In order to meet the requirement of high-speed and precision sowing operation of soybean,a spoon seed metering device was proposed,and its basic structure and working principle were analyzed.The numerical calculation method was used to design the plate and partition of the seed metering device.The diameter of the plate was designed as 260 mm,the number and radius of spoon were inversely proportional,and the angle of the mouth on the partition was from 5° to 90°.The optimal ranges of the radius and the inclination angle of the scoop were determined by single factor tests,which were obtained through simulation experiment by EDEM.The structure of the scoop edge was optimized through simulation experiment,and the optimal seeding performance was obtained when the scoop edge was inclined to both sides.The quadratic orthogonal rotation combination test was designed and the experimental data was processed by the Design-Expert 8.0 software.The regression model was established for the radius and inclination angle of the spoon about the qualified index and missing index.The optimal parameters of the scoop were radius of 6.8 mm,inclination angle of-9.4°,thickness of 2.2 mm and length of 14.1 mm,with the qualified index of 95.1％ and the missing index of 0.6％.The physical prototype was processed according to the optimal parameters and the bench test was carried out with results in accordance with simulation tests.The qualified index of the seeder was above 93％ and the missing index was less than 3％ when the speed of the planter was in the range of 6 km/h to 12 km/h,which satisfied the requirement of high-speed and precision sowing.%为满足大豆高速精密播种作业要求,设计一种凸勺排种器,阐述了其基本结构和工作原理,利用数值计算方法对其主要部件进行结构设计.利用离散元软件EDEM进行仿真试验,通过单因素试验确定凸勺半径和凸勺倾角的较优取值范围,并且对凸勺边缘结构进行优化试验,发现当凸勺边缘为两侧倾斜时排种性能较优;设计二次正交旋转组合试验,运用Design-Expert 8.0软件进行试验数据处理,建立凸勺半径、凸勺倾角与合格率和漏播率之间的回归模型,获得最优参数组合为凸勺半径6.8mm,凸勺倾角-9.4°,凸勺厚度2.2mm,型孔长度14.1 mm,此时合格率达到95.1％,漏播率为0.6％.台架试验结果与仿真结果一致,播种机前进速度在6～ 12 km/h时,合格率高于93％,漏播率低于3％,满足播种机高速精密作业要求.
展开▼
