VARIABLE DISPLACEMENT ENGINE ASSEMBLY INCLUDING PARTIAL BOOST ARRANGEMENT

• US 20120118274A1
• Filed: 11/17/2010
• Published: 05/17/2012
• Est. Priority Date: 11/17/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: KEATING, EDWARD J.
• Granted Patent: US 8,627,803 B2
• Time in Patent Office: Days
• US Class Current: 123/559.1
• CPC Class Codes: F01L 1/146 Push-rods
• CPC Class Codes: F01L 1/181 Centre pivot rocking arms
• CPC Class Codes: F01L 13/0031 by modification of tappet or pushrod length
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/011 having two or more purifying devices arranged in parallel
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02D 13/0226 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/06 Cutting-out cylinders
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 23/00 Controlling engines characterised by their being supercharged
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 9/02 concerning induction conduits throttle valves, or arrangements thereof in conduits F02D9/08
• CPC Class Codes: F02M 35/116 for engines with cylinders in V-arrangement or arranged oppositely relative to the main shaft
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An engine assembly may include an engine structure, a first intake valve, a first valve lift mechanism, a second intake valve, a second valve lift mechanism, and a boost mechanism. The first intake valve may be located in a first intake port and the first valve lift mechanism may be engaged with the first intake valve. The second intake valve may be located in a second intake port and the second valve lift mechanism may be engaged with the second intake valve and operable in first and second modes. The second intake valve may be displaced to an open position during the first mode and may be maintained in a closed position during the second mode. The boost mechanism may be in communication with an air source and the first intake port and isolated from the second intake port.

Claims

1. An engine assembly comprising:

a boost mechanism in communication with an air source;

an engine structure defining a first cylinder bore, a second cylinder bore, a first intake port in communication with the air source via the boost mechanism and the first cylinder bore, and a second intake port in communication with the air source and the second cylinder bore and isolated from the boost mechanism;

a first intake valve located in the first intake port;

a first valve lift mechanism engaged with the first intake valve;

a second intake valve located in the second intake port; and

a second valve lift mechanism engaged with the second intake valve and operable in first and second modes, the second intake valve being displaced to an open position by the second valve lift mechanism during the first mode and the second intake valve being maintained in a closed position by the second valve lift mechanism during the second mode.

2. The engine assembly of claim 1, further comprising a first intake manifold in communication with the first intake port and the air source via the boost mechanism and a second intake manifold in communication with the second intake port and the air source.

3. The engine assembly of claim 2, wherein the engine structure defines a first set of cylinder bores and a second set of cylinder bores disposed at an angle relative to the first set of cylinder bores, the first set of cylinder bores including the first cylinder bore and being in communication with the first intake manifold and the second set of cylinder bores including the second cylinder bore and being in communication with the second intake manifold.

4. The engine assembly of claim 3, wherein the first intake manifold is in communication with the boost mechanism and provides a compressed air flow to the first set of cylinder bores from the boost mechanism.

5. The engine assembly of claim 4, wherein the second intake manifold provides a naturally aspirated air flow to the second set of cylinder bores.

6. The engine assembly of claim 2, further comprising a first exhaust manifold in communication with the first cylinder bore and a second exhaust manifold in communication with the second cylinder bore.

7. The engine assembly of claim 6, wherein the boost mechanism includes a turbocharger in communication with the air source and the first exhaust manifold, the turbocharger driven by an exhaust gas exiting the first exhaust manifold and providing a compressed air flow to the first intake port, an exhaust gas exiting the second exhaust manifold being provided directly to a vehicle exhaust system.

8. The engine assembly of claim 1, wherein a first camshaft lobe is engaged with the first valve lift mechanism and a second camshaft lobe is engaged with the second valve lift mechanism, the second intake valve being displaced to the open position by a peak of the second camshaft lobe during the first mode and the second intake valve remaining in the closed position when the peak of the second camshaft lobe engages the second valve lift mechanism during the second mode.

9. The engine assembly of claim 1, further comprising an intake assembly including a first throttle valve and a second throttle valve, the first throttle valve being in communication with the first intake port and controlling an air flow into the first intake port and the second throttle valve being in communication with the second intake port and controlling an air flow into the second intake port.

10. The engine assembly of claim 1, wherein the engine structure defines a first set of cylinder bores including the first cylinder bore and a second set of cylinder bores including the second cylinder bore and disposed at an angle relative to the first set of cylinder bores, the first set of cylinder bores being in communication with the boost mechanism and the second set of cylinder bores being isolated from the boost mechanism.

11. A method comprising:

providing a compressed intake air flow to a first intake port of an engine assembly;

opening a first intake valve located in the first intake port with a first valve lift mechanism;

providing a naturally aspirated intake air flow to a second intake port of the engine assembly;

operating a second valve lift mechanism in a first mode where the second valve lift mechanism opens a second intake valve located in the second intake port; and

operating the second valve lift mechanism in a second mode where the second valve lift mechanism maintains the second intake valve in a closed position during engine operation.

12. The method of claim 11, wherein the first intake valve is opened when the first valve lift mechanism is engaged with a peak of a first camshaft lobe, operating the second valve lift mechanism in the first mode includes opening the second intake valve when the second valve lift mechanism is engaged with a peak of a second camshaft lobe and operating the second valve lift mechanism in the second mode includes the second intake valve remaining in the closed position when the peak of the second camshaft lobe engages the second valve lift mechanism.

13. The method of claim 12, wherein the second valve lift mechanism is operated in the second mode while the first valve lift mechanism is operated in a third mode where the first intake valve is opened when the first valve lift mechanism is engaged with the peak of the first camshaft lobe.

14. The method of claim 11, further comprising operating the first valve lift mechanism in a third mode where the first intake valve is opened with the first valve lift mechanism while the second valve lift mechanism operated in the first mode during a vehicle acceleration condition.

15. The method of claim 14, wherein the providing the compressed air flow includes driving a turbocharger with an exhaust gas flow from the engine assembly.

16. The method of claim 15, further comprising switching the second valve lift mechanism from the first mode to the second mode after the turbocharger reaches a predetermined boost condition.

17. The method of claim 14, wherein the first valve lift mechanism is operated in the third mode and the second valve lift mechanism is operated in the first mode during start-up of the engine assembly.

18. The method of claim 14, further comprising operating the engine assembly during a first power demand condition where a first engine power output is demanded and operating the engine assembly during a second power demand condition where a second engine power output greater than the first engine power output is demanded, the first valve lift mechanism being operated in the third mode during the first power demand condition and the second power demand condition and the second valve lift mechanism being operated in the second mode during the first power demand condition.

19. The method of claim 18, wherein the second valve lift mechanism is operated in the first mode during the second power demand condition.

20. The method of claim 19, wherein the second valve lift mechanism is operated in the first mode during a vehicle acceleration condition.