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Torque transfer system for a motor vehicle

Imported: 24 Feb '17 | Published: 13 Jan '04

Anton Fritzer, Franz Bitzer, Rainer Eidloth, Carsten Weinhold, Thomas Jager, Martin Vornehm, Hans-Jürgen Renk

USPTO - Utility Patents

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below as examples only, and no limitations are thereby implied. The description refers to the attached drawings, wherein

FIG. 1 represents a schematic view of a first example of an embodiment of the invention;

FIG. 2 represents a schematic view of a second example of an embodiment of the invention;

FIG. 3 represents a time graph of characteristic operational quantities to illustrate how the invention works in an exemplary embodiment of the invention;

FIG. 4 represents a time graph of the transmission rpm rate and the engine rpm rate when a vehicle equipped with a state-of-the-art torque transfer system is traveling on a downward grade; and

FIG. 5 represents a time graph of the transmission rpm rate and the engine rpm rate when a vehicle equipped with the torque transfer system according to the invention is traveling on a downward grade.

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:

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.

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

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