This paper presents a comprehensive view of the components-rolling process attained by detailed observations. In order to provide a fundamental approach to the rolling process of various rotational-type components, a series of experimental studies has been carried out. By means of experimental rolling of screw-like and gear-like components, features and shapes which blank cylinders come to develop in a process are observed in detail. In order to realize the characteristics of deformation, a method is taken in which experimental processes are examined comparatively by establishing a model process under some simple assumptions accepted as plausible. By this means, it becomes clear that a distortion observable in the cross sectional figure of a workpiece plays an important role in the rolling process. For detecting the deformation of material during the process, the split plug buried in the workpiece is employed. By examining a distorted grid of the plug, a three dimensional pattern of the material flow has become clear for the first time. It has been proved that the central portion of the blank cylinders does deform so as to proceed the rolling action and this central deformation affects drastically the formation of functional features of the component. Efficacy of forming depends solely on the balance of these exo- and endo-deformations. On the basis of this deformation analysis, the mechanics of a rolling process is clarified and the fundamental controlling factors are pointed out.
Shigeaki Tsutsumi (Sat,) studied this question.