PROBLEM TO BE SOLVED: To provide a working machine which can properly inhibit the devastating of a paddy field in response to various circumstances while maintaining a small circular turnabout performance of the machine body.SOLUTION: This working machine comprises (1) a turnabout angle sensor (193) which detects the operation of a manipulating means, and (2) a turnabout interlocking mechanism which intermittently throws a side clutch positioned inside the manipulated direction in "ON/OFF" positions, interlocked with the operation to manipulate a front wheel from a straight running state to a steering state by a steering mechanism, and always sets the side clutch positioned inside the manipulated direction in "IN" position, interlocked with the returning of the front wheel from the steering state to the straight running state. In addition, the working machine is equipped with a control device (163) which significantly changes the ratio of the "ON" state in a period in which the intermittent "ON/OFF" throwing operation by the turnabout interlocking mechanism takes place. The change of the ratio of the "ON" is given by detecting the fact that the cultivating platen is way deep enough with the help of an installed cultivating platen depth sensor (48) which detects the depth of the cultivating platen.COPYRIGHT: (C)2011,JPO&INPIT【課題】 本発明は、機体の小回り旋回性を維持しながら、各種の状況に応じて適切に圃場が荒れるのを抑えることを課題とする。【解決手段】 操向手段の操作を検出する旋回角度センサ(193)と、ステアリング機構により前輪が直進状態から操舵状態へ操向されるのに連動して操向内側のサイドクラッチを断続的に入/切し、前輪が操舵状態から直進状態へ戻るのに連動して操向内側のサイドクラッチを常時入状態にする旋回連動機構と、耕盤の深さを検出する耕盤深さセンサ(48)を設け、耕盤が深いことを耕盤深さセンサ(48)により検出すると、旋回連動機構により断続的に入/切する周期における入状態の割合を大きく変更する制御装置(163)を備えた作業機とした。【選択図】図5
