Kyrychenko A. Improving the thread feeding system of large diameter circular knitting machines based on tension stabilization

The dissertation is devoted to improvement of existing methods and means of research of conditions of processing of threads on circular knitting machines of big diameter at manufacturing of knitted cloths for clothes taking into account real physical and mechanical properties of raw materials. On the basis of theoretical researches the system of differential equations describing dynamics of movement of a thread rigid on a bend on a directing surface of big curvature in the form of a torus taking into account deformation in a contact zone, variable entrance tension and diameter of section that allowed to define a thread tension in the course of its interaction with structural elements of the thread feed system of large diameter circular knitting machines. Algorithms and computer programs have been developed to determine the value of tension when the thread interacts with the guides in the form of a torus feed system of circular knitting machines and the reduced friction coefficient based on the numerical implementation of the half-segment algorithm for solving transcendental equations. Based on the analysis of the structural elements of the thread feed system of circular knitting machines, the dependences for determining the output tension were obtained, which allowed to establish ways of their modernization to ensure the stabilization of tension. Based on theoretical and experimental research, new designs of thread tensioning devices and compensators have been developed, which has allowed to improve the thread feeding system on large-diameter circular knitting machines based on tension stabilization. Using a recursive approach, the structural schemes of the thread supply system of large-diameter circular knitting machines were improved, which allowed to reduce the unevenness of tension and get a technological effect: reduce breakage and improve the quality of knitted fabrics by reducing the cut of defective.