Exhaust gas purifying apparatus of internal combustion engine
US7127883B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1998 |
| Grant date | Oct 31, 2006 |
| Priority date | — |
| Expiry date | Nov 10, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purifying apparatus of an internal combustion engine is provided which includes: exhaust gas purifying means, provided in an exhaust passage of the engine, for adsorbing NOx in an exhaust gas when the air-fuel ratio of the exhaust gas is lean. The exhaust gas apparatus releases or reduces the adsorbed NOx when the oxygen concentration of the exhaust gas is reduced. A light-off catalyst is provided upstream of the exhaust gas purifying apparatus in the exhaust passage, which has a lower O2 storage capability than the exhaust gas purifying apparatus. There is a control device for controlling the air-fuel ratio of the exhaust gas so that an atmosphere having a reduced oxygen concentration is produced around the exhaust gas purifying apparatus when the NOx conversion efficiency of the exhaust gas purifying apparatus is decreased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.