Patent ID: 7849838

Claim:
A canister structure, comprising: a canister body coupled to a fuel tank and an intake system of an internal combustion engine of a vehicle via respective pipes, the canister body being operative to trap fuel vapor which evaporates in the fuel tank and supply the trapped fuel vapor to the intake system of the internal combustion engine; an outside-air connection pipe coupled to the canister body so as to open into an outside air at a fresh-air inlet thereof, the outside-air connection pipe interconnecting the inside of the canister body and the outside air; a branch pipe coupled to a middle portion of said outside-air connection pipe, a fresh-air inlet of the branch pipe opening into the outside air; and a check valve provided in said branch pipe, the check valve being operative to completely prevent air in said outside-air connection pipe from flowing out into the outside air via the branch pipe, by completely closing a passage of the branch pipe, and allow the outside air to flow into the outside-air connection pipe via the branch pipe only when an inside pressure of the outside-air connection pipe decreases to a specified negative pressure, by opening the passage of the branch pipe, wherein said fresh-air inlet of the branch pipe is positioned at a specified level which is higher than said fresh-air inlet of the outside-air connection pipe and disposed in a space which is formed between a vehicle body member to constitute a wheel house of the vehicle and a mud guard to cover the vehicle body member from a side of a vehicle wheel.