Abstract:

In order to meet the requirements of the motion of multi-bar warp-knitting machine groove needle，asymmetric linear-cosine-linear combined motion law was applied to achieve cam mechanism and insure its motion. The relationship between the expression parameters, offset, acceleration extreme and the composition of the motion law was analyzed. Based on these analyses the relationship between the ratio of three–stage cam angle and the kinematic parameters of the follower, which includes displacement, velocity, acceleration and jerk, was deduced. In addition, according to the boundary conditions, the integral constants and the acceleration extremes of each movement were determined. Compared with the law of asymmetric cosine acceleration movement, the values of acceleration and jerk of asymmetric linear-cosine-linear combined motion law decreased in different degrees. Employing this law to the cam mechanism motion of the warp knitting machine, the altitude of the groove needle’s trajectory ascends in some degree in the upswing. Which is beneficial to loop withdraw and to avoid the interference between the yarns on the front and the latter guided needle bars.