PROBLEM TO BE SOLVED: To increase the efficiency in collecting grains by sufficiently removing free grains over rack within a free grain over rack collection chamber.SOLUTION: A dust outlet communicating with the outside of a threshing chamber is opened at the terminal end of the threshing chamber in which a threshing drum is mounted, and the free grain over rack collection chamber for collecting free grains over rack stuck into grain culms after threshing is formed at a position in the rear of the dust outlet. A No.4 threshing drum 11 having a shaft core on a backward extension line of the axis of the threshing drum which journals the threshing drum is disposed inside the free grain over rack collection chamber to be rotationally driven together with the threshing drum, and a backing plate 16 which receives and supports roots of the grain culms is oppositely disposed below the No.4 threshing drum 11. An open space K which is opened downward is formed in a region of the backing plate 16 through which tips of the grain culms pass.COPYRIGHT: (C)2012,JPO&INPIT【課題】刺さり粒回収室内での刺さり粒の除去を十分に行い穀粒の回収効率を高める。【解決手段】扱胴を内装した扱室の終端に該扱室の外部へ連通する排塵口を開口し、該排塵口よりも後方の位置に脱穀後の穀稈に刺さり込んだ刺さり粒を回収する刺さり粒回収室を形成し、該刺さり粒回収室の内部には扱胴を軸支する扱胴軸の後方延長線上に軸芯を有し該扱胴と一体で回転駆動される4番処理胴11を設け、該4番処理胴11の下方に穀稈の株元側を下から受けて支持する受け板16を対向配置すると共に、該受け板16の穀稈穂先側が通過する部位には下方に向けて開放する開放空間Kを形成する。【選択図】図3
