To pump fuel vapor from a fuel vapor emission valve to a storage means.
An exhaust port of a fuel pump 38 is connected with a flow inlet of a venturi 48 installed in a tank 12. A dynamic pressure hole of a throttle part 50 of the venturi is connected with an leading pipe 52 to the exhaust port of a one-way exhaust valve formed at a bottom of a fuel vapor exhaust valve 16. Liquid fuel staged in the fuel vapor exhaust valve 16 is pumped out from the dynamic pressure hole by a decompression action at the venturi throttle part 50 caused by pumping the liquid fuel from the exhaust port of the venturi 48 into the fuel tank 12. The one-way exhaust valve is installed in a pipe line leading from the venturi throttle part to a valve chamber of the fuel vapor exhaust valve, so as to prevent the liquid fuel from flowing from the hole of the venturi throttle part 50 to the fuel vapor exhaust valve 12, even when hydrostatic pressure of the liquid fuel is received.
ALLMAN CRAIG H
JAHNKE RUSSELL C
