Ignition timing control device for spark ignition type IC engine

摘要

The ignition timing control device has a throttle opening variation value (delta theta) calculated on the basis of a value (theta) obtained by sampling a throttle opening degree of the engine by a throttle opening variation value sampling device (84). A real volume efficiency (Evr) is calculated on the basis of a real intake air value (A) and a real engine speed (Ne) by a real volume efficiency calculator (81). The real volume efficiency (Evr) is corrected on the basis of information relative to the throttle opening variation value (delta theta) by a volume efficiency corrector (83). An effective volume efficiency (Evm) is calculated. An ignition timing is set (58) in accordance with the effective volume efficiency (Evm) and the engine speed (Ne). An ignition timing control signal is outputted (68) on the basis of an ignition timing set (58) and an igniter (18) is activated in response to this ignition timing control signal. When the real volume efficiency (Evr) exceeds a predetermined threshold value corresp. to the vicinity of the full opening value of the throttle during acceleration, sampling operation of the throttle opening variation value sampling device (84) is prohibited (85).