Misfire detection based on crankshaft fluctuation
US5513521A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 17, 1995 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | Jan 17, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B3/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for detecting misfires in an internal combustion engine is given wherein: uneven-running values are detected which are a measure for the changes of the crankshaft rpm of the engine with the changes being caused by misfires; the spacing between bands of uneven-running values is computed; a check is made as to whether the computed band spacing is greater than a pregiven threshold spacing and, if this is the case, this data is used as an indication that misfires and not disturbances of the crankshaft rpm are present; in the case that no significant band spacing greater than the threshold spacing is determined and, in addition, uneven-running values drop below a pregiven negative threshold value, this is used as an indication that disturbances of the crankshaft rpm are present and the detection of misfires is interrupted. With this method, it is possible to reliably distinguish large uneven-running values caused by misfires from corresponding values which are caused by disturbances as they are transmitted to the engine from the drive train.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.