The potential role of flexible tools in metal forming

Abstract

During recent years flexible materials such as urethane have become popular in the design of tools and machinery for metal forming. Urethane, obtainable in a range of values of hardness, possesses some inherent advantages, and provides additional versatility to steel tools. Several techniques, recently introduced and developed, are presented in this paper to highlight the role of urethane in the design of metal forming tools. The production of sheet-metal ashtrays and plates, a clamp for holding cylindrical billets in semi-continuous forming operations, a tube-bulging technique, a novel blank-holding technique for the deep drawing of cups of different shapes, and the redrawing of cups, all using urethane, are considered. The principles involved in these techniques, the design of the urethane pads, the actual prototype devices fabricated and tested, and the experimental data from forming operations, are presented briefly. In each of these techniques the urethane plays a different role in the shaping of the metal. Several new proposals for the use of flexible tools in metal forming are also presented.