Influence of Separating Force and Axial Force of Point Bar on Piercing Pass of Two-Roll Rotary Piercer

With a view to studying the modeling of the rotary tube piercing, the influence of the separating force on the roll opening of the rotary rolling piercer, the parameters of the piercing deformation and lateral uniformity of the wall thickness of the shell pierced are theoretically analyzed. Furthermore, the effects of the axial force of the point bar on both the deformation parameters during piercing process and dimensional precision of the wall thickness are discussed. It is noteworthy that the variation of the toe-in angle caused by separating force may be neglected, but the effect of the separating force on the wall thickness is remarkable. The effects of position variation of the point bar, due to its axial force, on the wall thickness of the shell pierced and its lateral uniformity merit attention.