Reverse rotation intake manifold protection system and method

• US 20070163556A1
• Filed: 01/17/2006
• Published: 07/19/2007
• Est. Priority Date: 01/17/2006
• 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: Davis, Jason, Holm, Eric
• Granted Patent: US 7,543,564 B2
• Time in Patent Office: Days
• US Class Current: 123/631
• CPC Class Codes: F02D 2250/06 Reverse rotation of engine
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02P 11/02 Preventing damage to engines or engine-driven gearing

Abstract

A method of protecting an intake manifold of an engine of a hybrid propulsion system including an electric motor comprises detecting a reverse rotation of an engine. A fuel injector of the engine that is rotating in reverse is commanded to cease operation. A spark plug of the engine that is rotating in reverse is commanded to cease operation. The ceasing of reverse rotation of the engine is then confirmed.

Claims

1. A method of protecting an intake manifold of an engine of a hybrid propulsion system including an electric motor, comprising:

detecting a reverse rotation of an engine;

commanding a fuel injector of said engine that is rotating in reverse to cease operation;

commanding a spark plug of said engine that is rotating in reverse to cease operation; and

confirming reverse rotation of said engine has ceased.

2. The method of claim 1 further comprising notifying a diagnostic module of said reverse rotation.

3. The method of claim 1 further comprising commanding an electric motor to cease operation after detecting the reverse rotation.

4. The method of claim 3 wherein commanding said electric motor to cease operation further comprises commanding said electric motor to begin forward rotation.

5. The method of claim 1 further comprising commanding said fuel injector to re-enable and commanding said spark plug to re-enable after confirming reverse rotation of said engine has ceased.

6. The method of claim 1 wherein detecting a reverse rotation comprises comparing an actual cam sensor signal to an expected cam sensor signal, and wherein said expected cam sensor signal is determined based on said actual cam sensor signal and a crankshaft sensor signal.

7. The method of claim 6 wherein said expected cam sensor signal is set to a previously stored actual cam sensor signal, and wherein detecting a reverse rotation further comprises comparing a state of said actual cam sensor signal to a state of said expected cam sensor signal while said engine is operating in at least one of a first region and a second region and when a camshaft and crankshaft are synchronized.

8. The method of claim 6 wherein said expected cam sensor signal is set to an expected reverse cam sensor signal, and wherein detecting a reverse rotation further comprises comparing an edge of said actual cam sensor signal to an edge of said expected cam sensor signal for a selected crank angle region relative to top dead center of a specified cylinder when a camshaft and crankshaft are not synchronized.

9. An intake manifold protection system for a hybrid propulsion system with an internal combustion engine and an electric motor, comprising:

a fuel injector that supplies fuel to a cylinder of an engine;

a spark plug that that provides spark to said cylinder of said engine;

a control module that determines when said engine is rotating in reverse and that commands said fuel injector and said spark plug off when said engine is rotating in reverse.

10. The system of claim 9 further comprising an electric motor and wherein said control module commands said electric motor to cease operation when said engine is rotating in reverse.

11. The system of claim 10 wherein said engine further includes a crankshaft and wherein said electric motor is coupled to said crankshaft and wherein said control module commands said electric motor to rotate said crankshaft in a forward direction after said electric motor ceases operation.

12. The system of claim 9 wherein said control module notifies a diagnostic module of said reverse rotation.

13. The system of claim 9 wherein said control module confirms when said engine returns to rotating in forward direction.

14. The system of claim 13 wherein said control module commands said spark plug to re-enable and commands said fuel injector to re-enable.

15. An intake manifold protection system for a hybrid propulsion system including an engine that operates in a reverse rotational direction and an electric motor, comprising:

a cam sensor coupled to an engine that generates a cam sensor signal;

a crankshaft sensor coupled to said engine that generates a crankshaft sensor signal; and

a control module that receives said cam sensor signal and said crankshaft sensor signal and that detects when said engine is operating in a reverse rotational direction based on said cam sensor signal and said crankshaft sensor signal and that sends a cease operation command when said engine is operating in said reverse rotational direction.

16. The system of claim 15 further comprising an electric motor, wherein said control module sends said cease operation command to said electric motor.

17. The system of claim 15 further comprising at least one spark plug wherein said control module sends said cease operation command to said at least one spark plug.

18. The system of claim 17 further comprising at least one fuel injector wherein said control module sends said cease operation command to said at least one fuel injector.

19. The system of claim 16 wherein said control module sends a forward direction command to said electric motor.

20. The system of claim 15 further comprising a diagnostic module wherein said control module notifies said diagnostic module of said reverse rotation.

21. The system of claim 15 wherein said control module confirms said reverse rotation of said engine has stopped.

22. The system of claim 21 wherein said control module commands a commence operation command.