Patent ID: 8032290

Claim:
A control device for an internal combustion engine comprising: an evaporative fuel gas adsorption unit which adsorbs evaporative fuel gas from a fuel tank; an evaporative fuel gas purging unit which is internally provided with an opening-adjustable purge control valve and which purges evaporative fuel gas adsorbed by the evaporative fuel gas adsorption unit into an intake passage of the internal combustion engine; a fuel correction unit which feedback controls, based on an air-fuel ratio detected by an air-fuel ratio detection unit, an air-fuel ratio of an air-fuel mixture to be fed to the internal combustion engine to a prescribed value; a purge control valve opening control unit which performs control to open the purge control valve under a prescribed condition; a purge quantity calculation unit which, with the purge control valve open under the prescribed condition, calculates a quantity of purged evaporative fuel gas based on a fuel correction value determined by the fuel correction unit engaged in fuel correction calculation for realizing a prescribed air-fuel ratio; an adsorption quantity estimation unit which determines, based on a quantity of purged evaporative fuel gas calculated by the purge quantity calculation unit, a quantity of evaporative fuel gas adsorbed by the evaporative fuel gas adsorption unit; an adsorption quantity change calculation unit which changes, according to a condition of the internal combustion engine and vehicle, a quantity of evaporative fuel gas determined by the adsorption quantity estimation unit; an adsorption quantity correction unit which corrects, according to a condition of the fuel correction unit, a change value calculated by the adsorption quantity change calculation unit; and a fuel correction value calculation unit which calculates a fuel correction value based on an adsorption quantity change calculated by the adsorption quantity change calculation unit.