油菜联合收获机滚筒筛式复清装置设计与试验

针对油菜联合收获机脱粒分离作业后脱出物组分杂,籽粒细小不易分离,导致清选作业清洁率低、人工复清劳动强度大等问题,设计了一种挂接在粮箱上的模块化滚筒筛式复清装置。基于运动学与动力学分析了物料提升螺旋输送器和筛分装置的结构参数与运行参数范围;以滚筒筛式复清装置的损失率、清洁率及筛分效率为评价指标,以滚筒筛转速、筛网内助流螺旋叶片螺距和筛孔直径为影响因素,基于EDEM开展了三因素三水平正交试验,确定了最佳参数组合,并利用收获关键部件试验台开展了验证试验。仿真结果表明：当喂入量为0.6kg/s时,滚筒筛式复清装置的较优参数组合为筛孔直径5mm、滚筒筛转速105r/min、筛网内助流螺旋叶片螺距250mm,此时滚筒筛式复清装置损失率为0.92%、清洁率为98.96%、筛分效率为95.12%。台架验证试验表明,带有滚筒筛式复清装置的清选系统工作顺畅,在最佳参数组合条件下,滚筒筛式复清装置的损失率为0.96%、清洁率为98.67%、筛分效率为95.36%,对比未增加滚筒筛式复清装置前清洁率提升了4.38个百分点。研究可为油菜联合收获机清选装置结构改进和优化提供参考。

Design and Experiment of Cylinder Sieve Type Re-cleaning Device for Rape Combine Harvester

Existing rape combine harvester has the challenges to separate the small rapeseed from the threshing outputs whose components are mixed, highlighting the need to improve the cleaning rate to reduce the labor consumption in manual re-cleaning process. Therefore, a modularized re-cleaning cylinder sieve, which could hung on the grain tank, was designed. Based on the kinematics and dynamic analysis, the range of structure and operation parameters of the material lifting screw conveyor and screening device were analyzed. A three-factor and three-level orthogonal experiment was carried out by using EDEM. The loss rate, cleaning rate and screening efficiency were taken as the indexes. The rotating speed of cylinder sieve, the screw pitch of the spiral blade, and the diameter of the sieve hole were taken as the factors. The optimal parameter combination was determined by the orthogonal experiment, and verified by the bench verification experiment. The simulation results indicated that the optimal parameter combination of the diameter of sieve hole, the rotating speed of cylinder sieve, and the screw pitch of the spiral blade were 5mm, 105r/min and 250mm, respectively. When the feeding rate was 0.6kg/s, under this condition, the loss rate, cleaning rate, and screening efficiency of re-cleaning cylinder sieve were 0.92%, 98.96% and 95.12%, respectively. The results of bench experiment showed that the cleaning system with re-cleaning cylinder sieve could work smoothly. Under the optimal parameter combination, the loss rate, cleaning rate, and screening efficiency were 0.96%, 98.67% and 95.36%, respectively. Compared with the performance of the cyclone separation cleaning device without re-cleaning cylinder sieve, the cleaning rate was improved by 4.38 percentage points. The research could provide a reference for the structural improvement and optimization of cleaning device of rape combine harvester.