Exhaust emission control system of internal combustion engine
US7040086B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 2004 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | Apr 21, 2024 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/0818
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An exhaust purifying device is arranged in an exhaust gas passage extending from an internal combustion engine. The exhaust purifying device includes a NOx trapping catalyst that traps NOx in the exhaust gas when an exhaust air/fuel ratio is leaner than stoichiometric and releases the trapped NOx therefrom when the exhaust air/fuel ratio is richer than stoichiometric, and a particulate filter that collects a particulate matter in the exhaust gas. A condition detecting device is arranged to detect a condition of the particulate filter. An exhaust air/fuel ratio control device is arranged to control the exhaust gas from the engine in such a manner that the exhaust gas has a target exhaust air/fuel ratio. When the exhaust air/fuel ratio is changed from a stoichiometric or richer side to a leaner side, the exhaust air/fuel ratio control device varies the exhaust air/fuel ratio under the leaner air/fuel exhaust condition in accordance with the condition of the particulate filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.