Front chassis frame for automobile

In an automobile having a front chassis frame, including an elongated closed cross section front cross member disposed at a lower front end of an automobile and extending in a transverse direction of the automobile and in front of a power plant, and a side frame, extending in a longitudinal direction of the automobile, at each end of said front cross member and on opposite sides of said power plant, said front cross member having a leading edge, a trailing edge and upper and lower surfaces, the improvement comprising said cross member having a corrugation, extending in said transverse direction, formed on at least one of its upper surface and lower surface and in a location on said at least one of its upper surface and lower surface in front of said power plant, said corrugation weakening said cross member so that impact force acting in said longitudinal direction of said automobile deforms said cross member and is attenuated by deformation of said cross member.