轴流脱粒过程的动力学仿真研究

Simulation Research on the Dynamics in Axial Threshing Process.

运用变质量系统的基本原理 ,建立轴流脱粒空间内谷物运动的非线性力学模型。在计算机上对轴流脱粒过程谷物的力学状态进行仿真 ,并对脱粒机理进行理论分析。仿真结果表明 ,脱粒装置的反力和钉齿打击力都是谷物运动角位移的复杂周期函数 ,每一个周期又可分为冲击脱粒和茎秆疏松两个阶段 ,两者协调呼应交替出现 ,使谷物得以充分脱粒和分离。

Based on the principle of the varied mass system, the no-linear mathematical model of the crop mechanics in the axial threshing space has been set up. The result of simulation research and theoretical analysis on the model show that both the counteracting force of the threshing device and striking force of the tooth are complicated cycle functions to the angle displacement. Every cycle of these functions can been divided into two parts, viz.striking process and loosening process. The thresh is carried out mainly in the first half cycle, where the centrifugal force changes from minimum to maximum, and the striking force does from maximum to minimum. In the second half cycle stem is loosened completely so that the seed can been separated easily. At the same time, the angle velocity of the crop is decreased to minimum, which makes it possible for the crop to gain great striking force in the next cycle. The two processes carried through one after the other makes thresh and separation finished successfully.