CONTROL SYSTEM FOR A HYDRAULIC CIRCUIT INCLUDING A PLURALITY OF PARALLEL VARIABLE-DELIVERY PUMPS

摘要

A hydraulic circuit includes a plurality of parallel variable-delivery pumps (11-14) for supplying pressure fluid to an appliance such as an extrusion press (60). A control system is provided to optimize the operation of the pumps. This system utilizes a sensor which senses the quantity of fluid demanded by the appliance and a controller provides control signals which vary in accordance with the sensor function. These control signals in turn control solenoid valves (41-44) and regulators (31-34) which control the individual pumps in accordance with the demanded fluid.