Torque transfer system for a motor vehicle

• US 20020084129A1
• Filed: 11/27/2001
• Published: 07/04/2002
• Est. Priority Date: 05/27/1999
• Status: Active Grant

• Current Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Inventors: Renk, Hans-Jurgen, Fritzer, Anton, Eidloth, Rainer, Jager, Thomas, Vornehm, Martin, Bitzer, Franz, Weinhold, Carsten
• Granted Patent: US 6,676,561 B2
• Time in Patent Office: Days
• US Class Current: 180/246
• 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, the torque transfer system 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.

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 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 4, wherein the second traction load signal comprises an electrical signal.

7. 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.

8. The torque transfer system of claim 1, wherein the torque transfer system comprises a transmission device and a clutch device.

9. The torque transfer system of claim 8, wherein 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 threshold value based on a predetermined threshold value characteristic, said characteristic operating value being dependent on the first traction load signal in accordance with a predetermined characteristic relationship.

10. 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.

11. The torque transfer system of claim 9, wherein 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.

12. The torque transfer system of claim 11, wherein the predetermined characteristic operating value depends on the inclination angle signal in accordance with a predetermined inclination angle characteristic.

13. The torque transfer system of claim 11, wherein the predetermined characteristic operating value depends on at least one of a direction of travel of the motor vehicle, the selected shift position, and the inclination angle signal.

14. The torque transfer system of claim 11, wherein the predetermined characteristic operating value comprises at least one of an engine rpm threshold value and a transmission rpm threshold value.

15. The torque transfer system of claim 14, wherein under predetermined conditions the predetermined characteristic operating value is set lower when the vehicle is traveling on a downward grade than when the vehicle is traveling on a level grade.

16. The torque transfer system of claim 8, wherein the traction load sensor device is arranged substantially on at least one of the transmission device and the control device.

17. The torque transfer system of claim 11, wherein the motor vehicle comprises a fuel tank containing a fuel and the traction load sensor device comprises at least one fuel tank sensor arranged in the fuel tank.

18. The torque transfer system of claim 17, wherein the at least one fuel tank sensor is operable to detect a fill level.

19. The torque transfer system of claim 17, 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 18, wherein the at least one fuel tank sensor comprises a first fuel tank sensor for detecting a first fill level substantially at a central location 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.

21. The torque transfer system of claim 18, 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.

22. The torque transfer system of claim 18, 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.

23. The torque transfer system of claim 22, 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.

24. The torque transfer system of claim 11, wherein the at least one traction load sensor device comprises at least one acceleration sensor.

25. The torque transfer system of claim 24, wherein the at least one acceleration sensor comprises a collision sensor.

26. The torque transfer system of claim 24, wherein the at least one acceleration sensor is operable at least part of the time to determine an actual acceleration of the motor vehicle.

27. The torque transfer system of claim 26, 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.

28. The torque transfer system of claim 24, 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.

29. The torque transfer system of claim 24, 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 α

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

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

30. The torque transfer system of claim 24, 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.

31. The torque transfer system of claim 30, wherein the at least one further characteristic operating value comprises a travel acceleration determined from at least one wheel rpm rate.

32. The torque transfer system of claim 8, 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.

33. The torque transfer system of claim 32, 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.

34. The torque transfer system of claim 33, 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.

35. The torque transfer system of claim 33, wherein the motor vehicle comprises a clutch device, and 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.

36. The torque transfer system of claim 35, wherein the regulating of the clutch device comprises increasing the crawl torque if the traction load signal indicates a predetermined traction load increase.

37. The torque transfer system of claim 35, 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.

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

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

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

40. A method of operating a torque transfer system of a motor vehicle, said torque transfer system comprising a clutch device, wherein the method comprises the steps of:

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

b) taking the clutch device out of engagement at predetermined times dependent on the traction load and on at least one characteristic operating value of the clutch device.

41. The method of claim 40, wherein the at least one characteristic operating value of the clutch device comprises an amount of clutch torque.

43. The method of claim 40, wherein the at least one characteristic operating value of the engine comprises a start-up rpm rate.

53. A method of operating a motor vehicle comprising the step of utilizing the method of claim 40.

42. 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.

44. The method of claim 42, wherein step b) is performed in a manner that assures at least one of a start-up and driving behavior of the motor vehicle according to a predetermined start-up/driving characteristic.

46. The method of claim 45, further comprising the step of regulating at least one characteristic operating value of at least one of the torque transfer system and the engine according to the detection characteristic at the third point in time.

47. The method of claim 46, wherein the at least one characteristic operating value comprises a start-up rpm rate.

48. The method of claim 45, further comprising the step of storing, when an ignition switch of the engine is being it turned off, at least one of the detection characteristic and a characteristic value based on the detection characteristic.

49. The method of claim 48, further comprising the step of retrieving the at least one of the detection characteristic and the characteristic value at a subsequent time, when the ignition switch is being turned on again.

50. The method of claim 46, further comprising the steps of

detecting at least one of a gear shift and a reversal of driving direction;

and

regulating the at least one characteristic operating value dependent on what has been detected in the preceding step.

51. The method of claim 46, further comprising the steps of

detecting at least one of a gear shift and a reversal of driving direction;

and

determining the detection characteristic dependent on what has been detected in the preceding step.

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

detecting a first traction load of the motor vehicle according to a predetermined characteristic at a first point in time;

detecting a second traction load of the motor vehicle according to a predetermined characteristic at a second point in time;

evaluating the first and second traction loads to determine a detection characteristic for at least one of the purposes of predicting and detecting a traction load at a third, later point in time.