| 摘要 |
<p>A control circuit for controlling either the position and the speed of travel of a press table or the hydraulic pressure acting on the press table, or both, in a hydraulic press, in particular a press for wood-based boards, comprising an actual-value transmitter for the position of the press table, a pressure transmitter for the hydraulic pressure in the hydraulic press cylinder, a set point transmitter, and a control valve, actuated by the deviation of the actual value from the set point value, for the hydraulic cylinder by means of which the press table is moved. In order to produce a simple and inexpensive control circuit compared with conventional control circuits, in which the control valve is a complicated and expensive servo valve, the control valve is a pressure controlling proportional valve and the circuit can be designed to provide an arbitrary, e.g. rectilinear, control curve-with the position of the press table as a function of the time-during at least the high-pressure part of the closing sequence of the press.</p> |
