Air/fuel ratio sensor apparatus for use with internal combustion engine
US4753203A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1986 |
| Grant date | Jun 28, 1988 |
| Priority date | — |
| Expiry date | Feb 21, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4065
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An air/fuel ratio sensor apparatus which is capable of detecting deterioration of the sensing elements and correcting the output of the apparatus accordingly. The apparatus includes two sensing elements and a closed compartment of which the two sensing elements define at least portions. One of the sensing elements is used as an oxygen concentration measuring cell, and the other as an oxygen pump cell. When the internal combustion engine with which the sensor is associated is running without fuel supply, a reference voltage used for controlling the oxygen pumping current is set to a smaller value than that employed when the engine is running with a fuel supply. Deterioration of the sensing elements is then detected by comparing the output air/fuel ratio signal produced at that time with a preset fixed value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.