Method of fuel injection for a variable displacement engine

• US 9,506,408 B2
• Filed: 06/02/2014
• Issued: 11/29/2016
• Est. Priority Date: 06/02/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Glugla, Chris Paul, Surnilla, Gopichandra
• Primary Examiner(s): Nguyen, Hung Q
• Assistant Examiner(s): BAILEY, JOHN D
• Application Number:
  US14/294,035
• Publication Number:
  US 20150345407A1
• Time in Patent Office: 911 Days
• Field of Search: 123/403, 123/481, 123/673, 123/691, 123/692, 123/198.F, 701/103, 701/104
• US Class Current: 1/1
• CPC Class Codes: F01L 13/0005 Deactivating valves
• CPC Class Codes: F01L 2013/001 Deactivating cylinders
• CPC Class Codes: F01L 2800/03 Stopping; Stalling
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 2041/389 for injecting directly into the cylinder
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/0614 Actual fuel mass or fuel injection amount
• CPC Class Codes: F02D 2200/60 said parameters being related to the driver demands or status
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: F02D 41/3094 the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder
• CPC Class Codes: F02D 41/345 Controlling injection timing F02D41/365 takes precedence
• CPC Class Codes: F02D 41/402 Multiple injections
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02

Abstract

Various systems and methods are described for controlling fuel injection in a variable displacement engine. One method for a deactivatable cylinder comprises, before deactivating the cylinder responsive to operating conditions, disabling a port injector and fueling the cylinder only via the direct injector. The method further comprises, when reactivating the cylinder from deactivation, enabling both the port injector and the direct injector, and injecting a higher amount of fuel via the direct injector while simultaneously injecting a lower amount of fuel via the port injector.

Claims

1. A method for an engine including a selectively deactivatable cylinder, comprising:

decreasing an amount of fuel injected by a port injector while increasing an amount of fuel injected by a direct injector prior to deactivating the cylinder;

wherein the amount of fuel injected by the port injector is substantially zero;

further comprising discontinuing fueling via the direct injector when a quantity of intake port fuel puddle of the cylinder is completely consumed.

2. The method of claim 1, wherein the quantity of intake port fuel puddle of the cylinder is estimated based on one or more of airflow, amount of fuel injected by a port injector of the cylinder, intake manifold pressure, and intake manifold temperature.

3. The method of claim 1, further comprising trapping a fresh air charge before deactivating the cylinder, the trapping achieved by closing and maintaining closed each of an intake valve and an exhaust valve throughout one or more cylinder cycles after fresh air is drawn into the cylinder.

4. The method of claim 3, further comprising deactivating the cylinder by disabling each of the port injector and the direct injector, deactivating the intake valve and the exhaust valve, and disabling spark ignition within the deactivated cylinder.

5. The method of claim 4, further comprising adjusting an engine operating parameter in response to the deactivating of the cylinder to maintain engine torque.

6. The method of claim 5, wherein the engine operating parameter includes an opening of an intake throttle, and wherein the adjusting includes increasing the opening of the intake throttle.

7. The method of claim 5, wherein the engine operating parameter includes spark timing, and wherein the adjusting includes retarding the spark timing.

8. A method for an engine including a cylinder, comprising:

before selectively deactivating the cylinder in response to operating conditions, reducing

a first proportion of fuel injected by a port injector while correspondingly increasing a second proportion of fuel injected by a direct injector; and

when reactivating the cylinder from deactivation, increasing the second proportion of fuel delivered via the direct injector relative to the first proportion of fuel delivered via the port injector;

further comprising

estimating a quantity of fuel puddle at an intake port of the cylinder;

further comprising,

before selectively deactivating the cylinder, discontinuing fueling via the direct injector when the quantity of fuel puddle is completely consumed.

9. The method of claim 8, further comprising, when reactivating a cylinder, decreasing the second proportion of fuel delivered via the direct injector and concurrently increasing the first proportion of fuel delivered by the port injector responsive to the quantity of fuel puddle attaining a steady state value.

10. The method of claim 8, further comprising, when reactivating a cylinder, decreasing the second proportion of fuel delivered via the direct injector and concurrently increasing the first proportion of fuel delivered by the port injector responsive to the quantity of fuel puddle reaching a threshold, the threshold adjusted responsive to operating conditions.

11. The method of claim 8, further comprising, adjusting one or more engine operating parameters responsive to torque disturbances caused by reactivating the cylinder.

12. A system, comprising:

an engine including a cylinder capable of deactivation;

a port injector and a direct injector coupled to the cylinder; and

a controller with computer-readable instructions stored in non-transitory memory for;

before deactivating the cylinder responsive to operating conditions;

disabling the port injector; and

fueling the cylinder only via the direct injector; and

when reactivating the cylinder from deactivation;

enabling both the port injector and the direct injector; and

injecting a higher amount of fuel via the direct injector while simultaneously injecting a lower amount of fuel via the port injector

wherein before deactivating the cylinder responsive to operating conditions, the controller is further configured to discontinue the fueling via the direct injector when a fuel puddle in an intake port of the cylinder is consumed.

13. The system of claim 12, wherein the controller is further configured for estimating a quantity of the fuel puddle in the intake port of the cylinder based on one or more of airflow, amount of fuel injected by the port injector, manifold pressure, and intake manifold temperature.

14. The system of claim 13, wherein when reactivating the cylinder, the controller is further configured for decreasing the amount of fuel from the direct injector as the quantity of the intake port fuel puddle increases, and correspondingly increasing the amount of fuel from the port injector.

15. The system of claim 12, wherein the controller is further configured for, before deactivating the cylinder, trapping a fresh air charge within the cylinder, the fresh air charge not being fueled or combusted during the deactivation.