JP2008128278A - Diaphragm valve and seat assembly for valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly carry out opening/closing operation even to high pressure gas and to tightly weld metal plates constituting a diaphragm, and a shaft part penetrating it, besides excelling in durability. <P>SOLUTION: A propulsive screw member, an intermediate transmission implement, the diaphragm 18 and a closing member 19 are mounted in sequence from the outside in a closing valve mounting hole, and the closing member 19 is held in a closing valve chamber. An insertion hole 29 is provided penetrating the diaphragm 18. The shaft part 25 extended from the closing member 19 is inserted through the insertion hole 29 and fixed to the intermediate transmission implement. The closing valve chamber is partitioned in a tightly sealed state from an intermediate transmission implement holding space by the diaphragm 18. The diaphragm 18 is composed of a plurality of metal plates 26 placed one on top of another. A lubricating layer R is formed at the facing surfaces of the metal plates 26 adjoining each other. Two metal plates 26a weld the inner peripheral edge of the insertion hole 29 in a tightly sealed state to the shaft part 25. The welded metal plates 26a have the lubricating layer R formed of a silvered layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a diaphragm valve connected to a gas storage container, piping, etc., such as ultra-high purity gas used in a semiconductor manufacturing process, and a seat assembly used for the diaphragm valve. The present invention relates to a diaphragm valve and a valve seat assembly that can operate, have excellent durability, and can weld a metal plate constituting the diaphragm and a shaft portion penetrating the metal plate in a coherent manner.

  Ultra high-purity gas used in the semiconductor manufacturing process requires extremely high purity that does not allow the introduction of slight impurities, and has very special properties such as corrosive action and flammability. Care is required.

2. Description of the Related Art Conventionally, as a valve device used for the above-described semiconductor gas or the like, there is a diaphragm valve in which the tightness of a closing valve chamber is ensured by a thin plate-like diaphragm (see, for example, Patent Document 1, hereinafter referred to as Prior Art 1).
That is, this diaphragm valve is provided with an intermediate transmission device accommodating space, a closing valve chamber, and a closing valve seat in this order from the outside to the inside in a closing valve mounting hole formed in the housing, and propelled into the mounting hole. A screw member, an intermediate transmission tool, a diaphragm, and a closing member are attached in order from the outside. The closing member is housed in the closing valve chamber, and moves forward and backward through the intermediate transmission by the advancement of the propulsion screw member, so that the closing member contacts and separates from the closing valve seat. It is constituted as follows.

  The closing member has a shaft portion formed with a male screw projecting, and the diaphragm has an insertion hole through which the shaft portion is inserted. The shaft member inserted through the insertion hole is screwed into a female screw portion formed in the intermediate transmission device, so that the closing member and the intermediate transmission device are fixed to each other via the diaphragm.

  The diaphragm is composed of a plurality of thin metal plates overlapped with each other, and a part of the metal plates, for example, one or two on the closing member side, have the inner peripheral edge of the insertion hole as the shaft portion. It is fixed in a tightly welded manner. The other metal plate is superposed on the welded metal plate as a backup material. The outer peripheral edge portion of the diaphragm is fixed to the housing by a pressing sleeve, and thereby the shut-off valve chamber is partitioned from the intermediate transmission device accommodating space in a tightly sealed manner.

  The above metal plates are bent and rubbed each time the closing member is opened / closed, but the stress applied to each metal plate also increases particularly when the handling gas of the valve is increased, and the metal friction between the metal plates due to the above contact friction. There was a risk of seizing early or damage. In order to prevent this, it has been proposed to form a lubricating layer such as a lubricating oil or a plated layer between metal plates to prevent premature seizure or the like (see, for example, Patent Document 2, hereinafter, Prior Art 2). That said.)

JP 2001-263508 A Japanese Patent Laid-Open No. 5-26357

  In the prior art 2, the contact friction between the metal plates is reduced, and early seizure or the like is prevented. However, in the diaphragm valve of the type in which the shaft portion is inserted into the insertion hole formed in the metal plate and the shaft portion and the inner peripheral edge of the insertion hole are welded as in the prior art 1, the lubricating oil Lubricating layers such as these may deteriorate or decompose due to heating during welding and lose their lubricating action, and may generate harmful gases. On the other hand, when the lubricating layer is formed of a plated layer such as chromium, there is a problem that the plated layer is cracked or peeled off due to repeated deformation of the metal plate, resulting in poor durability. Also, in the case of a plated layer using copper with excellent ductility, if copper melts into the weld bead during the above welding, it precipitates at the weld bead interface, and cracks occur, making it impossible to ensure tightness there were.

  The technical problem of the present invention is to solve these problems, can open and close smoothly even for high-pressure gas, is excellent in durability, and has a metal plate constituting the diaphragm and a shaft portion penetrating the metal plate. It is an object of the present invention to provide a diaphragm valve and a valve seat assembly that can be welded in a sealed state.

In order to solve the above problems, the present invention is configured as follows, for example, based on FIGS. 1 to 4 showing an embodiment of the present invention.
That is, the present invention 1 relates to a diaphragm valve, and an intermediate transmission device accommodating space (15) and a closing valve chamber (10) are formed in the closing valve mounting hole (14) formed in the housing (2) from the outside toward the inside. In addition, the stop valve seat (20) is provided in the stop valve chamber (10), and the propulsion screw member (16), the intermediate transmission (17), and the diaphragm (18) are provided in the above-described stop valve mounting hole (14). And the closing member (19) are sequentially mounted from the outside, and the closing member (19) is accommodated in the closing valve chamber (10) so as to be movable back and forth with respect to the closing valve seat (20). The diaphragm (18) is provided with an insertion hole (29), and the closing member (19) and the intermediate transmission device (17) are connected to each other through a shaft portion (25) inserted into the insertion hole (29). A diaphragm valve which is fixed to each other and partitions the above-mentioned closing valve chamber (10) from the above-mentioned intermediate transmission device accommodating space (15) in a tightly sealed manner by the above-mentioned diaphragm (18), and a plurality of metal layers stacked on each other (26) constitutes the diaphragm (18), and forms a lubricating layer (R) on at least one opposing surface of the metal plates (26) adjacent to each other, so that at least one of the metal plates (26a) The inner peripheral edge of the insertion hole (29) is welded and fixed to the shaft portion (25) in a coherent manner, and the lubricating layer formed on the surface of the welded and fixed metal plate (26a) ( R) is a plating layer (31) made of a ductile metal of either silver or gold.

  The present invention 2 also relates to a valve seat assembly, a closing member (19) mounted in a closing valve chamber (10) formed in a housing (2) of a diaphragm valve (1), and the closing valve chamber (10). A valve seat assembly including a diaphragm (18) for partitioning in a confined manner, wherein an insertion hole (29) is provided through the diaphragm (18), and a shaft inserted through the insertion hole (29). The portion (25) is provided on the closing member (19), and the diaphragm (18) is constituted by a plurality of metal plates (26) overlapped with each other, and at least one of the metal plates (26) adjacent to each other A lubricating layer (R) is formed on the opposite surface, and at least one of the metal plates (26a) is welded in a tightly-tight manner to the shaft portion (25) at the inner periphery of the insertion hole (29). The lubricating layer (R) formed on the surface of the fixed and welded metal plate (26a) is made of a ductile metal of either silver or gold. Characterized in that it is a that a plating layer (31).

  The metal plate has a frictional resistance reduced by the plating layer constituting the lubricating layer, and the occurrence of seizure or the like is prevented. In addition, since this plating layer is excellent in heat resistance, it does not cause alteration / decomposition or generation of harmful gas by heating during welding, and it is made of ductile metal, so even if the metal plate is repeatedly deformed with the opening and closing operation of the valve device There is no risk of cracking. In addition, the silver and gold constituting the plating layer were satisfactorily melted into the bead during welding and did not precipitate at the weld bead interface.

The plating layer may be either silver or gold. However, it is preferable that the plating layer is composed of a silver plating layer because it is inexpensive and has excellent wear resistance, so that the durability can be further improved.
The metal plate is formed of, for example, a nickel alloy. In this case, if the strike nickel plating is applied as the base layer of the plating layer, the silver plating layer can be formed satisfactorily. And the shaft portion are preferably welded in a coherent manner because they can be welded satisfactorily without generating cracks.

  The shaft portion may be any member as long as it connects the closing member and the intermediate transmission device, and may be configured by a member different from the closing member and the intermediate transmission device. However, when this shaft portion is integrally extended to the intermediate transmission tool side on the closing member, it is only necessary to connect the shaft portion to the intermediate transmission tool after inserting the shaft portion into the insertion hole of the metal plate, and the shaft portion and the insertion hole. By welding the inner peripheral edge, it can be handled as a seat assembly in which the closing member, the shaft portion, and the diaphragm are combined into one unit, and the assembly operation to the housing of the valve device is easy, which is preferable.

  Since the present invention is configured and operates as described above, the following effects can be obtained.

  (1) The plated layer that forms the lubrication layer is made of a ductile metal of either silver or gold, so it has a low frictional resistance and can prevent seizure, and the metal plate can be repeated as the valve device is opened and closed. Even if it is deformed, there is no possibility of generating cracks, etc., and it can be smoothly opened and closed even for high-pressure gas, and it has excellent durability.

  (2) When welding the inner peripheral edge of the insertion hole formed in the diaphragm and the shaft part inserted through the insertion hole, the plating layer constituting the lubricating layer is excellent in heat resistance. In addition, the lubricating action can be maintained without being decomposed, and no harmful gas is generated. Moreover, since the ductile metal constituting this plating layer is silver or gold, it does not precipitate at the bead interface during welding, and cracks do not occur at the welded location. The shaft portion can be reliably welded in a tight manner.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show an embodiment of the present invention, FIG. 1 is a longitudinal sectional view of a diaphragm valve, FIG. 2 is a partially broken perspective view of a valve seat assembly, and FIG. 3 is a state before metal plates are overlapped. It is an expanded sectional view of the principal part of a diaphragm.

  As shown in FIG. 1, the diaphragm valve (1) has a housing (2) that is vertically long, and a leg screw part (3) formed at the lower part thereof is fixed to the neck part (5) of the gas cylinder (4). A gas extraction fitting (not shown) can be connected to an outlet nozzle (6) projecting laterally from a height portion on the way. The outlet nozzle (6) can be connected to a filling fitting (not shown) when the gas cylinder (4) is filled with fresh gas.

An inlet hole (7) is opened in the lower surface of the leg screw part (3), and an outlet hole (8) is opened in the end face of the outlet nozzle (6). In the housing (2), an inlet passage (9), a closing valve chamber (10), and an outlet passage (11) are formed in this order between the inlet hole (7) and the outlet hole (8). It is. A gas discharge passage (12) is branched in the middle of the inlet passage (9), and a safety valve (13) is provided in the gas discharge passage (12).
In addition, although this embodiment demonstrates the case where it applies to a cylinder valve, the diaphragm valve of this invention can be applied also to the valve provided in the middle of piping, and the shape and direction of a housing, an inlet hole, an inlet channel, The formation position of the outlet passage, the outlet hole, etc., the type of the safety valve, etc. are not limited to those of this embodiment.

  A closing valve mounting hole (14) is formed on the upper surface of the housing (2) downward, and the intermediate transmission device is sequentially inserted into the closing valve mounting hole (14) from the outside toward the inside. A housing space (15) and the above-described shut-off valve chamber (10) are formed. In this stop valve mounting hole (14), a spindle (16), an intermediate transmission (17), a metal diaphragm (18), and a closing member (19), which are propulsion screw members, are mounted in order from the outside. The closing member (19) is accommodated in the closing valve chamber (10). In the shut-off valve chamber (10), a shut-off valve seat (20) is formed around the open end of the inlet passage (9), and the shut-off member (19) is provided in the shut-off valve seat (20 ).

  In the intermediate transmission device accommodating space (15), a valve opening spring (21), an annular pressing sleeve (22), and an annular rotation restraining member (23) are arranged around the intermediate transmission device (17). is there. The outer peripheral edge of the diaphragm (18) has a gland nut (24) screwed to the housing (2) via the pressing sleeve (22) and a rotation restraining member (23) disposed above the pressing sleeve (22). It is firmly pressed against the peripheral wall of the shut-off valve chamber (10) by tightening and fixing. As a result, the shut-off valve chamber (10) is partitioned from the intermediate transmission device accommodating space (15) in a tightly sealed manner.

  A female thread is formed on the inner surface of the gland nut (24), and the male threaded portion (16a) of the spindle (16) is screwed into and supported rotatably. A handle (27) for opening / closing operation is fixed to the upper end of the spindle (16). The lower end of the spindle (16) is formed as a curved surface protruding downward, and is in contact with the upper surface of the intermediate transmission (17) via a thin plate-like sliding member (28). Thereby, when the spindle (16) is screwed, the thrust is transmitted to the intermediate transmission (17), but the rotational force is not easily transmitted to the intermediate transmission (17).

  The closing member (19) has a shaft portion (25) extending upward on the upper surface, and this shaft portion (25) is inserted into an insertion hole (29) formed in the central portion of the diaphragm (18). And fixedly screwed into the female screw hole of the intermediate transmission (17). By this screwing and fixing, the inner peripheral edge of the insertion hole (29) is securely sandwiched between the intermediate transmission (17) and the closing member (19).

  The valve-opening spring (21) is mounted between the lower inner surface of the pressing sleeve (22) and the upper outer surface of the intermediate transmission (17), and the elastic force of the valve-opening spring (21). As a result, the intermediate transmission (17) is urged upward. The rotation restraining member (23) is disposed above the pressing sleeve (22). Therefore, the rotation restraining member (23) does not receive the elastic force of the valve opening spring (21). Placed in position.

  The inner circumferential surface of the rotation restraining member (23) is non-rotatably fitted to the outer circumferential surface of the intermediate transmission (17), and the rotation restraining member (23) is connected to the ground nut ( It is fixed to the housing (2) by tightening and fixing 24). For this reason, the intermediate transmission tool (17) to which the rotation restraining member (23) is externally fitted is allowed to move forward and backward in the vertical direction, that is, in the axial center (30) direction of the intermediate transmission tool (17). It cannot rotate around the axis (30).

As shown in FIG. 2, the diaphragm (18), the closing member (19), and the shaft portion (25) are unitized as a valve seat assembly (A).
That is, the diaphragm (18) is composed of a plurality of thin metal plates (26), and the two metal plates (26a) on the side of the closing member (19) are arranged so that the inner peripheral edge of the insertion hole (29) is the axis described above. The base end outer peripheral surface of the portion (25) is fixed in a tightly sealed manner by, for example, electrobeam welding. On the upper side of the welded metal plate (26a), a predetermined number of metal plates (26b) are stacked as a backup material. The diaphragm (18) used in the present invention is fixed by welding the inner peripheral edge of the insertion hole (29) to the outer peripheral surface of the shaft portion (25) for any plurality or all of the metal plates (26). Also good.

  As shown in FIGS. 2 and 3, of the two metal plates (26a) welded and fixed to the shaft portion (25), both upper and lower surfaces of the upper metal plate (26a) have lubricating layers ( As R), a silver plating layer (31) is formed with a thickness of, for example, 5 to 10 μm. The metal plate (26a) is made of, for example, a nickel alloy, and the silver plating layer (31) is subjected to strike nickel plating and strike silver plating in this order as an underlayer. On the other hand, the metal plate (26b) as the backup material has a fluororesin coating layer (32) formed as a lubricating layer (R) on the upper surface thereof. Accordingly, each metal plate (26) has a lubricating layer (R) formed on one surface facing the adjacent metal plate (26). In this embodiment, the metal plate is formed of a nickel alloy, but it is needless to say that the metal plate of the present invention may be formed of other metal materials such as stainless steel.

Next, the opening / closing operation of the diaphragm valve (1) will be described.
When the handle (27) is rotated in the tightening direction, the spindle (16) is screwed and the intermediate transmission (17) receiving the thrust descends against the elastic force of the valve opening spring (21). . As a result, the radially intermediate portion of the diaphragm (18) is deformed downward, and the closing member (19) is lowered to contact the closing valve seat (20), thereby closing the valve.

  On the other hand, when the handle (27) is rotated in the loosening direction, the spindle (16) rises while rotating spirally, and the thrust applied to the intermediate transmission (17) is removed. As a result, the intermediate transmission (17) is raised by the elastic force of the valve opening spring (21), the radial intermediate portion of the diaphragm (18) is deformed upward, and the closing member (19) is raised to close the closing valve. Separated from the seat (20), this opens the valve.

  The lower end of the spindle (16) is formed in a protruding curved surface, and the sliding member (28) is arranged between the upper surface of the intermediate transmission (17), so the frictional resistance between them is small. In the above opening / closing operation, the rotational force of the spindle (16) is hardly transmitted to the intermediate transmission (17). Moreover, since the intermediate transmission (17) is linked to the externally-fitted rotation restricting member (23), it cannot rotate about the axis (30). For this reason, in the above opening / closing operation, the intermediate transmission (17) always only moves forward and backward along the vertical direction, that is, the axial center (30) direction, and the diaphragm (18) does not cause distortion due to rotation, Deforms only in the vertical direction.

  At this time, each metal plate (26) of the diaphragm (18) has a lubrication layer (R) formed on one facing surface with the adjacent metal plate (26), so that the contact friction is kept small. Even when a high gas pressure is applied from the inside of the shut-off valve chamber (10), the deformation can be smoothly repeated over a long period without causing seizure or the like. Moreover, since the lubrication layer (R) of the metal plate (26a) welded and fixed to the shaft portion (25) is composed of a silver plating layer (31), the lubrication layer (R) is altered by heating during welding. It does not occur and is welded well without cracking the weld bead. Therefore, the diaphragm (18) ensures that the shut-off valve chamber (10) is partitioned from the intermediate transmission device accommodating space (15) in a tightly sealed manner.

  In this embodiment, the lubrication layer (R) is formed on both surfaces of the upper metal plate (26a) fixed to the shaft portion (25), and the lubrication layer is formed only on the upper surface of the metal plate (26b) as a backup material. (R) was formed. However, in the present invention, the lubricating layer (R) may be formed on at least one opposing surface of the metal plates (26) adjacent to each other. For example, in Modification 1 shown in FIG. 4A, the lubricating layer (R) is formed on both sides only on every other metal plate (26). 4B, the lubricating layer (R) is formed on both surfaces of all the remaining metal plates (26) except the metal plate (26) closest to the closing member (19). is there.

  In the above embodiment, since the lubricating layer (R) formed on the metal plate (26b) as the backup material is formed of the fluororesin coating layer (32), it is easy to handle and can be implemented at low cost. However, in the present invention, if the lubricating layer (R) formed on the metal plate (26a) welded and fixed to the shaft portion (25) is a plated layer (31) made of a ductile metal of either silver or gold. Well, the lubricating layer (R) formed on the metal plate (26b) as a backup material can be made of any material that does not adversely affect the opening and closing operation, for example, ductile metal such as copper, silver, gold, etc. It is also possible to form with a plating layer or lubricating oil.

  Further, the diaphragm valve and the valve seat assembly described in the above-described embodiment and modification are illustrated to embody the technical idea of the present invention, and the shape, structure, arrangement, etc. of each part are described. It goes without saying that the present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the claims of the present invention.

  The diaphragm valve of the present invention can smoothly open and close even for high-pressure gas, and is excellent in durability, and since the metal plate constituting the diaphragm and the shaft portion penetrating the metal plate can be welded in a coherent manner, Although it is particularly suitable for a valve device connected to a gas storage container, piping, or the like, such as an ultra-high purity gas used in a semiconductor manufacturing process, it is also suitably used for a valve device that handles other types of gas.

It is a longitudinal cross-sectional view of the diaphragm valve which shows embodiment of this invention. It is a partially broken perspective view of the valve seat assembly of the embodiment of the present invention. It is an expanded sectional view of the important section of a diaphragm of a state before superposing a metal plate of an embodiment of the present invention. FIG. 4A shows a modification of the embodiment of the present invention, FIG. 4A is an enlarged cross-sectional view of the main part of the diaphragm in a state before the metal plates are overlaid, and FIG. FIG. 5 is an enlarged cross-sectional view of the main part of the diaphragm in a state before the metal plates are overlaid.

Explanation of symbols

1 ... Diaphragm valve 2 ... Housing
10 ... Closed valve chamber
14 ... Hole for closing valve
15 ... Intermediate transmission housing space
16 ... Propulsion screw member (spindle)
17 ... Intermediate transmission
18 ... Diaphragm
19 ... Closing member
20 ... Closed valve seat
25 ... Shaft
26 ... Metal plate
26a ... Metal plate welded to the shaft
29 ... insertion hole
31 ... Plating layer (silver plating layer)
A ... Seat assembly R ... Lubrication layer

Claims (7)

In the shut-off valve mounting hole (14) formed in the housing (2), an intermediate transmission tool accommodating space (15) and a shut-off valve chamber (10) are provided in order from the outside to the inside, and the stop valve chamber (10 ) Is provided with a closing valve seat (20)
Install the propulsion screw member (16), the intermediate transmission (17), the diaphragm (18), and the closing member (19) in order from the outside in the above-mentioned closing valve mounting hole (14),
The closing member (19) is accommodated in the closing valve chamber (10) so as to be movable back and forth with respect to the closing valve seat (20).
An insertion hole (29) is formed through the diaphragm (18), and the closing member (19) and the intermediate transmission (17) are connected to each other through a shaft portion (25) inserted through the insertion hole (29). Fixed to each other,
A diaphragm valve in which the stop valve chamber (10) is partitioned from the intermediate transmission device accommodation space (15) in a tightly sealed manner by the diaphragm (18),
A plurality of metal plates (26) superposed on each other constitute the diaphragm (18), and a lubricating layer (R) is formed on at least one opposing surface of the metal plates (26) adjacent to each other.
At least one of the metal plates (26a) is fixed by welding the inner peripheral edge of the insertion hole (29) to the shaft portion (25) in a close-packed manner,
The diaphragm valve, wherein the lubricating layer (R) formed on the surface of the welded and fixed metal plate (26a) is a plated layer (31) made of a ductile metal of either silver or gold. .   The diaphragm valve according to claim 1, wherein the plating layer (31) is made of silver.   The diaphragm valve according to claim 1 or 2, wherein strike nickel plating is applied as a base layer of the plating layer (31). A closing member (19) mounted in a closing valve chamber (10) formed in the housing (2) of the diaphragm valve (1), and a diaphragm (18) for partitioning the closing valve chamber (10) in a tight manner A valve seat assembly comprising:
The diaphragm (18) is provided with an insertion hole (29), and a shaft portion (25) to be inserted into the insertion hole (29) is provided in the closing member (19).
A plurality of metal plates (26) superposed on each other constitute the diaphragm (18), and a lubricating layer (R) is formed on at least one opposing surface of the metal plates (26) adjacent to each other.
At least one of the metal plates (26a) is fixed by welding the inner peripheral edge of the insertion hole (29) to the shaft portion (25) in a close-packed manner,
The above-mentioned lubricating layer (R) formed on the surface of the welded and fixed metal plate (26a) is a plated layer (31) made of a ductile metal of either silver or gold. Sheet assembly.   The valve seat assembly according to claim 4, wherein the plating layer (31) is made of silver.   The valve seat assembly according to claim 4 or 5, wherein strike nickel plating is applied as a base layer of the plating layer (31).   The valve seat assembly according to any one of claims 4 to 6, wherein the shaft portion (25) extends integrally with the closing member (19).

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