PROBLEM TO BE SOLVED: To automatically drive a work vehicle 1 loaded with consumer goods such as fertilizers and seedlings which influence the amount of change in the traveling direction S when the front wheels 2 are steered to change the traveling direction S of the working vehicle. Automatic steering of a work vehicle that can perform stable work driving while appropriately setting the steering amount of the front wheels 2 when traveling along the travel target route by the steering device and reducing unworked areas and overlapping work areas. Provide the device. SOLUTION: An automatic steering device sets a steering amount of a front wheel 2 when the front wheel 2 is steered with respect to a deviation from a travel target path of a work vehicle 1 to travel along a predetermined travel target path. or shared load W F applied to the front wheels 2 and rear wheels 3 is adjusted in accordance with the W R. [Selection diagram] Fig. 5【課題】前輪２を操舵して作業車輌の進行方向Ｓの変更を行う場合に、その進行方向Ｓの変更量に影響力を及ぼす肥料や苗等の消費財を積載する作業車輌１を、自動操舵装置によって走行目標経路に沿って走行させる際の前輪２の操舵量を適正に設定して、未作業領域や重複作業領域を減らしながら、安定した作業走行を行うことができる作業車輌の自動操舵装置を提供する。【解決手段】自動操舵装置は、作業車輌１の走行目標経路からの偏差に対して前輪２を操舵して予め定めた走行目標経路に沿って走行させる際の前輪２の操舵量を、前輪２又は前輪２と後輪３に加わる分担荷重ＷＦ、ＷＲに応じて調節する。【選択図】図５
