Air/fuel ratio controller for internal combustion engine
US6622477B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2002 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Jul 18, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A catalyst which has an oxygen storage function is provided in the exhaust gas pipe 2 of an engine 1. The oxygen storage amount is estimated based on the output of the air/fuel ratio sensor 4 upstream of the catalyst 3. The air/fuel ratio is controlled so that the oxygen storage amount coincides with the target value. When the output of the downstream air/fuel ratio sensor 5 continuously displays a rich or a lean value for more than a determination time which is varied continuously with respect to operating conditions, deterioration in the upstream air/fuel ratio sensor 4 is detected. Thus the output of the upstream air/fuel ratio sensor 4 is corrected based on the output of the downstream air/fuel ratio sensor 5. In this manner, output fluctuations are corrected based on the deterioration of the air/fuel ratio sensor 4 upstream of the catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.