高速播种机玉米姿控驱导式排种器设计与试验

针对机械式玉米排种器在播种机高速作业条件下排种精度下降且性能不稳定的问题，提出利用调姿齿与单元型孔对玉米种子充种姿态进行调控的技术思路，设计了一种姿控驱导式精量排种器，采用双侧种盘对置、单列排种结构布局，降低工作转速同时提高排种均匀性。完成了关键零部件的结构参数设计，分析了种子姿态调整原理，通过单因素试验与正交旋转组合试验获取排种器的最优参数组合，并开展排种性能对比试验。结果表明：调姿齿齿型为线型时，排种合格率提升效果最优，较无调姿齿可提升29.1个百分点；排种器的最优参数组合为：工作转速16.7r/min，型孔外壁面倾角46.9°与型孔圆角半径4.5mm，该条件下合格率、漏播率和重播率分别为91.6%、2.8%与5.6%；在作业速度8~14km/h范围内，排种器的合格率均高于90%，漏播率均低于3%，重播率均低于8%，破损率均低于0.5%，粒距均匀性变异系数均低于19%，且排种效果优于无姿态调控排种器与勺轮式排种器，满足玉米精量播种的技术要求。

Design and Test of Maize Posture Control and Driving Precision Metering Device for High-speed Seeder

Aiming at the problem that the precision and performance of maize mechanical seed-metering device was decreased and unstable when it was at high-speed sowing of the seeder. The technical idea of adjusting and controlling maize seed filling posture by using posture adjustment teeth and unit hole was put forward. A precision metering device with posture control and driving was designed. It adopted the structural layout of double sided seed discs opposed and single row seeding, so as to reduce the rotation speed and improve the uniformity of seed-metering. The structural parameters of the key components were designed. The principle of seed posture adjustment was analyzed. Through single factor test and combination test, the optimal parameters of the seed-metering device was obtained. Subsequently, the seed-metering performance comparison test were carried out. The results showed that when the type of the posture adjustment teeth was linear, the effect of improving the qualified index was the best, which can be increased by 29.1 percentage points compared with that of no posture adjustment teeth. When the rotation speed was 16.7r/min, the inclination angle of the hole outer wall was 46.9°and the fillet radius of the hole was 4.5mm, the qualified index, missed index and multiple index were 91.6%, 2.8% and 5.6%, respectively. Within the range of operating speed of 8~14km/h, the qualified index was over 90%, the miss index was below 3%, the multiples index was below 8%, the damage index was below 0.5%, and the variation coefficient of grain spacing uniformity was below 19%. Moreover, the seed-metering effect was better than that of no posture control seed-metering device and scoop type seed-metering device, which met the technical requirements of maize precision sowing.