Hydraulic operating system for plastics processing machines, especially

Abstract

A hydraulic operating system for plastic processing machines, especially for injection molding machines, comprises a hydraulic pump (1), which is driven by an electric motor (2), at least one hydraulic drive (3, 4, 5), a hydraulic line network (6), which connects the hydraulic pump (1) and the hydraulic drives (3, 4, 5), and a machine control (7), in which the hydraulic pump (1) is designed a continuous or constant transport pump and the electric motor (2) is operated at a variable rpm, being appropriately influenced by the machine control (7). So as to be able to dispense with an expensive pressure regulated valve, and thus to provide an economical injection molding machine, the invention specifies that the machine control (7) prescribes the current hydraulic volume (Q) that is needed according to program to the electric motor (2) as an rpm setpoint (n) and prescribes the current hydraulic pressure (p) that is needed according to program to the electric motor (2) as a torque setpoint (M), in which connection the electric setpoint data for the rpm (n) and the torque (M) and respectively for the hydraulic volume flow (Q) and for the hydraulic pressure (p) are stored in a memory (8), to which the machine control (7) has access.