Patent ID: 7899605

Claim:
A control device for an internal combustion engine comprising: an air-fuel (A/F) ratio sensor configured to detect a ratio between an air volume and a fuel amount during the lean combustion and the rich combustion of the internal combustion engine which are switched, where the lean combustion provides an excess air volume rather than an air volume in a stoichiometric air-fuel ratio for catalyst control, and the rich combustion provides an excess fuel amount rather than an fuel amount in the stoichiometric air-fuel ratio; air volume regulating means configured to regulate an air volume which is an air volume to be supplied to cylinders of the internal combustion engine; setting means configured to set a target air volume and a target fuel injection amount which are target values of the air volume and the fuel injection amount to be supplied into the cylinders; calculation means configured to calculate a compensation gain value which is a ratio between the target A/F value and the detected A/F value detected by the A/F ratio sensor, wherein the target A/F value, set by the setting means, is a ratio between the target air volume and the target fuel injection amount; and instruction means configured to instruct the air volume regulating means to regulate the air volume according to the compensation gain value calculated by the calculation means in order to decrease a torque difference between the lean combustion and the rich combustion.