JP4247576B2 - Exhaust valve - Google Patents

Description

  The present invention relates to an exhaust valve capable of adjusting a flow rate of the fluid flowing through the fluid passage by opening and closing a fluid passage through which the fluid flows.

  Conventionally, for example, in a processing apparatus such as a semiconductor wafer or a liquid substrate, the semiconductor wafer or liquid crystal substrate is placed in a processing chamber where various processes are performed, and an atmospheric pressure fluid is in a vacuum state under the action of a vacuum pump or the like. And a process for forming a film on the surface of the semiconductor wafer is performed. A product may adhere to the inner wall surface of the processing chamber due to gas or the like used to form a film on the semiconductor wafer.

  In such a case, after the processing step is completed, a fluid such as a gas inside the processing chamber is discharged to the outside by a vacuum pump. At that time, when a fluid such as a gas is discharged, a sudden pressure fluctuation occurs in the processing chamber, so that the product may be detached from the inner wall surface and enter the other processing chamber together with the fluid. . Therefore, an exhaust valve is provided to exhaust the fluid in the processing chamber, and by controlling the valve opening degree of the exhaust valve, it is possible to prevent a sudden pressure fluctuation from occurring in the processing chamber, and The fluid inside the processing chamber is exhausted to the outside.

  As such an exhaust valve, Patent Document 1 discloses that a single-acting pneumatic cylinder is connected to an upper portion of a valve body in which a set of ports is formed, and a piston is arranged along the axial direction inside the single-acting pneumatic cylinder. Displaceable. A piston rod is connected to the piston so as to be displaceable inside the valve body, and a poppet valve body for switching the communication state of the set of ports is attached to the end of the piston rod. . The outer peripheral surface of the piston rod is surrounded by a bellows-like bellows disposed between the poppet valve body and the valve body.

  Then, when the pressure fluid is supplied to the inside of the single acting pneumatic cylinder, the piston is displaced along the axial direction, and the poppet valve body approaches the valve seat via the piston rod that is displaced integrally with the piston. They are separated and the communication state of a set of ports is switched. At that time, the bellows is displaced while expanding and contracting integrally with the poppet valve body.

Japanese Patent No. 2624943

  By the way, in the prior art according to Patent Document 1, in the vacuum pressure control system to which the exhaust valve is applied, when the poppet valve body of the exhaust valve is separated from the valve seat and is opened, one port The fluid in the vacuum chamber connected to the gas flows through the inside of the exhaust valve and is sucked by the vacuum pump connected to the other port. At that time, dust or the like is generated in the vacuum chamber when, for example, a processing operation is performed with nitrogen gas. Therefore, the dust or the like circulates inside the valve body together with the fluid.

  Therefore, there is a concern that dust contained in the fluid adheres to the outer peripheral surface of the bellows surrounding the piston rod, and accordingly, maintenance work is required to remove the dust attached to the bellows. In addition, there is a problem that the maintenance cycle is shortened.

  On the other hand, there is a demand for further downsizing such an exhaust valve.

  The present invention has been made in consideration of the above-described various problems, and is intended to provide an exhaust valve capable of reducing the size and cost and preventing dust from adhering to the bellows. Objective.

To achieve the above object, the present invention provides an exhaust valve disposed between an upstream passage and a downstream passage of a fluid passage,
The exhaust valve has a valve body having first and second ports connected to the upstream side and the downstream side of the fluid passage, respectively.
A drive unit provided in the valve body and driven by an electrical signal;
A piston provided inside the valve body so as to be displaceable along an axial direction;
A pressure fluid supply section for supplying a pilot pressure to a cylinder chamber formed between the piston and the valve body;
A valve body connected to the piston and provided in a seatable / separable manner on a valve seat portion of the valve body;
An elastic member interposed between the piston and the valve body;
A bellows disposed inside the valve body and surrounding a support portion where the valve body is supported by the valve body;
A cover member that is attached to the valve body and closes the space of the valve body in which the bellows is disposed with respect to the first and second ports when the valve body is opened and separated from the valve seat portion; ,
With
When the valve body is separated from the valve seat portion, the valve body is displaced along the axial direction by the driving force of the driving portion and the pilot pressure supplied to the cylinder chamber.

  According to the present invention, in order to displace the valve body along the axial direction, a drive unit that is driven by an electric signal is provided, and pilot pressure is supplied to the cylinder chamber, and the valve body is displaced in the axial direction via the piston. A pressure fluid supply unit is provided. The valve body is displaced along the axial direction by the drive section and the pressure fluid supply section, so that the valve body is seated and separated from the valve seat section.

  Therefore, compared with the case where the valve body is displaced against the elastic force of the elastic member only by the drive unit, the valve body is simultaneously pressed by the pilot pressure, so the valve body is It is possible to reduce the load applied to the drive unit when displaced in the axial direction.

  As a result, it is possible to reduce the size of the drive unit, and accordingly, it is possible to reduce the size of the entire exhaust valve and to reduce the cost.

  Further, when the valve body is separated from the valve seat portion and the first port and the second port communicate with each other, the space in the valve body in which the bellows is disposed is closed by a cover member attached to the valve body. Yes. Therefore, dust or the like contained in the fluid flowing from the first port to the second port does not enter the space in which the bellows is disposed, and adhesion of the dust or the like to the bellows can be prevented. it can. As a result, the durability and maintainability of the expensive bellows can be improved.

Furthermore, the present invention provides an exhaust valve disposed between the upstream side passage and the downstream side passage of the fluid passage.
The exhaust valve has a valve body having first and second ports connected to the upstream side and the downstream side of the fluid passage, respectively.
A piston provided inside the valve body so as to be displaceable along an axial direction;
A pressure fluid supply section for supplying a pilot pressure to a cylinder chamber formed between the piston and the valve body;
A valve body connected to the piston and provided in a seatable / separable manner on a valve seat portion of the valve body;
An elastic member interposed between the piston and the valve body;
A bellows disposed inside the valve body and surrounding a support portion where the valve body is supported by the valve body;
A cover member that is attached to the valve body and closes the space of the valve body in which the bellows is disposed with respect to the first and second ports when the valve body is separated from the valve seat portion;
It is characterized by providing.

  According to the present invention, the piston is displaced along the axial direction by the pilot pressure supplied to the cylinder chamber from the pressure fluid supply portion, and the valve body connected to the piston is displaced, thereby seating / separating the valve seat portion. I am letting. When the valve body is separated from the valve seat portion and is in the valve open state, the supply amount of the pilot pressure supplied to the cylinder chamber is reduced to gently separate the valve body from the valve seat portion, After the body is separated from the valve seat portion by a predetermined interval and reaches a desired valve opening, the amount of pilot pressure supplied from the pressure fluid supply unit to the cylinder chamber is increased to increase the speed of the valve body. It is displaced along the axial direction.

  Therefore, since the valve body is displaced along the axial direction only by the pilot pressure supplied through the pressure fluid supply unit, the exhaust valve is compared with the case where the drive unit is provided separately from the pressure fluid supply unit. Therefore, the cost required for the drive unit can be made unnecessary, and the cost can be reduced.

  Furthermore, in a state where the valve body is separated from the valve seat portion and the first port and the second port communicate with each other, the space where the bellows in the valve body is disposed is blocked by a cover member attached to the valve body. ing. Therefore, dust or the like contained in the fluid flowing from the first port to the second port does not enter the space in which the bellows is disposed, and adhesion of the dust or the like to the bellows can be prevented. it can. As a result, the durability and maintainability of the expensive bellows can be improved.

Still further, the valve body is configured to block communication between the first port and the second port when the valve body is closed at a position facing the valve seat portion when the valve seat is closed. An airtight holding part for holding the airtightness inside the body is provided,
The airtight holding portion may include a holding member that is integrally attached to the valve body, and a seal member that is detachably attached to the holding member.

  Thereby, since only the seal member can be easily attached to and detached from the valve portion, it is possible to improve the maintainability when the seal member deteriorates due to long-term use, and only the seal member is used as the valve portion. On the other hand, since it is not necessary to replace the entire valve body, the cost can be reduced.

  Further, the control unit controls the supply amount of the electrical signal supplied to the drive unit and the supply amount of the pilot pressure supplied from the pressure fluid supply unit to the cylinder chamber. The parts should be connected.

  As a result, the drive amount of the drive unit is output to the control unit, and the control signal based on the output signal is output from the control unit to the drive unit and the pressure fluid supply unit, respectively. The drive amount of the drive unit and the supply amount of pilot pressure to the cylinder chamber can be controlled. As a result, it is possible to freely control the displacement speed of the valve body according to the valve opening degree via the control unit.

  Further, the valve body is provided with a detection unit capable of detecting a displacement amount along the axial direction of the valve body, and is supplied to the cylinder chamber from the pressure fluid supply unit to the detection unit and the pressure fluid supply unit. A control unit that controls the supply amount of pilot pressure is preferably connected. Thereby, since the valve opening degree of the valve body can be detected by the detection unit, the detection signal detected by the detection unit is output to the control unit, and the control signal based on the detection signal is output to the pressure fluid supply unit. By outputting, a supply amount of pilot pressure corresponding to the valve opening of the valve body can be supplied to the cylinder chamber. As a result, the displacement speed of the valve body can be freely controlled according to the valve opening.

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

  That is, as compared with the case where the valve body is displaced only by the drive unit by displacing the valve body in the axial direction by the driving part driven by the electric signal and the pilot pressure supplied from the pressure fluid supply part to the cylinder chamber. Since the pressing force by the pilot pressure is simultaneously applied to the valve body, it is possible to reduce the load applied to the drive unit when the valve body is displaced in the axial direction. Therefore, the size of the entire exhaust valve can be reduced along with the downsizing of the drive unit, and the cost can be reduced.

  Further, by controlling the supply amount of pilot pressure supplied from the pressure fluid supply unit to the cylinder chamber, when the valve body is separated from the valve seat portion and is opened, the pilot supplied to the cylinder chamber After the valve body is gently separated from the valve seat portion by reducing the pressure supply amount and the valve body is separated from the valve seat portion by a predetermined interval to reach a desired valve opening, the pressure fluid supply portion The supply amount of the pilot pressure supplied to the chamber can be increased, and the valve body can be displaced along the axial direction at high speed. Therefore, the valve body can be displaced along the axial direction only by the pilot pressure supplied through the pressure fluid supply unit, and the exhaust valve can be further reduced in size and cost.

  Furthermore, the space in which the bellows is disposed in the valve body is closed by the cover member attached to the valve body in a state in which the valve body is separated from the valve seat portion, thereby flowing from the first port to the second port. Dust and the like contained in the fluid can be prevented from adhering to the bellows. As a result, the durability and maintainability of the expensive bellows can be improved.

  Preferred embodiments of the exhaust 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 an exhaust valve according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the exhaust valve 10 is connected to a valve body (valve body) 16 having first and second ports 12 and 14 through which a pressure fluid flows, and the valve body 16. A guide body (valve body) 20 in which a piston 18 is displaceably provided, a cylindrical casing (valve body) 22 connected to the guide body 20, and the valve body 16 and the guide body 20 are provided inside. The valve mechanism 24 for switching the communication state of the pressure fluid in the valve body 16 and the casing 22 are connected to drive the valve body 26 of the valve mechanism 24 along the axial direction (directions of arrows A and B). And a driving unit 28 to be operated.

  The valve body 16 includes a first port 12 formed on the axis of the exhaust valve 10, a second port 14 formed substantially orthogonal to the first port 12, and the first port 12 and the second port 14. Adjacent to the communication chamber 30, a valve seat 32 formed between the first port 12 and the communication chamber 30 on which the valve body 26 in the valve mechanism 24 is seated, and the communication chamber 30. A cylindrical connecting portion 34 is formed and connected to the guide body 20.

  As shown in FIG. 5, the first port 12 is connected to a processing chamber 35 in a processing apparatus such as a semiconductor wafer via a fluid passage 37 a, while the second port 14 is connected to the processing chamber 35. Is connected to a vacuum pump 39 for sucking the fluid through a fluid passage 37b.

  Further, as shown in FIGS. 1 and 2, the inner wall surface of the communication chamber 30 has a circular shape so that the diameter gradually decreases toward the connection portion 34 (in the direction of arrow A) in the vicinity of the connection portion 34. It is formed in an arc shape. That is, by forming the circular arc surface 36 in the vicinity of the connection portion 34 in the communication chamber 30 in this way, when the pressure fluid flows from the first port 12 to the second port 14 through the communication chamber 30. The pressure fluid can be circulated smoothly.

  The guide body 20 protrudes toward the valve body 16 side (in the direction of the arrow B) of the main body portion 38, which is sandwiched between the valve body 16 and the casing 22. It consists of a guide part 40 inserted inside and a pilot port 42 formed on the side wall of the main body part 38. A ring member 44 is sandwiched between the main body 38 of the guide body 20 and the valve body 16, and the piston 18 extends along the axial direction (arrows A and B directions) inside the main body 38. Displaceable. A cylinder chamber 46 is formed between the end face of the piston 18 on the guide portion 40 side and the guide body 20.

  The pilot port 42 is formed so as to communicate the cylinder chamber 46 and the outside of the guide body 20 through the side wall of the main body 38. The pilot port 42 is connected to a control fluid (pressure fluid supply unit) 48 (for example, an electropneumatic proportional control valve) that is connected to a pressure fluid supply source (not shown) and that can supply and exhaust the pressure fluid. . That is, pressure fluid is supplied / exhausted into the cylinder chamber 46 through the pilot port 42 under the opening / closing action of the control valve 48, and the piston 18 provided in the cylinder chamber 46 is axially moved (in the directions of arrows A and B). Displacement along

  On the other hand, a guide hole 50 passes through the guide portion 40 along the axial direction (directions of arrows A and B), and the shaft portion 52 of the valve body 26 is inserted into the guide hole 50 so as to be displaceable. ing. A shaft packing 54 is attached to the inner wall surface of the guide hole 50 via an annular groove, and the airtightness between the guide hole 50 and the shaft portion 52 is maintained by the shaft packing 54.

  The valve mechanism portion 24 includes a valve body 26 that switches the communication state of the pressure fluid in the valve body 16, a piston 18 that is connected to one end portion of the shaft portion 52 of the valve body 26, and a space between the piston 18 and the casing 22. And a spring (elastic member) 56 interposed therebetween. A piston packing 82 and a wear ring 68 are provided on the outer peripheral surface of the piston 18 via an annular groove so as to be spaced apart from each other by a predetermined distance. When the piston 18 is displaced along the axial direction, the piston packing 82 and the wear ring 68 slides along the inner wall surface of the main body 38. Thereby, the airtightness between the piston 18 and the cylinder chamber 46 can be reliably maintained.

  Further, the spring 56 urges the piston 18 to press the piston 18 toward the valve body 16 (in the direction of arrow B) by its elastic force.

  The other end of the shaft portion 52 of the valve body 26 is formed with a valve portion 58 provided in the communication chamber 30 of the valve body 16 and seated on the valve seat portion 32 of the valve body 16. An airtight holding portion 60 is provided at a position facing the valve seat portion 32 in 58.

  The piston 18 is inserted into one end portion of the shaft portion 52, and a nut 62 is screwed into a screw portion carved on the outer peripheral surface of the shaft portion 52, whereby the piston 18 is integrated with the shaft portion 52. It is fixed to. An adapter 66 is screwed into the one end portion of the shaft portion 52 through a screw hole 64.

  On the other hand, the valve portion 58 of the valve body 26 is formed so as to gradually expand radially outward from the shaft portion 52 toward the valve body 16 side (arrow B direction). It is formed larger than the inner peripheral diameter of 1 port 12. An end surface of the valve portion 58 facing the first port 12 is formed in a substantially flat shape, and an airtight holding portion 60 is provided on the end surface of the valve body 16 facing the valve seat portion 32 via an annular groove. It has been.

  As shown in FIG. 3, the hermetic holding portion 60 includes a holding member 70 having a substantially rectangular cross section and a seal member 74 mounted in a mounting groove 72 having a substantially circular cross section formed inside the holding member 70. It consists of.

  The holding member 70 is made of a resin material, and as shown in FIGS. 3 and 4, a plurality of convex portions 78 inserted into a plurality of concave portions 76 formed in the annular groove of the valve portion 58 are formed on the outer wall of the holding member 70. They are formed at a predetermined interval. That is, when the holding member 70 is mounted in the annular groove, the convex portion 78 is inserted into the concave portion 76, thereby preventing the holding member 70 from dropping from the valve portion 58. The holding member 70 may be formed from an elastic material such as rubber.

  In addition, the mounting groove 72 formed in the holding member 70 is formed with an opening 80 that opens toward the valve seat portion 32 (in the direction of arrow B) when the holding member 70 is mounted on the valve portion 58. Yes. That is, as shown in FIG. 4, the seal member 74 attached to the holding member 70 can be freely attached and detached through the opening 80.

  Furthermore, as shown in FIG. 4, the width C of the opening 80 is smaller than the cross-sectional diameter D1 of the sealing member 74 made of an elastic material (for example, rubber) and the diameter D2 of the mounting groove 72. (C <D1, D2), the seal member 74 mounted in the mounting groove 72 does not drop through the opening 80.

  On the other hand, as shown in FIGS. 1 and 2, a disc-shaped cover member 84 is attached to the outer peripheral surface of the shaft portion 52, and the ring member is sandwiched between the valve body 16 and the guide body 20. A bellows 86 is interposed between 44 and the cover member 84 so as to surround the guide portion 40 of the guide body 20.

  The cover member 84 is attached to the shaft portion 52 through a substantially central hole, and the outer edge portion 88 of the cover member 84 gradually approaches toward the valve portion 58 side (arrow B direction). It is formed in such an arc shape. Further, the outer peripheral diameter of the cover member 84 is formed to be substantially equal to the inner peripheral diameter of the connection portion 34 in the valve body 16 (see FIG. 2). That is, the cover member 84 is integrally displaced when the valve body 26 is displaced along the axial direction (directions of arrows A and B), and when the valve body 26 is separated from the valve seat portion 32 (when the valve is opened). 2), the end of the arc surface 36 in the communication chamber 30 and the position of the outer edge portion 88 formed in the arc shape of the cover member 84 are formed to coincide with each other. In other words, when the valve body 26 is opened, the outer edge portion 88 of the cover member 84 abuts on the top of the arc surface 36 so that the inner surface of the outer edge portion 88 and the arc surface 36 are substantially flush with each other. Is formed.

  As a result, the space 89 in which the bellows 86 is disposed inside the valve body 16 is closed by the cover member 84 when the valve is opened (see FIG. 2), so that the fluid flowing through the communication chamber 30 is inside the space 89. It is possible to prevent dust or the like (for example, nitrided oxide) contained in the fluid from entering and adhering to the bellows 86 provided in the space 89.

  The bellows 86 is formed in a bellows shape from a metal material, and the valve body 26 is displaced along the axial direction (arrows A and B directions), whereby the bellows 86 is connected to one end thereof. Stretch and displace integrally. Therefore, dust or the like contained in the fluid flowing through the inside of the valve body 16 is prevented from adhering to the inside of the shaft portion 52 and the guide hole 50 of the valve body 26, and the valve body 26 extends along the axial direction. This prevents sliding resistance during displacement.

  The drive unit 28 is provided with a rotation drive source 90 made of, for example, a stepping motor, and a drive shaft (not shown) of the rotation drive source 90 is screwed to one end portion of the connecting shaft 92. The other end of the connecting shaft 92 is inserted into the casing 22 and integrally connected to an adapter 66 connected to the shaft portion 52 of the valve body 26. In addition, the displacement in the rotation direction of the connecting shaft 92 is restricted by a rotation restricting means (not shown).

  That is, when a drive shaft (not shown) is rotationally driven under the drive action of the rotational drive source 90, the connecting shaft 92 into which the drive shaft is screwed is displaced along the axial direction (arrows A and B directions). Then, the piston 18 and the valve body 26 connected to the connecting shaft 92 are displaced integrally along the guide hole 50.

  The drive unit 28 is provided with a rotation detection means (not shown) capable of detecting the rotation amount or rotation angle of the rotation drive source 90, and a detection signal detected by the rotation detection means is supplied to the drive unit. By outputting to the control unit 94 connected to 28, the rotation angle and the like can be controlled via the amount of current supplied to the rotation drive source 90.

  The control unit 94 is also connected to the control valve 48, and based on a control signal output from the control unit 94, a pilot fluid is supplied from a pressure fluid supply source (not shown) through the control valve 48. The supply amount of the pressure fluid supplied to 42 is controlled. That is, the control unit 94 controls the amount of current supplied to the rotational drive source 90 and the control signal output to the control valve 48, so that the driving force by the rotational drive source 90 and the pressure supplied through the control valve 48 are controlled. The amount of displacement of the valve body 26 that is displaced by the fluid can be controlled.

  The exhaust valve 10 according to the first embodiment of the present invention is basically configured as described above. Next, the operation, action, and effect thereof will be described. In the following description, as shown in FIG. 1, the valve body 26 is pressed toward the valve body 16 (in the direction of arrow B) via the piston 18 by the elastic force of the spring 56, so that the valve portion 58 is A state where the first port 12 and the second port 14 are blocked from being seated on the seat 32 will be described as an initial state.

  First, by driving a vacuum pump 39 (see FIG. 5) connected to the second port 14, negative pressure fluid from the vacuum pump 39 is supplied to the communication chamber 30 via the second port 14. . At this time, the negative pressure fluid supplied to the communication chamber 30 is blocked from being supplied to the first port 12 by the airtight holding portion 60 provided in the valve body 26.

  Next, a pressure fluid is supplied to the control valve 48 from a pressure fluid supply source (not shown), and the valve opening degree of the control valve 48 is changed based on a control signal from the control unit 94 to adjust the supply amount. Pressure fluid is supplied to the pilot port 42.

  At the same time, a control signal is output to the rotational drive source 90 via the control unit 94, so that the rotational drive source 90 is rotationally driven by a predetermined amount based on the control signal.

  Then, the pressure fluid is introduced into the cylinder chamber 46 from the pilot port 42, so that the piston 18 resists the elastic force of the spring 56 by the pressure fluid and moves toward the casing 22 (arrow A direction). At the same time, the drive shaft of the rotational drive source 90 is rotationally driven, whereby the valve body 26 is displaced toward the casing 22 (in the direction of arrow A) via the connecting shaft 92. That is, the driving force in the axial direction by the rotational drive source 90 and the pressing force of the pressure fluid supplied to the cylinder chamber 46 applied via the piston 18 are simultaneously applied to the valve body 26, and the valve body 26 Is displaced toward the casing 22 (in the direction of arrow A) against the elastic force of the spring 56.

  As a result, the valve portion 58 of the valve body 26 is separated from the valve seat portion 32 of the valve body 16, and the communication chamber 30 and the first port 12 are in communication with each other, and from the second port 14 to the communication chamber 30. The supplied negative pressure fluid is introduced into the processing chamber 35 (see FIG. 5) through the first port 12.

  The valve opening when the valve portion 58 is separated from the valve seat portion 32 is detected from the rotation amount or rotation angle of the rotation drive source 90, and a detection signal based on the rotation amount or rotation angle of the rotation drive source 90. Is output from the rotational drive source 90 to the control unit 94. In the control unit 94, when the valve opening becomes a desired opening based on the detection signal, the amount of current supplied to the rotation drive source 90 based on the detection signal detected by a rotation detection unit (not shown). Is increased to increase the amount of rotation of the rotary drive source 90, and at the same time, the amount of pressure fluid supplied to the cylinder chamber 46 through the control valve 48 is increased.

  Thereby, the driving force in the axial direction by the rotational drive source 90 applied to the valve body 26 and the pressing force of the pressure fluid supplied to the cylinder chamber 46 applied via the piston 18 can be increased. Therefore, it is possible to increase the displacement speed at which the valve body 26 is displaced toward the casing 22 (arrow A direction).

  That is, when the valve body 26 that blocks the communication between the first port 12 and the communication chamber 30 is separated from the valve seat portion 32 in this way, the valve body 26 is initially displaced at a low speed and the valve body 26 is displaced. 26 is gently separated from the valve seat portion 32, and after the valve body 26 is separated from the valve seat portion 32 by a predetermined distance, the displacement speed of the valve body 26 is increased and displaced toward the casing 22 at a high speed. Yes.

  As described above, when the valve body 26 is separated from the valve seat portion 32, the valve body 26 is gradually and gradually displaced from low speed to high speed, whereby the processing chamber 35 connected to the first port 12 when the valve is opened. It is possible to prevent sudden pressure fluctuations occurring in the interior. Therefore, the product (dust) adhering to the inner wall surface of the processing chamber 35 does not peel off due to a rapid pressure fluctuation, and the dust contained in the fluid flowing from the first port 12 to the second port 14 Content can be suppressed.

  On the other hand, the valve body 26 shown in FIG. 2 is separated from the valve seat portion 32, and the communication is blocked again by the valve body 26 from the valve open state in which the first port 12 and the second port 14 communicate with each other. In the case of the valve closed state (see FIG. 1), which is the initial state, the polarity of the current supplied to the rotary drive source 90 via the control unit 94 is reversed, and the cylinder chamber 46 is passed through the control valve 48. The supply of the supplied pressure fluid is stopped, and the pressure fluid in the cylinder chamber 46 is exhausted through the pilot port 42.

  As a result, the valve body 26 is displaced along the axial direction toward the valve body 16 (in the direction of arrow B), and the valve portion 58 is seated on the valve seat portion 32 and is provided on the valve portion 58. As a result of being seated on the valve seat portion 32, the communication between the first port 12 and the communication chamber 30 is shut off (see FIG. 1).

  As described above, in the first embodiment, the drive unit 28 that is rotationally driven by an electric current to displace the valve body 26 along the axial direction is provided, and the pressure fluid is supplied to the cylinder chamber 46 to supply the valve. The body 26 is displaced along the axial direction to switch the communication state of the first and second ports 12 and 14. Thereby, for example, compared with the case where the valve body 26 is displaced against the elastic force of the spring 56 only by the driving force of the rotational drive source 90, the pressing force by the pressure fluid is simultaneously applied to the valve body 26. Therefore, it is possible to reduce the load on the rotational drive source 90 when the valve body 26 is displaced.

  Therefore, the rotation drive source 90 can be reduced in size, and the size of the exhaust valve 10 can be reduced accordingly. It is also possible to reduce the amount of current consumed by the rotational drive source 90. On the other hand, the cost can be reduced by downsizing the rotary drive source 90.

  Further, the driving force by the rotational driving source 90 and the pressing force applied to the piston 18 by the pressure fluid supplied to the cylinder chamber 46 are combined, and the valve seat portion 32 is resisted against the elastic force of the spring 56. It is displaced in the direction of further separation. In other words, the rotational drive source 90 is provided with a suitable balance between the elastic force urged toward the valve body 16 by the spring 56 and the driving force of the rotational drive source 90 and the pressing force of the pressure fluid. The controller 94 can control the amount of current supplied and the amount of pressure fluid supplied through the control valve 48.

  Further, a disc-shaped cover member 84 is integrally attached to the shaft portion 52 of the valve body 26, and the outer peripheral diameter of the cover member 84 is substantially equal to the inner peripheral diameter of the connection portion 34 of the valve body 16. It is formed as follows. On the other hand, the outer edge portion 88 of the cover member 84 is formed in an arc shape that gradually approaches toward the valve portion 58 side (in the direction of arrow B).

  Therefore, the cover member 84 is formed in an arc shape of the arc surface 36 formed in the arc shape of the communication chamber 30 and the arc shape of the cover member 84 when the valve element 26 is opened from the valve seat portion 32. When the fluid circulates from the first port 12 to the second port 14 through the communication chamber 30, dust or the like contained in the fluid from the processing chamber 35 adheres to the bellows 86. There is nothing to do. As a result, the durability and maintainability of the expensive bellows 86 can be improved.

  Furthermore, the valve portion 58 of the valve body 26 is provided with an airtight holding portion 60 that blocks communication between the first port 12 and the second port 14 when the valve portion 58 is seated on the valve seat portion 32. . An annular seal member 74 is detachably provided on the airtight holding portion 60 via a holding member 70 attached to the valve portion 58. Thereby, since only the seal member 74 can be easily attached to and detached from the valve portion 58, the maintainability when the seal member 74 is deteriorated due to long-term use can be improved, and only the seal member 74 is provided. Therefore, it is not necessary to replace the entire valve body 26, and the cost can be reduced.

  Furthermore, the exhaust valve 10 is configured such that the valve body 26 is seated on the valve seat portion 32 by the elastic force of the spring 56 when the valve is closed. Therefore, the sealing member 74 is provided in the airtight holding portion 60 provided on the valve portion 58 of the valve body 26 and seated on the valve seat portion 32, and the valve body 26 is seated on the valve seat portion 32 only by the seal member 74. Let me seal. Thereby, it is possible to reduce the elastic force of the spring 56 required when the seal member 74 is seated on the valve seat portion 32, and the spring 56 can be reduced in size and cost.

  Next, an exhaust valve 100 according to a second embodiment is shown in FIG. The same components as those of the exhaust valve 10 according to the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the exhaust valve 100 according to the second embodiment, the valve body 26 is displaced along the axial direction (arrows A and B directions) only with the pressure fluid supplied to the cylinder chamber 46 through the control valve 48. The exhaust valve 10 according to the first embodiment is different from the exhaust valve 10 according to the first embodiment in that a detection unit 102 is provided for detecting the amount of displacement along the axial direction (arrow A, B direction) of the valve body 26. ing.

  A casing 104 that constitutes the exhaust valve 100 has a protruding portion 106 that protrudes toward the guide body 20 (in the direction of arrow B) at a substantially central portion. A detection sensor 108 (for example, a magnetic sensor) of the detection unit 102 is attached to the end surface of the protruding portion 106 so as to face the shaft portion 52 of the valve body 26, and the shaft portion 52 facing the detection sensor 108. A magnetic member 110 (for example, a permanent magnet) is attached to the end of the. The detection sensor 108 is connected to the control unit 94, and a detection signal detected by the detection sensor 108 is output to the control unit 94.

  That is, when the valve body 26 is displaced along the axial direction (the directions of arrows A and B), the detection sensor 108 and the magnetic member 110 are always opposed to each other. By detecting the separation distance, the displacement amount of the valve body 26 can be detected. In other words, by detecting the strength of the magnetic field between the detection sensor 108 and the magnetic member 110 by the detection sensor 108, it is possible to detect the valve opening degree of the valve body 26 provided with the magnetic member 110. It becomes.

  The detected displacement amount (valve opening degree) of the valve body 26 is output as a detection signal to the control unit 94 connected to the detection sensor 108.

  In the exhaust valve 100 configured as described above, when the valve body 26 is seated on the valve seat portion 32, the detection portion 102 detects that the valve body 26 is in the valve closed position, and the detection portion 102. The pressure fluid is supplied from the control valve 48 to the pilot port 42 based on the detection signal output from the control unit 94 to the control unit 94. Then, the pressure fluid is introduced into the cylinder chamber 46, the piston 18 is displaced toward the casing 104 against the elastic force of the spring 56, and the valve body 26 is separated from the valve seat portion 32.

  The detection sensor 108 detects the displacement of the valve body 26 toward the casing 104 (arrow A direction), and after the valve body 26 is separated from the valve seat portion 32 by a predetermined amount, the detection signal from the detection sensor 108 is detected. Based on this, the supply amount of the pressure fluid supplied from the control valve 48 to the cylinder chamber 46 is increased by a control signal from the control unit 94. As a result, the displacement speed of the valve body 26 toward the casing 104 (in the direction of arrow A) can be increased, and the valve body 26 is completely opened away from the valve seat portion 32 even faster. be able to.

  In other words, when the valve body 26 is separated from the valve seat portion 32, the supply amount of the pressure fluid supplied to the cylinder chamber 46 is controlled by the control valve 48, and the displacement speed of the valve body 26 is reduced. Thus, the valve body 26 is gently separated from the valve seat portion 32.

  On the other hand, after the valve body 26 is separated from the valve seat portion 32 by a predetermined interval to reach a desired valve opening, the supply amount of the pressure fluid controlled by the control valve 48 is increased, thereby causing the valve body 26 to It is displaced along the axial direction at high speed.

  As a result, when the valve body 26 is separated from the valve seat portion 32, the valve body 26 is gradually and gradually displaced from low speed to high speed, so that the processing chamber 35 connected to the first port 12 when the valve is opened Sudden pressure fluctuations occurring inside can be prevented. Therefore, the product (dust) adhering to the inner wall surface of the processing chamber 35 does not peel off due to a rapid pressure fluctuation, and the dust contained in the fluid flowing from the first port 12 to the second port 14 Content can be suppressed.

  Thus, since the valve body 26 is displaced along the axial direction only by the pressure fluid supplied through the control valve 48, the drive unit 28 provided in the exhaust valve 10 according to the first embodiment is unnecessary. It becomes. Therefore, the exhaust valve 100 can be further reduced in size and the cost can be reduced.

It is a longitudinal cross-sectional view of the exhaust valve which concerns on the 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the valve open state of the exhaust valve of FIG. FIG. 3 is an enlarged longitudinal sectional view showing the vicinity of an airtight holding portion of the valve body of FIG. 2. It is an exploded longitudinal cross-sectional view which shows the state which made the seal member detach | leave from the valve part of a valve body. It is a schematic block diagram which shows the flow path of the fluid in the system to which the exhaust valve of FIG. 1 is applied. It is a longitudinal cross-sectional view of the exhaust valve which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 100 ... Exhaust valve 12 ... 1st port 14 ... 2nd port 16 ... Valve body 18 ... Piston 22, 104 ... Casing 24 ... Valve mechanism part 26 ... Valve body 28 ... Drive part 30 ... Communication chamber 32 ... Valve seat part 40 ... Guide portion 42 ... Pilot port 48 ... Control valve 50 ... Guide hole 52 ... Shaft portion 56 ... Spring 58 ... Valve portion 60 ... Airtight holding portion 70 ... Holding member 72 ... Mounting groove 74 ... Seal member 80 ... Opening portion 84 ... Cover member 86 ... Bellows 88 ... Outer edge 90 ... Rotation drive source 92 ... Connection shaft 94 ... Control unit 102 ... Detection unit 108 ... Detection sensor 110 ... Magnetic member

Claims (5)

In the exhaust valve disposed between the upstream passage and the downstream passage of the fluid passage,
The exhaust valve has a valve body having first and second ports connected to the upstream side and the downstream side of the fluid passage, respectively.
A drive unit provided in the valve body and driven by an electrical signal;
A piston provided inside the valve body so as to be displaceable along an axial direction;
A pressure fluid supply section for supplying a pilot pressure to a cylinder chamber formed between the piston and the valve body;
A valve body connected to the piston and provided in a seatable / separable manner on a valve seat portion of the valve body;
An elastic member interposed between the piston and the valve body;
A bellows disposed inside the valve body and surrounding a support portion where the valve body is supported by the valve body;
A cover member that is attached to the valve body and closes the space of the valve body in which the bellows is disposed with respect to the first and second ports when the valve body is opened and separated from the valve seat portion; ,
With
When the valve body is separated from the valve seat portion, the valve body is displaced along the axial direction by the driving force of the driving portion and the pilot pressure supplied to the cylinder chamber. valve. In the exhaust valve disposed between the upstream passage and the downstream passage of the fluid passage,
The exhaust valve has a valve body having first and second ports connected to the upstream side and the downstream side of the fluid passage, respectively.
A piston provided inside the valve body so as to be displaceable along an axial direction;
A pressure fluid supply section for supplying a pilot pressure to a cylinder chamber formed between the piston and the valve body;
A valve body connected to the piston and provided in a seatable / separable manner on a valve seat portion of the valve body;
An elastic member interposed between the piston and the valve body;
A bellows disposed inside the valve body and surrounding a support portion where the valve body is supported by the valve body;
A cover member that is attached to the valve body and closes the space of the valve body in which the bellows is disposed with respect to the first and second ports when the valve body is separated from the valve seat portion;
An exhaust valve comprising: The exhaust valve according to claim 1 or 2,
The valve body is configured to block communication between the first port and the second port when the valve body is closed when the valve body is seated on the valve seat portion at a position facing the valve seat portion. An airtight holding part is provided to hold the airtightness inside the
The airtight holding section includes a holding member that is integrally attached to the valve body, and a seal member that is detachably attached to the holding member. The exhaust valve according to claim 1,
The drive unit and the pressure fluid supply unit control the supply amount of an electric signal supplied to the drive unit and also control the supply amount of pilot pressure supplied from the pressure fluid supply unit to the cylinder chamber. An exhaust valve to which a control unit is connected. The exhaust valve according to claim 2,
The valve body is provided with a detection unit capable of detecting a displacement amount along the axial direction of the valve body, and the detection unit and the pressure fluid supply unit are supplied from the pressure fluid supply unit to the cylinder chamber. An exhaust valve to which a control unit for controlling a supply amount of pilot pressure is connected.

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