Method to Reduce Engine Emissions for an Engine Capable of Multi-Stroke Operation and Having a Catalyst

• US 20070113542A1
• Filed: 01/05/2007
• Published: 05/24/2007
• Est. Priority Date: 03/19/2004
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lewis, Donald
• Granted Patent: US 7,650,745 B2
• Time in Patent Office: Days
• US Class Current: 60/285
• CPC Class Codes: F02D 13/06 Cutting-out cylinders
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method to control valves in a cylinder operating in a multi-stroke cylinder mode. Valves are controlled to improve engine emissions as operating conditions vary.

Claims

1. A method for controlling the number of cylinder strokes in at least a cylinder operating in a internal combustion engine, the method comprising:

operating at least a cylinder with a first number of strokes in a cycle of said cylinder, during at least a first operating condition of a catalyst; and

operating said cylinder with a second number of strokes in a cycle of said cylinder, during a second catalyst operating condition, said second catalyst operating condition different from said first catalyst operating condition.

2. The method of claim 1 wherein said operating state of said catalyst brick is a oxidant storage capacity.

3. The method of claim 1 wherein said operating state of said catalyst is an amount of oxidants stored by said catalyst brick.

4. The method of claim 1 wherein said catalyst state is temperature of said catalyst brick.

5-12. -12. (canceled)

13. A method for determining the number of cylinder strokes in a cycle an internal combustion engine, the method comprising:

determining an operating state of at least one catalyst brick located in an exhaust system of said internal combustion engine;

determining a number of cylinder strokes to delay a valve opening, in respective cylinders of said engine, after a combustion event, in respective cylinders, based on said catalyst brick operating state.

14. The method of claim 13 wherein said valve is an intake valve.

15. The method of claim 13 wherein said valve is an exhaust valve.

16. The method of claim 13 wherein said operating state of said catalyst brick is a oxidant storage capacity.

17. The method of claim 13 wherein said operating state of said catalyst is an amount of oxidants stored by said catalyst brick.

18. The method of claim 13 wherein said catalyst state is temperature of said catalyst brick.

19. A method for determining the number of cylinder strokes in a cycle of a cylinder of an internal combustion engine, the method comprising:

determining an operating condition of at least one catalyst brick located in an exhaust system of said internal combustion engine;

selecting a number of cylinders in which to delay a valve opening after a combustion event in respective cylinders based on said catalyst brick operating condition.

20. The method of claim 19 wherein said valve is an intake valve.

21. The method of claim 19 wherein said valve is an exhaust valve.

22. The method of claim 19 wherein said operating state of said catalyst brick is a oxidant storage capacity.

23. The method of claim 19 wherein said operating state of said catalyst is an amount of oxidants stored by said catalyst brick.

24. The method of claim 19 wherein said catalyst state is temperature of said catalyst brick.

25. A method for determining the number of cylinder strokes in a cycle of a cylinder of an internal combustion engine, the method comprising:

determining an operating condition of at least one catalyst brick located in an exhaust system of said internal combustion engine;

selecting a number of cylinders in which to delay a valve opening after a combustion event in respective cylinders based on said catalyst brick operating condition; and

adjusting an air-fuel mixture in said number of selected cylinders.

26. The method of claim 25 wherein said air-fuel is adjusted rich of stoichiometry.

27. The method of claim 25 wherein said air-fuel is adjusted lean of stoichiometry.

28. The method of claim 25 wherein said valve is an intake valve.

29. The method of claim 25 wherein said valve is an exhaust valve.

30. A method for determining the number of cylinder strokes in a cycle of a cylinder of an internal combustion engine, the method comprising:

determining an operating condition of at least one catalyst brick located in an exhaust system of said internal combustion engine;

selecting a number of cylinders in which to delay a valve opening after a combustion event in respective cylinders, based on said catalyst brick operating condition;

determining a number of valves to operate in said selected cylinders, based on said catalyst brick operating condition; and

operating said number of valves in said selected cylinders during a cycle of said internal combustion engine.

31. The method of claim 30 wherein said valve is an intake valve.

32. The method of claim 30 wherein said valve is an exhaust valve.

33. (canceled)

34. A method for determining a valve pattern to operate in an internal combustion engine operating in a multi-stroke cylinder mode, the method comprising:

determining an operating condition of at least one catalyst brick located in an exhaust system of said internal combustion engine;

operating at least two groups of cylinders, a first group operating in a first cylinder stroke mode, and a second group operating in a second cylinder stroke mode; and

determining a valve pattern to operate, based on said operating condition, in said first cylinder group and in said second cylinder group.

35. A computer readable storage medium having stored data representing instructions executable by a computer to control an internal combustion engine of a vehicle, said storage medium comprising:

instructions for operating at least a cylinder with a first number of strokes in a cycle of said cylinder, based at least on an operating condition of a catalyst; and

operating said cylinder with a second number of strokes in a cycle of said cylinder, based on a change in said catalyst operating condition.

36. A method for controlling the number of cylinder strokes in at least a cylinder operating in a internal combustion engine, the method comprising:

operating at least a cylinder with a first number of strokes in a cycle of said cylinder, based at least on an operating condition of a catalyst; and

operating said cylinder with a second number of strokes in a cycle of said cylinder, based on a change in said catalyst operating condition.