Apparatus for preventing the outlfow of a fuel from a fuel tank for vehicle

A fuel supply system for use in a vehicle having an engine which in turn includes an inlet system, comprising:

• a fuel tank for accommodating a liquid fuel and wherein a portion of the liquid fuel evaporates;
• a filler tube with a filler lid connected to the fuel tank to supply the liquid fuel into the fuel tank;
• a first canister;
• an evaporating tube connecting the fuel tank to the inlet system of the engine through the first canister to supply into the engine fuel evaporated in the fuel tank;
• a second canister;
• a vent tube extending into the fuel tank and connecting the fuel tank to the inlet system of the engine through the second canister, for supplying into the engine fuel evaporated in the fuel tank;
• a shut-off valve disposed to open and close in the vent tube between the second canister and the fuel tank;
• a seal member provided in the filler tube for preventing fuel from flowing out of the filler tube to the atmosphere;
• control means for controlling the opening and closing of the shut-off valve,
• the control means comprising an opener switch for detecting whether the filler lid is open or closed, a speed detecting switch for detecting whether the vehicle is stopped or moving, and means for opening the shut-off valve to pass the evaporated fuel when the filler lid is detected to be open and the vehicle is detected to be stopped and for closing the shut-off valve to interrupt the fuel when the vehicle is detected to be moving;
• and
• a float valve disposed at the vent tube within the fuel tank to block the vent tube when liquid fuel supplied from the filler tube has reached a predetermined level in the fuel tank, whereby liquid fuel is prevented from entering the vent tube.