METHOD FOR STARTING AN ENGINE

• US 20110132307A1
• Filed: 12/16/2009
• Published: 06/09/2011
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gibson, Alex O`Connor, Oshinsky, David, Ulrey, Joseph Norman, Liu, Xiangying, Patterson, Henry W.
• Granted Patent: US 7,962,278 B1
• Time in Patent Office: Days
• US Class Current: 123/179.3
• CPC Class Codes: F02N 11/00 Starting of engines by means of electric motors
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 11/0848 with means for detecting successful engine start, e.g. to stop starter actuation
• CPC Class Codes: F02N 11/0855 during engine shutdown or after engine stop before start command, e.g. pre-engagement of pinion
• CPC Class Codes: F02P 5/1506 with particular means during starting
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for improving starting of an engine that may be repeatedly stopped and started is presented. In one embodiment, the method disengages a starter in response to a first predicted combustion in a cylinder of the engine. The method may reduce one-way clutch degradation of a starter. Further, the method may reduce current consumption during engine starting.

Claims

1. A method for starting an engine, comprising:

stopping the engine;

predicting a first combustion cycle of a cylinder from engine stop in which an air-fuel mixture is combusted;

engaging a starter; and

disengaging said starter during the predicted first combustion cycle.

2. The method of claim 1 wherein said cylinder is a first cylinder to combust an air-fuel mixture since engine stop.

3. The method of claim 1 wherein said starter is disengaged during an expansion stroke and wherein said air-fuel mixture is a first combustion event since said engine stop.

4. The method of claim 1 wherein a pinion of said starter rotates at a first speed during engagement of said starter and wherein said pinion rotates at a second speed during cranking of said engine.

5. The method of claim 1 wherein said predicting occurs before said starter is engaged in response to an engine position at engine stop.

6. The method of claim 1 wherein said predicting occurs after said starter is engages and during rotation of said engine.

7. The method of claim 1 wherein said disengaging of said starter is related to a speed threshold of said engine.

8. The method of claim 7 wherein said speed threshold decreases as altitude increases and increases as altitude decreases.

9. The method of claim 1 wherein said starter is disengaged at a predetermined crankshaft angle during said cylinder cycle.

11. The method of claim 9 wherein said re-engaging said starter occurs before an end of an exhaust stroke of said cylinder cycle.

12. The method of claim 9 wherein a speed of a pinion of said starter is controlled to substantially match engine speed during said re-engaging of said starter.

13. A method of claim 9 wherein said starter is disengaged during an expansion stroke.

14. The method of claim 9 wherein said speed threshold increases as altitude decreases and decreases as altitude increases.

15. The method of claim 9 further comprising disengaging said starter at a predetermined crankshaft angle during a cycle of a second cylinder, said cycle of said second cylinder during a cylinder cycle that said second cylinder is predicted to combust said air-fuel mixture.

16. The method of claim 15 further comprising re-engaging said starter when a speed of said engine is less than a threshold during said cycle of said second cylinder cycle that said second cylinder is predicted to combust said air-fuel mixture.

10. A method for starting an engine, comprising:

predicting a first combustion cycle of a cylinder from engine stop in which an air-fuel mixture is combusted;

engaging a starter; and

disengaging said starter during the predicted first combustion cycle; and

re-engaging said starter when a speed of said engine is less than a threshold.

17. A method for starting an engine, comprising:

during a first condition;

engaging a starter to rotate an engine from a stop and disengaging said starter when a speed of said engine exceeds a threshold; and

during a second condition, different than said first condition;

stopping the engine;

predicting a first combustion cycle of a cylinder from engine stop in which an air-fuel mixture is combusted;

engaging a starter; and

disengaging said starter during the predicted first combustion cycle.

18. The method of claim 17 wherein said first condition is an engine temperature less than a threshold.

19. The method of claim 17 wherein said second condition is an engine temperature greater than a threshold.

20. The method of claim 17 wherein said starter is disengaged during said second condition during an expansion stroke of said predicted first combustion cycle.