BUMPER REINFORCEMENT AND METHOD FOR MANUFACTURING THE SAME

摘要

A bumper reinforcement is formed of a 7000 series aluminum alloy hollow extrusion and has crushed end portions. A portion of the end portions is heated to a temperature of 400° C. or more for reversion treatment, the heated portion is subjected to cold crushing, and then the whole bumper reinforcement is subjected to age hardening. Because of the age hardening, the heated portion has higher Vickers hardness than non-heated portions by Hv 10 or more. This compensates for a decrease in reaction force in a collision of an end portion resulting from a decrease in the section modulus of the crushed portion and thereby suppresses a decrease in energy absorption.

主权项

1. A bumper reinforcement, formed of a heat-treatable aluminum alloy hollow extrusion, comprising;
a central portion in an automobile width direction, end portions in an automobile width direction; the end portions configured to be subjected to crushing, and the whole bumper reinforcement configured to be subjected to age hardening after the crushing,wherein
the end portions are subjected to a reversion treatment before the crushing, and regions in the end portions subjected to the reversion treatment have higher hardness than the central portion which is not subjected to the reversion treatment.