US Patent 10513236 Energy absorbing member

An energy absorbing member (20) is formed of an aluminum alloy extruded material having a substantially quadrangular outer shape. Straight portions of a pair of long sides of a quadrangular shape are each segmented into three side walls (21a, 21b, 21c) by two arcuate internal projections (26) that project inward. Vertices of opposing internal projections (26) are joined by a rib (25). Accordingly, the energy absorbing member (20) is configured to have a shape in which three cylindrical portions having hollow portions (24a, 24b, 24c) are joined. Arc-shaped internal projections (23) that each project inward are provided in four corners of the quadrangular shape.