The Propulsive Force of the Water-jet to the Flying Weft in Water-jet Looms

In order to study the propulsive force on the water-jet to the flying weft in water-jet looms, a dynamic model has been established. Based on the analysis and example testing, an experiential formula of the propulsive force of the water-jet to the flying weft is obtained for the first time. The formula will profit the further research of the water-jet weft insertion and the production of textile.

Study of Water Jet Impulse in Water-Jet Looms

The watar jet impulse is brought forward to study the traction force of the water jet to the flying weft in water-jet looms. The distribution of the water jet impulse in the shed is tested by a sensor, and the influence of water jet parameters on the water jet impulse is analyzed.

An Analysis of the Orthogonal Crank-rocking Lever Spatial Mechanism for the Weft Insertion in Rapier Looms

On the basis of the analysis of typical orthogonal crankrocking lever spatial mechanism for the weft insertion in rapier looms, the rules of the outputting lever motion and the mechanism pressure-angle variety are studied when the maximum swing angle of rocking lever and the length of outputting lever have different values, and the optimum parameters suitable for motion transmission can be chosen. At the same time some existing shortpoints of the mechanism are also pointed out.

CONJUGATE CAM WITH FIVE-BAR LINKAGE MECHANISM FOR RAPIER DRIVE OF FLEXIBLE RAPIER LOOMS

A new type of rapier drive for flexible rapier loom through conjugate cams with five-bar linkage mechanism is raised and analyzed. Two designs suitable for the conversion of 1515-190.5 shuttle looms are given as examples. This mechanism can be applied to traditional shuttle looms as well as to new flexible rapier loom design.

THE POTENTIALITY OF ENERGY-SAVING IN SHUTTLE LOOMS

In this paper,the effects of loom speed fluctuation on the mean speed and on the power ofdriving motor were investigated and the expressions for these effects were derived.Based on theenergy relationships,a new index of equivalent fluctuation was introduced,the connection be-tween this equivalent fluctuation and the energy of speed function on frequency domain was thenfound.In addition to the above theme,the residual kinetic energy of the shuttle and pickingmechanism,taken as a considerable part in the potentiality of loom energy-saving was also ana-lysed.According to the results of theoretical analyses,the ways of energy-saving in looms weresuggested.Finally,taking the loom of 1511 type as a practical example,the potentiality ofenergy-saving was calculated.

Dynamics of Water Jet in Water Jet Looms

On the base of the study on dynamics of water jet in water jet looms, the parameters of water jet mechanism which affect the speed of water jet are analyzed and optimized. So the stability of the water jet can be improved to raise the speed of water jet as well as weft insertion rate and to enlarge the width of woven fabrics a lot. At the same time it also points out that to increase water jet speed and to prolong its affective jet time depend mainly on the accretion of spring rate (constant)of stiffness and the diminution of plunger's cross sectional area respectively.

A THEORETICAL ANALYSIS OF WORKING CHARACTER OF WEFT TENSION COMPENSATOR IN NEEDLE LOOMS

Based on the analysis, according to the principle of vibration, of the working character of weft tension compensator in needle looms, the paper studied the principle of tension compensation and introduced the idea of compensating coefficient. The paper also discussed some factors affecting the effect of tension compensation.

A STUDY ON THE DYNAMIC RESPONSE OF CAM BEAT-UP MOTIONS FOR RAPIER LOOMS

Based on the requirements of the two-phase rapier loom’s beat-up system characteristics, the dynamic responses of its beat-up system to three different types of cam input motion are studied in this paper. Also, their corresponding analytical comparisons are made. At the end of the paper, the authors put forward a proposal of new type cam beat-up motion for future practice.

Study on the Back Rest System of Looms

Periodic variations of warp tension during a weaving cycle result in corresponding change of back rest position, and the oscillation of back rest affects the fluctuation of warp yarn in return. A mechanical model of back rest system of looms is presented on basis of auto control theory, and the factors affecting the dynamic performance of the back rest are analyzed. In the model, warp yarn is regarded as a viscoelastic medium, and the adjustable parameters and the adjusting range of the back rest system are increased, so the loom's applicability for the fabric's variety is enhanced. Finally, the methods of designing and adjusting the back rest are discussed, and a trend of back rest system development is given.

Testing and Analysis of the Speed of Water Jet in Water Jet Looms

In the water jet looms, the distribution of the speed of water jet at the axis of the shed and its regularity are obtained by the Laser Doppler Tester. Based on the above, the water jet system is analyzed and the main effective approaches to increase the filling insertion rate and to widen the reed space of the loom are pointed out.

The kinematic Design of Beating-up Mechanism for Water-jet Loom Series Modified from Air-jet Loom

For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get four specifications of reed travel correspond-ing to the series of Tsudakoma water-jet looms,it canbe proved by comparisons of displacements,velocities,accelerations and transmission pressure angles that thosetwo series of mechanisms have very similar kinematicproperties.So the possibility of developing a series of wa-ter-jet looms modified from Toyoda air-jet looms isproved.It is beneficial to save the machine cost andbroaden the machine types.

从ITMA ASIA+CITME 2022看织造机械的技术进步

总结2022中国国际纺织机械展览会暨ITMA亚洲展览会上织造机械及织造准备的最新技术进展。织造机械的结构与性能不断优化,发展更加贴近市场需求。国产剑杆、喷气、喷水织机的制造水平发展迅速,提高了国产设备的核心竞争力。随着人工智能的爆发式增长,织造机械的数字化转型步伐加快,先进的信息技术和自动化工具的运用使织造机械呈现出个性化、智能化、绿色化发展新趋势。认为:近几年织造机械在高速化、自动化、绿色化方面进步显著。

连杆曲线导引的织机开口机构设计

传统连杆开口机构难以使梭口保持停歇,无法适应高速、宽幅的现代新型织机的工艺要求。引入特殊连杆曲线导引的概念,利用带鲍尔点和带圆点连杆曲线能使从动件产生停歇的原理,设计了两种新型连杆开口机构。该机构由四连杆机构和综框导引组件组成,四连杆机构的曲柄、连杆、摇杆和机架杆杆长比分别为1∶2∶2∶2.76、1∶2∶2∶2.3,连杆点的位置角分别为62.49°、49.15°,其与摇杆相连的连接杆与连杆等长。综框运动规律显示:两种机构梭口满开时主轴的相对静止角分别为约150°,40°和200°;综框处于最高和最低位时速度和加速度均为0,表明综框运动平稳,无冲击。该机构突破了传统连杆开口机构的局限,为低成本新型织机的开发创造了条件。

间隔织物双剑杆织机平行打纬机构箱体的振动分析

针对双剑杆织机共轭凸轮与四连杆组合的平行打纬机构箱体随着织机转速的提高产生强烈振动,影响打纬精度和可靠性的问题,采用理论分析与虚拟仿真结合的方法对打纬机构及箱体进行动应力和振动特性研究。建立了平行打纬机构的动态静力分析方程,运用ADAMS软件对机构进行多体动力学仿真,求解箱体所受的支反力;构建箱体—弹簧阻尼—柔性基础的系统模型,分析箱体在竖直方向的受迫振动,并在仿真过程中探索减小箱体振动的方法。研究结果表明:摆臂轴孔处箱体所受支反力峰值最大,打纬推程阶段箱体的受力最为集中;当凸轮轴转速为260 r/min时齿轮啮合频率与箱体一阶固有频率相等,会产生共振,应避免使用这一转速工作;箱体在竖直方向上产生周期性振动,增加螺栓个数和附加动力减震器有助于改善箱体的振动特性,振幅分别减少38%和23%。

基于运动合成的旋转变速运动建模及其驱动机构演变

为满足织机开口运动停—升—停的工艺特性及其动力学性能,提出一种基于运动合成的旋转变速运动规律构造方法。从组合机构角度提出旋转变速运动驱动机构及其演变,建立不同驱动机构的相对运动传递函数模型。采用目标优化法对旋转变速机构尺寸参数进行设计,在相同的中心距半径和转子臂初始位置的情况下建立优化函数并进行求解。仿真结果表明:偏移系数是影响旋转变速运动的关键参数,且变速运动静止时间、相对位移和速度峰值随偏移系数增加而减小;传递函数是影响旋转变速机构运动特性的重要参数,当偏移系数为0.4147时,随传动比的减小,转子臂相对位移减小,同时影响旋转变速机构凸轮特性,传动比大于0.9后不能满足旋转变速机构约束条件;用导杆滑块机构和铰接四杆机构对齿轮机构进行代换,可近似实现变速规律相对运动的传递,其传动误差分别为0.010、0.003 rad;通过减小中心距对铰接四杆机构重新优化可以提高旋转变速机构传动性能,满足高速运动需求。

喷水引纬机构动态特性对自由射流的影响

为适应不同喷水引纬织机幅宽的需求,基于伯努利与液体连续性原理建立喷水引纬机构动力学模型,喷嘴自由射流初始段最大距离与纬纱所受射流牵引力的数值模型,分析其动态特性并通过弹簧刚度系数确定凸轮系统最低转速,探讨不同弹簧刚度系数与弹簧最大压缩量条件下机构动态特性对柱塞运动周期、射流最大速度、雷诺数、射流初始段最大距离、纬纱所受射流牵引力的影响;仿真结果表明:弹簧刚度系数增大时,柱塞运动周期变小,对应的凸轮系统最低转速变大,当弹簧最大压缩量取0.029 m,弹簧刚度系数取40 000、50 000、60 000 N/m时,水射流速度最大值为62.19、69.85、78.99 m/s,射流初始段最大距离为937、1 000、1 074 mm,纬纱所受水射流牵引力为5.37、6.44、7.28 N;而弹簧最大压缩量对上述变量的影响幅度很小,故在大幅宽织机需求下应首要考虑使用更大刚度系数的弹簧。

小花楼织机织造技艺数字化教育设计研究

目的为了缓解小花楼织机织造技艺面临失传的问题,根据ARCS动机理论展开织造技艺数字化教育的设计研究,提升学习者在体验过程中的注意力和理解力,增强其掌握织造技艺的自信和满足感。方法结合ARCS动机理论和小花楼织机的织造技艺知识点,将数字化教育划分为三个教育单元,即小花楼织机的交互及展示设计、小花楼织机结构的模块化设计、实物模型控制及模拟设计,并在Unity平台中展开Arduino开发板以集成设计,由浅入深地构建数字化教育场景。结论对照实验结果表明,基于ARCS动机理论的数字化教育方式具有可行性和实践性,小花楼织机织造技艺的知识可达性和教育互动性有了显著提高,为蜀锦织造技艺的传承和发展提供了一定的参考价值和实践意义。

三维圆筒织物的织造工艺研究

为解决织造大直径三维圆筒织物时存在的边缝、缺经等问题,提出了一种三维圆筒机织法。根据三维圆筒织物结构,设计添经工艺,绘制纹板图,并在三维圆筒织机上进行织造。结果表明:采用三维圆筒机织法,应用弧形分布开口机构中的综眼和打纬优化后的纬密,并合理设计不同层的经纱数量,能够较好地织造出大直径的三维圆筒织物。认为:织物的尺寸以及规格由工艺结构、每次的卷曲长度、经纱纬纱数量及规格等决定,可以应用于大型筒状结构预制体的规格化、连续化生产。

铁木织机再研究

铁木织机是在中国晚清时期振兴实业背景下发展而来的特殊产物,无论从时间跨度还是技术转变角度来说都是中国近代纺织发展史中重要的一环。对铁木织机进行研究,一方面可以直观地再现中国近代手工纺织向动力纺织的转变过程,另一方面通过对其传播过程的考证,对学界现有的部分观点进行考辨与问疑,从而对中国农村手工业的发展具有更准确的认知。本文通过文献研究与实地考察发现:(1)铁木织机通过精巧的机械结构将开口、投梭、打纬、卷布、放经五个工序互联,提高了工作效率与布匹质量,缓解了当时洋纱、洋布对市场的垄断,更为中国纺织的机械化发展迈出坚实的一步;(2)铁木织机的发展脉络为19世纪英国将铁木织机传入日本,1887年日本掌握其制作技术,后于1903年由中国考察团将其从日本带回中国天津。铁木织机在政府、企业家等多方面的共同努力下仅用数十年的时间便在高阳、潍县等地得到快速发展,为中国近代纺织行业重心的散点式分布埋下伏笔。

云边端协同下的织机设备信息采集与监测系统

针对现阶段采用传统单一化上层云端对织造信息进行集中管理,易产生信息传输困难、可靠性低等情况,设计了一套基于云边端协同的织机设备信息采集与监测系统。首先,从中心云端、边缘端和设备终端对系统的总体架构进行设计;再从信息通信协同、数据存储协同和计算服务协同这3个方面对织机设备信息的通信、存储和应用服务展开研究;最后,以石家庄某织布车间的必佳乐OMNIPLUS-340型喷气织机作为测试对象验证系统的可靠性。结果表明,与纯云端通信模式对比,所设计系统平均通信延迟时间下降了20.8 s,平均通信吞吐率下降了446.58 Mb/h,为织造智能化生产提供了高可靠、高质量的数据支撑。