Engine system and operation method using engine braking mechanisms for early exhaust valve opening

• US 9,234,467 B2
• Filed: 02/25/2013
• Issued: 01/12/2016
• Est. Priority Date: 02/23/2012
• Status: Active Grant

• Current Assignee: Jacobs Vehicle Systems Incorporated (Cummins Incorporated)
• Original Assignee: Jacobs Vehicle Systems Incorporated (Cummins Incorporated)
• Inventors: Ernest, Steven N., Metha, Darius
• Primary Examiner(s): McMahon, Marguerite
• Assistant Examiner(s): HOLBROOK, TEUTA BAJRAMOVIC
• Application Number:
  US14/008,811
• Publication Number:
  US 20140373808A1
• Time in Patent Office: 1,051 Days
• Field of Search: 123/321, 123/322, 123/90.1, 123 9015- 9018, 123/90.27, 123/90.6
• US Class Current: 1/1
• CPC Class Codes: F01L 1/08 Shape of cams
• CPC Class Codes: F01L 1/24 by fluid means, e.g. hydraulically
• CPC Class Codes: F01L 13/0036 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
• CPC Class Codes: F01L 13/06 for braking
• CPC Class Codes: F02D 13/0246 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0273 Multiple actuations of a valve within an engine cycle
• CPC Class Codes: F02D 13/04 using engine as brake
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 41/006 using internal EGR control of valve overlap for internal EGR F02D13/0261; arrangements for internal EGR F02M26/01
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/12 for deceleration F02D41/0005, F02D41/107 take precedence
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A valve actuation system for an internal combustion engine is disclosed. The engine has a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves. The valve actuation system for the exhaust valves includes one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves, and one or more second cams having an early exhaust valve opening (EEVO) lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves. The valve actuation system may provide any combination of (i) main exhaust valve actuation with or without compression release actuation with (ii) main exhaust valve actuation with or without EEVO for the two sets of cylinders.

Claims

1. In an internal combustion engine having at least two cylinders and at least one exhaust valve providing selective communication between each cylinder and an exhaust manifold, a method of operating the engine and actuating the exhaust valves in each cylinder comprising the steps of:

providing one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to a first exhaust valve associated with a first cylinder;

providing one or more second cams having an early exhaust valve opening lobe and a main exhaust lobe adapted to transfer valve actuation motion to a second exhaust valve associated with a second cylinder; and

operating the engine in a first positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event without being actuated for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event without being actuated for an early exhaust valve opening event.

2. The method of claim 1, further comprising:

operating the engine in a second positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event without being actuated for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

3. The method of claim 2, further comprising:

operating the engine in a third positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

4. The method of claim 3, further comprising:

operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

5. The method of claim 2, further comprising:

operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

6. The method of claim 1, further comprising:

operating the engine in a third positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

7. The method of claim 6, further comprising:

operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

8. The method of claim 1, further comprising:

operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

9. The method of claim 1 wherein said one or more first cams is comprised of a single first cam having a compression-release lobe and a main exhaust lobe.

10. The method of claim 9 wherein said one or more second cams is comprised of a single second cam having an early exhaust valve opening lobe and a main exhaust lobe.

11. The method of claim 9 wherein said one or more second cams is comprised of two cams each having one of an early exhaust valve opening lobe or a main exhaust lobe.

12. The method of claim 1 wherein said one or more first cams is comprised of two cams each having one of a compression-release lobe or a main exhaust lobe.

13. The method of claim 12 wherein said one or more second cams is comprised of a single second cam having an early exhaust valve opening lobe and a main exhaust lobe.

14. The method of claim 12 wherein said one or more second cams is comprised of two cams each having one of an early exhaust valve opening lobe or a main exhaust lobe.

15. A valve actuation system for an internal combustion engine having a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves, said valve actuation system comprising:

one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves;

one or more second cams having an early exhaust valve opening lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves; and

one or more valve train elements connecting the first cams with the first set of exhaust valves and the second cams with the second set of exhaust valves.

16. The valve actuation system of claim 15, further comprising:

an engine controller adapted to operate the engine using the one or more valve train elements, first cams and second cams in;

a first positive power mode of operation in which the first set of exhaust valves are actuated for main exhaust events without being actuated for compression-release events, and the second set of exhaust valves are actuated for main exhaust events without being actuated for early exhaust valve opening events.

17. The valve actuation system of claim 16, wherein the engine controller is further adapted for operating the engine in a second positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event without being actuated for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

18. The valve actuation system of claim 17, wherein the engine controller is further adapted for operating the engine in a third positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

19. The valve actuation system of claim 18, wherein the engine controller is further adapted for operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

20. The valve actuation system of claim 17, wherein the engine controller is further adapted for operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

21. The valve actuation system of claim 16, wherein the engine controller is further adapted for operating the engine in a third positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

22. The valve actuation system of claim 21, wherein the engine controller is further adapted for operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

23. The valve actuation system of claim 16, wherein the engine controller is further adapted for operating the engine in a first engine braking mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event and for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event and for an early exhaust valve opening event.

24. The valve actuation system of claim 15 wherein said one or more first cams is comprised of a single first cam having a compression-release lobe and a main exhaust lobe.

25. The valve actuation system of claim 24 wherein said one or more second cams is comprised of a single second cam having an early exhaust valve opening lobe and a main exhaust lobe.

26. The valve actuation system of claim 24 wherein said one or more second cams is comprised of two cams each having one of an early exhaust valve opening lobe or a main exhaust lobe.

27. The valve actuation system of claim 15 wherein said one or more first cams is comprised of two cams each having one of a compression-release lobe or a main exhaust lobe.

28. The valve actuation system of claim 27 wherein said one or more second cams is comprised of a single second cam having an early exhaust valve opening lobe and a main exhaust lobe.

29. The valve actuation system of claim 27 wherein said one or more second cams is comprised of two cams each having one of an early exhaust valve opening lobe or a main exhaust lobe.