基于套种模式的中耕除草机设计与试验

Design and Experiment of Cultivator and Weeder Based on Intercropping Mode

摘要:

针对新疆地区“冬小麦+”套种模式小麦灌浆期后茬作物播种前，中耕除草作业缺乏适用机械的问题，本文设计了一种具有单体仿形功能的中耕除草机，阐述了整机结构与工作原理，并对仿形机构、旋耕刀动态运动过程等进行了分析。结合测定的典型杂草（藜草）特征参数，构建了基于Bonding V2的藜草与土壤复合体离散元模型，仿真分析揭示了藜草与土壤复合体失效过程，并明确了中耕除草机作业速度和刀辊转速是影响作业效果的主要参数;采用Box-Behnken试验与多目标优化求解，得出最佳作业参数组合为：刀辊转速270 r/min、作业速度3 km/h、耕深70 mm。以最佳参数组合开展田间试验，试验结果表明，机具除草率、碎土率和小麦伤苗率分别为95.3%、89.4%和4.23%，耕深稳定性系数为91.6%，田间碎土率与仿真结果基本一致。该机具作业稳定，能够满足套种模式下行间除草、碎土、低伤苗和稳定耕深作业要求。

Abstract:

Aiming to address the issue of lack of suitable machinery for intertillage and weeding operations after grain-filling stage of winter wheat and before sowing of subsequent crops in "winter wheat+" intercropping mode in Xinjiang, a mid-tillage and weeding machine with individual contour-following functionality was designed. The overall structure and working principle of the machine were elaborated, and the contour-following mechanism and dynamic motion process of the rotary tiller blade were analyzed. Based on the measured characteristic parameters of typical weed Chenopodium album, a discrete element model of Chenopodium album and soil complex was constructed by using Bonding V2. The simulation analysis revealed the failure process of the Chenopodium album and soil complex, and identified the operating speed of mid-tillage and weeding machine and the rotational speed of blade roller as main parameters affecting the operation effect. Using Box-Behnken experimentation and multi-objective optimization, the optimal operating parameter combination of blade roller rotational speed, operating speed, and tilling depth was determined to be 270 r/min, 3 km/h, and 70 mm, respectively. Field tests were conducted by using this optimal parameter combination. The results showed that the weed removal rate, soil fragmentation rate, and wheat seedling damage rate were 95.3%, 89.4%, and 4.23%, respectively. The tilling depth stability coefficient was 91.6%, and the field soil fragmentation rate was basically consistent with the simulation results. The machine operated stably and could meet the requirements of intertillage and weeding, soil fragmentation, low seedling damage, and stable tilling depth in the intercropping mode.