A solenoid valve that can improve control precision

Abstract

The present invention discloses a solenoid valve capable of improving control accuracy, which relates to the field of solenoid valves and aims to solve the problem that the existing solenoid valve adds a magnetic isolation gasket between the armature and the magnetic pole to control the stroke, which affects the control accuracy of the solenoid valve. The key points of its technical solution include a magnetic sleeve, an armature is slidably arranged inside the magnetic sleeve, and a magnetic pole is arranged at its end, the magnetic pole includes a closing part and a plug-in part, the closing part contacts the end of the magnetic sleeve, the plug-in part is embedded in the magnetic sleeve, a large spring in a compressed state is arranged between the plug-in part and the armature, and a clearance groove cooperating with the large spring is respectively provided on the plug-in part and the armature; the end face of the plug-in part opposite to the armature is provided with a plurality of protrusions that can contact the end face of the armature. The present invention can reduce the number of parts, reduce assembly costs, assembly errors and processing difficulties, and thus improve the control accuracy of the solenoid valve.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic valves, and more particularly to an electromagnetic valve capable of improving control accuracy. Background Art

[0002] Existing solenoid valves usually control the stroke by adding a magnetic isolation gasket between the armature and the magnetic pole. However, due to the increase in the number of parts and assembly errors, stroke errors will be introduced to a certain extent, reducing the control accuracy. Summary of the invention

[0003] In view of the deficiencies in the prior art, an object of the present invention is to provide a solenoid valve capable of improving control accuracy, which has the advantage of being able to improve control accuracy.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A solenoid valve capable of improving control accuracy comprises a magnetic sleeve, an armature is slidably arranged inside the magnetic sleeve, and a magnetic pole is arranged at the end thereof, the magnetic pole comprises a closing portion and a plug-in portion, the closing portion contacts the end of the magnetic sleeve, the plug-in portion is embedded in the magnetic sleeve, a large spring in a compressed state is arranged between the plug-in portion and the armature, and a clearance groove cooperating with the large spring is respectively provided on the plug-in portion and the armature; a plurality of protrusions capable of contacting the end face of the armature are arranged on the end face of the plug-in portion opposite to the armature.

[0006] Furthermore, the convex point is hemispherical.

[0007] Furthermore, a valve body is provided at one end of the magnetic sleeve away from the magnetic pole, a magnetic gasket is provided at one end of the valve body and is sleeved on the magnetic sleeve, and a filter screen is embedded in the other end, and a bushing is embedded in the filter screen; the filter screen includes a filter screen holder and a filter screen, wherein the valve body and the filter screen holder are plastic parts, the bushing, the magnetic gasket and the filter screen are metal parts, and the valve body, the bushing, the magnetic gasket and the filter screen are integrally formed.

[0008] Furthermore, an axial limiting structure is provided between the valve body and the bushing.

[0009] Furthermore, the axial limiting structure includes a limiting ring groove formed on the outer side wall of the bushing, and a limiting ring provided on the inner side wall of the valve body and cooperating with the limiting ring groove.

[0010] Furthermore, a plurality of stepped limiting posts are provided at the end of the valve body, and limiting holes cooperating with the limiting posts are provided in the magnetic conductive gasket.

[0011] Furthermore, an oil guide groove is provided on the inner wall of the valve body, one end of the oil guide groove is closed, and the other end extends to the end of the valve body, is open, and is opposite to the filter screen; a feedback hole connected to the oil guide groove is provided on the inner wall of the bushing.

[0012] Furthermore, a thin-walled sleeve is provided between the outer wall of the armature and the inner wall of the magnetic conductive sleeve.

[0013] Furthermore, the thin-walled sleeve is Teflon fiber cloth.

[0014] Furthermore, an electromagnetic coil is arranged on the outer side wall of the magnetic conductive sleeve, an electromagnetic valve shell is sleeved on the electromagnetic coil, and a positioning rib is protrudingly arranged on the outer side wall of the electromagnetic valve shell.

[0015] In summary, the present invention has the following beneficial effects:

[0016] 1. The use of convex points can reduce the number of parts and reduce costs on the one hand, and can reduce assembly and cumulative errors on the other hand, thereby improving control accuracy;

[0017] 2. The valve body, bushing, filter, filter bracket and magnetic gasket are integrally injection molded, eliminating the assembly process of multiple parts of the hydraulic part, reducing the assembly cost, assembly error and processing difficulty, thereby improving the control accuracy of the solenoid valve;

[0018] 3. The feedback hole and oil guide groove are used to reduce the coaxiality requirements and processing difficulty of the valve core and valve body, and improve the control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A cross-sectional view of a solenoid valve capable of improving control accuracy in an embodiment;

[0020] Figure 2 An exploded schematic diagram of a magnetic gasket, a valve body, a bushing and a filter screen in an embodiment;

[0021] Figure 3 Schematic diagram of the structure of the client in the embodiment.

[0022] In the figure: 1. Magnetic pole; 11. Bump; 12. Large spring; 2. Armature; 21. Thin-walled sleeve; 22. Gasket; 3. Magnetic sleeve; 4. Electromagnetic coil; 5. Solenoid valve housing; 51. Positioning rib; 6. Valve body; 61. Magnetic gasket; 611. Limiting hole; 612. Limiting column; 62. Limiting ring; 63. Oil guide groove; 64. Small spring; 65. Filter; 651. Filter bracket; 652. Filter; 7. Bushing; 71. Feedback hole; 72. Limiting ring groove; 8. Valve core; 81. Closing part; 9. Client; 91. Positioning groove. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0025] Example:

[0026] A solenoid valve capable of improving control accuracy, referring to Figure 1 It includes a magnetic sleeve 3, an armature 2 is slidably arranged inside the magnetic sleeve 3, and a magnetic pole 1 is arranged at its end; the magnetic pole 1 includes a closing portion and a plug-in portion, the closing portion contacts the end of the magnetic sleeve 3, the plug-in portion is embedded in the magnetic sleeve 3, a large spring 12 in a compressed state is arranged between the plug-in portion and the armature 2, and a clearance groove cooperating with the large spring 12 is respectively opened on the plug-in portion and the armature 2; a plurality of protrusions 11 that can contact the end surface of the armature 2 are evenly distributed on the end surface of the plug-in portion opposite to the armature 2, and the protrusions 11 in this embodiment are hemispherical.

[0027] Reference Figure 1 In this embodiment, the traditional magnetic isolation gasket is eliminated. Since the armature 2 and the magnetic pole 1 are in contact with the protrusion 11 when in the attracted state, the magnetic flux between the armature 2 and the protrusion 11 is small and the magnetic resistance is large. This achieves the same control stroke effect as the use of a magnetic isolation gasket, that is, it will not cause a sudden change in the linear electromagnetic force when in contact. Therefore, the use of the protrusion 11 can reduce the number of parts and reduce costs on the one hand, and can reduce assembly and cumulative errors on the other hand, thereby improving control accuracy.

[0028] Reference Figure 1 A thin-walled sleeve 21 is arranged between the outer wall of the armature 2 and the inner wall of the magnetic sleeve 3. In this embodiment, the thin-walled sleeve 21 is Teflon fiber cloth; Teflon fiber cloth is scientifically known as polytetrafluoroethylene coated glass fiber cloth, which is made of suspended polytetrafluoroethylene emulsion and impregnated with high-performance glass fiber cloth. It has the characteristics of weather resistance, aging resistance, non-adhesion, chemical corrosion resistance, low friction coefficient, high insulation performance and good dimensional stability; therefore, the thin-walled sleeve 21 made of Teflon fiber cloth can reduce the friction coefficient between the armature 2 and the magnetic sleeve 3, making the armature 2 slide more smoothly, thereby reducing the hysteresis of the solenoid valve, improving the response speed and control accuracy, and at the same time canceling the surface treatment process of the armature 2 and the magnetic sleeve 3, which can reduce the cost.

[0029] Reference Figure 1 and Figure 2A valve body 6 is provided at one end of the magnetic sleeve 3 away from the magnetic pole 1, a magnetic gasket 61 is provided at one end of the valve body 6 and is sleeved on the magnetic sleeve 3, and a filter screen 65 is embedded in the other end, and a bushing 7 is embedded in the filter screen 65; the filter screen 65 includes a filter screen bracket 651 and a filter screen 652, wherein the valve body 6 and the filter screen bracket 651 are plastic parts, the bushing 7, the magnetic gasket 61 and the filter screen 652 are metal parts, and the valve body 6, the bushing 7, the magnetic gasket 61 and the filter screen 65 are integrally formed by injection molding.

[0030] Reference Figure 1 and Figure 2 An axial limiting structure is arranged between the valve body 6 and the bushing 7, and the axial limiting structure includes a limiting ring groove 72 opened on the outer wall of the bushing 7, and a limiting ring 62 arranged on the inner wall of the valve body 6 and cooperating with the limiting ring groove 72; the limiting ring 62 cooperates with the limiting ring groove 72 to limit the relative movement of the bushing 7 and the valve body 6 along the axial direction, thereby improving the stability of the connection between the two; a plurality of stepped limiting columns 612 are arranged at the end of the valve body 6, and a limiting hole 611 cooperating with the limiting column 612 is arranged in the magnetic gasket 61.

[0031] Reference Figure 1 and Figure 2 The bushing 7, filter screen 652 and magnetic gasket 61 are metal parts, the valve body 6 and filter screen bracket 651 are plastic parts, and the magnetic gasket 61 is a stamping part. The limiting hole 611 is directly stamped out, and then the valve body 6, bushing 7, filter screen 652, filter screen bracket 651 and magnetic gasket 61 are integrally injection molded, eliminating the assembly process of multiple parts of the hydraulic part, reducing the assembly cost, assembly error and processing difficulty, thereby improving the control accuracy of the solenoid valve.

[0032] Reference Figure 1 A plurality of oil guide grooves 63 are evenly distributed on the inner wall of the valve body 6, one end of the oil guide groove 63 is closed, and the other end extends to the end of the valve body 6, is open, and is opposite to the filter screen 65; a feedback hole 71 connected to the oil guide groove 63 is opened on the inner wall of the bushing 7; in this embodiment, the valve body 6 is connected to the side wall of the bushing 7 and has two oil inlets, which are T port and P port in the accompanying drawings, and the opening of the bushing 7 close to the P port is the control oil return port, that is, the A port in the accompanying drawings, and the feedback hole 71 is located between the T port and the P port, that is, the P port is located between the feedback hole 71 and the A port.

[0033] Reference Figure 1A valve core 8 is slidably arranged in the bushing 7, and a small spring 64 is arranged between the valve core 8 and the filter screen 65; a gasket 22 is arranged at the end of the magnetic sleeve 3 away from the magnetic pole 1, and the end of the valve core 8 is against the gasket 22 after passing through the magnetic sleeve 3; two closing parts 81 are arranged on the valve core 8, which are respectively opposite to the T port and the P port; in this embodiment, the hydraulic feedback channel is arranged on the valve body 6, that is, the oil guide groove 63, and the oil at the oil supply end enters the interior of the valve body 6 through the P port, and then flows into the oil guide groove 63 through the feedback hole 71 and enters the A port. The hydraulic pressure of the A port will act on the bottom of the valve core 8 to form a liquid pressure difference, which pushes the valve core 8 to compress the large spring 12, thereby reducing the coaxiality requirements of the valve core 8 and the valve body 6 and improving the control accuracy.

[0034] Reference Figure 1 and Figure 3 An electromagnetic coil 4 is arranged on the outer wall of the magnetic sleeve 3, and an electromagnetic valve housing 5 is sleeved on the electromagnetic coil 4. A positioning rib 51 is protruded from the outer wall of the electromagnetic valve housing 5, and the positioning rib 51 is formed by stamping; when the electromagnetic valve is installed, it is connected to the client 9, and a positioning groove 91 cooperating with the positioning rib 51 is opened on the client 9; when the electromagnetic valve is installed, the positioning rib 51 cooperates with the positioning groove 91, which can play a positioning role and prevent the electromagnetic valve from rotating.

[0035] Here’s how it works:

[0036] The solenoid valve of the present invention realizes a linear change in the output electromagnetic force by changing the magnitude of the control current, thereby matching the elastic force of the large spring 12 and the hydraulic pressure to control the output hydraulic pressure and realize a linear change in the control pressure.

[0037] The oil at the oil supply end enters the valve body 6 through the P port, and then flows into the oil guide groove 63 through the feedback hole 71 and enters the A port. The hydraulic pressure of the A port will act on the bottom of the valve core 8, forming a liquid pressure difference, pushing the valve core 8 to compress the large spring 12.

[0038] When the solenoid valve is not energized, the hydraulic pressure Fh is balanced with the elastic force Fs of the large spring 12, and Fh=Fs.

[0039] When the solenoid valve is energized, the combined force of the electromagnetic force Fm and the hydraulic pressure Fh is balanced with the elastic force Fs of the large spring 12, Fm+Fh=Fs.

[0040] When the control current changes linearly, the electromagnetic force output by the solenoid valve remains linear. Then, according to the force balance relationship, the liquid pressure at port A will also change linearly, that is, the pressure regulation function of port A is achieved by changing the current size.

[0041] When the current increases, the electromagnetic force will further increase, the large spring 12 will be further compressed, the armature 2 and the magnetic pole 1 are in a fitted state, the armature 2 will contact the convex point 11, and the convex point 11 plays a limiting role. When the current decreases, the electromagnetic force decreases, the armature 2 will be pushed away by the large spring 12, and the armature 2 will maintain other control positions. Since the armature 2 and the magnetic pole 1 are in contact with the convex point 11 when they are in the attracted state, the magnetic flux between the armature 2 and the convex point 11 is small, and the magnetic resistance is large. This is the same as the effect of using a magnetic isolation gasket to achieve the same control stroke, that is, it will not cause a sudden change in linear electromagnetic force when in contact.

Claims

1. A solenoid valve capable of improving control accuracy, comprising a magnetic sleeve (3), an armature (2) being slidably arranged inside the magnetic sleeve (3), and a magnetic pole (1) being arranged at the end thereof, the magnetic pole (1) comprising a closing portion and a plug-in portion, the closing portion being in contact with the end of the magnetic sleeve (3), and the plug-in portion being embedded in the magnetic sleeve (3), characterized in that: A large spring (12) in a compressed state is arranged between the plug-in portion and the armature (2), and a clearance groove cooperating with the large spring (12) is respectively provided on the plug-in portion and the armature (2); a plurality of protrusions (11) capable of contacting the end surface of the armature (2) are arranged on the end surface of the plug-in portion opposite to the armature (2); A valve body (6) is arranged at one end of the magnetic sleeve (3) away from the magnetic pole (1); a magnetic gasket (61) sleeved on the magnetic sleeve (3) is arranged at one end of the valve body (6); a filter screen (65) is embedded at the other end, and a bushing (7) is embedded in the filter screen (65); the filter screen (65) comprises a filter screen support (651) and a filter screen (652); the valve body (6) and the filter screen support (651) are plastic parts, the bushing (7), the magnetic gasket (61) and the filter screen (652) are metal parts, and the valve body (6), the bushing (7), the magnetic gasket (61) and the filter screen (65) are integrally formed; The inner wall of the valve body (6) is provided with an oil guide groove (63), one end of the oil guide groove (63) is closed, and the other end extends to the end of the valve body (6), is open, and is opposite to the filter screen (65); the inner wall of the bushing (7) is provided with a feedback hole (71) connected with the oil guide groove (63); A valve core (8) is slidably disposed in the bushing (7), and a small spring (64) is disposed between the valve core (8) and the filter screen (65).

2. The solenoid valve capable of improving control accuracy according to claim 1, characterized in that: The convex point (11) is hemispherical.

3. The solenoid valve capable of improving control accuracy according to claim 1, characterized in that: An axial limiting structure is provided between the valve body (6) and the bushing (7).

4. The solenoid valve capable of improving control accuracy according to claim 3, characterized in that: The axial limiting structure comprises a limiting ring groove (72) formed on the outer side wall of the bushing (7), and a limiting ring (62) arranged on the inner side wall of the valve body (6) and cooperating with the limiting ring groove (72).

5. The solenoid valve capable of improving control accuracy according to claim 4, characterized in that: A plurality of stepped limiting posts (612) are provided at the end of the valve body (6), and limiting holes (611) cooperating with the limiting posts (612) are provided in the magnetic conductive gasket (61).

6. The solenoid valve capable of improving control accuracy according to claim 1, characterized in that: A thin-walled sleeve (21) is provided between the outer wall of the armature (2) and the inner wall of the magnetic conductive sleeve (3).

7. The solenoid valve capable of improving control accuracy according to claim 6, characterized in that: The thin-walled sleeve (21) is Teflon fiber cloth.

8. The solenoid valve capable of improving control accuracy according to claim 6, characterized in that: An electromagnetic coil (4) is arranged on the outer wall of the magnetic conductive sleeve (3), an electromagnetic valve housing (5) is sleeved on the electromagnetic coil (4), and a positioning rib (51) is protrudingly arranged on the outer wall of the electromagnetic valve housing (5).

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