Solenoid duty cycle modulation for dynamic control of refueling vapor purge transient flow

Patent · Tue Jul 07 04:00:00 EDT 1987

OSTI ID:6295366

Hamburg, D R

A method is described of controlling purging of fuel vapors from a vapor canister storing fuel vapors from the fuel tank of an internal combustion engine to the intake of an internal combustion engine, including the steps of: inducting a mixture of fuel and inlet air into the internal combustion engine; providing a purge command signal during the time desired to purge the canister of vapors; inducting purge air through the canister to induct a mixture of purge air and fuel vapor from the canister into the internal combustion engine in response to the purge command signal; sensing an output parameter in the exhaust of the internal combustion engine indicative of the air/fuel ratio of the internal combustion engine; regulating the mixture of fuel and inlet air in response to the output sensing to provide an air/fuel ratio of inlet air and purge air to fuel vapor and fuel within a predetermined range; and modulating the purge flow mixture of purge air and fuel vapor in response to initiation of the purge command signal. The modulate enables gradual increase of purge flow from no purge flow during a predetermined transient time at the beginning of command signal so that regulating step is able to prevent the air/fuel ratio from exceeding the predetermined range during the predetermined transient time. The predetermined transient time is approximately equal to the propagation time of a mixture of air and fuel through the same engine.

• Assignee: Ford Motor Co., Dearborn, MI
• Patent Number(s): US 4677956
• OSTI ID: 6295366
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
AUTOMOTIVE FUELS
CONTAINERS
DISPERSIONS
ELECTRIC COILS
ELECTRICAL EQUIPMENT
ENGINES
EQUIPMENT
EXHAUST GASES
FLUIDS
FUEL-AIR RATIO
FUELS
GASEOUS WASTES
GASES
HEAT ENGINES
INTAKE STRUCTURES
INTERNAL COMBUSTION ENGINES
MECHANICAL STRUCTURES
MIXTURES
MODULATION
SIGNALS
SOLENOIDS
TANKS
TIME DEPENDENCE
TRANSIENTS
VAPORS
WASTES