【作者】 苏成云；

【导师】 杜健民；

【作者基本信息】 内蒙古农业大学 ， 机械设计及理论， 2007， 硕士

【摘要】 为进一步研究高密度压捆的压缩过程,在9KG-350型液压式高密度压捆机上对含水率约70%的新鲜苜蓿进行压缩试验,结合虚拟样机技术对苜蓿压缩动力行为及运行方式进行了计算分析与动态仿真。通过对压缩力、压缩苜蓿草片位移及厚度等试验数据的分析处理,将苜蓿压缩分为压缩、流变、反弹三个阶段,得出各个阶段压缩力与草片变形量的关系,找出各阶段的仿真模型参数。利用虚拟样机技术构建压捆机的Pro/E三维数字模型,借用‘Parasolid’格式,将压捆机的CAD三维数字模型导入ADAMS。在ADAMS环境下对插草机构和压缩过程的三阶段分别进行动力行为仿真试验,得出了插草机构各杆件的最优化尺寸,并验证了压缩系统模型的正确性。利用ADAMS/controls & MATLAB/Simulink联合仿真技术,对压缩过程各阶段苜蓿的刚度系数进行参数控制,实现了苜蓿压缩过程的动力行为仿真,得出了压缩苜蓿功率消耗与压缩密度、刚度系数与压缩密度的关系。并对苜蓿的可压缩性进行仿真试验,得出苜蓿压缩存在临界密度的结论,在临界密度前后,压缩苜蓿所消耗的动力存在明显差异。更多还原

【Abstract】 For advanced study on the high density compression, fresh alfalfa with 70% moisture is compressed on the model 9KG-350 high density hydraulic baler. The dynamic behavior of alfalfa during compression process is analyzed and simulated with virtual prototyping. Through analyzing the experimental data about stress, displacement and thickness of grass piece, the compression process is divided into three phases: direct compression, rheology and rebound. The relation between stress and distortion of grass piece is gained, and the simulation parameters of the three phases are found. The digital model of high density bale is constructed with Pro/E, which is imported into ADAMS by‘Parasolid’format. Through analyzing and simulating the dynamic behavior of feeding mechanism and grass piece during the three phases with ADAMS, the optimum sizes of components in feeding mechanism are obtained and the model for compression is confirmed. By controlling the stiffness coefficient of alfalfa model during three compression phases with the con-simulation technique of ADAMS/controls & MATLAB/Simulink, the simulation of dynamic behavior is performed and the relation between power consuming and density, stiffness coefficient and density are found. The conclusion, there is a critical density in the process of compression, is drawn from the simulation experiment about compressibility of alfalfa. The power consuming is obviously different before and after the critical density.更多还原