HYDRAULIC DEVICE FOR CONSTRUCTION MACHINE

摘要

Disclosed is an invention relating to a hydraulic device for a construction machine, comprising: a boom joining control valve provided between a first hydraulic pump and a hydraulic cylinder for a work device and controlling the joining flow supplied to a boom cylinder during spool conversion; a boom control valve provided between a second hydraulic pump and the boom cylinder and controlling the movement of the boom; a controller electrically connected to an operation lever and outputting a preset control signal at the time of boom-down operation; and a boom-down acceleration control valve outputting pilot signal pressure for converting the spools of the boom joining control valve and the boom control valve during a boom-down operation of the operation lever such that a valve opening amount is controlled according to the control signal applied from the controller.