Adjustment unit of a steering column

Abstract

Adjustment unit of a vehicle's steering column, comprising: an adjustment device comprising at least one adjustment motor, An extension device comprising an extension carrier configured to be rotationally and axially fixed to a vehicle body, and at least one inner extension element arranged axially displaceable in the extension carrier, wherein at least one bearing arrangement is provided between the at least one inner extension element and the extension carrier, wherein the at least one bearing arrangement is formed from a ball recirculation segment, wherein the at least one ball recirculation segment (1) is spring-loaded by means of a spring element (2), wherein the spring element (2) has a central region (7) of a convex shape.

Description

Field of invention

[0001] 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. Background of the invention

[0002] Modern steering columns allow the steering wheel to be adjusted for both height and reach. With such adjustment systems, the steering column housing components must slide relative to each other. This is achieved through a telescopic arrangement of the housing components. This allows the steering wheel to be positioned optimally for the driver. Recently, there has been a requirement to retract the steering wheel into a stowable position within the dashboard.

[0003] To achieve a sufficient adjustment range, it is known from DE 10 2015 216 326 A1 to arrange several outer casing tubes so that they can be telescopically slid into one another. To adjust the stow position, the outer casing tubes can be pushed together until they are almost completely recessed into each other.

[0004] To allow for quick and safe adjustment of the steering column, it is essential that the outer tubes can move smoothly relative to each other, i.e., glide with minimal friction. This is often achieved using a plain bearing. In contrast, the steering wheel itself requires a very rigid mounting to prevent it from vibrating while driving. Summary of the invention

[0005] The object of the invention is to provide a bearing arrangement for a steering column housing of a motor vehicle which enables safe and quick adjustment of the steering column while maintaining high radial stiffness of the steering wheel.

[0006] According to the invention, this problem is solved by an adjustment unit of a steering column of a vehicle, comprising: an adjustment device comprising at least one adjustment motor, An extension device comprising an extension carrier configured to be rotationally and axially fixed to a vehicle body, and at least one inner extension element arranged to be axially displaceable in the extension carrier, wherein at least one bearing arrangement is provided between the at least one inner extension element and the extension carrier, 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 convex shape.

[0007] Such a design allows the steering column to be adjusted with low friction and high rigidity. Advantageously, several recirculating ball segments are arranged distributed around the circumference. The spring element is preferably made of a sheet metal part.

[0008] According to one embodiment of the invention, the spring element has a first and a second outer region, which adjoin the central region and each have a flat shape. This shape has the advantage that, during assembly, the flat regions are lifted and the central region is bent inwards. The convex 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 ball recirculation segment. The deformation is elastic, so that the spring plate returns to its convex outer shape as soon as the load is removed.

[0009] 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 significantly reduces component stresses under load, so that theoretically no cracks form in the spring element. Fixation is achieved at both ends of the cage via the two pins shown.

[0010] According to one embodiment of the invention, the ball recirculation segment has a cage with rolling elements guided therein. The cage can be made of a plastic.

[0011] According to one embodiment of the invention, the rolling elements are designed as spheres.

[0012] Further aspects of the invention relate to a steer-by-wire steering system with the use of an adjustment unit according to the invention. Brief description of the drawing

[0013] An embodiment of the invention is illustrated below with reference to four figures. It shows: Fig. 1 an exploded view of a ball recirculation segment before assembly of an adjustment unit according to the invention, Fig. 2 a view of a ball recirculation segment after assembly of an adjustment unit according to the invention, Fig. 3 a view of the spring plate of a ball recirculation segment. Fig. 4 a view of a ball recirculation segment of an adjustment unit according to the invention. Detailed description of the drawing

[0014] Fig. Figures 1 to 4 show a view of a ball recirculation segment 1 of an adjustment unit according to the invention, which is not shown in detail.

[0015] The ball recirculation segment 1 itself consists of at least one spring element 2 and a cage 3. Furthermore, the cage 3 is, for example, made of plastic and has two ball recirculation guides 4. Rolling elements 6, designed as balls 5, are arranged in the ball recirculation guides 4. The spring element 3 has a central section 7, which has a convex shape. Adjoining the central section 7 are first and second outer sections 8 and 9, respectively, which each have a flat shape. During assembly, the flat sections 8 and 9 are lifted and the central section 7 is bent inwards (see figure). Fig. 1 before assembly and Fig. 2 after assembly). Due to the convex outer shape of the middle area 7 before assembly ( Fig. 1) This prevents the spring element 2 from bending inwards and thereby exerting a radial load on a cage of the ball recirculation segment. The deformation is elastic, so that the spring element 2 returns to its convex outer shape as soon as the load is removed.

[0016] Fig. Figure 3 shows the spring element 2. Here, the central area 7 can be seen to have two additional openings 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 form in the spring element.

[0017] Out of Fig. 4 can be seen that the cage 3 has four crush ribs 12 which positively engage the spring element 2. Reference symbol list 1 ball recirculation segment 2 spring element 3 cage 4 ball screw guides 5 balls 6 rolling elements 7 Middle range 8 First outer area 9 Second outer area 10 Drilling 11 Breakthrough 12 squash ribs QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2015 216 326 A1

[0003]

Claims

[1] Adjustment unit of a steering column of a vehicle, comprising: an adjustment device comprising at least one adjustment motor, an extension device comprising an extension carrier configured to be rotationally and axially fixed to a vehicle body, and at least one inner extension element arranged to be axially displaceable within the extension carrier, wherein at least one bearing arrangement is provided between the at least one inner extension element and the extension carrier, wherein the at least one bearing arrangement is formed from a recirculating ball segment, characterized by , that the at least one ball recirculation segment (1) is spring-loaded by means of a spring element (2), wherein the spring element (2) has a central region (7) of a convex shape. [2] Adjustment unit according to claim 1, wherein the spring element (2) has a first and second outer region (8, 9) which connect to the middle 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). [5] Adjustment unit according to one of the preceding claims, wherein the ball recirculation segment (1) has a cage (3) with rolling elements (6) guided therein. [6] Adjustment 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 any of the preceding claims.

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