摘要
针对传统机械式玉米排种器作业性能不稳定、播种穴距合格率低、漏播率高的问题,该研究设计了一种链勺式玉米精量排种器。根据西南地区玉米种子的物理特性对排种器进行结构设计;对排种过程中玉米种子的受力和运动状态进行分析,确定了影响排种性能的关键参数;基于EDEM-Recurdyn耦合方法对排种器的工作过程进行仿真,模拟种子运动过程;进行二次回归正交旋转组合台架试验,得到各参数对穴距合格率和漏播率的影响从大到小依次为:充种型孔半径、种勺斜角、主动链轮转速,当充种型孔半径为5.45 mm、种勺斜角为3.42°、主动链轮转速为45.62 r/min时,排种性能最佳,穴距合格率为83.14%、漏播率为1.73%;田间试验结果表明,安装链勺式玉米精量排种器的播种机播种平均穴距合格率为81.67%、平均漏播率为1.67%,满足国内玉米精量播种要求。
Precision seed-metering is one of the most crucial procedures for the high yield of maize.However,the traditional seed-metering devices have been confined to unstable operation,seed damage,seed clogging,and low versatility in recent years.In this study,a chain-scoop precise seed-metering device was designed for maize.The seed-metering device primarily consisted of housing,seed scoop,seed metering chain,sprockets,drive shaft,bearings,mounting base,and seed box.According to the physical properties of the maize seeds,the structural parameters were optimized on the chain-scoop precise seed-metering device.The key component,the seed scoop,was also designed after optimization.The seed-metering chain was selected as the 06B chain number with a K-type attachment plate.The seed scoop was designed in a"7"-shaped structure,with the length determined as 20 mm,the width as 27 mm,and the height as 12.5 mm.The seed-filling hole and the bottom groove were designed in a spherical shape with evenly distributed elliptical notches.As such,the seeds were rested obliquely within the seed scoop.The radius of the seed-filling hole was ranged from 4.5 to 6 mm,while the short diameter of the elliptical notch was 1.05 mm,and the radius of the bottom groove was 4.17 mm.The chain-scoop assembly was designed to evenly attach the seed scoops to the seed-metering chain.A seed-metering motor was operated to implement four procedures:the seed filling,clearing,protection,and delivery.A theoretical analysis was conducted on the motion states of the target seeds during the process.The key influencing factors on the seed-metering performance were identified,such as the speed of the driving sprocket,the radius of the seed-filling holes,and the inclination angle of the seed scoop.The discrete element method(DEM)with multibody dynamics(MBD)was employed to examine the operational process of the chain-scoop precise seed-metering device.The mathematical model was then established to validate the motion of maize planting.The test results demonstrated that the maize seeds successfully passed through each working area of the seed-metering device.The seeding function of the chain-scoop planter fully met the requirements of the performance.A series of bench tests was carried out on the chain-scoop precise seed-metering device.Design Expert 12.0 software was utilized to perform a three-factor,three-level,second-order orthogonal rotational experiment.The operating parameters were fine-tuned to optimize the performance.A systematic analysis was made on the effects of these parameters—such as the speed of the driving sprocket,the radius of the seed-filling hole,and the inclination angle of the seed scoop—on the seeding performance,including the qualified rate of planting hole spacing and the miss-seeding rate.Subsequently,a regression equation was established using the collected data.The optimal operating parameters were identified for the maize seed planting:a sprocket speed of 45.6 r/min,a seed-filling hole radius of 5.45 mm,and a seed scoop inclination angle of 3.42°.Furthermore,the planting test was achieved in a qualified planting hole spacing rate of 83.14%and a miss-seeding rate of 1.73%.The feasibility rate of 98.3%was predicted under the optimal combination of the parameters.The prototype of the precise seed-metering device was designed for ready installation with the chain-scoop technology.Field tests were conducted according to the optimal combination of the operating parameters after bench tests.The better performance was achieved in an average qualified planting hole spacing rate of 81.67%and an average missing rate of 1.67%,fully meeting the national standards of precise seed planting.Therefore,the chain-spoon precision seed-metering device also shared the simple seeding structure and low cost suitable for use in small corn seeders.
作者
李明生
王鹏
鄢玉林
谢守勇
刘忠军
刘凡一
陈行政
LI Mingsheng;WANG Peng;YAN Yulin;XIE Shouyong;LIU Zhongjun;LIU Fanyi;CHEN Xingzheng(College of Engineering and Technology,Southwest University,Chongqing 400715,China;Chongqing Key Laboratory of Intelligent Agricultural Equipment in Hilly and Mountainous Areas,Chongqing 400715,China;Chinese Academy of Agricultural Mechanization Sciences Group Co.,Ltd.,Beijing 100083,China;National Key Laboratory of Agricultural Equipment Technology,Beijing 100083,China)
出处
《农业工程学报》
北大核心
2025年第16期77-89,共13页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点研发计划项目(2023YFD2301903)
重庆市农业农村委员会农业技术创新项目(202204)。
作者简介
李明生,博士,副教授,研究方向为丘陵山地农机装备。Email:li-ming.2004@163.com;通信作者:谢守勇,博士,教授,博士生导师,研究方向为智能农机装备。Email:xsyswu@163.com。
