Patent ID: 8746761

Claim:
A vehicle bumper device comprising a bumper reinforcement, wherein the bumper reinforcement extends in a width direction of a vehicle and has a pair of end portions, each of which is coupled to one of a pair of coupling members extending in a front-rear direction of the vehicle, the bumper reinforcement further including: an outer wall portion, which extends in the vehicle width direction and forms a front portion of the bumper reinforcement; an upper wall portion connected to an upper edge of the outer wall portion, wherein the upper wall portion, together with the outer wall portion, forming a hollow portion that opens in the vehicle width direction, the upper wall portion forming an upper half of a rear portion of the bumper reinforcement; a lower wall portion connected to a lower edge of the outer wall portion, wherein the lower wall portion, together with the outer wall portion, forming a hollow portion that opens in the vehicle width direction, the lower wall portion forming a lower half of the rear portion of the bumper reinforcement; an outer groove that is formed by denting the outer wall portion rearward, the outer groove extending in the vehicle width direction; a top wall forming a top of the upper wall portion; upper grooves that are formed in the top wall and arranged at intervals along the vehicle width direction, the upper grooves being formed by denting the top wall downward and extending in the vehicle front-rear direction; a bottom wall forming a bottom of the lower wall portion; and lower grooves that are formed in the bottom wall and at intervals arranged along the vehicle width direction, the lower grooves being formed by denting the bottom wall upward and extending in the vehicle front-rear direction; wherein a straight portion is formed in a center of the bumper reinforcement with respect to the vehicle width direction; wherein the end portions of the bumper reinforcement are inclined rearward from the ends of the straight portion; wherein the bumper reinforcement is bended to be inclined at boundaries between the straight portion and the end portions; wherein the upper grooves are formed at the end portions of the bumper reinforcement; wherein the upper well portion further has grooves extending in the front-rear direction of the vehicle, the grooves are formed by downwardly denting portions at the boundaries of the bumper reinforcement; wherein the outer groove extends in the vehicle width direction in the straight portion; and wherein a metal plate in which the outer groove, the upper groove, the lower groove and the groove have been formed in advance is subjected to roll forming and the portions at the boundaries are inclined to form the bumper reinforcement.