Gate valve

Abstract

To provide a gate valve that significantly improves leakage of the controlled gas by making the valve plate having a sealing material deformable, and also significantly improves the generation of vibrations due to the deformation of the valve plate. [Solution] The valve body plate 184, which is equipped with a sealing material 182 that constitutes the on / off valve 170, is made of a thin metal plate, so that the valve body plate 184 can deform in response to the deformation of the valve seat 172, thereby suppressing leakage of the controlled gas 20 when the valve is closed, and the vibration when the valve is opened caused by the deformable shape of the valve body plate 184 is suppressed by making the operating speed of the sealing material 182 provided on the valve body plate 184 separate from the valve seat 172 slower than the retraction speed of the valve body portion 180 equipped with the valve body plate 184, thereby suppressing the vibration when the valve is opened.

Description

Technical Field

[0001] The present invention relates to a gate valve for controlling the flow of a gas.

Background Art

[0002] In manufacturing equipment for precision parts, such as semiconductor manufacturing equipment, gas is often used for processing parts. In order to process precision parts with high accuracy, it is required to precisely control the supply of the gas used. A gate valve is used for such gas control. The gate valve includes an on-off valve for controlling the flow of gas, and when receiving a gas supply start command, it quickly opens the on-off valve to start the gas supply. Conversely, when receiving a gas supply stop command, it quickly closes the on-off valve to stop the gas supply.

[0003] It is very important for improving the quality and productivity of the products produced to be able to control the supply of the gas used in the manufacturing process at high speed and with high precision. However, when trying to control the on-off valve at high speed, vibration occurs in the on-off valve. Suppressing this vibration is a very important issue in the gate valve. The following describes patent documents that disclose technologies for suppressing vibration in the gate valve.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] Conventional gate valves described in Patent Documents 1 and 2 have a very robust valve body. This is because it was generally believed that a robust valve body structure would suppress deformation even during long-term use and prevent gas leakage when the valve is closed. In such conventional gate valves, as described in Patent Documents 1 and 2, the entire movable part of the valve body, including the valve body and the rod that moves the valve body for opening and closing operations, generates significant vibration when the valve is opened or closed. When vibration occurs throughout the entire movable part of the valve body, various problems arise as a result. Therefore, suppressing vibrations that occur throughout the entire movable part of the valve body is an important issue. Patent Documents 1 and 2 disclose measures to suppress the above vibration. However, in practice, these are still insufficient. There is a strong need for a gate valve that can suppress vibrations even more powerfully. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a gate valve that can suppress vibrations occurring throughout the entire movable part of the valve body of the on / off valve of the gate valve. [Means for solving the problem]

[0007] Conventional gate valves had a very robust valve body. This was because, as mentioned above, it was believed that making the valve body mechanically robust would prevent warping and deformation. As a result, the valve body of conventional gate valves had a large mass.

[0008] On the other hand, as mentioned above, gate valves require the opening and closing of the valve to be performed as quickly as possible. In order to move the large mass of the valve body at high speed, the entire movable structure, including the rod for moving the valve body, had to be made more robust, and the entire movable part of the valve body, including the valve body, had to have a large mass. The inertial force of the entire movable part of the valve body increased, and the operation of the valve was made faster by rapidly applying a large force to the entire movable part of the valve body to overcome this large inertial force. The inventors believed that these factors were the background to the generation of vibrations with a large amplitude.

[0009] The inventors, taking an approach contrary to conventional thinking, believed that making the valve body as lightweight as possible was crucial for suppressing vibrations of the entire movable part of the valve body, which has a large amplitude. Specifically, as detailed in the following embodiment, in order to reduce the mass of the valve body, the valve body was divided into a thin valve plate for tight contact with the valve seat and a fixing plate for fixing the valve plate to the rod. Furthermore, the mass was reduced by making the valve plate thin and easily deformable, taking an approach contrary to conventional thinking. Furthermore, the fixing plate used to secure the valve plate to the rod was made smaller in area than the valve plate itself, thereby reducing its mass. This structure allowed for a reduction in the mass of the valve body, which in turn reduced vibrations of the entire movable part of the valve body that occurred during high-speed opening and closing operations. This resulted in a significant reduction in the amplitude of vibrations, which had been a problem in the past. The reduction in the mass of the valve body 180 reduced the inertial force, which also improved the operation of the opening and closing valve at higher speeds.

[0010] However, it was found that by making the valve plate a thin, deformable shape, when the valve opens, an adhesive force acts on the valve plate to maintain its tight contact with the valve seat, causing the valve plate to deform, and after that deformation, the sealing material suddenly peels off from the valve seat. It was also found that by making the valve plate a thin shape, the valve plate acquires spring-like properties, and the valve plate itself generates vibrations.

[0011] The vibration of the valve plate itself has a completely different cause from the vibration of the entire movable part of a conventional valve body, and has the properties of low vibration energy and short vibration duration. Experiments have confirmed that the vibration of the valve plate itself can be suppressed by slowing down the speed at which the valve body portion moves away from the valve seat from the start of the valve opening operation until the sealing material provided on the valve plate peels off the valve seat. Experiments have confirmed that even if the movement time of the valve body portion is slowed down until the sealing material provided on the valve body portion peels off the valve seat, this time is originally short, and the overall time required for valve opening can be shortened by speeding up the movement of the rod having the valve body portion after the sealing material on the valve plate peels off the valve seat.

[0012] The vibrations that are problematic in conventional gate valves, as described above, are caused by applying a rapidly changing, large force to the other end of a rod, which is fixed to one end of the rod and has a very large mass. The vibrating part is the rod and the entire movable part of the valve body including the rod, and this vibrating part has a large mass and large vibration energy. Therefore, it has the characteristic that it takes a long time for the vibration to decay.

[0013] On the other hand, the vibrations that the present invention aims to suppress are vibrations based on the spring characteristics of the thin valve plate. The mass of the part to be vibrated is small, and the vibration energy is small. Therefore, the time required for damping is short. Also, the time it takes for the thin valve plate to detach from the valve seat is relatively short. Even if the movement speed of the valve plate is reduced from the start of valve opening until the valve plate detaches from the valve seat in order to suppress the generation of vibrations of the thin valve plate, the time it takes for the valve plate to detach from the valve seat is very short, so the valve opening time required to open the valve becomes very short, and the responsiveness of the valve opening operation is greatly improved.

[0014] The present invention aims to suppress vibrations of the valve body plate caused by thinning the valve body plate. However, in addition to the present invention, conventional measures to suppress vibrations of the entire movable part, including the rod and the valve body portion fixed to one end of the rod, may also be implemented.

[0015] The invention applied to the embodiments described below is described below.

[0016] [First Invention] The first invention is, A gate valve comprising: an on-off valve having a valve body portion and a valve seat provided with a sealing material to control the flow of gas; a rod arranged along a long axis and having the valve body portion on one side thereof; a drive mechanism; and a tilt control mechanism that moves the rod along the long axis based on the operation of the drive mechanism and changes the inclination of the rod with respect to the long axis to bring the sealing material provided on the valve body portion into close contact with the valve seat or separate it from the valve seat, The valve body portion comprises a valve plate, a sealing material provided on the front side of the valve plate, and a fixing plate smaller in shape than the valve plate provided on the back side of the valve plate, and the valve body portion is fixed to one side of the rod by fixing the fixing plate to the one side of the rod. In the valve opening operation for changing the valve from a closed state to an open state, the drive mechanism moves the tilt control mechanism in the other direction away from the valve body portion at a first predetermined speed, thereby reducing the inclination of the rod with respect to the long axis. When the sealing material provided on the front side of the valve plate is in close contact with the valve seat, the inclination of the rod with respect to the long axis is reduced, thereby curving the valve plate so that the central part of the valve plate moves away from the valve seat. In the state in which the valve plate is curved, the drive mechanism further moves the tilt control mechanism in the other direction, thereby separating the sealing material of the valve plate from the valve seat. After the sealing material of the valve body plate is separated from the valve seat, the drive mechanism moves the tilt control mechanism in the other direction at a second predetermined speed faster than the first predetermined speed, thereby moving the valve body portion to open the on-off valve. A gate valve characterized by the above.

[0017] 〔Second Invention〕 The second invention is the gate valve of the first invention, The valve body plate and the fixed plate are each a metallic plate, the thickness of the valve body plate is in the range of 10 mm to 20 mm, and the fixed plate has a thickness greater than that of the valve body plate. A gate valve characterized by the above.

[0018] 〔Third Invention〕 The third invention is the gate valve of the first invention, The valve body plate provided on the valve body portion is a metallic plate, and the lateral length L2 in a direction perpendicular to the rod longitudinal axis is longer than the longitudinal length L1 along the rod longitudinal axis, which is the longitudinal axis of the rod, forming a rectangular shape. The fixed plate is a metallic plate, and the fixed plate has a thickness greater than that of the valve body plate. The valve body plate is fixed to the fixed plate via a plurality of support blocks, and the plurality of support blocks are provided on both sides sandwiching the rod longitudinal axis of the rod. In the region sandwiched between the valve body plate and the fixed plate, a gap is formed between the plurality of support blocks. A gate valve characterized by the above.

[0019] 〔Fourth Invention〕 The fourth invention is the gate valve of the third invention, The fixed plate has a shape in which the lateral length L4 in a direction perpendicular to the rod longitudinal axis is longer than the longitudinal length L3 along the rod longitudinal axis. The transverse length L4 of the fixed plate is shorter than the transverse length L2 of the valve body plate, and the transverse length L4 of the fixed plate is shorter than 70% of the transverse length L2 of the valve body plate. A gate valve characterized by this.

[0020] 〔Fifth Invention〕 The fifth invention is the gate valve of the fourth invention, A detector is provided, and the detector detects that the sealing material provided on the valve body portion is separated from the valve seat. Based on the detection result of the detector, the moving speed of the tilt control mechanism by the drive mechanism is increased to the second predetermined speed faster than the first moving speed, and the valve body portion is moved to the retracted space at the second predetermined speed. A gate valve characterized by this.

[0021] 〔Sixth Invention〕 The sixth invention is the gate valve of the fifth invention, In order to change the valve body portion from the open valve state to the closed valve state, the drive mechanism moves the valve body portion in one direction, which is a direction approaching the valve seat at the second predetermined speed from the retracted space. The detector detects that the valve body portion has reached a position facing the valve seat, and based on the detection result of the detector, the drive mechanism switches the speed at which the tilt control mechanism is moved to the first predetermined speed slower than the second predetermined speed and moves the tilt control mechanism at the first predetermined speed to tilt the rod with respect to the long axis and press the sealing material provided on the valve body plate of the valve body portion against the valve seat. A gate valve characterized by this.

[0022] 〔Seventh Invention〕 The seventh invention is the gate valve of the third invention, The plurality of support blocks include outer peripheral support blocks provided at both ends of the fixing plate in the lateral direction relative to the long axis of the rod, and central support blocks provided on the fixing plate at a position close to the long axis of the rod. The thickness of the outer peripheral support block is greater than the thickness of the central support block. This is a gate valve characterized by the following features.

[0023] [The 8th Invention] The eighth invention is the gate valve of the seventh invention, The plurality of support blocks, including the outer peripheral support block and the central support block, each have a thickness in the range of 0.5 mm to 2 mm. This is a gate valve characterized by the following features. [Effects of the Invention]

[0024] According to the present invention, the valve plate having a sealing material in the valve body portion is made deformable. This significantly improves the effect of suppressing leakage of the controlled gas. Furthermore, by making the valve plate deformable, it is possible to provide a gate valve that can also significantly suppress vibrations of the valve plate that newly occur. [Brief explanation of the drawing]

[0025] [Figure 1] This is a cross-sectional view showing one embodiment of a gate valve to which the present invention is applied. [Figure 2] Figure 1 is a cross-sectional view illustrating the configuration of the gate valve shown. [Figure 3] This is an explanatory diagram showing the back surface of the valve body portion shown in Figure 1, which is the side opposite to the valve seat side. [Figure 4] Figure 3 is a cross-sectional view of the valve body portion AA, Figure 4A is a cross-sectional view in the closed state, and Figure 4B is a cross-sectional view in the state where the sealing material is completely separated from the valve seat. [Figure 5]These are explanatory diagrams illustrating the operation of the valve body during the opening operation of an on / off valve. Figure 5A is a cross-sectional view of the valve in the closed state. Figure 5B is a cross-sectional view of the valve body immediately after the start of the opening operation. Figure 5C shows the state of the valve plate at the start of vibration. Figure 5D is a cross-sectional view of the valve plate in the vibration state. Figure 5E is a cross-sectional view of the state in which the sealing material is completely separated from the valve seat and the vibration has stopped. [Figure 6] This is a diagram illustrating the control mechanism that controls the flow of drive air for opening and closing operations. [Figure 7] This is an explanatory diagram illustrating the valve opening operation to suppress vibrations. [Figure 8] This is an explanatory diagram illustrating the valve closing operation used to suppress vibrations. [Modes for carrying out the invention]

[0026] An embodiment of a gate valve 50 to which the invention is applied will be described. In this embodiment, components with the same reference numerals have basically the same configuration, perform the same function, and produce the same effect. In the embodiments described below, in order to avoid redundant explanations, explanations of components with the same reference numerals may be omitted.

[0027] 1. Description of the overall configuration of a gate valve 50, which is one embodiment to which the present invention is applied. (1.1) Explanation of the basic configuration of the gate valve 50 The basic configuration of one embodiment of a gate valve 50 to which the present invention is applied will be described with reference to Figures 1 and 2. The gate valve 50 of this embodiment can be used to control the supply of various types of gases in various devices. As a typical example of its use, an embodiment in which the gate valve 50 is used to control the supply of gas 20 to a semiconductor manufacturing apparatus will be described.

[0028] The gate valve 50 includes a valve mechanism 150 equipped with an on-off valve 170 for controlling whether to supply gas 20 to the semiconductor manufacturing equipment or to stop the supply of gas 20; a rod 112 for opening and closing the on-off valve 170; a tilt control mechanism 120 for controlling the opening and closing of the on-off valve 170 by controlling the angle of the rod 112 with respect to the long axis 115 and the movement of the rod 112 along the long axis 115; and a drive mechanism 60 for moving the rod 112 along the long axis 115 in one direction toward the valve mechanism 150, or in the other direction toward away from the valve mechanism 150. The detector 212 shown in Figure 1 has the function of detecting when the sealing material 182 provided on the valve body portion 180 is in a position facing the valve seat 172, when the sealing material 182 is separated from the valve seat 172, and when the sealing material 182 is in close contact with the valve seat 172.

[0029] 2. Explanation of the basic configuration and operation of the valve mechanism 150 (2.1) Explanation of the basic configuration The valve mechanism 150 comprises a valve mechanism body 152. The valve mechanism body 152 includes an inlet 154 for taking in the gas 20 to be controlled and an outlet 156 for sending out the gas 20 to be supplied to the semiconductor manufacturing equipment. The gas 20 sent out from the outlet 156 is supplied to the semiconductor manufacturing equipment via piping (not shown). A valve mechanism space 158 is formed between the inlet 154 and the outlet 156 of the valve mechanism body 152, and an on / off valve 170 for controlling the flow of gas 20 is arranged in the valve mechanism space 158.

[0030] The present invention is applicable whether the on-off valve 170 is configured to close the inlet 154, or to close the outlet 156, or to close both the inlet 154 and the outlet 156. In this embodiment, as an example, a gate valve 50 is shown that has a configuration to open and close the outlet 156. A valve seat 172 is provided that is continuous in shape with respect to the outlet 156, surrounding the opening 174 on the side of the valve mechanism space 158 that functions as an inlet. The valve body portion 180 attached to one end 113 of the rod 112 is provided with a valve body plate 184 on which a sealing material 182 is provided to make close contact with the valve seat 172 and close the opening 174, and a fixing plate 190 for fixing the valve body plate 184 to one end 113 of the rod 112.

[0031] By tilting the rod 112 with respect to its long axis 115 so that one end 113 of the rod 112 approaches the valve seat 172 which is provided to surround the opening 174, the valve body portion 180 fixed to the one end 113 of the rod 112 approaches the valve seat 172, and the sealing material 182 provided on the valve plate 184 of the valve body portion 180 presses against the valve seat 172 while surrounding the opening 174, and is held in a state of close contact with the valve seat 172. As a result, the opening 174 is closed by the valve body portion 180, and the delivery of gas 20 from the valve mechanism space 158 to the outlet 156 is stopped.

[0032] (2.2) Detailed description of the opening and closing operation of the on-off valve 170 In the open state of the on-off valve 170, although not shown in the diagram, one end 113 of the rod 112 shown in Figure 1 is moved to the other side, which is the drive mechanism 60, by the operation of the drive mechanism 60 described below. The valve body portion 180 fixed to the one end 113 of the rod 112 is held in a retracted state in the retraction space 142 formed on the other side of the valve mechanism space 158. The on-off valve 170 is not present inside the gas 20 movement passage from the inlet 154 of the valve mechanism body 152 through the valve mechanism space 158 to the outlet 156. The gas 20 is supplied from a source (not shown) to the inlet 154, sent from the valve mechanism space 158 to the outlet 156, and supplied from the outlet 156 to the semiconductor manufacturing equipment via piping (not shown). Various usage conditions exist, but for example, it is conceivable that the gas 20 pressurized to a pressure equivalent to 1 atmosphere is supplied to the semiconductor manufacturing equipment. In this case, the gas 20 moves under a force of 10 tons applied to a surface area of ​​1 square meter. Even if the gas 20 is the pressurized gas described above, the gate valve 50 with the valve mechanism 150 has the function of accurately controlling the flow of the gas 20.

[0033] When a closing command for the on-off valve 170 is sent from a semiconductor manufacturing apparatus (not shown) requesting the shutdown of the gas supply 20, the on-off valve 170 begins to transition from the open state to the closed state. During the closing operation, the drive mechanism 60 moves the rod 112 in one direction 10 toward the valve mechanism space 158. As the rod 112 moves in one direction 10, the on-off valve 170, which was fixed to one end 113 of the rod 112, moves from the retraction space 142 to the valve mechanism space 158. When the valve body portion 180 moves to a position facing the opening 174, the one-way movement of the rod 112 is stopped by the action of the position control groove 136 and the position control roller 137 provided on the rod 112, which will be described below.

[0034] When the position control roller 137 prevents the rod 112 from moving in one direction 10, the tilt control mechanism 120 operates to tilt the rod 112 with respect to the long axis 115 in the configuration described below. As a result, the valve body portion 180 moves toward the opening 174 of the outlet 156, and the sealing material 182 provided on the valve body portion 180 comes into contact with the valve seat 172. Furthermore, as the rod 112 tilts with respect to 115, the sealing material 182 presses against the valve seat 172, and the sealing material 182 of the valve body portion 180 becomes tightly attached to the valve seat 172. In other words, the on-off valve 170 becomes closed. The force with which the sealing material 182 on the valve body portion 180 presses against the valve seat 172 is based on the force generated by the spring 80 shown in Figure 2, and a stable force of a predetermined magnitude is applied to the sealing material 182 of the valve body portion 180. The configuration and effects of the tilt control mechanism 120 will be explained again below. The sealing material 182 of the valve body portion 180 pushes the valve seat 172 with a stable predetermined force, causing the on / off valve 170 to transition to the closed state and maintain the closed state stably.

[0035] As described above, when the on-off valve 170 is in the closed state, the sealing material 182 of the valve body portion 180 is pressed against the valve seat 172 with a predetermined force, and the entire sealing material 182, i.e., the entire circumference of the sealing material 182, is in close contact with the corresponding portion of the valve seat 172 located outside the opening 174, surrounding the opening 174, and this state is maintained. The operation of pressing the sealing material 182 of the valve body portion 180 against the valve seat 172 and the operation of peeling the sealing material 182 of the valve body portion 180 away from the valve seat 172 are performed by changing the inclination angle of the rod 112 with respect to the long axis 115 using the inclination control mechanism 120.

[0036] The tilt control mechanism 120 has a position control groove 136 formed in the tilt control mechanism body 122 to control the positional relationship between the valve body portion 180 and the valve seat 172, and further has a position control roller 137 that moves along the position control groove 136. It also has an opening / closing cam 66 and a roller 68 for controlling the inclination of the rod 112 with respect to the long axis 115. As shown in Figures 1 and 2, the position control groove 136 is formed in the tilt control mechanism body 122 of the tilt control mechanism 120 so as to straddle the rod 112 and be aligned with the long axis 115. The position control roller 137, which is a position control member, is arranged inside the position control groove 136, and the position control roller 137 moves along the position control groove 136 together with the rod 112. Since the position control roller 137 is fixed to the rod 112 via a support member 114, the position of the valve body portion 180 fixed to one end 113 of the rod 112 can be controlled by controlling the position of the position control roller 137. One end 134 of the position control groove 136 is positioned so that the valve body portion 180 faces the opening 174 of the outlet 156 of the on-off valve 170 and the valve seat 172. The other end 135 of the position control groove 136 is positioned so as to correspond to the position of the retraction space 142 where the valve body portion 180 is in a retracted state.

[0037] When the on-off valve 170 is in the closed position, the position control roller 137 fixed to the rod 112 is held in a position in contact with one end 134 of the position control groove 136. The position control groove 136 is formed in the tilt control mechanism body 122, and as described above, one end 134 acts to set the position where the valve body portion 180 faces the opening 174, that is, the position where the sealing material 182 of the valve body portion 180 faces the valve seat 172. When the position control roller 137 is in contact with one end of the position control groove 136, the position control roller 137 cannot move any further in one direction 10. Therefore, the rod 112 to which the position control roller 137 is fixed cannot move any further in one direction 10. As a result, the position of the valve body portion 180 along the long axis 115 is determined.

[0038] In this state, when the piston 64 of the drive mechanism 60 moves further in one direction 10, the movable pressing end 65 and the opening / closing cam 66 fixed to the piston 64 move in one direction. As described above, the rod 112 cannot move in one direction due to its relationship with the position control roller 137 and the position control groove 136, so the movement of the opening / closing cam 66 and the movable pressing end 65 in one direction 10 is absorbed by the compression of the spring 80. The opening / closing cam 66 has an opening / closing hole 67 formed therein to tilt the rod 112 with respect to the long axis 115. The opening / closing hole 67 is in the opposite direction to the valve seat 172 with respect to the long axis 115 and has a shape that extends slightly in the other direction 12 of the rod 112. The roller 68, which is located inside the opening / closing hole 67, is fixed to the rod 112. When the piston 64 of the drive mechanism 60 moves in one direction 10, the opening / closing cam 66 moves in one direction 10. As a result, the roller 68 moves in the opposite direction to the valve seat 172 according to the shape of the opening / closing hole 67. Since the roller 68 is fixed to the rod 112, the other end of the rod 112 moves in the opposite direction to the valve seat 172 relative to the long axis 115. A position control roller 137 is provided between one end and the other end of the rod 112, and since the roller 68, which is provided in the opposite direction to the position control roller 137, moves in the opposite direction to the valve seat 172, one end of the rod 112 moves toward the valve seat 172. Due to this movement, the sealing material 182 provided on the valve body portion 180 is pressed against the valve seat 172, resulting in a tight seal, i.e., a closed valve state.

[0039] (2.3) Step 1 of valve opening operation: Separation of the seal material 182 from the valve seat 172 Figure 1 is a cross-sectional view of the gate valve 50, and Figure 2 is a cross-sectional view of the gate valve 50 shown in Figure 1, viewed from the direction indicated by arrow 14. When the on-off valve 170 of the gate valve 50 is in the closed state, the sealing material 182 provided on the valve plate 184 of the valve body portion 180 is in close contact with the valve seat 172 formed on the outside of the opening 174. That is, the roller 68 provided on the other end 117, which is on the other direction 12 side of the rod 112, is pressed against the closed end surface 69 of the opening / closing hole 67 of the opening / closing cam 66. The closed end surface 69 is provided on the opposite side of the valve seat 172 with respect to the long axis 115. Because the piston 64 is located in the one direction 10, the opening / closing cam 66 is pushed in the one direction 10, and the opening / closing hole 67 pushes the roller 68 in the one direction 10. However, since the support member 114 is configured such that the position control roller 137 fixed to the support member 114 cannot move in one direction 10 due to one end 134 of the position control groove 136, the roller 68 provided on the other end 117 of the rod 112 is pressed against the closed end surface 69. The rod 112 tilts with respect to the long axis 115, with the position control roller 137 located in the position control groove 136 as the pivot point, and the sealing material 182 of the valve body portion 180 provided on one end 113 in one direction 10 of the rod 112 is pressed against the valve seat 172. As described above, the sealing material 182 provided on the valve plate 184 of the valve body portion 180 surrounds the opening 174 and is in close contact with the valve seat 172, preventing the gas 20 from flowing into the opening 174 of the outlet 156.

[0040] When the valve body portion 180 is in the closed state, for example, if an opening command to open the on / off valve 170 is sent to the gate valve 50 from the semiconductor manufacturing equipment, the gate valve 50 starts the opening operation. Opening fluid 75 is supplied to the opening valve 74 of the drive mechanism 60 shown in Figure 2, and the opening fluid 75 is sent into the opening chamber 76. As a result, the piston 64 moves slightly in the other direction 12. Along with this, the moving pressing end 65 also moves slightly in the other direction 12, but since the spring 80 continues to push the support member 114 in one direction, the valve body portion 180 changes its angle away from the opening 174, but hardly moves in the other direction 12.

[0041] In Figure 1, the angle of inclination of the rod 112 relative to the long axis 115 towards the valve seat 172 decreases slightly, and the orientation of the rod 112 changes slightly in the direction along the long axis 115. Specifically, as the piston 64 moves in the other direction, the opening / closing hole 67 of the opening / closing cam 66 moves slightly in the other direction 12 along the long axis 115. As a result, the roller 68 located inside the opening / closing hole 67 moves away from the closed end face 69 of the opening / closing hole 67 and moves along the inner surface of the opening / closing hole 67 from the right direction in Figure 1, where the valve seat 172 is located, to the left direction. The position control roller 137 fixed to the rod 112 acts as a fulcrum, and the portion of the rod 112 on the side of the position control roller 137 in one direction 10 moves in the opposite direction to the movement of the roller 68, away from the valve seat 172. As a result, the sealing material 182 of the valve body portion 180, which was in close contact with the valve seat 172, is peeled away from the valve seat 172, resulting in a non-contact state with the valve seat 172, that is, the sealing material 182 is separated from the valve seat 172. However, the valve body portion 180 is still located between the inlet 154 and the outlet 156, and in this state, the flow of gas 20 is obstructed by the valve body portion 180, preventing a smooth flow.

[0042] (2.4) Step 2 of valve opening operation: Retraction of valve body portion 180 to the retraction space 142 As the valve opening fluid 75 introduced into the valve opening chamber 76 from the valve opening valve 74 provided in the drive mechanism 60 moves the piston 64 located inside the cylinder 62 further in the other direction 12, the roller 68 provided at the other end 117 of the rod 112 moves along with the piston 64 in the other direction 12. Along with this movement, the valve body portion 180 moves in the other direction 12 along the long axis 115, and the valve body portion 180 is housed in the retraction space 142. In this state, the position control roller 137 reaches the other end 135 of the position control groove 136, and the other end 135 prevents the rod 112 from moving in the other direction. With the valve body portion 180 in the retraction space 142, the position control roller 137 reaches the other end 135, ending the movement of the valve body portion 180 in the other direction, and the valve body portion 180 stops moving. With the valve body portion 180 absent between the inlet 154 and outlet 156 of the valve mechanism 150, the gas 20 flows smoothly. The valve opening operation is completed when the valve body portion 180 moves to the retraction space 142.

[0043] (2.5) Step 1 of valve closing operation: Movement of valve body portion 180 from the retraction space 142 Next, the closing operation of the valve body portion 180 provided in the valve mechanism 150 will be explained. For example, when a closing command to close the on / off valve 170 is sent from the semiconductor manufacturing equipment to the gate valve 50, the gate valve 50 starts the closing operation. Closing fluid 73 is sent to the closing valve 72 of the drive mechanism 60 shown in Figure 2. As the closing fluid 73 is supplied to the chamber 71 inside the cylinder 62, the piston 64 moves in one direction 10. As the piston 64 moves, the moving pressing end 65 moves in one direction, and the support member 114 is strongly pushed in the one direction 10 by the spring 80. The support member 114 is fixed to the rod 112 and has a position control roller 137. Consequently, the rod 112 equipped with the valve body portion 180 moves in one direction 10, and when the valve body portion 180 is in a position facing the valve seat 172, the position control roller 137 reaches one end 134 of the position control groove 136, and the movement of the valve body portion 180 in the one direction 10 is stopped.

[0044] (2.6) Step 2 of valve closing operation: sealing material 182 makes contact with valve seat 172 After the position control roller 137 reaches one end 134, as the piston 64 is further moved in the direction 10, the roller 68 fixed to the other end 117 of the rod 112 moves along the inner surface of the opening / closing hole 67 of the opening / closing cam 66 in the opposite direction to the opening 174 relative to the long axis 115. As a result, with the position control roller 137 as a pivot point, the one end 113 of the rod 112 and the valve plate 184 move toward the valve seat 172, and the sealing material 182 provided on the valve plate 184 is pressed against the valve seat 172. With the sealing material 182 in close contact with the valve seat 172, the opening / closing valve 170 is closed.

[0045] 3. Configuration and effect of the valve body portion 180 in the on / off valve 170 (3.1) Configuration of valve body portion 180 It is desirable to consider that the gate valve 50, an example of which is shown in Figures 1 and 2, will be used for controlling high-temperature or high-pressure gases. Furthermore, it is required that stable airtightness be maintained between the sealing material 182 of the valve body 180 and the valve seat 172 over a long period of time. For this reason, in conventional gate valves 50, the valve body 180 is made of a very robust and thick structure. This is based on the idea of ​​preventing gas 20 leakage over a long period of time. However, with this approach, if, for example, the valve seat 172 itself undergoes a slight change in shape such as warping, the robust conventional structure of the valve body cannot cope, and only the sealing material 182 can cope with the change in shape. If the warping or deformation exceeds the limits of what the sealing material 182 can cope with, it becomes difficult to cope. Also, even if the valve body has a very robust structure, distortion and twisting will occur in the valve body and valve seat themselves over a long period of use. A further major problem is that the use of a valve body with a thick and robust structure leads to an increase in the mass of the operating part. As a result, the inertial force of the entire movable part, including the valve body, becomes large, and when attempting to open or close the valve in a short period of time, it becomes necessary to rapidly apply a large force to the movable part to overcome the inertial force.

[0046] Based on conventional thinking, if the valve body portion 180 were to be made thick and very robust, the valve body portion 180, which has a large mass completely opposite to that of this embodiment, would be fixed to one end 113 of the rod 112. In this case, it would be necessary to apply a large force suddenly to the other end 117 of the rod 112 during valve opening and closing operations. As a result, large vibrations are likely to occur in the entire movable part including the rod 112 and the valve body portion 180. In other words, for the movable part of the rod 112 and valve body portion 180, which have a large inertial force and are equipped with a conventional robust on-off valve 170, a large force is required to counteract the large inertial force, resulting in vibrations with a large amplitude, and moreover, due to the action of the large inertial force, these vibrations tend to last for a long time. Suppressing these vibrations is a major problem. In order to suppress these vibrations, the inventors proceeded with technological development based on the completely opposite idea that it is important to significantly reduce the mass of the valve body portion 180 and reduce the inertial force.

[0047] In this embodiment, as shown in Figures 3 and 4, instead of making the valve body portion 180 a robust structure, it is constructed by dividing it into a valve body plate 184 made of a thin, easily deformable flat plate and a small fixing plate 190 for fixing the valve body plate 184 to the rod 112. Furthermore, instead of fixing the valve body plate 184 and the fixing plate 190 in close contact, the valve body plate 184 is fixed to the fixing plate 190 via a structure that includes multiple support blocks, including an outer peripheral support block 191 and a central support block 192. As a result, multiple gaps 196 are formed between the valve body plate 184 and the fixing plate 190. By adopting this structure, the mass of the valve body portion 180 is reduced and the valve body plate 184 is made into a shape that is easily deformable. By making the valve body plate 184 of this application thin, the valve body plate 184 has a deformable shape. The valve body portion 180 was made according to an idea that is completely opposite to the idea of ​​using a robust valve body provided in conventional gate valves.

[0048] Figure 3 is a view of the valve body portion 180 from the back side, which is the side opposite to the valve seat 172. The valve body portion 180 comprises a metal valve plate 184 and a metal fixing plate 190 for fixing the valve plate 184 to one end 113 of the rod 112. Figure 4A shows a cross-sectional view AA in the closed state, where the sealing material 182 of the valve body portion 180 is in close contact with the valve seat 172. Figure 4B shows the state in which the sealing material 182 of the valve body portion 180 is completely separated from the valve seat 172.

[0049] As shown in Figures 3, 4A, and 4B, the valve plate 184 of the valve body portion 180 has a rectangular shape with a lateral length L2 perpendicular to the rod's major axis 111 and a longitudinal length L1 aligned with the rod's major axis 111. The thickness of the valve plate 184 is in the range of 10 mm to 20 mm, and it has a thickness that provides flexibility, making it easily deformable in both the lateral and longitudinal directions. The fixing plate 190 is smaller than the valve plate 184, with a lateral length L4 and a longitudinal length L3. The fixing plate 190 is thicker than the valve plate 184 to prevent deformation. The longitudinal length L3 and lateral length L4 of the fixing plate 190 are both less than 70% of the longitudinal length L1 and lateral length L2 of the valve plate 184.

[0050] At both ends of the fixing plate 190 in the lateral direction, multiple outer peripheral support blocks 191 are sandwiched between the fixing plate 190 and the valve body plate 184 and tightened with multiple fixing screws 193. In addition, in the central part of the fixing plate 190, which is close to the rod 112, multiple central support blocks 192 are sandwiched between the fixing plate 190 and the valve body plate 184 and tightened with multiple fixing screws 193. The embodiment shown in Figure 3 is an embodiment relating to a relatively large valve body portion 180, and in the case of a smaller valve body portion 180, there may be only one central support block 192.

[0051] (3.2) Effects based on the configuration of the valve body portion 180 As described above, the valve body portion 180 is composed of a valve plate 184 and a fixing plate 190, and the size of the fixing plate 190 for attaching the valve plate 184 to the rod 112 has been reduced. Specifically, the vertical length L3 and horizontal length L4 of the fixing plate 190 have been made smaller than 70% of the vertical length L1 and horizontal length L2 of the valve plate 184. Furthermore, the valve plate 184 has been made into a thin shape that is easily bent. With this structure, the mass of the valve body portion 180 can be significantly reduced. As a result, the mass of the rod 112 itself can be reduced, and the force applied to the other end of the rod 112 can also be reduced. By reducing the mass and inertial force of the entire movable part, including the valve body portion 180 fixed to one end 113 of the rod 112, it becomes easier to increase the operating speed of the valve opening and closing. In addition, because the inertial force has been reduced, the force applied for opening and closing the valve can be reduced, and vibration of the movable part, including the valve body portion 180 and the rod 112, is less likely to occur. Even if vibration occurs, the reduced inertial force of the vibrating part makes it easier to suppress the vibration. Furthermore, because the inertial force of the vibrating part is small, the vibration has the effect of being dampened quickly.

[0052] Furthermore, by making the shape of the valve body plate 184 thinner, the valve body plate 184 has the characteristic of being deformable. In addition, instead of making the fixed plate 190 and the valve body plate 184 tightly attached, an outer peripheral support block 191 and a central support block 192 are interposed between the fixed plate 190 and the valve body plate 184, thereby creating a configuration in which multiple air gaps 196 are formed between the fixed plate 190 and the valve body plate 184. With this configuration, when the valve body plate 184 deforms, it is less affected by the fixed plate 190, and the valve body plate 184 has the characteristic of being more easily deformable.

[0053] As described above, by providing the valve plate 184 with a shape and structure that makes it easily bendable, even if deformation occurs in the valve seat 172 which is provided to surround the outer circumference of the opening 174, the valve plate 184 itself can deform to compensate for the deformation of the valve seat 172. Furthermore, even if deformation or twisting occurs in the sealing material 182 attached to the valve plate 184, the flexibility of the valve plate 184 can compensate for these. In this way, the adhesion between the sealing material 182 and the valve seat 172 is greatly improved compared to conventional valve bodies. Therefore, under long-term use conditions, the sealing material 182 can stably press the valve seat 172, which is provided to surround the entire outer circumference of the opening 174, at a predetermined pressure, and press the entire valve seat 172 in a nearly uniform manner. Moreover, under use conditions, high pressure is often applied to the gas 20. Even in such cases, in order to prevent leakage of gas 20 when the on-off valve 170 is closed, instead of the conventional idea that the valve plate 184 should have a shape that is absolutely indeformable, the opposite idea of ​​making the valve plate 184 flexible has been adopted, which has made it possible to significantly improve the adhesion of the sealing material 182 to the valve seat 172.

[0054] As can be seen when viewing the on-off valve 170 from the direction of arrow 16 in Figure 4, the opening 174 has a shape that is elongated perpendicular to the long axis 115 (see Figure 1). Therefore, as shown in Figure 3, the valve plate 184 has a lateral length L2 in the longitudinal direction. The sealing material 182 provided on the valve plate 184 also has a lateral elongated shape, and the valve seat 172 facing the sealing material 182 also has a lateral elongated shape. In these lateral elongated shapes, it is usually very difficult to maintain a state in which no deformation such as warping occurs in the sealing material 182 and the valve seat 172. As mentioned above, the gas 20 to be controlled will leak even with slight warping. For this reason, giving the valve plate 184 a characteristic that makes it easily deformable, as in this embodiment, has a great effect. Furthermore, by giving the valve plate 184 flexibility in shape, it is possible to prevent gas 20 leakage that occurred in conventional devices due to deformation such as warping of the valve plate 184 itself.

[0055] (3.3) Utilization of the curvature of the valve plate 184 that constitutes the valve body portion 180 In Figures 3 and 4, an outer peripheral support block 191 and a central support block 192 are provided between the valve body plate 184 and the fixing plate 190, with the outer peripheral support block 191 being thicker than the central support block 192. Figure 4A shows the fully closed state. On the other hand, Figure 4B shows the state in which the sealing material 182 of the valve body portion 180 is completely separated from the valve seat 172. As will be explained below, Figure 5E also shows the state in which the sealing material 182 is completely separated from the valve seat 172. The outer peripheral support block 191 is thicker than the central support block 192, and the distance between the fixing plate 190 and the valve body plate 184 is set by the fixing screw 193 in accordance with the thickness of the central support block 192 and the outer peripheral support block 191. Therefore, when pressure is applied from the rod 112, the outer peripheral side of the valve body plate 184, where the sealing material 182 is provided, deforms into a shape that is pushed out toward the front side, which is toward the valve seat 172. When the sealing material 182 comes into contact with the valve seat 172, the force causing the deformation acts on the sealing material 182, increasing its pressing force. Since the force with which the sealing material 182 presses against the valve seat 172 is based on both the deformation of the valve plate 184 due to its curvature and the deformation of the sealing material 182, even if deformation occurs in the valve seat 172, it is absorbed by the deformation due to the curvature of the valve plate 184, expanding the range of airtight conditions that can be maintained. As a result, a highly flexible sealing effect is achieved. Furthermore, as will be explained below, it also has an effective effect in suppressing vibrations of the valve plate 184.

[0056] (3.4) New challenges based on the deformable valve plate 184 with improved airtightness The above structure has an excellent effect in preventing gas 20 leakage when the on-off valve 170 is closed. Furthermore, even when the on-off valve 170 of this embodiment is used for a long period of time, the above-mentioned leakage prevention effect is easily maintained. However, a new problem has been found in that, from a perspective different from the gas 20 leakage prevention function, a new type of vibration is more likely to occur than before. This problem will be explained using Figures 5A to 5E.

[0057] Figures 5A to 5E are cross-sectional views of BB in Figure 3. Figure 5A shows the valve body plate 184 and valve seat 172 in the closed state of the on-off valve 170, where the sealing material 182 of the valve body plate 184 is pressed against and tightly attached to the valve seat 172 formed around the entire perimeter of the opening 174. In this state, the valve body plate 184 has a shape that is close to a plane along the valve seat 172. The force applied from the rod 112 to the center of the fixing plate 190 is applied to the sealing material 182 via the outer peripheral support block 191, causing the sealing material 182 to tightly attach to the valve seat 172.

[0058] When the on-off valve 170 begins its opening operation, as shown in Figure 5B, the rod 112 first moves in the direction opposite to the valve seat 172, towards the back of the valve body portion 180, as indicated by arrow 6. As a result, the fixing plate 190 moves in the direction towards the back of the valve body portion 180, as indicated by arrow 6. Along with the movement of the fixing plate 190 towards the back, the central part of the valve body plate 184 moves in the direction towards the back of the valve body portion 180, as indicated by arrow 6. However, the sealing material 182 provided on the valve body plate 184 is in close contact with the valve seat 172, and a force acts to maintain the contact state. The valve body plate 184 is made thin to improve the contact, and the valve body plate 184 deforms into a curved shape with its central part bulging towards the back. In conventional gate valves 50, the valve body plate 184 has a thickness that prevents deformation, and there is no structure that provides support blocks 191 or 192, so the outer circumference of the valve body plate 184 does not deform. Rather, it is designed to be shaped in a way that prevents deformation. However, as described above, in this embodiment, the valve body plate 184 is designed to be shaped in a way that encourages deformation. As a result, first, as shown in Figure 5B, the valve body plate 184 becomes curved.

[0059] In Figure 5B, when the rod 112 is moved further to the back side of the valve body portion 180, as shown by arrow 6, the sealing material 182 provided on the outer circumference of the valve body plate 184 suddenly detaches from the valve seat 172. As a result, as shown in Figure 5C, the valve body plate 184 bends back in the opposite direction due to the recoil. As a result, the outer circumference of the valve body plate 184 vibrates, as shown in Figure 5D. This vibration causes the valve body portion 180 to shake, and the problem of particles scattering arises. The cause of this vibration is the bending of the valve body plate 184 as shown in Figure 5B and the rebound after the sealing material 182 detaches from the valve seat 172, as shown in Figure 5C. Minimizing the deformation of the valve body plate 184 in the states shown in Figures 5B and 5C is extremely important to suppress this vibration. As will be explained below, in this embodiment, the speed of movement of the rod 112 as shown by arrow 6 from Figure 5B to Figure 5C is slowed down. In other words, the rate of change in the angle of inclination of the rod 112 to open the valve is made gradual, or slower. By doing so, the amplitude of the rebound vibration shown in Figure 5C is suppressed, and vibration is either not generated or, if vibration occurs, is suppressed to a small amplitude. By doing so, the width of the curvature of the valve body plate 184 shown in Figure 5C, which is the source of the vibration shown in Figure 5D, is reduced. This control will be explained below using Figure 6. Note that if the seal material 182 is separated from the valve seat 172, the cause of vibration is eliminated. Figure 5E shows the state in which the seal material 182 is completely separated from the valve seat 172. Since the thickness of the outer peripheral support block 191 is greater than the thickness of the central support block 192, the valve body plate 184 is not flat, and the portion of the valve body plate 184 that is the seal material 182, i.e., the outer peripheral portion, is deformed to protrude toward the front of the on / off valve 170. Furthermore, in the open valve state, the valve plate 184 has the curved shape shown in Figure 5E, and the outer circumference of the valve plate 184 protrudes outward. This configuration reduces the range of recoil caused by the separation of the sealing material 182 from the valve seat 172, as explained in Figure 5C, leading to the suppression of vibration and reduction of vibration amplitude as described in Figure 5D.

[0060] (3.5) Differences between the vibrations of conventional gate valves and the vibrations of this embodiment Conventionally, there has been an approach to reduce vibration during the opening and closing of gate valves by slowing down the movement speed of the rod. However, there is a difference between the vibration suppression of the present invention and the vibration suppression of conventional gate valves. For example, in the gate valves described in Patent Documents 1 and 2 mentioned above, the valve bodies 10 and 11, or valve body 25, are described as not deforming. As a result, they generate vibrations that are completely different from the vibrations that are problematic in this embodiment, and these different vibrations are the ones that are problematic. Specifically, as described in paragraph

[0013] of Patent Document 1, the vibrations during the operation of the drive mechanism 5, the stopper mechanism 6, and the valve rod 4 are the problem. Also, as described in paragraph

[0088] of Patent Document 2, for example, the vibrations that occur in the valve body 2 and body-33 are the problem.

[0061] Conventional gate valves have a thick, robust seal material 182 mounted on a valve body portion 180. Therefore, the valve body portion 180 does not vibrate independently, but rather the valve body portion fixed to the rod vibrates together with the rod due to the long rod being connected to a rod tilting mechanism or rod moving mechanism having spring characteristics, resulting in vibration occurring throughout the entire movable part. The vibration of the valve body plate 184 in this embodiment described above is completely different from conventional vibration in terms of its cause and nature. That is, the vibration described in Figure 5 is a vibration that occurs only in a deformable, thin valve body plate 184. It is a vibration with low energy and a high vibration frequency.

[0062] In this invention as well, the movement speed of the piston 64 inside the cylinder 62 may be controlled by time control. However, a configuration that yields even better results is to provide a detector 212 to detect whether the seal material 182 on the valve plate 184 has separated from the valve seat 172 or not, since the cause of vibration is the deformation of the seal material 182 due to the separation of the seal material 182 from the valve seat 172, and to control the separation speed of the seal material 182. Until the seal material 182 separates from the valve seat 172, the piston 64 inside the cylinder 62 is moved slowly, and after the detector 212 detects that the seal material 182 on the valve plate 184 has separated from the valve seat 172, the cause of vibration is eliminated, so the movement speed of the piston 64 is increased. In this way, the vibration of the valve plate 184, which is a new problem, can be suppressed, and the responsiveness of the gate valve 50 can be maintained at a high level.

[0063] (3.6) Regarding the control of opening the on / off valve 170 Figure 6 shows a control device 200 for controlling the opening and closing of the on-off valve 170 of the valve mechanism 150 by controlling the direction and speed of movement of a piston 64 located inside the cylinder 62. Figure 7 shows an operation pattern for opening the on-off valve 170 from a closed state. When a request to start supplying gas 20 is sent to the control circuit 216 from a manufacturing device 214, such as a semiconductor manufacturing device, which is the recipient of the gas 20, the control circuit 216 sends a low-speed command to the speed switching device 206. Furthermore, the control circuit 216 sends an open valve command signal to the on-off switching device 210.

[0064] A drive fluid 202 for operating the drive mechanism 60 is supplied to the speed setting device 206 from a source not shown. When the opening operation of the on-off valve 170 begins, the speed setting device 206 selects the low-speed control device 207 and supplies the drive fluid 202 to the low-speed control device 207. The low-speed control device 207 has a function to reduce the amount of drive fluid 202 supplied per unit time in order to move the piston 64 slowly in the other direction 12, and supplies the drive fluid 202 from the low-speed control device 207 to the on-off switching device 210 in a low supply amount per unit time. The on-off switching device 210 supplies the drive fluid 202 supplied from the low-speed control device 207 to the valve opening valve 74. As a result, the on-off cam 66 of the tilt control mechanism 120 shown in Figures 1 and 2 moves slowly in the other direction 12. As a result, the rod 112, which was tilted toward the valve seat 172 with respect to the long axis 115, slowly reduces its tilt. Based on the movement of the rod 112, in Figure 5B, the rod 112 and the fixing plate 190 move slowly in the direction of arrow 6. The outer circumference of the valve body plate 184 curves as the sealing material 182 attempts to maintain a state in close contact with the valve seat 172, but because the rate of change in the tilt of the rod 112 is slow, the sealing material 182 of the valve body plate 184 separates from the valve seat 172 while the curvature is small. Since the movement speed of the rod 112 is suppressed, the width of the reverse curvature of the valve body plate 184 shown in Figure 5C is small. In addition, since the outer peripheral support block 191 is thicker than the central support block 192, the width of the reverse curvature of the valve body plate 184 shown in Figure 5C is suppressed due to the difference in thickness between the outer peripheral support block 191 and the central support block 192. Therefore, the occurrence of vibrations as shown in Figure 5D is suppressed, and even if they do occur, they are only very slight.

[0065] The detector 212 detects from the state of the opening / closing cam 66 and roller 68 that the sealing material 182 provided on the valve plate 184 has been detached from the valve seat 172. Based on this detection result, the control circuit 216 determines that the sealing material 182 has completely separated from the valve seat 172 and sends a command to the speed setting device 206 to move to high speed. The driving fluid 202 is sent to the high-speed control device 208 based on the operation of the speed setting device 206. The high-speed control device 208 supplies the amount of driving fluid 202 necessary to increase the movement speed of the piston 64 to the opening valve 74 via the opening / closing switching device 210. The rod 112 moves at high speed in the other direction 12, and the valve body portion 180 is stored in the retraction space 142 shown in Figure 1. The detector 212 is provided on the outer circumference of the cylinder 62, as shown in Figure 1, for example, and detects whether the sealing material 182 provided on the valve plate 184 is completely separated from the valve seat 172 based on the positional relationship of the opening / closing cam 66 and the roller 68 as described above. However, the detection of whether the sealing material 182 of the valve plate 184 is separated from the valve seat 172 may be performed by other means.

[0066] Figure 7 shows the above-described operation in a patterned manner. As shown in item 71, the valve opening control is performed in two steps. As shown in item 72, at the start of operation, while the seal material 182 is separating from the valve seat 172, the amount of drive fluid 202 supplied per unit time from the low-speed control device 207 to the valve opening valve 74 is suppressed by the low-speed control device 207, and as described in item 73, the piston 64 moves slowly in the other direction 12. As a result, as described in item 74, the curvature of the valve plate 184 becomes slow, and the amount of curvature of the valve plate 184 in the opposite direction is suppressed. As a result, the amplitude of vibration of the valve plate 184 becomes very small, damage to the seal material 182 is suppressed, and particle generation is suppressed.

[0067] When the detector 212 detects at time T72 that the separation of the seal material 182 from the valve seat 172 is complete, the process moves to the second step as described in item 71, and the drive fluid 202 is supplied via the high-speed control device 208 as described in item 72, significantly increasing the amount of drive fluid 202 supplied per unit time. As a result, as described in item 73, the piston 64 moves at high speed in the other direction 12, and the valve body portion 180 is retracted into the retraction space 142. As described in item 74, the process can respond quickly to requests from the manufacturing equipment 214.

[0068] (3.7) Closing operation of the on / off valve 170 Figure 8 shows the operation when the on-off valve 170 is in the open state and the manufacturing equipment 214 has sent a valve-closing request to the control circuit 216. When the valve-closing request is received from the manufacturing equipment 214 at time T81 as shown in Figure 8, the control signal from the control circuit 216 sends the drive fluid 202 to the valve-closing valve 72 via the high-speed control device 208. At item 81 as shown in Figure 8, the drive fluid 202 is supplied from the valve-closing valve 72 to the valve-closing chamber 71 of the drive mechanism 60 at a high supply rate per unit time. As shown in item 83, the rod 112 and valve body portion 180 move from the retraction space 142 to a position facing the opening 174. At time T82, the rod 112 and valve body portion 180 begin to tilt toward the opening 174. The detector 212 detects this state from the positional relationship between the opening / closing cam 66 and the roller 68, sends a command to the control circuit 216, and switches the speed setting device 206 so that the driving fluid 202 is sent to the closed valve 72 via the low-speed control device 207.

[0069] As described in item 81 of Figure 8, at time T82, based on the detection result of the detector 212, the process moves to the second step, and as described in item 82, the speed setting device 206 switches so that the driving fluid 202 is supplied to the closing valve 72 via the low-speed control device 207. As a result, as described in item 83, the movement speed of the rod 112 and the valve body portion 180 towards the valve seat 172 becomes very slow, and the sealing material 182 provided on the valve body portion 180 comes into close contact with the valve seat 172 at a very slow speed.

[0070] After the sealing material 182 contacts the valve seat 172, the rod 112 in the center of the fixing plate 190 moves further closer to the opening 174, causing the outer circumference of the valve plate 184 to deform slightly. However, because the movement is slow, the deformation of the valve plate 184 is slow, and the generation of vibrations on the outer circumference of the valve plate 184 is suppressed. Even if vibrations occur, the amplitude is small and suppressed. Therefore, damage to the sealing material 182 is suppressed, and the generation of particles is suppressed.

[0071] In conventional gate valves, the movement speed of the internal piston 64 of the cylinder 62 was slowed down to suppress vibration of the rod 112 when the valve was closed. However, the vibration being suppressed is a vibration that occurs in the entire movable part, including the rod 112 and the valve body fixed to the rod. Because the amount of vibration energy and the inertial force are large, it is a vibration that is difficult to dampen. The vibration that is considered problematic in this embodiment is the vibration associated with the warping deformation of the valve body plate 184, which is made thin and shaped to allow for warping and deformation of the valve body portion 180. Vibration associated with the warping deformation of the valve body plate 184 does not occur in conventional, robust valve bodies.

[0072] 4. Description of the invention applied to the examples (4.1) Description of the First Invention The first invention is, A gate valve 50 comprising: an on-off valve 170 having a valve body portion 180 provided with a sealing material 182 and a valve seat 172 to control the flow of gas 20; a rod 112 arranged along a long axis 115 with the valve body portion 180 provided on one side thereof; a drive mechanism 60; and a tilt control mechanism 120 that moves the rod 112 along the long axis 115 based on the operation of the drive mechanism 60 and changes the inclination of the rod 112 with respect to the long axis 115 to bring the sealing material 182 provided on the valve body portion 180 into close contact with the valve seat 172 or separate it from the valve seat 172, The valve body portion 180 comprises a valve plate 184, a sealing material 182 provided on the front side of the valve plate 184, and a fixing plate 190 provided on the back side of the valve plate 184, which is smaller in shape than the valve plate 184. The valve body portion 180 is fixed to the one side of the rod 112 by fixing the fixing plate 190 to that side of the rod 112. In the opening operation to change the on / off valve 170 from a closed state to an open state, the drive mechanism 60 moves the tilt control mechanism 120 in the other direction 12, which is away from the valve body portion 180, at a first predetermined speed, thereby reducing the tilt of the rod 112 with respect to the long axis 115. With the sealing material 182 provided on the front side of the valve plate 184 in close contact with the valve seat 172, the inclination of the rod 112 with respect to the long axis 115 is reduced, thereby curving the valve plate 184 so that the central part of the valve plate 184 moves away from the valve seat 172. With the valve plate 184 in a curved state, the drive mechanism 60 further moves the tilt control mechanism 120 in the other direction 12, thereby separating the sealing material 182 of the valve plate 184 from the valve seat 172. After the sealing material 182 of the valve plate 184 separates from the valve seat 172, the drive mechanism 60 moves the tilt control mechanism 120 in the other direction 12 at a second predetermined speed faster than the first predetermined speed, thereby moving the valve body portion 180 and opening the on / off valve 170. The gate valve 50 is characterized by the following features.

[0073] According to the first invention, the valve body portion 180 has a structure comprising a valve plate 184, a sealing material 182 provided on the front side of the valve plate 184 so as to face the valve seat 172, and a fixing plate 190 provided on the back side of the valve plate 184 and having a smaller shape than the valve plate 184. Furthermore, due to the reduction in the inclination of the rod 112 with respect to the long axis 115, a force acts on the central part of the valve plate 184 in a direction away from the valve seat 172, causing the central part of the valve plate 184 to curve in a shape away from the valve seat 172. By making the valve plate 184 such a curveable shape, for example, if a slight warp occurs in the valve seat 172, the shape of the valve plate 184 can be flexibly deformed, automatically responding to the slight warp of the valve seat 172 and suppressing leakage of gas 20. The same applies if a slight twist or deformation occurs in the sealing material 182. By making the valve plate 184 flexible, the present invention can automatically accommodate even slight twisting or deformation of the sealing material 182. As a result, it is possible to suppress gas leakage for a longer period of time compared to conventional gate valves.

[0074] However, a new problem arose: the valve plate 184 vibrated. To solve this problem, the movement speed of the piston 64 in the drive mechanism 60 was slowed down when the sealing material 182 was separated from the valve seat 172, thereby reducing the amplitude of vibration of the valve plate 184. As a result, damage to the sealing material 182 provided on the valve plate 184 was reduced, and the generation of particles was suppressed. As a result, it became possible to realize a gate valve 50 that can effectively suppress gas leakage over a long period of time.

[0075] (4.2) Description of the second invention The second invention relates to the gate valve 50 of the first invention, The valve plate 184 and the fixing plate 190 are each made of a metallic plate. The valve body plate 184 has a thickness in the range of 10 mm to 20 mm, and the fixing plate 190 has a shape in which the thickness is greater than the thickness of the valve body plate 184. The gate valve 50 is characterized by the following features.

[0076] In conventional gate valves, the valve body plate 184 was made from a thick, non-curving material to create a robust structure. In contrast, the present invention is designed to flexibly accommodate deformation, for example, if a part of the valve seat 172 deforms. To achieve this function and characteristic, the thickness of the valve body plate 184 was reduced, while the fixing plate 190 was made thicker. This structure reduces the overall mass of the movable part, including the rod 112 and the valve body portion 180, thereby reducing the inertial force of the entire movable part. As a result, it is possible to move the movable part with less driving force than before, and vibration of the entire movable part can be suppressed.

[0077] (4.3) Description of the third invention The third invention is the gate valve 50 of the first invention, The valve plate 184 provided on the valve body portion 180 is a metal plate and has a rectangular shape in which the horizontal length L2, which is perpendicular to the rod major axis 111, is longer than the vertical length L1 along the rod major axis 111, which is the longitudinal axis of the rod 112. The fixing plate 190 is a metal plate, and the fixing plate 190 is thicker than the valve body plate 184. The valve body plate 184 is fixed to the fixing plate 190 via a plurality of support blocks 191, and the plurality of support blocks 191 are provided on both sides of the long axis 111 of the rod 112, and a gap 196 is formed between the plurality of support blocks 191 in the region sandwiched between the valve body plate 184 and the fixing plate 190. The gate valve 50 is characterized by the following features.

[0078] In this invention, it is important that the valve plate 184 can bend as freely as possible and deform as freely as possible, thereby exhibiting the effect of preventing gas leakage. For this reason, the structure is not such that the entire opposing surfaces of the valve plate 184 and the fixing plate 190 are in contact with each other, but rather a part of them is fixed to each other by support blocks 191 and 192. The remaining parts are voids, and the voids are wider than the surface area. With this configuration, the valve plate 184 can bend and curve freely. As a result, new vibrations generated in the valve plate 184 can be suppressed.

[0079] (4.4) Description of the fourth invention The fourth invention is the gate valve 50 of the third invention, The fixing plate 190 has a shape in which the horizontal length L4, which is perpendicular to the rod's major axis 111, is longer than the vertical length L3 along the rod's major axis 111. The lateral length L4 of the fixing plate 190 is shorter than the lateral length L2 of the valve plate 184, and the lateral length L4 of the fixing plate 190 is shorter than 80% of the lateral length L2 of the valve plate 184. The gate valve 50 is characterized by the following features.

[0080] As described above, a sealing material 182 is provided on the outer circumference of the valve plate 184. In this embodiment, the outer circumference of the valve plate 184 is made flexible so that each part of the sealing material 182 is always in close contact with the corresponding part of the valve seat 172, and can deform in accordance with the valve seat 172. The fixing plate 190 serves to fix the valve plate 184 to the rod 112, but is designed so as not to impair the flexibility of the valve plate 184. For this reason, the size of the fixing plate 190 is made smaller than that of the valve plate 184, reducing its mass and thus reducing its inertial force. Reducing the mass reduces the vibration of the rod 112. This embodiment is the complete opposite of the conventional gate valve concept, in which the valve plate 184 that holds the sealing material 182 is made into a rigid structure that does not deform. Furthermore, according to the concept of this embodiment, even if the valve seat 172 is slightly twisted or warped, the flexible valve plate 184 can deform in response to the change in shape of the valve seat 172, thereby maintaining airtightness. As a result, the valve plate 184 automatically deforms in response to subtle changes in the shape of the valve seat 172, thereby preventing leakage of the gas 20.

[0081] (4.5) Description of the fifth invention The fifth invention is the gate valve 50 of the fourth invention, A detector 212 is provided, and the detector 212 detects when the sealing material 182 provided on the valve body portion 180 has separated from the valve seat 172. Based on the detection result of the detector 212, the movement speed of the tilt control mechanism 120 by the drive mechanism 60 is increased to a second predetermined speed which is faster than the first movement speed, and the valve body portion 180 is moved to the stowage space 142 at the second predetermined speed. The gate valve 50 is characterized by the following features.

[0082] The problem addressed in this invention is the vibration of the valve body plate 184 caused by making the valve body plate 184 flexible, such as by making the valve body plate 184 thin. The cause of this vibration is the warping of the valve body plate 184, as explained with reference to Figure 5C. After the sealing material 182 of the valve body plate 184 is completely separated from the valve seat 172, the cause of the vibration of the valve body plate 184 is eliminated. In this invention, a detector 212 is provided to detect when the sealing material 182 of the valve body plate 184 has completely separated from the valve seat 172. After the sealing material 182 has completely separated from the valve seat 172, the movement speed of the rod 112 and the valve body portion 180 is increased in order to improve the responsiveness of the gate valve 50.

[0083] (4.6) Description of the sixth invention The sixth invention is the gate valve 50 of the fifth invention, In order to close the valve body portion 180, the drive mechanism 60 moves the valve body portion 180 from the retraction space 142 at a second predetermined speed in one direction toward the valve seat 172. The detector 212 detects that the valve body portion 180 has reached a position facing the valve seat 172, and based on the detection result of the detector 212, the drive mechanism 60 switches the speed at which it moves the tilt control mechanism 120 to a first predetermined speed that is slower than the second predetermined speed, and moves the tilt control mechanism 120 at the first predetermined speed, tilting the rod 112 with respect to the long axis 115, and pressing the sealing material 182 provided on the valve plate 184 of the valve body portion 180 against the valve seat 172. The gate valve 50 is characterized by the following features.

[0084] As described above, in the embodiment of the present invention, the thickness of the valve body plate 184 is reduced and the valve body plate 184 has a deformable structure. As a result, when the sealing material 182 provided on the valve body plate 184 is forcefully struck against the valve seat 172 in order to close the fixed plate 190, vibration occurs in the valve body plate 184, causing the sealing material 182 to repeatedly strike the valve seat 172. This vibration damages the sealing material 182 and can also cause particle generation. In conventional gate valves, vibration is not generated in the valve body plate 184, but rather by the rod 112 or the spring in the configuration that moves the rod 112. For this reason, instead of using a detector 212, the movement speed of the rod 112 is changed based on the passage of time to suppress vibration. However, in this embodiment, the vibration is generated by the valve body plate 184. Therefore, instead of changing the speed of the rod 112 over time, the detector 212 is used to detect the relationship between the sealing material 182 and the valve seat 172, and the tilting speed of the rod 112 is controlled to prevent the sealing material 182 from colliding forcefully with the valve seat 172.

[0085] (4.7) Description of the seventh invention The seventh invention is the gate valve 50 of the third invention, The multiple support blocks include outer peripheral support blocks 191 provided at both ends of the fixing plate 190 in the lateral direction relative to the rod's long axis 111, and central support blocks 192 provided on the fixing plate 190 at a position close to the rod's long axis 111. The outer support block 191 has a thickness greater than the central support block 192. The gate valve 50 is characterized by the following features.

[0086] By making the outer support block 191 thicker than the central support block 192, the amplitude of vibration, which is the amount of warping shown in Figures 5C and 5D, can be suppressed. Furthermore, even if slight deformation occurs in the valve seat 172 due to long-term use, the deformation of the valve seat 172 is absorbed by the action of the valve body plate 184, which automatically changes the amount of warping, and the sealing material 182 seals the valve seat 1 The force pressing on 72 can be made uniform and stabilized over the entire circumference of the valve seat 172.

[0087] (4.8) Description of the eighth invention The eighth invention relates to the gate valve 50 of the seventh invention, wherein the plurality of support blocks, which include an outer peripheral support block 191 and a central support block 192, have a thickness in the range of 0.5 mm to 2 mm. The gate valve 50 is characterized by the following features.

[0088] There is a desirable size for the outer peripheral support block 191 and the central support block 192 when they are placed between the valve body plate 184 and the fixing plate 190, and when deformation such as warping of the valve body plate 184 is appropriately generated. Making the outer peripheral support block 191 and the central support block 192 thicker than necessary will not provide any benefit and may even cause problems. Durability will also be affected. [Explanation of Symbols]

[0089] 6: Arrow, 10: One direction, 12: Other direction, 14: Arrow, 16: Arrow, 20: Gas, 60: Drive mechanism, 62: Cylinder, 64: Piston, 65: Moving pressing end, 66: Opening / closing cam, 67: Opening / closing hole, 68: Roller, 69: Closed end face, 71: Closed valve chamber, 72: Closed valve, 73: Closed fluid, 74: Open valve, 75: Open fluid, 76: Open valve chamber, 80: Spring, 111: Rod long axis, 112: Rod, 113: One end, 114: Support member, 115: Long axis, 120: Tilt control mechanism, 122: Tilt control mechanism body, 132: Spring, 134: One end, 135: Other end, 136: Position control groove, 13 7: Position control roller, 142: Retreat space, 150: Valve mechanism, 152: Valve mechanism body, 154: Inlet, 156: Outlet, 158: Valve mechanism space, 170: On / off valve, 172: Valve seat, 174: Opening, 180: Valve body part, 182: Seal material, 184: Valve body plate, 190: Fixing plate, 191: Outer peripheral support block, 192: Central support block, 193: Fixing screw, 196: Gap, 200: Control device, 202: Driving fluid, 204: Speed ​​control unit, 206: Speed ​​setting device, 207: Low speed control device, 208: High speed control device, 210: On / off switching device, 212: Detector, 214: Manufacturing device, 216: Control circuit.

Claims

1. A gate valve comprising: an on-off valve having a valve body portion and a valve seat provided with a sealing material to control the flow of gas; a rod arranged along a long axis and having the valve body portion on one side thereof; a drive mechanism; and a tilt control mechanism that moves the rod along the long axis based on the operation of the drive mechanism and changes the inclination of the rod with respect to the long axis to bring the sealing material provided on the valve body portion into close contact with the valve seat or separate it from the valve seat, The valve body portion comprises a valve plate, a sealing material provided on the front side of the valve plate, and a fixing plate smaller in shape than the valve plate provided on the back side of the valve plate, and the valve body portion is fixed to one side of the rod by fixing the fixing plate to the one side of the rod. In the open state of the aforementioned on-off valve, the valve plate has a protruding shape that extends toward the outer circumference, with the valve plate protruding toward the front side. During the closing operation of the valve, as the rod increases its inclination relative to its long axis, the sealing material of the protruding valve plate comes into contact with the valve seat, and as the rod further increases its inclination relative to its long axis, the amount of protrusion of the protruding shape of the valve plate decreases, causing the sealing material to adhere tightly to the valve seat, and the valve closes. In the opening operation of the aforementioned on-off valve, the drive mechanism moves the tilt control mechanism in the opposite direction to the valve body portion at a first predetermined speed, thereby reducing the inclination of the rod with respect to the long axis. When the sealing material of the valve plate is in close contact with the valve seat, the amount of protrusion of the protruding shape of the valve plate is increased by reducing the inclination of the rod with respect to the long axis, and further, the drive mechanism moves the tilt control mechanism in the other direction, thereby separating the sealing material of the valve plate from the valve seat. After the sealing material of the valve plate separates from the valve seat, the drive mechanism moves the tilt control mechanism in the other direction at a second predetermined speed faster than the first predetermined speed, thereby opening the on / off valve. The valve plate provided in the valve body portion is a metal plate and has a rectangular shape in which the horizontal length L2, which is perpendicular to the rod's long axis, is longer than the vertical length L1, which is the longitudinal axis of the rod. The fixing plate is a metal plate, and the valve plate is thinner than the fixing plate, with the portion of the valve plate outside the fixing plate being thinner than the thickness of the outer circumference of the fixing plate, and in the open state of the on / off valve, the portion of the valve plate outside the fixing plate is deformed to protrude toward the front side of the valve plate. The valve body portion has a central support block and outer peripheral support blocks provided on both sides of the long axis of the rod between the fixing plate and the valve body plate. In the region sandwiched between the valve plate and the fixing plate, a gap is formed between the central support block and the outer peripheral support block. The outer peripheral support block is shaped to be thicker than the central support block, and the valve plate is deformed by the difference in thickness between the outer peripheral support block and the central support block. A gate valve characterized by the following features.

2. In the gate valve according to Claim 1, The outer peripheral support block and the central support block each have a thickness in the range of 0.5 mm to 2 mm. A gate valve characterized by the following features.

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