JPH0989143A - Solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase attraction force to act between a fixed iron core and a movable iron core without enlarging a coil bobbin in a solenoid of a solenoid valve. SOLUTION: A fixed iron core 36 and a movable iron core 34 are coaxially arranged in the internal space of a body 30, the movable iron core 34 is supported on the inner periphery of the body so as to be freely slid in the axial direction, a bobbin 40 on which a coil is wound is fitted on the outer periphery of the fixed iron core 36, and the fixed iron core 36 is made to project from the coil bobbin 40 to the movable iron core 34 side. An annular protrusion 2 to be fitted on the outer periphery of the projecting end of the fixed iron core 36 is formed on the end of the movable iron core 34 on the fixed iron core 36 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid of a solenoid valve for performing proportional control of fluid pressure and flow rate.

[0002]

2. Description of the Related Art As a solenoid of a solenoid valve, a movable iron core 2 is slidably accommodated in a cylindrical pressure vessel 1 as shown in FIG. 8, and the base end portion of the pressure vessel 1 is used as a fixed iron core 3. The non-magnetic body 5 is connected between the guide tube portion 4 and the non-magnetic body 5.
There is a bobbin 6 fitted with a coil on the outer circumference of the container 1 that straddles the above (Japanese Patent Laid-Open No. 54-122425).

When the coil bobbin 6 is energized, a magnetic path passing through the fixed iron core 3, the movable iron core 2 and the guide tube portion 4 is formed, and the attraction force generated between the fixed iron core 3 and the movable iron core 3 causes the movable iron core 3 to move. The core 2 slides and displaces the spool 8 of the valve body via the rod 7. Reference numeral 9 denotes a spring that biases the spool 8 to the neutral position.

An annular projection 10 is formed on the fixed iron core 3 to form a recess into which the movable iron core 2 can enter, and the annular projection 10 is formed.
In the stroke range in which the movable iron core 2 is fitted in, the attracting force acting between the coil current and the constant value of the coil current is kept substantially constant, so that the magnetic flux flows to the outer periphery of the tip of the annular protrusion 10. Taper portion 1 as a magnetic path forming portion for controlling
1 is provided.

Further, as shown in FIG. 9, a movable iron core 16 is slidably housed in the back of the body 15, and a fixed iron core 18 is integrally formed with a cap 17 that closes the opening of the body 15. Fit a bobbin 19 with a coil around the outer circumference of 18,
Movable iron core 16 between fixed iron core 18 and coil bobbin 19
There is one in which a concave portion 20 that opens to the side is provided and an annular protrusion 21 that can enter the concave portion 20 is formed on the movable iron core 16 (Japanese Utility Model Laid-Open No. 5-79154).

When the coil bobbin 19 is energized,
A magnetic path passing through the fixed iron core 18, the movable iron core 16 and the body 15 is formed, and the movable iron core 16 slides by the suction force acting between the fixed iron core 18 and the fixed iron core 18 to displace the spool 22 of the valve body. . In this case, the annular protrusion 21 that moves back and forth in the recess 20
Thereby, the movable iron core 16 is easily attracted to the fixed iron core 18 from the initial position. Reference numeral 23 denotes a spring that biases the spool 22 to the initial position.

[0007]

However, in the former case, since the sectional area of the movable iron core 2 is restricted by the inner diameter of the pressure vessel 1, the suction area generated between the movable iron core 2 and the fixed iron core 3 is increased. If the force is increased, there is a problem that the pressure vessel 1 and the coil bobbin 6 must be increased in diameter. In addition, the movable iron core 2 is restricted by the length dimension that secures the amount of wrapping between the fixed iron core 3 and the guide tube portion 4 that sandwich the non-magnetic body 5, and the length dimension cannot be further reduced. That is, there is a problem that the improvement of responsiveness due to the weight reduction of the movable iron core 2 is limited.

In the latter case, the length dimension is not particularly restricted, but since the cross-sectional area of the movable iron core 16 is restricted by the inner diameter of the coil bobbin 19, the cross-sectional area is increased and the fixed iron core 18 is provided.
However, there is a problem that the diameter of the coil bobbin 19 has to be increased in order to increase the suction force. Since the annular projection 21 of the movable iron core 16 has no magnetic path forming portion,
There is also a problem that it is difficult to perform proportional control of fluid pressure and flow rate.

An object of the present invention is to solve such a problem.

[0010]

According to a first aspect of the invention, a fixed iron core and a movable iron core are coaxially arranged in an internal space of a body, and the movable iron core is slidably supported in an axial direction inside a body. Then, attach a bobbin wound with a coil around the outer circumference of the fixed iron core, project the fixed iron core from the coil bobbin to the movable iron core side, and project the fixed iron core to the fixed iron core side end of the movable iron core. An annular protrusion is formed that fits on the outer circumference of the end.

In the second invention, the magnetic path forming portion for controlling the flow of the magnetic flux is provided on the annular projection of the movable iron core in the first invention.

According to a third invention, in the first invention, a pressure partition wall is provided between the inner circumference of the body and the outer circumference of the fixed iron core to partition the coil bobbin side from the inner space of the body.

[0013]

According to the first aspect of the invention, when the coil is energized, a magnetic path passing through the fixed iron core, the movable iron core and the body is formed, and the movable iron is attracted to the movable iron core by the attraction force. The core slides. In this case, since the annular protrusion of the movable iron core is fitted to the outer circumference of the end protruding from the coil bobbin, the movable iron core is increased to approximately the same size as the outer diameter of the fixed iron core without changing the coil bobbin in order to increase the suction force. It is possible to increase the cross-sectional area of. Further, since the magnetic flux passes through the outer peripheral surface of the movable iron core and the inner peripheral surface of the body, the length of the movable iron core can be shortened without lowering the attraction force due to the increase in the magnetic path resistance. That is, responsiveness can be improved by reducing the weight of the movable iron core.

According to the second aspect of the invention, in the stroke range in which the annular projection of the movable iron core fits the outer periphery of the end of the fixed iron core, the magnetic path forming portion controls the flow of magnetic flux.
Even if the position of the movable iron core changes, the attractive force is kept substantially constant for a constant value of the coil current.

According to the third invention, since the coil bobbin is sealed from the internal space of the body by the pressure partition wall, it is possible to prevent leakage of liquid inside the body to the coil side and deformation of the coil due to liquid pressure.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing a solenoid of an electromagnetic valve for performing proportional control of pressure and flow rate of a fluid.
0 is formed into a cylindrical shape in which the inner diameter gradually decreases from the opening at one end toward the back, and the rod 3 described later is provided at the center of the bottom.
One bearing 32 is provided. Small part 3 behind the body 30
A movable iron core 34 is slidably accommodated in the body 3, and a fixed iron core 36 that coaxially projects with the movable iron core 34 is integrally formed on a cap 35 that closes the opening of the body 30.

A non-magnetic rod 31 penetrating the axis of the fixed iron core 36 is provided, and the rod 31 is a bearing 32 of the body 30.
And the bearing 3 in the shaft hole 37 of the fixed iron core 36, respectively.
It is slidably supported via 8. The movable iron core 34 is fixed at a predetermined position on the rod 31, and the small-diameter portion 33 of the body 30 is slid by the suction force generated between the movable iron core 34 and the fixed iron core 36. Communicate through. The body 30 is made of a magnetic material, and an appropriate gap is provided between the inner peripheral surface of the small diameter portion 33 and the outer peripheral surface of the movable iron core 34.

A bobbin 40 around which a coil is wound is fitted on the outer circumference of the fixed iron core 36, and is fixed between the step portion 41 on the inner circumference of the body 30 and the cap 35. The fixed iron core 36 is inserted inside the bobbin 40, and its end on the movable iron core 34 side is formed to have a length protruding from the bobbin 40 by a predetermined amount. The movable iron core 34 has a diameter larger than that of the fixed iron core 36.
An annular protrusion 42 fitted to the outer periphery of the end of the fixed iron core 36 protruding from 0 is provided, and a taper 43 is formed on the outer periphery of the tip of the annular protrusion 42 as a magnetic path forming portion for controlling the flow of magnetic flux.

The storage space 44 for the movable iron core 34 inside the body 30 is filled with a low-pressure or high-pressure liquid, and the fixed iron core 36
Is provided with a passage 45 communicating with both surfaces of the. Further, in order to allow the liquid flow accompanying the sliding of the movable iron core 34 and the rod 31, a passage 46 communicating with both surfaces of the movable iron core 34,
A passage 47 that opens inside the bearing 32 is formed in the storage space 44 on the movable iron core 34 side.

With such a configuration, the coil bobbin 40
When the power to the fixed iron core 3 is turned on, a magnetic path passing through the fixed iron core 36, the movable iron core 34 and the body 30 is formed.
The movable iron core 34 slides by the suction force acting between the valve body 6 and the valve body 6, and the valve body (not shown) is displaced via the rod 31. In the stroke range where the annular protrusion 42 of the movable iron core 34 is fitted to the outer periphery of the end of the fixed iron core 36, the taper 43 of the annular protrusion 42 controls the flow of magnetic flux, so that the movable iron core 3
Even if the position of 4 changes, the attraction force is kept substantially constant for a constant value of the coil current.

In this case, the fixed iron core 36 is projected from the bobbin 40 to the movable iron core 34 side, while the annular projection 42 fitted to the outer periphery of the end portion is formed on the movable iron core 34, so that the coil bobbin 40 is not changed. In addition, the outer diameter of the movable iron core 34 can be increased up to almost the same size as the outer diameter of the bobbin. In FIG. 1, the movable iron core 34 is larger than the inner diameter of the bobbin 40.
The outer diameter of is increased by the thickness of the annular protrusion 42.

As a result, the suction force acting between the fixed iron core 36 and the movable iron core 34 can be increased without increasing the diameter of the coil bobbin 40 and increasing the number of windings of the coil. Further, since the movable iron core 34 is housed in the small diameter portion 33 of the body 30 with an appropriate gap therebetween, and the magnetic flux passes through the outer peripheral surface thereof and the inner peripheral surface of the small diameter portion 33, the magnetic path resistance is increased. The length dimension of the movable iron core can be shortened without lowering the suction force. That is, the responsiveness can be improved by reducing the weight of the movable iron core 34.

FIG. 2 shows another embodiment, in which a pressure partition 48 for partitioning the storage space 44 for the movable iron core 34 inside the body 30 and the coil bobbin 40 side is provided. Pressure partition 4
Reference numeral 8 is formed of a non-magnetic material, and is interposed between the inner periphery of the body 30 and the outer periphery of the fixed iron core 36 such that these gaps are sealed by brazing or welding.

According to this, the storage space 4 for the movable iron core 34
Coil bobbin 40 from low-pressure or high-pressure liquid filling 4
Since the pressure partition wall 48 protects the side, it is possible to effectively prevent leakage of the liquid to the coil bobbin 40 side and deformation of the coil due to the pressure of the liquid to cause insulation failure. In addition, in the storage space 44 inside the body 30, an air bleeder 49 is provided for stabilizing the sliding of the movable iron core 34 to remove the mixing of air into the liquid.

The pressure partition wall 48 is fixed between the inner circumference of the body 30 and the outer circumference of the fixed iron core 36 by a fastening member such as a snap ring 50 as shown in FIG. May be. In that case, by forming the pressure partition wall 48 with a resin having an electrical insulating property, it is possible to eliminate the eddy current generated therein, and the suction force and the like can be favorably maintained. In order to fix the pressure partition wall 48 without the retaining ring 50, a small diameter portion 36a is formed at the end of the fixed iron core 36 projecting from the bobbin 40 in FIG. 4, and the pressure partition wall 48 has the stepped portion 36b and the body 30. And the stepped portion 52 of the.

FIG. 5 shows still another embodiment.
The projecting end of the fixed iron core 36 to the movable iron core 34 side is formed to have a large diameter, and the movable iron core 34 and the annular protrusion 42 are also enlarged accordingly. As a result, the suction force acting between the fixed iron core 36 and the movable iron core 34 can be further increased as compared with the case of FIG. 1 without increasing the size of the coil bobbin 40.

As the magnetic path forming portion of the annular protrusion 42,
Forming the stepped portion 53 as shown in FIG. 6 or the groove 5 as shown in FIG.
4 may be formed. With these, the annular protrusion 4
In the stroke range where 2 is fitted to the fixed iron core 36,
As with the taper 43, even if the position of the movable iron core 34 changes,
Necessary characteristics can be obtained such that the attractive force is kept almost constant with respect to the constant value of the coil current.

The cross-sectional shape of the groove 54 may be a substantially semicircular shape, U-shape, triangular shape or quadrangular shape. In addition, the outer circumference of the tip of the annular protrusion 42 may be tapered 43 or the step 5 as necessary.
3 and the groove 54 having an appropriate sectional shape may be formed together. 2 to 7, the same parts as those in FIG. 1 are designated by the same reference numerals.

[0029]

According to the first aspect of the invention, the fixed iron core and the movable iron core are coaxially arranged in the internal space of the body, and the movable iron core is slidably supported in the body inner circumference in the axial direction. A bobbin wound with a coil is fitted around the outer circumference of the fixed iron core so that the fixed iron core projects from the coil bobbin to the movable iron core side, while the end of the fixed iron core protruding from the fixed iron core side end of the movable iron core. Since the annular projection fitted to the outer periphery is formed, the suction force acting between the fixed iron core and the movable iron core can be effectively increased without increasing the diameter of the coil bobbin and increasing the number of windings of the coil.

According to the second invention, since the magnetic path forming portion for controlling the flow of the magnetic flux is provided on the annular projection of the movable iron core in the first invention, the annular projection of the movable iron core has the end of the fixed iron core. In the stroke range fitted to the outer circumference of the part, even if the position of the movable iron core changes, the magnetic path forming part can keep the attraction force substantially constant with respect to the constant value of the coil current. Third
According to the invention, in the first invention, since the pressure partition wall that partitions the coil bobbin side from the inner space of the body between the inner periphery of the body and the outer periphery of the fixed iron core is provided, the coil bobbin is the pressure partition wall and the interior of the body. Since it is sealed from the space, it is possible to prevent leakage of liquid inside the body to the coil side and deformation of the coil due to liquid pressure.

[Brief description of drawings]

FIG. 1 is a sectional view of a solenoid for explaining an embodiment of the present invention.

FIG. 2 is a sectional view of a solenoid of the same.

FIG. 3 is a sectional view of the solenoid.

FIG. 4 is a sectional view of the solenoid.

FIG. 5 is a sectional view of the solenoid.

FIG. 6 is a sectional view of the solenoid of the same.

FIG. 7 is a sectional view of the solenoid.

FIG. 8 is a sectional view of a solenoid for explaining a conventional example.

FIG. 9 is a sectional view of the solenoid of the same.

[Explanation of symbols]

 30 body 31 non-magnetic rod 33 small diameter part of body 34 movable iron core 36 fixed iron core 40 coil bobbin 42 annular protrusion 43 taper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taro Matsumae 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (72) Inventor Jun Inoue 2-chome, Hamamatsucho, Minato-ku, Tokyo No. 4-1 World Trade Center Building Kayaba Industry Co., Ltd.

Claims (3)

[Claims] 1. A fixed iron core and a movable iron core are coaxially arranged in the internal space of the body, the movable iron core is supported in the inner circumference of the body so as to be freely slidable in the axial direction, and a coil is provided on the outer circumference of the fixed iron core. Fit the wound bobbin to project the fixed iron core from the coil bobbin to the movable iron core side, and at the end of the movable iron core on the fixed iron core side, an annular protrusion that fits on the outer periphery of the protruding end of the fixed iron core. A solenoid characterized by being formed. 2. The solenoid according to claim 1, wherein a magnetic path forming portion for controlling the flow of magnetic flux is provided on the annular protrusion of the movable iron core. 3. The solenoid according to claim 1, wherein a pressure partition wall is provided between the inner circumference of the body and the outer circumference of the fixed iron core to partition the coil bobbin side from the inner space of the body.