Steering wheel unit for a motor vehicle

• US 20030075004A1
• Filed: 09/19/2002
• Published: 04/24/2003
• Est. Priority Date: 09/19/2001
• Status: Active Grant

• Current Assignee: TRW Automotive Safety Systems GmbH (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Automotive Safety Systems GmbH & Co. KG
• Inventors: Kreuzer, Martin, Kerner, Wolfgang, Nigrin, Anke
• Granted Patent: US 6,976,404 B2
• Time in Patent Office: Days
• US Class Current: 74/552
• CPC Class Codes: B62D 1/105 Non-rotatable hubs, e.g. the central part of the steering wheel not rotating
• CPC Class Codes: B62D 1/11 incorporating energy-absorbing arrangements, e.g. by being yieldable or collapsible padded linings associated with the steering wheel B60R21/05; shock absorbers using plastic deformation of members in general F16F7/12
• CPC Class Codes: Y10T 74/20834 Hand wheels

Abstract

A steering wheel unit for a motor vehicle, in particular a passenger car, comprises a connection hub which may be non-rotatably connected with a steering shaft of a steering device, a steering wheel rim which is non-rotatably connected with the connection hub by means of spokes, and a central piece which is mounted by means of a spacer element to the connection hub so as to be rotatable relative to the steering shaft and the steering wheel rim. The steering wheel unit further comprises a coupling device which arrests the central piece with respect to a rotational movement of the steering wheel rim. The spacer element has a first end which is non-rotatably connected with the central piece, and has a second other end which is rotatably mounted to the connection hub and constructed as a crash element. The crash element fails after a predetermined failure value of a force driving the central piece towards the connection hub. The steering wheel rim is supported by means of its spokes on the central piece at least in a direction leading from the steering wheel rim to the connection hub and the spokes are rotatably mounted on the central piece in a region of the support.

Claims

1. A steering wheel unit for a motor vehicle, in particular a passenger car, said steering wheel unit comprising

a connection hub for being non-rotatably connected with a steering shaft of a steering device,

a steering wheel rim which is non-rotatably connected with said connection hub by means of spokes,

a central piece which is mounted by means of a spacer element to said connection hub so as to be rotatable relative to said steering shaft and said steering wheel rim,

a coupling device which arrests said central piece with respect to a rotational movement of said steering wheel rim,

said spokes having an inner end with a spoke support,

said spacer element having a first end which is non-rotatably connected with said central piece, and having a second other end which is rotatably mounted to said connection hub and constructed as a crash element, said crash element failing after a predetermined failure value of a force driving said central piece towards said connection hub,

the improvement consisting in that

said steering wheel rim is supported by means of its spokes on said central piece at least in a direction leading from said steering wheel rim to said connection hub, said spokes being rotatably mounted on said central piece in a region of said spoke support.

2. The steering wheel unit according to claim 1, wherein said central piece has a bearing carrier which is non-rotatably connected therewith, said spokes being rotatably mounted to said bearing carrier and said first end of said spacer element being non-rotatably fastened to said bearing carrier.

3. The steering wheel unit according to claim 1, wherein each spoke bifurcates in a section facing away from said steering wheel rim and has a first leg fastened to said connection hub and a second leg supported by and mounted to said central piece.

4. The steering wheel unit according to claim 3, wherein said spokes, in a section adjoining said connection hub, form a deformation section which yields after a predetermined failure value of a force driving said steering wheel rim towards said connection hub, said first leg comprising said deformation section.

5. The steering wheel unit according to claim 1, wherein each spoke is constructed in two parts, a first spoke part being fastened to said steering wheel rim and mounted to and supported by said central piece, and a second spoke part being fastened to said first spoke part and to said connection hub.

6. The steering wheel unit according to claim 5, wherein said spokes, in a section adjoining said connection hub, form a deformation section which yields after a predetermined failure value of a force driving said steering wheel rim towards said connection hub, said second spoke part comprising said deformation section.

7. The steering wheel unit according to claim 5, wherein said two spoke parts form a support for each other and are fastened to each other such that said spoke parts, in sections adjoining said support, are aligned with each other.

8. The steering wheel unit according to claim 4, wherein said failure value of said spacer element is smaller than said failure value of said spokes.

9. The steering wheel unit according to claim 1, wherein said second end of said spacer element is constructed as an annular body, at least two webs projecting from said annular body which are spaced apart from each other in a peripheral direction of said annular body and are connected with said central piece.

10. The steering wheel unit according to claim 9, wherein said webs are constructed so as to have a narrowed portion.

11. The steering wheel unit according to claim 1, wherein said spokes are non-rotatably connected to said connection hub by means of a hub plate.

12. The steering wheel unit according to claim 1, wherein said coupling device has a magnetic force mechanism with at least two magnet arrangements.

13. The steering wheel unit according to claim 1, wherein said coupling device has a toothed-wheel gearing with at least two toothed wheels.