Nissan Motor Company Limited

Toshio Enoshima

Hideyuki Tamura

Shoji Furuhashi

Jun-ichi Kuro

The voltage of the vehicle battery is checked to see whether the voltage is below a predetermined value or not. When the battery voltage is below the predetermined value, the engine crankshaft rotational speed is raised by increasing the amount of air fed to the engine so that the rotational speed of the alternator driven by the engine increases resulting in an increase in the charging current.

Apparatus for preventing a vehicle battery from being overdischarged

A comparator compares, either before or after being rectified, a signal obtained from the vibration signal representing the vibrations of a spark ignition internal combustion engine and which has passed through a signal transmitting circuit, with a reference level signal from a reference level signal forming circuit to produce a knock signal representing the occurrence of knocking when the former signal is greater in magnitude than the latter. The reference level signal forming circuit rectifies and smooths the vibration signal to produce a rectified smoothed signal, and includes a first amplifying circuit which amplifies the rectified smoothed signal to produce the reference level signal, mentioned above. When the engine speed is above a predetermined value, an engine speed determining circuit produces a drive signal to which a changeover circuit responds by changing the magnitude of at least one of the signal transmitting circuit and the reference level signal forming circuit from one value to another whereby possible knocking occurring in the overall range of higher and lower engine speeds is reliably detected for use in spark timing control in the spark ignition internal combustion engine.

Knock detector

A spark timing adjusting circuit receives a basic spark timing signal from a spark timing determining circuit and regulates the spark timing according to a knocking signal from a knocking detector. A speed changing circuit serves to increase the rate of advance of the spark timing after the spark timing has been retarded when the operational state of the engine is in a first predetermined range corresponding to a first speed range in which all the engine speeds are lower than a first predetermined value. The speed changing circuit may include a circuit which decreases the rate of retard of the spark timing when the operational state of the engine is in a second predetermined range corresponding to a second speed range in which all the engine speeds are higher than a second predetermined value which is higher than the first predetermined value, thereby avoiding rapid retardation of the spark timing. Alternatively, the first and second predetermined ranges of the operational state of the engine may be defined with respect to intake manifold vacuum, throttle valve opening or intake air amount to the engine.

Spark timing system for spark ignition internal combustion engine

A knocking control system includes a spark timing adjusting circuit which responds to the magnitude of knocking occurring in the engine to set an amount of retardation of the timing from a reference spark timing within a predetermined range. The spark timing adjusting circuit includes a range change circuit which responds to a drive signal produced from an engine operational state determining circuit, in order to change the predetermined range.

Growing community of inventors

Fujisawa, Japan

Toshio Enoshima