JPS643267A - Control device for ignition timing of internal combustion engine - Google Patents

Abstract

PURPOSE:To ensure high controlling accuracy of ignition timing by learning a value in which a reserved amount is subtracted from a knock correcting quantity which is calculated in accordance with knocking, and correctingly controlling ignition timing by means of feedback with this learned value as a reference. CONSTITUTION:A knock sensor (a) for detecting the knocking condition of an engine is provided, a knock correcting quantity is calculated by a knock correcting means (c) in accordance with the output of the sensor (a) and, when an engine is operated by a defined number of revolutions or for a defined time with the same load and in the same rotation zone as those at the point of time of calculating this knock correcting quantity, a value in which a defined value is subtracted as a reserved amount from the knock correcting quantity is stored as a leaned value by a memory means (d). On the other hand, a basic ignition timing operating means (b) operates a basic ignition timing based on the operating condition of the engine, which is corrected by a means (e) for correcting the basic ignition timing from the stored value and the knock correcting quantity. Since the ignition timing is controlled in accordance with this corrected value, the effect of dispersion in an engine or variation with time can be reduced ensuring the high controlling accuracy of ignition timing.