STEERING SYSTEM WITH INTEGRATED STRAIN GAUGE

• US 20090178877A1
• Filed: 01/16/2009
• Published: 07/16/2009
• Est. Priority Date: 01/16/2008
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Tedrive Holding BV (Special Situations Venture Partners II LP)
• Inventors: Wolff, Marco, Keller, Jens
• Granted Patent: US 8,020,661 B2
• Time in Patent Office: Days
• US Class Current: 180/446
• CPC Class Codes: B62D 1/16 Steering columns
• CPC Class Codes: B62D 6/10 characterised by means for sensing or determining torque
• CPC Class Codes: G01L 3/108 involving resistance strain gauges
• CPC Class Codes: G01L 5/221 to steering wheels, e.g. for power assisted steering

Abstract

The invention relates to a steering system (10) for a motor vehicle. It is characterized in that at least one component part of the steering system (10) is made from a fiber composite material and that a strain gauge (16) for measuring a steering torque is integrated at least in parts into the fiber composite plastic material

Claims

1. A steering system (10) for a motor vehicle, wherein at least one component part of said steering system (10) is made from a fiber composite material and a strain gauge (16) for measuring a steering torque and generating a measurement signal is integrated at least partially into the fiber composite plastic material.

2. The steering system (10) as set forth in claim 1, wherein the strain gauge (16) is integrated into a steering input shaft (12).

3. The steering system (10) as set forth in claim 1, wherein the strain gauge (16) is integrated into an extension shaft.

4. The steering system (10) as set forth in claim 1, wherein the strain gauge (16) is integrated into at least one component part of the steering column.

5. The steering system (10) as set forth in claim 1, wherein the fiber composite plastic material comprises fibers selected from glass fibers, carbon fibers or aramid fibers, or combinations thereof.

6. The steering system (10) as set forth in claim 1, wherein electrical contact of the strain gauge (16) is established through at least one slip ring (18) which supplies the strain gauge (16) with supply voltage and through which the measurement signal may be tapped.

7. The steering system (10) as set forth in claim 6, wherein slip ring tapping occurs through brushes (20) that are arranged in a steering tower.

8. The steering system (10) as set forth in claim 1, wherein electrical contact of the strain gauge (16) is established through a fixedly wired flat spiral spring which supplies the strain gauge (16) with supply voltage and through which the measurement signal may be tapped.

9. The steering system (10) as set forth in claim 1, wherein the measurement signal is tapped without contact.

10. The steering system (10) as set forth in claim 1, wherein supply voltage for the strain gauge (16) is provided and the measurement signal amplified by an amplifier (6) that is integrated into a control apparatus (22).

11. The steering system (10) as set forth in claim 10, wherein the measurement signal is provided to the control apparatus (22) as a function of the selected amplification 0V-5V or 0V-10V and is scaled to the corresponding torque after analogue/digital conversion.

12. The steering system (10) as set forth in claim 10, wherein the amplifier is configured to be a measurement bridge amplifier (24).

13. A steering system (10) for a motor vehicle comprising:

at least one component part made from a fiber composite material; and

a strain gauge (16) for measuring a steering torque and generating a measurement signal;

wherein the strain gauge (16) is integrated at least partially into the fiber composite plastic material forming the at least one component part.

14. The steering system (10) as set forth in claim 13, wherein the at least one component part is selected from a steering input shaft (12), a steering column, or an extension shaft (13).

15. The steering system (10) as set forth in claim 14 further comprising:

at least one slip ring (18) surrounding the steering input shaft (12) and contacting the strain gauge (16);

wherein the at least one slip ring (18) taps the measurement signal generated by the strain gauge (16).

16. The steering system (10) as set forth in claim 15 further comprising:

at least one brush (20) providing contact between the at least one slip ring (18) and the strain gauge (16);

wherein the at least one slip ring (18) taps the measurement signal generated by the strain gauge (16) via the at least one brush (20).

17. The steering system (10) as set forth in claim 13 further comprising:

a flat spiral spring contacting the strain gauge (16);

wherein the flat spiral spring taps the measurement signal generated by the strain gauge (16).

18. The steering system (10) as set forth in claim 13 further comprising:

a control apparatus (22) for processing the measurement signal generated by the strain gauge (16) and facilitating steering assistance, the control apparatus (22) in communication with the strain gauge (16); and

an amplifier (24) for providing supply voltage to the strain gauge (16) and amplifying the measurement signal, the amplifier integrated into the control apparatus (22).