摘要
针对卧辊式摘穗装置存在的玉米籽粒损失严重、含杂率高等问题,该文通过理论分析和台架试验相结合的方法对摘穗过程中两辊高度差对玉米损伤的影响及趋势进行了分析。单因素试验和方差分析表明,θ(两辊轴线垂直的平面内,两辊中心连线与水平面的夹角用θ表示)对玉米籽粒损失率有显著的影响(P<0.05)。θ在24°~30°范围内,玉米平均籽粒损失率呈现明显的下降趋势,θ在30°时玉米平均籽粒损失率最小,3次试验的平均籽粒损失为0.242%~0.483%;θ在33°、36°时,籽粒损失率较小,且相差不大。利用高速摄像技术对摘穗过程分析发现,θ较小时,果穗滞留摘穗辊和"弹跳"现象是造成果穗二次损伤的主要原因;θ较大时,玉米植株喂入困难,玉米秸秆弯曲严重甚至折断。为此,提出了在低位辊上安装弧形隔板的优化方案,试验验证表明,果穗通过弧形隔板滚动出摘穗区域,避免了低位辊对果穗的损伤,有效降低了玉米果穗的啃伤和籽粒损失率。该研究为卧辊式玉米摘穗装置的优化改进提供了参考。
In recent years, corn acreage has became the first place instead of wheat and rice in China. However, corn mechanical harvesting level is low, which has seriously affected the development of corn mechanization. Corn snapping device is a main component of corn harvesting machine, and plays an important role on the quality of harvester. Compared to other kinds of corn ear picking device, horizontal snapping rollers device is easy to cause serious corn grain loss rate and high impurity rate, which has been the choke points of corn harvester development for a long time. Height difference of snapping rollers is a significant factor that affects the ability of horizontal snapping rollers device to pick corn ears. If the height difference is too small, corn ears will stick on snapping rollers after picking, and the prolonged exposure increases corn grain loss seriously. When the height difference is too large, the center distance of snapping rollers remains constant that leads to small horizontal projection gap, and triangular domain shaped by the front cone of the snapping rollers still makes it difficult to feed for corn plant, finally corn plant will bent and broken off, which leads to serious grain impurity rate. Based on the issue of serious gnawing harm and loss of corn ears, experimental research was conducted to analyze the effect of height difference on grain loss. In order to improve the precision for adjustment on the height difference and determine the parameters, the angle between the line of centers of two snapping rollers and the horizontal surface (the angle 0) was employed to represent the height difference. The horizontal snapping rollers device was built, and the grain loss rate was taken as the index to estimate the effect on height difference. Through the single factor experiment, the impact of the angle 0 was analyzed. The harvesting process was captured with the high-speed photography, which was helpful to analyze comprehensively in the late period. Through the single factor experiment and the analysis of variance, it was found that the grain loss rate reduced quickly from 240-30° and changes were small and inconspicuous at 33° and 36°. The average grain loss was the least (0.354%) when the angle was 30°. High-speed cameras were used to collect image datum and analyze the datum. And two phenomena were discerned. It revealed that some corn ears stayed on the snapping rollers after picking, and there was also a "bouncing" phenomenon. Those phenomena caused secondary damage of corn ears and high impurity. In addition, when the angle 0 was too large, it was more difficult for corn stalk feeding, which made the corn stalk bending seriously and even to break, and even if the corn stalk was fed, it was easy to cause blocking on the snapping region. So if the large angle is employed, the gap between snapping rollers needs to be adjusted or the snapping rollers can be designed not to parallel with large backend and small front-end to ensure corn plant smoothly. For these phenomena, a curved bulkhead was installed above the low snapping roller. The contrast test showed that the solution reduced the chance of secondary damage to the corn ears. The single factor experiment showed that the grain loss rate reduced at each angle variously and grain loss rate was the least(0.164%) when the angle was 30°. The contrast test showed that the solution reduced the chance of secondary damage on the corn ears. It also prevented the snapping rollers fi'om impacting on the corn ears, thereby reducing loss of corn grain. This study provides a reference for optimization and improvement on horizontal snapping rolls device.
作者
陈美舟
孙雪峰
程修沛
贾晓东
李其昀
Chen Meizhou Sun Xuefeng Cheng Xiupei Jia Xiaodong Li Qiyun(School of Agricultural and Food Engineering, Shandong University of Technology, Zibo 255000, China Changzhou Dong/eng Agricultural Machinery Group Co.Ltd, Changzhou 213000, China College of Science, Shandong Jianzhu University, Jinan 250000, China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2017年第4期63-68,共6页
Transactions of the Chinese Society of Agricultural Engineering
基金
山东省重点研发计划项目(2015GGX101003)
公益性行业(农业)科研专项(200903059-0402)
山东省科技发展计划项目(2010GNC10965)
山东省自然科学基金专项(ZR2009DL012)
山东省自然科学基金项目(2010 ZRE04018)
农业科技成果转化资金项目(2014)
关键词
农业机械
方差分析
试验
卧辊式摘穗装置
高度差
二次损伤
籽粒损失
agricultural machinery
analysis of variance
experiments
horizontal snapping rollers device
height difference
secondary damage
grain loss