HIGH PRECISION PRESSURE CONTROL SYSTEM EMPLOYING HYDRAULIC VOLUME CONTROLLER

摘要

The high-precision pressure control device using the hydraulic volume control method of the present invention is to supply the pressurized fluid from the reservoir 10 to the working cylinder 14 as the actuator by the pump 12 driven by the motor 11, the working fluid One or more pressurized fluid volume controllers 39 are connected to the supply conduit 13.;The pipeline 13 for supplying the pressurized fluid to the operation cylinder 14 by the pump 12 is provided with a proportional valve or a servovalve 37 via the check valve 16 and thereafter an on / off valve. The on / off valve 15 is opened for initial pressure control and the pressure is controlled to 90% to 99% of the target pressure with the proportional valve or the servovalve 37. At this time, the volume controller 39 is not operating. When the pressure of the cylinder 14 reaches 90% to 99% of the target value, the on / off valve 15 is closed and the cylinder 14 and the on / off The off valves remain closed. In such a closed state, the volume controller 39 operates to precisely control the pressure of the cylinder to a target value, thereby inaccuracy due to a change in the working pressure in a predetermined band generated when the pressure is controlled by adjusting the working fluid using a conventional servo valve. Since the problem is eliminated, there is an advantage that it is possible to efficiently and easily perform precise inspection and calibration of the pressure sensor and the load sensor or the pressure retention test of the pressure vessel, the valve and the pipe.