Method and device for monitoring the functioning of a valve stroke adjusting device of an internal combustion engine during cold starts

• US 7,269,501 B2
• Filed: 06/07/2006
• Issued: 09/11/2007
• Est. Priority Date: 06/07/2005
• Status: Active Grant

• Current Assignee: Dr. Ing. H.C.F. Porsche Ag
• Original Assignee: Dr. Ing. H.C.F. Porsche Ag
• Inventors: Nagel, Nils, Melzig, Thomas
• Primary Examiner(s): Wolfe; Willis R.
• Assistant Examiner(s): Hoang; Johnny H.
• Application Number:
  US11/447,936
• Publication Number:
  US 20060283422A1
• Time in Patent Office: 461 Days
• Field of Search: 701/109, 701/111, 701/113, 701/114, 123/396, 123/399, 123/90.15, 123/90.16, 602/74, 602/76, 602/77, 602/81, 602/85, 602/86, 702/22, 702/108, 702/113, 702/114, 702/115, 731/16, 731/19.R, 731/173, 731/181
• US Class Current: 701/114
• CPC Class Codes: F01L 13/0015 for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
• CPC Class Codes: F01L 2800/00 Methods of operation using a variable valve timing mechanism
• CPC Class Codes: F01L 2800/02 Cold running
• CPC Class Codes: F02D 11/10 of the electric type
• CPC Class Codes: F02D 2041/002 by simultaneous control of throttle and variable valve actuation
• CPC Class Codes: F02D 2041/1409 using at least a proportional, integral or derivative controller
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method and device for monitoring the functionality of a valve stroke adjusting device of an internal combustion engine in a cold start phase. The internal combustion engine includes an electronically controllable throttle, the control utilizing an integral component to control the throttle, and the functionality is monitored by determining the integral component in a cold start phase, comparing the integral component with at least one predetermined threshold value and evaluating the functionality of the valve stroke adjusting device on the basis of the comparison.

Claims

1. A method for monitoring a functionality of a valve stroke adjusting device of an internal combustion engine in a cold start phase, the internal combustion engine including a throttle that is electronically controllable by a control, wherein the control utilizes an integral component to control the throttle, comprising the steps of:

determining the existence of a cold start phase;

acquiring the integral component in the cold start phase;

comparing the acquired integral component in the cold start phase with at least one predetermined threshold value; and

evaluating the functionality of the valve stroke adjusting device based on the result of the comparison in the comparing step.

2. The method according to claim 1, further comprising the steps of:

determining a time-span elapsed since the beginning of the cold start phase; and

determining whether the determined elapsed time-span is at least equal to a predetermined time-span,

wherein the integral component acquiring step is performed only if the determined elapsed time-span is at least equal to said predetermined time-span.

3. The method according to claim 2, wherein the threshold value in the comparing step is selected from a plurality of predetermined threshold values as a function of the determined elapsed time-span.

4. The method according claim 1, wherein the internal combustion engine includes two cylinder banks with separate valve stroke adjustment by the valve stroke adjusting device, wherein the comparing step and the evaluating step include:

a first comparison of the integral component acquired in the cold start phase with a predetermined first threshold value;

a first evaluation of the functionality of the valve stroke adjusting device of the two cylinder banks based on the result of the first comparison;

a second comparison of the integral component acquired in the cold start phase with a predetermined second threshold value if the first evaluation results in a determination that the functionality of the valve stroke adjusting device of at least one of the two cylinder banks is faulty; and

a second evaluation of the functionality of the valve stroke adjusting device of the two cylinder banks based on the result of the second comparison.

5. The method according to claim 4, wherein at least one threshold value is stored in a storage device.

6. The method according to claim 4, wherein at least one threshold value is set as a function of a throttle setpoint adaptation.

7. The method according to claim 1, wherein evaluated faults in the functioning of the valve stroke adjusting device are indicated via a display.

8. A device for monitoring a functionality of a valve stroke adjusting device of an internal combustion engine in a cold start phase, the internal combustion engine including a throttle that is electronically controllable by a control, the control programmed to use an integral component to control the throttle, comprising:

a detector for acquiring the integral component in the cold start phase; and

a comparator for comparing the integral component with at least one predetermined threshold value stored in a storage device and evaluating the functionality of the valve stroke adjusting device based on a result of the comparison.

9. The device according to claim 8, wherein

the valve stroke adjusting device includes a control for generating a control signal for indicating the cold start phase, and

said comparator is configured to perform the comparison only after receipt of the control signal.

10. The device according to claim 9, wherein

the control is configured to generate a time-span signal when a predetermined time-span has elapsed since the beginning of the cold start phase, and

the comparator is configured to perform the comparison only after receipt of the time-span signal.

11. The device according to claim 8, wherein

the control is configured to generate a time-span signal which indicates a time-span that has elapsed since the beginning of the cold start phase (KSP),

a plurality of predetermined threshold values corresponding to a plurality of times elapsed since the beginning of the cold start phase are stored in the storage device, and

the comparator is configured to select the at least one predetermined threshold value to compare with the acquired integral component based on the elapsed time-span.

12. The device according to claim 8, wherein

the internal combustion engine includes two cylinder banks with separate valve stroke adjustment by the valve stroke adjusting device, and

the comparator is configured to perform

a first comparison of the integral component acquired in the cold start phase with a predetermined first threshold value;

a first evaluation of the functionality of the valve stroke adjusting device of the two cylinder banks based on the result of the first comparison;

a second comparison of the integral component acquired in the cold start phase with a predetermined second threshold value if the first evaluation results in a determination that the functionality of the valve stroke adjusting device of at least one of the two cylinder banks is faulty; and

a second evaluation of the functionality of the valve stroke adjusting device of the two cylinder banks based on the result of the second comparison.

13. A device according to claim 12, further comprising:

a throttle adaptation device configured to adapt the throttle setpoint; and

a threshold value adaptation device configured to adapt at least one predetermined threshold value.

14. The device according to claim 13, further comprising:

a display, said display displaying evaluated faults in the functioning of the valve stroke adjusting device.