Method of detecting abnormality in a system for detecting exhaust gas ingredient concentration of an internal combustion engine
US4638658A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 16, 1985 |
| Grant date | Jan 27, 1987 |
| Priority date | — |
| Expiry date | Sep 16, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/148
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method of detecting an abnormality in a system for detecting the concentration of an ingredient contained in exhaust gases emitted from an internal combustion engine, including a sensor for detecting the same concentration, wherein a correction value for the air-fuel ratio of a mixture being supplied to the engine is set in response to an output signal from the sensor, the correction value thus set being applied in detecting the abnormality. A first predetermined value and a second predetermined value smaller than the first predetermined value are set, which both lie within a first range defined by an upper limit value of the correction value and a lower limit value of same that can be assumed when the engine is in normal operating conditions. When the correction value continues to fall outside a second range defined by the first predetermined value and the second predetermined value over a limited period of time, it is determined that the system for detecting the exhaust gas ingredient concentration including the sensor is abnormal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.