Device for detecting the degree of deterioration of a catalyst
US5414996A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1992 |
| Grant date | May 16, 1995 |
| Priority date | — |
| Expiry date | Nov 10, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A catalyst deterioration detecting device comprising a first air-fuel ratio sensor and a second air-fuel ratio sensor which are arranged in the exhaust passage upstream and downstream of the catalyst, respectively. When the air-fuel ratio of the mixture fed into the engine is changed over from the lean air-fuel ratio (A/F).sub.L to the rich air-fuel ratio (a/F).sub.R, the air-fuel ratio detected by the second air-fuel ratio sensor is changed to the rich air-fuel ratio (A/F).sub.R after it is maintained at the stoichiometric air-fuel ratio for a time AT.sub.R. The deterioration of the catalyst is detected based on the time T.sub.R, the amount of air and the difference between the rich air-fuel ratio (A/F).sub.R and the stoichiometric air-fuel ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.