Patent ID: 7213867

Claim:
A shock absorbing device for a vehicle, the shock absorbing device absorbing an axial compression load by means of plastic deformation in order to absorb an impact energy, wherein the shock absorbing device for a vehicle is hollowed and has an octagonal cross section, and wherein the shock absorbing device is made of a ferrous metal and, in cross section, includes: a pair of first sides extending so as to be parallel to each other; a pair of second sides extending so as to be parallel to each other in a direction perpendicular to the first sides; four connecting sides provided so as to connect each of adjacent first sides and the second sides; and assuming that a length of each of the first sides is set to “a”, a distance between the pair of second sides is set to A, a length of each of the second sides is set to “b”, and a distance between the pair of first sides is set to B, the distance A is set to be greater than the distance B, and a ratio of the length “a” relative to the distance A (a/A), and a ratio of the length “b” relative to the distance B (b/B), are set to the following ranges; 0.4 ≦a/A≦ 0.8 0.2 ≦b/B≦ 0.7.