Incremental Forming of Flanged Sheet Metal Components Without Dedicated Dies

Abstract

This paper describes research that has investigated a process for forming flanged sheet metal parts without dedicated tooling by repeated localized deformation—an incremental process. The complete formation of a shrink flange over a former by a grooved roller, moving around the flange in a series of passes, is analysed by the finite element method and reasonable agreement with experimental results shown. Some evidence is presented that the use of a grooved roller can extend the forming limits of a conventional single die pressing operation. The predicted reaction distribution at the fixed edge of a variety of flanges during their incremental formation by different rollers is then examined. It is shown that the most significant reactions are limited to the vicinity of the current position of the roller. This result leads to a proposal that the form tool might be replaced by non-dedicated tooling, to support the component web only in the region near to the roller. This proposal is tested experimentally and the principle of a dieless flange-forming process is successfully demonstrated. Such a process may be of benefit to any industry that produces a variety of flanged parts in small batches, for example airframe manufacture. Further research is proposed to develop a prototype machine based on the principle outlined here.