A thin-film pneumatic damping actuator

Abstract

The present invention discloses a thin-film pneumatic damping actuator, which includes a cylinder block, a diaphragm, a diaphragm plate, a bracket, a piston rod, a damping cylinder, a gas-liquid partition plate, a butterfly piston, a damping piston rod and a damping partition plate. The cylinder block is arranged on the bracket. The diaphragm is arranged in the middle of the cylinder block, dividing the cylinder block into two chambers. The diaphragm plate is installed on the diaphragm. The piston rod is slidably arranged on the cylinder block through a guide sleeve and is connected to the diaphragm plate. The damping cylinder is arranged on the cylinder block through the gas-liquid partition plate. The butterfly piston is arranged in the damping cylinder, and a flow-through hole is arranged on the butterfly piston. The damping piston rod is slidably arranged on the gas-liquid partition plate, connecting the butterfly piston and the diaphragm plate. The damping cylinder is filled with buffer oil. The damping partition plate is arranged in the damping cylinder, dividing the damping cylinder into a steady flow chamber and a damping chamber. In the present invention, the damping partition plate is arranged in the damping cylinder, dividing the damping cylinder into the steady flow chamber and the damping chamber, effectively reducing the influence of the cavity on the buffering process.

Description

Technical Field

[0001] The present invention relates to a thin-film pneumatic damping actuator. Background Art

[0002] As a special type of cylinder, the thin-film actuator is widely used in industry for its light weight, flexibility, simple installation, convenient maintenance and reliable operation. Its good tracking and following function is thus widely used in pipeline flow control in refineries and chemical plants and closing hydraulic valves, etc. However, when the working pressure varies greatly and changes rapidly, the thin-film actuator will produce a "bouncing" phenomenon, which greatly restricts the application of the thin-film actuator in linear stroke valves such as gate valves and orbital ball valves. Summary of the Invention

[0003] Aiming at the defects existing in the above prior art, the main purpose of the present invention is to overcome the deficiencies of the prior art and disclose a

[0004] Beneficial effects achieved by the present invention:

[0005] In the present invention, a damping partition is arranged in the damping cylinder, dividing the damping cylinder into a steady flow chamber and a damping chamber, effectively reducing the influence of the cavity on the buffering process. A check valve is designed on the damping cylinder to prevent the negative pressure in the cylinder from affecting the flow of the buffer liquid and the buffer effect is not ideal. A deflectable guide sleeve is adopted on the gas-liquid partition, and a floating structure is used to make the damping piston rod deflect a certain angle during movement, reducing the installation accuracy, protecting the dynamic seal mating surface and extending the service life. Description of the Drawings

[0006] Figure 1 It is a schematic structural diagram of a thin-film pneumatic damping actuator of the present invention;

[0007] Figure 2 For Figure 1 an enlarged view of A in

[0008] Figure 3 For Figure 1 an enlarged view of B in

[0009] The reference numerals are as follows:

[0010] 1. Cylinder block, 2. Diaphragm, 3. Diaphragm plate, 4. Bracket, 5. Piston rod, 6. Damping cylinder, 7. Gas-liquid partition, 8. Butterfly piston, 9. Damping piston rod, 10. Damping partition, 11. Deflectable guide sleeve, 12. Disc spring, 13. Pressure relief device, 14. Check valve, 61. Steady flow chamber, 62. Damping chamber, 63. Cylinder body, 64. Upper cover plate, 81. Flow hole, 101. Through hole. Detailed Embodiment

[0011] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0012] A film-type pneumatic damping actuator, as Figures 1-3 shown, includes a cylinder block 1, a diaphragm 2, a diaphragm plate 3, a bracket 4, a piston rod 5, a damping cylinder 6, a gas-liquid partition plate 7, a butterfly piston 8, a damping piston rod 9 and a damping partition plate 10. The cylinder block 1 is arranged on the bracket 4. The diaphragm 2 is arranged in the middle of the cylinder block 1, dividing the cylinder block 1 into two chambers. The diaphragm plate 3 is installed on the diaphragm 2 and is used for the conversion between air pressure and thrust. That is, when gas is introduced into the upper chamber, the air pressure increases, driving the diaphragm plate 3 to move downward; conversely, it moves upward. The piston rod 5 is slidably arranged on the cylinder block 1 through a guide sleeve, one end of which is connected to the diaphragm plate 3 and the other end extends into the bracket 4. The damping cylinder 6 is arranged on the cylinder block 1 through the gas-liquid partition plate 7, so that the damping cylinder 6 and the cylinder block 1 are independent cavities. The butterfly piston 8 is arranged in the damping cylinder 6. A circulation hole 81 is arranged on the butterfly piston 8. The damping piston rod 9 is slidably arranged on the gas-liquid partition plate 8, one end of which is connected to the butterfly piston 8 and the other end extends into the cylinder block 1 and is connected to the diaphragm plate 3. The damping cylinder 6 is filled with buffer oil. The butterfly piston 8 is provided with a circulation hole 81. When the butterfly piston 8 moves up and down, the buffer oil realizes self-circulation in the damping cylinder 6. The damping partition plate 10 is arranged in the damping cylinder 6, dividing the damping cylinder 6 into a steady flow chamber 61 and a damping chamber 62. A through hole 101 connecting the steady flow chamber 61 and the damping chamber 62 is arranged on the damping partition plate 10. The purpose is that when the butterfly piston 8 and the damping piston rod 9 are installed in the damping cylinder, if it is filled with buffer oil inside, but due to the small compression ratio of the buffer oil, the butterfly piston 8 will be very difficult to install. Therefore, when installing, a part of air will be reserved. Since the compression ratio of air is relatively large, the butterfly piston 8 can be smoothly installed, but there will be some residual gas in the damping cylinder 6. By forming the steady flow chamber 61 through the damping partition plate 10, the residual gas enters the steady flow chamber 61 through the through hole, which can effectively reduce the influence of the cavity on the buffering process. Preferably, the damping piston rod 9 and the diaphragm 2 are connected by a double-thread fastening and loosening method.

[0013] In one embodiment, as Figures 1-3As shown in the figure, it further includes a deflectable guide sleeve 11 and a disc spring 12. The deflectable guide sleeve 11 has a spherical structure, and a guide hole that is arranged through the center of the sphere and cooperates with the damping piston rod 9 is provided. A sealing ring is arranged in the guide hole, and the sealing ring is used for sealing connection with the damping piston rod 9. An installation cavity that cooperates with the deflectable guide sleeve 11 is provided on the gas-liquid partition plate 7. The deflectable guide sleeve 11 is elastically arranged in the installation cavity through the disc spring 12, enabling the damping piston rod 9 to deflect by a certain angle during movement, reducing the installation accuracy, protecting the dynamic sealing mating surface, and extending the service life. By pressing the deflectable guide sleeve 11 with the disc spring 12, a certain sealing force is generated, causing the compressed air in the cylinder to not enter the damping cylinder. When the butterfly piston 8 in the damping cylinder 6 moves at a relatively high speed, a relatively large hydraulic pressure will be generated, and the generated hydraulic pressure will assist in sealing to prevent the buffer liquid from entering the cylinder, which can well ensure gas-liquid separation and prevent mutual intrusion.

[0014] In one embodiment, as Figures 1-3 shown, it further includes a pressure relief device 13. The pressure relief device 13 is arranged on the butterfly piston 8. When the butterfly piston 8 moves upward and the oil pressure exceeds the opening pressure of the pressure relief device 13, the pressure relief device 13 opens, allowing the buffer oil to flow from the upper end of the butterfly piston 8 through the pressure relief device 13 into its lower end, preventing the cylinder from moving too fast, generating high pressure, damaging the seals, and causing oil leakage and air leakage. Of course, a reversely installed pressure relief device 13 can also be arranged on the butterfly piston 8, so that when the butterfly piston 8 moves downward and exceeds the pressure at which the pressure relief device 13 is unclamped, the buffer oil can also flow from the pressure relief device 8 into the upper end of the butterfly piston 8.

[0015] In one embodiment, as Figures 1-3 shown, the gas-liquid partition plate 7 has a stepped shaft structure. The upper part of the gas-liquid partition plate 7 is matched with the inner diameter of the damping cylinder 6, and a sealing ring is sleeved on the side wall of the upper part of the gas-liquid partition plate 7. A gasket is arranged between the damping cylinder 6 and the cylinder block 1. The gas-liquid partition plate 7 is arranged in the cylinder block 1 and fixed to the damping cylinder 6 through bolts. Through the sealing ring between the gas-liquid partition plate 7 and the damping cylinder 6, the buffer oil is prevented from flowing into the cylinder block 1; at the same time, through the gasket, the buffer oil is further prevented from flowing outwards.

[0016] In one embodiment, as Figures 1-3 shown, the damping cylinder 6 includes a cylinder body 63 and an upper cover plate 64. The cylinder body 63 has a cylindrical tubular structure, and the upper cover plate 64 is fixedly arranged on the upper surface of the cylinder body 63 through bolts, and a gasket is arranged between the cylinder body 63 and the upper cover plate 64.

[0017] In one embodiment, as Figures 1-3As shown in the figure, it further includes a one-way valve 14. The one-way valve 14 is arranged on the damping cylinder 6, connected to the steady flow chamber 61, and can only be opened unidirectionally from the outside to the steady flow chamber 61. After long-term use, negative pressure will be generated in the damping cylinder 6. The outside air is supplemented into the damping cylinder 6 through the one-way valve 14 to balance the internal and external pressures, prevent the negative pressure in the cylinder from affecting the flow of the buffer liquid, and avoid an unsatisfactory buffering effect.

[0018] In one embodiment, as Figures 1-3 shown, the diaphragm 2 is made of nitrile rubber.

[0019] When the present invention is in use, as Figures 1-3 shown, it is installed on the device through the bracket 4. The piston rod 5 is connected to the driving target. The diaphragm 2 is driven to move up and down by compressed gas, thereby driving the piston rod 5 to move up and down. At the same time, the damping piston rod 9 drives the butterfly piston 8 to move synchronously, thereby providing damping for the movement of the cylinder and enabling it to move smoothly.

[0020] The above are only the preferred embodiments of the present invention and are not used to limit the scope of implementation of the present invention; any modifications or equivalent replacements made to the present invention without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A diaphragm pneumatic damping actuator, characterized in that, it includes a cylinder block, a diaphragm, a diaphragm plate, a bracket, a piston rod, a damping cylinder, a gas-liquid partition plate, a butterfly piston, a damping piston rod and a damping partition plate. The cylinder block is arranged on the bracket. The diaphragm is arranged in the middle of the cylinder block, dividing the cylinder block into two chambers. The diaphragm plate is installed on the diaphragm. The piston rod is slidably arranged on the cylinder block through a guide sleeve. One end of the piston rod is connected to the diaphragm plate, and the other end extends into the bracket. The damping cylinder is arranged on the cylinder block through the gas-liquid partition plate. The butterfly piston is arranged in the damping cylinder. A flow-through hole is arranged on the butterfly piston. The damping piston rod is slidably arranged on the gas-liquid partition plate. One end of the damping piston rod is connected to the butterfly piston, and the other end extends into the cylinder block and is connected to the diaphragm plate. The damping cylinder is filled with buffer oil; The damping partition plate is arranged in the damping cylinder, and the damping partition plate is placed above the butterfly piston, dividing the damping cylinder into a steady flow chamber and a damping chamber. A through hole connecting the steady flow chamber and the damping chamber is arranged on the damping partition plate.

2. A diaphragm pneumatic damping actuator according to claim 1, characterized in that, it further includes a deflectable guide sleeve and a disc spring. The deflectable guide sleeve is of a spherical structure, and a guide hole for cooperating with the damping piston rod is arranged through the center of the sphere. A sealing ring is arranged in the guide hole. An installation cavity for cooperating with the deflectable guide sleeve is arranged on the gas-liquid partition plate. The deflectable guide sleeve is elastically arranged in the installation cavity through the disc spring.

3. A diaphragm pneumatic damping actuator according to claim 1, characterized in that, it further includes a pressure relief device. The pressure relief device is arranged on the butterfly piston. When the butterfly piston moves upward and the oil pressure exceeds the opening pressure of the pressure relief device, the pressure relief device opens, enabling the buffer oil to flow from the upper end of the butterfly piston through the pressure relief device into its lower end.

4. A diaphragm pneumatic damping actuator according to claim 1, characterized in that, the gas-liquid partition plate is of a stepped shaft structure. The upper part of the gas-liquid partition plate is matched with the inner diameter of the damping cylinder, and a sealing ring is sleeved on the side wall of the upper part of the gas-liquid partition plate. A gasket is arranged between the damping cylinder and the cylinder block. The gas-liquid partition plate is arranged in the cylinder block and is fixed to the damping cylinder through bolts.

5. A diaphragm pneumatic damping actuator according to claim 1, characterized in that, the damping cylinder includes a cylinder body and an upper cover plate. The cylinder body is of a cylindrical tubular structure. The upper cover plate is fixedly arranged on the upper surface of the cylinder body through bolts, and a gasket is arranged between the cylinder body and the upper cover plate.

6. A diaphragm pneumatic damping actuator according to claim 1, characterized in that, it further includes a one-way valve. The one-way valve is arranged on the damping cylinder and is connected to the steady flow chamber, and the one-way valve can only be opened unidirectionally from the outside to the steady flow chamber.

7. A diaphragm pneumatic damping actuator according to claim 1, characterized in that, The diaphragm is made of nitrile rubber.

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