FIELD: injector unit for casting machine for processing of thermoplastic material. SUBSTANCE: injector unit has one cylinder, screw conveyer and a screw conveyer drive consisting of two electric motors. One of the electric motors is intended for accomplishing rotary motion, and the other - for accomplishing axial movement of the screw conveyer. The axes of both electric motors are aligned with the axis of the screw conveyer. At least one electric motor is a motor with a hollow shaft. A feed screw nut engaged with a lead screw is fastened in the first motor with a hollow shaft. The frame of the first motor with a hollow shaft is attached to the body, in which the screw conveyer cylinder is installed. One end of the lead screw is connected to the screw conveyer. Drive journal passes through the lead screw on the other end, with its axial grooves the journal is engaged with the respective axial grooves inside the lead screw. The drive journal is connected to the hollow shaft of the second motor. The lead screw has an internal cylinder filled with pressure fluid, a piston located at the end of the drive journal passes in the cylinder. A duct running outside passes through the piston and drive journal, through this duct pressure fluid can flow through proportional pressure control valve into tank at a backpressure load acting on the screw conveyer. At motion of the screw conveyer in the opposite direction hydraulic oil from the tank is sucked in back through a straight-through valve. EFFECT: simplified design so as no electric control of the electric motor accomplishing axial movement of the screw conveyer is required for maintaining the back-pressure. 5 cl, 2 dwg
Authors
Dates
1999-04-20—Published
1994-12-21—Filed