Patent ID: 8177044

Claim:
An automotive impact absorbing member integrally formed of synthetic resin material having lengthwise shape that extends with a constant hollow cross section, the automotive impact absorbing member comprising: plate-shaped rib portions each extending in a direction perpendicular to an impact load input direction; and load transmitting portions connecting with the rib portions at either widthwise end thereof for transmitting a widthwise direction component force of an impact load to the rib portions, wherein at least one of the plate-shaped rib portions has a thin portion of minimum thickness dimension situated in a widthwise center section thereof, and has a pair of gradual change portions situated to either side of the thin portion in a width direction and which increase gradually in thickness dimension outwardly in the width direction, and wherein a ratio of a widthwise dimension of the thin portion to a total widthwise dimension of the plate-shaped rib portion is between 0 (exclusive) and 0.8 (inclusive) and a widthwise dimension of the gradual change portions to the total widthwise dimension of the plate-shaped rib portion is between 0.1 (inclusive) and 0.5 (inclusive).