PROBLEM TO BE SOLVED: To improve operability of a control valve in a paddy field working machine.SOLUTION: A paddy field working machine comprises: a float 12 which is liftably supported by a work device to follow in contact with the surface of a paddy field G； a lifting linkage mechanism 43, 44 which is installed across a control valve 24 and the float 12, and maintaining the work device at a prescribed height H1 from the paddy field G by operating the control valve 24 while mechanically transmitting the height of the work device with respect to the float 12 to the control valve 24； and a lifting control unit 101 which actuates, when a lifting actuator 56 capable of operating the control valve 24 and an operation tool 78 capable of being manually operated are given, the lifting actuator 56 with operations of the operation tool 78. The lifting control unit 101 actuates, when the operation tool 78 is operated into an elevated position U2, the lifting actuator 56 so that the control valve 24 is operated and maintained into the elevated working position in preference to the lifting linkage mechanism 43, 44.SELECTED DRAWING: Figure 19COPYRIGHT: (C)2020,JPO&INPIT【課題】水田作業機において、制御弁の操作性を向上させる。【解決手段】作業装置に昇降可能に支持されて田面Ｇに接地追従するフロート１２が備えられる。制御弁２４とフロート１２とに亘って設けられ、フロート１２に対する作業装置の高さを制御弁２４に機械的に伝達し制御弁２４を操作して、作業装置を田面Ｇから設定高さＨ１に維持する昇降連係機構４３，４４が備えられる。制御弁２４を操作可能な昇降アクチュエータ５６と、人為的に操作可能な操作具７８と、操作具７８の操作に基づいて昇降アクチュエータ５６を作動させる昇降制御部１０１とが備えられる。昇降制御部１０１は、操作具７８が上昇位置Ｕ２に操作されると、昇降連係機構４３，４４に優先して制御弁２４が上昇作動位置に操作されて維持されるように、昇降アクチュエータ５６を作動させる。【選択図】図１９
