油菜直播机开沟犁体曲面优化与试验

为减小油菜直播机开畦沟系统牵引阻力并分析机组不同作业速度对牵引阻力影响的规律,开展了开畦沟犁体曲面参数与作业速度的试验研究。建立了EDEM离散元土壤仿真模型,以犁体牵引阻力为试验指标分别开展以铧刃起土角、导曲线开度、直元线起始角、直元线最大角及作业速度为试验因素的试验;构建了犁体曲面优化模型,并开展了犁体曲面的3D打印及试制加工。仿真试验结果表明:在试验范围内,牵引阻力随铧刃起土角增大而减小,分别随导曲线开度、直元线起始角、直元线最大角增大而增大,随作业速度的增大而急剧增大,作业速度从1.0 m/s增加到2.0 m/s,牵引阻力及功耗分别为前者的1.98倍及3.97倍;仿真优化结果表明:当犁体在一定工作参数条件下,铧刃起土角为15°,导曲线开度为190 mm,直元线起始角为35°,直元线最大角为40°时,犁体牵引阻力最小为241.11 N,比优化前减少11.26%。为考察优化犁体实际田间作业效果,对犁体进行3D打印及试制加工并与原有犁体进行田间对比试验,结果表明优化犁体作业的畦沟沟底大块土垡少,残留土壤质量减少62.87%,沟底干净,T型沟明显。

Surface Optimization and Experiment on Ditch Plow of Direct Rapeseed Seeder

In order to reduce the traction resistance of ditch plow system and analyze the influence of operating speed on ditch plow system, the parameters of plow surface and operating speed were studied. The EDEM model of soil-plow simulation was established. The experiment was made with traction resistance as target and plow blade angle, opening of guiding curves, starting angle of straight-line elements, maximal angle of straight-line elements and operating speed as factors. The simulation results showed that during the range of the experiment, traction resistance decreased when plow blade angle increased while it increased when opening of guiding curves, starting angle of straight-line elements, maximal angle of straight line elements increased, respectively. Traction resistance increased rapidly when operating speed increased. When operating speed ranged from 1.0m/s to 2.0m/s, traction resistance and power consumption became 1.98 times and 3.97 times bigger, respectively. The simulation optimization results indicated that under certain working conditions, when the values of plow blade angle, opening of guiding curves, starting angle of straight-line elements, maximal angle of straight-line elements were 15°, 190mm, 35° and 40° respectively, the minimal value of traction resistance was 24111N, 11.26% less than before. In order to observe the field working performance of optimized plow, the plow were printed by 3D printers and manufactured in the factory, and contrastive experiment was carried out. The results showed that compared with the former, the number of large soil block was smaller and the quality of residual soil was 62.87% less at the bottom of ditch, and the T shape of ditch was more obviously. The research conclusions could provide reference for the future optimization of ditch plow system and operating study of actual field working speed.