Patent ID: 7213584

Claim:
A fuel supply apparatus for an internal combustion engine comprising: a fuel tank configured to store fuel to be supplied to the internal combustion engine; a fuel vapor purge system configured to trap fuel vapor generated inside the fuel tank in a canister and to purge the fuel vapor trapped in the canister into an intake passage of the internal combustion engine via a purge passage on which a purge control valve is provided; a cut valve configured to close a fresh air intake of the canister; a pressure sensor configured to detect a pressure in a fuel vapor path that is shut off by closing the purge control valve and the cut valve; an air pump configured to change a pressure in the fuel vapor path; and a control unit configured to output control signals to the cut valve, the purge control valve, and the air pump, to thereby diagnose whether or not there is any leak in the fuel vapor path based on a pressure calculated by inputting therein a detection signal of the pressure sensor, wherein the canister, the cut valve, the purge control valve, the pressure sensor, the air pump and the control unit are arranged within the fuel tank, and wherein one of two ports provided for the air pump is released toward the atmosphere outside the fuel tank, while permitting the other of the two ports to be released in the fuel vapor path within the fuel tank.