Design On The Control System Of The Pantyhose Machine

Pantyhose machine is a small kind of circular knitting machine,which is used to produce pantyhose that is strong demand in market.With the improvement of the quality requirements of the pantyhose,producing pantyhose with uniform pressure and comfortable feeling is the direction for the improvement of the pantyhose machine system.In the production of pantyhose,the accuracy of the volume of the yarn is directly related to the quality of the pantyhose.Most of the domestic panty hose machines still use passive yarn feeding.Foreign advanced circular knitting machine manufacturers have developed the active yarn feeding system suitable for pantyhose machines,and active yarn feeding instead of negative yarn feeding is the trend of panty hose machine system development.For the detection of yarn break in pantyhose machine,the contact yarn breaking detection device can not avoid the broken yarn detection failure caused by mechanical structure.The non-contact yarn break detection device will gradually replace the contact yarn break detection device.This paper take the real-time control system of panty hose as the research object,a positive yarn feeding system is developed for the pantyhose machine’s yarn feeding process.A non-contact yarn break detection system based on infrared sensing is developed for the yarn break detection requirements.In terms of yarn feeding,this paper analyzes the relationship between yarn feeding speed and knitted loop size(fabric density)and machine running speed,and designs yarn feeding control circuit and yarn feeding control program combined with the demand of positive yarn feeding process control.With the infrared sensing method,the yarn movement signal is transformed into electrical signal.The variation law of electrical signals in three states of induction zone,without yarn,yarn static and yarn movement is analyzed.Combined with the technological requirements of textile equipment,the judgment basis of broken yarn is summarized.The infrared photoelectric detection circuit and signal analysis and processing system are designed.On this basis,the design of the whole machine control system for the panty hose machine is completed based on the whole machine’s control requirements and technical requirements.The modules of the panty hose control system are tested and analyzed.The test results show that the functions of each module meet the design requirements,and the results improve the reliability and automation level of the pantyhose machine’s yarn feeding system and yarn breaking detection system.