| 摘要 |
PURPOSE:To improve the responsiveness of a pneumatic batch controller by providing a batch unit within a reset circuit to give a differential operation to an internal valve by the minimum necessary pressure and the real reset pressure. CONSTITUTION:A balance mechanism 10 consists of bellows 12-15 set opposite to each other at each terminal of a beam 11 whose medium position is supported rotatably at a fulcrum 18. A batch unit 20 contains two valve chests 22 and 23 divided by a wall 21. The 1st chest 22 is connected to a pressure source Psup via a pressure dividing circuit 30 consisting of throttle elements 31 and 32. The 2nd chest 23 accepts the meter pressure Pout and is also connected to a reset circuit. These two valve rooms are connected to each other by a communication hole 25 which is controlled by a plug 24. A drive part contains a batch pressure setting control screw 26 and a coil spring 27 at one side and a pressure room 29 at the other side as a reset pressure introduction part centering on a diaphragm 28. A reset mechanism 40 consists of a variable throttle valve 41 and a volume tank 42 and supplies the produced reset pressure to the bellows 15 as the positive feedback pressure. |
