马铃薯收获机扰动分离装置设计与试验

针对现有的小型马铃薯收获机筛面土块破碎效果不佳而影响分离效率和收获品质等问题，结合北方马铃薯主产区收获模式和常用杆条式分离装置，设计了一款马铃薯收获机扰动分离装置。在阐述总体结构及工作原理基础上，结合马铃薯的碰撞特性和土块的破碎过程分析，得到影响薯块损伤和土块破碎的主要因素为扰动深度、偏心轮转速和偏心距；通过EDEM-RecurDyn耦合构建仿真模型，单因素试验得到扰动杆数量最优为4，以扰动深度、偏心轮转速和偏心距为试验因素，以马铃薯碰撞力和土块破碎率为评价指标，运用Box-Behnken中心组合设计方法进行仿真试验，对试验结果进行方差分析，利用响应面分析了各交互因素对试验指标的影响规律，结合实际工况确定影响因素最佳取值。验证试验表明：当收获机分离筛运行速度为0.7m/s、扰动深度为51.5mm、偏心轮转速通过调速器设为2.3r/s、偏心距为31mm时，土块破碎率为60.7%，电子马铃薯采集的碰撞加速度峰值平均值为790.66m/s2，小于马铃薯临界损伤阈值。

Design and Experiment of Simple Harmonic Disturbance Separation Device for Potato Harvester

Combined with the harvesting mode and frequently-used rod-type separation devices in the main potato production areas of northern China, a disturbance separation device for potato harvester was designed to solve the problems of the poor soil fragmentation efficiency and harvest quality which existed in small-scale potato harvesters. On the basis of explaining the overall structure and working principle, combined with the analysis of the collision characteristics of potatoes and the fragmentating process of soil, the main factors which affected the the damage of potatoes and soil fragmentating were obtained. A simulation model was built through EDEM-RecurDyn coupling. The optimal number of disturbance rods obtained from single factor experiments was 4. The experimental factors were disturbance depth, eccentric wheel rotary speed, and eccentricity, and the collision force of potatoes and soil fragmentation rate were used as evaluation indicators. The method of Box-Behnken central combination design was used to conduct simulation experiments and work at the variance analysis on the experimental results. The response surface methodology was used to analyze the influence of various interaction factors on the experimental indicators. The optimum value of the influencing factors was determined based on actual operating conditions. The experiment showed that when the operating speed of the separating sieve of the harvester was 0.7m/s, the disturbance depth was 51.5mm, the rotary speed of the eccentric wheel was 2.3r/s set by the governor and the eccentricity was 31mm, the fragmentation rate of soil was 60.7%, and the average of the peak impact acceleration values collected by the impact recording device was 790.66m/s2. Both were below the critical damage threshold of potatoes.