Patent ID: 6793276
Filing Date: 2004-09-21
Classification: B62D

Abstract:
An automobile floor structure, wherein the automobile floor is partitioned into a plurality of areas by a floor tunnel portion extending in the lengthwise direction of the automobile body along a central portion in the automobile width, left and right side sills extending in the lengthwise direction of the automobile body along both side portions of the automobile width, side frames extending between the floor tunnel portion and the left and right side sills in the lengthwise direction of the automobile body, and cross members extending in the automobile width direction,wherein a floor panel of at least one area of the plurality of areas is bound at its perimeter by one of the side frames, two cross members and the floor tunnel portion or one of the side sills, and the floor panel is non rectangular in shape and has a floor panel structure in which a vibration mode is adjusted, wherein a rigidity adjustment portion with a higher surface rigidity than other portions is provided at a periphery of the non-rectangular floor panel, so that a substantially rectangular portion, which generates a stationary wave vibration a 2Ã—1 mode resulting in two antinodes in the lengthwise direction of the automobile body and one antinode in the automobile width direction, is formed in the non-rectangular floor panel, and wherein the rigidity of the substantially rectangular portion is partially increased such that a natural frequency of the 2Ã—1 mode is substantially matched to a tire cavity resonance frequency of the automobile.