Abnormality diagnosis device of internal combustion engine
US8407983B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 25, 2008 |
| Grant date | Apr 2, 2013 |
| Priority date | — |
| Expiry date | Dec 18, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A deviation amount of a downstream air-fuel ratio sensed with a downstream air-fuel ratio sensor, which senses an air-fuel ratio of exhaust gas downstream of a catalyst, from a target air-fuel ratio is integrated during a period in which the downstream air-fuel ratio continuously shows deviations from the target air-fuel ratio while main feedback control and sub feedback control are performed based on outputs of an upstream air-fuel ratio sensor and the downstream air-fuel ratio sensor respectively. The thus-calculated continuous deviation amount of the downstream air-fuel ratio (deterioration degree of exhaust gas purification rate) is compared with an abnormality determination value to determine existence/nonexistence of an abnormal state where the exhaust gas purification rate is deteriorated by an air-fuel ratio variation among cylinders (i.e., state where control center of main feedback control has shifted).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.