To provide an air-fuel ratio control device for an internal combustion engine, for surely occluding an amount sufficient for suppressing catalyst exhaust smell into an exhaust purifying catalyst, after fuel increase operation and deceleration of an internal combustion engine and until stop of the engine.
The air-fuel ratio control device is applied to an internal combustion engine in which the exhaust purifying catalyst 10 is disposed to an exhaust passage 4. The air-fuel ratio control device includes: a fuel cut means 12 for stopping supply of fuel into the internal combustion engine in the deceleration of the engine and if it is determined that a speed of the engine is higher than a fuel cut speed; and a fuel cut speed change means 12 changing the speed in the fuel cut depending on physical amount correlating with an emitted oxygen amount so that the speed in fuel cut becomes lower as the oxygen amount emitted from the exhaust purifying catalyst during the fuel amount increase operation of the engine.
| JP6167888 | An engine control device |
| JP2010138705 | AIR-FUEL RATIO CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE |
| JP6400457 | Exhaust purification device |
Tatsuo Egami
Satoshi Nakamura