Introduced the use of pneumatic actuators
Of pneumatic actuators also known as pneumatic devices or pneumatic executing agency commonly known as pneumatic head, execution device driver to open and close or gas pressure regulating valve. In this paper, the technical requirements of the pneumatic head elaborate. Structure 1, pneumatic devices by the cylinder, piston, gear shaft, end caps, seals, screws, etc.; sets of pneumatic devices should also include the opening direction, travel limit, solenoid valves, positioners, pneumatic components, manually institutions signal feedback and other components. 2, pneumatic and valve connection size shall conform to ISO5211 (at the bottom), the provisions of GB/T12222 and GB/T12223. With manual mechanism of pneumatic devices, manually bodies, should be used for the opening and closing operation of the valve in the gas source is interrupted, facing the hand wheel, hand wheel or handle counterclockwise rotation of the valve to open and clockwise to valve off. 4, the piston rod end is within the external thread when applicable, should be standard wrench wrench mouth. 5, the piston seals should be easy to replace and repair. 6, with the buffer mechanism of the pneumatic device, the stroke length of its buffer mechanism can refer to the provisions of "Table 1". With adjustable buffer institutions pneumatic device, should the cylinder external adjust its buffer institutions. 8 cylinder out of the air inlet thread size should to meet the MANUR NORM (Annex standard) GB/T7306.1 GB/T7306.2 GB/T7307 provisions. Performance pneumatic devices rated output force or torque should be consistent with the provisions of GB/T12222 and GB/T12223 2, in the no-load case, enter the cylinder according to Table 2 under air pressure, its actions should be smooth, no jamming and crawling phenomenon. 0.6MPa air pressure, pneumatic devices Kai closed in both directions of the output torque or thrust, its value should not be less than the values indicated by the pneumatic device signs, and action should be flexible, not allowed nuyd_5 parts appear permanent deformation and other anomalies. 4, the seal test to be tested with a maximum working pressure, the amount of air leaking from the side of the respective back pressure must not exceed (3 +0.15 D) cm3/min (standard state); leak out from the end cap, at an output shaft The amount of air allowed to exceed (3 +0.15 d) cm3/min. Strength test with a maximum working pressure of 1.5 times the test, and maintain the test pressure 3min after its cylinder end cap and the site does not allow static seal leakage and structural deformation. 6, the operation life count, a pneumatic device analog valve operation in the case of maintaining the output of the two directions of the torque or thrust capability, the opening and closing operation of the opening and closing times should be not less than 50000 times (Kai - Closed cycle was once). 7, with a buffer mechanism of the pneumatic device, and is not permitted when the piston moves to the end of stroke position, the impact phenomenon appears. The quality of the surface and the appearance of a casting cylinder end cap, end flange on the box may not have scratches, cuts, holes, burrs, etc.. Pneumatic device layer of the outer surface of the paint layer or chemical treatment should be flat, smooth, uniform color, no oil, dents and other mechanical damage.
The pneumatic head test method
Test Method no-load test, a pneumatic device placed horizontally and alternately applied to the cylinder on both sides of the "Table 2" a predetermined pressure, the exhaust-side open to the atmosphere, so that the pneumatic means for switching operation. The test results shall comply with the provisions of (performance).
2 cylinder with a buffering mechanism, making the no-load test, the cushion valve should be fully open. Strength test using 70% kerosene and 30% mixed oil of the spindle oil or compressed air as a medium, at 1.5 times the maximum cylinder pressure (allowing the use of the highest pressure value), alternately applying pressure to the cylinder, and maintaining the pressure 3min after observation cylinder appearance and the disintegration of the check, the results should be in line with the provisions of (performance). Air test must take safety precautions. Load test pneumatic devices installed on the test stand, 0.6MPa pressure of the compressed air is applied to the cylinder, is gradually applied to the output shaft torque or thrust, this time the amount of torque or thrust of the the pneumatic device's output, its value is not less than a pneumatic device signs, the predetermined value. Checked one by one manually institutions, opening direction travel limit, feedback, and other components at the same time, the results should be consistent with the provisions of (performance). The seal test pneumatic devices in the no-load case from the two air intakes are alternately applied to 1.1 times the maximum working pressure of compressed air, check the piston, the output shaft at the amount of leakage. Holding pressure 3min, the amount of leakage should be consistent with the provisions of (performance). Seal test, another test method: check the pressure gauge indicates pressure for 5 min, gauge pressure is not reduced to a qualified. Choose one of two methods. Action life Views test the pneumatic device is mounted on the bench, in the rated output torque of the load, the analog driving the valve for opening and closing action process cycle operation, until the pneumatic device output torque or thrust is less than a predetermined rated torque or thrust, then the number of operations is life times. The number of fume hoods action life should be consistent with the provisions of (performance).
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