Double air-fuel ratio sensor system in internal combustion engine
US5134847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1991 |
| Grant date | Aug 4, 1992 |
| Priority date | — |
| Expiry date | Mar 29, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
In a double air-fuel ratio sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, the actual air fuel ratio is adjusted in accordance with the air-fuel ratio correction amount calculated by using the output of the upstream-side air-fuel ratio sensor and the output of the downstream-side air-fuel ratio sensor. In this system, a detection whether or not the catalyst converter is deteriorated is carried out by using the output of the downstream-side air-fuel ratio sensor when the feedback control condition is satisfied. This detecting operation is prohibited when the upstream-side air-fuel ratio sensor is in an abnormal state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.