WO2018037786A1 - Diaphragm valve - Google Patents

Abstract

This diaphragm valve (18) is provided with: a housing (20, 30) having formed therein a fluid flow path (21) and a valve chamber (22); a valve seat (24) provided in the housing (20, 30) so as to annularly surround the opening of the flow path (21), which is open to the valve chamber (22); a diaphragm valve body (40) which is formed from a resin, divides the valve chamber (22) into the fluid flow path (21) and a non-flow path, and moves into contact with and away from the valve seat (24); a reciprocating member (61) connected to the diaphragm valve body (40) and reciprocating in a predetermined direction, which is the direction in which the reciprocating member (61) moves toward and away from the valve seat (24); a pressing section (70, 12) for applying force to the reciprocating member (61) to press the diaphragm valve body (40) against the valve seat (24); and a restriction member (91, 94) which is formed in a thin plate-like shape from metal, is mounted to the outer edge of the reciprocating member (61) extending in the predetermined direction, deforms in the predetermined direction to permit the reciprocation of the reciprocation member (61), and restricts the movement of the reciprocation member (61) in the direction perpendicular to the predetermined direction.

Description

Diaphragm valve Cross-reference of related applications

This application is based on Japanese Patent Application No. 2016-163996 filed on August 24, 2016, the contents of which are incorporated herein by reference.

The present disclosure relates to a diaphragm valve that connects a diaphragm valve body to a reciprocating member and opens and closes a flow path by the diaphragm valve body by reciprocating the reciprocating member.

Conventionally, in this type of diaphragm valve, a first piston portion urged in a direction approaching the valve seat by a first spring, and a slidably accommodated in the housing body, the first piston portion is accommodated inside. Some include a second piston portion that is biased toward the valve seat by a second spring (see Patent Document 1). In the thing of patent document 1, a 1st piston part descend | falls ahead of a 2nd piston part, and a 2nd piston part descend | falls after that, and the impact at the time of a valve body seating on a valve seat is carried out. It relaxes to suppress the generation of particles.

JP 2012-107695 A

By the way, the thing of patent document 1 has suppressed generation | occurrence | production of the particle by the impact when a valve body seats on a valve seat. However, the one described in Patent Document 1 is the generation of particles due to the rubbing of the valve body and the valve seat due to the swing of the central axes of the first piston and the second piston (reciprocating member), and the valve body. It is impossible to suppress the generation of particles due to the slanting and hitting the valve seat.

The present disclosure has been made to solve these problems, and provides a diaphragm valve capable of suppressing the generation of particles due to the swing of the central axis of a reciprocating member connected to the diaphragm valve body. There is.

The first means for solving the above problem is a diaphragm valve,
A housing in which a fluid flow path and a valve chamber are formed;
In the housing, a valve seat provided annularly around the opening of the flow path with respect to the valve chamber;
A resin diaphragm valve body that divides the valve chamber into a flow path and a non-flow path of the fluid, and contacts and separates from the valve seat;
A reciprocating member connected to the diaphragm valve body and reciprocating in a predetermined direction which is a direction approaching and separating from the valve seat;
A pressing portion that applies a force to the reciprocating member to press the diaphragm valve body against the valve seat;
A direction that is formed in a thin plate shape with metal and is attached to the outer edge of the reciprocating member that penetrates in the predetermined direction, deforms and permits the reciprocating motion of the reciprocating member in the predetermined direction, and is perpendicular to the predetermined direction A regulating member for regulating the movement of the reciprocating member to
Is provided.

According to the above configuration, the fluid flow path and the valve chamber are formed in the housing. In the housing, an annular valve seat is provided around the opening of the flow path with respect to the valve chamber. The valve chamber is partitioned into a fluid flow path and a non-flow path by a resin diaphragm valve body, and the diaphragm valve body is brought into contact with and separated from the valve seat. A reciprocating member is connected to the diaphragm valve body, and the reciprocating member is reciprocated in a predetermined direction which is a direction approaching and separating from the valve seat. A force is applied to the reciprocating member by the pressing portion, and the diaphragm valve body is pressed against the valve seat. When the diaphragm valve body is pressed against the valve seat, the flow path is closed, and when the diaphragm valve body is separated from the valve seat, the flow path is opened.

Here, since the diaphragm valve body is made of resin and the diaphragm portion needs to be flexible, it can be deformed in a direction other than the direction in which the valve seat comes into contact with or separates from the valve seat. For this reason, when the reciprocating member is reciprocated in a predetermined direction, the effect that the diaphragm valve body regulates that the central axis of the reciprocating member swings is small. When the center axis of the reciprocating member is shaken, particles may be generated by rubbing the diaphragm valve body and the valve seat, or by tilting the diaphragm valve body and hitting the valve seat.

In this regard, according to the above configuration, the reciprocating member passes through the regulating member formed in a thin plate shape with metal in the predetermined direction, and the regulating member is attached to the outer edge of the reciprocating member. Since the regulating member is formed in a thin plate shape with metal, the strength is higher than that of the diaphragm portion of the resin diaphragm valve body. The restricting member deforms and allows the reciprocating motion of the reciprocating member in a predetermined direction and restricts the movement of the reciprocating member in a direction perpendicular to the predetermined direction. For this reason, it is possible to suppress the swing of the central axis of the reciprocating member while allowing the reciprocating member to reciprocate in a predetermined direction and allow the diaphragm valve body to open and close the flow path. As a result, it is possible to suppress the generation of particles due to the swing of the central axis of the reciprocating member connected to the diaphragm valve element.

When only one regulating member is attached to the outer edge of the reciprocating member, the movement of the reciprocating member in the direction perpendicular to the predetermined direction can be regulated at the position of the regulating member. However, the central axis of the reciprocating member may be inclined with the position of the restricting member as a fulcrum.

In this regard, in the second means, the restriction member includes a first restriction member, a second restriction member attached to an outer edge of the reciprocating member at a position farther from the valve seat than the first restriction member, and Is included. Therefore, the position of the first restricting member and the position of the second restricting member attached to the outer edge of the reciprocating member at a position away from the valve seat from the first restricting member in a direction perpendicular to the predetermined direction. The movement of the reciprocating member can be restricted. Therefore, the central axis of the reciprocating member can be prevented from being inclined, and the generation of particles can be further suppressed.

Specifically, as in the third means, the first restricting member is attached to the end of the valve seat in the reciprocating member, and the second restricting member is in the reciprocating member. A configuration in which the valve seat is attached to an end opposite to the valve seat can be employed. According to such a structure, the space | interval of a 1st control member and a 2nd control member can be enlarged, and it can suppress effectively that the center axis | shaft of a reciprocating member tilts.

In the fourth means, the rotation of the regulating member relative to the housing around the reciprocating member is regulated.

According to the above configuration, since the rotation of the regulating member relative to the housing around the reciprocating member is regulated, the rotation of the reciprocating member and the diaphragm valve body can be regulated. For this reason, while being able to make the location of the diaphragm valve body which contact | abuts to a valve seat the same every time, it can suppress that a diaphragm valve body rubs with respect to a valve seat in the rotation direction centering on a reciprocating member. . Therefore, the generation of particles can be further suppressed.

In the fifth means, the restricting member is a metal diaphragm formed of metal.

According to the above configuration, since the restricting member is a metal diaphragm formed of metal, it can function as a diaphragm that suppresses the swing of the central axis of the reciprocating member and prevents fluid from entering.

In the sixth means, the metal diaphragm is a corrugated metal diaphragm having a corrugated cross section in the thickness direction passing through the center.

According to the above configuration, the metal diaphragm is a corrugated metal diaphragm having a wavy cross-sectional shape passing through the center. For this reason, the metal diaphragm has a characteristic that it is easily deformed in the predetermined direction and is not easily deformed in a direction perpendicular to the predetermined direction. Therefore, it is possible to effectively suppress the center axis of the reciprocating member from swinging while appropriately allowing the reciprocating member to reciprocate in a predetermined direction.

In the seventh means, the reciprocating member includes a first reciprocating member that reciprocates in the predetermined direction with respect to the housing, and the first reciprocating member supported by the first reciprocating member. A second reciprocating member that reciprocates in a predetermined direction, and the pressing portion reciprocates the first reciprocating member in the predetermined direction with respect to the housing; and the valve seat; A stopper for stopping movement of the first reciprocating member in a direction approaching the valve seat with a predetermined gap between the diaphragm valve body and the first reciprocating member in the predetermined direction with respect to the first reciprocating member; A second actuator that reciprocates the two reciprocating members.

According to the above configuration, the first reciprocating member is moved toward the valve seat by the first actuator, and the movement is stopped by the stopper, so that there is a predetermined gap between the valve seat and the diaphragm valve body. can do. For this reason, before making a valve seat and a diaphragm valve body contact | abut, the state which has a predetermined clearance gap between a valve seat and a diaphragm valve body is reliably realizable. In this state, the second actuator moves the second reciprocating member toward the valve seat with respect to the first reciprocating member, thereby reducing the collision between the valve seat and the diaphragm valve element. A diaphragm valve body can be brought into contact with the seat.

In an eighth means, the first actuator includes a first urging member that urges the first reciprocating member in a direction approaching the valve seat, and the first reciprocating member is moved by the first gas pressure. A gas pressure actuator that moves in a direction away from the valve seat, wherein the second actuator includes a second biasing member that biases the second reciprocating member in a direction away from the valve seat; A gas pressure actuator that moves the second reciprocating member in a direction to approach the valve seat.

According to the above configuration, the first urging member urges the first reciprocating member toward the valve seat. Then, the first reciprocating member is moved in a direction away from the valve seat by the first gas pressure. For this reason, by reducing the first gas pressure, the first reciprocating member can be moved in the direction approaching the valve seat, and the state in which the movement of the first reciprocating member is stopped by the stopper can be easily realized. Can do.

Further, the second urging member urges the second reciprocating member in a direction away from the valve seat. Then, the second reciprocating member is moved in the direction approaching the valve seat by the second gas pressure. Therefore, by adjusting the second gas pressure, the speed at which the diaphragm valve body approaches the valve seat and the force with which the diaphragm valve body is pressed against the valve seat can be adjusted.

The ninth means comprises a diaphragm valve of the eighth means, and is a control device for controlling the diaphragm valve,
The first reciprocating member is moved closer to the valve seat by lowering the first gas pressure from the state in which the first actuator is moved away from the valve seat by the first actuator. After moving until stopped by the stopper,
By raising the second gas pressure by the second actuator, the second reciprocating member is moved in a direction approaching the valve seat, and the diaphragm valve body is pressed against the valve seat.

According to the above configuration, the first reciprocating member is moved closer to the valve seat by reducing the first gas pressure from the state in which the first actuator is moved in the direction away from the valve seat by the first actuator. It is moved until it is stopped by the stopper. For this reason, the state in which the movement of the first reciprocating member is stopped by the stopper can be easily realized.

Thereafter, by raising the second gas pressure by the second actuator, the second reciprocating member is moved in the direction approaching the valve seat, and the diaphragm valve body is pressed against the valve seat. Therefore, by adjusting the second gas pressure from a state where there is a predetermined gap between the valve seat and the diaphragm valve body, the speed at which the diaphragm valve body approaches the valve seat, and the diaphragm valve body is pressed against the valve seat. The power can be adjusted.

In the tenth means, the speed at which the first actuator moves the first reciprocating member in the direction approaching the valve seat is moved in the direction in which the second actuator moves the second reciprocating member closer to the valve seat. The speed is set higher than

According to the above configuration, after moving the first reciprocating member in the direction approaching the valve seat until it is stopped by the stopper, the diaphragm valve body can be pressed against the valve seat at a slower speed. Therefore, the collision between the valve seat and the diaphragm valve body can be alleviated while suppressing the time required for closing the flow path by the diaphragm valve body from being increased.

In the eleventh means, the rising speed of the second gas pressure before the second reciprocating member starts moving in the direction approaching the valve seat is such that the second reciprocating member approaches the valve seat. It is set higher than the rising speed of the second gas pressure after the movement is started.

The second reciprocating member is urged by the second urging member in a direction away from the valve seat. For this reason, even when the second gas pressure is increased, while the force with which the second reciprocating member is pushed by the second gas pressure is smaller than the force with which the second urging member urges the second reciprocating member. The second reciprocating member does not start moving in the direction approaching the valve seat.

In this regard, according to the above configuration, the second gas pressure is increased before the second reciprocating member starts moving in the direction approaching the valve seat, and the second reciprocating member starts moving in the direction approaching the valve seat. After that, the second gas pressure can be increased at a slower rate. Therefore, it is possible to prevent a collision between the valve seat and the diaphragm valve body while suppressing an increase in the time required to close the flow path by the diaphragm valve body from a state where there is a predetermined gap between the valve seat and the diaphragm valve body. Can be relaxed.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings.
Sectional drawing which shows the control apparatus of a diaphragm valve in a neutral state. The expanded sectional view which shows the valve seat and diaphragm valve body in a neutral state. The graph which shows the relationship between 2nd port pressurization pressure and valve seat pressing force. The expanded sectional view which shows the valve seat and diaphragm valve body in a closed state. The time chart which shows the operating state of a diaphragm valve. Sectional drawing which shows the control apparatus of a diaphragm valve in an open state.

Hereinafter, an embodiment will be described with reference to the drawings. In the present embodiment, a semiconductor manufacturing apparatus or the like is embodied as a control device that controls a diaphragm valve that opens and closes a flow path of a chemical solution (fluid).

First, an overview of the control device 10 will be described with reference to FIG. As shown in FIG. 1, the control device 10 includes a diaphragm valve 18, a first pressure increasing / decreasing unit 11, a second pressure increasing / decreasing unit 12, and a controller 13. A chemical solution inflow passage is connected to the A port 25 of the diaphragm valve 18. A chemical liquid outflow passage is connected to the B port 26 of the diaphragm valve 18.

Then, the chemical liquid pressurized by a pump or the like flows from the A port 25 into the diaphragm valve 18. Diaphragm valve 18 opens and closes the flow path of the chemical solution connected from A port 25 to B port 26. That is, the diaphragm valve 18 switches between a state in which the chemical liquid is circulated and a state in which it is blocked.

The controller 13 is an electronic control unit mainly composed of a microcomputer including a CPU, various memories, an input / output interface, and the like. A command signal for opening and closing the diaphragm valve 18 is input to the controller 13 from a management computer (host computer) that manages the control device 10 in an integrated manner. The controller 13 controls the open / close state of the diaphragm valve 18 based on these inputs.

Next, the configuration of the diaphragm valve 18 will be described in detail. The diaphragm valve 18 includes a first housing 20, a diaphragm valve body 40, a second housing 30, a first piston 62, a first compression spring 71, a rod 61, a third housing 50, a second piston 82, a second compression spring 83, A first metal diaphragm 91, a second metal diaphragm 94, and the like are provided.

In the first housing 20 (housing), an A port 25 into which a chemical solution (fluid) flows and a B port 26 from which the chemical solution flows out are formed. The first housing 20 is made of a fluorine resin having chemical resistance, such as PTFE (Poly-Tetra-Fluoro-Ethylene). Inside the first housing 20, a first flow path 21 (flow path) connected to the A port 25, a second flow path 23 (flow path) connected to the B port 26, the flow paths 21, And a valve chamber 22 to which 23 is connected. The valve chamber 22 is formed as a columnar space and opens on the upper surface (predetermined surface) of the first housing 20. An annular valve seat 24 is provided at the connection between the valve chamber 22 and the first flow path 21, that is, around the opening of the first flow path 21 with respect to the valve chamber 22.

The valve chamber 22 is divided into a flow path (flow paths 21 and 23 side) and a non-flow path (second housing 30 side) by the diaphragm valve element 40. The diaphragm valve body 40 is made of a fluorine resin having chemical resistance, such as PTFE. The diaphragm valve body 40 includes a valve body portion 41 and a diaphragm portion 42. The valve body 41 is formed in a cylindrical shape. The outer edge portion 42 a of the diaphragm portion 42 is sandwiched between the first housing 20 and the pressing member 28. The pressing member 28 is formed in a cylindrical shape with a fluorine resin having chemical resistance, for example, PTFE. The diaphragm valve body 40 is accommodated in the valve chamber 22, and is disposed so that the valve body portion 41 faces the valve seat 24. When the valve body 41 is pressed against the valve seat 24, the flow of the chemical solution from the first flow path 21 to the valve chamber 22 is blocked.

The second housing 30 is attached to the top of the first housing 20. The second housing 30 is formed of stainless steel or a fluorine resin having chemical resistance. Inside the second housing 30, there are a valve chamber 32, a first accommodating portion 31 that is a cylindrical space, and a second accommodating portion 33 that is a cylindrical space having a diameter larger than that of the first accommodating portion 31. Is formed. The valve chamber 32 communicates with the valve chamber 22. One end of the first accommodating portion 31 communicates with the valve chamber 32, and the other end of the first accommodating portion 31 communicates with the second accommodating portion 33. The second housing portion 33 is open on the upper surface (predetermined surface) of the second housing 30. The valve chamber 22, the valve chamber 32, the first storage portion 31, and the second storage portion 33 have the same center axis.

The first piston 62 is housed in the space formed by the first housing portion 31 and the second housing portion 33. The first piston 62 (first reciprocating member) is formed in a cylindrical shape from metal, resin, or the like, and includes a small diameter portion 62a and a large diameter portion 62b. The small-diameter portion 62a and the large-diameter portion 62b have the same center axis.

The small diameter portion 62 a is inserted into the first accommodating portion 31, and the large diameter portion 62 b is inserted into the second accommodating portion 33. The space between the first housing portion 31 and the small diameter portion 62a is sealed by a seal member 63, and the space between the second housing portion 33 and the large diameter portion 62b is sealed by a seal member 65. The central axis of the second housing part 33 and the central axis of the large-diameter part 62b coincide, and the central axis of the first housing part 31 and the central axis of the small-diameter part 62a coincide.

A pressure chamber 35 defined by the inner peripheral surface of the second housing 30 and the outer peripheral surface of the first piston 62 is formed inside the second housing 30. The pressure chamber 35 is connected to the first pressure increasing / decreasing unit 11 through the first port 36.

The first pressure increasing / decreasing unit 11 (first actuator, gas pressure actuator) is constituted by a pneumatic circuit including a compressed air supply source, an electromagnetic valve, and the like. The first pressure increasing / decreasing unit 11 adjusts the pressure in the pressure chamber 35 by controlling the supply of compressed air to the pressure chamber 35 and the opening of the pressure chamber 35 to the atmosphere. Then, based on the pressure adjustment in the pressure chamber 35, a static load in the central axis direction (reciprocating direction, predetermined direction) is applied to the large diameter portion 62b (first piston 62). Specifically, the first pressure increasing / decreasing unit 11 urges the first piston 62 in the direction away from the valve seat 24 by the pressure of the compressed air. The first pressure increasing / decreasing unit 11 is controlled by the controller 13.

The third housing 50 is attached to the upper part of the second housing 30. The third housing 50 is formed of stainless steel or a fluorine resin having chemical resistance, such as PVDF (Poly Vinylidene Di Fluoride). Inside the third housing 50, a third accommodating portion 55, which is a cylindrical space, is formed. One end of the third accommodating portion 55 communicates with the second accommodating portion 33, and the other end of the third accommodating portion 55 communicates with the second port 56. The second piston 82 is accommodated in the third accommodating portion 55. The second piston 82 is formed in a cylindrical shape from metal, resin, or the like. A space between the third accommodating portion 55 and the second piston 82 is sealed by a seal member 67. A pressure chamber 57 defined by the inner peripheral surface of the third housing 50 and the outer peripheral surface of the second piston 82 is formed inside the third housing 50. In the third housing portion 55, the portion on the second housing 30 side of the seal member 67 is connected to a breathing passage 68 that is open to the atmosphere.

A stopper 70 is attached between the second housing 30 and the third housing 50. The stopper 70 is formed in a cylindrical shape from metal, resin, or the like, and includes an inner projecting portion 70a projecting inward and an outer projecting portion 70b projecting outward. The outer overhanging portion 70 b is sandwiched between the second housing 30 and the third housing 50. That is, the stopper 70 is fixed to the second housing 30 and the third housing 50. A first compression spring 71 (first urging member) is provided between the outer overhanging portion 70b and the large diameter portion 62b. The first compression spring 71 urges the large-diameter portion 62b (first piston 62) in a direction to approach the valve seat 24. The first housing 20, the second housing 30, and the third housing 50 constitute a housing.

The end of the diaphragm valve body 40 opposite to the valve seat 24 is connected to the rod 61 via a connecting member 61a. The rod 61 is formed in a cylindrical shape from stainless steel, chemical-resistant fluorine resin, or the like, and is inserted into the first piston 62. An intermediate member 73 is attached to the intermediate portion of the rod 61. The intermediate member 73 is formed in a cylindrical shape from a metal, resin, or the like, and includes an overhanging portion 73a that projects outward.

The rod 61 is inserted into the intermediate member 73. A second piston 82 is connected to the end of the rod 61 opposite to the diaphragm valve body 40. The intermediate member 73 is sandwiched between the rod 61 and the second piston 82. That is, the intermediate member 73 is fixed to the rod 61 and the second piston 82.

A second compression spring 83 (second urging member) is provided between the step on the inner peripheral side of the first piston 62 and the protruding portion 73a of the intermediate member 73. The second compression spring 83 urges the intermediate member 73 (rod 61, second piston 82) in a direction away from the valve seat 24. That is, the rod 61 and the second piston 82 are supported by the first piston 62 via the second compression spring 83.

A contact member 75 is attached to the upper part of the first piston 62 (the end opposite to the valve seat 24). The contact member 75 is formed in a cylindrical shape, and includes an inner projecting portion 75a projecting inward and an outer projecting portion 75b projecting outward. The inner overhang 75 a is opposed to the overhang 73 a of the intermediate member 73, and the outer overhang 75 b is opposed to the inner overhang 70 a of the stopper 70. In the second accommodating portion 33, the portion inside the first piston 62 and the portion above the first piston 62 (the side opposite to the valve seat 24) are opened to the atmosphere by the breathing hole 77.

When the first piston 62 is moved in the direction approaching the valve seat 24 by the first compression spring 71, the outer overhanging portion 75b of the abutting member 75 abuts on the inner overhanging portion 70a of the stopper 70 and the movement is stopped. . When the first piston 62 is moved away from the valve seat 24 by the first pressure increasing / decreasing unit 11, the first piston 62 comes into contact with the inner projecting portion 70a of the stopper 70 and the movement is stopped. Further, when the intermediate member 73 is moved away from the valve seat 24 by the second compression spring 83, the extension 73a of the intermediate member 73 comes into contact with the inner extension 75a of the contact member 75 and the movement is stopped. It is done. The rod 61, the intermediate member 73, and the second piston 82 constitute a second reciprocating member. The first reciprocating member and the second reciprocating member constitute a reciprocating member. Further, the first compression spring 71 and the second pressurizing / decreasing unit 12 constitute a pressing portion.

The second pressure increasing / decreasing unit 12 (second actuator, gas pressure actuator) is constituted by an electropneumatic regulator including a compressed air supply source, a solenoid valve, a vacuum source, and the like. The second pressurizing / depressurizing unit 12 adjusts the pressure in the third accommodating portion 55 by controlling the supply of compressed air to the third accommodating portion 55 through the second port 56 and the release of the third accommodating portion 55 to the atmosphere. To do. And based on the pressure adjustment in the 3rd accommodating part 55, the static load of a center axis line direction (reciprocating direction, predetermined direction) is made to act on the 2nd piston 82 (intermediate member 73, rod 61). Specifically, the second pressure increasing / decreasing unit 12 urges the second piston 82 in the direction of approaching the valve seat 24 by the pressure of the compressed air. The second pressure increasing / decreasing unit 12 is controlled by the controller 13.

Here, a valve opening load from the first flow path 21 to the valve chamber 22 (second housing 30) acts on the diaphragm valve body 40 by a chemical solution. The magnitude of the load (valve closing load) that urges the first piston 62 (rod 61, diaphragm valve body 40) in the direction in which the first compression spring 71 brings the diaphragm valve body 40 closer to the valve seat 24 is as described above. It is set larger than the valve opening load. For this reason, the rod 61 and the diaphragm valve body 40 are moved in the direction approaching the valve seat 24, and the movement is stopped by the stopper 70. In this state, as shown in FIG. 2, a predetermined gap G is formed between the valve seat 24 and the valve body portion 41 of the diaphragm valve body 40. In FIG. 2, the predetermined gap G is exaggerated. The predetermined gap G is set to 50 to 200 μm, preferably 50 to 100 μm.

Since the diaphragm valve body 40 is made of a fluororesin and the diaphragm portion 42 needs to be flexible, it can be deformed in directions other than the direction (predetermined direction) in contact with and away from the valve seat 24. For this reason, when the rod 61 is reciprocated in a predetermined direction, the effect that the diaphragm valve body 40 regulates that the central axis of the rod 61 swings is small. When the central axis of the rod 61 is swung, particles are generated by rubbing the valve body portion 41 and the valve seat 24 of the diaphragm valve body 40 or by tilting the valve body portion 41 against the valve seat 24. There is a fear.

Therefore, in the present embodiment, in order to prevent the central axis of the rod 61 from swinging when the rod 61 reciprocates in a direction (predetermined direction) in which the rod 61 approaches and separates from the valve seat 24, the first metal is applied to the rod 61. A diaphragm 91 and a second metal diaphragm 94 are attached. The first metal diaphragm 91 (first restricting member, restricting member) and the second metal diaphragm 94 (second restricting member, restricting member) are metal diaphragms formed in a thin disc shape with a metal such as stainless steel. The thickness of the metal diaphragms 91 and 94 is set to 30 to 100 μm, preferably 50 to 80 μm. The metal diaphragms 91 and 94 are corrugated metal diaphragms having a corrugated shape (cross section shown in FIG. 1) in the thickness direction passing through the center thereof. The rigidity (strength) of the metal diaphragms 91 and 94 is higher than that of the diaphragm portion 42 of the diaphragm valve body 40. In particular, since the metal diaphragms 91 and 94 are corrugated metal diaphragms, the inner peripheral side portion and the outer peripheral side portion are easily deformed relative to each other in the predetermined direction, but are not easily deformed otherwise. However, the force by which the second compression spring 83 urges the intermediate member 73 (rod 61) away from the valve seat 24 is set to be larger than the reaction force generated by the metal diaphragms 91 and 94.

The first metal diaphragm 91 is attached to the end of the rod 61 on the valve seat 24 side. The inner edge portion of the first metal diaphragm 91 is fixed to the outer edge of the rod 61 penetrating the first metal diaphragm 91 in the predetermined direction by a fixing member 93. The outer edge portion of the first metal diaphragm 91 is fixed to the first housing 20 and the second housing 30 via the spacer 92, the pressing member 28, and the outer edge portion 42 a of the diaphragm portion 42. For this reason, the rotation of the first metal diaphragm 91 relative to the second housing 30 around the rod 61 is restricted. The first metal diaphragm 91 hardly twists (is difficult to deform) in the circumferential direction. For this reason, the first metal diaphragm 91 restricts the rotation of the rod 61 around the central axis of the rod 61. The first metal diaphragm 91 divides the valve chamber 32 into a portion on the diaphragm valve body 40 side and a portion on the first piston 62 side. In other words, the first metal diaphragm 91 also functions as a diaphragm that prevents fluid from entering.

The second metal diaphragm 94 is attached to the end of the rod 61 opposite to the valve seat 24, that is, at a position farther from the valve seat 24 than the first metal diaphragm 91. Thereby, the space | interval of the 1st metal diaphragm 91 and the 2nd metal diaphragm 94 is made wide. The inner edge portion of the second metal diaphragm 94 is fixed to the outer edge of the rod 61 penetrating the second metal diaphragm 94 in the predetermined direction via the intermediate member 73 and the second piston 82. The outer edge portion of the second metal diaphragm 94 is fixed to the second housing 30 and the third housing 50 via a stopper 70. For this reason, the rotation of the second metal diaphragm 94 relative to the second housing 30 around the rod 61 is restricted. The second metal diaphragm 94 hardly twists (is difficult to deform) in the circumferential direction. For this reason, the second metal diaphragm 94 restricts the rotation of the rod 61 around the central axis of the rod 61. The second metal diaphragm 94 partitions the second housing portion 33 into a portion on the first piston 62 side and a portion on the second piston 82 side. That is, the second metal diaphragm 94 also functions as a diaphragm that prevents fluid from entering.

As shown in FIG. 2, in a state where a predetermined gap G is formed between the valve seat 24 and the valve body portion 41 of the diaphragm valve body 40, the metal diaphragms 91, 94 move in the direction toward the valve seat 24 and the valve seat. The natural state (neutral state) is not deformed in any direction away from 24. The metal diaphragms 91 and 94 allow the rod 61 to reciprocate by being elastically deformed (deformed) in a direction (predetermined direction) toward and away from the valve seat 24. That is, the metal diaphragms 91 and 94 are easily elastically deformed in the direction perpendicular to the surface of the thin plate (the main surface having the largest area). On the other hand, the metal diaphragms 91 and 94 restrict the movement of the rod 61 in the direction perpendicular to the central axis direction (predetermined direction) of the rod 61, respectively. That is, the metal diaphragms 91 and 94 hardly elastically deform (deform) (i.e., hardly deform) in the direction (radial direction) along the surface of the thin plate.

FIG. 3 is a graph showing the relationship between the second port pressurizing pressure and the valve seat pressing force. In a state where the pressurization pressure by the compressed air supplied from the second port 56 is 0 (atmospheric release state), a predetermined distance is provided between the valve seat 24 and the valve body portion 41 of the diaphragm valve body 40 as shown in FIG. A gap G is formed. As the pressurizing pressure is increased, the force acting on the second piston 82 becomes larger than the urging force of the second compression spring 83, and the rod 61 and the diaphragm valve body 40 move in a direction approaching the valve seat 24. Begin to. However, until the diaphragm valve body 40 moves the distance of the predetermined gap G, the force for pressing the valve body portion 41 of the diaphragm valve body 40 against the valve seat 24 is not generated. When the diaphragm valve body 40 moves the distance of the predetermined gap G, the valve body portion 41 comes into contact with the valve seat 24 as shown in FIG. Further, as the pressurizing pressure is increased, the force for pressing the valve element 41 against the valve seat 24 increases as shown in FIG. Specifically, the pressing force increases in proportion to the increase in the applied pressure. For this reason, the force which presses the valve body part 41 to the valve seat 24 can be adjusted by adjusting the pressurization pressure.

FIG. 5 is a time chart showing the operating state of the diaphragm valve 18. The operation of bringing the diaphragm valve 18 from the fully open state to the fully closed state and then bringing the diaphragm valve 18 back to the fully open state will be described.

At time t0, a command signal for opening the diaphragm valve 18 is transmitted from the management computer to the controller 13. For this reason, the operation pressure (first gas pressure) by the compressed air supplied from the first pressure increasing / decreasing unit 11 to the first port 36 by the controller 13 is set to the operation pressure P1. The operating pressure P1 is a pressure that can move the first piston 62 in a direction away from the valve seat 24 against the urging force of the first compression spring 71. At this time, the operation pressure (second gas pressure) by the compressed air supplied from the second pressurization / decompression unit 12 to the second port 56 by the controller 13 is set to 0 (open atmospheric pressure). For this reason, the stroke position of the valve body 41 of the diaphragm valve body 40 is a fully open position.

As shown in FIG. 6, when the diaphragm valve 18 is fully opened, the first piston 62 is moved away from the valve seat 24. The upper end portion (end portion on the stopper 70 side) of the large diameter portion 62b of the first piston 62 is in contact with the lower end portion (end portion on the first piston 62 side) of the inner overhang portion 70a of the stopper 70. . The intermediate member 73 is urged away from the valve seat 24 by the second compression spring 83, and the pressure of the chemical liquid acts on the diaphragm valve body 40, whereby the rod 61 and the diaphragm valve body 40 are removed from the valve seat 24. It has been moved away. Then, the upper end portion (the end portion on the contact member 75 side) of the overhang portion 73a of the intermediate member 73 contacts the lower end portion (the end portion on the valve seat 24 side) of the inner overhang portion 75a of the contact member 75. ing. In this state, a gap wider than the predetermined gap G is formed between the valve seat 24 and the valve body portion 41 of the diaphragm valve body 40. The metal diaphragms 91 and 94 are elastically deformed in a direction away from the valve seat 24, and restrict the movement of the rod 61 in the radial direction of the rod 61.

Slightly before time t1, a command signal for closing the diaphragm valve 18 is transmitted from the management computer to the controller 13. Time t1 is a time at which the operation pressure of the first pressure increasing / decreasing unit 11 is set to 0 and the valve closing operation is started, and a valve closing command is transmitted slightly before time t1 in consideration of a response delay or the like. . At time t1, the controller 13 sets the operating pressure of the first pressure increasing / decreasing unit 11 to 0 (open atmospheric pressure). As a result, the pressure in the pressure chamber 35 decreases, and the first piston 62 and the contact member 75 are moved in the direction approaching the valve seat 24 by the biasing force of the first compression spring 71. As a result, the rod 61 and the diaphragm valve body 40 are moved in the direction approaching the valve seat 24 together with the intermediate member 73 in contact with the contact member 75. At this time, the deflection of the central axis of the rod 61 is suppressed by the metal diaphragms 91 and 94.

At time t2, as shown in FIG. 1, the outer projecting portion 75b of the contact member 75 contacts the inner projecting portion 70a of the stopper 70 and approaches the valve seat 24 of the first piston 62 and the contact member 75. The movement to is stopped. At this time, the rod 61 and the diaphragm valve body 40 are urged away from the valve seat 24 by the urging force of the second compression spring 83 and the pressure of the chemical solution. The overhang portion 73 a of the intermediate member 73 is in contact with the inner overhang portion 75 a of the contact member 75. In this state, as shown in FIG. 2, a predetermined gap G is formed between the valve seat 24 and the valve body portion 41 of the diaphragm valve body 40. The metal diaphragms 91 and 94 are in a natural state (neutral state) that is not deformed in either the direction approaching the valve seat 24 or the direction away from the valve seat 24.

At time t3, the controller 13 sets the operation pressure of the second pressurization / decompression unit 12 to the operation pressure P21. As a result, the second piston 82, the rod 61, and the diaphragm valve body 40 begin to move in the direction approaching the valve seat 24 against the urging force of the second compression spring 83 and the pressure of the chemical solution. Thereafter, the controller 13 gradually increases the operating pressure of the second pressure increasing / decreasing unit 12 from P21. That is, the rising speed of the operating pressure before the second piston 82 and the rod 61 start moving in the direction approaching the valve seat 24 is after the second piston 82 and the rod 61 start moving in the direction approaching the valve seat 24. The operating pressure is set higher than the rate of increase.

The stroke position of the valve body portion 41 of the diaphragm valve body 40 is such that the predetermined gap G becomes 0 from the position before the valve is closed where the predetermined gap G is formed between the valve seat 24 and the valve body portion 41. The portion 41 gradually changes to the fully closed position where it is pressed against the valve seat. That is, the speed at which the first piston 62 is moved toward the valve seat 24 by the first compression spring 71 is the speed at which the second piston 82 and the rod 61 are moved toward the valve seat 24 by the second pressure-reducing unit 12. Is set higher than. At this time, the movement of the central axis of the rod 61 is suppressed by the metal diaphragms 91 and 94 restricting the movement of the rod 61 in the direction perpendicular to the predetermined direction.

At time t4, the controller 13 sets the operating pressure of the second pressure increasing / decreasing unit 12 to the operating pressure P22. The operating pressure P22 is set to a pressurizing pressure that can press the valve body 41 against the valve seat 24 with an optimum force in accordance with the characteristics shown in FIG.

Slightly before time t5, a command signal for opening the diaphragm valve 18 is transmitted from the management computer to the controller 13. Time t5 is the time when the operation pressure of the second pressure increasing / decreasing unit 12 is decreased and the valve opening operation is started, and the valve opening command is transmitted slightly before time t5 in consideration of response delay and the like. Then, from time t5, the controller 13 gradually decreases the operating pressure of the second pressure-increasing / decreasing unit 12 from the operating pressure P22. As a result, the pressure in the pressure chamber 57 decreases, and the second piston 82, the rod 61, and the diaphragm valve body 40 are moved away from the valve seat 24 by the urging force of the second compression spring 83 and the pressure of the chemical solution. It is done. Also at this time, the deflection of the central axis of the rod 61 is suppressed by the metal diaphragms 91 and 94.

At time t6, the stroke position of the valve body portion 41 of the diaphragm valve body 40 is a position before the valve is closed where a predetermined gap G is formed between the valve seat 24 and the valve body portion 41. The controller 13 sets the operating pressure of the second pressure increasing / decreasing unit 12 to 0 and the operating pressure of the first pressure increasing / decreasing unit 11 to the operating pressure P1. As a result, the pressure in the pressure chamber 35 rises and the first piston 62 and the contact member 75 are moved away from the valve seat 24 against the urging force of the first compression spring 71. As a result, the intermediate member 73, the rod 61, and the diaphragm valve body 40 are moved in a direction away from the valve seat 24. Also at this time, the deflection of the central axis of the rod 61 is suppressed by the metal diaphragms 91 and 94.

At time t7, the stroke position of the valve body 41 of the diaphragm valve body 40 becomes the fully open position, similarly to time t0.

The embodiment described above has the following advantages.

A metal diaphragm 91, 94 as a regulating member formed in a thin plate shape with metal is penetrated in a predetermined direction in which the rod 61 approaches and separates from the valve seat 24, and the regulating member is attached to the outer edge of the rod 61. Yes. Since the regulating member is formed in a thin plate shape with metal, the strength is higher than that of the diaphragm portion 42 of the resin diaphragm valve body 40. The restricting member deforms and allows the rod 61 to reciprocate in a predetermined direction and restricts the movement of the rod 61 in a direction perpendicular to the predetermined direction. For this reason, it is possible to prevent the central axis of the rod 61 from swinging while allowing the rod 61 to reciprocate in a predetermined direction and allow the diaphragm valve body 40 to open and close the flow path. As a result, the generation of particles due to the swing of the central axis of the rod 61 connected to the diaphragm valve body 40 can be suppressed.

When only one restricting member is attached to the outer edge of the rod 61, the movement of the rod 61 in the direction perpendicular to the predetermined direction can be restricted at the position of the restricting member. However, the central axis of the rod 61 may be inclined with the position of the restricting member as a fulcrum. In this regard, the restriction member includes a first metal diaphragm 91 as the first restriction member, and a second as the second restriction member attached to the outer edge of the rod 61 at a position farther from the valve seat 24 than the first restriction member. A metal diaphragm 94. For this reason, the position of the first restricting member and the position of the second restricting member attached to the outer edge of the rod 61 at a position farther from the valve seat 24 than the first restricting member in the direction perpendicular to the predetermined direction. The movement of the rod 61 can be restricted. Therefore, the center axis of the rod 61 can be prevented from being inclined, and the generation of particles can be further suppressed.

The first restricting member is attached to the end of the rod 61 on the valve seat 24 side, and the second restricting member is attached to the end of the rod 61 opposite to the valve seat 24. According to such a structure, the space | interval of a 1st control member and a 2nd control member can be enlarged, and it can suppress effectively that the central axis of the rod 61 inclines.

· Since the rotation of the restricting member with respect to the second housing 30 around the rod 61 is restricted, the rotation of the rod 61 and the diaphragm valve body 40 can be restricted. For this reason, while being able to make the location of the diaphragm valve body 40 contact | abutted with the valve seat 24 the same each time, it suppresses that the diaphragm valve body 40 is rubbed with respect to the valve seat 24 in the rotation direction centering on the rod 61. be able to. Therefore, the generation of particles can be further suppressed.

-Since the regulating member is a metal diaphragm formed of metal, it can function as a diaphragm that suppresses the swing of the central axis of the rod 61 and prevents the ingress of fluid.

Metal diaphragms 91 and 94 are corrugated metal diaphragms having a corrugated cross-sectional shape passing through the center. For this reason, the metal diaphragms 91 and 94 have a characteristic that they are easily deformed in the predetermined direction and are not easily deformed in a direction perpendicular to the predetermined direction. Therefore, it is possible to effectively prevent the central axis of the rod 61 from swinging while appropriately allowing the rod 61 to reciprocate in a predetermined direction.

A state in which there is a predetermined gap G between the valve seat 24 and the diaphragm valve body 40 by moving the first piston 62 in the direction approaching the valve seat 24 by the first compression spring 71 and stopping the movement by the stopper 70. Can be. For this reason, before the valve seat 24 and the diaphragm valve body 40 are brought into contact with each other, a state in which the predetermined gap G is present between the valve seat 24 and the diaphragm valve body 40 can be reliably realized. In this state, the rod 61 is moved toward the valve seat 24 with respect to the first piston 62 by the second pressure increasing / decreasing unit 12 to alleviate the collision between the valve seat 24 and the diaphragm valve body 40. The diaphragm valve body 40 can be brought into contact with the valve seat 24.

In the direction in which the first piston 62 approaches the valve seat 24 by lowering the operating pressure of the first port 36 from the state in which the first piston 62 is moved in the direction away from the valve seat 24 by the first pressure increasing / decreasing unit 11. It is moved until it is stopped by the stopper 70. For this reason, the state where the movement of the first piston 62 is stopped by the stopper 70 can be easily realized. Thereafter, the operating pressure of the second port 56 is increased by the second pressure increasing / decreasing unit 12, thereby moving the rod 61 in a direction approaching the valve seat 24 and pressing the diaphragm valve body 40 against the valve seat 24. For this reason, by adjusting the operating pressure of the second port 56 from a state where the predetermined gap G is between the valve seat 24 and the diaphragm valve body 40, the speed at which the diaphragm valve body 40 approaches the valve seat 24, and the diaphragm The force with which the valve body 40 is pressed against the valve seat 24 can be adjusted.

After moving the first piston 62 in the direction approaching the valve seat 24 until it is stopped by the stopper 70, the diaphragm valve body 40 can be pressed against the valve seat 24 at a slower speed. Therefore, the collision between the valve seat 24 and the diaphragm valve body 40 can be alleviated while suppressing the time required to close the first flow path 21 by the diaphragm valve body 40 from being increased.

The rod 61 is urged in the direction away from the valve seat 24 by the urging force of the second compression spring 83 and the pressure of the chemical solution. For this reason, even if the operating pressure of the second port 56 is increased, the force by which the rod 61 is pushed by the operating pressure of the second port 56 is smaller than the force of the biasing force of the second compression spring 83 and the pressure of the chemical liquid. The rod 61 does not start moving in the direction approaching the valve seat 24. In this regard, the operating pressure of the second port 56 is increased before the rod 61 starts moving in the direction approaching the valve seat 24, and the speed slower than that after the rod 61 starts moving in the direction approaching the valve seat 24. The operating pressure is increased. Therefore, the valve seat 24 is prevented from increasing the time required to close the first flow path 21 by the diaphragm valve body 40 from the state where the predetermined gap G is between the valve seat 24 and the diaphragm valve body 40. And the diaphragm valve body 40 can be mitigated.

It should be noted that the above embodiment can be modified as follows.

In the state of FIG. 2, the operating pressure of the second port 56 can be gradually increased at the same speed before and after the rod 61 starts moving in the direction approaching the valve seat 24.

-The increase in the operation pressure of the second port 56 can be started slightly before the operation pressure of the first port 36 becomes 0 (predetermined time).

The metal diaphragms 91 and 94 are not limited to corrugated metal diaphragms but may be flat metal diaphragms formed in a flat plate shape. The material of the metal diaphragms 91 and 94 is not limited to stainless steel, and Ti, Al, Cu, or the like can also be employed. The metal diaphragms 91 and 94 may not have the diaphragm function, but may have only the function of the regulating member.

The metal diaphragms 91 and 94 can be attached not only to both ends in the central axis direction of the rod 61 but also to an intermediate portion of the rod 61 or the like. Even in that case, it is desirable that the distance between the first metal diaphragm 91 and the second metal diaphragm 94 is wide. In addition to the first metal diaphragm 91 and the second metal diaphragm 94, a similar third metal diaphragm or fourth metal diaphragm can be provided.

It is also possible to adopt a configuration in which the rotation of the metal diaphragms 91 and 94 with respect to the second housing 30 around the rod 61 is not restricted.

The fluid that switches between the flow state and the shut-off state by the diaphragm valve 18 is not limited to a chemical solution, and other liquids such as pure water or gas can also be employed. And according to the kind of fluid, as a material of the diaphragm valve body 40, not only a fluororesin but other resin can also be employ | adopted.

A configuration in which the first piston 62 is moved in a direction approaching the valve seat 24 by energizing the first piston 62 in a direction away from the valve seat 24 by a compression spring and increasing an operation pressure applied to the first piston 62. Can also be adopted. The gas pressure is not limited to the pressure by compressed air, and the pressure by compressed nitrogen or the like can also be adopted. Further, the actuator for reciprocating the pistons 62 and 82 in the direction of approaching and separating from the valve seat 24 is not limited to a gas pressure actuator, and an electromagnetic actuator, a piezo element actuator, or the like can also be employed.

It is also possible to adopt a configuration in which the rod 61 is reciprocated in the direction approaching and separating from the valve seat 24 by only one actuator.

Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or the structure. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

DESCRIPTION OF SYMBOLS 10 ... Control apparatus, 11 ... 1st pressure increase / decrease unit (1st actuator), 12 ... 2nd pressure increase / decrease unit (2nd actuator), 18 ... Diaphragm valve, 20 ... 1st housing (housing), 21 ... 1st flow Path (flow path), 22 ... valve chamber, 24 ... valve seat, 30 ... second housing (housing), 32 ... valve chamber, 40 ... diaphragm valve body, 50 ... third housing (housing), 61 ... rod (first) 2 reciprocating members), 62 ... first piston (first reciprocating member), 70 ... stopper, 71 ... first compression spring (first urging member), 82 ... second piston (second reciprocating member), 83: second compression spring (second urging member), 91: first metal diaphragm (first regulating member), 94: second metal diaphragm (second regulating member).

Claims (11)

1. A housing in which a fluid flow path and a valve chamber are formed;
   In the housing, a valve seat provided annularly around the opening of the flow path with respect to the valve chamber;
   A resin diaphragm valve body that divides the valve chamber into a flow path and a non-flow path of the fluid, and contacts and separates from the valve seat;
   A reciprocating member connected to the diaphragm valve body and reciprocating in a predetermined direction which is a direction approaching and separating from the valve seat;
   A pressing portion that applies a force to the reciprocating member to press the diaphragm valve body against the valve seat;
   A direction that is formed in a thin plate shape with metal and is attached to the outer edge of the reciprocating member that penetrates in the predetermined direction, deforms and permits the reciprocating motion of the reciprocating member in the predetermined direction, and is perpendicular to the predetermined direction A regulating member for regulating the movement of the reciprocating member to
   A diaphragm valve comprising:
2. The said regulating member contains the 1st regulating member and the 2nd regulating member attached to the outer edge of the said reciprocating member in the position away from the said 1st regulating member from the said valve seat. Diaphragm valve.
3. The first restricting member is attached to an end of the valve seat side in the reciprocating member,
   The diaphragm valve according to claim 2, wherein the second restricting member is attached to an end of the reciprocating member on the side opposite to the valve seat.
4. The diaphragm valve according to any one of claims 1 to 3, wherein rotation of the restricting member relative to the housing around the reciprocating member is restricted.
5. The diaphragm valve according to any one of claims 1 to 4, wherein the restricting member is a metal diaphragm formed of metal.
6. 6. The diaphragm valve according to claim 5, wherein the metal diaphragm is a corrugated metal diaphragm having a corrugated cross-sectional shape passing through the center.
7. The reciprocating member is supported by the first reciprocating member and reciprocates in the predetermined direction with respect to the first reciprocating member and reciprocating in the predetermined direction with respect to the housing. A second reciprocating member,
   The pressing portion includes a first actuator that reciprocates the first reciprocating member in the predetermined direction with respect to the housing, and a first gap with a predetermined gap between the valve seat and the diaphragm valve body. A stopper that stops movement of the reciprocating member in a direction approaching the valve seat, and a second actuator that reciprocates the second reciprocating member in the predetermined direction with respect to the first reciprocating member. Item 7. The diaphragm valve according to any one of Items 1 to 6.
8. The first actuator includes a first urging member that urges the first reciprocating member in a direction approaching the valve seat, and the first reciprocating member is separated from the valve seat by a first gas pressure. A gas pressure actuator to be moved,
   The second actuator includes a second urging member that urges the second reciprocating member in a direction away from the valve seat, and moves the second reciprocating member closer to the valve seat by a second gas pressure. The diaphragm valve according to claim 7, which is a gas pressure actuator to be moved.
9. A control device comprising the diaphragm valve according to claim 8 and controlling the diaphragm valve,
   The first reciprocating member is moved closer to the valve seat by lowering the first gas pressure from the state in which the first actuator is moved away from the valve seat by the first actuator. After moving until stopped by the stopper,
   A control device for a diaphragm valve that raises the second gas pressure by the second actuator to move the second reciprocating member in a direction approaching the valve seat and press the diaphragm valve body against the valve seat. .
10. The speed at which the first actuator moves the first reciprocating member closer to the valve seat is set higher than the speed at which the second actuator moves the second reciprocating member closer to the valve seat. The control device for a diaphragm valve according to claim 9.
11. The rising speed of the second gas pressure before the second reciprocating member starts moving in the direction approaching the valve seat is after the second reciprocating member starts moving in the direction approaching the valve seat. The control device for a diaphragm valve according to claim 9 or 10, wherein the control device is set to be higher than a rising speed of the second gas pressure.

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