| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hydraulic circuit for construction equipment reducing energy consumption with simple operation required for straight driving. SOLUTION: In this hydraulic circuit for the construction equipment wherein a directional control valve controlling an actuator is connected to the output oil passage of a hydraulic pump and the lower stream of the directional control valve is connected to an oil tank, an unloading directional control valve is provided in the upper stream of the directional control valve, a first port of the output side of the unloading directional control valve is connected to the upper stream of the directional control valve, and a second port thereof is directly connected to the oil tank. When an unloading signal is impressed in a pilot port, the second port is selected and when a loading signal is impressed therein, the first port is selected except when all the directional control valves are in a neutral state.</p> |
