JP3822957B2 - Air operated valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air operated valve having a suck back function.
[0002]
[Prior art]
The flow rate of chemicals and the like used in manufacturing processes such as semiconductors and liquid crystals is controlled by a valve while being pumped 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 is dripped from the nozzle tip after stopping the discharge by sucking the chemical solution in the nozzle side flow path. Is 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]
Both the air operated valve 111 and the suck back device 121 are integrally formed with respect to 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 an input hole 104, a valve hole 105, and an adjustment chamber 106 are communicated from the input port 102 to the output port 103. A valve seat 107 is formed in the valve hole 105 that is opened upward, and a diaphragm valve body 108 that contacts and separates from the valve seat 107 is fixed by a cylinder 112. The diaphragm valve body 108 is fixed to the lower end of the rod 114 projecting from the piston 113. The air operated valve 111 is opened and closed by a balance between the biasing force of the spring 115 that biases the piston 113 toward the valve seat 107 and the air pressure that pressurizes the piston 113 from below.
[0004]
On the other hand, in the suck back device 121, a diaphragm 109 is fixed by a cylinder 122 so as to close the adjustment chamber 106 opened in the base 101. The diaphragm 109 is fixed to the lower end of the rod 124 protruding from the piston 123. The suck back device 121 moves the diaphragm 109 according to the balance between the biasing force of the spring 125 that biases the piston 123 upward and the air pressure that pressurizes the piston 123 from above, thereby changing the volume in the adjustment chamber 106. Let
For this reason, a chemical solution having a predetermined flow rate is discharged from the nozzle by opening and closing the air operated valve 111 while being pumped from a supply source (not shown) to the nozzle. 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 by the air pressure and stretching the diaphragm 109 downward, so that the air operated valve 111 When the valve is closed, the air that pressurizes the piston 123 is removed to increase the volume of the adjustment chamber 106 as shown in the figure, and the chemical solution in the nozzle side flow path is sucked. Therefore, the chemical liquid is prevented from dripping from the nozzle tip after the discharge is stopped.
[0005]
[Problems to be solved by the invention]
However, such a conventional suck-back device is provided separately in series with the air operated valve in the flow path, so it is necessary to secure a piping space, and the flow path is complicated in the apparatus, so the liquid Puddles were likely to occur.
For this reason, the need for securing the installation area hinders the miniaturization of the entire fluid device including the valve, and causes the purity of the discharged fluid to be reduced by the fluid remaining in the liquid reservoir.
Also, providing the suck-back device as a separate unit is not preferable from the viewpoint of cost.
[0006]
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 so as to solve such a problem.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an air operated valve according to the present invention includes a valve main body having a valve seat formed in a communication hole that communicates an input port and an output port, and an annular valve that contacts and separates from the valve seat. A diaphragm valve body including a body portion and a center fixing portion provided inside the valve body portion; a first piston including a guide tube into which a support tube fixed to the valve body portion is fitted ; A second piston having a rod which is inserted through the first piston into the guide tube and to which the center fixing portion is fixed; and a sliding chamber in which the first piston and the second piston are loaded. A cylinder, and the valve body is brought into contact with and separated from the valve seat by the operation of the first piston to open and close the valve, and the ring of the valve body of the diaphragm valve body is operated by the operation of the second piston. Suck back by deforming the inside It is characterized in.
[0008]
Accordingly, the guide pipe moves according to the first piston sliding in the cylinder by the air pressure, and the diaphragm valve element engaged with the guide pipe contacts and separates from the valve seat, thereby opening and closing the valve. . On the other hand, if the rod moves according to the second piston that slides in the cylinder by the air pressure, the volume of the output port side passage changes due to the deformation of the diaphragm attached to the rod, and when the valve is closed The suck back for sucking the fluid is performed by increasing the volume in the flow path.
Therefore, in the air operated valve of the present invention, the valve portion and the suck back portion can be integrated by configuring the suck back operation inside the annular valve body including the annular valve body, Since it is not necessary to provide a suck-back device separately, it is possible to reduce the size and the liquid pool. It also contributes to cost reduction.
[0009]
Air operated valve of the present invention includes a first biasing member that biases the first piston down direction, and a second urging member for urging the second piston in the upper side, the first and The first piston and the second piston are positioned by a relationship between a biasing force of the second biasing member and an air pressure of air supplied into the cylinder with respect to the biasing force.
Therefore, the air pressure applied to the first piston is adjusted to balance 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 and balanced with the urging force of the second urging member, and the diaphragm is deformed according to the operation of the second piston to perform the suck back.
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 parts penetrating the sliding chamber increases, so that the seal is sealed. Although it is necessary to use many members, the problem is solved because the urging member is provided and the air operation is performed only from one side.
[0010]
In addition, the air operated valve of the present invention is characterized by having an adjustment knob for restricting the rise 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, the volume change due to suck back can be adjusted.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an air operated valve according to the present invention will be described in detail. 1 to 3 are sectional views showing the air operated valve according to the present embodiment. FIG. 1 is when the valve is closed (when suckback is performed), FIG. 2 is opened, and FIG. 3 is when the valve is closed. It is the figure which showed the state of. The configuration will be described below with reference to FIG.
The air operated valve of the present embodiment is configured by integrating a valve body 1, a first cylinder 2, a second cylinder 3, and a cover 4.
In the valve body 1, an input port 11 and an output port 12 are communicated with each other through a valve hole 14 that forms a valve seat 13. The valve seat 13 protrudes upward, and the valve hole 14 has a diameter-enlarged side formed upward in a bowl shape, and a diameter-reduced side communicates with the output path 15. An input path 16 that is outside the valve hole 14 and communicates with the input port 11 is also opened above the valve body 1.
[0012]
A diaphragm valve element 5 that contacts and separates from the valve seat 13 is clamped and fixed between the valve body 1 and the first cylinder 2 that are integrally fixed. Therefore, the valve body 1 and the first cylinder 2 are hermetically 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 body 5 includes a ring-shaped valve body portion 5a that contacts the valve seat 13, an 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 portion. Is formed.
[0013]
The operating part for operating such a diaphragm valve body 5 is configured such that a stepped portion of the second cylinder 3 having a small-diameter stepped shape is fitted into the large-diameter first cylinder 2 to form a double-structure cylinder. ing.
In the first cylinder 2, a first piston 22 having a guide tube 21 that slides in a tube whose diameter is reduced in the middle is loaded. An operation port 24 formed in the first cylinder 2 is formed in the lower pressurizing chamber 23 partitioned by the first piston 22. In order to make the pressurizing chamber 23 airtight, seal rings 25 and 26 are fitted to sliding portions where the guide tube 21 and the first piston 22 slide on the inner surface of the first cylinder 2.
The first cylinder 2 is loaded with a first spring 27 that biases the first piston 22 downward. A support tube 28 that is fixed to the valve body 5 a of the diaphragm valve body 5 is fitted to the lower end of the guide tube 21.
[0014]
On the other hand, a second piston 32 having a rod 31 that slides through the guide tube 21 through the axial center of the first piston 22 is loaded in the second cylinder 3. The second cylinder 3 is closed by the cover 4, and an operation port 34 formed in the second cylinder 3 is formed in the pressurizing chamber 33 partitioned by the cover 4 and the second piston 32. In order to make the pressurizing chamber 33 airtight, a seal ring 35 is fitted on the outer periphery of the second piston 32 on which the second piston 32 slides on the inner surface of the second cylinder 3.
The second cylinder 3 is loaded with a second spring 36 that urges the second piston 32 upward. And the center fixing | fixed part 5c of the diaphragm valve body 5 is adhering to the rod 31 lower end.
[0015]
Further, the cover 4 is formed with an adjustment knob 41. The adjustment knob 41 is screwed with a rod 42 threaded coaxially with the second piston 32 and the like, a sliding part 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.
[0016]
And the air operated valve of this Embodiment which consists of such a structure will operate | move as follows.
First, in the valve closed state of FIG. 1, the first piston 22 is urged downward by the first spring 27, and the diaphragm valve body 5, particularly the valve body portion 5 a at the lower end of the guide pipe 21 is brought into contact with the valve seat 13. Yes. 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 | fixed part 5c of the diaphragm valve 5 exists in the raise state, and the volume of the valve hole 41 is taken large.
[0017]
Next, the air operated valve is opened from the closed state shown in FIG. 1 to the open state shown in FIG.
In that 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. Therefore, the first piston 22 rises against the urging force of the first spring 27 that urges downward. When the first piston 22 is raised, the valve body 5a of the diaphragm valve body 5 is lifted together with the integrally formed guide pipe 21 and support pipe 28, and the valve body 5a is separated from the valve seat 13 to open the valve. It is done.
[0018]
On the other hand, simultaneously with the supply of air from the operation port 24 to the pressurization chamber 23, air is also supplied from the operation port 34 to the pressurization chamber 33. Therefore, the upper surface of the second piston 32 is pressurized by the air pressure, and the second piston 32 descends against the biasing force of the second spring 36 biasing upward. When the second piston 32 is lowered, the center fixing portion 5c of the diaphragm valve body 5 is pushed down together with the rod 31 formed integrally. Therefore, the volume in the valve hole 14 decreases as the diaphragm located in the valve seat 13 projects downward.
Therefore, the fluid that has flowed into the valve body 1 from the input port 11 flows through the input path 16, the valve hole 14, the output path 15, and the output port 12 to the discharge side flow path connected to the nozzle (not shown). .
[0019]
When the air operated valve is opened in this way (FIG. 2) and a certain amount of fluid (chemical solution or the like) is discharged from the nozzle, the valve is closed again as shown in FIG.
In that case, the air supplied into the pressurizing chamber 23 when the valve is opened is removed from the operation port 24. Then, the first piston 22, the guide tube 21, and the support tube 28 are lowered by the biasing force of the first spring 27 that biases the first piston 22 downward, and the diaphragm valve fixed to the support tube 28. The valve body portion 5 a of the body 5 contacts the valve seat 13.
Therefore, the fluid flowing in from the input port 11 is blocked without flowing from the input path 16 to the valve hole 14.
[0020]
By the way, when the valve body portion 5a of the diaphragm valve body 5 comes into contact with the valve seat 13, the diaphragm in the valve body portion 5a tries to push the liquid toward the valve hole 14 side. Therefore, the pressure in the valve hole 14 closed by the diaphragm valve body 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 volume in the valve hole 14 is increased by raising the central portion 5c of the diaphragm valve body 5 lowered when the valve is opened (FIG. 2), and the fluid in the valve hole 14 is increased. The suck back is performed to reduce the pressure and suck the fluid filled in the discharge side flow path.
[0021]
Therefore, when the valve body 5a of the diaphragm valve body 5 is brought into contact with the valve seat 13 and closed (FIGS. 2 to 3), the diaphragm in the valve body 5a is raised at a predetermined timing ( FIG. 1).
That is, the air supplied into the pressurizing chamber 33 from the operation port 34 is opened when the valve is opened at a predetermined timing. If it does so, the 2nd piston 32 and the rod 31 will raise by the urging | biasing force of the 2nd spring 36 which urges | biases the 2nd piston 32 upwards, The center fixing | fixed part of the diaphragm valve body 5 fixed to the rod 31 5c goes up.
Accordingly, the diaphragm in the valve body 5a is pulled up, the volume in the valve hole 14 is increased, and the fluid pressure is decreased, whereby the fluid on the discharge side is sucked.
The suck back 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.
[0022]
Therefore, in the air operated valve of the present embodiment, the diaphragm valve body 5 is operated by the first piston 22 and the second piston 32 in which the annular valve body portion 5a and the center fixing portion 5c at the center thereof are provided coaxially. Therefore, the valve portion and the suck back portion can be integrated.
Therefore, it is not necessary to separately provide a suck-back device in addition to the on-off valve as in the conventional case, and it is not necessary to secure an installation space for the suck-back device, so that the entire fluid device can be reduced in size. It was.
Further, since the flow path in the apparatus where liquid pool is likely to occur can be omitted, the liquid pool generated in the apparatus can be eliminated, and the loss of the purity of the discharge fluid such as a chemical liquid can be prevented.
[0023]
In addition, the cost for one air operated valve could be reduced compared to 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 body 5 that is lowered when the valve is opened and raised when the valve is closed by the adjustment knob 41, so that the volume in the flow path associated with opening and closing of the valve is increased. It has become possible not to change.
[0024]
The air operated valve of the present invention is not limited to the one in the above embodiment, and various modifications can be made without departing from the spirit of the valve.
For example, in the above embodiment, the first and second pistons 22 and 32 are operated in balance with the air pressure using the first and second springs 27 and 36. However, as shown in FIG. Air pressure may be supplied to and exhausted from the operation ports 55, 56, 57, and 58 to the pressurizing chambers 51, 52, 53, and 54, and the pistons 59 and 60 may be operated.
[0025]
Further, for example, in the above-described embodiment, the second piston 32 is configured to slide in the second cylinder 3, but may be configured to be a diaphragm type actuator as shown in FIG. .
That is, the diaphragm 74 is sandwiched and fixed by the cover 72 and the cylinder 73 in which the operation port 71 is formed, and the diaphragm chamber 75 is formed on the cover 72 side. Then, the diaphragm 74 is sandwiched between the diaphragm receivers 76a and 76b, and is penetrated and fixed by the rod 77 having the diaphragm valve body 5 fixed to the lower end.
Therefore, by using an electropneumatic regulator (not shown) to balance the air pressure in the diaphragm chamber 75 above the diaphragm 74 and the spring 31, the suck back amount can be varied by remote operation.
[0026]
【The invention's effect】
The present invention provides a valve body formed by forming a valve seat in a communication hole that communicates an input port and an output port, an annular valve body portion that contacts and separates from the valve seat, and an inner side of the valve body portion. A diaphragm valve body having a center fixing portion formed therein, a first piston having a guide tube into which a support tube fixed to the valve body portion is fitted, and a center inserted through the first piston into the guide tube. A second piston having a rod to which the fixing portion is fixed; and a cylinder having a sliding chamber in which each of the first piston and the second piston is loaded. The valve is opened and closed by abutting and separating the valve, and the valve part and the suck back part are integrated by deforming the annular inside of the valve body part of the diaphragm valve body by the operation of the second piston. It is possible to provide a special air operated valve Was Tsu.
[0027]
Further, the present invention includes a first urging member for urging the first piston down direction, the second piston and a second urging member for urging the upper side, the first and second biasing By positioning the first piston and the second piston according to the relationship between the biasing force of the member and the air pressure of the air supplied into the cylinder with respect to the biasing force, it is possible to provide an air operated valve with few seal points. It has become possible.
In addition, since the present invention has an adjustment knob that restricts the rise of the second piston, it is possible to provide an air operated valve that can adjust the volume change due to suck back.
[Brief description of the drawings]
1 is a cross-sectional view when closed showing the shape condition of an embodiment of the air operated valve according to the present invention (case of performing suck-back).
2 is a cross-sectional view at the valve opening showing the shape condition of an embodiment of the air operated valve according to the present invention.
3 is a cross-sectional view at the time of closing showing the shape condition of an embodiment of the air operated valve according to the present invention.
FIG. 4 is a cross-sectional view showing an embodiment of a cylinder portion of an air operated valve according to the present invention.
FIG. 5 is a cross-sectional view showing an embodiment of an 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 body 2 1st cylinder 3 2nd cylinder 4 Cover 5 Diaphragm valve body 13 Valve seat 14 Valve hole 21 Guide pipe 22 1st piston 31 Rod 32 2nd piston 41 Adjustment knob

Claims (3)

A valve body in which a valve seat is formed in a communication hole communicating the input port and the output port;
A diaphragm valve body including an annular valve body portion that contacts and separates from the valve seat, and a center fixing portion provided inside the valve body portion ,
A first piston provided with a guide tube into which a support tube fixed to the valve body portion is fitted ;
A second piston having a rod that is inserted through the first piston into the guide tube and to which the center fixing portion is fixed ;
A cylinder having sliding chambers loaded with the first piston and the second piston,
The valve body is brought into contact with and separated from the valve seat by the operation of the first piston to open and close the valve, and the annular interior of the valve body of the diaphragm valve body is deformed by the operation of the second piston. An air operated valve characterized by performing back-up. The air operated valve according to claim 1,
Has a first biasing member for biasing said first piston down direction, and a second urging member for urging the second piston in the upper side,
The first piston and the second piston are positioned according to 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. Air operated valve. In the air operated valve according to claim 1 or 2,
An air operated valve having an adjustment knob for restricting the rise of the second piston.

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