| 摘要 |
The present invention is capable of reducing the cost of a direction-switching valve (a third direction-switching valve), despite having a configuration whereby oil is supplied from two pumps to one actuator (a third actuator). A hydraulic circuit (30) for construction machinery comprises: a first unloading passage (31) connected to a first pump (11); a second unloading passage (32) connected to a second pump (12); a first supply passage (41) connected to the first pump (11); a second supply passage (42) connected to the second pump (12); a third supply passage (43); and third direction-switching valves (53E, 53F). The third supply passage (43) is connected to the first supply passage (41) and the second supply passage (42). The third direction-switching valves (53E, 53F) are connected to the third supply passage (43), the first unloading passage (31), the second unloading passage (32), and a tank passage (35), and supply and discharge oil to/from the third actuators (23E, 23F). |
