gate valve

Abstract

Provided is a gate valve capable of imparting the strength of pressing force of a valve plate at the time of sealing. The gate valve (1(1A)) of the present invention is a gate valve (1) that opens and closes opening portions (7, 8) provided on both side surfaces of a valve case (2) using a valve plate (3(10, 11)) disposed in the valve case (2), and includes a valve stem (4) that is combined with the valve plate (3) and is supported in the valve case (2) so as to be able to be lifted and tilted, a drive mechanism (5) that is provided outside the valve case (2) and causes the valve stem (4) to be lifted and tilted by a predetermined stroke, and a stop mechanism (6) that is provided halfway through the stroke of the drive mechanism (5) and restricts or releases the lifting of the valve stem (4) using the supply or stop of compressed air, the stop mechanism (6) being configured to change the angle of tilt of the valve stem (4) by changing the height position of the drive mechanism (5) that tilts the valve stem (4), thereby imparting the strength of pressing force of the valve plate (3).

Description

Technical Field

[0001] The present invention relates to a double-sided sealed gate valve, for example, used in a semiconductor manufacturing apparatus and disposed between two chambers. Background Technology

[0002] Conventionally, a bidirectional gate valve as described in Patent Document 1 is known. This gate valve has a first blade and a second blade that operate independently vertically. When the first blade malfunctions, the second blade operates, allowing for simultaneous opening and closing of the passage while repairing the first blade. Furthermore, a first roller to a third roller are formed in the L-motion block and the moving unit that move the first blade vertically and horizontally, respectively. Rotational guide grooves, L-motion block moving grooves, and moving unit guide grooves are formed on the inner surfaces of both sides of the lower housing, allowing for accurate movement of the first blade. Guide rings for the second roller are formed on both sides of the L-motion block, ensuring accurate operation of the first blade as the L-motion block moves in the up, down, left, and right directions.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2017-062031 Summary of the Invention

[0004] Technical issues The existing gate valve described above uses two independently operating vanes. Even if the first vane malfunctions due to a mechanical defect, the second vane can still operate, allowing for smooth opening and closing of the first and second movement paths and facilitating the repair and maintenance of the first vane. However, this gate valve cannot adjust the sealing pressure of the vanes; a strong sealing pressure must always be applied to withstand back pressure sealing. Therefore, it suffers from wear and deformation of the gasket accompanying the sealing action, requiring frequent repair and replacement.

[0005] Therefore, the present invention was made to solve such a problem, and its object is to provide a gate valve that can impart varying degrees of pressure to the valve plate during sealing action.

[0006] Technical solution To achieve the aforementioned objective, the gate valve of the present invention utilizes a valve plate disposed within a valve housing to open and close openings on both sides of the valve housing. The gate valve comprises: a valve stem coupled to the valve plate and supported within the valve housing in a manner capable of lifting, lowering, and tilting; a drive mechanism disposed outside the valve housing to cause the valve stem to lift, lower, and tilt within a predetermined stroke; and a stop mechanism disposed midway through the stroke of the drive mechanism to limit or release the rise of the valve stem by supplying or stopping compressed air. The stop mechanism, by changing the height position of the drive mechanism that tilts the valve stem, alters the tilt angle of the valve stem, thereby increasing the strength of the pressing force applied to the valve plate.

[0007] Furthermore, in a gate valve composed of the aforementioned components, the stop mechanism can employ a structure in which a stop pin moves forward or backward in a horizontal direction orthogonal to the travel direction of the valve stem to restrict or release the upward movement of the valve stem.

[0008] Furthermore, in the gate valve composed of the aforementioned components, the stop mechanism can employ a structure that adjusts the opening and closing angle of the arm by controlling an air piston, allowing the height position of the stop pin at the front end of the arm to be variable.

[0009] Furthermore, in the gate valve composed of the aforementioned components, the stop mechanism can be structured such that the rotation angle of the piston rod can be adjusted by the control of a rotary actuator, allowing the height position of the stop pin at the front end of the piston rod to be variable.

[0010] Technical effect According to the gate valve of the present invention, by making the height position of the drive mechanism for tilting the valve stem variable, the tilt angle of the valve stem is changed, thereby altering the strength of the pressing force applied to the valve plate. Therefore, in the double-sided sealing structure, sealing can be achieved with appropriate pressing force based on pressure sealing, reverse pressure sealing, and positive pressure sealing. Thus, it has the following effect: it extends the maintenance cycle for repairs and replacements caused by wear and deformation of the gasket accompanying the sealing action, thereby extending the lifespan of the gate valve. Attached Figure Description

[0011] Figure 1 This is a perspective view showing the appearance of a first embodiment of the gate valve of the present invention.

[0012] Figure 2 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve in its fully open state.

[0013] Figure 3 yes Figure 2 A longitudinal sectional view of a gate valve.

[0014] Figure 4 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve under pressure sealing.

[0015] Figure 5 yes Figure 4 A longitudinal sectional view of a gate valve.

[0016] Figure 6 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve under back pressure sealing.

[0017] Figure 7 yes Figure 6 A longitudinal sectional view of a gate valve.

[0018] Figure 8 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve under positive pressure sealing.

[0019] Figure 9 yes Figure 8 A longitudinal sectional view of a gate valve.

[0020] Figure 10 This is a perspective view showing the appearance of a second embodiment of the gate valve of the present invention.

[0021] Figure 11 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve in its fully open state.

[0022] Figure 12 yes Figure 11 A longitudinal sectional view of a gate valve.

[0023] Figure 13 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve under pressure sealing.

[0024] Figure 14 yes Figure 13 A longitudinal sectional view of a gate valve.

[0025] Figure 15 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve under back pressure sealing.

[0026] Figure 16 yes Figure 15 A longitudinal sectional view of a gate valve.

[0027] Figure 17 This is a cross-sectional view and an enlarged view of the main parts showing the gate valve under positive pressure sealing.

[0028] Figure 18 yes Figure 17 A longitudinal sectional view of a gate valve.

[0029] Figure 19 These are cross-sectional and perspective views showing the rotary actuator of the gate valve.

[0030] Figure 20This is a cross-sectional view and perspective view showing the rotary actuator of the gate valve (another example).

[0031] Symbol Explanation PC: Process Chamber TC: Transmission Chamber 1: Gate valve 2: Valve box 3: Valve plate 4: Valve stem 5: Drive mechanism 6: Stopping mechanism 7: First opening 8: Second opening 9: Interior Space 10: First valve plate 11: Second valve plate 12: O-ring 13: O-ring 14: Bolts 15: Maintenance flange 16: Valve cover flange 17: Rod guide 18: Corrugated pipe 19: Pivot Roller 20: Roller guide 21: Direction switching roller 22: Cam 23: Cam groove 24: Cam plate 25: Coil spring 26: Cylinder 27: Pole 28: Load-bearing roller 29: Air Piston 30: Stop pin 31: Piston rod 32: Cylinder 33: Rod Cap 34: Padding 35: Piston 36: Spring 37: Headroom 38: Pole-side space 39: Air piping 40: Compressed air supply port 41: First contact surface 42: Second contact surface 43: Connector 44: Arm 45: Connector 50: Rotary actuator 51: Stop pin 52: Motor 53: Output shaft 54: Piston rod 55: Concave 56: Main Body 57: Rod Cap 58: Padding 59: Piston 60: Spring 61: Head Lateral Space 62: Pole-side space 63: Air piping 64: Compressed air supply port 65: First contact surface 66: Second contact surface 67: Shell 68: Rotation axis 69: Leaf blade 70: Air supply and exhaust ports 71: Air supply and exhaust ports Detailed Implementation

[0032] Hereinafter, the methods for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[0033] like Figure 1 and Figure 2 As shown, the gate valve 1 (1A) of this embodiment is a machine used in an apparatus for manufacturing flat panel displays or semiconductor substrates to isolate vacuum from vacuum or vacuum from atmosphere, and is used to isolate various processes during the manufacturing of displays or substrates. The gate valve 1 (1A) is a so-called valve box type double-sided sealed gate valve, which is configured to have a flat square valve box 2, a valve plate 3 housed inside the valve box 2, a valve stem 4 connected to the valve plate 3, a drive mechanism 5 for raising and lowering the valve stem 4 by a predetermined stroke and tilting action, and a stop mechanism 6 for limiting or releasing the rise of the valve stem 4.

[0034] like Figure 3 As shown, elongated openings (first opening 7 and second opening 8) are provided opposite each other on the left and right walls of the valve box 2 to allow the substrate to pass through. A process chamber PC is connected to the outer wall of the first opening 7, and a transfer chamber TC is connected to the outer wall of the second opening 8. The substrate transported from the transfer chamber TC to the process chamber PC through the valve box 2 is kept in a sealed environment by closing the gate valve 1 (1A), and various heat, gas, plasma, and other processes for film formation are performed inside the process chamber PC.

[0035] In the interior space 9 of the valve box 2, a pair of valve plates 3 (first valve plate 10 and second valve plate 11) are configured for selectively opening and closing openings 7 and 8. O-rings 12 and 13 are respectively embedded and fixed on the outer surfaces of the first valve plate 10 and the second valve plate 11 as elastic seals that are one size larger than the first opening 7 and the second opening 8.

[0036] The first valve plate 10 and the second valve plate 11 are joined together in a separable manner by being fixed with bolts 14, and are integrally formed into a conical shape that gradually tapers from the lower part of the valve plate surface toward the upper part of the valve plate surface. Because the valve plate surface of the valve plate 3 is inclined in this way, the O-rings 12 and 13 are pressed against the valve seat in parallel (with equal force) during sealing. In addition, a valve stem 4 is installed in a detachable manner in the center of the second valve plate 11 by bolts 14, allowing the valve plate 3 to be removed as a whole or only one side of the valve plate 3 (e.g., the first valve plate 10) to be removed from the valve stem 4. By removing the maintenance flange 15 on the top surface of the closed valve box 2 and opening the cover, the valve plates 3 (10, 11) can be taken out to the outside for surface cleaning, replacement of O-rings 12 and 13, and other maintenance operations.

[0037] The valve stem 4 extends outward from the center of the valve cover flange 16, which passes through the bottom surface of the closed valve box 2. A rod guide 17 is provided at the middle position of the valve stem 4 to support and guide its movement. Furthermore, a flexible metal bellows 18, such as a welded bellows or a shaped bellows, is installed between the rod guide 17 and the valve cover flange 16 to cover the circumference of the valve stem 4, completely isolating the valve stem 4 from the outside.

[0038] A pivot roller 19 is provided above the rod guide 17 and is supported by the roller guide 20 supporting the valve box 2 in a rotatable manner. Additionally, a direction switching roller 21 is provided at the lower end of the valve stem 4. The direction switching roller 21 engages with a cam groove 23 provided on the cam 22 and has a cross-section bent into a "U" shape, and is supported in a slidable manner. A cam plate 24 supporting the cam 22 is integrally connected to the lower end of the cam 22. Furthermore, a helical spring 25 is installed between the cam plate 24 and the rod guide 17, and a rod 27 of a lifting cylinder 26 is connected to the lower center of the cam plate 24 as a drive mechanism 5. It should be noted that load-bearing rollers 28, which serve as force points, are installed on the left and right ends of the cam plate 24 and are supported in a manner that allows them to move up and down along the roller guide 20.

[0039] If the cylinder 26 is driven by the aforementioned drive mechanism 5, the valve stem 4 will move up and down by a predetermined stroke via the cam 22 connected to the cam plate 24, and the valve plate 3 mounted on the valve stem 4 will move to a predetermined height within the valve box 2 and stop. Furthermore, when the direction switching roller 21 is at the upper end (center) of the cam groove 23, the valve stem 4 stands upright at the center of the valve box 2; when the direction switching roller 21 is at the middle (left) of the cam groove 23, the valve stem 4 rotates about the fulcrum roller 19 and tilts to the right; when the direction switching roller 21 is at the lower end (right) of the cam groove 23, the valve stem 4 rotates about the fulcrum roller 19 and tilts to the left. Thus, the configuration is such that at the upper end of the cam groove 23, if... Figure 3 As shown, the valve plates 3 (10, 11) installed on the valve stem 4 open both openings 7 and 8, and are located in the middle of the cam groove 23, as shown. Figure 5 , Figure 7 As shown, the first valve plate 10 closes the first opening 7 at the lower end of the cam groove 23, as... Figure 9 As shown, the second valve plate 11 closes the second opening 8.

[0040] The stop mechanism 6 is located midway through the stroke of the cylinder 26 and has the function of restricting or releasing the rise of the valve stem 4 by causing the stop pin 30 to move forward or backward in the horizontal direction through the supply or stop of compressed air. In this embodiment, the stop mechanism 6 is provided on the left and right sides of the drive mechanism 5 with a stop pin 30 of the opening and closing arm type using an air piston 29.

[0041] The air piston 29 is a multi-unit structure consisting of piston rods 31, 31, ... arranged in a transverse row on the left, center, and right. Each piston 35, sealed by a gasket 34, has a rod cap 33 mounted on a cylinder 32 within its enclosed space. Furthermore, the air pistons 29 on the left and right sides have the following structure: a piston rod 31, stressed by a spring 36, is housed within its enclosed space, with the front end of the piston rod 31 passing through the center of the rod cap 33 and protruding outwards. The enclosed space is divided into a head-side space 37 and a rod-side space 38 by the pistons 35 on the piston rods 31. A compressed air supply port 40, connected to air pipes 39 (A, B, C), is installed in the head-side space 37.

[0042] The stop pin 30 is formed in a stepped shape with different height abutment surfaces at its front end (a first abutment surface 41 at a lower position and a second abutment surface 42 at a higher position), and is installed on the upper end of the straight arm 44 via a connector 43. The lower end of the arm 44 is connected to the front end of the piston rod 31 via a connector 45, and the piston rod 31, arm 44, and stop pin 30 constitute an integrated linkage mechanism. Above the cam plate 24 opposite to the stop pin 30, a load-bearing roller 28 is provided corresponding to the position of the front end of the pin. It should be noted that, although not shown, slit machining or countersinking machining can also be performed on the front end of the stop pin 30 to mitigate the impact when colliding with the load-bearing roller 28 as a means of vibration reduction.

[0043] The above describes the structure of gate valve 1 (1A) according to this embodiment. Its operation will now be explained. In gate valve 1 (1A), Figure 2 and Figure 3 This shows the state when fully open. Figure 4 and Figure 5 This shows the state of the seal under the same pressure. Figure 6 and Figure 7 This shows the state of the seal under reverse pressure. Figure 8 and Figure 9 This shows the state of a positive pressure seal.

[0044] like Figure 2 and Figure 3 As shown, when gate valve 1 (1A) stops operating, the transfer chamber TC and process chamber PC are open to the atmosphere, and the two chambers are under the same pressure. At this time, the drive mechanism 5 stops, the valve stem 4 descends, and the direction switching roller 21 is located at the upper end (center) of the cam groove 23. Therefore, the valve is in an open state, with the valve stem 4 standing upright at the center of the valve box 2, and the first valve plate 10 and the second valve plate 11 descending to positions lower than the first opening 7 and the second opening 8, respectively. In this "open" state, the substrate can pass from the transfer chamber TC through the second opening 8 and the first opening 7 into the process chamber PC.

[0045] Furthermore, in the air piston 29 of the stop mechanism 6, the supply of compressed air from the air pipes 39 (A, B, C) is stopped, and the piston rods 31 on both sides are pressed towards the center by the spring force of the spring 36. Therefore, the arm 44 connected to the piston rod 31 is in a vertically upright state, and the front end of the stop pin 30 installed at the upper end of the arm 44 is retracted to the end face of the roller guide 20. Therefore, the load-bearing roller 28 of the cam plate 24 will not collide with the front end of the stop pin 30, the stop function is released, and the valve stem 4 can rise to the end of the stroke of the cylinder 27.

[0046] Next, as Figure 4 and Figure 5As shown, when gate valve 1 (1A) is operating normally, the transfer chamber TC and process chamber PC are under the same pressure (atmosphere to atmosphere, or vacuum to vacuum), with only the process chamber PC side sealed. Therefore, in the air piston 29 of the stop mechanism 6, as... Figure 4 As shown, compressed air is supplied from the air pipes 39 (A and C) on the left and right sides.

[0047] Therefore, compressed air is supplied from the compressed air supply port 40 into the head-side space 37 in the air pistons 29 on both sides, and the piston rod 31 is pushed outward against the spring force of the spring 36. Then, the piston 35 abuts against the inner wall of the rod cover 33, and the front end of the piston rod 31 protrudes to the maximum extent from the outer wall of the rod cover 33. Therefore, the arm 44 connected to the piston rod 31 tilts at the maximum tilt angle (opening and closing angle of 6 degrees) starting from the joint 45. As a result, the front end of the stop pin 30 installed at the upper end of the arm 44 advances in a horizontal direction orthogonal to the stroke direction of the valve rod 4, and becomes a state where it protrudes from the end face of the roller guide 20 to the first abutment surface 41.

[0048] Here, by driving the cylinder 26 of the drive mechanism 5, the cam plate 24 is pushed up from below using the force of compressed air. While compressing the coil spring 25, the valve stem 4 rises a predetermined stroke via the cam 22 that engages with the cam plate 24. Furthermore, if the fulcrum roller 19 of the rod guide 17 abuts against the upper end of the groove of the roller guide 20, the valve plates 3 (10, 11) move to the height position corresponding to the openings 7, 8. At this time, the cylinder 27 has a remaining stroke.

[0049] Then, the direction-switching roller 21 begins to move along the cam groove 23 and initiates the sealing action. At this time, the load-bearing roller 28 collidees with and jams against the first contact surface 41 of the stop pin 30, and the direction-switching roller 21 moves towards the middle position (left side) of the cam groove 23, causing the valve stem 4 to tilt to the right. As a result, the first valve plate 10 engages with the first opening 7, sealing the first opening 7, and the sealing action is completed. This is the "same-pressure sealing" action.

[0050] Next, as Figure 6 and 7 As shown, when maintaining the process chamber PC, the transfer chamber TC is under vacuum, and the process chamber PC is exposed to atmospheric pressure. Under reverse pressure, only the process chamber PC side is sealed. Therefore, in the air piston 29 of the stop mechanism 6, as... Figure 6 As shown, compressed air is stopped from being supplied from the left and right air pipes 39 (A and C), and compressed air is supplied only from the central air pipe 39 (B).

[0051] Therefore, in the air pistons 29 on both sides, the piston rod 31 is pressed towards the center by the spring force of the spring 36. However, in the central air piston 29, since compressed air is supplied from the compressed air supply port 40 into the head-side space 37, the piston rod 31 overcomes the spring force of the spring 36 and is pushed back outward by the stroke of the central air piston 29. Then, the piston 35 stops at the middle position in the sealed space, and the front end of the piston rod 31 protrudes slightly from the outer wall surface of the rod cover 33. Therefore, the arm 44 connected to the piston rod 31 tilts at a smaller angle (opening and closing angle of 3 degrees) than before, starting from the joint 45. As a result, the front end of the stop pin 30 installed at the upper end of the arm 44 advances in a horizontal direction orthogonal to the stroke direction of the valve rod 4, so that only a portion of the second contact surface 42 protrudes from the end face of the roller guide 20.

[0052] Here, the direction-switching roller 21 moves along the cam groove 23 and begins the sealing action. At this time, the load-bearing roller 28 collides with the second abutment surface 42 of the stop pin 30, and the direction-switching roller 21 moves to a position slightly lower than the middle position (left side) of the cam groove 23, causing the valve stem 4 to tilt further to the right. As a result, the first valve plate 10 engages with the first opening 7 with a stronger force than before, sealing the first opening 7, and the sealing action is completed. This is the "reverse pressure sealing" action. Thus, by making the height position of the stop pin 30 variable, the strength of the pressing force of the first valve plate 10 during the same pressure sealing and reverse pressure sealing is adjusted according to the different height positions of the direction-switching roller 21.

[0053] Finally, as Figure 8 and Figure 9 As shown, when maintaining gate valve 1 (1A), the transmission chamber TC is under vacuum, and the process chamber PC is under atmospheric pressure. Only the transmission chamber TC side is sealed under positive pressure. Therefore, in the air piston 29 of the stop mechanism 6, as... Figure 8 As shown, the supply of compressed air from all air pipes 39 (A, B, C) is stopped. Consequently, the piston rods 31 on both sides elastically recover under the spring force of the springs 36, returning to the state of being pressed towards the center. Therefore, the arm 44 connected to the piston rod 31 becomes vertically upright, and the front end of the stop pin 30 mounted on the upper end of the arm 44 moves horizontally, returning to the state where it has retracted to the end face of the roller guide 20.

[0054] Here, driven by cylinder 26, the cam plate 24 is pushed up from below by the force of compressed air, compressing the coil spring 25 while the valve stem 4 rises a predetermined stroke via the cam 22 engaged with the cam plate 24. At this time, since the load-bearing roller 28 of the cam plate 24 does not collide with the front end of the stop pin 30, the restriction on the valve stem 4 is released, and the valve stem 4 rises to the end of the stroke of cylinder 26. At this moment, the direction-switching roller 21 begins to move along the cam groove 23 and begins the sealing action. At this time, the direction-switching roller 21 moves to the lower end position (right side) of the cam groove 23, causing the valve stem 4 to tilt to the left. As a result, the second valve plate 11 engages with the second opening 8, sealing the second opening 8, and the sealing action is completed. This is the "positive pressure sealing" action.

[0055] In this "positive pressure seal" state, if the maintenance flange 15 of the valve box 2 is removed and the cover is opened, and the bolts 14 are loosened to remove the first valve plate 10 from the valve stem 4, the first valve plate 10 can be removed to the outside of the valve box 2. Therefore, by setting the side requiring resistance to O-rings 12 and 13 as the "reverse pressure seal" side, it is possible to maintain the airtightness of the chamber while performing maintenance operations such as cleaning the first valve plate 10 and replacing the O-rings 12 and 13 in the "positive pressure seal" state.

[0056] As explained above, the gate valve 1 (1A) of this embodiment can adjust the opening and closing angle of the arm 44 by controlling the air piston 29, changing the position of the stop pin 30 in three stages. Thus, the position of the direction switching roller 21 within the cam groove 23 can be switched to the upper position (center), middle position (upper left), middle position (lower left), and lower position (right). Therefore, it can handle four states: (A) open, (B) same-pressure sealing on the PC side of the process chamber, (C) reverse-pressure sealing on the PC side of the process chamber, and (D) positive-pressure sealing on the TC side of the transfer chamber, giving the strength of a single-sided seal to a double-sided sealing structure.

[0057] In the above embodiments, the stop mechanism 6 uses a stop pin 30 with an opening and closing arm controlled by an air piston 29. However, it can also be configured to use a stop pin 30 based on an air piston 29. Figure 10 The gate valve 1 (1B) has an electrically or pneumatically controlled rotary stop pin 51 with a rotary actuator 50 as shown.

[0058] The rotary actuator 50 in this embodiment is an electrically powered rotary drive mechanism equipped with a motor 52, the output shaft 53 of which is embedded in and connected to the recess 55 of the piston rod 54. Within the sealed space of the main body 56, which has a rod cover 57 installed, there is a piston 59 sealed by a gasket 58, and a piston rod 54 integrally formed with the piston 59 is housed therein. The piston rod 54 is structured such that, under the force of a spring 60, its front end passes through the center of the rod cover 57 and protrudes outward. The sealed space is divided by the piston 59 into a head-side space 61 and a rod-side space 62, and a compressed air supply port 64 connected to an air pipe 63 is installed in the head-side space 61.

[0059] like Figure 19 As shown, the stop pin 51 is formed in an L-shape with the front end of the piston rod 54 bent at 90 degrees and having abutment surfaces of different heights (a first abutment surface 65 at a lower position and a second abutment surface 66 at a higher position). The configuration is such that if the output shaft 53 rotates due to the drive motor 52, the piston rod 54 connected to the output shaft 53 rotates around its axis, and the stop pin 51 at the front end of the piston rod 54 rotates integrally. It should be noted that in this embodiment, the upper surface of the cam plate 24 collides with the stop pin 51, but slit machining or countersinking can also be performed on the front end of the stop pin 51 to mitigate the impact when colliding with the cam plate 24 as a vibration reduction measure.

[0060] The above describes the structure of the gate valve 1 (1B) according to this embodiment; however, its operation will now be explained. In the gate valve 1 (1B), Figure 11 and Figure 12 This shows the state when fully open. Figure 13 and Figure 14 This shows the state of the seal under the same pressure. Figure 15 and Figure 16 This shows the state of the seal under reverse pressure. Figure 17 and Figure 18 This shows the state of a positive pressure seal.

[0061] like Figure 11 and Figure 12 As shown, when the gate valve 1 (1B) stops operating, the supply of compressed air from the air pipe 63 is stopped in the rotary actuator 50 of the stop mechanism 6, and the piston rod 54 is pressed towards the motor 52 by the spring force of the spring 60. Therefore, the front end of the stop pin 51, which is integrated with the piston rod 54, is pushed further outward than the side of the cam plate 24. Thus, the cam plate 24 does not collide with the front end of the stop pin 51, the stop function is released, and the valve stem 4 can rise to the end of the stroke of the cylinder 27.

[0062] Next, as Figure 13 and Figure 14As shown, when the gate valve 1 (1B) is operating normally, compressed air is supplied from the air pipe 63 to the rotary actuator 50 of the stop mechanism 6. This supplies compressed air into the head-side space 61 from the compressed air supply port 64, causing the piston rod 54 to be pushed outward against the spring force of the spring 60. Then, the piston 59 abuts against the inner wall of the rod cover 57, and the front end of the piston rod 54 protrudes from the outer wall of the rod cover 57. Consequently, the front end of the stop pin 51, which is integrated with the piston rod 54, advances in a horizontal direction orthogonal to the stroke direction of the valve rod 4, becoming more inwardly protruding than the side of the cam plate 24. Furthermore, the output shaft 53 of the drive motor 52 rotates, driving the piston rod 54, which is connected to the output shaft 53, to rotate around its axis until the stop pin 51 rotates until the first contact surface 65 is in a vertically downward position.

[0063] Here, by driving the cylinder 26 of the drive mechanism 5, the cam plate 24 is pushed up from below by the force of compressed air, while compressing the coil spring 25, and the valve stem 4 rises a predetermined stroke via the cam 22 that is engaged with the cam plate 24. In addition, when the fulcrum roller 19 of the rod guide 17 abuts against the upper end of the groove of the roller guide 20, the valve plates 3 (10, 11) move to the height position corresponding to the openings 7, 8.

[0064] Then, the direction-switching roller 21 begins to move along the cam groove 23 and initiates the sealing action. At this time, the upper surface of the cam plate 24 collides with and locks against the first contact surface 65 of the stop pin 51, and the direction-switching roller 21 moves towards the middle position (left side) of the cam groove 23, causing the valve stem 4 to tilt to the right. As a result, the first valve plate 10 engages with the first opening 7, sealing the first opening 7, and the sealing action is completed. This is the "same pressure sealing" action.

[0065] Next, as Figure 15 and Figure 16 As shown, during maintenance in the process chamber PC, the drive motor 52 rotates the output shaft 53, and the piston rod 54 connected to the output shaft 53 rotates around the axis. The stop pin 51 rotates until the first abutment surface 65 is in a 90-degree horizontal position and the second abutment surface 66 is in a vertical downward position.

[0066] Here, the direction-switching roller 21 moves along the cam groove 23 and begins the sealing action. At this time, the upper surface of the cam plate 24 collides with the second abutment surface 66 of the stop pin 51, and the direction-switching roller 21 moves to a position slightly lower than the middle position (left side) of the cam groove 23, causing the valve stem 4 to tilt further to the right. As a result, the first valve plate 10 engages with the first opening 7 with a stronger force than before, sealing the first opening 7, and the sealing action is completed. This is the "reverse pressure sealing" action. Thus, by making the height position of the stop pin 51 variable, the strength of the pressing force of the first valve plate 10 during the same pressure sealing and reverse pressure sealing is adjusted according to the different height positions of the direction-switching roller 21.

[0067] Finally, as Figure 17 and Figure 18 As shown, during maintenance of gate valve 1 (1B), the supply of compressed air from air pipe 63 is stopped in the rotary actuator 50 of stop mechanism 6. As a result, piston rod 54 elastically recovers under the spring force of spring 60, returning to the state where it was pressed towards motor 52. Consequently, the front end of stop pin 51, integrated with piston rod 54, moves horizontally, returning to a state where it is retracted further outward than the side of cam plate 24.

[0068] Here, driven by cylinder 26, the cam plate 24 is pushed up from below by the force of compressed air, compressing the coil spring 25 while the valve stem 4 rises a predetermined stroke via the cam 22 engaged with the cam plate 24. At this time, the cam plate 24 does not collide with the front end of the stop pin 51, the restriction on the valve stem 4 is released, and the valve stem 4 rises to the end of the stroke of cylinder 26. At this moment, the direction switching roller 21 begins to move along the cam groove 23 and begins the sealing action. At this time, the direction switching roller 21 moves to the lower end position (right side) of the cam groove 23, causing the valve stem 4 to tilt to the left. As a result, the second valve plate 11 engages with the second opening 8, sealing the second opening 8, and the sealing action is completed. This is the "positive pressure sealing" action.

[0069] As explained above, the gate valve 1 (1B) of this embodiment can adjust the rotation angle of the piston rod 54 by driving the motor 52 through the electrical control of the rotary actuator 50, changing the position of the stop pin 51 in three stages. Thus, the position of the direction switching roller 21 can be switched within the cam groove 23 to the upper position (center), middle position (upper left), middle position (lower left), and lower position (right). Therefore, it can handle four states: (A) open, (B) same-pressure sealing on the PC side of the process chamber, (C) reverse-pressure sealing on the PC side of the process chamber, and (D) positive-pressure sealing on the TC side of the transfer chamber, giving the strength of a single-sided seal to a double-sided sealing structure.

[0070] It should be noted that in the above embodiment, the rotary actuator 50 is configured as an electrically powered rotary drive mechanism, but instead, as shown below... Figure 20 As shown, an air-driven rotary drive mechanism can also be used. This rotary actuator 50 houses a rotating shaft 68 within a housing 67, and the space within the housing 67 is divided into two chambers by blades 69 integrated with the rotating shaft 68. When compressed air is supplied to the chamber from one supply / exhaust port 70 and exhausted to the outside from the other supply / exhaust port 71, the blades 69, driven by the compressed air, rotate while sealing the inner wall of the housing 67. Thus, the piston rod 54, connected to the rotating shaft 68, is driven to rotate around its axis, and the stop pin 51 at the front end of the piston rod 54 rotates integrally. In this way, through air control of the rotary actuator 50, and with… Figure 19 Similarly, the electrical control can adjust the rotation angle of the piston rod 54 and change the position of the stop pin 51 in three stages.

Claims

1. A gate valve, characterized in that, It is a gate valve that uses a valve plate disposed inside a valve box to open and close openings on both sides of the valve box. The gate valve has the following features: The valve stem, which is connected to the valve plate, is supported within the valve box in a manner that allows it to be raised, lowered, and tilted. A drive mechanism, located outside the valve box, enables the valve stem to move up, down, and tilt within a predetermined stroke. as well as A stop mechanism, located midway through the stroke of the drive mechanism, restricts or releases the rise of the valve stem by supplying or stopping compressed air. The stop mechanism changes the tilt angle of the valve stem by making the height position of the drive mechanism that tilts the valve stem variable, thereby altering the strength of the pressing force on the valve plate.

2. The gate valve according to claim 1, characterized in that, The stop mechanism is a structure in which a stop pin moves forward or backward in a horizontal direction orthogonal to the travel direction of the valve stem to limit or release the upward movement of the valve stem.

3. The gate valve according to claim 2, characterized in that, The stop mechanism is a structure that uses the control of an air piston to adjust the opening and closing angle of the arm, so that the height position of the stop pin at the front end of the arm can be changed.

4. The gate valve according to claim 2, characterized in that, The stop mechanism is a structure in which the rotation angle of the piston rod is adjusted by the control of a rotary actuator, so that the height position of the stop pin at the front end of the piston rod is variable.

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