Patent ID: 7819272

Claim:
A fuel tank structure made of resin, comprising: interference sections for suppressing tank deformation caused by a negative pressure of a specified value or higher, the interference sections projecting inward in a fuel tank from an upper surface and a lower surface of the fuel tank, respectively, and substantially opposed with a specified interval therebetween, wherein the interference sections include an upper interference section defined by the upper surface and a lower interference section defined by the lower surface, and have an assisting section, which is provided based on at least one of structure, shape and configuration of the interference sections, for assisting mutual contact of the upper interference section and the lower interference section such that the upper interference section and the lower interference section move relative to each other in a displacement direction due to the negative pressure, and for maintaining contact between a projecting end of the upper interference section and a projecting end of the lower interference section even if the negative pressure causes at least one of the interference sections to deviate from the displacement direction; and wherein the assisting section is defined by at least one of the upper interference section and the lower interference section defining a baffle including first and second generally planar walls extending inwardly in the fuel tank and sloping toward one another.