【作者】 唐军；

【导师】 丁彩红；

【作者基本信息】 东华大学 ， 机械电子工程， 2009， 硕士

【摘要】 地毯簇绒机纱线牵引运动机理的研究对于理解和发现地毯生产过程中的问题十分关键。在纱线牵引过程中又以研究纱线张力变化为核心,牵引罗拉牵引纱线的过程就是一个调节纱线张力的过程。本文针对齿形牵引罗拉对纱线的牵引过程,重点研究了纱线在进入以及离开齿形牵引罗拉的过程中纱线张力的变化情况。主要研究内容有：(1)通过实验得到常用的地毯簇绒纱线尼龙S捻、尼龙Z捻和丙纶纱线的蠕变以及松弛曲线。根据实验曲线可以确定纱线并非弹性体,并提出纱线为粘弹性体的假设。另外还由实验曲线知在不同拉力大小下纱线表现出不同的性质。(2)通过在有限元分析软件ANSYS中利用其内置的粘弹性体的模型对纱线实验得到的曲线进行仿真拟合。由蠕变实验计算得到的参数输入ANSYS粘弹性体中进行松弛仿真,把仿真结果与纱线松弛实验得到的曲线进行比较,基本上能够确定纱线的粘弹性性质。(3)应用几何分析方法,根据牵引罗拉牵引纱线时的截面的平而几何关系推导纱线与齿形牵引罗拉间的包围角关系式,根据关系式分析15°循环周期内纱线在牵引罗拉上包围角的变化；分析得出影响包围角的因素主要为牵引罗拉的中心距；据此公式可以指导工艺调整。(4)利用多体动力学分析软件RecurDyn对牵引罗拉牵引纱线进行仿真分析。首先利用柔性衬套工具给出了纱线的计算机仿真模型；通过分析发现纱线在牵引罗拉齿上是一种既滚动又滑动的运动；接着分析了纱线、牵引罗拉的运动过程,发现从动罗拉以变角速度运动,主动罗拉与从动罗拉间不是以等角度转动;最后分析纱线张力的变化关系,并拟合出了纱线在输入端与输出端的张力关系,对经过一个齿以及多个齿的纱线张力进行拟合的曲线分别为：T出=T入·e-.30221·x+0.117375和T出=T入·e-0.3655x+0.3,基本符合欧拉公式。更多还原

【Abstract】 Mechanism research of drafting yarns for carpet tufting machine is very important to understand and discover problems in the process of producing tufted carpet. Research of yarn tension is the core of drafting yarns in the process and drafting yarns by drafting rollers is actually a process of adjusting yarn tension. This paper takes the gear-like drafting rollers as research object to highlight the yarn tension variation between the input and output part of drafting rollers of yarns. The main contents of this paper are as follows:(1) Obtain the creep deformation and relaxation curve of common used yarns such as Nylon S twist, Nylon Z twist and polypropylene by experiment. According to the curve it can be said that yarns are not elastomer and a hypothesis is made that yarns are viscoelastic material. Furthermore, it can be obtained that yarn characteristics are different when drag force is at different level.(2) Calculating the fitting curve to fit the experiment curve using the built-in model of ANSYS software. Simulating yarn relaxation in ANSYS using parameters obtained from yarn creep deformation experiment curve and compare the two relaxation curve, according to the curves it can be said that yarns are viscoelastic material.(3) Deduce the relational expression of wrap angle between yarn and drafting roller based on the geometrical relationship of section of yarn and drafting roller and analyze the variation of wrap angle during one cycle of the rotating drafting roller.(4) Simulate the yarn stress when yarn is drafted by drafting roller using multi-body analysis software RecurDyn. First, the yarn model for simulating in computer is given using the bushing tool; through analysis it is found that movement of yarn on the roller is a compound movement of roll and slide；then the movement process of yarn and roller is analyzed；at last,change of yarn tension is analyzed and yarn tension at input and output of rollers are fitted with a function and the results are T出=T入·e-0.30221·x+0.117375 and T出=T入·e-0.3655·x+0.3, they fit Euler’s formula well.更多还原