Patent ID: 8649944

Claim:
A blade control system, comprising: a lift frame vertically pivotably attached to a vehicle body; a blade attached to a tip of the lift frame; a lift cylinder configured to vertically drive the lift frame; a control valve configured to supply hydraulic oil to the lift cylinder; a blade angle calculating part configured to calculate sum of a forwardly tilting angle of the vehicle body with respect to a reference surface and a blade lifting angle of the lift frame with respect to a reference position; a difference angle calculating part configured to calculate a difference angle by subtracting a predetermined angle from the sum of the forwardly tilting angle and the blade lifting angle; an opening ratio setting part configured to set an opening ratio of the control valve based on the difference angle; and a lift controlling part configured to control the control valve in accordance with the opening ratio set by the opening ratio setting part until a predetermined period of time is elapsed from an onset of dozing by the blade.