JPH03107602A - Actuator for fluid control device - Google Patents

Abstract

PURPOSE:To obtain compactness of a device by providing a lever arm, whose one end abuts against the second piston of a tandem piston provided for adding each thrust force through mounting each piston on a stem and another end abuts against the stem, and by transmitting the sum of the thrust force of each piston to the stem with the force intensified. CONSTITUTION:A stem 3 penetrates a cylinder case 5 and has axial flexibility due to elastic bodies 6 and a spring seat 12. A first piston 7 and a second piston 8 are mounted airtightly on the stem 3 so that a sleeve 7a of the first piston 7 abuts against the second piston 8. One end of a lever arm 9 arranged radially abuts against the second piston 3 by means of a lever support axis 10, and another end of the lever arm 9 abuts against a lever arm engage collar 16 mounted on the stem 3 via a support roller 11. Consequently, the thrust force on the first piston 7 and that on the second piston 8 are added and transmitted to the stem 3 with its magnitude intensified by means of the lever arm 9. Therefore, it ia possible to obtain large thrust force without enlargement of the actuator, and also to get compactness of the device.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an improvement in an actuator for a fluid control device such as an automatic flow rate/pressure adjustment device, and the present invention relates to an actuator for a fluid control device such as an automatic flow rate/pressure adjustment device. The present invention relates to an actuator for a fluid control device that achieves miniaturization and high output by transmitting power to the fluid control device.

(Prior Art) In recent years, metal diaphragm type valves have come to be increasingly used as fluid control devices in semiconductor manufacturing equipment and the like from the viewpoint of cleaning piping paths. At the same time, there is a demand for miniaturization of semiconductor manufacturing equipment, etc., and along with this, demand for miniaturization of tall diaphragm valves is increasing.

However, as shown in Figure 5, in a metal diaphragm type valve, the pressure receiving area of the diaphragm A that forms the liquid contact part B (or the contact spring part) is relatively large. It is necessary to apply downward thrust. As a result, when the fluid pressure is high, high output is also required from the actuator D that actively opens and closes the valve.
There is a problem in that the actuator D inevitably becomes large and the fluid control device E cannot be made smaller.

That is, in the conventional actuator D, the thrust of the piston F is directly transmitted to the stem C, so it is necessary to increase the effective area of the piston F in proportion to the required thrust. The diameter increases significantly.

On the other hand, pistons F are stacked in two stages.

An actuator with a structure that doubles the thrust applied to the stem C has been developed. However, even in this type of actuator D, the height dimension of the actuator D becomes considerably long due to the two-stage piston F, which results in an increase in the size of the actuator.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problem in the conventional actuator for this type of fluid control device, namely, because it is configured to directly transmit the thrust of the piston to the stem, a high thrust is applied to the stem. The purpose of this project is to solve the problem of the actuator becoming extremely large and making it impossible to downsize the fluid control device when the actuator is required to do so. The present invention provides an actuator for a fluid control device that can be made smaller and has a higher output power by multiplying the thrust force and transmitting it to the stem.

(Means for Solving the Problems) The present invention has a cylinder case 5 which is fixed to the valve box 1 through the insertion of the stem 3; A first piston 7 and a second piston 8 are arranged in an overlapping manner and are actuated by fluid pressure; they are arranged radially with respect to the axis of the stem 3 and are swingably supported by a lever shaft 10; and a plurality of lever rods 9 having one end locked to the stem 3 and the other end facing the second piston 8; and an elastic body 6 that applies elastic force to the stem 3, so that both the pistons The basic configuration of the invention is that the sum of thrusts of 7.8 is multiplied by the lever 9 and transmitted to the stem 3.

(Operation) The respective thrusts of the first piston 7 and the second piston 8 operated by fluid pressure are combined, and the sum of the thrusts of both pistons 7.8 is applied to one end of the lever 9. The total thrust F0 of both pistons 7.8 applied to one end of the lever 9 is multiplied according to the lever ratio and then transmitted to the stem 3 via the other end of the lever 9. As a result, the stem 3 is moved in its axial direction against the elastic force of the elastic body 6, and the valve is opened or closed.

(Example) Hereinafter, an example of the present invention will be described based on FIGS.

FIG. 1 is a longitudinal cross-sectional view of an actuator for a fluid control device according to the present invention, with the left half showing the valve closed state and the right half showing the valve open state.

In Figure 1, ■ is the valve box, 2 is the lid, 3 is the stem, and 4
is a stem guide, 5 is a cylinder case, 6 is an elastic body, 7
is the first piston, 8 is the second piston, 9 is the lever, 10
1 is a lever support shaft, 11 is a support roller, and 12 is a spring receiver.

The valve box 1, lid body 2, stem 3, stem guide 4, etc. are all known, and as the stem 3 moves up and down, the valve body or diaphragm hits and leaves the valve seat. Opening and closing are performed.

(Illustration omitted).

The cylinder case 5 is formed of a case body 5a into which the stem guide 4 is inserted and hermetically fixed thereto, and a case lid 5b which is hermetically screwed onto the case body 5a. Working fluid supply port 13.1
4 are drilled in each case.

The elastic body 6 includes a spring receiver 1 fixed to the upper end of the stem 3.
2 and the case lid body 5b.

The elastic force of the elastic body 6 presses the stem 3 downward via the spring receiver 12, and the valve is held in the closed state. In this embodiment, a so-called disk spring is used as the elastic body 6, thereby reducing the height of the case 5.

The first piston 7 is slidably inserted into the cylinder case 5 at an upper position through the stem 3 in an airtight manner. Further, a cylinder 7a protruding downward is formed on the inner peripheral edge of the lower surface side of the first piston 7, and the lower end of the cylinder 7a is connected to the upper surface of the inner peripheral edge of the second piston 8, which will be described later. It touches the side.

The second piston 8 is located below the first piston 7,
The stem 3 is inserted through the stem 3 in an airtight manner and is slidably attached thereto. The outer circumferential edge 8a on the lower surface side of the second piston 8 is ring-shaped and slightly protrudes downward, and the lower end of this ring-shaped outer circumferential edge 8a is connected to the upper surface of the outer edge of a lever lever 9, which will be described later. It is in contact with.

As shown in FIG. 2, the lever rods 9 are located below the second screw line 8 and are horizontally arranged radially at equal intervals (90'') with respect to the axis of the stem 3. It is swingably supported by a lever support shaft 10 on a lever support 15. The roller receiver is formed with grooves 9a and 9b on the upper surface of the outer end and the upper surface of the inner end of the lever lever 9, respectively. , a support roller 11 is rotatably fitted into the grooves 9a and 9b of each roller receiver.The upper surface of the outer end of each lever 9 is connected to the second piston 8 via the support roller 11. The upper surface of the inner end of each lever 9 is in contact with the outer peripheral edge of the lower surface of the stem 3, and the upper surface of the inner end of each lever 9 is engaged with a lever engaging body 16 protruding from the outer peripheral surface of the stem 3 via a support roller 11. There is.

The lever support 15 is fixed to the upper end of the stem guide 4 (or the cylinder case 5) with the stem 3 slidably inserted therein, and the support piece 15a is formed in a cross shape. There is.

Further, in this embodiment, four lever rods 9 are arranged radially and horizontally at equal intervals, but the number of lever rods 9 may be two or three, or five or more. You can.

Next, the operation of the present invention will be explained.

As shown in FIG. 1 (left half) and FIG. 3, when the inside of the cylinder case 5 is not pressurized, the spring receiver 12 is pressed downward by the elastic force of the first elastic body 6, and the spring receiver 12 is pressed downward through the spring receiver 12. The stem 3 is pushed downwards by a certain distance, and the valve is held closed.

Further, when the valve is in the closed state, the lever engaging body 16 of the stem 3 presses the inner upper surface of the lever lever 9 downward. As a result, the second piston 8 and the first piston 7 pass through the upper surface of the outside of the lever 9.

It will be in a state where it is pushed upward.

On the other hand, when the working fluid is supplied from the fluid supply port 13.14, both pistons 7.8 are pressed downward by a certain distance, and the outer peripheral edge 8a of the second piston 8 pushes the upper surface of the outer end of the lever lever 9. , is pushed downward. This results in
The upper surface of the inner end of the lever 9 that engages with the lever engaging body 16 of the stem 3 is pushed upward around the lever support shaft 10.

As a result, the stem 3 will be pulled upwards and the valve will be opened.

In this embodiment, the so-called lever ratio of the lever 9 is 1:
3, and the thrust acting on stem 3 is 6 times the thrust of one piston (number of pistons: 2 x lever ratio: 3)
becomes. As a result, when the thrust force required for the stem 3 is the same, the height dimension has been reduced by approximately 1.
5%.

It has been demonstrated that the width dimension can be reduced by about 25%.

Further, in this embodiment, the actuator has a so-called normally closed: air toe open type structure, but it goes without saying that it may also be of a normally open: air toe closed type.

Further, in this embodiment, the elastic force for closing the valve is obtained by a disc spring, but a coil spring or the like may also be used.

Furthermore, in this embodiment, the lever lever 9 and the second piston, and the lever lever 9 and the stem 3 are made to face each other via the support rollers 11, but the tip of one of the members facing each other is formed into a spherical surface. Process it into shapes.

It is also possible to omit the bearing roller 11.

(Effects of the Invention) In the present invention, two sets of pistons 7.8 are arranged in the cylinder case so that their respective thrusts are combined, and the lever 9 is used to reduce the total thrust of both pistons 7.8. Since the structure is such that the thrust is multiplied and transmitted to the stem 3, even when a particularly high thrust is required for the operation of the stem 3, such as in a metal diaphragm valve, the operation of the stem 3 can be performed without increasing the size of the actuator. The thrust required for this can be obtained, and the fluid control device can be significantly downsized.

In addition, in the present invention, there are two
Since the above-mentioned lever rods 9 are arranged at equal intervals, and the inner end of each lever rod 9 is engaged with the stem 3, and the outer end thereof is brought into contact with the second piston 8, both pistons 7.
By the operation of 8, the lever 9 is synchronously and extremely smoothly swung, and as a result, the stem 3 is also moved up and down smoothly and effortlessly.

As mentioned above, the present invention can be used as an actuator for metal diaphragm valves etc. that require high thrust for stem operation.
It has excellent practical utility.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an actuator for a fluid control device according to the present invention. Fig. 2 is a plan view of the lever mechanism, Fig. 3 is a longitudinal sectional view of the lever mechanism in the valve closed state, and Fig. 4 is a longitudinal sectional view of the lever mechanism in the valve open state. be. FIG. 5 is a longitudinal sectional view of a conventional metal diaphragm type fluid control device. l Valve box lid Stem Stem guide Cylinder case Elastic body First piston Second piston Lever lever Lever shaft support Roller Spring bearing is operating fluid supply port Lever support Lever lever engaging body

Claims (4)

[Claims] (1) A cylinder case (5) into which the stem (3) is inserted and fixed to the valve box (1); a cylinder case (5) into which the stem (3) is slidably inserted and which is stacked in two stages so that the respective thrust forces are combined; a first piston (7) and a second piston (8) which are disposed in the shaft and actuated by fluid pressure; A plurality of lever levers (9) are rotatably supported, one end of which is locked to the stem (3), and the other end of which is in contact with the second piston (8); Elastic body that applies force (6
), wherein the sum of the thrusts of the pistons (7) and (8) is multiplied by a lever (9) and transmitted to the stem (3). . (2) Four lever rods (9) are arranged horizontally at a pitch of 90°, and the inner end of each lever rod (9) is connected to the stem (3).
2. The actuator for a fluid control device according to claim 1, wherein the actuator is configured to be locked to the lever and the outer end of each lever is brought into contact with the outer peripheral edge (8a) of the second piston (8). (3) The fluid control according to claim (1), wherein each lever lever (9) is configured to be pivotally supported by a lever support (15) disposed in the cylinder case (5) through the insertion of the stem (3). Actuator for equipment. (4) Each lever (9) and stem (3) and each lever (9)
) and the second piston (8), respectively, by a supporting roller (11).
Claim (1) in which the structure is such that the two are interposed to be locked and brought into contact with each other.
An actuator for a fluid control device according to.