An object of the present invention is to accurately determine the yield of grains. A threshing device for threshing a harvested crop, a grain tank for transporting and storing threshed grains by the threshing device, and a flow rate of grain transported for the grain tank during a harvesting operation. Is provided with a flow sensor 20, which detects with time the vibration transmitted to the flow sensor 20 during the harvesting work, and a control unit 73 which calculates the flow rate based on the value of the vibration. [Selection diagram] Fig. 5【課題】精度よく穀粒の収量を求めることを目的とする。【解決手段】収穫された作物を脱穀する脱穀装置と、脱穀装置で脱穀された穀粒が搬送されて貯留される穀粒タンクと、収穫作業中に穀粒タンクに搬送される穀粒の流量を経時的に検出する流量センサ２０と、収穫作業中に流量センサ２０に伝わる振動を経時的に検出する振動センサ１９と、振動の値に基づいて流量を演算する制御部７３とを備える。【選択図】図５
