HYDRAULIC DEVICE OF MOTOR-DRIVEN TYPE CONSTRUCTION MACHINE

摘要

PURPOSE: To reduce equipment costs of a hydraulic device by reducing capacity of a main hydraulic pump, reduce electric power consumption to drive the main hydraulic pump, and prevent heating of the hydraulic device and the degradation of operating fluid. CONSTITUTION: A hydraulic device is provided with an accumulator 12 to be connected to a main oil passage 21 through a directional control valve 11, an auxiliary hydraulic pump 5 to feed pressure oil in the accumulator 12, a motor-driven type auxiliary driving motor 6 to drive the auxiliary hydraulic pump 5 and a controller 10 to feed the pressure oil stored in the accumulator 12 to an actuator 1 by allowing the accumulator 12 to communicate with the main oil passage 21 by switching the directional control valve 11 when a load of the actuator 1 exceeds capacity of a main hydraulic pump 3.