锥向离心式排种器的设计与数值模拟及试验

为满足高速精量排种作业要求、提高机械式排种器作业效率、改善排种质量,设计了一种锥盘离心式高速精量排种器,阐述了其基本结构和工作原理,并运用数值模拟方法对排种性能进行分析研究。通过采集的不同尺寸分布的玉米籽粒,运用EDEM软件进行排种性能仿真,探究了充填过程中籽粒重播、漏播的形成姿态及产生原因。仿真结果表明:籽粒到达末端的出种口时的3种姿态出现的平均概率为平躺21%、侧卧66%、横立13%;当工作转速为45~75 r/min时,排种器对大圆粒形玉米籽粒排种性能最优,合格率大于92. 4%;对小圆粒和楔形籽粒排种性能次之;对马齿形和小球形籽粒排种性能较差,其合格率大于82%;随工作转速增加,排种器对各尺寸等级籽粒的排种性能皆呈下降趋势,满足精密播种要求。其籽粒运动规律与结论可为离心锥盘式排种器的改进及优化提供理论基础和实践依据。

Design and Numerical Analysis and Experiment on Centrifugal Cone Disk Metering Device

In order to meet the requirements of high speed and precision metering operation,improve the efficiency of mechanical seed metering device and improve the quality of seed metering,a kind of centrifugal high speed precision seeding device with cone disc is designed,its basic structure and working principle are expounded,and the performance of seed metering is analyzed with numerical simulation method.The seed of different size distribution of corn was simulated by EDEM software,and the main reasons for replanting and missing sowing were explored.The simulation results show that the average probability of three kinds of posture when the grain reaches the end is 21%,the lateral is 66%,the transverse is 13%.When the working speed is 45-75 r/min,the seed metering device has the best performance on the seed seed arrangement of the big round grain corn,and the qualified rate is greater than 92.4%;the seed performance of the small round and the wedged grains is more than 92.4%.The second is that the rate of qualified seeds is smaller than that of the smaller ones,and the qualified rate is more than 82%.With the increase of working speed,the seeding performance of seed metering device is decreasing.To meet the precision seeding requirements,the grain movement rule and conclusion provide theoretical basis and practical basis for the improvement and optimization of centrifugal cone tray seed metering device.