Authors

Abstract

Aiming at solving the problem of corn straw uneven-distribution of straw retention machine in North China, based on kinematic analysis, the straw spreading process and its straw dynamics model was studied. Then, effects of spreading angle (SA), spreading deflection angle (SDA) and height of guide vane (HGV) on straw spreading distance, width and uniformity were analyzed. Taking SA, SDA and HGV as experimental factors, the straw spreading distance, width and uniformity were used as experimental indicators. Then the optimization experiment of Box-Behnken design corresponding surface was conducted to obtained batter operating parameter of experimental factors. Simultaneously, mathematical regression model of experimental factors and indicators was established. The test results shown that SA, SDA and HGV had extremely significant effects on width, distance and uniformity of straw spreading, respectively; The SA had extremely significant effect on straw spreading uniformity, the SDA and HGV had significant effect on straw spreading uniformity; The interaction between SA and SDA had extremely significant effect on straw spreading distance and significant effect on spreading uniformity. Furthermore, through parameter optimization test, the better combination of parameters of SA, SDA and HGV were 20°, 11.51°, and 1.12m, respectively. By field test under working condition of better parameters combination, the test results shown that width, distance and uniformity of straw spreading was 2.58m, 3.89m and 95.8%, respectively. The error between the test and theoretical prediction value was less than 5%, proved the accuracy of the model. The study can provide theoretical reference for parameters design of straw choppers.

Abstract in Chinese

针对北方一年两熟区，现有秸秆还田机秸秆抛撒不均，影响后续播种作业等问题，本文基于动力学分析，研究秸秆的抛撒运动过程，建立相对应过程的秸秆运动学模型，分析各因素对于秸秆抛撒距离、幅宽和均匀性的影响规律。以秸秆抛射角、抛射偏角和导向叶片离地高度为试验因素进行Box-Behnken design响应面优化试验，结果表明，抛射角、抛射偏角和导向叶片离地高度均对秸秆抛撒幅宽和距离有极其显著影响，抛射角与抛射偏角之间交互作用对秸秆抛撒距离有极其显著影响；抛射角对秸秆抛撒均匀具有极其显著的影响，抛射偏角、导向叶片离地高度、抛射角与抛射偏角之间交互作用对秸秆抛撒均匀性有显著影响；通过参数优化，得到较优参数组合为秸秆抛射角为20°，秸秆抛射偏角为11.51°，导向叶片离地高度为1.12m。进行田间试验验证，在较优参数组合作业条件下，抛撒幅宽为2.58m，抛撒距离为3.89m，抛撒均匀度为95.8%，试验结果与理论预测值的误差均低于5%，证明了模型的准确性，满足秸秆抛撒技术要求。本文的研究结果为秸秆粉碎还田机参数的设计提供理论参考。