JP7025915B2 - Diaphragm valve - Google Patents

Description

The present invention relates to a diaphragm valve, for example, a diaphragm valve that requires extremely high functionality such as an ALD (Atomic Layer Deposition) process.

In recent years, in gas supply devices for semiconductor manufacturing, for example, a process of opening and closing a valve in a short time as typified by ALD has been introduced in many cases. In the ALD process, under a high temperature atmosphere of about 200 ° C. or higher, multiple types of gas such as precursor, inert gas, and oxidized gas are stabilized by high-speed switching in an extremely short cycle from the gas supply system. It is alternately supplied to the chamber at a flow rate, and atomic layers are uniformly and uniformly stacked layer by layer on the wafer in the chamber at the nano level to form a thin film.

At that time, in particular, the diaphragm valve used in the ALD process has heat resistance that can withstand high heat of about 200 ° C. and a flow rate that accurately supplies gas in a short time, in addition to ensuring sealing performance when the valve is closed. Functionality such as stability, high-speed operability to switch gas supply in a short time with high deadline performance to avoid gas mixing, and high durability that can withstand multiple valve opening / closing cycles is required. ..

In this case, in the ALD process, by opening and closing the diaphragm valve at high speed in a short time as described above, wear and deterioration are likely to proceed quickly, and when the valve body or valve seat breaks down or becomes dirty, the sealing property is improved. And the above functionality may not be maintained.
Maintenance is required to recover this, and when performing maintenance, usually, the inside is cleaned with parts such as the diaphragm valve body and valve seat incorporated in the main body, or the entire valve. Is often replaced.

On the other hand, in order to facilitate maintenance, it is known that a unit with a built-in diaphragm valve body and valve seat is provided, this unit can be removed from the main body, and the valve body and valve seat can be replaced together with the unit. There is.
For example, in the diaphragm valve of Patent Document 1, a diaphragm and a valve seat combined as a discrete valve assembly are described, whereby the valve assembly can be attached and detached for cleaning or can be replaced as a cartridge. In this valve assembly, the diaphragm valve body is fixed to the valve assembly by welding the diaphragm to the outer rim of the annular valve seat carrier.

Special Table 2016-505125 Gazette

However, when the diaphragm valve body is fixed to the valve seat carrier by welding as in the diaphragm valve of Patent Document 1, the diaphragm valve body and the valve seat carrier are thermally affected or distorted due to the influence of heat during welding, which is unnecessary. Stress may occur and remain. This may adversely affect the sealing performance when the valve is closed and its functionality. For example, in a diaphragm valve used in the ALD process, in addition to the occurrence of seal leakage, the heat resistance and flow rate during valve operation Functionality such as stability, high speed operability and durability may be reduced.

In addition to this, when the diaphragm valve body is fixed to the valve seat carrier by welding, it is necessary to fix it with high accuracy in a uniform welded state, so that the workability is deteriorated and the working time is lengthened, and the yield is lowered. It is easy to connect to.

The present invention has been developed in order to solve the above-mentioned problems, and an object thereof is a diaphragm valve body or a diaphragm valve that is removable and maintainable, such as a diaphragm valve body or a valve seat. To provide an easy-to-manufacture diaphragm valve that opens and closes while minimizing the effect on the valve function when the valve seat is installed, reliably preventing leakage when the valve is closed, and fully demonstrating its functionality. It is in.

In order to achieve the above object, in the invention according to claim 1, a diaphragm unit having a diaphragm valve body and a valve seat member to which the diaphragm valve body is attached and detached is detachably mounted in the body, and the diaphragm unit is , The diaphragm has a substantially annular holding member, and the valve seat member is fixed at a substantially central position of the holding member . It is a valve.

In the invention according to claim 2 , an annular protrusion is formed on the outer peripheral edge of the upper surface of the holding member, and the outer peripheral edge of the diaphragm valve body abuts on the inner peripheral surface of the annular protrusion to bring the diaphragm valve body into a centered state. It is a held diaphragm valve.

According to the third aspect of the present invention, the holding member has a primary side opening near the center and a plurality of secondary side openings provided around the primary side opening, and a valve seat is provided in the primary side opening. It is a diaphragm valve with a member mounted in a press-fitted state.

In the invention according to claim 4 , the holding member has a primary side opening near the center and a plurality of secondary side openings provided around the primary side opening, and a valve seat is provided in the primary side opening. It is a diaphragm valve in which a member is mounted via a holding member for holding.

The invention according to claim 5 is a diaphragm valve in which a holding member is fixed in a positioned state between a body and a bonnet mounted on the upper portion of the body, and the primary opening side of the valve seat member is in close contact with the body.

The invention according to claim 6 is a diaphragm valve in which a sealing portion for abutting and sealing is formed on the bottom surface side of the holding member at the position of the body.

The invention according to claim 7 is a diaphragm valve in which a gasket is mounted between the seal portion and the holding member.

According to the first aspect of the present invention, by providing the diaphragm unit with the diaphragm valve body, the valve seat member, and the holding member, the diaphragm unit can be integrally removed from the inside of the body. As a result, the entire diaphragm unit can be cleaned and replaced, and maintenance can be easily performed. The valve seat member is fixed at a substantially central position of the holding member, while the peripheral portion of the diaphragm valve body is held on the upper surface side of the holding member by plastic deformation of either one or both of the diaphragm valve body and the holding member. ing. For this reason, there is no risk of thermal effects, distortion, or extra stress being generated on these parts, minimizing the effect on the valve function when the diaphragm valve body or valve seat is installed, and preventing leakage when the valve is closed. While reliably preventing it, it will be possible to fully demonstrate its functionality as a diaphragm valve. When the valve operates, the diaphragm valve body held on the upper surface side of the holding member opens and closes with high accuracy with respect to the valve seat member fixed to the holding member. It is possible to open and close while fully exhibiting functionality such as flow rate stability, high-speed response, and durability. Moreover, since the diaphragm valve body can be mounted by plastic deformation, it is easy to manufacture. Furthermore, by caulking, the diaphragm unit can be easily configured with the diaphragm valve body held by the holding member, and there is no risk that the parts will be affected by heat, distortion, or extra stress during manufacturing. .. For this reason, the parts that adversely affect the valve opening / closing function of the diaphragm valve body are not deformed during processing, and while ensuring the sealing performance when the valve is closed, the functions of heat resistance, flow rate stability, high-speed response, and durability are achieved. It is possible to provide a high-precision diaphragm valve with excellent properties. Since the variation in processing accuracy for each diaphragm unit is reduced, the yield is also improved.

According to the invention of claim 2 , by holding the diaphragm valve body in the centered state with respect to the holding member, the valve body can operate with high accuracy and supply an appropriate amount of gas, and the performance of each different valve can be improved. It suppresses variations and individual differences, prevents biased force from being applied to the valve body, prevents external leaks and seat leaks, and can improve durability.

According to the third aspect of the present invention, the valve seat member is attached to the primary side opening of the holding member in a press-fitted state, and the valve seat member is pulled out from the holding member by using an appropriate jig. It can be exchanged. Therefore, it is possible to replace only the valve seat member and reuse other parts.

According to the fourth aspect of the present invention, by mounting the valve seat member on the primary side opening of the holding member via the pressing member, the pressing member is press-fitted into the valve seat member to hold the valve seat member. The force to hold the valve seat member can be exerted, and the valve seat member can be firmly fixed to the holding member. Moreover, if only the holding member is pulled out with an appropriate jig, the valve seat will naturally come off from the holding member, so the valve seat member can be easily removed without contacting the jig with the valve seat member and damaging it. Can be done. This makes it possible not only to replace only the valve seat member, but also to clean and reuse the valve seat member.

According to the fifth aspect of the present invention, the holding member is positioned and fixed between the body and the bonnet, and the primary opening side of the valve seat member is brought into close contact with the body to prevent leakage between the valve seat member and the body. It will be possible to prevent it with certainty.

According to the invention of claim 6 , the sealing portion formed at the position of the body abuts and seals on the bottom surface side of the holding member, so that leakage between the body and the holding member can be reliably prevented. ..

According to the invention of claim 7 , by mounting a gasket between the seal portion and the holding member, the sealing portion of the body and the holding member facing the seal portion of the body are crushed or scratched on the opposite side. It can be suppressed and the sealing performance can be maintained even when the diaphragm unit is repeatedly replaced.

It is sectional drawing of the main part which shows the embodiment of the diaphragm valve in this invention. It is an enlarged sectional view which shows the diaphragm unit in FIG. It is sectional drawing which shows the state which the diaphragm valve of FIG. 1 is separated. It is sectional drawing of the main part which shows the other embodiment of the diaphragm valve in this invention. It is an enlarged sectional view which shows the diaphragm unit in FIG. It is sectional drawing which shows the state which the diaphragm valve of FIG. 4 is separated.

Hereinafter, embodiments of the diaphragm valve in the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing a main part of an embodiment of the diaphragm valve of the present invention, and shows the vicinity of a flow path opening / closing part of the diaphragm valve. FIG. 2 shows a cross-sectional view of the diaphragm unit, and FIG. 3 shows a separated state of the diaphragm valve of FIG.

In FIGS. 1 to 3, the diaphragm valve of the present invention has a body 1, a diaphragm unit 2, a bonnet 3, a diaphragm piece 4, a drive shaft 5, and a base body 6.

The body 1 is integrally formed of a stainless steel material such as SUS316L in a substantially rectangular parallelepiped appearance and a body shape, an opening 10 is formed in the upper portion thereof, and a female screw 11 is formed on the inner peripheral side of the opening 10. Has been done. A circular fitting portion 12 is formed on the back side of the female screw 11, and a valve chamber 13 formed of a space is formed on the back side of the fitting portion 12.

On the bottom surface side of the body 1, a primary side flow path 14 and a secondary side flow path 15 are formed so as to communicate with the valve chamber 13, and the internal valve chamber is in a state of communicating with these primary and secondary side flow paths 14 and 15. The diaphragm unit 2 is detachably attached to the 13th.
An annular sealing portion 16 projecting in a trapezoidal cross section is formed at the position of the body 1 on the bottom surface side of the valve chamber 13 in the present embodiment, and the sealing portion 16 hits the bottom surface side of the holding member 20 described later. It is provided so that it can be contacted and sealed.

The diaphragm unit 2 has a diaphragm valve body 21, a valve seat member 22, and a holding member 20, which are integrally combined and detachably mounted inside the body 1.

The diaphragm valve body 21 is composed of a predetermined number of thin metal plate-shaped members stacked on top of each other, and has a substantially disk-like appearance having a gently convex curved surface shape with a central portion as an apex toward one side (upper side) in a natural state. It is formed in the natural state and has an elastic force that can self-return to this natural state. The diaphragm valve body 21 is attached to the holding member 20, and is provided so as to be detachable from the seal portion of the valve seat member 22 attached to the holding member 20.

The valve seat member 22 is provided in a substantially cylindrical shape with a resin material such as fluororesin, and is provided at a substantially central position of the holding member 20. An annular convex portion 25 having a predetermined height is formed at a substantially intermediate position on the outer peripheral surface of the valve seat member 22.

The holding member 20 is provided in a substantially annular shape made of a metal material, and has a primary side opening 26 composed of an insertion hole near the center, and an insertion hole having a diameter slightly smaller than that of the primary side opening 26 around the primary side opening 26. A plurality of secondary side openings 27 made of the same are formed. The primary side opening 26 has a slightly protruding protruding portion formed on both side surfaces of the holding member 20 to secure the length of the flow path, and the primary side opening 26 is located at a substantially intermediate position on the inner peripheral surface of the primary side opening 26. An annular recess 28 that can be fitted with the annular protrusion 25 of the valve seat member 22 is formed.

An annular protrusion 30 is formed on the outer peripheral edge of the upper surface of the holding member 20, and the inner peripheral surface of the annular protrusion 30 is provided with a diameter substantially equal to or slightly larger than the outer diameter of the diaphragm valve body 21. The upper end portion (tip side) of the annular protrusion 30 is provided so as to be bendable toward the inner diameter side (inside) by plastic working such as caulking. An annular trapezoidal portion 29 is formed on the inner peripheral side of the annular projection portion 30, and a flat annular sealing surface 32 is provided on the upper bottom side of the trapezoidal portion 29.

The valve seat member 22 described above is attached to the primary side opening 26 of the holding member 20 in a press-fitted state, whereby the valve seat member 22 is fixed at a substantially central position of the holding member 20. At this time, by fitting the annular convex portion 25 into the annular concave portion 28, the valve seat member 22 is firmly held by the holding member 20 in the positioned state, and the valve seat member 22 is prevented from slipping or falling off with respect to the holding member 20. To.

On the other hand, the diaphragm valve body 21 is placed on the sealing surface 32 on the upper part of the holding member 20, and in this state, the annular protrusion 30 is squeezed inward and plastically deformed by caulking. As a result, the peripheral edge of the diaphragm valve 21 is pressed by the deformed annular protrusion 30, and the diaphragm valve 21 is held against the holding member 20. At this time, the diaphragm valve body 21 is not completely fixed to the holding member 20, and is lightly held in a no-load state.
After the diaphragm valve body 21 was attached to the holding member 20, the outer peripheral edge of the diaphragm valve body 21 was in contact with the inner peripheral surface of the annular protrusion 30 which was a caulking portion, and the diaphragm valve body 21 was centered. It becomes a state.

The diaphragm unit 2 integrated as described above is mounted in the valve chamber 13 from above the body 1, and the base body 6 is fixed to the body 1 with the bonnet 3 and the diaphragm piece 4 mounted from above. And integrated.

The bonnet 3 is formed in a substantially tubular shape having a large-diameter portion 40 which is a large-diameter disk portion and a small-diameter portion 41 which is a small-diameter cylindrical portion. The large diameter portion 40 is provided with an outer diameter that can be fitted into the valve chamber 13, and the bottom surface side thereof is formed in a concave curved surface shape. As a result, an annular pressing portion 42 located at the lowermost part of the bonnet 3 in FIG. 1 is provided on the outer peripheral edge of the bottom surface of the large diameter portion 40. The small diameter portion 41 is provided with an outer diameter that can be fitted into the fitting recess 43 formed in the lower portion of the base body 6 described later.

A mounting hole 44 is formed in the central inner circumference of the bonnet 3, and the diaphragm piece 4 is mounted in the mounting hole 44. The diaphragm piece 4 is provided in a substantially columnar shape having an outer diameter that can be inserted into the mounting hole 44, and after mounting, the diaphragm piece 4 slides with respect to the mounting hole 44 and can move up and down in the bonnet 3.

The base body 6 is provided between the body 1 and an actuator (not shown), has a male screw 45 that can be screwed with the female screw 11 of the body 1 on the lower outer periphery thereof, and a small diameter portion 41 of the bonnet 3 on the lower inner peripheral side. A fitting recess 43 is formed in which the fitting recess 43 can be fitted. A male threaded portion 47 is formed on the upper outer peripheral side of the base body 6, and a through hole 48 is formed in the center of the base body 6.

A drive shaft 5 is movably inserted into the through hole 48 of the base body 6 via an O-ring 49, and an air-driven type having, for example, a piston and a cylinder (not shown) above the drive shaft 5. Air actuator is provided.

A small diameter portion 41 of the bonnet 3 is inserted into the fitting recess 43 of the base body 6 in a fitted state, and in this state, the male screw 45 and the female screw 11 are screwed together to form the base body 6 and the body 1. Be integrated. At that time, the diaphragm piece 4 is inserted into the mounting hole 44 of the bonnet 3. When the base body 6 and the body 1 are screwed together, the upper surface of the large diameter portion 40 of the bonnet 3 is pressed on the bottom surface side of the base body 6, and the pressing portion 42 on the bottom surface side of the bonnet 3 presses the outer peripheral edge of the upper surface of the diaphragm valve body 21. When pressed, the entire diaphragm unit 2 is fixed between the bonnet 3 and the seal portion 16 of the body 1.

As a result, the diaphragm unit 2 and the bonnet 3 to which the diaphragm piece 4 is mounted are interposed between the body 1 and the base body 6, and are integrated as a diaphragm valve.

With the above configuration, the diaphragm valve of the present embodiment is provided so that the operation of the air actuator can be transmitted to the diaphragm piece 4 via the drive shaft 5. When the drive shaft 5 is lowered and the diaphragm piece 4 is pressed at the tip thereof, the diaphragm piece 4 is lowered and the vicinity of the center of the diaphragm valve body 21 is pressed against the elastic force, and the diaphragm valve body 21 is pressed. Deforms around the center and sits on the valve seat member 22 to close the valve.

On the other hand, when the drive shaft 5 is raised by the air actuator, the diaphragm valve body 21 is deformed in a direction of returning to a convex curved surface shape while pushing up the diaphragm piece 4 by its elastic force, so that the diaphragm valve body 21 is displaced from the valve seat member 22. The valve is opened at a distance.

In the above embodiment, the diaphragm valve body 21 is held by the holding member 20 by plastic deformation due to caulking of the annular protrusion 30, but if the diaphragm valve body 21 can be held by plastic deformation, caulking is performed. Other plastic deformation means may be used. Further, the side to be plastically deformed is not limited to the holding member, and can be fixed by plastically deforming either one or both of the diaphragm valve body 21 and the holding member 20.

Further, the drive means is not limited to the air-driven actuator, and various actuators can be used as long as the diaphragm valve body 21 is deformed by the drive shaft 5 to open and close the flow path. Further, it may be other than the actuator, and for example, the drive shaft may be operated by a manual method having a handle (not shown).

Next, the operation of the actuator of the present invention in the above embodiment will be described.
In the actuator of the present invention, since the diaphragm unit 2 having the diaphragm valve body 21 and the valve seat member 22 is detachably mounted in the body 1, these diaphragm valve bodies 21 and the valve seat member 22 are used as the unit 2. It can be removed as a unit for maintenance. As a result, impurities adhering to the diaphragm valve body 21 and the valve seat member 22 can be removed by cleaning, or the entire diaphragm unit 2 can be replaced to restore the function as a valve.

When replacing the diaphragm unit 2, loosen the screw between the male screw 45 and the female screw 11, remove the base body 6 from the body 1, and take out the bonnet 3 and the diaphragm piece 4 from the base body 6.
On the other hand, on the body 1 side, the diaphragm unit 2 is taken out from the valve chamber 13, and a new diaphragm unit 2 or a cleaned diaphragm unit 2 is inserted into the valve chamber 13 through the opening 10.
In this state, the bonnet 3 and the diaphragm piece 4 are inserted into the body 1 from above the diaphragm unit 2, the base body 6 is tightened to the body 1 with a predetermined torque, and the male screw 45 and the female screw 11 are screwed together. To make it.

In the diaphragm unit 2, since the valve seat member 22 is fixed by press fitting at a substantially central position of the substantially annular holding member 20, assembly is easy.
The annular protrusion 30 of the holding member 20 is plastically deformed by caulking, and the diaphragm valve body 21 is held between the annular protrusion 30 and the annular sealing surface 32 so as to press the peripheral edge thereof. When the diaphragm unit 2 is formed, unnecessary deformation is not applied to the diaphragm valve body 21.
That is, by holding the diaphragm valve body 21 lightly in a no-load state without sticking to the holding member 20 during caulking, no extra stress or strain due to a strong tightening force is generated, and welding or the like is performed. Since it is not affected by heat, it is possible to eliminate factors that adversely affect assembly accuracy and durability.

Since the outer peripheral edge of the diaphragm valve body 21 comes into contact with the inner peripheral surface of the annular protrusion 30 which is a caulked portion and is held in a centered state with respect to the holding member 20, the diaphragm valve body 21 is held in a centered state with respect to the body 1. It can be assembled with high accuracy while preventing the center from shifting, and it is possible to prevent variations in valve performance and individual differences in valves. As a result, it is possible to prevent an unbalanced force during tightening due to screwing between the base body 6 and the body 1 to prevent external leaks and seat leaks, and to improve durability.

Moreover, when the base body 6 and the body 1 are screwed together, the diaphragm unit 2 is sandwiched between the sealing portion 16 of the body 1 and the pressing portion 42 of the bonnet 3. Therefore, the diaphragm valve body 21 in a state of being lightly held by the holding member 20 by caulking is uniformly pressed by the annular pressing portion 42 to hold the diaphragm valve body 21 in a centered state. Can be fixed in place. At that time, the diaphragm valve body 21 is pressed against the annular sealing surface 32, so that the sealing property between the diaphragm valve body 21 and the holding member 20 is ensured and leakage is reliably prevented. On the other hand, on the bottom surface side of the holding member 20, the seal portion 16 having a trapezoidal cross section is pressed against the outer diameter edge by a predetermined thrust, so that they are contact-sealed and leak from the valve chamber 13 to the bonnet 3 side. I'm preventing it.

In this case, by providing the seal portion 16 in a substantially trapezoidal protrusion shape, deformation such as crushing when the seal portion 16 and the holding member 20 are in pressure contact with each other can be generated on the holding member 20 side, and the metal Despite the fact that the body 1 and the holding member 20 are sealed from each other, there is no risk of damaging or crushing the body 1 (seal portion 16) side. From this, it is possible to replace only the diaphragm unit 2 without replacing the body 1, and recover the valve sealing performance and functionality such as heat resistance, flow rate stability, high-speed response, and durability each time the diaphragm unit 2 is replaced. , Even when supplying multiple types of gas at high speed in a high temperature atmosphere such as the ALD process, the diaphragm unit 2 can be replaced multiple times, and it is used while demonstrating high functionality due to stable operation. It will be possible.

As described above, the holding member 20 is fixed between the body 1 and the bonnet 3 mounted on the body 1 in a positioned state, so that the primary side sealing portion on the primary opening side of the valve seat member 22 Is brought into close contact with a predetermined position on the peripheral edge of the primary side flow path 14 of the valve chamber 13, and fluid leakage to the secondary side from other than the opening portion of the valve seat member 22 can be prevented.

4 to 6 show another embodiment of the diaphragm valve of the present invention. In this embodiment, the same parts as those in the above embodiment are represented by the same reference numerals, and the description thereof will be omitted.

In the diaphragm valve of this embodiment, the diaphragm unit 51 is detachably mounted in the body 50, and the diaphragm unit 51 has a diaphragm valve body 21, a valve seat member 52, a holding member 53, a holding member 54, and a gasket 55. is doing.

A primary side opening 56 is provided near the center of the holding member 53, and an annular step portion 57 is formed on the bottom surface side of the primary side opening 56.
The valve seat member 52 is formed in a substantially cylindrical shape, an annular protrusion 58 that can be engaged with the annular step portion 57 is formed on the outer periphery thereof, and an annular step portion 59 is formed on the inner peripheral bottom surface side.

The pressing member 54 is provided for holding the valve seat member 52 with respect to the primary side opening 56 of the holding member 53. The pressing member 54 is formed in a substantially cylindrical shape that can be fitted to the inner peripheral side of the valve seat member 52, and an annular flange portion that can be engaged with the annular stepped portion 59 of the valve seat member 52 is formed at the lower portion of the outer periphery thereof. 60 is formed.

The valve seat member 52 is press-fitted from below the primary side opening 56 of the holding member 53 to a position where the annular projection 58 engages with the annular step portion 57. In this state, the pressing member 54 is press-fitted from below the valve seat member 52 to a position where the annular flange portion 60 engages with the annular stepped portion 59. In this way, the valve seat member 52 is mounted in a positioned state between the holding member 53 and the pressing member 54.

On the outer peripheral side of the bottom surface of the holding member 53, an annular protrusion 30 on the upper surface side, an annular protrusion 30 having substantially the same shape as the trapezoidal portion 29 having the annular sealing surface 32, and a trapezoidal portion 29 are formed, respectively. A gasket 55 can be attached to the annular sealing surface 32 of the trapezoidal portion 29 on the bottom surface side.

The gasket 55 is coated with a fluororesin and provided in an annular shape, and is mounted on the inner peripheral side of the lower annular protrusion 30. In this state, the tip end side of the annular protrusion 30 is plastically deformed by caulking, so that the peripheral edge of the gasket 55 is held between the trapezoidal portion 29 and the deformed annular protrusion 30 and is placed at a predetermined position of the holding member 53. It will be installed.

In this embodiment, the valve seat member 52, the pressing member 54, and the gasket 55 are attached to the holding member 53 as described above, and the diaphragm unit 51 including the diaphragm valve body 21 is configured, and the diaphragm unit 51 is the body. It is mounted within 50.

An annular groove 61 is formed on the outer periphery of the bottom surface of the valve chamber 13 of the body 50, and the annular protrusion 30 on the bottom surface side of the holding member 53 after caulking is provided in the annular groove 61 at a depth that allows charging.

After the diaphragm unit 51 is attached to the body 50, the inner peripheral side of the annular groove portion 61 of the body 50 is in a state where the annular protrusion 30 which is the caulking portion on the bottom surface side of the holding member 53 is released to the annular groove portion 61 of the body 50. The flat sealing portion 62 formed on the surface and the annular sealing surface 32 of the holding member 53 are sealed via the gasket 55. Since the holding member 53 is attached via the gasket 55 in this way, deformation such as crushing is less likely to occur on both the body 50 and the holding member 53, and there is no possibility that the body 50 will be damaged. As a result, the diaphragm unit 51 can be replaced a plurality of times, and can be used while ensuring sealing performance and functionality.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the description of the embodiments, and is within the scope of the invention described in the claims of the present invention. Therefore, various changes can be made.

1 Body 2 Diaphragm unit 3 Bonnet 16 Seal part 20 Holding member 21 Diaphragm valve body 22 Valve seat member 26, 56 Primary side opening 27 Secondary side opening 30 Circular protrusion 54 Pressing member 55 Gasket

Claims (7)

A diaphragm unit having a diaphragm valve body and a valve seat member to which the diaphragm valve body is attached to and detached is detachably mounted in the body, and this diaphragm unit has a substantially annular holding member, which is an abbreviation for the holding member. A diaphragm valve characterized in that the valve seat member is fixed at a central position, and a peripheral edge portion of the diaphragm valve body is held by caulking the holding member at an upper portion of the holding member. Claim 1 in which an annular protrusion is formed on the outer peripheral edge of the upper surface of the holding member, and the outer peripheral edge of the diaphragm valve body abuts on the inner peripheral surface of the annular protrusion to hold the diaphragm valve body in a centered state. Diaphragm valve described in. The holding member has a primary side opening near the center and a plurality of secondary side openings provided around the primary side opening, and the valve seat member is press-fitted into the primary side opening. The diaphragm valve according to claim 1 or 2 mounted. The holding member has a primary side opening near the center and a plurality of secondary side openings provided around the primary side opening, and the valve seat member holds the valve seat member in the primary side opening. The diaphragm valve according to any one of claims 1 to 3, which is mounted via a presser member. One of claims 1 to 4 , wherein the holding member is fixed in a positioned state between the body and a bonnet mounted on the upper portion of the body, and the primary opening side of the valve seat member is in close contact with the body. Diaphragm valve described in. The diaphragm valve according to any one of claims 1 to 5 , wherein a seal portion is formed at the position of the body to abut and seal the bottom surface side of the holding member. The diaphragm valve according to claim 6 , wherein a gasket is mounted between the seal portion and the holding member.

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