Misfire detector for an internal combustion engine
US6968268B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 2004 |
| Grant date | Nov 22, 2005 |
| Priority date | — |
| Expiry date | Jan 15, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M15/11
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A misfire detector calculates the engine speed fluctuation quantity Δωn for a predetermined period of time on the basis of the average engine speed on, which is the reciprocal of the time T120n that the crankshaft of the engine takes to turn 120 degrees. By comparing the calculated engine speed fluctuation quantity Δωn with a misfire determination value REF, from which it can be determined whether the engine is misfiring, the misfire detector determines whether the engine is misfiring. The misfire detector detects the rotational fluctuation per combustion stroke of each engine cylinder and learns the variation of the detected rotational fluctuation values during normal combustion. From this learned value and the detected rotational fluctuation value per combustion stroke of the cylinder, the misfire detector determines whether the cylinder is misfiring or not.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.