Patent ID: 8082906

Claim:
An air duct for an engine, the air duct being connected between an intake system of the engine and an air cleaner, wherein the air duct is hollow and has an inner circumferential surface, wherein, when the engine is operating, an air flow from the air cleaner toward the engine is generated in the air duct, wherein the air duct comprises a cylindrical fuel adsorption filter that has an outer circumferential surface and air permeability, wherein the fuel adsorption filter is arranged in the air duct to be coaxial with respect to an axis of the air duct, such that a gap is defined between the inner circumferential surface of the air duct and the outer circumferential surface of the fuel adsorption filter, and wherein an upstream communication passage for drawing some of the air flow into the gap is formed between an air flow upstream area of the gap and the air flow.