Air-fuel ratio control system for an internal combustion engine

Patent · Tue Jul 21 04:00:00 EDT 1987

OSTI ID:6233363

Noguchi, K; Totsune, A; Kajita, K; Hosaka, T

This patent describes an air-fuel ratio control system which is operative to control the air intake side secondary air supply for an internal combustion engine having a fuel supply system including a carburetor with a slow speed fuel supply circuit which opens into an intake passage at a position near a throttle valve in the engine when the throttle valve is substantially fully closed. The control system includes a feedback control means in which air intake side secondary air is supplied to the carburetor, on the downstream side of the throttle valve, in response to a result of a detection of an air-fuel ratio by means of an oxygen concentration sensor which senses the oxygen concentration of an exhaust gas of the engine. The control system further includes control means for actuating the feedback control means to perform an air-fuel ratio control of air intake side secondary air supply and for substantially eliminating the operation of the slow speed fuel supply circuit of the fuel supply system in response to the result of the detection of the air-fuel ratio. Under a high load operating condition of the engine, the magnitude of the vacuum in the intake passage is on the downstream side of the throttle valve and is low.

• Assignee: Honda Giken Kogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4681078
• OSTI ID: 6233363
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
AIR FLOW
CARBURETORS
COMPUTERIZED CONTROL SYSTEMS
CONTROL EQUIPMENT
CONTROL SYSTEMS
ENGINES
EQUIPMENT
EXHAUST GASES
FEEDBACK
FLOW REGULATORS
FLUID FLOW
FLUIDS
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
GAS FLOW
GASEOUS WASTES
GASES
HEAT ENGINES
INTAKE STRUCTURES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
MECHANICAL STRUCTURES
METERS
OXYGEN METERS
VALVES
WASTES