STEERING COLUMN FOR A MOTOR VEHICLE AND MOTOR VEHICLE

Description

State of the art

[0001] The invention relates to a steering column for a motor vehicle, comprising a support unit having a holding section in which a steering shaft is rotatably mounted about its longitudinal axis extending in the longitudinal direction, and having at least one connecting section connected to the holding section. Furthermore, the invention relates to a motor vehicle with such a steering column, wherein at least one elastic support element is attached to the support unit in an outwardly projecting manner, wherein the connecting section has a connecting element oriented in a connecting direction transverse to the longitudinal direction.

[0002] The steering column of a motor vehicle comprises a steering shaft mounted for rotation about its longitudinal axis. Attached to the rear section of the steering shaft, which is typically located in the direction of travel and has a steering spindle, is a steering wheel or similar steering handle for inputting manual steering commands. A rotation of the steering shaft, input as a steering command, can be mechanically converted into a steering angle of the steerable wheels via a steering gear and tie rods in a conventional mechanical steering system, or detected in a steer-by-wire steering system using electrical angle sensors, which control electric motor actuators acting on the steerable wheels to generate a steering angle.

[0003] For mounting and positioning in the passenger compartment, the steering shaft is held in a support unit and is usually rotatably mounted in a casing unit held by the support unit. The support unit is firmly connected to a vehicle-mounted structure of the vehicle body, for example, by being fixed to a vehicle cross member, for example by screwing or the like.

[0004] The support unit has a holding section in which the steering shaft is rotatably mounted. In a common design, as described, for example, in JP 2010-023797 A, the bracket-like, U-shaped holding section has two side cheeks opposite each other with respect to the longitudinal axis and extending downwards transversely to the longitudinal axis in a vertical direction. Between these side cheeks, a casing unit supporting the steering shaft can be fixedly or adjustably secured. At least one connecting section is connected to the holding section, which serves to connect the support unit to the vehicle body.

[0005] A connection section can extend laterally, in a lateral direction transverse to the longitudinal direction relative to the holding section, wherein two connection sections can be attached laterally opposite one another to the longitudinal axis. Each connection section can be secured to the vehicle body via connection or fastening elements, for example fastening holes or form-fitting elements such as pins or the like. In the aforementioned embodiments, attachment takes place in a connection direction transverse to the longitudinal direction, for example by attaching the connection sections from below to the vehicle cross member. Connecting elements such as screws or the like are passed through the fastening holes, whose axial direction is parallel to the connection direction, so that the connection sections are firmly clamped to the vehicle body.

[0006] The aim for the steering column mounted in the vehicle is to be as rigid as possible, which corresponds to the highest possible natural frequency. This natural frequency is significantly influenced by the connection of the support unit to the vehicle body. In the prior art mentioned, it was proposed to use spring washers between the connection sections and a vehicle-fixed structure to ensure the bracing, which exert a preload force on the fastening elements in the connection direction. The disadvantage of this, however, is the undesirable reduction in the natural frequency. In addition, the use of spring washers between the connection sections and the vehicle-fixed structure requires the structural adaptation of the support unit, since without these adaptations, the position of the steering spindle and thus the steering wheel as intended in the vehicle can no longer be maintained. This is complex and expensive.

[0007] A steering column of the type mentioned above is known, for example, from US 2017 / 282960 A1 or US 5 743 150 A

[0008] In view of the problems explained above, it is an object of the present invention to provide an improved support unit which enables a higher natural frequency and requires only minor design-related adjustments. Description of the invention

[0009] This object is achieved according to the invention by the steering column having the features of claim 1 and the features of claim 15. Advantageous further developments emerge from the subclaims.

[0010] In a steering column for a motor vehicle, comprising a support unit which has a holding section in which a steering shaft is rotatably mounted about its longitudinal axis extending in the longitudinal direction, and which has at least one connecting section connected to the holding section, wherein at least one elastic support element is attached to the support unit in an outwardly projecting manner, wherein the connecting section has a connecting element which is oriented in a connecting direction transverse to the longitudinal direction, it is provided according to the invention that the support element protrudes in a supporting direction transverse to the longitudinal direction and transverse to the connecting direction, and has a contact region which is at a distance from the connecting section in the connecting direction.

[0011] Thanks to this inventive design, a higher natural frequency is possible and at the same time only minor design-related adaptations compared to the state of the art are necessary, so that the solution can be implemented cost-effectively and without significantly increased installation space requirements.

[0012] In the following, it is assumed by definition that the longitudinal direction of the steering shaft extends from rear to front with respect to the direction of travel of the vehicle, the vertical direction transverse to this from bottom to top, and the lateral direction laterally transverse to the longitudinal and vertical directions.

[0013] According to the invention, a support element is designed to be resilient, for example as a spring element, and is attached to the support unit in such a way that it protrudes resiliently outward therefrom in a support direction. The support element is arranged in such a way that, in the mounted state, it can be supported and elastically braced against a vehicle-fixed structure, for example a contact or support surface on a cross member. The elastic force of the support element acts on the support unit in the support direction, preferably approximately perpendicularly in a normal direction in the surface area where the support element is positioned on the support unit protruding outward.

[0014] In contrast to the prior art, in which a spring element is inserted between a support element and the vehicle-fixed structure, is attached and supported directly and without a distance to the support element, the support element according to the invention is arranged at a defined distance from the support element in such a way that it enables elastic support of the support unit on a vehicle-fixed structure outside the connection section, in particular at a distance from a connection element of the connection section, for example a connection or fastening opening through which a connecting means such as a screw or the like is passed.

[0015] According to the invention, the connecting section has a connecting element that is oriented in a connecting direction transverse to the longitudinal direction. Such a connecting element can, for example, be a fastening or connecting element such as a fastening bore or the like, the axis of which runs in a vertical direction. By means of a fastening element inserted through the connecting element, the connecting element and thus the support unit can be braced against a vehicle-mounted structure in a vertical direction identical to the connecting direction.

[0016] It is provided that the support element protrudes in a support direction transverse to the longitudinal direction and transverse to the connection direction. As a result, the support element can exert an additional support force on the support unit obliquely or perpendicular to the possible support directions in the current state by the steering shaft and / or the connection elements. The support direction points in a lateral direction, so that the support unit is additionally supported laterally by a support element. This enables an improved support effect in spatial directions that are only connected by friction in the prior art, for example, lateral support in the area of ​​the frictional connection between the connection sections and a cross member of the vehicle. The additional elastic fixation by the support element according to the invention at a distance from the connection section suppresses unwanted resonances from oscillatory masses arranged outside the connection section.This advantageously increases the natural frequency of the entire assembled steering column.

[0017] An elastic support element according to the invention has the further advantage over a rigid support in that potential constraint forces due to tolerance deviations can be elastically absorbed and thus limited. This enables better reproducibility of the increased natural frequency. Furthermore, it facilitates simpler manufacturing and assembly.

[0018] It is advantageous for the support element to be attached to the holding section. This allows the support unit to be fixed to the connection section by a fastening element and additionally supported by the support element on the holding section at a distance from the connection section. This enables an effective increase in the natural frequency.

[0019] Advantageously, a support element can be arranged on the holding section at a distance from the connection area where the connecting section is connected to the holding section. It can be advantageous for the support element to project laterally in the same direction as a connecting section, and to have a vertical distance from this connecting section that corresponds to the connection direction during installation of the connecting element in the vehicle. This allows the support unit to be supported laterally by the connecting section and additionally by the support element on the body, thereby effectively increasing the natural frequency.

[0020] It is possible for a connecting section to extend laterally transversely to the longitudinal axis from the holding section. The holding section can have, in a conventional manner, a bow-shaped, U-shaped profile with downward-facing side cheeks, between which the steering shaft is held and mounted. The connecting elements can extend laterally from the side cheeks or the base and can be arranged in a planar, plate-like manner perpendicular to the vertical direction. A support element according to the invention can also advantageously be arranged at a distance from the connecting section on the outside of a side cheek, preferably protruding in opposite lateral directions on both side cheeks, where the connecting sections can also be connected to the holding section.This allows for effective lateral support of the side panels against a dedicated support surface on the vehicle-mounted structure, against which the support elements can be elastically braced at a distance from the connecting elements. Because the support direction is directed laterally in the direction of the extension of the connecting sections, simple and effective support can be provided transversely to the connecting elements aligned in the connection or vertical direction, into which, for example, screws are inserted as fastening elements.

[0021] The support unit, including the holding and connecting sections, can be formed in one piece, for example as a metallic die-cast part, for example made of an aluminum or magnesium alloy, or as a sheet metal part, preferably made of sheet steel, or of a composite material. Alternatively, the support unit can be formed as a composite, for example from welded sheet metal parts. In any case, by using support elements according to the invention, a sufficiently high natural frequency can be achieved even with a simplified design, also for the realization of an advantageous lightweight construction.

[0022] It can advantageously be provided that at least two support elements are arranged in pairs with opposing support directions. For example, by having two support elements project laterally relative to the longitudinal axis in the direction of the extension of the connecting sections and each laterally supported against the vehicle-mounted structure, the support unit can be elastically clamped between the two support elements. This allows a particularly effective increase in the natural frequency to be achieved.

[0023] Preferably, two support elements can be attached to the holding section. For example, at least one support element can be arranged on the outside of each side wall of a U-shaped holding section. The U-shaped holding section can thus be elastically braced to the vehicle-mounted structure outside of its fixation via the connecting sections.

[0024] A further advantage of the invention is that the support unit can be adapted to existing crossbeam designs with minimal design effort by selecting the shape, dimensions, and positioning of the support elements. This allows for increased flexibility in structural design and manufacturing. Furthermore, by specifying the elastic properties of the support elements, targeted optimization of the vibration behavior and natural frequency can be achieved.

[0025] It is advantageous for a support element to comprise a spring element. A spring element can preferably be made of a metallic material, preferably spring steel. The use of specially adapted designs, such as coil, ring, wave, or leaf springs, or the like, allows for flexible and optimized adaptation to the available installation space, elastic properties, and other relevant parameters.

[0026] An advantageous embodiment provides for the spring element to have a curved leaf spring. A curved leaf spring can simply protrude convexly and / or concavely outwards from the support unit, whereby it can extend, for example, along an outer surface, for example laterally on a side cheek of a U-shaped holding section. One advantage is that a leaf spring simply enables a very flat design, which is determined only by the material thickness and the deflection of the spring leaf. Such a design can be structurally adapted and manufactured with little effort. A further advantage is that a leaf spring can be easily fixed at one end, for example by spot welding, riveting, or detachably by screwing.

[0027] It may be advantageous for the support element to be fixed to the support unit. A permanent connection can preferably be provided, for example, a material and / or form-fitting connection by welding, riveting, pressing, or the like. Alternatively, a detachable connection can also be made by screwing or the like.

[0028] The support element may be provided with a damping element. The damping element may, for example, comprise a friction element arranged parallel to the elastic deformation path of the support element and damping possible elastic vibrations of the support element through external friction or, alternatively or additionally, through internal friction. This can further reduce unwanted resonances and natural vibrations.

[0029] The holding section can have a U-shaped retaining bracket. In this known design, a U-profile extends longitudinally, and the steering shaft is accommodated between the downwardly directed U-legs. The connecting sections can preferably protrude outwardly from the U-legs on both sides. In a known manner, a casing unit that rotatably supports the steering shaft can be held between the U-legs.

[0030] In an advantageous further development, the support unit can have more than two connection sections, particularly preferably four connection sections.

[0031] Advantageously, a support element according to the invention can be provided for each connection section.

[0032] The steering shaft can be adjustable relative to the support unit. For example, the steering shaft can be rotatably mounted in a casing unit, which can be tilted vertically relative to the support unit to adjust the height of the steering wheel. Alternatively or additionally, the steering shaft and casing unit can be designed telescopically to allow adjustment of the steering wheel position along the longitudinal axis.

[0033] The adjustability can be designed manually in a manner known per se, wherein a clamping device acting between the support unit and the casing unit can be manually switched between a fixing or a release position, wherein in the fixing position the position of the steering shaft is releasably fixed to the support unit, and in the release position an adjustment in the height and / or longitudinal direction is released.

[0034] It is also possible to integrate a motorized adjustment drive between the steering shaft and the support unit. In a conventional manner, an electric motor-driven spindle drive can be arranged vertically between a sleeve unit supporting the steering shaft and the support unit, and additionally or alternatively in the longitudinal direction between telescopically adjustable sleeves and length-adjustable steering shaft parts.

[0035] Furthermore, the invention relates to a motor vehicle comprising a cross member coupled to a previously described steering column. By coupling the steering column and cross member, the elastic support element is preloaded and is in direct or indirect contact with the cross member. This increases the natural frequency of the steering column, and no significant structural modification of the support unit of the steering column or the cross member is required. Description of the drawings

[0036] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. In detail: Figure 1 shows a steering column according to the invention in a schematic perspective view, Figure 2 shows a further perspective view of the steering column according to Figure 1 , Figure 3 an enlarged detailed view of Figure 2 , Figure 4 an enlarged view of the steering column according to Figures 1 to 3 in the longitudinal direction, Figure 5 a motor vehicle according to the invention with a steering column according to the invention. Embodiments of the invention

[0037] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0038] Figures 1 and 2 show perspective overall views of a steering column 1 according to the invention schematically in the installed position in a motor vehicle, specifically on a cross member 2 of the motor vehicle not shown further.

[0039] The steering column 1 comprises a support unit 3 designed according to the invention, which is fixed to the cross member 2 and by which a steering shaft 4 is mounted so as to be rotatable about its longitudinal axis 40. At its rear end, the steering shaft 4 has a connecting section 41 for attaching a steering wheel (not shown).

[0040] By definition, the longitudinal axis 40 extends in a longitudinal direction L with respect to the direction of travel from rear to front, the height direction H runs transversely thereto from bottom to top and the lateral direction S laterally transversely to the longitudinal direction L and height direction H. The longitudinal direction L and height direction H are perpendicular to the lateral direction S, and the longitudinal direction L usually runs obliquely forwards and downwards.

[0041] The support unit 3 has a U-shaped holding section 31, from which two side cheeks 32, which form the U-legs, extend downward. Two connecting sections 33 are connected to the holding section 31 and protrude outwards in both lateral directions S relative to the side cheeks 32. Each connecting section 33 is connected—preferably in one piece—to a connecting section 34 of the holding section 31. The two connecting sections 34 extend essentially parallel to the side cheeks 32, and the connecting sections 33 extend flatly perpendicular to the height direction H, which represents the connection direction of these connecting sections 33.

[0042] The steering shaft 4 is mounted rotatably about its longitudinal axis 40 in a casing unit 5 arranged between the side cheeks 32. For fixing purposes, in a manually adjustable steering column 1, which is shown only as an example in the figures, a clamping device 6 can be provided which can be brought into either a fixing position or a release position, for example by manual switching. In the fixing position, the side cheeks 32 are clamped against the casing unit 5 in order to fix it relative to the holding section 31. In the release position, the clamping is released, so that the casing unit 5 together with the steering shaft 4 can be adjusted in the vertical direction H to adjust the steering wheel position. If necessary, the casing unit 5 and the steering shaft 4 can also be designed to be telescopic in the longitudinal direction L in order to enable longitudinal adjustment of the steering wheel.

[0043] As an alternative to the manual adjustment shown as an example, a motorized adjustment can also be provided. In this case, electromotive adjustment drives (not shown here) can be integrated between the support unit 3 and the steering shaft 4, for example, electromotively driven spindle drives, which enable adjustment in the vertical direction H and / or longitudinal direction L. The clamping device 6 can be omitted when using self-locking adjustment drives.

[0044] The steering column 1 is connected to two support struts 21 of the cross member 2, which are arranged in such a way that the two connection sections 33 can be attached to the support struts 21 from below in the height direction H and fixed thereto, as shown in the detailed view of Figure 2 and the axial view from behind in the longitudinal direction L of the longitudinal axis 40 of Figure 4 is recognizable.

[0045] The connecting sections 33 each have fastening bores 35 as connecting elements, with bore axes B pointing in the height direction H, i.e. in the connection direction.

[0046] A fastening element 36, for example a screw bolt or the like, is passed through each fastening bore 35 in order to clamp a connecting section 33 to the respective support strut 21 in the height direction H.

[0047] Support elements 7 according to the invention are attached to the holding section 31, projecting in the lateral direction, which in the example are each designed as a resilient leaf spring made of spring steel. Each support element 7 has a convexly outwardly projecting arcuate section 71 in the lateral direction S. Each leaf-shaped support element 7 is fixed on one side to the support unit 3 by a fastening section 72, for example, permanently by spot welding or the like. The free end 73 can be loosely supported from the outside against the support element 3, thereby allowing the arcuate section 71 to be elastically deflected laterally against the holding section 31 against the predetermined spring force F, as shown in Figures 3 and 4 The spring force F acts outwards in the support direction, which in the example shown corresponds to the lateral direction S.

[0048] In the outer contact area of ​​the curved section 71, each support element 7 rests against a support strut 21 in the lateral direction S, i.e., transversely to the vertical direction H, which corresponds to the connection direction in which the connection sections 33 are braced from below against the support struts 21 by means of the fastening elements 36. The two support elements 7 elastically clamp the support unit 3 practically above the connection sections 33 between the support struts 21.

[0049] According to the invention, the contact areas of the support elements 7 in the height direction H each have a distance A from the connecting section 33, specifically from the upper contact area of ​​the connecting section 33 which rests against the support strut 21 from below.

[0050] The Figure 5 shows schematically a motor vehicle 100 comprising a cross member 2 which is coupled to a steering column 1 according to the invention, wherein the steering column 1 is fixed to the cross member 2.

[0051] Because the support unit 3 is braced to the cross member 2 at its connection sections 33 in the vertical direction H, the connection direction, and is additionally braced and supported by the support elements 7 in the lateral direction between the support struts 21, the natural frequency of the steering column 1 is advantageously increased in the installed state shown. Tolerances can be elastically compensated by the elastic support elements 7, so that no undesirably high stresses occur. List of reference symbols

[0052] 1Steering column 2Cross member 21Support strut 3Support unit 31Holding section 32Side cheeks 33Connecting section 34Connecting section 35Mounting hole 36Mounting element 4Steering shaft 40Longitudinal axis 41Connecting section 5Shell unit 6Clamping device 7Support elements 71Curved section 72Mounting section 73Free end 100Motor vehicle LLongitudinal direction HHeight direction (connection direction) SLateral direction (support direction) BBore axes FFeel force ADistance

Claims

1. Steering column (1) for a motor vehicle, comprising a support unit (3) which has a holding section (31) in which a steering shaft (4) is mounted rotatably about its longitudinal axis (40) extending in the longitudinal direction (L), and which has at least one connecting section (33) connected to the holding section (31), wherein at least one resilient support element (7) is attached to the support unit (3) so as to project outwards, wherein the connecting portion (33) has a connecting element (35) which is aligned in a connecting direction (H) transverse to the longitudinal direction (L), characterized in in that the support element (7) projects in a support direction (S) transversely to the longitudinal direction (L) and transversely to the connection direction (H), and has a contact region which is at a distance (A) from the connection section (33) in the connection direction (H).

2. Steering column according to claim 1, characterized in that the support element (7) is attached to the retaining section (31).

3. Steering column according to one of the preceding claims, characterized in that a connecting section (33) extends laterally transversely to the longitudinal axis (40) of the retaining section (31).

4. Steering column according to one of the preceding claims, characterized in that at least two connecting sections (33) are arranged opposite one another with respect to the longitudinal axis (40).

5. Steering column according to one of the preceding claims, characterized in that at least two support elements (7) are arranged in pairs with opposite support directions.

6. Steering column according to one of the preceding claims, characterized in that one support element (7) comprises a spring element.

7. Steering column according to claim 6, characterized in that the spring element (7) comprises a curved leaf spring (7).

8. Steering column according to one of the preceding claims, characterized in that the support element (7) is fixed to the support unit (3).

9. Steering column according to one of the preceding claims, characterized in that the support element (7) has a damping element.

10. Steering column according to one of the preceding claims, characterized in that the retaining section (31) has a U-shaped retaining bracket.

11. Steering column according to one of the preceding claims, characterized in that the steering shaft (4) is adjustable relative to the support unit (3).

12. Steering column according to one of the preceding claims, characterized in that a motorized adjustment drive is incorporated between the steering shaft (4) and the support unit (3).

13. Motor vehicle (100) comprising a cross member (2) which is coupled to a steering column (1) according to one of claims 1 to 12.