JPH1078199A - Valve close detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect the closed state of a valve by forming a close position data on the basis of the stop position of a movable element before the opening and closing operation of the valve. SOLUTION: The initial set of a valve close detecting device 52 is performed. A control device 56 adds a prescribed bit number to the output bit number of a rotary encoder 54 corresponding to the stop position of a vane body (movable element) 22 obtained by the initial setting process by the valve close detecting device 52, and also subtracts it to form a close position data corresponding to the position range of the vane body 22 where a valve 14 is laid in close state. When the close position data is thus formed, the close position data is stored in the RAM 68 of a memory part 64, whereby the initial setting process is completed. After it, the environment capable of performing general valve opening and closing operation is formed. When the valve 14 is opened, the vane body 22 is rocked to the open end position, and when the valve 14 is closed, compressed air is supplied to the port of an actuator to rock the vane body 22 to the close position side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve opening and closing device for automatically opening and closing a valve of a gas container, and more particularly to a valve closing device for detecting that the valve is in a closed state from the state of an actuator of the valve opening and closing device. The present invention relates to a detection device.

[0002]

2. Description of the Related Art A special material gas used in semiconductor production or the like is usually used in a state of being stored in a portable gas container called a gas cylinder or a gas cylinder. Many of these special material gases for semiconductor manufacturing have risks such as flammability (explosiveness), toxicity, corrosiveness, and flammability, and their use must be done without sufficient safety considerations. No. For this reason, conventionally, a gas container in which a dangerous special material gas is sealed is housed in a box body called a cylinder cabinet having an exhaust duct, in preparation for an emergency gas leak.

When the gas container is housed in the cylinder cabinet as described above, it is desirable to automatically open and close the valve of the gas container by remote control for safety reasons, and various valve opening / closing devices have been conventionally developed. ing. As a conventional valve opening and closing device, for example, Japanese Utility Model 4-12315
Is known, which includes a pneumatic vane-type oscillating actuator disposed above a gas container, one end of which is connected to the output shaft of the actuator, and the other end of the gas container. A rotary shaft provided with a chuck for gripping a valve opening / closing handle. This valve opening / closing device is configured to open / close a valve handle by pneumatically controlling an actuator to rotate its output shaft and rotary shaft in either forward or reverse directions.

The vane-type swing actuator has a vane body rotatably mounted in a cylindrical cylinder. The vane body is closed and closed by supplying and discharging compressed air to and from a port provided in the cylinder. It can be swung between the position and the open end position.

Now, with the vane body at the closed end position,
A rotary shaft extending from the axis of the vane body is set on the handle of the valve of the closed gas container, and compressed air is supplied to one port to swing the vane body to the open end position. The handle rotates and the valve is opened. Thereafter, when compressed air is supplied to the other port, the vane swings in the opposite direction and returns to the closed end position. In this state, the valve may not be completely closed. This is desirable if the handle is not tightened further than its initial position (so-called "retightening"), as is typically the case when the valve has been used for a long time and the valve seat is slightly hardened. This is because the closed state may not be obtained.

Therefore, conventionally, the position of the vane body at the time of setting is set to a setting position shifted from the closed end position to the open end position by a predetermined angle, thereby avoiding the above-mentioned adverse effects. When the vane body is arranged at the setting position as described above, when the vane body is swung from the open end position to the closed end position, the vane body can swing beyond the setting position. Can be tightened. Note that a pressure reducing valve is provided in the compressed air supply line so that the valve is not excessively tightened, and is configured so that a torque greater than a certain value does not act on the handle of the valve.

[0007]

In the above-mentioned conventional valve opening / closing device, a limit switch is provided on the actuator for confirming that the valve is in a closed state, and the vane body is set to a closed end position and a setting position. It is possible to detect that it is within the range between the position.

However, since the limit switch is turned on regardless of the position of the vane body between the closed end position and the setting position, there is a problem that the reliability of the detection result is low. For example, when a malfunction such as a pressure control valve in a compressed air supply line not operating properly occurs, the swing of the vane body may stop before reaching a position where the valve is completely closed. Even in such a case, if the vane body is beyond the setting position, the limit switch is turned on, and it is determined that the valve is in a desired closed state.

Further, the position of the vane body in the closed state is as follows.
Since it fluctuates depending on the characteristics of the valve seat, the usage period, and the like, and fluctuates each time the valve is opened and closed, it is not appropriate to set a fixed narrow range as the closing position range and treat it as invariable.

An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a valve closing detection device capable of detecting the closing state of a valve with high accuracy.

[0011]

In order to achieve the above object, the present invention provides a rotary shaft connected to a handle for opening and closing a valve of a gas container, and a rotary shaft for driving the rotary shaft to open and close the handle. In a valve closing detection device used for a valve opening / closing device having a movable actuator, a position detecting means for detecting a position of a movable element (vane body) of the actuator which is interlocked with a rotating shaft, and a position of the movable element at which the valve is closed. When it is determined that the position of the movable element detected by the position detecting means is within the position range corresponding to the closing position data stored by the storage means in which the closing position data corresponding to the range is stored and the closing position data stored by the storing means. Determining means for determining that the valve is in the closed state, and closing position data based on the position of the movable element detected by the position detecting means. It is characterized in that it comprises updating means for storing the updated storage unit.

In this configuration, since the closing position data is created based on the stop position of the mover before the opening and closing operation of the valve, the closing state of the valve can be detected with high accuracy. In addition, since the closing position data can be updated for each opening / closing operation, reliability can be further improved.

[0013]

FIG. 1 shows a valve opening / closing device 10 to which the present invention can be applied, and a valve 14 of a gas container 12 to which the valve opening / closing device 10 is attached. The illustrated gas container 12 is disposed in a cylinder cabinet, and an actuator 18 of the valve opening / closing device 10 is installed on a top plate 16 of the cylinder cabinet. The actuator 18 is a pneumatic swing type, and includes a cylindrical cylinder 20 and a vane (movable element) 22 that is swingably arranged in the cylinder 20.
As shown in FIG. 2 which is a cross-sectional view taken along the line AA in FIG. 1, the cylinder 20 is provided with a partition wall 26 extending from the inner wall surface to the swing shaft 24 of the vane body 22. 26 and the vane body 22 divide the interior into two spaces. Ports 28 and 30 communicating with each space are formed in the cylinder 20. Each port 28,
An air pressure control circuit is connected to 30. The air pressure control circuit is provided with a compressed air supply source 32. By switching the flow of the compressed air from the compressed air supply source 32 by using a directional control valve 34, the compressed air is supplied to one of the ports 28 and 30. Then, the vane body 22 can be swung in either the forward or reverse direction. The points 36 and 38 in FIG. 2 are the limit points of the swing stroke of the vane body 22, and the point 36 is generally called the closed end position, and the point 38 is called the open end position. In the illustrated embodiment, the closed end position 3
6 to the open end position 38, ie the vane body 22
Has a maximum swing angle of 270 degrees.

The lower end of the swing shaft 24 of the vane body 22 extends downward through the lower plate of the cylinder 20 and the top plate 16 of the cylinder cabinet, and is connected to the rotating shaft 40. The lower end of the rotating shaft 40 is provided with the valve 14 of the gas container 12.
Chuck 44 for gripping the handle 42 is provided. Therefore, when the vane 22 is swung by controlling the air pressure of the actuator 18, the rotating shaft 40 rotates, and the handle 42 can be opened and closed.
Specifically, when compressed air is supplied to the port 28 of the actuator 18, the vane body 22 swings counterclockwise in FIG. 2 to rotate the handle 42 in the valve opening direction and compress the port 30. When air is supplied, the vane body 22 swings clockwise to tighten the handle 42.

When the valve opening and closing device 10 is mounted on the valve 14 of the gas container 12, the vane 22 is shifted from the closed end position 36 to the open end position 38 by a predetermined angle (30 degrees in the illustrated embodiment) as described above. In this state, the handle 42 of the valve 14 in the closed state is gripped by the chuck 44 of the rotating shaft 40. As a result, the vane body 22 can be further swung from the setting position 46 to the closed position, and the valve 14 can be further tightened with a predetermined torque. In order to keep the tightening torque constant, a pressure reducing valve 50 is provided in a pipe 48 for supplying compressed air to the port 30 so that the air pressure applied to the vane body 22 does not exceed a predetermined pressure. Also, even if the swing shaft 24 of the vane body 22 and the handle 42 of the valve 14 are slightly displaced, the rotating shaft 40 is provided so that the rotational driving force from the actuator 18 is reliably transmitted to the handle 42.
A universal joint 50 is interposed at an intermediate portion of.

The present invention provides an apparatus for detecting whether the valve 14 of the gas container 12 is closed by detecting the state of the valve opening and closing device 10.
The valve closing detection device 52 shown in FIG. 1 mainly includes an optical rotary encoder 54 for detecting the position (swing angle) of the vane body 22, and the rotary encoder 54.
Control device 56 for receiving and processing the output signal of
And a display monitor 58 for displaying the result obtained in step 6.

The rotary encoder 54 is installed on the cylinder 20 of the actuator 18, and the upper end of the swing shaft 24 of the vane 22 is connected to the center of a rotating disk (not shown). The rotary encoder 54 is of an absolute value type, and can recognize the position of the vane body 22 from the number of output bits. Here, for simplicity, the number of output bits from the rotary encoder 54 is “0” when the vane body 22 is at the closed end position 36, and the number of output bits is “270” when the vane body 22 is at the open end position. It is assumed that it is set so that

The control unit 56 includes an input unit 60 and an output unit 6
2, a microcomputer including a storage unit 64 and a central processing unit 66. The output terminal of the rotary encoder 54 is connected to the input unit 60 of the control device 56, and the output signal of the rotary encoder 54 is
6 to be sent. In the central processing unit 66,
A predetermined process is performed based on the execution program and data stored in the storage unit 64. In the present invention, what should be stored in the storage unit 64 is closed position data corresponding to the position range of the vane body 22 in which the valve 14 is closed, and this data is updated as described later. Therefore, the storage medium for the closing position data is the RAM 68,
Particularly, an SRAM which is a nonvolatile memory is preferable. Of course,
Those that do not require rewriting such as the execution program are stored in the ROM 70
Is stored. The result obtained by the central processing unit 66, that is, information on whether the valve 14 is in the closed state is output from the output unit 62 and displayed on the display monitor 58.

Next, the valve-closing detecting device 52 having the above-described structure is used.
Will be described in detail together with the processing contents of the controller 56.

First, the initial setting of the valve closing detection device 52 is performed. In this case, the chuck 44 at the lower end of the rotary shaft 40 is connected to the handle 42 of the closed valve 14 of the gas container 12 in a state where the vane body 22 of the actuator 18 of the valve opening / closing device 10 is arranged at the setting position 46 in advance. Keep it. At the start of the initial setting, since the vane body 22 is located at or near the setting position 46, the number of output bits from the rotary encoder 54 is generally “30”, and the control device 56 determines from this signal that the vane body 22 The position is recognized, and the position is displayed on the display monitor 58.

When the operator determines from the display monitor 58 that the state of the actuator 18 is proper, the operator supplies compressed air to the port 30 of the actuator 18 to close the vane body 22 until the vane body 22 stops. 3
Swing to the 6 side. At this time, if the number of bits input from the rotary encoder 54 fluctuates, the control device 56 determines that the vane body 22 is swinging. If the number of bits does not fluctuate for a certain time, the control device 5
6 determines that the vane body 22 has stopped, and determines the number of output bits of the rotary encoder 54 at that time.
Is recognized as the stop position.

FIG. 3 is a diagram for explaining the closed state of the valve 14 according to the position of the vane body 22, that is, the swing angle of the vane body 22. In this figure, points 72 and 7
4 are vane bodies 2 in the initial setting process described above.
Numeral 2 indicates the stopped position, with point 72 likely to be for a new valve and point 74 likely to be for an old valve. As described above, the stop position of the valve 14 differs depending on the type, the usage period, and the like even with the same torque.
When the vane body 22 stopped at the point 72 swings to the open end position 38 and swings again to the closed end position 36 to close the valve 14, the vane body 22 cannot return to the position of the point 72. At least, it stops within the position range indicated by reference numeral 76 centered on the point 72. Even in the case of the vane body 22 stopped at the point 74, the vane body 22 stops within the position range 78 centered on the point 74 in the reclosing operation.

The present invention is based on this finding, and the control device 56 sets the output bit number of the rotary encoder corresponding to the stop position of the vane body 22 obtained in the above-described initialization process to a predetermined bit number (shown in FIG. In the example, “5”) is added and subtracted to create closed position data corresponding to the position range. For example, when the vane body 22 stops at the position of the point 72 (the number of output bits is “10”), numerical data “5 to 15” is obtained as the closing position data. When the closing position data is created in this way, the closing position data is stored in the RAM 68 of the storage unit 64.
To complete the initialization process. Thereafter, an environment in which a normal valve opening / closing operation can be performed is provided.

When the valve 14 is opened, the vane 22
Is swung to the open end position 38, but if necessary, an indication that the vane body 22 has reached the closed end position 38 can be displayed. That is, if the open position data corresponding to the position range indicated by reference numeral 80 in FIG. 3 is stored in the storage unit 64 of the control device 56, the position signal of the vane body 22 from the rotary encoder 54 is compared with the open position data. However, when it is determined that the vane body 22 is substantially located at the valve open position, the display monitor 58 determines that the state is “normal”.
Can be displayed.

After the valve 14 is opened,
When closing the valve 14, compressed air is supplied to the port 30 of the actuator 18 to swing the vane 22 toward the closed end position 36. The control device 56 reads the number of output bits from the rotary encoder 54, and when the number of bits does not fluctuate for a certain period of time, determines that the vane body 22 has stopped, and turns the rotary encoder 5 at that time.
The output bit number of 4 is recognized as the stop position of the vane body 22. Then, the stop position bit number corresponding to the stop position is compared with the close position data previously stored in the RAM 68 of the storage unit, and if it is determined that the stop position bit number is within the close position data, " It is determined that the status is "normal", and that fact is displayed on the display monitor 58. If the data is outside the closing position data, "abnormal" is displayed on the display monitor 58. In the case of an abnormality, a warning means such as an alarm lamp may be used to actively notify the operator or the like of the abnormality.

Generally, once the valve 14 is opened and closed, the stop position of the vane 22 is slightly shifted from the stop position before the opening and closing operation. Therefore, if the number of output bits of the rotary encoder 54 corresponding to the stop position of the vane body 22 after the opening / closing operation is obtained, the control device 56 creates new closing position data in the same manner as described above, and 64 data are to be updated. By this processing, the latest closed position data according to the state of the valve 14 is always stored, so that the closed state of the valve 14 can be detected with high accuracy even after the opening and closing operations are repeated.

The closing position data stored in the storage section 64 does not need to have a width as described above, and the number of output bits from the rotary encoder 54 is stored as it is, and is used for comparison processing. Arithmetic processing for giving a range to the number of output bits may be performed.

Although the preferred embodiments of the present invention have been described in detail, it goes without saying that the present invention is not limited to the above embodiments. For example, the valve closing detection device of the above embodiment is directed to a valve opening / closing device having an oscillating vane type actuator, but the present invention is also applicable to a valve opening / closing device using a linear type actuator. In such a case, it is necessary to detect the position of the mover of the linear actuator that operates in correspondence with the handle of the valve. Therefore, a linear encoder is preferable as the position detecting means. Further, the position detecting means is not limited to the absolute value encoder, but an incremental encoder can be used, and other position sensors can be used.

[0029]

As described above, according to the present invention, since the closing position data is created based on the stop position of the actuator mover before the opening and closing operation of the valve, the closed state of the valve can be detected with high accuracy. Can be. In addition, since the closing position data is automatically updated for each opening / closing operation, the reliability of the detection result can be further improved. This allows
In particular, it is possible to easily and reliably perform safety management of a gas container filled with dangerous gas.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a valve opening / closing device provided with a valve closing detection device according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a diagram for explaining a closed state of a valve according to a position of a vane body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Valve opening / closing device, 12 ... Gas container, 14 ... Valve, 18 ... Actuator, 22 ... Vane body (movable element), 36 ... Closed end position, 38 ... Open end position, 40 ... Rotating shaft, 42 ... Handle, 44 ... Chuck, 46: setting position, 52: valve closing detection device, 54: rotary encoder, 56: control device, 58: display monitor,
Reference numeral 60: input unit, 62: output unit, 64: storage unit, 66: central processing unit, 68: RAM, 70: ROM.

Claims (6)

[Claims] 1. A valve for use in a valve opening / closing device having a rotary shaft connected to a handle for opening and closing a valve of a gas container, and an actuator for rotating the rotary shaft to open and close the handle. A valve closing detection device for detecting a closed state of the movable shaft, wherein: a position detecting means for detecting a position of a movable element of the actuator interlocked with the rotary shaft; and a closing corresponding to a position range of the movable element in which the valve is closed. When it is determined that the position of the movable element detected by the position detecting means is within a position range corresponding to the closing position data stored by the storing means storing the position data, Determining means for determining that the valve is in a closed state; and a position of the movable element detected by the position detecting means. Valve closing detecting apparatus comprising: an updating means for storing the updated the storage means the closed position data Hazuki, the. 2. When the movable element is operated so that the valve is closed and the movable element is stopped, and when the determination means determines that the valve is in the closed state, the updating means sets the valve in the closed state. The valve closing detection device according to claim 1, wherein the closing position data is updated. 3. The new updating means subtracts a first predetermined value and adds a second predetermined value to position data corresponding to the position of the mover detected by the position detecting means. 3. The valve closing detection device according to claim 1, wherein the closing position data is created. 4. The valve closing detecting device according to claim 1, wherein said position detecting means is an encoder. 5. The valve closing detection device according to claim 1, wherein said storage means is a nonvolatile memory. 6. The valve closing detection device according to claim 1, further comprising a display unit that displays a result of the determination by the determination unit.