Abstract: A system for controlling ignition timing in an engine wherein a knocking signal is generated by a sensor in response to knocking. The operation of the sensor is monitored, and when a fault in its operation is detected, a dummy signal, instead of the knocking signal is used to control engine timing. The dummy signal causes the engine timing to be retarded to a value at which knocking is unlikely to occur.

Abstract: A system for controlling ignition timings in an engine wherein ignition signals in the specific cylinders are previously advanced by a predetermined value over ignition signals in other cylinders, the knockings in the specific cylinders are detected, and ignition timings in all the cylinders are delayed in accordance with said knockings, whereby strong knockings which would otherwise be caused to all the cylinders are prevented in advance, the ignition timing control of knockings in the engine can be effected irrespective of the accuracies of a knocking sensor.

Abstract: Method and system for controlling ignition timing includes the steps of and means for discriminating when the time interval between knocking indicative signal pulses is shorter than a particular time period, and controlling ignition timing at a rate related to the frequency of occurrence of knocking to prevent the knocking from occurring. A pulse train is generated having an interval shorter than that of the knocking signal pulse train when the interval of the knocking signal pulse is shorter than the particular time period. The generated pulse train is fed to a control circuit for determining the time by which ignition pulses should be delayed.

Abstract: A knocking detector for an internal combustion engine includes a vibration unit comprising an inertial mass member and springs which are mounted in a housing attached to an engine body. The spring constants of the springs are so selected that the resonant frequency of the vibration unit becomes substantilly equal to the frequency of vibration due to knocking of the engine, and the vibration of the vibration unit is detected and converted into an electric signal.

Abstract: An ignition system for an internal combustion engine comprises knock detecting means for detecting knocking of the engine, and ignition timing control means for controlling the ignition timing of the engine in response to the presence or absence of the knocking condition. The knock detecting means detects the pressure in the cylinders of the engine to detect the occurrence of knocking by the fact that the detected pressure includes a high frequency pressure variation. The ignition timing control means is responsive to the output of the knock detecting means, whereby as long as no knocking is detected the ignition timing is controlled to provide the minimum advance for best torque (MBT) and ensure improved engine power efficiency and fuel consumption, whereas when knocking is detected the ignition timing is retarded in relation to the minimum advance for maximum torque (MBT) to prevent the engine from knocking.

Abstract: A device for controlling the vacuum advancing of ignition timing including a vacuum advancer, a diaphragm valve, a first vacuum port opened to an intake passage which is positioned so as to be immediately upstream of a throttle valve when it is fully closed and downstream of the throttle valve when it is slightly opened. A second vacuum port is located absolutely downstream of the throttle valve, wherein the diaphragm valve produces a fraction of the intake manifold vacuum when the throttle valve is fully closed while it communicates therethrough the intake manifold vacuum supplied from the second vacuum port when the throttle valve is opened so as to position the first vacuum port at the downstream thereof.

Abstract: An ignition system for an internal combustion engine is described, including an ignition timing control apparatus which is useful for cleaning the exhaust gas and saving fuel, which ignition timing control apparatus is controlled by first, second and third control signals in which the first control signal represents the rotating speed of a crank shaft, the second control signal represents the value of the negative pressure in an intake manifold and the third control signal indicates that the internal combustion engine is idle.

Abstract: A spark timing control device for use in an internal combustion engine, which includes a pressure control valve wherein when an input vacuum is not higher than a given vacuum level, an output vaccum remains at a zero level, and when the input vacuum is not lower than the given level, the output vacuum will be a product of a proportional constant and the difference between the input vacuum and the aforesaid given vacuum level; a pressure source; and a vacuum advance control mechanism. The pressure source is connected to the input side of the pressure control valve, while the output side of the pressure control valve is connected to the vacuum advance control mechanism.Various modifications of the pressure control valve employable in the spark timing control device are also presented.

Abstract: An ignition system for internal combustion engines wherein an ignition timing computer circuit starts the computation of an ignition timing in response to the detection of a predetermined angular position of the crankshaft of an internal combustion engine by an angular position detector, and an ignition device ignites the engine according to the computed ignition timing. A pressure detector detects variations of the pressure in the cylinders caused by the ignition of the engine and a retard-advance detector determines whether the angular position of the engine crankshaft corresponding to the maximum cylinder pressure agrees with the desired angular position. This retard-advance detector compensates the computation of ignition timing in the ignition timing computer circuit in accordance with its determination.