Device for controlling the position of a hydraulic advancing drive, in particular a hydraulic press or punch

摘要

The cylinder-piston arrangement of a hydraulic press or punch is described by the series connection of a PT2 element (6) and an integral element (5) which together constitute a controlled system (S) which is assigned the volume flow (q) of the hydraulic fluid as an input variable and the position (x) of the press or punch as an output variable. The controlled system (S) has connected upstream of it a technically extremely uncomplicated PT1 element as actuating element (SG) which has a corner frequency which is lower than the corner frequency of the PT2 element (6) of the controlled system (S). As a result, an uncritical position control can be achieved by means of a customary controller (R1). In order, nevertheless, to ensure a high control quality, a model (M) of the fault-free control circuit (RK) is provided whose reference position (xM) is compared with the actual position (x), the resulting difference correcting the input signal for the actuating element (SG) by means of an integrator (R2). <IMAGE>