Element crack detecting apparatus and method for oxygen sensor
US7311093B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 2006 |
| Grant date | Dec 25, 2007 |
| Priority date | — |
| Expiry date | Jul 10, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4175
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An element crack detecting apparatus for an oxygen sensor detects a sensor output voltage for an abnormality detection period after a fuel cut-off is started during operation of an engine. When the output voltage becomes negative, an abnormality counter is counted up. When the abnormality counter value reaches a determination value, it is determined that the element crack is present. The abnormality detection period is variably set in response to an engine rotational speed, an intake air quantity and the mixture state immediately before the fuel cut-off is effected. The determination value is variably set in response to the oxygen sensor temperature and the mixture state immediately before the fuel cut-off is effected. Further, the determination value is variably set in response to a magnitude of the negative voltage of the oxygen sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.