Tube Hydroforming of Fuel Filler Pipes with Movable Dies

Abstract

Tube hydroforming is a relatively new approach to manufacture light weight metal structures. As the manufacturing technology became advanced, demands of lighter and stronger metal structures are also increasing. This research is to use tube hydroforming to expand the tube of a fuel filler for cars. The pipe material is JIS G3141. The product has a large expansion ratio at the edge of the pipe. Traditional tube hydroforming is difficult to achieve this large expansion ratio of a metal product. Tube hydroforming with movable dies is proposed to enhance the capacity of tube hydroforming technology. With movable die design, product with more uniform thickness can be obtained, and the forming pressure becomes lower than that needed in tube hydroforming without movable dies. A finite element code DEFORM-3D is used to analyze the plastic flow pattern of the tube. The loading paths of internal pressure, axial punches and movable dies for obtaining a sound product are determined by an adaptive simulation algorithm. The thickness distributions of the product for different loading paths are discussed.