PROBLEM TO BE SOLVED: To prevent a useless longitudinal inclination motion due to acceleration change and a vibration of a machine body, and thereby improve stability and control accuracy of longitudinal inclination automatic control.SOLUTION: A combine 1 includes a longitudinal inclination sensor 25 for detecting the longitudinal inclination of a machine body 2, a hydraulic cylinder 21 for longitudinal inclination to incline back and forth the machine body 2, and a control unit 23 for automatically controlling the hydraulic cylinder 21 for the longitudinal inclination so that a detection value of the longitudinal inclination sensor 25 may maintain a predetermined neutralization value. The control unit 23 includes longitudinal horizontal automatic control means (step S24 shown in Fig. 11) for automatically controlling the hydraulic cylinder 21 for the longitudinal inclination in order to return the detection value to the neutral value side when the deviation of the detection value to the neutral value exceeds an insensitive area, and dead band change means (step S17 shown in Fig. 11) for changing the insensitive area according to the vehicle speed of the machine body 2. The dead band change means increases the insensitive area as a vehicle speed becomes fast, and the sensitivity of the longitudinal horizontal automatic control means is reduced.SELECTED DRAWING: Figure 11COPYRIGHT: (C)2017,JPO&INPIT【課題】機体の加速度変化や振動に起因する無駄な前後傾斜動作を抑制し、前後傾斜自動制御の安定性や制御精度を向上させる。【解決手段】機体2の前後傾斜を検出する前後傾斜センサ25と、機体2を前後傾斜させる前後傾斜用油圧シリンダ21と、前後傾斜センサ25の検出値が所定の中立値を維持するように前後傾斜用油圧シリンダ21を自動制御する制御部23と、を備えるコンバイン1であって、制御部23は、前記中立値に対する前記検出値の偏差が不感帯を超えたとき、前記検出値を前記中立値側に戻すべく前後傾斜用油圧シリンダ21を自動制御する前後水平自動制御手段(図11のステップS24)と、機体2の車速に応じて前記不感帯を変更する不感帯変更手段(図11のステップS17)と、を備え、不感帯変更手段が、車速が速くなるほど前記不感帯を大きくして前後水平自動制御手段の感度を鈍くする。【選択図】図11
