新型剑杆织机筘座支座的有限元分析及优化设计

介绍了有限元方法在剑杆织机开发中的应用。选择新型剑杆枳机关键零件筘座支座进行有限元分析，可以得到筘座支座的应力和应变。通过灵敏度分析确定各主要参数的变化范围，经过优化分析得到各个参数的最优值。最后将优化的结果反馈给产品设计系统完成改进设计。     

四连杆打纬机构的筘座前心位置分析

 为织造纬纱按预期方式疏密分布的疏密纬织物,在分析四连杆打纬机构筘座前心位置影响因素的基础上,针对某型喷气织机的四连杆打纬机构,建立了打纬机构的弹性动力学模型,定量分析了打纬阻力和织机车速对前心位置的筘座弹性位移量的影响,获得了筘座弹性位移量随打纬阻力和织机车速的变化曲线,并进行了验证。结果表明：打纬阻力对筘座弹性位移量的影响较小,织机车速对筘座弹性位移量的影响稍大,但都不会明显改变打纬终了处的纬纱位置。     

PAT-A-280型织机筘座断裂修复加固

比利时PAT-A-280型喷气织机,在我厂运行一年半后,29台织机筘座左端200mm处横向断裂。分析其原因,筘座在织机480r/min的速度往复摆动下,夹持主喷嘴的筘座下端200mm长度范围无支托,为悬臂状态;筘座自身重量加上其上主喷嘴负荷在工作中产生交变惯性力,力的作用点集中于距筘座端部200mm处的托脚底部螺纹联接处,长期在外应力和内     

非对称运动打纬凸轮的设计

无梭织机(包括片梭织机、挠性或刚性剑杆织机、喷气织机及喷水织机)普遍采用共轭凸轮打纬机构,其主要原因是: 1.因多数无梭织机均采用分离筘座,为了配合引纬运动的要求,筘座必须有停顿时间。一般筘座的运动时间约占工作周期的1/3左右,而筘座的停顿时间约占工作周期的2/3左右。采用共轭凸轮机构可以实现以上的运动要求。     

SGA731型剑杆织机的改造

由老机改造造成的ＳＧＡ７３１型剑杆 机,由于用的是长筘座脚和大钢筘摆幅,剑杆织机的速度不能有效地提高,本文指出这类剑杆织机的缺点,给出了缩短筘座脚和钢筘摆幅后的打纬传剑方案,对改造后的打纬传剑方案进行运动分析,并对改造前后打纬传剑方案进行比较,指出了改造前后的异同点。     

GA74系列剑杆织机改造后两种传剑方案的比较

由有梭织机改造成的ＧＡ７４系列剑杆织机,由于用的是长筘座脚和大钢筘摆幅,剑杆织机的速度不能有效地提高。本文给缩短筘座物钢筘摆幅后的两种传剑方案,对两种传剑方案进行运动分析,并比较了两种方案剑头的运动曲线及压力角曲线,提出了两种方案的异同点。     

校装织机筘座固定架及应用

织机平修既要求筘座左右水平又要求筘座两侧梭箱底板至摇轴等距,两者之一不标准,均易造成磨梭,飞梭,断边,跳纱,实物外观不良等故障。过去,筘座是在木工工作台上安装,无法校正梭箱底板至摇轴距离,筘座上机后很难同时达到上述两项要求,保全工推说是木工筘座装的不规格;木工埋怨是保     

剑杆织机筘座脚,摇轴的调整方法

一些挠性剑杆织机如石川725、丰田LT102、台湾亨得、香港捷豹等。采用共轭凸轮打纬。打纬机构采用共轭凸轮、筘座用空心梯形铝合金制成。筘座与传剑机构相分离,传剑机构安装在织机的另一固定位置上。筘座用共轭凸轮传动,引纬时筘座在后方静止,这种结构形式减轻了传剑部分的设计难度,增加投纬角     

剑杆织机柔性从动件共轭凸轮打纬机构动力学分析

针对剑杆织机共轭凸轮打纬机构因自身振动造成筘座角加速度偏差大,降低织造的质量,缩短共轭凸轮寿命的问题,对共轭凸轮打纬机构进行合理化简化后,采用Rayleigh-Ritz法对柔性从动件进行离散化处理,基于Lagrange方程建立了剑杆织机柔性从动件共轭凸轮打纬机构的动力学方程。运用Mat Lab软件对柔性从动件共轭凸轮打纬机构进行了动力学仿真分析,在仿真过程中通过改变打纬机构的结构参数探索减小打纬机构振动的方法。仿真结果表明,打纬机构在高速运动过程中柔性从动件产生的横向振动会导致筘座角加速度波动明显,提出了通过减小筘座脚质量来减小筘座角加速度偏差和机构振动的方法。     

FX—1型防稀密路装置

一、基本结构和作用原理 1.基本结构(如附图) 将原K23 K27一套去掉,在原位置安装本机构,在筘夹轴侧翼和中央翼原螺孔上配M8×50调节螺丝即可。 2.作用原理本机构只在筘座离前止点5mm处开始作用,此时调节螺丝与滑动轴上的垫皮1接触,推动滑动轴2向机前运动,压迫弹簧3至一定距离,筘座到达前止点,弹簧压缩量达到最大值,弹力亦最大。筘座后退,弹簧即复位。弹簧弹力由调节螺丝传递,通过筘夹轴侧翼和中央翼直     

Variation in optic zone radii of a contact lens during manufacturing and the effects of temperature on this variation

There is little information in the literature on the causes of variation in the optic zone radii of a contact lens and the effects of temperature on this variation. In this study, the lathe cutting method of producing contact lenses was reviewed. The cause of the variation in the back optic zone radius was then identified as change in the operating condition from that of the calibrating one. Also, using finite element and theoretical methods, it was found that the effect of an increase in lens blank temperature is to make the back optic zone radius obtained steeper than that required, and this effect was verified experimentally.     

在CW6163车床上铣大导程螺旋槽

制革机械中常见大导程螺旋槽,车削加工时质量差.为提高大导程螺旋槽的加工质量,可以在CW6163普通车床上进行铣削加工.但需要在车床上加装调速减速机来降低主轴转速;拆除车床小拖板,在中拖板上加装一个专用铣头带动铣刀旋转;改变车床挂轮箱的挂轮搭配,以适应不同导程的螺旋槽.实践证明,铣刀只需一次进给就能完成一根螺旋槽的加工,...     

细纱机双皮圈牵伸装置的静态正压力分析

为深入研究细纱机牵伸机构的工作情况,用UG建立牵伸机构的三维有限元模型,采用有限元软件ABAQUS对细纱机牵伸机构的工作状态进行仿真分析,得到上下皮圈之间的正压力分布.通过实验测得皮圈间的实际正压力分布.对这2种方法测得的正压力分布规律与数值进行对比分析发现,二者的正压力分布规律基本一致,其数值除在皮圈钳口与罗拉钳口处...     

六面顶压机上不同组装结构的温度研究

利用有限元软件ansys对合成金刚石复合片的腔体内温度分布进行了分析研究，并通过实际测量验证模型的合理性。通过调整材料改进局部发热量、采用旁热式和直热式发热组装结构、合成不同形状产品等分析研究，认为增加端片的发热和提高堵头可以使高压腔内温度分布更均匀，旁热式发热组装比直热式发热组装对均匀高压腔内温度具有更大优势。     

可调式盘环车床设计

本文首先对盘环类零件的特点进行分析,进而论证了在多品种、中小批量生产的企业中,有必要设计出一种既不同于专用机床,也不同于通用机床,专门用于加工各种盘环零件的可调式盘环车床;并结合具体实例,比较详细地介绍了设计这种机床的方法。     

Lathe check development and properties: effect of log soaking temperature,compression rate,cutting radius and cutting speed during peeling process of European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.) veneer

The depth of lathe checks and integrity of veneer have been shown to be critical factors affecting the bonding process but also affecting the mechanical properties of veneer-based products. This study shows how beech (Fagus sylvatica L.) veneer lathe checks interval and depths are affected by soaking temperature, compression rate, cutting radius and cutting speed during the peeling process in well-controlled conditions. Freshly felled European beech logs were soaked in a water tank at 50, 60, 70 or 80 °C. Following soaking, the logs were immediately peeled with laboratory scale lathe (SEM S500) to 3.5 mm thick veneer at a cutting speed of 1, 2 or 3 m s^?1 and pressure rates of 0, 5, 10 or 15%. The correlation between lathe check depth and frequency was validated using “Système de Mesure d’Ouverture des Fissures” (SMOF) device, which enables to measure check properties reliably on veneer ribbons. In a well-controlled peeling process, the strong correlation between check depth and interval was shown. At higher temperature, shallower and more frequent checks are created compared to lower temperature. However, the effect of soaking temperature (between 50 and 80 °C) on veneer checking is much smaller than the effect of compression rate during peeling process, where the higher compression rate produced veneer with shallower and more frequent checks. The results of the study also show that the direction of lathe check propagation could be affected by the rays in beech veneer. Rays resist crack growth in tangential direction, but act as weak planes in radial direction.     

Analysis of the colleting method of producing spherical surfaces in contact lens blanks using finite element and experimental methods.

In contact lens manufacturing, the collet chuck is one of the most common methods of holding a lens blank in a lathe in order to cut a back optic zone. In this method the lens blank is compressed by a colleting force, and the effects of this force on the back optic zone radius of the lens blank are not well known. If these effects are known, improved back optic zone radius dimensions may be obtained. In this paper, the finite element and experimental results obtained for the effects of colleting on the back optic zone radius are presented and discussed.     

考虑接触热阻效应的车床温度场分布仿真分析

在零件生产中,车床加工精度直接影响零件的精度,而在影响车床加工精度的因素中,由于加工过程中温度变化而产生的主轴热变形是其中一个主要的原始误差。本研究通过对45钢与大理石试件接触以及45钢与铸铁HT250接触的热传导温度场进行实验测试,得到了相应的瞬态以及稳态温度场分布数据。基于对不同材料接触时稳态温度的数据分析,分别计算了在不同载荷作用下相应的接触热阻。将实验所得的经验关系式代入Ansys软件对车床受到主轴箱中齿轮传动产生热量作用下的温度场进行仿真分析。同时以大理石材料的机床床身为例,分析床身材料的变化对车床温度场的影响。通过分析,说明了大理石材料机床床身相对于铸铁材料机床床身,其机床主轴箱以及床身可能产生的温度场分布变化。研究结果将为高精度车床设计提供建设性的参考意见。     

Some Textile Applications of Finite-element Analysis Part I: Finite Elements for Aligned Fibre Assemblies

A new approach to the application of finite elements to aligned-fibre-assembly problems is introduced. This more rigorous application of finite-element analysis will allow the solution of a range of problems that have been impossible to solve by using previous approaches. Difficulties with non-linear material properties and large-scale deformations are overcome by defining the element stiffness matrix in a co-ordinate system based on the energy modes of the element deformation. It is shown how algorithms can be used to supply non-linear relationships for various types of deformation, simplifying the task of using complex material properties. The transformation of the element properties back to a conventional co-ordinate system to allow assembly of all of the elements in the structure is presented.

A two-dimensional element is developed to model aligned fibre assemblies. To maintain fibre continuity between finite elements, twelve degrees of freedom are required for each element. The deformation modes of this element are derived in terms of the conventional co-ordinate system. The results from the finite-element analysis are compared favourably with measurements taken from a deformed array of springs.

This paper is the first part of a series of two papers. Part II will investigate the application of finite elements to yarn mechanics.     

基于三维编织模型的棉纤维集合体压缩过程有限元建模与仿真

为分析棉纤维集合体在压缩过程中纤维受力情况来提高棉花压缩打包的质量,结合三维编织复合材料的细观几何建模思想,将具有相同圆形截面的棉纤维束按照三维四向编织复合材料的纤维分布进行排列,构建新的棉纤维集合体模型。将该模型应用于棉纤维集合体压缩过程分析,研究了棉纤维集合体压应力与相对密度的变化关系及棉纤维应力变化情况,分析了回潮率对棉纤维集合体压应力的影响。结果表明：随回潮率的升高,棉纤维集合体应力呈现先降低后升高的趋势,当回潮率位于8.8%～12.3%之间时,棉纤维应力最小;仿真结果与试验结果相符,说明该棉纤维集合体模型具有合理性。