Exhaust gas purifying device of an engine
US5271223A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 19, 1993 |
| Grant date | Dec 21, 1993 |
| Priority date | — |
| Expiry date | Jan 19, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
An exhaust gas purifying device including a first O.sub.2 sensor, a first three-way catalyst, a secondary air feed port, a second O.sub.2 sensor, and a second three-way catalyst, which are arranged in the exhaust passage in that order. When not increasing the fuel supplied, the feeding of secondary air is stopped and feedback control is performed based on the output signals of the first O.sub.2 sensor and the second O.sub.2 Sensor so that the air-fuel ratio of the mixture fed to the engine cylinders becomes the stoichiometric air-fuel ratio. When increasing the fuel supplied, the feedback control of the air-fuel ratio is stopped, secondary air is fed from the secondary air feed port, and the amount of secondary air is controlled so that the air-fuel ratio of the gas flowing into the second three-way catalyst becomes the stoichiometric air-fuel ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.