Exhaust gas control apparatus and exhaust gas purification method for internal combustion engine
US6988359B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2003 |
| Grant date | Jan 24, 2006 |
| Priority date | — |
| Expiry date | Sep 16, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
An exhaust gas control apparatus and an exhaust gas purification method are for an internal combustion engine provided with a first catalyst portion disposed in an exhaust passage of the internal combustion engine, and a second catalyst portion disposed in the exhaust passage downstream of the first catalyst portion. A value that changes according to at least an amount of oxygen stored in the first catalyst portion is obtained as an obtained value. An air-fuel ratio of the internal combustion engine is controlled such that the obtained value matches a target value. A value that changes according to at least an amount of oxygen stored in the second catalyst portion is calculated as a calculated value, based on at least a state of exhaust gas flowing into the second catalyst portion. The target value is changed according to the calculated value. Accordingly, harmful components, such as unburned components and oxides of nitrogen, are able to be effectively purified even if the air-fuel ratio of the internal combustion engine changes abruptly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.