JP2009058057A - Liquid control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid control valve capable of preventing oil and the like from eluting from an annular seal member and the like of a driving part even if diaphragm valve element is broken, and quickly detecting abnormality such as breakage of the diaphragm valve element. <P>SOLUTION: This chemical fluid control valve 21 comprises a body 22 having a valve opening 28 formed in a middle of a liquid passage 27, a diaphragm valve element 24 for opening and closing the valve opening 28, and a pneumatic driving part 23 for actuating the valve element 24 to be opened and closed and provided with O-rings 14a, 14b at required portions. A diaphragm member 25 is installed between the driving part 23 and the diaphragm valve element 24, so as to prevent liquid from entering the pneumatic driving part 23. Even when the chemical liquid enters from a membrane part 24b, the chemical liquid can be exhausted from a groove 45 via a liquid leakage detection port 45a and detected by a liquid detection sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid control valve that controls a liquid used in manufacturing semiconductors.

  Conventionally, this type of liquid control valve includes, for example, a configuration shown in FIG. The liquid control valve 1 is roughly composed of components such as a body 2, a pneumatic drive unit 3, a diaphragm valve body 4, and a base plate 5. The body 2 includes a liquid passage 6 (indicated by an arrow 6 for convenience), and has an inlet 6a at one end, an outlet 6b at the other end, and a valve port 7 in the middle. The body 2 is formed with a surrounding wall-shaped attachment portion 8 so as to surround the valve port 7.

  The cylinder 9 of the pneumatic drive unit 3 is fixed to the mounting unit 8 by screwing four screw members (not shown) through the base plate 5 from below. The cylinder 9 accommodates a piston 12 that defines the base chamber 10 and the front chamber 11. The piston 12 is provided with a piston rod 12 a that extends toward the body 2. A partition wall 13 having a rod insertion hole 13a through which the piston rod 12a passes is provided at the lower end opening (lower side in FIG. 3) of the cylinder 9. An annular seal member (O-ring 14a) for hermetically sealing is provided between the rod insertion hole 13a and the piston rod 12a, and an O-ring 14b is disposed at a necessary portion of the pneumatic drive unit 3. Has been. The partition wall 13 and the cylinder 9 are formed with a breathing hole 13b that is located below the O-ring 14a and that allows the rod insertion hole 13a to communicate with the outside.

  The diaphragm valve body 4 integrally includes a valve body central portion 4a, a deformable thin film portion 4b, and an outer peripheral portion 4c. The valve body central portion 4a is attached to the tip of the piston rod 12a, and the outer peripheral portion 4c is It is watertightly fixed to the inner periphery of the mounting portion 8.

  As shown in FIG. 3, the piston 12 is configured so that the diaphragm valve body 4 closes the valve port 7 by being constantly biased downward by a compression coil spring 15 in the base chamber 10. When the liquid control valve 1 is opened from this state, compressed air is supplied from an air vent 11 a communicating with the front chamber 11. Then, the piston 12 moves in the direction of arrow A against the spring force of the compression coil spring 15, and accordingly, the valve body central portion 4a of the diaphragm valve body 4 moves in the direction of arrow A, and the valve port 7 Is released. As a result, the liquid flows through the liquid passage 6.

  On the other hand, when the liquid control valve 1 is closed from the open state, when compressed air is discharged from the air vent 11a of the front chamber 11, compressed air is supplied by the spring force of the compression coil spring 15 (or from the base chamber 10). The piston 12 moves in the direction of the arrow A, and the diaphragm valve body 4 closes the valve port 7.

A configuration similar to the liquid control valve 1 having the above-described configuration is also described in Patent Document 1.
JP 2005-163877 A

  By the way, when manufacturing semiconductors, so-called chemical solutions such as cleaning solutions and stripping solutions are used. Here, in the liquid control valve 1 having the above-described configuration, the diaphragm valve body 4 is in contact with the chemical solution, and the opening / closing operation by the diaphragm valve body 4 is repeatedly performed, whereby the thin film portion 4b of the diaphragm valve body 4 may be broken. . In this case, the oil solution such as grease adhering to the O-rings 14a and 14b and the grease adhering thereto is dissolved by the chemical solution that has entered the pneumatic drive unit 3 side from the thin film unit 4b, which causes great damage to the subsequent processes. . That is, since the chemical solution (for example, the stripping solution) is supplied from the liquid control valve 1 to the semiconductor through piping and other devices for immersion treatment, when the stripping solution containing the oil or the like flows into the liquid control valve 1. In addition to ruining the semiconductor itself, pipes and other equipment need to be cleaned, and the production line must be shut down, causing serious damage.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is a liquid control valve that opens and closes a diaphragm valve body by a drive unit. Even if the diaphragm valve body is broken, the drive unit has an annular shape. It is an object of the present invention to provide a liquid control valve that can prevent the elution of oil and the like from a seal member and the like and can quickly detect an abnormality such as a diaphragm valve body being broken.

  To achieve the above object, the present invention provides a body having a liquid passage and a valve port formed in the middle of the liquid passage, a diaphragm valve body for opening and closing the valve port, and opening and closing the diaphragm valve body. A liquid control valve that is operated and includes a drive unit in which an annular seal member is disposed at a necessary portion, and prevents liquid from entering the drive unit side between the drive unit and the diaphragm valve body. A diaphragm member is provided, and a liquid leakage detector is provided at a portion defined by the diaphragm valve body and the diaphragm member (invention of claim 1).

  According to this, when the diaphragm valve body is torn, the liquid leakage detection unit can detect the liquid leakage from the diaphragm valve body, and this liquid leakage detection can detect abnormalities such as the diaphragm valve body breaking, Since the diaphragm member can prevent the liquid from entering the drive unit (annular seal member) side, it is possible to reliably prevent the oil and the like described above from eluting into the flowing liquid.

  In the present invention, the diaphragm valve body and the diaphragm member may be made of polytetrafluoroethylene or an equivalent material (chemical-resistant synthetic resin material) (the invention of claim 2), and according to this, there is little deterioration. It can be excellent in chemical resistance.

  The present invention also includes a body having a liquid passage and a valve port formed in the middle of the liquid passage, a cylinder attached to the body, a piston rod extending toward the body, and a pneumatic drive unit having a piston. A partition wall portion having a rod insertion hole provided in the cylinder and through which the piston rod passes, an annular seal member mounted between the outer periphery of the piston rod and the rod insertion hole and hermetically sealed, and a valve body central portion The valve body central portion is attached to the tip of the piston rod and the outer peripheral portion is watertightly fixed to the body, and the valve opening is opened by the operation of the piston. A diaphragm valve body that opens and closes, and is disposed between the partition wall portion and the diaphragm valve body, and a central portion is attached to the piston rod, and an outer peripheral portion. A diaphragm member mounted watertightly on said cylinder, the portion defined by the diaphragm valve body and the diaphragm member, characterized in that a leakage detecting portion (the third aspect).

  According to this, since the diaphragm member is provided between the partition wall and the diaphragm valve body, it is possible to prevent the liquid from entering the pneumatic drive unit side. In addition, the same effect as that of the invention of claim 1 can be obtained.

  According to the liquid control valve of the present invention, liquid leakage from the diaphragm valve body can be detected by the liquid leakage detection unit, and liquid can be prevented from entering the drive unit side by the diaphragm member.

  Hereinafter, an embodiment in which the present invention is applied to a chemical control valve will be described with reference to FIGS. The chemical control valve 21 is roughly composed of components such as a body 22, a pneumatic drive unit 23, a diaphragm valve body 24, a diaphragm member 25, and a base plate 26.

  The body 22 disposed on the base plate 26 is made of, for example, PTFE (polytetrafluoroethylene) and includes a chemical liquid passage 27 (indicated by an arrow 27 for convenience) as a liquid passage, and an inflow port 27a at one end thereof. An outlet 27b is provided at the end, and a valve port 28 is provided in the middle. The body 22 is provided with a surrounding wall-shaped first attachment portion 29 so as to surround the valve port 28, and a female screw for attaching the pneumatic drive portion 23 to the inner peripheral surface of the first attachment portion 29. A portion 29a and a stepped outer ring receiving portion 29b are formed.

  The pneumatic drive unit 23 includes a cylinder 30, a piston 31, a piston rod 32, and a stuffing 33. The cylinder 30 includes a lower cylinder 30a and an upper cylinder 30b formed by molding from a synthetic resin material (for example, polypropylene). These components may be formed by cutting or the like.

  At the lower end of the lower cylinder 30a, a fitting portion 34 that abuts and fits with the outer peripheral portion of the first mounting portion 29 is integrally provided, and the female screw portion 29a of the body 22 is provided on the inner peripheral side of the fitting portion 34. A male screw portion 34a is formed to be screwed together. A second mounting portion 35 having substantially the same shape as the first mounting portion 29 is formed at the upper end portion of the lower cylinder 30a. On the inner peripheral surface of the second mounting portion 35, an internal thread portion 35a and a stepped outer ring portion receiving portion 35b are formed. The lower cylinder 30a is attached to the body 22 in a state where the fitting portion 34 is fitted to the first attachment portion 29 and the male screw portion 34a is screwed to the female screw portion 29a.

  A fitting portion 36 that abuts and fits with the outer peripheral portion of the second mounting portion 35 is integrally provided at the lower end portion of the upper cylinder 30b. The upper cylinder 30b is attached to the lower cylinder 30a in a state where the fitting portion 36 is fitted to the second attachment portion 35. The chemical control valve 21 is integrally formed by fixing a base plate 26, a body 22, a lower cylinder 30a, and an upper cylinder 30b with screws (not shown) arranged at four corners thereof.

  A stuffing 33 as a partition wall is disposed in the lower end opening of the upper cylinder 30b. The stuffing 33 is made of a synthetic resin material (for example, polypropylene). A male screw portion 33a is formed on the outer peripheral surface of the stuffing 33, and a piston rod 32 (detailed below, a base side rod 42) is slidably passed through the center portion. A base side insertion hole 33b (corresponding to a rod insertion hole) is formed. The stuffing 33 is attached to the inside of the second attachment portion 35 by the male screw portion 33 a being screwed into the female screw portion 35 a of the second attachment portion 35. An annular seal member (O-ring 37a) for hermetically sealing is provided between the piston rod 32 and the base side insertion hole 33b, and an O-ring 37b is disposed at a necessary part of the pneumatic drive unit 23. Has been.

  The upper cylinder 30b accommodates a piston 31 that defines the base chamber 38 and the front chamber 39 and slides in the upper cylinder 30b. A piston rod 32 that extends toward the body 22 is accommodated in the piston 31. Is provided. The upper cylinder 30b is provided with a base port 38a that communicates with the base chamber 38 and a front port 39a that communicates with the front chamber 39, and a compression coil spring 40 that holds and closes the base chamber 38. ing. The upper cylinder 30b and the stuffing 33 are formed with a breathing hole 41 that is located below the O-ring 37a and communicates the base side insertion hole 33b to the outside.

Specifically, the piston rod 32 includes a base side rod 42 and a front side rod 43 that are arranged vertically, and a diaphragm member 25 and a diaphragm valve body 24 are attached to the lower ends of the rods 42 and 43. Mounting recesses 42a and 43a are formed.
The diaphragm member 25 is integrally provided with a center mounting portion 25a, a deformable thin film portion 25b, and an outer ring portion 25c, and the center mounting portion 25a is mounted on the mounting recess 42a of the base side rod 42, and the outer ring The portion 25c is pressed and fixed in a watertight manner to the outer peripheral ring portion receiving portion 35b of the lower cylinder 30a by a pressing portion 33c at the lower end of the stuffing 33. A front rod 43 is attached to the center mounting portion 25a of the diaphragm member 25.

  The diaphragm valve body 24 is integrally provided with a valve body central portion 24 a, a deformable thin film portion 24 b, and an outer peripheral ring portion 24 c, and the valve body central portion 24 a is attached to the mounting recess 43 a of the distal end side rod 43. The outer ring part 24c is fixed in a watertight manner to the outer ring part receiving part 29b of the body 22 by a pressing part 34c at the lower end of the lower cylinder 30a. The diaphragm member 25 and the diaphragm valve body 24 are made of a chemical-resistant synthetic resin material (for example, polytetrafluoroethylene), and the thickness dimensions of the respective thin film portions 25b and 24b are set to, for example, 0.3 mm. Has been.

  A liquid leakage detector is provided in a portion defined by the diaphragm member 25 and the diaphragm valve body 24. Specifically, a front side insertion hole 44 through which the distal end side rod 43 slidably penetrates is formed at the center of the lower cylinder 30a, and a groove 45 is formed at the edge of the front side insertion hole 44. ing. The lower cylinder 30a is provided with a leak detection port 45a communicating with the groove 45, and a liquid detection sensor is connected to this port via a hose (pipe) (not shown). Although not shown, the liquid detection sensor has a well-known configuration that detects liquid leakage based on, for example, a signal output when a pair of electrodes are short-circuited with liquid leakage. Moreover, the groove part 45 and the leak detection port 45a comprise the leak detection part of this invention.

Next, the operation of the present embodiment configured as described above will be described.
As shown in FIG. 1, the piston 31 is always biased downward by the spring force of the compression coil spring 40, and the valve port 28 is closed by the diaphragm valve body 24. When the chemical control valve 21 is opened from this state, compressed air is supplied from the front port 39a. Then, the piston 31 moves in the direction of arrow A against the spring force of the compression coil spring 40, and accordingly, the valve body central portion 24a of the diaphragm valve body 24 moves in the direction of arrow A, and the valve port 28 Is released. As a result, a liquid (for example, a peeling liquid as a chemical liquid) flows through the chemical liquid passage 27.

On the other hand, when the chemical solution control valve 21 is closed from the open state, when the compressed air is discharged from the front port 39a, the piston 31 moves in the direction of the arrow A by the spring force of the compression coil spring 40, and the diaphragm valve body 24 Closes the valve opening 28.
Here, in the chemical liquid control valve 21, the diaphragm valve body 24 comes into contact with the stripping solution and the opening / closing operation by the diaphragm valve body 24 is repeatedly performed, whereby the thin film portion 24 b of the diaphragm valve body 24 may be broken. In this case, even if the peeling liquid enters the lower cylinder 30a side from the thin film portion 24b, the diaphragm member 25 is prevented from entering the upper side (pneumatic drive unit 23 side). The stripping liquid that has entered from the thin film portion 24b is discharged from the groove portion 45 of the lower cylinder 30a through the leak detection port 45a and the hose, and is detected by the liquid detection sensor.

  As described above, according to the present embodiment, the diaphragm member 25 is disposed between the stuffing 33 and the diaphragm valve body 24. Therefore, the diaphragm valve body 24 may be broken due to the influence of the stripping solution or deterioration of use. In addition, it is possible to prevent the stripping solution from entering the pneumatic drive unit 23, and as a result, it is possible to prevent the oil components of the O-rings 37a and 37b of the pneumatic drive unit 23 from dissolving into the stripping solution. Moreover, the leakage of the peeling liquid to the lower cylinder 30a side can be detected by the liquid leakage detection port 45a and the liquid detection sensor, and measures such as replacement of the diaphragm valve body 24 and replacement of the control valve 21 can be taken immediately.

  Unlike the present embodiment, in the liquid control valve 1 of the conventional configuration, the oil components such as the O-rings 14a and 14b and the grease attached to the O-rings 14a and 14b are dissolved by the peeling liquid that has entered the pneumatic drive unit 23 side. There was a possibility of causing great damage to this process. On the other hand, in the chemical control valve 21 of the present embodiment, it is possible to reliably prevent the peeling liquid from entering the O-rings 37a and 37b, so that the above problem can be reliably solved.

  Since the diaphragm member 25, the diaphragm valve body 24, and the body 22 are made of polytetrafluoroethylene, it can be excellent in chemical resistance with little deterioration, and the invasion prevention of the chemical liquid can be further ensured. Moreover, since the cylinder 30 and the stuffing 33 are made of polypropylene having excellent chemical resistance, the life of the chemical control valve 21 can be extended.

  Since the lower cylinder 30a is formed with the fitting portion 34 that comes into contact with the outer peripheral portion of the first mounting portion 29, it is possible to prevent the screwed portion between the lower cylinder 30a and the body 22 from being loosened, The pressing force (watertight holding force) of the outer ring portion 24c of the diaphragm valve body 24 by the lower cylinder 30a is not weakened, and liquid leakage (or intrusion) from the screw threaded portion and the outer ring portion 24c is surely prevented. it can. Similarly, since the upper cylinder 30b is formed with the fitting portion 34 that fits with the second mounting portion 35, the screwed portion between the stuffing 33 and the lower cylinder 30a can be prevented from loosening, and the stuffing 33 Thus, the pressing force of the outer ring portion 25c of the diaphragm member 25 is not weakened, and liquid leakage (or intrusion) from the screw threaded portion and the outer ring portion 25c can be prevented.

The present invention can be applied not only to a chemical control valve but also to a general liquid control valve that controls various liquids such as pure water.
Moreover, the drive part which opens and closes the diaphragm valve body 24 is not limited to the said structure. For example, the cylinder 30 is composed of the separate upper cylinder 30b and the lower cylinder 30a. However, the cylinder 30 may be integrally formed, or a partition wall portion integral with the cylinder 30 may be provided in place of the cylinder 30 and the separate stuffing 33. May be. Instead of the pneumatic drive unit 23, the diaphragm valve body 24 may be opened and closed by a solenoid.

  The liquid detection sensor may be accommodated in the lower cylinder 30a. In this case, the liquid detection sensor includes a light projecting unit and a light receiving unit, and the light receiving unit changes depending on the presence or absence of liquid in contact with a light irradiation part (for example, the inner wall surface of the lower cylinder 30a) from the light projecting unit. You may comprise so that a leak may be detected based on the amount of received light. Moreover, you may comprise so that it may alert | report with respect to a user (operator) when a liquid leak is detected by the liquid detection sensor. In addition, even if a liquid detection sensor is not provided in the liquid leakage detection port 45a, for example, a liquid leakage detection port 45a may be provided with a transparent window to visually detect liquid leakage. In addition, the present invention can be implemented with appropriate modifications without departing from the scope of the invention.

1 is a longitudinal front view of a liquid control valve showing an embodiment of the present invention. Side view 1 equivalent diagram showing a conventional example

Explanation of symbols

  In the drawing, 21 is a chemical control valve (liquid control valve), 22 is a body, 23 is a pneumatic drive unit (drive unit), 24 is a diaphragm valve body, 25 is a diaphragm member, 27 is a chemical channel (liquid channel), 28 Is a valve port, 30 is a cylinder, 31 is a piston, 32 is a piston rod, 33 is stuffing (partition wall), 37a and 37b are O-rings (annular seal members), 45 is a groove (leakage detection unit), and 45a is leakage A liquid detection port (leak detection part) is shown.

Claims (3)

A body having a liquid passage and a valve opening formed in the middle of the liquid passage, a diaphragm valve body for opening and closing the valve opening, and opening and closing the diaphragm valve body, and an annular seal member is disposed at a necessary portion A liquid control valve comprising a drive unit,
A diaphragm member is provided between the drive unit and the diaphragm valve body to prevent liquid from entering the drive unit side,
A liquid control valve characterized in that a liquid leakage detector is provided in a portion defined by the diaphragm valve body and the diaphragm member.   2. The liquid control valve according to claim 1, wherein the diaphragm valve body and the diaphragm member are made of polytetrafluoroethylene or an equivalent material. A body having a liquid passage and a valve port formed in the middle of the liquid passage;
A cylinder attached to the body, a piston rod extending toward the body, and a pneumatic drive unit having a piston;
A partition wall provided in the cylinder and having a rod insertion hole through which the piston rod passes,
An annular seal member mounted between the outer periphery of the piston rod and the rod insertion hole and hermetically sealed;
A central part of the valve body, a thin film part, and an outer peripheral part are integrally formed, the central part of the valve body is attached to the tip of the piston rod, and the outer peripheral part is fixed in a watertight manner to the body. A diaphragm valve body for opening and closing the valve opening;
A diaphragm member that is positioned between the partition wall and the diaphragm valve body, a central portion is attached to the piston rod, and an outer peripheral portion is watertightly attached to the cylinder;
A liquid control valve characterized in that a liquid leakage detection section is provided in a portion defined by a diaphragm valve body and a diaphragm member.

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