Oxygen concentration-detecting device for internal combustion engines
US5869744A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Oct 17, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/407
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An oxygen concentration-detecting device detects the concentration of oxygen present in exhaust gases emitted from an internal combustion engine. The device includes an oxygen sensor of a limit current type. A heater heats the oxygen sensor. A first voltage is applied to the oxygen sensor and the concentration of oxygen is detected based on a first output current from the oxygen sensor obtained when the first voltage is applied to the oxygen sensor. A second voltage is applied to the oxygen sensor at a first repetition period and the internal resistance of the oxygen sensor is detected based on a second output current from the oxygen sensor obtained when the second voltage is applied to the oxygen sensor. The oxygen sensor is heated by the heater based on the internal resistance of the oxygen sensor detected. Values of the concentration of oxygen are sampled based on the first output current from the oxygen sensor at a second repetition period shorter than the first repetition period and the sampled values of the concentration of oxygen are stored. The concentration of oxygen is estimated based on the sampled values of the concentration of oxygen stored. In another form of the inve…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.