Method and apparatus for detecting misfires in a controlled ignition internal combustion engine
US5606119A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1995 |
| Grant date | Feb 25, 1997 |
| Priority date | — |
| Expiry date | Jul 5, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method for producing of catalytic converter diagnostic signals and/or signals indicating that the harmful component emission threshold in exhaust gases has been exceeded. To produce the signal, the gas torque (Cg) for each combustion stroke in each cylinder is determined; the engine speed (N) and air inlet manifold pressure (Pca) during the corresponding previous inlet stroke is measured; the reference torque (C ref), which is a function of N and Pca, is calculated by interpolation from a map; C ref is weighted, for example, by multiplication with a coefficient (K) associated with the corresponding cylinder and/or with the steady or transient engine running mode in order to deduce the expected theoretical torque (Cpr) which is compared with the gas torque (Cg) to ascertain a combustion misfire if Cg/Cpr is less than S2 and if Cpr-Cg exceeds the S3 or S4 threshold, depending on whether the engine is in transient or steady mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.