Method and system for controlling secondary air for internal combustion engine
US5285639A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1992 |
| Grant date | Feb 15, 1994 |
| Priority date | — |
| Expiry date | Jul 10, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Secondary air is supplied to a position upstream of a catalyst disposed in an exhaust passage of an engine. An oxygen sensor is disposed between a secondary air supply portion of the exhaust passage and the catalyst. The supply amount of the secondary air is feedback controlled so that the oxygen concentration in the exhaust gas detected by the oxygen sensor approaches a target value corresponding to a theoretical air/fuel ratio. A second oxygen sensor for air/fuel ratio control is disposed upstream of the secondary air supply portion. Air/fuel ratio feedback control adjusts the air/fuel ratio of air entering the engine so that the oxygen concentration at the second oxygen sensor approaches the same target value as at the other oxygen sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.