Apparatus for detecting deterioration of exhaust gas purifying catalysts
US6463735B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2001 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Aug 10, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An engine has an upstream-side catalyst and a downstream-side catalyst. First and second air-fuel ratio sensors are provided on the upstream and downstream sides of the upstream-side catalyst, respectively. A third air-fuel ratio sensor is provided on the downstream side of the downstream-side catalyst. The deteriorating state of the upstream-side catalyst is diagnosed during a period of time in which the third sensor is outputting a voltage in a predetermined range, and the air-fuel ratio is controlled to maintain the voltage output of the third sensor in the predetermined range during the period of time to diagnose the deteriorating state of the upstream-side catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.