TORQUE BASED CLUTCH FUEL CUT OFF

• US 20100082220A1
• Filed: 12/02/2008
• Published: 04/01/2010
• Est. Priority Date: 10/01/2008
• 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: Kaiser, Jeffrey M., Whitney, Christopher E., Lu, Jun, Shupe, Todd R., Simon, Robert C. JR.
• Granted Patent: US 8,214,127 B2
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 41/022 in relation with the clutch status
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off

Abstract

An engine control system comprises a clutch cut off enable module and a torque control module. The clutch cut off enable module generates an enable signal based on a clutch engagement signal and an accelerator pedal signal. The torque control module reduces a spark advance of an engine to a minimum value and disables fueling of cylinders of the engine based on the enable signal. The minimum value is a minimum allowed spark advance for current engine airflow.

Claims

1. An engine control system comprising:

a clutch cut off enable module that generates an enable signal based on a clutch engagement signal and an accelerator pedal signal; and

a torque control module that reduces a spark advance of an engine to a minimum value and disables fueling of cylinders of the engine based on the enable signal, wherein the minimum value is a minimum allowed spark advance for current engine airflow.

2. The engine control system of claim 1 wherein the torque control module disables fueling of all cylinders of the engine based on the enable signal.

3. The engine control system of claim 1 wherein the clutch cut off enable module generates the enable signal when, within a predetermined period of each other, the clutch engagement signal indicates that a manual transmission clutch is disengaged and the accelerator pedal signal indicates that a pressure on an accelerator pedal is less than a threshold value.

4. The engine control system of claim 1 wherein the torque control module enables fueling of the cylinders based on an increasing torque request.

5. The engine control system of claim 4 further comprising a torque request module that generates the torque request, wherein the torque request begins at a first torque and increases to a driver requested torque.

6. The engine control system of claim 5 wherein the first torque is based on a minimum spark torque and the driver requested torque, wherein the minimum spark torque corresponds to all the cylinders being fueled and a minimum spark advance being used, and wherein the minimum spark advance is a minimum allowed spark advance for current engine airflow.

7. The engine control system of claim 6 wherein the first torque is set at a value between the minimum spark torque and the driver requested torque based on a percentage, wherein the percentage is determined based on engine speed and airflow.

8. The engine control system of claim 4 wherein the torque request is generated when engine speed reaches a predetermined speed after fueling of the cylinders has been disabled.

9. The engine control system of claim 8 wherein the predetermined speed is based on a gear ratio for a higher gear than a gear selected when the enable signal is generated.

10. The engine control system of claim 4 wherein the torque control module, after enabling fueling of the cylinders, performs a spark advance decrease corresponding to each of the cylinders, wherein the spark advance decrease offsets a torque increase realized from enabling fueling to the respective cylinder.

11. The engine control system of claim 1 wherein the minimum allowed spark advance for current engine airflow is calibrated to prevent misfire.

12. A method comprising:

generating an enable signal based on a clutch engagement signal and an accelerator pedal signal;

determining a minimum value of allowed spark advance for current engine airflow; and

reducing a spark advance of an engine to the minimum value and disabling fueling of cylinders of the engine based on the enable signal.

13. The method of claim 12 further comprising disabling fueling of all cylinders of the engine based on the enable signal.

14. The method of claim 12 further comprising generating the enable signal when, within a predetermined period of each other, the clutch engagement signal indicates that a manual transmission clutch is disengaged and the accelerator pedal signal indicates that a pressure on an accelerator pedal is less than a threshold value.

15. The method of claim 12 further comprising enabling fueling of the cylinders based on an increasing torque request.

16. The method of claim 15 further comprising generating the torque request, wherein the torque request begins at a first torque and increases to a driver requested torque, wherein the first torque is based on a minimum spark torque and the driver requested torque, wherein the minimum spark torque corresponds to all the cylinders being fueled and a minimum spark advance being used, and wherein the minimum spark advance is a minimum allowed spark advance for current engine airflow.

17. The method of claim 16 further comprising:

determining a percentage based on engine speed and airflow; and

setting the first torque at a value between the minimum spark torque and the driver requested torque based on the percentage.

18. The method of claim 15 further comprising generating the torque request when engine speed reaches a predetermined speed after fueling of the cylinders has been disabled.

19. The method of claim 18 further comprising determining the predetermined speed based on a gear ratio for a higher gear than a gear selected when the enable signal is generated.

20. The method of claim 15 further comprising, after enabling fueling of the cylinders, performing a spark advance decrease corresponding to each of the cylinders, wherein the spark advance decrease offsets a torque increase realized from enabling fueling to the respective cylinder.

21. The method of claim 12 wherein the minimum allowed spark advance for current engine airflow is calibrated to prevent misfire.