Internal combustion engine ignition systems

摘要

In an internal combustion engine ignition system having a knock sensor to back-off the ignition advance at the onset of pre-ignition knocking in the engine, the sensor is activated only during a fraction of the power stroke of each piston and the activation is achieved by processing of the ignition triggering signal rather than by incorporation of position sensors on the drive shaft of the engine/gearbox combination. The signal-processing device includes first stage means to generate a signal which is shifted by a constant time relative to the signal which it receives, and second stage means which generates a signal which is shifted relative to the incoming signal by a time corresponding to a constant angle of rotation of the engine (to take into account engine rotation speed) and these stages define the beginning and the end of the periodic signal required for control of the vibration sensor.