JP6632274B2 - Valve with actuator - Google Patents

Description

  The present invention relates to a valve with an actuator, and more particularly to a valve with an actuator suitable for use in a semiconductor manufacturing apparatus using an atomic layer deposition method (ALD method).

  2. Description of the Related Art In recent years, miniaturization of semiconductor elements and miniaturization of element structures have progressed, and a film formation technique called atomic layer deposition (ALD) has become mainstream in a manufacturing process. In the ALD method, a semiconductor manufacturing gas (source gas) heated to a high temperature is supplied to a process chamber of a semiconductor manufacturing apparatus through a supply valve attached to a supply pipe, and “adsorption of source gas atoms to a substrate surface”, “reaction” The principle of stratification is to repeatedly stack the atomic layers or molecular layers on the substrate installed in the chamber by repeatedly performing the cycle of “deposition by film formation” and “removal of excess molecules by purging”. For this reason, it is possible to form a high-quality film with excellent uniformity of film formation, and to form a thin film of a desired thickness on a substrate by repeating this cycle several tens to several thousand times. Can be.

  For this reason, a valve for supplying a source gas to a semiconductor manufacturing apparatus using the ALD method is capable of performing a high-speed opening / closing operation, being able to withstand a large increase in the number of opening / closing operations, and having a stable flow rate characteristic. Is required.

  As a valve for a semiconductor manufacturing apparatus using the ALD method, a metal diaphragm valve is often used. Compared with conventional semiconductor manufacturing equipment, semiconductor manufacturing equipment employing the ALD method greatly increases the number of opening and closing operations of the valve. Therefore, metal diaphragm valves have a problem that cracks are liable to occur in the diaphragm due to metal fatigue, resulting in poor durability. is there. In addition, due to variations in processing accuracy and assembly accuracy of parts constituting the valve, there is a problem that flow characteristics are different between valves of the same standard, and the flow characteristics of the valve are not stable. In a certain semiconductor manufacturing apparatus, the variation in the flow rate characteristic (Cv value) due to the valve has a great influence.

  Therefore, as a solution to such a problem, there has been proposed a direct touch type metal diaphragm valve in which the durability of the diaphragm is improved and the variation in the flow characteristics of the valve is reduced (for example, see Patent Document 1).

  In Patent Literature 1, a stroke adjusting mechanism is provided outside a bonnet portion of a metal diaphragm valve having the same configuration as a conventional one, and the maximum valve stroke is smaller than the maximum bulging height of the metal diaphragm (55 to the maximum bulging height). By limiting the size (70%), the amount of strain and strain stress applied to the metal diaphragm at the time of opening and closing the valve is reduced, and the durability of the metal diaphragm is improved. Specifically, in a direct touch type metal diaphragm valve having a fluid passage inner diameter of 6.35 to 9.52 mm and an outer diameter of a metal diaphragm of 20 to 26 mm, the valve stroke is set to a maximum value of 0.65 to 0.7 (metal By limiting the outer diameter of the diaphragm to about 0.7 mm with a 26 mm valve, the number of continuous opening / closing operations of about 50 million was achieved while obtaining the required Cv value of 0.5 to 0.6. An example is provided.

  The stroke adjusting mechanism includes a lock nut screwed on a support cylinder of the actuator screwed and fixed to the upper surface of the bonnet, a screw for screwing a lock nut provided on an outer peripheral surface of the support cylinder, and the like. By adjusting the height of the support cylinder screwed into the bonnet, the valve stroke can be adjusted and the variation in the Cv value due to the valve can be eliminated.

JP 2007-64333 A

  However, in the direct touch type metal diaphragm valve described in Patent Literature 1, the stroke adjustment mechanism limits the valve stroke to the maximum value of 0.65 to 0.7, and the required Cv value (0.5 to 0.0). 6) While obtaining the durability of the metal diaphragm by reducing the amount of strain and the strain stress applied to the metal diaphragm during the opening and closing operation of the valve, the amount of the raw material gas supplied to the semiconductor manufacturing apparatus is reduced. When the amount is large, it is necessary to use a valve having a larger Cv value, which leads to an increase in the size of the valve and the actuator.

  Further, as in the structure described in Patent Document 1, the height of the support cylinder portion screwed into the bonnet is adjusted by a lock nut screwed onto the support cylinder portion of the actuator screwed and fixed to the upper surface of the bonnet. In the structure that adjusts the screwing height of the support tube into the bonnet, the mounting height of the actuator varies slightly due to variations in the processing accuracy of the threaded portion. Workability is poor because the height needs to be adjusted.

  In addition, the heating temperature of the source gas supplied to the semiconductor manufacturing apparatus has been about 200 ° C. In recent years, there has been a demand for an ALD valve capable of flowing a large-capacity source gas heated to about 300 ° C. In addition, there has been a demand for a novel structure of a valve with an actuator, which includes a valve capable of flowing a large flow rate, stabilizing the flow rate, and being compact, highly durable, and capable of operating at high speed, and an actuator having a high-temperature countermeasure.

  Therefore, the present invention has been developed to solve the above-mentioned problems, and the object of the present invention is to achieve high durability with a high Cv value, excellent high-speed operation, and easy adjustment of the valve lift amount. An object of the present invention is to provide a valve with an actuator, which is composed of a valve that can be performed and an actuator that is small and has excellent measures against high temperatures and high durability, and is suitable for use in a semiconductor manufacturing apparatus using the ALD method.

In order to achieve the above object, the invention according to claim 1 is a valve seat provided in the body communicating with the flow passage of the entrance and exit, having an annular horizontal horizontal surface-like valve seat facing downward and a valve seat below the valve seat. Inverted seat seal provided with a valve body provided at the lower end of a stem which is moved up and down by an actuator at a position, and an annular and horizontal valve seat seal at a position facing the valve seat toward the upper side of the valve body A valve seat opening area having a curtain area formed in a vertical cylindrical shape with a horizontal plane at the top and bottom, between the valve seat seal and the valve seat. The area is set equal to or less than the minimum flow path area of the flow path in the body, and the valve seat seal diameter of the valve seat is 1.5 to 2 times the minimum diameter obtained from the minimum flow path area. Actuator set to a range and the lift amount of the valve body is set to a minimum. It is a mediator with a valve.

The invention according to claim 2 is a valve for restricting a lift amount of the valve element by screwing a restriction member on an upper portion of a stem integrally connected to the valve element and locking the restriction member below the restriction member. By disposing an opening stopper and adjusting a screwing height position of the regulating member with respect to the stem when the valve body is seated, an interval between the regulating member and the valve opening stopper is adjusted, and a lift amount of the valve body is adjusted. Is a valve with an actuator.

The invention according to claim 3 is the valve with an actuator according to claim 1 or 2, wherein a resin bellows is used for the actuator.

According to the invention according to claim 1, a valve seat opening area having a curtain area formed by a cylindrical shape in a vertical plane and a vertical state is formed between the valve seat seal and the valve seat. Is set to be equal to or less than the minimum flow path area of the flow path in the body, and the valve seat seal diameter is set within a predetermined range of the minimum diameter obtained from the minimum flow path area, thereby providing a valve having the same Cv value. , The lift amount of the valve body can be minimized. At this time, a valve seat provided in the valve chamber toward the lower side, a valve body provided at the lower end of the stem at a position below the valve seat, and a valve seat seal facing the valve seat toward the upper side of the valve body. With the inverted seat seal structure provided with the above, the operation time for opening and closing the valve is shortened, enabling high-speed operation, and contributing to high durability of the valve. For these reasons, for example, it is suitable for a valve for a semiconductor manufacturing apparatus using the ALD method. In addition, the inverted seat seal structure allows a small load to be applied to the valve closing spring regardless of the flow of fluid from either side of the valve, so that a small spring can be used for the valve closing spring. It becomes possible.

According to the invention according to claim 2 , by adjusting the screw height position of the regulating member with respect to the stem when the valve body is seated, the lift amount of the valve body can be reduced only by adjusting the interval between the regulating member and the valve opening stopper. Since it can be set to a constant value, even if there is variation in the processing accuracy and the like in the dimensions of the body and hood, the lift amount of the valve body is set to a constant value by a simple operation for each valve to obtain the desired Cv value. be able to. Therefore, it is not necessary to set the Cv value of the valve by a complicated operation such as checking the flow rate, so that the workability is greatly improved and the flow rate can be stabilized.

According to the third aspect of the present invention, since the resin bellows is used for the actuator, the bellows hardly suffers from fatigue failure, and the durability of the actuator is greatly improved. Further, since the bellows made of synthetic resin are inexpensive, an actuator excellent in high temperature resistance and high durability can be obtained at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is the front longitudinal cross-sectional view which showed the fully opened state of one Embodiment of the valve with an actuator of this invention. (A) is sectional drawing of a cap. (B) is a sectional view of the resin bellows. (C) is a front vertical sectional view of the valve with the actuator with the cap and the resin bellows removed. It is a partial expanded sectional view near the valve seat of a valve open state. It is the front longitudinal section showing the fully closed state of other embodiments of the valve with an actuator of the present invention.

  Hereinafter, an example of an embodiment in a case where a normally closed structure of a valve with an actuator according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a front vertical sectional view showing a fully opened state of a valve with an actuator according to the present embodiment. FIG. 2A is a front sectional view of a cap, FIG. 2B is a front sectional view of a resin bellows, and FIG. Is a front vertical cross section of the valve with the actuator with the cap and the resin bellows removed.

  In FIG. 1, a valve 1 with an actuator includes a valve 2 and an actuator 3 mounted on the valve 2.

  First, the configuration of the valve 2 will be described. The valve 2 includes a body 21, a valve body 22, a stem 23, a closing member 24, an annular member 25, and a gasket 26. Note that the stem 23 is also included in the configuration of the actuator 3 described later.

Body 21 of valve 2, for example, made of stainless steel SUS316L or the like having a high corrosion resistance, together with the flow passage 27 and the flow path 28 is a doorway from both sides of the body 21 is formed in the horizontal direction, the body 21 internal Is provided with a valve chamber 29 communicating with these flow paths 27 and 28. An actuator insertion hole 30 is formed in the upper part of the body 21 in the vertical direction, and a valve element mounting hole 31 is formed in the lower part in the vertical direction. The flow path 27 and the actuator insertion hole 30 communicate with each other through a vertical communication path 32 formed perpendicularly to the center of the bottom surface 30 a of the actuator insertion hole 30 . Is formed with an annular horizontal horizontal valve seat 33 toward the lower side . In addition, the flow path 28 and the actuator insertion hole 30 communicate with each other by an inclined communication path 34 formed obliquely. As described above, the flow path 27 and the flow path 28, the valve chamber 29, the vertical communicating path 32, the actuator insertion hole 30 communicates with through the inclined connecting passage 34, is provided so as to be more moved up and down to the stem 23 The valve body 22 is positioned so as to face the valve seat 33, and the valve seat seal 41 of the valve body 22 is seated or unseated on the valve seat 33 to open and close the vertical communication passage 32, whereby the flow path 27 and the flow path 28 can be controlled.

  Above the actuator insertion hole 30 formed vertically in the upper part of the body 21, an accommodation hole 35 having a diameter larger than that of the actuator insertion hole 30 is formed, and a stepped portion is provided between the actuator insertion hole 30 and the accommodation hole 35. 36 are formed. An actuator mounting hole 37 having a diameter larger than that of the housing hole 35 is formed above the housing hole 35, and a female screw portion 37 a for mounting the actuator 3 to the body 21 is formed on the inner periphery of the actuator mounting hole 37. Are formed.

  Below the valve body mounting hole 31 formed in the lower part of the body 21, a closing member mounting hole 38 having a diameter larger than that of the valve body mounting hole 31 is formed, and the valve body mounting hole 31 and the closing member mounting hole are formed. A step portion 39 is formed between 38. An annular member mounting hole 40 having a diameter larger than that of the closing member mounting hole 38 is formed below the closing member mounting hole 38, and an inner periphery of the annular member mounting hole 40 for mounting the annular member 25. A female thread portion 40a is formed.

The valve body 22 is made of, for example, stainless steel such as SUS316L having high corrosion resistance, is disposed below the surface of the valve seat 33 formed at the lower end of the vertical communication passage 32 of the body 21, and is a driving source of the actuator 3. It has a reverse seat seal structure that can move up and down. For this reason, when the fluid flows from the valve body 22 side, the fluid pressure is applied to the back surface of the valve body 22 and acts as a valve seat seal pressure, so that the load of the valve closing spring can be set to a minimum. In addition, the time required for the valve body 22 to be seated on the valve seat 33 can be shortened, and high-speed operation can be performed. When the fluid flows from the opposite side (the bellows 54 side), the valve body 22, the stem 23 and the bellows 54 are integrally connected as described later, so that the valve body seal area and the effective area of the bellows are provided. Are substantially equal, the load from the fluid received by the valve body and the bellows due to the fluid pressure is substantially balanced, and the load due to the fluid pressure does not increase, so that the load of the valve closing spring can be small. Therefore, the inverted seat seal structure allows the valve closing spring to have a small load regardless of the flow of the fluid from either side of the valve, so that a small spring can be used. can do.

  A groove 22b for mounting an annular valve seat seal 41 is formed in an upper surface 22a of the valve body 22, and a stem mounting hole 22c for mounting a stem 23 is formed in the center of the upper surface 22a. A female screw portion 22d is formed on the inner periphery.

The valve seat seal 41 is formed of a resin that is excellent in corrosion resistance, sealability, heat resistance, and abrasion resistance and has small thermal deformation. In the 200 ° C specification, for example, it is preferable to use a PFA (polytetrafluoroethylene) resin, and in the 300 ° C specification, it is preferable to use a PI resin (polyimide resin) or a PEEK (polyetheretherketone) resin.
The valve seat seal 41 has a valve seat seal diameter S set to 1.5 times or more the minimum flow path diameter D obtained from the minimum flow area A of the flow path formed in the body 21, and is provided on the upper surface 22 a of the valve body 22. It is attached by crimping to the formed groove 22b. Generally, when the valve seat seal diameter S is increased to obtain a large Cv value, the load increases due to the fluid pressure, the load required for closing the valve element increases, and the actuator increases in size. However, as described above, the reverse seat seal structure allows the valve closing spring to have a small load even if fluid flows from either side of the valve. Can be

  In the valve with an actuator according to the present invention, the valve seat seal diameter S of the valve seat seal 41 is set to be at least 1.5 times the minimum flow path diameter D obtained from the minimum flow area A of the flow path formed in the body. The reason is that the largest element that determines the Cv value of the valve is the minimum flow path area of the valve, and even if the lift amount of the valve element is set to the minimum to enable high-speed operation of the valve element, By setting the valve seat opening area formed between the valve element and the valve seat when the valve is in the open position to be equal to or less than the minimum flow area A of the flow path in the body, the Cv value of the valve is reduced. This is in order not to be greatly damaged.

  The relationship between the minimum flow path area A and the minimum flow path diameter D can be expressed as Equation 1 below.

When the valve seat seal diameter is S and the lift amount of the valve body is L, the valve seat opening area V is a diameter S formed below the valve seat 33 and has a height as shown in FIG. Since L is the side surface area (curtain area) of the cylinder, V = πSL. The lift amount L of the valve body at which the valve seat opening area V is equal to the minimum flow path area A is πSL = π (D / 2) because the minimum flow path area A can be expressed by A = π (D / 2) ^{2. 2} and finally L = D ² / 4S. Here, if the valve seat seal diameter S is set to n times the minimum flow path diameter D, S = nD, and the lift amount L of the valve body is L = D / 4n.
Therefore, when the value of n is set large and the valve seat seal diameter S is made larger than the minimum flow path diameter D, the valve seat opening area V becomes equal to or less than the minimum flow area A of the flow path formed in the body. By setting, the lift amount L of the valve body 22 can be reduced. For example, when n = 1.5, the lift amount of the valve body 22 is ６ of the minimum flow path diameter D. When the lift amount L of the valve body 22 is set small, the opening and closing operation of the valve body 22 can be accelerated, and the valve body operation amount (lift amount L) is minimized, so that the durability of the valve is improved. Can be. For this reason, in order to reduce the lift amount L of the valve body, the valve seat opening area V is preferably equal to or smaller than the minimum flow path area A of the flow path in the body, but may be equal.

  If the lift amount L is reduced and the valve seat opening area V is set to be extremely smaller than the minimum flow path area A in order to speed up the opening and closing operation of the valve body, the Cv value of the valve is reduced. In setting the lift amount, it is necessary to make a trade-off between securing the Cv value and increasing the speed of the valve opening / closing operation. Also, in setting the valve seat seal diameter S, restrictions due to the internal structure of the valve and a trade-off of minimizing the lift amount of the valve body are necessary. In application to an actual valve, the valve seat seal diameter S is It is appropriate to set the range to be about 1.5 to 2 times the minimum flow path diameter D.

The stem 23 is made of, for example, stainless steel having high corrosion resistance, such as SUS316L, is vertically provided below the vertical communication passage 32 from the actuator 3, and has a male screw portion 23a formed at a lower end thereof. The valve 22 is screwed into a female thread 22d formed on the inner periphery of the stem mounting hole 22c of the valve 22 to be integrated with the valve 22 so that the valve 22 can be moved up and down.

  The closing member 24 is made of, for example, stainless steel such as SUS316L having high corrosion resistance, is formed in a substantially cylindrical shape with an open upper end, and has a flange 24a on the outer periphery of the upper end. A gasket accommodating groove 24c is formed on the outer peripheral side of the upper surface 24b of the flange portion 24a.

  The annular member 25 is made of, for example, stainless steel such as SUS304, and is formed in an annular shape having a storage hole 25a for storing the closing member 24 in the center, and a spanner hooking portion 25b is formed at a lower end portion. An annular projecting portion 25d is formed on the outer peripheral portion of the upper surface 25c of the annular member 25, and a male screw portion 25f to be screwed with a female screw portion 40a provided in the annular member mounting hole 40 is provided on a substantially upper half of the side surface 25e. Are formed.

  The gasket 26 is made of, for example, stainless steel, nickel steel, or the like having heat resistance and high corrosion resistance, and is mounted in a gasket accommodating groove 24 c formed on the outer periphery of the upper surface 24 b of the flange 24 a of the closing member 24.

  After attaching the valve body 22 to the stem 23 inserted into the body 21 formed as described above and integrating it, the closing member 24 with the gasket 26 mounted in the gasket accommodating groove 24c is mounted in the closing member mounting hole 38. I do. After that, when the annular member 25 is screwed into the annular member mounting hole 40 and torque is applied, the annular protrusion 25 d formed on the outer peripheral portion of the upper surface 25 c of the annular member 25 passes through the flange 24 a of the closing member 24. The gasket 26 is strongly pressed by the step portion 39, so that the space between the body 21 and the closing member 24 can be reliably sealed.

  Next, the configuration of the actuator 3 will be described. 1 and 2, the actuator 3 has a cap 45, a housing 46, a resin bellows 47, a piston adjuster 48, a spring mechanism 49, a bonnet 50, a bearing 51, a valve closing spring 52, a stem 23, and a bellows 54. Mounted on top of valve 2.

  The cap 45 is made of a suitable material such as stainless steel (SUS304 or the like), aluminum, resin, or the like, is formed in a substantially cylindrical shape having an open lower end, and is provided so as to be capable of housing the resin bellows 47 and the like. A joint 56 is provided at the center of the upper surface 45a of the cap 45, and air is sucked and exhausted through a suction hole 56a provided in the joint 56. A step 45c for pressing the resin bellows 47 is formed below the inner peripheral surface 45b of the cap 45, and a female thread 45d for screwing with the housing 46 is formed on the inner periphery of the lower end opening. Is formed.

  The housing 46 is made of, for example, stainless steel such as SUS316L having high corrosion resistance, and is formed in a shape in which a substantially cylindrical upper housing 57 and a substantially cylindrical lower housing 58 smaller in diameter than the upper housing 57 are vertically connected. The upper and lower ends are open. The upper end surface 46a of the housing 46 has a function as a valve opening stopper, and is used when setting the lift amount of the valve body 22.

  The upper housing 57 is formed in a substantially cylindrical shape, and is provided so that the valve closing spring 52 and the like can be housed therein. A flange portion 57b is formed on an outer peripheral surface 57a of the upper housing 57, and an accommodation groove 57c for accommodating the spring mechanism 49 is formed on an upper surface of the flange portion 57b. On the outer periphery of the flange portion 57b, a male screw portion 57d for screwing with a female screw portion 45d formed on the inner periphery of the lower end opening of the cap 45 is formed.

  The lower housing 58 is formed in a substantially cylindrical shape, and a through hole 58a for inserting the bonnet 50 is formed in the center of the inside. On the outer peripheral surface 58b of the lower housing 58, a male screw portion 58c for screwing with a female screw portion 37a formed on the inner periphery of the actuator mounting hole 37 formed on the body 21 of the valve body 2 is formed. An annular projecting portion 58e is formed on the outer periphery of the lower surface 58d of the lower housing 58.

  The resin bellows 47 is made of, for example, a fluororesin such as PTFE and PFA having heat resistance and corrosion resistance, and is provided so that the piston adjuster 48 and the like can be housed inside. The resin bellows 47 is provided so as to be extendable and contractable, and is provided so as to exert a force for returning to the original state when compressed, like a general compression spring. A flange 47a is provided at a lower end of the resin bellows 47, and an O-ring 61 can be mounted on an upper surface 47b of the flange 47a. Since the bellows made of fluororesin are less likely to cause fatigue failure than the metal welded bellows, an actuator having high temperature resistance and high durability can be formed at low cost.

  The piston adjuster 48 is made of, for example, stainless steel such as SUS304 having high corrosion resistance, is formed in a substantially columnar shape, and is provided with a circumferential housing groove 48a for housing the valve closing spring 52 from the lower surface to the vicinity of the upper surface. At the same time, a screw hole 48b is formed at the center from the lower surface side to be screwed with the upper end of the stem 23, and a female screw portion 48c is formed on the inner periphery of the screw hole 48b. In the center of the upper surface 48d of the piston adjuster 48, a storage hole 48e for storing the head of the bolt 62 for fixing the piston adjuster 48 and the stem 23 is formed, and in the center of the bottom surface 48f of the storage hole 48e. Has a through hole 48g for inserting the bolt 62. When the lower end surface 48h of the piston adjuster 48 attached to the upper end portion of the stem 23 is locked to the upper end surface 46a (valve opening stopper) of the housing 46, the stem 23 operates downward (valve opening). Operation), and has a function as a regulating member for limiting the lift amount of the valve body 22 to a constant value.

  The spring mechanism 49 has a metal spring 49a and a retainer member 49b, and is housed in a housing groove 57c formed in a flange 57b of an upper housing 57 of the housing 46. The metal spring 49a is provided by a disc spring in this embodiment in order to achieve compactness while exerting a high load, and is made of a spring stainless steel such as SUS304-CSP which can be used even at a high temperature. It is formed in consideration of slippage. The metal spring 49a is not limited to the disc spring of the present embodiment, but may be one in which coil springs are arranged at equal intervals in the accommodation groove 57c. The spring mechanism 49 has a retainer member 49b disposed above the metal spring 49a so that the load of the metal spring 49a can be uniformly applied to the lower surface 47c of the flange portion 47a of the resin bellows 47. The retainer member 49b is also made of stainless steel such as SUS304 having heat resistance and corrosion resistance.

  The bonnet 50 is made of, for example, stainless steel such as SUS316L having high corrosion resistance, is formed in a substantially cylindrical shape with upper and lower ends opened, and is provided with a bearing 51 and a stem 23 so that it can be mounted inside. A flange 50a is formed at the lower end of the bonnet 50, and a gasket accommodating portion 50c is formed on the outer periphery of the lower surface 50b of the flange 50a. An accommodation hole 63 for accommodating the bearing 51 and an accommodation hole 64 for accommodating the stopper portion 23d of the stem are formed inside the bonnet 50. The accommodation holes 63 and 64 are stopper portions 65 having an insertion hole for the stem 23 at the center. Are separated by

  The bearing 51 is made of, for example, beryllium copper for a spring or PEEK (polyether ether ketone) resin having low friction and wear resistance and excellent heat resistance, and is formed in a substantially cylindrical shape. Inside the bearing 51, a through hole 51a for inserting a stem is formed, and the stem 23 is provided in the through hole 51a so as to be movable up and down. Since the bearing 51 formed by such a simple structure can smoothly support and slide the stem 23 without lubrication even at a high temperature of 300 ° C., an actuator having a simple structure and high durability can be provided. Can be configured.

  The valve closing spring 52 is made of, for example, SUS631-WPC or SWOSC-V, and is stored in a compressed state between the upper housing 57 and the piston adjuster 48, so that the piston adjuster 48 is always elastically pushed upward. I'm going. As a result, the valve body 22 integrated with the piston adjuster 48 and the stem 23 is constantly urged toward the valve seat 33, and the valve seat seal 41 is in contact with the valve seat 33. It is kept closed.

  A screw hole 23 b for screwing a piston adjuster 48 and a bolt 62 for fixing the stem 23 is formed at an upper end portion of the stem 23, and an inner periphery of a screw hole 48 b of the piston adjuster 48 is formed on an upper outer periphery of the stem 23. The male screw portion 23c for screwing with the female screw portion 48c formed is formed. By screwing the female thread portion 48c of the piston adjuster 48 into the male screw portion 23c, a gap adjusting screw is formed, and the vertical mounting position (mounting height) of the piston adjuster 48 on the stem 23 can be adjusted. . After adjusting the mounting position of the piston adjuster 48, the bolt 62 is screwed into the screw hole 23b, whereby the positional relationship between the stem 23 and the piston adjuster 48 can be fixed.

  A stopper 23d is provided in the middle of the stem 23, and the stopper 23d abuts against a stopper 65 provided on the upper part of the housing portion 64 of the bonnet 50, so that the upward movement of the stem 23 is regulated. This prevents an excessive load from acting on the valve seat seal 41. The male screw portion 23a is formed at the lower end portion of the stem 23 as described above, and the stem 23 is screwed into a female screw portion 22d formed on the inner periphery of the stem mounting hole 22c of the valve body 22. And can be integrated into one.

  The bellows 54 is formed of, for example, a heat-resistant cobalt alloy having a use temperature of 300 ° C., and is provided so as to be able to expand and contract. The bellows 54 is welded to the stem 23, and the valve body 22, the stem 23, and the bellows 54 are integrally formed. For this reason, as described above, when the fluid flows from the bellows 54 side, the valve body 22, the stem 23, and the bellows 54 are integrally connected, so that the valve body seal area and the effective area of the bellows are substantially equal. If so, the load due to the fluid pressure is balanced, and the load due to the fluid pressure does not increase. Therefore, the spring load for closing the valve can be reduced, and the actuator can be downsized.

  In assembling the valve 1 with an actuator configured as described above, the stem 23 to which the bellows 54 has been welded is inserted into the through hole 51a of the bearing 51 mounted inside the bonnet 50 from the upper end side, and the stopper 23d of the stem 23 is inserted. Until it comes into contact with a stopper portion 65 provided on the upper portion of the accommodation portion 64 of the bonnet 50.

  Next, a gasket 66 made of stainless steel, nickel steel or the like is attached to the gasket accommodating portion 50c of the flange portion 50a of the bonnet 50 similarly to the gasket 26, and then the actuator insertion hole 30 of the body 21 is inserted from the lower end side of the stem 23. And the flange 50a of the hood 50 is inserted into the accommodation hole 35, and the gasket 66 is brought into contact with the step 36. Thereafter, the housing 46 is screwed into the female screw portion 37a on the inner periphery of the actuator mounting hole 37 while the bonnet 50 is inserted through the through hole 58a of the lower housing 58. At this time, the distance H from the valve seat 33 surface of the body 21 to the upper end surface 46a of the housing 46 is fixed so that the housing 46 is securely screwed to the body 21 by applying a constant torque.

  Next, the valve body 22 is inserted from the valve body mounting hole 31 below the body 21, and the valve body 22 is screwed into the male screw portion 23 a formed at the lower end of the stem 23, and then the closing member 24 with the gasket 26 attached thereto is removed. The annular member 25 is inserted into the closing member mounting hole 38 and the annular member 25 is screwed into the annular member mounting hole 40.

  Thereafter, the lower end of the opening / closing spring 52 is accommodated in the housing 46, and the upper end of the opening / closing spring 52 is accommodated in the accommodation groove 48a of the piston adjuster 48, and is formed in the inner periphery of the screw hole 48b of the piston adjuster 48. The female screw portion 48c is screwed into the male screw portion 23c formed on the outer periphery of the upper end of the stem 23. When the female screw portion 48c of the piston adjuster 48 and the male screw portion 23c of the stem 23 are screwed together, a gap adjusting screw is formed. At this stage, the lift amount L of the valve body 22 can be adjusted.

In adjusting the lift amount L, as shown in FIG. 2C, a gap gauge 68 is inserted between the upper end surface 46a of the housing 46 (valve opening stopper) and the lower end surface 48h of the piston adjuster 48 (restriction member). Then, the piston adjuster 48 is screwed into the male screw portion 23c of the stem 23 until the upper end surface 46a of the housing 46 and the lower end surface 48h of the piston adjuster 48 abut against the clearance gauge (lift setting shim) 68, and the engagement is maintained. After the bolt 62 is tightened in this state to fix the screwing height position of the piston adjuster 48 with respect to the stem 23, it is only necessary to remove the clearance gauge 68. As shown in the drawing, since the diameter of the lower end surface 48h of the piston adjuster 48 is substantially the same as the diameter of the upper end surface 46a of the housing 46, the piston adjuster 48 operates in the direction to separate the valve body 22 (the valve opening direction). When the lower end surface 48h of the piston adjuster 48 comes into contact with the upper end surface 46a of the housing 46, the upper end surface 46a of the housing 46 acts as a valve opening stopper and is locked. The thickness of the shim 68 becomes the lift amount L of the valve body 22 as it is. According to this adjustment method, even if the dimensions of the valve body and the bonnet vary due to processing accuracy and the like, the gap between the lower end surface 48h (the regulating member) of the piston adjuster 48 and the upper end surface 46a (the valve opening stopper) of the housing 46. The Cv value can be obtained by simply adjusting the lift amount and setting the lift amount to a constant value for each valve. Since there is no need to set the Cv value, not only the workability is greatly improved, but also the flow rate can be stabilized. If gap gauges having different thicknesses (for example, about 0.8 mm to 1.2 mm) are prepared in advance corresponding to each Cv value, the Cv value of the valve can be easily set to a required value. Is also possible.
Adjustment of the gap (interval) between the upper end surface 46a of the housing 46 and the lower end surface 48h of the piston adjuster 48 is the simplest and most reliable method using the above-described gap gauge (lift setting shim). However, besides this, the gap can be adjusted by measuring the gap using a caliper or the like.

  Next, the spring mechanism 49 is housed in the housing groove 57c formed in the flange portion 57b of the upper housing 57 of the housing 46, and the resin bellows 47 is put on the outside of the piston adjuster 48. When screwed into a male screw portion 57d formed on the outer periphery of the resin bellows 47, the space between the inside of the cap 45 and the resin bellows 47 is sealed by an O-ring 61 mounted on the outside of the resin bellows 47, and the flange portion of the resin bellows 47 is formed. The space between 47a, the spring mechanism 49 and the retainer member 49b is sealed by the retainer member 49b pressing the lower surface 47c of the flange portion 47a of the resin bellows 47 by the elastic force of the metal spring 49a of the spring mechanism 49. As a result, a closed space B is formed inside the cap 45 and outside the resin bellows 47.

When air is supplied into the space B from an air source (not shown) via the joint 56, the air pressure in the space B rises and presses the upper surface of the resin bellows 47 downward. When the pressing force of the air overcomes the resilience of the valve closing spring 52 which presses the piston adjuster 48 from the inside via the piston adjuster 48, the stem 23 fixed to the piston adjuster 48 by the bolt 62 causes the piston adjuster 48 to move. 3 is pushed down until the lower end face 48h of the housing abuts on the upper end face 46a of the housing 46 functioning as a valve opening stopper . In FIG. 3, the valve body 22 is separated from the valve seat 33 by a predetermined lift amount L to reduce the curtain area. A cylindrical valve seat opening area V is formed as shown by a broken line, and a fluid can be supplied at a predetermined Cv value. When the supply of air from the air source is stopped, the resiliency of the valve closing spring 52 pushes up the valve body 22 via the piston adjuster 48, and the valve seat seal 41 is seated on the valve seat 33.

  When the temperature of the actuator becomes high as a result of supplying the high-temperature raw material gas, the metal cap 45 and the synthetic resin resin bellows 47 have different coefficients of thermal expansion. Therefore, an O-ring for sealing between the cap 45 and the resin bellows 47. The sealing effect of 61 is limited to 200 to 250 ° C., but at a higher temperature, the lower surface 47 c of the flange portion 47 a of the resin bellows 47 is pressed by the retainer member 49 b receiving the elastic force of the metal spring 49 a of the spring mechanism 49. By pressing, the sealing property can be maintained.

Next, another embodiment will be described with reference to FIG. The same parts as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
In another embodiment, a cobalt alloy bellows 69 is used instead of the resin bellows. The cobalt alloy bellows 69 is formed of a cobalt alloy having a thickness of 0.2 mm to 0.3 mm and is attached to the lower end of the inner peripheral surface 45b of the cap 45 by a welded seal structure. It has the advantage of being able to be used in high temperature conditions up to this point and of having no fear of external leakage, but it is more expensive than resin bellows.
In this other embodiment, a cobalt alloy bellows 69 is used instead of the resin bellows, and the cobalt alloy bellows 69 is welded to the lower end of the inner peripheral surface 45b of the cap 45, except that the embodiment shown in FIG. Since the configuration is the same as that of the embodiment, the configuration, operation, and effect of the other portions are the same as those of the embodiment shown in FIG.

〔Example〕
Next, the effects of the valve with actuator of the present invention will be described with reference to examples. In the example, a valve having the same structure as that of the embodiment shown in FIG. 1 was used, and therefore, in this description, the reference numerals in FIGS. In the embodiment, the diameters of the flow paths 26 and 27 are 10.2 mm, the diameter of the vertical communication path 32 is 10.9 mm, and the diameter of the inclined communication path 34 is 8.5 mm. This is the portion of the passage 34, the minimum flow path diameter is 8.5 mm, and the minimum flow path area is 56.7 mm ² .

In the valve with an actuator according to the present invention, the valve seat seal diameter is set to 1.5 times or more of the minimum flow path diameter. However, in this embodiment, the valve seat seal diameter is set to 1. It was set to 14 mm which is a value slightly larger than 12.75 mm which is five times. When the valve seat lift diameter at which the valve seat opening area is equal to or less than the minimum flow path area when the valve seat seal diameter is 14 mm is obtained, the valve seat opening area is determined by the following equation. Rate) multiplied by the valve lift amount, and is equal to or less than the minimum flow passage area. Therefore, the minimum flow passage area (56.7 mm ² ) is determined by the valve seat seal diameter (14 mm) and π. The lift amount was set to 1.2 mm which was smaller than the divided value of 1.29 mm, and the valve seat opening area was set to 52.8 mm ^{2 which} was equal to or less than the minimum flow path area.

  In this example set as described above, the Cv value of the valve at a valve body lift amount of 1.2 mm was measured, and as a result, the Cv value was 1.2. In the conventional metal diaphragm valve, the lift amount of the metal diaphragm is limited to secure the durability of the metal diaphragm, and therefore, the Cv value is about 0.6 at the maximum. On the other hand, since the Cv value of the present embodiment is 1.2, the valve with an actuator according to the present invention can supply a flow rate about twice as large as that of a conventional metal diaphragm valve. Further, as a result of simultaneously measuring the operation speed of the valve, the opening and closing operation of the valve element is performed at a high speed in a short time of about 10 ms, and the effect of setting the valve element lift amount to a minimum is remarkable.

  As described above, in the valve with an actuator according to the present invention, in the valve body in which the valve seat opening area is set equal to or less than the minimum flow passage area of the flow passage in the body, the valve seat seal area is changed from the minimum flow passage diameter. By setting the minimum diameter to 1.5 times or more of the obtained minimum diameter, the lift amount of the valve body can be minimized, and a high-speed opening and closing operation of the valve body can be performed while securing a high Cv value. Durability can be improved. In addition, even if the dimensions of the valve body and bonnet vary, the desired Cv value can be easily set by adjusting the lift amount to a constant value for each valve using a clearance gauge. The workability is extremely excellent, and the flow rate can be stabilized.

  The valve with an actuator according to the present invention is suitable not only for a semiconductor manufacturing apparatus using the ALD method but also for the chemical industry and the pharmaceutical industry.

1 Valve with actuator 2 Valve
3 Actuator 21 Body 22 Valve Body 23 Stem 33 Valve Seat 41 Valve Seat Seal 46 Housing 46a Upper End (Valve Opening Stopper)
47 Resin bellows 47a Flange part 48 Piston adjuster 48h Lower end surface (restriction member)
49a Metal spring
51 Bearing 68 Clearance gauge (lift setting shim)
A Minimum flow area B Space D Minimum flow path diameter L Lift amount S Valve seat seal diameter V Valve seat opening area

Claims (3)

  A valve seat provided in a valve chamber provided inside a body communicating with the flow passage of the entrance and exit, having an annular horizontal horizontal surface facing downward, and a valve body provided at a lower end of a stem which is moved up and down by an actuator below the valve seat. And an inverted horizontal seat seal structure provided with an annular and horizontal valve seat seal at a position facing the valve seat toward the upper side of the valve body, and between the valve seat seal and the valve seat. A valve seat opening area having a curtain area that is formed in a cylindrical shape in which the upper and lower surfaces are horizontal and vertical is formed, and the valve seat opening area is equivalent to the minimum flow path area of the flow path in the body. Or less than or equal to, the valve seat seal diameter of the valve seat is set in the range of 1.5 to 2 times the minimum diameter obtained from the minimum flow area, and the lift amount of the valve body is minimized A valve with an actuator, characterized in that it is set. A regulating member is screwed onto an upper portion of a stem integrally connected to the valve body, and a valve opening stopper for locking the regulating member and limiting a lift amount of the valve body is disposed below the regulating member, by adjusting the screwing height position relative to the stem of the body the regulating member during seating, by adjusting the distance between the valve open stopper and the regulating member, the claims and to set the lift amount of the valve body 2. The valve with an actuator according to 1 . The valve with an actuator according to claim 1 or 2, wherein a resin bellows is used for the actuator.

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