solenoid valve

Abstract

The utility model belongs to solenoid valve technical field, specifically provides a solenoid valve. The utility model aims at solving the problem that the solenoid coil is big in power consumption and serious in heating when the existing solenoid valve maintains the air path blocking for a long time. For this purpose, the solenoid valve of the utility model includes valve body assembly, valve core assembly and reset spring. Valve body assembly has air inlet and air outlet and is provided with magnet on its magnetic yoke. Valve core assembly includes core body, armature and valve rod, the core body is used to control the on-off of the air path between the air inlet and the air outlet, and the armature can be attracted by the magnet. Reset spring is arranged between the magnetic yoke and the armature to drive the valve core assembly to open the air path between the air inlet and the air outlet. The magnet is used to provide the force for the valve core assembly to keep blocking the air path between the air inlet and the air outlet, to reduce the current of the solenoid coil, thereby reducing the power consumption and heating of the solenoid coil.

Description

Technical Field

[0001] This utility model belongs to the field of electromagnetic valve technology, and specifically provides an electromagnetic valve. Background Technology

[0002] Solenoid valves, as actuators for controlling the opening and closing of air passages, are widely used in industrial control, rail transportation, automobiles, and other fields. A typical solenoid valve consists of a valve body, a valve core assembly, a solenoid coil, and a return spring. The electromagnetic force generated by energizing the solenoid coil drives the valve core assembly to move, thus opening or closing the air passage. After de-energization, the return spring drives the valve core assembly to reset.

[0003] In practical applications, some scenarios require solenoid valves to maintain the air circuit blocked state for extended periods. To achieve this holding function, traditional solenoid valves require a continuous large current to be supplied to the solenoid coil to generate sufficient electromagnetic force to balance the spring force of the reset spring and the air medium pressure. This results in high energy consumption of the solenoid valve, and prolonged energization can easily cause the coil to consume a lot of power, generate excessive heat, age prematurely, shorten its service life, and increase the burden on the power supply system. Utility Model Content

[0004] One objective of this invention is to solve the problem of high power consumption and severe heat generation of the electromagnetic coil when the existing solenoid valve maintains the air circuit blockage for a long time.

[0005] To achieve the above objectives, this utility model provides a solenoid valve, comprising: A valve body assembly defines an air inlet, an air outlet, an on / off control chamber, and a drive chamber. The valve body assembly includes an electromagnetic coil, a magnetic yoke, and a magnet fixed on the magnetic yoke. At least a portion of the magnetic yoke is located between the on / off control chamber and the drive chamber to separate the on / off control chamber and the drive chamber. The magnetic yoke is also provided with a through hole connecting the on / off control chamber and the drive chamber. The valve core assembly includes a core disposed in the on / off control chamber, an armature disposed in the drive chamber, and a valve stem passing through the through hole and fixedly connected to the core and the armature respectively. The core is used to control the on / off of the air passage between the air inlet and the air outlet. A return spring is disposed between the magnetic yoke and the armature to drive the valve core assembly to open the air passage between the air inlet and the air outlet; The magnet provides a force to the valve core assembly to maintain the air passage between the air inlet and the air outlet, thereby reducing the current in the electromagnetic coil.

[0006] Optionally, the magnetic yoke has an annular groove on the side facing the armature, and the magnet is embedded in the annular groove to avoid the valve stem and the return spring.

[0007] Optionally, the through hole includes a valve core clearance section and a spring positioning section, the annular groove is connected to the spring positioning section, and the outer diameter of the annular groove, the diameter of the spring positioning section and the diameter of the valve core clearance section decrease sequentially, so that the through hole and the annular groove form a stepped hole; the valve core clearance section is clearance-fitted with the valve stem, and the spring positioning section is used to accommodate a part of the return spring.

[0008] Optionally, the ratio of the radial thickness of the magnet to the radial thickness of the armature is selected from any value from 0.2 to 0.8; and / or, the radial thickness of the magnet is greater than or equal to the axial height of the magnet.

[0009] Optionally, the valve body assembly further includes a shock-absorbing member disposed on the side of the yoke facing the armature to reduce the impact of the armature on the yoke.

[0010] Optionally, the damping component is an annular sheet structure to make the impact of the armature on the yoke more uniform.

[0011] Optionally, the shock-absorbing member covers the end of the magnet near the armature to prevent the armature from striking the magnet.

[0012] Optionally, the valve core assembly further includes an on / off sealing ring disposed on the core body. The on / off sealing ring is used to abut against the valve body assembly to block the air passage between the air inlet and the air outlet. When the electromagnetic coil is de-energized, the axial clearance between the on / off sealing ring and the valve body assembly is greater than the axial clearance between the shock-absorbing member and the armature, so that the armature impacts the shock-absorbing member before the on / off sealing ring abuts against the valve body assembly, thereby weakening the impact force on the on / off sealing ring.

[0013] Optionally, the elastic modulus of the damping component is less than that of the on / off sealing ring, to ensure that the on / off sealing ring can abut against the valve body assembly and generate sufficient deformation to block the air passage between the air inlet and the air outlet.

[0014] Optionally, the solenoid valve is suitable for adjusting the stiffness of the air spring.

[0015] Based on the foregoing description, those skilled in the art will understand that in the aforementioned technical solution of this utility model, by fixing a magnet on the yoke of the valve body assembly and making the magnet provide a force to the valve core assembly to maintain and block the air passage between the air inlet and the air outlet, the current of the electromagnetic coil is reduced, thereby reducing the power consumption and heat generation of the electromagnetic coil.

[0016] Furthermore, by setting an annular groove on the side of the magnetic yoke facing the armature and embedding the magnet in the annular groove, the distance between the magnet and the armature is smaller when the valve core assembly keeps blocking the air passage between the air inlet and the air outlet, thus providing a greater magnetic force to the armature.

[0017] Furthermore, by providing a shock-absorbing component on the side of the yoke facing the armature, the impact of the armature on the yoke is reduced. By covering the end of the magnet near the armature with the shock-absorbing component, the armature is prevented from colliding with the magnet, thus providing good protection for the magnet.

[0018] Other beneficial effects of this utility model will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the improvement purpose, features and advantages of this utility model. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this utility model, some embodiments of this utility model will be described below with reference to the accompanying drawings. Those skilled in the art should understand that the same reference numerals may indicate the same or similar components or parts in different drawings; the drawings of this utility model are not necessarily drawn to scale. In the drawings: Figure 1 This is a perspective view (first axonometric view) of the solenoid valve in some embodiments of this utility model. Figure 2 This is a perspective view (second axonometric view) of the solenoid valve in some embodiments of this utility model. Figure 3 This is an exploded view of the structure of the solenoid valve in some embodiments of this utility model; Figure 4 yes Figure 1 and Figure 2 Radial view of the gas flow shut-off valve; Figure 5 In some embodiments of this utility model, the valve body assembly is along Figure 4 A cross-sectional view along the AA direction; Figure 6 In some embodiments of this utility model, the magnetic yoke along Figure 4 A cross-sectional view along the AA direction; Figure 7 In some embodiments of this utility model, the valve core assembly is along Figure 4 A cross-sectional view along the AA direction; Figure 8 In some embodiments of this utility model, the solenoid valve edge Figure 4 Cross-sectional view along the AA direction (power off); Figure 9 yes Figure 8 Enlarged view of the F1 section; Figure 10 yes Figure 8 Enlarged view of section F2; Figure 11 In some embodiments of this utility model, the solenoid valve edge Figure 4 Cross-sectional view along the AA direction (with power on).

[0020] Explanation of reference numerals in the attached figures: 001. Solenoid valve; 100. Valve body assembly; 101. Air inlet; 102. Air outlet; 103. On / off control chamber; 104. Drive chamber; 111. Valve seat; 112. Valve cover; 113. Housing; 114. Power plug; 120. Magnetic yoke; 121. Through hole; 1211. Valve core clearance section; 1212. Spring positioning section; 122. Annular groove; 130. Valve sleeve; 140. Coil mounting bracket; 150. Electromagnetic coil; 161. Sliding seal ring; 162. Mounting seal ring; 170. Magnet; 180. Vibration damping component; 200, Valve core assembly; 210, Core body; 211, Pressure equalizing hole; 220, Armature; 230, Valve stem; 240, On / off sealing ring; 250, Buffer component; 300. Return spring; r, radial; o, axial. Detailed Implementation

[0021] Those skilled in the art should understand that the embodiments described below are merely some embodiments of the present invention, and not all embodiments of the present invention. These embodiments are intended to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those skilled in the art without creative effort should still fall within the scope of protection of the present invention.

[0022] It should be noted that in the description of this utility model, terms such as "center," "upper," "lower," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the corresponding device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. For example, unless otherwise specified, the terms "installation," "connection," "joining," and "fixing" can specifically refer to any feasible connection form such as bolt connection, screw connection, welding, insertion, riveting, fusion welding, or snap-fit.

[0024] Furthermore, it should be noted that in the description of this utility model, mm represents millimeter, cm represents centimeter, and m represents meter.

[0025] like Figures 1 to 8 As shown, in some embodiments of this utility model, the solenoid valve 001 includes a valve body assembly 100, a valve core assembly 200, and a return spring 300. The valve core assembly 200 is disposed within the valve body assembly 100 to open and close the solenoid valve 001, and the return spring 300 is used to drive the valve core assembly 200 to reset.

[0026] like Figure 5 As shown, in some embodiments of this utility model, the valve body assembly 100 defines an air inlet 101, an air outlet 102, an on / off control chamber 103, and a drive chamber 104. Furthermore, the valve body assembly 100 includes a valve seat 111, a valve cover 112, a housing 113, a power plug 114, a magnetic yoke 120, a valve sleeve 130, a coil mounting bracket 140, an electromagnetic coil 150, a sliding sealing ring 161, a mounting sealing ring 162, a magnet 170, and a shock-absorbing component 180.

[0027] The valve seat 111 and valve cover 112 are located at opposite ends of the housing 113 along the axial direction (o), and are fixedly connected to the housing 113 to encapsulate and protect components such as the magnetic yoke 120, valve sleeve 130, and electromagnetic coil 150. The valve seat 111, valve cover 112, and housing 113 can be fixed together in any feasible manner, such as interference fit, fusion welding, welding, or threaded connection.

[0028] The power plug 114 is installed on the valve cover 112 and electrically connected to the solenoid coil 150 to provide power to the solenoid coil 150. The power plug 114 and the valve cover 112 can be fixed together in any feasible way, such as interference fit, fusion welding, welding, threaded connection, etc.

[0029] The magnetic yoke 120 is sleeved together with the valve sleeve 130, and the two can be fixed together in any feasible way, such as interference fit, welding, etc. At least a portion of the magnetic yoke 120 is located between the on / off control cavity 103 and the drive cavity 104 to separate the on / off control cavity 103 and the drive cavity 104. The magnetic yoke 120 is also provided with a through hole 121 connecting the on / off control cavity 103 and the drive cavity 104.

[0030] The coil mounting bracket 140 is fixedly connected to or integrally formed with the power plug 114, and together with the valve seat 111, clamps the magnetic yoke 120.

[0031] The electromagnetic coil 150 is mounted on the coil mounting bracket 140. When the electromagnetic coil 150 is energized, the magnetic field generated can act on the magnetic yoke 120 and the valve core assembly 200 to drive the valve core assembly 200 to move. The magnetic yoke 120 is used to constrain the magnetic field generated by the electromagnetic coil 150 to improve the efficiency of the magnetic field.

[0032] The sliding sealing ring 161 is clamped by the valve seat 111 and the magnet 170 in the axial direction o.

[0033] The valve seat 111 and the housing 113 are respectively fitted with mounting sealing rings 162. The mounting sealing rings 162 are used to achieve a seal between the valve body assembly 100 and the installation object (such as a metal block with a insertion hole, a pipe, etc.) to prevent high-pressure gas leakage.

[0034] The magnet 170 is fixedly connected to the yoke 120 and is used to provide the valve core assembly 200 with a force to keep blocking the air passage between the air inlet 101 and the air outlet 102, so as to reduce the current of the electromagnetic coil 150.

[0035] In some embodiments of this invention, the magnet 170 can be a ring-shaped component or multiple continuous or spaced components. Furthermore, the magnet 170 can be made of any permanent magnet material capable of generating a magnetic field. For example, the magnet 170 can be a ferrite magnet, a samarium cobalt magnet, a neodymium iron boron magnet, an alnico magnet, etc.

[0036] The shock-absorbing component 180 is disposed on the side of the magnetic yoke 120 facing the armature 220 to reduce the impact of the armature 220 on the magnetic yoke 120. The shock-absorbing component 180 can be fixedly connected to the magnetic yoke 120 (e.g., glued, snapped, etc.) or can be movably placed on the side of the magnetic yoke 120 facing the armature 220.

[0037] like Figure 5 As shown, the damping member 180 has a ring-shaped sheet structure to make the impact of the armature 220 on the yoke 120 more uniform. In addition, the damping member 180 covers the end of the magnet 170 near the armature 220 to prevent the armature 220 from hitting the magnet 170.

[0038] from Figures 1 to 5 As can be seen from the figure, in some embodiments of this utility model, the air inlet 101 is formed at the axial end of the valve seat 111 away from the magnetic yoke 120, and the air outlet 102 is formed on the circumferential sidewall of the valve seat 111. The valve seat 111 is axially aligned with the magnetic yoke 120, and an inwardly protruding annular structure (not marked in the figure) is provided between the air inlet 101 and the air outlet 102. A conical ring is provided on the side of this annular structure closest to the magnetic yoke 120. This conical ring abuts against the valve core assembly 200, thus sealing the air inlet 101.

[0039] It should be noted that in actual use, the air inlet 101 can also be used as the air outlet, and the air outlet 102 can be used as the air inlet.

[0040] Furthermore, in other embodiments of this utility model, those skilled in the art may omit at least one of the valve seat 111, valve cover 112, housing 113, power plug 114, valve sleeve 130, mounting sealing ring 162, and shock-absorbing component 180 as needed. For example, the valve sleeve 130 may be omitted.

[0041] like Figure 6 As shown, the magnetic yoke 120 has an annular groove 122 on the side facing the armature 220, and the magnet 170 is embedded in the annular groove 122 to avoid the valve stem 230 and the return spring 300 of the valve core assembly 200 (e.g., Figure 3 and Figure 8 (As shown).

[0042] like Figure 6 As shown, in some embodiments of this utility model, the through hole 121 includes a valve core clearance section 1211 and a spring positioning section 1212.

[0043] from Figure 6 As can be seen, the annular groove 122 connects to the spring positioning section 1212, and the outer diameter of the annular groove 122, the diameter of the spring positioning section 1212, and the diameter of the valve core clearance section 1211 decrease sequentially, so that the through hole 121 and the annular groove 122 form a stepped hole. The valve core clearance section 1211 is clearance-fitted with the valve stem 230 (e.g., Figure 8 As shown), to ensure that the valve core assembly 200 can move within the valve body assembly 100. The spring positioning section 1212 is used to accommodate a portion of the return spring 300 to fix the return spring 300 and prevent the return spring 300 from being displaced.

[0044] like Figure 7 As shown, in some embodiments of this utility model, the valve core assembly 200 includes a core 210, an armature 220, a valve stem 230, an on / off sealing ring 240, and a buffer member 250.

[0045] The core 210 and armature 220 are arranged at intervals and are fixedly connected to the valve stem 230 respectively, so as to fix the core 210 and armature 220 together. The core 210 and armature 220 can be fixedly connected to the valve stem 230 by any feasible method such as interference fit, welding, threaded connection, etc.

[0046] The on / off sealing ring 240 is installed on the core 210 and located on the side of the core 210 away from the armature 220, so that the on / off sealing ring 240 abuts against the valve body assembly 100, thereby causing the core 210 to disconnect the air passage between the air inlet 101 and the air outlet 102, that is, to disconnect the air inlet 101 and the air outlet 102.

[0047] In some embodiments of this utility model, the on / off sealing ring 240 and the core 210 can be fixedly connected together by any feasible method such as bonding or interference fit.

[0048] The buffer member 250 is mounted on the core 210 and located on the side of the core 210 facing the armature 220 to reduce the impact of the core 210 on the yoke 120.

[0049] In some embodiments of this utility model, the core 210 is provided with an annular groove on the side facing the armature 220. The buffer member 250 includes an annular portion (not marked in the figure) embedded in the groove and a plurality of protrusions (not marked in the figure) on the side facing the armature 220, so that the buffer member 250 is fixed to the core 210 through the annular portion and abuts against the armature 220 through the protrusions.

[0050] Furthermore, in some embodiments of this utility model, the on / off sealing ring 240 and the buffer member 250 can each be an elastic member made of rubber material.

[0051] Furthermore, in other embodiments of this invention, those skilled in the art may omit at least one of the on / off sealing ring 240 and the buffer member 250 as needed. For example, the core 210 may be made entirely of rubber material.

[0052] like Figure 8 As shown, in the assembled state, the valve stem 230 passes through the through hole 121 on the magnet 170, so that the core 210 is located in the on / off control cavity 103 and the armature 220 is located in the drive cavity 104. Furthermore, the core 210 also slides in contact with the sliding sealing ring 161 through its outer peripheral surface to prevent gas from escaping between the core 210 and the valve body assembly 100 in the radial gap.

[0053] Go back and refer to Figure 3The core 210 may be provided with pressure equalization holes 211 to balance the air pressure on both sides of the core 210 along the axial direction o, and prevent the air pressure difference on both sides of the valve core assembly 200 along the axial direction o during the movement of the valve core assembly 200, which would hinder the movement of the valve core assembly 200.

[0054] like Figures 8 to 10 As shown, in some embodiments of this utility model, when the electromagnetic coil 150 is de-energized, the axial gap J2 between the on / off sealing ring 240 and the valve body assembly 100 is greater than the axial gap J1 between the shock-absorbing member 180 and the armature 220, so that before the on / off sealing ring 240 abuts against the valve body assembly 100, the armature 220 first impacts the shock-absorbing member 180, thereby weakening the impact force on the on / off sealing ring 240.

[0055] Furthermore, the elastic modulus of the damping component 180 is less than that of the on / off sealing ring 240, to ensure that the on / off sealing ring 240 can abut against the valve body assembly 100 and generate sufficient deformation to block the air passage between the air inlet 101 and the air outlet 102.

[0056] Those skilled in the art will understand that by making the elastic modulus of the damping member 180 less than that of the on / off sealing ring 240, the damping member 180 is more prone to deformation than the on / off sealing ring 240. By making the axial clearance J2 between the on / off sealing ring 240 and the valve body assembly 100 greater than the axial clearance J1 between the damping member 180 and the armature 220, when the solenoid valve 001 is energized, that is, when the valve core assembly 200 moves from... Figure 8 Move to the position shown Figure 11 During the process shown, the armature 220 first comes into contact with the damping member 180 and compresses the damping member 180, thereby reducing the moment of inertia of the valve core assembly 200. This reduces the impact force generated when the valve core assembly 200 comes into contact with the valve seat 111 during the on / off sealing ring 240.

[0057] like Figure 9 As shown, in some embodiments of this utility model, the ratio of the radial thickness b1 of the magnet 170 to the radial thickness b2 of the armature 220 is selected from any value from 0.2 to 0.8, such as any feasible value such as 0.2, 0.25, 0.3, 0.4, 0.43, 0.5, 0.56, 0.6, 0.7, 0.75, 0.8, etc.

[0058] Those skilled in the art will understand that the above-mentioned relationship between b1 and b2, while the magnet 170 provides the valve core assembly 200 with the force to keep blocking the air passage between the air inlet 101 and the air outlet 102, and reduces the current of the electromagnetic coil 150, also avoids that the magnet 170 has too great a attraction force on the armature 220, which would affect the rebound of the return spring 300.

[0059] Continue reading Figure 9 In some embodiments of this utility model, the radial thickness b1 of the magnet 170 is greater than or equal to the axial height d of the magnet 170, so as to ensure that the magnet 170 can generate a sufficiently large axial magnetic field on the armature 220.

[0060] Continue reading Figure 9 In some embodiments of this utility model, the ratio of the radial thickness b3 of the damping member 180 to the radial thickness b2 of the armature 220 is selected from any value from 0.7 to 1, such as any feasible value such as 0.7, 0.75, 0.8, 0.83, 0.89, 0.91, 0.96, 1, etc.

[0061] Those skilled in the art will understand that the above-described relationship between b3 and b2 enables the damping member 180 to provide a uniform buffering force to the armature 220.

[0062] The following reference Figure 8 and Figure 11 The working principle of the solenoid valve 001 in some embodiments of this utility model will be briefly explained below.

[0063] like Figure 8 As shown, when the electromagnetic coil 150 is de-energized, under the action of the return spring 300, the armature 220 and the yoke 120 move away from each other, thereby causing the valve core assembly 200 to open the air inlet 101, making the air inlet 101 and the air outlet 102 connected. In this state, gas can flow from the air inlet 101 to the air outlet 102.

[0064] When the electromagnetic coil 150 is energized, the magnetic field generated by the electromagnetic coil 150 acts on the armature 220 and the yoke 120, causing the armature 220 and the yoke 120 to attract each other. This magnetic force overcomes the elastic force of the return spring 300, driving the valve core assembly 200 from... Figure 8 Move to the position shown Figure 11 The location shown.

[0065] like Figure 11 As shown, when the electromagnetic coil 150 is energized, the valve core assembly 200 abuts against the magnetic yoke 120 of the valve seat 111, sealing the air inlet 101. High-pressure gas in the upstream air path connected to the air inlet 101 flows to the top side of the valve core assembly 200 through the pressure equalization hole 211, thereby equalizing the air pressure on both sides of the valve core assembly 200 along the axial direction (o), thus minimizing the pressure difference experienced by the valve core assembly 200. Simultaneously, the high-pressure gas on the top side of the valve core assembly 200 fills the entire interior of the valve body assembly 100 through the gap between the valve stem 230 and the magnetic yoke 120, and through the armature 220 and the valve sleeve 130, minimizing the pressure difference experienced by the entire valve core assembly 200 along the axial direction (o).

[0066] Continue reading Figure 11 When the electromagnetic coil 150 is energized, the armature 220 approaches the magnet 170, thereby generating a magnetic attraction between the magnet 170 and the armature 220. This allows the magnet to provide a force to the valve core assembly 200 to maintain and block the air passage between the air inlet 101 and the air outlet 102, reducing the holding current of the electromagnetic coil 150, thereby reducing the power consumption and heat generation of the electromagnetic coil 150.

[0067] When the electromagnetic coil 150 is de-energized, the return spring 300 drives the valve core assembly 200 from... Figure 11 Move to the position shown Figure 8 The position shown. At the instant the valve core assembly 200 disengages from the valve seat 111, the high-pressure air inside the valve body assembly 100 is quickly released through the pressure equalization hole 211, the gap between the valve stem 230 and the magnetic yoke 120, and the gap between the armature 220 and the valve sleeve 130, ensuring that the movement of the valve core assembly 200 is not affected by the air pressure difference.

[0068] Furthermore, the solenoid valve 001 described in any of the preceding embodiments of this utility model can be used to adjust the stiffness of the air spring and can be installed in a car.

[0069] The technical solution of this utility model has been described in conjunction with several embodiments above. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is not limited to these specific embodiments. Without departing from the technical principles of this utility model, those skilled in the art can disassemble and combine the technical solutions in the above embodiments, and can also make equivalent changes or substitutions to the relevant technical features. Any changes, equivalent substitutions, improvements, etc., made within the technical concept and / or technical principles of this utility model will fall within the protection scope of this utility model.

Claims

1. A solenoid valve, characterized in that, include: A valve body assembly defines an air inlet, an air outlet, an on / off control chamber, and a drive chamber. The valve body assembly includes an electromagnetic coil, a magnetic yoke, and a magnet fixed on the magnetic yoke. At least a portion of the magnetic yoke is located between the on / off control chamber and the drive chamber to separate the on / off control chamber and the drive chamber. The magnetic yoke is also provided with a through hole connecting the on / off control chamber and the drive chamber. The valve core assembly includes a core disposed in the on / off control chamber, an armature disposed in the drive chamber, and a valve stem passing through the through hole and fixedly connected to the core and the armature respectively. The core is used to control the on / off of the air passage between the air inlet and the air outlet. A return spring is disposed between the magnetic yoke and the armature to drive the valve core assembly to open the air passage between the air inlet and the air outlet; The magnet provides a force to the valve core assembly to maintain the air passage between the air inlet and the air outlet, thereby reducing the current in the electromagnetic coil.

2. The solenoid valve according to claim 1, characterized in that, The magnetic yoke has an annular groove on the side facing the armature, and the magnet is embedded in the annular groove to avoid the valve stem and the return spring.

3. The solenoid valve according to claim 2, characterized in that, The through hole includes a valve core clearance section and a spring positioning section. The annular groove is connected to the spring positioning section, and the outer diameter of the annular groove, the diameter of the spring positioning section, and the diameter of the valve core clearance section decrease sequentially, so that the through hole and the annular groove form a stepped hole; The valve core clearance section is clearance-fitted with the valve stem, and the spring positioning section is used to accommodate a portion of the return spring.

4. The solenoid valve according to claim 2, characterized in that, The ratio of the radial thickness of the magnet to the radial thickness of the armature is selected from any value between 0.2 and 0.8; and / or, The radial thickness of the magnet is greater than or equal to the axial height of the magnet.

5. The solenoid valve according to any one of claims 1 to 4, characterized in that, The valve body assembly also includes a shock-absorbing member disposed on the side of the yoke facing the armature, to reduce the impact of the armature on the yoke.

6. The solenoid valve according to claim 5, characterized in that, The shock-absorbing component is a ring-shaped sheet structure to make the impact of the armature on the yoke more uniform.

7. The solenoid valve according to claim 6, characterized in that, The shock-absorbing component covers the end of the magnet near the armature to prevent the armature from striking the magnet.

8. The solenoid valve according to claim 5, characterized in that, The valve core assembly also includes an on / off sealing ring disposed on the core body, the on / off sealing ring being used to abut against the valve body assembly to block the air passage between the air inlet and the air outlet; When the electromagnetic coil is de-energized, the axial gap between the on / off sealing ring and the valve body assembly is greater than the axial gap between the damping member and the armature, so that the armature impacts the damping member first before the on / off sealing ring abuts against the valve body assembly, thereby weakening the impact force on the on / off sealing ring.

9. The solenoid valve according to claim 8, characterized in that, The elastic modulus of the damping component is less than that of the on / off sealing ring, so as to ensure that the on / off sealing ring can abut against the valve body assembly and generate sufficient deformation to block the air passage between the air inlet and the air outlet.

10. The solenoid valve according to any one of claims 1 to 4, characterized in that, The solenoid valve is used to adjust the stiffness of the air spring.

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