Ignition timing control apparatus for internal combustion engine

Abstract

An ignition timing control apparatus for an internal combustion engine, when determining that recalculations are possible from the time when final ignition timing is calculated normally to final ignition timing, recalculates the correction amount of the ignition timing by feedback control and the final ignition timing. Accordingly, engine speed at a time closer to actual ignition timing is reflected on the final ignition timing. This configuration prevents overshoot from occurring even when a feedback gain is made greater and thus allows highly-responsive feedback control of the ignition timing thereby suppressing the change in rotation of the engine effectively. When the recalculations are not performed, the final ignition timing based on the correction amount, as normally calculated, is used. Thus, the final ignition timing is maintained at certain accuracy and abnormal ignition such as accidental fire is prevented.