Air-fuel ratio feedback control
US6253542A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Aug 17, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/1422
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method of controlling the air-fuel ratio of an internal combustion engine having an exhaust passage including a catalytic converter. The method includes providing a first air-fuel ratio sensor upstream of the catalytic converter, and providing a second air-fuel ratio sensor downstream of the catalytic converter. A control module having an input connected to the first and second air-fuel ratio sensors and an output connected to actuators for controlling the engine is also provided. This establishes a first feedback loop including the first air-fuel ratio sensor and a second feedback loop including the second air-fuel ratio sensor. The method further includes detecting an output value of the second air-fuel ratio indicative of a rich or lean exhaust gas air-fuel ratio. In response to the output value, the system monitors the engine mass airflow, and controls the duration of air-fuel ratio of the engine as a function of the engine mass airflow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.