Misfire detecting apparatus using difference in engine rotation speed variance
US5728941A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1996 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Oct 9, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M15/11
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a misfire detecting apparatus of an internal combustion engine, a difference in rotational-speed variance from a rotation signal NE of a crankshaft and the difference in rotational-speed variance is compared with a predetermined misfire criterion value in order to make a determination as to whether a misfire has occurred in the internal combustion engine. The misfire detecting apparatus is applied to a six-cylinder internal combustion engine. An ECU employed in the misfire detecting apparatus is used for calculating differences in rotational-speed variance by using a 720.degree. CA, a 360.degree. CA, and a 120.degree. CA differential techniques. The differences in rotational-speed variance computed by using the differential techniques are each compared with a respective predetermined misfire criterion value. An outcome of the comparison is used for updating a misfire count. The ECU makes a final determination as to whether a misfire has occurred in the internal combustion engine from data of a plurality of such misfire counts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.