Patent ID: 7665447

Claim:
A fuel vapor control device comprising: a fuel tank for storing fuel; a canister for adsorbing fuel vapor produced in the fuel tank; an evaporation path communicating between the fuel tank and the canister; wherein the fuel 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; and a pressure regulating valve that can perform a relief function for opening the evaporation path during the expansion of the volume of the fuel tank to a set volume; wherein the pressure regulating valve closes the evaporation path if the pressure inside the tank is lower than a first set value; wherein the pressure regulating valve opens the evaporation path if the pressure inside the fuel tank is equal to or higher than the first set value; and wherein the pressure regulating valve opens when the pressure inside the fuel tank becomes less than the pressure inside the canister by a second set value.