Filler neck integrated with a corrugated pipe and a method of manufacturing the same

A method of manufacturing a filler neck integrated with a corrugated pipe part, the method comprising molding a filler pipe having an end portion including the corrugated pipe part,

• wherein the end portion is configured to be connected to a fuel tank, and
• wherein in a cross-sectional shape of the corrugated pipe part, a thickness of an upper portion of the corrugated pipe part in a cross section is larger than a thickness of each of a left portion and a right portion of the corrugated pipe part in the cross section.

A filler pipe of a filler neck, the filler pipe comprising:

• a main pipe part;
• and
• a corrugated pipe part having a first end and a second end, wherein the first end of the corrugated pipe part is integrally formed with the main pipe part.