JP2023159992A - solenoid valve - Google Patents

Abstract

To secure flat suction characteristics of a fixed iron core in a wide range even if a moving core moves in an axial direction, concerning an electromagnetic valve in which the fixed iron core attracts the moving core in the axial direction by magnetic force of a coil.SOLUTION: A solenoid valve 1 includes a coil 2, a core body 11 having the coil 2 arranged outside, and a valve 4 opposed to the core body 11 in a reciprocating manner on the same axis. The solenoid valve 1 is configured such that the core body 11 attracts the valve 4 in an axial direction by magnetic force generated by the coil 2 in order to reciprocate the valve 4. The core body 11 has a bore 11b therein, and the valve 4 is disposed so as to be movable in the axial direction so that at least a part of the valve enters and exits the bore 11b. Holding means is provided to keep a constant area where an inner periphery of the bore 11b and an outer periphery of the valve 4 closely face each other when the inner circumference of the boa 11b and the outer periphery of the valve 4 oppose accompanying movement in the axial direction of the valve 4. The holding means is a recessed portion 4c provided on the outer periphery of the valve 4.SELECTED DRAWING: Figure 1

Description

The technology disclosed in this specification relates to a solenoid valve configured such that a fixed core attracts a movable core in the axial direction by magnetic force generated by a coil in order to cause the movable core to reciprocate.

Conventionally, as this type of technology, for example, a "linear solenoid" described in Patent Document 1 below is known. This linear solenoid includes a coil, a fixed core provided within the coil, and a movable core coaxially opposed to the fixed core. Here, the fixed core has a first suction section in which a tapered recess that widens toward the movable core is formed at the end facing the movable core, and an annular first suction section provided on the movable core side from the first suction section. It has two suction parts. The second suction portion is formed with a cylindrical inner circumferential surface that is continuous with the tapered surface of the recess.

Japanese Patent Application Publication No. 2000-277327

By the way, in the linear solenoid described in Patent Document 1, when the movable core enters the recess of the fixed core, the axial attraction force that the movable core receives increases, thereby compensating for the influence of the magnetic force taken away in the radial direction of the movable core. It looks like this. That is, when the movable core enters the recess of the fixed core, the magnetic force taken away from the movable core in the radial direction increases, and the magnetic force received from the axial direction of the movable core also increases. The balance between these two magnetic forces creates a region where the fixed core has flat attractive force characteristics with respect to the movable core. However, in the linear solenoid described above, the suction force of the fixed core increases when the movable core gets too close to the fixed core, and decreases when the movable core gets too far away from the fixed core. That is, the attraction force of the fixed core is affected by the displacement of the movable core. Therefore, the flat suction characteristics of the fixed core were limited to a narrow range.

This disclosed technology has been developed in view of the above circumstances, and its purpose is to provide a solenoid valve that is configured so that a fixed core attracts a movable core in the axial direction by magnetic force generated by a coil. The purpose is to ensure flat suction characteristics of the fixed iron core over a wide range regardless of movement (displacement) in the direction.

In order to achieve the above object, the technology according to claim 1 includes a coil that generates a magnetic force when energized, a fixed core on which the coil is disposed on the outside, and a movable core that faces the fixed core so that it can reciprocate on the same axis. In a solenoid valve, the fixed core is configured to attract the movable core in the axial direction by magnetic force generated by a coil in order to cause the movable core to reciprocate. However, when the movable core is arranged to be movable in the axial direction so that at least a portion thereof moves in and out of the bore, and as the movable core moves in the axial direction, the inner periphery of the bore and the outer periphery of the movable core face each other. The purpose of the present invention is to provide a holding means for keeping constant the area of close facing of the inner periphery of the bore and the outer periphery of the movable iron core.

According to the configuration of the above technology, the movable core coaxially faces the fixed core so as to be able to reciprocate, and in order to cause the movable core to reciprocate, the fixed core moves the movable core in the axial direction by the magnetic force generated by the coil. Configured to suction. Here, the movable core is arranged to be movable in the axial direction so that at least a portion of the movable core moves in and out of the bore of the fixed core, and a portion of the outer periphery of the movable core forms a magnetic circuit with the fixed core. When the outer periphery of the movable iron core faces the inner periphery of the bore as the movable iron core moves in the axial direction, the retaining means prevents the close opposing area between the inner periphery of the bore and the outer periphery of the movable iron core at the opposing location. It remains constant regardless of the movement of the movable iron core. Therefore, the magnetic force flowing from the movable iron core to the fixed iron core is kept constant regardless of the movement (displacement) of the movable iron core in the axial direction.

In order to achieve the above object, the technique according to claim 2 is the technique according to claim 1, in which the holding means is a recess provided on the outer periphery of the movable iron core.

According to the configuration of the above technique, in addition to the effect of the technique described in claim 1, the holding means is configured by simply providing a recess on the outer periphery of the movable core.

In order to achieve the above object, the technique according to claim 3 is the technique according to claim 1, in which the holding means is a recess provided on the inner periphery of the bore of the fixed iron core.

According to the configuration of the above technology, in addition to the effect of the technology described in claim 1, the holding means is configured simply by providing a recessed portion on the inner periphery of the bore of the fixed iron core.

In order to achieve the above object, the technique according to claim 4 is the technique according to any one of claims 1 to 3, in which the holding means is exposed such that the outer periphery of the movable core is opposed to the inner periphery of the bore. It is intended to be a non-magnetic material provided around the outer periphery of the movable core so that the area is constant.

According to the configuration of the above technology, in addition to the effects of the technology according to any one of claims 1 to 3, the area where the outer periphery of the movable core is exposed so as to face the inner periphery of the bore is reduced regardless of the movement of the movable core. It is kept constant by non-magnetic material. Therefore, the flow of magnetic force from the movable iron core to the fixed iron core is blocked by the nonmagnetic material.

According to the technology described in claim 1, the electromagnetic valve is configured such that the fixed iron core attracts the movable iron core in the axial direction by the magnetic force generated by the coil, regardless of the movement (displacement) of the movable iron core in the axial direction. The flat suction characteristics of the fixed core can be ensured over a wide range.

According to the technique set forth in claim 2, in addition to the effects of the technique set forth in claim 1, processing of the movable iron core for forming the holding means can be simplified.

According to the technique set forth in claim 3, in addition to the effects of the technique set forth in claim 1, processing of the fixed core for forming the holding means can be simplified.

According to the technology set forth in claim 4, in addition to the effects of the technology set forth in any one of claims 1 to 3, stable suction characteristics of the fixed core can be ensured.

FIG. 1 is a sectional view showing a solenoid valve according to the first embodiment. FIG. 2 is an enlarged sectional view showing the vicinity of the ring of the electromagnetic valve of FIG. 1 according to the first embodiment. FIG. 3 is a cross-sectional view further enlarging and showing the vicinity of the upper end of the valve in FIG. 2 according to the first embodiment. FIG. 3 is a cross-sectional view showing a step-by-step process of moving the valve according to the first embodiment. FIG. 3 is a cross-sectional view showing a step-by-step process of moving the valve according to the first embodiment. FIG. 3 is a cross-sectional view showing a step-by-step process of moving the valve according to the first embodiment. FIG. 6 is a cross-sectional view showing a step-by-step process of moving a valve according to a comparative example of the first embodiment. FIG. 6 is a cross-sectional view showing a step-by-step process of moving a valve according to a comparative example of the first embodiment. FIG. 6 is a cross-sectional view showing a step-by-step process of moving a valve according to a comparative example of the first embodiment. 4 is a graph showing an image of the suction force characteristics of the valve due to the core body according to the first embodiment. 4 is a graph showing an image of the suction force characteristics of the valve due to the core body according to the first embodiment. 7 is a graph showing an image of the suction force characteristics of the valve due to the core body according to a comparative example of the first embodiment. 7 is a graph showing an image of the suction force characteristics of the valve due to the core body according to a comparative example of the first embodiment. FIG. 4 is a sectional view similar to FIG. 3 showing the vicinity of the upper end of a solenoid valve according to a modification of the first embodiment. FIG. 4 is a sectional view similar to FIG. 3 showing the vicinity of the upper end of a solenoid valve according to the second embodiment.

<First embodiment>
Hereinafter, a first embodiment embodying a solenoid valve will be described in detail with reference to the drawings.

[About the configuration of the solenoid valve]
FIG. 1 shows a sectional view of a solenoid valve 1 of this embodiment. This electromagnetic valve 1 includes a coil 2 that generates magnetic force when energized, a substantially cylindrical stator core 3 with the coil 2 arranged on the outside and bores 11b and 12a inside, and can reciprocate on the same axis as the stator core 3. A substantially cylindrical valve 4 is provided. The coil 2 is covered with a casing 5 made of resin, and the outside of the casing 5 is covered with a yoke 6 made of a magnetic material. A power supply connector 7 is formed in a part of the casing 5 .

The stator core 3 is made of a magnetic material and includes a core body 11 located on the upper side of FIG. 1, and a cylindrical body 12 coaxially extending downward from the core body 11. The core body 11 has a bore 11a extending in its axial direction and a bore 11b continuous with the bore 11a, and the body 12 has a bore 12a extending in its axial direction. The valve 4 is made of iron, which is a magnetic material, and has a hollow hole 4 a and a tip hole 4 b that penetrates from the hollow hole 4 a toward the valve seat 14 . A ring 13 made of a non-magnetic material is arranged between the core body 11 and the body 12. The core main body 11 and the body 12 are connected by a ring 13, and their adjacent inner peripheries are set to have the same inner diameter, but are separated by the ring 13 and form a recess. The valve 4 coaxially faces the core body 11 so as to be able to reciprocate. In this embodiment, the core body 11 is made of iron and corresponds to an example of a fixed iron core of this disclosed technology, and the valve 4 corresponds to an example of a movable iron core of this disclosed technology. A valve seat 14 on which the valve 4 can be seated is arranged at the lower end of the body 12 at a position facing the lower end of the valve 4 . The valve seat 14 has a valve hole 14a and is made of a non-magnetic material. A spring 15 is provided between the upper end of the valve 4 and the lower end of the core body 11 to bias the valve 4 in the direction of seating the valve seat 14 (valve closing direction). In this electromagnetic valve 1, when the coil 2 is energized, a magnetic circuit 16 is formed between the members 4, 6, 11, and 12 as shown by broken lines in FIG.

This electromagnetic valve 1 is configured such that the stator core 3 (core body 11) attracts the valve 4 in the axial direction by the magnetic force generated by the coil 2 in order to cause the valve 4 to reciprocate. That is, when opening the solenoid valve 1, the stator core 3 (core body 11) attracts the valve 4 in the axial direction against the biasing force of the spring 15 due to the magnetic force generated by the coil 2. As a result, the valve 4 is separated from the valve seat 14 (opened), and the valve hole 14a is opened. In this valve open state, the valve hole 14a, the middle hole 4a of the valve 4, and the bore 11b and the middle hole 11a of the core body 11 communicate with each other, and fluid flows through the flow path. When closing the electromagnetic valve 1, the generation of magnetic force by the coil 2 is stopped, and the attraction of the valve 4 by the stator core 3 (core body 11) is stopped. As a result, the valve 4 is seated (closed) on the valve seat 14 due to the biasing force of the spring 15, and the valve hole 14a is closed. This electromagnetic valve 1 constitutes a linear solenoid valve in that it causes the valve 4 to reciprocate with respect to the stator core 3 (core body 11).

In this embodiment, the bore 11b of the core body 11 is formed in two stages, the inner diameter of which is large and small. The valve 4 is arranged so that its upper end in FIG. 1 can move in and out of the bore 11b in the axial direction. In this electromagnetic valve 1, when the outer circumference of the upper end of the valve 4 faces the inner circumference of the bore 11b as the valve 4 moves in the axial direction, the inner circumference of the bore 11b and the outer circumference of the valve 4 become close to each other. A holding means is provided for keeping the area of close facing each other constant within the range in which the valve 4 moves.

[About holding means]
The solenoid valve 1 of this embodiment, which is a linear solenoid valve, is a combination of a cylinder type (a type in which the valve 4 is housed in the core body 11) and an opposed magnetic pole type (a type in which the valve 4 is axially opposed to the core body 11). configured. The proportional region (region having flat suction force characteristics with respect to displacement of the valve 4) obtained by this synthetic type is originally limited. Therefore, in this embodiment, the holding means is defined as follows in order to be able to expand the region having flat suction force characteristics with respect to the displacement of the valve 4.

FIG. 2 shows an enlarged sectional view of the vicinity of the ring 13 of the electromagnetic valve 1 of FIG. FIG. 3 shows a further enlarged cross-sectional view of the vicinity of the upper end of the valve 4 of FIG. In this embodiment, as shown in FIGS. 2 and 3, the holding means is constituted by a recess 4c provided on the outer periphery of the tip of the bulb 4. That is, as shown in FIG. 3, the outer periphery of the tip of the valve 4 has an edge surface 4d adjacent to the end edge that can face the inner periphery of the bore 11b of the core body 11, and an edge surface 4d on the edge surface 4d. A subsequent recess 4c is formed. This edge surface 4d constitutes a close opposing surface where the inner periphery of the bore 11b and the outer periphery of the valve 4 closely oppose each other. On the other hand, in the recess 4c, although the outer periphery of the valve 4 can face the inner periphery of the bore 11b, it is separated from the inner periphery of the bore 11b by the depth D1 (see FIG. 3) of the recess 4c, and the outer periphery of the valve 4 is magnetically There is a gap and they are not close together. In this embodiment, the length L1 (see FIG. 3) of the recess 4c in the axial direction of the valve 4 is set to approximate the length by which the valve 4 moves (displaces) in the axial direction.

[About the action and effects of the solenoid valve]
According to the configuration of the solenoid valve 1 of this embodiment described above, the valve 4 coaxially faces the core body 11 so as to be able to reciprocate, and in order to reciprocate the valve 4, the magnetic force generated by the coil 2 is Accordingly, the core body 11 is configured to attract the valve 4 in the axial direction. Here, the valve 4 is arranged to be movable in the axial direction so that the upper end in FIG. A magnetic circuit 16 is formed. When the outer periphery of the valve 4 faces the inner periphery of the bore 11b as the valve 4 moves in the axial direction, the inner periphery of the bore 11b and the outer periphery of the valve 4 are held together by the recess 4c (holding means) at the opposing location. The close facing area between the valve 4 and the valve 4 is kept constant regardless of the movement of the valve 4.

In FIGS. 1 to 3, the valve 4 is moved upward by the suction of the core body 11. 4 to 6 show stepwise cross-sectional views of the movement process of the valve 4. FIG. 4 shows the closed state of the valve 4 shown in FIGS. 1 to 3, and FIG. 5 shows the valve 4 in the closed state. Figure 6 shows the state in which the valve 4 has moved upward by "X + α (α is a predetermined value smaller than X) (mm)" from the closed state. Each state is shown below. As shown in FIGS. 4 to 6, the outer periphery of the tip (upper end) of the valve 4 faces the inner periphery of the bore 11b of the core body 11 as the valve 4 moves; The only surface that closely faces the circumference is the above-mentioned edge surface 4d. That is, even if the valve 4 moves upward, the recessed portion 4c does not come close to and face the inner periphery of the bore 11b. The area where the edge surface 4d of the valve 4 and the inner periphery of the bore 11b face each other remains constant regardless of the movement (displacement) of the valve 4 in the axial direction. Therefore, as shown by broken line arrows in FIGS. 4 to 6, the magnetic force flowing from the valve 4 to the core body 11 is kept constant regardless of the movement (displacement) of the valve 4 in the axial direction. Therefore, in this embodiment, the solenoid valve 1 is configured such that the core body 11 attracts the valve 4 in the axial direction by the magnetic force generated by the coil 2, regardless of the movement (displacement) of the valve 4 in the axial direction. The flat suction characteristics of the core body 11 can be ensured over a wide range.

FIGS. 7 to 9 are cross-sectional views showing step-by-step the movement process of the valve 4 in a comparative example that does not have the holding means (recess 4c) of this embodiment. 7 shows the valve 4 in the closed state, FIG. 8 shows the state in which the valve 4 has moved upward by "X (mm)" from the closed state, and FIG. 9 shows the state in which the valve 4 has moved upward by "X mm)" respectively indicate the state of moving upward. As shown in FIGS. 7 to 9, the outer periphery of the tip (upper end) of the valve 4 is such that the entire portion of the valve 4 that sinks into the bore 11b as the valve 4 moves is close to the inner periphery of the bore 11b. We will be facing each other. The area where the outer periphery of the valve 4 and the inner periphery of the bore 11b face each other increases as the valve 4 moves (displaces) in the axial direction. Therefore, as shown by broken line arrows in FIGS. 7 to 9, the magnetic force flowing from the valve 4 to the core body 11 increases as the valve 4 moves (displaces) in the axial direction. Therefore, in this comparative example, the suction force of the core body 11 changes due to the movement (displacement) of the valve 4 in the axial direction, and the flat suction characteristics of the core body 11 cannot be ensured.

Here, FIGS. 10 and 11 are graphs showing images of the suction force characteristics of the valve 4 due to the core body 11 of this embodiment. On the other hand, FIGS. 12 and 13 are graphs showing images of the suction force characteristics of the valve 4 using the core body 11 of a comparative example. 10 and 12, the horizontal axis shows the valve stroke, and the vertical axis shows the attraction force (of the core body 11) and the current value (of the coil 2), respectively. 11 and 13, the horizontal axis shows the current value (of the coil 2), and the vertical axis shows the valve stroke (fluid flow rate), respectively. In FIGS. 10 to 13, the relationship between the suction force by the core body 11 and the suction force required to move the valve 4 is plotted with black circles.

As shown in FIGS. 12 and 13, it can be seen that in the comparative example, the slope of the valve stroke (flow rate) becomes smaller as the current value increases. On the other hand, as shown in FIGS. 10 and 11, in this embodiment, the decrease in the suction force due to the increase in the valve stroke is suppressed, and thereby the decrease in the slope of the valve stroke (flow rate) due to the increase in the current value is suppressed. It can be seen that it is suppressed.

Further, according to the configuration of this embodiment, the holding means is configured simply by providing the recess 4c on the outer periphery of the valve 4. As a result, the processing of the valve 4 for constructing the holding means can be simplified.

[Modified example of the first embodiment]
Here, a modification of the first embodiment will be described. FIG. 14 shows the vicinity of the upper end of the valve 4 of the electromagnetic valve 1 in a sectional view similar to FIG. 3 according to this modification. In the first embodiment, a recess 4c is provided on the outer periphery of the tip of the bulb 4 as a holding means. On the other hand, as a modification thereof, as shown in FIG. 14, a non-magnetic material 21 may be provided in the recess 4c. That is, the non-magnetic material 21 is provided on the outer periphery of the bulb 4 so that the area exposed so that the outer periphery of the tip of the bulb 4 faces the inner periphery of the bore 11b of the core body 11 is constant. As the non-magnetic material 21, steel, cast iron, copper, aluminum, or an alloy thereof can be used.

[About the action and effect of the modified solenoid valve]
According to the configuration of this modified example, in addition to the functions and effects of the first embodiment, the following functions and effects can be obtained. That is, in this modification, regardless of the movement of the valve 4 in the axial direction, the area where the outer periphery of the valve 4 is exposed so as to face the inner periphery of the bore 11b of the core body 11 is kept constant by the non-magnetic material 21. It will be done. Therefore, the flow of magnetic force from the valve 4 to the core body 11 is blocked by the non-magnetic material 21. Therefore, stable suction characteristics of the core body 11 can be ensured.

<Second embodiment>
Next, a second embodiment embodying a solenoid valve will be described in detail with reference to the drawings. In the following description, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted, and the following description focuses on the differences.

[About holding means]
This embodiment differs from the first embodiment in the configuration of the holding means. FIG. 15 is a sectional view similar to FIG. 3 showing the vicinity of the upper end of the valve 4 of the electromagnetic valve 1 of this embodiment. As shown in FIG. 15, in this embodiment, the holding means is constituted by a recess 11c provided on the inner periphery of the bore 11b of the core body 11. That is, as shown in FIG. 15, the outer periphery of the valve 4 is not provided with a recess 4c, and the outer periphery of the tip of the valve 4 is provided on the inner periphery of the bore 11b of the core body 11, adjacent to its open end. An edge surface 11d that can face the edge surface 11d and a recess 11c continuing to the edge surface 11d are formed. This edge surface 11d constitutes a close opposing surface where the outer periphery of the valve 4 and the inner periphery of the bore 11b closely oppose each other. On the other hand, in the recess 11c, although the inner periphery of the bore 11b can face the outer periphery of the valve 4, it is separated from the outer periphery of the valve 4 by the depth of the recess 11c, creating a magnetic gap. I haven't. In this embodiment, the length of the recess 11c in the axial direction of the bore 11b is set to approximate the length by which the valve 4 moves (displaces) in the axial direction.

[About the action and effects of the solenoid valve]
According to the configuration of the electromagnetic valve 1 of this embodiment described above, unlike the first embodiment, the holding means is configured by simply providing the recess 11c on the inner periphery of the bore 11b of the core body 11. Therefore, the processing of the core body 11 for constructing the holding means can be simplified.

<Another embodiment>
Note that the disclosed technology is not limited to the above-described embodiments, and may be implemented by appropriately changing a part of the configuration without departing from the spirit of the disclosed technology.

(1) In the modification of the first embodiment, the non-magnetic material 21 is provided in the recess 4c provided on the outer periphery of the bulb 4, but the non-magnetic material 21 is provided on the outer periphery of the bulb without forming a recess on the outer periphery of the bulb. It is also possible to coat the bulb with a film or to make the outer periphery of the bulb non-magnetic.

(2) In the second embodiment, the recess 11c is provided on the inner periphery of the bore 11b of the core body 11 as a holding means. It is also possible to coat the inner periphery of the bore with a non-magnetic film or to make the inner periphery of the bore non-magnetic.

(3) In each of the embodiments described above, the stator core 3 is composed of a plurality of parts, that is, the core body 11, the body 12, and the ring 13, but the stator core can also be composed of a single part.

The disclosed technology can be applied to linear solenoid type electromagnetic valves used to control fluid flow.

1 Solenoid valve 2 Coil 4 Valve (movable iron core)
4c Recess (holding means)
4d Edge surface 11 Core body (fixed core)
11b Bore 11c Recess (holding means)
11d Edge surface 21 Non-magnetic material

Claims (4)

A coil that generates magnetic force when energized,
a fixed core on the outside of which the coil is disposed;
A movable core coaxially and reciprocatably opposed to the fixed core, and in order to cause the movable core to reciprocate, the fixed core attracts the movable core in the axial direction by magnetic force generated by the coil. In a solenoid valve configured with
The fixed iron core has a bore therein, and the movable iron core is arranged to be movable in the axial direction so that at least a portion thereof moves in and out of the bore,
When the outer periphery of the movable iron core faces the inner periphery of the bore as the movable iron core moves in the axial direction, the close facing area where the inner periphery of the bore and the outer periphery of the movable iron core closely face each other is defined as A solenoid valve characterized in that it is provided with a holding means to keep it constant. The solenoid valve according to claim 1,
The electromagnetic valve is characterized in that the holding means is a recess provided on the outer periphery of the movable iron core. The solenoid valve according to claim 1,
The electromagnetic valve is characterized in that the holding means is a recess provided on the inner periphery of the bore of the fixed iron core. The solenoid valve according to any one of claims 1 to 3,
The holding means is a non-magnetic material provided on the outer periphery of the movable iron core so that the exposed area of the outer periphery of the movable iron core facing the inner periphery of the bore is constant. Solenoid valve.

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