Authors

Abstract

The DEM (discrete element method) simulation and optimization of the shapes and quantity of spoons of spoon-wheel disc in the spoon-wheel seed-metering device under vibrational conditions are investigated in this paper. EDEM (Engineering-DEM) software was adopted to establish DEM models of ‘Zhongyu No.3’ coated maize seeds and the spoon-wheel seed-metering device first, and four additional spoons of various shapes (labeled as K1~K5, respectively) were designed. The test results indicated that the acceleration of seeds in the Y-direction in spoons (K2~5) was all less fluctuating than those in the original spoon (K1), and the multiple rate was the largest in spoon (K5). The ultimate optimal working speed of the spoon-wheel maize precision planter in southwest China was identified as 3 km/h, with 22 spoons and the ideal spoon shape being K3. The bench validation test was executed under vibrational conditions based on the optimal spoon structure and operation settings. The qualified rate exceeded 94.5% at an operating speed of 3~4 km/h, while the multiple rate was less than 4%, the leakage rate was lower than 1.5%, and the variation coefficient was smaller than 25.5%. The variety adaptability test was launched when the working speed was 3 km/h. The qualified rates of various maize varieties were all more than 96.5%; the multiple and leakage rates were both less than 2%, which satisfied the technical requirements of maize precision sowing in southwest China. The qualified rates of various maize varieties were all more than 96.5%, and the multiple and leakage rates were both less than 2%, which satisfied the technical requirements of maize precision sowing in southwest China.

Abstract in Chinese

本文研究了振动条件下勺轮式排种器中排种盘勺轮的形状和数量的DEM(离散元法)仿真和优化。首先采用EDEM (工程-离散元法)软件建立了"仲玉3号 "包衣玉米种子和勺轮式排种器的 DEM 模型，并设计了4个不同形状的附加勺子(分别标记为K1~K5)。试验结果表明，勺子(K2~5)内种子在Y方向的加速度波动均小于原勺子(K1)，且勺子(K5)内种子加速度的重播指数最高。最终确定西南地区勺轮玉米精量播种机的最佳工作速度为3 km/h，勺子数量为22个，理想勺子形状为 K3。根据最佳勺子结构和操作设置，在振动条件下进行了台架验证试验。在工作速度为3~4 km/h 时，合格指数超过94.5%，重播指数小于 4%，漏播指数小于1.5%，变异系数小于25.5%。在工作速度为3 km/h 时进行了品种适应性试验，各玉米品种合格指数均在96.5%以上，重播指数和漏播指数均小于2%，满足了西南地区玉米精量播种的技术要求。