| 摘要 |
PURPOSE: A hydraulic circuit of construction equipment is provided to increase a lifting speed for a boom by efficiently using first, second, third pumps supplying hydraulic oil to three system circuits when lifting the boom. CONSTITUTION: A hydraulic circuit of construction equipment comprises a first unload path(12) connected to a first pump, a first system circuit, a second unload path(13) connected to a second pump, a third unload path(29) connected to a third pump, and a third system circuit. The first system circuit is connected to the first unload path and has a direction changing valve(4x) for a boom supplying hydraulic oil to an actuator(57) for the boom. A second system circuit is connected to the second unload path and has a direction changing valve(5y) for an arm supplying the hydraulic oil to an actuator(58) for the arm. The third system circuit is connected to the third unload path and has a direction changing valve(6w) for rotation supplying the hydraulic oil to an actuator(61) for rotation. [Reference numerals] (AA) Third system circuit; (BB) Second system circuit; (CC) First system circuit |
