Method of detecting combustion misfires

US5691469A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Manfred Mezger · Markgröningen, DE
• Andrea Lohmann · Forstau, AT
• Klaus Ries-Muller · Bad Rappenau, DE
• Jurgen Forster · Tegernheim, DE

Key dates

• Filing date: Aug 29, 1996
• Grant date: Nov 25, 1997
• Expiry date: Aug 29, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M15/11
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention is directed to a method for detecting combustion misfires in an internal combustion engine on the basis of a first signal wherein the nonuniformity of the rotational movement of the crankshaft of the engine is imaged. The method includes the steps of: generating a second signal which is periodic and has a period duration corresponding to one of the following: the cycle duration of a complete work cycle of the engine or the cycle duration divided by a whole number, and the second signal having a fixed phase relationship to the rotational movement of said crankshaft; providing an ancillary signal based on the first signal; modulating the second signal with the ancillary signal and filtering the second signal to form a third signal; and, utilizing the third signal for detecting the presence of misfires and for identifying the cylinder affected by the misfires.