油莎豆收获机风筛选式清选机构的设计与试验

Design and Experiment of Cleaning Device of Cyperus Esculentus Harvester

针对油莎豆收获机清选环节草、豆、土分离不彻底、损失率高、含杂严重等难题,设计了一种风筛选式清选机构。运用动态静力学的方法研究了筛面物料的相对运动,分析了物料相对于筛面上滑、下滑和从筛面抛起的极限条件,确定了振动筛主要运动参数(其中包括振动筛振幅和振动频率)的理论域值,并通过理论计算确定了吸杂风机的转速范围;然后,以振动筛振幅、振动频率、风机转速作为试验因素,以上述得到的范围确定试验因素的水平值,设计了3因素3水平Box-Behnken试验,分析各因素对清选损失率、荚果含杂率的影响,并进行参数优化,寻求最优参数组合。试验结果表明:最优参数组合为振动筛振幅11mm、振动频率9Hz、风机转速1442r/min,此时清选损失率为4.35%、荚果含杂率为5.49%。研究可以为油莎豆收获机清选机构的设计提供理论参考。

Grain cleaning is the core technology of cyperusesculentus harvest. Therefore, in the process of cyperusesculentus harvesting, how to enhance operation fluency and efficiency, and to ensure technical indicators such as low loss rate of cleaning, low impurity rate of cyperusesculentus pods, has been a difficult technical problem of cyperusesculentus harvester. In order to settle the above difficulties, a cleaning device was designed, realizing the grain winnowed combined with screened. Utilizing kineto-statics method, in this paper, we researched relative motion of grain on the sieve surface, analyzed limiting conditions of grain upglide, downglide, jump from sieve surface, and determined the key motion parameter in theory. In addition, based on Box Benhnken’s central combination theory, response surface tests were carried out with three factors as influencing factors, namely, the vibrating screen amplitude, vibration frequency and revolving speed of fan. The effects of various factors on loss rate of cleaning and impurity rate of cyperusesculentus pods were analyzed and the influencing factors were optimized. The experiment results show that the optimal parameter combination is the vibrating screen amplitude of 11mm, the vibration frequency of 9hz and the revolving speed of fan of 1442r/min. The field test shows that at this time, the loss rate of cleaning is 4.35% and the impurity rate of cyperusesculentus pods is 5.49%. This study can provide a theoretical reference for the design of cleaning device of cyperusesculentus harvester.