| 摘要 |
PROBLEM TO BE SOLVED: To provide an air fuel ratio control device capable of accurately controlling air fuel ratio of air fuel mixture to desired ratio in an internal combustion engine provided with a lift change mechanism. SOLUTION: This device is adopted to the internal combustion engine including the lift change mechanism changing lift VL of an intake valve. An oxygen sensor outputting signal corresponding to oxygen concentration in exhaust gas is provided in a downstream side of an exhaust emission control catalyst in an exhaust gas passage of the internal combustion engine. Correction quantity is established based on output value of the oxygen sensor and air fuel ratio control is executed with correcting fuel injection quantity command value by the correction quantity. A relation between the lift VL and steady deviation of the correction quantity from a reference value (small lift learning value Gksm, middle lift learning value Gkmd) is learned. Deviation learning value Gka is calculated based on the lift VL from the leaned relation, and fuel injection quantity command value is corrected by correction quantity including the calculated deviation quantity learning value Gka. COPYRIGHT: (C)2007,JPO&INPIT
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