旱作板结土壤下组合式机械除草单体设计与试验

Structural Design and Testing of Combined Mechanical Weeding Unit for Compacted Soil in Dry Farming

摘要:

为解决新疆旱作板结土壤中传统除草机构入土性能差、除草率低、伤苗风险高的问题,以玉米行间与株间协同除草为目标,本研究设计了一种由铲齿和指轮式除草盘构成的组合式除草单体,包含人字除草铲、柔性橡胶指轮和刚性指盘。基于EDEM建立了土壤-除草部件的互作仿真模型,模拟分析了指轮式除草盘对土壤扰动、土壤颗粒运动和除草盘受力变化等过程,以除草盘直径、刚性指盘折弯角、柔性指轮齿数为因素,通过正交试验及SPSS分析获得指轮式除草盘最优结构参数：除草盘直径为200 mm、刚性指盘折弯角为130°、柔性指轮齿数为16。开展了组合式除草单体三因素三水平田间试验和作业参数优化,得到最优作业参数组合：人字除草铲距苗16 cm、入土深度8 cm、除草盘距苗20 cm。田间性能试验结果表明,优化后组合式除草单体除草率为82.4%、伤苗率为2.65%、碎土率为91.87%,平均耕作阻力为1 052 N,有效解决了指轮式除草盘入土难和伤苗的问题,满足旱作板结土壤的行间与株间协同除草作业的需求,为智能除草机械优化提供支撑。

Abstract:

Aiming to address the problems of poor soil penetration performance,low weeding efficiency and high risk of seedling damage of traditional weeding mechanisms in dryland compacted soil in Xinjiang,the coordinated weeding between rows and plants of corn was selected and a combined weeding unit composed of shovel teeth and finger-wheel weeding discs was designed. This single unit consisted of a herringbone weeding shovel,flexible rubber finger wheels and rigid finger discs. Based on EDEM,a simulation model of the interaction between soil and weeding components was established. The processes of soil disturbance caused by the finger-type weeding disc,soil particle movement and force changes on the weeding disc were simulated and analyzed. Taking the diameter of the weeding disc,the bending angle of the rigid finger-type disc and the number of teeth of the flexible finger-type disc as factors,the optimal structural parameters of the finger-type weeding disc were obtained through orthogonal experiments and SPSS analysis: the diameter of the weeding disc was 200 mm,the bending angle of the rigid finger disc was 130°,and the number of teeth on the flexible finger wheel was 16. Field performance tests and operation parameter optimization of the combined weeding unit were carried out. The optimal operation parameter combination was obtained as the distance between the shovel teeth and the seedlings being 16 cm,the depth of soil penetration being 8 cm,and the distance between the weeding tray and the seedlings being 20 cm. The field performance test results showed that the optimized combined weeding unit had a weed removal rate of 82.4%,a seedling damage rate of 2.65%,a soil fragmentation rate of 91.87%,and an average tillage resistance of 1 052 kN. It effectively solved the problems of difficult penetration of finger-type weeding discs into the soil and seedling damage,and met the requirements of inter-row and inter-plant coordinated weeding operations in dryland compacted soil. The research result can provide support for the optimization of intelligent weeding machinery.