PROBLEM TO BE SOLVED: To provide a simple structure riding type farm implement having a monocyclic driving wheel, which can ensure straightness on works and can improve steering performance.SOLUTION: The riding type paddy field furrow opener comprises the monocyclic driving wheel, a body frame for supporting the driving wheel, and a furrow opening blade 40 disposed on the body frame. The furrow opening blade 40 has an upper attaching member 49 fixed to the body frame, and a lower attaching member 48 fixed to the upper side of the front end portion of the furrow opening blade 40. The lower attaching member 48 is attached to the upper attaching member 49 in a state capable of being axially freely moved and rotated in the longitudinal travel direction. By the biasing forces of coil springs 57, 57, movements from a neutral position in a state that the upper attaching member 49 and the lower attaching member 48 are approximately arranged within a plane are limited. When the lower attaching member 48 is moved from the neutral position, the biasing forces of the coil springs 57, 57 act to return the lower attaching member 48 to the neutral position.COPYRIGHT: (C)2010,JPO&INPIT【課題】一輪の駆動用車輪を有する簡易な構造の乗用型農作業機において、作業時の直進性を確保するとともに操舵性能を向上できる乗用型農作業機を提供する。【解決手段】乗用型水田溝切り機は、1輪の駆動用車輪と、駆動用車輪に支持される本体フレームと、本体フレームに設けられた溝切り刃40とを備える。溝切り刃40は、本体フレームに固定された上取付部材49と、溝切り刃40の前端部上面側に固定される下取付部材48を有する。上取付部材49に下取付部材48が進行方向である前後方向に沿った軸回りに回転移動自在に取り付けられている。コイルスプリング57,57の付勢力により、上取付部材49と下取付部材48とが一つの平面内にほぼ配置された状態の中立位置からの移動が制限される。中立位置から下取付部材48が移動した場合には、コイルスプリング57.57の付勢力が中立位置に戻るように作用する。【選択図】図4
