Patent ID: 8731784
Filing Date: 2014-05-20
Classification: E02F

Abstract:
1. A blade control system, comprising: a lift frame vertically pivotably attached to a vehicle body; a blade supported by a tip of the lift frame; a lift cylinder configured to vertically pivot the lift frame; a proportional control valve connected to the lift cylinder; an angle obtaining part configured to obtain an angle of the lift frame with respect to a designed surface in a side view of the vehicle body, the designed surface formed as a three-dimensionally designed landform indicating a target contour of an object for dozing; an open ratio setting part configured to set an open ratio of the proportional control valve based on the angle; a distance calculating part configured to calculate a distance between the designed surface and a cutting edge of the blade; a determining part configured to determine whether or not the distance between the designed surface and the cutting edge of the blade is less than or equal to a threshold; a lift cylinder controlling part configured to open the proportional control valve at the open ratio set by the open ratio setting part for elevating the blade when the determining part determines that the distance between the designed surface and the cutting edge of the blade is less than or equal to the threshold:, a speed obtaining part configured to obtain a speed of the cutting edge of the blade approaching the designed surface in a direction perpendicular to the designed surface; and a threshold setting part configured to increase the threshold in proportion to magnitude of the speed.