Device for purifying exhaust gas of internal combustion engine
US6119452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1998 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | May 13, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A three-way catalyst (8a) is connected to a first cylinder group 1a. The exhaust gas of the first cylinder group (1a), which has passed through the three-way catalyst (8a), and the exhaust gas of a second cylinder group (1b) are introduced to an exhaust gas purifying catalyst (14). The second cylinder group (1b) performs the lean operation. The first cylinder group (1a) performs the rich operation to synthesize NH.sub.3 from NO.sub.X in the exhaust gas of the first cylinder group (1a) in the three-way catalyst (8a). In the exhaust gas purifying catalyst (14), NO.sub.X in the exhaust gas of the second cylinder group 1b is purified by NH.sub.3 from the three-way catalyst (8a). The amount of HC flowing to the three-way catalyst (8a) is obtained. When the HC amount exceeds a predetermined amount, the first cylinder group 1a must perform the lean operation temporarily, to thereby maintain the excellent catalytic activity of the three-way catalyst (8a).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.