| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a bumper structure by joining a bumper stay to a bumper beam through electromagnetic molding, which can secure joining force required between the bumper beam and the bumper stay even when the front wall and the outer wall of the bumper beam are reduced in thickness and input energy during electromagnetic molding needs to be suppressed. SOLUTION: A stay intermediate material 3A having a shaft flange 18 along a shape of a circumferential edge of an opening at a front surface side of a burring hole 13 is preliminarily generated by expanding one end of a cylindrical extruded member of an aluminum alloy. The burring hole 13 is formed at the crushed end of the bumper beam 2, a shaft part 15 of a stay stock 3A is passed through the burring hole 13 from a front side, and the shaft flange 18 is made to abut on the opening at the front surface side of the burring hole 13. The stay stock 3A is expanded by electromagnetic molding at that state, the shaft part 15 is stuck to the burring hole 13, and the rear side of the burring hole 13 is protruded in an outer diameter direction to form a protrusion 19. COPYRIGHT: (C)2010,JPO&INPIT |
