JPH0416073Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a cylinder main valve emergency shutoff device, and in particular, when the main valve of a cylinder storing gas is closed by driving an actuator, the main valve closes. The present invention relates to an emergency shutoff device for a cylinder main valve, which is configured to reliably detect the occurrence of an accident.

Conventional technology For example, semiconductor material gases used in semiconductor manufacturing processes may be highly toxic, flammable, self-combustible, combustible, or a combination of these gases, depending on the type of gas. There are some things of a similar nature. The cylinders storing these harmful gases were housed in cylinder storage boxes equipped with exhaust ducts, and a main valve was attached to the top of the cylinders to open and close the cylinders in order to supply the gas inside the cylinders to the outside.

The applicant previously proposed in Japanese Patent Application No. 60-181542 an emergency shut-off device for a cylinder main valve, which is configured to close the cylinder main valve by remote control. In this proposed device, piping is connected to an actuator that drives the main valve to close, and when the solenoid valve is actuated by an operation signal, operating air is supplied from the piping into the actuator. Further, the driving force of the actuator is transmitted to the operating handle of the main valve via transmission members such as an output shaft, a universal joint, and a chuck. In this way, when closing the main valve by remote control, it is necessary to confirm that the main valve is closed. In the device proposed above, a limit switch is provided as a means for detecting that the main valve is closed, which detects when the output shaft that transmits the driving force of the actuator to the main valve has rotated to the valve closing position. The detection signal output from the main valve indicates that the main valve is closed.

Problems that the invention aims to solve: However, with the above device, for example, the transmission member that transmits the driving force of the actuator to the main valve may become disconnected, or the chuck attached to the operating handle of the main valve may become loose. If this occurs, even if the actuator operates, the driving force may not be transmitted to the main valve. in this case,
Although the output shaft rotates due to the operation of the actuator, the main valve does not close. However, since the limit switch detects that the output shaft has rotated to the valve-closing position, there is a risk that the valve will be displayed as closed even if the main valve is not closed. For this reason, it has been desired that the above-mentioned device be capable of reliably detecting that the main valve of the cylinder is closed by the operation of the actuator.

Therefore, an object of the present invention is to provide a cylinder main valve emergency shutoff device that meets the above-mentioned needs.

Means and Effects for Solving Problems The present invention provides the cylinder main valve emergency shutoff device described above, which includes a detection switch that detects when the actuator closes the main valve, and a detection switch that detects when the actuator closes the main valve. A detection device detects this and outputs a detection signal, and after a detection switch outputs a valve closing signal,
An alarm device that monitors the detection signal from the detection device for a predetermined time and notifies the shortage of cutoff torque when the detection signal is not output within the predetermined time; This allows detection to confirm that the main valve is reliably closed.

Embodiment FIGS. 1 and 2 show an embodiment of the cylinder main valve emergency shutoff device according to the present invention. In both figures, for example, a cylinder 1 is filled with a highly concentrated semiconductor material gas. Each cylinder 1 is held vertically at a predetermined distance from each other and placed in a cylinder storage box 2.
It is stored inside. At the top of cylinder 1 is the main valve 3.
is installed.

The main valve 3 is opened or closed by rotating the operating handle 3a. When the main valve 3 is opened, the gas in the cylinder 1 is supplied to the outside of the cylinder storage box 2 via the pipe 4 connected to the main valve 3. In addition, the main valve 3 is the operation handle 3 from opening to closing.
The operating angle of a is approximately 160°.

5 is the actuator, cylinder storage box 2
It is arranged on the upper surface of the top plate 2a of the cylinder 1, and is located at a position apart from the cylinder 1. The output shaft 6 of the actuator 5 passes through the top plate 2a and connects to the cylinder storage box 2.
protrudes inward. In addition, the output shaft 6 is connected to a universal joint 7.
is connected to.

Reference numeral 8 denotes a chuck, which is fitted onto the outer periphery of the operating handle 3a of the main valve 3. Further, a shaft 8a protruding from the top of the chuck 8 is connected to the universal joint 7.
Therefore, the output shaft 6 of the actuator 5 is connected to the chuck 8 via the universal joint 7. 9
is an actuator, which is installed in a central control room, etc. away from the cylinder storage box 2, and is operated by the actuator 5.
It has open and close valve switches 9a and 9b that supply open and close signals for opening and closing the main valve 3. Reference numeral 10 denotes an air pipe that supplies air pressure to the actuator 5 to operate the actuator 5 and rotationally drive the output shaft 6 .

Here, the configuration of the actuator 5 will be explained. The actuator 5 has electromagnetic valves 16 and 17 that are actuated by an operation signal from the operation device 9.
The solenoid valves 16 and 17 are connected to air piping 1 as described later.
0 is connected. When the solenoid valves 16 and 17 operate, air from the air pipe 10 flows through the solenoid valves 16 and 1.
7 into the cylinder section 18. The solenoid valves 16 and 17 are respectively spring offset solenoid type switching valves, and when an open/close signal is supplied from the operating device 9, the solenoids 16a and 17a are energized to switch against the springs 16b and 17b. . Normally, the solenoid valves 16 and 17 are open to the atmosphere when not in operation.

In addition, the solenoid 17a of the solenoid valve 17 for valve closing
A timer 27 is connected as shown in FIG. Therefore, as will be described later, the timer 27 controls the solenoid valve 17 by supplying the valve closing signal to the actuator 5.
The solenoid valve 17 is kept in an operating state by being energized for a predetermined time longer than the valve closing operation time. That is, when the main valve 3 is closed, the solenoid valve 17 continues to operate for a certain period of time after closing. During this period, even after the valve is closed, the cylinder part 1
Air is supplied to the right cylinder chamber 18c of the cylinder 8 through the valve-closing pipe 21, and continues to drive the main valve 3 to close.

Further, the solenoid valves 16 and 17 are each connected to a check valve 19.
Branch piping 10 connected to air piping 10 via
It has ports 16c and 17c that communicate with ports a and 10b. Note that one of the solenoid valves 16 is a switching valve for valve opening, and has a port 16d communicating with a valve opening pipe 20 connected to the left cylinder chamber 18a of the cylinder portion 18. The other solenoid valve 17 is a switching valve for closing the valve, and a port 17d communicates with the valve closing pipe 21 connected to the right cylinder chamber 18c of the cylinder portion 18.
has.

A pressure reducing valve 22 is provided in the middle of the valve-closing pipe 21. Reference numeral 23 denotes a check valve, which is provided in the middle of a branch pipe 24 branching from the valve-closing pipe 21.

Further, a pressure switch (detection device) 25, which is a main part of the present invention, is disposed midway through the valve-closing pipe 21 between the pressure reducing valve 22 and the cylinder 18. This pressure switch 25 detects the air pressure supplied to the right cylinder chamber 18c via the valve closing pipe 21. The set value Po of the pressure switch 25 is set to a pressure value Po≦Ps, which is slightly lower than the set pressure Ps of the pressure reducing valve 22. Therefore, when the air pressure in the right cylinder chamber 18c rises to a value between Po and Ps, the pressure switch 25 detects this and outputs the detection signal.

Note that when the actuator 5 is operated to close the valve,
The solenoid 17a of the electromagnetic valve 17 is energized for a predetermined time (t seconds) by the action of the timer 27, during which time air is supplied to the right cylinder chamber 18c to tighten the operating handle 3a of the main valve 3. While tightening the operating handle 3a in this manner, the air pressure supplied to the right cylinder chamber 18c is a predetermined pressure set by the pressure reducing valve 22.

Note that when air is supplied to the right cylinder chamber 18c, the piston 18b slides in the direction of arrow _X2 . This displacement of the piston 18b is converted into a rotational displacement of the output shaft 6, and is transmitted to the operating handle 3a via the universal joint 7 and chuck 8. When the main valve is closed by the valve-closing operation of the operating handle 3a, the shutoff torque of the main valve 3 increases. Along with this, the air pressure in the right cylinder chamber 18c and the valve-closing pipe 21 is also increased.

Therefore, when the main valve 3 closes, the pressure switch 25 detects that the air pressure in the right cylinder chamber 18c has exceeded the set value Po, and outputs the detection signal.

In addition, the pressure switch 25 is connected to a notification means 2 such as an alarm device or a failure indicator lamp provided on the operating device 9.
6. Therefore, when the valve is closed, the air pressure in the right cylinder chamber 18c is maintained at a predetermined set value.
If the pressure does not rise above Po, that is, after a valve closing signal is output from the valve closing limit switch (detection switch) 29a, which will be described later, the detection signal from the pressure switch 25 is monitored for a predetermined time (t seconds), and within this predetermined time. When no detection signal is output from the pressure switch 25, it is assumed that the main valve 3 is not closed due to insufficient shutoff torque, and the notification means 26 is activated to notify that the main valve 3 is not closed.

As shown in FIG. 4, the upper end 6a of the output shaft 6 projects from the upper part of the actuator 5. Output shaft 6
Four cams 28a to 28d are attached to the upper end 6a. Furthermore, limit switches 29a to 29d are provided at the top of the actuator 5, facing the four cams 28a to 28d.

Each cam 28a to 28d provided on the output shaft 6 closes each limit switch 29a to 29d according to the rotational position of the output shaft 6 in order to detect the open/closed state of the main valve 3 when opening or closing the main valve 3.

As shown in FIG. 5A, the limit switch 29a
is a switch that detects the valve closed position. cam 28
A is opposed to the limit switch 29a, and has a cam portion _28a1 that protrudes within a range of 20 degrees from a position 160 degrees from the fully open position. For this reason, as shown in diagram I in Fig. 6, the output shaft 6 is 160 degrees
When rotated to a position of ~180°, the cam portion 28a ₁ comes into contact with the contact piece 29a ₁ and closes the limit switch 29a. Further, the limit switch 29a is also connected to the notification means 26.

As shown in FIG. 5B, the limit switch 29b
is a switch that detects the proper position of connection when the chuck 8 is attached to the operating handle 3a in the valve closed position. The cam 28b faces the limit switch 29b, and has a cam portion _28b1 that projects within a range of 5° from a position 165° from the fully open position. Therefore, as shown in the diagram in FIG. 6, when the output shaft 6 rotates from the fully open position to a position of 165 to 170 degrees, the cam portion _28b1 comes into contact with the contact piece _29b1 , closing the limit switch 29b. do.

As shown in FIG. 5C, the limit switch 29c
is a switch that detects that the output shaft 6 has rotated excessively. Cam 28c is limit switch 29
c and from a position 175° from the fully open position.
It has a cam portion 28c ₁ that protrudes within a range of 5°.
Therefore, as shown in the diagram in FIG. 6, when the output shaft 6 rotates from the fully open position to a position of 175 to 180 degrees, the cam portion 28c ₁ contacts the contact piece 29c ₁ and closes the limit switch 29c. .

As shown in FIG. 5D, the limit switch 29d
is a switch that detects that the main valve 3 is fully open. The cam 28d faces the limit switch 29d, and has a cam portion _28d1 that projects within a range of 5° from the fully open position. Therefore, as shown in the diagram in FIG. 6, when the output shaft 6 rotates from the fully open position to a position of 0 to 5 degrees, the cam portion _28d1 comes into contact with the contact piece _29d1 , closing the limit switch 29d. do.

As shown in FIG. 3, the limit switches 29a-29d are respectively connected to indicator lamps 30a-30d disposed in a central control room or the like. Therefore, as described below, the limit switch 29
When a to 29d are closed, the indicator lamps 30a to 3
0d is lit to indicate whether the main valve 3 is open or closed.

Next, the operation of the cylinder main valve emergency shutoff device having the above structure will be explained.

First, when opening the main valve 3, the valve opening switch 9a of the operating device 9 is pressed. When a valve opening signal is supplied from the operating device 9 to the actuator 5, the solenoid 16 of the solenoid valve 16 for opening the valve is energized as shown in the middle diagram in FIG. Therefore, the solenoid valve 16 is activated, and the air from the air pipe 10 is supplied to the ports 16c and 1.
6d into the left cylinder chamber 18a. As a result, the piston 18b is displaced in the direction of arrow _X1 . The output shaft 6 is rotationally driven via a rack, pinion, etc. by displacement of the piston 18b. Further, the rotation of the output shaft 6 is transmitted to the operating handle 3a via a universal joint 7 and a chuck 8.
Therefore, as shown in the middle diagram of FIG. 7, the main valve 3 is opened by the operation of the actuator 5.

When the main valve 3 is fully opened, the cam 28d closes the limit switch 29d as shown in the middle line diagram in FIG. 7A, and this is detected. limit switch 29d
When the valve is closed, a cylinder valve open indicator lamp 30d, which indicates that the main valve 3 of the cylinder 1 disposed in a central control room or the like is fully opened, lights up. Furthermore, solenoid valve 1
The power supply to the solenoid 16a of the actuator 6 is cut off, and the operation of the actuator 5 is stopped.

Next, when closing the main valve 3, the valve closing switch 9b of the operating device 9 is pressed. When a valve closing signal is supplied to the actuator 5 from the operating device 9, the valve closing solenoid 17a is energized as shown in the middle diagram in FIG. Therefore, the solenoid valve 17 is activated, and air from the air pipe 10 is introduced into the right cylinder chamber 18c via the ports 17c and 17d. Therefore, the piston 18b is pressed in the direction of arrow _X2 and displaced in the same direction, and the actuator 5 operates in the valve closing direction as shown in the middle diagram of FIG. Therefore, the output shaft 6 rotates due to the displacement of the piston 18b, the operating handle 3a is driven in the valve closing direction, and the main valve 3 is closed. When the output shaft 6 rotates to a position 160 degrees from the fully open position, the main valve 3 closes and the cam 28a closes the limit switch 29a.

As shown in the middle diagram in FIG. 7, it is detected that the main valve 3 is closed due to the closing of the limit switch 29a, and the cylinder valve close indicator lamp 30a disposed in the central control room etc. lights up. indicate.
Further, after the valve is closed, the solenoid 17a is energized for t seconds set by the timer 27 and continues to operate.

Therefore, even after the main valve 3 is closed, air from the air pipe 10 is introduced into the right cylinder chamber 18c. Therefore, even after the valve is closed, the piston 18b remains in the direction of the arrow
The operating handle 3a of the main valve 3 is pressed in the _X2 direction and continues to be driven in the valve closing direction to perform additional tightening. As a result, although the operating force of the operating handle 3a becomes large immediately before the valve is closed, the main valve 3 is further driven to close for a predetermined period of time and is reliably closed. That is, not only does the gasket of the main valve 3 contact the valve seat, but the gasket also bites into the valve seat to completely close the valve. Therefore, the main valve 3 can stably maintain the closed state even after the solenoid 17a is de-energized and the introduction of air into the right cylinder chamber 18c is stopped.

Furthermore, when the main valve 3 is closed as described above, the air pressure in the right cylinder chamber 18c increases as the shutoff torque increases, so the pressure switch 25 causes the air pressure in the right cylinder chamber 18c to increase as shown in the diagram in FIG. It detects that the air pressure has exceeded a predetermined set value Po and outputs a detection signal. Therefore, it can be confirmed that the actuator 5 has been driven to close the valve by closing the limit switch 29a for detecting the valve closing position.
It can be confirmed from the detection signal of the pressure switch 25 that the main valve 3 is closed.

Therefore, when an AND between the detection signal of the pressure switch 25 and the closing signal of the limit switch 29a is obtained, it can be seen that the main valve 3 has normally closed.

However, if, for example, the chuck 8 that transmits the driving force of the actuator 5 to the operating handle 3a becomes loose, the chuck 8 will rotate idly relative to the operating handle 3a even if the output shaft 6 is rotationally driven. Note that the pressure in the right cylinder chamber 18c gradually increases after the piston 18b is displaced, and as a result reaches a predetermined pressure. In such a case, the output shaft 6 is closed by driving the actuator 5 to close the valve.
is rotationally driven, the limit switch 29 is closed by the cam 28a. However, since the operating handle 3a does not rotate and the main valve 3 remains open, the air pressure in the right cylinder 18c does not increase immediately. For this reason, the limit switch 29a
Even if the valve is closed, the detection signal of the pressure switch 25 is not outputted within a predetermined time, indicating that the main valve 3 is not closed due to insufficient cutoff torque after the valve closing operation. Therefore, when the closing signal of the limit switch 29 and the detection signal of the pressure switch 25 cannot be ANDed, the notification means 26 is activated to notify that some kind of failure has occurred.

Furthermore, when the output shaft 6 rotates to a position of 175° to 180°, the over-rotation detection limit switch 29c closes and the indicator lamp 30c lights up. For this reason,
In the central control room, it can be confirmed that the main valve 3 is not closed not only by the notification means 26 but also by the display lamp 30c. Further, even if the pressure switch 25 does not operate normally, the operator in the central control room can monitor the opening and closing operations of the main valve 3 using the limit switch 29c.

Therefore, the operator in the central control room can monitor fluctuations in the shutoff torque of the main valve 3 using the pressure switch 25, and can therefore accurately confirm that the main valve 3 has been closed by operating the valve-closing switch 9b. . Further, when the main valve 3 does not close even though the valve close switch 9b is pressed to close the valve, the cause of the failure can be quickly determined. Therefore, when the main valve 3 does not close when opening and closing the cylinder 1 sealed with harmful gas, it is possible to promptly respond to this and prevent the occurrence of a disaster.

In the above explanation, the pressure switch is used to detect pressure changes due to fluctuations in the shut-off torque. However, the present invention is not limited to this. For example, if a strain gauge is attached to the output shaft 6, the shut-off torque can be detected from the strain generated on the output shaft 6 when the valve is closed. It may also be possible to detect that the value has exceeded a predetermined value.

In addition, if you want to determine the cut-off torque of main valve 3 in more detail, you can use the CPU connected to the pressure switch.
An ideal diagram showing the relationship between the shutoff pressure and time when the main valve 3 normally closes using the ROM is stored in the ROM. When the main valve 3 is closed, the shutoff pressure is measured in synchronization with clock pulses every 10 msec, for example. It is determined whether the resulting diagram showing the relationship between cut-off pressure and time matches an ideal diagram in the ROM connected to the CPU.

Furthermore, set the permissible error percentage of the measured diagram relative to the ideal diagram.
The CPU may calculate whether or not the above error is allowable. That is, when the error in the measured diagram exceeds the set value, it can be seen that the main valve 3 is not closed.

Effects of the Invention As described above, the cylinder main valve emergency shutoff device according to the present invention detects that the shutoff torque of the main valve exceeds a predetermined value due to the valve closing operation of the main valve, and outputs a detection signal. Since the device is provided, it is possible to monitor fluctuations in the cut-off torque due to opening and closing of the main valve. For example, by detecting that the air pressure inside the actuator has increased to a predetermined pressure or higher due to fluctuations in the cut-off torque, it is possible to monitor the open and closed states of the main valve.In particular, this pressure detection signal can cause the main valve to close. You can confirm that the valve is correct.
In addition, for example, if the driving force of the actuator is not transmitted to the main valve and the main valve does not close even though the valve is closed, the cut-off torque at the time of valve closing becomes extremely small, so that the air supplied to the actuator is reduced. The pressure did not rise immediately, and even though the valve closing signal was output from the detection switch that detected that the actuator had driven the main valve to close, the detection device detected that the cut-off torque was not reached within a predetermined time. If the value cannot be detected, it can be confirmed that the main valve is not closed. Therefore, even if the main valve does not close, it is possible to promptly deal with the occurrence of a failure, and safety can be further improved, especially for the main valve of a cylinder sealed with harmful gas. . Therefore, it has features such as being able to prevent the occurrence of disasters and further improving the reliability of the device.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of an embodiment of the cylinder main valve emergency shutoff device of the present invention, Figure 2 is a configuration diagram for explaining the main parts of the invention, and Figure 3 is a circuit applied to the device. Figure 4 is a front view for explaining the mechanism for detecting the rotation angle of the output shaft of the actuator.
5A to 5D are plan views for explaining each limit switch and cam, FIG. 6 is a diagram for explaining the operation of each limit switch according to the rotation angle of the output shaft, and FIG. 7 is an operation signal. FIG. 2 is a diagram for explaining the operations of a limit switch, an actuator, and a pressure switch when opening and closing the main valve. 1...Cylinder, 2...Cylinder storage box, 3
... Main valve, 5 ... Actuator, 9 ... Operator, 9a ... Valve open switch, 9b ... Valve close switch, 16, 17 ... Solenoid valve, 16a, 17a ...
Solenoid, 18...Cylinder part, 18c...Right cylinder chamber, 20...Valve opening piping, 21...Valve closing piping, 25...Pressure switch, 26...Notification means.

Claims (1)

[Scope of Utility Model Registration Claim] A cylinder filled with gas, a main valve attached to the cylinder to open and close the cylinder, and an actuator that is supplied with air from piping and closes the main valve in response to an operation signal. A cylinder main valve emergency shutoff device comprising: a detection switch that detects that the actuator has closed the main valve; and a detection switch that detects that the shutoff torque of the main valve has exceeded a predetermined value, and sends a detection signal thereof. After the valve closing signal is output from the detection switch, the detection signal from the detection device is monitored for a predetermined period of time, and when the detection signal is not output within the predetermined period of time, an insufficient cut-off torque is notified. A cylinder main valve emergency shutoff device comprising: