Pedestrian protecting front bumper structure for a motor vehicle

The bumper structure comprises: an upper beam (10), a bumper fascia (12) which covers the upper beam (10) and extends downwards so as to form a lower edge (14) projecting frontward, and a reinforcement structure (16) for stiffening the lower edge (14) of the bumper fascia (12). The reinforcement structure (16) comprises: a lower beam (18) which supports the lower edge (14) of the bumper fascia (12) from behind; a pair of push-rods (20) laterally interposed between the lower beam (18) and a structural element (22) of the vehicle frame, and a pair of side bands (24) firmly secured on the one hand to the lower beam (18) and on the other to a respective push-rod (20). The reinforcement structure (16) is configured in such a manner that, in case of impact of the lower edge (14) of the bumper fascia (12) against the lower part of a pedestrian leg (25), the lower beam (18) transmits the impact force to the push-rods (20) via the bands (24), thereby causing the push-rods (20) to deform under bending. The lower part of the bumper structure has a substantially uniform stiffness along the transverse direction of the vehicle. Moreover, in case of impact the bumper fascia (12) is subject to a substantially rectangular deceleration profile, which makes it possible efficiently to absorb the impact energy and therefore to reduce the severity of the injuries to the legs of the pedestrian.