Bidirectional sealing pneumatic butterfly valve

Abstract

The invention relates to a bidirectional sealing pneumatic butterfly valve which is mainly composed of a valve body, a valve rod, a butterfly plate, a valve seat, an air source, a pneumatic actuator and the like. A first air bag assembly is arranged in the butterfly plate, a second air bag assembly is arranged in the valve seat, the valve body is provided with an air connector communicated with an air source and the second air bag assembly, and the two air bag assemblies are communicated when the butterfly plate is closed. The air bag assembly is filled with high-pressure air provided by the air source, and bidirectional sealing of the butterfly plate and the valve seat is achieved. Meanwhile, cleaning paddles are arranged on the two sides of the butterfly plate, and fluid drives the butterfly plate to rotate to clean attachments on the butterfly plate when the valve is opened. The butterfly valve prevents frictional wear between the butterfly plate and the valve seat through air bag sealing, improves the sealing effect and prolongs the service life; the performance of the butterfly plate is guaranteed by cleaning paddles; the sealing performance can be recovered quickly, the structure is simple, installation and maintenance are convenient, practicability and economical efficiency are high, and the device is suitable for industrial pipeline system flow control and cut-off.

Description

Technical Field

[0001] The present invention relates to the technical field of butterfly valves, and in particular to a bidirectional sealing pneumatic butterfly valve. Background Art

[0002] A pneumatic butterfly valve uses compressed air as its power source. A pneumatic actuator drives the valve stem, which in turn rotates the circular disc to open and close or adjust its angle. Its core structure comprises a disc, stem, seat, and sealing assembly. It features a compact size, fast opening and closing speed, and low flow resistance. It is widely used for flow control and shutoff in industrial piping systems.

[0003] In actual use, the current pneumatic butterfly valve relies on the squeeze between the edge of the butterfly plate and the inner wall of the valve seat to seal. After long-term use, the butterfly plate will produce friction with the inner wall of the valve seat when rotating, thereby affecting the sealing effect of the butterfly plate. Summary of the Invention

[0004] The purpose of the present invention is to provide a bidirectional sealing pneumatic butterfly valve to solve the above-mentioned problems existing in the current pneumatic butterfly valve.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A two-way sealed pneumatic butterfly valve comprises a valve body, a valve stem, a butterfly plate, a valve seat, an air source and a pneumatic actuator, wherein the valve seat is arranged in the valve body, the butterfly plate is arranged in the valve seat, the valve stem is arranged in the valve body and connected to the butterfly plate, the pneumatic actuator is arranged on the valve body and connected to the valve stem, and the butterfly plate is driven to rotate in the valve seat by the pneumatic actuator; a first airbag assembly is arranged in the butterfly plate, a second airbag assembly is arranged in the valve seat, a gas interface is provided on the valve body, the gas interface and the pneumatic actuator are both connected to the air source, and the gas interface is communicated with the second airbag assembly, and the first airbag assembly is arranged to be communicated with the second airbag assembly when the butterfly plate is closed, so that the high-pressure gas input through the gas interface fills the first airbag assembly and the second airbag assembly to seal the butterfly plate.

[0006] Further preferably, the butterfly plate includes a first sealing plate, a second sealing plate and a support plate, the first sealing plate and the second sealing plate are respectively arranged on both sides of the support plate, and the supporting first sealing plate and the second sealing plate are both circular, the diameters of the first sealing plate and the second sealing plate are the same, and both are larger than the maximum diameter of the support plate, the first airbag assembly is arranged at the radial edge of the first sealing plate and the second sealing plate, and is sealed with the first sealing plate and the second sealing plate, and a first inflation chamber is formed between the first sealing plate and the second sealing plate and between the first airbag assembly and the support plate, when high-pressure gas is input into the first inflation chamber, the first airbag assembly extends outward along the radial direction of the first sealing plate and the second sealing plate to maintain the sealing of the butterfly plate and the valve seat, and an air duct for communicating with the second airbag assembly is provided on the first airbag assembly.

[0007] Further preferably, the diameter of the valve stem is smaller than the thickness of the support plate and smaller than the thickness of the first airbag assembly, a first fixing hole for the valve stem to pass through is provided on the support plate along its radial direction, a second fixing hole for the valve stem to pass through is provided on the first airbag assembly, and the valve stem is sealed and connected to the second fixing hole.

[0008] It is further preferred that a fixing ring groove is provided on the inner side surfaces of the first sealing plate and the second sealing plate that are relatively arranged, and the fixing ring groove is provided on the radial edges of the first sealing plate and the second sealing plate, and fixing ring convexities are correspondingly provided on both side surfaces of the first airbag assembly, and the fixing ring convexities are clamped in the fixing ring groove.

[0009] Further preferably, the second airbag assembly includes a second inflation chamber, a third inflation chamber and a gas channel, the second inflation chamber and the third inflation chamber are both arranged in the valve seat and are arranged through the circumferential direction of the valve seat, the second inflation chamber and the third inflation chamber are arranged at intervals in the axial direction of the valve seat, the gas channel is arranged between the second inflation chamber and the third inflation chamber along the axial direction of the valve seat, and the gas channel passes through the second inflation chamber and the third inflation chamber, a vent is provided on the side wall of the valve seat, the vent is connected to the gas channel, and the gas interface is connected to the vent.

[0010] Further preferably, the cavity volumes of the second air-filling cavity and the third air-filling cavity decrease sequentially from the inside to the outside along the radial direction of the valve seat.

[0011] Further preferably, a avoidance hole for the valve stem to pass through is provided on the valve seat in a radial direction, the avoidance hole is provided through the gas channel, and an anti-leakage seat is provided on the valve seat around the avoidance hole, the avoidance hole is provided on the anti-leakage seat, and the anti-leakage seat is partially located in the gas channel.

[0012] Further preferably, the vent hole is provided through the side wall of the valve seat, and one end of the vent hole close to the inner wall of the valve seat is used to communicate with the vent provided on the first airbag assembly when the butterfly plate is closed.

[0013] Further preferably, limiting rings for limiting axial displacement of the valve seat are provided on the valve body and on both sides of the valve seat, and flanges are provided at both ends of the valve body.

[0014] Further preferably, cleaning blades are rotatably provided on both side surfaces of the butterfly plate, and the bottoms of the cleaning blades abut against the two side surfaces of the butterfly plate. When the butterfly plate is opened, the fluid in the pipeline flushes the cleaning blades to drive the cleaning blades to rotate, and the rotation of the cleaning blades cleans the attachments attached to the two side surfaces of the butterfly plate. The cleaning blades include a rotating shaft and a plurality of blades. The rotating shaft is rotatably provided on the side surfaces of the butterfly plate, and each of the blades is connected to the rotating shaft at intervals.

[0015] Beneficial effects of the present invention: Compared to the traditional method of relying on the squeeze seal between the edge of the butterfly plate and the inner wall of the valve seat, the bidirectional sealing pneumatic butterfly valve of the present invention realizes bidirectional sealing between the butterfly plate and the valve seat by providing a first airbag assembly and a second airbag assembly. When the butterfly plate is closed, the high-pressure gas provided by the air source fills the airbag assembly, thereby realizing bidirectional sealing between the butterfly plate and the valve seat. This sealing method can effectively avoid the friction between the butterfly plate and the inner wall of the valve seat when the butterfly plate rotates, reduce the wear of the sealing surface, thereby significantly improving the sealing effect, reducing the risk of fluid leakage, and ensuring that the valve can reliably realize the sealing function under various working conditions. Because the airbag sealing method reduces the direct friction between the butterfly plate and the inner wall of the valve seat, the degree of wear on the sealing surface is greatly reduced, so that the service life of the valve is effectively extended. This not only reduces the replacement frequency of the valve and reduces maintenance costs, but also improves the operational stability and reliability of the entire pipeline system.

[0016] Furthermore, rotating cleaning blades are installed on both sides of the butterfly disc. When the disc opens, the fluid in the pipeline flushes the cleaning blades, driving their rotation. The rotation of the cleaning blades promptly removes debris adhering to the disc's sides, preventing it from affecting the disc's rotation and sealing performance. This feature ensures that the disc maintains excellent rotational flexibility and sealing performance during long-term use, further extending the valve's service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a structural diagram of the bidirectional sealing pneumatic butterfly valve of the present invention in an open state; Figure 2 2. It is a structural schematic diagram of the closed state of the butterfly plate of the bidirectional sealing pneumatic butterfly valve of the present invention; Figure 3 This is a schematic structural diagram (stereoscopic diagram) of the butterfly plate in the bidirectional sealing pneumatic butterfly valve of the present invention; Figure 4 This is a structural diagram (exploded view) of the butterfly plate in the bidirectional sealed pneumatic butterfly valve of the present invention; Figure 5 It is a structural schematic diagram of the butterfly plate in the bidirectional sealing pneumatic butterfly valve of the present invention; Figure 6 yes Figure 5 Schematic diagram of AA in the middle; Figure 7 This is a schematic structural diagram of the bidirectional sealing pneumatic butterfly valve of the present invention after the butterfly plate is removed; Figure 8 It is a structural schematic diagram of the valve seat in the bidirectional sealing pneumatic butterfly valve of the present invention; Figure 9 1. It is a cross-sectional view of the valve seat in the bidirectional sealing pneumatic butterfly valve of the present invention; Figure 10 Schematic diagram of the valve seat in the bidirectional sealing pneumatic butterfly valve of the present invention; Figure 11 yes Figure 10 Schematic diagram of the middle BB; Figure 12 yes Figure 10 Schematic diagram of CC.

[0018] The names corresponding to the marks in the figure are: 1. Valve body, 2. Valve stem, 3. Butterfly plate, 31. First sealing plate, 32. Second sealing plate, 33. Support plate, 331. First fixing hole, 35. First inflation chamber, 4. Valve seat, 5. Pneumatic actuator, 6. First airbag assembly, 61. Second fixing hole, 62. Fixing ring protrusion, 63. Ventilation channel, 7. Second airbag assembly, 71. Second inflation chamber, 72. Third inflation chamber, 73. Gas channel, 74. Vent hole, 75. Avoidance hole, 76. Anti-leakage seat, 8. Gas interface, 9. Flange, 10. Limiting ring, 11. Clean the blades, 111. Rotating shaft, 112. Blades. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0020] Referring to Figures 1 to 12, this bidirectional sealed pneumatic butterfly valve primarily consists of a valve body 1, a valve stem 2, a butterfly plate 3, a valve seat 4, an air source (not shown), and a pneumatic actuator 5. The valve seat 4 is mounted within the valve body 1, the butterfly plate 3 is positioned within the valve seat 4, the valve stem 2 is mounted within the valve body 1 and connected to the butterfly plate 3, and the pneumatic actuator 5 is mounted on the valve body 1 and connected to the valve stem 2. The pneumatic actuator 5 drives the butterfly plate 3 to rotate within the valve seat 4, opening and closing the valve or adjusting its angle. A first airbag assembly 6 is provided in the butterfly plate 3, a second airbag assembly 7 is provided in the valve seat 4, and a gas interface 8 is provided on the valve body 1. The gas interface 8 and the pneumatic actuator 5 are both connected to the gas source, and the gas interface 8 is connected to the second airbag assembly 7. When the butterfly plate 3 is closed, the first airbag assembly 6 is connected to the second airbag assembly 7, and the high-pressure gas provided by the gas source fills the first airbag assembly 6 and the second airbag assembly 7 through the gas interface 8, thereby achieving a seal between the butterfly plate 3 and the valve seat 4.

[0021] Figure 3-Figure 5 As shown, the valve body 1 is the main supporting structure of the bidirectional sealing pneumatic butterfly valve. It is tubular in shape, with flanges 9 at both ends. Flanges 9 are provided with multiple bolt holes for bolting to other components in the pipeline system to secure the valve. The inner wall of the valve body 1 has a specific shape and size to accommodate the valve seat 4 and ensure its stable installation. Stop rings 10 are installed on both sides of the valve body 1 and the valve seat 4 to limit the axial displacement of the valve seat 4. Stop rings 10 are attached to the inner wall of the valve body 1 by welding or other fixing methods. Their inner diameter is slightly larger than the outer diameter of the valve seat 4. They effectively prevent axial movement of the valve seat 4 within the valve body 1, ensuring the stability of the relative position between the valve seat 4 and the valve body 1, thereby ensuring the overall performance of the valve.

[0022] The valve stem 2 is a key component that transmits power from the pneumatic actuator 5 to rotate the butterfly disc 3. The diameter of the valve stem 2 is smaller than the thickness of the support plate 33 in the butterfly disc 3 and also smaller than the thickness of the first airbag assembly 6. A first fixing hole 331 is radially defined on the support plate 33 for the valve stem 2 to pass through. The diameter of the first fixing hole 331 matches the diameter of the valve stem 2 to ensure smooth passage and a stable connection. A second fixing hole 61 is defined on the first airbag assembly 6 for the valve stem 2 to pass through. The valve stem 2 and the second fixing hole 61 are sealed, for example, with a sealing ring or sealant, to prevent high-pressure gas from leaking through the gap between the valve stem 2 and the second fixing hole 61, thus ensuring the airbag assembly's sealing performance. One end of the valve stem 2 is connected to the output shaft of the pneumatic actuator 5, and the other end is connected to the butterfly plate 3. When the pneumatic actuator 5 is activated, the butterfly plate 3 is driven to rotate through the valve stem 2 to open and close the valve.

[0023] The butterfly disc 3 is the core component that enables the valve to open, close, and seal. Its structure is shown in Figure 3. The butterfly disc 3 comprises a first sealing plate 31, a second sealing plate 32, and a support plate 33. The first and second sealing plates 31, 32 are respectively positioned on either side of the support plate 33 and are both circular. The diameters of the first and second sealing plates 31, 32 are identical and both are larger than the maximum diameter of the support plate 33.

[0024] The first airbag assembly 6 is positioned at the radial edges of the first and second sealing plates 31, 32 and is sealed therewith. Specifically, the assembly is secured by retaining ring grooves on the opposing inner surfaces of the first and second sealing plates 31, 32. The retaining ring grooves are located along the radial edges of the first and second sealing plates 31, 32. Retaining ring protrusions 62 are positioned on corresponding sides of the first airbag assembly 6, which snap into the retaining ring grooves. This snap-fit ​​connection ensures a stable connection between the first and second sealing plates 31, 32 and ensures a tight seal. In actual production, the first airbag assembly is secured between the first and second sealing plates using a rubber vulcanization process.

[0025] A first inflation chamber 35 is formed between the first and second sealing plates 31 and 32, and between the first airbag assembly 6 and the support plate 33. When high-pressure gas is introduced into the first inflation chamber 35, the first airbag assembly 6 extends outward radially from the first and second sealing plates 31 and 32. This extension allows the first airbag assembly 6 to fit snugly against the inner wall of the valve seat 4, thereby maintaining the seal between the butterfly plate 3 and the valve seat 4. A vent 63 is provided on the first airbag assembly 6 for communication with the second airbag assembly 7. When the butterfly plate 3 is closed, the vent 63 connects to the second airbag assembly 7, allowing high-pressure gas to flow smoothly into both the first and second airbag assemblies 6 and 7.

[0026] also, Figure 3 As shown, cleaning blades 11 are rotatably mounted on both sides of the butterfly disc 3. These cleaning blades 11 comprise a rotating shaft 111 and multiple blades 112. The shaft 111 is rotatably mounted on the side of the butterfly disc 3, with the blades 112 connected to the shaft 111 at intervals. The bottoms of the cleaning blades 11 abut against the sides of the butterfly disc 3. When the butterfly disc 3 opens, the fluid in the pipeline flushes the cleaning blades 11, driving them to rotate. The rotation of the cleaning blades 11 removes debris adhering to the sides of the butterfly disc 3, preventing it from affecting the disc's rotation and sealing performance, thereby ensuring proper valve operation.

[0027] The valve seat 4 is one of the key components to achieve the sealing of the butterfly plate 3. Its structure is shown in Figure 7- Figure 12 As shown in FIG. Valve seat 4 is mounted within valve body 1, with its outer wall tightly fitted with the inner wall of valve body 1 and its axial displacement limited by retaining ring 10. A second airbag assembly 7 is disposed within valve seat 4 and includes a second inflation chamber 71, a third inflation chamber 72, and a gas passage 73.

[0028] The second and third inflation chambers 71, 72 are both disposed within the valve seat 4 and extend circumferentially through the valve seat 4. These chambers are spaced axially from each other, allowing them to cooperate with each other during inflation, applying sealing pressure to the butterfly disc 3 from different positions. A gas passage 73 is disposed axially between the second and third inflation chambers 71, 72, along the valve seat 4. The passage 73 extends through both chambers, allowing high-pressure gas to flow between them.

[0029] A vent 74 is provided on the sidewall of the valve seat 4 and communicates with the gas passage 73. The gas interface 8 is connected to the vent 74, allowing high-pressure gas from the gas source to enter the vent 74 through the gas interface 8 and then enter the second and third inflation chambers 71 and 72, respectively, through the gas passage 73. The vent 74 extends through the sidewall of the valve seat 4, and the end of the vent 74 near the inner wall of the valve seat 4 is used to communicate with the vent 63 provided on the first airbag assembly 6 when the butterfly disc 3 is closed. When the butterfly disc 3 is closed, the vent 63 aligns with the vent 74 and communicates with it, allowing high-pressure gas to enter the first inflation chamber 35 of the first airbag assembly 6, achieving simultaneous inflation of the first and second airbag assemblies 6 and 7, thereby ensuring a bidirectional seal between the butterfly disc 3 and the valve seat 4.

[0030] The volumes of the second and third inflation chambers 71, 72 decrease radially from the inside outward along the valve seat 4. This design allows gas to be more concentrated on the contact area between the inner wall of the valve seat 4 and the butterfly disc 3 during inflation, improving sealing effectiveness. Furthermore, because the outer inflation chambers have smaller volumes, the sealing pressure is reached more quickly during inflation, further enhancing sealing performance.

[0031] Figure 8 and Figure 9 As shown, a radially extending escape hole 75 for the valve stem 2 to pass through is provided on the valve seat 4. This escape hole 75 extends through the gas passage 73. To prevent high-pressure gas from leaking through the escape hole 75, a leak-proof seat 76 is provided on the valve seat 4 around the escape hole 75. The escape hole 75 is located on the leak-proof seat 76, and the leak-proof seat 76 is partially located within the gas passage 73. The leak-proof seat 76 isolates the connection between the gas passage 73 and the valve stem 2, ensuring that high-pressure gas in the gas passage 73 does not leak through the escape hole 75, thus maintaining the sealing performance of the airbag assembly.

[0032] It should be noted that the second inflation chamber 71 and the third inflation chamber 72 are both inside the valve seat. During production, the second inflation chamber 71 and the third inflation chamber 72 are set separately, and then the two separate bodies are connected together through an injection molding process, so that the second inflation chamber 71 and the third inflation chamber 72 are both inside the valve seat 4.

[0033] The air source is a device that provides high-pressure gas, powering the pneumatic actuator 5 and the airbag assembly. The air source is connected to the gas port 8 and the pneumatic actuator 5 via pipelines, providing the necessary air pressure to support valve operation. The pneumatic actuator 5 is mounted on the valve body 1, with its output shaft connected to the valve stem 2. The pneumatic actuator 5 receives control signals to control the rotation of the valve stem 2, thereby driving the butterfly disc 3 to rotate within the valve seat 4, opening and closing the valve. The specific structure and control principles of the pneumatic actuator 5 are state-of-the-art and will not be elaborated here.

[0034] 3. Working Principle (1) Valve opening process When the valve needs to be opened, an opening signal is sent to pneumatic actuator 5, which activates it, rotating valve stem 2. This rotation drives butterfly disc 3 within valve seat 4. As butterfly disc 3 rotates, cleaning blade 11, flushed by the fluid in the pipeline, begins to rotate. The rotation of cleaning blade 11 removes debris adhering to both sides of butterfly disc 3, preventing it from affecting its rotation and sealing performance. As butterfly disc 3 rotates, the valve gradually opens, allowing fluid in the pipeline to pass smoothly through the valve.

[0035] (2) Valve closing and sealing process When the valve needs to be closed and sealed, a closing signal is sent to the pneumatic actuator 5, which activates it, driving the valve stem 2 to rotate in the opposite direction, gradually closing the butterfly plate 3. When the butterfly plate 3 is fully closed, the vent 63 on the first airbag assembly 6 aligns with and connects to the vent hole 74 on the valve seat 4. At this point, high-pressure gas from the gas source enters the vent hole 74 through the gas interface 8 and then flows through the gas channel 73 into the second and third inflation chambers 71 and 72, respectively. Simultaneously, the high-pressure gas enters the first inflation chamber 35 of the first airbag assembly 6 through the vent 63.

[0036] As high-pressure gas continues to flow in, the first airbag assembly 6 extends outward radially along the first and second sealing plates 31, 32, closely fitting against the inner wall of the valve seat 4. The second and third inflation chambers 71, 72 expand, applying sealing pressure to the butterfly plate 3 from different positions, further enhancing the seal between the butterfly plate 3 and the valve seat 4. Because the first and second airbag assemblies 6, 7, inflate simultaneously, a bidirectional seal is achieved between the butterfly plate 3 and the valve seat 4, effectively preventing fluid leakage in the pipeline.

[0037] Over extended use, the sealing performance between the disc 3 and the valve seat 4 may be affected. However, since this bidirectionally sealed pneumatic butterfly valve utilizes an airbag seal structure, if the sealing performance degrades, simply refilling the airbag assembly with high-pressure gas from the air source will inflate the first and second airbag assemblies 6 and 7, restoring the sealing performance between the disc 3 and the valve seat 4. Furthermore, the cleaning paddle 11 continuously rotates during valve operation, effectively cleaning debris from both sides of the disc 3, minimizing its impact on the disc's rotation and sealing performance, and extending the valve's service life.

[0038] In summary, this bidirectional sealing pneumatic butterfly valve, through its unique structural design and operating principle, achieves efficient and reliable sealing, offering significant advantages and promising application prospects. In practical applications, the valve can be appropriately sized and optimized to meet the requirements of different piping systems, to meet the demands of various operating conditions.

[0039] The above is a detailed description of the specific implementation of the bidirectional sealed pneumatic butterfly valve. Through the introduction of the above structure and working principle, the technical solution and beneficial effects of the present invention can be clearly understood. In the actual production and use process, the size, material, etc. of each component can be reasonably selected and adjusted according to the specific situation to ensure the performance and quality of the valve. At the same time, with the continuous development and progress of technology, the bidirectional sealed pneumatic butterfly valve of the present invention can be further optimized and improved to adapt to a wider range of application scenarios and higher performance requirements. For example, the material of the airbag assembly can be improved to improve its pressure resistance and wear resistance; the structure of the cleaning blade can be optimized to improve the cleaning effect, etc. It is believed that in the process of continuous research and development and innovation, the bidirectional sealed pneumatic butterfly valve will play a greater role in the field of industrial pipeline systems.

[0040] Through this detailed explanation of the specific implementation methods of this bidirectional sealed pneumatic butterfly valve, we believe that relevant technical personnel will be able to fully understand the technical solutions of this invention and apply and promote them in actual production and use. As technology continues to advance and market demand changes, this bidirectional sealed pneumatic butterfly valve can continue to be improved and innovated to meet the requirements of use in different fields and working conditions, making greater contributions to industrial development.

Claims

1. A bidirectional sealed pneumatic butterfly valve, characterized by: It includes a valve body, a valve stem, a butterfly plate, a valve seat, an air source and a pneumatic actuator, the valve seat is arranged in the valve body, the butterfly plate is arranged in the valve seat, the valve stem is arranged in the valve body and connected to the butterfly plate, the pneumatic actuator is arranged on the valve body and connected to the valve stem, and the butterfly plate is driven to rotate in the valve seat by the pneumatic actuator; a first airbag assembly is arranged in the butterfly plate, a second airbag assembly is arranged in the valve seat, a gas interface is provided on the valve body, the gas interface and the pneumatic actuator are both connected to the air source, and the gas interface is communicated with the second airbag assembly, and the first airbag assembly is arranged to be communicated with the second airbag assembly when the butterfly plate is closed, so that the high-pressure gas input through the gas interface fills the first airbag assembly and the second airbag assembly to seal the butterfly plate.

2. The bidirectional sealing pneumatic butterfly valve according to claim 1, characterized in that: The butterfly plate includes a first sealing plate, a second sealing plate and a support plate, the first sealing plate and the second sealing plate are respectively arranged on both sides of the support plate, and the supporting first sealing plate and the second sealing plate are both circular, the first sealing plate and the second sealing plate have the same diameter and are both larger than the maximum diameter of the support plate, the first airbag assembly is arranged at the radial edge of the first sealing plate and the second sealing plate, and is sealed with the first sealing plate and the second sealing plate, a first inflation chamber is formed between the first sealing plate and the second sealing plate and between the first airbag assembly and the support plate, when high-pressure gas is input into the first inflation chamber, the first airbag assembly extends outward along the radial direction of the first sealing plate and the second sealing plate to maintain the sealing of the butterfly plate and the valve seat, and an air duct for communicating with the second airbag assembly is provided on the first airbag assembly.

3. The bidirectional sealing pneumatic butterfly valve according to claim 2, characterized in that: The diameter of the valve stem is smaller than the thickness of the support plate and smaller than the thickness of the first airbag assembly. A first fixing hole for the valve stem to pass through is provided on the support plate along its radial direction. A second fixing hole for the valve stem to pass through is provided on the first airbag assembly, and the valve stem is sealed and connected to the second fixing hole.

4. The bidirectional sealing pneumatic butterfly valve according to claim 3, characterized in that: A fixing ring groove is provided on the inner side surfaces of the first sealing plate and the second sealing plate which are arranged opposite to each other. The fixing ring groove is provided on the radial edges of the first sealing plate and the second sealing plate. Fixed ring protrusions are correspondingly provided on both side surfaces of the first airbag assembly. The fixed ring protrusions are clamped in the fixing ring groove.

5. The bidirectional sealing pneumatic butterfly valve according to claim 2, characterized in that: The second airbag assembly includes a second inflation chamber, a third inflation chamber and a gas channel. The second inflation chamber and the third inflation chamber are both arranged in the valve seat and are arranged through the circumferential direction of the valve seat. The second inflation chamber and the third inflation chamber are arranged at intervals in the axial direction of the valve seat. The gas channel is arranged between the second inflation chamber and the third inflation chamber along the axial direction of the valve seat, and the gas channel passes through the second inflation chamber and the third inflation chamber. A vent is provided on the side wall of the valve seat, the vent is connected to the gas channel, and the gas interface is connected to the vent.

6. The bidirectional sealing pneumatic butterfly valve according to claim 5, characterized in that: The volumes of the second and third air-filling chambers decrease sequentially from the inside to the outside along the radial direction of the valve seat.

7. The bidirectional sealing pneumatic butterfly valve according to claim 6, characterized in that: A avoidance hole for the valve stem to pass through is provided on the valve seat in a radial direction, the avoidance hole is provided through the gas channel, and an anti-leakage seat is provided on the valve seat around the avoidance hole, the avoidance hole is provided on the anti-leakage seat, and the anti-leakage seat is partially located in the gas channel.

8. The bidirectional sealing pneumatic butterfly valve according to claim 7, characterized in that: The vent hole is arranged through the side wall of the valve seat, and one end of the vent hole close to the inner wall of the valve seat is used to communicate with the vent provided on the first airbag assembly when the butterfly plate is closed.

9. The bidirectional sealing pneumatic butterfly valve according to claim 5, characterized in that: Limiting rings for limiting the axial displacement of the valve seat are provided on the valve body and on both sides of the valve seat, and flanges are provided at both ends of the valve body.

10. The bidirectional sealing pneumatic butterfly valve according to claim 1, characterized in that: Cleaning blades are rotatably provided on both sides of the butterfly plate, and the bottoms of the cleaning blades abut against the two sides of the butterfly plate. When the butterfly plate is opened, the fluid in the pipeline flushes the cleaning blades to drive the cleaning blades to rotate, and the rotation of the cleaning blades cleans the attachments attached to the two sides of the butterfly plate. The cleaning blades include a rotating shaft and a plurality of blades. The rotating shaft is rotatably provided on the side of the butterfly plate, and each of the blades is connected to the rotating shaft at intervals.

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