JPH05187572A - Controller - Google Patents

Abstract

PURPOSE:To enable a controller to be used even in a range of high temperatures as well as to enhance sealing performance in a fluid actuation type controller. CONSTITUTION:This is a fluid actuation type controller equipped with a fluid pressure actuator 7 elevating a stem 5, which is supported by a bonnet 3 in such a way as to be freely elevated. The actuator 7 is made up of an actuator cylinder 15 which is fitted on the bonnet 3 in such a manner that it surrounds the upper portion of the stem 5, and is also furnished with an entrance port 22 for working fluid, a piston 16 which is disposed in the upper end portion of the stem 5, and is moved up and down within the cylinder 15, and a metallic bellows 17 which is interposed between the actuator cylinder 15 and the piston 16 so as to seal a space between them, and is excellent in heat resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used for adjusting the flow rate of high-purity gas used in semiconductor manufacturing equipment, nuclear power plants, etc., and is a fluid used especially in a high temperature range. Actuated controller.

[0002]

2. Description of the Related Art In general, a controller for high-purity gas used in a semiconductor manufacturing apparatus or the like is strictly required to have so-called particle-free and dead-space-free characteristics. Therefore, in the field of semiconductor manufacturing, a diaphragm type controller (particularly a direct diaphragm valve) which is structurally easy to satisfy the above-mentioned requirements of particle-free and dead space-free is widely used. Conventionally, as this type of controller, for example, a controller having a structure shown in FIG. 3 is known.
That is, the controller maintains the airtightness of the body 29 having the fluid inlet 25, the fluid outlet 26, the valve chamber 27 and the valve seat 28, and the central portion thereof moves up and down to move the valve seat 2
Diaphragm 30 which is seated on and off to 8, and diaphragm 30
A cylindrical bonnet 31 that holds the rim of the hood in a gas-tight manner with the body 29, a bonnet nut 32 that fixes the bonnet 31 to the body 29, and a bonnet 31 that is supported so that it can move up and down. A stem 33 for lowering the portion, a fluid pressure actuator 34 provided on the bonnet 31 for driving the stem 33, a spring 35 for constantly urging the stem 33 upward, and the like are provided, and the valve is always open. There is. Further, the fluid pressure actuator 34 is attached to the bonnet 31 so as to surround the upper portion of the stem 33, and is provided with a working fluid inlet / outlet port 36.
From the seal material 39, which is provided on the piston 38 and slides on the inner peripheral surface of the actuator cylinder 37, and the like. Become. Thus, the actuator cylinder 37
When the working fluid (pressure fluid) is supplied into the inside, the piston 38 and the stem 33 are lowered against the elastic force of the spring 35, and the central portion of the diaphragm 30 is pushed downward to abut against the valve seat 28, Also, actuator cylinder 3
When the fluid pressure in 7 is released, the piston 38 and the stem 33 are raised by the elastic force of the spring 35, and the diaphragm 30 is raised by the elastic force and the fluid pressure in the body 29 to separate from the valve seat 28. It has become. The controller has an excellent practical utility such as preventing leakage of fluid from the valve chamber.

[0003]

By the way, in a semiconductor manufacturing apparatus or the like, the controller may be used in a high temperature region, for example, inside or near various furnaces used in the semiconductor manufacturing apparatus. However, in the conventional controller,
An O-ring is usually used for the sealing material 39 of the fluid pressure actuator 34, and the operating temperature limit of this O-ring is about 180 ° C. Therefore, when the controller is used in a high temperature range, the sealing material 39, that is, the O-ring is affected by heat and the life is shortened, or the sealing performance of the fluid pressure actuator 34 is deteriorated, so that the fluid pressure actuator 34 is kept in good condition. There is a problem that it does not work correctly. Further, there is also a problem that the controller cannot be used in a high temperature region above the operating temperature limit of the O-ring.

The present invention was devised in order to solve the above problems, and its purpose is to provide a fluid-operated controller which can be used favorably even in a high temperature region and has excellent sealing property. There is

[0005]

In order to achieve the above object, the controller of the present invention supports a stem to a body having a fluid inlet, a fluid outlet, a valve chamber and a valve seat so as to be able to move up and down via a bonnet. In a fluid-operated controller in which the stem is moved up and down by a fluid pressure actuator provided in a bonnet to open and close a fluid passage formed in the body, the fluid pressure actuator surrounds the upper portion of the stem. Therefore, an actuator cylinder that is attached to the bonnet and has a working fluid inlet / outlet, a piston that is provided at the upper end of the stem and that moves up and down in the actuator cylinder, and is interposed between the actuator cylinder and the piston It is composed of a metal bellows having excellent heat resistance for sealing.

[0006]

When the controller is, for example, a normally-open diaphragm valve, when the working fluid is supplied into the actuator cylinder, the piston and stem are lowered against the elastic force of the spring, and the central portion of the diaphragm is lowered. When it is pushed down, it directly or indirectly hits the valve seat, and the valve is closed. When the fluid pressure in the actuator cylinder is released, the piston and stem rise due to the elastic force of the spring, and the diaphragm is displaced upward due to the elastic force and fluid pressure to move away from the valve seat to open the valve. Become. Since this controller uses a metal bellows with excellent heat resistance as the sealing material for the fluid pressure actuator, it can be used in a fairly high temperature range and the sealing material is not easily affected by heat. Become. As a result, the life of the sealing material is not shortened or the sealing property is not deteriorated. As a result, it will operate well and accurately even when used in a high temperature region.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a vertical cross-sectional view of a fluid actuated controller according to a first embodiment of the present invention, in which the diaphragm is opened and closed by directly contacting a diaphragm 2 with a valve seat. Valve, body 1, diaphragm 2,
It is composed of a bonnet 3, a bonnet nut 4, a stem 5, a diaphragm retainer 6, a fluid pressure actuator 7, a spring 8 and the like, and is of a normally open type.

The body 1 is made of a metal material such as stainless steel having excellent heat resistance. The fluid inlet 9 and the fluid outlet 10 are connected to both sides of the body 1, and the fluid inlet 9 and the fluid outlet 10 are connected to the upper portion of the body 1. Recessed valve chambers 11 each having an open upper portion are formed. Further, the valve seat 12 is provided on the bottom surface of the valve chamber 11.
And a step portion is formed on the lower side of the inner peripheral surface of the valve chamber 11. Incidentally, 13 is a sleeve welded to the fluid inlet 9 and the fluid outlet 10, and 14 is a union nut fitted on the sleeve 13.

The diaphragm 2 is disposed above the valve seat 12 and maintains the airtightness of the valve chamber 11, and the central portion of the diaphragm 2 moves up and down to be seated on the valve seat 12. There is. In the present embodiment, the diaphragm 2 is formed in a plate shape with a central portion bulging upward from a thin metal plate made of special stainless steel or the like having excellent heat resistance, and its peripheral portion is the inner peripheral surface of the valve chamber 11. The bonnet 3 is placed on the stepped portion and is inserted into the valve chamber 11 by the lower end portion of the bonnet 3 and the bonnet nut 4 screwed to the body 1, and is pressed toward the stepped portion side and fixed in an airtight state.

The bonnet 3 is formed of a metal material such as stainless steel having excellent heat resistance into a tubular shape, and is inserted into the valve chamber 11 of the body 1 and then the bonnet nut 4 is tightened, whereby the body 1 is closed. It is pressed and fixed to the side.

The stem 5 is made of a metal material such as stainless steel having excellent heat resistance, and is inserted into the bonnet 3 so that its upper portion projects from the bonnet 3 so that the stem 5 can move up and down. Further, at the lower end of the stem 5, there is provided a diaphragm retainer 6 that abuts the center of the diaphragm 2, and this diaphragm retainer 6 is also formed of a metal material such as stainless steel having excellent heat resistance.

The fluid pressure actuator 7 is provided on the bonnet 3 and lowers the stem 5 with an operating fluid such as air. The fluid pressure actuator 7 includes an actuator cylinder 15, a piston 16 and a bellows 17. Specifically, the actuator cylinder 15 is formed of a metal material such as stainless steel having excellent heat resistance, and has a disk-shaped actuator body 18 screwed onto the upper portion of the bonnet 3, and a bolt on the actuator body 18. It comprises an annular flange 20 fixed by 19, an actuator cap 21 that is welded to the flange 20 and surrounds the stem 5, a connector 23 that is screwed to the actuator cap 21 and has an inlet / outlet port 22 for a working fluid, and the like. The piston 16 is made of a metal material having excellent heat resistance, such as stainless steel, and has a disk shape. The piston 16 is fixed to the upper end of the stem 5 by a nut 24 so that the piston 16 moves up and down in the actuator cylinder 15 together with the stem 5. Has been done by. Further, the bellows 17 is made of a stainless material having excellent heat resistance, and the actuator cylinder 1
5 and the piston 16 are provided to seal between the two. That is, the bellows 17 has its upper end fixed to the piston 16 and its lower end fixed to the flange 20, respectively.

The spring 8 is made of a metal material such as stainless steel having excellent heat resistance, and has an actuator body 18 of the fluid pressure actuator 7 and a piston 1.
6 is interposed between them and always urges the stem 5 upward.

Next, the operation of the controller will be described. When the controller is closed, the connector 23
A working fluid (pressure fluid) is supplied into the actuator cylinder 15 from the inlet / outlet port 22 of the. Then, the piston 16 and the stem 5 are lowered against the elastic force of the spring 8, and the central portion of the diaphragm 2 is pushed downward via the diaphragm retainer 6. As a result, the diaphragm 2 is elastically deformed and abuts against the valve seat 12 to close the valve. When the controller is opened,
The pressure in the actuator cylinder 15 is released. Then, the piston 16 and the stem 5 are raised by the elastic force of the spring 8, and the diaphragm 2 is restored to its original shape by the elastic force and the fluid pressure, and is separated from the valve seat 12 to be in the valve open state. Since each member of this controller is made of a metal material having excellent heat resistance, it can be used even in a fairly high temperature range (about 350 ° C. in this embodiment). Further, since the metal bellows 17 having excellent heat resistance is used as the sealing material of the fluid pressure actuator 7, the sealing material is less likely to be adversely affected by heat. As a result, the life of the sealing material is not shortened or the sealing property is not deteriorated. As a result, it will operate well and accurately even when used in a high temperature region.

FIG. 2 is a vertical sectional view of a fluid actuated controller according to a second embodiment of the present invention, in which the disc 40 provided at the lower end of the stem 5 contacts the valve seat 12. A bellows valve that is separated from the seat to open and close and that prevents leakage of fluid by the bellows 41. The body 1, the bonnet 3, the stem 5, the disc 40, the cover 42, the bellows 41 made of stainless steel, and the fluid pressure actuator. 7 and a spring 8 and the like, and the fluid pressure actuator 7 has the same structure as that of the first embodiment. This controller can also achieve the same effect as that of the first embodiment.

In the first embodiment, the diaphragm 2 is directly seated on and off the valve seat 12. However, a disc is arranged below the diaphragm 2 so that it can be raised and lowered, and a disc packing provided on the disc. The valve seat 12 may be moved to and away from the valve seat 12.

Although the controller is of the normally open type in the first embodiment, it may be of the normally closed type.

In each of the above-mentioned embodiments, the spring 8 is provided between the actuator body 18 and the piston 16 so that the stem 5 is always urged upward. Alternatively, the stem 5 may be interposed so as to always urge the stem 5 upward.

In each of the above embodiments, the fluid pressure actuator 7 is attached to each of the diaphragm valve and the bellows valve, but the structure of the valve (controller) to which the fluid pressure actuator 7 is attached is that of each of the above embodiments. The controller is not limited to the above, and the fluid pressure actuator 7 may be attached to a controller having any structure as long as the fluid passage of the body 1 is opened and closed by the vertical movement of the stem 5. For example, the fluid pressure actuator 7 may be attached to a globe valve, a gate valve or a needle valve.

[0020]

As described above, in the fluid actuated controller of the present invention, a metal bellows excellent in heat resistance is provided between the actuator cylinder and the piston of the fluid pressure actuator, and the bellows is used. Since the seal between the actuator cylinder and the piston is used, it can be used in a fairly high temperature range as compared with the conventional fluid-operated controller that uses an O-ring as the sealing material of the fluid pressure actuator. Moreover, the sealing material (bellows) is not easily affected by heat. As a result, the life of the sealing material is shortened or the sealing performance is not deteriorated due to the heat. In turn, the controller will work well and accurately when used in hot regions.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a fluid actuated controller according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a fluid actuated controller according to a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a conventional fluid-operated controller.

[Explanation of symbols]

1 is a body, 3 is a bonnet, 5 is a stem, 7 is a fluid pressure actuator, 9 is a fluid inlet, 10 is a fluid outlet, 11
Is a valve chamber, 12 is a valve seat, 15 is an actuator cylinder,
16 is a piston and 17 is a bellows.

Claims (1)

[Claims] 1. A body having a fluid inlet, a fluid outlet, a valve chamber, and a valve seat supports a stem so as to be able to move up and down via a bonnet, and the stem is moved up and down by a fluid pressure actuator provided in the bonnet to be formed on the body. In the fluid-operated controller configured to open and close the fluid passage, the fluid pressure actuator is attached to a bonnet so as to surround the upper portion of the stem, and an actuator cylinder having a working fluid inlet / outlet and a stem It is characterized in that it is composed of a piston provided at an upper end portion, which moves up and down in the actuator cylinder, and a metal bellows, which is interposed between the actuator cylinder and the piston and has excellent heat resistance, which seals between the two. Controller to do.