BLADE CONTROL SYSTEM, CONSTRUCTION MACHINE, AND BLADE CONTROL METHOD

摘要

This blade control system is provided with: a blade angle calculation unit that calculates the sum of the front tilt angle of a vehicle body with respect to a reference plane and the lift angle of a lift frame with respect to a reference position; a slope angle acquisition unit that calculates the slope angle with respect to a reference plane of a set surface indicating the target shape of a subject of excavation; an angle difference calculation unit that calculates the angle difference between the blade angle and the slope angle; a first aperture setting unit that sets a first aperture of a proportional control valve on the basis of the angle difference; a blade load acquisition unit that acquires the blade load that the blade is incurring; a load difference calculation unit that calculates the load difference between the blade load and a target blade load; a second aperture setting unit that sets a second aperture of the proportional control valve on the basis of the load difference; and a lift control unit that controls the proportional control valve in accordance with the second aperture when the blade load is outside a predetermined load range, and that controls the proportional control valve in accordance with the first aperture when the blade load is within the predetermined range.