新疆膜下大豆收获机脱粒装置设计与脱出物分布规律研究OA

Aiming to address the uneven distribution of threshed material and unstable threshing quality caused by the green stems and leaves,high straw-to-grain ratio,and high moisture content of soybeans planted under plastic film in Xinjiang during the harvest period,key material parameters were clarified through systematic measurement of the plant's morphological characteristics,moisture content of its components,and frictional properties between the material and threshing components.Based on these parameters,a vertical axial-flow threshing device was designed.Single-factor threshing experiments were conducted with drum speed,feed rate,and threshing clearance as experimental factors to systematically analyze the distribution pattern of the threshed material.The results indicated that the average stem diameter of the soybeans was approximately 9.59 mm,and the tri-axial dimensions of the seeds approximately followed a normal distribution.The lateral compressive force threshold for seeds did not exceed 73.7 N.The friction coefficient between stems and steel plate was the highest at 0.58,and the stem moisture content was the highest at 34.0％.The mass of threshed material along the drum axis showed a trend of rapid increase followed by a slow decrease,while the radial distribution was characterized by higher mass at both sides and lower in the center.At a drum speed of 500 r/min,the axial and radial coefficients of variation were decreased to 50.05％and 50.82％,respectively,indicating optimal distribution uniformity.An increase in feed rate led to a significant rise in the radial coefficient of variation and a decrease in uniformity.The radial distribution was most uniform at a threshing clearance of 25 mm,with a coefficient of variation of 59.73％.The findings can provide a reference for the structural optimization of threshing devices and the setting of operational parameters to adapt to the material characteristics of soybeans under plastic film mulch.