Low cost low noise stiffness valve

Abstract

The application provides a low-cost low-noise stiffness valve and relates to the field of metering valves. The low-cost low-noise stiffness valve comprises an outer magnetic sleeve, the inside of the outer magnetic sleeve is provided with a driving coil holder, the outer surface of the driving coil holder is wound with driving coil enameled wire, the inner circle of the driving coil enameled wire is provided with a magnetic valve core, the middle part of the magnetic valve core is assembled and connected with a valve core connecting rod, the up-and-down movement of the magnetic valve core drives the valve core connecting rod to realize air tightness switching, when the magnetic circuit force is balanced, the diameter of the magnetic valve core is 16.5-20 mm, the number of turns of the driving coil enameled wire is 300-500 turns, and the thickness of the outer magnetic sleeve at the driving coil holder is 1.6-3 mm. The low-cost low-noise stiffness valve can reduce the total length of the enameled wire used by the coil by increasing the area of the coil, keeping the wire diameter of the coil unchanged, and cooperating with the reduction of the number of turns. Compared with the traditional parameter setting, the reduction of the total length of the single coil enameled wire can reduce the amount of copper, and batch production can greatly reduce the cost.

Description

Technical Field

[0001] This invention relates to the field of metering valves, specifically a low-cost, low-noise stiffness valve. Background Technology

[0002] The stiffness valve is a key valve in an air suspension system used to dynamically adjust the stiffness of the air springs. It achieves rapid switching between suspension stiffness by controlling the gas flow between the air chambers. Due to installation environment and operating conditions, its size is generally limited to standard dimensions, with the PH-LV15 stiffness valve being a common model.

[0003] PWM drive current curve: Based on the control current of the suspension control system of each product, reliable opening and closing of the valve body is ensured. To achieve a long opening and closing life under PWM drive, the valve body movement speed must be as low as possible during opening and closing, while simultaneously minimizing force and noise, and meeting the opening and closing time requirements. Its core structure is a hard magnet that generates eddy currents with the movement of the valve core.

[0004] Meanwhile, the enameled wire used to construct its energized coil is made of copper, and the increased amount of copper used leads to higher production costs for the device. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a low-cost, low-noise stiffness valve, which solves the problems of high production costs and the need for complex installation methods to install hard magnets to reduce the movement speed at the valve body end in the background technologies mentioned above.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a low-cost, low-noise rigidity valve, comprising an outer magnetic sleeve, a drive coil frame inside the outer magnetic sleeve, a drive coil enameled wire wound on the outer surface of the drive coil frame, a magnetic valve core within the inner ring of the drive coil enameled wire, and a valve core connecting rod assembled and connected to the middle of the magnetic valve core. The magnetic valve core moves up and down, driving the valve core connecting rod to achieve airtightness switching. When the magnetic circuit force is balanced, the diameter of the magnetic valve core is 16.5-20mm, the number of turns of the drive coil enameled wire is 300-500 turns, and the thickness of the outer magnetic sleeve at the drive coil frame is 1.6-3mm.

[0007] Preferably, the downward moving end of the magnetic valve core is provided with a magnetic short-circuit ring, which is sleeved on the outer ring of the magnetic valve core, and there is a radial magnetic gap between the magnetic short-circuit ring and the magnetic valve core.

[0008] Preferably, the radial magnetic gap between the magnetic short-circuit ring and the magnetic valve core is 0.1-0.5 mm, the height of the magnetic short-circuit ring is 1-5 mm, and the thickness is 0.5-3 mm.

[0009] Preferably, the magnetic valve core has a bearing hole inside, and a protrusion concentric with the bearing hole is provided inside the bearing hole. The valve core connecting rod has an insertion hole concentric with the valve core connecting rod at its top end. The valve core connecting rod, the bearing hole, the protrusion, and the insertion hole form a two-stage interference fit.

[0010] Preferably, the control end of the valve core connecting rod is connected to a sealing valve core assembly, and both the upper and lower ends of the sealing valve core assembly are provided with elastic damping components. The upper elastic damping component is provided with an even number of equally spaced damping heads, and the center of the sealing valve core assembly is also provided with an odd number of equally spaced clearance grooves.

[0011] Preferably, a sealing coupling element is provided on the outer side of the sealing valve core assembly, and a lower magnetic seat and a valve seat are provided on the lower part of the inner side of the outer magnetic sleeve. The sealing coupling element includes a rubber sealing ring provided on the inner ring. The sealing ring forms a middle ring in the middle of the inner ring, and side rings protruding from the middle ring and inclined in the direction of the middle ring are formed on the upper and lower sides of the inner ring. A snap-fit ​​groove is provided on the outer side of the sealing ring, and a support frame is provided inside the snap-fit ​​groove. The inner ring of the support frame contacts the sealing ring at intervals, and the outer ring of the support frame snaps between the lower magnetic seat and the valve seat.

[0012] Preferably, the snap-fit ​​groove is a spherical cap rotating body with a spherical radius of 0.5-2mm and a spherical cap height of 0.1-0.5mm, and the inner ring of the support frame is adapted to the snap-fit ​​groove.

[0013] Preferably, the valve seat is provided with air holes, and the reinforcing ribs forming the edge of the air holes account for 17%-19% of the total air hole flow channel area. Increasing the area of ​​the air holes can effectively ensure the air flow, but it is also necessary to ensure the strength of this part of the valve seat.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This low-cost, low-noise stiffness valve increases the coil area while keeping the coil wire diameter constant. Combined with a reduction in the number of winding turns, it can reduce the total length of the enameled wire used in the coil. Compared with traditional parameter settings, the reduction in the total length of the enameled wire of a single coil can reduce the amount of copper used, and mass production can significantly reduce costs.

[0015] 2. This low-cost, low-noise stiffness valve, by setting a magnetic short-circuit ring and optimizing the parameters of the magnetic short-circuit ring and the gap between the magnetic short-circuit ring and the magnetic valve core, can achieve the same deceleration effect at the end of the movement without the traditional hard magnet. This setting can reduce the use of hard magnets, reduce the number of parts, and facilitate assembly. At the same time, the cost increase is relatively small when the magnetic short-circuit ring is molded together, thus saving the cost of hard magnets. In addition, the magnetic short-circuit ring can reduce the end speed of magnetic attraction movement, thereby reducing the generation of noise.

[0016] 3. This low-cost, low-noise rigid valve has a bearing hole inside the solenoid valve core, and a protrusion concentric with the bearing hole inside the bearing hole. The top of the valve core connecting rod has an insertion hole concentric with the valve core connecting rod. The valve core connecting rod, the bearing hole, the protrusion and the insertion hole form a two-stage interference fit, which can limit the connection position relationship between the valve core connecting rod and the solenoid valve core, thereby ensuring the assembly accuracy.

[0017] 4. This low-cost, low-noise rigid valve has elastic damping components at both the upper and lower ends of the sealing valve core assembly. The upper elastic damping component has an even number of equally spaced damping heads. The more heads there are, the more even the damping force will be. However, the manufacturing difficulty needs to be considered. With more heads, the cross-sectional area of ​​each damping head will decrease, and it will be easy for it to fall off after repeated reciprocating motion. Setting the number of damping heads to an even number can avoid the displacement caused by uneven force.

[0018] 5. This low-cost, low-noise rigid valve also has an odd number of equally spaced clearance grooves at the center of the sealing valve core assembly. The odd number of clearance grooves ensures the concentricity of the assembly during installation.

[0019] 6. This low-cost, low-noise rigid valve features a central ring formed in the middle of the sealing ring, which improves the sealing effect and allows for adjustment of the valve body's movement speed, reducing opening and closing noise. The side ring also contributes to the sealing effect. A key improvement is the support frame, whose inner ring is designed to intermittently contact the sealing ring, allowing space for elastic deformation of the sealing ring. Additionally, part of the support frame is positioned on the outside of the sealing ring, providing a snap-fit ​​connection for easier installation.

[0020] 7. This low-cost, low-noise rigid valve features a snap-fit ​​groove made of a rotating spherical cap with a ball radius of 0.5–2 mm and a cap height of 0.1–0.5 mm. The inner ring of the support frame is fitted to the snap-fit ​​groove. This design reduces discontinuous contact between the support frame and the snap-fit ​​groove, thus preventing stress concentration in the sealing ring.

[0021] 8. The valve seat is provided with air holes, and the reinforcing ribs forming the edge of the air holes account for 17%-19% of the total air hole flow area. Increasing the area of ​​the air holes can effectively ensure the air flow, but it is also necessary to ensure the strength of this part of the valve seat. Attached Figure Description

[0022] Figure 1 This is a comparison table showing the influence of the outer magnetic sleeve thickness on the present invention; Figure 2 This is a comparative table showing the effects of radial clearance on the present invention; Figure 3 This is a comparison diagram showing the influence of the magnetic short-circuit ring height on the invention. Figure 4This is a comparison table showing the influence of the thickness of the magnetic short-circuit ring on the invention. Figure 5 This is a comparison table showing the influence of the number of coil turns on the invention. Figure 6 This is a comparison table of the effects of permanent magnets in this invention; Figure 7 This is a half-sectional schematic diagram of the present invention; Figure 8 This is a schematic diagram of the outer magnetic sleeve of the present invention; Figure 9 This is a schematic diagram of the magnetic valve core connection of the present invention; Figure 10 This is a schematic diagram of the sealing ring of the present invention; Figure 11 This is a schematic diagram of the support frame of the present invention; Figure 12 This is a schematic diagram of the connection of the sealing valve core assembly of the present invention; Figure 13 This is a schematic diagram of the valve seat connection of the present invention; Figure 14 This is a half-section view of the existing structure; Figure 15 This is a chart representing the control group of the present invention; Figure 16 This is a chart representing the control group of the present invention; Figure 17 The three charts represent the control group of this invention; Figure 18 Four charts representing the control group of this invention; Figure 19 Five charts representing the control group of this invention; Figure 20 The six figures represent the control group of this invention.

[0023] In the diagram: 1. Outer magnetic sleeve; 2. Upper magnetic cover; 3. Lower magnetic seat; 4. Drive coil frame; 5. Drive coil enameled wire; 6. Drive signal plug; 7. Plug socket; 8. Upper sealing ring of valve body; 9. Valve seat; 10. Lower sealing ring of valve body; 11. Self-lubricating grinding disc; 12. Magnetic valve core; 13. Magnetic isolation sealing sleeve; 14. Valve core connecting rod; 15. Return spring; 16. Lower magnetic seat sealing ring; 17. Sealing coupling element; 18. Sealing valve core assembly; 19. Magnetic short-circuit ring; 121. Bearing hole; 122. Protrusion; 141. Insertion hole; 181. Elastic damping element; 1811. Damping head; 182. Relief groove; 171. Sealing ring; 1711. Middle ring; 1712. Side ring; 172. Snap-fit ​​groove; 173. Support frame; 901. Air hole. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0025] It should be noted that all directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0026] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0028] like Figure 1-14 As shown, a low-cost, low-noise rigidity valve includes an outer magnetic sleeve 1, an upper magnetic cover 2 and a lower magnetic seat 3 disposed inside the outer magnetic sleeve 1, a drive coil frame 4 disposed in the space between the upper magnetic cover 2 and the lower magnetic seat 3, a drive coil enameled wire 5 wound on the outer surface of the drive coil frame 4, drive signal plugs 6 leading upward from both ends of the drive coil enameled wire 5, a plug seat 7 disposed on the outer ring of the drive signal plug 6, and a valve body upper sealing ring 8 disposed between the plug seat 7 and the outer magnetic sleeve 1; A valve seat 9 is connected to the lower part of the outer magnetic sleeve 1, and a valve body lower sealing ring 10 is provided on the bottom outer ring of the valve seat 9; The inner ring of the drive coil frame 4 is provided with a self-lubricating grinding plate 11 inside the outer magnetic sleeve 1. The inner ring of the self-lubricating grinding plate 11 is provided with a magnetic valve core 12. A magnetic sealing sleeve 13 is provided between the magnetic valve core 12 and the self-lubricating grinding plate 11. A valve core connecting rod 14 is assembled and connected in the middle of the magnetic valve core 12. The bottom end of the valve core connecting rod 14 extends into the interior of the valve seat 9. A return spring 15 for resetting is sleeved on the outer surface of the valve core connecting rod 14. A lower magnetic seat sealing ring 16 is provided between the lower magnetic seat 3, the outer magnetic sleeve 1 and the valve seat 9. A sealing coupling element 17 is fixedly snapped between the lower magnetic seat 3 and the valve seat 9. A sealing valve core assembly 18 is installed on the outer ring of the valve core connecting rod 14. The sealing valve core assembly 18 and the sealing coupling element 17 are slidably connected. There are also other mechanisms that assist in the operation of the lifting device.

[0029] When the magnetic circuit force is balanced, the diameter of the magnetic valve core 12 will be increased to 16.5-20mm, and the number of turns of the enameled wire 5 of the drive coil will be set to 300-500 turns. In Figure 5, with the competitor as the comparison value, the effect of the drive coil enameled wire 5 with different number of turns on the whole is tested to determine that the effect of the drive coil enameled wire 5 within this range can be better than the standard value.

[0030] Simultaneously, the thickness of the outer magnetic sleeve 1 at the drive coil frame 4 was increased to 1.6-3mm. In Figure 1, using competing products as a comparison, experiments were conducted with different thicknesses to determine that an effect superior to the standard value could be achieved within this range.

[0031] By increasing the coil area while keeping the coil wire diameter constant, and by reducing the number of winding turns, the total length of the enameled wire used in the coil can be reduced. Compared with traditional parameter settings, the reduction in the total length of the enameled wire in a single coil can save 30 grams of copper, and mass production can significantly reduce costs.

[0032] A magnetic short-circuit ring 19 is provided at the downward moving end of the magnetic valve core 12. The magnetic short-circuit ring 19 is sleeved on the outer ring of the magnetic valve core 12. The magnetic short-circuit ring 19 should form a fixed connection with the lower magnetic base 3. It can be integrally formed or assembled later. The height of the magnetic short-circuit ring 19 is 1-5mm, and the thickness is 0.5-3mm. At the same time, there is a radial magnetic gap of 0.1-0.5mm between the magnetic short-circuit ring 19 and the magnetic valve core 12. Based on the overall judgment of Figures 2, 3, 4 and 6, the magnetic short-circuit ring 19 with these parameters can achieve the effect of replacing the traditional hard magnet.

[0033] By setting the magnetic short-circuit ring 19 and optimizing its parameters and the gap between it and the magnetic valve core 12, the same deceleration effect at the end of the motion can be achieved without the traditional hard magnet. This setting reduces the use of hard magnets, decreases the number of parts, and facilitates assembly. At the same time, the cost increase is relatively small when the magnetic short-circuit ring 19 is molded together, thus saving the cost of hard magnets. In addition, the magnetic short-circuit ring 19 can reduce the end speed of magnetic attraction movement, thereby reducing noise generation.

[0034] The solenoid valve core 12 has a bearing hole 121 inside, and a protrusion 122 concentric with the bearing hole 121 is provided inside the bearing hole 121. The valve core connecting rod 14 has an insertion hole 141 concentric with the valve core connecting rod 14 at its top end. The valve core connecting rod 14, the bearing hole 121, the protrusion 122 and the insertion hole 141 form a two-stage interference fit.

[0035] The valve core connecting rod 14 has high requirements for concentricity during assembly. Traditional connections do not specify requirements for its connection method or tolerances, which leads to a large positional offset of the valve core connecting rod 14 after assembly. This offset increases wear and can also cause air leakage, resulting in poor assembly consistency that cannot be detected in the early stages of use. Therefore, the two-stage interference fit can limit the connection position relationship between the valve core connecting rod 14 and the solenoid valve core 12, thereby ensuring assembly accuracy.

[0036] Both the upper and lower ends of the sealing valve core assembly 18 are provided with elastic damping components 181. The upper elastic damping component 181 is provided with an even number of equally spaced damping heads 1811. The center of the sealing valve core assembly 18 is also provided with an odd number of equally spaced relief grooves 182. Generally, there are four equally spaced damping heads 1811. The more the number, the more uniform the damping force. At the same time, the processing difficulty needs to be considered. With the increase of the number, the cross-sectional area of ​​a single damping head 1811 decreases, and it is easy to fall off after repeated reciprocating motion. Setting the number of damping heads 1811 to an even number can avoid the displacement caused by uneven force. The number of relief grooves 182 is an odd number to ensure the concentricity of the assembly during installation.

[0037] The sealing coupling member 17 includes a rubber sealing ring 171 disposed in the inner ring. The sealing ring 171 forms a middle ring 1711 in the middle of the inner ring. The sealing ring 171 forms side rings 1712 on the upper and lower sides of the inner ring, which protrude from the middle ring 1711 and are inclined in the direction of the middle ring. The outer side of the sealing ring 171 is provided with a snap-fit ​​groove 172. The inside of the snap-fit ​​groove 172 is provided with a support frame 173. The inner ring of the support frame 173 contacts the sealing ring 171 at intervals, and the outer ring of the support frame 173 is snapped between the lower magnetic seat 3 and the valve seat 9.

[0038] The formation of a middle ring 1711 in the middle of the sealing ring 171 can improve the sealing effect and adjust the valve body movement speed, reducing valve body opening and closing noise. The side ring 1712 can also achieve the sealing effect. The key improvement is the support frame 173. The inner ring of the support frame 173 is set to intermittently contact the sealing ring 171, which can reserve space for the elastic deformation of the sealing ring 171. At the same time, it is partially set on the outside of the sealing ring 171, thus reserving a snap-fit ​​part, making the installation simpler.

[0039] The snap-fit ​​groove 172 is a spherical cap rotating body with a spherical radius of 0.5-2mm and a spherical cap height of 0.1-0.5mm. The inner ring of the support frame 173 is adapted to the snap-fit ​​groove 172. This arrangement reduces discontinuous contact between the support frame 173 and the snap-fit ​​groove 172, thus avoiding stress concentration in the sealing ring 171 and improving the overall structure of the support frame 173.

[0040] The valve seat 9 is provided with an air hole 901. The reinforcing ribs forming the edge of the air hole 901 account for 17%-19% of the total flow channel area of ​​the air hole 901. Increasing the area of ​​the air hole 901 can effectively ensure the air flow, but it is also necessary to ensure the strength of this part of the valve seat 9.

[0041] like Figure 1-6 Each variable involved in this application was adjusted individually, and the adjusted variables were compared with those of competing products containing hard magnets to clarify the positive significance of adjusting the variable.

[0042] like Figures 15-20 The simulation magnetic circuit analysis diagram of the competing product with hard magnets was made, and the magnetic force was tested at different distances. The same simulation magnetic circuit analysis diagram of the improved parameters of this application was made, and the magnetic force was tested at different distances.

[0043] This technical solution involves adjusting multiple data points. After finding the optimal value within the adjustment range, the next variable is changed, and the optimal value among the secondary variables is found. This process continues until the optimal value is obtained for all data.

[0044] Through data comparison, when the initial magnetic and electromagnetic forces meet the corresponding electromagnetic force of the valve core, the final electromagnetic force is significantly less than that of competing products. As the electromagnetic force drives the valve core's movement, a reduction in external force leads to a decrease in acceleration, and consequently, a reduction in the final velocity per unit time. This results in a lower collision velocity with the valve seat, producing less noise. This application achieves both reduced hard magnetism and sufficient response speed, while simultaneously reducing the final velocity. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0045] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-cost, low-noise stiffness valve, comprising an outer magnetic sleeve (1), characterized in that: The outer magnetic sleeve (1) is provided with a drive coil frame (4), the outer surface of the drive coil frame (4) is wound with drive coil enameled wire (5), the inner ring of the drive coil enameled wire (5) is provided with a magnetic valve core (12), the middle part of the magnetic valve core (12) is assembled and connected with a valve core connecting rod (14), the magnetic valve core (12) moves up and down to drive the valve core connecting rod (14) to achieve airtightness switching; When the magnetic circuit force is balanced, the diameter of the magnetic valve core (12) is 16.5-20mm, the number of turns of the enameled wire (5) of the drive coil is 300-500 turns, and the thickness of the outer magnetic sleeve (1) located at the drive coil frame (4) is 1.6-3mm.

2. The low-cost, low-noise stiffness valve according to claim 1, characterized in that: The magnetic valve core (12) is provided with a magnetic short-circuit ring (19) at the downward moving end. The magnetic short-circuit ring (19) is sleeved on the outer ring of the magnetic valve core (12), and there is a radial magnetic gap between the magnetic short-circuit ring (19) and the magnetic valve core (12).

3. The low-cost, low-noise stiffness valve according to claim 2, characterized in that: The radial magnetic gap between the magnetic short-circuit ring (19) and the magnetic valve core (12) is 0.1-0.5 mm, the height of the magnetic short-circuit ring (19) is 1-5 mm, and the thickness is 0.5-3 mm.

4. A low-cost, low-noise stiffness valve according to any one of claims 1-3, characterized in that: The magnetic valve core (12) has a bearing hole (121) inside. The bearing hole (121) has a protrusion (122) concentric with the bearing hole (121) inside. The valve core connecting rod (14) has an insertion hole (141) concentric with the valve core connecting rod (14) at its top end. The valve core connecting rod (14) forms a two-stage interference fit with the bearing hole (121), the protrusion (122) and the insertion hole (141).

5. A low-cost, low-noise stiffness valve according to claim 4, characterized in that: The control end of the valve core connecting rod (14) is connected to a sealing valve core assembly (18). Both the upper and lower ends of the sealing valve core assembly (18) are provided with elastic damping components (181). The upper elastic damping component (181) is provided with an even number of equally spaced damping heads (1811). The center of the sealing valve core assembly (18) is also provided with an odd number of equally spaced clearance grooves (182).

6. The low-cost, low-noise stiffness valve according to claim 5, characterized in that: A sealing coupling element (17) is provided on the outside of the sealing valve core assembly (18). A lower magnetic seat (3) and a valve seat (9) are provided on the lower part of the outer magnetic sleeve (1). The sealing coupling element (17) includes a rubber sealing ring (171) provided on the inner ring. The sealing ring (171) forms a middle ring (1711) in the middle of the inner ring. The sealing ring (171) forms side rings (1712) on the upper and lower sides of the inner ring that protrude from the middle ring and are inclined in the direction of the middle ring. A snap-fit ​​groove (172) is provided on the outside of the sealing ring (171). A support frame (173) is provided inside the snap-fit ​​groove (172). The inner ring of the support frame (173) contacts the sealing ring (171) at intervals. The outer ring of the support frame (173) is snapped between the lower magnetic seat (3) and the valve seat (9).

7. A low-cost, low-noise stiffness valve according to claim 6, characterized in that: The snap-fit ​​groove (172) is a spherical cap rotating body with a spherical radius of 0.5-2mm and a spherical cap height of 0.1-0.5mm. The inner ring of the support frame (173) is adapted to the snap-fit ​​groove (172).

8. A low-cost, low-noise stiffness valve according to claim 7, characterized in that: The valve seat (9) is provided with an air hole (901). The area of ​​the reinforcing ribs forming the edge of the air hole (901) accounts for 17%-19% of the flow channel area of ​​the entire air hole (901). By increasing the area of ​​the air hole (901), the air volume can be effectively guaranteed, but the strength of this part of the valve seat (9) also needs to be guaranteed.

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