Patent ID: 9020739
Filing Date: 2015-04-28
Classification: F01N,F02B,F02D,F02M,Y02T

Abstract:
1. A control device for an internal combustion engine, comprising: an Exhaust Gas Recirculation (EGR) path that connects an exhaust path and an intake path of the internal combustion engine; an EGR catalyst that is disposed in the EGR path and capable of purifying exhaust gas; an EGR valve that opens and closes the EGR path, the EGR valve being disposed downstream of the EGR catalyst in the EGR path; an EGR path oxygen sensor that acquires an exhaust gas air-fuel ratio in the EGR path (hereinafter referred to as the EGR path air-fuel ratio), the EGR path oxygen sensor being disposed between the EGR catalyst and the EGR valve; EGR path air-fuel ratio judgment means for judging whether the EGR path air-fuel ratio is richer than a threshold value when EGR is stopped with the EGR valve closed; and target air-fuel ratio setup means for setting a target air-fuel ratio for the internal combustion engine to be leaner than a stoichiometric air-fuel ratio when the EGR path air-fuel ratio judgment means concludes that the EGR path air-fuel ratio is richer than the threshold value.