Air-fuel ratio controller for multiple cylinder bank engine
US5341788A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1993 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Mar 18, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1443
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
This invention relates to an engine provided with a plurality of cylinder banks, exhaust manifolds for collecting exhaust from each bank, an exhaust branch pipe for combining the flows from the exhaust manifolds, and a three-way catalyst interposed in the exhaust branch pipe. An air-fuel ratio sensor is interposed in the exhaust manifold for each cylinder bank, and feedback control of the air-fuel ratio of each bank is performed based on the air-fuel ratio detected by the sensor of a specific bank such that this air-fuel ratio varies with a predetermined amplitude about the theoretical value as center value. The rich and lean times of the air-fuel ratio of the other banks are also measured from the output of the sensor at each bank, and feedback control is corrected for each bank such that the rich time is equal to the lean time for any bank. The number of sensors required for air-fuel ratio control of a multi-bank engine can therefore be reduced, and as the air-fuel ratio detected at the location of the three-way catalyst varies within a suitable range of tolerance, the exhaust cleaning performance of the three-way catalyst is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.