Air-fuel ratio control system for internal combustion engine having improved air-fuel ratio-shift correction method
US5423307A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1993 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Jun 30, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/0042
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air-fuel ratio control system for an internal combustion engine which includes an evaporative fuel purge system having a canister for temporarily storing fuel vapor, detects an air to fuel ratio in the exhaust gas from the engine. An air-fuel ratio controller controls the air-fuel ratio in exhaust gas from the engine by varying a fuel quantity supplied to the engine so that the air-fuel ratio approaches a predetermined target air-fuel ratio. The evaporated fuel is purged from the canister at a specific purging rate determined based on engine operating conditions. An air-fuel ratio-shift is controlled based on the derivation of an amount by which the air-fuel ratio has shifted from the target air-fuel ratio due to a cause independent of the purging operation. The first amount, which is relatively constant over time in comparison to a second amount of air-fuel ratio shift occurring as a result of the purging operation, is derived based on a first detected air-fuel ratio-shift amount when the purge system is purging at a first purging rate. The second air-fuel ratio-shift amount is detected when the purge system is purging at a second purging rate different from the first purging r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.