Internal combustion engine air-fuel ratio feedback control method functioning to compensate for aging change in output characteristic of exhaust gas concentration sensor
US4739740A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1987 |
| Grant date | Apr 26, 1988 |
| Priority date | — |
| Expiry date | Jun 1, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1477
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method of feedback-controlling the air-fuel ratio of a mixture, supplied to an internal combustion engine, by at least one of proportional control and integral control in dependence upon the results of a comparison between the output of an exhaust gas concentration sensor and a predetermined reference value. The method includes obtaining the ratio of a first time period required for an output value from the exhaust gas concentration sensor to make a transition from a peak value on a rich side to a predetermined reference value with respect to the predetermined reference value, and a second time period required for the output value to make a transition from a peak value on a lean side to the predetermined reference value with respect to the predetermined reference value, and altering, in dependence upon the ratio obtained, at least one predetermined control factor applied to control of the air-fuel ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.