曲面轮齿斜置式稻田行间除草装置设计与试验
Design and Experiment of Curved-tooth Oblique Type Inter-row Weeding Device for Paddy Field
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摘要: 针对东北地区稻田行间除草装置存在除草率低、易伤苗等问题,设计一种曲面轮齿斜置式稻田行间除草装置。通过对除草轮作业时轮齿入土压埋过程和出土脱附过程进行力学分析,建立了土壤颗粒在除草轮齿上的相应力学模型,研究了轮齿结构对作业性能的影响;通过理论分析确定了影响除草性能的除草轮主要结构参数和各参数的取值范围,并设计了单铰链结构仿形机构。基于显式动力学LS-DYNA仿真技术建立了除草轮与水-土壤流固耦合模型,通过正交旋转虚拟试验获得曲面轮齿除草轮的最优结构参数组合,并通过田间对比试验验证了该装置的作业性能。结果表明:曲面结构轮齿除草轮的杂草压埋效果和脱土效果均优于直面结构轮齿的除草轮,影响该装置作业性能的主要结构参数为除草轮曲率半径和偏心距;通过仿真试验得到最优参数组合为曲率半径65.86 mm、偏心距113.27 mm。田间试验表明,在轮齿曲率半径为66 mm、偏心距为113 mm最优参数组合下,该装置平均除草率和平均伤苗率分别为89.66%和2.1%,作业性能稳定,满足稻田机械除草作业农艺和技术要求。Abstract: Aiming at the problems of low weeding rate,easy damage to seedlings during operation of paddy field weeding devices in Northeast China,a curved-tooth oblique type inter-row weeding device was designed. Through the mechanical analysis of the buried ability of the wheel tooth entering the soil and the process of unearthed desorption during the operation of the weeding wheel,the corresponding mechanical model of the soil particles on the weeding wheel teeth was established,and the influence of the tooth structure on the operating performance was explored. The main structural parameters affected the weeding effect and the range of the parameters were determined through theoretical analysis,and a singlehinge structure profiling mechanism was designed. Combining with LS-DYNA simulation of display dynamics and rotating orthogonal experiment design,the optimal structure parameter combination of the curved-tooth oblique inter-row weeding wheel was obtained. The operation performance of the device was verified by field experiments. The research results showed that the weed burying effect and removal effect of the curved-tooth surface was better than that of the straight surface and the main structural parameters affected the performance of the curved-tooth oblique type inter-row weeding device were the curvature radius and the eccentricity of the weeding wheel. The simulation test showed that the optimal parameter combination was 65. 86 mm and 113. 27 mm,respectively. Field test results showed that the average weeding rate and average seedling damage rate of the device were 89. 66% and 2. 1%,respectively. The operation performance was stable,which can meet the agronomic and technical requirements of paddy field mechanical weeding operations.