纵轴流双柔性碾搓式谷子脱粒装置设计与试验

针对谷子机械收获过程中谷码率高、破损率高、未脱净损失率高的问题，设计了一种纵轴流双柔性碾搓式谷子脱粒装置。该装置采用纵轴流脱粒滚筒，脱粒滚筒上通过安装柔性橡胶辊降低了谷子籽粒破损率，从而实现谷子柔性低损伤脱粒，橡胶圈外表面的波浪形凸起对谷子具有很好的碾搓脱粒性能。柔性凹板筛由空心圆柱旋转筛分单元两两相互交错组成，每组两排空心圆柱旋转筛分单元相互交错配合，形成适合谷子籽粒分离的U形孔，凹板筛支撑装置具有微动性，与柔性凹板筛配合形成柔性微动凹板筛，有利于谷子籽粒分离和降低谷码率。选取喂入量、滚筒转速和脱粒间隙为试验因素，以谷码率、破损率、未脱净损失率和功耗为指标，进行了三元二次回归正交旋转组合试验，确定了喂入量、滚筒转速和脱粒间隙的最佳参数组合。结果表明：当喂入量1.4kg/s、滚筒转速735r/min和凹板间隙9mm时，谷子籽粒破损率为0.35%，谷码率为1.78%，未脱净损失率为0.64%，功耗为10.6kW。

Design and Experiment of Longitudinal Axial Flow Double Flexible Rolling and Kneading Threshing Device for Millet

Aiming at the problems of high millet agglomerates rate, high damage rate and high undelivered net loss rate in the process of mechanical harvesting, a longitudinal axial flow double flexible rolling threshing device was designed. The device adopted longitudinal axial flow threshing drum, and flexible rubber roller was installed on the threshing drum, which can reduce the damage rate of millet grain and realize the flexible and low damage threshing of millet. The rubber surface had wavy protrusion, which had good milling and threshing performance for millet. The flexible concave grate was composed of two hollow cylindrical nylon screening units, and each group of two rows of hollow cylindrical nylon screening units were mutually staggered to form U-shaped holes suitable for the separation of millet seeds. The support device of concave grate had micro motion, and the flexible micro motion concave grate was formed with the flexible concave grate, which was conducive to the separation of millet seeds and the reduction of grain rate. The feed rate, drum speed and threshing clearance were selected as the experimental factors, and the grain rate, damage rate and net undelivered loss rate were taken as the indexes to carry out the ternary quadratic regression orthogonal rotation combination test, and the optimal parameter combination of feed rate, drum speed and threshing clearance was determined. The results showed that when the feeding rate was 1.4kg/s, the roller speed was 735r/min and the concave gap was 9mm, the damage rate of millet grain was 0.35%, the millet agglomerates rate was 1.78%, and the undelivered net loss rate was 0.64%, power consumption was 10.6kW, which provided the basis for the further development of a type of millet threshing device.