Gate valve

Abstract

To suppress twisting and dust emission of a seal material in a gate valve.SOLUTION: A gate valve includes linear motion mechanisms 35, 41 which move a gate plate 20 for opening and closing an opening 11 in a direction along a surface of a gate plate 20, and Scott Russell mechanisms 51, 53 which opens and closes the opening 11 by moving the gate plate 20 in a direction orthogonal to the surface direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a gate valve. [Background technology]

[0002] In gate valves, a gate plate is moved vertically and then horizontally to close an opening. By moving the gate plate horizontally when closing an opening, twisting of the sealing material and dust generation can be suppressed. For example, a method is known in which a valve rod is raised with pressurized air to raise a gate plate attached to the end of the valve rod to a position facing the opening, and then a rack and pinion and a screw are used to move the gate plate horizontally backward, thereby pressing the sealing material fixed to the gate plate against the valve seat (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-173805 Summary of the Invention [Problem to be solved by the invention]

[0004] When the gate plate is raised by pressurized air, precise speed control can be difficult and particles can be generated. Multiple power sources may also be required. Therefore, there is room for improvement in the structure to prevent twisting of the sealing material and dust generation.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to suppress twisting of a sealing material and dust generation in a gate valve. [Means for solving the problem]

[0006] The gate valve according to the present disclosure includes: a linear motion mechanism that moves a gate plate that opens and closes an opening in a surface direction of the gate plate; a Scott-Russell mechanism that opens and closes the opening by moving the gate plate in a direction perpendicular to the surface direction; Equipped with. [Effects of the Invention]

[0007] This makes it possible to suppress twisting of the sealing material and dust generation in the gate valve. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a gate valve according to an embodiment; [Figure 2] FIG. 1 is a perspective view of a lifting device according to an embodiment. [Figure 3] 2 is a view of the lifting device according to the embodiment as seen from the right side in the X axis direction. FIG. [Figure 4] 2 is a view of the lifting device according to the embodiment as seen from above in the Z-axis direction. FIG. [Figure 5] 5A to 5C are diagrams illustrating the operation of a first link and a second link according to the embodiment. [Figure 6] 10A and 10B are diagrams illustrating the operation of a first link and a third link according to the embodiment. [Figure 7] 10A and 10B are diagrams showing the shape of a cam groove formed in a middle plate according to the embodiment; [Figure 8] 10 is a diagram illustrating a state in which the lifting device according to the embodiment moves the middle plate from the bottom to the upper side in the Z-axis direction. FIG. [Figure 9] 10 is a diagram showing the positional relationship between the cam follower and the cam groove immediately after the lifting device according to the embodiment has moved the middle plate upward from the lowest position in the Z-axis direction. FIG. [Figure 10] 10A and 10B are diagrams illustrating the positional relationship between the cam follower and the cam groove when the lifting device according to the embodiment is moving the middle plate from the bottom to the upper side in the Z-axis direction. [Figure 11] 10 is a diagram illustrating a state immediately after the lifting device according to the embodiment has moved the middle plate to the top in the Z-axis direction. FIG. [Figure 12] 10 is a diagram illustrating a state in which the lifting device according to the embodiment has moved the middle plate downward from the top in the Z-axis direction by a predetermined distance. FIG. [Figure 13] 10A and 10B are diagrams illustrating the positional relationship between the cam follower and the cam groove when the lifting device according to the embodiment is moving the middle plate downward from the top in the Z-axis direction by a predetermined distance. [Figure 14] 10 is a diagram showing the positional relationship between the cam follower and the cam groove when the lifting device according to the embodiment moves the middle plate downward from the top in the Z-axis direction by a predetermined distance. FIG. [Figure 15] 10 is a diagram illustrating a state in which the lifting device according to the embodiment moves the middle plate downward from the top in the Z-axis direction by a predetermined distance and then moves it upward in the Z-axis direction. FIG. [Figure 16] 10 is a diagram showing the positional relationship between the cam follower and the cam groove when the lifting device according to the embodiment is moving the middle plate to the top in the Z-axis direction again. FIG. [Figure 17] 10 is a diagram illustrating a state in which the lifting device according to the embodiment has again moved the middle plate to the top in the Z-axis direction. FIG. [Figure 18] 10 is a diagram showing the positional relationship between the cam follower and the cam groove 55 when the lifting device according to the embodiment moves the middle plate 39 to the uppermost position in the Z-axis direction again. FIG. [Figure 19] 10 is a diagram illustrating a state in which the lifting device according to the embodiment has moved the middle plate to the lowest position in the Z-axis direction. FIG. [Figure 20] 10A and 10B are diagrams illustrating the positional relationship between the cam followers and the cam grooves when the lifting device according to the embodiment moves the middle plate from the top to the bottom in the Z-axis direction. [Figure 21] 10A and 10B are diagrams illustrating the positional relationship between the cam follower and the cam groove while the lifting device according to the embodiment is moving the middle plate from the top to the bottom in the Z-axis direction. [Figure 22] 4 is a flowchart showing an example of opening and closing control of a gate valve according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The gate valve according to the present disclosure has a gate plate that opens and closes an opening. The gate valve is closed when the gate plate closes the opening, and is opened when the gate plate opens the opening. The gate plate is moved in the plane direction of the gate plate by a linear motion mechanism. For example, as a preliminary step to closing the gate valve, the gate plate is moved to the front of the opening by the linear motion mechanism. Furthermore, the gate plate is moved in a direction perpendicular to the plane direction of the gate plate by a Scott Russell mechanism. At this time, the gate plate moves linearly toward the opening by Scott Russell's strict linear motion. Therefore, when the gate plate closes and opens the opening, the gate plate abuts perpendicularly against the surface that forms the opening (opening surface), thereby suppressing twisting of the sealing material and dust generation.

[0010] The gate valve according to the present disclosure may also include a single motor. This motor moves the first plate in the first and second directions, for example, by rotating a feed screw forward and backward. As another example, the first plate may be moved using gears, a belt, or the like. A first joint on one end of the first link and a third joint on one end of the second link may be disposed on the first plate. Furthermore, a second joint on the other end of the first link and a fourth joint on the other end of the second link may be disposed on the gate plate. The first link and the second link may form a parallel link. Thus, the gate plate may be configured to be able to move in parallel by the first link and the second link. The gate plate opens and closes the gate valve by opening and closing the opening. The gate plate is parallel when it closes the opening and when it opens the opening.

[0011] The second plate may be arranged to be movable relative to the first plate in the first and second directions. The first and second plates may be parallel plates with their widest surfaces facing each other. A fifth joint on one end of the third link and a seventh joint on one end of the fourth link may be arranged on the second plate. The third link and the fourth link are links that change the relative positions of the first and second plates.

[0012] The fifth joint on one end of the third link may be disposed on the second plate at a position offset from the first joint in the second direction and offset from the second joint in a third direction perpendicular to the first direction. The joint on the other end of the third link may be disposed on the first link between the first joint and the second joint. Therefore, the distance between the first joint on one end of the first link and the fifth joint on one end of the third link changes in response to the relative movement of the first plate and the second plate in the first and second directions. Similarly, the distance between the second joint on the other end of the first link and the fifth joint on one end of the third link changes in response to the relative movement of the first plate and the second plate in the first and second directions. In this case, the shorter the distance between the first joint on one end of the first link and the fifth joint on one end of the third link, the longer the distance between the second joint on the other end of the first link and the fifth joint on one end of the third link. That is, by moving the second plate relative to the first plate in a first direction, the distance between the first joint on one end of the first link and the fifth joint on one end of the third link becomes shorter, and the distance between the second joint on the other end of the first link and the fifth joint on one end of the third link becomes longer, so that the gate plate moves in a direction to close the opening. On the other hand, by moving the second plate relative to the first plate in a second direction, the distance between the first joint on one end of the first link and the fifth joint on one end of the third link becomes longer, and the distance between the second joint on the other end of the first link and the fifth joint on one end of the third link becomes shorter, so that the gate plate moves in a direction to open the opening.

[0013] The fourth link may have a seventh joint on one end disposed on the second plate, and a moving part disposed on an eighth joint on the other end. The moving part may be configured to be movable along a groove formed in the first plate. When the moving part moves along the groove, the relative position of the first plate and the second plate changes via the fourth link. Therefore, the control device can control the motor to change the relative position of the first plate and the second plate, thereby moving the gate plate.

[0014] When closing the gate valve, the control device may control the motor to move the first plate in a first direction from a first position to a second position, and then move the first plate in a second direction to a third position between the first and second positions. The first position is the position of the first plate when the gate valve is in an open state. The second position is a position of the first plate where the gate plate is positioned in a direction perpendicular to the opening surface of the opening. The third position is a position of the first plate where the gate plate closes the opening. That is, by moving the first plate from the first position to the second position, the control device moves the gate plate to a position perpendicular to the opening surface of the opening, and further by moving the first plate from the second position to the third position, the gate plate moves in a direction perpendicular to the opening surface of the opening to close the opening.

[0015] Furthermore, when opening the gate valve, the control device may control the motor to move the first plate from the third position in the first direction to the second position, and then move it in the second direction to the first position. That is, by moving the first plate from the third position to the second position, the control device moves the gate plate in a direction perpendicular to the opening surface of the opening to open the opening. Furthermore, by moving the first plate from the second position to the first position, the control device moves the gate plate parallel to the opening surface of the opening while being separated from the opening.

[0016] The groove formed in the first plate may have a first portion that supports the moving part when the first plate moves from the first position to the second position in the first direction. By the first portion supporting the moving part, the first portion pushes the moving part in the first direction. Therefore, both the first plate and the second plate The gate plate moves in the first direction. At this time, the distance between the second joint at the other end of the first link and the fifth joint at one end of the third link becomes relatively small, so there is a sufficient gap between the gate plate and the opening.

[0017] Furthermore, the groove formed in the first plate may have a second portion formed at a position to which the moving portion moves when the first plate moves from the second position in the second direction to the third position. That is, the relative positions of the first plate and the second plate can be changed by the moving portion moving to the second portion. At this time, the distance between the second joint on the other end of the first link and the fifth joint on one end of the third link becomes relatively large, and the gate plate closes the opening.

[0018] Furthermore, the groove formed in the first plate may have a third portion formed at a position to which the moving portion moves when the first plate moves from the third position in the first direction to the second position. That is, the relative positions of the first plate and the second plate can be changed by the moving portion moving to the third portion. At this time, the distance between the second joint on the other end of the first link and the fifth joint on one end of the third link becomes relatively small, and the gate plate opens the opening.

[0019] Furthermore, the groove formed in the first plate may have a fourth portion that supports the moving portion when the first plate moves from the second position to the first position in the second direction. By supporting the moving portion, the fourth portion pushes the moving portion in the second direction. Therefore, the first plate and the second plate move together in the second direction. During this movement, the gate plate and the opening are maintained apart from each other.

[0020] Furthermore, the groove may be formed in the first plate such that the moving part rotates in the order of the first part, the second part, the third part, the fourth part, and the second part. By having the moving part rotate around the groove, the moving part can be rotated continuously by the control device simply moving the first plate, so that the gate plate can be opened and closed by the control device simply moving the first plate.

[0021] The first link and the third link may also constitute a Scott-Russell mechanism. In this case, the joint at one end of the first link and the joint at one end of the third link move relative to each other, causing the joint at the other end of the first link to move linearly relative to the joint at one end of the third link. Therefore, when the opening is closed or opened, the gate plate can be moved perpendicular to the plane of the opening.

[0022] When the control device moves the first plate from the second position in the second direction to the third position, the second plate moves relative to the first plate in the first direction; the first joint of the first link and the fifth joint of the third link approach each other, the second joint of the first link and the fifth joint of the third link are separated, The gate plate moves in a fourth direction opposite to the third direction, whereby the gate plate closes the opening, When the control device moves the first plate from the third position in the first direction to the second position, the second plate moves relative to the first plate in the second direction, the first joint of the first link and the fifth joint of the third link are separated, the second joint of the first link and the fifth joint of the third link approach each other, The gate plate moves in the third direction, and thereby the gate plate closes the opening. By moving each link in this way, the gate valve can be opened and closed.

[0023] The second portion is formed at a position closer to the first direction than the first portion, the third portion is formed at a position closer to the second direction than the second portion, the fourth portion is formed at a position closer to the first direction than the first portion and the third portion and closer to the second direction than the second portion, The groove is When the first plate moves from the first position to the second position in the first direction, the moving portion moves from the fourth portion to the first portion, When the first plate moves from the second position to the third position in the second direction, the moving portion moves from the first portion to the second portion, when the first plate moves from the third position to the second position in the first direction, the moving portion moves from the second portion to the third portion; When the first plate moves from the second position to the first position in the second direction, the moving portion moves from the third portion to the fourth portion. It may be formed as follows.

[0024] The first portion is a portion that the moving portion reaches when the first plate moves from the first position to the second position in the first direction. The second portion is a portion that the moving portion reaches when the first plate moves from the second position to the third position in the second direction. The third portion is a portion that the moving portion reaches when the first plate moves from the third position to the second position in the first direction. The fourth portion is a portion that the moving portion reaches when the first plate moves from the second position to the first position in the second direction. In this way, the relative positions of the first plate and the second plate can be changed by the moving portion moving inside the groove.

[0025] The first plate may be provided with a linear guide for guiding the second plate in the first direction and the second direction. Such a linear guide can limit the direction of movement of the second plate relative to the first plate. The first plate may also be guided in the first direction and the second direction by another linear guide.

[0026] Specific embodiments of the present disclosure will be described below with reference to the drawings. The dimensions, materials, shapes, numbers, relative positions, etc. of the components described in the present embodiments are not intended to limit the technical scope of the disclosure unless otherwise specified.

[0027] <Embodiment> FIG. 1 is a diagram showing the schematic configuration of a gate valve 1 according to this embodiment. The gate valve 1 opens and closes an opening at a communication portion between a transfer chamber and a process chamber, or at a communication portion between a transfer chamber and a load (unload) lock chamber in, for example, a semiconductor manufacturing device. The transfer chamber, the process chamber, and the load (unload) lock chamber are each depressurized by a vacuum pump. Note that although the gate valve 1 according to this embodiment is a rectangular gate valve, gate valves of other shapes can also be used in the same manner.

[0028] The gate valve 1 is configured to include a gate plate 20 in a housing 10 and an elevator device 30 that raises and lowers the gate plate 20. The housing 10 and the gate plate 20 are made of metal. The housing 10 is provided with a first opening 11 and a second opening 12 through which wafers used in semiconductor manufacturing pass. The gate plate 20 is a plate-shaped member that opens and closes the first opening 11 of the housing 10, and has a connecting rod 21 that connects to the elevator device 30. A sealant 22 is arranged on the first opening 11 side of the gate plate 20. The sealant 22 is disposed when the gate plate 20 closes the first opening 11. The lifting device 30 lifts and lowers the gate plate 20 and presses it against the first opening 11 via a connecting rod 21. The lifting device 30 is fixed to the inner wall surface 13 of the housing 10.

[0029] In the following description, an XYZ Cartesian coordinate system is set, and the position of each component is described with reference to this XYZ Cartesian coordinate system. The direction from the second opening 12 to the first opening 11 of the housing 10 is defined as the X-axis direction, the longitudinal direction of the housing 10 is defined as the Y-axis direction, and the direction in which the gate plate 20 rises is defined as the Z-axis direction. The X-axis direction is the thickness direction of the gate plate 20. The Y-axis direction is the longitudinal direction of the gate plate 20. The Z-axis direction is the lateral direction of the gate plate 20 and is also the vertical direction. The XY plane is a horizontal plane. In the Z-axis direction, the direction in which the gate plate 20 moves from the lifting device 30 side to the first opening 11 side is defined as the upward direction of the gate valve 1. When viewed from the Y-axis direction, the first opening 11 side is defined as the right side of the X-axis direction, and the second opening side is defined as the left side of the X-axis direction. Furthermore, when viewed from the Y-axis direction, the XZ plane side of the inner wall surface 13 of the housing 10 on which the lifting device 30 is arranged is defined as the rear side in the Y-axis direction, and the XZ plane side on which the lifting device 30 is not arranged is defined as the front side in the Y-axis direction. The direction from the bottom to the top in the Z-axis direction is an example of a first direction, and the direction from the top to the bottom in the Z-axis direction is an example of a second direction. The direction from the right to the left in the X-axis direction is an example of a third direction, and the direction from the left to the right in the X-axis direction is an example of a fourth direction.

[0030] FIG. 2 is a perspective view of the lifting device 30 according to this embodiment. FIG. 3 is a view of the lifting device 30 according to this embodiment as seen from the right side in the X-axis direction. FIG. 4 is a view of the lifting device 30 according to this embodiment as seen from above in the Z-axis direction. The lifting device 30 has a base 31 fixed to the inner wall surface 13 of the housing 10, for example, by bolts. The base 31 is a metal plate-shaped member parallel to the XZ plane. A motor 33 is attached to the base 31 via a bracket 32 bent at a right angle. The bracket 32 has a portion parallel to the XZ plane and a portion parallel to the XY plane. The portion of the bracket 32 parallel to the XZ plane is fixed to the front side of the base 31 in the Y-axis direction, and the motor 33 is attached below the portion parallel to the XY plane in the Z-axis direction.

[0031] The motor 33 is an electric motor that operates when supplied with electric power. The motor 33 has an output shaft 331 disposed in the Z-axis direction. The output shaft 331 is disposed facing upward in the Z-axis direction. The lower end of a screw shaft 35 of a feed screw is connected to the upper end of the output shaft 331 of the motor 33 via a coupling 34. The screw shaft 35 of the feed screw is disposed on the same straight line as the output shaft 331 of the motor 33. The screw shaft 35 is rotatably supported by two brackets 36 having portions parallel to the XY plane. The two brackets 36 are bent at right angles and fixed to the base 31 with, for example, bolts. A nut 37 is attached to the screw shaft 35 of the feed screw. The nut 37 moves in the Z-axis direction along the screw shaft 35, which rotates when the motor 33 is operated.

[0032] A middle plate 39 is fixed to the nut 37 via a bracket 38. The middle plate 39 is a metal plate-like member parallel to the XZ plane. The middle plate 39 is an example of a first plate. The bracket 38 is a plate-like member bent at a right angle and having portions parallel to the XY plane and the YZ plane, and the portion parallel to the XY plane is fixed to the nut 37 by, for example, a bolt. The left end of the middle plate 39 in the X axis direction is fixed to the right side of the portion of the bracket 38 parallel to the YZ plane by, for example, a bolt. The shape of the bracket 38 is just an example, and other shapes can be used as long as they connect the nut 37 and the middle plate 39. The bracket 38 and the middle plate 39 may be formed integrally.

[0033] A first linear guide 400 is disposed between the base portion 31 and the intermediate plate 39. A first block 40 of the first linear guide 400 is attached to the inner side of the intermediate plate 39 in the Y-axis direction. In addition, a first rail 41 of a first linear motion guide 400 that pairs with the first block 40 is arranged in the Z-axis direction on the base portion 31. When the middle plate 39 moves up and down in the Z-axis direction, the first block 40 moves along the first rail 41, so that the first linear motion guide 400 guides the middle plate 39 in the Z-axis direction. The screw shaft 35 of the feed screw, the nut 37, and the first linear motion guide 400 are an example of a linear motion mechanism.

[0034] The upper plate 42 is disposed on the nearer side in the Y-axis direction than the middle plate 39. The upper plate 42 is a metal plate-shaped member parallel to the XZ plane. In FIG. 2, the upper plate 42 is indicated by a dashed line for easier viewing of the drawing. The upper plate 42 is an example of a second plate. A second linear guide 401 is disposed between the upper plate 42 and the middle plate 39. A second block 43 of the second linear guide 401 is attached to the rear side of the upper plate 42 in the Y-axis direction. Furthermore, a second rail 44 of the second linear guide 401 that pairs with the second block 43 is disposed in the Z-axis direction on the nearer side in the Y-axis direction than the middle plate 39. When the middle plate 39 and the upper plate 42 move relative to each other in the Z-axis direction, the second block 43 moves along the second rail 44, thereby guiding the upper plate 42 in the Z-axis direction.

[0035] A first link 51 and a second link 52 are arranged on the front side of the middle plate 39 in the Y axis direction. The first link 51 and the second link 52 are a pair of parallel links. One end of the first link 51 is rotatably supported by a first joint 511. The first joint 511 is arranged in the Y axis direction and fixed to the middle plate 39. A second joint 512 that rotatably supports the connecting rod 21 is arranged on the front side of the other end of the first link 51 in the Y axis direction. The second joint 512 is arranged in the Y axis direction and fixed to the first link 51.

[0036] One end of the second link 52 is rotatably supported by a third joint 521. The third joint 521 is disposed in the Y-axis direction and fixed to the middle plate 39. A fourth joint 522 that rotatably supports the connecting rod 21 is disposed on the front side of the other end of the second link 52 in the Y-axis direction. The fourth joint 522 is disposed in the Y-axis direction and fixed to the second link 52.

[0037] FIG. 5 is a diagram showing the operation of the first link 51 and the second link 52 according to this embodiment. The first joint 511 and the third joint 521 are arranged offset from each other on the same straight line parallel to the Z-axis direction. The distance from the first joint 511 to the second joint 512 is equal to the distance from the third joint 521 to the fourth joint 522. The first link 51 and the second link 52 are parallel to each other, forming a parallel link. When the first link 51 rotates around the first joint 511, the second link 52 also rotates around the third joint 521 in the same direction and at the same angle. Therefore, the connecting rod 21 moves while remaining parallel to the YZ plane. Therefore, the gate plate 20 can move while remaining parallel to the opening plane of the first opening 11.

[0038] A third link 53 is disposed on the front side of the upper plate 42 in the Y axis direction. One end of the third link 53 is rotatably supported by a fifth joint 531. The fifth joint 531 is disposed in the Y axis direction and fixed to the front side of the upper plate 42 in the Y axis direction. A sixth joint 532 that rotatably supports the first link 51 is disposed on the other end of the third link 53. The sixth joint 532 is disposed in the Y axis direction and fixed to the third link 53. The sixth joint 532 is disposed on the first link 51 between the first joint 511 and the second joint 512. The fifth joint 531 is disposed below the first joint 511 in the Z axis direction.

[0039] A fourth link 54 is disposed on the rear side of the upper plate 42 in the Y-axis direction. One end of fourth link 54 is rotatably supported by seventh joint 541. Seventh joint 541 is disposed in the Y-axis direction, and is fixed to the rear side of top plate 42 in the Y-axis direction. A cam follower 542 is disposed on the rear side of the other end of fourth link 54 in the Y-axis direction. Cam follower 542 is disposed inside cam groove 55 formed in middle plate 39 so as to protrude toward the rear side in the Y-axis direction. Cam follower 542 is configured to include a bearing that rotates around a shaft (eighth joint 543) disposed in the Y-axis direction.

[0040] FIG. 6 is a diagram showing the operation of the first link 51 and the third link 53 according to this embodiment. The fifth joint 531 and the first joint 511 are arranged on the same line parallel to the Z-axis direction, and the fifth joint 531 is arranged below the first joint 511. The second joint 512 and the fifth joint 531 are arranged on the same line parallel to the X-axis direction, and the second joint 512 is arranged to the right of the fifth joint 531. The first link 51 and the third link 53 form a Scott-Russell mechanism. A force corresponding to the mass of the gate plate 20 is applied to the first link 51 and the second link 52. The upper plate 42 moves relative to the middle plate 39 in the Z-axis direction, changing the distance between the first joint 511 and the fifth joint 531. At this time, the upper plate 42 moves along the second rail 44, and the first joint 511 moves relative to the fifth joint 531 in the Z-axis direction. On the other hand, the second joint 512 moves parallel to the X-axis due to Scott Russell strict linear motion. For example, when changing from the state shown in the upper part of FIG. 6 to the state shown in the lower part of FIG. 6, the upper plate 42 moves downward in the Z-axis direction relative to the middle plate 39. As a result, the second joint 512 moves parallel to the X-axis so as to approach the fifth joint 531. Therefore, the connecting rod 21 moves parallel to the X-axis direction by the parallel link shown in FIG. 5 and the Scott Russell mechanism shown in FIG. 6. This allows the gate plate 20 to move parallel to the X-axis (i.e., horizontally) while maintaining a state parallel to the opening plane of the first opening 11. In other words, the gate plate 20 can move perpendicular to the opening plane of the first opening 11.

[0041] The cam follower 542 moves along the cam groove 55, thereby moving the upper plate 42 relative to the middle plate 39 in the Z-axis direction.

[0042] 7 is a diagram showing the shape of cam groove 55 formed in middle plate 39 according to this embodiment. Cam groove 55 is formed to allow cam follower 542 to move. In this embodiment, cam follower 542 moves counterclockwise within cam groove 55 as viewed from the front side in the Y-axis direction. However, it is also possible to configure cam follower 542 to move clockwise by, for example, making cam groove 55 a shape that is left-right inverted from the shape shown in FIG. 7.

[0043] The cam groove 55 is a groove recessed from the front side to the rear side of the middle plate 39 in the Y-axis direction and is defined by an outer wall 55A, an inner wall 55B, and a bottom surface 55C. A first convex portion 551, a second convex portion 552, a third convex portion 553, and a first concave portion 554 are formed on the outer wall 55A. The first convex portion 551, the second convex portion 552, and the third convex portion 553 are portions that protrude toward the outside of the cam groove 55. The first concave portion 554 is a portion that is recessed toward the inside of the cam groove 55. A fourth convex portion 555, a fifth convex portion 556, a sixth convex portion 557, and a second concave portion 558 are formed on the inner wall 55B. The fourth convex portion 555, the fifth convex portion 556, and the sixth convex portion 557 are portions that protrude toward the outside of the area surrounded by the inner wall 55B. The second recess 558 is a portion recessed inward from the portion surrounded by the inner wall 55B.

[0044] The second convex portion 552 is located at the top of the cam groove 55, and the first convex portion 551 and the third convex portion 553 are located at the bottom of the cam groove 55. In addition, a first recessed portion 554, a sixth convex portion 557, a fourth convex portion 555, a second recessed portion 558, a fifth convex portion 556, and the second convex portion 552 are formed in this order from the first convex portion 551 and the third convex portion 553 upward. 6 are formed on the same straight line parallel to the Z-axis direction. The fifth convex portion 556 is formed to the right of the second convex portion 552 in the X-axis direction. The fourth convex portion 555 is formed to the right of the fifth convex portion 556 in the X-axis direction, and the first convex portion 551 is formed to the right of the fourth convex portion 555 in the X-axis direction. The first recessed portion 554 is formed to the left of the second convex portion 552 in the X-axis direction. The third convex portion 553 is formed to the left of the first recessed portion 554 in the X-axis direction, and the sixth convex portion 557 is formed to the left of the third convex portion 553 in the X-axis direction.

[0045] The gate valve 1 includes a control device 100 that controls the motor 33. The control device 100 may be configured as a computer having a processor and memory. The control device 100 is configured to execute a predetermined control program stored in the memory. The control device 100 may also be a device that controls semiconductor manufacturing equipment. When the first opening 11 is closed by the gate plate 20, the control device 100 rotates the motor 33 in one direction to move the nut 37 from the bottom to the top, thereby moving the middle plate 39 from the bottom to the top. The bottom of the middle plate 39 is an example of a first position, and the top is an example of a second position. Thereafter, the control device 100 further rotates the motor 33 in the other direction to lower the nut 37 a predetermined distance from the top, thereby lowering the middle plate 39 a predetermined distance from the top. The position where the middle plate 39 is lowered a predetermined distance is an example of a third position. Furthermore, the control device 100 then stops the motor 33.

[0046] On the other hand, when opening the first opening 11, the control device 100 rotates the motor 33 in one direction to raise the nut 37 to the top again, thereby moving the middle plate 39 to the top. Thereafter, the control device 100 further rotates the motor 33 in the other direction to lower the nut 37 from the top to the bottom, thereby lowering the middle plate 39 from the top to the bottom. After that, the control device 100 stops the motor 33. By operating the motor 33 in this manner, the cam follower 542 moves around the cam groove 55 counterclockwise as viewed from the front side in the Y-axis direction.

[0047] The first convex portion 551, the second convex portion 552, the third convex portion 553, and the second concave portion 558 are examples of the first portion, the second portion, the third portion, and the fourth portion, respectively.

[0048] Next, the operation of the lifting device 30 will be described. First, the operation of closing the first opening 11 with the gate plate 20 will be described. FIG. 8 is a diagram showing the state when the lifting device 30 according to this embodiment is moving the middle plate 39 upward from the bottom in the Z-axis direction. When the middle plate 39 is located at the bottom in the Z-axis direction, the gate plate 20 opens the first opening 11. To move the middle plate 39 upward, the control device 100 activates the motor 33 to rotate the screw shaft 35 in one direction. This causes the nut 37 to move upward in the Z-axis direction. As the nut 37 rises, the middle plate 39 also moves upward from the bottom in the Z-axis direction. At this time, the first block 40 fixed to the middle plate 39 moves along the first rail 41 to guide the middle plate 39 in the Z-axis direction.

[0049] 9 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 immediately after the lifting device 30 according to this embodiment has moved the middle plate 39 upward from the bottom in the Z axis direction. In FIG. 9, the white arrow indicates the movement direction of the middle plate 39, and the black arrow indicates the relative movement direction of the cam follower 542 with respect to the middle plate 39. When the middle plate 39 is located at the bottom, the cam follower 542 is positioned so as to come into contact with the second recessed portion 558. When the middle plate 39 moves upward, the cam follower 542 moves relatively downward of the middle plate 39. At this time, the first recessed portion 554 is located to the left of the second recessed portion 558 in the X axis direction, and therefore the central axis of the cam follower 542 is located to the right of the first recessed portion 554 in the X axis direction. In this case, the cam follower 542 passes to the right of the first recessed portion 554 in the X axis direction and contacts the outer wall 541. 55A toward first convex portion 551. Then, when cam follower 542 reaches first convex portion 551, cam follower 542 is pressed against first convex portion 551 and the relative movement stops. In this manner, movement of cam follower 542 causes upper plate 42 to move downward in the Z-axis direction relative to middle plate 39. When cam follower 542 reaches first convex portion 551, the distance in the Z-axis direction between first joint 511 and fifth joint 531 becomes the largest, and the distance in the X-axis direction between fifth joint 531 and second joint 512 becomes the smallest. This causes gate plate 20 to be separated from the opening surface of first opening 11.

[0050] 10 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 while the lifting device 30 according to this embodiment is moving the middle plate 39 upward from the bottom in the Z axis direction. In FIG. 10, the white arrow indicates the direction of movement of the middle plate 39, and the hatched arrow indicates the force acting on the cam follower 542. When the cam follower 542 reaches the first protrusion 551, the cam follower 542 is no longer able to move relative to the middle plate 39 and receives an upward force from the outer wall 55A, moving upward together with the middle plate 39. Therefore, the relative movement between the first joint 511 and the fifth joint 531 in the Z axis direction also stops, and the connecting rod 21 moves upward in the Z axis direction.

[0051] 11 is a diagram showing the state immediately after the lifting device 30 according to this embodiment has moved the middle plate 39 to the top in the Z axis direction. Even when the middle plate 39 reaches the top, the cam follower 542 is in contact with the first protrusion 551, so the relative position between the middle plate 39 and the top plate 42 does not change. Therefore, the gate plate 20 remains spaced apart from the first opening 11. Also, at this time, the gate plate 20 is spaced apart to the left of the first opening 11 in the X axis direction, and if the gate plate 20 moves in the X axis direction, it is able to close the first opening 11.

[0052] 12 is a diagram showing a state when the lifting device 30 according to this embodiment has moved the middle plate 39 downward a predetermined distance from the uppermost portion in the Z-axis direction. This predetermined distance is at least the distance required for the cam follower 542 to move to the second convex portion 552.

[0053] FIG. 13 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 while the lifting device 30 according to this embodiment is moving the middle plate 39 downward a predetermined distance from the uppermost portion in the Z axis direction. In FIG. 13 , the white arrow indicates the movement direction of the middle plate 39, and the black arrow indicates the relative movement direction of the cam follower 542 with respect to the middle plate 39. When the cam follower 542 is positioned at the first convex portion 551, the cam follower 542 moves upward relative to the middle plate 39 as the middle plate 39 moves downward. At this time, the fourth convex portion 555 is positioned to the left of the first convex portion 551 in the X axis direction, and therefore the central axis of the cam follower 542 is positioned to the right of the fourth convex portion 555 in the X axis direction. The cam follower 542 then passes to the right of the fourth convex portion 555 in the X axis direction and moves along the outer wall 55A toward the second convex portion 552. At this time, the distance in the Z-axis direction between the first joint 511 and the fifth joint 531 gradually decreases, and the distance in the X-axis direction between the fifth joint 531 and the second joint 512 gradually increases. As a result, the gate plate 20 moves to the right in the X-axis direction toward the first opening 11.

[0054] FIG. 14 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 when the lifting device 30 according to this embodiment moves the middle plate 39 downward by a predetermined distance from the top in the Z-axis direction. In FIG. 14, the white arrow indicates the movement direction of the middle plate 39, and the black arrow indicates the relative movement direction of the cam follower 542 with respect to the middle plate 39. When the cam follower 542 reaches the second convex portion 552, which is the top of the cam groove 55, the relative movement of the cam follower 542 with respect to the middle plate 39 stops. In this way, when the cam follower 542 reaches the second convex portion 552, the control device 100 stops the motor 33. At this time, because the cam follower 542 is located at the top of the cam groove 55, the upper plate 42 moves downward in the Z-axis direction relative to the middle plate 39. As a result, the gate plate 20 is most displaced upward in the Z-axis direction. Therefore, the distance between the first joint 511 and the fifth joint 531 in the Z-axis direction is smallest. Therefore, the distance between the fifth joint 531 and the second joint 512 in the X-axis direction is longest, and the gate plate 20 is pressed against the housing 10 so as to block the first opening 11. At this time, as described with reference to FIG. 6 , the connecting rod 21 moves parallel to the X-axis direction due to Scott-Russell strict linear motion, and the gate plate 20 moves horizontally to block the first opening 11. This can suppress twisting of the sealing material 22 and dust generation. By maintaining this state, the first opening 11 can be kept closed. In this manner, the gate valve 1 is closed.

[0055] Next, the operation of opening the first opening 11 will be described. Fig. 15 is a diagram showing a state in which the lifting device 30 according to this embodiment moves the middle plate 39 downward a predetermined distance from the top in the Z-axis direction and then moves it upward in the Z-axis direction. The control device 100 moves the middle plate 39 downward a predetermined distance from the top in the Z-axis direction and then moves it back to the top in the Z-axis direction.

[0056] FIG. 16 is a diagram showing the positional relationship between cam follower 542 and cam groove 55 while lifting device 30 according to this embodiment is moving middle plate 39 back to the top in the Z axis direction. In FIG. 16, the white arrow indicates the direction of movement of middle plate 39, the black arrow indicates the direction of relative movement of cam follower 542 with respect to middle plate 39, and the hatched arrow indicates the force acting on cam follower 542. When cam follower 542 is positioned at second convex portion 552, upward movement of middle plate 39 causes cam follower 542 to move downward relative to middle plate 39. At this time, fifth convex portion 556 is positioned to the right of second convex portion 552 in the X axis direction, and therefore the central axis of cam follower 542 is positioned to the left of fifth convex portion 556 in the X axis direction. As a result, the cam follower 542 passes to the left of the fifth protrusion 556 in the X-axis direction and moves from the left side of the fifth protrusion 556 along the inner wall 55B toward the third protrusion 553. At this time, the distance between the first joint 511 and the fifth joint 531 in the Z-axis direction gradually increases, and the distance between the fifth joint 531 and the second joint 512 in the X-axis direction gradually decreases. As a result, the gate plate 20 moves to the left in the X-axis direction, moving away from the first opening 11. At this time, the gate plate 20 moves parallel to the X-axis due to Scott-Russell strict linear motion. This can suppress twisting of the sealant 22 and dust generation.

[0057] 17 is a diagram showing a state when the lifting device 30 according to this embodiment has again moved the middle plate 39 to the uppermost position in the Z-axis direction. The middle plate 39 has reached the uppermost position, and the cam follower 542 is in contact with the third convex portion 553.

[0058] FIG. 18 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 when the lifting device 30 according to this embodiment moves the middle plate 39 to the uppermost position in the Z axis direction again. In FIG. 18, the black arrow indicates the relative movement direction of the cam follower 542 with respect to the middle plate 39. As the middle plate 39 moves upward, the cam follower 542 moves relatively downward along the inner wall 55B of the middle plate 39. When the cam follower 542 passes the sixth convex portion 557, the cam follower 542 advances toward the outer wall 55A below in the Z axis direction. Thereafter, the cam follower 542 moves toward the third convex portion 553 along the outer wall 55A. When the cam follower 542 reaches the third convex portion 553, the cam follower 542 is pressed against the third convex portion 553, and the relative movement stops. At this time, the cam follower 542 is positioned at the bottom of the cam groove 55, so the distance in the Z axis direction between the first joint 511 and the fifth joint 531 is the largest. Therefore, the distance in the X axis direction between the fifth joint 531 and the second joint 512 is the smallest, and the gate plate 20 is sufficiently separated from the first opening 11.

[0059] 19 is a diagram showing a state when the lifting device 30 according to this embodiment has moved the middle plate 39 to the lowest position in the Z-axis direction. At this time, the middle plate 39 has reached the lowest position, and the cam follower 542 is in contact with the second recess 558.

[0060] FIG. 20 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 when the lifting device 30 according to this embodiment moves the middle plate 39 from the top to the bottom in the Z axis direction. In FIG. 20 , the white arrow indicates the movement direction of the middle plate 39, and the hatched arrow indicates the force acting on the cam follower 542. When the cam follower 542 is positioned at the third convex portion 553, the cam follower 542 moves upward relative to the middle plate 39 as the middle plate 39 moves downward. At this time, the sixth convex portion 557 is positioned to the left of the third convex portion 553 in the X axis direction, and therefore the central axis of the cam follower 542 is positioned to the right of the sixth convex portion 557 in the X axis direction. The cam follower 542 then passes to the right of the sixth convex portion 557 in the X axis direction and moves from the right side of the sixth convex portion 557 along the inner wall 55B toward the second recess 558.

[0061] FIG. 21 is a diagram showing the positional relationship between the cam follower 542 and the cam groove 55 while the lifting device 30 according to this embodiment is moving the middle plate 39 from the top to the bottom in the Z axis direction. In FIG. 21 , the white arrow indicates the direction of movement of the middle plate 39, and the hatched arrow indicates the force acting on the cam follower 542. As the middle plate 39 moves downward, the cam follower 542 moves along the inner wall 55B to the second recess 558. When the cam follower 542 reaches the second recess 558, the relative movement of the cam follower 542 with respect to the middle plate 39 stops, and the cam follower 542 receives a downward force from the inner wall 55B and moves downward together with the middle plate 39. At this time, the cam follower 542 is positioned between the bottom and top of the cam groove 55, so the amount of upward displacement of the upper plate 42 in the Z axis direction relative to the middle plate 39 is between the minimum and maximum. Therefore, the distance in the Z-axis direction between the first joint 511 and the fifth joint 531 is medium. Therefore, the distance in the X-axis direction between the fifth joint 531 and the second joint 512 is also medium, and the gate plate 20 moves downward in the Z-axis direction while being spaced apart from the first opening 11. Note that the position of the second recess 558 may be determined depending on the distance between the gate plate 20 and the first opening 11 required at this time. Then, the gate plate 20 can be moved downward from between the first opening 11 and the second opening 12, allowing the wafer to pass through the gate valve 1. In this manner, the gate valve 1 is opened.

[0062] In this way, the gate plate 20 can be moved up and down and left and right by the cam follower 542 going around the cam groove 55. The shape of each link, the arrangement of each link, and the shape of the cam groove are determined so that the gate plate 20 can close and open the first opening 11 when the cam follower 542 goes around the cam groove 55 as described above.

[0063] 22 is a flowchart showing an example of the opening and closing control of the gate valve 1 according to this embodiment. The routine shown in FIG. 22 is executed by the control device 100 at predetermined time intervals. In step S101, the control device 100 determines whether or not a valve closing request has been made. A valve closing request is a request to close the gate valve 1, and is made at a predetermined valve closing timing in, for example, semiconductor manufacturing equipment. If the control device 100 makes a positive determination in step S101, the process proceeds to step S102, and if the control device 100 makes a negative determination, the process proceeds to step S107.

[0064] In step S102, the control device 100 rotates the motor 33 in the forward direction. At this time, the control device 100 rotates the motor 33 in one direction at a predetermined speed. The rotation direction is determined according to the orientation of the feed screw. The rotation direction at this time is the direction in which the nut 37 moves upward in the Z-axis direction. Next, in step S103, the control device 100 determines whether the intermediate plate 39 is in the first position. In step S103, the control device 100 determines whether the middle plate 39 has reached a first position. The first position is, for example, the uppermost position in the Z-axis direction. For example, the relationship between the rotation angle of the motor 33 and the position of the middle plate 39 in the Z-axis direction may be stored in memory in advance, and the control device 100 may make a positive determination when the middle plate 39 reaches the rotation angle required to reach the first position. As another example, a sensor may be attached to detect that the middle plate 39 has reached the first position, and the control device 100 may make a determination based on the output of this sensor. If the control device 100 makes a positive determination in step S103, the process proceeds to step S104, and if the control device 100 makes a negative determination, the control device 100 executes the process of step S103 again.

[0065] In step S104, the control device 100 reverses the motor 33. At this time, the control device 100 rotates the motor 33 in the other direction at a predetermined speed. Next, in step S105, the control device 100 determines whether the middle plate 39 has reached a third position. The third position is, for example, a position obtained by moving a predetermined distance downward from the uppermost position in the Z-axis direction. For example, the control device 100 may make a positive determination when the rotation angle of the motor 33 reaches a rotation angle at which the middle plate 39 reaches the third position. As another example, a sensor may be attached to detect that the middle plate 39 has reached the third position, and the control device 100 may make a determination based on the output of this sensor. If the control device 100 makes a positive determination in step S105, the process proceeds to step S106. If the control device 100 makes a negative determination, the control device 100 executes the process of step S105 again. Then, in step S106, the control device 100 stops the motor 33. At this time, the gate plate 20 closes the first opening 11. The state in which the gate plate 20 closes the first opening 11 is maintained until the control device 100 makes an affirmative determination in step S107.

[0066] In step S107, the control device 100 determines whether or not a valve-opening request has been made. The valve-opening request is a request to open the gate valve 1, and is made at a predetermined valve-opening timing in, for example, a semiconductor manufacturing device. If the control device 100 makes a positive determination in step S107, the process proceeds to step S108, and if the control device 100 makes a negative determination, the routine ends.

[0067] In step S108, the control device 100 rotates the motor 33 in the forward direction. At this time, the control device 100 rotates the motor 33 in one direction at a predetermined speed. Next, in step S109, the control device 100 determines whether the middle plate 39 has reached the first position. If the control device 100 makes a positive determination in step S109, the process proceeds to step S110, and if the control device 100 makes a negative determination, the control device 100 executes the process of step S109 again.

[0068] In step S110, the control device 100 reverses the motor 33. At this time, the control device 100 rotates the motor 33 in the other direction at a predetermined speed. Next, in step S111, the control device 100 determines whether the middle plate 39 has reached a second position. The second position is, for example, the lowest position in the Z-axis direction. For example, the control device 100 may make a positive determination when the rotation angle of the motor 33 reaches the rotation angle at which the middle plate 39 reaches the second position. As another example, a sensor may be attached to detect that the middle plate 39 has reached the second position, and the control device 100 may make a determination based on the output of this sensor. If the control device 100 makes a positive determination in step S111, the process proceeds to step S112. If the control device 100 makes a negative determination, the control device 100 executes the process of step S111 again. Then, in step S112, the control device 100 stops the motor 33. At this time, the gate plate 20 opens the first opening 11, and is shifted downward in the Z-axis direction from the first opening 11. The state in which the gate plate 20 opens the first opening 11 is maintained until the control device 100 makes a positive determination in step S101.

[0069] As described above, according to this embodiment, the first opening 11 can be closed and opened by translating the gate plate 20 in a direction perpendicular to the opening surface of the first opening 11. In other words, when the gate plate 20 is moved horizontally, vertical movement of the gate plate 20 can be prevented. This prevents twisting of the sealing material 22 and dust generation. Furthermore, a sufficient gap can be secured between the gate plate 20 and the housing 10 when the gate plate 20 is raised or lowered, thereby preventing dust generation. Furthermore, the movement of the gate plate 20 in the Z-axis direction and the X-axis direction can be performed by a single motor 33. This allows for cost reduction. Furthermore, the motor 33 can be controlled by rotation angle control or position control, eliminating the need for complex control. Furthermore, the movement speed of the gate plate 20 in the Z-axis direction can be controlled by controlling the rotation speed of the motor 33. This allows for precise speed control. Furthermore, bolt-on assembly is possible, reducing the assembly man-hours. [Explanation of symbols]

[0070] 1 gate valve, 10 housing, 11 first opening, 13 inner wall surface, 20 gate plate, 22 sealing material, 30 lifting device, 33 motor, 39 middle plate, 42 upper plate, 51 first link, 52 second link, 53 third link, 54 fourth link, 55 cam groove, 100 control device, 542 cam follower

Claims

1. a linear motion mechanism that moves a gate plate that opens and closes the opening in a surface direction of the gate plate; a Scott-Russell mechanism that opens and closes the opening by moving the gate plate in a direction perpendicular to the surface direction; A gate valve comprising:

2. a first plate that moves in a first direction that is the surface direction of the gate plate and in a second direction opposite to the first direction; a motor that generates power to move the first plate; a first link connecting the first plate and the gate plate, the first link having a first joint on one end thereof disposed on the first plate and a second joint on the other end thereof disposed on the gate plate; a second link that forms a parallel link with the first link and connects the first plate and the gate plate, the second link having a third joint on one end disposed on the first plate and a fourth joint on the other end disposed on the gate plate; a second plate that moves relative to the first plate in the first direction and the second direction; a third link connecting the second plate and the first link, wherein a fifth joint on one end side is disposed on the second plate corresponding to a position shifted from the first joint in the second direction and a position shifted from the second joint in a third direction perpendicular to the first direction, and a sixth joint on the other end side is disposed on the first link between the first joint and the second joint; a fourth link having a seventh joint on one end side disposed on the second plate and a moving part that moves along a groove formed in the first plate disposed on an eighth joint on the other end side; a controller configured to control the motor; A gate valve comprising: The control device When the gate valve is closed, the motor is controlled to move the first plate from a first position to a second position in the first direction, and then move the first plate in the second direction to a third position between the first position and the second position, When the gate valve is opened, the motor is controlled to move the first plate from the third position to the second position in the first direction, and then move the first plate in the second direction to the first position; The groove is a first portion that supports the moving portion when the first plate moves from the first position in the first direction to the second position; a second portion formed at a position to which the moving portion moves when the first plate moves from the second position to the third position in the second direction; a third portion formed at a position to which the moving portion moves when the first plate moves from the third position to the second position in the first direction; a fourth portion that supports the moving portion when the first plate moves from the second position to the first position in the second direction; having The gate valve of claim 1 .

3. The groove is formed in the first plate so that the moving portion circumferentially moves in the order of the first portion, the second portion, the third portion, the fourth portion, and the second portion. The gate valve of claim 2 .

4. the first link and the third link constitute the Scott-Russell mechanism. The gate valve of claim 2 .

5. When the control device moves the first plate from the second position in the second direction to the third position, the second plate moves relative to the first plate in the first direction; the first joint of the first link and the fifth joint of the third link approach each other, the second joint of the first link and the fifth joint of the third link are separated, The gate plate moves in a fourth direction opposite to the third direction, whereby the gate plate closes the opening, When the control device moves the first plate from the third position in the first direction to the second position, the second plate moves relative to the first plate in the second direction, the first joint of the first link and the fifth joint of the third link are separated, the second joint of the first link and the fifth joint of the third link approach each other, The gate plate opens the opening by moving in the third direction. The gate valve of claim 2 .

6. the second portion is formed at a position closer to the first direction than the first portion, the third portion is formed at a position closer to the second direction than the second portion, the fourth portion is formed at a position closer to the first direction than the first portion and the third portion and closer to the second direction than the second portion, The groove is When the first plate moves from the first position to the second position in the first direction, the moving portion moves from the fourth portion to the first portion, When the first plate moves from the second position to the third position in the second direction, the moving portion moves from the first portion to the second portion, when the first plate moves from the third position to the second position in the first direction, the moving portion moves from the second portion to the third portion; When the first plate moves from the second position to the first position in the second direction, the moving portion moves from the third portion to the fourth portion. It is formed as follows: The gate valve of claim 2 .

7. A linear guide is disposed on the first plate to guide the second plate in the first direction and the second direction. The gate valve of claim 2 .

Images