Engine air-fuel ratio control apparatus
US4676213A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 26, 1986 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | Sep 26, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1456
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air-fuel ratio control apparatus is disclosed in which an air-fuel ratio sensor disposed in the exhaust system of an internal combustion engine produces a voltage signal correlated with the excess air ratio of the ambient gas surrounding it and has such an output characteristic as to produce a maximum output only when the ambient gas is filled with air, the air-fuel ratio of the internal combustion engine being controlled to a proper value on the basis of the detection signal of the air-fuel ratio sensor. The air-fuel ratio control apparatus further comprises a sampling device for sampling the maximum output (V.sub.x) when it is decided that the output of the air-fuel ratio sensor is maintained for a predetermined length of time or longer at a predetermined value or higher, a memory for storing the sample value of the maximum output (V.sub.x) produced by the sampling device and updating the preceding sample value (V.sub.x-1) to the present sample value (V.sub.x) when a new maximum output is sampled each time of the decision, and a calibrator for calibrating the output characteristic of the air-fuel ratio sensor on the basis of the latest updated sample value (V.sub.x).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.