JP3239123B2 - Actuator for fluid control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in an actuator for a fluid control device such as an automatic flow rate / pressure adjusting device, and more particularly, to a system in which the thrust of a piston operated by a fluid pressure is increased to increase the thrust of the piston. TECHNICAL FIELD The present invention relates to an actuator for a fluid control device, which achieves miniaturization and high output by transmitting the actuator to an actuator.

(Prior Art) In a semiconductor manufacturing apparatus and the like, a metal diaphragm type valve has recently been widely used as a fluid control device from the viewpoint of making pipes and the like clean.
At the same time, miniaturization of semiconductor manufacturing equipment and the like has been demanded, and along with this, demands for miniaturization of medal diaphragm valves have been increasing.

However, in the metal diaphragm type valve, as shown in FIG. 5, since the pressure receiving area of the diaphragm A forming the liquid contact part B (or the spring contact part) is relatively large, the stem C is required to bring the valve to the fully closed state. A large downward thrust must be applied. As a result, when the fluid pressure is high, a high output is also required for the actuator D for opening and closing the valve, and there is a problem that the actuator D is inevitably increased in size and the fluid control device E cannot be reduced in size.

That is, in the conventional actuator D, since the thrust of the piston F is directly transmitted to the stem C, 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, an actuator having a structure in which the pistons F are stacked in two stages and the thrust applied to the stem C is doubled has been developed. However, also in this type of actuator D, the height dimension of the actuator D is considerably lengthened by setting the piston F in two stages, which leads to an increase in the size of the actuator.

(Problems to be Solved by the Invention) The present invention has the above-mentioned problem in the conventional actuator for this type of fluid control device, that is, since the thrust of the piston is directly transmitted to the stem, the stem has high thrust. Is required, the actuator becomes extremely large,
In order to solve the problem that the fluid control device cannot be downsized, the so-called leverage principle is applied to the stem drive mechanism of the actuator, and the thrust of the piston is multiplied and transmitted to the stem to reduce the size. -It is intended to provide an actuator for a fluid control device which enables high output.

(Means for Solving the Problems) The present invention relates to a cylinder case 5 in which a stem 3 is inserted and fixed to a valve box 1; and a cylinder in which a stem 3 is slidably inserted so that respective thrusts unite. An upper first piston 7 and a lower second piston 8 which are disposed in a case 5 in a two-stage manner and are actuated by fluid pressure;
A partition member 17 disposed between the piston 7 and the second piston 8 and forming a pressurizing chamber of the second piston 8 having an outer peripheral edge fixed to the cylinder case 5;
A working fluid passage 18 for introducing the working fluid supplied to the pressurizing chamber of the first piston 7 into the pressurizing chamber of the second piston 8;
A lever support member 15 in which the stem 3 is inserted and disposed in the cylinder case 5; a lever which is radially disposed with respect to the axis of the stem 3 and which is swingable to the lever support member 15 by the lever support shaft 10. At least three supported levers 9; a support roller 11 rotatably inserted into a roller receiving groove 9b formed at an inner end of each lever 9 and engaged with the stem 3; 9
A bearing roller 11 rotatably fitted into a roller receiving groove 9a formed at an outer end of the piston and abutting against a piston; and an elastic body 6 for applying an elastic force to the stem 3.
The basic configuration of the invention is that the sum of the thrusts of 7, 8 is multiplied by the lever 9 and transmitted to the stem 3.

(Operation) The thrust of the piston operated by the fluid pressure is applied to the outer end of the lever 9. The thrust of the piston applied to the outer end of the lever 9 is doubled in accordance with the lever ratio, and then transmitted to the stem 3 via the inner end of the lever 9. As a result, the stem 3 is moved in the axial direction against the elastic force of the elastic body 6, and the valve is opened or closed.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

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

In FIG. 1, 1 is a valve box, 2 is a lid, 3 is a stem,
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
Is a lever support shaft, 11 is a bearing roller, 12 is a spring receiver, 13 is a working fluid supply port, 14 is an exhaust port, 15 is a lever support, 16 is a lever rod engaging body, and 17 is a partition of a pressure chamber. is there.

The valve box 1, the lid 2, the stem 3, the stem guide 4 and the like are all publicly known. When the stem 3 moves up and down, the valve body or the diaphragm contacts and separates from the valve seat, and the valve Opening and closing are performed (not shown).

The cylinder case 5 includes a case body 5a into which the slam guide 4 is inserted and airtightly fixed thereto, and a case lid 5b screwed to the case body 5a in an airtight manner. A supply port 13 for the working fluid is formed.

The elastic body 6 has a spring receiver fixed to the upper end of the stem 3.
The stem 3 is disposed between the case 12 and the case lid 5b, and the stem 3 is pressed downward by the elastic force of the elastic body 6 via the spring receiver 12 to keep the valve closed. In this embodiment, a so-called disc spring is used for the elastic body 6, thereby reducing the height of the case 5.

The first piston 7 is slidably inserted into the upper part of the cylinder case 5 by inserting the stem 3 in an airtight manner. A cylindrical body 7a protruding downward is formed on the inner peripheral edge on the lower surface side of the first piston 7,
The lower end of the cylindrical body 7a contacts the upper surface of the inner peripheral edge of the second piston 8, which will be described later, in a state in which a central portion of a partition 17 of the pressurizing chamber described later is slidably inserted. are doing.

The second piston 8 is slidably inserted into the stem 3 at a position below the first piston 7 so that the stem 3 is hermetically inserted therethrough. An outer peripheral edge 8a on the lower surface side of the second piston 8 projects slightly downward in a ring shape, and a lower end of the ring-shaped outer peripheral edge 8a is formed on an upper surface of an outer end portion of a lever rod 9 described later. Is in contact with

Between the first piston 7 and the second piston 8, a partitioning member 17 of a pressurizing chamber disposed in an airtight manner between the inner wall surface of the cylinder case 5 and the outer peripheral surface of the cylinder 7 a of the first piston 7. The working fluid which is partitioned and supplied from the working fluid supply port 13 is supplied to the pressurizing chamber above the first piston 7 and the pressurizing chamber above the second piston 8 respectively.

In FIG. 1, reference numeral 18 denotes a working fluid passage formed in the stem 3. Further, in the present embodiment, two pistons are used, but it goes without saying that three pistons may be used.

As shown in FIG. 2, the lever rod 9 is located below the second piston 8 and is horizontally disposed radially at an interval (90 °) with respect to the axis of the stem 3. The lever 10 is pivotally supported by a lever support 15 so as to be swingable. A roller receiving groove 9 is provided on the upper surface of the outer end and the upper surface of the inner end of the lever 9.
a and 9b are formed respectively, and a bearing roller 11 is rotatably fitted into each of the roller receiving grooves 9a and 9b. The upper surface of the outer end of each lever 9 is in contact with the outer peripheral edge 8a on the lower surface side of the second piston 8 via the support roller 11, and the upper surface of the inner end of each lever 9 is Bearing roller 11
Through the lever 3 to a lever rod engaging body 16 protruding from the outer peripheral surface of the stem 3.

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

In this embodiment, four levers 9 are arranged radially and horizontally at equal intervals, but the number of levers 9 may be three.

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

As shown in FIG. 1 (left half) and FIG. 3, when the inside of the cylinder case 5 is not pressurized, the spring force 12 is pressed downward by the elastic force of the elastic body 6, and The stem 3 is pushed downward by a certain dimension, and the valve is kept closed. In the closed state of the valve, the lever rod engaging body 16 of the stem 3 presses the inner end of the lever rod 9 downward via the support roller 11. As a result, the second piston 8 and the first piston 7 are pushed upward through the support roller 11 provided at the outer end of the lever 9.

On the other hand, when the working fluid is supplied from the fluid supply port 13, the pressurizing chamber above the first piston 7 is pressurized, and the second piston 8 passes through the working fluid passage 18 provided in the stem 3.
The working fluid is supplied to the pressurizing chamber above the above. As a result, the two pistons 7, 8 are pressed downward by a certain distance, and the outer end of the lever 9 is pushed downward by the outer peripheral edge 8a of the second piston 8 via the support roller 11.
Thereby, the support roller 11 is attached to the lever rod engaging body 16 of the stem 3.
The inner end of the lever 9 engaged through the lever is pushed upward about the lever support shaft 10. As a result, the stem 3 is pulled upward against the elastic force of the elastic body 6, and the valve is opened.

In this embodiment, the lever ratio of lever lever 9 is 1:
3 and the thrust acting on the stem 3 is 6 times the thrust of one piston (number of pistons 2 x leverage ratio 3)
Becomes As a result, when the thrust required for the stem 3 is the same, the height is reduced by about 15 times compared to the conventional actuator of the type that directly drives the stem with one piston.
% And the width can be reduced by about 25%.

In this embodiment, the actuator is a so-called normal actuator.
Closed: air-to-open type configuration, but of course, normally open: air-to-closed type may be used.

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

(Effects of the Invention) In the present invention, two pistons 7, 8 are arranged in a cylinder case so that their thrusts are united, and two pistons 7, 8 are Is transmitted to the stem 3 by multiplying the total thrust of the stem 3 even if the actuation of the stem 3 requires a particularly high thrust, such as a metal diaphragm valve, without increasing the size of the actuator. The thrust required for the operation can be obtained, and the fluid control device can be significantly reduced in size.

In the present invention, three or four levers 9 are radially arranged at equal intervals with respect to the axis of the stem 3, and each lever 9
The inner end of the piston 7 is engaged with the stem 3 via the support roller 11 and the outer end thereof is brought into contact with the second piston 8 via the support roller 11. As a result, the lever 9 is swung extremely smoothly and smoothly synchronously, and as a result, the stem 3 is smoothly and smoothly moved up and down.

As described above, the present invention has excellent practical utility as an actuator such as a metal diaphragm valve which requires a high thrust for stem operation.

[Brief description of the 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 a valve closed state, and FIG. 4 is a longitudinal sectional view of the lever mechanism in a valve open state. . FIG. 5 is a longitudinal sectional view of a conventional metal diaphragm type fluid control device. 1 is a valve box, 2 is a lid, 3 is a stem, 4 is a stem guide,
5 is a cylinder case, 6 is an elastic body, 7 is a first piston,
8 is a second piston, 9 is a lever rod, 9a and 9b are roller receiving grooves, 10 is a lever support shaft, 11 is a support roller, 12 is a spring support, 13
Is a working fluid supply port, 15 is a lever support, 16 is a lever rod engaging body, 17 is a partition of a pressurizing chamber, and 18 is a working fluid passage.

Claims (1)

(57) [Claims] 1. A cylinder case (5) having a stem (3) inserted therein and fixed to a valve box (1); and a cylinder (3) slidably inserted through a stem (3) so that thrusts thereof are united. An upper first piston (7) and a lower second piston (7) are arranged in a case (5) in a two-stage
A pressurizing chamber of a second piston (8) disposed between the first piston (7) and the second piston (8) and having an outer peripheral portion fixed to a cylinder case (5); A partition body (17) forming; a stem (3);
A working fluid passage (18) for introducing the working fluid supplied to the pressurizing chamber of the first piston (7) into the pressurizing chamber of the second piston (8) and a stem (3) are inserted into the cylinder case. (5) a lever support (15) disposed inside; and a lever support shaft (1) disposed radially with respect to the axis of the stem (3).
0) at least three lever rods (9) pivotally supported on the lever support (15); rotating into roller receiving grooves (9b) formed at the inner end of each lever rod (9); A bearing roller (11) which is freely inserted and engaged with the stem (3); and a piston which is rotatably inserted into a roller receiving groove (9a) formed at the outer end of each lever rod (9). And a resilient member (6) for applying an elastic force to the stem (3). The sum of the thrusts of the pistons (7) and (8) is determined by a lever (9). An actuator for a fluid control device, wherein the actuator is multiplied and transmitted to a stem (3).