气动切断阀实现三位控制的探讨

对如何实现气动切断阀完全切断、50％开阀及全开的三位控制进行了探讨。主要阐述了分别采用单作用和双作用两种执行机构的不同气路控制方案。对于单作用执行机构方案，利用三通电磁阀来控制气路，由气动阀门定位器进行精确定位；而双作用执行机构方案则利用四通电磁阀控制气路，用力的平衡原理进行定位。比较了这两种控制方案，分析了各自的优缺点。

How to Control the 3-Stage of Pneumatic Shut-off Valve

The method of controlling the shut off,1/2 open,open stage of pneumatic shut off valve is discussed. It mainly describes the idea that the control schemes of spring return type actuator and double acting type actuator. For the spring return type actuator,the 3 way solenoid valves are used to control air loop,the p/p positioner is used for locating the position. For the double acting type actuator,the 4 way solenoid valves are used to control air loop,the principle of force balance is used for locating the position. The two control schemes are compared;the merit and defect are analyzed.