Methods and systems for engine control
AssigneeFord Global Technologies, LLC
InventorsAdam Banker, Amey Karnik, Michael Howard Shelby, Russell Senior, Adam Krach
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for improving fuel efficiency and tailpipe emissions of a variable displacement engine. Fueling is initially disabled in cylinders selected to be deactivated while pumping air through the cylinders to an exhaust after-treatment catalyst, and then valve operation is disabled. On reactivation, if manifold vacuum is dissipated, one bank of cylinders are reactivated while the other bank is operated in DFSO with valves pumping air until manifold vacuum is reestablished.
Claims20
A method for an engine, comprising:
- operating an engine with cylinder valves and fuel injectors of a first and a second group of cylinders deactivated;
- and
- responsive to cylinder cut-off exit conditions being met,
- operating the first group of cylinders with cylinder valves reactivated and fuel injectors disabled while operating the second group of cylinders fueled and with all engine cylinder valves reactivated until manifold pressure is lower than a threshold.
A method for an engine, comprising:
- deactivating all engine cylinder valves of a first and second group of cylinders responsive to deceleration cylinder cut-off (DCCO) entry conditions being met;
- and
- responsive to DCCO exit conditions being met while manifold pressure is higher than a threshold,
- operating the first group of cylinders with fuel disabled and all engine cylinder valves reactivated while operating the second group of cylinders fueled at stoichiometry and with all engine cylinder valves activated.
An engine system, comprising:
- a first cylinder on a first engine bank and a second cylinder on a second engine bank;
- selectively deactivatable fuel injectors correspondingly coupled to the first and second cylinder;
- selectively deactivatable valve mechanisms correspondingly coupled to an intake valve and an exhaust valve of the first and second cylinder;
- an exhaust after-treatment system including a first exhaust catalyst coupled downstream of the first engine bank and a second exhaust catalyst coupled downstream of the second engine bank;
- a manifold pressure sensor;
- and
- a controller with computer readable instructions stored on non-transitory memory that when executed cause the controller to:
- responsive to decreased operator torque demand, operate the first and second cylinder with fuel and valve operation disabled;
- and
- responsive to increased operator torque demand, transition the first cylinder to a deceleration fuel shut-off mode with fuel disabled and valve operation enabled while reactivating fuel and valve operation of the second cylinder if manifold pressure is higher than a threshold at the increased operator torque demand.
Dependencies are inferred from the claim text.