| 摘要 |
PURPOSE:To make the device respond accurately even when an excessive output occurs by leading reset pressure formed by a resetting mechanism into a batch unit and operating a plug member in the unit differentially by the pressure and batch force. CONSTITUTION:Set pressure SP, process pressure PV and positive and negative feedback pressure PF, NF are led to bellows 12-15 and a lever 11 is supported by a fulcrum 18, and a deviation is detected 16 and amplified 17. A batch unit 20 has an entrance chamber 21 and an exit chamber 22 of amplified output POUT and has a driving section in the upper part making a wall 23 a boundary. A screw for setting batch pressure 27 and a coil spring 28 are provided in the driving section and a pressure chamber 30 to which reset pressure is led are provided with a diaphragm between. A communicated hole 26 is opened and closed by a plug 24 by vertical movement of the diaphragm 29. Pressure of the pressure chamber 30 is transmitted to the bellows 15 to open and close the plug 24, and at the same time, to operate a resetting mechanism 40. Thus, accurate response can be made even when excessive pressure is generated. |
