Method and Apparatus for Hydro-Forming An Elongated Tubular Member

摘要

A method of hydro-forming an elongated tubular member that has areas of predicted high strain and areas of predicted low strain. The tubular member is initially deformed into a preliminary preform shape by compression in a preform die. Metal in the areas of predicted low strain is stretched during the preforming process by radially deforming the tube between two halves of the preform die. The preliminary preform is then expanded with internal hydro-forming pressure to form a preformed tube. The preformed tube is then hydro-formed into a final die to form the final shape for the part. The extra metal in the areas of low strain is stretched into the areas of high strain in the final hydro-forming operation.