IC engine knock vibration sensor - has electrodes in combustion chamber aligned with vibration propagation direction and scoured by gases

摘要

A sensor for detecting the vibrations occurring in an i.c. engine because of knocking has an ion current measurement path subjected to the combustion chamber gases and a rod-shaped electrode with aninsulated mounting in the combustion chamber wall. It is insensitive to contamination and is scoured by the combustion gases flowing past it. The sensor can operate in the engine for long periods. The electrode (14) projects directly into the combustion chamber. A further rod-shaped electrode (15) has an insulated mounting in the chamber wall. The electrodes are arranged so that the imaginary line joining them together lies in the direction of propagation of the Knock vibrations. Their separating distance is in a fixed proportion to the wavelength of the Knock vibrations.