玉米扰动辅助充种高速气吸式排种器设计与试验

针对现有玉米气吸式排种器高速作业引起的种子漏吸，导致作业效果不佳的问题，通过增大充种区域，增加排种盘的充种时间，加强种群离散度，减小吸附压力，并基于此设计一种双重扰动辅助充种高速气吸式排种器。分析不同高度种层种子的受力平衡方程，计算扩容板位置和结构参数。分析扰种台柱和型孔作用下种子运动力学模型，并确定了带扰种台柱的中字型吸种孔排种盘的关键结构参数。以颗粒瞬态法向力为评价指标，运用EDEM软件仿真分析3种排种盘的扰动性能，结合台架试验检测3种排种盘充种性能，得到所设计的排种盘能够有效加强对种群的离散，强化排种盘的吸种性能。台架试验结果显示，当扰动辅助充种高速气吸式玉米排种器作业速度为8~10km/h、吸附负压为3.0~4.0kPa时，漏播指数不高于5.1%，重播指数不大于4.2%，粒距合格指数不小于94.6%，合格粒距变异系数不大于15.33%；当作业速度为12~14km/h、吸附负压为3.5~4.0kPa时，漏播指数不高于7.9%，重播指数不大于1.3%，粒距合格指数不小于92.1%，合格粒距变异系数不大于17.67%，高速条件下作业性能较好，各项指标均优于国家标准。

Design and Experiment of Corn High Speed Air Suction Seed Metering Device with Disturbance Assisted Seed-filling

Aiming at the problem of poor operation effect caused by seed leakage due to the high speed operation of the existing corn high speed air suction seed metering device, a double disturbance auxiliary filling high speed air suction seed metering device was designed by increasing the seed filling area, increasing the seed filling time of the seed metering disk, strengthening the dispersion of the population and reducing the adsorption pressure. The stress balance equation of seed layer with different heights was analyzed, and the position and structural parameters of expansion plate were calculated. The mechanical model of seed movement under the action of disturbing seed column and shaped hole was analyzed, and the key structural parameters of seed metering disc with middle shaped seed suction hole with disturbing seed column were determined. Taking the transient normal stress of particles as the evaluation index, the disturbance performance of the three seed trays was simulated by EDEM software, and the seed filling performance of the three seed trays was tested by bench test. The results showed that the designed seed trays can effectively strengthen the dispersion of the population and strengthen the seed absorption performance of the seed trays. The bench test results showed that when the operating speed of the high speed air suction maize seed metering device with disturbance assisted seed filling was 8~10km/h and the adsorption negative pressure was 3.0~4.0kPa, the leakage absorption rate was less than 5.1% and the gravity absorption rate was less than 4.2%, the qualified index of grain distance was greater than 94.6%, and the coefficient of variation of qualified grain distance was less than 15.33%. When the operating speed was 12~14km/h and the adsorption negative pressure was 3.5~4.0kPa, the leakage and absorption rate was not higher than 7.9% and the gravity rate was not higher than 1.3%, the qualified index of grain distance was greater than 92.1%, and the coefficient of variation of qualified grain distance was less than 17.67%. The operating performance was better at high speed, and all the indexes were better than that of the national standard.