MOTOR-ADJUSTABLE STEERING COLUMN FOR A MOTOR VEHICLE

Abstract

A motor-adjustable steering column for a motor vehicle, includes a support unit, which can be mounted on a vehicle body, and by which an actuator unit is held, in which a steering spindle is rotatably mounted about a longitudinal axis. An adjusting drive is connected to the support unit and to the actuator unit, and by which the actuator unit can be adjusted relative to the support unit. The adjusting drive includes a drive unit and a threaded spindle engaging in a spindle nut with a threaded spindle axis, wherein the threaded spindle can be driven in rotation or in translation by the drive unit. The drive unit is connected to a component of the steering column such that it is movable in a transverse direction transversely to the threaded spindle axis.

Claims

1.-14. (canceled)

15. A motor-adjustable steering column for a motor vehicle, comprising: a support unit, which is configured to mount on a vehicle body, an actuator unit held by the support unit, a steering spindle rotatably mounted in the actuator unit about a longitudinal axis, an adjusting drive connected to the support unit and to the actuator unit, and configured such that the actuator unit is adjustable relative to the support unit, wherein the adjusting drive comprises a drive unit and a threaded spindle engaging in a spindle nut and having a threaded spindle axis, wherein the threaded spindle is driven in rotation or in translation by the drive unit, and wherein the drive unit is connected to a component of the steering column which is formed by the support unit, the actuator unit or a casing unit holding the actuator unit and connected to the support unit, such that the drive unit is movable in a direction transverse to the threaded spindle axis.

16. The steering column of claim 15, wherein the drive unit is displaceable in a linear manner relative to the component substantially transversely to the threaded spindle axis and transversely to the longitudinal axis.

17. The steering column of claim 15, wherein the drive unit is spring-loaded by at least one spring element.

18. The steering column of claim 15, wherein a holding element is arranged on the component, against which element the drive unit is braced at least in the transverse direction.

19. The steering column of claim 18, wherein at least one spring element is arranged between the holding element and the drive unit and/or between the drive unit and the component.

20. The steering column of claim 18, wherein the holding element is configured as a spring-elastic holding bracket.

21. The steering column of claim 20, wherein the holding element and/or the component comprises a holding protrusion which engages with a holding recess of the drive unit.

22. The steering column of claim 21, wherein a ring-shaped spring element is arranged on the holding protrusion.

23. The steering column of claim 21, wherein the holding protrusion is resilient.

24. The steering column of claim 21, wherein at least one holding protrusion is arranged on the drive unit.

25. The steering column of claim 21, wherein the holding protrusion is convex rounded.

26. The steering column of claim 20, wherein the holding element is a sheet metal part.

27. The steering column of claim 20, wherein the axis lying in the transverse direction extends through the holding element and/or the holding protrusion.

28. A motor-adjustable steering column for a motor vehicle, comprising: a support unit configured to be mounted on a vehicle body, an actuator unit held by the support unit, a steering spindle rotatably mounted in the actuator unit about a longitudinal axis, an adjusting drive connected to the support unit and to the actuator unit, and configured such that the actuator unit is adjustable relative to the support unit, wherein the adjusting drive comprises a drive unit and a threaded spindle engaging in a spindle nut and having a threaded spindle axis, wherein the threaded spindle is driven in rotation or in translation by the drive unit, wherein the drive unit is connected to a component of the steering column which is formed by the support unit, the actuator unit or a casing unit holding the actuator unit and connected to the support unit, such that it swivels about an axis lying in a transverse direction.

29. The steering column of claim 28, wherein the drive unit is displaceable in a linear manner relative to the component substantially transversely to the threaded spindle axis and transversely to the longitudinal axis.

30. The steering column of claim 28, wherein the drive unit is spring-loaded by at least one spring element.

31. The steering column of claim 28, wherein a holding element is arranged on the component, against which element the drive unit is braced at least in the transverse direction.

Description

DESCRIPTION OF THE DRAWINGS

[0041] Advantageous embodiments of the invention shall be explained more closely in the following with the aid of the drawings. Specifically, there are shown:

[0042] FIG. 1 a steering column according to the invention in a schematic perspective view,

[0043] FIG. 2 the steering column of FIG. 1 in a schematic perspective view of the opposite side,

[0044] FIG. 3 a partial view of the steering column of FIG. 1 in disassembled state,

[0045] FIG. 4 a partial view of a cross section transversely to the longitudinal axis through a steering column as per FIGS. 1 to 3,

[0046] FIG. 5 an enlarged cutout view of FIG. 4,

[0047] FIG. 6 an enlarged cutout view as in FIG. 5 of a second embodiment of a steering column,

[0048] FIG. 7 an enlarged cutout view as in FIG. 5 of a third embodiment of a steering column,

[0049] FIG. 8 an enlarged cutout view as in FIG. 5 of a fourth embodiment of a steering column,

[0050] FIG. 9 an enlarged cutout view as in FIG. 5 of a fifth embodiment of a steering column,

[0051] FIG. 10 a holding element of a steering column as per FIG. 9 in a perspective view,

[0052] FIG. 11 a partial view of the steering column of FIG. 2 in disassembled state,

[0053] FIG. 12 an adjusting unit in an alternative embodiment with a threaded spindle movable in translation in longitudinal section,

[0054] FIG. 13 a partial view of the adjusting unit of FIG. 12 in a cross section.

EMBODIMENTS OF THE INVENTION

[0055] In the various figures, identical parts are always provided with the same reference numbers and therefore in general will only be named or mentioned once.

[0056] FIGS. 1 and 2 show a steering column 1 according to the invention in schematic perspective views laterally from above, diagonally to the left (FIG. 1) and diagonally to the right (FIG. 2), of the rear end in relation to the driving direction of a vehicle, not shown.

[0057] The steering column 1 comprises a casing unit 2, which is attached to a support unit 3 about a swivel axis 31 situated horizontally transversely to the longitudinal axis L, having fastening means 32 formed as bracket pieces for connecting to a motor vehicle body, not shown.

[0058] The casing unit 2 holds an actuator unit 4, comprising an inner casing tube 41, in which a steering spindle 42 is mounted rotatably about a longitudinal axis L. At the rear end with respect to the driving direction, the steering spindle 42 is provided with a fastening segment 43 for attachment of a steering wheel, not represented here. The actuator unit 4 is axially telescopically retractable and extensible relative to the casing unit 2 in the direction of the longitudinal axis L, i.e., in the longitudinal direction, as indicated by the double arrow in FIGS. 1 and 2.

[0059] An adjusting unit 5 comprises a drive unit 51 with a servomotor 52, which is designed as an electric motor, preferably an electric DC motor, and a gearing 53 coupled to it. In this embodiment, the gearing 53 is designed as a worm gear gearing, wherein a worm is connected in rotationally fixed manner to a rotor shaft of the electric motor, and the worm engages with the toothing of a worm gear, the worm gear being connected in rotationally fixed manner to the threaded spindle 55. The drive unit 51 comprises a bearing segment 54, by which it is mounted according to the invention on the casing unit 2, as will be further discussed in detail below.

[0060] From the drive unit 51, a threaded spindle 55 coupled to the output of the gearing 53 can be driven in rotation about its threaded spindle axis R, extending substantially in the direction of the longitudinal axis L. The threaded spindle 55 engages with a spindle nut 56, which is connected firmly to the actuator unit 4 in rotationally fixed manner with respect to the threaded spindle axis R, in the direction of the longitudinal axis L. In this way, a spindle drive is formed, whereby a rotation of the threaded spindle 54 by means of the servomotor 52 results in a displacement of the spindle nut 56 in the direction of the threaded spindle axis R, and the actuator unit 4 connected to the spindle nut 56 is retracted in the direction of the longitudinal axis L into the casing unit 2 or extended out from it, depending on the direction of rotation.

[0061] A second adjusting unit 6 is fastened to the casing unit 2 by means of a holding element 8. Like the first adjusting unit 5, the adjusting unit 6 comprises a drive unit 61 with an electric motor 62, a gearing 63, which is likewise formed as a worm gearing, and a rotatably driven threaded spindle 65, which engages with a spindle nut 66. The spindle nut 66 is arranged in rotationally fixed manner at one end of an adjusting lever 67, which by its other end is hinged at a tilting lever 68 to the casing unit 2. The tilting lever 68 is hinged by a first joint 31 to the support unit 3, with the first joint 31 providing for a length equalization. A second joint 32 is provided between the tilting lever 68 and the casing unit 2. By turning of the threaded spindle 65, the spindle nut 66 and with it the adjusting lever 67 and thus the one end of the tilting lever 68 is displaced, so that the casing unit 2 is swiveled relative to the support unit 3 about a swivel axis, wherein the actuator unit 4 together with the casing unit 2 is adjustable in the height direction H relative to the support unit 3, as indicated in FIG. 2 by the double arrow. In this way, a motorized height adjustment of a steering wheel (not shown) attached to the fastening segment 43 is made possible by means of the adjusting unit 6.

[0062] FIG. 3 shows a detail view of the drive unit 51, which is shown schematically in an exploded view in a transverse direction Q with respect to the threaded spindle axis R and pulled apart and out from the casing unit 2 in this exemplary embodiment with respect to the longitudinal axis L. The casing unit 2 corresponds to the component of the steering column to which the drive unit 51 is connected. The transverse direction Q stands transverse to the threaded spindle axis R and as shown in this exemplary embodiment transverse to the longitudinal axis L, the orientation of the outward transverse direction Q being defined by the arrow in FIG. 3.

[0063] An enlarged cross section through the steering column 1 along the transverse direction Q indicated in FIG. 3 is shown in FIG. 4. It can be seen how the drive unit 51 is fastened to the outside of the casing unit 2 (as seen from the longitudinal axis L) at its bearing segment 54 by means of a holding element designed as a holding bracket 7.

[0064] The holding bracket 7 is fabricated as an angle-shaped sheet metal part, having a first leg serving as a bearing leg 71 and a holding leg 72 joined to it at an angle. The bearing leg 71 extends parallel to the transverse direction Q and to the threaded spindle axis R of the threaded spindle 55; the holding leg 72 extends transverse to the transverse direction Q and parallel to the threaded spindle axis R. The holding leg 72 encloses the bearing segment 54 on the outside, while the bearing segment 71 braces the bearing segment 54 at the bottom. The holding bracket 7 is secured by means of fastening elements 21, such as screws, to the casing unit 2.

[0065] The bearing segment 54 comprises two sliders 57 and 58, which are arranged opposite each other with respect to the threaded spindle axis R, at the top and bottom of the bearing segment 54 in the drawing. The slider 57 rests against a guideway 22 on the casing unit 2, the slider 58 rests against a guideway 73 on the bearing leg 71 of the holding bracket 7. The guideways 22 and 73 run parallel to each other parallel to the transverse direction Q and form a sliding guide for the sliders 57 and 58. The sliders 57, 58 are fashioned as rivet elements, which connect the bearing segment 54 to the gearing housing of the gearing 53. In this way, a sliding bearing is realized, in which the bearing segment 54 and thus the drive unit 51 is mounted able to move in and against the transverse direction Q relative to the casing unit 2, as indicated by the arrows to the left and right of the threaded spindle axis R. The mobility according to the invention of the drive unit 51 is realized by the transversely displaceable mounting, so that this can compensate for the angle offset occurring during an unwanted, yet unavoidable deviation in the parallel orientation of the threaded spindle axis R to the longitudinal axis L due to tolerances, by giving way in the transverse direction Q. In this way, constrained states and a skewing of the threaded spindle 55 relative to the spindle nut 56 can be avoided.

[0066] For the holding of the drive unit 51 on the casing unit 2, the bearing segment 54 comprises holding recesses 59 and 591 on opposite sides. A holding pin 23 formed on the casing unit 2 engages with the holding recess 591 facing toward the casing unit 2 in the transverse direction Q, preferably in form-fitting manner or in loose form fit. A holding protrusion 74 directed inward, as per the above definition counter to the transverse direction Q, engages with the opposite holding recess 59 facing outward away from the casing unit 2, and thus facing toward the holding leg 72, likewise in form-fitting manner or in loose form fit. In this way, the drive unit 51 is secured in the longitudinal direction or in the direction of the threaded spindle axis R on the casing unit 2. The holding recesses 59 and 591 may be designed as cylindrical bores, and the holding protrusions 74 and 23 may be designed as cylindrical pins corresponding to the bores.

[0067] Different embodiments of the holding protrusion 74 are shown in FIGS. 5 to 9, each of which show enlarged partial views of FIG. 4 in the area of the holding leg 72 of the holding bracket 7.

[0068] In FIG. 5, the holding protrusion 74 is configured as a tubular section projecting inwardly from the holding leg 72 counter to the transverse direction Q, which can be formed for example by a molding of the holding bracket 7, fashioned as a sheet metal part, said molding having been produced by a pressing process.

[0069] On the holding protrusion 74 in FIG. 5 there is mounted a spring element in the form of a conical ring-shaped disk spring 81, in FIG. 6 in the form of a hemispherically convex rounded ring-shaped disk spring 82. The disk spring 81, 82 is installed under pretensioning between the holding leg 72 and the bearing segment 54, so that a spring force F, as an elastic pretensioning force, is exerted by the holding leg 72 of the holding element 7 on the bearing segment 54, and accordingly the drive unit 51 is spring-loaded and pretensioned by at least the spring element 81 or 82, and this counter to the transverse direction Q indicated by the arrow. This direction corresponds to the guiding and sliding direction which is dictated by the above-described sliding bearing, which is formed by the sliders 57 and 58 as well as the guideways 22 and 73. As a result of the spring element 81 and 82, the drive unit 51 is pressed elastically inward by the spring force F against the casing unit 2 or in the direction of the longitudinal axis L. In the event of an angle offset between the longitudinal axis L and the threaded spindle axis R of the threaded spindle 55, the bearing segment 54 and thus the overall drive unit 51 can give way against the elastic spring force of the spring element 81 and 82 during the displacement in the transverse direction Q.

[0070] FIG. 9 shows an embodiment in which the holding protrusion 74 is resilient in itself, as a result of a plurality of bending-elastic spring tongues 83 arranged radially in a star pattern and formed as an integral single piece with the wall of the tubular holding protrusion 74. By this arrangement as well, the bearing segment 54 is elastically pretensioned with the spring force F counter to the transverse direction Q.

[0071] FIG. 10 shows the holding bracket 7 of FIG. 9 with the holding protrusion 74, having resilient holding tongues 83, in a perspective view. It can be seen here that the holding bracket 7 is configured as a single integral sheet metal piece, making it unnecessary to use additional spring elements. The holding tongues 83 consist of the same material as the holding bracket 7, for example steel or spring steel, and can be made by pressing and punching. To stiffen the bend of the holding bracket 7, a reinforcing bead 701 may be provided.

[0072] Another option of pretensioning the bearing segment 54 in resilient manner is shown in FIG. 8. Here, the holding leg 72 is naturally bending-elastic and resilient and thus itself exerts the spring force F on the bearing segment 54.

[0073] An alternative option is shown in FIG. 7. Here, the holding leg 72 has a holding recess 721 in the form of a cylindrical bore. A holding protrusion 592 engaging with this holding recess 721 is attached to the bearing segment 54, being transversely pretensioned outwardly against the bearing segment 54 by a spring 84.

[0074] In all the embodiments of FIGS. 5 to 10, the drive unit 51 is pretensioned elastically against the casing unit 2, transversely to the longitudinal axis L. The drive unit 51 and thus the threaded spindle 55 can give way to the outside against the spring force F so exerted, in order to equalize tolerances.

[0075] In order to allow the drive unit 51 to give way not only transversely to the outside, but also in the opposite direction toward the casing unit 2, a second spring element 84 can be arranged between the bearing segment 54 and the casing unit 2, as can be seen in FIG. 4. This spring element 84 may be fashioned as a ring-shaped disk spring, which is mounted on the holding pin 23 of the casing unit 2. The bearing segment 54 is then clamped in and against the transverse direction Q resiliently between this second spring element 84 and the spring element 81, 82 or 83 realized in the particular embodiment or the naturally resilient holding leg 72.

[0076] In order to equalize any axial offset caused by tolerances between the holding protrusion 74 or 592 and the oppositely situated holding pin 23, the holding protrusion 74 or 592 may have a spherical or conical convex rounded area 91 at its free end face, so that a kind of conical or spherical joint head or ball joint head is formed. With the convex area 91, the holding protrusion 74 or 592 engages with the associated holding recess 59 or 721. In the embodiments of FIGS. 5 and 6, the convex area 91 rests in linear manner against the edge of the holding recess 59; in the embodiment of FIG. 7, it lies against the edge of the holding recess 721.

[0077] In order to enlarge the bearing area, a concave indentation 93 may be formed at the edge of the holding recess 59, being adapted to the convex area 91 on the holding protrusion 74 to form a ball joint type arrangement.

[0078] As a result of the convex area on the holding protrusion 74 or 592, a joint arrangement is formed in conjunction with the edge of the holding recess 59 or 721, or a concave indentation 93 formed at the edge of the holding recess 59, with which axial offset can be equalized, thereby improving the holding effect.

[0079] FIG. 11 shows a partial view of the steering column of FIG. 2 in disassembled state. The drive unit 61 of the second adjusting unit 6 is fastened to the casing unit 2 by the holding element 8, which is shown in an exploded view schematically in a transverse direction Q with respect to the threaded spindle axis R and pulled out from the casing unit 2. The casing unit 2 corresponds to the component of the steering column 1 to which the drive unit 61 is connected. The transverse direction Q stands transverse to the threaded spindle axis R, while the orientation of the transverse direction Q to the outside is defined by the arrow in FIG. 11. The holding element 8 is secured by fastening means to the casing unit 2. The holding element 8 takes up a bolt-shaped protrusion 631 of the drive unit 61 pivotably about an axis in the direction of the transverse direction Q. The holding element 8 is a spring configured as a leaf spring, in order to allow a movement of the drive unit 61 in the transverse direction Q transversely to the threaded spindle axis R of the threaded spindle 65. Alternatively or additionally, spring elements may be provided on the bolt-shaped protrusion 631, which pretension the drive unit 61 against the holding element in the direction of the transverse direction Q.

[0080] FIGS. 12 and 13 show an alternative embodiment of the first adjusting unit 5. Here, the adjusting unit 5 comprises an electric servomotor 52 and a drive unit 51. The holding element 7 for connecting the drive unit 51 to the casing unit 2 corresponds to the one in FIG. 8. In this holding element, the holding leg 72 is elastically resilient in itself and thus itself exerts the spring force F on the bearing segment 54. The drive unit 51 of FIGS. 12 and 13 comprises a threaded spindle 55 displaceable in translation in the direction of the threaded spindle axis R. The threaded spindle 55 engages with the worm gear 56, drivable by a worm 561. As a result of the rotation of the worm gear 56, the threaded spindle 55 is moved in translation in the direction of the threaded spindle axis R. The actuator unit 4, connected to the threaded spindle 55 via the connecting part 561, is adjusted by the translatory movement of the threaded spindle 55 relative to the support unit 3. The alternative embodiment of the first adjusting unit 5 represented in FIGS. 12 and 13 may also be applied analogously to the second adjusting unit 6 and is thus also suited to the realizing of a height adjustment.

LIST OF REFERENCE NUMBERS

[0081] 1 Steering column [0082] 2 Casing unit [0083] 21 Fastening elements [0084] 22 Guideway [0085] 23 Holding pin [0086] 3 Support unit [0087] 31 Swivel axis [0088] 32 Fastening means [0089] 4 Actuator unit [0090] 41 Casing tube [0091] 42 Steering spindle [0092] 43 Fastening segment [0093] 5, 6 Adjusting unit [0094] 51, 61 Drive unit [0095] 52, 62 Servomotor [0096] 53, 63 Gearing [0097] 54 Bearing segment [0098] 55, 65 Threaded spindle [0099] 56, 66 Spindle nut [0100] 57, 58 Sliders [0101] 59, 591 Holding recess [0102] 592 Holding protrusion [0103] 67 Adjusting lever [0104] 7 Holding bracket [0105] 71 Bearing leg [0106] 72 Holding leg [0107] 721 Holding recess [0108] 73 Guideway [0109] 74 Holding protrusion [0110] 81, 82 Disk spring [0111] 83 Spring tongue [0112] 91 Convex area [0113] 93 Concave indentation [0114] L Longitudinal axis [0115] H Height direction [0116] Q Transverse direction [0117] F Spring force