Patent ID: 7059298
Filing Date: 2006-06-13
Classification: F02D

Abstract:
1. An evaporative fuel processing device for an internal combustion engine comprising: a purge unit for supplying a purge gas, which contains evaporative fuel generated within a fuel tank, to an internal combustion engine's intake path; an air-fuel ratio feedback control unit for learning purge gas density from the difference between exhaust air-fuel ratio and target air-fuel ratio, which prevails during an operation of the purge unit, and controlling the amount of fuel injection in accordance with the learned purge gas density; a purge control unit for controlling the operation of the purge unit so that a purge gas flow rate matches the operating state of the internal combustion engine, stopping the operation of the purge unit when a fuel cut is performed, and providing a lower purge gas flow rate setting during a predetermined purge resumption period subsequent to recovery from a fuel cut than during a steady operation period; and a judgment unit for judging whether the internal combustion engine is operated by a special operation method in which a fuel cut is performed more frequently than predefined depending on the operation of an accelerator pedal; wherein the purge control unit provides a shorter purge resumption period subsequently to recovery from a fuel cut when the judgment unit judges that the internal combustion engine is operated by the special operation method than when the judgment unit judges that the internal combustion engine is not operated by the special operation method.