Method of detecting deterioration of exhaust gas ingredient concentration sensor
US5179929A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1991 |
| Grant date | Jan 19, 1993 |
| Priority date | — |
| Expiry date | Nov 22, 2011 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/2448
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method of detecting deterioration of an exhaust gas ingredient concentration sensor for use in controlling an air-fuel ratio of a mixture supplied to an internal combustion engine having an exhaust system in which the sensor is arranged. The sensor has an output characteristic approximately proportional to concentration of a specific ingredient in exhaust gases emitted from the engine. The air-fuel ratio is feedback-controlled to a desired air-fuel ratio by calculating an amount of fuel supplied to the engine by the use of a desired air-fuel ratio coefficient indicative of the desired air-fuel ratio and set in dependence on operating conditions of the engine, and an air-fuel ratio correction coefficient set in dependence on a value of an output from the sensor and the desired air-fuel ratio coefficient. A plurality of average values of the air-fuel ratio correction coefficient are calculated, respectively, when the desired air-fuel ratio falls within a plurality of predetermined ranges. The average values thus calculated are compared with each other. A degree of deterioration of the sensor is determined from results of the comparison. Further, a method of feedback-controlling the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.