Torque transfer system for a motor vehicle

• US 6,676,561 B2
• Filed: 11/27/2001
• Issued: 01/13/2004
• Est. Priority Date: 05/27/1999
• Status: Expired due to Fees

• Current Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Inventors: Eidloth, Rainer, Jager, Thomas, Bitzer, Franz, Weinhold, Carsten, Renk, Hans-Jürgen, Fritzer, Anton, Vornehm, Martin
• Primary Examiner(s): Parekh, Ankur
• Application Number:
  US09/995,254
• Publication Number:
  US 20020084129A1
• Time in Patent Office: 777 Days
• Field of Search: 477/70, 477/83, 477/174, 477/900, 477/901, 701/94, 701/110, 701/67, 123/339.16
• US Class Current: 477/70
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16D 2500/30806 Engaged transmission ratio
• CPC Class Codes: F16D 2500/30825 Speed of the output shaft
• CPC Class Codes: F16D 2500/3102 Vehicle direction of travel, i.e. forward/reverse
• CPC Class Codes: F16D 2500/3109 Vehicle acceleration
• CPC Class Codes: F16D 2500/3112 Vehicle acceleration change rate
• CPC Class Codes: F16D 2500/3127 Road slope
• CPC Class Codes: F16D 2500/31426 Brake pedal position
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/31473 Parking brake lever
• CPC Class Codes: F16D 2500/70282 Time
• CPC Class Codes: F16D 2500/7104 Visual alarms
• CPC Class Codes: F16D 48/066 : Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence
• CPC Class Codes: F16D 48/068 : using signals from a manually actuated gearshift linkage
• CPC Class Codes: Y10S 477/901 : Control signal is slope

Abstract

A torque transfer system of a motor vehicle has a clutch, a transmission, a control device, and a traction load detecting device. The traction load is the variable resistance that a vehicle has to overcome to start or to keep moving, e.g., going uphill or downhill, with a heavy or light load, with or without a trailer or a roof load. The control device controls the torque transfer system, in particular the clutch, dependent on input signals received from the traction load detecting device.

Claims

1. A torque transfer system arranged in a power train of a motor vehicle with an engine, comprising an input shaft with an input rpm rate and an input torque, an output shaft with an output rpm rate and an output torque, a control device, and a traction load detecting device with at least one traction load sensor device, wherein:

the torque transfer system is operable to have an effect on an rpm ratio between the input rpm rate and the output rpm rate and on a torque ratio between the input torque and the output torque;

the torque transfer system is settable to and shiftable between a plurality of shift positions, said effect on the rpm ratio and the torque ratio being dependent on the shift positions;

the control device is operable to control the setting and shifting of a selected shift position among said plurality of shift positions in accordance with a predetermined shift-control characteristic;

the motor vehicle is subjected to a traction load, which is detected by the traction load detecting device through the at least one traction load sensor device; and

the control device under predetermined conditions is connected to the traction load detecting device to receive from the latter a first traction load signal dependent on the traction load that has been detected,

the torque transfer system comprises a transmission device and a clutch device;

the control device is further operable to generate a clutch control signal for controlling a state of engagement of the clutch device, whereby under certain conditions the clutch is taken at least partially out of engagement if a predetermined characteristic operating value has reached a predetermined threshold value, said predetermined threshold value being dependent on the first traction load signal in accordance with a predetermined characteristic relationship;

the traction load detecting device comprises an inclination angle detecting device that generates an inclination angle signal dependent on an inclination angle by which the motor vehicle is inclined in relation to a horizontal position; and

the predetermined threshold value comprises at least one of an engine rpm threshold value and a transmission rpm threshold value.

2. The torque transfer system of claim 1, wherein the detection of the traction load by the traction load detecting device is based on monitoring a single traction-load characterizing value through the at least one traction load sensor device.

3. The torque transfer system of claim 1, wherein the detection of the traction load by the traction load detecting device is independent of a comparative mathematical evaluation of the input rpm rate, output rpm rate, input torque, and output torque.

4. The torque transfer system of claim 1, wherein the traction load detecting device is operative to send a second traction load signal to an optical device and the predetermined shift-control characteristic depends on said second traction load signal.

5. The torque transfer system of claim 4, wherein the second traction load signal is sent when the motor vehicle is connected to a trailer.

6. The torque transfer system of claim 5, wherein the optical device comprises an indicator light giving an indication based on the second traction load signal.

7. The torque transfer system of claim 4, wherein the second traction load signal comprises an electrical signal.

8. The torque transfer system of claim 1, wherein the traction load detecting device is operable to detect whether the motor vehicle is connected to a trailer.

9. The torque transfer system of claim 1, wherein the predetermined threshold value depends on the inclination angle signal in accordance with a predetermined inclination angle characteristic.

10. The torque transfer system of claim 1, wherein the predetermined threshold value depends on at least one of a direction of travel of the motor vehicle, the selected shift position, and the inclination angle signal.

11. The torque transfer system of claim 1, wherein under predetermined conditions the predetermined threshold value is set lower when the vehicle is traveling on a downward grade than when the vehicle is traveling on a level grade.

12. The torque transfer system of claim 1, wherein the traction load sensing device is arranged substantially on at least one of the transmission device and the control device.

13. The torque transfer system of claim 1, wherein the motor vehicle comprises a fuel tank containing a fuel and the at least one traction load sensor device comprises at least one fuel tank sensor arranged in the fuel tank.

14. The torque transfer system of claim 13, wherein the at least one fuel tank sensor is operable to detect a fill level.

15. The torque transfer system of claim 14, wherein the at least one fuel tank sensor comprises a first fuel tank sensor for detecting a first fill level substantially at the center of a fuel surface and at least one further fuel tank sensor for detecting at least one further fill level at an eccentric location of the fuel surface.

16. The torque transfer system of claim 14, wherein the at least one fuel tank sensor comprises a plurality of fuel tank sensors for detecting a plurality of fill levels at different places of a fuel surface and for generating a corresponding plurality of fill level signals, and wherein at least part of the time the inclination angle is determined based on differences between the fill level signals.

17. The torque transfer system of claim 14, wherein the at least one fuel tank sensor generates a fill level signal that changes with fluctuations in the fill level, wherein the control device monitors and evaluates the fill level fluctuations within time windows of different length in accordance with a predetermined fill level evaluation characteristic, wherein said evaluation of fill levels encompasses at least one of the phenomena consisting of a change in fill level within one of the time windows, a change in fill level from one to another of the time windows, and a change in a time gradient of the fill level from one to another of the time windows, and wherein based on said evaluation the control device can distinguish a change in the fill level signal due to a change of fuel volume in the fuel tank from a change in the fill level signal due to a change of the inclination angle.

18. The torque transfer system of claim 17, wherein the time windows of different length comprise at least a first, second and third time window which at least partially overlap each other, the first time window extending over a long time period, the second time window extending over an intermediate time period, and the third time window extending over a short time period, and wherein the change in fill level detected within the first time window is used to determine the change of fuel volume in the tank, the change in fill level detected within the second time window is used to determine the change of the inclination angle, and the change in fill level detected within the third time window is used to determine short irregularity in travel conditions of the vehicle.

19. The torque transfer system of claim 13, wherein the at least one fuel tank sensor is operable at least part of the time to detect a position change of the fuel within the fuel tank, said position change serving to determine the inclination angle.

20. The torque transfer system of claim 1, wherein the at least one traction load sensor device comprises at least one acceleration sensor.

21. The torque transfer system of claim 20, wherein the at least one acceleration sensor comprises a collision sensor.

22. The torque transfer system of claim 20, wherein the at least one acceleration sensor is operable at least part of the time to determine an actual acceleration of the motor vehicle.

23. The torque transfer system of claim 22, wherein the actual acceleration comprises at least part of the time a gravitational acceleration component acting in a direction of the inclination angle while the motor vehicle is standing still.

24. The torque transfer system of claim 20, wherein the control device determines the inclination angle at least part of the time dependent on a change in acceleration according to a predetermined acceleration characteristic.

25. The torque transfer system of claim 20, wherein the control device determines the inclination angle at least part of the time dependent on at least one of the acceleration and the change in acceleration, taking into account that a=g×

sin ∝

, where a represents an effective acceleration of the motor vehicle, ∝

represents the inclination angle, and g stands for gravitational acceleration.

26. The torque transfer system of claim 20, wherein the control device determines the inclination angle at least part of the time dependent on the acceleration as determined by the acceleration sensor and at least one further characteristic operating value.

27. The torque transfer system of claim 26, wherein the at least one further characteristic operating value comprises a travel acceleration determined from at least one wheel rpm rate.

28. The torque transfer system of claim 1, wherein the control device is further operable under predetermined conditions and dependent on the traction load signal to control predetermined characteristic operating values of the motor vehicle in accordance with a predetermined operating characteristic.

29. The torque transfer system of claim 28, wherein the predetermined conditions comprise that the traction load signal is in a predetermined traction load signal range and the controlling of the predetermined characteristic operating values comprises changing of a start-up rpm rate of the engine.

30. The torque transfer system of claim 29, wherein the predetermined traction load signal range comprises traction load signals larger than a predetermined traction load threshold signal and the changing of the start-up rpm rate of the engine comprises increasing said start-up rpm rate to a value where the engine delivers a maximum engine torque.

31. The torque transfer system of claim 29, wherein the control device under certain conditions regulates the clutch device in such a manner that the latter transmits a crawl torque of a magnitude that depends on the traction load signal.

32. The torque transfer system of claim 31, wherein the regulating of the clutch device comprises increasing the crawl torque if the traction load signal indicates a predetermined traction load increase.

33. The torque transfer system of claim 31, wherein the control device under predetermined conditions selects from a plurality of drive-behavior control programs for controlling the motor vehicle, and wherein said selection depends on the at least one traction load signal.

34. The torque transfer system of claim 1, wherein the at least one traction load signal comprises an analog traction load signal.

35. The torque transfer system of claim 1, wherein the at least one traction load signal comprises a digital traction load signal.

37. A method of operating a motor vehicle comprising the step of utilizing the torque transfer system of claim 1.

36. A method of operating at least one of a torque transfer system and an engine of a motor vehicle, comprising the steps of:

a) detecting a traction load of the motor vehicle according to a predetermined characteristic; and

b) regulating at least one characteristic operating value of the engine according to a predetermined characteristic dependent on the traction load;

wherein the at least one characteristic operating value of the engine comprises a start-up rpm rate.