Patent ID: 8443781

Claim:
A control apparatus for an internal combustion engine, comprising: a purge control unit that performs purge control to cause fuel evaporative emission to be introduced into an intake passage so as to attain a purge flow rate based on a pressure in the intake passage, to which the fuel evaporative emission is supplied; a fuel cut return control unit that performs a fuel cut return rich control or a fuel cut return normal control different than the fuel cut return rich control, the fuel cut return rich control sets a target air-fuel ratio to a rich air-fuel ratio when returning from fuel cut and controls an injector fuel supply rate in a feedback manner on the basis of the target air-fuel ratio, the purge flow rate and an intake air flow rate so as to attain the target air-fuel ratio; a fuel increase upper limit setting unit that sets an allowable rich upper limit for an increase in injector fuel supply rate in the fuel cut return rich control and an allowable normal upper limit for an increase in the injector fuel supply rate in the fuel cut return normal control, the allowable normal upper limit is greater than the allowable rich upper limit; and an actual air-fuel ratio control unit that in a first operating mode controls the fuel cut return control unit to prohibit the fuel cut return rich control when an actual air-fuel ratio, obtained during the fuel cut return rich control, is a lean air-fuel ratio and the injector fuel supply rate in the fuel cut return rich control has reached the allowable rich upper limit, the actual air-fuel ratio control unit controls the purge control unit to perform purge control and the actual air-fuel ratio control unit controls the fuel cut return control unit to perform the fuel cut return normal control to allow the injector fuel supply rate to increase above the allowable rich upper limit to control the actual air-fuel ratio to a richer air-fuel ratio.