| 摘要 |
PURPOSE:To execute feedback control to keep the actual air-fuel ratio always equal to a desired air-fuel ratio, by varying the correction value for the quantity of air or fuel contained in air-fuel mixture in case that the characteristics of the injection quantity of a fuel injection valve is changed even if the operational conditions of an engine is not changed. CONSTITUTION:An air-fuel ratio controlling apparatus of this invention comprises a datum pulse determining circuit 11 for determining the datum pulse equivalent to the injection quantity of fuel corresponding to the value of a signal relating to the quantity of intake air supplied from an air-flow meter 5, an air- fuel ratio sensor 7, a desired value setting circuit 12, a memory circuit 14, and a control circuit 15. The memory circuit 14 has a plurality of addresses for storing the rate of change for both of the outputs of an engine speed sensor 8 and a load sensor 9, and rates of output change of the air-fuel ratio sensor 7 caused by the change of the injection quantity of a fuel injection valve 4 according to various operational conditions of an engine are pre-stored in each address. Here, if the characteristics of a nozzle relating to the injection quantity of fuel is changed, the rates of output change pre-stored in the memory circuit 14 is cleared. |
