Abstract: A knock control apparatus and method for an internal combustion engine serves to simplify hardware components employed to reduce the load thereon, and hence minimize the cost of manufacture while improving the freedom of control of an engine control unit. Vibrations of a cylinder are sensed to generate a vibration level which is then averaged to provide an average value. A knock determination threshold is generated based on the average value. The vibration level is compared with the threshold for determining whether knock is taking place in the cylinder. When the vibration level exceeds the threshold, engine control parameters are controlled in a direction to suppress knocking in the cylinder. Preferably, the averaging of the vibration level comprises averaging the vibration level to provide a first average value, and averaging the first average value to provide a second average value.

Abstract: An improved knocking suppression apparatus for an internal combustion engine is able to determine whether there is knocking in the engine through a microcomputer, reduce the load on the electric circuits employed and simplify the arrangement thereof. A knock interface circuit including a peak holding circuit and an averaging circuit is connected to receive the output signal of a knock sensor for generating a peak-hold signal (V.sub.P) representative of a peak in the knock sensor output signal and for generating an average signasl (V.sub.A) representative of an average of the knock sensor output signal. A microcomputer, based on the average signal (V.sub.A), sets a threshold level (V.sub.TH) and makes a comparison between the peak-hold signal (V.sub.P) and the threshold level (V.sub.TH) to determine when knocking occurs. An ignition timing controller retards the ignition timing as the number of revolutions per minute of the engine increases.

Abstract: An ignition timing control apparatus for a multi-cylinder internal combustion engine has a position sensor for generating a series of position signals. Each signal corresponds to one of the cylinders of the engine and indicates a first position and a second position with respect to top dead center of the piston of the corresponding cylinder. The number of degrees of crankshaft rotation between the first and second positions is different for a prescribed reference cylinder of the engine than for the other cylinders of the engine. A cylinder recognizing portion of a microcomputer recognizes the reference cylinder based on the signal from the position sensor. An ignition timing braking portion of the microcomputer performs ignition timing braking when the target ignition timing falls during a prescribed braking period and ignition has yet to take place when a piston reaches its second position.

Abstract: An ignition timing controller for an internal combustion engine calculates a first ignition delay time and generates an ignition signal when the first delay time has elapsed subsequent to a prescribed first piston position of the engine. When a second position occurs before the first delay time has elapsed, the first delay time of replaced by a second delay time measured from the second piston position, and an ignition signal is generated when the second delay time elapses. An igniter ignites a cylinder of the engine when the ignition signal is generated.

Abstract: An ignition timing control device for a multi-cylinder internal combustion engine is disclosed, which determines the control timings of the ignition system on the basis of a rotational position signal, the leading and trailing edges of the pulses of which signal correspond to the first and second rotational positions of the crankshaft in relation to respective cylinders, wherein the second rotational position with respect to a specific cylinder is displaced by an offset angle. The pulses corresponding to the specific cylinder are identified by a cylinder identifying means on the basis of duty ratio t/T of the pulses.