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US 9,528,406 B2Granted
Systems and methods for purge and PCV control
AssigneeFord Global Technologies, LLC
InventorsChris Paul Glugla, Daniel Joseph Styles, Michael Howard Shelby
Life of this patent
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Abstract
Methods and systems are provided for improving purge air-fuel ratio control. Fuel vapors from a canister and the crankcase are selectively purged to a group of cylinders and not to remaining engine cylinders. Exhaust is recirculated from the selected group of cylinders to the engine intake wherefrom the EGR is ingested in the remaining engine cylinders and the selected group of cylinders.
Claims20
A method, comprising:
- selectively purging fuel vapors from one or more of a fuel system canister and a crankcase to only a dedicated EGR cylinder group of a multi-cylinder engine to enrich the dedicated EGR cylinder group;
- and
- recirculating exhaust gas from the dedicated EGR cylinder group to each of remaining engine cylinders and the dedicated cylinder group.
A method, comprising:
- adjusting fueling of a dedicated cylinder, configured to recirculate exhaust to each of remaining engine cylinders, responsive to an estimate of fuel vapors purged only to the dedicated cylinder and responsive to a first exhaust air-fuel ratio of the dedicated cylinder;
- and
- adjusting fueling of the remaining engine cylinders responsive to the first exhaust air-fuel ratio and responsive to a second air-fuel ratio of the remaining engine cylinders.
An engine system, comprising:
- a first group of cylinders;
- a second group of cylinders;
- a first exhaust catalyst coupled downstream of only the first group of cylinders;
- a second exhaust catalyst coupled downstream of the second group of cylinders;
- an EGR passage configured to recirculate exhaust from only the first group of cylinders to a common engine intake, the common engine intake supplying aircharge to each of the first and second group of cylinders;
- a fuel system canister;
- a crankcase;
- a purge passage configured to purge fuel vapors from each of the canister and the crankcase to only the first group of cylinders;
- a first exhaust air-fuel ratio sensor coupled downstream of the first group of cylinders;
- a second exhaust air-fuel ratio sensor coupled downstream of the second group of cylinders;
- and
- a controller with computer-readable instructions for:
- adjusting fueling of the first group of cylinders based on an amount of purge fuel vapors received at the first group of cylinders to provide a target exhaust gas recirculation combustion tolerance to all the cylinders;
- and
- adjusting fueling of the second group of cylinders based on the exhaust gas recirculation received from the first group of cylinders to maintain a stoichiometric exhaust air-fuel ratio.
12 more elements
Dependencies are inferred from the claim text.