Engine air-fuel ratio control with fuel vapor pressure-based feedback control feature
US6338336B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 6, 1999 |
| Grant date | Jan 15, 2002 |
| Priority date | — |
| Expiry date | Aug 6, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/2454
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for controlling the air-fuel ratio of an internal combustion engine that prevents erroneous learning while properly setting a learning frequency to thereby execute highly accurate air-fuel ratio control. Fuel vapor generated in a fuel tank is temporarily adsorbed in a canister via a tank inner pressure-regulating valve, and the adsorbed vapor is discharged to an engine intake system via a purge solenoid valve. A sensor for detecting tank inner pressure is arranged in the fuel tank, and an ECU calculates a feedback correction amount based on an oxygen concentration in exhaust gas and executes air-fuel ratio feedback control by using the feedback correction amount. The ECU prohibits the air-fuel ratio learning value from being updated when the tank inner pressure exceeds a predetermined criterion value based on the tank inner pressure detected by the tank inner pressure sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.