【作者】 易博；

【导师】 叶国铭；

【作者基本信息】 东华大学 ， 机械设计及理论， 2007， 硕士

【摘要】 原棉经过清、梳工序制成的生条已经成为连续的条状半制品，但还不能将它通过环锭细纱机或新型纺纱机直接纺成细纱。因为生条的质量和结构状态离成纱的要求还有很大差距，这些都会影响成纱的质量。因此，生条必须再经过并条工序进一步加工。在纺纱线过程中，将棉条以一定的圈条成形，有规律地盛放于条筒中，以供下道工序使用。完成该圈条成形的机构，称为圈条机构。并条机圈条机构中圈条盘的功用是是使压辊输出的棉条成摆线轨迹存放在条筒中。圈条盘圈条斜管形式采用直线斜管，在化纤与棉混纺及纯纺大量出现工况下，易出现斜管堵塞和筒底乱条的毛病，严重制约了纺部生产的正常进行。为解决此问题，袁景山设计了螺旋形曲线斜管圈条盘。经过在纺织厂现场试验，螺旋曲线斜管高速时纺化纤条不堵，出条不乱，生产效果改进非常明显。但是袁景山对棉条在斜管中的运动受力分析只是简要定性分析，提出与直线斜管相比，采用螺旋形曲线斜管能减少棉条圈条过程中的阻力，文中并没有做定量分析，因此所求取到的曲线不是具有严格理论意义的最优曲线。本文对棉条圈条过程定量地进行了运动学与动力学分析，以棉条所受曲线斜管摩擦力最小为目标函数，基于变分问题直接法原理设计出圈条盘螺旋形曲线斜管。这种螺旋形曲线斜管充分利用的圈条盘的转动对棉条产生离心力甩摆作用，使棉条所受曲线斜管摩擦力较小，从而使出条更顺畅。从理论上完善了现有纺织机械教科书关于圈条盘螺旋形曲线斜管章节理论，具有一定的创新性；在实践上对并条机圈条盘螺旋形曲线斜管的设计具有指导意义，一定程度上降低圈条盘螺旋形曲线斜管堵眼频率与条筒乱条几率，更适应现代并条机生产高速化，提高生产效率。实际结构常常受到随时间变化的动载荷作用。当动载荷与静载荷相比很小时，可忽略不计其影响，只需进行静态分析计算即可。若所受到的动载荷比较大，或者虽不大，但由于作用力的频率与结构的某一固有频率相接近时，结构将产生强烈的振动，在其内部引起很高的动应力，造成断裂或产生不允许的大变形。对于受这种动载荷作用的结构，就必须进行振动分析。传统的并条机圈条盘速度日益提高，由于并条机圈条盘高速旋转，并条机上与圈条盘相连接的轴承、齿型皮带易磨损、失效。无故障工作时间日益减少，圈条盘的振动成为需要分析与改进的问题。对传统的并条机圈条盘的设计进行借鉴分析，利用振动学原理以及有限元原理来研究圈条盘的工况，对圈条盘结构进行模态参数识别，评价现有结构系统的动态特性，为其结构动态特性的预估和优化设计及结构动力修改提供数据依据，减少振动对轴承、齿型皮带易磨损、失效的影响，以满足并条机的日益高速化的技术需求与生产需求。本文采用Solidworks三维绘图软件对ASFA328型号圈条盘进行三维建模，运用Ansys有限元软件计算出ASFA328型号并条机圈条盘的理论模态频率。实验模态分析中，分别通过采用柔软海绵垫支撑圈条盘与橡皮绳来悬挂圈条盘的方式，选取单点拾振、多点移步激励的方法，运用Cras实验模态软件求出ASFA328型号并条机圈条盘的实验模态频率。圈条盘有限元模态分析与实验模态分析相辅相成，两者分别从理论与实验的角度来求取圈条盘模态参数，评价现有结构系统的动态特性；并进行了理论模态频率与实验模态频率的对比分析，进行了圈条盘初步动力修改，为圈条盘的动态特性进一步改善提供了分析依据与实验数据。更多还原

【Abstract】 Cotton wool becomes continuous strip semi-products after the process of cleaning and combing, but it still cannot become fine yarn through loop spindle fine yarn machine or new spinning machine. Because there’s still a gap in the quality and structure between the raw sliver and yarn, all these will affect the quality of the yarn. Therefore, raw sliver needs the further process of drawing frame.In the process of yarning, the sliver needs to be circled and put regularly in the barrel for the use of next procedure. The framework of the circling is called circling framework. The function of coiler can is to make the sliver outputted by roller place in the barrel in the trail of cycloid. If using the line tube in coiler can, the problem of jam and disorder will appear on the condition of the mixture of chemical fiber and cotton, which restrict the normal production. To solve this problem, Yuan Jinshan designed screw curve coiler can. After the on-the-spot experiment in textile factory, the improvement is effective and feasible. But what Yuan Jingshan did is only the brief qualitative analysis of force and movement of sliver in the screw tube instead of the quantity analysis. So the curve concluded by his is not he optimized one with theoretic significance.According to the dynamics analysis of the cotton sliver coiling process, this paper considers minimum friction as objective function and explains the design of screwy pipe of coiler can based on the theory of the variational direct-method. This screwy pipe makes use of centrifugal effect from rolling can coiler and makes friction minimum. As a result, this screwy pipe avails the smoother output of cotton sliver; the decrease of jam frequency of the screwy pipe on the coiler can and coiling turbulence to some extend; better adaptability of high-speed manufacture process of modern draw frame.The actual structure is affected by the dynamic load of time variation. When the difference of dynamic load and static load is minor, we can ignore the effect of dynamic load and calculate the static load only. If the dynamic load is obvious, or when the force frequency is close to some fixed frequency, the strong vibration of the structure will happen so that the inside dynamic stress leads to the rupture or unaccepted distortion. In this case, vibration analysis is necessary.Traditional coiler can speed of drawing frame improves, its high speed of revolving increase the possibility of the damage and invalidity of the bearing and tooth belt connecting the coiler can. The effective working time reduces, the vibration of coiler can becomes the problem to be analyzed and improved. To distinguish the model parameter of coiler can, evaluate the dynamic characteristics of current structure by the theory of vibration and finite elements. And it provides the data foundation for the forecast and optimization design of structure dynamic characteristics & structure modification. It reduces the effect of vibration upon the bearing and tooth belt which meets the technical and production requirement.This paper applies Solidworks to build the 3-dimention model of ASFA328 coiler can, Ansys finite elements software to calculate the theoretic model frequency, Cras experiment model software to come out the experiment model frequency. In the model analysis of experiment, 2ways were selected, one is using the soft sponge as the support of coiler can, and the other is the rubber rope to suspend the coiler can, choosing the MISO method. The finite elements model analysis and experiment model analysis supplement each other and get the coiler can model parameter from both the theoretic and experimental points of views. It evaluates the dynamic characteristics of current structure system, analyze contrastively the theoretic model frequency and experimental model frequency, primitively carry out the dynamics modification of the coiler can which provides the analytical basis and experiment data for the improvement of dynamic characteristics of coiler can.更多还原