Valve

Abstract

To provide a valve which can be used for a long period of time without causing seizure or the like even in high-temperature use.SOLUTION: The valve 1 includes the actuators 20 each having the first support portion (40, 26D) that slidably supports the stems 25 and 26, the diaphragm 11 that can open and close the fluid passages 2b and 2c by coming into contact with and separating from the 2D of the valve seat, and the disk 15 that presses the diaphragm 11 in conjunction with the stems 25 and 26. The second support portion (13) that slidably supports the disk 15 is provided in the body 2, the first sliding portion is constituted by a portion where the stems 25 and 26 and the first support portion (40, 26D) come into contact with each other, the second sliding portion is constituted by a portion where the disk 15 and the second support portion (13) come into contact with each other, and at least a part of the first sliding portion and at least a part of the second sliding portion are made of a carbonaceous material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a valve used in a semiconductor manufacturing device or the like. [Background technology]

[0002] The high-temperature valve disclosed in Patent Document 1 is equipped with a booster mechanism that amplifies the driving force of a driving pressure (e.g., compressed air), and the booster mechanism operates a valve stem, a disc, and a valve body to open and close a fluid passage. The valve stem and disc are supported by a bonnet so that they can move up and down. Grease is usually applied between the valve stem and disc and the bonnet to prevent seizure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 07-139648 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when valves are used at high temperatures for a long period of time, even if high-temperature grease is used, the grease can dry up, causing seizure and other problems, which can lead to valve malfunction.

[0005] Therefore, an object of the present disclosure is to provide a valve that can be used for a long period of time without seizing or the like even when used at high temperatures. [Means for solving the problem]

[0006] In order to achieve the above object, one aspect of the present disclosure provides a valve comprising: an actuator having a body with a fluid passage formed therein and including a valve seat; a stem that is capable of moving toward and away from the body; and a first support part that slidably supports the stem; a valve element that can open and close the fluid passage by abutting against and moving away from the valve seat; and a disk that moves in conjunction with the stem and presses the diaphragm, wherein a second support part that slidably supports the disk is provided within the body, a first sliding part is formed by a portion where the stem and the first support part contact each other, and a second sliding part is formed by a portion where the disk and the second support part contact each other, and at least a portion of the first sliding part and at least a portion of the second sliding part are made of a carbon material.

[0007] In the above valve, the actuator may have a third support part that slidably supports the stem at a position different from the first support part, and a third sliding part may be formed by a part where the stem and the third support part contact each other, and at least a part of the third sliding part may be formed from a carbon material.

[0008] In the above valve, the carbon material may be electrographitic. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a valve that can be used for a long period of time without seizing or the like even under high temperature use. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows a longitudinal cross-sectional view of a valve in a closed state in this embodiment. [Figure 2] FIG. 2 is a perspective view showing a partial cross section of a booster mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0011] A valve according to an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 shows a longitudinal cross-sectional view of a valve 1 in a closed state in this embodiment. While the type of valve is not limited, the valve 1 is a diaphragm valve and is used, for example, in a chamber of a semiconductor manufacturing device. The valve 1 comprises a body 2, a bonnet 10, and an actuator 20. In the following description, the actuator 20 of the valve 1 is referred to as the upper side, and the body 2 side is referred to as the lower side. Unless otherwise specified, each member constituting the valve 1 in this embodiment is assumed to be made of, for example, stainless steel.

[0012] The body 2 is formed with a valve chamber 2a, and an inlet passage 2b and an outlet passage 2c that communicate with the valve chamber 2a. An annular valve seat 2D that protrudes toward the bonnet portion 10 is provided on the periphery of the portion of the body 2 where the inlet passage 2b and the valve chamber 2a communicate (the opening of the inlet passage 2b). The body 2 has a cylindrical portion 2E. The cylindrical portion 2E is provided so as to extend upward, has a cylindrical shape, and is formed with a male thread portion on its outer periphery. The bonnet portion 10 is provided on the cylindrical portion 2E.

[0013] The bonnet portion 10 includes a diaphragm 11 , a bonnet 12 , a guide ring 13 , a retainer adapter 14 , a disc 15 , and a diaphragm retainer 16 .

[0014] The diaphragm 11, which serves as the valve element, is made of, for example, a nickel-cobalt alloy and is composed of multiple diaphragms. The outer periphery of the diaphragm 11 is compressed by an annular retaining adapter 14, and the diaphragm 11 is held against the body 2. The diaphragm 11 is generally spherical, and in its natural state, it has a generally upwardly convex arc shape. The diaphragm 11 contacts and separates from the valve seat 2D, thereby establishing or blocking communication between the inlet channel 2b and the outlet channel 2c. When the valve 1 is in the closed state, the diaphragm 11 contacts the valve seat 2D, blocking the inlet channel 2b and the outlet channel 2c.

[0015] The bonnet 12 is generally cylindrical and is inserted into the cylindrical portion 2E of the body 2 from above, abutting against the holding adapter 14 from above. The guide ring 13 is cylindrical and is inserted into a recess 12a formed on the inner periphery of the bonnet 12. The guide ring 13 abuts against the holding adapter 14 from above. The guide ring 13 is made of electrographite. Electrographite is, for example, artificial graphite that has excellent heat resistance and thermal conductivity in an inert atmosphere and has the property of excellent sliding properties under dry conditions. The guide ring 13 corresponds to the second support portion.

[0016] The disk 15 and the diaphragm retainer 16 are integrally formed into a generally cylindrical shape and are inserted into the bonnet 12 so as to be able to press the center of the diaphragm 11. The disk 15 is supported by a guide ring 13 so as to be able to slide in its axial direction (up and down).

[0017] The actuator 20 has a casing 21, a bellows 22, a piston 23, a piston ring 24, a booster mechanism 30, a first stem 25, a second stem 26, a disc spring 27, a first ring 40, and a second ring 41.

[0018] The casing 21 has a lower casing 21A, a middle casing 21B, and an upper casing 21C, and forms an accommodation chamber 21g that accommodates the booster mechanism 30 and the like.

[0019] The lower casing 21A has a disk portion 21A1, a lower protrusion 21A2, and an upper protrusion 21A3. The disk portion 21A1 is disk-shaped and has a through-hole 21d formed in its center. The first ring 40 is annular, fitted into the through-hole 21d, and fixed to the disk portion 21A1. The first ring 40 supports the lower end 26D of the second stem 26 (described below) so that it can slide in the vertical direction. The first ring 40 is made of electrographite.

[0020] The lower protrusion 21A2 is cylindrical and protrudes downward from the lower surface of the disk portion 21A1. A female thread is formed on the inner peripheral surface of the lower protrusion 21A2, and this female thread is screwed into the male thread of the cylindrical portion 2E of the body 2. This fixes the lower casing 21A to the body 2. The bonnet 12 is pressed downward by the disk portion 21A1, and the pressing adapter 14 presses the outer peripheral edge of the diaphragm 11. The upper protrusion 21A3 is cylindrical and protrudes upward from the top surface of the disk portion 21A1. A male thread is formed on the outer peripheral surface of the upper protrusion 21A3.

[0021] The intermediate casing 21B is cylindrical, and has female threads formed on the inner circumferential surfaces of its upper and lower ends. The female threads on the lower end are screwed into the male threads on the upper protrusion 21A3 of the lower casing 21A, thereby fixing the intermediate casing 21B to the lower casing 21A. A protrusion 21E protruding inward is provided on the inner circumferential surface of the intermediate casing 21B above the upper protrusion 21A3.

[0022] The upper casing 21C is generally disk-shaped, with a male thread formed on its outer periphery and a through-hole 21f formed in its center. The male thread is screwed into a female thread at the top end of the intermediate casing 21B, thereby fixing the upper casing 21C to the intermediate casing 21B. A driving pressure introduction joint 28 is attached to the through-hole 21f. In this embodiment, the driving pressure introduction joint 28 is attached to the upper casing 21C by welding.

[0023] Bellows 22 is cylindrical overall, and the outer edge of its upper end is fixed so as to be in close contact with the lower surface of upper casing 21C. Bellows 22 is a so-called welded bellows, and is made by alternately welding together the inner diameter portions and outer diameter portions of a plurality of annular metal plates.

[0024] The piston 23 is generally disk-shaped, and the outer periphery of the upper surface of the piston 23 is fixed so that the outer edge of the lower end of the bellows 22 is in close contact with the outer periphery of the upper surface. In this manner, the upper casing 21C, the bellows 22, and the piston 23 are integrated to form a driving pressure introducing chamber 23a. The piston ring 24 is annular and is fixed to the outer periphery of the lower surface of the piston 23.

[0025] Next, the booster mechanism 30 will be described with reference to Figures 1 and 2. Figure 2 is a perspective view showing a partial cross section of the booster mechanism 30.

[0026] The booster mechanism 30 includes a retainer 31 , six bearings 32 , three shafts 33 , three arms 34 , three parallel pins 35 , six washers 36 , and three retaining rings 37 .

[0027] The retainer 31 has a disk-shaped bottom 31A and a pin support 31B that protrudes upward from the bottom 31A. A stem hole 31c that penetrates the bottom 31A and the pin support 31B in the vertical direction is formed. The inner peripheral portion (stem hole 31c) of the bottom 31A supports a second ring 41 of a second stem 26 (described later) so that the second ring 41 can slide vertically. The outer peripheral edge of the bottom 31A is sandwiched between the protrusion 21E and the upper protrusion 21A3, thereby fixing the retainer 31 to the casing 21. Three radially extending grooves 31d are formed in the pin support 31B at equal intervals (120° apart) in the circumferential direction. A notch 31e is formed in the outer peripheral portion of the pin support 31B between the three grooves 31d. Bearing holes 31f are formed in the pin support portion 31B at portions positioned on either side of the groove portion 31d, and both ends of each bearing hole 31f open to the groove portion 31d and the notch 31e, respectively.

[0028] Each bearing 32 is made of electrographite and has a cylindrical shape. Each bearing 32 is inserted into a corresponding bearing hole 31f. Each shaft 33 passes through a pair of bearings 32 positioned on either side of groove 31d.

[0029] Each arm 34 has a pin hole 34a formed therethrough in a direction perpendicular to the longitudinal direction. Each arm 34 is disposed in the groove 31d, and a shaft 33 passes through the pin hole 34a and is supported so as to be able to swing. Each shaft 33 is press-fitted into the pin hole 34a of the arm 34, so that swinging of the arm 34 causes the shaft 33 to rotate. Each arm 34 has an inner end 34B and an outer end 34C in the radial direction of the shaft 33. The inner end 34B is located below a flange 25B (described below) of the first stem 25 within the stem hole 31c. The outer end 34C is located below the piston ring 24 and can abut against the underside of the piston ring 24.

[0030] Each parallel pin 35 is fitted into a pin groove formed in the inner end 34B. The parallel pin 35 can abut against the underside of the flange 25B of the first stem 25. The central axis of each shaft 33 is configured to be located closer to the inner end 34B than the midpoint between the abutting portion of the outer end 34C against the piston ring 24 and the abutting portion of the parallel pin 35 against the flange 25B.

[0031] In this way, because the central axis of the shaft 33 is located closer to the inner end 34B than to the outer end 34C, the force acting on the outer end 34C is amplified at the inner end 34B, and the amplified force acts on the first stem 25. The amplification factor is approximately (distance from the central axis of the shaft 33 to the abutting portion of the outer end 34C of the arm 34 against the piston ring 24) / (distance from the central axis of the shaft 33 to the abutting portion of the parallel pin 35 against the flange 25B).

[0032] Each washer 36 is provided on both ends of each shaft 33. Each retaining ring 37 is provided on one end of each shaft to prevent each shaft 33 from slipping out of the retainer 31.

[0033] As shown in Fig. 1, the first stem 25 includes a main body 25A extending in the vertical direction and a flange 25B protruding outward from the main body 25A. A male thread is formed at the lower end of the main body 25A. The flange 25B is inserted into a stem hole 31c of the retainer 31, and the first stem 25 is movable in the vertical direction within the stem hole 31c. The flange 25B is located above the inner ends 34B (parallel pins 35) of the three arms 34.

[0034] The second stem 26 is generally cylindrical and has a base 26A, an upper end 26B, a flange 26C, and a lower end 26D. Recesses with female threads are formed in the centers of the base 26A and the upper end 26B. The male threads of the first stem 25 are threadedly engaged with the female threads, thereby integrating the first stem 25 and the second stem 26.

[0035] The second ring 41 has a cylindrical ring body 41A and an annular flange 41B protruding outward from the lower end of the ring body 41A. The second ring 41 is made of electrographite. The ring body 41A is attached to the outer periphery of the upper end 26B. The lower end of the ring body 41A and the flange 41B are located in an annular recess formed in the upper surface of the base 26A. An annular stem plate 42 is disposed on the upper surface of the base 26A to cover the flange 41B. The stem plate 42 is fixed to the upper surface of the base 26A with multiple flat head screws 43. The stem plate 42 prevents the ring body 41A from slipping off the upper end 26B. The ring body 41A is inserted into the stem hole 31c and supported on the inner periphery of the bottom 31A so as to be slidable in the vertical direction. The second ring 41 constitutes part of the second stem 26.

[0036] The flange portion 26C protrudes outward from between the base portion 26A and the lower end portion 26D. The lower end portion 26D is inserted into a first ring 40 provided in the lower casing 21A and abuts against the disk 15 from above. The second stem 26 is supported so as to be movable in the vertical direction by inserting the second ring 41 attached to the upper end portion 26B into the stem hole 31c (the inner peripheral portion of the bottom portion 31A) and the lower end portion 26D into the first ring 40. In this way, the first stem 25 and the second stem 26 are configured to be movable toward and away from the body 2.

[0037] A plurality of disc springs 27 are arranged between the bottom portion 31A of the retainer 31 and the flange portion 26C of the second stem 26, and constantly urge the first stem 25 and the second stem 26 downward.

[0038] When valve 1 is in the closed state, first stem 25 and second stem 26 are urged downward by disc spring 27, and second stem 26 presses against disc 15 and diaphragm retainer 16, thereby pressing diaphragm 11 against valve seat 2D and blocking communication between inlet channel 2b and outlet channel 2c. Flange 25B of first stem 25 presses parallel pin 35 downward, and outer end 34C of arm 34 is positioned above inner end 34B.

[0039] When driving pressure is introduced into driving pressure introducing chamber 23a via driving pressure introducing joint 28, a downward force acts on piston 23. When piston 23 moves downward, piston ring 24 pushes outer end 34C of arm 34 downward. Arm 34 swings about the axis of shaft 33, and inner end 34B of arm 34 moves upward. When the upward force of inner end 34B (parallel pin 35) of arm 34, the force with which gas flowing through inlet channel 2b presses against diaphragm 11, and the restoring force of diaphragm 11 become greater than the biasing force of disc spring 27, first stem 25 and second stem 26 move upward, and the force pressing downward on disc 15 and diaphragm retainer 16 becomes smaller. As a result, diaphragm 11 is pushed up by the restoring force and the pressure of the fluid, and is separated from valve seat 2D, opening the valve.

[0040] As the first stem 25 and the second stem 26 move up and down, the lower end 26D slides against the first ring 40, and the second ring 41 slides against the inner periphery of the bottom 31A of the retainer 31. The first ring 40 corresponds to the first support portion or the third support portion, and the inner periphery of the lower end 26D corresponds to the first support portion or the third support portion. Furthermore, as the disc 15 and the diaphragm presser 16 move up and down, the disc 15 slides against the guide ring 13. The guide ring 13 corresponds to the second support portion.

[0041] As described above, in valve 1 of this embodiment, a sliding portion (corresponding to the first sliding portion or the third sliding portion) is formed by the portion where lower end portion 26D of second stem 26 and first ring 40 contact each other, a sliding portion (corresponding to the second sliding portion) is formed by the portion where disc 15 and guide ring 13 contact each other, and a sliding portion (corresponding to the first sliding portion or the third sliding portion) is formed by the portion where second ring 41 of second stem 26 and the inner periphery of bottom portion 31A contact each other. Guide ring 13, first ring 40, and second ring 41, which are part of each sliding portion, are made of a carbon material.

[0042] According to this configuration, the carbon material has high heat resistance, wear resistance, and sliding properties, so even if the valve 1 is used at high temperatures (e.g., 300°C or higher), it can be used for a long period of time without seizure or the like occurring in the sliding parts, thereby achieving high durability. Since the second stem 26 is slidably supported at two points, the first ring 40 and the inner circumferential part of the bottom portion 31A, the axis of the second stem 26 and the axis of the actuator 20 can be appropriately aligned.

[0043] The guide ring 13, the first ring 40, and the second ring 41 are made of electro-graphite, so that the sliding portions can have excellent sliding properties even without grease.

[0044] The present disclosure is not limited to the above-described embodiments, and those skilled in the art may make various additions and modifications within the scope of the present disclosure.

[0045] For example, in the above embodiment, electrographite was used as the carbon material constituting the guide ring 13, the first ring 40, and the second ring 41. However, for example, carbon fiber composite material or graphite may also be used. Using a carbon fiber composite material as the carbon material can improve the sliding properties of the sliding parts. When a carbon fiber composite material is used as the carbon material, aligning the fiber direction of the guide ring 13, the first ring 40, and the second ring 41 with the movement direction (sliding direction) of the second stem 26 and the disc 15 can further improve the sliding properties. While the second stem 26 is slidably supported at two locations, the first ring 40 and the inner periphery of the bottom portion 31A, it may be supported at any one location. To slidably support the second stem 26 by the first ring 40, the second ring 41 can be removed from the second stem 26. When the second stem 26 is slidably supported by the inner periphery of the bottom portion 31A, the first ring 40 can be removed from the disk portion 21A1.

[0046] The first ring 40 is attached to the through-hole 21d of the disk portion 21A1, but a ring made of a carbon material may be attached to the outer periphery of the lower end 26D of the second stem 26, and the ring at the lower end 26D may be slidably supported on the disk portion 21A1. The second ring 41 is attached to the upper end 26B of the second stem 26, but a ring made of a carbon material may be attached to the stem hole 31c of the bottom portion 31A, and the upper end 26B may be slidably supported by the ring. The guide ring 13 is provided inside the bonnet 12, but a ring made of a carbon material may be attached to the outer periphery of the disk 15, and the ring may be slidably supported on the bonnet 12, or the entire disk 15 may be made of a carbon material. All of the members constituting the sliding portion may be made of a carbon material.

[0047] The booster mechanism 30 is not limited to the configuration of the above embodiment, and may have other configurations. The actuator 20 is configured to generate a driving force by a driving pressure, but may be configured to generate a driving force by a solenoid, for example. [Explanation of symbols]

[0048] 1: Valve, 2: Body, 2b: Inlet passage, 2c: Outlet passage, 2D: Valve seat, 11: diaphragm, 13: guide ring, 15: disc, 25: first stem, 26: second stem; 26D: lower end portion; 31A: bottom portion; 40: first ring; 41: Second Ring

Claims

1. a body having a fluid passage formed therein and including a valve seat; an actuator having a stem that is provided so as to be able to approach and move away from the body, and a first support portion that slidably supports the stem; a valve body that can open and close the fluid passage by coming into contact with and separating from the valve seat; a disk that is coupled to the stem and presses the diaphragm, a second support portion that slidably supports the disk is provided within the body; a first sliding portion is formed by a portion where the stem and the first support portion contact each other, a second sliding portion is formed by a portion where the disk and the second support portion contact each other, At least a portion of the first sliding portion and at least a portion of the second sliding portion are made of a carbon material.

2. the actuator has a third support portion that slidably supports the stem at a position different from the first support portion, a third sliding portion is formed by a portion where the stem and the third support portion contact each other, 2. The valve according to claim 1, wherein at least a portion of the third sliding portion is made of a carbon material.

3. 3. The valve of claim 2, wherein the carbon material is electrographitic.

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