Patent attributes
A fuel vapor control device include a fuel tank for storing fuel, a canister for adsorbing fuel vapor produced in the fuel tank, and an evaporation path communicating between the fuel tank and the canister. The tank has a resiliently deformable wall portion that can resiliently deform in response to an amount of the fuel vapor in the fuel tank, so that volume of the fuel tank can be varied. A pressure regulating valve can perform a relief function for opening the evaporation path during the expansion of volume of the fuel tank to a set volume. The pressure regulating valve closes the evaporation path if pressure inside the fuel tank is lower than the set value. On the other hand, the pressure regulating valve opens the evaporation path if the pressure inside the fuel tank is equal to or higher than the set value.
