Catalytic converter deterioration detecting system for engine
US5412942A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1993 |
| Grant date | May 9, 1995 |
| Priority date | — |
| Expiry date | Aug 26, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A catalytic converter deterioration detecting system for an engine derives a low-frequency component in an output of a downstream-side oxygen sensor provided downstream of a catalytic converter. The system detects deterioration of the catalytic converter based on the low-frequency component, such as, an amplitude of the low-frequency component or a period of the low-frequency component. For higher detection accuracy, an amplitude of a high-frequency component in the output of the downstream-side oxygen sensor is additionally used for detecting deterioration of the catalytic converter. Specifically, the system determines that the catalytic converter is deteriorated when the low-frequency amplitude is smaller than a given value and the high-frequency amplitude is greater than a given value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.