JP2000074254A - Device and method for controlling pneumatic cylinder operating valve for supplying pure water and chemical - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust from being generated form the whole pure water and chemicals supplying system by eliminating the occurrence of water hammer as well as to prevent dust from being generated from a valve element and a valve seat by softly landing the valve element on the valve seat without using an oil damper and a rubber cushion. SOLUTION: A pneumatic cylinder operating valve 1 is so arranged that its back pressure side opposing to the flowing directions of pipes 11a, 11b may be taken as an inflow port. A pneumatic controlling controller 14 is incorporated on the way of an air pressure control line 13 extending from an air supplying source 12 to an air supplying port 10 of the pneumatic cylinder operating valve 1. When the pneumatic cylinder operating valve 1 is controlled, pressure is stepwise controlled by using the pneumatic controlling controller 14, each time, the operation of a piston 3 is delayed by being held to the stop state for about one to two seconds, and a valve element 4 is softly landed on a valve seat 7 or softly separated form the valve seat 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device and a control method of a pneumatic cylinder operating valve for supplying pure water and a chemical solution, which is suitable for use in an apparatus for cleaning and manufacturing semiconductor wafers and the like.

[0002]

2. Description of the Related Art A valve of a pure water / chemical solution supply system used in a cleaning and manufacturing apparatus for semiconductor wafers and the like, reduces the yield of semiconductor wafers and the like when particles are generated when the valve is opened and closed. Less is required. Conventionally, in this type of valve, in order to prevent the generation of particles, an oil damper is built in, or a rubber cushion is attached to the piston to cushion the impact force, so that the valve body is soft-landed on the valve seat. Configuration is provided.

[0003]

However, in the configuration of the above-mentioned conventional example, it is difficult to arbitrarily set the valve according to the operating conditions of the valve. Further, due to the structure, the occurrence of a water hammer due to the opening and closing of the valve cannot be prevented, and dust generation from the entire pure water / chemical solution supply system has been forced.

[0004] With the single wafer processing, unlike the batch system, the cleaning liquid cannot be circulated and filtered. Therefore, it is required that only one valve is used for the cleaning device or the like, and that no dust is generated.

Therefore, the present invention can softly land the valve body on the valve seat without using an oil damper or a rubber cushion, thereby suppressing generation of dust from the valve body and the valve seat itself. It is an object of the present invention to provide a control device and a control method of a pneumatic cylinder operating valve for supplying pure water / chemical liquid, which prevent generation of a water hammer and suppress generation of dust from the entire pure water / chemical liquid supply system. .

[0006]

A control device for a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to the present invention for solving the above-mentioned problem communicates with an air supply port of the pneumatic cylinder operating valve for supplying pure water / chemical liquid. And a pneumatic control means which is incorporated in the middle of the pneumatic control line to control the pressure when the pneumatic cylinder operation valve is closed in a step-wise manner.

According to another aspect of the present invention, there is provided a control device of a pneumatic cylinder operating valve for supplying pure water and chemicals, wherein the pneumatic control means controls the pressure when the pneumatic cylinder operating valve is opened. The control is performed stepwise.

[0008] The pure water of the present invention for solving the above-mentioned problems.
The control method of the pneumatic cylinder operating valve for chemical liquid supply is pure water
The pressure of the pneumatic cylinder operating valve for chemical liquid supply at the time of closing the valve is controlled stepwise by the pneumatic control means to delay the operation of the piston of the pneumatic cylinder operating valve, and the valve body is softly seated on the valve seat. Things.

According to another aspect of the present invention, there is provided a method of controlling a pneumatic cylinder operating valve for supplying pure water and a chemical liquid, the method comprising the steps of: The operation of the piston of the pneumatic cylinder operation valve is delayed by controlling in a step manner.

In each of the above control devices and control methods, it is preferable that the pneumatic cylinder operation valve is disposed so that pure water or a chemical solution flows from the back pressure side.
It is preferable that the air pressure control means stop the air pressure control step by step so as not to affect the inertia of the piston.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described. As shown in FIG. 1, the pneumatic cylinder operation valve 1 can operate the piston 3 in the cylinder 2 by using pneumatic pressure to open and close the valve element 4. In this embodiment, the pneumatic cylinder operating valve 1 has a valve body 4 which is a diaphragm. Usually, a piston 3 is lowered by a spring 5 and the center of the diaphragm 4 connected to a rod 6 projecting downward from the piston 3. As shown in the left half of FIG. 1, the part is configured as a normally closed type in which the flow paths 8a and 8b are closed by being seated on a valve seat 7. Therefore, when air is supplied from the air supply port 10 to the lower chamber 9 of the cylinder 2, the air pressure causes the piston 3 and the diaphragm 4 to oppose the elasticity of the spring 5 as shown in the right half of FIG. And the center of the diaphragm 4 is separated from the valve seat 7 and the flow path 8a,
8b is communicated. Thereby, the pipe 11a, the flow path 8
a, pure water or a chemical solution is supplied to a cleaning / manufacturing apparatus or the like via the flow path 8b and the pipe 11b. Then, the pneumatic cylinder operation valve 1 is connected to pure water or a chemical liquid supply system piping 11a, 11b.
The flow path 8a is arranged so that the flow path 8a on the back pressure side is on the inflow side contrary to the normal flow direction.

An air pressure control controller 14 is incorporated in the air control line 13 which connects the air supply port 10 and the air supply source 12. The air pressure control controller 14 includes, as an example, a control valve 15 including a proportional solenoid valve, a piezo valve, and the like in the middle of the air control line 13, and downstream of the control valve 15 between the air supply port 10 of the pneumatic cylinder operation valve 1. A pressure sensor 16 of a capacitance type, a resistance type or the like is provided, and an electric control system 17 having a comparison control circuit / drive circuit operated by a signal of the pressure sensor 16 is provided. The electric control system 17 controls the control valve 15 to open and close in a stepwise manner, and can maintain the air pressure control to be stopped for a desired period of time at each step. As the pneumatic air controller 14, an electronic regulator, an electropneumatic regulator, or the like having the above-described configuration integrated can be used. An air release line 18 is provided between the air pressure control controller 14 and the air supply port 10 of the pneumatic cylinder operation valve 1 to allow an arbitrary amount of air to escape at an arbitrary pressure, and a throttle portion 19 is provided in the air release line 18. ing. The pressure on the primary side of the throttle unit 19 is changed in accordance with the escape flow rate. As the throttle unit 19, one having a fixed Cv value, such as a thin tube or a nozzle, or a variable one such as a needle, can be used. The escape amount is set arbitrarily in consideration of the performance of the control valve 15.

A method of controlling the pneumatic cylinder operating valve 1 for supplying pure water / chemical liquid with the above configuration will be described. The pressure in the lower chamber 9 of the cylinder 2 in the process of the pneumatic cylinder operating valve 1 from the valve open state to the valve closing is adjusted with respect to the time axis in consideration of the hysteresis of the pneumatic cylinder operating valve 1 and the inertia of the cylinder 2 in advance. The set program is incorporated in the comparison control circuit of the electric control system 17 of the pneumatic pressure controller 14 and is operated based on this program. That is, the electric control system 1
7, a program start signal is input from the outside, and the pressure of air sent to the lower chamber 9 of the cylinder 2 is detected by the pressure sensor 16 in the air control line 13 communicating from the air supply source 12 to the lower chamber 9 of the cylinder 2. When the detection signal is sent to the comparison control circuit of the electric control system 17, the drive circuit of the electric control system 17 operates based on a preset program to control the opening of the control valve 15 in the closing direction. Air control line 13 and air release line 1
An arbitrary amount of air is released from the throttle unit 19 at an arbitrary pressure through the air outlet 8. Then, the pressure of air sent from the air supply source 12 to the lower chamber 9 of the cylinder 2 of the pneumatic cylinder operating valve 1 is controlled in a stepwise manner as shown in FIG.
, The operation of the piston 3 being pressurized by the spring 5 is delayed. In the present embodiment, the piston 3 is stopped so as to be stopped for about 1 second to about 2 seconds, so that the piston 3 can be reliably stopped, and the influence of the inertia of the piston 3 can be eliminated. The valve body 4 can be softly seated on the valve seat 7.

In order to control the pneumatic cylinder operating valve 1 from valve closing to valve opening, when a program opening start signal is input from the outside to the electric control system 17, a drive circuit operates based on a preset program, and an arbitrary pressure is set. The opening degree of the control valve 15 is controlled in the opening direction, and the air pressure supplied from the air supply source 12 to the air supply port 10 of the pneumatic cylinder operating valve 1 via the air control line 13 is closed as shown in FIG. The control is performed in a reverse step manner, and the operation of the piston 3 pressurized by the spring 5 is delayed, so that the valve element 4 is released from the valve seat 7 softly. In the case where the step-type control is not performed in the valve opening control of the pneumatic cylinder operation valve 1,
Control valve 15 is connected to pneumatic controller 1
The air supply source 12 may be forcibly opened to supply air from the air supply source 12 to the air supply port 10 of the pneumatic cylinder operation valve 1 irrespective.

Next, a second embodiment of the present invention will be described. As shown in FIG. 2, in the present embodiment, a shut-off valve 20 is provided in the air control line 13 between the air pressure control controller 14 and the air supply source 12. And the air pressure control controller 1
4, air is released at an arbitrary flow rate from a fixed volume (including the internal volume of the cylinder 2) between the shut-off valve 20 and the cylinder 2 and the pressure in the cylinder 2 is controlled. Pneumatic cylinder operating valve 1
An air release line 21 is branched from an air supply line 10 between the air supply line 10 and a control valve 15 is provided in the air release line 21, and the control valve 15 is connected to the air control line 13 in the middle of the air control line 13. An electric control system 17 having a comparison control circuit and a drive circuit operated by a detection signal of a pressure sensor 16 provided on the supply port 10 side controls opening and closing in a stepwise manner, and stops the air pressure control for a desired time every step. It is designed to be held as follows. For other configurations, see the first
This is the same as the embodiment.

A method of controlling the pneumatic cylinder operating valve 1 for supplying pure water / chemical liquid with the above configuration will be described. The pressure of the pneumatic cylinder operating valve 1 is controlled by the pneumatic controller 14.
In order to control the valve from the open state to the closed state by closing the shut-off valve 20, the electric control system 1
7, the OFF signal of the shut-off valve 20 is input, the pressure sensor 16 in the air control line 13 detects the pressure of the air sent to the lower chamber 9 of the cylinder 2, and the detected signal is compared with the electric control system 17 for comparison control. When sent to the circuit, the electric control system 1 is controlled based on a preset program here.
7 operates, and the air release line 2 branching upstream of the pressure sensor 16 of the air control line 13 is provided.
The opening degree of the control valve 15 is controlled in the opening direction. Then, air is released from the fixed volume between the shut-off valve 20 and the lower chamber 9 of the cylinder 2 at an arbitrary flow rate, and the pressure of the air in the lower chamber 9 of the cylinder 2 is controlled stepwise as shown in FIG. The operation of the piston 3 pressurized by the spring 5 in the pneumatic cylinder operation valve 1 is delayed. In this embodiment, for about 1 second to about 2 seconds,
By holding the piston 3 so as to be stopped, the piston 3 can be reliably stopped, and the influence of the inertia of the piston 3 can be eliminated.
Can be softly seated.

In order to control the pneumatic cylinder operating valve 1 from the closed state to the open state, the shut-off valve 20 is opened, and when the ON signal of the shut-off valve 20 is input to the electric control system 17, The drive circuit operates based on the set program, controls the opening of the control valve 15 in the closing direction, and supplies air from the air supply source 12 to the pneumatic cylinder operating valve 1 via the shut-off valve 20 and the air control line 13. As shown in FIG. 5, the air pressure supplied to the port 10 is controlled in a step type reverse to that when the valve is closed, the operation of the piston 3 pressurized by the spring 5 is delayed, and the valve body 4 is moved to the valve seat 7. From the soft. In the case where the step-type control is not performed in the valve opening control of the pneumatic cylinder operating valve 1, the control valve 15 is forcibly opened without controlling the step-type control and the air supply port 10 is controlled.
Air may be supplied to

Next, a third embodiment of the present invention will be described. As shown in FIG. 3, in the present embodiment, a shut-off valve 20 is provided in the air control line 13 between the air pressure control controller 14 and the air supply source 12. And the air pressure control controller 1
4, an air release line 21 is branched and provided in the air control line 13 between the shutoff valve 20 and the air supply port 10 of the cylinder 2, and the air release line 21 is provided.
The throttle section 19 and the ON-OFF valve 22 are provided in series,
The ON / OFF valve 22 is stepped open / close controlled by an electric control system 17 having a comparison control circuit / drive circuit operated by a detection signal of a pressure sensor 16 provided in the middle of the air control line 13, Each time, the air pressure control is held so as to be stopped for a desired time. Other configurations are the same as those in the first embodiment.

A method of controlling the pneumatic cylinder operating valve 1 for supplying pure water / chemical liquid with the above configuration will be described. The pressure of the pneumatic cylinder operating valve 1 is controlled by the pneumatic controller 14.
In order to control the valve from the open state to the closed state by closing the shut-off valve 20, the electric control system 1
7, the OFF signal of the shut-off valve 20 is input, the pressure sensor 16 in the air control line 13 detects the pressure of the air sent to the lower chamber 9 of the cylinder 2, and the detected signal is compared with the electric control system 17 for comparison control. When sent to the circuit, the electric control system 1 is controlled based on a preset program here.
7 operates, and the air release line 2 branching upstream of the pressure sensor 16 of the air control line 13 is provided.
The opening degree of the ON-OFF valve 22 in 1 is controlled in the opening direction. Then, from the shut-off valve 20 to the cylinder 2
The amount of air flowing into the lower chamber 9 is controlled in a stepwise manner as shown in FIG. 5 according to the amount of air escaping from the air release line 21 to control the air pressure, and pressurized by the spring 5 in the pneumatic cylinder operating valve 1. The operation of the piston 3 is delayed. In the present embodiment, the effect of the inertia of the piston 3 can be eliminated by holding the stop for about 1 second to about 2 seconds, so that the valve element 4 made of a diaphragm is attached to the valve seat 7. Can be seated softly.

In order to control the pneumatic cylinder operating valve 1 from the valve closed state to the valve open state, the shutoff valve 20 is opened to allow the air supply source 12 to control the pneumatic cylinder operating valve 1 via the shutoff valve 20 and the air control line 13. Air is supplied to the air supply port 10 of the pneumatic cylinder operation valve 1 and the spring 5
The valve body 4 can be detached from the valve seat 7 by operating the pressurized piston 3.

Next, a fourth embodiment of the present invention will be described. In the embodiment shown in FIG. 3, the air pressure cannot be controlled stepwise when the valve is opened. Therefore, in the present embodiment, as shown in FIG. 4, a shut-off valve 20 is provided as an air pressure control controller 14 on the air supply source 12 side in the air control line 13 and an air release line is provided downstream thereof. A pressure sensor 16 is provided between the pressure sensor 16 and the air supply port 10 of the pneumatic cylinder operating valve 1 downstream thereof, and a throttle 19 is provided between the air release line 21 and the pressure sensor 16. ON-OFF valve 2 in air release line 21
2 are provided. An electric control system 17 having a comparison control circuit / drive circuit operated by a detection signal of the pressure sensor 16 causes a shut-off valve 20, an ON-OF
The F-valve 22 is controlled to open and close, and the air pressure control is held in a step-wise manner so as to be stopped for a desired time. Other configurations are the same as those in the first embodiment.

A method of controlling the pneumatic cylinder operating valve 1 for supplying pure water / chemical liquid with the above configuration will be described. The pressure of the pneumatic cylinder operating valve 1 is controlled by the pneumatic controller 14.
In order to control the valve from the open state to the valve closed state, a program open start signal is input from the outside to the electric control system 17 and sent to the lower chamber 9 of the cylinder 2 by the pressure sensor 16 in the air control line 13. Air pressure is detected,
When the detection signal is sent to the comparison control circuit of the electric control system 17, the drive circuit of the electric control system 17 operates based on a preset program, closes the shut-off valve 20 on the side, and the downstream side. Is controlled to alternately open and close the ON-OFF valve 22 in the air release line 21 provided in the branch. The amount of air flowing from the shut-off valve 20 to the lower chamber 9 of the cylinder 2 is controlled in a stepwise manner as shown in FIG. 5 according to the amount of air escaping from the air release line 21 to control the air pressure. The operation of the piston 3 pressurized by the spring 5 in the operation valve 1 is delayed. In the present embodiment, the effect of the inertia of the piston 3 can be eliminated by holding the stop for about 1 second to about 2 seconds, whereby the valve element 4 made of the diaphragm is moved to the valve seat 7.
Can be softly seated.

In order to control the pneumatic cylinder operating valve 1 from the valve closed state to the valve open state, when an external program opening start signal is input to the electric control system 17, the electric control system 17 turns the ON-OFF valve 22 on. Close and shut off valve 2
0 is alternately opened and closed, and the amount of air flowing into the lower chamber 9 of the cylinder 2 of the pneumatic cylinder operation valve 1 per unit time is controlled by the throttle unit 19,
As shown in FIG. 5, when the valve is open, similarly to when the valve is closed,
By controlling the air pressure in a step manner, the operation of the piston 3 pressurized by the spring 5 is delayed, and the valve body 4 can be released from the valve seat 7 softly.

Next, test examples of the present invention will be described.
FIG. 6 is an explanatory diagram showing a test example. In FIG. 6, 24
Is a pipe of an ultrapure water supply system, and a pressure gauge 25, a filter 26, and a needle valve 27 are provided upstream of the pneumatic cylinder operation valve 1.
The beaker 28 and the particle tester 29 are provided downstream of the pneumatic cylinder operation valve 1. 13
Is a pneumatic control line to the lower chamber 9 of the cylinder 2 of the pneumatic cylinder operating valve 1. A pneumatic controller 14 is provided in the middle of the pneumatic control valve, and in this test example, a pneumatic controller 14 shown in FIG. A regulator 30 is provided. In this test line, 1/4 "pneumatic cylinder operating valve 1 and 1/2" pneumatic cylinder operating valve 1
Are opened and closed for 5 cycles per minute, and the number of particles of 0.1 to 0.5 μm generated in 10 mL of ultrapure water is controlled by the pneumatic controller 14 with respect to the number of generated particles and when the pneumatic control is not performed. As a result of the measurement, the results shown in Table 1 below were obtained.

[0025]

[Table 1]

As is clear from Table 1 above, the 1/4 "pneumatic cylinder operating valve without pneumatic control and the 1/2" pneumatic cylinder operating valve have extremely few particles generated in 10 mL of ultrapure water. On the other hand, the 1/4 "pneumatic cylinder operating valve and the 1/2" pneumatic cylinder operating valve pneumatically controlled by the pneumatic controller 14 have an extremely small number of particles generated in 10 mL of ultrapure water. I understand.

The pressure fluctuation in the piping of the ultrapure water supply system when the 1/4 ″ pneumatic cylinder operating valve is opened and closed without air pressure control is as shown in FIG. FIG. 8 shows the pressure fluctuation in the piping of the ultrapure water supply system when the 2 ″ pneumatic cylinder operating valve is opened and closed. As is evident from these results, when air pressure control was not performed, the rapid rise and fall caused impact at the valve seat and water hammer, increasing the number of particles generated in the entire system. I support it. On the other hand, the pressure fluctuation of the piping of the ultrapure water supply system when the 1/4 ″ pneumatic cylinder operating valve is opened and closed by pneumatic control by the pneumatic controller 14 is as shown in FIG. The pressure fluctuation in the piping of the ultrapure water supply system when the 1/2 ″ pneumatic cylinder operation valve is opened and closed by air pressure control by the control controller 14 is as shown in FIG. As is evident from the above, by performing pneumatic control, rapid rise and fall are eliminated, impact and water hammer are prevented by the valve seat, and the number of particles generated in the entire system is significantly reduced. I support it.

The pneumatic control means of the pneumatic cylinder operating valve 1 is not limited to each of the above embodiments. For example, the throttle section 19 and the ON-O in the third embodiment may be used.
The FF valve 22 is arranged in reverse, and the shutoff valve 20
And the ON-OFF valve 22 may be set to be a two-way three-way version. Further, a core is provided in a movable part such as the piston 3 of the cylinder 2 in place of the pressure sensor, and the mutual induction action of the coil is provided. The linear displacement is measured by using the valve 1 and the valve 1 in the second, third and fourth embodiments is measured from the measured value.
5 and 22 can be controlled, and the position of the piston 3 of the cylinder 2 can be read from a change in capacitance as a dielectric or a change in resistance as a resistor other than the differential pressure. It is possible. Further, the pneumatic cylinder operating valve 1 may be of various types other than the above-described embodiment, and the influence of the inertia of the piston may be reduced corresponding to the pneumatic cylinder operating valve 1 which also applies the stop holding time controlled in a step manner. It can be chosen appropriately to have no effect. In addition, the present invention can be variously changed in design without departing from the basic technical idea.

[0029]

As described above, according to the present invention, the pressure at the time of closing the pneumatic cylinder operating valve is controlled in a step manner, so that the valve can be controlled without using an oil damper or a rubber cushion as in the prior art. The body can be seated softly on the valve seat, suppressing dust generation from the valve body and the valve seat itself, and preventing water hammer and generating water from the entire pure water / chemical solution supply system. Since dust can be suppressed, the production yield of semiconductor wafers and the like can be improved.

Further, by controlling the pressure of the pneumatic cylinder operating valve when the valve is opened in a step-like manner,
Water hammer at the time of valve opening can also be prevented, and dust generation from the entire pure water / chemical solution supply system can be further effectively suppressed.

Further, by arranging the pneumatic cylinder operation valve so that pure water or chemical liquid flows from the back pressure side, fluctuations in fluid pressure can be avoided, and controllability can be further improved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a control device of a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to a first embodiment of the present invention.

FIG. 2 is a system diagram showing a control device of a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to a second embodiment of the present invention.

FIG. 3 is a system diagram showing a control device for a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to a third embodiment of the present invention.

FIG. 4 is a system diagram showing a control device of a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a state in which a valve element of a pneumatic cylinder operating valve in a system valve is steppedly seated on a valve seat or separated from the valve seat by a control device for a pneumatic cylinder operating valve for pure water / chemical liquid supply of the present invention It is a figure showing the point of pressure control.

FIG. 6 is an explanatory diagram showing a test example of a control method of the pneumatic cylinder operation valve for supplying pure water / chemical liquid of the present invention.

FIG. 7 is a diagram showing pressure fluctuations in piping of an ultrapure water supply system when a 1/4 ″ pneumatic cylinder operating valve is opened and closed without pneumatic control.

FIG. 8 is a diagram showing pressure fluctuations in piping of an ultrapure water supply system when a 1/2 ″ pneumatic cylinder operating valve is opened and closed without pneumatic pressure control.

FIG. 9 is a diagram showing pressure fluctuations in piping of an ultrapure water supply system when a 1/4 ″ pneumatic cylinder operation valve is opened and closed by pneumatic control according to the present invention.

FIG. 10 is a diagram showing pressure fluctuations in piping of an ultrapure water supply system when a 1/2 ″ pneumatic cylinder operation valve is opened and closed by pneumatic control according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pneumatic cylinder operation valve 2 Cylinder 3 Piston 4 Valve body (diaphragm) 7 Valve seat 10 Air supply port 12 Air supply source 13 Air control line 14 Controller for air pressure control

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koichi Ishikawa 11-5 Kamibahakodatemachi, Minami-ku, Kyoto-shi, Kyoto F-term in ESTEC Co., Ltd. 3H056 AA01 BB04 BB12 BB37 BB41 CA01 CB03 CB09 CC02 CD04 CE03 EE08 GG05 GG11

Claims (6)

[Claims] 1. A pneumatic control which is incorporated in a pneumatic control line communicating with an air supply port of a pneumatic cylinder operating valve for supplying pure water and chemical liquid, and which controls the pressure of the pneumatic cylinder operating valve when the valve is closed in a step manner. Pure water with means
Control device for pneumatic cylinder operating valve for chemical liquid supply. 2. The control device for a pneumatic cylinder operating valve for supplying pure water and chemical liquid according to claim 1, wherein the pneumatic pressure control means controls the pressure of the pneumatic cylinder operating valve when the valve is opened in a stepped manner. 3. The control device for a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to claim 1, wherein the pneumatic cylinder operating valve is arranged so that pure water or chemical liquid flows from the back pressure side. 4. A pure water / pneumatic cylinder operating valve for controlling the pressure of a pneumatic cylinder operating valve for supplying pure water / chemical liquid when the valve is closed is controlled stepwise by an air pressure control means to delay the operation of the piston of the pneumatic cylinder operating valve. Control method of pneumatic cylinder operation valve for chemical liquid supply. 5. The pneumatic cylinder operating valve for supplying pure water / chemical liquid when the valve is opened is controlled stepwise by a pneumatic pressure control means to delay the operation of the piston of the pneumatic cylinder operating valve. The control method of the pneumatic cylinder operating valve for supplying pure water and chemical liquid described in the above. 6. The control method for a pneumatic cylinder operating valve for supplying pure water / chemical liquid according to claim 4, wherein the pneumatic cylinder operating valve is arranged so that pure water or chemical liquid flows from the back pressure side.