JPH08189574A - Valve - Google Patents

Abstract

PURPOSE: To provide a valve having a valve seat which is stable even in a system using fluid such as N2 O degrading and swelling a valve seat material and a system using the valve by heating it. CONSTITUTION: A valve is composed of a valve main body l having an inflow passage 1a and an outflow passage 1b of fluid, a hood 2, a shaft 3, a spring 4, a handle 6 or the like. A ball plate 10 and an actuator button 11 are housed in a through hole of an actuator button holder 9 positioned in a bottom part of the hood 2. A valve seat 12 is installed above a main body central place between the inflow passage 1a and the outflow passage 1b by a valve seat holder 13, and a diaphragm 14 is arranged between an upper part of the valve seat 12 and the actuator button holder 9. The valve seat 12 is composed of polybenzimidazole resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to valves, and in particular
The present invention relates to a valve such as a diaphragm valve or a bellows seal valve, which can be suitably used for a high-purity line for general gas or liquid, a special gas line, etc., mainly in the field of manufacturing semiconductors, liquid crystals, etc.

[0002]

2. Description of the Related Art As an example of a conventional structure of a valve as described above, for example, a purging gas (inert gas such as nitrogen gas or argon gas) is continuously flowed in a gas piping system of ultra-high purity gas in a semiconductor manufacturing line. There are diaphragm valves used in some cases. In this diaphragm valve, for example, a main body having an inflow passage and an outflow passage, a valve seat (seat) arranged around the inflow passage of the main body, a diaphragm arranged on the valve seat, a piston provided above the diaphragm. And a drive unit that drives the piston unit in the vertical direction. Here, the drive unit is, for example, an air type (pneumatic type)
In the case of, it is operated by compressed air.

In this conventional structure, the valve seat of the valve is required to have many characteristics such as heat resistance, chemical resistance, mechanical properties and non-absorption property. Conventionally, various polymer materials have been used as materials satisfying such requirements. Above all, a structure using a trifluorochloroethylene (PCTFE) resin, which is excellent in these properties as compared with other polymer materials, has been adopted.

[0004]

However, in the valve structure using the PCTFE resin as the valve seat as in the above-mentioned conventional case, when this valve is used in, for example, a semiconductor manufacturing process, the N ₂ O gas or the like is not contained in the PCTFE gas. It deteriorates the properties of the resin. For this reason, the function as the valve seat material of the valve cannot be fully exerted.

That is, valve swelling due to swelling of the valve seat, or valve seat leakage in which gas leaks from the valve seat due to deterioration of mechanical properties, or seat creep in which part of the valve seat collapses occurs. Then, there is a problem that the function as a valve is deteriorated due to valve closing or valve seat leakage, or the diaphragm or bellows is damaged due to an increase in lift due to seat creep.

In addition, for example, when the process gas cannot obtain a sufficient vapor pressure at room temperature, the line is heated to supply the gas. In this case, the valve is also heated to be used. Problems similar to the above occur.

The present invention has been made to solve the above-mentioned problems of the prior art, and is used by heating a system or valve using a fluid that deteriorates or swells a valve seat material such as N ₂ O. An object of the present invention is to provide a valve having a valve seat that is stable in the system.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and includes a body having a fluid inflow passage and an outflow passage, and a valve seat arranged around the inflow passage. A diaphragm disposed on the valve seat for opening and closing the inflow passage and the outflow passage, and a drive unit provided on the diaphragm for opening and closing the valve seat and the diaphragm. A diaphragm valve provided is characterized in that the valve seat is made of polybenzimidazole (PBI) resin.

Further, according to the present invention, a body having a fluid inflow passage and an outflow passage, a valve seat disposed on the inflow passage for opening and closing the inflow passage and the outflow passage, and an upper portion of the valve seat In the bellows seal valve, which is provided in the above, and is provided with a drive unit for driving the valve seat in the vertical direction, the valve seat is made of PBI resin.

More specifically, the above-mentioned PBI resin is called poly [2-2 '-(m-phenylene) -5,5'-bibenzimidazole] and is represented by the following chemical formula. Is.

[0011]

(Equation 1)

[0012]

The PBI resin has less volume change due to swelling or deterioration due to a fluid such as N ₂ O as compared with PCTFE resin which has been conventionally used as a valve seat material in a valve used in a gas system for semiconductor manufacturing. The thermal characteristics are also good. Therefore, by using a valve seat made of PBI resin, it is possible to remarkably reduce the above-mentioned valve blockage, deterioration of function, breakage of diaphragm and bellow, and the like.

[0013]

【Example】

(Embodiment 1) FIG. 1 shows the structure of a diaphragm valve according to an embodiment of the present invention. This diaphragm valve has a fluid inflow passage 1
a, a valve body 1 having an outflow passage 1b, a hollow cylindrical bonnet 2 fitted inside the valve body 1, a shaft 3 provided at a central portion of the bonnet 2, and an interposing between the bonnet 2 and the shaft 3. Spring 4, shaft 3
The handle 6 is fixed to the upper part of the.

An O-ring 8 for sealing the space between the shaft 3 and the bonnet 2 is provided on the outer periphery of the shaft 3. An actuator button holder 9 is located at the bottom of the bonnet 2. Actuator button holder 9
The ball plate 10 and the actuator button 11 are housed in the central through hole. A ball 10a is interposed between the shaft 3 and the actuator button holder 9.

A cylindrical valve seat 12 is attached by a valve seat holder 13 to the upper portions of the inflow passage 1a and the outflow passage 1b located in the central portion of the main body 1. A diaphragm 14 is arranged between the upper portion of the valve seat 12 and the actuator button holder 9. In the above configuration, the main body 1
The valve seat holder 13 is made of stainless steel, the valve seat 12 is made of polybenzimidazole resin, and the diaphragm 14 is made of nickel alloy.

The diaphragm 14 functions as a valve body that opens and closes between the inflow passage 1a and the outflow passage 1b. That is, FIG.
Actuator button holder 9
Is sandwiched between the lower surface of the outer peripheral portion and the upper surface of the outer peripheral portion of the valve seat holder 13, and the central portion thereof contacts or separates from the valve seat 12, thereby opening and closing the passage between the inflow passage 1a and the outflow passage 1b. .

The bonnet 2 is screwed to the valve body 1. Then, by rotating the handle 6 clockwise or counterclockwise, for example, the shaft 3 moves upward or downward.

Therefore, the opening and closing of the inflow passage 1a and the outflow passage 1b by the diaphragm 14 and the valve seat 12 is performed by the above-described rotation operation of the handle 6. That is, in this embodiment, when closing the space between the inflow passage 1a and the outflow passage 1b, the handle 6 is rotated clockwise, for example. Then, the shaft 3 moves downward due to the rotation of the handle 6. By this movement, the actuator button 11 is pushed down via the ball plate 10. As a result, the diaphragm 14 is pressed against the valve seat 12, and the valve seat 12 is sealed and closed by the diaphragm 14.

On the other hand, when the space between the inflow passage 1a and the outflow passage 1b is opened, the handle 6 is rotated counterclockwise, for example. Then, the shaft 3 moves upward due to the rotation of the handle 6. By this movement, the depression of the actuator button 11 via the ball plate 10 is released. As a result, the valve seat 1 of the diaphragm 14
The pressing force to 2 is lost, and the diaphragm 14 and the valve seat 1
It will be in a state of being open between 2 and.

(Embodiment 2) FIG. 3 shows another embodiment of the diaphragm valve of the present invention. This diaphragm valve has a valve body 2 having a fluid inflow passage 21a and a fluid outflow passage 21b.
1, a hollow cylinder cylinder body 22 fitted inside the valve body 21, a piston 23 provided in the central portion of the cylinder body 22, a cylinder cover 25 arranged on the outer periphery of the piston 23, and the like. Cylinder cover 2
An air supply port 25a into which compressed air is introduced is formed in the center of the upper portion of the No. 5. A drive unit 27 is integrally formed on the piston 23. The drive unit 27
In the figure, the left drive unit 27a is shown as a NO (normally open) type structure, and the right drive unit 27b is shown as an NC (normally closed) type structure. In addition, the drive units 27a, 27
The springs 24a and 24b are provided in b, respectively. Further, the drive units 27a and 27b and the cylinder cover 2
5, and O-rings 26, 2 for sealing between them
6a and 26b are provided.

An O-ring 28 for sealing the space between the piston 23 and the cylinder body 22 is provided on the outer circumference of the piston 23.
Is provided. An actuator button holder 29 is located at the bottom of the cylinder body 22. A ball plate 30 is housed in the central through hole of the actuator button holder 29. An actuator button 31 is located below the ball plate 30. In addition, a spacer 3 is provided between the piston 23 and the ball plate 30.
0a is interposed.

A cylindrical valve seat 32 is attached by a valve seat holder 33 to the upper portion of the inflow passage 21a and the outflow passage 21b located at the central portion of the main body 21. A diaphragm 34 is arranged between the upper portion of the valve seat 32 and the actuator button holder 29. In the above configuration, the main body 21 and the valve seat holder 33 are made of stainless steel, the valve seat 32 is made of polybenzimidazole resin, and the diaphragm 34 is made of nickel alloy or the like, as in the above embodiment.

Similarly to the above, the diaphragm 34 functions as a valve body that opens and closes between the inflow passage 21a and the outflow passage 21b. In this embodiment, the opening / closing operation of the diaphragm 34 is
It is performed by supplying compressed air to the air supply port 25a,
Further, a force for deforming the diaphragm 34 to seal the valve seat 32 is applied to the diaphragm 34 from the drive unit 27 via the ball plate 30 and the actuator button 31.

That is, in this embodiment, the sealing of the valve seat 32 by the diaphragm 34 is performed as follows. In the case where the drive unit 27 is the NO type drive unit 27a, the diaphragm valve of the embodiment has the internal spring 2 in the drive unit 27a in a normal state in which compressed air is not supplied.
As a result of being pushed upward by the elasticity of 4a, the valve is in an open state.

When it is desired to close the valve in this state,
Compressed air is supplied to the air supply port 25a. Then, the drive portion 27a is pushed down while resisting the elasticity of the spring 24a, and the piston 23 is driven by the drive portion 27a.
Through the ball plate 30 and the actuator button 3
1 is pushed down. As a result, the diaphragm 34 is pressed by the valve seat 32 and the valve is closed.

When opening the valve from this state,
The supply of the compressed air is released. Thereby, the drive unit 2
7a is pushed up by the elasticity of the inner spring 24a, a gap is created between the diaphragm 34 and the valve seat 33, and the diaphragm 34 is opened.

On the other hand, the drive unit 27 is an NC type drive unit 27b.
In this case, in the normal state in which compressed air is not supplied, the drive portion 27b is pushed down by the elasticity of the internal spring 24b. For this reason, the actuator button 31 b is moved by the elastic force of the spring 32 into the valve seat 33.
And the valve seat 33 is sealed, and the diaphragm 34 is closed. When compressed air is supplied from the air supply port 25a, the drive portion 27b is pushed up against the elasticity of the spring 24b, and as a result, a gap is created between the diaphragm 34 and the valve seat 33, and the diaphragm 34 opens. It becomes the state of.

When the valve is closed from this state,
When the supply of the compressed air is released, the drive portion 27b is pushed down by the elasticity of the spring 24a. As a result, the actuator button 31 is pressed down and the diaphragm 34 is pressed against the valve seat 33, and as a result, the valve is closed.

(Embodiment 3) FIG. 4 shows another embodiment of the diaphragm valve of the present invention. More specifically, this diaphragm valve is a caulking seat type diaphragm valve,
A valve body 41 having a fluid inflow passage 41a and an outflow passage 41b, a hollow cylindrical bonnet 42 fitted inside the valve body 41, a shaft 43 provided at the center of the bonnet 42, a bonnet 42 and a shaft 43. It is composed of a spring 44 interposed between them, a handle 46 fixed to the upper portion of the shaft 43, and the like.

An actuator button 51 is located below the shaft 43. Actuator button 51
An actuator button holder 49 is provided on the outer periphery of the. In addition, the main body 4 of the inflow passage 41a and the outflow passage 41b
A cylindrical valve seat 52 is attached to a portion located in the central portion of 1. Here, as shown in detail in FIG. 5, the valve seat 52 has the annular seat formed in the upper part of the inflow passage 41a and the outflow passage 41b of the main body 41, and the valve seat 52 is attached to the annular recess.
By caulking the mounting portion of the main body 41, the main body 41 is fixedly held.

A diaphragm 54 is arranged between the upper portion of the valve seat 52 and the actuator button 51 and the actuator button holder 49. In the above structure, the main body 41 is made of stainless steel, and the valve seat 52
Is a polybenzimidazole resin, and the diaphragm 54 is made of a nickel alloy or the like. The other structure of this diaphragm valve is similar to that of the embodiment shown in FIG.

The sealing operation of the valve seat 52 by the diaphragm 54 in this embodiment is the same as that in the embodiment of FIG. That is, when the space between the inflow passage 41a and the outflow passage 41b is closed, the handle 46 is rotated, for example, in the clockwise direction to move the shaft 43 downward, whereby the diaphragm 5 is moved.
4 is bent and pressed against the valve seat 52, whereby the valve is closed. Further, when the space between the inflow passage 41a and the outflow passage 41b is opened, the handle 46 is rotated, for example, in the counterclockwise direction to move the shaft 53 upward, so that the pressing force of the diaphragm 54 against the valve seat 52 disappears. , The state between the diaphragm 54 and the valve seat 52 is opened.

(Embodiment 4) FIG. 6 shows another embodiment of the diaphragm valve of the present invention. This diaphragm valve is a caulking seat type diaphragm valve similar to the above, and includes a valve main body 61 having a fluid inflow passage 61a and an outflow passage 61b, a hollow cylindrical cylinder main body 62 fitted inside the valve main body 61, and a cylinder. The main body 62 is composed of a piston 63, a cylinder cover 65, an air supply port 65a, and the like provided in the central portion.

This embodiment is the same as the embodiment shown in FIG. 4 except that the mechanism for driving the piston 63 is constructed by compressed air as in the embodiment shown in FIG. Since the holder 69, the valve seat 72, the diaphragm 74 and the like have the same structure, the description of other parts will be omitted for convenience.

In this embodiment, the sealing of the valve seat 72 by the diaphragm 74 is performed by supplying or stopping compressed air to the air supply port 65a, as in the embodiment shown in FIG.

(Embodiment 5) FIG. 7 shows an embodiment of the bellows seal valve of the present invention. This bellows seal valve includes a valve body 81 having a fluid inflow passage 81a and a fluid outflow passage 81b.
A hollow cylindrical bonnet 82 fitted inside the valve body 81, a shaft 83 provided in the central portion of the bonnet 82, a spring 84 interposed between the bonnet 82 and the shaft 83, and fixed to the upper portion of the shaft 83. And a handle 86, etc.

Below the shaft 83, a bellows 83 is provided. Further, between the upper portion of the inflow passage 1a and the outflow passage 1b located in the central portion of the main body 1 and the bellows 83,
A valve seat 92 is provided. In the above structure, the main body 81 is made of stainless steel, and the valve seat 92 is made of polybenzimidazole resin.

In the bellows seal valve of this embodiment, the opening / closing between the inflow passage 81a and the outflow passage 81b is performed by the above-described rotation operation of the handle 86. That is, the inflow path 81a
In order to close the space between the outlet and the outflow passage 81b, the handle 86 is rotated, for example, in the clockwise direction. This allows the shaft 8
3 moves downward, the lower end of the bellows 83 presses the valve seat 92, and the valve seat 92 closes the passage between the inflow passage 81a and the outflow passage 81b.

On the other hand, when the space between the inflow passage 81a and the outflow passage 81b is opened, the handle 86 is rotated counterclockwise, for example. As a result, the shaft 83 moves upward, the lower end of the bellows 83 and the valve seat 92 are opened, and the above passage is opened.

(Embodiment 6) FIG. 8 shows another embodiment of the bellows seal valve of the present invention. This bellows seal valve includes a valve main body 101 having a fluid inflow passage 101a and an outflow passage 101b, a hollow cylindrical cylinder main body 102 fitted inside the valve main body 101, and a piston 103 provided in the center of the cylinder main body 102. , Cylinder cover 105,
It is composed of an air supply port 105a and the like.

This embodiment is the same as the embodiment of FIG. 7 except that the mechanism for driving the shaft 63 has a structure in which compressed air is used as in the embodiment of FIG.
4. Since the valve seat 112 and the like have the same structure, the description of other parts will be omitted for convenience.

Then, in this embodiment, the valve seat 112
The opening and closing of the passage between the inflow passage 1a and the outflow passage 1b by
Similar to the embodiment of FIG. 3, it is performed by supplying or stopping compressed air to the air supply port 105a.

Next, an experiment conducted on the change in volume and the change in hardness of the valve seat made of PBI resin will be described. In this experiment, the valve seat was filled with N ₂ O liquid at a pressure of 60 kg.
With encapsulating at / cm ^2, in which examine changes in volume and hardness for encapsulating time (Hour). Also, as a reference, the same experiment was performed using PCTFE resin as the valve seat material. As PBI resin, Hoechst Japan (JPN) / Hoechst Celanese Company (USA)
The product sold under the trademark "Celazole" manufactured by the company was used.

The above volume change is shown in FIG. 9 and the hardness change is shown in FIG. From these graphs, PB
It can be seen that the valve seat of the present invention made of I resin as a material has a significantly smaller volume change and hardness change than the conventional valve seat, and shows a good value.

The following two reliability tests were conducted on the valve of the present invention (example) and the conventional valve (conventional example A) after the valves were assembled. The valve of Example 1 shown in FIG. 1 was used as the valve of Example. Further, in the conventional example A, the valve seat material in Example 1 is PCTFE.
It has the same structure except that it is made of resin.

The first reliability test is a test of deadline performance after enclosing the N ₂ O liquid. That is, the N ₂ O liquid was sealed from the inflow passage side of each valve, and the shutoff performance of the valve was confirmed at every predetermined standing time. This result is as shown in FIG. 11, and the valve of the example in which the PBI resin was used for the valve seat maintained the initial performance. On the contrary,
The conventional valve using PCTFE for the valve seat is N ₂ O
The cut-off performance deteriorates with the passage of the enclosure time and is finally degraded to about 1/7 of the initial value. this is,
This is because, in the valves of the examples, the initial mechanical strength of the valve seat is maintained, whereas in the conventional example A, the mechanical strength of the PCTFE resin that is the valve seat material is significantly reduced.

The second reliability test is a test of valve closing performance after enclosing the N ₂ O liquid. That is, the N ₂ O liquid was filled from the inflow passage side of each valve, and the closing property of the valve was confirmed after a predetermined standing time. This result is shown in Figure 1.
As shown in 2. In the figure, Conventional Example B is a caulking seat type diaphragm valve as shown in FIG. 4, which has the same structure except that the valve seat material is PCTFE resin. Further, in FIG. 12, the back side shows the flow rate before N ₂ O is sealed, and the front side shows the flow rate after N ₂ O is sealed, respectively.

From FIG. 12, in the embodiment in which the PBI resin is used for the valve seat, the initial flow rate is maintained even after the sealing. On the other hand, in Conventional Examples A and B, the flow rate after encapsulation was reduced. In particular, in the case of the crimped sheet type conventional example B, the flow rate was remarkably reduced, and the clogging phenomenon due to the sheet swelling was confirmed.

[0049]

As described above, according to the present invention, the PBI resin is used as the valve seat material because it has little volume change due to swelling or deterioration due to fluid such as N ₂ O and is thermally stable. Further, valve seat leakage due to valve seat swelling and deterioration of mechanical properties can be significantly reduced. As a result, it becomes possible to prevent the valve from being closed or the diaphragm or the bellows from being damaged.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a diaphragm valve according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part in the embodiment of FIG.

FIG. 3 is a sectional view showing another embodiment of the diaphragm valve of the present invention.

FIG. 4 is a sectional view showing another embodiment of the diaphragm valve of the present invention.

5 is an enlarged view of a main part in the embodiment of FIG.

FIG. 6 is a cross-sectional view showing another embodiment of the diaphragm of the present invention.

FIG. 7 is a sectional view showing an embodiment of the bellows seal valve of the present invention.

FIG. 8 is a sectional view showing another embodiment of the bellows seal valve of the present invention.

FIG. 9 is a graph showing a change in volume of a valve seat according to the present invention.

FIG. 10 is a graph showing changes in hardness of the valve seat according to the present invention.

FIG. 11 is a graph showing the results of reliability tests of the valve of the example of the present invention and the conventional valve.

FIG. 12 is a graph showing the results of a reliability test of the valve of the example of the present invention and the conventional valve.

[Explanation of symbols]

 1, 21, 41, 61 Valve body, 1a, 21a, 41a, 61a Inflow passage, 1b, 21b, 41b, 61b Outflow passage, 2, 42, 82 Bonnet, 22, 62 Cylinder body, 23, 63 Piston, 25a, 65a air supply port, 27a, 27b drive part, 12, 32, 52, 62, 72, 92, 112 valve seat, 13, 33 valve seat holder, 14, 34, 54, 74 diaphragm, 83, 114 bellows.

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[Procedure amendment]

[Submission date] April 10, 1996

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

Claims (6)

[Claims] 1. A body having a fluid inflow passage and an outflow passage, a valve seat disposed around the inflow passage, and a valve seat disposed on the valve seat between the inflow passage and the outflow passage. In a diaphragm valve including a diaphragm that opens and closes, and a drive unit that is provided above the diaphragm and that opens and closes between the valve seat and the diaphragm, the valve seat is made of polybenzimidazole resin. A valve characterized by being a thing. 2. The valve according to claim 1, wherein the drive unit is a manual type using a handle and a shaft. 3. The valve according to claim 1, wherein the drive unit is an air type using compressed air. 4. A body having a fluid inflow passage and an outflow passage, a valve seat arranged on the inflow passage to open and close between the inflow passage and the outflow passage, and provided on an upper portion of the valve seat. And a drive unit for driving the valve seat in the vertical direction, the valve seat being made of polybenzimidazole resin. 5. The valve according to claim 4, wherein the drive unit is a manual type using a handle and a shaft. 6. The valve according to claim 4, wherein the drive unit is an air type using compressed air.