To perform reaping height control of a combine which safely perform harvest work by surely performing lift control of a before-reaping processing part even when an irregularity is present in a field.SOLUTION: A combine comprises on left and right parts of a bottom part of a before-reaping processing part 3, a left reaping height ground sensor 25L and a right reaping height ground sensor 25R, the combine is configured to input a ground height of the before-reaping processing part 3 detected by the left reaping height ground sensor 25L and the right reaping height ground sensor 25R to a reaping height controller 27 and control the lift cylinder 24 for lifting up the before-reaping processing part 3, if any of the left reaping height ground sensor 25L and right reaping height ground sensor 25R is equal to or less than or more than the reference height, and a difference of detection values of the left and right reaping height ground sensors 25L, 25R exceeds a prescribed range, the combine outputs continuous drive signals or drive signals whose frequency is higher than a prescribed level, to the lift cylinder 24, for lifting up the before-reaping processing part 3.SELECTED DRAWING: Figure 4【課題】本発明は、圃場に凹凸があっても刈取前処理部の昇降制御を確実に行って安全に収穫作業が行えるコンバインの刈高さ制御を行うことが課題である。【解決手段】刈取前処理部３の左右底部に左刈高さ接地センサ２５Ｌと右刈高さ接地センサ２５Ｒを設け、左刈高さ接地センサ２５Ｌおよび右刈高さ接地センサ２５Ｒで検出する刈取前処理部３の地上高を刈高さ制御装置２７に入力し昇降シリンダ２４を制御して刈取前処理部３を昇降するコンバインにおいて、左刈高さ接地センサ２５Ｌおよび右刈高さ接地センサ２５Ｒのいずれかが基準高さ以下或いは以上を検出しかつ左刈高さ接地センサ２５Ｌおよび右刈高さ接地センサ２５Ｒの検出値の違いが所定範囲を超えた場合に、昇降シリンダ２４に連続的な或いは頻度が所定レベルより高い駆動信号を出力して刈取前処理部３を昇降させるコンバインとする。【選択図】図４
