Exhaust purification device of internal combustion engine
US5471836A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1993 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Jun 14, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An NO.sub.x absorbent (19) is disposed in an exhaust passage of an internal combustion engine and an NO.sub.x oxidizing agent (18) is disposed in the exhaust passage upstream of the NO.sub.x absorbent (19). The NO.sub.x absorbent (19) absorbs the NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (19) is lean and releases the absorbed NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (19) becomes the stoichiometric air-fuel ratio or rich. When the lean air-fuel mixture is burned, if the temperature of the NO.sub.x absorbent (19) is low, the NO.sub.x oxidized by the NO.sub.x oxidizing agent (18) is absorbed by the NO.sub.x absorbent (19), while if the temperature of the NO.sub.x absorbent (19) is high, the NO.sub.x is oxidized by the NO.sub.x absorbent (19) and absorbed in the NO.sub.x absorbent (19).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.