FUEL VAPOR DISPOSAL MEANS WITH CLOSED CONTROL OF AIR FUEL RATIO

摘要

FUEL VAPOR DISPOSAL MEANS WITH CLOSED CONTROL OF AIR FUEL RATIO In an engine fuel system including a carburetor, a liquid fuel tank and a fuel vapor reservoir for the storage of fuel evaporated from the liquid fuel tank, a conduit is provided between the fuel vapor reservoir and carburetor induction passage to supply fuel vapor from the fuel vapor reservoir to the engine for combustion during engine operation. The carburetor is set for an air-fuel ratio leaner than stoichiometric; and a valve is provided in the conduit to control the flow of fuel vapor therethrough in accordance with the output signal of a zirconia sensor in the engine exhaust in closed loop control to maintain a constant air-fuel ratio near stoichiometric. An air inlet is provided in the fuel vapor reservoir to ensure a continual rich mixture of fuel vapor and air therefrom during engine operation.