一、前言 我国南方稻麦产区在推广农业机械化过程中,广泛使用4马力手扶拖拉机为动力的割晒机。它有16把定刀和15把动刀,工作时,在一定的压力下,动刀片相对于定刀片作1600次/分切割运动,切割前进速度约为1.5米/秒,连续将稻杆切断。工作一段时间后,刀片刀口由于切割而磨薄磨钝,动定刀之间间隙增加,以致不能切割稻杆而失效报废。 I. Introduction In China’s southern rice and wheat producing areas in the promotion of agricultural mechanization, extensive use of 4 horsepower tractor powered windrower. It has 16 fixed knives and 15 moving knives, work, under certain pressure, the moving blade relative to the fixed blade for 1600 times / min cutting movement, cutting forward speed of about 1.5 m / s, the continuous cut rice stem . After working for a period of time, the cutting edge of the blade is worn and blunt, and the gap between the fixed and fixed blades is increased, so that the straw can not be cut and the scrapped is discarded.