JPH0783351A - Method and device for displaying opening/closing of valve body - Google Patents

Abstract

PURPOSE:To provide a method for displaying opening/closing of a valve body and its device accurate and further simple by detecting a change of force applied to the valve body. CONSTITUTION:A valve body 7 is placed in a valve closing condition, when brought into pressure contact with a valve seat 35, and in a valve opening condition when released from the press contact, and in a prescribed part of a valve actuator 1 serving as driving the valve body 7, distortion is generated by moving this valve body opened/closed. By taking out this distortion by a strain gage 40, opening/closing the of the valve body 7 are accurately displayed outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opening / closing display of a valve body, and more particularly to a valve body opening / closing display method and apparatus for a valve actuator for controlling the flow of a high pressure fluid.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for valve actuators that handle high-pressure gas or vacuum in semiconductor factories, chemical factories and the like.

Such a valve actuator has an accurate and strong control force, and also has an opening / closing stroke of the valve body.
The distance between the so-called valve body and the valve seat is very small. Due to this minute stroke, it is not possible to accurately determine whether the valve body is open or closed by a normally used limit switch or the like. As a countermeasure, it is possible to increase the accuracy by amplifying the movement of the piston of the valve body, but the structure becomes complicated.

Therefore, there is a technique using a magnetic sensor as disclosed in Japanese Laid-Open Patent Publication No. 60-155078. For example, a magnet is embedded in a piston made of tetrafluoroethylene resin and the outer wall of a cylinder corresponding to the magnet is embedded. Has two Hall element sensors attached.

The position of the hall element sensor is the position where the piston is lowered, that is, the position of the gas on-off valve is OFF (closed), and the position of the hall element sensor is the position where the piston is raised, that is, the position of the on-off valve is turned on (open). ) Position. In this way, the Hall element changes the offset voltage due to the magnetic field generated by the magnet, and the stop position of the piston can be confirmed by detecting it.

[0006]

However, in order to accurately obtain the change in the magnetic field, a predetermined relative movement range between the piston and the cylinder is required, and even if this device is used, the inaccuracy cannot be denied.

According to the present invention, an accurate and simple method for displaying and opening a valve body and its apparatus are realized by detecting not a movement of a valve body, a piston, a cylinder or the like but a change of a force exerted on the valve body. The purpose is to provide.

[0008]

According to the valve body open / close display method of the present invention, the strain of a predetermined portion of the valve actuator generated by the drive of the valve actuator for opening / closing the valve body is measured by a strain gauge, and the change of the strain is measured. It is characterized in that whether the valve body is in the valve opening position or the valve closing position is displayed outside the valve actuator.

The valve disc open / close display device of the present invention is a valve actuator for opening / closing a valve disc, and a strain gauge is attached to a predetermined portion where a strain is generated by being used for driving the valve disc. It is characterized in that the opening and closing of the valve is displayed to the outside by applying a predetermined voltage to the strain gauge and converting the change in strain into a change in voltage.

[0010]

The valve element is in a closed state when the valve element is pressed against the valve seat, and in an open state when the pressure contact is released. The predetermined portion of the valve actuator used to drive the valve element is distorted by the opening / closing movement. Occur. By taking out this strain with a strain gauge, the opening and closing of the valve element can be accurately displayed on the outside.

[0011]

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

The valve actuator 1 of the present invention has, as basic constituent elements, a housing composed of a bottom plate 2, a cylinder body 3 and a lid body 4, and a first housing slidably accommodated in the housing.
And second pistons 5, 6.

The first piston 5 integrally has a valve operating rod 8 for operating the valve body 7, and this valve operating rod 8
Penetrates the second piston 6 and contacts the upper end surface of the valve body 7 in the valve housing 9. Further, the first piston 5 is biased in the direction of closing the valve body 7 by a disc spring 10 as a biasing means that is contracted between the first piston 5 and the lid body 4 of the housing. As shown in FIG. 2, for example, four strain gauges 40 are attached to both sides of the disc spring 10, and the strain gauges 40 form a bridge on the circuit as described later and the inside of the lid body 4 is formed. The electric wire 41 is taken out to the outside through the through hole 13 for communicating the space 14 of the above with the outside air.

The lid 4 of the housing is, for example, a threaded portion 1
It can be fixed to the cylindrical body 3 via 1. However, in this case, the detent pin 12 should be interposed between the lid body 4 and the first piston 5 so that an undesired turning torque does not act on the compression spring 10 when the lid body 4 is screwed. Is.

The second piston 6 which is penetrated by the valve operating rod 8 of the first piston 5 has a small diameter portion 15 and a large diameter portion 16.
Is a stepped piston having a reduced diameter portion 17 of the cylindrical body 3.
It faces the first piston 5 with a small diameter portion 15 that slides inside.

A space surrounded by the cylindrical body 3, the first piston 5 and the small diameter portion 15 of the second piston 6 constitutes a pressure increasing chamber 18, and is formed by a dichroic oil 19 as an incompressible fluid. be satisfied. in this case,
As is apparent from the drawing, the first
The pressure receiving area of the piston 5 is the small diameter portion 1 of the second piston 6.
5 is larger than the pressure receiving area.

In order to easily fill and discharge the dichroic oil 19 and adjust the capacity of the pressure boosting chamber 18,
The first piston 5 has a small diameter portion 20 extending through the lid 4 of the housing toward the side opposite to the pressure increasing chamber 18.
And a plurality of through holes 40 are formed in the small diameter portion 20.
A passage 21 that communicates with the pressure boosting chamber 18 via a valve, and an adjusting sealing screw 23 that is screwed into a screw hole 22 on the outlet side of the passage 21 are provided.

The large-diameter portion 16 of the second piston 6 cooperates with the cylindrical body 3 of the housing and the bottom plate 2 to form a pressurizing chamber 24. Compressed air, nitrogen gas, or the like can be introduced into the pressurizing chamber 24 through a connector member 26 connected to the through hole 25 of the bottom plate 2.

Further, a cup-shaped guide member 27 is fixed to the bottom plate 2 of the housing, and the valve operating rod 8 penetrates the center of the guide member 27 and projects outward. Also,
The guide member 27 has a recess 28 so as to surround the valve operating rod 8.
And a relatively weak compression spring 29 for constantly urging the second piston 6 toward the first piston 5 is provided in the recess 28. This compression spring 2
Since the pressure increasing chamber 18 is always pressurized to the atmospheric pressure or more through the second piston 6 by 9, the outside air does not enter the pressure increasing chamber 18 at all, and the volume of the pressure increasing chamber 18 increases. Has a secure function.

The valve actuator 1 having such a structure is
It is connected in any way to a valve chamber opening 33 of the valve housing 9 having an inlet passage 30, an outlet passage 31 and a valve chamber 32. A compression spring 34 is provided in the valve chamber 32 of the valve housing 9.
The valve body 7 biased in the valve opening direction is accommodated therein, and the valve operating rod 8 of the first piston 5 is in contact with the upper end surface of the valve body 7 as described above.

In the above structure, each coupling portion and sliding portion are provided with various kinds of O-rings (for example, 38) for ensuring the sealing, and the valve body 7 is provided in the valve chamber 32. Valve seat insert 3 for sealing the provided valve seat 35
6 is provided.

The space 37 located above the large diameter portion 16 of the second piston 6 communicates with the atmosphere via a passage 39.

Next, the operation will be described.

First, when the pressurized fluid is not supplied to the pressurizing chamber 24, the second piston 6 is always urged upward by the relatively weak compression spring 29. When the pressure of the hydraulic oil 19 rises, the second piston 6 moves downward against the compression spring 29 and absorbs the pressure. Therefore, since the volume of the pressure boosting chamber 18 due to the fine movement of the first piston 5 is ensured to be constant, the first piston 5 does not cause the locking phenomenon and the urging force of the strong disc spring 10 is almost completely eliminated. It can be transmitted to the valve body 7 via the valve actuating rod 8 and therefore the valve seat insert 36 of the valve body 7 can be moved with sufficient force to the valve seat 35.
Pressed against. In this way, the inlet passage 30 and the outlet passage 31 are completely shut off by the valve body 7.

Next, when a pressure fluid is supplied into the pressurizing chamber 24 through the connector member 26, the pressure of the pressure fluid acts on the large diameter portion 16 of the second piston 6, so
The piston 6 rises and presses the dichroic oil 19 in the pressure boosting chamber 18 with the small diameter portion 15. In this case, since the pressure receiving area of the first piston 5 is larger than the pressure receiving area of the small diameter portion 15 of the second piston 6, the second piston 6 to the first piston 5 are driven by Pascal's principle.
The amplified push-up force is transmitted to. In other words, the pressure of the pressure fluid to be supplied to the pressurizing chamber 24, which is necessary to push up the first piston 5 against the strong disc spring 10, is smaller than the conventional pressure.

When the first piston 5 rises together with the valve operating rod 8, the valve body 7 also rises due to the biasing force of the compression spring 34, and when the valve seat insert 36 is separated from the valve seat 35, the inlet passage 30 And the outlet passage 31 are connected.

In this way, the inlet passage 30 and the outlet passage 31
When the valve element 7 is disconnected or connected by the valve element 7, force is constantly applied to the disc spring 10, but the valve element 10 is separated from the valve seat 35 more than when the valve element 7 contacts the valve seat 35. In this case, the strain applied to the disc spring 10 becomes larger.

This distortion is taken out as a signal by the circuit shown in FIG. That is, four strain gauges 40 form a bridge circuit 42, a voltage of, for example, 2 volts is applied to the point a from the circuit 47 through the constant voltage circuit 43, and the point c is grounded by the circuit 48. . Also, b
The points a and a are tangent to the amplifier circuit 44, and the circuit 47 is also connected to the amplifier circuit. The amplifier circuit 44 is a comparison circuit 45.
It is connected to the signal circuit 46 via the so that the output signal can be taken out from the line 49.

Therefore, if the comparison circuit is adjusted and the above-mentioned state where the valve body 7 is in contact with the valve seat 35 is set as the standard point of the signal, when the valve body 7 separates from the valve seat 35, the signal output is performed. A potential signal flows from circuit 46 via line 49. By changing this signal into a light emission signal using a lamp or a light emitting diode (LED), the opening / closing of the valve body can be easily confirmed from the outside.

FIG. 4 and FIG. 5 show a second embodiment of the present invention. The valve actuator 1 is similar to that of the first embodiment, but the piston receives air pressure directly and the valve body is It is a form of opening up.

The valve body 50 is connected to a piston 52 by a valve operating rod 51, and the piston 52 is surrounded by a cylindrical body 54 together with an upper bellows 53. In addition, compressed air can be pressed into the space between the cylindrical body 54 and the piston 52 from an upper through hole 55.

Inside the piston 52 and the bellows 53, a coil spring 56 for pressing the piston 52 downward is interposed between the lid 58 and the piston 52 via an annular pressing piece 57. The lid 58 has a through hole 59 for communicating the inside of the bellows 53 with the outside air, and a portion where the annular pressing piece 57 abuts downward is a thin portion 60.

A strain gauge 40 is attached to the upper surface of the thin portion 60, and an upper portion of the strain gauge 40 is made of epoxy resin or the like.
The signal is taken out by the electric wire 41 as in the first embodiment.

FIG. 5 shows the adhered portion of the strain gauge 40. When compressed air is introduced from the through hole 55 and the valve body 50 is opened, compressive strain is generated in the coil spring 56, The annular pressing piece 57 intensively applies a pressing force to the thin portion 60. Therefore, distortion occurs in the thin portion 60, and the thin portion undergoes a slight deformation as shown by the broken line, and this distortion is taken out as a valve opening / closing signal in the same circuit as in the first embodiment.
The upper portion of the annular pressing piece 57 is tapered, so that stress can be easily collected.

As described above, in the present invention, the signal due to the movement of the valve disc is not used, but the strain at a predetermined position associated with the opening / closing of the valve disc is measured and the opening / closing of the valve disc is displayed. Accurate open / close display of the valve body is possible without causing malfunction of the open / close display.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions may be made without departing from the scope of the present invention. Included in the present invention. For example, in the present embodiment, four strain gauges are used to accurately display the open / closed state of the valve body, but it is also possible to extract the change in resistance due to strain with one strain gauge and to extract it as a voltage change. it can.

[0037]

When the valve body is pressed against the valve seat, the valve is closed, and when the pressure contact is released, the valve is open. , Distortion occurs. By taking out this strain with a strain gauge, the opening / closing of the valve body can be accurately displayed to the outside.

[0038]

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the present invention in a closed position.

FIG. 2 is a perspective view of a disc spring portion of the embodiment.

FIG. 3 is a circuit diagram of a strain gauge of the same example.

FIG. 4 is a vertical cross-sectional view of a second embodiment of the present invention in a closed position.

FIG. 5 is a local enlarged cross-sectional view of the same embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Valve actuator 2 Bottom plate 3 Cylindrical body 4 Lid body 5 First piston 6 Second piston 7 Valve body 8 Valve operating rod 9 Valve housing 10 Disc spring 11 Threaded part 12 Whirl-stop pin 13 Through hole 14 Space 15 Small diameter part 16 Large Diameter Part 17 Reduced Diameter Part 18 Pressure Boosting Chamber 19 Dycron Oil 20 Small Diameter Part 21 Passage 22 Screw Hole 23 Adjusting Seal Screw 24 Pressurizing Chamber 25 Through Hole 26 Connector Member 27 Guide Member 28 Recess 29 Compressor Spring 30 Inlet Passage 31 Exit Passage 32 Valve chamber 33 Valve chamber opening 34 Compression spring 35 Valve seat 36 Valve seat insert 37 Space 38 O-ring 39 Passage 40 Strain gauge 41 Wire 42 Bridge circuit 43 Constant voltage circuit 44 Amplification circuit 45 Comparison circuit 46 Signal circuit 47 Line 48 Line 49 Line 50 Valve body 51 Valve operating rod 52 Piston 53 Snake 54 the cylindrical body 55 through hole 56 coil spring 57 annular pressing piece 58 lid 59 hole 60 thin portion 61 sealing material

[Procedure amendment]

[Submission date] October 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

SUMMARY OF THE INVENTION A valve disc open / close display method according to the present invention measures a strain of a predetermined portion of a valve actuator generated by driving a valve actuator that opens and closes the valve disc, extracts a change in the strain, and The body is in the open position,
The feature is that whether the valve is in the closed position or not is displayed outside the valve actuator.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

The valve element is in a closed state when the valve element is pressed against the valve seat, and in an open state when the pressure contact is released. The predetermined portion of the valve actuator used to drive the valve element is distorted by the opening / closing movement. Occur. By taking out this strain, the opening / closing of the valve body is accurately displayed to the outside.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

[0037]

When the valve body is pressed against the valve seat, the valve is closed, and when the pressure contact is released, the valve is open. , Distortion occurs. By extracting this strain, the opening / closing of the valve body can be accurately displayed to the outside.

Claims (4)

[Claims] 1. A strain of a predetermined portion of a valve actuator generated by driving a valve actuator that opens and closes a valve body,
A valve body open / close display method characterized by measuring with a strain gauge, taking out this change in strain, and displaying outside the valve actuator whether the valve body is in a valve opening position or a valve closing position. 2. A valve actuator for opening and closing a valve body, wherein a strain gauge is attached to a predetermined portion where strain is generated by being used for driving the valve body, and a predetermined voltage is applied to the strain gauge, A valve body opening / closing display device, which displays the opening / closing of a valve by converting a change in strain into a change in voltage. 3. The valve element open / close display device according to claim 2, wherein a strain gauge is attached to a disc spring that biases the valve element. 4. The valve body open / close display device according to claim 2, wherein a thin portion is provided on a lid that closes the valve actuator from above, and a strain gauge is attached to the thin portion.