Authors

Abstract

In this paper, a new horizontal-shaft roller-type cotton stalk puller was designed to address the problems of weak research on cotton stalk pulling and harvesting machines, poor agronomic adaptability, and insufficient research. First, the physical and mechanical properties of cotton stalk were experimentally studied, and the cotton stalk pulling force test was conducted. and it was positively correlated with the cotton stalk diameter. Then, the moisture content and the bending characteristics of cotton stalk were evaluated. The test results showed the bending characteristics were positively correlated with the moisture content but were not evidently influenced by the diameter. Second, with the missed pulling rate and pull-off rate as the evaluation indexes and three independent variables, namely, forward speed, linear speed of stalk pulling rod, and rotation speed of stalk pulling roller, as the influencing factors, a 3D response surface model was established. On this basis, the lack-of-fit term P (p = 0.3650) > 0.05 of the evaluation index—missed pulling rate P1—was acquired, and the P value of pull-off rate P2 was always smaller than 0.0001. Finally, the results demonstrated that the influence of various factors on the missed pulling rate of cotton stalk is significant and followed the order forward speed > linear speed of stalk pulling rod > rotation speed of stalk pulling roller; the significance level regarding the influence on the pull-off rate followed the order rotation speed of stalk pulling roller > linear speed of stalk pulling rod > forward speed. Through the parameter optimization analysis, the optimal parameter combination was obtained which coincide with the model optimization and prediction result. The proposed method provides a basis and experimental reference for studying cotton stalk harvesting machineries.

Abstract in Chinese

针对棉秆起拔收获机研究薄弱，农艺适应性差，研究不足等问题，本文设计了一种新型横轴对辊式棉花拔秆机。首行进行了物理力学特性和棉秆起拔力试验，开展棉秆含水率和棉秆抗弯特性试验，结果显示棉秆起拔力与棉秆直径呈正相关关系，抗弯特性与含水率呈正相关，棉秆直径对抗弯特性影响并不明显。其次以漏拔率、拔断率作为评价响应指标，选取前进速度、拨禾杆线速度、拔秆辊转速3个自变量为影响因素，建立起响应面三维模型，得出评价指标棉秆漏拔率P1的失拟项P（P=0.3650）>0.05，拔断率P2的P值均小于0.0001；开展试验结果显示各因素对棉秆漏拔率的影响显著性顺序为前进速度>拨禾杆线速度>拔秆辊转速；对拔断率的影响显著性为拔秆辊转速>拨禾杆线速度>前进速度。通过参数优化得到最佳组合，与模型优化预测结果基本吻合。该装置为棉花秸秆收获机械的研究提供依据及实验参考。