ADJUSTMENT DRIVE FOR A STEERING COLUMN, AND STEERING COLUMN FOR A MOTOR VEHICLE

Abstract

An adjustment drive can be used in a steering column for a motor vehicle. In some examples, the adjustment drive may include a threaded spindle that engages with an outer thread in a spindle nut and a drive unit that is coupled to the threaded spindle or the spindle nut in such a manner that the threaded spindle and the spindle nut can be driven in rotation relative to each other. The drive unit may have a torque-transmitting slip clutch that is coupled to the threaded spindle or the spindle nut. The slip clutch may include friction faces that contact each other in a frictionally engaging manner.

Claims

1.-15. (canceled)

16. An adjustment drive for a steering column of a motor vehicle, comprising: a threaded spindle that engages with an outer thread in a spindle nut; and a drive unit that is coupled to the threaded spindle or the spindle nut such that the threaded spindle and the spindle nut are drivable in rotation relative to each other, wherein the drive unit includes a torque-transmitting slip clutch that is coupled to the threaded spindle or the spindle nut.

17. The adjustment drive of claim 16 wherein a motor of the drive unit is coupled to the slip clutch.

18. The adjustment drive of claim 16 wherein the slip clutch includes friction faces that contact each other in a frictionally engaging manner.

19. The adjustment drive of claim 18 wherein at least one of the friction faces is configured in a friction-increasing manner.

20. The adjustment drive of claim 18 wherein the slip clutch includes a pretensioning device.

21. The adjustment drive of claim 20 wherein the pretensioning device includes at least one of a resilient element or an adjustable adjustment means.

22. The adjustment drive of claim 16 wherein the slip clutch is arranged coaxially relative to the threaded spindle.

23. The adjustment drive of claim 16 wherein the slip clutch is connected to a gear wheel.

24. The adjustment drive of claim 23 wherein a rotationally drivable drive wheel of the drive unit is in meshing engagement with the gear wheel.

25. The adjustment drive of claim 23 wherein the gear wheel is connected to the spindle nut or the threaded spindle.

26. The adjustment drive of claim 23 wherein the slip clutch is disposed between a sprocket and a hub of the gear wheel.

27. The adjustment drive of claim 26 wherein the hub is connected to the spindle nut or the threaded spindle.

28. The adjustment drive of claim 26 wherein the hub and the sprocket have mutually opposing friction faces.

29. The adjustment drive of claim 16 wherein the slip clutch is connected to a gear wheel, wherein the gear wheel includes a pretensioning device.

30. A steering column for a motor vehicle, comprising: a carrier unit that is configured to be fitted to a body of the motor vehicle; an adjustment unit that is retained in the carrier unit; a steering spindle rotatably supported in the adjustment unit; and an adjustment drive that includes: a threaded spindle that engages with an outer thread in a spindle nut, and a drive unit that is coupled to the threaded spindle or the spindle nut such that the threaded spindle and the spindle nut are drivable so as to rotate relative to each other, wherein the adjustment drive is connected to the carrier unit or the adjustment unit.

31. The steering column of claim 30 wherein the drive unit includes a torque-transmitting slip clutch that is coupled to the threaded spindle or the spindle nut.

Description

DESCRIPTION OF THE DRAWINGS

[0037] Advantageous embodiments of the invention are explained in greater detail below with reference to the drawings, in which:

[0038] FIG. 1 shows a schematic, perspective view of a steering column according to the invention,

[0039] FIG. 2 shows another perspective view of the steering column according to the invention according to FIG. 1 from another viewing angle,

[0040] FIG. 3 shows an adjustment drive according to the invention of a steering column according to FIGS. 1 and 2 in a cut-away schematic view,

[0041] FIG. 4 shows the gear wheel of the adjustment drive as an exploded illustration,

[0042] FIG. 5 shows a longitudinal section along the spindle axis through the adjustment drive according to FIG. 3,

[0043] FIG. 6 shows an enlarged detailed illustration from FIG. 5.

EMBODIMENTS OF THE INVENTION

[0044] In the various Figures, identical components are always given the same reference numerals and are therefore generally also only set out or mentioned once.

[0045] FIG. 1 shows a steering column 1 according to the invention as an oblique schematic perspective view from the top right toward the rear end, with respect to the travel direction of a vehicle which is not illustrated, wherein a steering wheel which is not illustrated in this instance is retained in the operating region. FIG. 2 shows the steering column 1 as a view from the opposing side, that is to say, when viewed from the top right.

[0046] The steering column 1 comprises a carrier unit 2 which is in the form of a console, which has securing means 21 in the form of securing holes for fitting to a vehicle body which is not illustrated. The carrier unit 2 retains an adjustment unit 3 which is received in a covering unit 4—which is also referred to as a guiding box or a boxed rocker.

[0047] The adjustment unit 3 has a covering pipe 31 in which there is rotatably supported about a longitudinal axis L a steering spindle 32 which extends axially in the longitudinal direction, that is to say, in the direction of the longitudinal axis L. At the rear end, there is formed on the steering spindle 32 a securing portion 33 to which a steering wheel which is not illustrated can be fitted.

[0048] In order to produce a longitudinal adjustment in the covering unit 4, the adjustment unit 3 is received so as to be able to be displaced in the manner of a telescope in the direction of the longitudinal axis L in order to be able to position the steering wheel which is connected to the steering spindle 32 relative to the carrier unit 2 back and forth in the longitudinal direction, as indicated with the double-headed arrow parallel with the longitudinal axis L.

[0049] The covering unit 4 is supported in a pivot bearing 22 on the carrier unit 2 so as to be able to be pivoted about a horizontal pivot axis S which is located transversely with respect to the longitudinal axis L. In the rear region, the covering unit 4 is connected to the carrier unit 2 by means of an adjustment lever 41. As a result of a rotational movement of the adjustment lever 41 by means of an adjustment drive 6 which is not illustrated (see FIG. 2), the covering unit 4 can be pivoted relative to the carrier unit 2 about the pivot axis S which is located horizontally in the installation state, whereby an adjustment of a steering wheel which is fitted to the securing portion 33 can be carried out in the vertical direction H, which is indicated with the double-headed arrow.

[0050] A first adjustment drive 5 for longitudinal displacement of the adjustment unit 3 relative to the covering unit 4 in the direction of the longitudinal axis L has a spindle drive having a spindle nut 51 having an inner thread 74 which extends along an axis G and in which a threaded spindle 52 engages, that is to say, is screwed with the outer thread thereof into the corresponding inner thread 74 of the spindle nut 51. The threaded spindle axis of the threaded spindle 52 is identical to the axis G and extends substantially parallel with the longitudinal axis L.

[0051] The spindle nut 51 is rotatably supported about the axis G in a bearing housing 53 which is securely connected to the covering unit 4. In the direction of the axis G, the spindle nut 51 is axially supported on the covering unit 4 by means of the bearing housing 53. The adjustment drive 5 is accordingly a so-called immersion spindle drive.

[0052] The threaded spindle 52 is connected to the adjustment unit 3 with a securing element 54 which is formed at the rear end thereof by means of a transmission element 34, in a manner fixed in the direction of the axis G or the longitudinal axis L and fixed in position with respect to the rotation about the axis G. As a result of the rotationally drivable spindle nut 51 and the threaded spindle 52 which is fixed with respect to rotation, a so-called immersion spindle drive is produced.

[0053] The transmission element 34 extends from the adjustment unit 3 through a slot-like through-opening 42 in the covering unit 4. In order to adjust the steering column 1 in the longitudinal direction, the transmission element 34 can be moved freely along in the through-opening 42 in the longitudinal direction.

[0054] The adjustment drive 5 has an electric drive motor 55 by means of which the spindle nut 51 can be driven in rotation with respect to the axis G relative to the fixed threaded spindle 52. As a result—depending on the rotation direction of the drive motor 55—the threaded spindle 52 can be displaced in the direction of the axis G in translation relative to the spindle nut 51 so that the adjustment unit 31 which is connected to the threaded spindle 52 is accordingly displaced relative to the covering unit 4 which is connected to the spindle nut 51 in the direction of the longitudinal axis L. The drive of the spindle nut 51 and the support of the spindle nut 51 in the direction of the axis G on the covering unit 4 is explained in detail below.

[0055] In FIG. 2, which shows a perspective view of the steering column 1 from the side located at the rear in FIG. 1, it can be seen how a second adjustment drive 6 for adjusting in the vertical direction H is fitted to the steering column 1. This adjustment drive 6 comprises a spindle nut 61 in whose inner thread 74 a threaded spindle 52 engages along an axis G. The threaded spindle 52 is rotatably supported about the axis G in a bearing housing 63 which is secured to the covering unit 4 and axially supported on the covering unit 4 in the direction of the axis G and can be driven in rotation about the axis G by an electric drive motor 65 selectively in both rotation directions. Accordingly, the adjustment drive 6 is a so-called rotary spindle drive.

[0056] The spindle nut 61 which may be formed from plastics material or a non-ferrous heavy metal such as brass or the like, is fitted in a fixed manner with respect to a rotation about the axis G to one end of the two-armed adjustment lever 41 which is pivotably supported about a pivot bearing 23 on the carrier unit 2 and whose other arm is connected with the other end to the covering unit 4.

[0057] By rotating the threaded spindle 61—depending on the rotation direction of the drive motor 65—the spindle nut 61 can be displaced in translation relative to the threaded spindle 52 in the direction of the axis G so that the covering unit 4 which is connected to the spindle nut 61 by means of the adjustment lever 41 together with the adjustment device 3 which is received therein can accordingly be adjusted upward or downward in a vertical direction H relative to the carrier unit 2, as indicated with the double-headed arrow.

[0058] FIG. 3 shows the adjustment drive 5 which is in the form of an immersion spindle drive as a separate cut-away illustration, wherein the bearing housing 53 has been omitted for greater clarity. FIG. 5 shows a longitudinal section along the spindle axis G and FIG. 6 shows an enlarged detailed view therefrom.

[0059] The adjustment drive 5 has a gear wheel 7 which comprises a hub element 71 (=hub) which has the spindle nut 51 with the inner thread 511 and which is arranged in this instance coaxially with respect to the spindle axis G. The spindle nut 51 and the hub element 71 may preferably be constructed integrally as illustrated. However, it is also conceivable and possible for the spindle nut 51 to be formed from a metal material and for the hub element 72 which may be formed from a plastics material to be injected thereon with the plastics material injection-molding method.

[0060] A sprocket 72 having an externally circumferential tooth arrangement 721 is arranged coaxially with respect to the hub element 71 and connected by means of a slip clutch 8 according to the invention which will be explained in greater detail below.

[0061] A worm 56 which is connected to the motor shaft of the motor 55 is in toothed engagement with the tooth arrangement 721 of the sprocket 72.

[0062] The slip clutch 8 according to the invention which is integrated in the gear wheel 7 is shown in the assembled state in FIGS. 5 and 6 and as an exploded illustration pulled apart in the direction of the spindle axis G in FIG. 4.

[0063] The hub element 71 has a radially circumferential projection 711 which has at the axial sides thereof annularly circumferential axial friction faces 712 and 713. The friction faces 712 and 713 are consequently formed by the shoulders of the circumferential projection 711. In the installed state, the friction face 712 is axially opposite a corresponding, similarly annular axial friction face 722 internally on the sprocket 72. The sprocket 72 has to this end an inwardly protruding portion which has a shoulder which comprises the friction face 722.

[0064] Axially between the friction faces 712 and 722, an annular-disk-like friction element 73 is arranged in a frictionally engaging manner.

[0065] At the side facing away from the friction face 722, an annular adjustment screw 74 is screwed into a coaxial inner thread 723 of the sprocket 72. The adjustment screw 74 has an axial friction face 741 which is axially opposite the friction face 713.

[0066] An annular, axially resilient element 75, for example, a helical spring, ondular washer or disk spring, or an O-ring formed from an elastomer material and a friction element 76 is arranged axially between the friction face 741 of the adjustment screw 74 and the friction face 713 of the hub element 71 and may be constructed in a similar manner to and substantially with the same function as the above-mentioned friction element 73.

[0067] The friction elements 73 and 76 each have outwardly protruding pins 731 and 761 which are preferably arranged in a state distributed in a uniform manner over the circumference of the friction elements 73 and 76. The sprocket 72 preferably has internal grooves 724 in which the pins 731 and 761 of the friction elements 73 and 76 engage and secure them with respect to the sprocket in a rotation direction about the spindle axis G. Consequently, the friction elements 73 and 76 cannot be rotated with respect to the sprocket 72 about the spindle axis G.

[0068] As a result of the adjustment screw 74, the friction element 76 is loaded via the resilient element 75 with a defined pretensioning force with respect to the friction face 713 of the hub element 71. At the same time, the hub element 71 is thereby pressed with the friction face 712 axially via the friction element 73 with the pretensioning force axially against the corresponding friction face 722 of the sprocket 77. As a result, the hub element 71 is coupled via the friction faces 712 and 713 to the corresponding friction faces 722 and 741 on the sprocket 72 in a frictionally engaging, that is to say, non-positive-locking manner. As a result of the cooperation described, the slip clutch 8 according to the invention, by means of which the torque discharged by the motor 55 is transmitted to the gear wheel 7 and the threaded spindle 52 is formed. The maximum torque can be adjusted by screwing in or unscrewing the adjustment nut 74, whereby the axial pretensioning force acting between the friction faces 712, 713, 722 and 741 can be adjusted.

LIST OF REFERENCE NUMERALS

[0069] 1 Steering column [0070] 2 Carrier unit [0071] 21 Securing means [0072] 22, 23 Pivot bearing [0073] 3 Adjustment unit [0074] 31 Covering pipe [0075] 32 Steering spindle [0076] 33 Securing portion [0077] 34 Transmission element [0078] 4 Covering unit [0079] 41 Adjustment lever [0080] 42 Through-opening [0081] 5, 6 Adjustment drive [0082] 51, 61 Spindle nut [0083] 511 Inner thread [0084] 52, 62 Threaded spindle [0085] 53, 63 Bearing housing [0086] 54 Securing element [0087] 55, 65 Motor (drive motor) [0088] 56, 66 Worm [0089] 7 Gear wheel [0090] 71 Hub element [0091] 711 Projection [0092] 712 Friction face [0093] 713 Friction face [0094] 72 Sprocket [0095] 721 Tooth arrangement [0096] 722 Friction face [0097] 73, 76 Friction element [0098] 74 Adjustment screw [0099] 741 Friction face [0100] 75 Resilient element [0101] 8 Slip clutch [0102] L Longitudinal axis [0103] H Vertical direction [0104] G Spindle axis (threaded spindle axis)