Fuel tank cap

摘要

A fuel cap structure which enables part of a flange member to be readily broken when an external force is applied via a cover member in any direction. A fuel cap includes a casing body and a cover member attached to the flange member formed on the upper portion of the casing body. The flange member includes a joint member to join the upper portion of the casing body with an outer ring member, in which the cover member is fitted. The joint member has fragile portions including notches. Each fragile portion starts a break of the joint member when an external force is applied to the flange member via the cover member in a variety of directions.