Rotary drive gate valve

Abstract

To provide a rotary drive gate valve that can achieve space saving at low cost. [Solution] The rotary drive gate valve 1 (1A) of the present invention comprises a valve box 4 having opposing first and second openings 7 and 8, a valve plate unit 5 (5A) housed within the valve box 4 and selectively opening and closing the first and second openings 7 and 8, and a drive mechanism 6 that drives the valve plate unit 5 (5A). The valve plate unit 5 (5A) is composed of a first valve plate 9 that opens and closes the first opening 7, a second valve plate 10 that opens and closes the second opening 8, a rotary plate 11 that is rotated by the drive mechanism 6 and rotates the first valve plate 9 and the second valve plate 10 to an open position or a closed position, and a slide plate 12 that follows the rotation of the rotary plate 11 and slides the first valve plate 9 or the second valve plate 10 in a direction that brings them into contact with or away from the first opening 7 or the second opening 8 using an internal cam mechanism.

Description

Technical Field

[0001] The present invention relates to a rotary drive type gate valve that rotates a valve plate to open and close an opening of a valve box.

Background Art

[0002] Conventional general gate valves employ a method of sealing an opening of a valve box by causing a valve plate having a sealing material to perform a lifting and lowering operation and an adhering operation, or a method of directly sealing an opening of a valve box by sandwiching an air cylinder between two opposing valve plates and applying air to the valve plate at a closed position (for example, see Patent Document 1 for the former method and Patent Document 2 for the latter method).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the former type of gate valve, in order to obtain the valve plate sealing force by the action of a lever, depending on the size of the opening of the valve box, the mechanism part becomes large and complex, and there is a problem that it has no competitiveness in terms of weight and cost. Further, regarding the latter type of gate valve, although it is effective particularly for large openings, the valve plate structure is complex, and it is difficult to develop products for small gate valves including those for semiconductors.

[0005] Therefore, the present invention has been made to solve such problems, and an object thereof is to provide a rotary drive type gate valve capable of simplifying the opening and closing mechanism of a valve plate, reducing the number of parts, and achieving cost reduction and space saving.

Means for Solving the Problems

[0006] To achieve the above objective, the rotary-driven gate valve of the present invention comprises a valve body having an opening, a valve plate unit housed within the valve body, and a drive mechanism for driving the valve plate unit, wherein the valve plate unit consists of a valve plate that opens and closes the opening, a rotating plate that rotates by the drive mechanism and moves the valve plate to an open or closed position, and a sliding plate that follows the rotation of the rotating plate and slides the valve plate in a direction that brings it into contact with or away from the opening by an internal cam mechanism. The valve body has opposing first and second openings, and the valve plate unit is composed of a first valve plate that opens and closes the first opening, a second valve plate that opens and closes the second opening, a rotating plate that rotates by the drive mechanism and moves the first and second valve plates to an open or closed position, and a sliding plate that follows the rotation of the rotating plate and slides the first or second valve plate in a direction that brings it into contact with or away from the first or second opening by an internal cam mechanism, thereby selectively opening and closing the first and second openings. It is characterized by the following:

[0008] Furthermore, the present invention is characterized in that, in a rotary-driven gate valve having the above configuration, a packing is fitted into the sealing surface of the valve plate, and the sealing groove into which the packing is fitted is formed with respect to a flat surface and a curved surface smoothly connected thereto, and is formed in a circular cross-sectional shape that is constricted near the entrance like an inverted Ω shape, and wider at the back than the constriction near the entrance. [Effects of the Invention]

[0009] As is clear from the above configuration, the rotary-driven gate valve of the present invention employs an opening and closing mechanism that rotates the valve plate using a rotating plate and slides the valve plate using a sliding plate. This simplifies the opening and closing mechanism of the valve plate, reduces the number of parts, and has the effect of reducing costs and saving space. [Brief explanation of the drawing]

[0010] [Figure 1] Overall view showing the appearance of semiconductor manufacturing equipment and the rotary-driven gate valve of the present invention. [Figure 2] Exploded view showing the components of the rotary-driven gate valve of the first embodiment. [Figure 3] Cross-sectional view showing the state of the rotary-driven gate valve of the first embodiment when the valve is open. [Figure 4] Cross-sectional view showing the state of the rotary-driven gate valve of the first embodiment when the valve is closed. [Figure 5] Operational diagram of the valve plate unit in the rotary-driven gate valve of the first embodiment. [Figure 6] Exploded view showing the components of the rotary-driven gate valve of the second embodiment. [Figure 7] Cross-sectional view showing the state of the rotary-driven gate valve of the second embodiment when the valve is open. [Figure 8] Cross-sectional view showing the state of the rotary-driven gate valve of the second embodiment when the valve is closed. [Figure 9] Operational diagram of the valve plate unit in the rotary-driven gate valve of the second embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[0012] As shown in Figure 1, the rotary-driven gate valve 1(1A) of this embodiment is a gate valve used to isolate vacuum from vacuum, or vacuum from air, in equipment for manufacturing flat panel displays and semiconductor substrates, and is used to isolate various processes in the manufacturing of displays and substrates. The valve body 2 of this rotary-driven gate valve 1(1A) is a so-called valve box type valve, and is composed of a rectangular valve box 4 having a top plate 3, a valve plate unit 5(5A) housed inside the valve box 4, and a drive mechanism 6 attached to the outside of the valve box 4 to drive the valve plate unit 5(5A).

[0013] On both the left and right sides of the valve body 4, there are a pair of elongated, opposing openings (first opening 7 and second opening 8) for passing substrates through. The process chamber PC is connected to the outer wall surface of the first opening 7, and the transfer chamber TC is connected to the outer wall surface of the second opening 8. The substrates, transported from the transfer chamber TC through the valve body 4 to the process chamber PC, are placed in a sealed environment by closing the first opening 7 with the valve plate unit 5 (5A), and various processes such as heat, gas, and plasma for film formation are performed inside the vacuum-evacuated process chamber PC.

[0014] The interior space of the valve body 4 is provided with a valve plate unit 5(5A) that selectively opens and closes the first opening 7 and the second opening 8. Figure 2 is an exploded view of the components with the top plate 3 and valve body 4 omitted. As shown in the figure, the valve plate unit 5(5A) consists of a first valve plate 9 that opens and closes the first opening 7, a second valve plate 10 that opens and closes the second opening 8, a rotating plate 11(11a,11b) that rotates these two valve plates, and a sliding plate 12(12a,12b) that slides each of the two valve plates.

[0015] The first valve plate 9 and the second valve plate 10 are designed to fit the first opening 7 and the second opening 8, and are formed in a circular arc shape in cross-section and a horizontally elongated rectangular shape in plan. Flat mounting pieces 13 (13a, 13b) are provided on the inner surfaces of the first valve plate 9 and the second valve plate 10, respectively. A straight elongated hole 14 with a straight cross-section is formed in the mounting piece 13a of the first valve plate 9, and a bent elongated hole 15 with a curved cross-section is formed in the mounting piece 13b of the second valve plate 10, which penetrates in the longitudinal direction. Packings 16, 16 are fitted and fixed to the outer circumferential surfaces of the first valve plate 9 and the second valve plate 10 as elastic sealing materials that adhere closely to the opening edges of the first opening 7 and the second opening 8, respectively.

[0016] Here, since the sealing surfaces of the first valve plate 9 and the second valve plate 10 are curved surfaces (arc-shaped in cross-section), the sealing groove for fitting the packing 16 of the sealing material adopts the sealing groove of the patent invention (Patent No. 5639767) held by the applicant. That is, this sealing groove is formed with respect to a plane and a curved surface smoothly connected thereto, and has a circular cross-sectional shape where the vicinity of the entrance is constricted like an inverted Ω shape and the depth is wider than the constriction in the vicinity of the entrance. As a forming method, on the valve plate surface where the plane and the curved surface are smoothly connected, the groove cutter for forming the sealing groove of the cross-sectional shape along the plane is translated parallel on the plane, and on the curved surface, the groove cutter is rotated around a point separated by a predetermined distance from the curved surface, so that the cross-sectional shape of the sealing groove is the same on the plane and the curved surface. Thereby, the depth of the groove does not differ between the plane and the curved surface, the protruding height of the packing 16 protruding from the sealing groove becomes uniform, and the sealing performance by the valve plate is improved.

[0017] The rotating plate 11 is composed of a pair of circular plates 17, 17 arranged front and rear, and a rotating shaft 18 is provided at the center of each circular plate 17. In the circular plate 17, arc-shaped slots 19, 19 symmetrically arranged in the circumferential direction of the rotating shaft 18 and circular shaft holes 20, 20 symmetrically arranged at the peripheral portion of the circular plate 17 are formed therethrough. On the other hand, the slide plate 12 is composed of a pair of square plates 21, 21 arranged front and rear, and a shaft hole 22 is provided at the center of each square plate 21. In the square plate 21, two pins 23, 23 that can limit the rotation of the slide plate 12 to 0 degrees to 90 degrees by following the long slot formed in the slot 19 and the flange 28, and left and right mounting recesses 24, 24 corresponding to the mounting piece 13 are formed.

[0018] Then, one shaft 25 each is inserted into the linear elongated hole 14 and the bent elongated hole 15, and both ends of the shaft 25 are fixed to the shaft holes 20, 20 of the front and rear circular plates 17, 17. Thereby, the first valve plate 9 and the second valve plate 10 are connected to and integrated with the rotating plate 11. Also, by fitting and fixing the mounting pieces 13a, 13b into the left and right mounting recesses 24, 24 of the square plate 21, the first valve plate 9 and the second valve plate 10 are connected to and integrated with the slide plate 12. Further, the two pins 23, 23 of the square plate 21 are respectively fitted into a pair of slots 19, 19 of the circular plate 17 and long slots formed in the flange 28, and the rotating shaft 18 of the circular plate 17 is fitted into the shaft hole 22 of the square plate 21, whereby the rotating plate 11 and the slide plate 12 are connected to and integrated with each other.

[0019] In this way, the first valve plate 9, the second valve plate 10, the rotating plate 11, and the slide plate 12 are integrated to form the valve plate unit 5 (5A). Also, inside the valve plate unit 5 (5A), a cam mechanism (Scotch yoke mechanism) is provided to convert the rotational movement of the rotating plate 11 into the linear movement of the slide plate 12, which consists of a driving section composed of the slot 19 of the rotating plate 11 and the shaft 25 connected to the rotating plate 11, and a driven section composed of the linear elongated hole 14 of the first valve plate 9, the bent elongated hole 15 of the second valve plate 10, and the pin 23 of the slide plate 12.

[0020] The valve plate unit 5 (5A) configured as described above is rotationally driven by a drive mechanism 6 provided with a motor 26. That is, the output shaft 27 of the motor 26 passes through the boss hole 29 provided at the center of the flange 28 and is directly connected to the rotating shaft 18 of the right rotating plate 11b, whereby the valve plate unit 5 (5A) is connected to the motor 26. Thereby, when the motor 26 is driven and the output shaft 27 rotates, the front and rear rotating plates 11a, 11b are integrally rotationally driven via the rotating shaft 18, and the first valve plate 9 and the second valve plate 10 connected thereto rotate around the axis and are configured to reciprocate between the open position and the closed position of the opening.

[0021] Furthermore, when the front and rear rotating plates 11a and 11b are driven to rotate together, the front and rear sliding plates 12a and 12b connected to them are driven, and the rotational motion is converted into linear motion by an internal cam mechanism. As a result, the first valve plate 9 slides toward the first opening 7, and the second valve plate 10 slides toward the second opening 8, respectively, either in a direction of contact or separation.

[0022] The above describes the structure of the rotary-driven gate valve 1(1A) of the first embodiment. Next, its basic operation will be explained with reference to Figures 3 to 5.

[0023] Regarding this rotary-driven gate valve 1(1A), Figure 3 shows the valve in the open position, Figure 4 shows the valve in the closed position, and Figure 5 shows the operation of each component constituting the valve plate unit 5(5A). First, in the valve open position shown in Figure 3, the motor 26 that drives the valve plate unit 5(5A) is stopped, and the valve plate unit 5(5A) is stopped at a rotation angle of 0 degrees inside the valve casing 4. That is, the first valve plate 9 is located on the top surface of the valve casing 4, and the second valve plate 10 is located on the bottom surface of the valve casing 4, so the first opening 7 and the second opening 8 are fully open. In this fully open state, the substrate can be passed from the second opening 8 (transfer chamber TC side) to the first opening 7 (process chamber PC side).

[0024] In this state, as shown in Figure 5(A), the valve plate unit 5(5A) has a rotating plate 11 with the pin 23 positioned on a horizontal plane passing through its axis within the slot 19. The slide plate 12 is also tilted sideways, with the straight elongated hole 14 and the bent elongated hole 15, which house the shaft 25, positioned parallel to the horizontal plane. This is the "OPEN" position of the valve plate unit 5(5A).

[0025] To close the first opening 7 (process chamber PC side) to the CLOSE position, the motor 26 of the drive mechanism 6 is driven to rotate the valve plate unit 5 (5A) from a rotation angle of 0 degrees to a position of 90 degrees. When the motor 26 is driven and the output shaft 27 rotates, the rotating plate 11 rotates as shown in Figure 5(B), and the sliding plate 12 connected to it follows and rotates. As a result, the pin 23 and the shaft 25 rotate respectively, and the first valve plate 9 and the second valve plate 10 connected to the shaft 25 rotate around their axis and move from the open position to the closed position. This is the "OPEN→CLOSE" operation of the valve plate unit 5 (5A).

[0026] Then, as shown in Figure 5(C), when the rotating plate 11 rotates 90 degrees, the pin 23 in the slot 19 moves onto the vertical plane and comes into contact with the end of the long slot of the fixed flange 28. The sliding plate 12 also rotates 90 degrees in response, moving from a horizontal position to a vertical position. As a result, the straight elongated hole 14 and the bent elongated hole 15 containing the shaft 25 are positioned parallel to the vertical plane, and the first valve plate 9 and the second valve plate 10 connected to the shaft 25 rotate to a position where they face the first opening 7 and the second valve plate 10. This is the "CLOSE" position of the valve plate unit 5(5A).

[0027] Here, as shown in Figure 5(D), when the rotating plate 11 rotates from the "CLOSE" position to the 110-degree position, the sliding plate 12 remains stopped at the 90-degree position, its movement in the rotational direction is restricted, and it slides horizontally to the left due to the internal cam mechanism. That is, as the shaft 25 connected to the rotating plate 11 moves along the holes of the straight elongated hole 14 and the bent elongated hole 15, the first valve plate 9 integrated with the mounting piece 13 is pushed toward the first opening 7, and the packing 16 on the outer surface of the first valve plate 9 comes into close contact with the opening edge of the first opening 7. Therefore, when the motor 26 is stopped at the 110-degree rotation angle position, the first opening 7 is sealed by the first valve plate 9, ensuring airtightness on the process chamber PC side. This is the "LOCK1" position of the valve plate unit 5(5A).

[0028] Furthermore, as shown in Figure 5(E), when the rotating plate 11 rotates from the "LOCK1" position to a position of 130 degrees, the sliding plate 12 is restricted from moving in the rotational direction and slides horizontally to the right due to the internal cam mechanism. That is, as the shaft 25 connected to the rotating plate 11 moves along the holes of the straight elongated hole 14 and the bent elongated hole 15, the first valve plate 9 integrated with the mounting piece 13 separates from the first opening 7, and at the same time the second valve plate 10 is pushed toward the second opening 8, and the packing 16 on the outer surface of the second valve plate 10 comes into close contact with the opening edge of the second opening 8. Therefore, when the motor 26 is stopped at the position of a rotation angle of 130 degrees, the first opening 7 opens, the second opening 8 is sealed by the second valve plate 10, and airtightness on the transfer chamber TC side is ensured. This is the "LOCK2" position of the valve plate unit 5(5A).

[0029] The above describes the closing operation of the valve plate unit 5(5A), but the opening operation is the reverse. That is, when the motor 26 that drives the valve plate unit 5(5A) is rotated in reverse, the second valve plate 10 first separates from the second opening 8 by the internal cam mechanism, and the first valve plate 9 comes into close contact with the first opening 7 (states shown in Figures 5(E) to (D)). If the motor 26 continues to rotate in reverse, the first valve plate 9 separates from the first opening 7 (state shown in Figure 5(C)), and if the rotation continues further, the valve plate unit 5(5A) rotates 90 degrees by the rotating plate 11, and the valve plate unit 5(5A) returns to its original "OPEN" position (states shown in Figures 5(B) to (A)).

[0030] Thus, according to the rotary-driven gate valve 1(1A) of the first embodiment, by rotating the motor 26 of the drive mechanism 6, the first valve plate 9 comes into contact with or separates from the first opening 7, and the second valve plate 10 comes into contact with or separates from the second opening 8, thereby allowing selective opening and closing of the first opening 7 and the second opening 8. This makes it possible to remove the top plate 3 and take out the other valve plate while maintaining the airtightness of the chamber with one of the openings closed, making maintenance work such as cleaning and gasket replacement easier. In this way, by adopting a rotary-driven single-sided sealing mechanism, maintainability can be improved and downtime can be reduced.

[0031] In the first embodiment described above, the first opening 7 and the second opening 8 are selectively opened and closed by a valve plate unit 5 (5A) having two valve plates (first valve plate 9 and second valve plate 10). However, it is also possible to adopt a structure in which only one of the openings is opened and closed by a single valve plate.

[0032] Figures 6-9 show a rotary-driven gate valve 1(1B) of the second embodiment of the present invention. Figure 6 is an exploded view of the components with the top plate 3 and valve body 4 omitted. As shown in the figure, the valve plate unit 5(5B) of the second embodiment consists of a first valve plate 9 that opens and closes the first opening 7, a rotating plate 11(11a,11b) that rotates the first valve plate 9, and a sliding plate 12(12a,12b) that slides the first valve plate 9.

[0033] The rotating plate 11 is composed of a pair of circular plates 17, 17 arranged front to back, with a circular shaft hole 20 formed through only one location on the periphery of each circular plate 17. In contrast, the sliding plate 12 is composed of a pair of semicircular plates 30, 30 arranged front to back, with a mounting recess 24 corresponding to the mounting piece 13 formed on only one side of each semicircular plate 30. The other components are the same as in the first embodiment, so the same reference numerals are used for the same components and detailed descriptions are omitted.

[0034] Then, a shaft 25 is inserted into the elongated straight hole 14, and both ends of the shaft 25 are fixed to the shaft holes 20, 20 of the front and rear circular plates 17, 17, thereby connecting and integrating the first valve plate 9 with the rotating plate 11. In addition, a mounting piece 13 is fitted and fixed into a mounting recess 24 formed on one side of the semicircular plate 30, thereby connecting and integrating the first valve plate 9 with the sliding plate 12. Furthermore, two pins 23, 23 of the semicircular plate 30 are fitted into a pair of slots 19, 19 of the circular plate 17, and the rotation axis 18 of the circular plate 17 is fitted into the shaft hole 22 of the semicircular plate 30, thereby connecting and integrating the rotating plate 11 and the sliding plate 12.

[0035] In this way, the first valve plate 9, the rotating plate 11, and the sliding plate 12 are integrated to form the valve plate unit 5(5B) of the second embodiment. Inside the valve plate unit 5(5B), a cam mechanism (Scotch yoke mechanism) is provided, which converts the rotational motion of the rotating plate 11 into the linear motion of the sliding plate 12, using a driving link consisting of a slot 19 in the rotating plate 11 and a shaft 25 connected to the rotating plate 11, and a driven link consisting of a linear elongated hole 14 in the first valve plate 9 and a pin 23 in the sliding plate 12.

[0036] The above describes the structure of the rotary-driven gate valve 1(1B) of the second embodiment. Next, its basic operation will be explained with reference to Figures 7 to 9.

[0037] Regarding this rotary-driven gate valve 1(1B), Figure 7 shows the valve in the open position, Figure 8 shows the valve in the closed position, and Figure 9 shows the operation of each component constituting the valve plate unit 5(5B). First, in the valve open position shown in Figure 7, the motor 26 that drives the valve plate unit 5(5B) is stopped, and the valve plate unit 5(5B) is stopped at a rotation angle of 0 degrees inside the valve casing 4. That is, since the first valve plate 9 is located on the top surface of the valve casing 4, the first opening 7 and the second opening 8 are fully open. In this fully open state, the substrate can be passed from the second opening 8 (transfer chamber TC side) to the first opening 7 (process chamber PC side).

[0038] In this state, as shown in Figure 9(A), the valve plate unit 5(5B) has a rotating plate 11 with the pin 23 positioned on a horizontal plane passing through its axis within the slot 19. The slide plate 12 is also tilted sideways, and the elongated straight hole 14 containing the shaft 25 is positioned parallel to the horizontal plane. This is the "OPEN" position of the valve plate unit 5(5B).

[0039] To close the first opening 7 (process chamber PC side) to the CLOSE position, the motor 26 of the drive mechanism 6 is driven to rotate the valve plate unit 5 (5B) from a rotation angle of 0 degrees to a position of 90 degrees. When the motor 26 is driven and the output shaft 27 rotates, the rotating plate 11 rotates as shown in Figure 9(B), and the sliding plate 12 connected to it follows and rotates. As a result, the pin 23 and the shaft 25 rotate respectively, and the first valve plate 9 connected to the shaft 25 rotates around its axis and moves from the open position to the closed position. This is the "OPEN→CLOSE" operation of the valve plate unit 5 (5B).

[0040] Then, as shown in Figure 9(C), when the rotating plate 11 rotates 90 degrees, the pin 23 in the slot 19 moves onto the vertical plane. The sliding plate 12 also rotates 90 degrees in response, moving from a horizontal position to a vertical position. As a result, the elongated straight hole 14 containing the shaft 25 is positioned parallel to the vertical plane, and the first valve plate 9 connected to the shaft 25 rotates to a position facing the first opening 7. This is the "CLOSE" position of the valve plate unit 5(5B).

[0041] Here, as shown in Figure 9(D), when the rotating plate 11 rotates from the "CLOSE" position to the 110-degree position, the sliding plate 12 remains stopped at the 90-degree position, its movement in the rotational direction is restricted, and it slides horizontally to the left due to the internal cam mechanism. That is, as the shaft 25 connected to the rotating plate 11 moves along the linear elongated hole 14, the first valve plate 9 integrated with the mounting piece 13 is pushed toward the first opening 7, and the packing 16 on the outer surface of the first valve plate 9 comes into close contact with the opening edge of the first opening 7. Therefore, when the motor 26 is stopped at the 110-degree rotation angle position, the first opening 7 is sealed by the first valve plate 9, ensuring airtightness on the process chamber PC side. This is the "LOCK1" position of the valve plate unit 5(5B).

[0042] The above describes the closing operation of the valve plate unit 5(5B), but the opening operation is the opposite. That is, when the motor 26 that drives the valve plate unit 5(5B) is rotated in the reverse direction, the first valve plate 9 moves away from the first opening 7 (state shown in Figure 9(C)), and as the rotation continues, the rotating plate 11 rotates the valve plate unit 5(5B) by 90 degrees, and the valve plate unit 5(5B) returns to its original "OPEN" position (states shown in Figures 9(B) to (A)).

[0043] Thus, according to the rotary-driven gate valve 1(1B) of the second embodiment, the first valve plate 9 can be brought into close contact with or separated from the first opening 7 by rotating the motor 26 of the drive mechanism 6, thereby opening and closing the first opening 7. If it is only desired to open and close the second opening 8, the second valve plate 10 can be installed in place of the first valve plate 9 in the valve plate unit 5(5B). This allows the top plate 3 to be removed and the other valve plate to be taken out while maintaining the airtightness of the chamber with one of the openings closed, making maintenance work such as cleaning and gasket replacement easier. In this way, by adopting a rotary-driven single-sided sealing mechanism, maintainability can be improved and downtime can be reduced. [Explanation of Symbols]

[0044] 1: Rotary-driven gate valve 2: Valve body 3: Top plate 4: Valve box 5: Valve plate unit 6: Drive mechanism 7:First opening 8:Second opening 9:First valve plate 10:Second valve plate 11: Rotating plate 12: Sliding plate 13: Mounting piece 14: Straight elongated hole 15: Bent long hole 16: Packing 17: Circular plate 18: Rotation axis 19: Slot 20: Shaft hole 21: Square plate 22: Shaft hole 23: Pin 24: Mounting recess 25: Shaft 26: Motor 27: Output shaft 28: Flange 29: Boss hole 30: Semicircular plate

Claims

1. A valve body having an opening; a valve plate unit accommodated in the valve body; a drive mechanism for driving the valve plate unit, The valve plate unit includes: A valve plate that opens and closes the opening; a rotary plate that is rotated by the drive mechanism and rotates the valve plate to an open position or a closed position; a slide plate that is driven by the rotation of the rotary plate and slides the valve plate in a direction to contact with or move away from the opening by an internal cam mechanism; The valve body has opposing first and second openings, The valve plate unit includes: A first valve plate that opens and closes the first opening; A second valve plate that opens and closes the second opening; a rotary plate that is rotated by the drive mechanism and rotates the first valve plate and the second valve plate to an open position or a closed position; a slide plate that is driven by the rotation of the rotary plate and slides the first valve plate or the second valve plate in a direction of contacting with or separating from the first opening or the second opening by an internal cam mechanism, A rotary drive gate valve that selectively opens and closes the first opening and the second opening.

2. 2. The rotary drive gate valve according to claim 1, characterized in that a packing is fitted onto the sealing surface of the valve plate, and a seal groove into which the packing is fitted is formed on a flat surface and a curved surface smoothly connected thereto, and is formed into a circular cross-sectional shape in which the vicinity of the inlet is narrowed like an inverted Ω shape and the inner part is wider than the narrowed portion near the inlet.

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