Electromagnetic proportional valve

Abstract

The utility model relates to an electromagnetic proportional valve, which comprises an outer frame; an excitation coil; the fixed iron core is fixedly installed on the outer frame, the fixed iron core is provided with a first end part and a second end part and is provided with a fluid channel which is through in the axial direction, and the second end part is provided with a first end face which extends in the radial direction; a fluid inlet located outside the outer frame and a fluid outlet located inside the outer frame are formed in the first end and the second end of the fluid channel respectively. The movable iron core is installed in the outer frame in an axial sliding mode, the movable iron core is provided with a valve part close to the fixed iron core, and the valve part is provided with a second end face extending in the radial direction; when current is input into the magnet exciting coil, the movable iron core is subjected to magnetic force pointing to the fixed iron core; and the limiting ring is constructed to be capable of being arranged on the outer side of the valve part in a sleeving mode and fixedly connected with the valve part, the limiting ring comprises a cylindrical surface part which extends in the axial direction and makes contact with the peripheral surface of the valve part and a limiting part which extends in the radial direction and makes contact with the second end face, and the limiting part is used for limiting the minimum distance between the first end face and the second end face.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of valve, especially an electromagnetic proportional valve. BACKGROUND

[0002] The electromagnetic proportional valve usually comprises a coil capable of establishing a magnetic field by being electrified, a movable iron core, a fixed iron core and a force applying part for providing a restoring force for the movable iron core, the movable iron core can be matched with a fluid outlet formed in the electromagnetic proportional valve to adjust the fluid flow through the fluid outlet.

[0003] The movable iron core and the fixed iron core are both composed of soft magnetic material, and can be magnetized by the magnetic field generated by the coil when the coil is electrified. The magnetized movable iron core and the fixed iron core generate a mutual magnetic force, the movable iron core overcomes the force applying part and moves towards the fixed iron core until the magnetic force acting on the movable iron core is equal to the force of the force applying part. Thus, by controlling the current input to the electromagnetic proportional valve, the stop position of the movable iron core can be adjusted, and then the fluid flow is adjusted.

[0004] The current electromagnetic proportional valve has the following common technical problems: since the magnetic force between the movable iron core and the fixed iron core is inversely proportional to the square of the distance between them, when the movable iron core is close to the fixed iron core, a small change in distance will greatly increase or decrease the magnetic force, and the amplitude of the above-mentioned magnetic force change far exceeds the adjustable amplitude of the force applying part. Therefore, in a small area close to the fixed iron core, the travel of the movable iron core is difficult to fine adjust, and the movable iron core shows a "jumping" phenomenon, which is easily adsorbed on the fixed iron core. After the movable iron core is adsorbed on the fixed iron core, the electromagnetic proportional valve needs to reduce the excitation voltage to a low level to make the two separate.

[0005] The invention patent with publication number CN110693477B provides a flow control valve, which comprises a solenoid, an iron core provided with a flow outlet, a slidable plunger and a valve body mounted on the plunger opposite to the flow outlet, and the end surface of the valve body opposite to the plunger is convex outward. When the fluid control valve is in a completely closed state, there is a spacing of 0.2mm or more between the plunger and the iron core to define the minimum spacing between the two. However, the flow control valve is limited by the elastic valve body, and after long-term use, the valve body will irreversibly deform, which will not ensure the minimum spacing.

[0006] There is also a way to limit the minimum spacing between the movable iron core and the fixed iron core by adding a gasket to the end surface of the movable iron core opposite to the fixed iron core. However, since the gasket is usually a flat diaphragm, the edge part of its surface will curl under long-term collision with the fixed iron core, hindering the movement of the movable valve core, resulting in the electromagnetic proportional valve not being tightly closed. UTILITY MODEL CONTENTS

[0007] The utility model discloses a kind of electromagnetic proportional valves for the technical problems existing in the above electromagnetic proportional valve, and the purpose is to provide a kind of electromagnetic proportional valve with the minimum gap between fixed iron core and movable iron core can be stabilized and limited fixed and has the function of magnetic separation.

[0008] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme: an electromagnetic proportional valve, comprising: an outer frame; an excitation coil fixedly arranged inside the outer frame and capable of establishing a magnetic field when an input current is applied; a fixed iron core fixedly installed on the outer frame, the fixed iron core having a first end portion and a second end portion that are away from each other and being provided with a fluid passage extending in an axial direction, the second end portion having a first end face extending in a radial direction; the fluid passage is formed with a fluid inlet located outside the outer frame and a fluid outlet located inside the outer frame at the first end portion and the second end portion, respectively; a movable iron core axially slidably installed inside the outer frame, the movable iron core having a valve portion close to the fixed iron core, the valve portion having a second end face extending in a radial direction; when an input current is applied to the excitation coil, the movable iron core is subjected to a magnetic force directed towards the fixed iron core; a limiting ring configured to be fitted on the outer side of the valve portion and fixedly connected with the valve portion, the limiting ring including a cylindrical portion extending in an axial direction and contacting the outer peripheral side surface of the valve portion and a limiting portion extending in a radial direction and contacting the second end face, the cylindrical portion being connected to the outer edge of the limiting portion, and the limiting portion being used to limit the minimum distance between the first end face and the second end face; and a force applying member arranged inside the outer frame and capable of applying a restoring force to the movable iron core.

[0009] In the above technical solution, preferably, the thickness of the limiting portion is in the range of 0.1-0.4 mm.

[0010] In the above technical solution, preferably, the valve portion is provided with an elastic valve body facing the fluid outlet, and the limiting portion is provided with an intermediate opening for the elastic valve body to protrude out.

[0011] In the above technical solution, preferably, the cylindrical portion is in interference fit with the valve portion. Further preferably, the outer peripheral side surface of the valve portion is formed with an interference segment protruding outward in a radial direction and a relief groove recessed inward in a radial direction in an axial direction, the interference segment is closer to the second end face than the relief groove, and the interference segment is in interference fit with the cylindrical portion. Still further preferably, the ratio of the length of the interference segment in the axial direction to the length of the relief groove in the axial direction is in the range of 1:1-1:3.

[0012] In the above technical solution, preferably, the outer circumferential surface of the valve portion is formed with a mating groove recessed inward in a radial direction, and the main surface portion is formed with a mating protrusion at least partially entering the mating groove.

[0013] In the technical scheme above, preferably, the limiting ring further comprises an outer ring portion extending radially outward away from the contact portion, and the valve portion is formed with a stepped surface supporting the outer ring portion; and the force applying member is a spring, one end of the spring abutting against the fixed core and the other end abutting against the outer ring portion.

[0014] In the technical scheme above, preferably, the electromagnetic proportional valve further comprises a bobbin fixedly installed inside the outer frame, the bobbin defining an axially extending sliding cavity; the excitation coil is wound on the outer wall of the bobbin, and the movable core is installed in the sliding cavity. Further preferably, the movable core has a main body portion in sliding fit with the cavity wall of the sliding cavity.

[0015] In the technical scheme above, preferably, the limiting ring is made of copper, aluminum, rubber, plastic or stainless steel material treated by demagnetization process.

[0016] Compared with the prior art, the technical scheme of the utility model provides the proportional valve with a limiting ring used to limit the minimum distance between the fixed core and the movable core, the limiting ring is configured to be fixed on the valve portion of the movable core in a sleeving manner, and the installation is convenient. In addition, since the limiting ring has a cylindrical portion connected to the outer edge of the limiting portion, the surface edge of the limiting portion can be prevented from being curled to hinder the movement of the movable core after being subjected to long-term impact. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a perspective view of the electromagnetic proportional valve provided by the utility model;

[0018] Figure 2 is Figure 1 a sectional view of the electromagnetic proportional valve shown in the figure;

[0019] Figure 3 is Figure 2 a local enlarged view;

[0020] Figure 4 is a perspective view of the limiting ring provided by the utility model;

[0021] Figure 5 is the limiting ring and the movable core of another embodiment provided by the utility model.

[0022] Markings in the figure:

[0023] 100, electromagnetic proportional valve; L, axis;

[0024] 11, shell; 12, bottom cover;

[0025] 2, spool; 21, sliding cavity;

[0026] 3, exciting coil;

[0027] 4, movable core; 41, main body part; 42, valve part; 43, elastic valve body; 44, step face;

[0028] 45, guide section; 46, interference section; 47, avoiding groove;

[0029] 5, fixed core; 51, fluid passage; 52, first end face;

[0030] 6, force applying part;

[0031] 7, limiting ring; 71, limiting part; 72, cylindrical part; 73, middle opening; 74, outer ring part. DETAILED DESCRIPTION

[0032] To describe the technical contents, structural features, achieved purposes and effects of the present application in detail, the technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0033] In the present application, spatial relative terms such as "below", "under", "lower", "above", "upper", "on", "higher", "side" (for example, as in "sidewall") are used herein for describing the relationship between one element and another element as shown in the drawings. The spatial relative terms are intended to encompass different orientations of the device in use, operation and / or manufacture in addition to the orientations depicted in the drawings. For example, if the device in the drawings is turned over, an element described as "below" or "under" another element or feature would then be oriented "above" the other element or feature. Thus, the example term "below" can encompass both an orientation of above and below. In addition, the device can be otherwise oriented (for example, rotated 90 degrees or at other orientations) and the spatial relative descriptors used herein interpreted accordingly.

[0034] In the present application, the term "fixed connection" means that two components are connected in a manner that can be kept relatively fixed under no external force by means of interference fit, gluing, screwing, integral forming, etc. It can be understood that the "fixed connection" includes detachable fixed connection.

[0035] In the present application, the term "axial" means the direction of the axial center line of the electromagnetic proportional valve, and the term "radial" means the direction perpendicular to the axial center line of the electromagnetic proportional valve, unless otherwise specified.

[0036] The utility model provides a kind of electromagnetic proportional valve, it aims at providing a kind of spacing ring for limiting movable core and fixed core minimum spacing and having the function of magnetic isolation, the spacing ring has the characteristics of convenient installation, reliable and durable, to make up for the shortcomings of spacing part in prior art.

[0037] Specifically, as shown in Figures 1-2 The electromagnetic proportional valve 100 is defined with an axial line L and includes an outer frame for providing support for other components, a bobbin 2 fixedly installed inside the frame, an excitation coil 3 supported on the bobbin 2, a movable core 4 movable in the axial direction, a fixed core 5 fixedly installed inside the frame, a force applying component 6 for applying a restoring force to the movable core 4, and a spacing ring 7 for limiting the minimum spacing between the movable core 4 and the fixed core 5.

[0038] The outer frame includes a U-shaped housing 11 and a bottom cover 12 installed at the bottom of the housing 11. The housing 11 has a pair of axially extending sides and an end face perpendicular to the axial line L, and the bottom cover 12 is perpendicular to the axial line L and is arranged opposite to the above-mentioned end face. Among them, the housing 11 and the bottom cover 12 can be detachably connected by riveting or the like, or can be fixedly connected by welding or the like.

[0039] The housing 11 and the bottom cover 12 are both made of soft magnetic material, and the material is preferably electromagnetic steel plate or cold-rolled steel plate with high magnetic permeance. The housing 11 and the bottom cover 12 not only constitute the frame of the electromagnetic proportional valve 100, but also serve as a magnetic yoke to adjust the path of the magnetic field lines generated by the energization of the excitation coil 3.

[0040] The bobbin 2 is received in the space enclosed by the housing 11 and the bottom cover 12, and has a cylindrical structure coaxially arranged with the electromagnetic proportional valve 100. The bobbin 2 defines an axially extending sliding cavity 21, and the movable core 4 is axially slidably received in the sliding cavity 21. The bobbin 2 is composed of a cylindrical member made of non-magnetic material, such as a resin member represented by polyethylene terephthalate. In other embodiments, the movement direction of the movable core can also be defined by components other than the bobbin, and several guide rails are slidably fitted with the movable core.

[0041] The excitation coil 3 is formed by winding a wire on the outer circumferential surface of the bobbin 2. When the excitation coil 3 is connected to the input current, a corresponding magnetic field is generated.

[0042] In combination Figure 4The fixed iron core 5 is fixedly installed in the outer frame and coaxially arranged with the electromagnetic proportional valve 100. The fixed iron core 5 has a first end portion (not labeled in the figure) and a second end portion (not labeled in the figure) which are away from each other and is provided with a fluid passage 51 which penetrates the first and second end portions in the axial direction. The first end portion of the fixed iron core 5 protrudes outward relative to the outer frame, the fluid passage 51 forms a fluid inlet (not labeled in the figure) on the first end portion for fluid to enter the fluid passage 51 (i.e. enter the electromagnetic proportional valve 100), and the fluid passage 51 forms a fluid outlet (not labeled in the figure) on the second end portion for fluid to enter the sliding cavity 21, the fluid inlet and the fluid outlet are respectively located outside and inside the outer frame. The fixed iron core 5 has a first end face 52 which extends in the radial direction and a convex lip (not labeled in the figure) which is formed around the fluid outlet.

[0043] The movable iron core 4 is coaxially arranged with the electromagnetic proportional valve 100 and has a main body portion 41 which forms a sliding fit with the inner wall of the sliding cavity 21 and a valve portion 42 which is close to the fixed iron core 5. The valve portion 42 forms a gap fit with the sliding cavity 21 to facilitate the installation of the limiting ring 7. The valve portion 42 of the movable iron core 4 is fixedly installed with an elastic valve body 43 which faces the fixed iron core 5. It can be understood that by changing the position of the movable iron core 4, the fluid outlet can be selectively closed and opened, and the flow of fluid through the fluid outlet can be controlled. The valve portion 42 has a second end face (not labeled in the figure) which extends in the radial direction and faces the fixed iron core 5, and the elastic valve body 43 protrudes outward in the axial direction relative to the second end face to contact and close the fluid outlet.

[0044] The limiting ring 7 provided in the embodiment is made of a non-magnetic material, preferably copper, aluminum, plastic or rubber which has good ductility to facilitate molding. In other embodiments, the limiting ring can also be made of stainless steel which is treated by a demagnetization process. This material has the advantages of low cost and high toughness, and is not easy to break or curl under repeated impact of the movable iron core and the fixed iron core.

[0045] The limiting ring 7 can be installed on the outside of the valve portion 42 in a sleeved manner and is fixedly connected with the valve portion 42. The limiting ring 7 includes a limiting portion 71 which extends in the radial direction and a cylindrical portion 72 which extends in the axial direction and is connected to the outer edge of the limiting portion 71. The cylindrical portion 72 contacts the outer circumferential side surface of the valve portion 42, and the limiting portion 71 contacts the second end face of the valve portion 42 and is provided with an intermediate opening 73 which exposes the elastic valve body 43 to the outside, and the limiting portion 71 is used to limit the minimum distance between the first end face 52 and the second end face.

[0046] The limiting ring 7 described above is easy to install and has the cylindrical portion 72 which is connected to the outer edge of the limiting portion 71, which can avoid the surface edge of the limiting portion 71 from curling after being subjected to long-term impact to hinder the movement of the movable iron core 4.

[0047] In this embodiment, the thickness of the limiting portion is selected in the range of 0.1-0.4 mm to ensure that the movable iron core 4 and the fixed iron core 5 will not enter the area where the "jumping" phenomenon may occur.

[0048] Further, the cylindrical portion 72 of the limiting ring 7 is formed in interference fit with the outer peripheral side surface of the valve portion 42, so that the limiting ring 7 can be fixedly installed on the valve portion 42. This installation mode can avoid the use of glue between the limiting ring 7 and the valve portion 42 to prevent the adhesive overflow from adhering to the elastic valve body 43 and affecting the normal operation of the elastic valve body 43.

[0049] In other embodiments, an inwardly recessed fitting groove can also be formed on the outer peripheral side surface of the valve portion, and a plurality of fitting protrusions formed at least partially into the fitting groove can be formed on the cylindrical portion to fix the limiting ring on the valve portion. The fitting protrusions described above can be formed in advance on the inner side of the cylindrical portion of the limiting ring, or can be formed by pin-pointing and pressing after the limiting ring is sleeved on the valve portion.

[0050] Figure 5 The limiting ring 7' of another embodiment is provided with the movable iron core 4'. As shown, the outer peripheral side surface of the valve portion 42' of the movable iron core 4' is sequentially provided with a guide section 45 close to the second end surface, an interference section 46 protruding radially outward, and a relief groove 47 recessed radially inward in the axial direction. The guide section 45 gradually expands in diameter in the direction away from the second end portion to facilitate the sleeving of the limiting ring 7' on the valve portion 42'; the interference section 46 is formed in interference fit with the cylindrical section 72' of the limiting ring 7'; and the relief groove 47 is provided for the cylindrical section 72' of the limiting ring 7' to return to the natural state, so that the cylindrical section 72' at this position can form a structure similar to a reverse buckle to prevent the limiting ring 7' from being separated from the valve portion 42'.

[0051] Further, in order to ensure the formation of the reverse buckle, the valve portion 42' is configured such that the ratio of the length of the interference section 46 in the axial direction to the length of the relief groove 47 in the axial direction is in the range of 1:1-1:3.

[0052] Returning to Figures 1-4 In this embodiment, the force applying member 6 is a spring. The limiting ring 7 further includes an outer ring portion 74 extending radially outward away from the limiting portion 71 and connected to the edge of the cylindrical portion 72. The movable iron core 4 is formed with a stepped surface 44 for supporting the outer ring portion 74. The force applying member 6 is loaded inside the sliding cavity 21, with one side end portion abutting against the outer wall of the fixed iron core 5 and the other side end portion abutting against the outer ring portion 74 of the limiting ring 7 to prevent the limiting ring 7 from being separated from the valve portion 42.

[0053] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit of the present application should be covered within the protection scope of the present application.

Claims

1. An electromagnetic proportional valve characterized by comprising: The utility model relates to a solenoid valve, comprising: an outer frame; an excitation coil fixedly arranged inside the outer frame and capable of establishing a magnetic field when an input current is applied thereto; a fixed core fixedly mounted on the outer frame, the fixed core having a first end portion and a second end portion distanced from each other and being provided with a fluid passage extending axially therethrough, the second end portion being provided with a first end face extending radially, the fluid passage being provided with a fluid inlet located outside the outer frame and a fluid outlet located inside the outer frame at the first end portion and the second end portion respectively; a movable core axially slidably mounted inside the outer frame, the movable core having a valve portion close to the fixed core, the valve portion being provided with a second end face extending radially, the movable core being subjected to a magnetic force directed towards the fixed core when the excitation coil is applied with the input current; a limiting ring configured to be sleeved outside the valve portion and fixedly connected with the valve portion, the limiting ring comprising a cylindrical portion extending axially and contacting an outer circumferential side surface of the valve portion and a limiting portion extending radially and contacting the second end face, the cylindrical portion being connected to an outer edge of the limiting portion, the limiting portion being used to define a minimum distance between the first end face and the second end face; and a force applying member arranged inside the outer frame and capable of applying a restoring force to the movable core.

2. The electromagnetic proportional valve according to claim 1, characterized in that The thickness of the limiting portion is in a range of 0.1-0.4 mm.

3. The electromagnetic proportional valve according to claim 1, characterized in that The valve portion is provided with an elastic valve body facing the fluid outlet, and the limiting portion is provided with an intermediate opening for the elastic valve body to protrude out.

4. The electromagnetic proportional valve according to claim 1, characterized in that The cylindrical portion is in interference fit with the valve portion.

5. The electromagnetic proportional valve according to claim 4, characterized in that The outer circumferential side surface of the valve portion is provided with an interference segment protruding radially outward and a relief groove recessed radially inward in an axial direction, the interference segment being closer to the second end face than the relief groove, and the interference segment is in interference fit with the cylindrical portion.

6. The electromagnetic proportional valve according to claim 5, characterized in that The ratio of the length of the interference segment in the axial direction to the length of the relief groove in the axial direction is in a range of 1:1-1:

3.

7. The electromagnetic proportional valve according to claim 1, characterized in that The outer circumferential side surface of the valve portion is provided with a cooperation groove recessed radially inward, and the cylindrical portion is provided with a cooperation protrusion at least partially entering the cooperation groove.

8. The electromagnetic proportional valve according to claim 1, characterized in that The limiting ring further comprises an outer ring portion distanced from the limiting portion and extending radially outward, and the valve portion is provided with a stepped face supporting the outer ring portion, and the force applying member is a spring, one end of the spring being abutted against the fixed core and the other end being abutted against the outer ring portion.

9. The electromagnetic proportional valve according to claim 1, characterized in that The utility model further comprises a bobbin fixedly mounted inside the outer frame, the bobbin defining a sliding cavity extending axially, the excitation coil being wound around an outer wall of the bobbin, and the movable core being mounted in the sliding cavity.

10. The electromagnetic proportional valve according to claim 9, characterized in that The movable core has a main body portion in sliding fit with a cavity wall of the sliding cavity.

11. The electromagnetic proportional valve according to claim 1, characterized in that The limiting ring is made of copper, aluminum, rubber, plastic or stainless steel material treated by a demagnetization process.

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