Air-to-fuel ratio control system
US4980834A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1988 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Jun 30, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1488
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air-to-fuel ratio control system executes a feedback control of air-to-fuel ratio based on an output of an oxygen sensor. The oxygen sensor is judged to be active when a change of the output therefrom occurs to make a fuel mixture rich. For detecting the failure or breakdown of the oxygen sensor when the feedback air-to-fuel control is suspended, the air-to-fuel ratio control system comprises an activity sensor for detecting whether the oxygen sensor is active or inactive, an air-to-fuel ratio altering device for enforcing an alteration of air-to-fuel ratio to make a fuel mixture rich, and a judging device for judging the oxygen sensor to be broken down when no activity detection is made while the alteration of air-to-fuel ratio has been effected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.