JPH06185658A - Check valve drive device - Google Patents

Abstract

PURPOSE:To eliminate abrupt opening operation of a valve element while maintaining surely opening operation of the valve element. CONSTITUTION:In a check valve drive device comprising an air feed passage 9 for feeding air as it is without lowering the pressure thereof, and a pressure reducing passage 9 for feeding air whose pressure is reduced by a pressure reducing valve 23, a three-way selector valve 22 is changed over so as to feed air into an air cylinder 6 from the pressure reducing passage 21 so as to inhibit abrupt opening operation of a three-way valve 22 when the valve element 5 is opened, and further, the valve 22 is changed over so as to feed air into the air cylinder 6 from the air feed passage 9 after the valve element 5 is fully opened, thereby it is possible to surely maintain the opening of the valve element 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve drive device,
This is to prevent the sudden opening operation at the time of opening operation.

[0002]

2. Description of the Related Art A check valve used as a practical valve is shown in FIG.
It will be described with reference to FIG. FIG. 2 shows a schematic configuration of the open state,
FIG. 3 shows a schematic configuration in the closed state.

In the figure, reference numeral 1 denotes a valve box, which connects a high pressure side upstream chamber 2 and a low pressure side downstream chamber 3 through a port 4. The port 4 is opened and closed by the valve body 5, which is the upstream chamber 2
It is provided inside. A force acts on the valve body 5 in a closing direction by the fluid from the upstream chamber 2 side, and a force acts in the opening direction by the fluid from the downstream chamber 3 side. The valve body 5 is driven by an air cylinder 6, and a piston 7 of the air cylinder 6 is biased by a spring 8 toward the side that closes the valve body 5. Air is supplied to the air cylinder 6 by an air supply passage 9.
An air supply solenoid valve 10 is provided in the air supply passage 9, and an exhaust passage 11 is connected between the air supply solenoid valve 10 and the air cylinder 6. An exhaust solenoid valve 12 is provided in the exhaust passage 11. A stopper 13 is provided in the upstream chamber 2 of the valve box 1, and when the valve body 5 is fully opened, the valve body 5 abuts on the stopper 13 and the fully opened position is regulated.

The operation of opening the check valve will be described with reference to FIG.

Air is supplied from the air supply passage 9 to the air cylinder 6 by closing the exhaust solenoid valve 12 and opening the air supply solenoid valve 10. The piston 7 is pushed up against the urging force of the spring 8 and opens until the valve body 5 contacts the stopper 13.
By continuing to supply air from the air supply passage 9 to the air cylinder 6, the valve body 5 is maintained in the open state.

The operation of closing the check valve will be described with reference to FIG.

The air supply solenoid valve 10 is closed and the exhaust solenoid valve 12 is opened, so that the compressed air stored in the air cylinder 6 is exhausted from the exhaust passage 11. The piston 7 is lowered by the weight of the valve body 5 and the spring force of the spring 8 to close the valve body 5.

[0008]

When the check valve described above is used to open the valve body 5 from the closed state to the open state, air is supplied to the air cylinder 6, but the upstream side chamber 2 on the high pressure side and the downstream side on the low pressure side. When the pressure difference between the side chambers 3 is large, a force for operating the valve body 5 in the closing direction works due to this pressure difference, and the internal pressure of the air cylinder 6 rises more than necessary. In this state, when the internal pressure of the air cylinder 6 exceeds the closing operation force of the valve body 5 due to the differential pressure, the valve body 5 starts to operate in the opening direction. At this moment, the upstream chamber 2
The pressure in the downstream chamber 3 is equalized, and the operating force of the valve body 5 in the closing direction disappears. Therefore, the high-pressure air accumulated inside the air cylinder 6 expands rapidly, causing the valve body 5 to open rapidly. As a result, the valve body 5 may collide with the stopper 13.

[0009]

The structure of the present invention for solving the above-mentioned problems is such that when the fluid flows from the upstream chamber to the downstream chamber, the valve body closes while the fluid flows from the downstream chamber to the upstream chamber. In a check valve drive mechanism that drives a check valve that opens, the fluid pressure cylinder that drives the valve body in the opening direction and the flow path that supplies the drive fluid to the fluid pressure cylinder are Depressurizing flow path to supply to the pressure cylinder,
It is characterized by further comprising: a selecting unit that selects either the flow passage or the pressure reducing passage to supply the fluid to the fluid pressure cylinder.

[0010]

When the closed valve body is opened, the depressurizing passage is selected by the selecting means and the depressurized driving fluid is sent from the depressurizing passage to the fluid pressure cylinder to prevent the driving of the fluid pressure cylinder at a dangerously high pressure. After the valve body is opened, the flow path is selected by the selection means and the driving fluid is sent to the fluid pressure cylinder as it is, and the fluid pressure cylinder is driven by high pressure to overcome the valve closing force due to the fluid flow acting on the valve body. Ensure valve opening.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of a check valve equipped with a drive device according to an embodiment of the present invention. 2 and 3
The same members as the members shown by are denoted by the same reference numerals, and the overlapping description will be omitted.

A decompression flow path 21 is provided in a branched manner in an air supply path (flow path) 9 on the upstream side of the air supply solenoid valve 10.
The depressurization flow path 21 is connected to the air supply path 9 by a three-way switching valve 22 as a selection means. A decompression valve 23 is provided in the decompression flow path 21, and the pressure of the air flowing through the decompression flow path 21 is reduced to keep the pressure after decompression constant.

The operation of opening the valve body 5 in the closed state will be described.

The three-way switching valve 22 is switched to a state in which air passes through the pressure reducing passage 21, the electromagnetic valve 12 for exhaust is closed, and the electromagnetic valve 10 for air supply is opened. Air is decompressed by the decompression valve 23 and sent to the air cylinder 6, and the decompressed air drives the air cylinder 6 to open the valve body.

When the differential pressure between the upstream side chamber 2 and the downstream side chamber 3 is high, the air cylinder 6 is driven by the depressurized air, so that the internal pressure of the air cylinder 6 does not rise more than necessary and the valve body The opening action of 5 is blocked. This eliminates the risk of the valve body 5 suddenly opening.

When the pressure difference between the upstream side chamber 2 and the downstream side chamber 3 is sufficiently low, the valve body 5 is opened by the air cylinder 6 driven by the depressurized air. On this occasion,
Since the air that drives the air cylinder 6 is depressurized,
The valve body 5 does not collide with the stopper 13.

When the valve body 5 is fully opened and comes into contact with the stopper 13, the three-way switching valve 22 is switched by the fully open signal, and the air is not depressurized through the air supply passage 9 and the air cylinder 6 is opened.
The air cylinder 6 is driven by the high-pressure air that is not depressurized. As a result, the valve body 5 is maintained in the open state with a high operating force, and the valve opening can be maintained even if the valve body 5 is acted on in the closing direction by the flow of the fluid flowing through the upstream chamber 2 and the downstream chamber 3.

When the valve body 5 is closed, the air supply solenoid valve 10 is closed and the exhaust solenoid valve 12 is opened to operate the valve body 5 in the closing direction.

When performing the opening operation from the closed state, the above-described check valve drives the air cylinder 6 with the air reduced in pressure by the pressure reducing valve 23, so that the differential pressure between the upstream side chamber 2 and the downstream side chamber 3 is high. However, the internal pressure of the air cylinder 6 does not rise more than necessary. Therefore, the valve body 5 does not suddenly open. Further, after the valve body 5 is fully opened, the air cylinder 6 is driven by high-pressure air that is not depressurized, so that the valve opening is reliably maintained.

[0020]

The check valve drive device of the present invention comprises a flow passage for directly supplying the drive fluid without depressurizing it and a depressurization flow passage for supplying the drive fluid under reduced pressure. It is designed to drive a fluid pressure cylinder that opens the valve element using a flow path, and it is possible to prevent the rapid opening operation of the valve element by selecting a decompression flow path when opening the valve element. In addition, it is possible to reliably maintain the open state of the valve body by selecting the flow path when the valve body is in the fully open state. As a result, it is possible to maintain the reliable valve opening of the valve body and eliminate the sudden opening operation of the valve body.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a check valve including a check valve drive device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional check valve.

FIG. 3 is a schematic configuration diagram of a conventional check valve.

[Explanation of symbols]

 2 Upstream side chamber 3 Downstream side chamber 5 Valve body 6 Air cylinder 9 Air supply path 21 Pressure reducing flow path 22 Three-way switching valve 23 Pressure reducing valve

Claims (1)

[Claims] 1. A check valve drive means for driving a check valve, wherein a valve body is closed when a fluid flows from an upstream chamber to a downstream chamber, while a valve body is opened when a fluid flows from a downstream chamber to an upstream chamber, A fluid pressure cylinder that drives the valve element in the opening direction, a flow path that supplies the drive fluid to the fluid pressure cylinder, a decompression flow path that decompresses the drive fluid and supplies the fluid pressure cylinder to the fluid pressure cylinder, and a flow path or a decompression flow path. A non-return valve driving device comprising: a selecting unit that selects one of the two and supplies the fluid to a fluid pressure cylinder.