JP2006155133A - Flow rate control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely control the flow rate of fluid circulating through a valve body through first and second ports. <P>SOLUTION: For a valve body 16 having a first port 12 connected to a processing chamber 37 and a second port 14 connected to a vacuum pump 39, a first valve seat part 36 where the first valve body 30 is seated on an internal wall face faced to the first port 12 and a second valve seat part 36 where a second valve body 34 is seated in the external direction of the radius of the first valve seat part 32, are formed. Then, a piston 20 formed in a guide body 22 is displaced by pressure fluid so that the second valve body 34 can be isolated from the second valve seat part 36, and that fluid can circulate between the first valve body 30 and the first vale seat part 32. An isolated distance between the first valve body 30 and the first valve seat part 32 is changed under a driving action by a driving part 24 so that the flow rate of the fluid circulating from the first port 12 to the second port 14 can be controlled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flow rate control valve capable of controlling the flow rate of fluid flowing through the fluid passage by opening and closing the fluid passage.

  Conventionally, for example, in a processing apparatus such as a semiconductor wafer or a liquid crystal substrate, the semiconductor wafer or the liquid crystal substrate is placed in a processing chamber where various processes are performed, and a vacuum state is formed on the surface of the semiconductor wafer under the action of a vacuum pump. Processing to form a film is performed. At this time, the pressure in the processing chamber is kept constant in order to ensure a constant film thickness formed on the surface of the semiconductor wafer.

  On the other hand, after the processing step is completed, the processing chamber in the atmospheric pressure state is again evacuated by the vacuum pump. At this time, a by-product may adhere to the inner wall surface of the processing chamber due to a gas used when forming a film on a semiconductor wafer. Therefore, a flow control valve is provided separately from the valve that opens and closes the fluid passage leading to the processing chamber in order to prevent separation of the by-product from the inner wall surface due to sudden pressure fluctuations during exhaust, and the flow control valve The flow is exhausted to the outside while controlling the flow rate exhausted from the processing chamber via a valve (see, for example, Patent Documents 1 and 2).

JP 2000-163136 A Japanese Patent No. 3330839

  By the way, in the prior art which concerns on patent documents 1 and 2, when controlling the flow volume of the fluid which distribute | circulates a valve body to the axial direction and distribute | circulates between the said valve body and a valve seat, the said valve body is made into a pressure fluid. It is displaced under the pressing action. With this configuration, it is difficult to control the displacement amount along the axial direction of the valve body with high accuracy, and accordingly, the flow rate of the fluid controlled by the separation distance between the valve body and the valve seat There is a difficulty in performing control accurately.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a flow rate control valve capable of controlling the flow rate of fluid flowing through the valve body with high accuracy.

In order to achieve the above object, the present invention provides a flow rate control valve that is disposed between an upstream side passage and a downstream side passage of a fluid passage and controls a flow rate of a fluid flowing through the fluid passage.
A valve body having first and second ports connected respectively to the upstream side and the downstream side of the fluid passage;
A drive unit provided in the valve body and driven to rotate by an electrical signal;
A conversion mechanism for converting the rotational driving force of the driving unit into a linear motion along the axial direction;
A first valve body provided so as to be displaceable along the axial direction via the conversion mechanism, and provided so as to be seated and separated from the first valve seat portion of the valve body;
A second valve body connected to a piston that is displaced along the axial direction by a pilot pressure, and having a seal member on a seating surface seated on the second valve seat portion of the valve body;
A detecting unit for detecting a rotational driving amount of the driving unit;
With
The communication state of the first port and the second port is switched under the displacement action of the second valve body, and the first port and the second port are circulated under the displacement action of the first valve body. The flow rate of the fluid is controlled.

  According to the present invention, when the second valve body is separated from the second valve seat portion by the pilot pressure, the shut-off state between the first port and the second port by the seal member attached to the second valve body is released. The fluid flows through a minute gap between the first valve body and the first valve seat portion. For example, in order to set the pressure in the processing chamber connected to the first port to a predetermined desired pressure, the first valve body is separated from the first valve seat portion by a predetermined interval under the drive action of the drive portion. The pressure in the processing chamber is adjusted by controlling the flow rate of the fluid flowing from the first port to the second port.

  Therefore, the amount of displacement along the axial direction of the first valve body can be detected with high accuracy based on the amount of rotation of the drive unit detected by the detection unit, and the pressure in the processing chamber and a preset pressure are detected. An electric signal corresponding to the difference between the first valve body and the first valve body can be displaced by a predetermined amount under the driving action of the drive section. By controlling based on the detection result, the flow rate of the fluid flowing from between the first valve body and the first valve seat is controlled with high accuracy, and the fluid in the processing chamber is controlled by the first port and the second port. And the pressure in the processing chamber can be set to a desired pressure.

  The first valve body may be provided inside the second valve body so as to be displaceable, and the first valve body and the second valve body may be provided independently so as to be displaceable. As a result, the first and second valve bodies can be displaced independently of each other, so that the second valve body provided outside the first valve body is separated from the second valve seat portion. After the communication state is established, only the first valve body is displaced along the axial direction to control the separation distance between the first valve body and the first valve seat portion, thereby controlling the flow rate of the fluid with high accuracy. Can be done.

  Further, the first valve body is connected to the conversion mechanism via the first valve shaft, and the first valve shaft is displaced into the second valve shaft that connects the second valve body and the piston. It is good to arrange freely. As a result, the first valve body can be displaced along the axial direction with respect to the second valve body via the first valve shaft, so that the first valve body and the second valve body are always coaxial. It can arrange | position and can make the said 1st and 2nd valve body seat reliably with respect to a 1st and 2nd valve seat part, respectively.

  Furthermore, a spring that urges the second valve body in a direction to seat the second valve body on the second valve seat portion may be provided between the valve body and the second valve body. As a result, even if the electrical signal supplied to the drive unit stops for some reason and the first valve body cannot be displaced in the axial direction, the second valve body is moved by the spring force of the first valve body. It is possible to block the communication state between the first port and the second port by seating on the two valve seats. Thus, in the flow rate control valve, the fluid communication state can be reliably interrupted by the second valve body even when the drive operation of the drive unit is stopped.

Still further, the present invention provides a flow control valve that is disposed between the upstream side passage and the downstream side passage of the fluid passage and controls the flow rate of the fluid flowing through the fluid passage.
A valve body having first and second ports connected respectively to the upstream side and the downstream side of the fluid passage;
A drive unit provided in the valve body and driven to rotate by an electrical signal;
A rotary valve connected to the drive unit and rotated and displaced inside the first port or the second port under the rotational action of the drive unit;
A valve body connected to a piston that is displaced along an axial direction by a pilot pressure, and having a seal member on a seating surface that seats on a valve seat portion of the valve body;
A detecting unit for detecting a rotational driving amount of the driving unit;
With
The communication state of the first port and the second port is switched under the displacement action of the valve body, and the fluid flowing between the first port and the second port under the rotation action of the turning valve It is characterized by controlling the flow rate.

  According to the present invention, when the valve body is separated from the valve seat portion by the pilot pressure, the blocking state between the first port and the second port by the seal member attached to the valve body is released, and Fluid flows through a minute gap between the valve and the valve. For example, in order to set the pressure in the processing chamber connected to the first port to a desired pressure set in advance, the rotary valve is rotated and displaced by a predetermined amount under the drive action of the drive unit, and the first The pressure in the processing chamber is adjusted by controlling the flow rate of the fluid flowing from the port to the second port.

  Therefore, it is possible to control the flow rate of the fluid flowing between the first port and the rotation valve with high accuracy by detecting the rotation amount of the rotation valve by the detection unit. An electrical signal corresponding to the difference between the indoor pressure and a preset pressure is supplied to the drive unit, and the rotary valve can be displaced by a predetermined amount under the drive action of the drive unit, The flow rate of the fluid flowing from between the valve seat portion and the valve seat portion can be controlled with high accuracy, and the pressure in the processing chamber can be set to a desired pressure.

  According to the present invention, the following effects can be obtained.

  That is, the communication state between the first port and the second port can be switched by the second valve body, and the flow rate of the fluid flowing between the first port and the second port can be controlled by the first valve body. At this time, since the displacement amount along the axial direction of the first valve body can be detected with high accuracy based on the rotation amount of the drive unit detected by the detection unit, the first valve body and the first valve body The flow rate of the fluid flowing from between the one valve seat portion can be controlled with high accuracy.

  In addition, the communication state between the first port and the second port is switched under the displacement action of the valve body, and the fluid flowing between the first port and the second port is changed by rotating the rotary valve. The flow rate can be controlled. At this time, the flow rate of the fluid flowing from between the first port and the rotary valve can be controlled with high accuracy by detecting the rotation amount of the rotary valve by the detection unit.

  A preferred embodiment of a flow control valve according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a flow control valve according to the first embodiment of the present invention.

  The flow control valve 10 includes a valve body 16 having first and second ports 12 and 14 through which pressure fluid flows, a valve mechanism 18 that switches a communication state of the pressure fluid in the valve body 16, and the valve body 16. A guide body 22 connected to the valve mechanism 18 so that the piston 20 is displaceable, a drive unit 24 that is rotationally driven by an electrical signal, the drive unit 24 and the valve mechanism unit 18, and A conversion mechanism 26 that converts the rotational driving force from the drive unit 24 into linear motion is provided.

  The valve body 16 is formed in a substantially cylindrical shape, and is formed on the axial line of the flow control valve 10 and opened downward. The valve body 16 is formed on the side of the valve body 16 so as to be substantially orthogonal to the first port 12. A second port 14 formed between the first port 12 and the communication chamber 28, and a communication chamber 28 communicating the first port 12 and the second port 14. The first valve seat portion 32 on which the first valve body 30 is seated and the second valve seat portion 36 on which the second valve body 34 of the valve mechanism portion 18 is seated.

  The first port 12 is connected to a processing chamber 37 (for example, a chamber) in a processing apparatus such as a semiconductor wafer through a fluid passage, while the second port 14 exhausts the fluid in the processing chamber 37. Is connected to a vacuum pump 39 through a fluid passage.

  Further, the inner peripheral surface of the first valve seat portion 32 is formed in an inclined shape that gradually decreases in diameter toward the first port 12 side.

  Inside the guide body 22 is formed a piston chamber 38 in which the piston 20 of the valve mechanism 18 is provided so as to be displaceable along the axial direction. A pilot port 40 to which a pressure fluid is supplied from a pressure fluid supply source (not shown) is formed at the side of the guide body 22, and the pressure fluid (pilot air) supplied to the pilot port 40 is inside the piston chamber 38. The piston 20 is displaced along the axial direction.

  In addition, a protrusion 42 that protrudes toward the valve body 16 (in the direction of arrow A) is formed at a substantially central portion of the guide body 22, and the second valve of the valve mechanism 18 is formed in the internal space of the protrusion 42. The body 34 is movably held through the holding hole 44.

  On the other hand, a casing 46 having a substantially U-shaped cross section is connected to the upper portion of the guide body 22, and the conversion mechanism 26 is provided inside the casing 46.

  The valve mechanism portion 18 is connected to a valve shaft (first valve shaft) 48 that is held inside the valve body 16 and the guide body 22 so as to be displaceable along the axial direction, and one end portion of the valve shaft 48. The first valve body 30 seated on the first valve seat portion 32 of the body 16, the piston 20 provided in the piston chamber 38 of the guide body 22, and connected to the piston 20 so as to surround the valve shaft 48. And a spring 50 interposed between the second valve body 34 and the end surface of the guide body 22.

  The valve shaft 48 is held in the guide hole 52 of the casing 46 so as to be displaceable along the axial direction via the bush 54, and is held inside the insertion hole 56 of the second valve body 34.

  The first valve body 30 is formed in a disc shape, and is integrally connected to one end portion of the valve shaft 48 via a bolt 58. The outer peripheral surface of the first valve body 30 is formed so as to be gradually reduced in diameter toward the first port 12 side, and the first valve body 30 is seated on the first valve seat portion 32. In this case, the outer peripheral surface comes into contact with the first valve seat portion 32 formed to be inclined.

  The second valve body 34 is formed on the side of the valve body 16 of the shaft portion 60 and the shaft portion (second valve shaft) 60 that is held in the holding hole 44 of the guide body 22 so as to be displaceable along the axial direction. A cylindrical diameter-enlarged portion 62 that is expanded in the radially outward direction, and a cylindrical valve body portion that is further expanded in the radially outward direction from the expanded-diameter portion 62 and whose end face is seated on the second valve seat portion 36. 64. The inner peripheral diameter of the valve body portion 64 is formed larger than the inner peripheral diameter of the first port 12.

  The shaft portion 60 is formed in a long cylindrical shape along the axial direction, and a valve shaft 48 is inserted through the insertion hole 56 therein and supported so as to be displaceable along the axial direction. That is, since the shaft portion 60 and the valve shaft 48 are arranged so as to be coaxial, the second valve body including the first valve body 30 and the shaft portion 60 connected to the valve shaft 48. 34 can be reliably and accurately seated on the first valve seat portion 32 and the second valve seat portion 36, respectively.

  Since the seal member 66 is mounted on the inner wall surface of the holding hole 44 that holds the shaft portion 60 and the inner wall surface of the center hole formed in the piston 20 via an annular groove, The airtightness inside the piston chamber 38 is reliably maintained. The piston 20 is connected to the end portion of the shaft portion 60 via a connection nut 68.

  A bellows-like first bellows 70 is interposed between the inner diameter of the enlarged diameter portion 62 between the inner wall surface of the enlarged diameter portion 62 on the shaft portion 60 side and the first valve body 30, and can be expanded and contracted. Similarly, a bellows-like second bellows 72 is interposed between the body portion 64 and the end surface of the guide body 22 so as to be extendable. A spring 50 is housed inside the second bellows 72, and one end of the spring 50 surrounds the protrusion 42 of the guide body 22 and is seated on the bottom of the guide body 22. The elastic force of the spring 50 urges the second valve body 34 toward the second valve seat portion 36 (in the direction of arrow A).

  An O-ring (seal member) 74 is attached to the valve body portion 64 through an annular groove on the end surface facing the second valve seat portion 36, and the valve body portion 64 is seated on the second valve seat portion 36. As a result, the O-ring 74 comes into contact with the second valve seat portion 36 and the communication state between the first port 12 and the second port 14 is blocked. Note that the valve body portion 64 of the second valve body 34 is formed so as to expand radially outward from the first valve body 30, and thus is disposed so as to cover the first valve body 30. That is, when the first valve body 30 is seated on the first valve seat portion 32, the first valve body 30 is surrounded by the second valve body 34 seated on the second valve seat portion 36 (see FIG. 1).

  A piston packing 76 is attached to the outer peripheral surface of the piston 20 via an annular groove, and a wear ring 78 is attached at a predetermined interval in the axial direction. Thereby, the airtightness inside the piston chamber 38 can be suitably maintained by the piston packing 76 or the like.

  The drive unit 24 includes a rotation drive source 80 such as a stepping motor, and is provided on a cover member 82 that closes the casing 46. For example, a detection unit 84 such as a rotary encoder is provided inside the drive unit 24 to detect a rotation amount such as a rotation angle or a rotation number of the drive unit 24.

  That is, the detection signal detected by the detection unit 84 is output to a control unit (not shown) connected to the drive unit 24, and the amount of current supplied to the rotary drive source 80 is controlled by the control unit. This makes it possible to control the amount of rotation of the rotational drive source 80.

  The conversion mechanism 26 is provided inside the casing 46, and is connected to a drive shaft 86 of the rotational drive source 80 via a coupling member 88. The conversion mechanism 26 is displaceable with respect to the ball screw shaft 90. The flange 94 of the displacement member 92 is connected to the end of the valve shaft 48 via a bolt 58.

  The ball screw shaft 90 is rotatably supported at one end side connected to the drive shaft 86 by a bearing 96 provided inside the cover member 82 and has a bush 98 provided at the casing 46 at the other end side. It is hold | maintained so that rotation is possible.

  The flow control valve 10 according to the first embodiment of the present invention is basically configured as described above. Next, the operation, action, and effect will be described. In addition, as FIG. 1 shows, the valve closed state in which the 1st and 2nd valve bodies 30 and 34 were each seated in the 1st and 2nd valve seat parts 32 and 36 of the valve body 16 is demonstrated as an initial state.

  In such an initial state, the outer peripheral surface of the first valve body 30 is seated on the peripheral surface of the first valve seat portion 32, and the valve body portion 64 of the second valve body 34 is second due to the elastic force of the spring 50. The communication between the first port 12 and the second port 14 is blocked by the O-ring 74 that is seated on the valve seat portion 36 and is in contact with the second valve seat portion 36. Is in a state.

  First, by energizing the vacuum pump 39 connected to the second port 14, the pressure of the second port 14 is reduced under the energizing action of the vacuum pump 39. The fluid in the 2-port 14 is exhausted. At this time, the fluid inside the processing chamber 37 is blocked from communicating with the first port 12 and the second port 14 by the first and second valve bodies 30 and 34 of the valve mechanism 18, so There is no distribution from the first port 12 to the second port 14.

  Next, a pressure fluid (for example, compressed air) is supplied from a pressure fluid supply source (not shown) to the pilot port 40 of the guide body 22, and the pressure fluid is introduced into the piston chamber 38. 20 is displaced to the drive unit 24 side (arrow B direction). Along with this, the second valve body 34 connected to the piston 20 is displaced toward the drive section 24, and the valve body section 64 is separated from the second valve seat section 36.

  Thereby, as shown in FIG. 2, the valve closed state of the second valve seat portion 36 by the second valve body 34 in which the O-ring 74 is attached to the valve body portion 64 is released, and the high pressure processing chamber 37 is released. Under the urging action of the vacuum pump 39, the fluid flows to the communication chamber 28 and the second port 14 where the pressure is low. Specifically, the fluid flows through the gap between the outer peripheral surface of the first valve body 30 and the peripheral surface of the first valve seat portion 32 by a minute flow rate.

  That is, since a minute gap exists on the contact surface between the first valve body 30 and the first valve seat portion 32, the fluid in the processing chamber 37 flows into the communication chamber 28 and the second port 14. The fluid flows from the first port 12 to the second port 14 through the gap due to the pressure difference with the fluid, and a small amount of the fluid in the processing chamber 37 is exhausted to the second port 14.

  At this time, the pressure value in the processing chamber 37 is always detected by a pressure detection unit (not shown) that detects the pressure in the processing chamber 37, and the pressure value is output to a control unit (not shown). Yes. Then, a control signal is output from the control unit to the rotational drive source 80 of the drive unit 24 so that the pressure in the processing chamber 37 becomes a preset value.

  As a result, the rotational drive source 80 is rotationally driven by a predetermined amount based on the control signal, and the rotational drive force of the rotational drive source 80 is transmitted to the ball screw shaft 90 via the coupling member 88 to be transmitted to the ball. Under the rotational action of the screw shaft 90, the displacement member 92 is displaced in the axial direction toward the drive unit 24 side (arrow B direction).

  Then, the valve shaft 48 connected to the displacement member 92 is displaced in the direction of arrow B, and the first valve body 30 connected to the valve shaft 48 retracts the first bellows 70 from the first valve seat portion 32. The first port 12 and the second port 14 are separated from each other via the communication chamber 28. As a result, the fluid in the processing chamber 37 flows to the second port 14 side where the pressure is low under the urging action of the vacuum pump 39, and the fluid in the processing chamber 37 passes through the communication chamber 28 to the second port 14. Is exhausted.

  That is, in the initial stage of exhaust of the processing chamber 37 by the flow control valve 10, the fluid in the processing chamber 37 is separated from the first port 12 to the communication chamber 28 and the first valve body 30 by separating the first valve body 30 from the first valve seat portion 32. When the first valve element 30 is separated from the first valve seat 32 so that the minute flow rate is gradually exhausted to the second port 14 and the pressure in the processing chamber 37 becomes a desired pressure. The amount of displacement is controlled.

  As described above, after the second valve body 34 is separated from the second valve seat portion 36, the displacement amount of the first valve body 30 is controlled by the detection unit 84 provided in the drive unit 24, thereby the first valve By controlling the separation distance between the body 30 and the first valve seat 32, the flow rate of the fluid flowing from the first port 12 to the second port 14 can be controlled with high accuracy.

  Therefore, the pressure in the processing chamber 37 can be maintained at a desired value with high accuracy, and the first valve body 30 and the second valve body 34 are opened in a stepwise manner, and the pressure inside the processing chamber 37 is increased. The fluid can be exhausted slowly from the first port 12 to the second port 14, and sudden pressure fluctuations that occur inside the processing chamber 37 connected to the first port 12 when the valve is opened can be prevented. it can.

  In addition, after the second valve body 34 is separated from the second valve seat portion 36, a judgment is made by comparing the set pressure in the processing chamber 37 preset in the control portion with the detected pressure value in the processing chamber 37, Feedback control for outputting a control signal based on the difference between the set pressure and the pressure value to the drive unit 24 is performed. As a result, the rotational drive source 80 is rotationally driven based on the control signal, and the separation distance between the first valve body 30 and the first valve seat portion 32 is controlled. The flow rate of the fluid exhausted through 12 can be controlled with high accuracy.

  At that time, the amount of rotation of the rotary drive source 80 is detected by the detector 84, so that the displacement amount of the first valve body 30 along the axial direction of the first valve body 30 is reliably and highly accurate based on the amount of rotation. Therefore, stable displacement of the first valve body 30 can be performed, and reproducibility of the displacement position of the first valve body 30 is ensured.

  On the contrary, when the valve closed state in which the communication state between the first port 12 and the second port 14 is blocked by the first valve body 30 and the second valve body 34, the rotational drive source 80 of the drive unit 24 is used. By reversing the polarity of the output control signal, the rotational drive source 80 is rotationally driven in the opposite direction. Then, the displacement member 92 is displaced toward the valve body 16 (in the direction of arrow A) under the rotational action of the rotational drive source 80, and the first valve body 30 is seated on the first valve seat portion 32 (see FIG. 2). ).

  Further, the supply of the pressure fluid supplied to the piston chamber 38 is stopped, and the piston chamber 38 is opened to the atmosphere through the pilot port 40, so that the piston 20 is relieved by the spring force of the second valve seat 36. Displacement toward the side (arrow A direction). As a result, the valve body portion 64 of the second valve body 34 connected to the piston 20 is seated on the second valve seat portion 36, and the communication between the first port 12 and the second port 14 is blocked (see FIG. 1).

  As described above, in the flow rate control valve 10, the fluid is exhausted from the first port 12 to the second port 14, and the gap between the first valve body 30 and the first valve seat portion 32 in the initial stage of the exhaust. Therefore, for example, it is possible to prevent the sealing member and the first valve seat portion 32 from sticking to each other when a sealing member made of an elastic material is provided on the contact surface of the first valve body 30. . Therefore, there is no problem that the first valve body 30 is fixed to the first valve seat portion 32 and is not separated. Therefore, in the conventional flow rate control valve, when the seal member mounted on the seating surface of the valve body is fixed to the valve seat, it is possible to prevent the pop-out phenomenon that has occurred due to sudden pressure fluctuation. .

  In addition, even when the supply of the current supplied to the drive unit 24 is stopped for some reason, the first valve body 34 is seated on the second valve seat portion 36 by the elastic force of the spring 50, whereby the first The valve 12 can be closed with the communication between the port 12 and the second port 14 blocked. Thereby, even when the drive of the drive part 24 stops for some reason, it is possible to prevent the fluid in the processing chamber 37 from being exhausted from the first port 12 to the second port 14.

  Next, a flow control valve 150 according to a second embodiment is shown in FIGS. In addition, the same referential mark is attached | subjected to the component same as the flow control valve 10 which concerns on this Embodiment mentioned above, and the detailed description is abbreviate | omitted.

  In the flow control valve 150 according to the second embodiment, a throttle valve 156 that opens and closes under the drive action of the drive unit 154 is provided inside the first port 12 of the valve body 152, It differs from the flow control valve 10 according to the first embodiment in that a single valve body 160 is seated on the valve seat 158 of the 1 port 12.

  In the flow control valve 150, a rotary shaft 162 of a throttle valve 156 is rotatably held inside the first port 12 so as to be substantially orthogonal to the axis of the first port 12. A disc-shaped valve plate 164 is mounted. The rotation shaft 162 is rotatably held by a pair of bearings 166 a and 166 b provided on the wall portion of the first port 12.

  In this case, the rotation shaft 162 is connected to the drive shaft 86 of the drive unit 154 provided on the side portion of the first port 12. The drive unit 154 is provided with a detection unit 84 that detects the amount of rotation of the drive unit 154.

  Further, the diameter of the valve plate 164 made of a metal material is formed to be slightly smaller than the inner peripheral diameter of the first port 12, and the valve plate 164 is rotated under the rotating action of the rotating shaft 162 by the drive unit 154. The first port 12 is opened and closed by the pivotal displacement of 164. Specifically, as shown in FIG. 4, when the valve plate 164 is set to a substantially horizontal state, the communication state between the first port 12 and the communication chamber 28 is cut off. By setting the valve plate 164 to a substantially vertical state, the first port 12 and the communication chamber 28 communicate with each other (see FIG. 6).

  On the other hand, a valve seat portion 158 is formed in the valve body 152 facing the first port 12, and a valve shaft 48 connected to the piston 20 provided in the guide body 22 is provided in the valve seat portion 158. A plate-like valve body 160 is provided to be seated.

  In the flow control valve 150 configured as described above, first, in the valve closed state in which the communication between the first port 12 and the second port 14 is blocked by the throttle valve 156 and the valve body 160 shown in FIG. Under the urging action of the vacuum pump 39 connected to the 2 port 14, the fluid in the second port 14 and the communication chamber 28 is exhausted. At that time, the fluid in the processing chamber 37 is circulated from the first port 12 to the second port 14 because the communication between the first port 12 and the second port 14 is blocked by the valve body 160. There is nothing.

  Next, as shown in FIG. 5, by supplying a pressure fluid (for example, compressed air) from a pressure fluid supply source (not shown) to the pilot port 40 of the guide body 22, the piston 20 moves to the drive unit 154 side. The valve body 160 is separated from the valve seat portion 158 by being displaced (in the direction of arrow B).

  As a result, the valve closed state of the valve seat portion 158 by the valve body 160 to which the O-ring 74 is attached is released, so that the fluid in the processing chamber 37 is brought into contact with the valve plate 164 under the negative pressure action in the communication chamber 28. Only a minute flow rate flows through a gap between the first port 12 and the inner wall surface.

  Next, when a control signal is output from the control unit (not shown) to the drive unit 154, the drive shaft 86 of the drive unit 154 is rotationally driven by a predetermined amount based on the control signal. Rotating shaft 162 connected to is integrally rotated and displaced. As a result, the valve plate 164 mounted on the rotating shaft 162 is rotated and displaced, the closed state of the first port 12 is released, and the valve plate 164 rotated by a predetermined angle with the rotating shaft 162 as a fulcrum, The first port 12 and the second port 14 communicate with each other via the inner wall surface of the first port 12 (see FIG. 6).

  As a result, the fluid inside the processing chamber 37 is exhausted from the first port 12 to the second port 14 through the communication chamber 28. At that time, the flow rate of the fluid is controlled with high accuracy under the action of rotation of the throttle valve 156, and the inside of the processing chamber 37 can be set to a predetermined pressure set in advance.

It is a longitudinal cross-sectional view of the flow control valve which concerns on the 1st Embodiment of this invention. FIG. 2 is a longitudinal sectional view showing a state in which only a second valve body is separated from a second valve seat portion in the flow control valve of FIG. 1. FIG. 3 is a longitudinal sectional view showing a state in which the first valve body is separated from the first valve seat portion and the first port and the second port communicate with each other in the flow control valve of FIG. 2. It is a longitudinal cross-sectional view of the flow control valve which concerns on the 2nd Embodiment of this invention. FIG. 5 is a longitudinal sectional view showing a state in which the valve body is separated from the valve seat portion of the valve body in the flow control valve of FIG. 4. FIG. 6 is a longitudinal sectional view showing a state in which the valve plate of the throttle valve is rotated and displaced by a predetermined angle in the flow rate control valve of FIG. 5 so that the first port and the second port communicate with each other.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 150 ... Flow control valve 12 ... 1st port 14 ... 2nd port 16, 152 ... Valve body 18 ... Valve mechanism part 20 ... Piston 22 ... Guide body 24, 154 ... Drive part 26 ... Conversion mechanism 28 ... Communication chamber 30 ... 1st valve body 32 ... 1st valve seat part 34 ... 2nd valve body 36 ... 2nd valve seat part 38 ... Piston chamber 40 ... Pilot port 46 ... Casing 48 ... Valve shaft 50 ... Spring 64 ... Valve body part 70 ... 1st bellows 72 ... 2nd bellows 74 ... O-ring 80 ... Rotation drive source 82 ... Cover member 84 ... Detection part 90 ... Ball screw shaft 92 ... Displacement member 156 ... Throttle valve 158 ... Valve seat part 160 ... Valve body 162 ... Time Driving shaft 164 ... Valve plate 166a, 166b ... Bearing

Claims (5)

A flow rate control valve disposed between an upstream side passage and a downstream side passage of the fluid passage and controlling a flow rate of the fluid flowing through the fluid passage;
A valve body having first and second ports connected respectively to the upstream side and the downstream side of the fluid passage;
A drive unit provided in the valve body and driven to rotate by an electrical signal;
A conversion mechanism for converting the rotational driving force of the drive unit into linear motion along the axial direction;
A first valve body that is provided so as to be displaceable along the axial direction via the conversion mechanism, and that is provided so as to be freely seated and separated from the first valve seat portion of the valve body;
A second valve body connected to a piston that is displaced along the axial direction by a pilot pressure and having a seal member on a seating surface that seats on the second valve seat portion of the valve body;
A detecting unit for detecting a rotational driving amount of the driving unit;
With
The communication state of the first port and the second port is switched under the displacement action of the second valve body, and the first port and the second port are circulated under the displacement action of the first valve body. A flow control valve for controlling a flow rate of a fluid. The flow control valve according to claim 1, wherein
The first valve body is provided inside the second valve body so as to be freely displaceable, and the first valve body and the second valve body are provided independently so as to be freely displaceable. . In the flow control valve according to claim 1 or 2,
The first valve body is connected to the conversion mechanism via a first valve shaft, and the first valve shaft is displaced inside a second valve shaft that connects the second valve body and the piston. A flow control valve characterized by being arranged freely. The flow control valve according to claim 1, wherein
A flow control valve, characterized in that a spring is provided between the valve body and the second valve body to urge the second valve body in a direction to seat the second valve body on the second valve seat portion. In a flow rate control valve that is disposed between the upstream side passage and the downstream side passage of the fluid passage and controls the flow rate of the fluid flowing through the fluid passage,
A valve body having first and second ports connected respectively to the upstream side and the downstream side of the fluid passage;
A drive unit provided in the valve body and driven to rotate by an electrical signal;
A rotary valve connected to the drive unit and rotated and displaced inside the first port or the second port under the rotational action of the drive unit;
A valve body connected to a piston that is displaced along an axial direction by a pilot pressure, and having a seal member on a seating surface that seats on a valve seat portion of the valve body;
A detecting unit for detecting a rotational driving amount of the driving unit;
With
The communication state of the first port and the second port is switched under the displacement action of the valve body, and the fluid flowing between the first port and the second port under the rotation action of the turning valve A flow control valve characterized by controlling a flow rate.

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