| 摘要 |
PROBLEM TO BE SOLVED: To provide a bumper stiffener comprising a creaseless curved bumper stiffener while curving with an optional total curvature radius Ra based on the assumption of roll-forming. SOLUTION: In this bumper stiffener being a bumper strengthening member arranged in front or rear of a body member and having a hollow, approximately rectangular cross section enclosed by a front surface 13, upper and lower side surfaces 11, 12 and back surfaces 15, 16, a curved front member 13 is formed in which a corner curvature radius Rc of outer curved corner sections 17, 17 being a boundary among the upper and lower side surfaces 11, 12 and back surface 8 (15, 16) is set to be three to ten times the thickness t of the outer curved corner sections 17, 17. The bumper stiffener 1 is formed in a manner that the front surface 13 of the curved front member 3 is regarded as a periphery, the back surface 8 (15, 16) is regarded as an inner surface, and the excess of the upper and lower side surfaces 11, 12 or the back surface 8 (15, 16) relatively shrunk is swollen by the outer curved corner sections 17, 17, thereby the curved front member 3 is curved to reduce the corner curvature radius Rc. COPYRIGHT: (C)2004,JPO |
