A study of effects of roller path profiles on tool forces and part wall thickness variation in conventional metal spinning

Sheet metal spinning has seen significant developments in recent years. However, in the present industrial practice, the process design still highly relies on undocumented expertise; trial-and-error approach is commonly used to design the roller path and passes. In this paper, four different roller path profiles, i.e. combined concave and convex, convex, linear, and concave, have been designed and used to carry out spinning experiments and to conduct finite element (FE) analysis. The effects of these roller paths on tool forces, part wall thickness and stress variations in conventional metal spinning have been analysed numerically. The results show that the concave path produces highest tool forces among these four roller path profiles. Using the concave roller path tends to cause higher reductions of wall thickness of the spun part and using the convex roller path helps to maintain the original wall thickness unchanged. A greater curvature of the concave path would result in more thinning in wall thickness of the spun part.