Deteriorated condition detecting apparatus for an oxygen sensor
US4177787A · kind A · utility
43Cited by
4References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 14, 1977 |
| Grant date | Dec 11, 1979 |
| Priority date | — |
| Expiry date | Jul 14, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N2550/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for detecting a deteriorated condition of an oxygen concentration sensor mounted in an exhaust pipe for an internal combustion engine for controlling an air-fuel ratio is described. The apparatus includes, in addition to the sensor, a reference oxygen concentration sensor mounted in the exhaust pipe downstream of a cleaning device, and a discrimination unit for determining the deterioration of the oxygen concentration sensor for controlling the air-fuel ratio by measuring at least one of a duty factor and a period of an output signal from the reference oxygen concentration sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.