JP7178109B2 - Valve device and manufacturing method thereof - Google Patents

Description

The present invention relates to a valve device and a manufacturing method thereof.

A diaphragm valve is known as one of fluid control devices for controlling the flow of various processing gases in various manufacturing processes such as semiconductor manufacturing processes. In the diaphragm valve, a valve seat is mounted in a seat mounting groove of a valve body, and the diaphragm is provided in the valve body so as to contact and separate from the valve seat, thereby opening and closing the flow path (see, for example, Patent Document 1). -3, etc.).

JP-A-06-265035 JP-A-07-004542 Japanese Utility Model Laid-Open No. 61-206171

In Patent Documents 1 and 2, the valve seat is fixed to the valve body by plastically deforming a crimped portion that is a part of the valve body provided on one of the two opposing side walls of the seat mounting groove.
However, such an assembly method requires a large number of man-hours because it is necessary to deform a part of the valve body, and it is difficult to automate the assembly.
In Patent Document 3 described above, a notch recess 4 formed in the inner peripheral wall of a valve seat mounting plate has a protrusion 9 protruding from the inner wall 6 thereof, and a groove fitted with the protrusion 9 is formed on the outer periphery of a valve seat 12. 14 is formed, and a structure is disclosed in which the valve seat 12 is fitted into the notch recess 4 . However, although this structure facilitates the mounting process of the valve seat, it is difficult to obtain reliable and stable sealing performance between the valve seat 12 and the valve seat mounting plate.

An object of the present invention is to provide a valve device having a resin valve seat that can reduce manufacturing man-hours and has excellent sealing performance, and a manufacturing method thereof.

The valve device according to the present invention defines a flow path, and is made of metal and has an annular support surface formed around an opening of the flow path and an annular locking protrusion formed projecting from the support surface. a valve body;
an annular seat surface on which the valve body supported by the valve body abuts and separates; an annular supported surface supported by the support surface of the valve body arranged opposite to the seat surface; a ring-shaped resin valve seat having an inner circumferential surface defining a flow path communicating with the flow path and an annular engaging recess formed in the supported surface;
The valve seat is fixed to the support surface of the valve body with the locking concave portion engaging with the locking convex portion of the valve body. It is in close contact with the supported surface of the valve seat.

Preferably, the locking projection has an annular facing surface facing the supporting surface,
A part of the valve seat may be interposed between the support surface and the opposing surface, and may be brought into close contact with the support surface and the opposing surface by elastic restoring force.
It is also possible to adopt a configuration in which the valve seat has a flat surface for press-fitting the valve seat. Further, the end portion of the inner peripheral surface of the valve seat on the side of the supported surface faces the outer peripheral side with respect to the inner peripheral surface so that the inner peripheral edge portion of the supported surface is positioned within the support surface. It is also possible to employ a configuration in which the surface is an inclined surface that is inclined at all directions.
Preferably, the valve seat is made of PFA or PTFE.

A method of manufacturing a valve device according to the present invention defines a flow path, and includes an annular support surface formed around an opening of the flow path, and an annular locking projection formed projecting from the support surface. A metal valve body with
An annular seat surface with which the valve body supported by the valve body abuts and separates, an annular supported surface supported by the support surface of the valve body, and an annular engaging recess formed in the supported surface. Prepare a resin valve seat formed in an annular shape,
The valve seat is fixed to the supporting surface by engaging the locking convex portion with the locking concave portion, and the elastic restoring force of the valve seat brings the supporting surface and the supported surface into close contact with each other.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing man-hour of a valve apparatus provided with resin-made valve seats can be reduced, and a manufacturing cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The front view containing the cross section of the valve apparatus which concerns on one Embodiment of this invention. FIG. 2 is an enlarged cross-sectional view of a main part showing a closed state of the valve device of FIG. 1; FIG. 2 is an enlarged cross-sectional view of a main part showing an open state of the valve device of FIG. 1; FIG. 4 is an enlarged cross-sectional view of the periphery of the locking projection of the valve body according to the embodiment of the present invention; 1 is a cross-sectional view of a valve seat according to one embodiment of the present invention; FIG. Explanatory drawing for demonstrating a press-fitting process. FIG. 4 is a diagram for explaining an elastic restoring force acting between the valve body and the valve seat after press-fitting; Sectional drawing which shows the modification of a valve seat.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, components having substantially the same functions are denoted by the same reference numerals, and redundant explanations are omitted.
FIG. 1 is a diagram showing the configuration of a valve device 1 according to one embodiment of the present invention. In the drawing, arrows A1 and A2 indicate the vertical direction, with A1 indicating the upward direction and A2 indicating the downward direction.
The valve device 1 has an actuator 10 , a diaphragm 35 as a valve body, a valve body 40 and a valve seat 70 fixed to the valve body 40 .

Actuator 10 has an actuator rod 11 projecting from its lower end. The actuator rod 11 is supported by the actuator 10 so as to be movable in the vertical directions A1 and A2. Actuator 10 is connected to bonnet nut 15 . A threaded portion formed on the outer peripheral side of the cylindrical portion 15 a of the bonnet nut 15 is screwed into a threaded portion formed on the inner peripheral side of the cylindrical portion 47 of the valve body 40 , so that the actuator 10 is attached to the valve body 40 . It is connected.

The bonnet 16 is formed in a cylindrical shape, accommodates the coil spring 20 and the presser holder 31 on the inner peripheral side, and is pressed downward A2 by the lower end of the cylindrical portion 15a of the bonnet nut 15 . The pressing adapter 32 is formed in an annular shape, is arranged on the outer peripheral portion of the diaphragm 35 , and is pressed toward the valve body 40 by the lower end portion of the bonnet 16 . Thereby, the diaphragm 35 is fixed to the valve body 40 . The diaphragm 35 functions as a valve body, has a diameter larger than that of the valve seat 70, and is made of a metal such as stainless steel, a NiCo-based alloy, or a fluorine-based resin so as to be elastically deformable into a spherical shell. The diaphragm 35 is supported by the valve body 40 so as to be able to contact and separate from the valve seat 70 .
The coil spring 20 constantly urges the diaphragm presser 30 downward A<b>2 via the presser holder 31 .
The actuator rod 11 is connected to the presser holder 31 by screwing a threaded portion formed at the tip thereof into a threaded portion on the inner periphery of the cylindrical portion 31 a of the presser holder 31 .
The actuator 10 incorporates a drive source such as a pneumatic drive source and a motor drive source. It is possible to move to A1. As a result, the diaphragm 35 is released from the pressure exerted by the diaphragm retainer 30 and restores its spherical shell shape.

The valve body 40 is made of metal and formed in a block shape, defines flow paths 41 and 42 through which fluid flows, and has openings 41a and 42a on its bottom surface. The channels 41 and 42 are connected to other channel members via seal members (not shown).
The valve seat 70 is fixed to the valve body 40, and the detailed structure of the valve seat 70 and the detailed structure of the area of the valve body 40 where the valve seat 70 is fixed will be described later.

2A and 2B show enlarged sectional views around the valve seat 70 of the valve device 1. FIG.
2A shows the valve closed state in which the diaphragm 35 is pressed against the valve seat 70, and FIG. 2B shows the valve open state in which the diaphragm 35 is separated from the valve seat 70. FIG.
When the diaphragm retainer 30 is pressed downward A<b>2 by the restoring force of the coil spring 20 , the diaphragm 35 is elastically deformed and comes into contact with the seat surface 71 of the valve seat 70 to close the flow path 41 .
When the actuator 10 is driven to move the diaphragm retainer 30 in the upward direction A1 against the restoring force of the coil spring 20, the diaphragm 35 is separated from the valve seat 70, and the flow paths 41 and 42 are separated from each other. It communicates through the gap between 35 and the seat surface 71 to open the valve.

FIG. 3 is an enlarged cross-sectional view of a region of the valve body 40 to which the valve seat 70 is fixed.
The valve body 40 is made of a metal such as a stainless alloy, and has an annular support surface 43 around the opening 41 b of the flow path 41 . An annular locking projection 45 is formed so as to protrude from the support surface 43 .
As can be seen from FIG. 3, the engaging projection 45 has a tip end surface 45t formed of a flat surface parallel to the support surface 43 at the tip end, and an inclined surface 45a1 inclined inwardly from the tip end surface 45t and an outer circumference. It has an inclined surface 45a2 that inclines toward the side. Further, the engaging projection 45 has a facing surface 45f1 facing the support surface 43 at the lower end of the inclined surface 45a1, and similarly has a facing surface 45f2 facing the supporting surface 43 at the lower end of the inclined surface 45a2. The support surface 43 and the facing surfaces 45f1 and 45f2 are arranged substantially parallel to each other, but this is not the only option.

4 shows the structure of the valve seat 70. As shown in FIG.
The valve seat 70 is annularly formed of resin such as PFA, PTFE, or the like.
The valve seat 70 has an annular seat surface 71 on the upper end surface side with which the diaphragm 35 supported by the valve body 40 abuts and separates, and the valve body 40 arranged on the lower end surface side opposite to the seat surface 71 . an annular supported surface 72 supported by the supporting surface 43 of the valve body 40; an inner peripheral surface 73 defining a flow path communicating with the flow path 41 of the valve body 40; 74. Further, the valve seat 70 has an annular flat surface 75 for press fitting, which will be described later, on the outer peripheral side of the seat surface 71 . In the case where the flat surface 75 is located on the outer peripheral side of the seat surface 71, the primary side liquid pooling points are reduced when the valve is closed, thereby particularly improving the replacement characteristics on the primary side.
The flat surface 75 may be located on the inner peripheral side of the seat surface 71 . When the flat surface 75 is located on the inner peripheral side of the seat surface 71, the secondary side liquid pooling points are reduced when the valve is closed, thereby particularly improving the replacement characteristics of the secondary side.
The flat surface 75 may be provided on each of the inner peripheral side and the outer peripheral side of the seat surface 71 . Since the flat surfaces 75 are present on the inner peripheral side and the outer peripheral side of the seat surface 71, the valve seat 70 can be press-fitted into the valve body 40 more parallel. As a result, the seat surface 71 after press fitting becomes parallel to the outer peripheral edge of the diaphragm 35, and when the diaphragm 35 abuts against the seat surface 71, a uniform load is applied, thereby improving sealing performance.

The cross-sectional shape of the locking recess 74 is formed so as to substantially match the cross-sectional shape of the locking projection 45 of the valve body 40, but the dimensions may be appropriately set to dimensions suitable for press-fitting, which will be described later. can.
The flat surface 75 is formed substantially parallel to the supported surface 72 .
The inner peripheral surface 73 has an inner diameter such that when the valve seat 70 is attached to the valve body 40, it is substantially flush with the inner wall surface of the flow path 41 on the opening 41b side.

Next, referring to FIG. 5 , a step of attaching the valve seat 70 by engaging the locking recess 74 of the valve seat 70 with the locking projection 45 of the valve body 40 , more specifically, attaching the valve seat 70 to the valve body 40 . A description will be given of the process of press-fitting into.
As shown in FIG. 5 , a holding mechanism (not shown) is used to align the tip surface 45 t of the engaging projection 45 of the valve body 40 with the opening of the engaging recess 74 of the valve seat 70 .
Then, the flat surface 75 of the valve seat 70 is pressed toward the valve body 40 with a uniform force F using a pressing jig (not shown). A pressing jig (not shown) may have an annular pressing surface that contacts the flat surface 75 entirely.

When the valve seat 70 is pressed toward the valve body 40 , the two inclined surfaces 45 a 1 and 45 a 2 prompt the locking projection 45 to press fit into the locking recess 74 .
When the locking protrusion 45 is press-fitted into the locking recess 74 in this manner, the locking protrusion 45 and the locking recess 74 are brought into the state shown in FIG.
As shown in FIG. 6, a portion 70p1 of the valve seat 70 is press-fitted between the opposing surface 45f1 of the locking projection 45 and the supporting surface 43, and a valve seat 70p1 is press-fitted between the opposing surface 45f2 and the supporting surface 43. A portion 70p2 of 70 is press-fitted. If the press-fitting of the portions 70p1 and 70p2 of the valve seat 70 is not sufficient, each of the portions 70p1 and 70p2 may be additionally pressed from the radial direction. Can be added as standard.
In the above-described press-fitting step, the valve seat 70 is press-fitted into the valve body 40 using a holding mechanism and a pressing jig (not shown). automation can be achieved. In this case, the outer peripheral surface of the valve seat 70 and the flat surface 75 are held by a jig, and after alignment, the pressing surface formed in the portion that contacts the flat surface 75 presses and press-fits.

As can be seen from FIG. 6, the portions 70p1 and 70p2 of the valve seat 70, which are press-fitted between the opposing surfaces 45f1 and 45f2 and the support surface 43, are subjected to elastic deformation, so that the elastic restoring force FR1 is maintained at all times. , FR2 on the opposing surfaces 45f1 and 45f2 and the supporting surface 43. As shown in FIG. This force keeps the supported surface 72 of the valve seat 70 in constant contact with the supporting surface 43 , thereby reliably sealing the space between the supported surface 72 and the supporting surface 43 .

According to this embodiment, the valve seat 70 can be fixed onto the support surface 43 of the valve body 40 without plastically deforming a part of the valve body 40 . Moreover, since an elastic restoring force that restores the elastic deformation caused by the press-fitting of the valve seat 70 always acts between the supported surface 72 and the supporting surface 43, the supported surface 72 and the supporting surface 43 are in contact with each other. A reliable seal is achieved by close contact over the entire surface. Since the valve body 40 does not have a plastically deformed portion, the gas-contacting surface of the valve device 1, which is in contact with the gas or the like, is kept smooth. As a result, the replacement characteristics and cleanliness are improved. That is, when the valve body 40 is plastically deformed, unevenness is generated on the gas-contacting surface around the plastically deformed area, and contaminants such as dust tend to remain on this uneven surface, and part of the unevenness is caused by contaminants. It could be part of it.

FIG. 7 shows a modification of the valve seat.
In the valve seat 70B shown in FIG. 7, the end portion of the inner peripheral surface 73 on the side of the supported surface 72 forms an inclined surface 73t inclined toward the outer peripheral side with respect to the inner peripheral surface 73. As shown in FIG.
As a result, the inner peripheral edge portion 72 e of the supported surface 72 is reliably accommodated within the support surface 43 of the valve body 40 . When the inner peripheral edge portion 72e is securely accommodated within the support surface 43, the inner peripheral edge portion 72e is reliably pressed against the support surface 43 by the elastic restoring force described above. As a result, it is possible to reliably prevent the intrusion of fluid from between the inner peripheral edge portion 72e and the support surface 43, thereby enhancing the sealing performance.

In the above embodiment, a so-called normally closed type valve device was exemplified, but the invention is not limited to this, and the present invention is applicable even to a normally open type valve device.
In the above embodiment, the cross-sectional shapes of the engaging projections and the engaging recesses are substantially compatible with each other, but the present invention is not limited to this, and different shapes are also possible.
In the above embodiment, the seat surface 71 is formed by a flat surface, but may be formed by an R surface.

1 valve device 10 actuator 11 actuator rod 15 bonnet nut 15a cylindrical portion 16 bonnet 20 coil spring 30 diaphragm presser 31 presser holder 31a cylindrical portion 32 presser adapter 35 diaphragm (valve element)
40 Valve bodies 41, 42 Flow paths 41a, 42a Opening 41b Opening 43 Supporting surface 45 Locking projections 45f1, 45f2 Opposing surfaces 70, 70B Valve seats 70p1, 70p2 Part 71 Seat surface 72 Supported surface 72e Inner peripheral edge 73 Inner peripheral surface 73t Inclined surface 74 Lock recess 75 Flat surface

Claims (6)

a metal valve body defining a flow path and comprising an annular support surface formed around an opening of the flow path and an annular locking projection protruding from the support surface;
an annular seat surface on which the valve body supported by the valve body abuts and separates; an annular supported surface supported by the support surface of the valve body arranged opposite to the seat surface; a ring-shaped resin valve seat having an inner circumferential surface defining a flow path communicating with the flow path and an annular engaging recess formed in the supported surface;
the inner peripheral surface of the valve seat and the inner peripheral surface of the flow path of the valve body are flush with each other;
The valve seat is fixed to the support surface of the valve body with the locking concave portion engaging with the locking convex portion of the valve body. The supported surface of the valve seat is in close contact ,
The locking projection has an annular facing surface facing the supporting surface,
A valve device , wherein a portion of the valve seat is interposed between the supporting surface and the opposing surface and adheres to the supporting surface and the opposing surface by elastic restoring force . 2. The valve device according to claim 1 , wherein said facing surface partially overlaps said support surface when viewed in a direction perpendicular to said seat surface . 3. The valve device according to claim 1, wherein the valve seat has a flat surface for press-fitting the valve seat. An end portion of the inner peripheral surface of the valve seat on the supported surface side is inclined toward the outer peripheral side with respect to the inner peripheral surface so that the inner peripheral edge portion of the supported surface is positioned within the supporting surface. 4. The valve device according to any one of claims 1 to 3, which has an inclined surface that The valve device according to any one of claims 1 to 4, wherein the valve seat is made of fluororesin. a metal valve body defining a flow path and including an annular support surface formed around an opening of the flow path and an annular locking projection protruding from the support surface;
An annular seat surface with which the valve body supported by the valve body abuts and separates, an annular supported surface supported by the support surface of the valve body, and an annular engaging recess formed in the supported surface. Prepare a resin valve seat formed in an annular shape,
the inner peripheral surface of the valve seat and the inner peripheral surface of the flow path of the valve body are flush with each other;
The locking projection has an annular facing surface facing the supporting surface,
The valve seat is fixed to the supporting surface by engaging the locking convex portion with the locking concave portion, and the supporting surface and the supported surface are brought into close contact with each other by the elastic restoring force of the valve seat . is interposed between the supporting surface and the opposing surface and brought into close contact with the supporting surface and the opposing surface by elastic restoring force .

Images