Authors

Abstract

Traditional corn threshing devices face issues of high unthreshed grain rate and high breakage rate under conditions of high feeding rates. To address this, a high-throughput double longitudinal axial flow corn threshing device was designed in this study. Based on a stress analysis of the interaction between threshing components and corn ears, an arc-shaped plate tooth structure was developed to progressively increase the squeezing force between the plate teeth and the ears. A combined threshing element, integrating arc-shaped plate teeth and round-headed nail teeth, was designed to improve threshing cleanliness and minimize grain breakage under high feed capacity conditions. The crucial parameters of the threshing cylinder were determined by theoretical analysis. Threshing bench experiments were conducted to investigate the effects of feed rate, threshing cylinder speed, and guide plate angle on the device's grain breakage rate and unthreshed grain rate. Based on the findings, the optimal parameter ranges were identified. An orthogonal test involving three factors at three levels each was conducted to determine the optimal working parameters of the device. The results indicated that the ideal conditions were a feed rate of 16 kg/s, a threshing cylinder speed of 400 r/min, and a guide plate angle of 26°. Under these parameters, the grain breakage rate was 5.02%, and the unthreshed grain rate was 0.171%. The operational performance met the actual harvesting requirements. This research could offer a reference for the design of large-feed-rate threshing devices and related harvesters.

Abstract in Chinese

当前传统的玉米脱粒装置在大喂入量条件下，存在籽粒未脱净率高、破碎率高的问题，对此本研究设计了一种大喂入量双纵轴流玉米脱粒装置。基于脱粒元件与玉米果穗的受力分析，本研究设计了弧形板齿结构，逐步增加板齿与果穗之间的挤搓力，有利于脱下不同脱粒难度的玉米籽粒；本研究设计了“弧形板齿+圆头钉齿”组合式脱粒元件，满足了大喂入量条件下装置实现高脱净率和籽粒破碎；通过理论分析的方法确定了脱粒滚筒的关键参数。通过台架试验研究了该装置中喂入量、滚筒转速和导流板角度对籽粒破碎率和未脱净率的影响规律，并确定了较优参数区间。通过三因素三水平正交试验，确定了该装置的最佳工作参数为：喂入量为16kg/s、滚筒转速为400r/min、导流板角度为26°，此时籽粒破碎率为5.02%，未脱净率为0.171%，作业性能满足了实际收获需求。该研究可为大喂入量脱粒装置和相关收获机设计提供参考。