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US 10,119,479 B2Granted
Methods and systems for boost control based on exhaust pressure greater than a threshold
AssigneeFord Global Technologies, LLC
InventorsPhilip Andrew Fabien, Stephen George Russ, Michael A. Mancini, Jonathan Cherry
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for mitigating excessive exhaust pressures in an engine. In one example, a method may include adjusting an intake throttle responsive to exhaust pressure upstream of an exhaust turbine being higher than a threshold without reducing boost level. In this way, boost pressures may be maintained while reducing exhaust pressures.
Claims18
A method for an engine, comprising:
- adjusting an intake throttle responsive to pre-turbine exhaust pressure greater than a threshold without reducing boost level and while maintaining valve timing,
- wherein the threshold is based on a pressure required to force open a closed exhaust valve.
A method for an engine, comprising:
- treating engine exhaust gas with a particulate filter, the particulate filter positioned downstream of a turbocharger turbine;
- estimating exhaust pressure upstream of the turbocharger turbine based on soot loading of the particulate filter;
- and
- reducing intake airflow if the estimated exhaust pressure is greater than a threshold,
- wherein the threshold is based on a pressure that will force open an exhaust valve when the exhaust valve would otherwise be closed.
2 more elements
An engine system, comprising:
- an engine including an intake and an exhaust;
- an engine cylinder including an intake valve and an exhaust valve;
- a turbocharger for providing a boosted intake airflow, the turbocharger including an exhaust turbine;
- an intake throttle;
- an exhaust wastegate;
- an intake cam for adjusting an intake valve timing;
- a particulate filter coupled downstream of the exhaust turbine;
- a pressure sensor coupled downstream of the exhaust turbine;
- and
- a controller with computer readable instructions stored on non-transitory memory for:
- operating the engine with boost enabled and with positive valve overlap to blow-through an amount of boosted air from the intake to the exhaust via the engine cylinder;
- estimating exhaust pressure upstream of the exhaust turbine based on soot loading of the particulate filter;
- and
- if the estimated exhaust pressure is greater than a threshold, reducing one or more of intake airflow via the intake throttle and the amount of blow-through boosted air,
- wherein reducing the amount of blow-through boosted air includes adjusting a timing of the intake cam to reduce the positive valve overlap between an intake valve and an exhaust valve.
12 more elements
Dependencies are inferred from the claim text.