JP2007321958A - Chemical valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical valve low in cost with stable sealing force. <P>SOLUTION: The chemical valve has a resin valve body 1 formed with a valve seat 41; a diaphragm valve element 30; and a resin valve upper body 11 holding the diaphragm valve element 30 together with the valve body 12. An annular protruding part 36 is formed at the held part of the diaphragm valve element 30. The valve body 12 has an inner annular seal part 31 and an outer annular seal part 32 forming an insertion groove 33 into which the annular protruding part 36 of the diaphragm valve element 30 is inserted. A press-in part 34 is formed at the inner surface of the inner annular seal part 31. When the annular protruding part 36 is inserted into the insertion groove 33, the annular protruding part 36 is elastically deformed outward by abutting on the press-in part 34, and the outer annular seal part 32 is pressed by the annular protruding part 36 and elastically deformed outward. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin chemical valve used in a semiconductor manufacturing process or the like, and more particularly, to a seal structure for preventing external leakage of the chemical valve.

In the semiconductor manufacturing process, a highly corrosive chemical solution or the like is used. A chemical valve for controlling the supply of the chemical liquid is formed of a resin such as a fluororesin in order to cope with a highly corrosive chemical liquid. Moreover, in order to shut off a chemical | medical solution and a valve operation mechanism, many resin-made diaphragm valve bodies are used.
If the valve body that holds the diaphragm valve body and the valve upper body are made of resin, the resin will be sealed, but there will be a problem that the sealing force will decrease due to dimensional changes due to creep and temperature changes. There was a problem that a sufficient sealing force could not be secured.
In order to solve the problem, in the invention described in Patent Document 1 as the prior art, an annular convex portion is formed on the lower surface of the diaphragm valve body, and an insertion groove for inserting the annular convex portion is provided as a resin valve body. It is formed on the top surface. Then, by making the width of the annular convex portion of the diaphragm valve body larger than the width of the insertion groove of the valve main body, the annular convex portion is brought into a press-fit state when inserted into the insertion groove.
In the invention described in Patent Document 2, sealing is performed by welding the diaphragm valve body and the valve body.

Japanese Patent Laid-Open No. 2003-247650 FIG. JP 2005-163877

However, the prior art has the following problems.
(1) In the semiconductor manufacturing process, as the degree of integration of semiconductors increases, chemicals with higher permeability such as hydrofluoric acid, which are more dangerous, have come to be used. ing.
In the invention described in Patent Document 1, the press-fitting allowance must be increased in order to increase the sealing force. However, when the press-fitting allowance is increased, there is a problem that the insertion becomes difficult. Further, when the press-fitting allowance is increased and the force is inserted forcibly, the diaphragm peripheral protrusion may be bent and buckled.
In addition, when controlling high-temperature chemicals, the sealing force decreases due to the creep phenomenon of the valve body and valve body. Could become impossible.

(2) As a means for solving the above problem, the invention described in Patent Document 2 is effective. However, in the invention described in Patent Document 2, materials suitable for welding are limited, a structure that can be locally heated is required, and process management such as temperature management and component management is difficult. There was a problem that the manufacturing cost increased.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a chemical valve that can improve the sealing performance without increasing the cost.

In order to solve the above problems, the chemical valve of the present invention has the following configuration.
(1) A chemical valve having a resin valve body in which a valve seat is formed, a diaphragm valve body, and a resin upper body sandwiching and holding the diaphragm valve body together with the resin valve body, the diaphragm valve An annular convex portion is formed at a portion where the body is sandwiched, and the resin valve main body has an inner annular seal portion and an outer annular seal portion that form an insertion groove into which the annular convex portion of the diaphragm valve body is inserted. A press-fit portion is formed on the inner surface of the seal portion, and when the annular convex portion is inserted into the insertion groove, the annular convex portion comes into contact with the press-fit portion and elastically deforms outward, and is pressed by the annular convex portion to be the outer annular seal portion. Elastically deforms outward.
(2) In the chemical valve described in (1), the annular convex part of the diaphragm valve body is pushed by the resin upper body outside the outer annular seal part, and the inner annular seal part is A resin valve main body inclined portion that presses against the press-fitting portion is formed.

(3) In the chemical valve described in (2), when the annular convex portion of the diaphragm valve body starts to contact the inner annular seal portion, the inclined portion of the outer annular seal portion is It is not in contact with the body.
(4) In any one of the liquid chemical valves of (1) to (3), the inner annular seal portion is provided on the inner periphery of the annular convex portion of the diaphragm valve body, and the annular convex portion of the diaphragm valve body is provided. It is characterized in that a diaphragm inclined portion is formed to be pressed to the portion side.
(5) In any one of the liquid chemical valves of (2) to (4), an elastic member is attached to a seat surface of a fastening screw that fastens the diaphragm valve body and the resin valve main body, or An elastic member is mounted between the resin valve main body and the substrate to which the chemical valve is attached.

Next, the action and effect of the chemical valve having the above-described configuration will be described.
When inserting the annular convex part formed in the diaphragm valve body into the insertion groove formed in the resin valve body while being pressed into the press-fitting part of the inner annular seal part, the annular convex part of the diaphragm valve body is It is elastically deformed outward and comes into contact with the outer annular seal portion, and the outer annular seal portion is pushed by the annular convex portion and elastically deformed. Since the width of the annular convex portion of the inserted diaphragm valve body is wider than the width of the insertion groove formed in the resin valve main body, the annular convex portion of the diaphragm valve body is compressed inside the resin valve main body, Since the press-fitting allowance formed in the annular seal portion is pressed, a strong sealing force can be obtained stably.
Further, a resin valve body inclined portion is formed outside the outer annular seal portion, and the resin upper body inclined portion formed on the resin upper body abuts on the resin valve body inclined portion, and the outer annular shape is formed. Since the seal portion is pressed inward, a stronger sealing force can be obtained stably.

Further, when the annular convex portion of the diaphragm valve body starts to contact the inner annular seal portion, the resin valve body inclined portion of the outer annular seal portion is in contact with the resin upper inclined portion of the resin upper body. First, when the annular convex part enters the insertion groove to the predetermined depth, the main body inclined part comes into contact with the upper body inclined part. Can be easily inserted without strongly contacting the inner annular seal portion. After the annular convex portion enters the insertion groove to a predetermined depth, the main body inclined portion of the outer annular seal portion is brought into contact with the upper body inclined portion. You can gain power.
Furthermore, since the inner annular seal portion is formed on the inner circumference of the annular convex portion of the diaphragm valve body and the diaphragm inclined portion is pressed against the annular convex portion side of the diaphragm valve body, the inner annular seal portion is elastically deformed inward. Therefore, a strong sealing force can be obtained more stably.

A chemical valve that is an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of the chemical valve, and FIG. 2 is an exploded cross-sectional view of the chemical valve of FIG. As shown in FIG. 2, the chemical valve is large, and is configured by fastening a fluorine resin valve body 12 and a resin valve upper body 11 with fastening screws 13.
FIG. 3 shows a bottom view of FIG. The four fastening screws 13 fasten the valve upper body 11 and the valve body 12 at the positions shown in the drawing.
The valve body 12 is formed with a first port 42, a second port 43, and a valve seat 41 formed on the outer periphery of the valve hole.
The valve upper body 11 has a cylinder structure. A resin lid member 22 is attached to the resin cylinder body 21 to form a cylinder chamber. The cylinder body 21 and the lid member 22 are made of a PPS material having high strength and excellent temperature characteristics among resins. The cylinder chamber is divided into an upper cylinder chamber 26 and a lower cylinder chamber 27 by a piston 23. The piston is slidably held on the cylinder body 21, and an O-ring 29 is mounted as a seal member on the sliding portion.

  An upper port 25 communicates with the upper cylinder chamber 26. A lower port 28 communicates with the lower cylinder chamber 27. A main body portion of a fluororesin diaphragm valve body is fixed to the lower portion of the piston. The outer peripheral portion of the diaphragm valve body is held between the valve main body 12 and the cylinder main body 21 constituting the valve upper body 11. The structure will be described later. The main body portion of the diaphragm valve body can contact or be separated from the valve seat 41. The piston 23 is urged in a direction in which the diaphragm valve body 30 contacts the valve seat 41 by a compression spring 24 attached with one end contacting the piston 23 and the other end contacting the lid member 22.

In the chemical valve having such a structure, the chemical liquid usually only flows from the first port 42 to the second port 43 through the valve hole formed at the center of the valve seat 41, and the diaphragm valve body 30 seals. Since this is done, the chemical solution does not leak into the valve body.
However, there is a possibility that it will not be possible to cope with the high temperature and high penetration of chemicals that are expected to be developed in the future, and further safety against external seals is desired. The present invention provides a seal structure that can exert a stronger and more stable sealing force than before.

Next, FIG. 4 shows an enlarged cross-sectional view of part A of FIG. FIG. 5, FIG. 6, and FIG. 7 show assembly process diagrams of FIG.
A ring-shaped annular convex portion 36 is formed in a portion that the diaphragm valve body 30 is sandwiched between the valve main body 12 and the cylinder main body 21 of the valve upper body 11 so as to protrude downward. The annular convex portion 36 has a constant thickness, and is chamfered to serve as a guide for insertion on the inner peripheral portion of the tip.
An insertion groove 33 into which the annular convex portion 36 of the diaphragm valve body 30 is inserted is formed on the upper surface of the valve body 12. The insertion groove 33 is formed so as to be surrounded by an annular inner annular seal portion 31 that protrudes upward and extends around the entire circumference, and an annular outer annular seal portion 32 that also protrudes upward and extends around the entire circumference. .

A press-fit portion 34 is formed on the inner surface of the inner annular seal portion 31 so that the annular convex portion 36 of the diaphragm valve body 30 is pressed and sealed.
On the outer peripheral surface of the outer annular seal portion 32, a main body inclined surface 32a is formed over the entire periphery.
On the other hand, the lower surface of the cylinder body 21 is formed with an annular upper body convex portion 21a that protrudes downward and has an annular shape over the entire circumference. A body inclined surface 21b is formed on the inner peripheral surface of the annular body convex portion 21a. The main body inclined surface 32a and the upper body inclined surface 21b are inclined with substantially the same inclination angle in opposite directions, and function as wedges.

Next, the case of assembling from the state of FIG. 2 to the state of FIG. 1 will be described with reference to FIGS.
As shown in FIG. 5, in the disassembled state, the diaphragm valve body 30 is fixed to the lower portion of the piston 23, and the piston 23 is urged downward by the compression spring 24, so the diaphragm valve body 30 Is at a position away from the cylinder body 21 by a predetermined distance.
Next, as shown in FIG. 6, the valve upper body 11 is pressed against the valve body 12 and inserted so that the annular convex portion 36 of the diaphragm valve body 30 is inserted into the insertion groove 33 of the valve body 12. The height of the outer annular seal portion 32 is about 1.5 times higher than the height of the inner annular seal portion 31. The inner diameter of the outer annular seal portion is the same as or smaller than the outer diameter of the diaphragm valve body. The annular convex portion 36 is guided by the inner surface of the outer annular seal portion 32 before being inserted into the insertion groove 33.

When the insertion of the annular convex portion 36 into the insertion groove 33 is started, as shown in FIG. 6, between the body inclined surface 21b of the annular body convex portion 21a and the main body inclined surface 32a of the outer annular seal portion 32, A predetermined gap is formed. Therefore, the annular convex portion 36 comes into contact with the press-fit portion 34 and elastically deforms outward, and is pushed by the annular convex portion 36, and the outer annular seal portion 32 is elastically deformed outward.
The width of the insertion groove 33 is formed slightly narrower than the width of the annular protrusion 36, but there is a gap between the upper body inclined surface 21b and the main body inclined surface 32a, so that it is not pressed inward. Can be inserted easily.

Next, when the annular convex portion 36 further enters the insertion groove 33, as shown in FIG. 7, the upper body inclined surface 21b of the annular upper body convex portion 21a and the main body inclined surface 32a of the outer annular seal portion 32 come into contact with each other. start.
As a result, the outer annular seal portion 32 that has been elastically deformed while the annular convex portion 36 is inserted into the insertion groove 33 is returned inward by the upper body inclined surface 21b via the main body inclined surface 32a. The convex portion 36 is strongly pressed against the inner annular seal portion 31. As shown in FIG. 4, in the fully inserted stage, the annular convex portion 36 is strongly pressed against the inner annular seal portion 31, so that a strong and stable sealing force can be obtained.

  As described in detail above, according to the chemical valve of the present embodiment, the resin valve body 12 with the valve seat 41 formed thereon, the diaphragm valve body 30, and the valve body 12 sandwich the diaphragm valve body 30 together. The liquid valve has a resin valve upper body 11 that is held by a ring-shaped convex portion 36 at a portion where the diaphragm valve body 30 is sandwiched, and the valve main body 12 is formed of the annular convex portion 36 of the diaphragm valve body 30. It has an inner annular seal portion 31 and an outer annular seal portion 32 that form an insertion groove 33 to be inserted. When this occurs, the annular convex portion 36 comes into contact with the press-fit portion 34 and elastically deforms outward, and the outer annular seal portion 32 is elastically deformed outward by being pushed by the annular convex portion 36. Since the body inclined surface 21 b and the main body inclined surface 32 a do not come into contact with each other at the initial stage of insertion, the annular convex portion 36 can be easily inserted into the insertion groove 33.

Further, a main body inclined surface that is pushed by the cylinder main body 21 of the valve upper body 11 and presses the annular convex portion 36 of the diaphragm valve body 30 against the press-fit portion 34 of the inner annular seal portion 31 outside the outer annular seal portion 32. Since 32a is formed, the annular convex portion 36 can be pressed more strongly and stably against the press-fit portion 34 by returning the elastic deformation of the outer annular seal portion 32, so that a strong and stable sealing force can be obtained. it can.
Further, when the annular convex portion 36 of the diaphragm valve body 30 starts to contact the inner annular seal portion 31, the main body inclined surface 32 a of the outer annular seal portion 32 does not contact the cylinder main body 21 of the valve upper body 11. Since the main body inclined surface 32a of the outer annular seal portion 32 comes into contact with the upper body inclined surface 21b after the annular convex portion 36 enters the insertion groove 33, the annular convex portion 36 becomes the inner annular seal portion. It is pressed by 31 and a strong sealing force can be obtained.

Next, a chemical valve according to a second embodiment of the present invention will be described. The chemical valve of the second embodiment is almost the same as that of the first embodiment, so only the different parts will be described and the description of the same parts will be omitted.
FIG. 10 shows a drawing corresponding to FIG. 4, and FIGS. 8 and 9 show drawings corresponding to FIG. 6 and FIG. In FIG. 10, a main body inner inclined surface 31 a is formed on the inner periphery of the inner annular seal portion 31 over the entire circumference. A diaphragm inclined surface 35 is formed on the lower surface of the diaphragm valve body 30.
As shown in FIGS. 8 and 9, the diaphragm inclined surface 35 does not contact the main body inner inclined surface 31 a until just before the annular convex portion 36 of the diaphragm valve body 30 enters the insertion groove 33. Then, as shown in FIG. 10, just before the diaphragm valve body 30 is completely held, the diaphragm inclined surface 35 comes into contact with the main body inner inclined surface 31 a, and the inner annular seal portion 31 that is slightly elastically deformed is provided. A force is applied in the direction of pressing against the annular protrusion 36. Thereby, a strong and stable sealing force can be obtained. In addition, when the high temperature fluid is allowed to flow through the chemical valve, the inner annular seal portion 31 can be prevented from being deformed due to creep or thermal deformation.

  As described above, according to the chemical valve of the second embodiment, the inner annular seal portion 31 and the annular convex portion 36 of the diaphragm valve body 30 are provided on the inner periphery of the annular convex portion 36 of the diaphragm valve body 30. Since the diaphragm inclined surface 35 that is pressed to the side is formed, the inner annular seal portion can be prevented from elastically deforming inward, so that a strong sealing force can be obtained more stably.

The valve body 12 and the diaphragm valve body 30 are made of a fluororesin having excellent corrosion resistance, and are sandwiched between the cylinder body 21 and the substrate 44 and fastened by screws 13. When the temperature rises, the compressive stress of the valve body 12 and the diaphragm valve body 30 sandwiched between the cylinder body 21 and the substrate 44 increases due to expansion. Due to the creep phenomenon that is a characteristic of the resin, deformation occurs to relieve the compressive stress, and when the temperature returns to room temperature, a gap is formed.
Due to this gap, the fastening force of the screw is weakened, and the sealing force at the peripheral edge of the diaphragm is reduced. Among the resins, the fluororesin tends to cause a creep phenomenon, and the fastening force is remarkably reduced.
As a preventive measure, it is advisable to use a disc spring washer 51 for the fastening screw 13 as shown in FIG. This is because the disc spring washer 51 absorbs the difference in elongation accompanying the temperature change generated between the fastening screw 13 and the valve body 12 / valve upper body 11.
The disc spring washer 51 may be attached to an upper fastening screw 52 that fastens the lid member 22 and the cylinder body 21.

In addition, as shown in FIG. 12, a wave washer may be attached between the valve body 12 and the substrate 44 and fastened with the fastening screw 13.
Further, as shown in FIG. 13, only the upper fastening screw 52 may be configured to be fastened to a nut insert-molded on the substrate 44, and a compression spring may be mounted between the valve body 12 and the substrate 44.

Although the embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various applications are possible.
For example, in the present embodiment, the fluororesin has been described as the material of the valve body 12 and the like, but the same applies to other resins.

It is sectional drawing which shows the structure of the chemical | medical solution valve of 1st Embodiment of this invention. It is an exploded view of the chemical | medical solution valve of FIG. It is a top view of the chemical | medical solution valve of FIG. It is the A section enlarged view of FIG. It is a 1st process drawing which shows a chemical | medical solution valve assembly process. It is a 2nd process figure which shows a chemical | medical solution valve assembly process. It is a 3rd process figure which shows a chemical | medical solution valve assembly process. It is a 1st process drawing which shows the chemical | medical solution valve assembly process of 2nd Embodiment. It is a 2nd process figure which shows the chemical | medical solution valve assembly process of 2nd Embodiment. It is a 3rd process figure which shows the chemical | medical solution valve assembly process of 2nd Embodiment. It is a fragmentary sectional view of the 1st example which shows a countermeasure against creep. It is a fragmentary sectional view of 2nd Example which shows a countermeasure against creep. It is a fragmentary sectional view of 3rd Example which shows a countermeasure against creep.

Explanation of symbols

11 Valve upper body 12 Valve main body 21 Cylinder main body 21a Annular upper body convex part 21b Upper body inclined surface 30 Diaphragm valve body 31 Inner annular seal part 32 Outer annular seal part 32a Main body inclined surface 33 Insertion groove 35 Diaphragm inclined surface 36 Annular convex part 41 Valve seat

Claims (5)

In a chemical valve having a resin valve body formed with a valve seat, a diaphragm valve body, and a resin upper body holding the diaphragm valve body together with the resin valve body,
An annular convex portion is formed in a portion where the diaphragm valve body is sandwiched,
The resin valve body has an inner annular seal portion and an outer annular seal portion that form an insertion groove into which the annular convex portion of the diaphragm valve body is inserted;
A press-fit portion is formed on the inner surface of the inner annular seal portion,
When the annular convex portion is inserted into the insertion groove, the annular convex portion comes into contact with the press-fit portion and elastically deforms outward, and is pushed by the annular convex portion, so that the outer annular seal portion faces outward. A chemical valve characterized by elastic deformation. In the chemical valve according to claim 1,
Formed on the outside of the outer annular seal portion is a resin valve body inclined portion that is pushed by the resin upper body and presses the annular convex portion of the diaphragm valve body against the press-fit portion of the inner annular seal portion. The liquid valve characterized by being made. In the chemical valve according to claim 2,
When the annular convex portion of the diaphragm valve body begins to contact the inner annular seal portion, the inclined portion of the outer annular seal portion does not contact the resin upper body. . In any one of the chemical | medical solution valves of Claims 1 thru | or 3,
A medicinal solution valve characterized in that a diaphragm inclined portion is formed on an inner periphery of the annular convex portion of the diaphragm valve body to press the inner annular seal portion toward the annular convex portion side of the diaphragm valve body. In any one of the chemical | medical solution valves of Claim 2 thru | or 4,
Mount an elastic member on the seating surface of the fastening screw that fastens the diaphragm valve body and the resin valve body, or mount an elastic member between the resin valve body and the substrate on which the liquid valve is mounted. A liquid valve characterized by

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