Optical engine knock sensing system

US4369748A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Leo Steinke · Waiblingen, DE
• Ernst Linder · Mühlacker, DE
• Helmut Maurer · Rodenbach, DE
• Klaus Muller · Tamm, DE
• Franz Rieger · Aalen, DE

Key dates

• Filing date: Jun 1, 1981
• Grant date: Jan 25, 1983
• Expiry date: Jun 1, 2001

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor (10) optically coupled to the combustion chamber (10') of an internal combustion (IC) engine is kept free from contaminating or dirt deposits, or the like, by subjecting the sensor to mechanical shocks or vibration. The mechanical shocks or vibration are obtained by the engine itself by controlling the engine to operate for a predetermined time period as set by a monostable flip-flop (FF) (18) under controlled knocking conditions, the shock waves within the combustion chamber causing flaking off or dropping off of contaminating deposits. Controlled knocking can be obtained by advancing ignition timing by additional control of an ignition system (19) in a direction of excessive spark advance, or overriding a knocking inhibiting system already present on the engine. The degree of contamination of the sensor can be determined, for example, by integrating the light received over a predetermined angle of rotation of the engine crankshaft and comparing this rotation with the amount of fuel supplied to the engine for combustion, for example by comparison with timing of a fuel injection pulse, or the like.