JP2001021052A - Diaphragm valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely discover the operation failure of a diaphragm valve while maintaining a basic valve structure. SOLUTION: A diaphragm valve is constructed in such a manner that a conductive film 20 is deposited on the contact surface of the diaphragm presser 14A of a driving body 14 with a diaphragm 13, the conductive film 20 of the diaphragm presser 14A and the diaphragm 13 are electrically brought into contact with each other, and in the conductive film 20 and the diaphragm 13, a photocoupler 21 is provided as a means for detecting conduction between these parts 20 and 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm valve, and more particularly, to a diaphragm valve that can easily and reliably detect a malfunction if there is a malfunction.

[0002]

2. Description of the Related Art In a production plant, various pipes are laid to supply and discharge fluids such as gas and liquid. Various types of valves are used for controlling the flow rate of the fluid in these pipes. A diaphragm valve is used as one of such valves for flow control. Diaphragm valves are widely used in semiconductor manufacturing plants that do not like impurities such as dust since there is no portion that generates dust such as sliding portions on the fluid flow path side.

As shown in FIG. 3, for example, a diaphragm valve is provided with a flow passage 2 formed in a valve body (body) 1.
A metal diaphragm 3 for opening and closing the flow path 2;
A driving body 4 that comes into contact with the diaphragm 3 and drives the diaphragm 3, and the bulge of the central portion of the diaphragm 3 elastically deforms following the elevation of the driving body 4 and is fixed to the flow path 2. The flow path 2 is opened and closed by being separated from and brought into contact with a ring sheet 5 made of steel. Body 1
A holding member 6 for holding the periphery of the diaphragm 3 against the ring-shaped projection 1A is housed therein, and the holding member 6 is fixed by a bonnet 7 screwed inside the body 1. The arrows in FIG. 3 indicate the flow direction of the fluid.

[0004] Thus, as shown in FIG.
A diaphragm holder 4A made of synthetic resin for pressing the bulge at the central portion of the diaphragm 3, a metal disk 4B fitted with the diaphragm holder 4A on the lower surface and having a larger diameter than the diaphragm holder 4A, A stem 4C connected to the upper end, and a diaphragm holder 4A
Are in contact with the bulge at the center of the diaphragm 3.
Therefore, when the driving body 4 descends, the bulge at the central portion of the diaphragm 3 is pressed to close the flow path 2, and when the driving body 4 rises, the bulge at the central part of the diaphragm 3 returns with its elasticity to open the flow path 2. . At this time, the driving body 4 is
In the range of the gap δ formed between the flange portion and the reduced diameter portion of the bonnet 7.

[0005]

However, in the conventional diaphragm valve, the bulge at the central portion of the diaphragm 3 resiliently moves up and down following the driving body 4 so that it repeatedly flows and separates from the ring sheet 5. Since the path 2 is opened and closed, the diaphragm 3 does not follow the movement of the driver 4 even when the driver 4 rises as shown in FIG. There is a problem that even if an operation failure occurs, the operation failure does not occur, and such an operation failure cannot be found. Therefore, it is necessary to determine whether or not there is a malfunction in all valves of the piping system, and there is a problem that a great deal of time and labor is consumed for the determination.

Japanese Unexamined Patent Publication No. 6-101774 proposes a technique for detecting breakage of a diaphragm or the like. However, this technique cannot detect a malfunction when the diaphragm is separated from a driving body. Also, Japanese Patent Publication No. 577-1
No. 0364 proposes a flow rate sensing device which has a diaphragm and an operating rod connected to the diaphragm, detects movement of the diaphragm via the operating rod, and causes an abnormal flow rate in the gas pipe. It is used as a pressure sensing means and not as a valve.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a diaphragm valve which can easily and reliably know a malfunction of a diaphragm while maintaining a basic valve structure. I have.

[0008]

According to a first aspect of the present invention, there is provided a diaphragm valve comprising: a valve body; a flow path formed in the valve body; a conductive diaphragm for opening and closing the flow path; A driving body which comes into contact with the diaphragm and drives the diaphragm; and a means for electrically contacting the driving body and the diaphragm and detecting conduction between the two is provided. .

A diaphragm valve according to a second aspect of the present invention is the diaphragm valve according to the first aspect, wherein a conductive film is provided on a contact surface of the driving body with the diaphragm. is there.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. The diaphragm valve 10 of the present embodiment has basically the same structure as a conventional one as shown in FIG. 2, for example. That is, the diaphragm valve 10 of the present embodiment includes a metal valve body (body) 11 made of stainless steel or the like, a flow path 12 formed in the body 11, and a nickel alloy or the like that opens and closes the flow path 12. A diaphragm 13 made of a metal or other conductive material having conductivity, and a driving body 14 that contacts the diaphragm 13 and drives the diaphragm 13, and the diaphragm 13 follows the movement of the driving body 14 to flow. Ring sheet 15 made of synthetic resin fixed to road 12
The flow path 12 is opened and closed by contacting and separating from the flow path. Diaphragm 1
3 has its peripheral edge fixed by the protrusion 11A, the pressing member 16 and the bonnet 17, and the bulge at the center moves up and down via the driving body 14, and opens and closes the flow path 12 as described above. The pressing member 16 and the bonnet 17 are also formed of metal such as stainless steel. The driving body 14 has a diaphragm holder 14A, a disk 14B and a stem 14C made of synthetic resin. Incidentally, in FIG.
Is a bonnet nut, and 19 is a drive source of the driving body 14.

In this embodiment, the diaphragm 13
And the diaphragm retainer 14A are in electrical contact with each other in a freely conductive manner. That is, as schematically shown in FIG. 1, a conductive film 20, such as a metal thin film, is adhered to the contact surface of the diaphragm retainer 14A with the diaphragm 13, and the conductive film 20 and the diaphragm 13 adhere to each other and conduct with each other. It is free. The conductive film 20 may be formed on the contact surface with the diaphragm 13, or may be formed on at least a part of the contact surface of the diaphragm holder 14 </ b> A and can conduct with the diaphragm 13.

Further, as shown in FIG. 1, a photocoupler 21 is electrically connected between the driving body 14 and the diaphragm 13 as means for detecting whether or not the two are electrically connected to each other. When the diaphragm holder 14A (drive body 14) separates from the diaphragm 13 due to a contact failure with the diaphragm 20, a contact failure (conduction failure) between the two 13 and 14 is detected as an operation failure via the photocoupler 21 and a control device (shown in the drawing). )). The photocoupler 21 includes a light emitting diode 21A and a phototransistor 21B, and operates at a power supply voltage Vcc (for example, 5 V). As schematically shown in FIG.
The conductive wire 22 on the anode side of A is connected to the diaphragm 13 side, and the conductive wire 23 on the cathode side is connected to the conductive film 20 side which covers the diaphragm holder 14A through the through hole 14D in the axial direction of the driver 14. . For example, an insulating coating is formed on the cathode-side conductor 23, and this conductor 23
And the constituent members of the driving body 14, the diaphragm retainer 14A,
No short circuit occurs between the disk 14B and the stem 14C.

The phototransistor 21B is connected to a control device.
The on / off signal of B is monitored. When an abnormal signal is detected by the photocoupler 21, an alarm (not shown) such as an alarm lamp or an alarm is activated to notify that the diaphragm 13 has been separated from the diaphragm holder 14A, that is, an operation failure. I have.

Next, the operation will be described. For example, when the flow path 12 of the diaphragm valve 10 is opened, when the driving body 14 rises via the driving source 19, the diaphragm 1
The bulge of the central portion of 3 follows the movement of the driving body 14 and resiliently returns to the original state in which the pressing force is not received, and separates from the ring sheet 15 to open the flow channel 12 in the direction indicated by the arrow in FIG. Flow fluid to When the flow path 12 is closed, the driving source 1
When the driving body 14 descends via the diaphragm 9, the diaphragm 13
The bulge at the central portion of the is elastically deformed and pressed by the driving body 14 to be seated on the ring seat 15 to close the flow path 12 and cut off the fluid flow.

When the diaphragm is deteriorated, the diaphragm 13 cannot follow the movement of the driving body 14 when the flow path 12 is opened, and the driving body 14 rises from the position shown by the solid line to the position shown by the one-dot chain line as shown in FIG. Even if the bulge at the center of the diaphragm 13 is depressed while sitting on the ring sheet 15, the channel 12 may not be opened without returning to the original state. In such a case, in the present embodiment, when the diaphragm holder 14A of the driver 14 moves away from the diaphragm 13, a current flows through the light emitting diode 21A of the photocoupler 21 to emit light, and this optical signal is transmitted to the phototransistor 2
1B, the control device activates an alarm based on a signal from the phototransistor 21B, and automatically notifies the diaphragm valve 10 that an operation failure has occurred.

As described above, according to the present embodiment,
A conductive film 20 is applied to a contact surface of the diaphragm retainer 14A of the driving body 14 with the diaphragm 13, and the conductive film 20 of the diaphragm retainer 14A and the diaphragm 13 are brought into electrical contact with each other. When the flow path 12 is opened, the diaphragm 13 does not follow the movement of the driving body 14, that is, the diaphragm presser 14A, so that the diaphragm 13 does not follow the movement of the diaphragm 13. When the presser 14A is released, the photocoupler 21 detects that fact, notifies the operation failure of the diaphragm 13 via the control device, and automatically detects the operation failure of the diaphragm valve 10, and, as a result, in the piping system. Easily and surely identifies the diaphragm valve 10 having a malfunction Door can be.

Further, even if the driving body 14 operates suddenly and the diaphragm 13 cannot follow the driving body 14 and the driving body 14 is temporarily separated from the diaphragm 13, the bulge of the central portion of the diaphragm 13 is increased. It may return to the original state in a short time and come into contact with the driving body 14. In such a case, in the control device, the temporary separation of the driving body 14 and the diaphragm 13 is not treated as an operation failure, so that a malfunction does not occur.

Further, by providing a light emitting diode instead of the photocoupler 21 as means for detecting the presence or absence of conduction between the diaphragm 13 and the conductive film 20 of the diaphragm holder 14A, the lighting of the light emitting diode can be directly visually recognized. It is also possible to know the operation failure of the diaphragm valve 10.

In the above embodiment, the case where a photocoupler or a light emitting diode is provided as the conduction detecting means has been described. However, any other means that can detect the presence or absence of conduction between the conductive film 20 and the diaphragm 13 can be used. Detection means can be used.

[0020]

According to the first and second aspects of the present invention, there is provided a diaphragm valve capable of easily and reliably detecting a malfunction of a diaphragm while maintaining a basic valve structure. be able to.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a main part of an embodiment of a diaphragm valve of the present invention.

FIG. 2 is a sectional view showing a main part of a mechanical structure of the diaphragm valve shown in FIG.

FIG. 3 is a sectional view of a main part showing an example of a conventional diaphragm valve.

FIG. 4 is a cross-sectional view showing a state of malfunction of the diaphragm valve shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Diaphragm valve 11 Body (valve main body) 12 Flow path 13 Diaphragm 14 Driver 20 Conductive film 21 Photocoupler (Conduction detecting means)

Claims (2)

[Claims] A valve body, a flow path formed in the valve body, a conductive diaphragm that opens and closes the flow path, and a driver that contacts the diaphragm and drives the diaphragm. A diaphragm valve provided with means for electrically contacting the driving body and the diaphragm and detecting conduction between the two. 2. The diaphragm valve according to claim 1, wherein a conductive film is provided on a contact surface of the driving body with the diaphragm.