New Sequential Forming Process Involving Single-forming Machine for Hat Cross-sectional Panels with Various In-plane Curvatures

Automobile demand is expected to be increasingly diverse in the future. To satisfy this demand, a suitable technology is required to manufacture various car body parts using a single-forming machine. We focus on a technology for the general-purpose production of hat cross-sectional press-formed panels. In general press forming, a single die-set is used for each panel. Manufacturing various panels involves the manufacturing cost of the die-set and the storage space. Herein, we present a new sequential forming process that can form panels with several shapes in the longitudinal direction. This process sequentially performs narrow-width press forming along the longitudinal direction using small dies instead of a die-set. A machine is prototyped to demonstrate this process. Multiple hat cross-sectional panels with different curvatures along the longitudinal direction are formed using this machine. Subsequently, the strengths and shapes of the formed panels are examined. The buckling strength during the bending of the panels is 13% higher than that of panels formed using a general bending machine. However, shape distortion occurred in these panels, which shall be addressed in the future.