PRESSURE CONTROL DEVICE FOR EXTRUSION MOLDING MACHINE

摘要

PURPOSE:To obtain a stable molding by preventing a sudden change in operation quantity even when manual operation is changed over to automatic operation in an extrusion molding machine. CONSTITUTION:An objective value changeover part 23 stores the newest measured value PV and an objective value setting part 27 sets the objective value of the resin pressure of an extruder and a subtraction part 25 outputs the deviation of the objective value of the objective value setting part 27 and the measured value while a control operation part 29 operates operation quantity from the deviation. A manual operation setting part 33 inputs and sets the operation quantity operating the resin pressure of the extruder manually from the outside and a changeover part 31 changes over the operation quantity from the control operation part 29 and the operation quantity from the manual operation setting part 33 to output a signal to the extruder and outputs a changeover signal at the time of the changeover from automatic operation to manual operation and the objective value changeover part 23 sets the newest measured value to the objective value setting part 27 as an objective value on the basis of the changeover signal.