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US 9,316,172 B2Granted
Reducing enrichment due to minimum pulse width constraint
AssigneeFord Global Technologies, LLC
InventorsThomas G. Leone, William Charles Ruona, Todd Anthony Rumpsa
Life of this patent
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Abstract
Methods and systems are provided for maintaining stoichiometry of an exhaust gas during operation of a fuel injector at a threshold pulse width. In response to operation of a fuel injector at the threshold pulse width and a rich exhaust gas air-fuel ratio, airflow is increased to the intake manifold. Engine actuators may also be adjusted to maintain torque during the increased airflow while operating the fuel injectors at the threshold pulse width.
Claims18
An engine method, comprising:
- during operation of a fuel injector at a threshold pulse width, increasing engine airflow to maintain an exhaust as mixture stoichiometric air-fuel ratio while adjusting an engine actuator to maintain torque;
- and
- increasing engine airflow responsive to a fuel pressure greater than a threshold pressure during the operation of the fuel injector at the threshold pulse width.
An engine method, comprising:
- in response to operation of a fuel injector at a threshold pulse width, when an air-fuel ratio of an exhaust gas is less than a stoichiometric ratio, increasing engine airflow by an amount based on the air-fuel ratio of the exhaust gas and greater than requested by a vehicle operator, without increasing engine torque by adjusting an engine actuator to maintain torque responsive to operation of the fuel injector at the threshold pulse width when a fuel pressure is greater than a threshold pressure, the amount of increase in engine airflow further increasing with increasing fuel pressure.
An engine system, comprising:
- an engine including an intake manifold and an engine cylinder;
- an intake throttle positioned upstream of the intake manifold;
- a fuel system having a fuel injector for injecting fuel into the engine cylinder;
- and
- a controller with computer readable instructions for adjusting a position of the intake throttle to increase engine airflow while maintaining engine torque, in response to operation of the fuel injector at a threshold fuel pulse width when a fuel pressure is greater than a threshold pressure, an amount of increase in engine airflow further increasing with increasing fuel pressure.
2 more elements
Dependencies are inferred from the claim text.