Air-fuel ratio control device of an internal combustion engine

Patent · Tue Jun 27 04:00:00 EDT 1989

OSTI ID:5614957

Uranishi, K; Itou, T

This patent describes an internal combustion engine having at least one cylinder; and intake passage and an exhaust passage. The engine consists of: a charcoal canister containing activated carbon therein and connected to the intake passage via a purge passage; fuel supply means arranged in the intake passage to feed fuel into the intake passage; an oxygen concentration detector arranged in the exhaust passage to produce a lean signal when an air-fuel ratio of an air-fuel mixture fed into the cylinder is larger than a predetermined air-fuel ratio and to produce a rich signal when the air-fuel ratio of the air-fuel mixtures is smaller than the predetermined air-fuel ratio; first means producing an electric correction signal for correcting the amount of fuel fed from the fuel supply means in response to the lean signal and the rich signal to equalize the air-fuel ratio of the air-fuel mixture with the predetermined air-fuel ratio, the electric correction signal having a level which normally varies between a predetermined upper limit and a predetermined lower limit and reaches either one of the predetermined upper limit and the predetermined lower limit when the air-fuel mixture fed into the cylinder becomes excessively rich; determining means for determining whether or not the level of the electric correction signal reaches either one of the predetermined upper limit and the predetermined lower limit.

• Assignee: Toyota Jidosha Kabushiki Kaisha, Toyota
• Patent Number(s): US 4841940
• OSTI ID: 5614957
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL EQUIPMENT
DESIGN
ELECTRICAL EQUIPMENT
ENGINES
ENRICHMENT
EQUIPMENT
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
OXYGEN ENRICHMENT