Authors

Abstract

At present, the quality of chopping stalks with the use of a corn combine harvester needs improvement. Therefore, this study aims at designing a hob-type stalk chopping device to be installed under the header which can realize multiple groups of parallel longitudinal arrangements. Moreover, the device will be able to cut and crush the root and the middle and upper parts of the stalks. The performance of a finite element analysis corroborated the satisfactory strength and stiffness of the designed chopping blade as the mechanical requirements. Moreover, the influencing working and structural parameters were determined using a theoretical analysis. Regarding the test factors, i.e., the tip angle of the blades, fixed angle and the rotational speed of chopper shaft, single-factor and central composite design tests were also performed. Furthermore, the percentage of the qualified length of chopped stalk and the power consumption of cutting stalk were taken as the evaluation indexes. Accordingly, the results revealed the influencing parameters to be ordered as the spindle speed > fixed angle > tip angle of the blades. Subsequently, the parameters were optimized using the response surface method. Based on the obtained results, the optimized parameters including the spindle speed, the fixed angle and the tip angle of the blades were specified as 1050 r/min, 56°, and 40°, respectively. The experimental validation was also carried out on the optimal combination of the parameters. The qualified lengths of the chopped stalks were found to be 92.9%, which were consistent with the predicted results of the model. Hence, the test results met the design requirements.

Abstract in Chinese

针对目前玉米联合收获机茎秆切碎质量低的问题，设计了一种可以安装在割台下方的滚刀式茎秆切碎装置，该装置可实现多组并行纵向布置，实现对茎秆根部和中上部的分别切割粉碎。运用SOLIDworks软件建立茎秆切碎装置模型，运用ANSYS软件对切断刀片和切碎刀片进行有限元静力学分析，结果表明刀片的强度刚度满足力学要求。通过对切碎茎秆过程动力学分析得到影响茎秆切碎效果的作业参数和结构参数。采用单因素和二次通用旋转组合试验，以刀尖刃角、刀片安装角、刀轴转速作为试验因素，以茎秆切碎长度合格率和切割功耗作为评价指标。结果表明，影响茎秆切碎长度合格率和切割功耗的主次因素为：刀轴转速 >刀片安装角 >刀尖刃角。采用多目标优化算法进行参数优化，优化结果为：刀轴为1050r/min，刀片安装角为56°，刀尖刃角为40°。以优化后参数组合进行试验验证，茎秆粉碎长度合格率达到92.9%，与预测值相近，满足设计要求。