Exhaust emission control for engine
US6637194B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 2001 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Feb 16, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An engine exhaust emission control arrangement has a catalytic converter including a three-way catalyst. A first oxygen sensor detects an oxygen concentration of exhaust gas upstream of the catalyst and a second oxygen sensor detects an oxygen concentration of exhaust gas downstream of the catalyst. A microprocessor calculates a specific period oxygen storage amount of a catalyst while the upstream oxygen concentration is higher than the stoichiometric concentration and the downstream oxygen concentration is in a predetermined concentration range which has a value approximately equal to the stoichiometric oxygen concentration. The microprocessor also calculates a specific period oxygen release amount of a catalyst while the upstream oxygen concentration is lower than the stoichiometric concentration and the downstream oxygen concentration produces an indication of a predetermined concentration range. A specific period oxygen storage amount is sampled at a time at which the downstream oxygen concentration becomes greater than the predetermined concentration range as a maximum oxygen storage amount and a specific period oxygen release amount is sampled at a time at which the downstre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.