JPS55119837A - Straight digging control device for working machine - Google Patents

Abstract

PURPOSE:To simplify the constitution of a controlling system without lowering the accuracy of finish by a device wherein a boom alone is automatically controlled by the operation of an arm, while a bucket being manually controlled for the correction of the angle thereof. CONSTITUTION:An operating circuit 61 for the angle of the blade-edge of a bucket determines an angle phi based on the angles of boom, arm and bucket detected. A register 62 stores the detected value of the angle phi0 of the blade-edge of the bucket on starting digging. A comparator 65 compares the angle phi of the bucket with the angles phi0+DELTAphi and phi0-DELTAphi which are limits of the allowable area and, when the angle is expressed as phi0-DELTAphi<phi<phi0+DELTAphi, no signal is delivered to either of output lines l1 and l2, on the basis that the angle is within the allowable range. When the angle of the bucket exceeds the upper or lower limit of the allowable value, a signal is delivered and lamps 66 and 67 are connected to the lines l1 and l2, so as to give information to an operator by lighting. The lighting of the lamp 66 is to instruct to rotate the bucket 3 toward the direction of damping, while that of the lamp 67 instructs toward the direction of tilting, and thereby a manual operation is conducted until the lighting is out.