Solenoid valve

Abstract

A solenoid valve, relating to the technical field of solenoid valves. The solenoid valve comprises: a valve assembly, a coil assembly, a magnetic conductive frame (3) and a protective housing (4), wherein the magnetic conductive frame (3) is mounted on the valve assembly; the coil assembly comprises a coil (21) and a circuit board (22), the coil (21) being located in a coil mounting space formed by the magnetic conductive frame (3), the circuit board (22) being electrically connected to the coil (21), and the coil (21) and the circuit board (22) being arranged in the protective housing (4); and the protective housing (4) is partially mounted within the coil mounting space, and is separated from the magnetic conductive frame (3). The solenoid valve can simplify the mounting processes for the protective housing (4) and the magnetic conductive frame (3), thereby facilitating the assembly and disassembly thereof.

Description

Solenoid valve

[0001] Cross-references

[0002] This disclosure claims priority to Chinese Patent Application No. 202520175474.3, filed on January 26, 2025, entitled "Solenoid Valve", and Chinese Patent Application No. 202520175448.0, filed on January 26, 2025, entitled "Solenoid Valve Circuit and Solenoid Valve", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of solenoid valve technology, and more specifically, to a solenoid valve. Background Technology

[0004] Currently, solenoid valves are commonly used in the field of fluid control technology to adjust the flow direction of liquids and achieve functions such as pipeline switching. A solenoid valve consists of a coil and a valve assembly. By energizing or de-energizing the coil, the valve assembly is driven to achieve the on / off control of the solenoid valve.

[0005] A protective housing is typically installed around the coil to protect it. A magnetic guide frame can be mounted outside the coil to concentrate the dispersed magnetic field. Existing technology usually involves assembling the coil and magnetic guide frame together and then encasing them in a protective housing. However, the installation process for the protective housing and magnetic guide frame is relatively complex and inconvenient to disassemble.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] A type of solenoid valve.

[0008] The electromagnetic valve disclosed herein includes: a valve assembly, a coil assembly, a magnetic guide, and a protective housing;

[0009] The magnetic guide frame is mounted on the valve assembly, and the coil assembly includes a coil and a circuit board; the coil is located within the coil mounting space formed by the magnetic guide frame; the circuit board is electrically connected to the coil.

[0010] The coil and the circuit board are housed within the protective housing, and the protective housing is partially installed within the coil mounting space and is separate from the magnetic guide frame.

[0011] In one exemplary embodiment of this disclosure, the valve assembly has a limiting surface and a cylindrical surface; the magnetic guide frame is mounted on the limiting surface of the valve assembly; the coil is sleeved outside the cylindrical surface and located within the coil mounting space;

[0012] The protective housing includes a coil protection section and a circuit board protection section; the coil protection section at least partially surrounds the coil; and the circuit board is disposed within the circuit board protection section.

[0013] In one exemplary embodiment of this disclosure, the coil protection part is installed in the coil mounting space and is separately disposed from the valve assembly.

[0014] In one exemplary embodiment of this disclosure, the coil is electrically connected to the circuit board via a first wiring connection, and the circuit board is electrically connected to the power module via a second wiring connection.

[0015] In one exemplary embodiment of this disclosure, the magnetic guide frame includes a first horizontal plate, a first vertical plate, and a second horizontal plate connected in sequence, the first horizontal plate, the first vertical plate, and the second horizontal plate forming the coil mounting space.

[0016] In one exemplary embodiment of this disclosure, the bottom surface of the circuit board protection portion is higher than the top surface of the magnetic guide frame.

[0017] In one exemplary embodiment of this disclosure, the portion of the circuit board protection portion projected onto the top surface of the magnetic guide frame is located within the outer contour of the top surface of the magnetic guide frame.

[0018] In one exemplary embodiment of this disclosure, the coil and the circuit board are electrically connected via a first wiring connection, and the coil protection part and the circuit board protection part are connected via a coil support part. The first wiring connection is disposed within the coil support part. The coil support part is disposed on the side of the magnetic guide frame. The magnetic guide frame includes a first horizontal plate, a first vertical plate, and a second horizontal plate connected in sequence. The first horizontal plate, the first vertical plate, and the second horizontal plate enclose the coil mounting space. One or both sides of the first horizontal plate adjacent to the first vertical plate have a clearance portion, and a portion of the coil support part is located within the clearance portion. The extending direction of the coil support part is parallel to the extending direction of the cylindrical surface, and the circuit board protection part is disposed on the side of the coil support part away from the limiting surface.

[0019] In one exemplary embodiment of this disclosure, the protective housing further includes a wiring portion connected to the coil protection portion; the extending direction of the wiring portion is perpendicular to the extending direction of the cylindrical surface, and at least a portion of the second wiring is disposed in the wiring portion.

[0020] In one exemplary embodiment of this disclosure, the circuit board protection portion is provided with a potting layer, the circuit board is encapsulated in the potting layer, and the circuit board is fixed to the circuit board protection portion by the potting layer.

[0021] In one exemplary embodiment of this disclosure, the valve assembly includes a valve body, a stationary iron core, a moving iron core, and a sleeve, wherein the moving iron core is movably disposed within the sleeve; the stationary iron core is connected to the valve body, and the sleeve is located on the side of the stationary iron core away from the valve body and is connected to the stationary iron core.

[0022] In one exemplary embodiment of this disclosure, the valve assembly includes a valve body, a stationary iron core, a moving iron core, a sleeve, and a valve cover. The moving iron core is movably disposed within the sleeve. The valve cover is connected to the valve body. One end of the sleeve is connected to the valve cover, and the other end of the sleeve is connected to the stationary iron core.

[0023] In one exemplary embodiment of this disclosure, the valve body includes a valve seat and a piston. The valve seat has a receiving cavity and a valve port communicating with the receiving cavity. The piston is received within the receiving cavity to open or close the valve port.

[0024] In one exemplary embodiment of this disclosure, the circuit board is provided with a solenoid valve circuit, which includes a power supply circuit, a control circuit, and a drive circuit; the power supply circuit is connected in series between the power module and the first input terminal of the drive circuit, so that the power module supplies power to the drive circuit through the power supply circuit; the output terminal of the drive circuit is connected to the solenoid valve interface, which is located at the coil.

[0025] The control circuit includes a control chip. The output terminal of the power supply circuit is connected to the voltage detection terminal and the voltage input terminal of the control chip. The control terminal of the control chip is connected to the second input terminal of the drive circuit to output a pulse width modulation signal to the drive circuit. The drive circuit adjusts the coil voltage input to the solenoid valve according to the voltage of the first input terminal and the pulse width modulation signal of the second input terminal.

[0026] In one exemplary embodiment of this disclosure, the power supply circuit includes a first diode and a second diode. The input terminal of the first diode is connected to the power supply module, and the output terminal of the first diode is connected to the output terminal of the power supply circuit. The input terminal of the second diode is grounded, and the output terminal of the second diode is connected to the power supply module.

[0027] In one exemplary embodiment of this disclosure, a first inductor and a first diode are connected in series between the power supply module and the output terminal of the power supply circuit; at least one capacitor is provided between the anode of the first diode and the ground terminal of the power supply circuit; at least one capacitor is provided between the cathode of the first diode and the ground terminal of the power supply circuit.

[0028] In one exemplary embodiment of this disclosure, the solenoid valve interface includes a first solenoid valve interface and a second solenoid valve interface, the first solenoid valve interface being connected to the first input terminal and the second solenoid valve interface being grounded; the drive circuit includes a first switch and a second switch; the first switch is disposed between the first input terminal and the first solenoid valve interface, and the second switch is disposed between the first input terminal and the ground terminal of the drive circuit.

[0029] In one exemplary embodiment of this disclosure, the source of the first switching transistor is connected to the first input terminal, and the drain of the first switching transistor is connected to the first solenoid valve interface through a second inductor; the collector of the second switching transistor is connected to the first input terminal through a first resistor and a second resistor connected in parallel, and the emitter of the second switching transistor is connected to the ground terminal of the driving circuit; the gate of the first switching transistor is connected to the emitter of the second switching transistor, and the base of the second switching transistor is connected to the second input terminal through a third resistor, and the base of the second switching transistor is also connected to the ground terminal of the driving circuit through a fourth resistor.

[0030] In one exemplary embodiment of this disclosure, a sixth resistor and an eighth resistor are connected in series between the first solenoid valve interface and the second solenoid valve interface. The voltage between the sixth resistor and the eighth resistor is connected to the voltage feedback terminal of the control chip. The control chip is used to control the pulse width modulation signal according to the voltage of the voltage feedback terminal.

[0031] In one exemplary embodiment of this disclosure, the output terminal of the power supply circuit is connected to the voltage detection terminal of the control chip through a fifth resistor. The control chip is used to output a first pulse width modulation signal to the drive circuit through the control terminal of the control chip when the voltage at the voltage detection terminal of the control chip is greater than or equal to 9V.

[0032] In one exemplary embodiment of this disclosure, the control chip is used to output a second pulse width modulation signal to the driving circuit through the control terminal of the control chip when the first pulse width modulation signal is output for a first preset time. The duty cycle of the second pulse width modulation signal is less than the duty cycle of the first pulse width modulation signal.

[0033] In one exemplary embodiment of this disclosure, a voltage conversion chip is connected in series between the output terminal of the power supply circuit and the voltage input terminal of the control chip. The voltage conversion chip is used to convert the 12V voltage at the output terminal of the power supply circuit into the 5V voltage at the voltage input terminal of the control chip.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0036] Figure 1 is a schematic diagram of an exemplary embodiment of the solenoid valve of this disclosure.

[0037] Figure 2 is a schematic diagram of an exemplary embodiment of the solenoid valve of this disclosure from another perspective.

[0038] Figure 3 is a schematic diagram of the valve assembly and magnetic guide frame in an exemplary embodiment of the solenoid valve of this disclosure.

[0039] Figure 4 is a cross-sectional schematic diagram of an exemplary embodiment of the solenoid valve of this disclosure.

[0040] Figure 5 is a schematic diagram of the magnetic guide frame and protective housing in an exemplary embodiment of the solenoid valve of this disclosure.

[0041] Figure 6 is a cross-sectional schematic diagram of an exemplary embodiment of the solenoid valve of this disclosure.

[0042] Figure 7 is a schematic diagram of another exemplary embodiment of the solenoid valve of this disclosure.

[0043] Figure 8 is a schematic diagram of the valve assembly in another exemplary embodiment of the solenoid valve of this disclosure.

[0044] Figure 9 is a schematic diagram of the solenoid valve circuit in an exemplary embodiment of the solenoid valve disclosed herein.

[0045] Figure 10 is a schematic diagram of the power supply circuit in an exemplary embodiment of the solenoid valve of this disclosure.

[0046] Figure 11 is a schematic diagram showing the connection between the output terminal of the power supply circuit and the voltage detection terminal of the control chip in an exemplary embodiment of the solenoid valve of this disclosure.

[0047] Figure 12 is a schematic diagram of the control chip in an exemplary embodiment of the solenoid valve of this disclosure.

[0048] Figure 13 is a schematic diagram showing the connection between the output terminal of the power supply circuit and the voltage input terminal of the control chip in an exemplary embodiment of the solenoid valve of this disclosure.

[0049] Figure 14 is a schematic diagram of the drive circuit in an exemplary embodiment of the solenoid valve of this disclosure. Detailed Implementation

[0050] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0051] Unless otherwise specified or stated, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “a,” “an,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “comprising” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to those listed; the terms “first” and “second” are used only as illustrative marks and are not intended to limit the number, importance, or order of the objects.

[0052] The terms “connection” and “fixed” should be interpreted broadly. For example, unless otherwise specified or stated, “connection” can be a fixed connection, a movable connection, an integral connection, or a detachable connection. It can be a direct connection or an indirect connection through an intermediate medium.

[0053] Furthermore, it should be understood that the directional terms such as "top / bottom," "upper / lower," and "inner / outer" described in the exemplary embodiments of this disclosure are merely used to indicate relative positional relationships. For convenience, descriptions are made based on angles shown in the accompanying drawings, or on the general understanding of solenoid valves in the art, and should not be construed as limiting the exemplary embodiments of this disclosure. For example, unless otherwise specified, in the description of this disclosure, the axial direction of the solenoid valve assembly is used as a reference, with the end of the valve assembly near the iron core designated as "upper / top," and the end of the valve assembly near the valve port designated as "lower / bottom." This reference direction is consistent with the reference in the accompanying drawings provided in this disclosure. Those skilled in the art will understand that when the absolute position of the described object changes, the relative positional relationship may also change accordingly; "upper" may become "lower," "left," or "right." Such changes will not hinder the understanding of those skilled in the art.

[0054] This disclosure provides a solenoid valve, as shown in FIG1, comprising: a valve assembly, a coil assembly, a magnetic guide frame 3, and a protective housing 4. The magnetic guide frame 3 is mounted on the valve assembly, and the coil assembly includes a coil 21 and a circuit board 22; the coil 21 is located within the coil mounting space formed by the magnetic guide frame 3; the circuit board 22 is electrically connected to the coil 21; wherein, the coil 21 and the circuit board 22 are disposed within the protective housing 4, and the protective housing 4 is partially mounted within the coil mounting space and is separately disposed from the magnetic guide frame 3.

[0055] The solenoid valve disclosed herein features a magnetic guide frame 3 that encloses a coil mounting space. The coil 21 is housed within this space. The magnetic guide frame 3 concentrates the dispersed magnetic field, thereby enhancing the electromagnetic force of the coil 21 and strengthening its switching control capability over the solenoid valve. A circuit board 22 is electrically connected to the coil 21. The power circuit within the circuit board 22 controls the current flowing through the coil 21, reducing its power consumption or allowing for a reduction in the number of turns while maintaining the same power output. Both the coil 21 and the circuit board 22 are housed within a protective housing 4, providing protection for both and improving the solenoid valve's operational safety. Furthermore, a portion of the protective housing 4 is also installed within the coil mounting space, but is separate from the magnetic guide frame 3. Compared to a design where the magnetic guide frame 3 is also located within the protective housing 4, the protective housing 4 and the magnetic guide frame 3 are independent components, allowing for easy separation and assembly.

[0056] Specifically, refer to Figure 2, which shows a schematic diagram of the solenoid valve from another perspective; Figure 3, which shows a schematic diagram of the valve assembly and the magnetic guide frame 3 being installed; and Figure 4, which shows a cross-sectional view of an exemplary embodiment of the solenoid valve. The valve assembly has a limiting surface 101 and a cylindrical surface 102. The magnetic guide frame 3 can be installed on the limiting surface 101 of the valve assembly. The coil 21 is sleeved outside the cylindrical surface 102 and located within the coil mounting space. The magnetic guide frame 3 may include a first horizontal plate 31, a first vertical plate 32, and a second horizontal plate 33 connected in sequence, forming a coil mounting space. The first horizontal plate 31 and the second horizontal plate 33 are directly opposite each other at the upper and lower ends of the coil 21, which can enhance the focusing effect on the magnetic field of the coil 21 and increase the electromagnetic force of the coil 21.

[0057] For example, referring to FIG4, a coil support 23 may be fitted over the cylindrical surface 102. The coil support 23 has upper and lower ends and a winding portion between the two ends, and the coil 21 is wound around the winding portion of the coil support 23. For example, the coil 21 may be a winding made of enameled wire. During installation, the coil 21 can be formed by winding the enameled wire around the winding portion of the coil support 23.

[0058] For example, referring to Figure 4, the second horizontal plate 33 of the magnetic guide frame 3 is disposed on the limiting surface 101, and the bottom surface of the coil support 23 can be in contact with the surface of the second horizontal plate 33 away from the limiting surface 101, that is, in contact with the top surface of the second horizontal plate 33; the top surface of the coil support 23 can be in contact with the surface of the first horizontal plate 31 near the limiting surface 101, that is, in contact with the bottom surface of the first horizontal plate 31.

[0059] In one exemplary embodiment of this disclosure, the protective housing 4 includes a coil protection part 41 and a circuit board protection part 42. Refer to Figures 1, 2, and 4 for schematic diagrams of the solenoid valve, and Figure 5 for a schematic diagram of the assembly of the magnetic guide frame 3 and the protective housing 4. It should be noted that, for clarity, the cross-sectional lines of the protective housing 4 are omitted in the cross-sectional schematic diagram of Figure 4.

[0060] The coil protection portion 41 at least partially surrounds the coil 21; the circuit board 22 is disposed within the circuit board protection portion 42; the coil protection portion 41 is connected to the circuit board protection portion 42. For example, referring to FIG4, the circuit board protection portion 42 forms a circuit board receiving space 421, the circuit board 22 is disposed within the circuit board receiving space 421, and a protective cover 422 closes the circuit board receiving space 421. For example, the circuit board receiving space 421 opens towards the top, and the protective cover 422 closes the circuit board receiving space 421 at the top.

[0061] Exemplarily, a potting layer is provided within the circuit board protection portion 42, and the circuit board 22 is encapsulated within the potting layer. The circuit board 22 is fixed to the circuit board protection portion 42 by the potting layer. Specifically, after the circuit board 22 is installed in the circuit board receiving space 421 within the circuit board protection portion 42, potting compound can be injected into the circuit board receiving space 421. The potting compound can cure under specific conditions to form a potting layer, which seals and protects the circuit board 22. Exemplarily, the height of the potting layer is greater than that of the circuit board 22, that is, the potting compound covers the circuit board 22. Exemplarily, the height of the potting layer is lower than the bottom surface of the protective cover plate 422. The material of the potting layer may include epoxy resin, polyurethane, or silicone.

[0062] In one exemplary embodiment of this disclosure, referring to Figures 2, 4, and 5, the coil protection part 41 is installed within the coil mounting space and is separately disposed from the valve assembly. Specifically, the bottom surface of the second horizontal plate 33 of the magnetic guide frame 3 is attached to the limiting surface 101, and the bottom surface of the coil protection part 41 can be attached to the surface of the second horizontal plate 33 away from the limiting surface 101, that is, to the top surface of the second horizontal plate 33; the top surface of the coil protection part 41 can be attached to the surface of the first horizontal plate 31 near the limiting surface 101, that is, to the bottom surface of the first horizontal plate 31. In this exemplary embodiment of the disclosure, the coil protection part 41 can be separated from the valve assembly and can be independently disassembled and assembled without affecting each other.

[0063] In one exemplary embodiment of this disclosure, the coil 21 is electrically connected to the circuit board 22 via a first wiring connection, and the circuit board 22 is electrically connected to the power module via a second wiring connection. The circuit board 22 is connected in series between the coil 21 and the power module circuit. Compared to a direct connection between the coil 21 and the power module, the power circuit within the circuit board 22 can adjust the control voltage input to the coil 21 according to actual needs. For example, it can increase the output power of the coil 21 when the solenoid valve is engaged; decrease the output power of the coil 21 when the solenoid valve is held, thereby reducing the power consumption and temperature rise of the coil 21 and improving its operational reliability; or reduce the number of turns of the coil 21 while maintaining the same power output, achieving cost reduction. Furthermore, the connection between the coil 21 and the power module via the circuit board 22, and the adjustment of the voltage input to the coil 21 via the circuit board 22, facilitates matching with various power modules, reduces user-side control, and broadens the application of the solenoid valve. Exemplarily, the circuit board 22 can be implemented as a component with a control chip, which enables corresponding control functions.

[0064] Referring to Figures 1 and 4, the coil protection part 41 and the circuit board protection part 42 are connected by the coil support part 43, thereby allowing the circuit board protection part 42 to be spatially separated from the magnetic guide frame 3. By placing the circuit board 22 within the circuit board protection part 42, outside the magnetic guide frame 3, such as within the circuit board receiving space 421, the circuit board 22 can be spatially separated from the magnetic guide frame 3, making the arrangement of the circuit board 22 more flexible. For example, the first wiring can be disposed within the coil support part 43. The coil support part 43 can protect the first wiring.

[0065] In one exemplary embodiment of this disclosure, the coil support portion 43 is disposed on the side of the magnetic guide frame 3, as shown in Figures 1, 4, and 5. The side of the magnetic guide frame 3 refers to the position adjacent to the first horizontal plate 31 and the second horizontal plate 33 of the magnetic guide frame 3. Exemplarily, the coil support portion 43 is disposed on the side adjacent to the first vertical plate 32 of the magnetic guide frame 3, which facilitates the installation of the protective housing 4.

[0066] In one exemplary embodiment of this disclosure, referring to Figures 3 and 5, the first horizontal plate 31 has a clearance portion 34 on one or both sides adjacent to the first vertical plate 32, and part of the coil support portion 43 is located within the clearance portion 34. This helps to shorten the size of the protective housing 4 in the direction perpendicular to the axis of the valve assembly, making the structure of the protective housing 4 more compact.

[0067] For example, referring to Figures 1 to 5, the extending direction of the coil support portion 43 is parallel to the extending direction of the cylindrical surface 102. For example, the cylindrical surface 102 extends along the axial direction of the valve assembly, and the coil support portion 43 also extends along the axial direction of the valve assembly. In one exemplary embodiment, referring to Figures 1, 4, and 5, the circuit board protection portion 42 is disposed on the side of the coil support portion 43 away from the limiting surface 101, and the bottom surface of the circuit board protection portion 42 is higher than the top surface of the magnetic guide frame 3. In the exemplary embodiment, by disposing of the circuit board protection portion 42 above the magnetic guide frame 3, the structural design of the protective housing 4 and the arrangement of the circuit board 22 can be made more flexible. For example, referring to Figures 1, 4, and 5, the portion of the circuit board protection portion 42 projected onto the top surface of the magnetic guide frame 3 is located within the outer contour of the top surface of the magnetic guide frame 3, which helps to shorten the size of the protective housing 4 in the direction perpendicular to the axial direction of the valve assembly, making the structure of the protective housing 4 more compact and the arrangement more flexible.

[0068] In one exemplary embodiment of this disclosure, referring to Figures 1, 2, 4, and 5, the protective housing 4 further includes a wiring portion 44. The wiring portion 44 is connected to the coil protection portion 41; the extending direction of the wiring portion 44 is perpendicular to the extending direction of the cylindrical surface 102. For example, referring to Figures 1, 2, 4, and 5, the extending direction of the wiring portion 44 is consistent with the direction of two adjacent surfaces of the first vertical plate 32 facing each other. At least a portion of the second wiring may be provided in the wiring portion 44, which can protect the second wiring. In some exemplary embodiments of this disclosure, the coil protection portion 41 can protect the coil 21; the circuit board protection portion 42 can protect the circuit board 22; the coil support portion 43 can connect the coil protection portion 41 and the circuit board protection portion 42 and protect the first wiring; the wiring portion 44 can protect the second wiring, thereby the protective housing 4 can provide sufficient protection for the entire coil assembly, preventing damage to the coil 21, circuit board 22, first wiring, and second wiring, as well as water ingress. Exemplarily, the protective housing 4 may include a plastic material. In one exemplary embodiment of this disclosure, referring to Figures 1, 2, 4 and 5, the wiring portion 44 can be connected to the coil support portion 43.

[0069] The valve assembly of the solenoid valve provided in this disclosure will now be described with reference to Figures 4 and 6.

[0070] Referring to Figures 4 and 6, the valve assembly may include a valve body, a stationary iron core 12, a moving iron core 13, and a sleeve 14, with the moving iron core 13 movably disposed within the sleeve 14.

[0071] In one exemplary embodiment of this disclosure, referring to FIG4, the stationary iron core 12 is connected to the valve body, and the sleeve 14 is located on the side of the stationary iron core 12 away from the valve body and is connected to the stationary iron core 12. The stationary iron core 12 and the sleeve 14 form at least a partial cylindrical surface 102. The limiting surface 101 may be located in the valve body, or in the stationary iron core 12, or the limiting surface 101 may be partially located in the valve body and partially located in the stationary iron core 12. Specifically, the valve body may include a valve seat 11 and a piston 17. The valve seat 11 has a receiving cavity and a valve port 111 communicating with the receiving cavity. The piston 17 is received in the receiving cavity to open or close the valve port 111.

[0072] Referring to Figure 4, the stationary iron core 12 includes a plugging section 121 and a guide section 122 connected to each other. The plugging section 121 is connected to the valve seat 11. The guide section 122 forms at least a partial cylindrical surface 102. The coil support 23 and the magnetic guide frame 3 are at least partially sleeved on the guide section 122. The radial dimension of the guide section 122 is smaller than the radial dimension of the plugging section 121. The plugging section 121 and the guide section 122 can be integrated to ensure a high coaxiality requirement between the stationary iron core 12 and the valve seat 11. Alternatively, the plugging section 121 and the guide section 122 can be separate components for easier processing and installation.

[0073] The valve assembly may further include a valve stem 16, one end of which engages with the end of the piston 17 away from the valve port 111, and the other end passes through the stationary iron core 12 and the moving iron core 13, abutting against the first elastic member 181. The first elastic member 181 is disposed between the top of the sleeve 14 and the valve stem 16. The valve assembly also includes a second elastic member 182, which is disposed between the stationary iron core 12 and the moving iron core 13. The second elastic member 182 is used to compress when the stationary iron core 12 and the moving iron core 13 approach and attract each other, and to drive the stationary iron core 12 and the moving iron core 13 to separate from each other through elastic force when the attraction between the stationary iron core 12 and the moving iron core 13 is released. When coil 21 is energized, driving the moving iron core 13 to move towards the stationary iron core 12, the valve stem 16 moves towards the valve port 111 under its own gravity and the elastic force of the first elastic element 181, driving the piston 17 to move towards the valve port 111 until the piston 17 is in contact with the valve port 111, thus closing the valve. When coil 21 is de-energized, the moving iron core 13 and the stationary iron core 12 separate under the elastic force of the second elastic element 182, and the valve stem 16 moves away from the valve port 111 following the moving iron core 13, driving the piston 17 away from the valve port 111, thus opening the valve, as shown in Figure 4.

[0074] Specifically, referring to Figure 4, a pilot valve port 171 is provided at the end of the piston 17 near the valve stem 16. The valve stem 16 opens and closes the pilot valve port 171 under the drive of the moving iron core 13. A pilot hole 172 is provided at the center of the piston 17, axially penetrating the piston 17, and the pilot hole 172 is connected to the pilot valve port 171. By providing the pilot valve port 171 and the pilot hole 172, a pressure difference force exists on both sides of the piston 17 when opening or closing the valve. The piston 17 is pushed by the pressure difference force, reducing the difficulty of opening or closing the valve.

[0075] For example, when coil 21 is not energized, referring to Figure 4, the moving iron core 13 and the stationary iron core 12 separate under the elastic force of the second elastic element 182, and the valve stem 16 opens the pilot valve port 171. At this time, the chamber on the side of piston 17 closest to valve stem 16 is depressurized through pilot valve port 171 and pilot hole 172, forming a liquid pressure difference at both ends of piston 17 and maintaining balance. Under the action of the pressure difference, piston 17 moves upward away from valve port 111, thus opening valve port 111. When coil 21 is energized, the moving iron core 13 overcomes the elastic force of the second elastic element 182 and moves towards the stationary iron core 12. Valve stem 16 resets under its own gravity and the elastic force of the first elastic element 181, thereby closing pilot valve port 171. Piston 17 moves downward, closing valve port 111.

[0076] In another exemplary embodiment of this disclosure, referring to FIG6, the valve assembly further includes a valve cover 15 connected to the valve body, specifically, the valve cover 15 is connected to the valve seat 11. A stationary iron core 12 is disposed away from the valve seat 11. One end of a sleeve 14 is connected to the valve cover 15, and the other end is connected to the stationary iron core 12. A movable iron core 13 is movably disposed within the sleeve 14. The stationary iron core 12 and the sleeve 14 form at least a partial cylindrical surface 102. A limiting surface 101 may be located in the valve body, specifically in the valve seat 11, or in the valve cover 15, or the limiting surface 101 may be partially located in the valve seat 11 and partially in the valve cover 15.

[0077] Referring to Figure 6, the valve assembly also includes a valve stem 16. One end of the valve stem 16 engages with the end of the piston 17 away from the valve port 111, and the other end passes through the moving iron core 13 and can move within the moving iron core 13. One end of the third elastic element 183 abuts against the end of the valve stem 16 near the stationary iron core 12, and the other end abuts against the end of the cavity in the moving iron core 13 that accommodates the valve stem 16 near the valve port 111. A fourth elastic element 184 is provided between the stationary iron core 12 and the moving iron core 13. The elastic force of the fourth elastic element 184 is used to drive the moving iron core 13 and the valve stem 16 to move towards the piston 17, pushing the piston 17 towards the valve port 111 until the piston 17 is in contact with the valve port 111, thus closing the valve. When the coil 21 is energized, it drives the moving iron core 13 to move towards the stationary iron core 12, causing the valve stem 16 to push the piston 17 away from the valve port 111, thus opening the valve.

[0078] Specifically, referring to Figure 6, a pilot valve port 171 is provided at the end of the piston 17 near the valve stem 16. The valve stem 16 opens and closes the pilot valve port 171 under the drive of the moving iron core 13. A pilot hole 172 is provided at the center of the piston 17, axially penetrating the piston 17, and the pilot hole 172 is connected to the pilot valve port 171. By providing the pilot valve port 171 and the pilot hole 172, a pressure difference force exists on both sides of the piston 17 when opening or closing the valve. The piston 17 is pushed by the pressure difference force, reducing the difficulty of opening or closing the valve.

[0079] For example, when coil 21 is energized, the moving iron core 13 moves upward against the elastic force of the fourth elastic element 184, driving the valve stem 16 to move away from the pilot valve port 171 to open the pilot valve port 171. At this time, the chamber on the side of piston 17 closest to valve stem 16 is depressurized through pilot valve port 171 and pilot hole 172, forming a liquid pressure difference between the upper and lower ends of piston 17 and maintaining balance. Under the action of the pressure difference, piston 17 moves upward away from valve port 111, realizing the opening of valve port 111. When coil 21 is de-energized, under the action of the fourth elastic element 184 and the gravity of valve stem 16, valve stem 16 returns to its original position, pilot valve port 171 closes, piston 17 moves downward, closing valve port 111. The pressure on the upper side of piston 17 increases, thereby pressurizing piston 17 and making the sealing effect of piston 17 on valve port 111 better.

[0080] In other embodiments of this disclosure, the valve assembly of the solenoid valve may also be in other forms. For example, referring to Figures 7 and 8, the body of the valve assembly may be a multi-way valve, which does not affect the installation of the magnetic guide 3, the coil 21 and the protective housing 4.

[0081] For example, referring to Figures 7 and 8, Figure 7 shows a schematic diagram of a solenoid valve in an exemplary embodiment, and Figure 8 shows a schematic diagram of the valve assembly of the solenoid valve shown in Figure 7. The cylindrical surface 102 of the valve assembly may not be coaxial with the valve body. For example, the cylindrical surface 102 is located outside the valve seat 11 and is connected to the outer wall of the valve seat 11 through the limiting surface 101. The axis of the cylindrical surface 102 may be parallel to the axis of the valve seat 11. Referring to Figure 7, the magnetic guide frame 3 can be installed in the valve assembly shown in Figure 8. The coil 21 and the protective housing 4 can be located within the coil mounting space formed by the magnetic guide frame 3 and are separately arranged from the magnetic guide frame 3. The internal structure of the valve assembly can refer to multi-way valves in related technologies, such as the four-way valve shown in Figure 8, which will not be described in detail here.

[0082] In one exemplary embodiment of this disclosure, a solenoid valve circuit is provided on the circuit board 22. The solenoid valve circuit includes a power supply circuit, a control circuit, and a drive circuit. The power supply circuit is connected in series between the power module and the first input terminal of the drive circuit so that the power module supplies power to the drive circuit through the power supply circuit. The output terminal of the drive circuit is connected to the solenoid valve interface, which is located on the coil 21.

[0083] The control circuit includes a control chip. The output terminal of the power supply circuit is connected to the voltage detection terminal and the voltage input terminal of the control chip. The control terminal of the control chip is connected to the second input terminal of the drive circuit to output a pulse width modulation signal to the drive circuit. The drive circuit adjusts the coil voltage of the input solenoid valve according to the voltage of the first input terminal and the pulse width modulation signal of the second input terminal.

[0084] Specifically, Figure 9 shows a schematic diagram of the solenoid valve circuit architecture, Figure 10 shows a schematic diagram of the power supply circuit, Figures 11 and 12 show schematic diagrams of the connection between the output terminal of the power supply circuit and the voltage detection terminal of the control chip, Figure 12 shows a schematic diagram of the control chip, Figure 13 shows a schematic diagram of the connection between the output terminal of the power supply circuit and the voltage input terminal of the control chip, and Figure 14 shows a schematic diagram of the drive circuit.

[0085] Referring to Figures 9 to 14, the power supply module supplies power to the control chip and the drive circuit through the power supply circuit. The control chip can collect the input working voltage according to the voltage detection terminal and adjust the pulse width modulation signal output to the drive circuit according to the input working voltage. The drive circuit adjusts the voltage at the first input terminal to the coil voltage of the input solenoid valve coil according to the input pulse width modulation signal.

[0086] The solenoid valve circuit disclosed herein is located on circuit board 22, and the solenoid valve interface is located on coil 21. The solenoid valve circuit can control the coil voltage of the solenoid valve through a pulse-width modulation signal output by a control chip. This allows for different input voltages to coil 21 based on the solenoid valve's operating state and actual requirements, maintaining the coil voltage at the minimum necessary operating voltage. This reduces product temperature rise and extends product lifespan. Furthermore, because the solenoid valve's coil voltage is adjustable, it can be matched with various power supplies, reducing the need for user-side control and thus broadening its application.

[0087] For example, compared to directly connecting the coil pin to the power module and directly outputting the power supply voltage to the solenoid valve coil, the solenoid valve circuit of this disclosure can maintain the coil voltage at a larger value when the solenoid valve is open, thereby providing sufficient electromagnetic force to the coil 21. The moving iron core 13 and the stationary iron core 12 of the valve assembly can be fully attracted to ensure reliable start-up of the solenoid valve. In the holding state after the solenoid valve is fully opened, the electromagnetic force required to maintain the attraction of the moving iron core 13 and the stationary iron core 12 is relatively small. The solenoid valve circuit of this disclosure can reduce the coil voltage, thereby reducing the coil temperature rise and improving reliability. At the same time, the number of enameled wire turns can be reduced, thus reducing costs.

[0088] For example, when a solenoid valve using the solenoid valve circuit of this disclosure is matched with a power supply module of different voltage, the coil voltage can be controlled by the solenoid valve circuit to convert the voltage of the power supply module into the required coil voltage, thereby improving the adaptability of the solenoid valve to the power supply module.

[0089] In one exemplary embodiment of this disclosure, referring to FIG10, the power supply circuit includes a first diode D1 and a second diode D2. VBAT represents the input terminal where the power module outputs power voltage to the power supply circuit, V12V represents the output terminal of the power supply circuit, and GND represents the ground terminal of the circuit. The input terminal of the first diode D1 is connected to the power module, and the output terminal of the first diode D1 is connected to the output terminal V12V of the power supply circuit; the input terminal of the second diode D2 is grounded, and the output terminal of the second diode D2 is connected to the input terminal VBAT of the power supply circuit. The second diode D2 can prevent the power supply circuit input terminal VBAT from being reverse-connected to the ground terminal GND, thereby improving the safety of the solenoid valve circuit.

[0090] In one exemplary embodiment of this disclosure, referring to FIG10, a first inductor L1 and a first diode D1 are connected in series between the power supply voltage input terminal VBAT and the output terminal V12V of the power supply circuit; at least one capacitor is provided between the anode of the first diode D1 and the ground terminal GND of the power supply circuit. For example, referring to FIG10, capacitors C6 and C7 are provided between the anode of the first diode D1 and the ground terminal GND of the power supply circuit. Exemplarily, the inductance of the first inductor L1 is 10uH; the capacitance of capacitor C6 is 4.7uF, and the capacitance of capacitor C7 is 0.1uF.

[0091] In one exemplary embodiment of this disclosure, at least one capacitor is provided between the cathode of the first diode D1 and the ground terminal GND of the power supply circuit. For example, referring to FIG10, capacitors C1, C2, C3, C4, and C5 are provided between the cathode of the first diode D1 and the ground terminal GND of the power supply circuit. Exemplarily, multiple capacitors with equal capacitance are provided between the cathode of the first diode D1 and the ground terminal GND of the power supply circuit. For example, the capacitance of capacitors C1, C2, C3, C4, and C5 is all 10uF.

[0092] In one exemplary embodiment of this disclosure, referring to FIG14, the solenoid valve interface includes a first solenoid valve interface and a second solenoid valve interface, which are respectively identified as pin 1 and pin 2 of connector J1 in the drive circuit shown in FIG14. Since the first input terminal of the drive circuit is connected to the output terminal of the power supply circuit, the first input terminal of the drive circuit is also identified as V12V; the second input terminal is used to receive pulse width modulation signals and is identified as PWM, and GND represents the ground terminal of the circuit. Referring to FIG14, the first solenoid valve interface is connected to the first input terminal V12V, and the second solenoid valve interface is connected to the ground terminal GND. The drive circuit may include a first switching transistor Q1 and a second switching transistor Q2; the first switching transistor Q1 is located between the first input terminal V12V and the first solenoid valve interface, and the second switching transistor Q2 is located between the first input terminal V12V and the ground terminal GND of the drive circuit.

[0093] Specifically, referring to Figure 14, the source of the first switch Q1 is connected to the first input terminal V12V, and the drain of the first switch Q1 is connected to the first solenoid valve interface through the second inductor L2; the collector of the second switch Q2 is connected to the first input terminal V12V through the parallel first resistor R1 and the second resistor R2, and the emitter of the second switch Q2 is connected to the ground terminal GND of the drive circuit; the gate of the first switch Q1 is connected to the emitter of the second switch Q2, and the base of the second switch Q2 is connected to the second input terminal PWM through the third resistor R3. The base of the second switch Q2 is also connected to the ground terminal GND of the drive circuit through the fourth resistor R4.

[0094] The drive circuit can control the voltage of the input solenoid valve interface J1 according to the duty cycle of the pulse width modulation signal at the second input terminal. For example, the duty cycle of the pulse width modulation signal corresponds one-to-one with the coil voltage of the input solenoid valve of the drive circuit, so that the drive circuit can convert the fixed voltage of the first input terminal V12V into the required coil voltage according to the pulse width modulation signal output by the control chip U1.

[0095] For example, the first switch Q1 is a field-effect transistor, and the second switch Q2 is a transistor. The inductance of the second inductor L2 is 3.3uH, the resistances of the first resistor R1, the second resistor R2, and the third resistor R3 are all 10kΩ, and the resistance of the fourth resistor R4 is 100kΩ.

[0096] Referring to Figure 14, in an exemplary embodiment of this disclosure, the drain of the first switching transistor Q1 is connected to the cathode of the third diode D3, and the anode of the third diode D3 is connected to the ground terminal GND of the drive circuit. An electrolytic capacitor EC1 and a capacitor C9 are connected in parallel between the first solenoid valve interface and the second solenoid valve interface. Exemplarily, the capacitance of electrolytic capacitor EC1 is 220uF, and the capacitance of capacitor C9 is 0.1uF.

[0097] In one exemplary embodiment of this disclosure, referring to Figures 12 and 14, a sixth resistor R6 and an eighth resistor R8 are connected in series between the first solenoid valve interface and the second solenoid valve interface. The voltage between the sixth resistor R6 and the eighth resistor R8 is connected to the voltage feedback terminal (Votage_FeedBack) of the control chip U1. The control chip U1 controls the pulse width modulation signal based on the voltage at the voltage feedback terminal (Votage_FeedBack). The voltage between the voltage divider resistors R6 and R8 is positively correlated with the coil voltage of the solenoid valve. The control chip U1 can monitor the operating coil voltage of the solenoid valve using the Votage_FeedBack pin. When there is a deviation between the operating coil voltage and the target voltage, the control chip U1 adjusts the operating coil voltage of the solenoid valve by adjusting the pulse width modulation signal output from the control terminal, for example, by changing the duty cycle of the pulse width modulation signal, to make it consistent with the target voltage. This exemplary embodiment improves the accuracy of regulating the coil voltage of the solenoid valve by monitoring the operating coil voltage of the solenoid valve through the Votage_FeedBack pin.

[0098] In one exemplary embodiment of this disclosure, referring to FIG11, the output terminal V12V of the power supply circuit is connected to the voltage detection terminal Input_Votage of the control chip U1 through a fifth resistor R5. Exemplarily, a capacitor C8 is also provided between the output terminal V12V of the power supply circuit and the ground terminal GND, with a capacitance of, for example, 4.7uF. A fifth resistor R5 and a seventh resistor R7 are connected in series between the output terminal V12V of the power supply circuit and the ground terminal GND, with the resistance of the fifth resistor R5 being, for example, 820kΩ and the resistance of the seventh resistor R7 being, for example, 150kΩ. The interface connecting the power supply circuit and the power module is connector J2. Referring to FIG11, pin 1 of connector J2 is grounded, and pin 2 of connector J2 is connected to the input terminal VBAT of the power supply circuit.

[0099] In one exemplary embodiment of this disclosure, the control chip U1 outputs a first pulse width modulation signal to the drive circuit via its control terminal PWM when the voltage at its voltage detection terminal Input_Votage is greater than or equal to 9V. Exemplarily, after the power supply circuit and the control chip U1 are powered on, the voltage at the voltage detection terminal Input_Votage gradually increases. When the voltage at Input_Votage reaches 9-16V, the power supply to the power module enters a stable phase. When the voltage at the voltage detection terminal Input_Votage is greater than or equal to 9V, the control chip U1 outputs the first pulse width modulation signal, corresponding to the first coil voltage, causing the solenoid valve to start working. This prevents the solenoid valve from operating under unstable power supply conditions of the power module and power supply circuit, thus protecting the solenoid valve circuit.

[0100] In one exemplary embodiment of this disclosure, the control chip U1 is used to output a second pulse width modulation signal to the driving circuit through its control terminal when the first pulse width modulation signal is output for a first preset time. The duty cycle of the second pulse width modulation signal is less than that of the first pulse width modulation signal. For example, the control chip U1 may output the second pulse width modulation signal to the driving circuit 1 minute after outputting the first pulse width modulation signal. Alternatively, the control chip U1 may output the second pulse width modulation signal to the driving circuit 2 minutes after outputting the first pulse width modulation signal. The duty cycle of the second pulse width modulation signal is less than that of the first pulse width modulation signal; for example, the duty cycle of the first pulse width modulation signal is 80%, and the duty cycle of the second pulse width modulation signal is 60%; or, for example, the duty cycle of the first pulse width modulation signal is 85%, and the duty cycle of the second pulse width modulation signal is 55%.

[0101] Referring to Figures 12 and 13, the RST_TGT pin is the power-on reset pin; SWD_DIO is the serial data pin, used for data reading and writing; SWD_CLK is the serial...

[0102] The clock pin provides the required clock signal; RESET is the reset pin. The voltage input terminal VDD of control chip U1 is identified as V5V. The VSS pin of control chip U1 is grounded. Capacitors C11, C12, and C13 can be placed between the VDD and VSS pins. For example, capacitor C11 has a capacitance of 0.1uF, capacitor C12 has a capacitance of 10uF, and capacitor C13 has a capacitance of 0.1uF. The programming port of control chip U1 is shown in connector J3. Pin 1 of connector J3 is the V5V pin, pin 2 is the ground (GND) pin, pin 3 is the SWD_CLK serial clock pin, and pin 4 is the SWD_DIO serial data pin.

[0103] In one exemplary embodiment of this disclosure, a voltage conversion chip U2 is connected in series between the output terminal V12V of the power supply circuit and the voltage input terminal V5V of the control chip U1. The voltage conversion chip U2 is used to convert the 12V voltage at the output terminal V12V of the power supply circuit to the 5V voltage at the voltage input terminal V5V of the control chip U1. In this exemplary embodiment, the solenoid valve can be used in an automotive environment. The voltage conversion chip U2 can convert the 12V automotive power supply voltage to the 5V voltage required by the VDD pin of the control chip U1, thereby improving the adaptability of the solenoid valve circuit to different power supply voltages.

[0104] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A solenoid valve, characterized in that, It includes a valve assembly, a coil assembly, a magnetic guide frame (3), and a protective housing (4); The magnetic guide frame (3) is mounted on the valve assembly, and the coil assembly includes a coil (21) and a circuit board (22); the coil (21) is located in the coil mounting space formed by the magnetic guide frame (3); the circuit board (22) is electrically connected to the coil (21); The coil (21) and the circuit board (22) are located inside the protective housing (4). The protective housing (4) is partially installed within the coil mounting space and is separately installed from the magnetic guide frame (3).

2. The solenoid valve according to claim 1, characterized in that, The valve assembly has a limiting surface (101) and a cylindrical surface (102); the magnetic guide frame (3) is installed on the limiting surface (101) of the valve assembly; the coil (21) is sleeved outside the cylindrical surface (102) and located within the coil mounting space; The protective housing (4) includes a coil protection part (41) and a circuit board protection part (42); the coil protection part (41) at least partially surrounds the coil (21); the circuit board (22) is disposed inside the circuit board protection part (42).

3. The solenoid valve according to claim 2, characterized in that, The coil protection part (41) is installed in the coil mounting space and is separately set from the valve assembly.

4. The solenoid valve according to claim 2, characterized in that, The coil (21) is electrically connected to the circuit board (22) via a first wiring connection, and the circuit board (22) is electrically connected to the power module via a second wiring connection.

5. The solenoid valve according to claim 1, characterized in that, The magnetic guide frame (3) includes a first horizontal plate (31), a first vertical plate (32) and a second horizontal plate (33) connected in sequence, and the first horizontal plate (31), the first vertical plate (32) and the second horizontal plate (33) form the coil mounting space.

6. The solenoid valve according to claim 2, characterized in that, The bottom surface of the circuit board protection part (42) is higher than the top surface of the magnetic guide frame (3).

7. The solenoid valve according to claim 2, characterized in that, The portion of the circuit board protection part (42) projected onto the top surface of the magnetic guide frame (3) is located within the outer contour of the top surface of the magnetic guide frame (3).

8. The solenoid valve according to claim 2, characterized in that, The coil (21) is electrically connected to the circuit board (22) via a first wiring connection. The coil protection part (41) and the circuit board protection part (42) are connected via a coil support part (43). The first wiring connection is located inside the coil support part (43). The coil support part (43) is located on the side of the magnetic guide frame (3). The magnetic guide frame (3) includes a first horizontal plate (31), a first vertical plate (32), and a second horizontal plate (33) connected in sequence. The first horizontal plate (31), the first vertical plate (32), and the second vertical plate (33) are connected in sequence. The vertical plate (32) and the second horizontal plate (33) enclose the coil mounting space; the first horizontal plate (31) has a clearance portion (34) on one or both sides adjacent to the first vertical plate (32), and part of the coil support portion (43) is located in the clearance portion (34); the extension direction of the coil support portion (43) is parallel to the extension direction of the cylindrical surface (102), and the circuit board protection portion (42) is provided on the side of the coil support portion (43) away from the limiting surface (101).

9. The solenoid valve according to claim 4, characterized in that, The protective housing (4) further includes a wiring section (44) connected to the coil protection section (41); the extension direction of the wiring section (44) is perpendicular to the extension direction of the cylindrical surface (102), and at least a portion of the second wiring is provided in the wiring section (44).

10. The solenoid valve according to claim 2, characterized in that, The circuit board protection part (42) is provided with a potting layer, the circuit board (22) is encapsulated in the potting layer, and the circuit board (22) is fixed to the circuit board protection part (42) through the potting layer.

11. The solenoid valve according to claim 1, characterized in that, The valve assembly includes a valve body, a stationary iron core (12), a moving iron core (13), and a sleeve (14). The moving iron core (13) is movably disposed inside the sleeve (14). The stationary iron core (12) is connected to the valve body, and the sleeve (14) is located on the side of the stationary iron core (12) away from the valve body and is connected to the stationary iron core (12).

12. The solenoid valve according to claim 1, characterized in that, The valve assembly includes a valve body, a stationary iron core (12), a moving iron core (13), a sleeve (14), and a valve cover (15). The moving iron core (13) is movably disposed inside the sleeve (14). The valve cover (15) is connected to the valve body. One end of the sleeve (14) is connected to the valve cover (15), and the other end of the sleeve (14) is connected to the stationary iron core (12).

13. The solenoid valve according to claim 11 or 12, characterized in that, The valve body includes a valve seat (11) and a piston (17). The valve seat (11) has a receiving cavity and a valve port (111) communicating with the receiving cavity. The piston (17) is housed in the receiving cavity to open or close the valve port (111).

14. The solenoid valve according to claim 1, characterized in that, The circuit board (22) is provided with an electromagnetic valve circuit, which includes a power supply circuit, a control circuit and a drive circuit; the power supply circuit is connected in series between the power module and the first input terminal of the drive circuit, so that the power module supplies power to the drive circuit through the power supply circuit; the output terminal of the drive circuit is connected to the electromagnetic valve interface, which is located on the coil (21). The control circuit includes a control chip. The output terminal of the power supply circuit is connected to the voltage detection terminal and the voltage input terminal of the control chip. The control terminal of the control chip is connected to the second input terminal of the drive circuit to output a pulse width modulation signal to the drive circuit. The driving circuit adjusts the coil voltage input to the solenoid valve according to the voltage at the first input terminal and the pulse width modulation signal at the second input terminal.

15. The solenoid valve according to claim 14, characterized in that, The power supply circuit includes a first diode and a second diode. The input terminal of the first diode is connected to the power module, and the output terminal of the first diode is connected to the output terminal of the power supply circuit. The input terminal of the second diode is grounded, and the output terminal of the second diode is connected to the power module.

16. The solenoid valve according to claim 15, characterized in that, The power module and the output terminal of the power supply circuit are connected in series with a first inductor and a first diode; at least one capacitor is provided between the anode of the first diode and the ground terminal of the power supply circuit; at least one capacitor is provided between the cathode of the first diode and the ground terminal of the power supply circuit.

17. The solenoid valve according to claim 14, characterized in that, The solenoid valve interface includes a first solenoid valve interface and a second solenoid valve interface. The first solenoid valve interface is connected to the first input terminal, and the second solenoid valve interface is grounded. The drive circuit includes a first switch and a second switch. The first switch is located between the first input terminal and the first solenoid valve interface, and the second switch is located between the first input terminal and the ground terminal of the drive circuit.

18. The solenoid valve according to claim 17, characterized in that, The source of the first switching transistor is connected to the first input terminal, and the drain of the first switching transistor is connected to the first solenoid valve interface through a second inductor; the collector of the second switching transistor is connected to the first input terminal through a first resistor and a second resistor connected in parallel, and the emitter of the second switching transistor is connected to the ground terminal of the driving circuit; the gate of the first switching transistor is connected to the emitter of the second switching transistor, and the base of the second switching transistor is connected to the second input terminal through a third resistor, and the base of the second switching transistor is also connected to the ground terminal of the driving circuit through a fourth resistor.

19. The solenoid valve according to claim 17, characterized in that, A sixth resistor and an eighth resistor are connected in series between the first solenoid valve interface and the second solenoid valve interface. The voltage between the sixth resistor and the eighth resistor is connected to the voltage feedback terminal of the control chip. The control chip is used to control the pulse width modulation signal according to the voltage of the voltage feedback terminal.

20. The solenoid valve according to claim 14, characterized in that, The output terminal of the power supply circuit is connected to the voltage detection terminal of the control chip through a fifth resistor. When the voltage at the voltage detection terminal of the control chip is greater than or equal to 9V, the control chip outputs a first pulse width modulation signal to the drive circuit through its control terminal.

21. The solenoid valve according to claim 20, characterized in that, The control chip is used to output a second pulse width modulation signal to the driving circuit through the control terminal of the control chip when the first pulse width modulation signal is output for a first preset time. The duty cycle of the second pulse width modulation signal is less than the duty cycle of the first pulse width modulation signal.

22. The solenoid valve according to claim 14, characterized in that, A voltage conversion chip is connected in series between the output terminal of the power supply circuit and the voltage input terminal of the control chip. The voltage conversion chip is used to convert the 12V voltage at the output terminal of the power supply circuit into the 5V voltage at the voltage input terminal of the control chip.

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