PROBLEM TO BE SOLVED: To provide a working machine which can maintain the working depth of a ground working machine at a set working depth or a depth close to the depth, while preventing the increase in the traveling load or driving load of a self-propelled vehicle.SOLUTION: This working machine is equipped with a driving mechanism for lifting or lowering a ground working device 20 connected to a self-propelled vehicle body relative to the self-propelled vehicle body, and with a connection mechanism S for linking a working depth-detecting mechanism 50 disposed in the ground working device 20 to detect the working depth of the ground working device 20 and the operation portion 30 of the driving mechanism to operate the driving mechanism so that the detected working depth of the working depth-detecting mechanism 50 becomes a set working depth. The driving mechanism is operated with the connection mechanism S in a state that the lifting amount of the ground working device 20 by the unit change of a detected working depth on the deep side with the working depth-detecting mechanism 50 is larger than the lowering amount of the ground working device 20 by the unit change of a detected working depth on the shallow side with the working depth-detecting mechanism 50.COPYRIGHT: (C)2009,JPO&INPIT【課題】 自走車の走行や駆動負荷の増大を発生しにくくしながら対地作業装置による作業深さを設定作業深さ又はそれに近い深さに維持することができる作業機を提供する。【解決手段】 自走車体に連結された対地作業装置20を自走車体に対して昇降操作する駆動機構と、対地作業装置20の作業深さを検出するよう対地作業装置20に設けられた作業深さ検出機構50と駆動機構の操作部30とを連係させて、作業深さ検出機構50による検出作業深さが設定作業深さになるよう駆動機構を操作させる連係機構Sを備えてある。作業深さ検出機構50による検出作業深さが深い側に単位変化量を変化することによって対地作業装置20が上昇する上昇変位量が、作業深さ検出機構50による検出作業深さが浅い側に前記単位変化量を変化することによって対地作業装置20が下降する下降変位量よりも大になる状態で、連係機構Sが駆動機構を操作させるよう構成してある。【選択図】 図6
