| 摘要 |
PURPOSE: To suppress generation of changeover shock in a device where theoretical air-fuel ratio control is changed over with lean air-fuel ratio control by detecting combustion fluctuation of an engine at the changeover time, and varying a changeover determination value when the fluctuation is different from the reference case. CONSTITUTION: During operation of an engine, it is determined whether or not lean air-fuel ratio controlling is performed, theoretical air-fuel ratio control was performed in the former time, acceleration is performed. When acceleration is determined,δNE calculation is allowed. An engine speed NEMAX immediately before reduction and an engine speed NEMIN immediately before rising are stored, and difference therebetwen (amplitude) is calculated. A level for determining presence of torque shock and corresponding correction factor are selected based on the NEMAX by the use of a table. When the valueδNE is the determination level which is selected based on the NEMAX at that time or more, the correction factor is largely corrected.
|
