Flow channel closure mechanism and vacuum gate valve

Abstract

The application provides a flow channel closing mechanism and a vacuum gate valve. The flow channel closing mechanism comprises a first output shaft, a second output shaft and a valve plate. The second output shaft is connected with the first output shaft and can move relative to the first output shaft in the radial direction of the first output shaft. The valve plate is connected to the end of the second output shaft away from the first output shaft and is used for closing and opening the flow channel on the valve seat. When the valve plate is offset by external force, the valve plate drives the second output shaft to slide relative to the first output shaft, so that the axis of the second output shaft is dislocated from the axis of the first output shaft, thereby preventing the first output shaft from being elastically bent, preventing the end cover part from being pressed by the first output shaft and preventing the end cover part from being abraded, so as to improve the service life of the vacuum gate valve.

Description

Technical Field

[0001] This application belongs to the field of semiconductor manufacturing technology, and more specifically, relates to a flow channel closing mechanism and a vacuum gate valve. Background Technology

[0002] Valves, as key components in semiconductor manufacturing equipment, are widely used in vacuum process equipment such as etching and chemical vapor deposition (CVD). They are mainly used to achieve vacuum isolation between chambers, prevent process gas leakage and cross-contamination, and ensure the stability of the chamber vacuum environment.

[0003] Currently, some existing valves use a piston and an actuator shaft to drive the valve plate. The piston reciprocates within the valve cylinder, and one end of the actuator shaft is connected to the piston, while the other end passes through the valve end cap and connects to the valve plate. This valve opens and closes by pushing the valve plate with the piston and actuator shaft.

[0004] The problem with the above technical solution is that the actuator shaft and the valve plate are rigidly connected, the valve plate is wedge-shaped, and the sealing structure on the valve plate is asymmetrically designed. This causes the valve plate to deviate when it is in the closed state, which in turn causes the actuator shaft to deviate. This causes the actuator shaft to press against the end cover of the cylinder, resulting in abnormal load on the end cover, causing end cover wear and reduced valve life. Utility Model Content

[0005] The purpose of this application is to provide a flow channel closing mechanism and a vacuum gate valve to solve the technical problems in the prior art where the valve plate offset causes the actuator shaft to offset, resulting in end cover wear and reduced life of the compression mechanism.

[0006] To achieve the above objectives, the first aspect of this application is to provide a flow channel closing mechanism, comprising: First output axis; A second output shaft is connected to the first output shaft, and the second output shaft is capable of moving relative to the first output shaft in the radial direction of the first output shaft; A valve plate, connected to the end of the second output shaft away from the first output shaft, is used to close and open the target flow channel; When the valve plate is subjected to an external force and shifts, the valve plate causes the second output shaft to slide relative to the first output shaft, so that the axis of the second output shaft is misaligned with the axis of the first output shaft.

[0007] Optionally, the first output shaft is provided with a mounting hole, and the second output shaft is provided with a first connecting part, which is installed in the mounting hole; Along the sliding direction perpendicular to the second output shaft, the diameter of the mounting hole is larger than the diameter of the first connecting part.

[0008] Optionally, along the sliding direction perpendicular to the second output shaft, the mounting hole is provided with a first guide surface and a second guide surface spaced in parallel, and the first connecting part is provided with a third guide surface and a fourth guide surface spaced in parallel. The third guide surface slides against the first guide surface, and the fourth guide surface slides against the second guide surface.

[0009] Optionally, the first output shaft and the second output shaft are connected by a pin, wherein the axial direction of the pin is perpendicular to the sliding direction of the second output shaft; The first output shaft is provided with a first pin through hole, and the second output shaft is provided with a second pin through hole. The position of the second pin through hole corresponds to the position of the first pin through hole, and the pin is installed in the first pin through hole and the second pin through hole. Along the radial direction of the first output shaft, both the first pin through hole and the second pin through hole have a first diameter, and along the axial direction of the first output shaft, both the first pin through hole and the second pin through hole have a second diameter. The first diameter is greater than the second diameter, and the second diameter is equal to the diameter of the pin.

[0010] Optionally, the valve plate is rotatably connected to the second output shaft.

[0011] Optionally, the second output shaft is provided with a second connecting part, and the valve plate is provided with an adapter hole, and the second connecting part is rotatably connected to the adapter hole.

[0012] Optionally, the second connecting portion is provided with a first limiting structure; The inner wall of the adapter hole is provided with a second limiting structure, the shape of which is adapted to the shape of the first limiting structure. The first limiting structure is housed within the second limiting structure, and the perimeter of the first limiting structure is smaller than the perimeter of the second limiting structure. When the valve plate rotates relative to the second output shaft, the first limiting structure and the second limiting structure are used to limit the rotation angle of the valve plate.

[0013] Optionally, the first limiting structure includes a plurality of first limiting surfaces, which are evenly distributed along the circumference of the first connecting portion; The second limiting structure includes a plurality of second limiting surfaces, which are evenly distributed along the circumference of the limiting hole, and the plurality of second limiting surfaces correspond one-to-one with the plurality of first limiting surfaces.

[0014] Optionally, the connection between any two adjacent first limiting surfaces and the connection between any two adjacent second limiting surfaces are provided with rounded corners.

[0015] The beneficial effects of the flow channel closing mechanism provided in this application are as follows: Compared with the prior art, the flow channel closing mechanism provided in this application includes a first output shaft, a second output shaft, and a valve plate. The second output shaft is connected to the first output shaft and can move relative to the first output shaft in the radial direction. The valve plate is connected to the end of the second output shaft away from the first output shaft and is used to close and open the target flow channel. When the valve plate is deflected by an external force, the valve plate drives the second output shaft to slide relative to the first output shaft, so that the axis of the second output shaft is misaligned with the axis of the first output shaft, thereby preventing the first output shaft from elastically bending, thus preventing the first output shaft from pressing the end cover part in the cylinder, preventing the end cover part from wearing, and thus improving the service life of the valve.

[0016] Secondly, this application provides a vacuum gate valve, comprising: A drive cylinder is provided with a piston inside, and the piston reciprocates within the drive cylinder. End cap, connected to the drive cylinder body; A flow channel closing mechanism is connected to the piston and extends to the outside of the end cap, wherein the flow channel closing mechanism is any one of the flow channel closing mechanisms described above; The valve seat has a flow channel, and the valve plate in the flow channel closing mechanism is used to close and open the flow channel.

[0017] The beneficial effects of the vacuum gate valve provided in this application are as follows: Compared with the prior art, the vacuum gate valve provided in this application includes a drive cylinder, an end cover, a valve seat, and any one of the above-mentioned flow channel closing mechanisms. The flow channel closing mechanism includes a first output shaft, a second output shaft, and a valve plate. The second output shaft is connected to the first output shaft, and the second output shaft can move relative to the first output shaft in the radial direction. The valve plate is connected to the end of the second output shaft away from the first output shaft and is used to close and open the flow channel on the valve seat. When the valve plate is deflected by an external force, the valve plate drives the second output shaft to slide relative to the first output shaft, so that the axis of the second output shaft is misaligned with the axis of the first output shaft, thereby preventing the first output shaft from elastically bending, thus preventing the first output shaft from pressing the end cover part, preventing the end cover part from wearing, and thus improving the service life of the vacuum gate valve. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the vacuum gate valve in the open state provided in an embodiment of this application; Figure 2 This is a schematic diagram of the vacuum gate valve in the closed state provided in an embodiment of this application; Figure 3 This is a schematic diagram of the flow channel closing mechanism provided in the embodiments of this application; Figure 4 This is a schematic diagram of the flow channel closing mechanism provided in an embodiment of this application from another perspective; Figure 5 A cross-sectional view of the flow channel closing mechanism provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of the first output shaft provided in an embodiment of this application; Figure 7 This is a structural schematic diagram of the first output shaft from another perspective, provided in an embodiment of this application. Figure 8 This is a schematic diagram of the structure of the second output shaft provided in an embodiment of this application; Figure 9 This is a structural schematic diagram of the second output shaft from another perspective, provided in an embodiment of this application. Figure 10 This is a schematic diagram of the first limiting structure provided in an embodiment of this application; Figure 11 This is a schematic diagram of the valve plate provided in an embodiment of this application; Figure 12 This is a schematic diagram of the second limiting structure provided in an embodiment of this application.

[0020] The following are the labeling elements in the figure: 100. Flow channel closing mechanism; 110. First output shaft; 111. Mounting hole; 112. First guide surface; 113. Second guide surface; 114. First pin through hole; 120. Second output shaft; 121. First connecting part; 122. Third guide surface; 123. Fourth guide surface; 124. Second pin through hole; 125. Second connecting part; 126. First limiting structure; 127. First limiting Surface; 128, threaded hole; 200, valve plate; 210, O-ring; 220, polyetheretherketone gasket; 230, adapter hole; 231, second limiting structure; 232, second limiting surface; 240, through hole; 250, bolt; 300, pin; 400, vacuum gate valve; 410, drive cylinder; 420, piston; 430, end cap; 440, valve seat; 441, flow channel; 442, receiving groove. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0023] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] In vacuum process equipment such as etching and chemical vapor deposition (CVD), valves are mainly used to achieve vacuum isolation between chambers. A valve primarily includes a valve seat 440 and a valve plate 200. The valve seat 440 has a flow channel 441, and the valve plate 200 is wedge-shaped. The valve seat 440 has a receiving groove 442 that matches the shape of the valve plate 200. The valve plate 200 is driven by a cylinder, which contains a reciprocating piston 420 and an actuator shaft connected to the piston 420. The upper surface of the valve plate 200 has an O-ring 210, and the lower surface has a polyetheretherketone (PEEK) pad 220, causing the valve plate 200 to... The upper and lower surfaces of valve plate 200 are asymmetrical. When valve plate 200 blocks the flow channel 441 on valve seat 440, valve plate 200 is inserted into receiving groove 442. At this time, O-ring 210 will be squeezed, and valve plate 200 will shift toward the side where O-ring 210 is located, thereby causing the actuator shaft to shift. This causes the actuator shaft to press the end cover 430 of the cylinder, causing the end cover 430 to bear abnormal load, resulting in problems such as wear of end cover 430 and reduced valve life.

[0026] Please refer to the following: Figures 1 to 12 The flow channel closing mechanism and vacuum gate valve provided in the embodiments of this application will now be described.

[0027] To solve the above problems, the first aspect of this application is to provide a flow channel closing mechanism 100, which is applied in a valve. The flow channel closing mechanism 100 includes a first output shaft 110, a second output shaft 120 and a valve plate 200.

[0028] Specifically, the second output shaft 120 is connected to the first output shaft 110, and the second output shaft 120 is capable of moving relative to the first output shaft 110 in the radial direction. The valve plate 200 is connected to the end of the second output shaft 120 away from the first output shaft 110, and is used to close and open the target flow channel 441.

[0029] When the valve plate is subjected to an external force and shifts, the valve plate causes the second output shaft 120 to slide relative to the first output shaft 110, so that the axis of the second output shaft 120 is misaligned with the axis of the first output shaft 110, thereby preventing the valve plate from causing the first output shaft 110 and the second output shaft 120 to bend.

[0030] Compared with the prior art, the flow channel closing mechanism 100 provided in this application includes a first output shaft 110, a second output shaft 120, and a valve plate 200. The second output shaft 120 is connected to the first output shaft 110 and can move relative to the first output shaft 110 in the radial direction. The valve plate 200 is connected to the end of the second output shaft 120 away from the first output shaft 110 and is used to close and open the target flow channel 441. When the valve plate 200 is subjected to an external force, the valve plate 200 drives the second output shaft 120 to slide relative to the first output shaft 110, so that the axis of the second output shaft 120 is misaligned with the axis of the first output shaft 110, thereby preventing the first output shaft 110 from elastically bending, and thus preventing the first output shaft 110 from pressing the end cover 430 in the cylinder, preventing wear on the end cover 430, and thus improving the service life of the valve.

[0031] In this application, a mounting hole 111 is provided on a first output shaft 110, and a first connecting part 121 is provided on a second output shaft 120. The first connecting part 121 is installed in the mounting hole 111. Along the sliding direction perpendicular to the second output shaft 120, the diameter of the mounting hole 111 is larger than the diameter of the first connecting part 121.

[0032] Specifically, the mounting hole 111 is located at the end of the first output shaft 110 facing the second output shaft 120. The first connecting part 121 is installed in the mounting hole 111. Due to the asymmetrical design of the upper and lower surfaces of the valve plate 200, when the valve plate 200 closes the flow channel 441 and the valve plate 200 is offset toward the side where the O-ring 210 is located, the second output shaft 120 can slide relative to the first output shaft 110. When the valve plate 200 causes the second output shaft 120 to deform due to the offset, the second output shaft 120 slides relative to the first output shaft 110 in the mounting hole 111 to prevent the second output shaft 120 from causing the first output shaft 110 to deform, thereby preventing the first output shaft 110 from pressing the cylinder block end cover 430.

[0033] In this application, along the sliding direction perpendicular to the second output shaft 120, the mounting hole 111 is provided with a first guide surface 112 and a second guide surface 113 that are parallel and spaced apart. The first connecting part 121 is provided with a third guide surface 122 and a fourth guide surface 123 that are parallel and spaced apart. The third guide surface 122 slides against the first guide surface 112, and the fourth guide surface 123 slides against the second guide surface 113.

[0034] Specifically, as shown in the figure, the distance between the first guide surface 112 and the second guide surface 113, which are horizontally parallel and spaced apart within the mounting hole 111, is smaller than the distance between the upper and lower ends of the mounting hole 111. When the first connecting part 121 on the second output shaft 120 slides within the mounting hole 111, it is guided by the sliding contact between the third guide surface 122 and the first guide surface 112, and the sliding contact between the fourth guide surface 123 and the second guide surface 113, thereby limiting the sliding direction of the first connecting part 121 within the mounting hole 111.

[0035] In this application, the first output shaft 110 and the second output shaft 120 are connected by a pin 300.

[0036] Specifically, the axial direction of the pin 300 is perpendicular to the sliding direction of the second output shaft 120. The first output shaft 110 has a first pin through hole 114, and the second output shaft 120 has a second pin through hole 124. The position of the second pin through hole 124 corresponds to the position of the first pin through hole 114, and the pin 300 is installed within both the first pin through hole 114 and the second pin through hole 124. Both the first pin through hole 114 and the second pin through hole 124 have a first diameter along the radial direction of the first output shaft 110, i.e., along the sliding direction of the second output shaft 120 relative to the first output shaft 110. The first diameter is larger than the diameter of the pin 300, so that the second output shaft 120 slides relative to the first output shaft 110 along its radial direction. Along the axial direction of the first output shaft 110, that is, along the direction perpendicular to the sliding of the second output shaft 120 relative to the first output shaft 110, both the first pin through hole 114 and the second pin through hole 124 have a second diameter, which is equal to the diameter of the pin 300, to prevent the second output shaft 120 from sliding relative to the first output shaft 110 along the axial direction of the first output shaft 110.

[0037] The second output shaft 120 is rotatably connected to the first output shaft 110 by a pin 300, thereby increasing the degree of freedom of the second output shaft 120 and further reducing the wear of the first output shaft 110 on the end cover 430.

[0038] In one embodiment of this application, the valve plate 200 is rotatably connected to the second output shaft 120 to increase the degree of freedom of the valve plate 200 to rotate along the axial direction of the second output shaft 120, so that the valve plate 200 can better adapt to the receiving groove 442.

[0039] Specifically, the second output shaft 120 is provided with a second connecting part 125, and the valve plate 200 is provided with a transition hole 230. The second connecting part 125 is rotatably connected to the transition hole 230.

[0040] Meanwhile, to ensure the reliability of the connection between the valve plate 200 and the second output shaft 120, the valve plate 200 and the second output shaft 120 are connected by bolts 250. The second output shaft 120 has a threaded hole 128 at one end near the valve plate 200, and the valve plate 200 has a through hole 240. The bolt 250 passes through the through hole 240 and is threaded into the threaded hole 128 to fix the valve plate 200 onto the second output shaft 120. Furthermore, the diameter of the through hole 240 is larger than the diameter of the bolt 250 to ensure relative rotation between the valve plate 200 and the second output shaft 120.

[0041] In this application, a first limiting structure 126 is provided on the second connecting part 125, and a second limiting structure 231 is provided on the inner wall of the adapter hole 230. The first limiting structure 126 and the second limiting structure 231 cooperate to limit the rotation angle of the valve plate 200 relative to the second output shaft 120.

[0042] Specifically, the shape of the second limiting structure 231 is adapted to the shape of the first limiting structure 126. The first limiting structure 126 is housed within the second limiting structure 231, and the perimeter of the first limiting structure 126 is smaller than the perimeter of the second limiting structure, thereby creating a gap between the first limiting structure 126 and the second limiting structure 231, allowing the first limiting structure 126 to rotate within the second limiting structure 231.

[0043] In this application, the first limiting structure 126 includes a plurality of first limiting surfaces 127, which are evenly distributed along the circumference of the first connecting portion 121. The second limiting structure 231 is disposed on the inner wall of the adapter hole 230, and includes a plurality of second limiting surfaces 232, which are evenly distributed along the circumference of the adapter hole 230, and each of the plurality of second limiting surfaces 232 corresponds to one of the plurality of first limiting surfaces 127.

[0044] For ease of explanation, in this application, the number of the first limiting surface 127 and the second limiting surface 232 is the same and both are even. For example, the number of the first limiting surface 127 and the second limiting surface 232 are both 4. The distance between any two opposite first limiting surfaces 127 is less than the distance between any two opposite second limiting surfaces 232, so that there is a gap between the first limiting structure 126 and the second limiting structure 231.

[0045] In one embodiment of the application, the connection between any two adjacent first limiting surfaces 127 and the connection between any two adjacent second limiting surfaces 232 are provided with rounded corners to ensure the stability of the first limiting structure 126 when rotating relative to the second limiting structure 231.

[0046] Secondly, this application provides a vacuum gate valve 400, including a drive cylinder 410, a piston 420, an end cap 430, a flow channel closing mechanism 100, and a valve seat 440. The piston 420 is housed inside the drive cylinder 410 and reciprocates within it. The end cap 430 is connected to the drive cylinder 410. The flow channel closing mechanism 100 is connected to the piston 420, and the flow channel closing mechanism 100 is any of the flow channel closing mechanisms provided above. A first output shaft 110 of the flow channel closing mechanism 100 is connected to the piston 420, passes through the end cap 430, and extends to the outside of the end cap 430. The valve seat 440 has a flow channel 441, and the valve plate 200 of the flow channel closing mechanism 100 is used to close and open the flow channel 441.

[0047] Compared with the prior art, the vacuum gate valve 400 provided in this application includes a drive cylinder 410, an end cap 430, a valve seat 440, and any one of the above-mentioned flow channel closing mechanisms 100. The flow channel closing mechanism 100 includes a first output shaft 110, a second output shaft 120, and a valve plate 200. The second output shaft 120 is connected to the first output shaft 110, and the second output shaft 120 can move relative to the first output shaft 110 in the radial direction. The valve plate 200 is connected to the second output shaft 110. The end of the valve plate 20 away from the first output shaft 110 is used to close and open the flow channel 441 on the valve seat 440. When the valve plate is subjected to external force, the valve plate drives the second output shaft 120 to slide relative to the first output shaft 110, so that the axis of the second output shaft 120 is misaligned with the axis of the first output shaft 110, so as to prevent the first output shaft 110 from elastically bending, thereby preventing the first output shaft 110 from pressing the end cover 430, preventing wear on the end cover 430, and thus improving the service life of the vacuum gate valve 400.

[0048] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A flow channel closing mechanism for driving a valve plate, characterized in that, include: First output axis; A second output shaft is connected to the first output shaft, and the second output shaft is capable of moving relative to the first output shaft in the radial direction of the first output shaft; The valve plate is connected to the end of the second output shaft away from the first output shaft, and is used to close and open the target flow channel; When the valve plate is subjected to an external force and shifts, the valve plate causes the second output shaft to slide relative to the first output shaft, so that the axis of the second output shaft is misaligned with the axis of the first output shaft.

2. The flow channel closing mechanism as described in claim 1, characterized in that, The first output shaft is provided with a mounting hole, and the second output shaft is provided with a first connecting part, which is installed in the mounting hole; Along the sliding direction perpendicular to the second output shaft, the diameter of the mounting hole is larger than the diameter of the first connecting part.

3. The flow channel closing mechanism as described in claim 2, characterized in that, Along the sliding direction perpendicular to the second output shaft, the mounting hole is provided with a first guide surface and a second guide surface that are parallel to each other, and the first connecting part is provided with a third guide surface and a fourth guide surface that are parallel to each other. The third guide surface slides against the first guide surface, and the fourth guide surface slides against the second guide surface.

4. The flow channel closing mechanism as described in claim 3, characterized in that, The first output shaft and the second output shaft are connected by a pin, and the axial direction of the pin is perpendicular to the sliding direction of the second output shaft; The first output shaft is provided with a first pin through hole, and the second output shaft is provided with a second pin through hole. The position of the second pin through hole corresponds to the position of the first pin through hole, and the pin is installed in the first pin through hole and the second pin through hole. Along the radial direction of the first output shaft, both the first pin through hole and the second pin through hole have a first diameter, and along the axial direction of the first output shaft, both the first pin through hole and the second pin through hole have a second diameter. The first diameter is greater than the second diameter, and the second diameter is equal to the diameter of the pin.

5. The flow channel closing mechanism as described in claim 1 or 4, characterized in that, The valve plate is rotatably connected to the second output shaft.

6. The flow channel closing mechanism as described in claim 5, characterized in that, The second output shaft is provided with a second connecting part, and the valve plate is provided with an adapter hole, and the second connecting part is rotatably connected to the adapter hole.

7. The flow channel closing mechanism as described in claim 6, characterized in that, The second connecting part is provided with a first limiting structure; The inner wall of the adapter hole is provided with a second limiting structure, the shape of which is adapted to the shape of the first limiting structure. The first limiting structure is housed within the second limiting structure, and the perimeter of the first limiting structure is smaller than the perimeter of the second limiting structure. When the valve plate rotates relative to the second output shaft, the first limiting structure and the second limiting structure are used to limit the rotation angle of the valve plate.

8. The flow channel closing mechanism as described in claim 7, characterized in that, The first limiting structure includes a plurality of first limiting surfaces, which are evenly distributed along the circumference of the first connecting portion; The second limiting structure includes multiple second limiting surfaces, which are evenly distributed along the circumference of the limiting hole, and each of the multiple second limiting surfaces corresponds to one of the multiple first limiting surfaces.

9. The flow channel closing mechanism as described in claim 8, characterized in that, The connection between any two adjacent first limiting surfaces and the connection between any two adjacent second limiting surfaces are provided with rounded corners.

10. A vacuum gate valve, characterized in that, include: A drive cylinder is provided with a piston inside, and the piston reciprocates within the drive cylinder. End cap, connected to the drive cylinder body; A flow channel closing mechanism is connected to the piston and extends to the outside of the end cap, wherein the flow channel closing mechanism is the flow channel closing mechanism according to any one of claims 1-9; The valve seat has a flow channel, and the valve plate in the flow channel closing mechanism is used to close and open the flow channel.

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