IGNITION TIMING CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

PURPOSE:To perform constantly excellent decision of the occurrence of knocking not depending upon unevenness in manufacture and deterioration with age by accumulating vibration data where no knocking occurs and vibration data where knocking occurs, and deciding the occurrence of knocking through comparison of the two data with each other. CONSTITUTION:A control unit 9 receives detection signals from an intake air amount sensor 2, a crank angle sensor 12, and a vibration sensor 17, etc., and computes an ignition timing and a fuel injection amount. In this control unit, the magnitude of a vibration component responding to a crank angle in an ignition timing range in which no knocking is supposed to take place during operation of an internal combustion engine 7 is determined so as to be stored. Further, the magnitude of a vibration component responding to a crank angle in an ignition timing range in which knocking is supposed to take place, so as to be stored. A difference or a ratio between the magnitudes of the abovementioned vibration components is determined. By deciding whether or not knocking characteristics represented by taking the difference or the ratio are contained in vibration data provided each time ignition, the occurrence of knocking is decided.