JP2003042331A - Shut-off valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shut-off valve for preventing the generation of bubble of the fluid with a pressure fluctuation when operating the valve for shut-off and capable of securely shutting the fluid when concluding shut-off. SOLUTION: This shut-off valve has a housing 20 formed with a flow-in passage 22 and a flow-out passage 24 and provided with an opening part 25 for communicating them with each other, a piston rod 26 provided with a valve element 27 for opening and closing the opening part 25 and installed in the housing 20 freely to be slid, and a piston rod 38 installed in the housing 20 freely to be slid and arranged in series to the piston rod 26. These piston rods 26 and 38 are separately driven in the closing direction by spring members 37 and 46, and driven in the opening direction by the pressure of pressurization chambers 31 and 40. Flow velocity of the fluid is lowered step by step without generating a pressure fluctuation to close the opening part 25 by driving the piston rod 38 in the opening direction after driving the piston rod 26 in the closing direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutoff valve for controlling supply and stop of supply of fluid.

[0002]

2. Description of the Related Art In a manufacturing process in various technical fields such as a semiconductor wafer manufacturing technique, a liquid crystal substrate manufacturing technique, a magnetic disk manufacturing technique, and a multilayer wiring substrate manufacturing technique, a photoresist liquid and a spinion glass liquid are used. , Polyimide resin solution, pure water, developing solution, etching solution,
A chemical solution such as an organic solvent is used.

For example, when a photoresist solution is applied to the surface of a semiconductor wafer, the photoresist solution is dropped on the surface of the semiconductor wafer while the semiconductor wafer is rotated in a horizontal plane. Such a dropping device for dropping the photoresist liquid is equipped with a shutoff valve for controlling the supply and stop of the supply of the photoresist liquid.

As this shut-off valve, there is an air-operated valve in which the valve body is closed by a piston rod and the closing operation is controlled by using air pressure. The air operated valve applies a thrust force in the direction of closing the valve body to the piston rod by a spring member, and supplies compressed air to a pressure chamber provided on one side of the piston, so that the piston rod operates in the valve body opening direction. I try to add thrust. When closing the flow path by closing the valve body, the air in the pressurizing chamber is exhausted, so that the piston rod is closed by the spring force.

[0005]

However, since the shut-off valve for controlling the photoresist liquid to be dripped is small, it is difficult to secure a sufficient exhaust capacity of the piston, and it is possible to control the flow rate of minute exhaust gas. It is difficult to control the operating speed of the valve body. If the valve is shut off while the operating speed is high, the photoresist solution will be dammed abruptly.Therefore, positive and negative pressure waves are generated by the water hammer phenomenon on the upstream side of the valve body, and on the downstream side of the valve body. A negative pressure wave will be generated.

When the shut-off valve which causes pressure fluctuation is used in the dropping device as described above, the gas dissolved in the photoresist liquid by the negative pressure wave may become bubbles, and if the photoresist liquid containing bubbles is dropped, application failure occurs. Occurs, which deteriorates the yield of semiconductor wafers. In addition, if a spring member with a low spring constant is used in order to control the forward speed of the piston rod and avoid the occurrence of pressure fluctuations, it is not possible to obtain sufficient surface pressure between the valve body and valve seat, and leakage occurs after shutting off. May occur.

An object of the present invention is to provide a shutoff valve which prevents the generation of air bubbles in the fluid due to pressure fluctuations during shutoff operation, and shuts off the fluid reliably when shutoff is completed.

[0008]

SUMMARY OF THE INVENTION A shutoff valve according to the present invention includes a housing provided with an inflow passage and an outflow passage and having an opening communicating with these passages, and the opening provided in the housing. And a plurality of piston rods, each of which is provided with a piston, and which is linearly mounted on the housing so as to be movable in the opening / closing direction of the valve body, and each of which is provided on the housing. And a closing biasing means for applying thrust in the direction of closing the valve body, and an opening biasing means provided in the housing for applying thrust in the direction of opening the valve body to each of the pistons. It is characterized in that the piston rods are closed in stages when closing the openings.

The shut-off valve of the present invention is provided with a housing having an opening for forming an inflow passage and an outflow passage and connecting these passages, a valve body for opening and closing the opening, and the valve. A first piston for forming a first pressure chamber for urging thrust in a direction of opening the body is provided in the housing, and a first piston rod movably mounted in the housing and the valve body are opened. A second piston rod that forms a second pressure chamber for urging a thrust force in a direction in which the second piston rod is movably mounted on the housing linearly with respect to the first piston. And a closing urging means provided on the housing for urging a thrust force in a direction of closing the valve body on each of the piston rods. When closing the opening by the valve body, the first Addition And discharging air from the second pressure chamber after discharging the chamber air, characterized in that closing operation of two of said piston rod stepwise.

The shut-off valve of the present invention is characterized in that the closing biasing means is a spring member.

According to the present invention, by adopting a structure capable of performing a breaking operation in multiple stages, it is possible to prevent pressure fluctuation due to a rapid change in the flow velocity of the fluid at the time of breaking, and to prevent generation of bubbles due to decompression. A shutoff valve can be obtained.

According to the present invention, by adopting a structure capable of performing the breaking operation in two stages, it is possible to prevent pressure fluctuation due to a rapid change in the flow velocity of the fluid at the time of breaking, and to prevent generation of bubbles due to pressure reduction. A shutoff valve can be obtained.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic view of a drug droplet dropping device to which a shutoff valve according to an embodiment of the present invention is applied. As shown in FIG. 1, the chemical liquid in the chemical liquid tank 10 is pumped up by a pump 11, supplied to a dripping nozzle 14 via a shutoff valve 12 and a suck back valve 13, and dripping onto a work 15. When the shutoff valve 12 is activated and the supply of the chemical liquid is stopped, the suck back valve 13 is activated to prevent the chemical liquid from dripping from the dropping nozzle 14.

The shut-off valve 12 has a housing 20 composed of a plurality of members. The housing 20 has a flow path block 20a, which is sequentially arranged from one end to the other end, and a first block.
The block 20b and the second block 20c are composed of a mounting plate 20d attached to one end and a cover 20e attached to the other end, which are assembled by a screw member (not shown).

An inflow port 21 to which a pipe from the pump 11 is connected is connected to the flow path block 20a of the housing 20.
And an inflow channel 22 for guiding the chemical liquid from the inflow port 21
Are formed, and an outflow port 23 to which a pipe to the suck back valve 13 is connected, and an outflow passage 24 that guides the chemical solution to the outflow port 23 are formed. The inflow passage 22 and the outflow passage 24 communicate with each other through the opening 25.

The piston rod 2 is attached to the first block 20b.
6 is provided slidably in the axial direction, and a diaphragm type valve body 27 is provided at the front end of the piston rod 26. The valve body 27 is made of polytetrafluoroethylene (PT
A main body portion 27a that is molded by a fluororesin such as FE) and is screwed to the tip end portion of the piston rod 26,
It has an elastically deformable disc portion 27b. Disk part 2
The outer peripheral portion of 7b includes the flow path block 20a and the first block 2
It is sandwiched by the flow path block 20a by an annular stopper 28 which is fixed to 0b. As the piston rod 26 to which the valve body 27 is attached slides in the axial direction, the axial distance between the valve seat 29 forming the opening 25 and the valve body 27 changes.

A male screw portion 26a is formed on the piston rod 26, and a piston 30 is screwed thereto. The piston 30 is slidably provided on the first block 20b, and the piston 3 is formed by the first block 20b and the piston 30.
A pressure chamber 31 as an opening urging unit is formed on the front end face side of 0. Further, the control pipe 3 is provided in the first block 20b.
A control port 33 to which 2 is connected, and a control channel 34 that connects the control port 33 and the pressurizing chamber 31 are formed,
When compressed air is supplied from the control port 33, the piston rod 26 is pressed in the opening direction of the valve body, and the inflow passage 2
2 and the outflow passage 24 are in communication with each other.

A spring chamber 35 is formed on the rear end face side of the piston 30 by the piston 30 and the second block 20c,
A communication hole 36 that communicates the outside with the spring chamber 35 is formed in the second block 20c. A spring member 37 as a closing urging unit is attached to the spring chamber 35, and the pressure chamber 3
When the compressed air of No. 1 is discharged, the piston rod 26 is pressed in the closing direction of the valve body, the opening degree of the opening 25 is reduced, and the flow rate from the inflow passage 22 to the outflow passage 24 is reduced. The spring constant of the spring member 37 closes the piston rod 26 when the spring member 37 is compressed to the open position rather than the pressing force of the valve body 27 pressed by the chemical liquid to press the piston rod 26 in the opening direction. The pressing force for pushing in the direction is stronger than the discharge pressure of the pump 11 for supplying the chemical liquid, and the valve body 27
The surface pressure between the valve seat 29 and the valve seat 29 is set to be low.
Therefore, even if the piston rod 26 is driven in the closing direction by the spring force of the spring member 37, the chemical liquid is not blocked and the flow rate is reduced and guided to the outflow passage 24.

The piston rod 3 is attached to the second block 20c.
8 is provided coaxially with the piston rod 26 so as to be slidable in the axial direction. A male screw portion 38a is formed at the end of the piston rod 38, and the piston 39 is screwed thereto. The piston 39 is slidably provided on the second block 20c, and the second block 20c and the piston 39 form a pressurizing chamber 40 as an opening urging means on the front end face side of the piston 39. Also, the second block 20c
Is formed with a control port 42 to which a control pipe 41 is connected, and a control flow path 43 that connects the control port 42 and the pressurizing chamber 40. When compressed air is supplied from the control port 42, the piston rod 38 is formed. Is driven in the opening direction.

A spring chamber 44 is formed on the rear end surface side of the piston 39 by the piston 39 and the cover 20e, and a communication hole 45 for communicating the outside with the spring chamber 44 is formed in the cover 20e. A spring member 46 as a closing biasing means is mounted in the spring chamber 44, and when the compressed air in the pressurizing chamber 40 is discharged, the piston rod 38 is pressed in the closing direction and the front end of the piston rod 38 and the piston rod 26. The rear end contacts the piston rod 26 and presses the piston rod 26 in the closing direction. The spring constant of the spring member 46 is higher than the discharge pressure of the pump 11 that supplies the chemical liquid, and the spring constant of the other spring member 37.
At the same time, the surface pressure generated when the valve body 27 is pressed against the valve seat 29 is set to be high. Therefore, when the piston rods 26 and 38 are driven in the closing direction, the opening 25 is fully closed and the supply of the chemical liquid is stopped.

In order to control the shutoff valve 12 as described above,
The control ports 33 and 42 have control pipes 32 and 41, respectively.
Are connected. The respective control pipes 32 and 41 are exhaust pipes 51 and 53 provided with flow rate control valves 50 and 52.
And the air supply pipe 5 that bypasses the flow control valves 50 and 52.
5, 57, and check valves 54, 56 are provided in the air supply pipes 55, 57. Compressed air from an air pressure source 58 is supplied to the air supply pipes 55 and 57 to supply pressure to the pressure chambers 31 and 4.
Between the pipes 59 and 60 communicating with the air pressure source 58 and the pipes 61 and 62 communicating with the air supply pipes 51 and 53 and the exhaust pipes 55 and 57 in order to discharge 0 compressed air from the exhaust pipes 51 and 53. Electromagnetic switching valves 63 and 64 having exhaust ports 63a and 64a are connected to the.

The operation of the shutoff valve 12 will be described below. FIG. 2 is a sectional view showing a communication state of the shutoff valve 12 according to the embodiment of the present invention, and FIG. 3 is a sectional view showing a state of the shutoff valve 12 during a shutoff operation. FIG. 4 is a cross-sectional view showing the shutoff state of the shutoff valve 12.

As shown in FIG. 2, in the communication state in which the inflow passage 22 and the outflow passage 24 of the shutoff valve 12 communicate with each other,
The two electromagnetic switching valves 63 and 64 shown in FIG. 1 are both energized, the pipes 59 and 60 and the pipes 61 and 62 communicate with each other, and the compressed air from the air pressure source 58 is supplied to the supply pipes 55 and 57.
Is guided to the control port 33, via the check valves 54, 56.
42 respectively. In this way, the pressurizing chamber 31,
By supplying compressed air to the pistons 40,
9 drives the piston rods 26 and 38 in the opening direction. At this time, the opening 25 is fully opened, and the chemical liquid discharged from the pump 11 is supplied to the dropping nozzle 14 through the cutoff valve 12.

Next, as shown in FIG. 3, when the shutoff operation of the shutoff valve 12 is started, the electromagnetic switching valve 64 shown in FIG.
The energization of the electromagnetic switching valve 63 is cut off while maintaining the energization to the. By shutting off the energization of the electromagnetic switching valve 63, the exhaust port 63a provided in the electromagnetic switching valve 63 communicates with the pipe 61, and the compressed air supplied to the pressurizing chamber 31 is the flow control valve 50 provided in the exhaust pipe 51. Through the exhaust port 63a. As the pressure in the pressurizing chamber 31 decreases, the piston 30
Is pressed in the closing direction by the spring force of the spring member 37,
The piston rod 26 is driven in the closing direction. Then, the piston rod 26 is driven in the closing direction until the spring force of the spring member 37 and the pressing force with which the flowing chemical liquid presses the valve body 27 in the opening direction are balanced. On the other hand, the piston rod 38 is held in the open position because the electromagnetic switching valve 64 is energized. In this way, by driving only the piston rod 26 in the closing direction, the opening degree of the opening 25 is reduced without blocking the opening 25, and the chemical liquid guided to the outflow passage 24 is reduced. The piston rod 2
The drive speed of No. 6 is changed by adjusting the flow control valve 50.

Under this condition, as shown in FIG. 4, to shut off the shutoff valve 12, the electromagnetic switching valve 64 shown in FIG. 1 is shut off. By shutting off the energization of the electromagnetic switching valve 64, the exhaust port 64a provided in the electromagnetic switching valve 64 and the pipe 6
The compressed air, which is in communication with the pressure chamber 40 and is supplied to the pressurizing chamber 40, is discharged from the exhaust port 64a via the flow rate control valve 52 provided in the exhaust pipe 53. As the pressure in the pressure chamber 40 is reduced, the piston 39 is pressed by the spring force of the spring member 46 to drive the piston rod 38 in the closing direction. Then, the piston rod 38 contacts the piston rod 26, and the piston rod 26 is further driven in the closing direction by the spring force of the spring member 46. In this way, the piston rod 26 is driven in the closing direction further than the driving position shown in FIG. 3 by driving the piston rod 38, and the valve body 27 stops the supply of the chemical liquid by fully closing the opening 25. .
The surface pressure between the valve body 27 and the valve seat 29 is kept higher than the discharge pressure of the pump 11 by the spring force of the spring members 37 and 46, and the chemical solution does not flow into the outflow passage 24.

To summarize the above-described shut-off operation, first, the compression of only the spring member 37 is released, and the piston rod 26 provided with the valve body 27 is driven forward to reduce the opening degree of the opening 25. The flow velocity of the chemical liquid flowing through the inflow passage 22 and the outflow passage 24 is reduced. Next, the compression of the spring member 46 in addition to the spring member 37 is released, and the piston rod 26
Is further driven in the closing direction to fully close the opening 25 and secure the surface pressure between the valve body 27 and the valve seat 29. In this way, the pressing force for operating the valve body when reducing the flow velocity and the pressing force applied to the valve body 27 when securing the surface pressure can be set separately for the two spring members 37 and 46. Even if it is difficult to control the operating speed of the valve body 27 by the flow control valve, the flow velocity is gradually reduced without causing a sudden pressure change, and the surface of the valve body 27 and the valve seat 29 is closed at the time of shutoff. The structure allows sufficient pressure to be secured. Therefore, it is possible to prevent the generation of bubbles due to the negative pressure state of the chemical liquid, and to provide a shutoff valve that reliably stops the supply of the chemical liquid when shutting off.

It is needless to say that the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the invention. For example, the shutoff valve 12 shown in the figure performs the shutoff operation in two stages, but the shutoff operation may be performed in more than two stages by providing a plurality of piston rods and a plurality of spring members. Further, although the spring members 37 and 46 are used as the closing urging means, a pressure accumulator may be connected to the spring chambers 35 and 44 to press the pistons 30 and 39 by fluid pressure.
Nos. 7 and 45 can be used even if they have a constant spring constant or if the spring constant changes depending on the amount of compression displacement. Further, the shutoff valve 12 can be used even if integrated with the suck back valve 13,
The inflow passage 22 and the outflow passage 24 can be used even if the arrangements are interchanged.

[0029]

According to the present invention, by adopting a structure capable of performing a breaking operation in multiple stages, it is possible to prevent pressure fluctuation due to a sudden change in the flow velocity of the fluid at the time of breaking, and to prevent bubbles from being generated due to decompression. A blocking valve can be obtained to prevent it.

According to the present invention, by adopting a structure capable of performing the breaking operation in two stages, it is possible to prevent the pressure fluctuation due to the abrupt flow velocity change of the fluid at the time of breaking, and to prevent the generation of bubbles due to the pressure reduction. A shutoff valve can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a drug droplet dropping device to which a shutoff valve according to an embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view showing a shutoff valve according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a shutoff valve according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a shutoff valve according to an embodiment of the present invention.

[Explanation of symbols]

10 Chemical tank 11 pumps 12 shut-off valve 13 suck back valve 14 Dripping nozzle 15 work 20 housing 20a channel block 20b first block 20c Second block 20d mounting plate 20e cover 21 Inflow port 22 Inflow channel 23 Outflow port 24 Outflow channel 25 openings 26 Piston rod (first piston rod) 27 valve body 27a main body 27b Disk part 28 Stopper 29 seat 30 pistons (first piston) 31 pressurizing chamber (opening biasing means, first pressurizing chamber) 32 control piping 33 control port 34 control flow path 35 spring chamber 36 communication holes 37 Spring member (closing urging means) 38 Piston rod (second piston rod) 39 piston (second piston) 40 pressurizing chamber (opening biasing means, second pressurizing chamber) 41 Control pipe 42 control port 43 control channel 44 Spring chamber 45 communication holes 46 Spring Member (Occlusion Energizing Means) 50 Flow control valve 51 Exhaust pipe 52 Flow control valve 53 Exhaust pipe 54 Check valve 55 Air supply piping 56 Check valve 57 Air supply piping 58 Air pressure source 59-62 piping 63, 64 Solenoid switching valve 63a, 64a exhaust port

Claims (3)

[Claims] 1. A housing having an inflow passage and an outflow passage formed with an opening communicating with these passages, a valve body provided in the housing for opening and closing the opening, and a piston provided therein. And a plurality of piston rods linearly mounted on the housing so as to be movable in the opening / closing direction of the valve body, and a closure provided on the housing for applying thrust to each piston in a direction of closing the valve body. Urging means, and an opening urging means provided in the housing for applying a thrust in a direction of opening the valve body to each piston, and each piston rod when closing the opening portion by the valve body A shut-off valve which is characterized by performing a closed operation in stages. 2. A housing provided with an inflow passage and an outflow passage and having an opening communicating with these passages, a valve body for opening and closing the opening, and a direction for opening the valve body. A first piston for forming a first pressurizing chamber for urging the thrust in the housing, and a first piston rod movably mounted in the housing, and a thrust in a direction for opening the valve body. A second piston is provided which forms a biasing second pressure chamber in the housing,
A second piston rod linearly movably mounted on the housing with respect to the first piston; and a thrust provided in the housing for biasing the piston rod in a direction to close the valve body. A closing biasing means, and when discharging the air of the first pressurizing chamber when the valve body closes the opening, the air of the second pressurizing chamber is exhausted,
A shut-off valve characterized by gradually closing the two piston rods. 3. The shutoff valve according to claim 1, wherein the closing biasing means is a spring member.