Study On The Design Of Double - Needle Bed Warp Knitting Machine

In order to enhance the ability of the enterprise in developing double bar warp knitting machines, a preliminary exploration and research in theory and practical application about the circling equipments of the double bar warp knitting machines are studied in the paper.The structure composition, function of each part and the circle process of the double bar warp knitting machine are analyzed firstly, the motion state diagrams of knitting elements are presented, these motion state diagrams mainly include the position of the needle, sinker bar and comb at each time node position and their relative position relationship with other knitting elements. According to the loop forming process, the movement requirements of the needle, sinker and comb are presented, which include the motion form and motion size requirements. The requirements of the knitting needle, sinker bar are reciprocating linear motion with two dwells, the movement of comb can be divided into two parts, one part is the three equal amplitude oscillating motion and the other one is the bias motion of comb. Three reciprocating swing movements of comb have the equal amplitude, but each oscillation cycle not necessarily has the same time, the bias motion of comb is a reciprocating swing motion with two dwells.For each loop forming element, the corresponding motorial achievement mechanism type is choosed. These motion achievement mechanism types are planar multiple linkage mechanisms or planar linkage-cam combination mechanisms. For each motion achievement mechanism, their mechanism dimensions are synthesized by graphic method, analytic method or link curve atlas.A design example is studied by designing circling equipments of a RDJ4/2 double bar warp knitting machine, each loop formation mechanism and their mechanical structures are designed according to the motion requirements.A model and simulation through 3D software about the circling equipments are established, motorial strokes or dwell time sizes of the needle, sinker, three reciprocating equal amplitude swing of the comb and the bias motion of comb are presented, and a comparison with theoretical values is studied. The operation and weaving results of the actual machine show that the designed circling motion equipments have achieved expected effects, then design methods are useful.