Detecting knock vibrations in IC engines - using optical sensor in separate screw=in unit, with optical transducer placed directly behind window

摘要

A sensor arrangement, for detecting the vibrations caused by knocking in an internal combustion engine has one or more conventional optical pick-ups in the combustion chamber. The use of an independent unit which is screwed into the wall of the combustion chamber enables a large measurement window to be used. The measurement window is protected from fouling by a forward vol. (3) in the front section of the sensor arrangement whose end is sealed by a transparent window (5). The optical transducer (10) may be placed directly behind the window (5) or connected via an optical conductor. The window is in the form of a lens. A filter (9) is mounted between it and the optical sensor (10). The forward chamber (3) contains a constriction (4) and a heater in front of the window.