PROCESS FOR PRESS FORMING METAL TUBES

摘要

Sub-blanks having different thicknesses and/or different materials are joined together along a joint line or boundary line. The joint line can have an axial directional component and/or a radial directional component. The blank is formed into a U-shaped structure with two substantially parallel arms and the arms can be overbent toward each other by a distance that varies along the axial length of the U-shaped member. The U-shaped member can be subjected to a press forming operation to form a substantially tubular member. The substantially tubular member can have a non-circular cross-sectional shape. A step can be formed at the joint line as a result of different thickness sub-blanks. The step is placed in a press forming die facing outwardly so that the step is reduced during the press forming operation.