Gate valve

Abstract

To suppress twisting and dust emission of a seal material in a gate valve by a more simple structure.SOLUTION: A gate valve includes an opening face 11A which is a face in which an opening 11 opens on an internal wall surface of a housing 10, a gate plate 20 which opens and closes the opening 11, a driving part 33 which moves the gate plate 20 in a first direction when the opening 11 is closed and moves the gate plate 20 in a second direction opposite to the first direction when the opening 11 is opened, and a linear motion guide 400 which guides the gate plate 20 in the first direction and the second direction. The opening face 11A is sloped toward the inside of the housing 10 as moving in the first direction, and the gate plate 20 is formed parallel to the opening face 11A.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] It is known that an opening provided in an inclined surface inclined in the axial direction of a drive shaft is closed by a seal valve that moves in the axial direction of the drive shaft (see, for example, Patent Document 1). The seal valve is supported on the drive shaft by a support pin and is connected so that it can tilt and rotate freely. In addition, an abutment plate that abuts against a stopper is attached to the lower end of the seal valve. The stopper has a protrusion on the opening side of the lower end of its side. In this configuration, when the seal valve rises due to the movement of the drive shaft, the seal valve covers the opening. Then, when the abutment plate abuts against the protrusion provided on the stopper in the final stage of its upward movement, the seal valve tilts and rotates toward the inclined surface and is pressed against the opening, closing it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 63-62972 Summary of the Invention [Problem to be solved by the invention]

[0004] The seal valve disclosed in Patent Document 1 is supported by a support pin, which may cause rattle. Furthermore, when the seal valve opens the opening, the rattle of the seal valve may cause abnormal noise.

[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 with a simpler structure. [Means for solving the problem]

[0006] The gate valve according to the present disclosure includes: an opening surface, which is a surface on an inner wall surface of a housing where an opening portion opens; a gate plate that closes and opens the opening; a drive unit that moves the gate plate in a first direction when closing the opening and moves the gate plate in a second direction opposite to the first direction when opening the opening; a linear guide that guides the gate plate in the first direction and the second direction; A gate valve comprising: the opening surface is inclined toward the inside of the housing as it advances in the first direction, The gate plate is formed parallel to the opening surface. [Effects of the Invention]

[0007] In the gate valve, twisting of the sealing material and dust generation can be suppressed with a simpler structure. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a gate valve according to a first embodiment. [Figure 2] 1 is a perspective view of a lifting device according to a first embodiment. [Figure 3] 1 is a view of the lifting device according to the first embodiment as seen from the right side in the X axis direction. [Figure 4] 1 is a view of the lifting device according to the first embodiment, seen from above in the Z-axis direction. [Figure 5] 4 is a diagram showing a projection portion when a first opening according to the first embodiment is projected onto a gate plate. FIG. [Figure 6] 4 is a flowchart showing an example of opening and closing control of a gate valve according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing a schematic configuration of a linear guide according to a second embodiment. [Figure 8] FIG. 10 is a cross-sectional view of an inner block according to a second embodiment taken along an XY plane. DETAILED DESCRIPTION OF THE INVENTION

[0009] The gate valve according to the present disclosure has an opening. The opening is closed and opened by a gate plate. An opening surface through which the opening opens is formed on the inner wall surface of the housing. The opening can be closed by the gate plate coming into contact with the opening surface. The gate plate is moved in a first direction and a second direction by a drive unit. The drive unit includes, for example, a motor. The motor moves the gate plate in the first direction and the second direction by, for example, rotating a feed screw or a ball screw forward and backward. The opening surface is inclined more inwardly in the first direction than in the first direction. Therefore, the opening opens onto the inclined surface. Furthermore, the gate plate is also inclined similarly to the opening surface. The gate plate and the opening surface are parallel regardless of whether the opening is closed or open. Furthermore, the gate plate when the opening is closed and the gate plate when the opening is open are parallel. Furthermore, when the opening is open, the gate plate is positioned in the second direction relative to the opening. Furthermore, the gate plate is guided by a linear guide. Therefore, the gate plate can be moved accurately in the first direction and the second direction.

[0010] In the gate valve configured in this manner, an opening is formed in the first direction from the gate plate. Therefore, when the gate plate is moved in the first direction by the drive unit, the gate plate comes into contact with the opening surface. Then, because the gate plate and the opening surface are formed parallel to each other, the gate plate closes the opening surface. At this time, the distance that the gate plate slides over the opening surface is relatively short, which can suppress twisting of the sealing material and dust generation.

[0011] The valve may also include a base on which the drive unit and the linear guide are disposed, and the base may be fixed to the housing. This simplifies the positioning of each component compared to when the drive unit and the linear guide are separately attached to the housing. For example, when assembling a gate valve, it is necessary to position the gate plate and the drive unit so that the gate plate and the opening surface are parallel. If each component is attached separately, it is possible that the gate plate and the opening surface will not be parallel due to the tolerances of each component. On the other hand, if each component is positioned in advance by placing it on the base, positioning can be easily performed by simply attaching the base to the housing.

[0012] The drive unit may include a motor that rotates the screw shaft of the ball screw, and the linear guide may include a nut that corresponds to the screw shaft of the ball screw. For example, by arranging the screw shaft of the ball screw on the central axis of the linear guide, it is possible to save space and achieve high rigidity.

[0013] The angle of inclination of the opening surface and the gate plate with respect to the first direction may be greater than 0 degrees and equal to or less than 45 degrees. By setting the angle of inclination to such an angle, it is possible to prevent the gate valve from becoming large.

[0014] 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.

[0015] First Embodiment 1 is a diagram showing a schematic configuration of a gate valve 1 according to a first embodiment. The gate valve 1 is, for example, opened at a communication part between a transfer chamber and a process chamber, or at a communication part between a transfer chamber and a load (unload) lock chamber in a semiconductor manufacturing device. The transfer chamber, process chamber, and load (unload) lock chamber are each depressurized by a vacuum pump. Note that although the gate valve 1 according to this embodiment is a square gate valve, gate valves of other shapes can also be used in the same way.

[0016] The gate valve 1 is configured to include a gate plate 20 housed within a housing 10 and an elevating 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 elevating device 30. A sealant 22 is disposed on the side of the gate plate 20 facing the first opening 11. The sealant 22 is a member that seals the periphery of the first opening 11 when the gate plate 20 closes the first opening 11. The elevating device 30 raises and lowers the gate plate 20 and presses it against the first opening 11 via the connecting rod 21. The elevating device 30 is fixed to an inner wall surface 13 of the housing 10.

[0017] In the following description, an XYZ Cartesian coordinate system is set, and the position of each component will be 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 direction in which the wafer passes. The Z-axis direction 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. As viewed from the Y-axis direction, the first opening 11 side is defined as the right side in the X-axis direction, and the second opening side is defined as the left side in the X-axis direction. As viewed from the Y-axis direction, the XZ plane side of the inner wall surface 13 of the housing 10 where the lifting device 30 is located is defined as the back side in the Y-axis direction, and the XZ plane side where the lifting device 30 is not located 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.

[0018] FIG. 2 is a perspective view of the lifting device 30 according to the first embodiment. FIG. 3 is a view of the gate valve 1 in an open state as viewed from the front side in the Y axis direction. FIG. 4 is a view of the gate valve 1 in a closed state as viewed from the front side in the Y 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.

[0019] 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.

[0020] The connecting rod 21 is connected to the nut 37 via two brackets 38 and 39. The bracket 38 is a plate-like member parallel to the XY plane, and is fixed to the nut 37 by, for example, a bolt. The bracket 39 is located at the rear side in the Y-axis direction parallel to the XZ plane (hereinafter, The bracket 39 has a first portion 39A (hereinafter referred to as a first portion 39A), a portion on the front side in the Y-axis direction parallel to the XZ plane (hereinafter referred to as a second portion 39B), and a portion parallel to the XY plane connecting the first and second portions 39A and 39B (hereinafter referred to as a third portion 39C). The third portion 39C connects the upper end of the first portion 39A to the lower end of the second portion 39B. A block 40 of a linear motion guide 400 (described later) is fixed to the first portion 39A of the bracket 39, for example, by a bolt. A connecting rod 21 is fixed to the second portion 39B of the bracket 39, for example, by a bolt. The third portion 39C of the bracket 39 is fixed to the bracket 38, for example, by a bolt. The shapes of the brackets 38 and 39 are merely examples, and other shapes may be used as long as they connect the nut 37, the connecting rod 21, and the block 40. The brackets 38 and 39 may be integrally formed.

[0021] A linear guide 400 is disposed between the base portion 31 and the bracket 39. A block 40 of the linear guide 400 is attached to the rear side of the bracket 39 in the Y-axis direction. Furthermore, a rail 41 of the linear guide 400 that pairs with the block 40 is disposed in the Z-axis direction on the base portion 31. When the bracket 39 moves up and down in the Z-axis direction, the block 40 moves along the rail 41, thereby guiding the bracket 39 in the Z-axis direction.

[0022] As shown in FIGS. 3 and 4 , the inner wall surface (hereinafter referred to as opening surface 11A) of the gate plate 20 and the first opening 11 that open into the interior of the housing 10 is a plane that is inclined with respect to the YZ plane. This inclination is formed so that the upper side in the Z axis direction is directed leftward in the X axis direction. In other words, the opening surface 11A is a plane that inclined toward the interior of the housing 10 the higher side in the Z axis direction. The inclination of opening surface 11A with respect to the YZ plane is defined as angle A1. Similarly, the surface of the gate plate 20 facing right in the X axis direction is also inclined with respect to the YZ plane. The inclination of gate plate 20 with respect to the YZ plane is also angle A1. Note that it is sufficient that the inclination at angle A1 is formed at the point where the gate plate 20 and opening surface 11A meet when the gate valve 1 is closed. In this way, since both the gate plate 20 and opening surface 11A are inclined at angle A1, they are parallel to each other.

[0023] Furthermore, when the gate plate 20 opens the first opening 11, the first opening 11 and the gate plate 20 are arranged so that, when the opening surface 11A is projected onto the gate plate 20 in the Z-axis direction, the projected portion of the first opening 11 is located inside the sealing material 22 of the gate plate 20. Here, FIG. 5 is a diagram showing the projected portion when the first opening 11 according to the first embodiment is projected onto the gate plate 20. In FIG. 5, the black arrow indicates the projected portion. The projected portion is located inside the sealing material 22. In this case, by moving the gate plate 20 upward in the Z-axis direction, the gate plate 20 can cover the first opening 11.

[0024] Note that angle A1 may be limited by the length of the housing 10 in the X-axis direction, the distance the gate plate 20 moves when raised and lowered, and other factors. For example, if angle A1 is increased, there is a risk that the gate plate 20 will come into contact with the housing 10 on the second opening 12 side. While it is possible to avoid this contact by increasing the length of the housing 10 in the X-axis direction, there may be cases where such space is not available in the semiconductor manufacturing equipment. It is also possible to avoid contact with the gate plate 20 by reducing the thickness of the housing 10, but there is a limit to how much rigidity can be achieved. Therefore, angle A1 is preferably, for example, greater than 0 degrees and less than or equal to 45 degrees.

[0025] The gate valve 1 has a control device 100 that controls the motor 33. The control device 100 can be configured as a computer having a processor and a 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 a semiconductor manufacturing device. When the first opening 11 is closed by the gate plate 20, the control device 100 controls the motor 33 to rotate in one direction. The control device 100 then stops the motor 33.

[0026] On the other hand, when opening the first opening 11, the control device 100 rotates the motor 33 in the other direction to lower the nut 37 from the top to the bottom, thereby lowering the gate plate 20 from the top to the bottom. Thereafter, the control device 100 stops the motor 33. By operating the motor 33 in this manner, the gate plate 20 rises and falls in the Z-axis direction.

[0027] 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. As shown in FIG. 3, when the nut 37 is located at the lowest position in the Z-axis direction, the gate plate 20 opens the first opening 11. To move the gate plate 20 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 gate plate 20 also moves upward from the lowest position in the Z-axis direction. At this time, the block 40 fixed to the bracket 39 moves along the rail 41 to guide the bracket 39 in the Z-axis direction. Therefore, the gate plate 20 accurately rises in the Z-axis direction.

[0028] 3, when the gate plate 20 is at the lowest position, there is a certain amount of gap between the gate plate 20 and the opening surface 11A. This prevents the seal material 22 of the gate plate 20 from coming into contact with the housing 10 around the first opening 11. This prevents the seal material from twisting or generating dust when the gate plate 20 moves up.

[0029] As shown in FIG. 4, when the gate plate 20 moves to the top, it contacts the opening surface 11A. Because the opening surface 11A and the gate plate 20 are inclined at the same angle A1, the gate plate 20 can cover the entire first opening 11 and close the first opening 11. In this state, the control device 100 stops the motor 33, thereby maintaining the first opening 11 in a closed state. The sealant 22 of the gate plate 20 does not contact the opening surface 11A until just before closing the first opening 11, and the distance that the sealant 22 moves in the Z-axis direction while sliding on the opening surface 11A is short. Therefore, twisting of the sealant 22 and dust generation when closing the first opening 11 can be suppressed.

[0030] Next, the operation of opening the first opening 11 will be described. As shown in FIG. 4 , when the nut 37 is positioned at the top in the Z-axis direction, the gate plate 20 closes the first opening 11. To move the gate plate 20 downward, the control device 100 activates the motor 33 to rotate the screw shaft 35 in the other direction. This causes the nut 37 to move downward in the Z-axis direction. As the nut 37 descends, the gate plate 20 also moves downward from the top in the Z-axis direction. At this time, because the opening surface 11A and the gate plate 20 are inclined at the same angle A1, the gate plate 20 quickly separates from the opening surface 11A. Therefore, the distance the sealant 22 moves in the Z-axis direction while sliding along the opening surface 11A is short. In this way, twisting and dust generation of the sealant 22 can be suppressed when the first opening 11 is opened. Thereafter, the sealant 22 remains separated from the inner wall surface of the housing 10 until the gate plate 20 reaches the bottom, thereby suppressing twisting and dust generation of the sealant 22. When the gate plate 20 reaches the lowest position, the control device 100 stops the motor 33, thereby maintaining the first opening 11 in an open state.

[0031] FIG. 6 is a flowchart showing an example of the opening and closing control of the gate valve 1 according to the first embodiment. The routine shown in FIG. 6 is executed by the control device 100 at predetermined time intervals. In step S101, the control device 100 determines whether 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, a semiconductor manufacturing device. 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 S105.

[0032] 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 a direction that moves the nut 37 upward in the Z-axis direction.

[0033] Next, in step S103, the control device 100 determines whether the gate plate 20 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 gate plate 20 in the Z-axis direction may be stored in memory in advance, and the control device 100 may make a positive determination when the gate plate 20 reaches the rotation angle required to reach the first position. As another example, a sensor may be attached to detect that the gate plate 20 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. If the control device 100 makes a negative determination, the control device 100 executes the process of step S103 again.

[0034] Then, in step S104, the control device 100 stops the motor 33. At this time, the gate plate 20 is in a state of closing the first opening 11. Then, the state in which the gate plate 20 closes the first opening 11 is maintained until the control device 100 makes a positive determination in step S105.

[0035] In step S105, 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 S105, the process proceeds to step S106, and if the control device 100 makes a negative determination, the routine ends.

[0036] In step S106, 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 S107, the control device 100 determines whether the gate plate 20 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 gate plate 20 reaches the second position. As another example, a sensor may be attached to detect that the gate plate 20 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 S107, the process proceeds to step S108. If the control device 100 makes a negative determination, the control device 100 executes the process of step S107 again. Then, in step S108, 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.

[0037] As described above, according to this embodiment, the opening surface 11A of the first opening 11 and the gate plate 20 are inclined so as to be parallel to each other, so that the sealing material 22 of the gate plate 20 can be prevented from sliding on the opening surface 11A when the gate plate 20 moves up and down. Therefore, twisting of the sealing material 22 and dust generation can be prevented. Furthermore, a sufficient gap can be secured between the inner wall of the housing 10 when the gate plate 20 moves up and down, so that dust generation can be prevented. The gate valve 1 can be opened and closed using a single motor 33, thereby reducing costs. The motor 33 can be controlled by rotation angle control or position control, eliminating the need for complex control. 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 number of assembly steps. For example, when attaching the lifting device 30 to the housing 10, simply fastening the base 31 to the inner wall surface 13 of the housing 10 simplifies positioning and reduces the number of assembly steps. Furthermore, because the gate plate 20 is guided by the linear guide 400, rattles and noises caused by the gate plate 20 can be reduced. Therefore, the first opening 11 can be more reliably closed.

[0038] Second Embodiment In the first embodiment, the screw shaft 35 and the rail 41 are arranged to be offset in the X-axis direction. On the other hand, in the second embodiment, a linear guide 50 is arranged in which the screw shaft and the rail are integrally configured.

[0039] FIG. 7 is a diagram showing a schematic configuration of a linear guide 50 according to a second embodiment. Some components are shown in cross section in FIG. 7. FIG. 8 is a cross-sectional view of an inner block 56 according to the second embodiment, taken along the XY plane. The linear guide 50 includes a first housing 51 to which the motor 33 is fixed, a ball screw threaded shaft 52, and a second housing 53 and a third housing 54 that rotatably support the ball screw threaded shaft 52. The second housing 53 supports the ball screw threaded shaft 52 on its upper side in the Z axis direction, and the third housing 54 supports the ball screw threaded shaft 52 on its lower side in the Z axis direction. The output shaft of the motor 33 is connected to the ball screw threaded shaft 52 via a coupling, as in the first embodiment. Outer rails 55 are disposed on the right and left sides of the ball screw threaded shaft 52 in the X axis direction, respectively. The outer rails 55 guide the inner block 56 in the Z axis direction. The ball screw threaded shaft 52 penetrates the inner block 56 in the Z axis direction.

[0040] A ball screw nut 57 corresponding to the screw shaft 52 of the ball screw is formed on the inner block 56. Balls 58 are arranged between the screw shaft 52 and the nut 57. The inner block 56 also has a plurality of ball rows 59. In each ball row 59, a plurality of balls are arranged in the Z-axis direction. Four directions (radial direction) acting on the inner block 56 are Each ball row is 5mm thick so that it has the same rated load for all loads (forward, reverse radial and lateral directions). The ball rows 59 are arranged so that the contact angle between the ball bearing 9 and the outer rail 55 is, for example, 45 degrees.

[0041] The connecting rod 21 is then fixed to the inner block 56, for example, with a bolt, either directly or via a bracket similar to the bracket 39 described in the first embodiment. The structures of the housing 10 and the gate plate 20 are the same as those of the first embodiment. By using such a linear guide 50 integrated with a ball screw to raise and lower the gate plate 20, space can be saved and rigidity can be increased. Therefore, when the gate plate 20 closes the first opening 11, the seal material 22 can be appropriately pressed against the opening surface 11A, thereby preventing air from entering the gate valve 1. [Explanation of symbols]

[0042] 1 gate valve, 10 housing, 11 first opening, 13 inner wall surface, 20 gate plate, 22 sealing material, 30 lifting device, 33 motor, 39 bracket, 100 control device, 400 linear guide

Claims

1. an opening surface on an inner wall surface of the housing where the opening is open; a gate plate that closes and opens the opening; a drive unit that moves the gate plate in a first direction when closing the opening and moves the gate plate in a second direction opposite to the first direction when opening the opening; a linear guide that guides the gate plate in the first direction and the second direction; A gate valve comprising: the opening surface is inclined toward the inside of the housing as it advances in the first direction, The gate plate is formed parallel to the opening surface. Gate valve.

2. a base portion on which the drive portion and the linear guide are disposed, The base portion is fixed to the housing. The gate valve of claim 1 .

3. the drive unit includes a motor that rotates the screw shaft of the ball screw, The linear guide includes a nut corresponding to the screw shaft of the ball screw. The gate valve of claim 1 .

4. The inclination angle of the opening surface and the gate plate with respect to the first direction is greater than 0 degrees and less than 45 degrees. The gate valve of claim 1 .

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