Abstract: A hydraulic circuit for construction equipment is provided, which supplements hydraulic fluid of a hydraulic pump for a cooling fan and hydraulic fluid of a main hydraulic pump and uses the supplemented hydraulic fluid as a hydraulic source of a RCV in order to supply signal pressure to a control valve that controls the driving of a hydraulic actuator.

Abstract: A hydraulic circuit for construction equipment is provided, which supplements hydraulic fluid of a hydraulic pump for a cooling fan and hydraulic fluid of a main hydraulic pump and uses the supplemented hydraulic fluid as a hydraulic source of a RCV in order to supply signal pressure to a control valve that controls the driving of a hydraulic actuator.

Abstract: Disclosed is a hydraulic system for a construction machine, which makes it possible to adjust the geometric position of a working device comprising a boom and an arm by means of a single manipulation lever, thereby enabling a leveling/flattening process to be conveniently performed. The hydraulic system includes: a working mode selection switch for selecting a leveling/flattening process; a boom driving switch valve for controlling the driving of a boom cylinder in response to a control signal from a first manipulation lever; an arm driving switch valve for controlling the driving of an arm cylinder in response to a control signal from a second manipulation lever; a shuttle valve including input parts that connect to both an electronic proportional control valve and to the first manipulation lever, respectively, and an output part connecting to the boom driving switch valve; and an electronic controller.