Investigation on variation characteristics of bent tube axis and determination of bending die motion trajectory in free bending process

In free bending process, the axis shape of bent tube is determined by motion trajectory die. The tubes with different radii and directions can be formed continuously adjusting position posture To accurately form pre-designed tube, formation mechanism arc in process was analyzed. mathematical model between radius deviation established moving direction die also according to plane space azimuth where segment located. transition segments variable curvature illustrated during movement die, influence on explored. By comparing experimental simulated tubes, length path optimized. Finally, applicability forming technology features verified conducting experiments three typical shapes. Due high flexibility technology, work this paper could promote engineering application precise control tube.