JPS5817909B2 - safety valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solenoid valve equipped with a safety device.

Conventionally known two-port solenoid valves displace the valve body together with the movable iron core when the solenoid section is energized or disconnected, thereby opening and closing the valve seat. If energization is unexpectedly resumed after a failure occurs and the flow path is closed, there is a risk that an accident may occur due to the accompanying sudden fluid supply.

In order to solve this problem, even if the current is turned off and then turned on again, the valve body will not be driven and the fluid flow path will return to the switching state when it is not energized. However, there are problems such as the structure of the solenoid valve becoming significantly more complicated and the addition of the required control circuit to the electrical system making the entire system extremely expensive. .

An object of the present invention is to construct a safety valve using a small, low-power solenoid, as described above, in which the valve body is not driven even if the current is turned off and then turned on again.

In order to solve this problem, the safety valve of the present invention has a pressure chamber formed on the output port side of the valve seat provided in the communication path between the input port and the output port of the valve body, and a suction iron core and a suction iron core in the solenoid part. The movable iron is provided with a movable iron core that is attracted to it by energization, and a permanent magnet located on the opposite side of the movable iron core with the adsorption iron core in between.

The valve body provided in the core is urged by a spring in the direction of contacting the valve seat, and the adsorption iron core is moved to a downward position where it gives a small stroke to the movable iron core, and is attracted by the permanent magnet to close the valve seat. When the solenoid is energized, the pressure-receiving area on the pressure chamber side of the suction iron core is increased by the fluid in the pressure chamber when the solenoid is energized. The pressure is set to such an extent that the suction core moves to the upward movement position, and a release mechanism is provided to manually return the suction core in the upward movement position to the downward movement position.

The safety valve configured as described above operates as follows.

That is, when the solenoid section is energized, the movable core is attracted to the suction core, and the valve body slightly opens the valve seat, whereby the movable core and the suction core are driven as one by the fluid pressure flowing into the pressure chamber. The valve seat is then attracted to the permanent magnet, opening the valve seat wider.

When the solenoid section is de-energized, the suction iron core maintains its position, the movable iron core returns to its original position, and the valve body closes the valve seat. Since the cores are far apart, unless the release mechanism returns the suction core to its original position, the movable core will not be attracted to the suction core, and the closed state of the valve seat by the valve body will be maintained.

According to the safety valve of the present invention, the following unique effects can be obtained.

In other words, fluid can be extremely safely supplied to fuel combustion equipment and other various devices, and the suction force of the movable core in the suction core may be relatively small, so a small and low-power solenoid is used as the solenoid. This allows the entire device to be constructed in a compact and economical manner.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, numeral 1 is a valve main body equipped with a fluid input port 2 and an output port 3, and numeral 4 is a direct current operated solenoid section disposed above the valve main body.

In the above valve body 1, input port 2 and output port 3
A pressure chamber 6 is formed on the output port 3 side of the valve seat 5 provided in the communication path between the A movable core 9 that is electromagnetically attracted to the core 8 is slidably inserted, a valve body 10 is provided at the tip of the movable core 9, and this is connected between the stepped portion 9a of the movable core and the inner wall of the pressure chamber 6. The biasing force of the first spring 11 compressed between the valve body 10 is biased in the direction of contacting the valve seat 5, and when the valve body 10 closes the valve seat 5, the upper surface of the movable core 9 and the suction at the position shown in the figure are The lower surface of the iron core 8 is configured to be separated by a stroke S1.

The suction iron core 8 is slidably disposed on a locking step 7a in a guide pipe 7 of a solenoid section around which a coil 12 is provided, with a backing 13 interposed between it and the inner surface of the guide pipe 7. The pressure receiving area of the adsorption core 8 on the pressure chamber 6 side is set to the pressure receiving area of the pressure chamber 6 when the solenoid is energized.
The fluid pressure is set to such an extent that the suction core 8 moves to the upward movement position, and a permanent magnet 15 that attracts and holds the suction core 8 in the upward movement position is placed between the suction core 8 and the opposite side of the movable iron core 9.

The permanent magnet 15 serves as a holding mechanism for the suction core 8, and provides the suction core 8 with a stroke S2 between the downward movement position where it locks on the locking step portion 7a and the above movement position, and serves as a holding mechanism for the suction core 8. As a release mechanism for returning the suction core 8 held by suction to the downward movement position, a pressing plate 16a at the tip of the return rod 16 fitted into the cover 14 is brought into contact with the concave hole 8a on the top surface of the suction core 8. At the same time, a second spring 17 is compressed between the pressing plate 16a and the inner surface of the cover 14, and the spring 17 biases the suction core 8 in the direction of locking the locking step portion 7a. .

The downward movement position of the attracting iron core 8 is a position that gives a small stroke S1 to the movable iron core 9, and the above movement position is between the movable iron core 9 which is attracted to the permanent magnet 15 and closing the valve seat 5. (s1)
+82) and is set to Sl<S2.

Next, the operation of the safety valve will be explained.

FIG. 1 shows a state in which the coil 12 is not energized, and the valve body 10 of the movable core 9 has the valve seat 5 biased by the first spring 11.
, and the supply of fluid from the input port 2 to the output port 3 is stopped.

If the coil 12 is energized now, the movable core 9 will be attracted to the suction core 8 against the biasing force of the first spring 11 and will move upward by the stroke S1, thereby opening the valve seat 5 by 81. First, a small amount of fluid is supplied from the input port 2 to the output port 3 via the pressure chamber 6.

Along with this, the pressure inside the pressure chamber 6 increases, and this pressure acts on the movable core 9 and the suction core 8 that has attracted it, so those cores 9 and 8 are moved by the first spring 11 and the second spring. It further moves upward by a stroke S2 against the biasing force of the screw 17, whereby the attracting iron core 8 is attracted to the permanent magnet 15,
The state shown in Figure 2 will be reached.

Therefore, the valve body 10 also moves upward by the stroke S2 to open the valve seat 5 more widely, and a large amount of fluid is supplied from the input port 2 to the output port 3.

In this state, if the coil 12 becomes de-energized due to a power outage, electrical system failure, etc., the movable core 9 will separate from the attracted core 8, which is still attracted to the permanent magnet 15, due to the urging force of the first spring 11. and stroke (S1+82)
2, and the valve body 10 is moved downward by
The valve seat 5 is closed and the supply of fluid from the input port 2 to the output port 3 is stopped.

As a result, the pressure inside the pressure chamber 6 decreases, but the suction core 8
remains attracted to the permanent magnet 15.

After this, even if the coil 12 is energized, the movable core 9 is separated from the suction core 8 by a stroke (S1+82) and is located outside the suction action area of the suction core 8, so it is affected by the suction force of the suction core 8. The position indicated by the chain line in FIG. 2 is maintained without any change, so that the supply of fluid from the input boat 2 to the output port 3 remains stopped.

In order to open the valve seat 5 again, the attraction core 8 is separated from the permanent magnet 15 by manually pressing the return rod 16, and the lower end of the attraction core 8 is guided by the second spring 17. It is sufficient to move the pipe 7 downward until it hits the locking step 7a and return it to the original position shown in FIG. will be released.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing different operating states in an embodiment of the present invention. 1... Valve body, 2... Input port, 3
...Output port, 4...Solenoid section, 6...Pressure chamber, 8...Adsorption core, 9
......Movable iron core, 10...Valve body, 11.
...Spring, 15...Permanent magnet, 16...
...Return lever.

Claims (1)

[Scope of Claims] 1. A pressure chamber is formed on the output port side of a valve seat provided in a communication path between an input port and an output port of a valve body, and a pressure chamber is formed on the output port side of the valve seat, and the pressure chamber is attracted to the solenoid by an adsorption iron core and energization. A permanent magnet is disposed on the opposite side of the movable core, sandwiching the movable core and the suction core, and urges the valve body provided on the movable core in the direction of contacting the valve seat with a spring, and A lower moving position in which the attracting iron core gives a small stroke to the movable iron core, and an upward moving position in which the movable iron core is attracted to the permanent magnet and maintains a stroke such that it cannot be attracted between the movable iron core and the valve seat. The pressure receiving area on the pressure chamber side of the suction core is set to such an extent that when the solenoid is energized, the suction core is moved to the upward movement position by the fluid pressure in the pressure chamber, and the suction core in the upward movement position is A safety valve equipped with a release mechanism that manually returns the iron core to the downward position. □