OIL-PRESSURE CIRCUIT FOR OIL-PRESSURE TYPE WORKING MACHINE

摘要

PURPOSE:To enhance the efficiency of operations by a method in which a cylinder to open or close a bucket and a bucket cylinder to tilt and dump the bucket are provided, and the dumping operation is made in an interlocking manner with the opening operation of the bucket. CONSTITUTION:A pilot pipeline 9b between an operating valve 13 for opening and closing a bucket and a flow rate regulating valve 19 is connected with a pilot pipeline 10b between a check valve 20 and a switch valve 17 by a pipeline 9c. Pressure oil from the pipeline 10b to the pipeline 9b is interrupted by the check valve 18. When opening the bucket 6 by operating the valve 13, pressure oil is flowed into the pipeline 10b to automatically switch the pilot switch valve 10, and a bucket cylinder 7 is contracted for dumping operation of the bucket 6. The loss of soil when discharging soil in the bucket 6 to a truck can thus be eliminated and cycle time can be shortened for enhancing the efficiency of operations.