An electromagnetic valve

Abstract

The present application relates to the technical field of pneumatic components, in particular to an electromagnetic valve, which is characterized in that an annular sealing groove is arranged on the inner wall of a magnetic guide sleeve, and a pressure-bearing flange in sealing sliding cooperation with the annular sealing groove is arranged on the outer periphery of a moving iron core, so that the fluid medium in the valve cavity is introduced into a lower back pressure cavity or an upper back pressure cavity formed by the pressure-bearing flange and the annular sealing groove, respectively, through the flow guide channel in the magnetic guide sleeve, and the stable axial locking force is exerted on the moving iron core by the medium pressure at the opening position or the closing position, thereby solving the problems of magnetic performance attenuation and poor anti-vibration performance caused by the dependence of the existing electromagnetic valve on permanent magnets to realize self-retention.

Description

Technical Field

[0001] This invention relates to the field of pneumatic components technology, specifically to a solenoid valve. Background Technology

[0002] Solenoid valves, as key actuators in industrial automation control systems, are widely used for controlling the on / off and reversing of fluid media. Conventional solenoid valves generally adopt a "power-on to open, power-off to close" operating mode, where the displacement of the moving iron core relies entirely on the electromagnetic force generated by the excitation coil to overcome the resistance of the return spring. Although this structure has simple control logic, under operating conditions requiring long-term open operation, the coil must remain continuously energized, resulting in significant energy waste, excessive coil temperature rise, accelerated insulation aging, and even safety hazards.

[0003] To address the issue of continuous power consumption, self-holding solenoid valves based on the principle of permanent magnet adsorption have emerged. These valves utilize the electromagnetic force generated upon energization to drive the moving iron core to engage, and then rely on the residual magnetism provided by the permanent magnet to maintain the adsorption state, theoretically achieving zero-power position retention. However, this magnetic holding solution has revealed serious reliability shortcomings in practical applications. First, the magnetic properties of permanent magnets are inherently unstable. With prolonged service life and fluctuations in ambient temperature, permanent magnets inevitably undergo irreversible demagnetization, leading to a gradual weakening of the adsorption force and compromising the valve's shut-off sealing or opening stability after long-term use. Second, permanent magnet adsorption is a rigid connection with extremely poor vibration resistance. When solenoid valves are used in applications with high-frequency vibration, such as engineering machinery, rail transportation, or pump pipelines, the periodic impact loads on the moving iron core can easily exceed the adsorption threshold of the permanent magnet, causing the iron core to bounce or detach instantaneously, leading to media leakage or system malfunction. Summary of the Invention

[0004] To address the problems existing in the prior art, a solenoid valve is provided. By setting an annular sealing groove on the inner wall of the magnetic sleeve and providing a pressure-bearing flange that slides and seals with the moving iron core on the outer periphery, the fluid medium in the valve cavity is introduced into the lower back pressure cavity or the upper back pressure cavity formed by the pressure-bearing flange and the annular sealing groove through the flow channel inside the magnetic sleeve. The medium pressure applies a stable axial locking force to the moving iron core in the open or closed position, which solves the problems of magnetic performance attenuation and poor vibration resistance caused by the reliance on permanent magnets for self-holding in existing solenoid valves.

[0005] To address the problems of existing technologies, this invention provides a solenoid valve, including a valve seat and an electromagnetic drive assembly mounted on the valve seat. The valve seat has a valve cavity, an inlet channel, and an outlet channel. The electromagnetic drive assembly includes a magnetic sleeve, a stationary iron core and a moving iron core housed within the magnetic sleeve, an excitation coil wound around the outer periphery of the magnetic sleeve, and a reset elastic element abutting between the moving iron core and the stationary iron core. One end of the moving iron core extends into the valve cavity and selectively blocks the valve port communicating with the outlet channel. The inner wall of the magnetic sleeve has an opening that... The moving iron core has a coaxial annular sealing groove; the outer periphery of the moving iron core is provided with a pressure-bearing flange coaxial with it, the outer peripheral surface of the pressure-bearing flange is in sealing sliding cooperation with the inner peripheral wall of the annular sealing groove, and the end of the pressure-bearing flange facing the valve cavity and the corresponding end of the annular sealing groove are surrounded to form a lower back pressure cavity. The magnetic sleeve is provided with a flow guiding channel. When the moving iron core is disengaged from the valve port of the discharge channel and the valve cavity is opened, the flow guiding channel introduces the fluid in the valve cavity into the lower back pressure cavity, and uses the increased fluid pressure in the lower back pressure cavity to lock the moving iron core in the open position.

[0006] Preferably, a first elastic buffer assembly is sandwiched between the side of the pressure-bearing flange facing the valve cavity and the corresponding end of the annular sealing groove. The first elastic buffer assembly and the pressure-bearing flange enclose the lower back pressure cavity. The flow guide channel extends through the lower back pressure cavity. The increase in fluid pressure in the lower back pressure cavity causes the first elastic buffer assembly to undergo elastic deformation, so as to adaptively adjust the volume of the lower back pressure cavity.

[0007] Preferably, the first elastic buffer assembly includes: a lower buffer ring, which is coaxially slidably disposed in the annular sealing groove and has a sealing sliding fit with the groove wall of the annular sealing groove and the circumferential surface of the moving iron core; and a lower elastic element, which is coaxially disposed between the lower buffer ring and the corresponding end of the annular sealing groove.

[0008] Preferably, the end of the pressure-bearing flange away from the valve cavity and the corresponding end of the annular sealing groove form an upper back pressure cavity. When the moving iron core blocks the valve port of the drainage channel, the guide channel introduces the fluid in the valve cavity into the upper back pressure cavity, and uses the increased fluid pressure in the upper back pressure cavity to lock the moving iron core in the closed position.

[0009] Preferably, a second elastic buffer assembly is sandwiched between the side of the pressure-bearing flange away from the valve cavity and the corresponding end of the annular sealing groove. The second elastic buffer assembly and the pressure-bearing flange enclose the upper back pressure cavity. The flow guide channel extends through the upper back pressure cavity. The increase in fluid pressure in the upper back pressure cavity causes the second elastic buffer assembly to undergo elastic deformation, so as to adaptively adjust the volume of the upper back pressure cavity.

[0010] Preferably, the second elastic buffer assembly includes: an upper buffer ring, which is coaxially slidably disposed in the annular sealing groove and has a sealing sliding fit with the groove wall of the annular sealing groove and the circumferential surface of the moving iron core; and an upper elastic element, which is coaxially disposed between the upper buffer ring and the corresponding end of the annular sealing groove.

[0011] Preferably, the flow channel has an axial section extending along the axial direction of the magnetic sleeve and a radial section extending along the radial direction of the magnetic sleeve. The inlet end of the axial section extends into the valve cavity, and the outlet end of the radial section selectively communicates with the lower back pressure cavity or the upper back pressure cavity, so as to form a fluid passage between the valve cavity and the lower back pressure cavity or the upper back pressure cavity when the moving iron core switches between the open position and the closed position.

[0012] Preferably, the electromagnetic drive assembly further includes a bracket and a permanent magnet disposed in the bracket that can attract the moving iron core.

[0013] Preferably, the device further includes a junction box and a timer electrically connected to the junction box. The timer is electrically connected to the excitation coil, and the timer triggers the excitation coil to switch current directions after a set duration is reached.

[0014] Preferably, a rubber plug is provided at the contact end between the moving iron core and the valve port.

[0015] The advantages of this application compared to the prior art are: This application achieves position locking of the moving iron core through pressure changes in the fluid medium, eliminating the instability of holding force caused by permanent magnet demagnetization or temperature drift. Forward and reverse currents are used to control the opening, locking, and resetting / closing of the moving iron core, respectively. The fluid pressure locking mechanism formed by the lower back pressure chamber has high shear resistance, effectively resisting displacement of the moving iron core caused by external vibrations, thus improving the operational reliability of the solenoid valve under complex operating conditions. Furthermore, since energization is only required during state switching, the power consumption and coil heat generation of the solenoid valve are significantly reduced, which helps extend the equipment's maintenance cycle.

[0016] This application, through the constant-flow design of the valve chamber and the inlet channel, establishes an alternating pressure supply logic between the lower back pressure chamber and the upper back pressure chamber: when the moving iron core is in the open position, the lower back pressure chamber is locked by fluid pressure; when the moving iron core is in the closed position, the upper back pressure chamber is locked by fluid pressure, ensuring that the moving iron core can obtain a stable fluid pressure locking effect in any stationary position without relying on external electromagnetic force. Attached Figure Description

[0017] Figure 1 This is a perspective view of an electromagnetic valve according to the present invention.

[0018] Figure 2 This is a three-dimensional sectional view of an electromagnetic valve when the valve port is closed according to the present invention.

[0019] Figure 3 yes Figure 2 A magnified view of part A.

[0020] Figure 4 This is a cross-sectional view of a solenoid valve of the present invention when the valve port is closed.

[0021] Figure 5 yes Figure 4 A magnified view of section B.

[0022] Figure 6 This is a three-dimensional exploded view of the valve seat and electromagnetic drive assembly in an electromagnetic valve according to the present invention, viewed from a first perspective.

[0023] Figure 7 This is a perspective exploded view of the valve seat and electromagnetic drive assembly in an electromagnetic valve according to the present invention, viewed from a second perspective.

[0024] Figure 8 This is a perspective view of the first and second elastic buffer components in a solenoid valve according to the present invention.

[0025] Figure 9 This is a cross-sectional view of a solenoid valve with its valve port open according to the present invention.

[0026] Figure 10 yes Figure 9 A magnified view of a portion of point C.

[0027] The following are the labels in the diagram: 1. Valve seat; 11. Valve cavity; 12. Inlet channel; 13. Outlet channel; 14. Valve port; 21. Magnetic sleeve; 211. Guide channel; 212. Annular sealing groove; 213. Lower back pressure chamber; 214. Upper back pressure chamber; 22. Static iron core; 23. Moving iron core; 231. Pressure-bearing flange; 24. Reset elastic element; 25. Excitation coil; 26. Bracket; 27. Permanent magnet; 28. Rubber plug; 31. Lower buffer ring; 32. Lower elastic element; 41. Upper buffer ring; 42. Upper elastic element; 5. Timer; 6. Junction box. Detailed Implementation

[0028] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 , Figure 6 , Figure 7 , Figure 9 and Figure 10As shown, a solenoid valve includes a valve seat 1 and an electromagnetic drive assembly mounted on the valve seat 1. The valve seat 1 has a valve cavity 11, an inlet channel 12, and an outlet channel 13. The electromagnetic drive assembly includes a magnetic sleeve 21, a stationary iron core 22 and a moving iron core 23 housed within the magnetic sleeve 21, an excitation coil 25 wound around the outer periphery of the magnetic sleeve 21, and a reset elastic element 24 abutting between the moving iron core 23 and the stationary iron core 22. One end of the moving iron core 23 extends into the valve cavity 11 and selectively blocks the outlet channel 13 and the valve cavity 11. The valve port 14 is connected. The inner wall of the magnetic sleeve 21 is provided with an annular sealing groove 212 coaxial with it. The outer periphery of the moving iron core 23 is provided with a pressure-bearing flange 231 coaxial with it. The outer peripheral surface of the pressure-bearing flange 231 is sealed and slides with the inner peripheral wall of the annular sealing groove 212. The end of the pressure-bearing flange 231 facing the valve cavity 11 and the corresponding end of the annular sealing groove 212 surrounds to form a lower back pressure cavity 213. The magnetic sleeve 21 is provided with a flow guiding channel 211. Regardless of whether the valve port 14 is closed or not, the valve cavity 11 is always connected to the inlet channel 12.

[0030] During operation, when a positive current is input to the excitation coil 25, the excitation coil 25 generates an electromagnetic field. Under the action of electromagnetic attraction, the moving iron core 23 overcomes the elastic force of the reset elastic element 24 and moves towards the stationary iron core 22, causing the moving iron core 23 to disengage from the valve port 14 of the drain channel 13, and the valve chamber 11 becomes connected to the drain channel 13. Simultaneously, as... Figure 10 As shown, the moving iron core 23 and the pressure-bearing flange 231 move upward synchronously until the bottom end of the pressure-bearing flange 231 is higher than the outlet of the guide channel 211 (i.e., as shown). Figure 10 The guide channel 211 (high port shown) connects its outlet to the lower back pressure chamber 213. Because the fluid in the valve chamber 11 is a high-pressure fluid, the fluid medium in the valve chamber 11 flows into the lower back pressure chamber 213 through the guide channel 211, causing the fluid pressure in the lower back pressure chamber 213 to increase. This pressure acts on the end face of the pressure-bearing flange 231 facing the valve chamber 11, generating axial hydraulic pressure that pushes the moving iron core 23 tightly against the stationary iron core 22, thereby locking the moving iron core 23 in the open position. After the moving iron core 23 is locked, the current to the excitation coil 25 can be cut off, and the moving iron core 23 can still maintain its current position by relying on the fluid pressure in the lower back pressure chamber 213. When a reverse current is input to the excitation coil 25, the excitation coil 25 generates an electromagnetic field opposite to that of the forward current. The moving iron core 23 is subjected to an electromagnetic repulsive force that is opposite to that of the stationary iron core 22. This electromagnetic repulsive force, together with the reset force of the reset elastic element 24, drives the moving iron core 23 to move away from the stationary iron core 22. The volume of the lower back pressure chamber 213 increases and the internal pressure decreases. The moving iron core 23 re-seals the valve port 14 of the drain channel 13, blocking the connection between the valve chamber 11 and the drain channel 13.

[0031] like Figure 10 As shown, a first elastic buffer assembly is sandwiched between the side of the pressure-bearing flange 231 facing the valve cavity 11 and the corresponding end of the annular sealing groove 212. The first elastic buffer assembly and the pressure-bearing flange 231 enclose the lower back pressure cavity 213. The flow guide channel 211 extends into the lower back pressure cavity 213. The increase in fluid pressure in the lower back pressure cavity 213 causes the first elastic buffer assembly to undergo elastic deformation, so as to adaptively adjust the volume of the lower back pressure cavity 213.

[0032] During operation, when the moving iron core 23 moves towards the stationary iron core 22, causing the pressure in the lower back pressure chamber 213 to increase, the first elastic buffer component undergoes elastic compression deformation under fluid pressure, adaptively increasing the volume of the lower back pressure chamber 213, thereby damping the rate of pressure increase within the chamber. When the moving iron core 23 moves back under the action of the reset elastic element 24 and seals the valve port 14, the pressure-bearing flange 231 simultaneously squeezes the first elastic buffer component, and the volume of the lower back pressure chamber 213 decreases accordingly. Due to the compressibility of the first elastic buffer component, it can absorb the decrease in volume through deformation, avoiding the pressure increase caused by the inability to depressurize the medium within the chamber due to premature disconnection between the lower back pressure chamber 213 and the flow channel 211, ensuring that the moving iron core 23 can smoothly reset to the closed position.

[0033] like Figure 10 As shown, the first elastic buffer assembly includes: a lower buffer ring 31, which is coaxially and slidably disposed in the annular sealing groove 212 and has a sealing sliding fit with the groove wall of the annular sealing groove 212 and the circumferential surface of the moving iron core 23; and a lower elastic element 32, which is coaxially disposed between the lower buffer ring 31 and the corresponding end of the annular sealing groove 212.

[0034] The lower elastic element 32 coaxially abuts against the side of the lower buffer ring 31 facing away from the valve chamber 11 and the corresponding groove wall of the annular sealing groove 212, providing preload force for the lower buffer ring 31. During operation, when the moving iron core 23 opens the valve port 14 and fluid is injected into the lower back pressure chamber 213 through the guide channel 211, the fluid pressure acts on the lower buffer ring 31, causing the lower buffer ring 31 to compress the lower elastic element 32 and slide away from the stationary iron core 22, thereby increasing the volume of the lower back pressure chamber 213 to buffer pressure peaks. When the moving iron core 23 resets, the lower buffer ring 31 moves back synchronously with the pressure-bearing flange 231 under the rebound force of the lower elastic element 32, absorbing the change in chamber volume while preventing high-pressure medium from accumulating in the lower back pressure chamber 213, ensuring smooth reset of the moving iron core 23 and long-term stability of the valve port 14 sealing surface.

[0035] like Figures 2 to 5As shown, the end of the pressure-bearing flange 231 facing away from the valve cavity 11 and the corresponding end of the annular sealing groove 212 form an upper back pressure cavity 214. When the moving iron core 23 blocks the valve port 14 of the drainage channel 13, the guide channel 211 introduces the fluid in the valve cavity 11 into the upper back pressure cavity 214, and uses the increased fluid pressure in the upper back pressure cavity 214 to lock the moving iron core 23 in the closed position.

[0036] The valve chamber 11 is always connected to the inlet channel 12. Regardless of whether the valve port 14 is closed, either the lower back pressure chamber 213 or the upper back pressure chamber 214 is always able to receive pressure from the inlet channel 12.

[0037] The end of the pressure-bearing flange 231 facing away from the valve cavity 11 and the corresponding end of the annular sealing groove 212 enclose each other to form an upper back pressure cavity 214. The valve cavity 11 is always connected to the inlet channel 12. Regardless of whether the moving iron core 23 blocks the valve port 14 of the outlet channel 13, the fluid pressure in the inlet channel 12 continuously acts on the valve cavity 11. The guide channel 211 extends to the upper back pressure cavity 214. When the moving iron core 23 blocks the valve port 14 of the outlet channel 13 under the action of the reset elastic member 24, the fluid in the valve cavity 11 flows into the upper back pressure cavity 214 through the guide channel 211, causing the fluid pressure in the upper back pressure cavity 214 to increase. This pressure acts on the end face of the pressure-bearing flange 231 facing away from the valve cavity 11, generating axial hydraulic pressure that pushes the moving iron core 23 tightly against the valve port 14 to block the flow channel, thereby locking the moving iron core 23 in the closed position.

[0038] Based on the normally open design of the valve chamber 11 and the inlet channel 12, an alternating pressure supply logic is formed between the lower back pressure chamber 213 and the upper back pressure chamber 214: when the moving iron core 23 is in the open position, the lower back pressure chamber 213 is locked by fluid pressure; when the moving iron core 23 is in the closed position, the upper back pressure chamber 214 is locked by fluid pressure.

[0039] like Figure 5 As shown, a second elastic buffer assembly is sandwiched between the side of the pressure-bearing flange 231 away from the valve cavity 11 and the corresponding end of the annular sealing groove 212. The second elastic buffer assembly and the pressure-bearing flange 231 enclose the upper back pressure cavity 214. The flow guide channel 211 extends into the upper back pressure cavity 214. The increase in fluid pressure in the upper back pressure cavity 214 causes the second elastic buffer assembly to undergo elastic deformation, so as to adaptively adjust the volume of the upper back pressure cavity 214.

[0040] When the moving iron core 23 blocks the valve port 14 of the drainage channel 13, the fluid in the valve chamber 11 flows into the upper back pressure chamber 214 through the guide channel 211, causing the fluid pressure in the upper back pressure chamber 214 to increase. This pressure acts on the end face of the pressure-bearing flange 231 facing away from the valve chamber 11, generating axial hydraulic pressure that pushes the moving iron core 23 to press against the valve port 14, thereby locking the moving iron core 23 in the closed position. During this process, the second elastic buffer assembly undergoes elastic compression deformation under the action of fluid pressure, adaptively increasing the volume of the upper back pressure chamber 214, damping and buffering the rate of pressure rise in the chamber, and preventing the moving iron core 23 from generating a rigid impact on the valve port 14.

[0041] When the moving iron core 23 is driven to move towards the stationary iron core 22 to open the valve port 14, the pressure-bearing flange 231 rises synchronously, and the volume of the upper back pressure chamber 214 gradually decreases as the moving iron core 23 moves. Based on the compressibility of the second elastic buffer assembly, it can absorb the change in the volume of the upper back pressure chamber 214 through elastic deformation. Before and after the pressure-bearing flange 231 cuts off the connection between the upper back pressure chamber 214 and the flow channel 211, it effectively avoids the pressure increase phenomenon caused by the inability to depressurize the medium in the chamber, ensuring that the moving iron core 23 can smoothly detach from the valve port 14 and preventing the sealing surface of the valve port 14 from being damaged due to abnormal high pressure.

[0042] like Figure 5 and Figure 8 As shown, the second elastic buffer assembly includes: an upper buffer ring 41, which is coaxially slidably disposed in the annular sealing groove 212 and has a sealing sliding fit with the groove wall of the annular sealing groove 212 and the circumferential surface of the moving iron core 23; and an upper elastic element 42, which is coaxially disposed between the upper buffer ring 41 and the corresponding end of the annular sealing groove 212.

[0043] During operation, when the moving iron core 23 resets and blocks the valve port 14 of the drainage channel 13, the fluid is injected into the upper back pressure chamber 214 through the guide channel 211. The fluid pressure acts on the upper buffer ring 41, causing the upper buffer ring 41 to compress the upper elastic element 42 and slide towards the valve chamber 11. By increasing the volume of the upper back pressure chamber 214, the pressure peak is buffered, avoiding the moving iron core 23 from generating a rigid impact on the valve port 14. When the moving iron core 23 moves towards the stationary iron core 22 to open the valve port 14, the upper buffer ring 41 moves down synchronously with the pressure bearing flange 231 under the action of the rebound force of the upper elastic element 42. While absorbing the reduction in the volume of the upper back pressure chamber 214, it eliminates the pressure increase phenomenon caused by the inability to release pressure due to the retention of the medium, ensuring that the moving iron core 23 smoothly disengages from the valve port 14 and preventing damage to the sealing surface.

[0044] like Figure 5 and Figure 10As shown, the flow channel 211 has an axial section extending along the axial direction of the magnetic sleeve 21 and a radial section extending along the radial direction of the magnetic sleeve 21. The inlet end of the axial section extends into the valve chamber 11, and the outlet end of the radial section selectively communicates with the lower back pressure chamber 213 or the upper back pressure chamber 214 to form a fluid passage between the valve chamber 11 and the lower back pressure chamber 213 or the upper back pressure chamber 214 when the moving iron core 23 switches between the open position and the closed position.

[0045] When the moving iron core 23 is in the closed position, the pressure-bearing flange 231 and the first elastic buffer assembly disposed thereon form a relative position relationship with the annular sealing groove 212, so that the outlet end of the radial section is directly opposite the upper back pressure chamber 214, and the fluid in the valve chamber 11 flows into the upper back pressure chamber 214 in sequence through the axial section and the radial section, establishing a fluid pressure locking mechanism for the upper back pressure chamber 214.

[0046] When the moving iron core 23 is driven to move towards the stationary iron core 22 to the open position, the pressure-bearing flange 231 moves axially with the moving iron core 23, and the outlet end of the radial section is then aligned with the lower back pressure chamber 213. The fluid passage is switched to the lower back pressure chamber 213, and the fluid pressure in the lower back pressure chamber 213 is used to maintain the open state of the moving iron core 23.

[0047] The flow channel 211 structure achieves automatic switching of the flow outlet through the axial displacement of the pressure-bearing flange 231, eliminating the need for additional valve components to control the flow direction, simplifying the internal structure, and ensuring that the lower back pressure chamber 213 and the upper back pressure chamber 214 can alternately receive fluid pressure replenishment according to the position change of the moving iron core 23, thereby realizing pure hydraulic self-locking of the valve in both opening and closing positions.

[0048] like Figure 5 As shown, the electromagnetic drive assembly also includes a bracket 26 and a permanent magnet 27 disposed in the bracket 26 to attract the moving iron core 23. The permanent magnet provides auxiliary attraction at the open position, and its attraction force is less than the elastic force of the reset elastic member 24.

[0049] The permanent magnet 27 is configured to provide auxiliary attraction as the moving iron core 23 approaches the opening position, thereby reducing the starting current required for the excitation coil 25 to achieve the attraction action. At the same time, after the moving iron core 23 is in the opening position and the excitation coil 25 is de-energized, the constant magnetic flux generated by the permanent magnet 27 can work in conjunction with the fluid locking force in the lower back pressure cavity 213 to further enhance the holding torque on the moving iron core 23.

[0050] When the moving iron core 23 is reset to the closed position, the direction or distribution of the magnetic field generated by the permanent magnet 27 is configured so as not to exert a significant attraction force on the moving iron core 23 that would hinder its reset, or the weak magnetic reluctance effect it generates can be overcome by the locking pressure of the upper back pressure chamber 214 and the elastic force of the reset elastic element 24. By setting the permanent magnet 27, while retaining the high vibration resistance and no pressure increase risk brought by fluid pressure locking, the electro-magnetic-mechanical energy conversion efficiency of the solenoid valve is further optimized, achieving compatibility between low-pressure drive and high holding force. Moreover, since the position locking mainly relies on fluid pressure rather than simple magnetic attraction, the problem of easy demagnetization and instability due to vibration interference caused by relying solely on the permanent magnet 27 is effectively alleviated.

[0051] like Figure 4 and Figure 9 As shown, it also includes a junction box 6 and a timer 5 electrically connected to the junction box 6. The timer 5 is electrically connected to the excitation coil 25 and controls the excitation coil 25 to exchange the current direction within a set time.

[0052] The junction box 6 is used to connect to an external power source and control signals. The timer 5 is configured to output a commutation signal according to a preset time period to control the excitation coil 25 to automatically exchange the current direction within a set time window.

[0053] During operation, when the moving iron core 23 is in the open position, the timer 5 controls the excitation coil 25 to receive a positive current to complete the initial engagement. Subsequently, the main current is cut off, maintaining only a small holding current or completely de-energizing the coil, relying on the fluid pressure in the lower back pressure chamber 213 for main locking. After a preset locking time, the timer 5 triggers the excitation coil 25 to receive a reverse current. Under the combined action of the reverse electromagnetic force and the reset elastic element 24, the moving iron core 23 moves towards the closed position. At this time, the flow channel 211 switches its flow path, and the upper back pressure chamber 214 builds pressure to lock the closed state. By setting the timer 5, the solenoid valve achieves a timed automatic reversing function without human intervention, eliminating the need for an external controller to continuously send pulse signals and simplifying the control logic of the host computer.

[0054] like Figure 4 As shown, a rubber plug 28 is provided at the contact end between the moving iron core 23 and the valve port 14, and the moving iron core 23 and the rubber plug 28 are connected by adhesive, threaded connection or snap-fit ​​connection.

[0055] When the moving iron core 23 moves toward the valve port 14 under the action of the reset elastic element 24, the rubber plug 28 contacts the valve port 14 before the metal substrate of the moving iron core 23. It absorbs the impact kinetic energy of the moving iron core 23 by its own elastic deformation, avoiding wear and noise caused by hard metal contact, and significantly improving the sealing performance and service life of the valve port 14.

[0056] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A solenoid valve, comprising a valve seat and an electromagnetic drive assembly mounted on the valve seat, wherein the valve seat has a valve cavity, an inlet channel, and an outlet channel, the electromagnetic drive assembly comprising a magnetic sleeve, a stationary iron core and a moving iron core housed within the magnetic sleeve, an excitation coil wound around the outer periphery of the magnetic sleeve, and a reset elastic element abutting between the moving iron core and the stationary iron core, wherein one end of the moving iron core extends into the valve cavity and selectively blocks the valve port communicating with the outlet channel and the valve cavity, characterized in that, The inner wall of the magnetic sleeve is provided with an annular sealing groove coaxial with it. The outer periphery of the moving iron core is provided with a pressure-bearing flange coaxial with it. The outer peripheral surface of the pressure-bearing flange is in sealing sliding fit with the inner peripheral wall of the annular sealing groove. The end of the pressure-bearing flange facing the valve cavity and the corresponding end of the annular sealing groove form a lower back pressure cavity. The magnetic sleeve is provided with a flow guiding channel. When the moving iron core is disengaged from the valve port of the discharge channel and the valve cavity is opened, the flow guiding channel introduces the fluid in the valve cavity into the lower back pressure cavity. The increased fluid pressure in the lower back pressure cavity locks the moving iron core in the open position. The end of the pressure-bearing flange away from the valve cavity and the corresponding end of the annular sealing groove form an upper back pressure cavity. When the moving iron core blocks the valve port of the drainage channel, the guide channel introduces the fluid in the valve cavity into the upper back pressure cavity, and uses the increased fluid pressure in the upper back pressure cavity to lock the moving iron core in the closed position. The flow channel is selectively connected to the lower back pressure chamber or the upper back pressure chamber to form a fluid passage between the valve chamber and the lower back pressure chamber or the upper back pressure chamber when the moving iron core switches between the open position and the closed position.

2. The solenoid valve according to claim 1, characterized in that, A first elastic buffer assembly is sandwiched between the side of the pressure-bearing flange facing the valve cavity and the corresponding end of the annular sealing groove. The first elastic buffer assembly and the pressure-bearing flange enclose the lower back pressure cavity. The flow guide channel extends through the lower back pressure cavity. The increase in fluid pressure in the lower back pressure cavity causes the first elastic buffer assembly to undergo elastic deformation, so as to adaptively adjust the volume of the lower back pressure cavity.

3. A solenoid valve according to claim 2, characterized in that, The first elastic buffer component includes: The lower buffer ring is coaxially and slidably disposed in the annular sealing groove, and is in sealing and sliding cooperation with the groove wall of the annular sealing groove and the circumferential surface of the moving iron core; The lower elastic element is coaxially disposed between the lower buffer ring and the corresponding end of the annular sealing groove.

4. A solenoid valve according to claim 1, characterized in that, A second elastic buffer assembly is sandwiched between the side of the pressure-bearing flange away from the valve cavity and the corresponding end of the annular sealing groove. The second elastic buffer assembly and the pressure-bearing flange enclose the upper back pressure cavity. The flow guide channel extends through the upper back pressure cavity. The increase in fluid pressure in the upper back pressure cavity causes the second elastic buffer assembly to undergo elastic deformation, so as to adaptively adjust the volume of the upper back pressure cavity.

5. A solenoid valve according to claim 4, characterized in that, The second resilient buffer component includes: The upper buffer ring is coaxially and slidably disposed in the annular sealing groove, and is in sealing and sliding cooperation with the groove wall of the annular sealing groove and the circumferential surface of the moving iron core; An upper elastic element is coaxially disposed between the upper buffer ring and the corresponding end of the annular sealing groove.

6. A solenoid valve according to claim 1, characterized in that, The flow channel has an axial section extending along the axial direction of the magnetic sleeve, and the inlet end of the axial section extends into the valve cavity.

7. A solenoid valve according to any one of claims 1-3, characterized in that, The electromagnetic drive assembly also includes a bracket and a permanent magnet disposed in the bracket that can attract the moving iron core.

8. A solenoid valve according to any one of claims 1-3, characterized in that, It also includes a junction box and a timer electrically connected to the junction box. The timer is electrically connected to the excitation coil. After the timer reaches a set duration, it triggers the excitation coil to change the current direction.

9. A solenoid valve according to any one of claims 1-3, characterized in that, A rubber plug is provided at the contact end between the moving iron core and the valve port.

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