| 摘要 |
PURPOSE:To automatically control both locus and angle of an bucket by using only one expensive flow control valve by providing an arithmetic unit to output a signal by which the flow control valve is controlled so as to keep the angle of the bucket at a given value to an oil-pressure circuit. CONSTITUTION:A switch 37 is turned OFF, switch valves 11 and 13 are manually operated, and a boom 2 and a bucket 4 are manually operated regardless of the signal X. When the switch 37 is turned ON, the switch valve 13 is set at a pressing position, and the arm 3 is moved upwards in a rocking manner, the signal X of a control mode selective signal generator 34 becomes the first state, the flow control valve 30 is controlled according to a control signal I3, the boom 2 is operated according to the signal I3, and the locus of the tip of the arm 3 is made horizontal. When the switch 37 is turned ON, the switch valve 11 is set to a boom-raising position, and the boom 2 is moved downwards, the signal X becomes the second state, the flow control valve 30 is opened in compliance with a control signal I4, and the bucket 4 is turned upwards at all times. |
