A pneumatic expansion butterfly valve

Abstract

This utility model discloses a pneumatic expansion butterfly valve, including a valve seat, a pneumatic drive device on the top of the valve seat, a valve disc at the center of the valve seat, a valve stem inserted at the center of the valve disc, the top of the valve stem connected to the power output end of the pneumatic drive device, an air bladder embedded in the inner wall of the valve seat, an air inlet pipe on the top side wall of the pneumatic drive device, a tee at the input end of the air inlet pipe, an air supply pipe connected to the bottom of the tee, a sleeve at the bottom end of the air supply pipe, a connecting pipe inserted at the top of the sleeve, the connecting pipe being sealed to the air bladder, and a piston slidingly inserted inside the sleeve. This utility model, through the mechanical linkage design of dynamic sealing between the pneumatic drive device and the air bladder, achieves air bladder expansion to compensate for the sealing gap between the valve disc and the valve seat when the valve is closed, effectively reducing leakage and extending service life; the wear-resistant coating and material optimization of the cam and the contact part reduce friction loss, and the spring return and pressure relief pipe ensure reliable air bladder reset.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a pneumatic expansion butterfly valve. Background Technology

[0002] Butterfly valves are commonly used flow control devices in industrial pipeline systems. However, traditional butterfly valves have several limitations when facing certain special operating conditions. For example, in scenarios involving the transportation of high-pressure and highly corrosive media, the sealing performance of ordinary butterfly valves is difficult to guarantee. The valve disc and valve seat are prone to wear due to media erosion, scouring, and frequent opening and closing actions, leading to leakage. This not only wastes resources but may also cause safety hazards.

[0003] Furthermore, the sealing performance of existing butterfly valves gradually declines with the aging of components during long-term use, resulting in high maintenance costs and difficulties, which seriously affects the continuity and stability of industrial production. To overcome these problems, developing a butterfly valve that can maintain good sealing performance under complex operating conditions, has a long service life, and is easy to maintain has become an urgent technical challenge for the industry. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a pneumatic expansion butterfly valve.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A pneumatic expansion butterfly valve includes a valve seat, a pneumatic drive device on the top of the valve seat, a valve disc at the center of the valve seat, a valve stem inserted at the center of the valve disc, the top of the valve stem being connected to the power output end of the pneumatic drive device, an air bladder embedded in the inner wall of the valve seat, an air inlet pipe on the top side wall of the pneumatic drive device, a tee at the input end of the air inlet pipe, an air supply pipe connected to the bottom of the tee, a sleeve at the bottom end of the air supply pipe, a connecting pipe inserted at the top of the sleeve, the connecting pipe being sealed to the air bladder, a piston slidingly inserted inside the sleeve, a pull rod coaxially provided at the end of the piston, the pull rod slidingly passing through the sleeve, a connecting rod coaxially provided at one end of the bottom end of the valve stem extending to the outside of the valve seat, a cam at the bottom end of the connecting rod, and an abutment part for abutting against the cam at the end of the pull rod.

[0007] Preferably, a return spring is fitted on the outer circumference of the pull rod located between the inner wall of the sleeve and the piston.

[0008] Preferably, a pressure relief pipe is provided at the top of the sleeve.

[0009] Furthermore, an exhaust pipe is also provided on the top side wall of the air-driven device.

[0010] Furthermore, the airbag is made of fluororubber or EPDM rubber, and its inner wall is reinforced with a metal mesh layer.

[0011] Preferably, the working surface of the cam that contacts the abutment part is coated with boron nitride, and the abutment part is made of polytetrafluoroethylene.

[0012] The beneficial effects of this utility model are as follows:

[0013] This pneumatic expansion butterfly valve utilizes a mechanical linkage design that combines a pneumatic drive device with dynamic sealing of the air bladder. This allows the air bladder to expand and compensate for the sealing gap between the valve disc and the valve seat when the valve is closed, effectively reducing leakage and extending service life. The wear-resistant coating and optimized materials of the cam and the contact part reduce friction loss, while the spring return and pressure relief pipe ensure reliable air bladder reset. The fluororubber-reinforced air bladder enhances corrosion resistance and fatigue resistance, and the redundant air supply system strengthens sealing reliability. It is suitable for precise control and long-term stable operation in high-pressure and highly corrosive media environments.

[0014] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of a pneumatic expansion butterfly valve proposed in this utility model;

[0016] Figure 2 This is a front view schematic diagram of a pneumatic expansion butterfly valve proposed in this utility model;

[0017] Figure 3 This utility model proposes a pneumatic expansion butterfly valve. Figure 2 A magnified schematic diagram of the local structure at point A;

[0018] Figure 4 This is a schematic diagram of the internal structure of the sleeve of a pneumatic expansion butterfly valve in the open state, as proposed in this utility model.

[0019] In the diagram: 1. Valve seat; 2. Pneumatic actuator; 3. Exhaust pipe; 4. Intake pipe; 5. Tee; 6. Air supply pipe; 7. Valve stem; 8. Valve disc; 9. Airbag; 10. Sleeve; 11. Piston; 12. Pull rod; 13. Return spring; 14. Connecting pipe; 15. Pressure relief pipe; 16. Cam; 17. Abutment part; 18. Connecting rod. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0021] Example 1, referring to Figures 1 to 4 A pneumatic expansion butterfly valve includes a valve seat 1, a pneumatic drive device 2 on the top of the valve seat 1, a valve disc 8 at the center of the valve seat 1, a valve stem 7 inserted at the center of the valve disc 8, the top of the valve stem 7 being connected to the power output end of the pneumatic drive device 2, an air bladder 9 embedded in the inner wall of the valve seat 1, an air inlet pipe 4 on the top side wall of the pneumatic drive device 2, a tee 5 at the input end of the air inlet pipe 4, an air supply pipe 6 connected to the bottom of the tee 5, a sleeve 10 at the bottom end of the air supply pipe 6, a connecting pipe 14 inserted at the top of the sleeve 10, the connecting pipe 14 being sealed to the air bladder 9, a piston 11 slidingly inserted inside the sleeve 10, a pull rod 12 coaxially provided at the end of the piston 11, the pull rod 12 slidingly passing through the sleeve 10, a connecting rod 18 coaxially provided at one end of the bottom end of the valve stem 7 extending to the outside of the valve seat 1, a cam 16 at the bottom end of the connecting rod 18, and an abutment part 17 for abutting against the cam 16 at the end of the pull rod 12.

[0022] In this embodiment, a return spring 13 is sleeved on the outer circumference of the pull rod 12 located between the inner wall of the sleeve 10 and the piston 11. A pressure relief pipe 15 is provided at the top of the sleeve 10. An exhaust pipe 3 is also provided on the top side wall of the pneumatic drive device 2. The airbag 9 is made of fluororubber or EPDM rubber and has a metal mesh reinforcement layer on its inner wall. The working surface of the cam 16 that contacts the abutment part 17 is coated with boron nitride. The abutment part 17 is made of polytetrafluoroethylene.

[0023] The working principle of this embodiment:

[0024] Gas supply and drive phase

[0025] Compressed air enters through intake pipe 4 and splits into two paths via tee 5:

[0026] Pneumatic drive device 2: Drives the internal piston or diaphragm, which in turn drives the valve disc 8 to rotate to the closed position via the valve stem 7.

[0027] Gas supply pipe 6: Gas enters the sleeve 10, and under the action of the return spring, the piston cannot be moved.

[0028] Cam linkage and airbag inflation

[0029] When the valve disc closes, the cam 16 rotates with the valve stem 7 to a specific angle, and the abutment part 17 is pressed by the cam, pushing the pull rod 12 to move further. At this time:

[0030] Piston 11 opens the inlet end of the connecting tube, and gas is injected into the airbag 9 through the connecting tube 14.

[0031] The airbag 9 inflates and fits tightly against the valve disc 8 and the inner wall of the valve seat 1, forming a double seal and reducing leakage.

[0032] Maintaining sealing and reset mechanism

[0033] Return spring 13: When the air supply stops, the spring pushes the piston 11 to return to its original position, and the airbag 9 deflates and contracts through the pressure relief pipe 15.

[0034] Exhaust pipe 3: Expels residual gas from the gas-driven device 2, ensuring that the valve can be opened freely.

[0035] Startup process

[0036] When air is supplied in reverse, the air drive device 2 drives the valve stem 7 to rotate in the opposite direction, and the valve disc 8 opens. Simultaneously:

[0037] When the cam 16 disengages from the abutment part 17, the piston 11 moves under the action of the spring 13, the air bag 9 is completely depressurized, the valve disc separates from the valve seat, and the fluid can pass through normally.

[0038] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A pneumatic expansion butterfly valve, comprising a valve seat (1), the top of which is provided with a gas drive device (2), the center of which is provided with a valve flap (8), the center of which is provided with a valve rod (7), the top end of which is connected with the power output end of the gas drive device (2), characterized in that, The valve seat (1) is fitted with an air bladder (9) on its inner wall. The air drive device (2) is provided with an air inlet pipe (4) on its top side wall. The air inlet pipe (4) is provided with a three-way valve (5) at its input end. The bottom of the three-way valve (5) is connected to an air supply pipe (6). The bottom end of the air supply pipe (6) is provided with a sleeve (10). The top of the sleeve (10) is provided with a connecting pipe (14). The connecting pipe (14) is sealed to the air bladder (9). A piston (11) is slidably inserted inside the sleeve (10). The end of the piston (11) is coaxially provided with a pull rod (12). The pull rod (12) slides through the sleeve (10). The bottom end of the valve stem (7) extends to the outside of the valve seat (1) and is coaxially provided with a connecting rod (18). The bottom end of the connecting rod (18) is provided with a cam (16). The end of the pull rod (12) is provided with an abutment part (17) for abutting against the cam (16).

2. A gas loaded butterfly valve according to claim 1, wherein, A return spring (13) is fitted on the outer circumference of the pull rod (12) located between the inner wall of the sleeve (10) and the piston (11).

3. A gas loaded butterfly valve according to claim 1, wherein, The top of the sleeve (10) is provided with a pressure relief pipe (15).

4. A pneumatic expansion butterfly valve according to claim 1, characterized in that, The top side wall of the pneumatic drive device (2) is also provided with an exhaust pipe (3).

5. A pneumatic expansion butterfly valve according to claim 1, characterized in that, The airbag (9) is made of fluororubber or EPDM rubber, and its inner wall is reinforced with a metal mesh layer.

6. A pneumatic expansion butterfly valve according to claim 1, characterized in that, The working surface of the cam (16) in contact with the abutment (17) is coated with boron nitride, and the abutment (17) is made of polytetrafluoroethylene.

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