JPH10169802A - Diaphragm for controlling fluid pressure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of the creep, and to obtain the excellent pressure tightness by providing a flexible diaphragm for controlling the hydraulic pressure under the pressure of the pressure fluid which comprises a first thin film and a second thin film to be stacked on the first thin film. SOLUTION: When the secondary pressure is lower than the primary pressure, and a diaphragm 48 for controlling the hydraulic pressure is pressed upward by the pressure fluid to be supplied from a primary port 12, the diaphragm 48 is gradually elevated against the elastic force of a pressure regulating spring 68, and a valve disk 32 is seated on a seat part 42, leading to the set pressure. In a pressure regulating valve 10, the diaphragm 48 for controlling the hydraulic pressure is formed by stacking thin film bodies 58, 60 comprising separate thin film diaphragms. The thin film body 58 comprises, for example, a rubber diaphragm having a base cloth, the thin film body 60 comprises a resin diaphragm made of fluorocarbon resin, and excellent pressure tightness can be obtained thereby without degrading the responsiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure control diaphragm provided in a fluid pressure device such as a pressure reducing valve and performing a pressure regulating function.

[0002]

2. Description of the Related Art Conventionally, for example, a diaphragm having a function of reducing a primary pressure and adjusting a secondary pressure to a predetermined set value is incorporated in a pressure reducing valve or the like. The diaphragm is formed in a thin film shape from, for example, a resin material such as a fluororesin, and is interposed between a pressure reducing valve main body and a bonnet constituting a pressure reducing valve to form a diaphragm chamber.

In this case, a pressure fluid supplied from a primary port is introduced into the diaphragm chamber, and a force for pressing the diaphragm upward under the action of the pressure fluid and a pressure regulating device for pressing the diaphragm downward. The secondary pressure introduced into the fluid pressure device is regulated by opposing the spring force of the spring.

[0004]

When the pressure reducing valve is attached to a wafer cleaning line or the like that constitutes a semiconductor manufacturing apparatus disposed in a clean room, the diaphragm is acted upon by the pressure of a chemical solution flowing through the pressure reducing valve. Creep may occur in the thin film portion, and the creep may cause the thin film portion to expand and deteriorate the pressure regulation effect, or the thin film portion may be broken.

Further, in general, when an attempt is made to reduce the thickness of the diaphragm in order to increase the response sensitivity of the diaphragm, there is a disadvantage that the pressure resistance of the thin film portion is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned disadvantages, and does not cause creep even when receiving a fluid pressure due to a chemical solution or the like. It is an object of the present invention to provide a fluid pressure control diaphragm capable of obtaining a fluidity.

[0007]

In order to achieve the above object, the present invention provides a fluid pressure control diaphragm having flexibility under the pressure receiving action of a pressure fluid, comprising: a first thin film member;
It is characterized by comprising a second thin film formed of a material different from and distinct from the first thin film and superimposed on the first thin film.

According to the present invention, the first thin film and the second thin film made of different and different materials are superposed to form a two-layer structure, so that high pressure resistance can be obtained without causing creep. Obtainable.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a diaphragm for controlling fluid pressure according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes a pressure reducing valve in which a fluid pressure control diaphragm according to an embodiment of the present invention is incorporated.

The pressure reducing valve 10 has a body 16 in which a primary port 12 and a secondary port 14 are formed coaxially.
And a hood 18 fitted on the upper part of the body 16.
And a shaft 2 having a thread portion engraved in a predetermined range on the outer peripheral surface.
A handle 22 rotatably supported on the upper portion of the bonnet 18 around the center of rotation 0 and an opening formed on the bottom surface of the body 16 and a closure provided with a plurality of ribs (not shown). And a member 24.

A stem 26 is provided between the primary side port 12 and the secondary side port 14 of the body 16 so as to be displaced in the direction of arrow A or B. The stem 26 is provided in a hole in the body 16. It is slidably disposed with respect to the fixed holding member 28. A diaphragm sheet 30 interposed between the body 16 and the closing member 24 abuts on a lower end of the stem 26, and further, the diaphragm sheet 3
0 is formed so as to cover one end of the valve body 32. A valve spring 34 inserted into the hole of the closing member 24 is engaged with the flange of the valve body 32. In this case, the valve spring 34 acts so as to always press the valve body 32 in the direction of the arrow A by its resilient force.

The primary port 12 and the secondary port 14
A communication path 36 is formed between the primary port 12 and the secondary port 14 to communicate with each other.
Are a first chamber 38 adjacent to the primary port 12, a second chamber 40 formed below the first chamber 38 and closed by the diaphragm sheet 30, and a valve body formed above the second chamber 40. The third chamber 44 is configured such that the state of communication with the second chamber 40 is cut off when the seat 32 is seated on the seat portion 42. Between the third chamber 44 and the secondary port 14, a hole 46 having a wall surface having a predetermined inclination angle and gradually increasing in diameter toward the secondary port 14 is formed.

A diaphragm 48 for controlling fluid pressure is stretched between the body 16 and the hood 18, and a diaphragm chamber 50 is formed by the diaphragm 48 for controlling fluid pressure and a side wall of the body 16. The first diaphragm chamber 50 communicates with the third chamber 44 of the communication passage 36.
A passage 52 and a second passage 54 communicating with the secondary port 14 via the hole 46 are formed, and the first passage 52 and the second passage 54 are each formed to have a predetermined diameter.
The fluid pressure control diaphragm 48 is provided with a set of valve seats 5.
6a and 56b, one end of the stem 26 abuts against the bottom surface of the valve seat 56b.

The fluid pressure control diaphragm 48 is a first thin film member 58 on the upper side composed of a separate and independent thin film diaphragm.
And the second thin film member 60 on the lower side are overlapped and formed. The first thin film member 58 is made of, for example, a rubber diaphragm containing a base cloth, and the second thin film member 60 is made of, for example, a fluororesin. Composed of a resin diaphragm. In this case, the fluid pressure control diaphragm 48
Are a first thin film member 58 and a second thin film member 6 made of different materials.
Since the first and second thin film members 58 and 60 are overlapped without being adhered, the operating resistance due to the flexibility between the first thin film member 58 and the second thin film member 60 is reduced, and the response sensitivity is deteriorated. A high pressure resistance can be obtained without causing this.

The diaphragm sheet 30 includes a first thin film member 62 made of a rubber diaphragm containing a base cloth and a second thin film member 64 made of a resin-made diaphragm made of a fluororesin, similarly to the diaphragm 48 for controlling fluid pressure. Are superimposed.

A holding member 28 and a stem 26 are provided between the diaphragm chamber 50 and the third chamber 44, and the diaphragm chamber 50 and the communication passage 36 are shut off by the holding member 28 and the stem 26. Therefore, the communication path 36
A part of the pressure fluid supplied from the primary side port 12 through the first port 52 is introduced into the diaphragm chamber 50 through the first passage 52 having a predetermined diameter.

The shaft 2 fixed to the handle 22
A screw receiving member 66 is screwed into the thread portion of No. 0, and the fluid pressure control diaphragm 48 is moved by an arrow B by the elastic force of a pressure adjusting spring 68 mounted between the spring receiving member 66 and the valve seat 56a. A pressing force acts in the direction. in this case,
The pressure adjusting spring 68 serves to adjust the pressure of the diaphragm 48 for controlling fluid pressure, and the spring receiving member 66 is displaced in the direction of the arrow A or B along the threaded portion of the shaft 20 under the turning action of the handle 22. I do. The hood 18
Is provided with a locking member 70 which engages with the spring receiving member 66 and performs the function of preventing the spring receiving member 66 from rotating.

The pressure reducing valve 10 incorporating the fluid pressure control diaphragm 48 according to the embodiment of the present invention is basically configured as described above. Next, the operation and the effect of the pressure reducing valve 10 will be described. I do.

First, a pressure fluid supply source (not shown) is connected to the primary port 12, and a desired fluid pressure device (not shown) is connected to the secondary port 14 in advance. Further, a set pressure on the secondary side to be supplied to the fluid pressure device by turning the handle 22 in a predetermined direction is set in advance.

That is, the spring receiving member 66 is displaced along the axial direction of the shaft 20 under the rotating action of the handle 22, and the diaphragm for fluid pressure control is passed through the pressure adjusting spring 68 compressed by the spring receiving member 66. 48 to arrow B
By pressing in the direction, the stem 26 and the valve body 32 are integrally lowered.

Accordingly, the valve element 32 is displaced in the direction of arrow B to be separated from the seat 42 by a predetermined distance, and the first chamber 38 forming the communication path 36 between the primary port 12 and the secondary port 14 is formed. , The second chamber 40 and the third chamber 44 are in communication with each other (see FIG. 2).

When the secondary pressure is lower than the primary pressure,
The pressurized fluid (for example, a wafer cleaning chemical) introduced from the primary port 12 under the urging action of the pressurized fluid supply source sequentially flows through the first chamber 38, the second chamber 40, and the third chamber 44,
The fluid is supplied to the hydraulic device through the hole 46 and the secondary port 14. In this case, a part of the pressure fluid supplied from the primary port 12 is supplied to the third chamber 44 through the first passage 52.
The pressure is introduced into the diaphragm chamber 50 to generate a force that presses the fluid pressure control diaphragm 48 upward. Therefore, the force for pushing the fluid pressure control diaphragm 48 generated by the pressure fluid supplied from the primary port 12 upward and the resilience of the pressure adjusting spring 68 are opposed to each other, so that the fluid is introduced into the fluid pressure device. The secondary pressure is regulated.

As described above, while the secondary pressure is lower than the set value, the inflow of the pressurized fluid into the fluid pressure device is continued,
As the difference between the primary and secondary pressures decreases,
The diaphragm 48 for fluid pressure control gradually rises against the resilience of the pressure regulating spring 68, and the stem 26 and the valve body 32 rise integrally with the diaphragm 48 for fluid pressure control. The seat 32 is seated on the seat 42 and reaches the set pressure. In this way, the pressure fluid adjusted to the desired set pressure is supplied to a fluid pressure device (not shown).

In the present embodiment, the first thin film member 58 and the second thin film member 60, which are made of different materials, have a two-layered structure as compared with the prior art constituted by one layer of resin diaphragm. Accordingly, high pressure resistance can be obtained without generating creep on the pressure receiving surface of the pressure fluid.

When a resin diaphragm and a rubber diaphragm are integrally attached with an adhesive or the like,
There is a problem in that the relative displacement between the resin diaphragm and the rubber diaphragm is restricted by the adhesive surface formed between the resin diaphragm and the rubber diaphragm, and the smooth flexibility of the pressure receiving surface is hindered.

On the other hand, in the present embodiment, by adopting a structure in which the first thin film member 58 made of a rubber diaphragm and the second thin film member 60 made of a resin diaphragm are overlapped, the first thin film member 58 is formed. Thin film body 58 and second thin film body 60
Are independently and independently displaced and have smooth flexibility, so that the response speed can be improved. Therefore,
Even if the fluid pressure control diaphragm 48 is formed small, large flexibility can be obtained.

Further, the valve element 32 provided between the primary side port 12 and the secondary side port 14 is covered with a diaphragm sheet 30 having a two-layer structure in the same manner as the fluid pressure control diaphragm 48. By displacing the diaphragm sheet 30 and the valve body 32 integrally, there is an advantage that the pressure fluid is prevented from remaining in the fluid passage.

Although the present embodiment has been described using the fluid pressure control diaphragm 48 incorporated in the pressure reducing valve 10, the present invention is not limited to this. Of course, it can be applied to various fluid pressure devices.

[0030]

According to the present invention, the following effects can be obtained.

That is, as compared with the prior art constituted by one layer of resin diaphragm, the first material having a different material is used.
With the two-layer structure in which the thin film body and the second thin film body are overlapped, high pressure resistance can be obtained without generating creep on the pressure receiving surface of the pressure fluid.

Also, by adopting a structure in which the first thin film and the second thin film are overlapped with each other, as compared with the case where the resin diaphragm and the rubber diaphragm are integrally attached by an adhesive or the like. Since the first thin film body and the second thin film body are independently and independently displaced and have smooth flexibility, the response speed can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a pressure reducing valve incorporating a fluid pressure control diaphragm according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which a valve body is separated from a seating part in the pressure reducing valve shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Pressure reducing valve 12 ... Primary side port 14 ... Secondary side port 16 ... Body 18 ... Bonnet 20 ... Shaft 22 ... Handle 24 ... Closure member 26 ... Stem 28 ... Holding member 30 ... Diaphragm sheet 32 ... Valve body 34 ... Valve spring 36 ... communication passage 38, 40, 44 ... chamber 46 ... hole 48 ... fluid pressure controlling diaphragm 50 ... diaphragm chamber 52, 54 ... passage 56a, 56b
... valve seats 58, 60, 62, 64 ... thin film body 68 ... pressure regulating spring

Claims (3)

[Claims] 1. A diaphragm for controlling fluid pressure having flexibility under the pressure receiving action of a pressure fluid, comprising: a first thin film member; and a material different from and distinct from the first thin film member. A diaphragm for controlling fluid pressure, comprising: a first thin film member and a second thin film member superimposed on the first thin film member. 2. The diaphragm according to claim 1, wherein the first thin film is formed of a rubber material, and the second thin film is formed of a resin material. 3. The diaphragm according to claim 1, wherein the diaphragm for controlling fluid pressure is incorporated in a fluid pressure device including at least a pressure reducing valve.