双盘交错气压式玉米品字形密植高速精量排种器研究

Design and Experiment of Twin Discs Intertwined Air-pressure High-speed Precision Seed-metering Device for Maize Delta-row Dense Plantings

针对目前玉米宽窄行品字形密植模式下精量排种器高速(10~16 km/h)作业时排种均匀性差且对品字形播种效果缺乏针对性评价指标的问题,设计了一种双腔双盘交错同步回转的气压式高速精量排种器,并提出了品字合格指数对排种效果进行评价。阐述了排种器基本结构与工作原理,运用理论分析与数值模拟的方法确定了排种盘的关键结构参数,建立了种子充种过程的力学模型,确定充种高度、作业速度、气腔正压是影响排种器性能的主要因素;以充种高度、作业速度、气腔正压作为试验因素,以品字合格指数、双行株距变异系数作为试验指标进行了三因素五水平中心组合试验,得到了排种器最优参数组合并对其进行了试验验证,选用“和育187”、“迪卡C2235”、“奥洋红A9”、“法尔利1439”4种类型的玉米种子进行了排种器适播试验。结果表明:排种器最优参数组合为:充种高度40.598 mm、气腔正压3.763 kPa、作业速度11.358 km/h,验证试验表明该参数组合品字合格指数为94%、双行株距变异系数为6.11%,与优化结果相符,可满足玉米宽窄行品字形密植模式的高速精量播种要求。

Aiming at the uniformity of current corn wide and delta-row narrow planting mode under high speed(10~16 km/h)operation of precision seed-metering device and the delta-row sowing effect of lack of targeted evaluation indexes of the problem,a double-cavity double-disc staggered synchronous rotary pneumatic high-speed precision planter was designed and the zigzag qualification index of the“delta-row”evaluation of the effect was put forward.The effect of“delta-row”was evaluated.The basic structure and working principle of the seed discharger were described,the key structural parameters of the seed discharging disc were determined by theoretical analysis and numerical simulation,the mechanical model of the seed charging process was established,and it was determined that the charging height,operating speed,and the positive pressure value of the air cavity were the main factors affecting the performance of the seed discharger.The three-factor,five-level Central Composite test was conducted with seed filling height,operating speed,air cavity pressure value as the influencing factors,and the“delta-row”qualification index and the maize seeds,namely“WAYO 187”,“DECA C2235”,“AOYO RED A9”and“FARLEY 1439”,were used to conduct the sowing test of the optimal parameter combinations of seeders.The results showed that the optimal parameter combination of the seed dispenser was 40.598 mm of seed filling height,3.763 kPa of positive air cavity pressure and 11.358 km/h of operation speed,and the delta-row qualification index W of the parameter combination was 94%and the coefficient of variation of the two-row spacing W1 was 6.11%,which was in line with the optimization results,and it can satisfy the requirements of high-speed precision sowing of maize in the delta-row dense-planting mode.