SYSTEM FOR CONTROLLABLY DISABLING CYLINDERS IN AN INTERNAL COMBUSTION ENGINE

• US 20030131820A1
• Filed: 01/15/2002
• Published: 07/17/2003
• Est. Priority Date: 01/15/2002
• Status: Active Grant

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Nichols, Gary Arthur, Mckay, Daniel Lee
• Granted Patent: US 6,619,258 B2
• Time in Patent Office: Days
• US Class Current: 123/198F
• CPC Class Codes: F01L 13/0005 Deactivating valves
• 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 2011/102 at least one throttle being moved only by an electric actuator
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2200/602 Pedal position
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/0225 in relation with the gear ratio or shift lever position
• CPC Class Codes: F02D 41/187 using a hot wire flow sensor

Abstract

A system (10) for controllably disabling cylinders in an internal combustion engine (12) includes a throttle (18) controlling air flow to an intake manifold (14), a number of cylinder deactivation devices (100₁-100_K) and an engine controller (28) controlling fueling (90), ignition timing (94) and throttle position (86). The controller (28) is operable to activate only the minimum number of cylinders required to achieve a desired engine/vehicle operating parameter value, open the throttle (18) to a computed throttle position, control ignition timing sufficiently to drive the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value, and to then control the flow area of the throttle (18) while also controlling ignition timing to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value. The engine/vehicle operating parameter may be engine output torque, engine speed or vehicle speed.

Claims

1. A method of controllably disabling cylinders in an internal combustion engine, the method comprising the steps of:

computing a minimum number of a total number of cylinders required to achieve a desired engine/vehicle operating parameter value;

computing a maximum throttle position of an air intake throttle controlling air flow into an intake manifold of the engine;

enabling operation of the minimum number of cylinders while disabling operation of remaining ones of the total number of cylinders;

opening the air intake throttle to the maximum throttle position;

determining a current value of the engine/vehicle operating parameter; and

controlling ignition timing sufficiently to drive the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value.

2. The method of claim 1 further including the step of modifying the flow area of the air intake throttle while modifying ignition timing sufficiently to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value.

3. The method of claim 2 wherein the enabling step includes enabling operation of the minimum number of cylinders by activating selected ones of a number of cylinder deactivation devices associated with the cylinders of the engine.

4. The method of claim 2 wherein the enabling step includes enabling operation of the minimum number of cylinders by enabling fuel delivery thereto;

and further including the step of controlling fuel delivery to the minimum number of cylinders to provide a lean air-to-fuel ratio.

5. The method of claim 1 wherein the engine/vehicle operating parameter is one of engine output torque and engine output power.

6. The method of claim 1 wherein the engine/vehicle operating parameter is vehicle speed.

7. The method of claim 1 wherein the engine/vehicle operating parameter is engine speed.

8. The method of claim 2 further including the step of determining air pressure within the intake manifold;

and wherein the step of computing a maximum throttle position includes computing the maximum throttle position as a function of the air pressure within the intake manifold.

9. The method of claim 8 wherein the maximum throttle position corresponds to an amount of air flow into the intake manifold sufficient to cause the current value of the engine/vehicle operating parameter to exceed the desired engine/vehicle operating parameter value after the enabling and opening steps but before the controlling step.

10. The method of claim 9 wherein the controlling step includes retarding ignition timing sufficiently to decrease the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value.

11. The method of claim 10 wherein the modifying step includes decreasing the flow area of the air intake throttle while advancing ignition timing sufficiently to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value.

12. The method of claim 8 wherein the maximum throttle position corresponds to an amount of air flow into the intake manifold sufficient to cause the desired engine/vehicle operating parameter value to be below the current value of the engine/vehicle operating parameter after the enabling and opening steps but before the controlling step.

13. The method of claim 12 wherein the controlling step includes advancing ignition timing sufficiently to increase the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value.

14. The method of claim 13 wherein the modifying step includes increasing the flow area of the air intake throttle while retarding ignition timing sufficiently to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value.

15. A method of controllably disabling cylinders in an internal combustion engine, the method comprising the steps of:

determining air pressure within an intake manifold of the engine;

determining rotational speed of the engine;

determining road speed of a vehicle carrying the engine; and

disabling operation of a number of cylinders of the engine while maintaining an engine/vehicle operating parameter near a desired value of the engine/vehicle operating parameter if the air pressure is below a pressure threshold, the rotational speed of the engine is greater than an engine speed threshold and the road speed of the vehicle is greater than a vehicle speed threshold.

16. The method of claim 15 further including the step of determining whether the desired value of the engine/vehicle operating parameter can be achieved by operation of the currently enabled cylinders of the engine;

and wherein the disabling step is further conditioned upon the desired value of the engine/vehicle operating parameter being achievable by operation of the currently enabled cylinders of the engine.

17. The method of claim 16 further including the following steps if the desired value of the engine/vehicle operating parameter cannot be achieved by operation of the currently enabled cylinders of the engine:

determining whether the number of currently operating cylinders equals the total number of cylinders of the engine;

increasing the number of cylinders in operation if the number of currently operating cylinders does not equal the total number of cylinders and executing the disabling step thereafter, and otherwise inhibiting execution of the disabling step.

18. The method of claim 15 wherein the disabling step includes:

computing a minimum number of a total number of cylinders required to achieve the desired value of the engine/vehicle operating parameter;

computing a maximum throttle position of an air intake throttle controlling air flow into an intake manifold of the engine;

enabling operation of the minimum number of cylinders while disabling operation of remaining ones of the total number of cylinders;

opening the air intake throttle to the maximum throttle position;

determining a current value of the engine/vehicle operating parameter;

controlling ignition timing sufficiently to drive the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value; and

modifying the flow area of the air intake throttle while controlling ignition timing sufficiently to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value.

19. The method of claim 15 wherein the engine/vehicle operating parameter is one of engine output torque and engine output power.

20. The method of claim 15 wherein the engine/vehicle operating parameter is the rotational speed of the engine.

21. The method of claim 15 wherein the engine/vehicle operating parameter is the road speed of the vehicle.

22. A method of controllably disabling cylinders in an internal combustion engine, the method comprising the steps of:

determining air pressure within an intake manifold of the engine; and

disabling operation of a number of cylinders of the engine while maintaining a current value of an engine/vehicle operating parameter near a desired value of the engine/vehicle operating parameter if the air pressure is below a first pressure threshold and one of the desired value of the engine/vehicle operating parameter is below an operating parameter threshold and the air pressure is below a second pressure threshold.

23. The method of claim 22 further including the following steps if one of the desired value of the engine/vehicle operating parameter is below the operating parameter threshold and the air pressure is below the second pressure threshold:

determining whether the number of cylinders currently in operation equals the total number of cylinders of the engine;

increasing the number of cylinders currently in operation if the number of cylinders currently in operation does not equal the total number of cylinders and executing the disabling step thereafter, and otherwise inhibiting execution of the disabling step.

24. The method of claim 22 further including the following steps if the air pressure is not below the first pressure threshold:

determining whether cylinder disabling operation is allowed; and

decreasing the number of cylinders currently in operation if cylinder disabling operation is allowed and the desired value of the engine/vehicle operating parameter is not below the operating parameter threshold and executing the disabling step thereafter.

25. The method of claim 24 further including the step of inhibiting execution of the disabling step if cylinder disabling operation is not allowed.

26. The method of claim 24 further including the following steps if cylinder disabling operation is allowed and the desired value of the engine/vehicle operating parameter is below the operating parameter threshold:

determining whether the number of cylinders currently in operation equals the total number of cylinders of the engine;

increasing the number of cylinders currently in operation if the number of cylinders currently in operation does not equal the total number of cylinders and executing the disabling step thereafter, and otherwise inhibiting execution of the disabling step.

27. The method of claim 22 wherein the disabling step includes:

computing a minimum number of a total number of cylinders required to achieve the desired value of the engine/vehicle operating parameter;

computing a maximum throttle position of an air intake throttle controlling air flow into an intake manifold of the engine;

enabling operation of the minimum number of cylinders while disabling operation of remaining ones of the total number of cylinders;

opening the air intake throttle to the maximum throttle position;

determining a current value of the engine/vehicle operating parameter;

controlling ignition timing sufficiently to drive the current value of the engine/vehicle operating parameter to the desired engine/vehicle operating parameter value; and

modifying the flow area of the air intake throttle while controlling ignition timing sufficiently to maintain the current value of the engine/vehicle operating parameter near the desired engine/vehicle operating parameter value.

28. The method of claim 22 wherein the engine/vehicle operating parameter is one of engine output torque and engine output power.

29. The method of claim 22 wherein the engine/vehicle operating parameter is the rotational speed of the engine.

30. The method of claim 22 wherein the engine/vehicle operating parameter is the road speed of the vehicle.