| 摘要 |
PURPOSE:To effect united operation and speed-up of a plural number of actuators such as cylinders and motors, by employment of a plural number of hydraulic pumps with which a plural number of logical valves are combined. CONSTITUTION:The diagram shows an application to a hydraulic circuit of a crawler excavator. As for united operation, even when pressurized fluid from the 2nd pump P2 is cut off by operating a left traveling selector valve 9, pressurized fluid from the 3rd pump P3 is delivered to an arm selector valve 17 and the 2nd boom selector valve 18 to keep this circuit activated. When a right traveling selector valve 8 is operated, a logical valve is shut by activation of a shut-off valve 7 to that pressurized fluid from the 2nd and 3rd pumps flows into the upstream side of a bucket selector valve 10 and is supplied also to the boom selector valve. As for speed-up, when a selector valve for speed-up 26 is operated with valves 8, 9 operated, pressurized fluid from the 3rd pump P3 is supplied with divided flow through a logical valve 14 to pipes 4, 5. Therefore, speed-up can be made as much as the additional divided flow is supplied. |
