PROBLEM TO BE SOLVED: To provide a control portion structure of a riding type working machine, in which a maintenance work performed in a state that the upper portion of the engine of the riding type working machine is opened can easily be opened and operated in a relatively simple constitution.SOLUTION: This control portion structure of the riding type working machine is characterized by pivotally supporting one end of the first support arm 6 on the first vertical shaft 9 disposed on a machine frame 8 at the rear laterally central position of an operation frame 5, pivotally supporting the other end on the second vertical shaft 10 disposed on the left front side of the operation frame 5, pivotally supporting one end of the second support arm 7 on the third vertical shaft 11 disposed on the machine frame 8 on the right side of the first vertical shaft 9, and pivotally supporting the other end on the fourth vertical shaft 12 disposed at the approximately lateral center of the operation frame 5 on the right side of the second vertical shaft 10, and pulling out to the first opened position A in which the operation frame 5 is pulled out in the side direction in a state that a grain tank 21 is fixed to a normal position on the machine frame, or to the second opened position B in which the grain tank 21 is moved in the side direction, and the operation frame 5 is then further largely moved in the side direction.COPYRIGHT: (C)2010,JPO&INPIT【課題】乗用型作業機のエンジンの上部を開放して行なうメンテナンス作業を、比較的簡単な構成で楽に開放操作できるようにする。【解決手段】第一支持アーム6の一端を操作部フレーム5の後部左右略中央位置で機体フレーム8に設ける第一縦軸9で枢支し他端を操作部フレーム5の左前側に設ける第二縦軸10で枢支し、第二支持アーム7の一端を第一縦軸9の右側で機体フレーム8に設ける第三縦軸11で枢支し他端を第二縦軸10の右側で操作部フレーム5の略左右中央に設ける第四縦軸12で枢支し、グレンタンク21を機体上の正規位置に固定したままで操作部フレーム5を側方へ引き出す第一開放位置Aと、グレンタンク21を側方へ移動した後に操作部フレーム5をさらに大きく側方へ移動する第二開放位置Bまで引き出し可能に構成する。【選択図】図4
