JPH1151223A - Air operate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air operate valve in which the valve element part is formed in a single piece with a suck-back part. SOLUTION: An air operate valve is equipped with a valve body 1 having a valve seat 13 at a communication hole 14 leading from an input port 11 to an output port 12, a diaphragm valve element 5 furnished with a ring-shaped valve element part 5a to be contacted with and separated from the valve seat 13, a first piston 22 furnished with a guide pipe 21 to be engaged by the valve element part 5a, a second piston 32 furnished with a rod 31 inserted into the guide pipe 21 upon penetrating the first piston 22 and engaged by the center part of the diaphragm valve element 5, and cylinders 2 and 3 consisting of slide chambers in which the first 22 and second pistons 32 are fitted respectively, wherein the valve is opened and closed by contacting and separating the valve element part 5a with/from the valve seat 13 through the motions of the first piston 22, and suck-back is made by deforming the ring-shaped inside of the valve element part 5a of the diaphragm valve element 5 through the motions of the second piston 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air operated valve having a suck-back function.

[0002]

2. Description of the Related Art The flow rate of a chemical solution or the like used in the manufacturing process of semiconductors or liquid crystals is controlled by a valve while being fed from a supply source to a discharge port such as a nozzle. At that time, the valve is opened and closed at regular intervals in order to supply a certain amount of the chemical solution, but when the valve is closed, the chemical solution in the nozzle-side flow path is sucked, so that the chemical solution drops from the nozzle tip after the discharge is stopped. Has been prevented. A suck-back device is used as a configuration for sucking the chemical solution. FIG. 5 is a cross-sectional view showing an air operated valve and a suck back device provided in a flow path from a chemical solution supply source to a nozzle.

[0003] The air operated valve 111 and the suck back device 121 are both formed integrally with the base 101 in which the flow path is formed. An input port 102 and an output port 103 are formed in the base 101, and the input port 10 extends from the input port 102 to the output port 103.
4, the valve hole 105 and the adjustment chamber 106 are communicated.
The valve seat 107 is formed in the valve hole 105 opened upward,
A diaphragm valve element 108 that comes into contact with and separates from the cylinder valve 108 is fixed by a cylinder 112. The diaphragm valve element 108 includes a rod 114 protruding from a piston 113.
It is fixed to the lower end. The air operated valve 111 is opened and closed by a balance between a biasing force of a spring 115 for biasing the piston 113 toward the valve seat 107 and an air pressure for pressing the piston 113 from below.

On the other hand, in the suckback device 121, a diaphragm 109 is fixed by a cylinder 122 so as to close an adjustment chamber 106 opened in the base 101.
The diaphragm 109 is fixed to a lower end of a rod 124 protruding from a piston 123. The suckback device 121 moves the diaphragm 109 by the balance between the urging force of the spring 125 that urges the piston 123 upward and the air pressure that pressurizes the piston 123 from above, and changes the volume in the adjustment chamber 106. Let it. For this reason, while being pressure-fed from a supply source (not shown) to the nozzle, a predetermined flow rate of the liquid medicine is discharged from the nozzle by opening and closing the air operated valve 111. Then, when the air operated valve 111 is opened, the suck back device 121 reduces the volume in the adjustment chamber 106 by pressurizing the piston 123 with air pressure to stretch the diaphragm 109 downward. At the time of closing the valve, the air pressurizing the piston 123 is released to increase the volume of the adjustment chamber 106 as shown in the diagram of the diaphragm 109 to suck the chemical solution in the nozzle-side flow path. Therefore, after the discharge is stopped, the chemical liquid is prevented from dropping from the nozzle tip.

[0005]

However, such a conventional suck-back device is provided in the flow path as a separate device in series with the air operated valve. Since the flow path became complicated, liquid pools were easily generated. Therefore, the necessity of securing the installation area hinders the miniaturization of the entire fluid device including the valve, and causes the purity of the discharged fluid to decrease due to the fluid remaining in the liquid pool. Providing the suck-back device as a separate device is not preferable in terms of cost.

Accordingly, an object of the present invention is to provide an air operated valve in which a valve portion and a suck back portion are integrated, in order to solve such a problem.

[0007]

According to the present invention, there is provided an air operated valve, comprising: a valve body having a valve seat formed in a communication hole communicating an input port and an output port;
A diaphragm valve body having an annular valve body portion which comes into contact with and separates from the valve seat, a first piston provided with a guide tube engaged with the valve body portion, and A second piston having a rod inserted into the guide tube and engaged with the center of the diaphragm valve body; and a cylinder comprising a sliding chamber for loading the first piston and the second piston, respectively. The operation of the first piston causes the valve body to contact and separate from the valve seat to open and close the valve, and the operation of the second piston deforms the annular interior of the valve body of the diaphragm valve body. It is characterized by performing suckback.

Accordingly, the guide tube moves in accordance with the first piston sliding in the cylinder by the air pressure, and the diaphragm valve element engaged with the guide tube comes into contact with or separates from the valve seat to open and close the valve. Is performed. On the other hand, if the rod moves according to the second piston that slides in the cylinder by air pressure, the volume of the output port side flow path changes due to the deformation of the diaphragm that is engaged with the rod, and the valve closes when the valve is closed. By increasing the volume in the flow path, suckback is performed to suck the fluid. Therefore, in the air operated valve of the present invention, the suck back operation is performed in the annular inside of the diaphragm valve body having the annular valve body.
The valve part and the suck back part can be integrated,
Since there is no need to separately provide a suck-back device, it is possible to reduce the size and reduce the amount of liquid pool. It also contributes to cost reduction.

The air operated valve of the present invention has a first urging member for urging the first piston upward and a second urging member for urging the second piston downward,
The first piston and the second piston are positioned according to a relationship between an urging force of a second urging member and an air pressure of air supplied into the cylinder with respect to the urging force. Therefore, the air pressure applied to the first piston is adjusted to balance with the urging force of the first urging member, and the diaphragm valve body is brought into contact with and separated from the valve seat according to the operation of the first piston. On the other hand, the air pressure applied to the second piston is adjusted to balance with the urging force of the second urging member, and the diaphragm is deformed according to the operation of the second piston to perform suckback. Therefore, in the case of air operation,
The chamber in the cylinder partitioned by the piston is required to be airtight. In particular, if the piston has a sliding chamber for each piston, the number of locations penetrating through the sliding chamber increases, so it is necessary to use a lot of seal members. However, the problem is solved because the biasing member is provided so that the air operation is performed from only one side.

The air operated valve according to the present invention is characterized in that the air operated valve has an adjusting knob for limiting the elevation of the second piston. Therefore, by limiting the sliding distance of the second piston connected to the diaphragm inside the annular valve body by the adjustment knob, it is possible to adjust a change in volume due to suckback.

[0011]

Next, an embodiment of an air operated valve according to the present invention will be described in detail. 1 to 3 are cross-sectional views showing the air operated valve according to the present embodiment. FIG. 1 shows a state when the valve is closed (when suck back is performed), FIG. 2 shows a state when the valve is opened, and FIG. FIG. Hereinafter, the configuration will be described with reference to FIG.
The air operated valve of the present embodiment is configured such that the valve body 1, the first cylinder 2, the second cylinder 3, and the cover 4 are integrated. In the valve body 1, an input port 11 and an output port 12 are communicated via a valve hole 14 forming a valve seat 13. The valve seat 13 projects upward and has a valve hole 14.
A large diameter side formed in a pot shape is opened upward, and a small diameter side communicates with the output path 15. Also, the valve hole 14
The input path 16 which is located outside and communicates with the input port 11 is also opened above the valve body 1.

A diaphragm valve element 5 that comes into contact with or separates from the valve seat 13 is clamped and fixed between the integrally fixed valve body 1 and the first cylinder 2. Therefore, the valve body 1 and the first cylinder 2 are airtightly partitioned by the diaphragm valve body 5, and the fluid flowing in the valve body 1 does not leak to the cylinder 2 side. The diaphragm valve element 5 is provided with a valve seat 13.
The valve body 5a is formed of a ring-shaped valve body portion 5a that abuts the outer peripheral fixing portion 5b sandwiched between the valve body 1 and the first cylinder 2, and a central fixing portion 5c at the center.

An operating part for operating such a diaphragm valve element 5 is a double-cylinder cylinder in which a stepped portion of a second cylinder 3 having a small-diameter stepped shape is fitted into a large-diameter first cylinder 2. Is configured. In the first cylinder 2, a first piston 22 provided with a guide tube 21 that slides in a tube whose diameter is reduced on the way is loaded. The first piston 2
The first cylinder 2 is provided in the lower pressurizing chamber 23 partitioned by the first cylinder 2.
An operation port 24 is formed in the hole. In order to make the pressurizing chamber 23 airtight, seal rings 25 and 26 are fitted to a sliding portion where the guide tube 21 and the first piston 22 slide on the inner surface of the first cylinder 2. Further, a first spring 27 for urging the first piston 22 downward is loaded in the first cylinder 2. The lower end of the guide pipe 21 has a valve body 5 of the diaphragm valve body 5.
The support tube 28 fixed to a is fitted.

On the other hand, a second piston 32 having a rod 31 that slides in the guide tube 21 through the axis of the first piston 22 is loaded in the second cylinder 3. Second
The cylinder 3 is closed by a cover 4, and the pressurizing chamber 33 partitioned by the cover 4 and the second piston 32 has a second
An operation port 34 formed in the cylinder 3 is provided. Then, in order to make the pressurizing chamber 33 airtight,
A seal ring 35 is fitted around the outer periphery of the second piston 32 in which the piston 32 slides on the inner surface of the second cylinder 3.
A second spring 36 for urging the second piston 32 upward is loaded in the second cylinder 3. The center fixing portion 5c of the diaphragm valve body 5 is fixed to the lower end of the rod 31.

Further, the cover 4 has an adjustment knob 41 formed thereon. A rod 42 threaded coaxially with the second piston 32 and the like is screwed into the adjustment knob 41, a sliding portion is fixed inside the cover 4, a handle 43 is fixed outside the cover 4, and a lock nut 44 is fixed. It is screwed.

The air operated valve according to the present embodiment having such a configuration operates as follows. First, in the closed state of FIG.
Is biased downward by the first spring 27, and the diaphragm valve body 5 at the lower end of the guide tube 21, particularly, the valve body part 5 a is in contact with the valve seat 13. The second piston 32 is urged upward by the second spring 36 and is in contact with the rod 42 of the adjustment knob 41. Therefore, the center fixing portion 5c of the diaphragm valve 5 is in a raised state, and the volume of the valve hole 41 is large.

Next, the air operated valve is opened from the closed state shown in FIG. 1 to the opened state shown in FIG. In this case, air is supplied from the operation port 24 into the pressurizing chamber 23, and the lower surface of the first piston 22 is pressurized by the air pressure. Then, the first piston 22 rises against the urging force of the first spring 27 that urges downward. When the first piston 22 rises, the valve body 5a of the diaphragm valve body 5 is lifted together with the guide tube 21 and the support tube 28 integrally formed, and the valve body 5a is
The valve is opened apart from.

On the other hand, simultaneously with the supply of air from the operation port 24 to the pressurizing chamber 23, the operation port 34 also supplies air to the pressurizing chamber 33.
The air is supplied to the Then, the upper surface of the second piston 32 is pressurized by air pressure, and the second piston 32 descends against the urging force of the second spring 36 which urges upward. When the second piston 32 descends, the center fixing portion 5c of the diaphragm valve body 5 is pushed down together with the rod 31 formed integrally. Therefore, the valve seat 13
The volume in the valve hole 14 is reduced by the diaphragm located inside projecting downward. Therefore, input port 1
The fluid flowing from 1 into the valve body 1 passes through the input path 16, the valve hole 14, the output path 15, and the output port 12, and flows into a discharge-side flow path connected to a nozzle (not shown).

The air operated valve is thus opened (FIG. 2), and when a certain amount of fluid (such as a chemical) is discharged from the nozzle, the valve is closed again as shown in FIG. In this case, the air supplied into the pressurizing chamber 23 when the valve is opened is extracted from the operation port 24. Then, the first piston 22, the guide tube 21, and the support tube 28 are lowered by the urging force of the first spring 27 that urges the first piston 22 downward, and the diaphragm valve fixed to the support tube 28 The valve body portion 5a of the body 5 contacts the valve seat 13. Therefore, the fluid flowing from the input port 11 is blocked without flowing from the input path 16 to the valve hole 14.

Incidentally, the valve body 5 of the diaphragm valve body 5
When a contacts the valve seat 13, the diaphragm in the valve body 5 a tries to push the liquid toward the valve hole 14. For this reason, the pressure in the valve hole 14 closed by the diaphragm valve element 5 increases, and the fluid drops from the nozzle immediately after the valve is closed. In the air operated valve of the present embodiment, the central portion 5c of the diaphragm valve body 5 lowered when the valve is opened (FIG. 2).
By raising the pressure, the volume in the valve hole 14 is increased, the fluid pressure in the valve hole 14 is reduced, and suckback is performed to suck the fluid filled in the discharge-side flow path.

Therefore, the valve element portion 5a of the diaphragm valve element 5
When the valve is brought into contact with the valve seat 13 to close the valve (FIGS. 2 to 3), the diaphragm in the valve body 5a is raised at a predetermined timing (FIG. 1). That is, the air supplied from the operation port 34 into the pressurizing chamber 33 is released at a predetermined timing when the valve is opened. Then, the second piston 32 and the rod 31 are raised by the urging force of the second spring 36 that urges the second piston 32 upward, and the center fixing portion of the diaphragm valve body 5 fixed to the rod 31. 5c rises. Therefore, the diaphragm in the valve body 5a is pulled up, the volume in the valve hole 14 is increased, and the fluid pressure is reduced, so that the fluid on the discharge side is sucked. The suckback amount, that is, the volume change amount in the valve hole 14 can be adjusted by changing the position of the rod 42 by operating the adjustment knob 41.

Accordingly, in the air operated valve of the present embodiment, the diaphragm valve 5 is provided with the first piston 22 and the second piston 32 in which the annular valve body 5a and the center fixing portion 5c at the center thereof are provided coaxially. Thus, the valve portion and the suck back portion can be integrated. Therefore, unlike the conventional case, there is no need to separately provide a suck-back device in addition to the on-off valve, and there is no need to secure an installation space for the suck-back device, so that the entire fluid device can be downsized. Was. In addition, since the flow path in the apparatus in which the liquid pool easily occurs can be omitted, the liquid pool generated in the apparatus can be eliminated, and the purity of the discharge fluid such as a chemical solution can be prevented from being impaired.

Further, the cost for one air operated valve can be reduced as compared with the cost required for the conventional on-off valve and suck-back device. In addition, the air operated valve adjusts the moving distance of the center fixing portion 5c of the diaphragm valve element 5 which is lowered when the valve is opened and is raised when the valve is closed by the adjusting knob 41, so that the volume in the flow path accompanying the opening and closing of the valve is reduced. It is also possible to make it unchanged.

It should be noted that the air operated valve of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist thereof. For example,
In the embodiment, the first and second springs 27, 3
6, the first and second pistons 22, 32 were operated in balance with air pressure. However, as shown in FIG. 5
The air pressure may be balanced by supplying and discharging air from 6, 57, 58 to operate the pistons 59, 60.

For example, in the above embodiment, the second
Although the piston 32 is configured to slide in the second cylinder 3, the piston 32 may be changed to a diaphragm type actuator as shown in FIG. That is, the diaphragm 74 is sandwiched and fixed between the cover 72 on which the operation port 71 is formed and the cylinder 73, and the diaphragm chamber 75 is formed on the cover 72 side. And the diaphragm 74
Is sandwiched between the diaphragm receivers 76a and 76b, and is fixed by being penetrated by the rod 77 to which the diaphragm valve body 5 is fixed at the lower end. Therefore, by using an electropneumatic regulator (not shown) to balance the air pressure of the diaphragm chamber 75 above the diaphragm 74 and the spring 31, the suckback amount can be changed by remote control.

[0026]

According to the present invention, there is provided a diaphragm having a valve body in which a valve seat is formed in a communication hole communicating an input port and an output port, and an annular valve body which comes into contact with and separates from the valve seat. A second piston having a valve body, a first piston having a guide tube engaged with the valve body portion, and a rod inserted through the first piston into the guide tube and engaged with a central portion of the diaphragm valve body; And a cylinder comprising a sliding chamber into which the first piston and the second piston are loaded, respectively, and the operation of the first piston causes the valve body to contact and separate from the valve seat to open and close the valve. By performing the suck back by deforming the annular inside of the valve body of the diaphragm valve body by the operation of the two pistons, it is possible to provide an air operated valve in which the valve unit and the suck back unit are integrated. Was.

Also, the present invention has a first urging member for urging the first piston upward and a second urging member for urging the second piston downward, and the first and second urging members are provided. To provide an air operated valve with a small number of seal points by positioning the first piston and the second piston based on the relationship between the urging force of the urging member and the air pressure of the air supplied into the cylinder with respect to the urging force. Became possible. Further, since the present invention has the adjustment knob for limiting the elevation of the second piston, it has become possible to provide an air operated valve capable of adjusting a volume change due to suckback.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an air operated valve according to an embodiment of the present invention when the valve is closed (when suck back is performed).

FIG. 2 is a cross-sectional view of an air operated valve according to an embodiment of the present invention when the valve is opened.

FIG. 3 is a cross-sectional view of the air operated valve according to the embodiment of the present invention when the valve is closed.

FIG. 4 is a cross-sectional view showing one embodiment of a cylinder portion of the air operated valve according to the present invention.

FIG. 5 is a cross-sectional view showing an embodiment of the air operated valve according to the present invention.

FIG. 6 is a cross-sectional view showing a conventional air operated valve and suck-back device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve main body 2 1st cylinder 3 2nd cylinder 4 Cover 5 Diaphragm valve 13 Valve seat 14 Valve hole 21 Guide tube 22 1st piston 31 Rod 32 2nd piston 41 Adjustment knob

Claims (3)

[Claims] 1. A valve body having a valve seat formed in a communication hole communicating an input port and an output port, and a diaphragm valve body having an annular valve body portion which comes into contact with and separates from the valve seat. A first piston having a guide tube engaged with the valve body, and a second piston having a rod inserted through the first piston into the guide tube and engaged with a central portion of the diaphragm valve body. A piston comprising a sliding chamber for loading the first piston and the second piston respectively, wherein the operation of the first piston causes the valve body to contact and separate from the valve seat. An air operated valve that opens and closes a valve and deforms the annular interior of the valve body of the diaphragm valve body by the operation of the second piston to perform suckback. 2. The air operated valve according to claim 1, further comprising: a first urging member for urging the first piston upward, and a second urging member for urging the second piston downward. The position of the first piston and the position of the second piston are determined by a relationship between an urging force of the first and second urging members and an air pressure of air supplied into the cylinder with respect to the urging force. And air operated valve. 3. The air operated valve according to claim 1, further comprising an adjusting knob for restricting a rise of the second piston.