Reinforcement for vehicle hollow structural member, having decreasing-thickness end portions

摘要

A vehicle hollow structural member including a hollow body portion, and a reinforcement having a hollow structure fixedly disposed within the body portion in close contact with the inner surface of the hollow body portion. The reinforcement includes a thick-walled portion as a longitudinal central portion thereof, and two decreasing-thickness portions longitudinally opposite end portions. Each decreasing-thickness portion has a wall thickness which continuously decreases in a longitudinal direction from the thick-walled portion toward the longitudinal end of the corresponding end portion of the reinforcement, such that the wall thickness at the longitudinal end is substantially zero.