HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE INCLUDING EMERGENCY CONTROL UNIT FOR ELECTRIC HYDRAULIC PUMP

摘要

The present invention relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily driving the construction machine when an electronic control unit controlling the electric hydraulic pumps fails to operate. To this end, disclosed is the hydraulic system including the electric hydraulic pump, the electric control unit for controlling the electric hydraulic pump, and the emergency control unit, which operates when the electric control unit fails to operate, so as to temporarily control the electric hydraulic pump in accordance with to a predetermined condition, which can effectively respond to a low load work corresponding to predetermined pressure (P1) and to a high load work corresponding to higher pressure (P2), by selectively operating the emergency control unit according to different optional conditions, based on the amount of load (low load, high load) of the working machine that is required when the electric control unit fails to operate.