Engine air-fuel ratio controller
US6494038B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2001 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Feb 23, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/0814
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A catalyst 3 which has oxygen storage performance is installed in an engine exhaust passage 2, an oxygen storage amount is estimated based on the output of an upstream air-fuel ratio sensor 4 installed in the upstream of the catalyst 3, and an air-fuel ratio is controlled so that this oxygen storage amount coincides with a target value. When the output of a downstream air-fuel ratio sensor 5 has become lean or rich for longer than a fixed time, the output of the upstream air-fuel ratio sensor 4 is corrected based on the output of the downstream air-fuel ratio sensor 5 placed in the downstream of the catalyst 3. In this way, the output fluctuation due to deterioration of the air-fuel ratio sensor 4 upstream of the catalyst is corrected, and the catalyst oxygen storage amount is always precisely controlled to the target value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.