurate neutral position and maintaining accuracy and stability even after long-term use. By adjusting the plug and guide seat, and replacing the washers at both ends of the spring, the valve core's neutral position can be adjusted within a certain range during valve body assembly, improving the accuracy of the solenoid valve. When the valve body stroke is less than the electromagnet stroke, the propulsion stroke can also be changed by adjusting the washers to prevent misalignment between the valve core and the valve sleeve. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of the single-coil three-position four-way solenoid valve of the present invention;

[0020] Figure 2 This is a top view of the single-coil three-position four-way solenoid valve of the present invention.

[0021] Figure 3 For the present invention Figure 2 A schematic diagram of the cross-sectional structure at point AA;

[0022] Figure 4 This is an exploded structural diagram of the centering mechanism in this invention;

[0023] Figure 5 For the present invention Figure 4 A schematic diagram of the cross-sectional structure;

[0024] Figure 6 This is a cross-sectional view of Embodiment 2 of the present invention;

[0025] Figure 7 This is a schematic diagram of the exploded structure of the centering mechanism in Embodiment 2 of the present invention;

[0026] Figure 8 For the present invention Figure 7 A schematic diagram of the cross-sectional structure;

[0027] In the diagram: 10. Valve assembly; 11. Valve sleeve; 12. Valve core; 20. Bidirectional electromagnet; 21. Housing; 22. Coil; 23. Armature; 24. Push rod; 25. Plug; 26. Plug; 30. Centering mechanism; 31. Guide seat; 32. Connecting sleeve; 33. Return spring; 34. Hook connector; 35. Spring washer; 36. Limiting washer; 37. Washer. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] like Figures 1 to 8 As shown;

[0031] A single-coil three-position four-way solenoid valve includes a valve assembly 10, which includes a valve sleeve 11 and a valve core 12 slidably connected in the valve sleeve 11. A bidirectional electromagnet 20 is mounted on one side of the valve assembly 10. An armature 23 in the bidirectional electromagnet 20 is connected to a push rod 24. The bidirectional electromagnet 20 drives the valve core 12 through the push rod 24. A centering mechanism 30 for resetting is installed between the valve assembly 10 and the bidirectional electromagnet 20. The centering mechanism 30 includes a guide seat 31, one end of which is inserted into... It is threaded into the bidirectional electromagnet 20. A connecting sleeve 32 is installed on the exposed end of the guide seat 31. The connecting sleeve 32 is used to connect the valve sleeve 11 and the guide seat 31. A return spring 33 is provided inside the guide seat 31 and sleeved outside the push rod 24. The middle part of the push rod 24 is a boss structure. One side of the return spring 33 is provided on the boss of the push rod 24, and the other side is provided with a hook connector 34 and abuts against the surface of the hook connector 34. The hook connector 34 is connected to the valve core 12.

[0032] In this embodiment: When the invention is working, the bidirectional electromagnet 20 drives the valve core 12 in the valve assembly 10. Due to the bidirectional movement of the bidirectional electromagnet 20, the valve core 12 can move left or right in the valve sleeve 11, so that the valve assembly 10 has three valve positions, namely left position, center position and right position. Taking the initial state of center position as an example, when a constant DC current is applied to the bidirectional electromagnet 20, it generates electromagnetic attraction and moves the armature 23 to one side, thereby driving the push rod 24 to move. The push rod 24 overcomes the elastic force of the return spring 33 and drives the valve core 12 to move. When the bidirectional electromagnet 20 is de-energized, the return spring 33 in the centering mechanism 30 resets, driving the valve core 12 back. When the valve reaches the neutral position, a constant DC current in the opposite direction is applied to the bidirectional electromagnet 20, causing the armature 23 to move to the other side, thereby driving the valve core 12 to move in the opposite direction. Since the neutral position of the valve group 10 is reset by a reset spring 33, which has a preload and is limited by the guide seat 31 and the valve core 12, the reset spring 33 can keep the valve core 12 in a stable and accurate position when it is reset. Compared with the common reset mechanism with two springs set opposite each other, it has higher accuracy and longer service life. Since the armature 23 and the valve core 12 are connected by the push rod 24, the repositioning of the valve core 12 and the movement of the armature 23 are synchronized, and its response speed is rapid and stable.

[0033] It should be noted that the return spring 33 has a certain preload.

[0034] It should be noted that the distance from armature 23 to screw plug 26 and guide seat 31 is ±A, where A is the driving stroke of bidirectional electromagnet 20.

[0035] Furthermore:

[0036] When the stroke of the valve core 12 is less than the stroke of the electromagnet, the centering mechanism 30 includes a spring pad 35 disposed on the surface of the hook connector 34. The spring pad 35 is sleeved on the surface of the hook connector 34. One side of the spring pad 35 abuts against one end of the return spring 33, and the inner edge of the other side engages with the boss of the hook connector 34. The valve sleeve 11 has a stepped structure formed on the inner side of one end inside the connecting sleeve 32. The bottom of the stepped structure engages with the limiting pad 36. The outer edge of the hook connector 34 corresponds to the limiting pad 36, and the distance from the hook connector 34 to the limiting pad 36 is B. The connecting sleeve 32 is sleeved on the surface of the guide seat 31 and the valve sleeve 11, and a gap is provided between the guide seat 31 and the valve sleeve 11. The spring pad 35 is disposed in this gap, and its outer wall is in contact with the connecting sleeve 32. The distance from the spring pad 35 to the end face of the guide seat 31 is also B.

[0037] In this implementation scheme: when A>B, that is, when the displacement stroke of the bidirectional electromagnet 20 is greater than the stroke of the valve core 12, in this case, when the valve core 12 moves to the left and right positions, the bidirectional electromagnet 20 fails to move to the end of its stroke.

[0038] like Figure 3 As shown, the valve core 12 is in the neutral position at this time. When the bidirectional electromagnet 20 is energized and the armature 23 moves to the right, it drives the push rod 24 to move to the right. The boss in the middle of the push rod 24 pushes the left end of the return spring 33 to move to the right. The right end of the return spring 33 abuts against the surface of the spring pad 35. The spring pad 35 abuts against the end face of the valve sleeve 11 for limiting, so that the return spring 33 is in a compressed state. The push rod 24 pushes the hook connector 34 and the valve core 12 to move to the right until the edge of the hook connector 34 abuts against the surface of the limiting pad 36. At this time, the valve core 12 completes the movement to the right by B.

[0039] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 drives the boss in the middle of the push rod 24 to move until the left end of the return spring 33 moves and abuts against the bottom of the guide seat 31. The guide seat 31 limits the return spring 33, and at this time the valve core 12 is reset in the middle position.

[0040] When the bidirectional electromagnet 20 is energized in reverse, the armature 23 moves to the left, which drives the push rod 24 to move to the left. The push rod 24 drives the hook connector 34 and the valve core 12 to move to the left. At the same time, the hook connector 34 drives the spring pad 35 to slide along the inner wall of the connecting sleeve 32 until the surface of the spring pad 35 abuts against the end face of the guide seat 31. The spring pad 35 drives the return spring 33 to be in a compressed state. At this time, the valve core 12 completes the leftward movement B.

[0041] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 abuts against the bottom of the guide seat 31, and the right end of the return spring 33 moves and drives the spring pad 35 to move to the right along the inner wall of the connecting sleeve 32 until the spring pad 35 moves to the end face limit of the valve sleeve 11. The spring pad 35 drives the hook connector 34 to move to the limit, and at this time the valve core 12 is reset to the middle position.

[0042] Example 2

[0043] When A=B, the end of the hook connector 34 away from the return spring 33 is integrally formed with the valve core 12. The inner walls of the hook connector 34 and the valve sleeve 11 are provided with slots, and the end of the return spring 33 is set in the slots. The return spring 33 abuts against the inner walls of the hook connector 34 and the valve sleeve 11.

[0044] In this embodiment: when A=B, that is, when the displacement stroke of the bidirectional electromagnet 20 is equal to the stroke of the valve core 12, in this case, when the valve core 12 moves to the left position and the right position, the bidirectional electromagnet 20 also moves to the end of the stroke, without the need for other limiting.

[0045] like Figure 6As shown, the valve core 12 is in the neutral position at this time. When the bidirectional electromagnet 20 is energized and the armature 23 moves to the right, it drives the push rod 24 to move to the right. The boss in the middle of the push rod 24 pushes the left end of the return spring 33 to move to the right. The right end of the return spring 33 abuts against the valve sleeve 11 for limiting, so that the return spring 33 is in a compressed state. The push rod 24 pushes the hook connector 34 and the valve core 12 to move to the right until the armature 23 moves to the end of its stroke. At this time, the valve core 12 has completed moving to the right by A.

[0046] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 drives the boss in the middle of the push rod 24 to move until the left end of the return spring 33 moves and abuts against the bottom of the guide seat 31. The guide seat 31 limits the left end of the return spring 33, and at this time the valve core 12 is reset in the middle position.

[0047] When the bidirectional electromagnet 20 is energized in reverse, the armature 23 moves to the left, which drives the push rod 24 to move to the left. The push rod 24 drives the hook connector 34 and the valve core 12 to move to the left. At the same time, the hook connector 34 drives the right end of the return spring 33 to move to the left. The bottom of the guide seat 31 limits the left end of the return spring 33, keeping it in a compressed state, until the armature 23 moves to the end of its stroke. At this time, the valve core 12 completes the leftward movement A.

[0048] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 abuts against the bottom of the guide seat 31, and the right end of the return spring 33 moves and drives the hook connector 34 to move to the right until the right end of the return spring 33 moves to the slot of the valve sleeve 11 and is limited. The hook connector 34 and the valve core 12 move to the middle position, completing the reset.

[0049] Furthermore:

[0050] In an optional embodiment, the guide seat 31 has a channel in the middle that matches the boss of the push rod 24, and the boss of the push rod 24 slides in the channel.

[0051] In this embodiment: With this design, the push rod 24 slides smoothly in the guide seat 31, which makes it easy for the armature 23 to drive the push rod 24 to move left and right along the guide seat 31.

[0052] Furthermore:

[0053] In an optional embodiment, the bidirectional electromagnet 20 includes a housing 21, a coil 22 wound inside the housing 21, an armature 23 slidably connected inside the coil 22, a push rod 24 installed in the middle of the armature 23, a plug 25 installed on the top of the housing 21, a screw plug 26 threadedly connected to the side of the housing 21, the screw plug 26 extending to the inner side of the coil 22 and symmetrically arranged with the guide seat 31, and two sets of permanent magnets symmetrically arranged installed in the middle of the inner side of the coil 22.

[0054] In this embodiment: Through this design, the bidirectional electromagnet 20 of the present invention can achieve bidirectional driving operation.

[0055] When not powered on, the two sets of permanent magnets are symmetrically arranged, with their N and S poles positioned on the left and right. Under symmetrical conditions, the magnetic fields of the two sets of permanent magnets cancel each other out. Therefore, the armature 23 does not tend to move to the sides and remains in a stable state without external force. At this time, the preload of the return spring 33 plays a dominant role, keeping the valve core 12 in the neutral position.

[0056] When a constant DC current is applied, taking the right position as an example, the coil 22 generates a magnetic field, and the magnetic field is superimposed on the right permanent magnet and canceled out by the left permanent magnet, causing a large difference in the magnetic fields on the left and right sides of the armature 23, thereby causing the armature 23 to move to the right, thus driving the valve core 12 to overcome the reset spring 33 and move to the right position.

[0057] When a constant DC current is applied in reverse, coil 22 generates a reverse magnetic field. The magnetic field is superimposed on the left permanent magnet and canceled out by the right permanent magnet, causing a large difference in the magnetic fields on the left and right sides of armature 23. This causes armature 23 to move to the left, thereby driving valve core 12 to move to the left position against the return spring 33. Screw plug 26 limits armature 23, and guide seat 31 limits the right side of armature 23.

[0058] Furthermore:

[0059] In an optional embodiment, washers 37 are provided at both ends of the return spring 33. The washers 37 are made of metal and are used to increase the contact area of ​​the return spring 33.

[0060] In this embodiment: With this design, the washer 37 is a plane, which makes it easier to abut against the plane compared to the return spring 33, and the abutment is more stable. In addition, during the manufacture and assembly of this invention, the preload of the return spring 33 can be adjusted by changing the thickness of the washer 37.

[0061] Furthermore:

[0062] In an optional embodiment, both the middle part of the hook connector 34 and the valve core 12 are provided with pin holes, and the hook connector 34 and the valve core 12 are pin-connected.

[0063] In this embodiment: This design facilitates the installation and disassembly of the hook connector 34. The size of the hook connector 34 can be adjusted by B, thereby adapting to different models of valve cores 12, and facilitating the assembly, inspection and maintenance of this invention.

[0064] Furthermore:

[0065] In an optional embodiment, the end face of the push rod 24 is a frustum structure, and the hook connector 34 is provided with a T-shaped through groove at the position corresponding to the push rod 24. The hook connector 34 and the push rod 24 are engaged through the T-shaped through groove.

[0066] In this embodiment: With this design, when installing the valve assembly 10, the push rod 24 is locked in the hook connector 34, and then the valve assembly 10 is rotated into the connecting sleeve 32 to complete the installation of the valve assembly 10. This structure facilitates the assembly of the present invention and will not cause the valve sleeve 11 and valve core 12 to rotate or shift.

[0067] Furthermore:

[0068] In an optional embodiment, both the screw plug 26 and the guide seat 31 are made of soft magnetic material.

[0069] In this embodiment: Through this design, the screw plug 26 and the guide seat 31 serve as the iron core, which facilitates the coil 22 to generate a larger and more stable magnetic force, and facilitates the attraction of the armature 23 to move.

[0070] The overall working principle and usage process of the present invention: When the present invention is working, the bidirectional electromagnet 20 drives the valve core 12 in the valve group 10. Due to the bidirectional movement of the bidirectional electromagnet 20, the valve core 12 can move to the left or right in the valve sleeve 11, so that the valve group 10 has three valve positions, namely the left position, the middle position and the right position. The present invention takes the initial state of the middle position as an example.

[0071] When A>B, that is, when the displacement stroke of the bidirectional electromagnet 20 is greater than the stroke of the valve core 12, in this case, when the valve core 12 moves to the left and right positions, the bidirectional electromagnet 20 fails to move to the end of its stroke.

[0072] like Figure 3 As shown, the valve core 12 is in the neutral position at this time. When the bidirectional electromagnet 20 is energized and the armature 23 moves to the right, it drives the push rod 24 to move to the right. The boss in the middle of the push rod 24 pushes the left end of the return spring 33 to move to the right. The right end of the return spring 33 abuts against the surface of the spring pad 35. The spring pad 35 abuts against the end face of the valve sleeve 11 for limiting, so that the return spring 33 is in a compressed state. The push rod 24 pushes the hook connector 34 and the valve core 12 to move to the right until the edge of the hook connector 34 abuts against the surface of the limiting pad 36. At this time, the valve core 12 completes the movement to the right by B.

[0073] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 drives the boss in the middle of the push rod 24 to move until the left end of the return spring 33 moves and abuts against the bottom of the guide seat 31. The guide seat 31 limits the return spring 33, and at this time the valve core 12 is reset in the middle position.

[0074] When the bidirectional electromagnet 20 is energized in reverse, the armature 23 moves to the left, which drives the push rod 24 to move to the left. The push rod 24 drives the hook connector 34 and the valve core 12 to move to the left. At the same time, the hook connector 34 drives the spring pad 35 to slide along the inner wall of the connecting sleeve 32 until the surface of the spring pad 35 abuts against the end face of the guide seat 31. The spring pad 35 drives the return spring 33 to be in a compressed state. At this time, the valve core 12 completes the leftward movement B.

[0075] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 abuts against the bottom of the guide seat 31, and the right end of the return spring 33 moves and drives the spring pad 35 to move to the right along the inner wall of the connecting sleeve 32 until the spring pad 35 moves to the end face limit of the valve sleeve 11. The spring pad 35 drives the hook connector 34 to move to the limit, and at this time the valve core 12 is reset in the middle position.

[0076] When A=B, that is, when the displacement stroke of the bidirectional electromagnet 20 is equal to the stroke of the valve core 12, in this case, when the valve core 12 moves to the left position and the right position, the bidirectional electromagnet 20 also moves to the end of the stroke, without the need for other limits.

[0077] like Figure 6 As shown, the valve core 12 is in the neutral position at this time. When the bidirectional electromagnet 20 is energized and the armature 23 moves to the right, it drives the push rod 24 to move to the right. The boss in the middle of the push rod 24 pushes the left end of the return spring 33 to move to the right. The right end of the return spring 33 abuts against the valve sleeve 11 for limiting, so that the return spring 33 is in a compressed state. The push rod 24 pushes the hook connector 34 and the valve core 12 to move to the right until the armature 23 moves to the end of its stroke. At this time, the valve core 12 has completed moving to the right by A.

[0078] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 drives the boss in the middle of the push rod 24 to move until the left end of the return spring 33 moves and abuts against the bottom of the guide seat 31. The guide seat 31 limits the left end of the return spring 33, and at this time the valve core 12 is reset in the middle position.

[0079] When the bidirectional electromagnet 20 is energized in reverse, the armature 23 moves to the left, which drives the push rod 24 to move to the left. The push rod 24 drives the hook connector 34 and the valve core 12 to move to the left. At the same time, the hook connector 34 drives the right end of the return spring 33 to move to the left. The bottom of the guide seat 31 limits the left end of the return spring 33, keeping it in a compressed state, until the armature 23 moves to the end of its stroke. At this time, the valve core 12 completes the leftward movement A.

[0080] When the bidirectional electromagnet 20 is de-energized, the return spring 33 returns to its original state from compression. The left end of the return spring 33 abuts against the bottom of the guide seat 31, and the right end of the return spring 33 moves and drives the hook connector 34 to move to the right until the right end of the return spring 33 moves to the slot of the valve sleeve 11 and is limited. The hook connector 34 and the valve core 12 move to the middle position, completing the reset.

[0081] Since the valve assembly 10 is reset in the middle position by a reset spring 33, which has a preload and is limited by the guide seat 31 and the valve core 12, the reset spring 33 can keep the valve core 12 in a stable and accurate position when it is reset. Compared with the common reset mechanism with two springs set opposite each other, it has higher accuracy and longer service life. Since the armature 23 and the valve core 12 are connected by the push rod 24, the repositioning of the valve core 12 and the movement of the armature 23 are synchronized, and its response speed is fast and stable.

[0082] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A single-coil three-position four-way solenoid valve, characterized in that: The system includes a valve assembly (10), which includes a valve sleeve (11) and a valve core (12) slidably connected in the valve sleeve (11). A bidirectional electromagnet (20) is mounted on one side of the valve assembly (10). An armature (23) in the bidirectional electromagnet (20) is connected to a push rod (24). The bidirectional electromagnet (20) drives the valve core (12) through the push rod (24). A centering mechanism (30) for resetting is installed between the valve assembly (10) and the bidirectional electromagnet (20). The centering mechanism (30) includes a guide seat (31), one end of which is inserted and threaded. Inside the bidirectional electromagnet (20), a connecting sleeve (32) is installed on the exposed end of the guide seat (31). The connecting sleeve (32) is used to connect the valve sleeve (11) and the guide seat (31). A return spring (33) is provided inside the guide seat (31) and sleeved on the push rod (24). The middle part of the push rod (24) is a boss structure. One side of the return spring (33) is provided on the boss of the push rod (24), and the other side is provided with a hook connector (34) and abuts against the surface of the hook connector (34). The hook connector (34) is connected to the valve core (12). The centering mechanism (30) includes a spring pad (35) disposed on the surface of the hook connector (34). The spring pad (35) is sleeved on the surface of the hook connector (34). One side of the spring pad (35) abuts against one end of the return spring (33), and the inner edge of the other side engages with the boss of the hook connector (34). The valve sleeve (11) has a stepped structure formed on the inner side of one end inside the connecting sleeve (32). The bottom of the stepped structure engages with a limit pad (36). The outer edge of the hook connector (34) corresponds to the limiting pad (36), and the distance from the hook connector (34) to the limiting pad (36) is B. The connecting sleeve (32) is sleeved on the surface of the guide seat (31) and the valve sleeve (11), and a gap is provided between the guide seat (31) and the valve sleeve (11). The spring pad (35) is provided at this gap, and its outer wall is in contact with the connecting sleeve (32). The distance from the spring pad (35) to the end face of the guide seat (31) is also B. The bidirectional electromagnet (20) includes a housing (21), a coil (22) is wound inside the housing (21), an armature (23) is slidably connected inside the coil (22), a push rod (24) is installed in the middle of the armature (23), a plug (25) is installed on the top of the housing (21), a screw plug (26) is threadedly connected to the side of the housing (21), the screw plug (26) extends to the inner side of the coil (22) and is symmetrically arranged with the guide seat (31), and two sets of permanent magnets are symmetrically arranged in the middle of the inner side of the coil (22).

2. The single-coil three-position four-way solenoid valve according to claim 1, characterized in that: The guide seat (31) has a channel in the middle that matches the boss of the push rod (24), and the boss of the push rod (24) slides in the channel.

3. The single-coil three-position four-way solenoid valve according to claim 1, characterized in that: The end of the hook connector (34) away from the return spring (33) is integrally formed with the valve core (12). The inner walls of the hook connector (34) and the valve sleeve (11) are provided with slots. The end of the return spring (33) is placed in the slots. The return spring (33) abuts against the inner walls of the hook connector (34) and the valve sleeve (11).

4. The single-coil three-position four-way solenoid valve according to claim 1, characterized in that: Both ends of the return spring (33) are provided with washers (37), which are made of metal and are used to increase the contact area of ​​the return spring (33).

5. The single-coil three-position four-way solenoid valve according to claim 2, characterized in that: Both the middle part of the hook connector (34) and the valve core (12) are provided with pin holes, and the hook connector (34) and the valve core (12) are pin-connected.

6. The single-coil three-position four-way solenoid valve according to claim 1, characterized in that: The end face of the push rod (24) is a frustum structure. The hook connector (34) is provided with a T-shaped through groove corresponding to the position of the push rod (24). The hook connector (34) and the push rod (24) are engaged through the T-shaped through groove.

7. The single-coil three-position four-way solenoid valve according to claim 1, characterized in that: Both the plug (26) and the guide seat (31) are made of soft magnetic material.

8. The single-coil three-position four-way solenoid valve according to claim 1, characterized in that: The distance from the armature (23) to the screw plug (26) and the guide seat (31) is ±A, where A is the driving stroke of the bidirectional electromagnet (20).

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