JP2004225839A - Flow control valve and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow control valve having a reduced total length, allowing the discharge of a minute flow rate of controlled fluid in a semiconductor manufacturing device. <P>SOLUTION: The flow control valve comprises a piston 52 slidably loading a cylinder for holding a valve element 54, a spring 53 for energizing the piston 52 in a valve opening direction, a valve opening control rod 64 rotation-inhibited for controlling movement of the piston 52, and a differential screw for adjusting the position of the valve opening control rod 64 with the feed of an inner screw 72 and an outer screw 71. The inner screw 72 consists of a screw portion of a stroke control rod 62 threaded to the valve opening control rod 64. After the piston 52 is energized to the direction of the valve seat 23 by the spring 53 to open the valve, the stroke control rod 62 is rotated in the given direction and moved to the valve opening direction and the state of the valve opening control rod 64 abutting on the piston 52 is set as an initial position, specified turns are given to the stroke control rod 62 in the opposite direction to the given direction to set the stroke of the valve opening control rod 64. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flow control valve capable of discharging a minute flow of control fluid in a semiconductor manufacturing apparatus or the like.
[0002]
[Prior art]
Various types of flow control valves capable of discharging a minute flow rate of control fluid in semiconductor manufacturing equipment and the like have been conventionally proposed. For example, as shown in a sectional view of FIG. There is a flow control valve 100 for finely adjusting the opening.
[0003]
When the diaphragm valve element 101 is pushed down by the slide stem 103 via the disk 102 and abuts on the valve seat 104, and the slide stem 103 is raised, the flow regulating valve 100 moves upward by the reaction force of the spring 105. It is separated from the valve seat 104. The slide stem 103 is configured to move up and down by screw feed by a differential screw. The slide stem 103 has a female screw formed on the inner circumference and is screwed with a male screw formed on the outer circumference of the spindle 106, and a screw portion between the slide stem 103 and the spindle 106 forms an internal screw 121. . Further, the spindle 106 is fixed to the outer sleeve 107 with a nut 108, and a male screw formed on the outer periphery of the outer sleeve 107 is screwed with a female screw formed on the inner periphery of the base tube 109 to form an outer screw 122. Is composed. A handle 110 is fixed to an upper end portion of the outer sleeve 107 with a fixing screw 111.
[0004]
With this configuration, when the handle 110 is rotated in a predetermined direction, the outer sleeve 107 is rotated by the external screw 122 to descend, and the slide stem 103 screwed to the descending spindle 106 is stopped from rotating. Relatively rise by the inner screw 121. Thus, the slide stem 103 is lowered by the pitch difference between the inner screw 121 and the outer screw 122, or is raised by the reverse rotation of the handle 110, and the opening degree of the diaphragm valve body 101 pressed against the slide stem 103 is delicate. It can be adjusted (for example, see Patent Document 1).
[0005]
Such a flow control valve 100 is incorporated in a chemical supply line of a semiconductor manufacturing apparatus or the like. A plurality of chemical liquid supply lines are provided to control a plurality of chemical liquids, and a fluid control device such as a flow control valve 100 or a flow control open / close valve is provided for each line. In this case, for example, the flow rate control valve 100 and the flow rate control opening / closing valve are juxtaposed in the flow path block to form a unit, thereby eliminating a connection joint and shortening the chemical supply line. (For example, see Patent Document 2).
[0006]
[Patent Document 1]
Japanese Utility Model Registration No. 2541613 (pages 2 to 4, FIG. 1)
[Patent Document 2]
JP 2001-263507 A (pages 3 to 5, FIG. 2)
[0007]
[Problems to be solved by the invention]
However, in the flow control valve 100 shown in FIG. 5, the stroke of the slide stem 103 is determined by the amount of movement of the disk 102, and the amount of movement of the disk 102 depends on the height of the valve seat 104 and the thickness of the thin film portion of the diaphragm valve body 101. To be directly affected by dimensional tolerances such as the thickness and the thickness of the disk 102, extra screws must be formed on the slide stem 103 in consideration of the dimensional tolerances of each member.
[0008]
Specifically, when the pitch of the outer screw 122 is 0.55 mm, the pitch of the inner screw 121 is 0.50 mm, and the integrated value of the dimensional tolerance of each member affecting the moving amount of the disk 102 is 0.50 mm, Since the pitch difference between the outer screw 122 and the inner screw 121 is as small as 0.05 mm, it is necessary to rotate the handle 110 a lot to raise and lower the slide stem 103. In order to secure the screw, the total length of the slide stem 103 must be reduced. It had to be 5.00 mm longer than when dimensional tolerances were not considered. Accordingly, the overall height of the flow control valve 100 has also increased by about 5.00 mm.
[0009]
This is not preferable because, for example, when the flow control valve 100 is incorporated into a semiconductor manufacturing apparatus in which the size of the apparatus has been reduced, the flow control valve 100 projects and hinders the flow. In particular, for example, by providing a differential screw on the upper part of the flow control on-off valve and integrating the flow control on-off valve and the flow control valve, when trying to reduce the size of the device, simply adjusting the flow rate If the structure of the differential screw of the valve 100 is only applied to the on-off valve for adjusting the flow rate, the overall height becomes high, and the above problem becomes remarkable.
[0010]
Then, this invention is made in order to solve the said problem, and an object of this invention is to provide the flow control valve with low total height.
[0011]
[Means for Solving the Problems]
The flow control valve according to the present invention has the following configuration in order to solve the above problems.
(1) A piston for holding a valve body and a cylinder for slidably holding a piston in a flow control valve for finely adjusting a valve opening for separating a valve body from a valve seat to adjust a flow rate of a control fluid. And a piston urging member housed in the cylinder to urge the piston in the valve closing direction, a valve opening adjustment rod that is stopped from rotating to adjust the amount of movement of the piston, and a screw of an inner screw and an outer screw. A differential screw for adjusting the position of the valve opening adjustment rod by feeding, and an internal screw is formed of a thread portion of a stroke adjustment rod screwed to the valve opening adjustment rod, and the piston is biased by a piston urging member. After biasing in the valve seat direction to close the valve, rotating the stroke adjusting rod in a predetermined direction and moving it in the valve opening direction, and setting the state in which the valve opening adjusting rod abuts against the piston as an initial position, Stroke adjustment lock It a is obtained by the rotation speed rotation of the provisions in the predetermined direction and the opposite direction, characterized by.
[0012]
(2) In the invention described in (1), an external thread is provided by a screw portion screwed to the cylinder, and an operation member fixed to the stroke adjusting rod is connected to the operation member in a play direction of the external screw. And a lock member for locking the operation member.
[0013]
(3) The invention according to (1) or (2), further comprising a rod urging member for urging the valve opening adjustment rod in the valve opening direction.
[0014]
(4) The position of the valve opening adjustment rod that adjusts the amount of movement of the piston that holds the valve element that comes into contact with or separates from the valve seat is adjusted by the screw feed of the inner screw and the outer screw of the differential screw, and the position of the piston is adjusted. When the operation air is supplied to the valve seat side, the piston moves in the valve opening direction against the urging force of the piston urging member to separate the valve body from the valve seat. An adjustment method, in which a piston is moved in a valve closing direction by an urging force of a piston urging member to close the valve, and is screwed to a valve opening adjustment rod, and an internal screw of a differential screw is provided at the screw portion. The adjustment rod is rotated in a predetermined direction to move in the valve opening direction, a position where the valve opening adjustment rod is abutted against the piston is set as an initial position, and the stroke adjustment rod is rotated in a predetermined direction in a direction opposite to the predetermined direction. It is characterized by rotating several times.
[0015]
(5) In the invention described in (4), when the initial position is set, the operating air is supplied to the valve seat side of the piston and the fine pressure air is supplied to the primary side, and the secondary pressure of the fine pressure air is supplied to the primary side. When the stroke adjustment rod set at the initial position is rotated in the direction opposite to the predetermined direction, the supply of the operation air is stopped.
[0016]
(6) In the invention described in (4) or (5), in a state where the operating air is supplied to the valve seat side of the piston, an external screw is provided with a screw portion which is fixed to the stroke adjusting rod and screwed with the cylinder. The flow rate is adjusted by rotating the operation member, and further, the operation member is locked by connecting the lock member to the operation member in the valve opening direction.
[0017]
Therefore, according to the invention having the above configuration, the piston is biased by the piston biasing member in the valve closing direction, and the stroke adjusting rod is rotated in the predetermined direction to move the valve in the valve opening direction. By moving the valve opening adjustment rod relatively in the valve closing direction and abutting against the piston, setting the state as an initial position, and then rotating the stroke adjustment rod in a predetermined number of rotations in a direction opposite to the predetermined direction. It is moved in the valve closing direction to set the stroke of the stroke adjusting rod. Therefore, the stroke of the stroke adjusting rod is excluded from the influence of dimensional tolerances of other members.
[0018]
Here, the prescribed number of rotations refers to the number of rotations required to set the valve opening adjustment rod to an arbitrary stroke. The stroke of the valve adjustment rod is calculated by dividing the stroke of the stroke adjustment rod by the pitch of the external thread of the differential screw, and subtracting the pitch of the internal thread of the differential screw from the pitch of the external thread of the differential screw. And the pitch between the outer screw and the inner screw of the differential screw is constant. Therefore, if the stroke of the stroke adjusting rod is set, the stroke of the valve opening adjusting rod is uniquely set. Because. As a result, the stroke of the valve opening adjustment rod, like the stroke adjustment rod, is also free from the effects of dimensional tolerances of other members, and the valve opening adjustment rod is finely adjusted according to the amount of rotation of the differential screw. It is in a state where it can be done.
[0019]
As a result, the flow rate characteristic corresponding to the rotation amount of the differential screw can always be obtained on the user side, and the valve opening adjustment can be performed accurately and easily. This is because, in a semiconductor manufacturing apparatus having a plurality of chemical liquid supply lines, when a flow control valve is used in a part of each chemical liquid supply line, without being disturbed by the rotational speed of the differential screw in other flow control valves, This is effective in that the valve opening of each flow control valve can be adjusted.
[0020]
As described above, the present invention eliminates the influence of dimensional tolerances of other members (for example, the height of the valve seat and the thickness of the valve body) when setting the stroke of the valve opening adjustment rod, and sets the differential. Since the position of the valve opening adjustment rod can be adjusted according to the amount of rotation of the screw, it is not necessary to form an extra screw on the valve opening adjustment rod, and the overall height can be reduced.
[0021]
At this time, operating air is supplied to the valve seat side of the piston to pressurize the valve opening adjustment rod and stroke adjustment rod in the valve opening direction, and leakage of the micro-pressure air supplied to the primary side to the secondary side is detected. While setting the initial positions of the valve opening adjustment rod and the stroke adjustment rod, the supply of the operating air to the valve seat side of the piston is stopped, and the strokes of the valve opening adjustment rod and the stroke adjustment rod are set. Accordingly, the position of the piston at which the flow rate of the control fluid becomes zero can be set accurately.
[0022]
After the stroke adjustment of the valve opening adjustment rod has been completed, the operation member is screwed into the cylinder and fixed to the stroke adjustment rod. The flow control valve locks the operating member with a lock member when using the product.However, when the operation air is supplied and stopped to the piston valve seat side during product assembly and the stroke of the valve opening adjustment rod is adjusted, In addition, play in the valve opening direction occurs on the outer screw of the differential screw. In this regard, if the operating air is supplied to the valve seat side of the piston at the time of flow rate adjustment, and the lock member is connected to the operating member in the play direction of the external thread, that is, in the valve opening direction, when the lock member is attached, The valve opening adjustment rod is not displaced from an arbitrary position, and the flow characteristics are not changed.
[0023]
However, depending on the use of the flow control valve, there may be a case where it is desired to control the flow without supplying the operating air to the valve seat side of the piston. In this case, the play direction of the differential screw may not be determined, and may have a flow rate characteristic different from that when the operation air is supplied to the valve seat side of the piston to adjust the flow rate.
[0024]
Therefore, a rod urging member is disposed between the valve opening adjustment rod and the piston, and the valve opening adjustment rod is moved in the valve opening direction, that is, the pressurizing direction of the operating air supplied to the valve seat side of the piston. Always bias in the same direction. With this, the differential screw is constantly urged in the direction of pressurizing the operating air supplied to the valve seat side of the piston via the valve opening adjustment rod even when the product is assembled or stopped. The backlash of the differential screw during the flow rate adjustment can be prevented, and the flow characteristic corresponding to the rotation amount of the differential screw can always be obtained.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a flow control valve according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of the flow control valve 1.
The flow rate adjusting valve 1 is a normally closed type air operated on-off valve, and the valve opening is adjusted by the screw feed of a differential screw. The flow control valve 1 has a body 2 integrally formed with a cylinder 5 including a cylinder tube 3 and a cover 4, and a differential screw projects from the cylinder 5.
[0026]
The piston chamber 51 of the cylinder 5 is slidably loaded with a piston 52 and is airtightly partitioned into an upper chamber 51A and a lower chamber 51B. The upper chamber 51A has a breathing hole 41 formed in the cover 4. The pilot port 31 formed in the cylinder tube 3 is opened in the lower chamber 51B. A control system for supplying operation air is connected to the pilot port 31. Further, a spring (corresponding to a “piston biasing member”) 53 is contracted in the upper chamber 51A, and constantly pushes down the piston 52 in the valve closing direction. The piston 52 has a reduced diameter portion 52a, and a diaphragm valve 54 is fixedly provided at the lower end thereof. The diaphragm valve element 54 has a peripheral portion sandwiched between the body 2 and the cylinder 5, and airtightly partitions a valve element storage chamber 55 formed between the body 2 and the cylinder 5.
[0027]
In the body 2, an input port 21 and an output port 22 are formed so as to communicate with a valve body storage chamber 55, and a valve seat 23 that communicates the input port 21 with the output port 22 is formed. When the diaphragm valve element 54 comes into contact with or separates from the valve seat 23, the communication state between the input port 21 and the output port 22 is switched.
[0028]
On the other hand, a guide tube 42 is protruded from the cover 4, and the guide tube 42 has a male screw formed on an outer periphery and an inner periphery as a sliding surface. The guide tube 42 is covered with a bag-shaped handle (corresponding to an “operating member”) 61 having a female screw formed on the inner periphery, and the handle 61 is adjusted in stroke by protruding from the through hole 44 of the cover 4. It is integrated with the rod 62 by a set screw 63 to form a differential screw as set forth in the claims. Here, a screw portion where the guide tube 42 of the cover 4 and the handle 61 are screwed together is referred to as an external screw 71 of a differential screw. The stroke adjusting rod 62 is formed to have a large diameter from a central portion so as to slide on the inner periphery of the guide tube 42 and has a step 62a. A female screw is formed on the inner periphery of the large diameter portion, and the outer periphery is formed. A valve opening adjusting rod 64 having a male screw formed therein is inserted therein. Here, the screw portion where the stroke adjustment rod 62 and the valve opening adjustment rod 64 are screwed together is referred to as an internal screw 72 of a differential screw. Note that a lock nut (corresponding to a “lock member”) 65 is attached to the handle 61 so as not to disturb the set screw position.
[0029]
The valve opening adjusting rod 64 has a large diameter portion slidably in contact with the guide tube 42 of the cover 4 to prevent shaft runout, and has a detent pin 66 attached thereto. The detent pin 66 is slidably inserted into a vertically extending slit 43 formed on the side surface of the cover 4, and restricts rotation of the valve opening adjustment rod 64. The valve opening adjustment rod 64 protrudes from the guide pipe 42 of the cover 4 to the upper chamber 51A of the cylinder chamber 51, and is provided so as to be able to contact and separate from the piston 52.
[0030]
Therefore, the assembly in the flow control valve 1 is performed in the following procedure. 2 and 3 are explanatory views of the assembly of the flow control valve 1. FIG.
[0031]
First, the cylinder tube 3 is fixed to the body 2 without the cover 4, the handle 61, the stroke adjustment rod 62, and the valve opening degree adjustment rod 64. At this time, the piston 52 integrated with the diaphragm valve element 54 is loaded in the cylinder tube 3, and the peripheral portion of the diaphragm valve element 54 is clamped between the body 2 and the cylinder tube 3.
[0032]
Thereafter, as shown in FIG. 2, the valve opening adjustment rod 64 is inserted into the stroke adjustment rod 62, and the valve opening adjustment rod 64 and the stroke adjustment rod are inserted so that the stroke adjustment rod 62 protrudes from the through hole 44 of the cover 4. After inserting 62 into the guide tube 42 of the cover 4, the detent pin 66 is attached to the valve opening adjustment rod 64 from the slit 43 of the cover 4. Then, a spring 53 is attached to the piston 52, and the cover 4 is fixed to the cylinder tube 3 with screws, thereby creating a positional relationship among the stroke adjustment rod 62, the valve opening degree adjustment rod 64, and the piston 52. At this time, the piston 52 is pushed down by the urging force of the spring 53, and the diaphragm valve body 54 is in contact with the valve seat 23 of the body 2.
[0033]
Next, while supplying operation air to the pilot port 31 and supplying micro-pressure air to the input port 21, the stroke protruding from the through hole 44 of the cover 4 is detected while detecting the leakage of the micro-pressure air to the output port 22. The adjustment rod 62 is raised by rotating the adjustment rod 62 in the arrow direction K1 in the figure. At this time, since the valve opening adjustment rod 64 is stopped by the rotation stop pin 66, it is lowered by the screw feed of the inner screw 72. The descending valve opening adjustment rod 64 is eventually abutted against the piston 52 against the thrust of the piston 52 by the operating air, and is locked to the valve seat 23 via the piston 52 and the diaphragm valve body 54. On the other hand, in the stroke adjusting rod 62, the step 62 a is locked to the guide tube 42 of the cover 4. At this time, the leakage of the fine pressure air becomes zero, and the positions of the stroke adjusting rod 62 and the valve opening adjusting rod 64 are set as initial positions.
[0034]
Then, as shown in FIG. 3, after the operation air to the pilot port 31 is stopped, the stroke adjusting rod 62 is rotated by a predetermined number of revolutions in the direction of arrow K2 in the figure. Thereby, only the stroke adjusting rod 62 is lowered, and the stroke St of the stroke adjusting rod 62 is set.
[0035]
Then, as shown in FIG. 1, a lock nut 65 is attached to the guide tube 42 of the cover 4, and the handle 61 is put on the guide tube 42 of the cover 4 and screwed into place. Fix to 62. Then, the lock nut 65 is screwed into the male screw of the guide tube 42 and connected to the handle 61.
[0036]
The flow control valve 1 assembled in this way is connected to another fluid control device via a connection joint (not shown), constitutes a part of a chemical liquid supply line of the semiconductor manufacturing apparatus, and adjusts the flow according to the intended use. Specifically, when the lock nut 65 is released with the operation air supplied to the pilot port 31 and the handle 61 is rotated in the predetermined direction K1 (or K2), the stroke adjustment rod 62 is raised by the screw feed of the external screw 71. On the other hand, the valve opening adjustment rod 64 screwed to the stroke adjustment rod 62 relatively lowers (ups) by the screw feed of the inner screw 72, and as a result, the valve opening adjustment rod 64 The valve opening of the diaphragm valve body 54 is finely adjusted by rising (falling) by the pitch difference (P1−P2) between the inner screw 71 and the inner screw 72. Then, the lock nut 65 is connected to the handle 61 to prevent the handle 61 from rotating.
[0037]
When the operating air is not supplied to the pilot port 31, the piston 52 is pushed down by the urging force of the spring 53 to bring the diaphragm valve body 54 into contact with the valve seat 23 when the operation air is not supplied to the pilot port 31. The chemical is not supplied from the input port 21 to the output port 22. On the other hand, when the operation air is supplied to the pilot port 31, the piston 52 rises until the piston 52 is stopped by the valve opening adjustment rod 64 against the urging force of the spring 53, and the diaphragm valve 54 is moved from the valve seat 23. Separate. As a result, the chemical supplied to the input port 21 is adjusted to a minute flow rate, and is discharged from the output port 22 in an appropriate amount.
[0038]
Therefore, according to the flow control valve 1 of the present embodiment, the piston 52 is urged in the valve closing direction by the spring 53, and the stroke adjusting rod 62 is rotated in a predetermined direction (the direction of arrow K1 in FIG. 2). By raising, the valve opening adjustment rod 64 is relatively lowered by the screw feed of the inner screw 72 and abuts against the piston 52, and after setting the state as an initial position, the stroke adjustment rod 62 is moved in the opposite direction to the predetermined direction. The stroke St of the stroke adjusting rod 62 is set by lowering by rotating a predetermined number of rotations in a direction (arrow direction K2 in FIG. 3). Therefore, the stroke St of the stroke adjusting rod 62 is free from the influence of dimensional tolerances of other members.
[0039]
Here, the prescribed number of rotations refers to the number of rotations required to set the valve opening adjustment rod to an arbitrary stroke. The stroke of the valve opening adjusting rod 64 is obtained by subtracting the pitch P2 of the internal screw 72 from the pitch P1 of the external screw 71 to a value (St / P1) obtained by dividing the stroke St of the stroke adjusting rod 62 by the pitch P1 of the external screw 71. (St / P1 * (P1-P2)), and the pitches P1 and P2 of the outer screw 71 and the inner screw 72 are constant. This is because if the stroke St is set, the stroke of the valve opening adjustment rod 64 is uniquely set. Therefore, similarly to the stroke adjusting rod 62, the stroke of the valve opening adjusting rod 64 is also free from the influence of dimensional tolerances of other members, and the valve opening adjusting rod 64 is delicate in accordance with the amount of rotation of the handle 61. The position can be adjusted.
[0040]
In the present embodiment, the specified rotation speed is a rotation speed at which the valve opening adjustment rod 64 can be moved up and down by a minimum stroke amount necessary for the diameter of the flow rate adjustment valve 1. This is to secure a wide flow rate adjustment region.
[0041]
As a result, on the user side, a flow characteristic in accordance with the amount of rotation of the handle 61 can always be obtained, and the adjustment of the valve opening can be performed accurately and easily. Specifically, when the pitch P1 of the outer screw 71 is 0.75 mm and the pitch P2 of the inner screw 72 is 0.70 mm and the valve opening adjustment rod 64 is to be raised by 0.2 mm, the user side It is sufficient to always rotate the handle 61 four times in the direction opposite to the predetermined direction (the direction K2 in FIG. 1). This is because, in a semiconductor manufacturing apparatus having a plurality of chemical liquid supply lines, when the flow rate adjusting valve 1 is used in a part of each chemical liquid supply line, the rotation speed of the differential screw in the other flow rate adjusting valve 1 is misleading. This is effective in that the valve opening of each flow control valve 1 can be adjusted.
[0042]
As described above, when the stroke of the valve opening adjustment rod 64 is set, the flow control valve 1 measures the dimensions of other members (for example, the height of the valve seat 23 and the thickness of the outer edge of the diaphragm valve element 54). Since the influence of the tolerance is eliminated and the position of the valve opening adjustment rod 64 can be adjusted according to the amount of rotation of the handle 61, there is no need to form an extra screw on the valve opening adjustment rod 64, and the overall height is reduced. be able to.
[0043]
At this time, as described above, the operation air is supplied to the pilot port 31 to pressurize the valve opening adjustment rod 64 and the stroke adjustment rod 62 in the valve opening direction, and the output port of the micro-pressure air supplied to the input port 21 is supplied. The initial positions of the valve opening adjustment rod 64 and the stroke adjustment rod 62 are set while detecting leakage to the valve 22, and then the supply of operation air to the pilot port 31 is stopped to stop the valve opening adjustment rod 64 and the stroke adjustment. Since the stroke of the rod 62 is set, the position of the piston 52 at which the flow rate of the chemical liquid as the control fluid becomes zero can be set accurately.
[0044]
After the stroke adjustment of the valve opening adjusting rod 64 is completed, the handle 61 is screwed into the cover 4 of the cylinder 5 and fixed to the stroke adjusting rod 62 with a set screw 63. The flow control valve 1 locks the handle 61 with the lock nut 65 when the product is used. However, when the product is assembled, the operation air is supplied to and stopped from the pilot port 31 so that the stroke of the valve opening adjustment rod 64 is adjusted. Above, play in the valve opening direction occurs on the outer screw 71 of the differential screw. In this regard, if air is supplied to the pilot port 31 during flow rate adjustment and the lock nut 65 is connected to the handle 61 in the play direction of the external screw 71, that is, in the valve opening direction, the mounting of the lock nut 65 Sometimes, the valve opening adjustment rod 64 is not shifted from an arbitrary position, and the flow characteristics are not changed.
[0045]
However, depending on the use of the flow control valve 1, there may be a case where it is desired to perform the flow control without supplying the operation air to the pilot port 31. In this case, the play direction of the differential screw may not be determined, and may have a flow rate characteristic different from that when the operation air is supplied to the pilot port 31 to adjust the flow rate.
[0046]
Therefore, as in a flow control valve 80 shown in FIG. 4, a rod spring (corresponding to a "rod urging member") 81 is contracted between the valve opening adjusting rod 64 and the piston 52, and the valve is reduced. The opening adjustment rod 64 is constantly urged in the valve opening direction, that is, in the same direction as the direction in which the operating air supplied to the pilot port 31 is pressurized. As a result, the differential screw is constantly pushed up in the pressurizing direction of the operation air supplied to the pilot port 31 via the valve opening adjustment rod 64 even when the product is assembled or stopped. The backlash of the differential screw at the time of adjustment can be prevented, and a flow characteristic corresponding to the rotation amount of the handle 61 can always be obtained.
[0047]
As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and various applications are possible.
[0048]
(1) For example, in the above embodiment, the initial position of the stroke adjusting rod 62 is set by locking the step 62a of the stroke adjusting rod 62 to the guide portion 42 of the cover 4. On the other hand, the stroke adjusting rod 62 may be locked by a stopper or the like and set to the initial position.
[0049]
(2) For example, in the above-described embodiment, at the time of assembling the flow rate adjusting valve 1, after supplying operation air to the pilot port 1 and setting the stroke adjusting rod 62 and the valve opening degree adjusting rod 64 to the initial position, The supply of operation air to the port 31 was stopped, and the stroke St of the stroke adjusting rod 62 was set. On the other hand, the flow regulating valve 1 may be simply assembled without supplying operation air to the pilot port 31.
[0050]
(3) For example, in the above-described embodiment, when the stroke adjusting rod 62 is rotated in the direction opposite to the predetermined direction (the arrow direction K2 in FIG. 3) at the time of assembling the product, only the valve opening adjusting rod 64 is turned on. It is assumed that the valve opening adjustment rod 64 is lowered and does not rise. On the other hand, when the friction between the stroke adjustment rod 62 and the valve opening adjustment rod 64 is large, a situation in which the valve opening adjustment rod 64 rises as the stroke adjustment rod 62 descends can be assumed. In this case, the stroke adjusting rod 62 is rotated by a predetermined number of revolutions, and when the handle 61 is fixed to the stroke adjusting rod 62, the stroke adjusting rod 62 is pushed down to move the valve opening degree adjusting rod 64 to the piston 52. To eliminate the influence of the friction.
[0051]
(4) For example, in the above embodiment, when assembling the flow control valve 1 to the gas supply unit, the input port 21 and the output port 22 of the body 2 are connected to another fluid control device via a connection joint (not shown). Like that. On the other hand, by using a flow path block instead of the body 2, the connection member may be omitted, and the installation area may be reduced.
[0052]
(5) For example, in the above embodiment, the flow control valve 1 has been described as an on-off valve, but may be a control valve that adjusts the opening in accordance with the operation air supplied from the pilot port 31.
[0053]
(6) For example, in the above embodiment, the flow control valve 1 is assembled to the chemical supply line of the semiconductor manufacturing apparatus. On the other hand, as long as the control fluid is controlled to a minute amount, the present invention can be applied to apparatuses other than the semiconductor manufacturing apparatus. Further, the control fluid is not limited to a chemical solution, but may be a working gas or the like.
[0054]
【The invention's effect】
According to the flow control valve of the present invention, in the flow control valve for controlling the flow rate of the control fluid by finely adjusting the valve opening for separating the valve body from the valve seat, the piston holding the valve body, the piston A cylinder that is slidably held, a piston biasing member that is housed in the cylinder and biases the piston in a valve closing direction, and a valve opening adjustment rod that is stopped from rotating to adjust the amount of movement of the piston. A differential screw for adjusting the position of the valve opening adjustment rod by screw feed between the screw and the outer screw, and the inner screw is formed of a thread portion of a stroke adjustment rod screwed to the valve opening adjustment rod; A state in which the piston is biased by the piston biasing member in the valve seat direction to close the valve, the stroke adjustment rod is rotated in a predetermined direction to move the valve in the valve opening direction, and the piston is brought into contact with the valve opening adjustment rod. Set as initial position Since is obtained by the rotation speed rotation of defining the stroke adjusting rod in the direction opposite to the predetermined direction, there is no need to form extra screw in the valve opening control rod without reducing the overall height.
[0055]
Further, according to the method of adjusting the flow rate adjusting valve of the present invention, the position of the valve opening adjusting rod that adjusts the amount of movement of the piston that holds the valve body that comes into contact with or separates from the valve seat is adjusted by adjusting the inner screw of the differential screw. When the operating air is supplied to the valve seat side of the piston, the piston is moved in the valve opening direction against the urging force of the piston urging member to move the valve body from the valve seat. A method of adjusting a flow control valve using a flow control valve to be separated, wherein the piston is moved in a valve closing direction by an urging force of a piston urging member to close the valve, and is screwed into a valve opening degree adjusting rod. The stroke adjusting rod for providing the inner thread of the differential screw at the screw portion is rotated in a predetermined direction and moved in the valve opening direction, and the position where the valve opening degree adjusting rod is abutted against the piston is set as an initial position, and the stroke is adjusted. Adjusting rod is specified in the direction opposite to the specified direction Since rotation speed can be not necessary to form an extra screw in the valve opening control rods, the overall height low.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a flow control valve according to an embodiment of the present invention.
FIG. 2 is also an explanatory view for assembling a flow regulating valve.
FIG. 3 is also an explanatory view of assembling a flow regulating valve.
FIG. 4 is a diagram showing a modification of the flow control valve.
FIG. 5 is a cross-sectional view of a conventional flow control valve.
[Explanation of symbols]
1,80 Flow control valve
3 cylinder
23 valve seat
52 piston
53 spring
61 handle
62 Stroke adjustment rod
64 Valve opening adjustment rod
65 Lock nut
66 Lock pin
71 Outside screw
72 Inner screw
81 Rod Spring

Claims (6)

By finely adjusting the valve opening that separates the valve body from the valve seat, the flow regulating valve that regulates the flow rate of the control fluid,
A piston for holding the valve element;
A cylinder that slidably holds the piston,
A piston biasing member housed in the cylinder and biasing the piston in a valve closing direction;
A valve opening adjusting rod that is stopped to adjust the amount of movement of the piston,
Having a differential screw that adjusts the position of the valve opening adjustment rod by screw feed of an inner screw and an outer screw,
The inner screw is formed of a thread portion of a stroke adjustment rod screwed into the valve opening adjustment rod,
The piston is biased by the piston biasing member in the valve seat direction to close the valve, the stroke adjustment rod is rotated in a predetermined direction to move the valve in the valve opening direction, and the piston is pushed by the valve opening degree adjustment rod. A flow control valve, characterized in that the stroke adjustment rod is rotated a prescribed number of revolutions in a direction opposite to the predetermined direction after setting the applied state as an initial position. The flow control valve according to claim 1,
An operating member fixedly provided on the stroke adjusting rod, wherein the external screw is provided with a screw portion screwed to the cylinder,
A flow control valve, comprising: a lock member connected to the operation member in a play direction of the outer screw to lock the operation member. In the flow control valve according to claim 1 or 2,
A flow regulating valve comprising a rod urging member for urging the valve opening adjusting rod in a valve opening direction. The position of a valve opening adjustment rod that adjusts the amount of movement of a piston that holds a valve body that abuts or separates from a valve seat is adjusted by screw feed of an inner screw and an outer screw of a differential screw, and the valve seat of the piston is adjusted. Flow control valve using a flow control valve that moves the piston in the valve opening direction against the urging force of the piston urging member and separates the valve body from the valve seat when the operating air is supplied to the side. Adjustment method,
Moving the piston in the valve closing direction by the biasing force of the piston biasing member to close the valve,
A stroke adjusting rod screwed into the valve opening adjusting rod and provided with the inner screw of the differential screw at a screw portion thereof is rotated in a predetermined direction and moved in a valve opening direction, and the valve opening adjusting rod is Setting the position abutted against the piston as an initial position,
A method for adjusting a flow control valve, characterized in that the stroke adjusting rod is rotated a predetermined number of revolutions in a direction opposite to the predetermined direction. The method for adjusting a flow control valve according to claim 4,
When setting the initial position, the operation air is supplied to the valve seat side of the piston, and the fine pressure air is supplied to the primary side, while detecting the leakage of the fine pressure air to the secondary side. ,
When the stroke adjusting rod set at the initial position is rotated in a direction opposite to a predetermined direction, the supply of the operation air is stopped. In the adjusting method of the flow regulating valve according to claim 4 or 5,
In a state in which the operating air is supplied to the valve seat side of the piston, the flow rate is adjusted by rotating an operating member that is fixed to the stroke adjusting rod and provides the external thread with a screw portion screwed with the cylinder, Further, a method of adjusting the flow regulating valve, wherein a lock member is connected to the operation member in a valve opening direction to lock the operation member.

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