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US 9,284,920 B2Granted
Systems and methods for stopping and starting an engine with dedicated EGR
AssigneeFord Global Technologies, LLC
InventorsThomas G. Leone, Chris Paul Glugla, James Alfred Hilditch, Michael Damian Czekala, Daniel Joseph Styles
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for operating an engine including a DEGR system during start-stop and DFSO conditions. In one example, the DEGR cylinder may be deactivated prior to deactivating the non-DEGR cylinder group and stopping the engine, to purge EGR from the intake system.
Claims21
A method for operating an engine, comprising:
- deactivating a dedicated EGR (DEGR) cylinder group of a multi-cylinder engine in response to an imminent engine shutdown condition and prior to deactivating a non-DEGR cylinder group to purge EGR from an intake system;
- monitoring an EGR amount after deactivating;
- and
- deactivating the non-DEGR cylinder group and shutting down the engine in response to the monitored EGR amount falling below a threshold.
1 more element
A method for operating an engine, comprising:
- stopping fuel to a dedicated EGR (DEGR) cylinder group of a multi-cylinder engine in response to a deceleration fuel shut off (DFSO) condition while continuing fueling to a non-DEGR cylinder group;
- monitoring an EGR rate after stopping fuel to the DEGR cylinder group;
- and
- stopping fuel to each cylinder of the non-DEGR cylinder group responsive to the EGR rate below a threshold rate, wherein EGR is provided to the non-DEGR cylinder group solely via exhaust flow from the DEGR cylinder group.
1 more element
A method for operating an engine, comprising:
- during a first condition deactivating a dedicated EGR (DEGR) cylinder and deactivating each cylinder of a non-DEGR cylinder group after a first duration after deactivating the DEGR cylinder;
- and
- during a second condition stopping fuel to the DEGR cylinder and stopping fuel to each cylinder of the non-DEGR cylinder group after a second duration after stopping fuel to the DEGR cylinder.
A method for operating an engine, comprising:
- during a first condition, deactivating fuel injection to a dedicated EGR cylinder group of a multi-cylinder engine in response to an imminent engine shutdown condition while continuing fuel injection to a non-dedicated EGR cylinder group, and shutting down the engine, including the non-dedicated EGR cylinder group, only after purging at least a threshold amount of exhaust from the dedicated EGR cylinder group to an intake;
- and
- during a second condition, concurrently deactivating the dedicated EGR cylinder group and the non-dedicated EGR cylinder group of the multi-cylinder engine in response to the imminent engine shutdown condition, and blocking flow from the dedicated EGR cylinder group to the intake.
Dependencies are inferred from the claim text.