Adjustment unit of a steering column

Abstract

The invention relates to an adjustment unit of a steering column of a vehicle, comprising: an adjustment device which has at least one adjustment motor; a pull-out device which has a pull-out carrier which is designed to be arranged in a rotationally and axially fixed manner on a body of the vehicle; and at least one inner pull-out element which is arranged in an axially movable manner in the pull-out carrier, wherein at least one bearing arrangement is provided between the at least one inner pull-out element and the pull-out carrier, wherein the at least one bearing arrangement is formed from a recirculating ball segment, wherein the at least one recirculating ball segment (1) is spring-loaded by means of a spring element (2), wherein the spring element (2) has a rounded central region (7).

Description

[0001] Title of the invention

[0002] Adjustment unit of a steering column

[0003] Description

[0004] Field of the invention

[0005] The present invention relates to an adjustment unit of a steering column of a vehicle and a steer-by-wire steering system with such an adjustment unit.

[0006] Background of the invention

[0007] Today's steering columns feature height and reach adjustments. With such steering column adjustment systems, the steering column housing sections must be able to move relative to each other. This is achieved by a telescopic arrangement of the housing sections. This allows the steering wheel to be adjusted to a position that suits the driver. Recently, there has been a requirement for the steering wheel to be retracted into a stowed position in the dashboard.

[0008] To achieve sufficient adjustment range, DE 10 2015 216 326 A1 discloses arranging several jacket tubes so that they can be telescopically moved inside one another. To adjust the stowage position, the jacket tubes can be pushed together until they are almost completely recessed.

[0009] To adjust the steering column quickly and safely, it is essential that the steering column tubes can move smoothly relative to each other, i.e., slide smoothly with minimal friction. For this purpose, plain bearings are often used. In contrast, the steering wheel requires a very rigid bearing to prevent it from swinging while driving.

[0010] Summary of the invention

[0011] The object of the invention is to provide a bearing arrangement of a steering column housing of a motor vehicle which enables safe and rapid adjustment of the steering column while simultaneously ensuring high radial rigidity of the steering wheel.

[0012] According to the invention, this object is achieved by an adjustment unit of a steering column of a vehicle, comprising: an adjustment device which has at least one adjustment motor, a pull-out device which has a pull-out support which is designed to be arranged in a rotationally and axially fixed manner on a body of the vehicle, and at least one inner pull-out element which is arranged axially displaceably in the pull-out support, wherein at least one bearing arrangement is provided between the at least one inner pull-out element and the pull-out support, wherein the at least one bearing arrangement is formed from a recirculating ball segment, wherein the at least one recirculating ball segment is spring-loaded by means of a spring element, wherein the spring element has a central region of a spherical shape.

[0013] Such a design allows for adjustment of the steering column with low friction and high rigidity. Advantageously, several recirculating ball segments are provided, distributed around the circumference. The spring element is preferably made of sheet metal.

[0014] According to one embodiment of the invention, the spring element has a first and a second outer region, which adjoin the central region and which each have a flat shape. Such a shape has the advantage that during assembly, the flat regions are raised and the central region is bent inwards. The spherical outer shape of the central region before assembly prevents the spring from bending inwards and thereby exerting a radial load on a cage of the recirculating ball segment. The deformation is elastic, so that the spring plate returns to its spherical outer shape as soon as the load is no longer present.

[0015] According to one embodiment of the invention, the spring element has at least one opening, preferably two or more, in its central region. These openings are preferably designed as bores. These serve to fix the recirculating ball segment to an element of the adjustment unit. This can significantly reduce component stresses under load, so that theoretically no cracks can occur in the spring element. Fixation is achieved at both ends of the cage via the two pins shown.

[0016] According to one embodiment of the invention, the recirculating ball segment has a cage with rolling elements guided therein. The cage can be made of a plastic material.

[0017] According to one embodiment of the invention, the rolling elements are designed as balls.

[0018] Further aspects of the invention relate to a steer-by-wire steering system using an adjustment unit according to the invention. Brief description of the drawing

[0019] An exemplary embodiment of the invention is illustrated below with reference to four figures. It shows:

[0020] Fig. 1 is an exploded view of a ball bearing segment before assembly of an adjustment unit according to the invention,

[0021] Fig. 2 is a view of a ball bearing segment after assembly of an adjustment unit according to the invention,

[0022] Fig. 3 a view of the spring plate of a ball bearing segment.

[0023] Fig. 4 is a view of a ball bearing segment of an adjusting unit according to the invention.

[0024] Detailed description of the drawing

[0025] Figures 1 to 4 show a view of a ball bearing segment 1 of an adjustment unit according to the invention, not shown in detail.

[0026] The recirculating ball segment 1 itself consists of at least one spring element 2 and a cage 3. Furthermore, the cage 3 is made of plastic, for example, and has two recirculating ball guides 4. Rolling elements 6 in the form of balls 5 are arranged in the recirculating ball guide 4. The spring element 3 has a central region 7 which has a spherical shape. The central region 7 is followed by a first and a second outer region 8, 9, each of which has a flat shape. During assembly, the flat regions 8, 9 are raised and the central region 7 is bent inwards (see Figure 1 before assembly and Figure 2 after assembly). The spherical outer shape of the central region 7 before assembly (Figure 1) prevents the spring element 2 from bending inwards and thus exerting a radial load on a cage of the recirculating ball segment.The deformation is elastic, so that the spring element 2 returns to its spherical outer shape as soon as the load is no longer present.

[0027] Figure 3 shows the spring element 2. Here, it can be seen that the central region 7 additionally has two holes 11 designed as bores 10. These serve to fix the recirculating ball segment 1 to an element of the adjustment unit. This allows the component stresses to be significantly reduced under load, so that, theoretically, no cracks will develop in the spring element.

[0028] From Figure 4 it can be seen that the cage 3 has four crush ribs 12 which positively receive the spring element 2.

[0029] List of reference symbols

[0030] Ball bearing segment

[0031] spring element

[0032] cage

[0033] recirculating ball bearing guide

[0034] balls

[0035] Rolling elements

[0036] Middle range

[0037] First outer area

[0038] Second outer area

[0039] drilling

[0040] breakthrough

[0041] crush ribs

Claims

Patent claims 1. Adjustment unit of a steering column of a vehicle, comprising: an adjustment device which has at least one adjustment motor, an extension device which has a extension support which is designed to be arranged in a rotationally and axially fixed manner on a body of the vehicle, and at least one inner extension element which is arranged axially displaceably in the extension support, wherein at least one bearing arrangement is provided between the at least one inner extension element and the extension support, wherein the at least one bearing arrangement is formed from a recirculating ball segment, characterized in that the at least one recirculating ball segment (1) is spring-loaded by means of a spring element (2), wherein the spring element (2) has a central region (7) of a spherical shape.

2. Adjustment unit according to claim 1, wherein the spring element (2) has a first and a second outer region (8, 9) which adjoin the central region (7) and which each have a planar shape.

3. Adjustment unit according to one of the preceding claims, wherein the spring element (2) has at least one opening (11) in its central region (7).

4. Adjustment unit according to claim 3, wherein the opening (11) is designed as a bore (10) is formed.

5. Adjustment unit according to one of the preceding claims, wherein the ball-circulating segment (1) has a cage (3) with rolling elements (6) guided therein.

6. Adjusting unit according to claim 4, wherein the rolling elements (6) are balls (5).

7. Steer-by-wire steering system comprising an adjustment unit according to one of the preceding claims.

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