JP2002054761A - Fluid control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact fluid control valve having an actuator so as to ensure thrust required for sealing a metallic valve seat by a metallic valve element. SOLUTION: Thrust in the direction of advance (valve main body 3 side) is generated in a rod 21 by increasing an energizing force of an output coil spring 19 by a lever mechanism such as a lever 16 and making the force act so that a metallic diaphragm 26 adheres closely to the metallic valve seat 27. Consequently, thrust required for sealing the metallic valve seat 27 by the metallic diaphragm 26 is ensured, and allowance for reducing an outside diameter of the output coil spring 19 occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid control valve for bringing a metal valve body into close contact with and away from a metal valve seat.

[0002]

2. Description of the Related Art Conventionally, among fluid control valves used in a semiconductor manufacturing apparatus, most of valves for controlling a high-temperature fluid are made of a metal material in order to resist a heat load. Therefore, in order to bring the metal valve into close contact with the metal valve seat and seal the metal valve seat with the metal valve, the metal valve is strongly pressed against the metal valve seat. There is a need.

Therefore, for example, in the fluid control valve shown in FIGS. 9 and 10, in order to strongly press a metal valve body against a metal valve seat, an actuator described in JP-A-9-26052 is used. Used as a drive unit.

Referring to FIGS. 9 and 10, the fluid control valve shown in FIGS. 9 and 10 uses a metal diaphragm 114 as a metal valve body. Then, in FIG.
When high-pressure air is introduced into the air chamber 103 from the high-pressure air introduction port 102 of the housing cap 101, the piston 105 is pushed out, whereby the roller 107 at the other end of the cam 106 is pushed to rotate around the pin 108. As shown in FIG.
To move the shaft 110 in the direction opposite to the direction in which the piston 105 is pushed out. As a result, the stem 111 connected to the shaft 110 moves integrally against the spring 112, so that the pressing force of the diaphragm push-in piece 113 is lost, and as a result, the diaphragm 114 is displaced by its own elastic restoring force. Since it is separated from the seat 115, the gas inflow passage 116 and the gas outflow passage 117 communicate with each other, and the valve is opened.

On the other hand, when the high-pressure air is discharged from the air chamber 103, the force for pushing out the piston 105 is eliminated, and the roller 107 at the other end of the cam 106 is released. As shown in FIG. The stem 111 moves toward the valve main body 118 due to the restoring force of the spring 112, so that the diaphragm pushing piece 113 is pressed, so that the diaphragm 114 comes into pressure contact with the valve seat 115, and the valve is closed.

That is, in the fluid control valve shown in FIG. 9 and FIG.
2 is applied directly to the valve main body 118 side, so that the metal diaphragm 114 is connected to the metal valve seat 11.
I was pressing strongly on 5.

[0007]

However, in the fluid control valve shown in FIG. 9 and FIG.
A lever mechanism composed of the roller 107, the pin 108, and the like moves the metal diaphragm 114 to the metal valve seat 115.
It is used not as a means for pressing strongly against the spring but as a means for countering the restoring force of the spring 112 when the metal diaphragm 114 is separated from the metal valve seat 115.

Therefore, the thrust required to seal the metal valve seat 115 with the metal diaphragm 114 is secured only by the restoring force of the spring 112 directly acting on the stem 111. There is a limit in minimizing the outer diameter of the actuator 100, which is a major factor that hinders miniaturization of the actuator 100.

Accordingly, the present invention has been made to solve the above-mentioned problems, and has a thrust required to seal a metal valve seat with a metal valve body (hereinafter referred to as "seal thrust"). It is an object of the present invention to provide a fluid control valve having an actuator that is reduced in size while ensuring the above.

[0010]

According to a first aspect of the present invention, there is provided a fluid control valve, wherein an urging force of an output coil spring acts on one end of a lever of a lever mechanism. By doing so, the rod engaged with the other end of the lever is advanced, while the piston receiving the drive source pressure moves to compress the output coil spring. An actuator that releases from the urging force of the output coil spring and retracts the rod by the urging force of the return coil spring, and closes and separates the metal valve body from the metal valve seat by the actuator. , Is characterized.

According to a second aspect of the present invention, in the fluid control valve according to the first aspect, the valve body is a diaphragm.

According to a third aspect of the present invention, in the fluid control valve according to the first or second aspect, the fluid control valve is used for a semiconductor manufacturing apparatus.

[0013] The fluid control valve of the present invention having the above-mentioned features is characterized in that a metal valve element is made of metal by an actuator including a lever mechanism having a lever and the like, a piston, a rod, an output coil spring, a return coil spring, and the like. Close and separate from the valve seat. That is, in the normal state, the urging force of the output coil spring acts on one end of the lever of the lever mechanism, and a forward thrust is generated in the rod engaging with the other end of the lever. Will closely contact the metal valve seat. On the other hand, in the non-normal state, the output coil spring is compressed by the movement of the piston under the pressure of the drive source, so that one end of the lever is released from the urging force of the output coil spring. As a result, a thrust in the backward direction is generated on the rod, so that the metal valve element is separated from the metal valve seat.

Therefore, in the fluid control valve of the present invention, the urging force of the output coil spring is increased by the lever ratio of the lever mechanism to act on the rod, thereby generating a thrust in the forward direction on the rod, thereby making the metal valve body. Is in close contact with the metal valve seat, which ensures "seal thrust".
The minimum required biasing force of the output coil spring is a value obtained by dividing the "seal thrust" by the leverage ratio. Therefore, it is possible to minimize the outer diameter of the output coil spring by an amount corresponding to the difference between the value obtained by dividing the “seal thrust” by the leverage ratio and the value of the “seal thrust”, and incorporate the output coil spring. Since the size of the actuator can be reduced, it is possible to provide a fluid control valve having an actuator whose size is reduced while ensuring "seal thrust".

These points also apply to a fluid control valve in which a metal diaphragm is brought into close contact with or separated from a metal valve seat by an actuator.

Further, in a semiconductor manufacturing apparatus, a high-temperature fluid is often controlled, and a fluid control valve used therein has a structure in which a metal valve body is brought into close contact with and separated from a metal valve seat. I need. Furthermore, when used in semiconductor manufacturing equipment, the fluid control valve always
There is a demand for higher barrier properties and further miniaturization.
Therefore, from these viewpoints, the fluid control valve of the present invention can be said to be optimal.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are cross-sectional views of a fluid control valve 1 according to the present embodiment. FIG. 1 shows a normally closed valve state. FIG. 2 shows a non-normal state of the valve opening. As shown in FIGS. 1 and 2, the fluid control valve 1 can be roughly classified into a housing 22, a cap 11 screwed to an upper portion of the housing 22, and a valve body 3 screwed to a lower portion of the housing 22.

A piston 13 is inserted into the cap 11, and an air chamber 34 is formed by sealing the inside of the cap 11 and the outer periphery of the piston 13 with a heat-resistant packing 12. The air chamber 34 communicates with the outside via the inlet 33. Further, the cap 11 is
The lever base 15 is internally provided so as to be sandwiched between the cap 11 and the housing 22 by being screwed into the upper portion of the lever 2.

As shown in the partial cross-sectional view of FIG. 5 and the rear view of FIG. 6, the lever base 15 has a rod insertion opening 42 formed at the center thereof, and three transmission holes are formed at equal intervals around the rod insertion opening 42. A rod insertion hole 41 is formed, and a lever base 43 having a parallel pin insertion hole is provided inside the transmission rod insertion hole 41 on the rear surface. Then, between the three lever base portions 43, the lever 16 having the parallel pin insertion hole (see FIGS. 7 and 8) is rotatably supported as shown in FIGS. 1 and 2. You.

For this purpose, here, the axis of the parallel pin insertion hole drilled in the lever mount 43 and the axis of the parallel pin insertion hole drilled in the lever 16 are overlapped. The operation is performed by setting the lever 16 between them and allowing the parallel pins 17 to pass through the insertion holes for the parallel pins.

On the other hand, an output coil spring 19 is built in the housing 22, and the output coil spring 1
A coil spring retainer 18 is mounted on the upper end of 9. When the cap 11 is screwed into the upper part of the housing 22, one ends of the three levers 16 rotatably supported by the lever base 15 are pressed against the upper surface of the coil spring retainer 18. At this time, the lever base 1 is located between the upper surface of the coil spring retainer 18 and the piston 13.
The transmission rod 14 is inserted through the transmission rod insertion opening 41 (see FIGS. 5 and 6).

A rod 21 is attached to the inside of the housing 22 with its lower end penetrating the valve body 3 on its center line. And cap 1
When 1 is screwed into the upper portion of the housing 22, both ends of the return coil spring 20 inserted into the rod 21 come into pressure contact with the bottom surface of the housing 22 and the flange portion of the rod 21. Further, at this time, the other ends of the three levers 16 rotatably supported by the lever base 15 come into pressure contact with the engagement portions formed on the rod 21, and
Of the lever base 15 is inserted into the rod insertion port 42 of the lever base 15 (see FIGS. 5 and 6).

FIG. 3 is a sectional view taken along line AA in FIG. 1, and FIG. 4 is a sectional view taken along line BB in FIG.

An inflow passage 31 and an outflow passage 32 are formed in the valve body 3, and a valve seat 27 located at an end of the inflow passage 31 and a start end of the outflow passage 32 are covered with a diaphragm 26. I have. The peripheral edge of the diaphragm 26 is in contact with the peripheral projection of the holder 23, and when the lower portion of the housing 22 is screwed into the valve body 3, the diaphragm 26 is sandwiched between the holder 23 and the valve body 3. In addition,
Since the first stem 24 is fitted in the center of the holder 23, the upper surface of the first stem 24 is in contact with the lower end of the rod 21, and the lower surface of the first stem 24 is
It comes into contact with the upper surface of the diaphragm 26 via the second stem 25 screwed into the lower surface of the stem 24.

In the fluid control valve 1 having such a configuration, all components except the heat-resistant packing 12 and the second stem 25 are made of a metal material in order to control a high-temperature fluid of about 250 ° C. For example, the diaphragm 26 is made of a Ni—Co alloy, and many other components are made of SUS316.

Next, the operation of the fluid control valve 1 of the present embodiment will be described. As shown in FIG. 1, in the normal rod 21, the urging force of the output coil spring 19 acts on the valve body 3 via the coil spring press 18 and the lever 16, and at the same time, the urging force of the return coil spring 20 is applied. Acts on the cap 11 side. Therefore, the direction in which the biasing force of the output coil spring 19 acts and the direction in which the biasing force of the return coil spring 20 acts face each other. However, the biasing force of the output coil spring 19 is much larger than the biasing force of the return coil spring 20, and the lever 1
6 and lever mechanism consisting of lever base 15
Since it acts by increasing to the size multiplied by the leverage ratio,
When the rod 21 is in the normal state, a large thrust is generated on the valve body 3 side. Therefore, the rod 21 in the normal state moves forward to the valve body 3 side, and as a result, the lower end of the rod 21 presses against the upper surface of the first stem 24 and the second stem 2
Since the diaphragm 5 can strongly press the diaphragm 26 against the valve seat 27, the valve is closed even if the diaphragm 26 and the valve seat 27 are made of metal.

On the other hand, in the fluid control valve 1 in the valve closed state, when compressed air serving as a driving source is charged into the air chamber 34 through the inlet 33, as shown in FIG.
3 moves to the valve body 3 side under the pressure of the compressed air. When the piston 13 moves toward the valve body 3, the coil spring retainer 18 also moves toward the valve body 3 via the transmission rod 14, and the output coil spring 19 is compressed. The urging force of the coil spring 19 does not work. Therefore, the rod 21
Only the urging force of the return coil spring 20 acts, and a thrust is generated on the cap 11 side.
It will retreat to one side. As a result, it becomes impossible for the lower end of the rod 21 to apply pressure to the upper surface of the first stem 24, and the first stem 24 and the second stem 25 are pushed up to the cap 11 side by the reaction force of the diaphragm 26. As a result, the diaphragm 26 separates from the valve seat 27 and shifts to the valve open state.

As described above in detail, the fluid control valve 1 according to the present embodiment includes a lever mechanism having a lever 16, a piston 13, a rod 21, and an output coil spring 1.
9. The metal diaphragm 26 is brought into close contact with and separated from the metal valve seat 27 by the actuator 2 including the return coil spring 20 and the like. That is, at normal time,
As shown in FIG. 1, at one end of a lever 16 of the lever mechanism,
An output coil spring 19 is provided via a coil spring retainer 18.
Is applied, and a thrust in the forward direction (on the valve body 3 side) is generated on the rod 21 which engages with the other end of the lever 16, so that the metal diaphragm 26 is connected to the metal valve seat. 27. On the other hand, in the non-normal state, the piston 13 receives the pressure of the compressed air and moves as shown in FIGS.
Since the output coil spring 19 is compressed via the coil spring 4 and the coil spring holder 18, one end of the lever 16 is released from the urging force of the output coil spring 19. As a result, the urging force of the return coil spring 20 generates a thrust in the rod 21 in the retreating direction (the cap 11 side), so that the metal diaphragm 26 is separated from the metal valve seat 27.

Therefore, the fluid control valve 1 of the present embodiment
Then, the urging force of the output coil spring 19 is increased by the lever ratio of the lever mechanism having the lever 16 and the like to act, thereby generating a thrust in the forward direction (on the valve body 3 side) on the rod 21, and Diaphragm 26 is in close contact with the metal valve seat 27, thereby providing a "seal thrust".
, The minimum required output coil spring 1
The biasing force of No. 9 is a value obtained by dividing “the seal thrust” by the lever ratio. Therefore, the outer diameter of the output coil spring 19 can be minimized by an amount corresponding to the difference between the value obtained by dividing the “seal thrust” by the leverage ratio and the value of the “seal thrust”. Since the built-in actuator 2 can be downsized, the fluid control valve 1 having the downsized actuator 2 while ensuring "seal thrust"
Can be provided.

In the present embodiment, the value of the "seal thrust" is 980 N, and the minimum required biasing force of the output coil spring 19, which is a value obtained by dividing the "seal thrust" by the leverage ratio, is as follows. , 490N.

Further, the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the present invention. For example, in the fluid control valve 1 of the present embodiment, the metal diaphragm 26 is brought into close contact with and separated from the metal valve seat 27. However, this is not intended to limit the invention to the metal diaphragm 26. The valve element made of a metal may be brought into close contact with or separated from a metal valve seat.

In this embodiment, the place where the fluid control valve 1 is used is not mentioned. However, in a semiconductor manufacturing apparatus, a high-temperature fluid is often controlled.
Therefore, the fluid control valve used needs a structure in which a metal valve body is brought into close contact with and separated from a metal valve seat. Further, when used in a semiconductor manufacturing apparatus, a fluid control valve is required to always have a higher degree of shutoff and a further miniaturization. Therefore, from these viewpoints, it can be said that the fluid control valve 1 of the present embodiment is optimal.

[0033]

According to the fluid control valve of the present invention, the thrust in the forward direction is generated on the rod by increasing the urging force of the output coil spring at the lever ratio of the lever mechanism to act on the rod. Is tightly adhered to the metal valve seat, thereby securing "seal thrust" .The minimum required biasing force of the output coil spring is the value obtained by dividing "seal thrust" by the leverage ratio. Become. Therefore, it is possible to minimize the outer diameter of the output coil spring by an amount corresponding to the difference between the value obtained by dividing the “seal thrust” by the leverage ratio and the value of the “seal thrust”, and incorporate the output coil spring. Since the size of the actuator can be reduced, it is possible to provide a fluid control valve having an actuator whose size is reduced while ensuring "seal thrust".

These points also apply to the fluid control valve in which the metal diaphragm is brought into close contact with and separated from the metal valve seat by the actuator.

Further, in a semiconductor manufacturing apparatus, a high-temperature fluid is often controlled, and a fluid control valve used therein has a structure in which a metal valve body is brought into close contact with and separated from a metal valve seat. I need. Furthermore, when used in semiconductor manufacturing equipment, the fluid control valve always
There is a demand for higher barrier properties and further miniaturization.
Therefore, from these viewpoints, the fluid control valve of the present invention can be said to be optimal.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fluid control valve of the present invention, showing a valve closed state.

FIG. 2 is a cross-sectional view of the fluid control valve of the present invention, showing a valve open state.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a sectional view taken along line BB in FIG. 1;

FIG. 5 is a partial cross-sectional view of a lever base used in the fluid control valve of the present invention.

FIG. 6 is a rear view of a lever base used in the fluid control valve of the present invention.

FIG. 7 is a front view of a lever used in the fluid control valve of the present invention.

FIG. 8 is a side view of a lever used in the fluid control valve of the present invention.

FIG. 9 is a cross-sectional view of a prior art fluid control valve,
It shows the valve closed state.

FIG. 10 is a cross-sectional view of a conventional fluid control valve, showing a valve open state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid control valve 2 Actuator 13 Piston 16 Lever 19 Output coil spring 20 Return coil spring 21 Rod 26 Diaphragm 27 Valve seat

Claims (3)

[Claims] 1. A rod engaged with the other end of the lever is advanced by an urging force of an output coil spring acting on one end of a lever of the lever mechanism, while the piston receiving the pressure of the driving source is moved by the piston. By moving and compressing the output coil spring, one end of the lever is released from the urging force of the output coil spring, and the actuator is configured to retract the rod by the urging force of the return coil spring, A fluid control valve, wherein a metal valve body is brought into close contact with and separated from a metal valve seat by the actuator. 2. The fluid control valve according to claim 1, wherein the valve body is a diaphragm. 3. The fluid control valve according to claim 1, wherein the fluid control valve is used in a semiconductor manufacturing apparatus.