Research On Dynamic Tension Control System For High Speed Warp Knitting Of Staple Fiber Yarn

The tension compensation device is an indispensable part of the high-speed warp knitting machine,and its performance plays a very important role in alleviating the yarn tension fluctuation,the weaving efficiency of the warp knitting machine and the quality of the fabric.With the optimization of the warp knitting industry structure,warp knitting products are gradually extending to high-end and functionalization.Warp knitting products such as cotton and wool have gradually come to the fore in the textile industry.However,due to the fast running speed of warp knitting machines,The thread quality requirements are relatively high,and the physical characteristics of spun yarns such as low breaking strength,poor extensibility,and high hairiness make it difficult to ensure the continuous high-speed warp knitting production of spun yarns using traditional tension compensation devices.In order to better adjust the yarn tension,this article will propose a dynamic tension control program for warp knitting yarns,design a dynamic tension control system for spun yarn warp knitting,and build a high-frequency dynamic tension detection platform to test and verify the practicability and superior performance of the proposed scheme.First of all,This article takes the warp knitting tension adjusting appliance as the object of study,and combines the research foundation of yarn warp knitting tension control at home and abroad to explore the working methods and working principles of tension regulators in the warp knitting field.In order to focus on the analysis of the tension generation mechanism of warp knitted yarns and the factors affecting tension fluctuations,the characteristics of tension fluctuations are analyzed through the combination of the sequence logic of the displacement change of the loop-forming machine and the angle of the spindle.Through the analysis of warp knitting yarn tension generation mechanism and fluctuation,it can be known that the two-way composite movement of the guide yarn bar is the main cause of warp knitting tension fluctuation,and then by analyzing the changes in the yarn path of each looping cycle during the weaving process,and calculate the yarn consumption in different periods of a looping cycle can provide a theoretical prerequisite for the design of active yarn tension compensation schemes.Secondly,after clarifying the design requirements of the dynamic tension control system for the high-speed warp knitting machine,a dynamic tension control system with three levels of distributed control of the movement management level,the motion control level and the motion executive level was constructed,and explains how the system works.Dynamic analysis through the tension compensation device,it is believed that the natural frequency and stiffness of the warp knitting tension compensation device have a greater impact on its dynamic control performance.Therefore,an active tension control mechanism is designed according to the Controlling demand.Following the control goal of high dynamic response and high Control precision,in the system design process,the selection and design of key links and components such as the movement law curve of the tension rod drive,the response performance of the servo drive,the servo control mode,and the accuracy of the spindle signal are carried out in-depth research.Clearly described the dynamic online tension control ideas and designed the tension model control algorithm.Finally,Set up a high-frequency dynamic tension detection and experiment platform to test the performance of the designed spun yarn high-speed warp-knitted yarn dynamic tension control system.The tension control effect and tension fluctuation under different tension compensation schemes and different process parameters were tested respectively,and the overall weaving level of yarn tension and the performance of the tension control system were evaluated through the distribution of yarn tension.Experimental result demonstrates that this warp knitting dynamic tension control system has strong practicability and fast response speed,and the weaving tension of spun yarn is relatively uniform.It can achieve the controlling demand of "peak cutting and filling valley" and produce good control effects.It has vast potential for future development and promotion value.