JP2000130632A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power of a solenoid by filling a magnetic fluid into a clearance between a magnetic plate having a hollow part, which is a part of a magnetic frame surrounding a coil of a solenoid part opening and closing a valve seat by driving a valve member and in which a movable iron core is inserted, and the movable iron core. SOLUTION: When a coil 9 is not excited, a movable iron core 3 lowers, a supply valve member 24 closes a supply valve seat 21, and a discharge valve member 26 opens a discharge valve seat 22 to communicate an output port A and a discharge port R mutually. When the coil 9 is excited in this condition, the movable iron core 3 is attracted to a fixed iron core 4, the supply valve member 24 opens the supply valve seat 21, and the discharge valve member 26 closes the discharge valve seat 22 to communicate an input port P and an output port A mutually. At this time, since magnetic fluid 7 is filled into a clearance between a magnetic plate 6 and the movable iron core 3, the viscosity of the magnetic fluid 7 increases, and a speed at which the movable iron core 3 is attracted to the fixed iron core 4 is reduced when the coil 9 is excited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve for switching a flow path by using a solenoid.

[0002]

2. Description of the Related Art In general, a solenoid valve for switching a flow path by a solenoid generally has a valve member for opening and closing a valve seat in a fluid flow path, which is held by a movable iron core of the solenoid.
When the coil is energized, the movable core is attracted to the fixed core to drive the valve member, and when the energization is released, the movable core is separated from the fixed core by the force of the return spring to return the valve member and the flow path is closed. It is configured to perform switching. In such a solenoid valve, when the movable iron core is attracted to the fixed iron core, the two iron cores collide violently at high speed, so that the attracting surfaces of these two iron cores are easily worn, and the movable iron core and the fixed iron core collide with each other. There is a problem in that a loud collision sound is emitted. Also,
The movable iron core is normally slidably inserted into an iron core hole provided in a solenoid coil, and a part of the iron core hole is a part of a magnetic frame provided so as to surround the coil. Is formed by a hollow portion of a metal magnetic plate, but a small gap between the movable iron core and the magnetic plate becomes a gap of a magnetic path and a magnetic resistance is increased. For this purpose, it is effective to reduce the magnetic resistance.

[0003]

SUMMARY OF THE INVENTION The technical problem of the present invention is to provide a solenoid valve in which a flow path is switched by a solenoid. It is an object of the present invention to provide an electromagnetic valve capable of suppressing the adsorption speed of the electromagnetic valve. Another technical object of the present invention is to provide a solenoid valve capable of reducing magnetic resistance caused by a gap in a magnetic path between the movable iron core and a magnetic plate, thereby saving power of a solenoid.

[0004]

In order to solve the above-mentioned problems, a solenoid valve of the present invention comprises a plurality of ports through which compressed fluid flows in or out, a valve seat provided in a flow path connecting the ports, and A valve member that opens and closes the valve seat, and a solenoid portion that opens and closes the valve seat by driving the valve member with a movable iron core, wherein the solenoid portion fixes a fixed iron core to an iron core hole in the coil, A magnetic plate, which is slidably fitted with the movable core adsorbed on the fixed core in the core hole, is a part of a magnetic frame surrounding the coil, and has a hollow portion through which the movable core is inserted, and the movable core. The magnetic gap is filled with a magnetic fluid, and the magnetic frame has magnetism necessary for holding the magnetic fluid.

In the solenoid valve having the above structure, when a coil is energized, the movable iron core is attracted to the fixed iron core, and the valve member is driven.
When the energization is released, the movable core separates from the fixed core, and the valve member returns. In this case, since the magnetic fluid is filled in the gap between the magnetic plate and the movable iron core, the magnetic fluid sharply increases its viscosity by the magnetic field excited by the coil during energization, so that the magnetic core has a magnetic fluid. The adsorption speed to the fixed core is suppressed, and as a result, severe collision with the fixed core is prevented,
It is possible to suppress wear of the suction surface between the two iron cores and collision noise. In addition, the magnetic fluid eliminates the gap in the magnetic path between the movable iron core and the magnetic plate, and greatly reduces the magnetic resistance therebetween, so that the power consumption of the solenoid can be reduced.

In the present invention, the magnetism imparted to the magnetic frame can be imparted by attaching permanent magnets to both ends of the magnetic plate, and the magnetic plate and / or the movable core are formed of a hard or semi-hard magnetic material. However, the magnetism provided to the magnetic frame can be provided by the residual magnetism.
Thus, the magnetic fluid can be reliably held in the gap between the movable iron core and the magnetic plate.

[0007]

FIG. 1 shows an embodiment of a solenoid valve according to the present invention. The solenoid valve of this embodiment has a valve section 2 for switching a fluid flow path by a valve member, and energization of a coil 9. And a solenoid 1 for operating the valve member. The valve section 2 has a valve body 20. The valve body 20 has an input port P connected to a supply source of compressed air, an output port A connected to an actuator such as an air cylinder, and the like. An exhaust port R that is exhausted to the outside is provided.

An input port P is provided inside the valve body 20.
A supply valve seat 21 is provided in a flow path connecting the output port A and the output port A via a communication hole 29, and a discharge valve seat 22 is provided in a flow path connecting the output port A and the discharge port R on the same axis. They are arranged in opposite directions. Further, a supply valve member 24 for opening and closing the supply valve seat 21 is provided in a supply valve chamber 23 in which the supply valve seat 21 is opened while being held by the movable iron core 3 of the solenoid 1, and a discharge valve is provided. Seat 22
Is opened, a discharge valve member 26 for opening and closing the discharge valve seat 22 is urged in a direction to close the discharge valve seat 22 by a valve spring 28 contracted between the discharge valve member 22 and a spring seat 27. It is arranged in the state where it was done.

A pressure rod 30 that does not hinder the flow of fluid is inserted into the communication hole 29, and the lower end of the pressure rod 30 is connected to the upper surface of a cap-shaped pressure member 31 mounted on the discharge valve member 26. On the other hand, the upper end of the pressing rod 30 is in contact with the lower surface of the cap 15 attached to the lower end of the movable core 3 of the solenoid 1. When the movable iron core 3 descends and the supply valve member 24 is
Is closed by the movable iron core 3, whereby the discharge valve member 26 is pressed down to release the discharge valve seat 2.
When the movable iron core 3 moves upward and the supply valve member 24 opens the supply valve seat 21,
The pressing of the discharge valve member 26 is released, and the discharge valve member 22 is moved upward by the bias of the valve spring 28 to close the discharge valve seat 22.

The solenoid 1 includes a coil 9 formed by winding a conductive wire around a bobbin 17, a magnetic frame 5 surrounding the coil 9, and a core hole 1 provided in the bobbin 17 with the coil 9.
0 fixed iron core 4 fixed to one end of abutment and abutted on magnetic frame 5
The movable core 3 slidably inserted into the core hole 10, and a return spring 12 for urging the movable core 3 in a direction away from the fixed core 4. The above iron core hole 10
The magnetic plate 6 is disposed so as to contact the hole in the bobbin 17 and the end face of the bobbin 17 as a part of the magnetic frame 5.
The fixed core 4 is fixed to the upper end of the core hole 10, and the movable iron core 18 is inserted below the fixed core 4.

The movable iron core 3 has a recess 3a at the lower end surface thereof. The supply valve member 24 and a valve spring 16 for urging the supply valve member 24 in a direction protruding from the recess 3a are provided in the recess 3a. Is accommodated, and the supply valve member 24 is
The cap 15 made of an elastic material such as a synthetic resin is attached to the small-diameter portion 3b at the lower end of the movable iron core 3 in order to prevent the movable iron core 3 from jumping out.

The cap 15 is inserted into the hollow portion 6a of the magnetic plate 6 so that the movable iron core 3 can slide in the iron core hole 10 without swinging. A guide cylinder 15a having an outer diameter slightly smaller than the diameter is provided to guide the sliding direction of the movable iron core 3 in the hollow portion 6a. This prevents mutual contact between the movable iron core 3 and the magnetic plate 6, so that the movable iron core 3 can be operated stably without being interfered by the magnetic plate 6.

As shown in detail in FIG. 2, the gap between the magnetic plate 6 and the movable core 3 in the hollow portion 6a of the magnetic plate 6 is substantially equal on the peripheral surface of the movable core 3. The gap is filled with the magnetic fluid 7. However, the inner wall of the core hole 10 in the hollow portion 6a of the magnetic plate 6 and the bobbin 17 has
Flow paths 8a and 8b are provided for allowing compressed air to flow from the supply valve chamber 23 into and out of the space 13 between the movable core 3 and the fixed core 4 to balance the air pressure acting on both ends of the movable core 3. . The flow passages 8a and 8b can be provided on the peripheral surface of the movable iron core 3 and other arbitrary portions. The magnetic fluid 7 is prepared by, for example, mixing iron powder with oil or another liquid, and has a viscosity that rises rapidly due to the action of a magnetic field.

At both ends of the magnetic plate 6, the magnetic fluid 5 is applied to the magnetic frame 5 in order to prevent the magnetic fluid 7 from leaking from a gap or flowing out into the supply valve chamber 23 through the flow passage 8 a. A permanent magnet 14 for providing magnetism necessary for holding the fluid 7 is attached, and the magnetic fluid 7 is securely held in the gap by the surface tension of the fluid 7 itself and the magnetism of the permanent magnet 14. Has become.

In the solenoid valve having the above structure, when the coil 9 is de-energized, the movable iron core 3 descends as shown in the left half of FIG. The supply valve seat 21 is closed and the pressing member 31 is closed.
The discharge valve member 21 pressed by the button opens the discharge valve seat 22,
The output port A and the discharge port R communicate with each other. When the coil 9 is energized, the movable iron core 3 is attracted to the fixed iron core 4 against the biasing force of the return spring 12 as shown in the right half of FIG. At the same time as opening 21, the discharge valve member 26 closes the discharge valve seat 22 by the urging force of the valve spring 28, and the input port P and the output port A communicate with each other.

In this case, since the magnetic fluid 7 is filled in the gap between the magnetic plate 6 and the movable core 3, when the coil 9 is energized, the magnetic fluid 7 is excited by the magnetic field excited by the coil 9. The viscosity is sharply increased, and the speed of adsorption of the movable core 3 to the fixed core 4 is reduced.
And the fixed iron core 4 can be prevented from violently colliding with each other, so that mutual attraction surfaces can be worn out and collision noise can be suppressed. Therefore, the solenoid valve having this configuration is suitable for use in equipment used in a quiet environment such as a medical facility.

The gap between the movable core 3 and the magnetic plate 6 is filled with the magnetic fluid 7 so that the movable core 3
Since there is no gap in the magnetic path between the magnetic plate 6 and the magnetic plate 6 and the magnetic resistance at this portion is significantly reduced, power saving of the solenoid 1 can be achieved.

In the above embodiment, the magnetism given to the magnetic frame 5 is provided by attaching permanent magnets 14 to both ends of the magnetic plate 6. For example, the magnetic plate 6 and / or the movable core 3 may be formed of a hard or semi-hard magnetic material.
The magnetism given to the magnetic frame 5 can be given by the residual magnetism, and such a magnetic material and a permanent magnet may be used in combination.

In the above embodiment, a three-port valve is used.
The solenoid valve of the present invention is not limited to this, but may be any valve having a plurality of ports.

[0020]

As described above in detail, according to the solenoid valve of the present invention, the gap between the magnetic plate and the movable iron core is filled with the magnetic fluid, so that the magnetic fluid is excited by the coil when energized. Since the viscosity is rapidly increased by the applied magnetic field, the adsorption speed of the movable iron core to the fixed iron core is reduced, and as a result, a violent collision with the fixed iron core is prevented. The sound is suppressed. Further, the magnetic fluid eliminates the gap in the magnetic path between the movable iron core and the magnetic plate, and the magnetic resistance at that portion is significantly reduced, so that the power consumption of the solenoid can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing one embodiment of a solenoid valve of the present invention. However, the right half shows when the coil is energized, and the left half shows when the coil is not energized.

FIG. 2 is an enlarged sectional view of a main part taken along line BB of FIG.

[Explanation of symbols]

 Reference Signs List 1 solenoid 3 movable iron core 4 fixed iron core 5 magnetic frame 6 magnetic plate 6a hollow portion 7 magnetic fluid 9 coil 10 iron core hole 13 space 14 permanent magnet

Continued on the front page F term (reference) 3H106 DA08 DA23 DB02 DB12 DB23 DB32 DC09 DD07 EE19 EE20 EE22 GA11 GA25 GA30 KK04 KK12

Claims (3)

[Claims] A plurality of ports through which compressed fluid flows in and out; a valve seat provided in a flow path connecting the ports;
A valve member that opens and closes the valve seat, and a solenoid portion that opens and closes the valve seat by driving the valve member with a movable iron core, wherein the solenoid portion fixes a fixed iron core to an iron core hole in the coil, A magnetic plate, which is slidably fitted with the movable core adsorbed on the fixed core in the core hole, is a part of a magnetic frame surrounding the coil, and has a hollow portion through which the movable core is inserted, and the movable core. The magnetic valve is filled with a magnetic fluid in the gap between them, and the magnetic frame has magnetism necessary for holding the magnetic fluid. 2. The solenoid valve according to claim 1, wherein the magnetism imparted to the magnetic frame is provided by attaching permanent magnets to both ends of the magnetic plate. 3. The solenoid valve according to claim 1, wherein
The magnetic plate and / or the movable core are formed of a hard or semi-hard magnetic material, and the magnetism imparted to the magnetic frame is given by the residual magnetism.