【摘要】 针对玉米免耕播种机在麦茬地作业时机具通过困难、苗带草土混杂、作业质量差等问题,提出驱动切茬和被动导草联合作业的技术思路,设计了一种切茬导草组合式草土分离装置,实现了秸秆及杂草的切割拨抛和引导分流。对凹面缺口圆盘刀和导草板等关键部件与秸秆及杂草间的相互作用规律进行理论分析,确定了关键影响因素及其取值范围;运用CFD仿真技术确定了导草板的最优参数;借助EDEM离散元仿真技术建立了草土分离装置-土壤-秸秆相互作用的仿真模型,确定凹面缺口圆盘刀的最优结构参数组合;通过田间试验对该装置的作业性能进行了验证。研究结果表明:影响切茬导草组合式草土分离装置作业性能的主要结构参数为凹面缺口圆盘刀刀盘入土深度、刀齿高度和刀盘偏角。当刀盘入土深度为73. 63 mm、刀齿高度为69. 70 mm、刀盘偏角为23. 41°时,该装置机具通过性良好,且作业性能稳定,苗带秸秆清除率和土壤扰动量平均值分别为90. 16%和20. 85%,符合玉米免耕播种作业农艺和技术要求。更多还原

【Abstract】 Aiming at the problems of no-till corn planter,such as difficulty of passing through stubble fields,mixing of grass and soil in the seeding strip and the poor operation quality,a grass-soil separation device with combination of stubble cutting and grass guiding was designed based on the technical idea of combined operation of driving stubble cutting and passive guide grass.Several functions were achieved using the device,including cutting,poking,throwing,guiding,separation and flowing of both straw and grass.Based on the theoretical analysis of the interaction law between the key components(e.g.,concave notched disc cutter and guide grass board) and straw and grass,key influencing factors and their value ranges were investigated.The optimal parameters of the guide board were determined by using CFD simulation software.To determine the optimal combination of structural parameters of concave notched disc cutter,the interaction model of grass-soil separation device-soil-straw was established by using EDEM discrete element simulation technology.The results showed that the main structural parameters affecting the tool performance were embedded depth,the height of cutter tooth and the angle of blade.When the embedded depth,blade height and knife dish angle were 73.63 mm,69.70 mm and 23.41°,respectively,the performance of the device was the best,as indicated by good passage of the device with seeding straw cleaning rate of 90.16% and soil disturbance of 20.85%,which could meet the agronomic and technical requirements of no-till corn planter.Moreover,the device working performance was stable.更多还原