Air-fuel ratio control system
This patent describes a vehicle having an air-fuel ratio control system for an internal combustion engine comprising: an induction passage; means for supplying air-fuel mixture to the engine via the induction passage; an electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by the supply means; an O/sub 2/ sensor for detecting oxygen concentration in exhaust gases of the engine; an ignition pulse generator for producing an engine speed signal; a coolant temperature sensor for sensing temperature of coolant of the engine; and a feedback control circuit including comparator means for comparing the output of the O/sub 2/ sensor with a reference value and for producing an output signal responsive to the comparison. The feedback control circuit includes pulse generating circuit means responsive to the output signal of the comparator means for generating pulses having a duty ratio which is dependent on the output signal of the comparator means. The first pulses are for driving the electromagnetic valve to correct the air-fuel ratio. The improvement described here comprises: an engine restart detecting means including an engine speed detecting circuit for producing a restart signal when the engine speed signal is below a predetermined value; and second pulse generating means responsive to a signal of the coolant temperature sensor for producing second pulses having a duty ratio which is dependent on the coolant temperature.
- Assignee:
- Fuji Jukogyo Kabushiki Kaisha, Tokyo
- Patent Number(s):
- US 4655181
- OSTI ID:
- 6548556
- Country of Publication:
- United States
- Language:
- English
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Air-fuel ratio control system
Air-fuel ratio control system
Related Subjects
330100* -- Internal Combustion Engines
COMPARATOR CIRCUITS
CONTROL EQUIPMENT
CONTROL SYSTEMS
COOLANTS
DISPERSIONS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
ENGINES
EQUIPMENT
EXHAUST GASES
FLOW REGULATORS
FLUIDS
FUEL-AIR RATIO
FUNCTION GENERATORS
GASEOUS WASTES
GASES
HEAT ENGINES
IGNITION SYSTEMS
INTAKE STRUCTURES
INTERNAL COMBUSTION ENGINES
MAGNETS
MEASURING INSTRUMENTS
MECHANICAL STRUCTURES
METERS
MIXTURES
OXYGEN METERS
PULSE GENERATORS
SIGNALS
THERMOSTATS
VALVES
VELOCITY
WASTES