HYDRAULIC CONTROL DEVICE FOR EXTRUDERS USED FOR CASTING AND PLASTIC WORKING OF RUBBER

摘要

Disclosed is a hydraulically controlled extruder injection molding unit which includes a measured value pick-up for the position of the piston rod of the working cylinder and/or of the injection piston. A pressure control valve which can be switched on is provided in the line leading to the surge chamber of the working cylinder for the piston. A proportionally controlled pressure valve is provided in the line to the other surge chamber, the value being controlled as a function of dropping control values when switching from subsequent pressure to dynamic pressure until the measured value pick-up emits an output signal. The then existing instantaneous value of the dynamic pressure is then added to the preselected dynamic pressure. Consequently, the dynamic pressure phase takes place under a corrected dynamic pressure.