Theoretical analysis of die-less U-bending process - development of die-less bending process for precision bent tube I

摘要

A new precision tube bending process without bending die, i.e. a die-less bending process, has been developed. The bending facility consists of feeding rolls, a bending roller and a rotating arm with a clamp for fastening the tube. The bending radius after springback is controlled by two bending conditions, the position of the bending roller LR and the velocity ratio of tube-feeding to the rotating armη. The influences of these bending conditions on the bending radius were studied by theoretical analysis. The simulated moment distribution during bending and the bending shape after springback were in good agreement with the experimental measurements. The die-less bending process has successfully been developed and can be applied to produce precision U-bent tubes.