JP2003166663A - Electromagnetic valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution having little affect on an electromagnetic circuit, capable of assuring electromagnetic properties even when the number of components is decreased. <P>SOLUTION: Holes are axially formed at a plunger, and a part of a yoke opposing to the holes is made of a nonmagnetic member. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solenoid valve.

[0002]

2. Description of the Related Art As a conventional technique, for example, Japanese Patent Laid-Open No.
There is a publication of 122412. This solenoid valve consists of a core (fixed iron core) with a coil mounted on the outer circumference, a sleeve fixed to the yoke via a housing and having a port, and a plunger (movable An iron core), a spool slidably arranged on the inner circumference of the sleeve to open and close the port, and a spring for urging the spool.

This solenoid valve has a structure in which a plunger is supported by a yoke and a spool is supported by a sleeve so as to be independently slidable. The plunger and the spool are biased by a spring arranged in the spool, and the spring biases the plunger toward the plunger to bring the end surface of the spool into contact with the end surface of the plunger. This solenoid valve excites a coil to generate a force due to the magnetic flux acting on the plunger, and slides the plunger with respect to the yoke to slide the spool, the end face of which is opposed to the spool, with respect to the sleeve. The sleeve port is opened and closed by moving it.

[0004]

However, in the solenoid valve of the above-mentioned conventional apparatus, the plunger is supported by the yoke and the spool is supported by the sleeve independently of each other, so that the end face of the plunger and the spool are independently supported. In order to dispose the end face and the end face so as to contact each other, for example, the plunger and the spool are slidable on the yoke and the sleeve, respectively, with a high dimensional accuracy so that the plunger and the spool are in the proper positions on the same axis. Must support. Therefore, in the solenoid valve described above, the shaft serving as the shaft of the plunger is held by the bearing member, which complicates the component structure and invites an increase in cost. Further, when the plunger slides, the magnetic transfer portion facing the plunger has no groove for allowing the fluid to escape, which may hinder the operation of the plunger.

Therefore, it is a technical object of the present invention to provide a structure that does not easily affect the electromagnetic circuit so that the above-mentioned inconvenience is not caused and that the electromagnetic characteristics can be secured even if the number of components is reduced.

[0006]

In order to solve the above-mentioned technical problems, the invention of claim 1 has a sleeve having a substantially cylindrical shape and having a plurality of openings, and a sleeve substantially coaxial with the sleeve. A spool mounted on the inner circumference of the sleeve, a plunger joined to the spool substantially coaxially, and a bobbin around which a coil is wound are arranged and joined to the outer circumference of the plunger coaxially with the sleeve. In the electromagnetic valve having a yoke, the plunger has a hole formed in the axial direction, and a part of the yoke facing the hole is a non-magnetic member.

The moving passage of the fluid existing in the gap between the plunger and the inner peripheral surface of the yoke is arranged in the central portion of the shaft of the plunger, which has little influence on the magnetic characteristics, so that the flow passage with less loss of the magnetic characteristics is formed. Can be configured. Further, in order to prevent the plunger from being attracted to the yoke and being prevented from being separated when the plunger moves within the shaft, the central portion of the shaft of the concave portion of the yoke is formed of a non-magnetic member. Since the yoke is composed of one integrated component, complicated assembly is unnecessary.

Preferably, at the tip of the other end of the plunger which is not joined to the spool, a relief groove or an escape groove is formed at right angles to a hole formed in the axial direction of the plunger. Let it be a solenoid valve with a hole formed.

When the plunger moves on the shaft on the inner circumference of the yoke, the fluid filled in the gap between the yoke and the plunger hinders the movement of the plunger. Therefore, by forming an escape groove or hole in contact with a hole formed in the axial direction of the plunger, when the plunger slides, the surrounding fluid can be escaped, so that the turbulent flow of the internal fluid is suppressed. ,
A given valve movement can be achieved.

Further, as described in claim 3, the non-magnetic member of the yoke is an electromagnetic valve formed by a partial reforming method or a metal powder injection method using a different material.

In order to integrally form a single component by mixing a magnetic member and a non-magnetic member, the yoke is processed by a partial reforming method or a metal powder or resin injection method using a different material. As described above, since the yoke can be configured as one component, the number of assembling steps can be reduced, and the electromagnetic portion can be configured with a smaller number of components than in the past, so that work mistakes can be reduced and product quality can be improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a solenoid valve of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, a solenoid valve 1 includes a control valve portion 4 mainly composed of a sleeve 2 and a spool 3, a coil 5, a yoke 6, a part of which is made of a non-magnetic material, and a magnetic valve. A plunger 7 made of a material is mainly configured, and an electromagnetic portion 9 housed in a case 8 is configured.

The sleeve 2 has a cylindrical shape with both ends open, and a plurality of opening holes 21 are formed in its peripheral wall. The spool 3 has a columnar shape with a plurality of lands 31 formed therein, and is coupled to a plunger 7 described later in a substantially coaxial manner. The spool 3 is located substantially coaxially within the sleeve 2 and is slidably instructed by the sleeve 2. The spool 3 moves in the axial direction thereof and the land 31 of the spool 3 causes the port 2 to move.
Open and close 1. The coil 5 is wound around the outer circumference of a cylindrical bobbin 51, and the yoke 6 is arranged on the inner circumference of the bobbin 5. The yoke 6 is composed of a front yoke portion and a rear yoke portion, each of which is a non-magnetic portion 6 of the front yoke portion.
1 and the magnetic portion 62 of the front yoke portion, the non-magnetic portion 63 of the rear yoke portion, and the magnetic portion 64 of the rear yoke portion. The nonmagnetic parts 61 and 63 of the yoke 3 are partially reformed by equipping the magnetic part with nickel chrome by a laser or by kneading nonmagnetic stainless powder with a binder and using a metal powder injection molding device. It is molded and processed, and is integrated into one component. At this time, the metal powder to be used may be selected from non-magnetic metal powder such as aluminum and copper in addition to the above. Depending on the characteristics of the product, a resin member may be used for part of this non-magnetic portion. The yoke 6 has a cylindrical shape so that an inner peripheral surface having a portion to which the sleeve 2 is fixed and a portion for exchanging magnetic flux with the plunger 7 is formed.
The boundary between the magnetic portion 62 of the front yoke portion and the non-magnetic portion 63 of the rear yoke portion is tapered. The collar portion of the yoke 6 is coupled to the sleeve 2 substantially coaxially. A spring 10 is arranged between the inner peripheral surface of the magnetic portion 62 of the rear yoke portion of the yoke 6 and the plunger 7, and the plunger 7 and the spool 3 receive the biasing force of the spring 10 and are shown in FIG. Always biased in the direction. The plunger 7 is coupled to the spool 3 substantially coaxially as described above.

Next, the operation will be described.

When the coil 5 is excited in the state of FIG. 1, a magnetic flux is generated on the yoke 6 and the plunger 7. As a result, the plunger 7 slides against the yoke 6 in the right direction in FIG. 1 against the biasing force of the spring 10. By this operation, the land 31 of the spool 3 connected to the plunger 7 opens and closes the port 21 of the sleeve 2. At this time, by increasing or decreasing the current value supplied to the coil 5 to change the magnetic flux acting on the plunger 7, the spool 3 becomes
The spring 10 slides with a stroke according to the load-deflection characteristics. As described above, the fluid is controlled by linearly controlling the relative position of the spool 3 with respect to the sleeve 2. In the above operation, for example, when the plunger 7 slides rightward in FIG. 1, the fluid existing in the recessed portion in the central portion of the yoke 6 moves from the relief groove 71 formed at the tip of the plunger 7 to the fluid of the plunger 7. It flows in the direction of the valve portion 4 along the flow path 11 formed in the shaft.

2 and 3 show another embodiment of the present invention.

FIG. 2 shows another embodiment in which the convex portion of the plunger 7 is eliminated. The non-magnetic portion 61 of the front yoke portion of the yoke 6 is formed on the recessed surface of the outer periphery of the spring 10. By configuring the electromagnetic part in this way, the plunger 7
The shape of can be simplified.

Further, as shown in FIG. 3, the non-magnetic portion 61 of the front yoke portion of the yoke 6 is formed with a fluid escape groove 12 in a cylindrical head portion as shown in FIG. At the same time, the peripheral portion of the escape groove 12 is made of a non-magnetic member. With the above configuration, the plunger 7 can adopt a simple shape as shown in FIG. 2, and at the same time, the same performance as in FIG. 1 can be achieved.

[0019]

As described above, according to the present invention, the flow path that serves as a magnetic gap is not formed between the yoke 6 and the plunger 7 that form the magnetic circuit, and the shaft of the plunger 7 is less affected by the magnetic characteristics. By providing a flow path in the center,
The area on the magnetic circuit can be expanded, and as a result, the attraction force for moving the plunger 7 can be improved with the same coil specifications. Further, a yoke composed of a non-magnetic material is used at the center of the yoke shaft. Since the yoke is composed of one integrated part, complicated assembling is unnecessary, and the number of working steps can be reduced, which is very effective.

[Brief description of drawings]

FIG. 1 is a sectional view of a solenoid valve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view corresponding to FIG. 1 showing a first modification of the solenoid valve according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view corresponding to FIG. 1, showing a second modification of the solenoid valve according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a magnetic portion and a non-magnetic portion of a yoke 6 according to the embodiment of the present invention.

FIG. 5 is an enlarged perspective view of a relief groove 12 provided in a central portion of a shaft of a yoke according to another embodiment of the present invention.

[Explanation of symbols] 1: Solenoid valve 2: Sleeve 3: Spool 4: Control valve section 5: coil 6: York 61: Non-magnetic part of front yoke 62: Magnetic part of front yoke 63: Non-magnetic part of rear yoke 64: Magnetic part of rear yoke 7: Plunger 9: Electromagnetic part 10: Spring 11: flow path 12: escape groove

Claims (3)

[Claims] 1. A sleeve having a substantially cylindrical shape and having a plurality of openings, a spool mounted on the inner circumference of the sleeve substantially coaxially with the sleeve, and a plunger joined substantially coaxially to the spool. And a yoke having a bobbin around which a coil is wound, and a yoke joined to the outer periphery of the plunger coaxially with the sleeve, wherein the plunger is formed with a hole in the axial direction and the hole is formed. A part of the yoke facing the electromagnetic valve is made of a non-magnetic member. 2. A relief groove or hole is formed at a tip end portion of the other end of the plunger which is not joined to the spool, at right angles to a hole formed in the axial direction of the plunger. The solenoid valve according to claim 1. 3. The solenoid valve according to claim 1, wherein the non-magnetic member of the yoke is formed by a method of partial modification or a metal powder injection method of different materials.