Research And Analysis Of Double-needle-bar Multi-guide-bar Warp Knitting Machine Knitting Institutions

Warp knitting and weft knitting are two major parts of knitting industry, warp knittingbecause of its product variety, wide application range, high production efficiency has beendeveloping rapidly in recent years,especially in the aspect of forming fabric weave,double-needle-bar multi-guide-bar warp knitting machine’s forming fabric weaving capacity hasbeen neck and neck with seamless underwear machine, with the use of the Piezo jacquardtechnology, warp knitting forming fabric jacquard ability has overtaken weft knitting formingfabric. Domestic technology of double-needle-bar multi-guide-bar warp knitting machines hascertain gap with the foreign, with the high speed of the machine, there are problems such as themachine’s stability is not strong, the agency reliability is poor, it seriously restrict thedevelopment of warp knitting industry. This is the result of the domestic enterprises lack oftheoretical research of warp knitting machines and blind imitation. Therefore, through thein-depth theoretical research and dynamic analysis to knitting institutions of double-needle-barmulti-guide-bar warp knitting machine, complete the elastic dynamics modeling and kinematicsimulation of knitting institutions, improve the reliability of the whole machine, promote therunning smoothness of knitting elements.This article is based on the analysis of the knitting institutions’ structure and principle, useKED analytical method to analyze the elastic dynamics property of knitting institutions and fourbar linkage, based on Solidworks’ powerful three-dimensional modeling and simulationmovement function, realize the parametric modeling and movement simulation of knittinginstitutions, have in-depth study for the dynamic properties of knitting institutions which is underhigh speed movement condition. From two aspects of working principle of the piezoelectricloop-formed jacquard and piezoelectric loop-formed jacquard fabric characteristics to explorethe jacquard process of double-needle-bar multi-guide-bar warp knitting machine.Using highspeed photography technology to record real motion state of the knitting institutions, combinedwith image processing software to interpolation fitting and differential displacement parameters,to obtain the displacement, velocity and acceleration curve. Experimental results effectively verify the correctness of the knitting institutions’ theoretical dynamic analysis, provide a basisfor the further optimization design of knitting institutions.Paper main research content includes:1. Paper had a in-depth study for the structure and the principle of knitting institutions.Using the vector analysis method to study the knitting technology and knitting institutions’movement coordination, main technical parameters are as follows:Latch needle’s maximumdisplacement is20mm,sinker’s maximum displacement is33mm, thread stripping comb’smaximal displacement is8.4mm.2. For the issue that led to the poor stability of the machine which is caused by knittinginstitutions’ elastic deformation under high speed motion state, we use the the theory of themotion elastodynamics to set up the elastic dynamic mathematical model, analyse the elasticstress distribution of the knitting institutions;Using the finite element analysis method, throughmodeling research, realized the elastic dynamics analysis of knitting linkage mechanism.3. Based on Solidworks software establish three-dimensional digital model of knittinginstitutions, realize the mathematical calculating and motion simulation of the model, obtainknitting institutions’ displacement, velocity and acceleration curve, which makes the elasticstress distribution reflected in the form of kinetic parameters. when the latch needle speed is1.116m/s, maximum acceleration is-427.68m/s2, when sinker speed is-3.41m/s, maximumacceleration is686.88m/s2, when the guide needle speed is-0.18m/s, maximum acceleration is427.68m/s2.4. Study the Piezo jacquard device structure characteristics, basic principle and jacquardtechnology, explore the characteristics of double-needle-bar multi-guide-bar warp knittingjacquard fabrics, solve the technology bottleneck of domestic double-needle-bar multi-guide-barwarp knitting jacquard process.5. Using high speed photography technology, filming the real motion state of knittinginstitutions, combined with image processing software, and obtain the real motion curve. Bycomparing the high-speed photography experimental curve and Soildworks simulation curve,both consistent, it verifys the correctness of the modeling study of knitting institutions.Paper through double-needle-bar multi-guide-bar warp knitting machine knittinginstitutions’s knitting technology and dynamics research, realize the knitting institutions’s elasticdynamics modeling and kinematic simulation, it provides the way of technical analysis for further optimizing the design of knitting institutions and improving the reliability and stability ofthe whole machine.