Ignition timing control device for internal combustion engines

Claim 1

An ignition timing control device for an internal combustion engine, comprising: first means for setting the normal ignition timing of the engine; second means responsive to occurrence of knocking in said engine for providing a first signal; p1 third means responsive to manipulation of the engine for achieving an acceleration higher than a predetermined acceleration level, for providing a second signal; and fourth means for determining the actual ignition timing of the engine, said fourth means being adapted, responsive to said first signal, for setting the ignition timing for an optimum knocking condition, said fourth means being also adapted, responsive to said second signal, for causing said normal ignition timing to be quickly retarded in accordance with said second signal to such an extent that knocking tending to occur when said manipulation of the engine is made can be avoided, and for causing said normal ignition timing to be recovered immediately after the end of the retardation thereof, said third means comprising: a monostable multivibrator responsive to a signal derived from said first means; an integrator circuit adapted to be reset by a signal obtained in said third means in response to said manipulation of the engine and for integrating the output of said monostable multivibrator for a period of time corresponding to a predetermined number of ignitions occurring subsequent to said manipulation of the engine so that the duration of said ignition timing retardation is determined on the basis of said predetermined number of ignitions; and a comparator for comparing the output of said integrator circuit with a reference signal corresponding to said predetermined acceleration level, thereby providing said second signal.