PROBLEM TO BE SOLVED: To provide a structure that is simple and reduced in the number of parts in an electric height adjustment mechanism of a leveling device, while preventing breakage by the sharp push-up to the leveling device.SOLUTION: A rice planting machine includes a leveling device, a support link mechanism for supporting the leveling device in a vertically movable manner, and height-adjusting means for adjusting the height of the leveling device by an electric motor. The height-adjusting means includes an electric drive source, a turning member turned by the drive of the electric drive source, and a supported member supported from the lower part by the turning member and vertically moving the leveling device through the support link mechanism with the turning by the turning member. The movement of the supported member to the upper part is permitted while the supported member is supported by the turning member.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2018,JPO&INPIT【課題】整地装置の電動式高さ調節機構において、整地装置への急激な突き上げによる破損を防止しつつ、シンプルかつ部品点数の少ない構造を提供する。【解決手段】整地装置と、前記整地装置を上下動可能に支持する支持リンク機構と、前記整地装置の高さを電動で調節する高さ調節装置とを備える田植機において、前記高さ調節装置は、電動駆動源と、前記電動駆動源の駆動によって回動される回動部材と、前記回動部材によって下方から支持されるとともに、当該回動部材による回動に伴って前記支持リンク機構を介して前記整地装置を上下動する被支持部材と、を備え、前記回動部材によって前記被支持部材が支持されている状態で、前記被支持部材の上方への移動が許容されている。【選択図】図5
