JPH11230398A - Solenoid-operated pilot valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widely open and close a main valve with the use of a small-sized solenoid coil having a low energizing current. SOLUTION: In a solenoid-operated pilot valve 10 in which a pilot hole 11 is opened/closed from a pressure regulating chamber 9 side by means of a pilot valve 10 coupled to a moving iron core 21 which is attracted to a stator core 23 by a magnetic force generated from a magnetic coil 24, and accordingly, a main valve 6 is opened and closed through the pilot operation, the stator core 23 is arranged so as to extend and retract in a same direction as the moving iron core 21, and inter-core space holding means 26, 30 for holding the space between the stator core 23 and the moving iron core 21 at a predetermined distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid driven pilot valve in which a pilot hole formed in a main valve is opened and closed by a pilot valve connected to a solenoid so that the main valve is opened and closed by a pilot operation.

[0002]

2. Description of the Related Art A solenoid-operated pilot valve generally has
A main valve is disposed facing a high pressure side on a valve seat formed in a communication passage between the high pressure side flow path and the low pressure side flow path, and a control valve formed at a position corresponding to the back side of the main valve when viewed from the valve seat. The pressure chamber communicates with the low pressure side flow path through a pilot hole formed in the main valve and communicates with the high pressure side flow path through a leak path, and the movable iron core is driven in the axial direction by magnetic force generated from an electromagnetic coil. The pilot hole is opened and closed from the pressure regulation chamber side by the connected pilot valve, and the main valve is opened and closed by the pilot operation.

[0003]

In the above-described solenoid-operated pilot valve, if the main valve is opened by, for example, 5 mm from the valve seat in the open state, the pilot valve moves in the same direction as the main valve. Also needs to be advanced or retracted by 5 mm or more. Therefore, the movable iron core connected to the pilot valve is at least 5 mm away from the fixed iron core when the solenoid is off.

When the solenoid is turned on, the movable iron core is attracted to the fixed iron core by the electromagnetic force. At this time, the electromagnetic force required to move the movable iron core is the square of the distance between the two iron cores. In order to increase the opening of the main valve, it is necessary to supply a large current using an extremely large electromagnetic coil.

Accordingly, an object of the present invention is to provide a solenoid-operated pilot valve that can open and close a main valve largely by using a small electromagnetic coil having a small energizing current.

[0006]

In order to achieve the above object, a solenoid-operated pilot valve according to the present invention includes a valve seat formed in a communication passage between a high pressure side flow path and a low pressure side flow path. The main valve is disposed so as to be able to move forward and backward from the main valve, and a pressure regulation chamber formed on the back side of the main valve when viewed from the valve seat is connected to the low pressure side flow path side through a pilot hole formed in the main valve. The pilot hole is opened and closed from the pressure regulation chamber side by a pilot valve connected to the movable iron core which communicates with the high pressure side flow path side through the leak path and is attracted to the fixed iron core by the magnetic force generated from the electromagnetic coil. In the solenoid-operated pilot valve, wherein the main valve is driven to open and close by a pilot operation, the fixed iron core is arranged so as to be able to advance and retreat in the same direction as the movable iron core, and the electromagnetic coil is Characterized by providing an iron core distance holding means for holding the distance between the fixed core and the movable iron core at predetermined intervals when no power is supplied to.

The fixed iron core is disposed behind the movable iron core as viewed from the main valve, and the iron core interval holding means urges the fixed iron core toward the main valve. And a spacing member interposed between the fixed iron core and the main valve.

Alternatively, the movable iron core is disposed behind the fixed iron core as viewed from the main valve, and the fixed iron core is integrally connected to the main valve, and passes through the fixed iron core. The pilot hole is formed, and in the iron core interval holding means, when the interval between the fixed iron core and the movable iron core is smaller than the predetermined interval, the distance between the fixed iron core and the movable iron core is reduced. May be provided to act in the direction of increasing the distance between the two.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a closed state of a normally-closed type solenoid-operated pilot valve to which the present invention is applied, and a high-pressure side flow path 2 to which an upstream fluid pipe to which fluid is sent is connected; Is formed in the block body 1 so as to intersect at a right angle with the low pressure side flow path 3 to which the downstream fluid pipe to which the fluid is fed is connected.

A communication passage 4 formed at an intermediate portion between the high-pressure passage 2 and the low-pressure passage 3 communicates with the inner wall surface of the low-pressure passage 3 in a short cylinder. A valve seat 5 having a protruding shape is formed.

A main valve 6, which is arranged to face the valve seat 5 from the upstream side, is mounted so as to close a bottom surface of a main valve holding cylinder 7 arranged in the communication passage 4 portion. The main valve holding cylinder 7 is fitted in a cylinder hole 13 formed in the block body 1 so as to be able to advance and retreat in the axial direction. When the main valve holding cylinder 7 advances and retreats, the main valve 6 moves with respect to the valve seat 5. Contact.

An annular seal member 8 for movement is mounted on the outer peripheral surface of the main valve holding cylinder 7. The communication passage 4 is provided by the main valve holding cylinder 7 at a position corresponding to the back side of the main valve 6 when viewed from the valve seat 5. And a pressure regulating chamber 9 partitioned between the two.

However, the pressure regulating chamber 9 communicates with the low-pressure side flow path 3 through a pilot hole 11 penetrated through the center position of the main valve 6 and holds the main valve with a much smaller diameter than the pilot hole 11. Through a leak hole 12 formed on the side surface of the cylinder 7,
The pressure regulation chamber 9 communicates with the high pressure side flow path 2 side.

The outer diameter of the main valve holding cylinder 7 (that is, the inner diameter of the cylinder hole 12) is formed to be larger than the diameter of the valve seat 5, so that the main valve holding cylinder 7 receives the pressure from the fluid. The area is larger than the inner area of the valve seat 5. Therefore, when the pressure in the pressure regulating chamber 9 is the same as that in the low-pressure side flow path 3,
The pressure in the high-pressure side channel 2 acts to move the main valve holding cylinder 7 in a direction away from the valve seat 5.

A pilot valve 10 for opening and closing the pilot hole 11 is connected to a movable iron core 21 of a solenoid 20 in the pressure adjustment chamber 9. In this embodiment, the pilot valve 10 is
It is integrally formed by itself.

Reference numeral 17 denotes a pedestal made of a nonmagnetic material to which a solenoid 20 is attached, and the pressure regulating chamber 9 is completely sealed from the outside by O-rings 18 and 19 attached to the pedestal for fixing. Have been.

The movable iron core 21 is inserted into a sleeve 22 arranged so that its axis coincides with the main valve 6 so as to be able to advance and retreat in the axial direction, and is generated from an electromagnetic coil 24 arranged around the sleeve 22. It moves in the axial direction by the applied electromagnetic force. Reference numerals 25 and 28 denote yokes made of a magnetic material such as iron.

At a position behind the movable iron core 21 as viewed from the main valve 6, a fixed iron core 23 is disposed by being inserted into a sleeve 22. However, this fixed iron core 23 is
, And is fitted in the sleeve 22 so as to be able to advance and retreat in the axial direction.

A rod 3 is provided between the fixed iron core 23 and the main valve 6.
0 (interval holding member) is sandwiched between the fixed iron core 23
Is biased in a direction approaching the main valve 6 by a first coil spring 26 disposed in the sleeve 22.

As a result, the rod 30 is sandwiched between the fixed iron core 23 and the main valve 6 by the urging force of the first coil spring 26, and the distance between the fixed iron core 23 and the main valve 6 is increased. It is always kept constant. Therefore, the fixed iron core 23
Is substantially fixed to the main valve 6 and does not move by the electromagnetic force generated from the electromagnetic coil 24.

The rod 30 is shown in FIG.
As shown in FIG.
In the two grooves formed symmetrically, they are arranged so as to be able to advance and retreat in the axial direction, respectively.

Between the fixed iron core 23 and the movable iron core 21,
When the electromagnetic coil 24 is in the off state, the movable iron core 21 is pressed against the main valve 6 to close the pilot hole 11.
Are disposed. The urging force of the second coil spring 27 is weaker than the urging force of the first coil spring 26, and does not affect the operation of the fixed iron core 23.

FIG. 1 shows a state in which the solenoid-operated pilot valve configured as described above is not energized to the electromagnetic coil 24, and the pilot valve 10 is mainly driven by the urging force of the second coil spring 27. It is pressed against the valve 6 to close the pilot hole 11.

Therefore, the inside of the pressure regulating chamber 9 is communicated with the high pressure side flow path 2 through the leak hole 12 and is at a high pressure, and the difference between the pressure in the pressure regulating chamber 9 and the pressure in the low pressure side flow path 3 is maintained. Due to the pressure, the main valve 6 is firmly pressed against the valve seat 5 and is in a closed state.

Then, when the electromagnetic coil 24 is energized, as shown in FIG. 3, the movable iron core 21 is attracted to the fixed iron core 23 by the electromagnetic force generated by the electromagnetic coil 24, and the second coil spring 27 is moved. The pilot valve 10 is separated from the main valve 6 so that the pilot hole 11 is opened.

Then, the inside of the pressure regulating chamber 9 communicates with the low pressure side flow path 3 through the pilot hole 11 to reduce the pressure, so that the pressure acting on the main valve holding cylinder 7 on the high pressure side flow path 2 side and the pressure regulating chamber The main valve holding cylinder 7 moves in a direction in which the main valve 6 moves away from the valve seat 5 as shown in FIG.

Then, the fixed iron core 23 is pushed via the rod 30, and the main valve 6, the rod 30 and the second coil spring are kept in a state where the movable iron core 21 is attracted to the fixed iron core 23. 27 move together with the first coil spring 26 in the direction of compressing and contracting, and the main valve 6 is stopped in an open state largely separated from the valve seat 5.

In such an open state, the electromagnetic coil 2
4 is turned off, the fixed iron core 23 is
5, the movable iron core 21 is pushed by the urging force of the second coil spring 27 and moves to a state in which the pilot hole 11 is closed, as shown in FIG.

Then, the pressure inside the pressure regulating chamber 9 becomes high due to the fluid leaking into the pressure regulating chamber 9 from the high pressure side flow path 2 side through the leak hole 12, and the main valve is actuated by the pressure difference with the low pressure side flow path 3 side. The holding cylinder 7 moves to the valve seat 5 side, and enters the valve closed state shown in FIG. During this time, the fixed iron core 23 moves together with the movable iron core 21, and the distance between the two iron cores 21 and 23 does not change.

In the solenoid-operated pilot valve configured as described above, even when the main valve 6 is largely opened and closed with respect to the valve seat 5, the movable iron core 21 when the electromagnetic coil 24 is not energized is connected to the movable iron core 21. The distance between the fixed iron core 23 and the fixed iron core 23 can be made a very narrow constant distance. Therefore,
The main valve 6 can be operated by a small electromagnetic force, and the main valve 6 can be largely opened and closed using a small solenoid 20 having a small energizing current.

FIG. 6 shows the inner yoke 2 of the above embodiment.
5 is omitted, and the pedestal 17 is formed of a magnetic material to serve also as a yoke, and the outer yoke 28 is formed in a flat plate shape so that the solenoid 20 does not project from the block body 1 so that It is arranged in.

FIG. 7 shows an open state of a normally open type solenoid driven pilot valve to which the present invention is applied. In this embodiment, substantially the same portions as those in the above-described normally closed type embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, a main valve 56 formed in an annular shape facing the valve seat 5 is fixed to the main valve holding cylinder 7, and a fixed iron core 73 is integrated with the main valve holding cylinder 7. The fixed iron core 73 is configured to move together with the main valve 56. 83 is a main valve holding cylinder 7 and a fixed iron core 7
3 is an O-ring for sealing a fixed portion for sealing a gap between the O-ring 3 and the fixing portion 3.

The fixed iron core 73 is loosely fitted in the sleeve 22 and is movable in the axial direction.
Is formed at the axial position of the fixed iron core 73,
One end thereof opens into the sleeve 22 and directly communicates with the inside of the pressure regulation chamber 9.

The movable iron core 71 is disposed at a position behind the fixed iron core 73 when viewed from the main valve 56 so as to be able to advance and retreat in the axial direction within the sleeve 22. A pilot valve 60 is attached to a position facing the opening of the pilot valve.

FIG. 8 is an enlarged view of a portion where the movable iron core 71 and the fixed iron core 73 face each other.
7 are locked by flanges 71a, 73a projecting from the movable iron core 71 and the fixed iron core 73, respectively. The distance between the iron core 71 and the fixed iron core 73 is maintained at a predetermined length by the natural length of the coil spring 77.

When the electromagnetic coil 24 is energized and an electromagnetic force acts on the movable iron core 71, the movable iron core 71 is drawn toward the fixed iron core 73 while compressing the coil spring 77, and the pilot hole 61 is moved to the pilot valve. Blocked by 60. When the electromagnetic coil 24 is turned off, the movable iron core 7 is pressed by the urging force (restoring force) of the coil spring 77.
1 returns to a state separated from the fixed iron core 73 by a predetermined distance.

FIG. 7 shows a state in which the normally open type solenoid-operated pilot valve configured as described above is not energized to the electromagnetic coil 24, and the pilot valve 60 separates from the mouth of the pilot hole 61. The inside of the pressure regulating chamber 9 communicates with the low-pressure side flow path 3 through the pilot hole 61 to have a low pressure. As a result, the main valve holding cylinder 7 is pushed so that the main valve 56 is separated from the valve seat 5 by the pressure on the high-pressure side flow path 2 acting on the main valve holding cylinder 7 (differential pressure between the pressure regulating chamber 9). The valve has been opened.

Then, when the electromagnetic coil 24 is energized, as shown in FIG. 9, the movable iron core 71 is attracted to the fixed iron core 73 by the electromagnetic force generated by the electromagnetic coil 24, and the coil spring 77 is compressed. Thereby, the pilot hole 61 is closed by the pilot valve 60.

Then, the pressure inside the pressure regulating chamber 9 becomes high due to the fluid leaking into the pressure regulating chamber 9 from the high pressure side flow path 2 through the leak hole 12, and the main valve is actuated by the pressure difference from the low pressure side flow path 3 side. The holding cylinder 7 moves to the valve seat 5 side, and the main valve 56 is pressed against the valve seat 5 as shown in FIG.

When the energization of the electromagnetic coil 24 is turned off in this valve closed state, the fixed iron core 73 does not attract the movable iron core 71, and as shown in FIG. The core 71 returns to a position separated from the fixed iron core 73 by a predetermined distance.

As a result, the inside of the pressure regulating chamber 9 communicates with the low pressure side flow path 3 side through the pilot hole 61 to become low pressure, and the pressure on the high pressure side flow path 2 side acting on the main valve holding cylinder 7 (pressure regulating chamber side) 9), the main valve holding cylinder 7 moves in a direction in which the main valve 56 moves away from the valve seat 5, and the valve is brought into an open state shown in FIG.
During this time, the fixed iron core 73 moves together with the movable iron core 71, and the interval between the two iron cores 71, 73 does not change.

In the solenoid-operated pilot valve constructed as described above, when the main valve 56 is opened and closed largely with respect to the valve seat 5, the movable iron core 71 and the fixed iron core when the electromagnetic coil 24 is not energized. The interval between the two can be made a very narrow constant interval. Therefore, the main valve 56 can be operated with a small electromagnetic force, and the main valve 56 can be largely opened and closed using the small solenoid 20 having a small electric current.

In the case of a normally open type solenoid-operated pilot valve, the coil spring 77 does not necessarily need to be used as shown in the above embodiment, but may be fixed to the movable iron core 71 as shown in FIG. The coil spring 77 is mounted in a compressed state in a direction away from the iron core 73, and the two iron cores 71, 7 are caught by a claw-shaped tubular member 80 or the like which is hooked on the flange 73 b of one of the iron cores.
The maximum interval between the three (interval at the time of non-energization) may be regulated.

[0045]

According to the present invention, the fixed iron core is arranged so as to be able to advance and retreat in the same direction as the movable iron core, and the distance between the fixed iron core and the movable iron core when the electromagnetic coil is not energized. Is provided between the fixed iron core and the movable iron core when the electromagnetic coil is not energized, even when the main valve is opened and closed greatly by providing the iron core interval holding means for holding the iron core at a predetermined interval. Can be made very small, and the main valve can be largely opened and closed using a small solenoid with a small energizing current.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a solenoid-operated pilot valve according to a first embodiment of the present invention in a non-energized (closed) state.

FIG. 2 is a sectional view taken along line II-II of the solenoid-operated pilot valve according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the solenoid-operated pilot valve according to the first embodiment of the present invention in a state immediately after energization.

FIG. 4 is a longitudinal sectional view of the solenoid-operated pilot valve according to the first embodiment of the present invention in an energized (opened) state.

FIG. 5 is a longitudinal sectional view of the solenoid-operated pilot valve according to the first embodiment of the present invention in a state immediately after the energization is stopped.

FIG. 6 is a longitudinal sectional view of a solenoid-operated pilot valve according to a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a solenoid-operated pilot valve according to a third embodiment of the present invention in a non-energized (opened) state.

FIG. 8 is a partially enlarged sectional view of a solenoid-operated pilot valve according to a third embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of a state immediately after energization of a solenoid driven pilot valve according to a third embodiment of the present invention.

FIG. 10 is a longitudinal sectional view of a solenoid-operated pilot valve according to a third embodiment of the present invention in an energized (closed) state.

FIG. 11 is a longitudinal sectional view of a state immediately after the energization of a solenoid driven pilot valve is stopped according to a third embodiment of the present invention.

FIG. 12 is a partially enlarged sectional view of a solenoid-operated pilot valve according to a fourth embodiment of the present invention.

[Explanation of symbols]

 2 High pressure side flow path 3 Low pressure side flow path 5 Valve seat 6,56 Main valve 7 Main valve holding cylinder 9 Pressure regulation chamber 10,60 Pilot valve 11,61 Pilot hole 12 Leak hole 20 Solenoid 21,71 Movable iron core 23, 73 Fixed iron core 24 Electromagnetic coil 26, 27, 77 Coil spring 30 Rod

Claims (3)

[Claims] A main valve is disposed in a valve seat formed in a communication passage between a high pressure side flow path and a low pressure side flow path so as to be able to move forward and backward from the high pressure side, and the main valve is viewed from the valve seat. A pressure regulating chamber formed on the back side of the valve communicates with the low pressure side flow path side through a pilot hole formed in the main valve and communicates with the high pressure side flow path side through a leak path. In a solenoid-driven pilot valve, the pilot hole is opened and closed from the pressure regulation chamber side by a pilot valve connected to a movable iron core attracted to a fixed iron core, and the main valve is opened and closed by a pilot operation. The fixed iron core is arranged so as to be able to advance and retreat in the same direction as the movable iron core, and a gap between the fixed iron core and the movable iron core is maintained at a predetermined interval when the electromagnetic coil is not energized. A solenoid-operated pilot valve provided with an iron core interval maintaining means for performing the operation. 2. The fixed iron core is disposed behind the movable iron core as viewed from the main valve, and the iron core interval holding means urges the fixed iron core toward the main valve. 2. The solenoid-operated pilot valve according to claim 1, further comprising an urging means for performing the operation, and a spacing member interposed between the fixed iron core and the main valve. 3. The movable iron core is disposed behind the fixed iron core as viewed from the main valve, and the fixed iron core is integrally connected to the main valve, and passes through the fixed iron core. The pilot hole is formed, and in the iron core interval holding means, when the interval between the fixed iron core and the movable iron core is smaller than the predetermined interval, the distance between the fixed iron core and the movable iron core is reduced. 2. The solenoid-operated pilot valve according to claim 1, further comprising an urging means that acts in a direction to increase a distance between the solenoids.