To provide a combine capable of reducing a threshing load and enhancing working capacity by reducing an engine load.SOLUTION: A combine comprises dust feeding adjustment means (18) for adjusting threshing processing objects including waste straw or dust generated by receiving action of a thresh (15) in a threshing chamber (14) between a state for promoting transfer of the threshing processing objects to a rear side of the threshing chamber 14 and a state for applying resistance to transfer of the threshing processing objects to the rear side of the threshing chamber (14). The combine further comprises control means for increasing transport speed of a feed chain (8) of a threshing part (7) due to high load on an engine, and adjusting the dust feeding adjustment means (18) to a side for promoting transfer to the rear side of the threshing chamber (14) in reaping and threshing works with low speed. When any of transport speed of the feed chain (8) and layer thickness of transported grain culm is not detected, the dust feeding adjustment means (18) is actuated by a constant amount to a direction for decreasing transfer speed to a rear side of the threshing chamber (14).SELECTED DRAWING: Figure 6【課題】脱穀負荷を低減し、エンジン負荷の低減によって作業能率を高める。【解決手段】扱室（１４）内で扱胴（１５）の作用を受けて発生する藁屑などの塵埃や穀粒を含む脱穀処理物に対して、扱室（１４）後方への移送を促進する状態と、扱室（１４）後方への移送に抵抗を掛ける状態とに調節可能な送塵調節手段（１８）を備えたコンバインにおいて、低速での刈取脱穀作業時に、エンジンの高負荷に起因して脱穀部（７）のフィードチェン（８）の搬送速度を速くし、かつ、送塵調節手段（１８）を扱室（１４）後方への移送を促進する側に調節する制御手段を設ける。また、フィードチェン（８）の搬送速度と搬送穀稈の層厚のいずれかが検出されない場合には、送塵調節手段（１８）を扱室（１４）後方への移送速度を遅くする方向に一定量作動させる構成とする。【選択図】図６
