WO2024057597A1

WO2024057597A1 - Diaphragm valve

Info

Publication number: WO2024057597A1
Application number: PCT/JP2023/014673
Authority: WO
Inventors: 直也金井
Original assignee: イハラサイエンス株式会社
Priority date: 2022-09-12
Filing date: 2023-04-11
Publication date: 2024-03-21
Also published as: JP7220830B1; JP2024039790A

Abstract

A diaphragm valve (1) comprises: a valve box (10) which has a first flow path (11), a second flow path (12), and a valve seat (15); a lid body (20) which is attached by screwing to the valve box (10); a valve rod (30) which is screwed to the lid body (20) so as to be movable up and down, and which can be rotatably operated; a stem (40) which is connected to the valve rod (30) and has a screw shaft (42) aligned with the valve rod (30); a holder (50) which is screwed to the screw shaft (42), and which comes into contact with and separates from the valve seat (15) to open and close the connection between the first flow path (11) and the second flow path (12); and an annular diaphragm (60) through which the screw shaft (42) is inserted. The outer circumferential portion (61) of the diaphragm (60) is mechanically fastened and fixed between the valve box (10) and the lid body (20), and the inner circumferential portion (62) of the diaphragm (60) is mechanically fastened and fixed between the stem (40) and the holder (50).

Description

diaphragm valve

The present invention relates to a diaphragm valve that adjusts the flow rate of fluid flowing through a flow path and opens and closes the valve.

Conventionally, metal diaphragm valves are known as diaphragm valves in which a metal diaphragm is disposed between a thrust button that moves up and down via a valve stem when a handle is rotated, and a valve seat provided in a valve box. (See Patent Document 1). The periphery of the diaphragm is tightly held by the valve box, and the center portion of the diaphragm is shaped to bulge upward (towards the thrust button).

This metal diaphragm valve is used in semiconductor manufacturing equipment, etc. A thrust button that descends when the handle is operated presses the diaphragm into contact with the valve seat, while the thrust button moves upward when the handle is operated. By releasing the pressure on the diaphragm by the button and allowing the diaphragm to self-return to its original shape, the diaphragm is separated from the valve seat, and by operating the diaphragm in this way, the flow rate is adjusted. has been done.

Japanese Patent Application Publication No. 8-105554

By the way, in the metal diaphragm valve described in Patent Document 1, since the diaphragm is configured to separate from the valve seat by self-return, the diaphragm is forcibly separated from the valve seat beyond self-return to increase the flow rate. It is difficult to achieve this goal.
For example, it would be possible to weld the diaphragm to a thrust button, etc., and forcibly move the diaphragm away from the valve seat by raising the thrust button, but this would require welding work to manufacture the metal diaphragm valve, making it difficult to manufacture. It is difficult to keep costs down.

An object of the present invention is to provide a diaphragm valve that can achieve a large flow rate by forcibly operating a diaphragm, and can reduce manufacturing costs.

The diaphragm valve of the present invention includes a main body having a first flow path, a second flow path, and a valve seat, a lid body that is screwed onto the main body, and a rotation operation that is screwed into the lid body so that it can be raised and lowered. a stem connected to the valve stem and having a threaded shaft along the valve stem; a stem threadedly coupled to the threaded shaft and moving toward and away from the valve seat; and a holder that opens and closes between the second flow path and an annular diaphragm into which the screw shaft is inserted, and an outer peripheral edge of the diaphragm is mechanically tightened between the main body and the lid. The inner peripheral edge of the diaphragm is mechanically tightened and fixed between the stem and the holder.
According to the diaphragm valve of the present invention, since the inner peripheral edge of the diaphragm is tightened and fixed between the stem and the holder, the diaphragm can be forcibly raised and lowered in accordance with the raising and lowering of the valve stem. Compared to a case where a diaphragm valve is provided that adjusts the flow rate by the self-return of the diaphragm, the flow path can be opened beyond the self-return of the diaphragm, so a large flow rate can be achieved. Further, since both the outer circumferential edge and the inner circumferential edge of the diaphragm are mechanically tightened and fixed, there is no need to weld the diaphragm to the stem, etc., and the manufacturing cost of the diaphragm valve can be reduced.

In the diaphragm valve of the present invention, the stem includes a stem body having the threaded shaft, and a contact body through which the threaded shaft is rotatably inserted into the stem body and abuts against the diaphragm. However, the outer diameter of the abutting body may be the same as the outer diameter of the stem body.
According to such a configuration, when the holder is screwed onto the screwing shaft of the stem body, the holder and the contact body rotate together with the diaphragm, thereby preventing friction between the diaphragm, the stem, and the holder. Can be reduced. In addition, since the outer diameter of the abutting body is the same as the outer diameter of the stem body, the diaphragm of the abutting body can be adjusted to the extent that the abutting body does not interfere with the lid when the stem moves up and down with the valve stem. It is possible to enlarge the area of contact with the object. Therefore, the diaphragm, which receives the pressure of the fluid flowing inside the main body, can be received by the aforementioned large contact area of the contact body.

In the diaphragm valve of the present invention, the stem includes a stem body having the threaded shaft, and a contact body through which the threaded shaft is rotatably inserted into the stem body and abuts against the diaphragm. The main body and the lid are fixed by tightening the outer peripheral edge of the diaphragm so that the diaphragm faces diagonally upward toward the stem, and the abutment body is a flat receiver that receives the diaphragm. The receiving surface may have a convex curved surface continuous to the outer periphery of the receiving surface.
According to such a configuration, when the receiving surface of the abutting body is disposed below the tightening and fixing position of the outer peripheral edge of the diaphragm due to the stem descending, it becomes diagonally upward toward the stem side. As shown, the part of the diaphragm whose outer peripheral edge is tightened and fixed is curved diagonally downward toward the stem side than the part closer to the outer peripheral side of the diaphragm, but the above-mentioned convex curved surface is formed on the contact body. Therefore, stress concentration on the diaphragm can be suppressed.

In the diaphragm valve of the present invention, the stem includes a stem body having the threaded shaft, and a contact body through which the threaded shaft is rotatably inserted into the stem body and abuts against the diaphragm. The holder has a screw hole that is open on its upper surface and into which the screw shaft is screwed, and the contact body has a tapered surface that is inclined diagonally upward toward the screw shaft. A corner portion where the upper surface of the holder and the screwing hole are continuous may be formed at an acute angle and may be arranged to overlap in the vertical direction with respect to the tapered surface.
According to such a configuration, the inner peripheral edge of the diaphragm can be firmly tightened and fixed so that the corner of the holder is wedged between the tapered surface of the abutting body and the screw shaft, and the inner peripheral edge of the diaphragm can be firmly fixed by welding as described above. Even without it, the risk of fluid leakage can be further reduced.
Further, since the inner circumferential edge of the diaphragm is tightened and fixed in this manner, the tightened and fixed portion has a shape that is inclined obliquely downward toward the outer circumferential side. Therefore, when the inner circumferential edge of the diaphragm is lowered, it is possible to suppress the occurrence of abnormal noise due to vertical inversion of the shape of the diaphragm, and it is also possible to improve the durability of the diaphragm.

In the diaphragm valve of the present invention, the diaphragm has an annular flat plate shape in its original shape, and the inner peripheral edge of the diaphragm is positioned above or below the outer peripheral edge of the diaphragm depending on the elevation of the stem and the holder. It may be placed at a location.
According to such a configuration, the inner circumferential edge of the diaphragm, which has an annular flat plate shape, is forcibly disposed above or below the outer circumferential edge of the diaphragm. Compared to the case of using a dome-shaped diaphragm in which the diaphragm bulges upward, the generation of abnormal noise can be further suppressed.

According to the present invention, it is possible to provide a diaphragm valve that can achieve a large flow rate by forcibly operating a diaphragm, and can also reduce manufacturing costs.

FIG. 1 is a perspective view showing a diaphragm valve according to an embodiment of the present invention. FIG. 4 is a vertical cross-sectional view showing an open state of the diaphragm valve according to the embodiment. It is a longitudinal cross-sectional view showing an intermediate state of the diaphragm valve according to the embodiment. It is a longitudinal cross-sectional view showing a closed state of the diaphragm valve according to the embodiment. FIG. 2 is an enlarged schematic diagram showing the main parts of the diaphragm valve according to the embodiment in an open state. FIG. 2 is an enlarged schematic diagram showing the main parts of the diaphragm valve according to the embodiment in an intermediate state. FIG. 2 is an enlarged schematic diagram showing the main parts of the diaphragm valve according to the embodiment in a closed state.

[Configuration of this embodiment]
Embodiments of the present invention will be described below based on the drawings.
In FIGS. 1 to 4, a diaphragm valve 1 according to the present embodiment is a metal diaphragm valve that controls the flow rate of various fluids in semiconductor manufacturing equipment and the like, and is a large-flow type valve that requires a high Cv value. This diaphragm valve 1 is made of metal, and includes a valve box 10 as a main body, a lid body 20 screwed onto the valve housing 10, and a valve stem 30 screwed onto the lid body 20 so as to be movable up and down. , a stem 40 connected to the valve stem 30 and having a threaded shaft 42 along the valve stem 30, a holder 50 threaded onto the threaded shaft 42, and an annular diaphragm 60 into which the threaded shaft 42 is inserted. It is equipped with A handle 70 for rotating the valve stem 30 is attached to the valve stem 30.
In the following description, the left-right direction of the diaphragm valve 1 is referred to as the X-axis direction, the front-rear direction of the diaphragm valve 1 is referred to as the Y-axis direction, and the up-down direction of the diaphragm valve 1 is referred to as the Z-axis direction. The X, Y, and Z axis directions are orthogonal to each other. In this embodiment, for convenience of explanation, the vertical and horizontal directions of the diaphragm valve 1 are specified, but the vertical and horizontal directions may vary depending on the actual installation direction.

The valve box 10 includes a first flow path 11 on the inlet side into which fluid flows, a second flow path 12 on the outlet side from which the fluid flows out, and a cavity 131 that communicates with the first flow path 11 and the second flow path 12. 13.

In this embodiment, the first flow path 11 is formed to have an L-shaped cross section, and the end located on one side in the X-axis direction is open at a position protruding from the outer peripheral surface 14 of the valve box 10. The end located on the other side in the X-axis direction is open at approximately the center of the bottom surface 132 forming the cavity 131, and a valve seat 15 that projects slightly upward from the bottom surface 132 is formed around the opening periphery. ing.

In this embodiment, the second flow path 12 is formed to have a substantially doglegged cross section, and the end located on one side in the X-axis direction is connected to a bottom surface 132 forming a cavity 131 and an inner peripheral surface It is open throughout and is located on the other side of the other end of the first flow path 11 in the X-axis direction. The end of the second flow path 12 located on the other side in the X-axis direction is open at a position protruding from the outer circumferential surface 14 of the valve box 10 .

The rising portion 13 is composed of a cylindrical portion raised from the periphery of the cavity 131 in the Z-axis direction, and an upper portion 134 of the rising portion 13 is formed with a female screw portion 135 into which the lid 20 is screwed. The lower portion 136 of the raised portion 13 is thicker toward the inner circumference than the upper portion 134. An annular stepped portion 137 is formed between the upper portion 134 and the lower portion 136 of the upright portion 13 . This annular step portion 137 is formed with an annular groove portion over which an annular protrusion 239 of a diaphragm suppressor 235 (described later) overlaps in the Z-axis direction.

The lid body 20 is formed into a cylindrical shape, and in this embodiment, integrally includes an upper annular lid portion 21, an intermediate annular lid portion 22, and a lower annular lid portion 23. A diaphragm restraint 235 is provided. In this lid body 20, the outer diameter of the intermediate annular lid 22 is larger than the outer diameter of the upper annular lid 21, and the lower annular lid 23 is larger than the outer diameter of the intermediate annular lid 22. The outer diameter of the lower annular lid 23 is larger than the inner diameter of the upper annular lid 21 and the intermediate annular lid 22.

An indicator 71 is fitted onto the outer peripheral portion 211 of the upper annular lid portion 21 so as to be rotatably guided around an axis along the Z-axis direction. The inner peripheral portion of the upper annular lid portion 21 is formed as a female thread portion 212 into which the valve rod 30 is screwed. The indicator 71 has OPEN and CLOSE displayed on its upper surface, and is configured to be visible through a hole 72 formed in the handle 70. The indicator 71 is fitted with the handle 70 at a predetermined position in the rotational direction, and rotates together with the handle 70 in the fitted state.

The inner peripheral portion 222 of the intermediate annular lid portion 22 is in sliding contact with the valve stem 30 so that the valve stem 30 can move up and down in the Z-axis direction.

The outer circumferential portion of the lower annular lid portion 23 is formed as a male screw portion 231 that is screwed into the upper portion 134 of the upright portion 13 . The inner diameter of the inner peripheral portion 232 of the lower annular lid portion 23 is larger than the outer diameter of the stem 40. The lower annular lid portion 23 is provided with the aforementioned diaphragm restraint 235.
The diaphragm restrainer 235 includes a cylindrical part 236 disposed between the inner peripheral part 232 and the stem 40, and a hollow disc-shaped restraint part 237 extending from the lower end of the cylindrical part 236 to the outer peripheral side. There is. A lower surface 238 (see FIG. 5) of the holding portion 237 is inclined diagonally upward from the outer circumferential side toward the inner circumferential side (the stem 40 side). A downwardly protruding annular protrusion 239 is formed at the lower part of the outer peripheral edge of the diaphragm retainer 235 . The outer peripheral edge 61 of the diaphragm 60 is mechanically fastened and fixed (screwed in this embodiment) between the annular protrusion 239 and the annular step 137 of the upright portion 13 . Here, the annular protrusion 239 of the diaphragm suppressor 235 provided on the lid body 20 overlaps the aforementioned groove in the annular step 137 of the valve box 10 in the Z-axis direction, and the diaphragm 60 is placed between the annular step 137 and The outer peripheral edge 61 of the Therefore, the outer peripheral edge 61 of the diaphragm 60 is fastened and fixed by the valve box 10 and the lid body 20 so that the diaphragm 60 faces diagonally upward toward the stem 40 side. Note that the outer peripheral edge 61 of the diaphragm 60 is not welded to the annular protrusion 239 and the annular step 137.

The valve stem 30 extends along the Z-axis direction, and includes an upper valve stem 31 having a male threaded portion 311 formed on its outer circumference to be screwed into the female threaded portion 212 of the upper annular lid 21 , and an intermediate annular lid 22 . It has a lower valve stem 32 whose outer circumferential part slides into sliding contact with the inner circumferential part 222 so that it can move up and down, and in this embodiment, one O-ring is fitted to the outer circumference of the lower valve stem 32. . A handle 70 is attached to the upper end 33 of the valve rod 30, and a stem 40 is attached to the lower end 34.

The stem 40 includes a stem body 41 having a threaded shaft 42 and a recess 43, and a contact body 45 (piece) through which the threaded shaft 42 is rotatably inserted into the stem body 41 and abuts against the diaphragm 60. have.

The stem body 41 is formed of a short cylindrical body except for the screw shaft 42 and the recess 43. The screw shaft 42 extends downward from the lower surface of the aforementioned short cylindrical body, and has a male thread formed on its outer peripheral surface. This screwing shaft 42 is arranged on the rotation axis center line along the Z-axis direction of the valve rod 30. The recess 43 is open at the upper surface of the aforementioned short cylindrical body, and the lower end 34 of the valve stem 30 is rotatably fitted therein. The stem body 41 has an outer diameter larger than the outer diameter of the valve stem 30.

The contact body 45 is formed of a metal annular plate. As shown in FIG. 5, the contact body 45 has an upper surface 451, a lower surface 452, an inner peripheral surface 453, and an outer peripheral surface 454, and the lower surface 452 is configured as a planar receiving surface for receiving the diaphragm 60. There is. As shown in FIGS. 5 to 7, the contact body 45 is formed with a tapered surface 455 that is continuous with the lower surface 452 and the inner circumferential surface 453 and is inclined obliquely upward toward the screw shaft 42 side. Further, the abutment body 45 is formed with a convex curved surface 456 that is continuous with the lower surface 452 (outer circumference of the receiving surface) and the outer circumferential surface 454 and is convexly curved toward the outer circumferential side. The outer diameter of the abutting body 45 is the same as the outer diameter of the stem body 41.

A seal ring 51 is attached to the holder 50 so as to be able to come into contact with the valve seat 15, and a screw hole 52 is formed on the inner circumferential surface with a female thread that screws into the male screw of the screw shaft 42. It is formed. The screw hole 52 is open at the upper surface 53 of the holder 50. The upper surface 53 of the holder 50 is inclined diagonally downward from the screw shaft 42 side (inner circumferential side) toward the upright portion 13 side (outer circumferential side), and the shape of the diaphragm 60 when the valve stem 30 is raised is It is formed along the A corner 54 where the upper surface 53 and the screw hole 52 are continuous has an acute angle smaller than 90°, and is arranged to overlap the tapered surface 455 described above in the Z-axis direction. Here, the inner circumferential edge 62 of the diaphragm 60 is pushed upward by the corner 54 and its vicinity, and comes into contact with the contact body 45 at a position on the outer circumferential side of the corner 54 . Therefore, the inner circumferential edge 62 of the diaphragm 60 is mechanically fastened and fixed (screwed in this embodiment) so that the diaphragm 60 is inclined diagonally downward toward the outer circumferential side. Note that the inner peripheral edge portion 62 of the diaphragm 60 is not welded to either the stem 40 or the holder 50.

The diaphragm 60 is made of metal, has an annular flat plate shape, and is elastically deformable in the Z-axis direction. The outer peripheral edge 61 of the diaphragm 60 is arranged so that when the lid 20 is screwed onto the valve box 10, the diaphragm 60 faces obliquely upward toward the stem 40. 20, and is mechanically tightened and fixed without welding. Further, the inner peripheral edge 62 of the diaphragm 60 is arranged between the stem 40 and the holder 50 so that when the holder 50 is screwed onto the stem 40, the diaphragm 60 is inclined diagonally downward toward the outer peripheral side. They are mechanically tightened and fixed without welding. The tightening force applied to the outer circumferential edge 61 and inner circumferential edge 62 of the diaphragm 60 is appropriately set according to the size within a range that does not cause fluid leakage or excessive collapse of the diaphragm. This diaphragm 60 partitions the space of the cavity 131.

The opening and closing operations of the diaphragm valve 1 will be explained below.
2 and 5 show the diaphragm valve 1 in an open state, FIGS. 3 and 6 show the diaphragm valve 1 in an intermediate state, and FIGS. 4 and 7 show the diaphragm valve 1 in a closed state. . In the open state, the seal ring 51 of the holder 50 is spaced upward from the valve seat 15 of the valve box 10, and the first flow path 11 and the second flow path 12 communicate with each other through the space of the cavity 131. are doing. In the intermediate state, the holder 50 is arranged closer to the valve seat 15 than in the open state, and restricts the flow path that communicates the first flow path 11 and the second flow path 12 in the space of the cavity 131. In the closed state, the seal ring 51 of the holder 50 is in contact with the valve seat 15 and blocks the first flow path 11 and the second flow path 12.

[Closing action]
First, with the diaphragm valve 1 in the open state shown in FIGS. 2 and 5, the handle 70 is rotated around the axis of the valve stem 30 to rotate the valve stem 30. When the valve rod 30 descends due to this rotation, the stem 40 and the holder 50 descend without rotating, and the abutting body 45 of the stem 40 pushes down the inner peripheral edge 62 of the diaphragm 60, so that the diaphragm valve 1 , the intermediate state shown in FIGS. 3 and 6, and then the closed state shown in FIGS. 4 and 7. In the intermediate state of FIG. 6, the position of the inner peripheral edge 62 is at approximately the same height position (up and down position) as the position of the outer peripheral edge 61, and in the closed state of FIG. It is arranged at a lower position with respect to the section 61. If the position of the inner peripheral edge part 62 in the intermediate state is taken as the reference position, the position of the inner peripheral edge part 62 in the closed state is located at a lower position lower than the reference position by a range of less than 1 mm. Further, in the intermediate state and the closed state, the abutting body 45 is arranged at a position protruding downward from the inner peripheral side portion of the suppressing portion 237 of the diaphragm suppressing portion 235. In the intermediate state shown in FIG. 6 and the closed state shown in FIG. It can abut the diaphragm 60 . The outer peripheral edge 61 and inner peripheral edge 62 of the diaphragm 60 are uniquely tightened and fixed as described above, so that in the intermediate state and the closed state, the outer peripheral edge 61 is diagonally upward toward the inner peripheral side. The intermediate portion closer to the inner peripheral edge 62 than the outer peripheral edge 61 is inclined diagonally downward toward the inner peripheral side, and the inner peripheral edge 62 closer to the inner peripheral edge than the intermediate portion is inclined downwardly toward the inner peripheral side. The slope is also gentle. Since the diaphragm 60 is forcibly curved into a unique shape in this way, the diaphragm 60 is less likely to generate abnormal noises such as clicking sounds when the diaphragm valve 1 is operated to open and close. Furthermore, since the corner portion 54 is arranged to overlap the tapered surface 455 in the Z-axis direction, the inner peripheral edge 62 of the diaphragm 60 can be aligned to the inner peripheral side of the contact body 45 and the holder 50 without welding. It can be firmly tightened and fixed in place. In this embodiment, the forced deformation of the diaphragm 60 based on the rotation of the handle 70 when closing the flow path is performed within a range in which the diaphragm 60 can be elastically deformed without causing plastic deformation. By keeping the deformation within this range, for example, plastic deformation of the diaphragm 60 and a decrease in durability are suppressed.
In this way, in the diaphragm valve 1, the holder 50 comes into contact with the valve seat 15 and closes off between the first flow path 11 and the second flow path 12.

[Opening operation]
First, with the diaphragm valve 1 in the closed state shown in FIGS. 4 and 7, the handle 70 is rotated in the opposite direction around the axis of the valve stem 30 to rotate the valve stem 30 in the opposite direction. When the valve rod 30 rises due to this rotation, the stem 40 and the holder 50 rise without rotating, and the holder 50 pushes up the inner peripheral edge 62 of the diaphragm 60, and the diaphragm valve 1 is moved upward as shown in FIGS. 3 and 6. By setting the intermediate state shown in FIG. 2 and then forcibly pushing the diaphragm 60 upward beyond its self-returning state, the open state shown in FIGS. 2 and 5 is achieved. In this open state, the diaphragm 60 is separated from the valve seat 15 by a large distance compared to when the diaphragm 60 self-returns upward, so the communication area between the first flow path 11 and the second flow path 12 can be expanded and further improved. Large flow rate can be achieved. In this embodiment, the forced deformation of the diaphragm 60 based on the rotation of the handle 70 when opening the flow path is performed within a range in which the diaphragm 60 can be elastically deformed without causing plastic deformation. By keeping the deformation within this range, for example, plastic deformation of the diaphragm 60 and a decrease in durability are suppressed. In the open state shown in FIG. 5, the position of the inner circumferential edge 62 is located above the position of the outer circumferential edge 61. Further, in the open state, the lower surface 452 of the contact body 45 is disposed at a vertical position roughly along the inner circumferential side portion of the suppressing portion 237 of the diaphragm suppressor 235, and the upper surface 53 of the holder 50 is located at the inner circumferential edge of the diaphragm 60. 62 is received from below. In the open state, the diaphragm 60 has a substantially dome shape that is inclined diagonally upward from the outer peripheral edge 61 to the inner peripheral edge 62. If the position of the inner peripheral edge part 62 in the intermediate state is taken as the reference position, the position of the inner peripheral edge part 62 in the open state is located at an upper position that is 1 to 2 mm higher than the reference position.
In this way, in the diaphragm valve 1, the holder 50 is separated from the valve seat 15, and the first flow path 11 and the second flow path 12 are communicated with each other.

As described as the diaphragm valve 1 of the present embodiment, the inventor proposed that in the diaphragm valve 1 for large flow rate with a large stroke in which the diaphragm 60 is fixed to the stem 40, the diaphragm 60 is not welded to the stem 40. By stress analysis of the shape of the parts that are mechanically fixed and mechanically sandwich the diaphragm 60, they invented a diaphragm valve 1 that combines stroke, sealing performance, and durability.

[Effects of this embodiment]
In this embodiment, in particular, the diaphragm valve 1 has an outer peripheral edge 61 of the diaphragm 60 mechanically tightened and fixed between the valve box 10 and the lid body 20, and an inner peripheral edge 62 of the diaphragm 60 between the stem 40 and the holder 50. Since the diaphragm 60 is mechanically tightened and fixed between the positions, the diaphragm 60 can be forcibly raised and lowered in accordance with the rise and fall of the valve stem 30. Compared to the case where a valve is provided, in particular, the flow path can be opened beyond the self-return of the diaphragm 60, so that a larger flow rate can be achieved. Further, since both the outer circumferential edge 61 and the inner circumferential edge 62 of the diaphragm 60 are mechanically tightened and fixed, there is no need to weld the diaphragm 60 to the stem 40 or the like, and the manufacturing cost of the diaphragm valve 1 can be suppressed.

In this embodiment, in particular, since the outer diameter of the contact body 45 is the same as the outer diameter of the stem body 41, when the holder 50 is screwed onto the threaded shaft 42 of the stem body 41, the holder 50 Since the contact body 45 rotates together with the diaphragm 60, it is possible to reduce friction between the diaphragm 60, the stem 40, and the holder 50. Furthermore, since the outer diameter of the abutting body 45 is the same as the outer diameter of the stem body 41, the abutting body 45 does not interfere with the lid 20 etc. when the stem 40 moves up and down together with the valve rod 30. In this way, the contact area of the contact body 45 with respect to the diaphragm 60 can be increased. Therefore, the diaphragm 60 that receives the pressure of the fluid flowing inside the valve box 10 can be received by the aforementioned large contact area of the contact body 45.

In this embodiment, in particular, the valve box 10 and the lid body 20 are fixed by tightening the outer peripheral edge 61 of the diaphragm 60 so that the diaphragm 60 faces obliquely upward toward the stem 40, and the abutting body 45 is Since it has a lower surface 452 as a planar receiving surface for receiving the diaphragm 60 and a convex curved surface 456 continuous to the outer periphery of the lower surface 452, when the stem 40 descends, the lower surface of the abutting body 45 452 is arranged below the tightening and fixing position of the outer peripheral edge 61 of the diaphragm 60, the outer peripheral side of the diaphragm 60 where the outer peripheral edge 61 is tightened and fixed so as to face diagonally upward toward the stem 40 side. The portion closer to the inner circumference than the closer portion is curved diagonally downward toward the stem 40 side, but since the abutment body 45 is formed with the aforementioned convex curved surface 456, stress concentration occurs on the diaphragm 60. can be suppressed.

In this embodiment, in particular, the contact body 45 is formed with a tapered surface 455 that is inclined obliquely upward toward the screw shaft 42 side, and the corner portion 54 where the upper surface 53 of the holder 50 and the screw hole 52 are continuous is formed at an acute angle and is arranged to overlap with the tapered surface 455 in the Z-axis direction, so that the corner 54 of the holder 50 is aligned with the tapered surface 455 of the contact body 45 and the screw shaft 42. The inner circumferential edge 62 of the diaphragm 60 can be firmly tightened and fixed by being wedged between the inner circumferential edges 62 and the possibility of fluid leakage can be further reduced without welding the inner circumferential edge 62. Further, since the inner circumferential edge portion 62 of the diaphragm 60 is tightened and fixed in this manner, the tightened and fixed portion has a shape that is inclined obliquely downward toward the outer circumferential side. Therefore, when the inner circumferential edge portion 62 of the diaphragm 60 is lowered, it is possible to prevent the shape of the diaphragm 60 from vertically inverting and generate abnormal noise, and the durability of the diaphragm 60 can be improved.

In this embodiment, the original shape of the diaphragm 60 is an annular flat plate, and the inner peripheral edge 62 of the diaphragm 60 is positioned above or above the outer peripheral edge 61 of the diaphragm 60 depending on the elevation of the stem 40 and the holder 50. Since the inner circumferential edge 62 of the diaphragm 60, which has an annular flat plate shape, is forcibly disposed at a position higher than the outer circumferential edge 61, or at a lower position, For example, compared to the case of using a dome-shaped diaphragm whose original shape bulges upward, the generation of abnormal noise can be further suppressed.

[Modified example]
In the embodiment, the outer diameter of the contact body 45 is the same as the outer diameter of the stem body 41, but is not limited to this, and may be smaller than the outer diameter of the stem body 41, for example. Alternatively, the outer diameter of the abutting body 45 may be larger than the outer diameter of the stem main body 41 as long as it does not interfere with the vertical movement of the stem main body 41.

In the embodiment, the outer diameter of the holder 50 is larger than the outer diameter of the stem 40, but the outer diameter is not limited to this, and may be equal to or smaller than the outer diameter of the stem 40.

In the embodiment, the stem 40 is configured such that the abutting body 45 is rotatably provided with respect to the stem body 41, and when the holder 50 is screwed onto the screwing shaft 42, the abutting body 45 is rotated with the diaphragm 60. rotates to suppress the occurrence of friction against the diaphragm 60. However, if the diaphragm valve 1 could be constructed without taking such points into consideration, the contact body 45 could be integrated with the stem body 41. may be formed. The integrally formed stem 40 has a portion (non-rotatable) corresponding to the abutting body 45.

In the embodiment described above, the inner circumferential edge 62 of the diaphragm 60 is firmly tightened and fixed by the tapered surface 455 of the abutting body 45 and the acute corner 54 of the holder 50. 455 and the acute angle portion 54, as long as the inner circumferential edge portion 62 of the diaphragm 60 can be tightened and fixed without welding, it is not necessary to have these structures.

In the embodiment, the valve box 10 and the lid body 20 are fixed by tightening the outer peripheral edge 61 of the diaphragm 60 so that the diaphragm 60 faces diagonally upward toward the stem 40 side, and when the diaphragm 60 operates, the diaphragm 60 Even when the inner circumferential edge 62 of the diaphragm 60 is disposed at a lower position with respect to the outer circumferential edge 61, abnormal noise that may occur due to the inversion of the diaphragm 60 is suppressed. If it is not necessary, the valve box 10 and the lid body 20 do not need to be tightened and fixed with the outer peripheral edge 61 of the diaphragm 60 in the above-described direction; for example, the diaphragm 60 may be tightened and fixed with the diaphragm 60 oriented horizontally.

In the embodiment described above, the abutting body 45 is formed with the aforementioned convex curved surface 456, but if there is no problem in the operation of the diaphragm 60 even without the convex curved surface 456, the configuration of the convex curved surface 456 can be omitted. You may.

In the above embodiment, the diaphragm valve 1 has been described as a large-flow type metal diaphragm valve used in semiconductor manufacturing equipment, etc., but it can also be used in the liquid crystal market as well as the semiconductor market.

DESCRIPTION OF SYMBOLS 1... Diaphragm valve, 10... Valve box (main body), 11... First flow path, 12... Second flow path, 13... Standing part, 131... Cavity, 132... Bottom surface, 133, 453... Inner peripheral surface, 134... Upper part, 135, 212... Female thread part, 136... Lower part, 137... Annular step part, 14... Outer peripheral surface, 15... Valve seat, 20... Lid body, 21... Upper annular lid part, 211... Outer periphery part, 22 ...Middle annular lid part, 222, 232... Inner peripheral part, 23... Lower annular lid part, 231, 311... Male thread part, 235... Diaphragm suppressor, 236... Cylindrical part, 237... Suppression part, 238, 452... Bottom surface , 239... Annular protrusion, 30... Valve stem, 31... Valve stem upper part, 32... Valve stem lower part, 33... Upper end part, 34... Lower end part, 40... Stem, 41... Stem body, 42... Threaded shaft, 43 ... recess, 45 ... contact body, 451, 53 ... upper surface, 454 ... outer peripheral surface, 455 ... tapered surface, 456 ... convex curved surface, 50 ... holder, 51 ... seal ring, 52 ... screw hole, 54 ... corner, 60... Diaphragm, 61... Outer peripheral edge, 62... Inner peripheral edge, 70... Handle, 71... Indicator, 72... Hole.

Claims

a main body having a first flow path, a second flow path and a valve seat;
a lid body that is screwed and attached to the main body;
a rotatably operable valve stem that is screwed into the lid so that it can be raised and lowered;
a stem connected to the valve stem and having a threaded shaft along the valve stem;
a holder that is screwed onto the threaded shaft and moves toward and away from the valve seat to open and close between the first flow path and the second flow path;
an annular diaphragm through which the screw shaft is inserted;
The outer peripheral edge of the diaphragm is mechanically tightened and fixed between the main body and the lid,
A diaphragm valve in which an inner peripheral edge of the diaphragm is mechanically tightened and fixed between the stem and the holder.
The stem includes a stem body having the threaded shaft, and a contact body through which the threaded shaft is rotatably inserted into the stem body and abuts against the diaphragm,
The diaphragm valve according to claim 1, wherein the outer diameter of the abutting body is the same as the outer diameter of the stem body.
The stem includes a stem body having the threaded shaft, and a contact body through which the threaded shaft is rotatably inserted into the stem body and abuts against the diaphragm,
The main body and the lid are fixed by tightening the outer peripheral edge of the diaphragm so that the diaphragm faces obliquely upward toward the stem,
The diaphragm valve according to claim 1 or 2, wherein the abutting body has a planar receiving surface that receives the diaphragm, and a convex curved surface continuous to the outer periphery of the receiving surface.
The stem includes a stem body having the threaded shaft, and a contact body through which the threaded shaft is rotatably inserted into the stem body and abuts against the diaphragm,
The holder has a screw hole that is open on its upper surface and into which the screw shaft is screwed,
The abutting body is formed with a tapered surface that is inclined diagonally upward toward the screw shaft side,
According to any one of claims 1 to 3, the upper surface of the holder and the corner where the screwing hole is continuous are formed at an acute angle and are arranged to overlap in the vertical direction with respect to the tapered surface. Diaphragm valve as described.
The diaphragm has an annular flat plate shape in its original shape,
5. The diaphragm valve according to claim 4, wherein the inner circumferential edge of the diaphragm is located above or below the outer circumferential edge of the diaphragm depending on the elevation of the stem and the holder.