Analysis on the opening of pass in rotary tube expanding mills and the cone angle in the smoothing zone of plugs

Based on the special spatial structure of a rotary tube expanding mill,a conditional extremum method was used to determine the position of aperture points on the roller surface,to resolve the space coordinates of aperture points,and to construct a model for calculating the opening of holes in the formation zone of rotary tube expanding.The cone angle in the smoothing zone of plugs suitable for the opening of pass was calculated with the model.The calculation results are in agreement with the actual parameters of production.