Steering spindle for a steering system of a motor vehicle and method for mounting a steering handle on a steering spindle

Abstract

Steering spindle (1) for a steering system of a motor vehicle, which is rotatably mounted in a steering column about a longitudinal axis (L) and can be connected in a rotationally fixed manner to a steering handle that can be operated by a vehicle driver, wherein the steering spindle (1) is designed in two parts, comprising a first steering spindle part (10) with a stepped connecting section (12) pointing towards the steering handle, wherein the connecting section (12) has a first connecting section (12.1) with a first outer diameter (d1) and a first toothing (14.1) which, in the assembled state, is in engagement with a hub or coupling part of the steering handle, and a second connecting section (12.2) adjoining the first connecting section (12.1) in the direction of the steering handle, with a second outer diameter (d2) and a second toothing (14.2), wherein the first outer diameter (d1) is larger than the second outer diameter (d2) and wherein the second toothing (14.2) is aligned with the first toothing (14.1), and a second, sleeve-shaped steering spindle part (20) with an inner side (22) and an outer side (24) opposite it, characterized by the fact that the second steering spindle part (20) has, on its inner side (22), at least partially circumferentially, a toothing (26) corresponding to the second toothing (14.2), and the toothing (26) of the second steering spindle part (20) is in engagement with the second toothing (14.2) in the assembled state, wherein the second steering spindle part (20) serves as an aid for determining the correct assembly position of the steering handle on the steering spindle (1) due to the aligned arrangement of the first and second toothing (14.1, 14.2). and wherein at least one positioning means (30) is arranged on the second steering spindle part (20) by means of which the steering handle can be easily aligned and positioned during assembly on the steering spindle (1).

Description

[0001] The invention relates to a steering spindle for a steering system, in particular a steer-by-wire steering system without a mechanical fallback level, of a motor vehicle, such as a passenger car, truck, bus, tractor, etc., and a method for mounting a steering handle on such a steering spindle.

[0002] First, a distinction must be made between different types of steering systems for vehicles, in particular between mechanical steering systems and steer-by-wire steering systems. In conventional mechanical steering systems for motor vehicles, there is a mechanical coupling between the steering wheel and the vehicle wheels steered by the steering wheel; that is, the steering movement exerted by the driver is transmitted from the steering wheel via the steering column to a steering gear and from there to a tie rod connected to the vehicle wheels.

[0003] Meanwhile, steer-by-wire steering systems are also available for motor vehicles, eliminating the mechanical connection between the steering wheel and the vehicle wheels. Steer-by-wire systems generally consist of a steering wheel actuator, which generates the steering feel and digitally transmits the driver's manual steering command (by turning the steering wheel) to a rack and pinion actuator or steering actuator, and a rack and pinion actuator or steering actuator, which receives the steering signal from the steering wheel actuator and sets the desired position of the vehicle wheels. Such steer-by-wire steering systems are known, for example, from DE 10 2020 121 912 A1 and DE 10 2021 204 136 B3.

[0004] The generic patent US 2014 / 0119810A1 discloses a steering wheel shaft holding device comprising a steering column and a maintenance tool, wherein the steering column has a steering shaft with a mounting groove and a holding device arranged in the mounting groove, wherein the holding device has at least one elastic locking projection configured to move between a locking position and an unlocking position;

[0005] Furthermore, a steering arrangement comprising a steering spindle head is known from DE 10 2024 000 570 A1.

[0006] Regardless of the specific steering system type, the steering wheel is typically mounted on a steering column during vehicle assembly. In practice, mounting the steering wheel to the steering column is often difficult, as it is essential that the steering wheel is precisely aligned and positioned relative to the column. Only by accurately aligning the steering wheel with the column can it be ensured that, with the wheels at rest, the spokes of the steering wheel are in a specific position, thus indicating to the driver that the wheels are in a straight-ahead position. Because of this precise alignment, mounting the steering wheel is often tedious and very time-consuming.

[0007] With a so-called steer-by-wire steering system without a mechanical fallback, the steering wheel can, in certain situations, such as during assembly, turn almost without force. This occurs when the system is not powered. Consequently, the assembly process differs from that of a conventional mechanical steering system, where the steering spindle is held rotationally fixed in the steering column during assembly, compared to the assembly of a steer-by-wire steering system.

[0008] For positioning or orientation of the steering wheel relative to the steering column, mechanical steering systems typically use optical features, such as markings. In contrast, steer-by-wire steering systems generally use so-called poka-yoke features to position the steering wheel relative to the steering column. However, poka-yoke features are problematic in mechanical steering systems, as they tend to be more of a hindrance. This necessitates the production of different types of steering columns for mechanical and steer-by-wire systems. This problem arises particularly in vehicles where, depending on the model series, either a mechanical or a steer-by-wire system can be installed, requiring the production of a steering column with a specially designed steering column head for each system.

[0009] The task is therefore to provide a steering spindle for a motor vehicle steering system that overcomes the disadvantages of the current state of the art. The steering spindle should allow for simple and precise positioning of the steering handle relative to the spindle, be usable for as many steering systems as possible, and be cost-effective to manufacture. Furthermore, the mounting of the steering handle to the steering spindle or to the steering spindle head should be as simple as possible.

[0010] This problem is solved according to the invention by the steering spindle for a steering system, in particular a steer-by-wire steering system, of a vehicle according to claim 1 and by a method for mounting a steering handle on a steering column according to claim 10.

[0011] The steering spindle according to the invention for a steering system, in particular a mechanical steering system or a steer-by-wire steering system or a steer-by-wire system without a mechanical fallback, of a motor vehicle is rotatably mounted in a steering column about a longitudinal axis and can be connected in a rotationally fixed manner to a steering handle, such as a steering wheel, which can be operated by a driver, wherein the steering spindle is designed in two parts. The two-part steering spindle comprises a first steering spindle part with a stepped connecting section facing the steering handle, wherein the connecting section has a first connecting section with a first outer diameter and a first toothing, which in the assembled state is in engagement with a hub or coupling part of the steering handle, and a second connecting section adjoining the first connecting section in the direction of the steering handle, with a second outer diameter and a second toothing.wherein the first outer diameter is larger than the second outer diameter and wherein the second toothing is aligned with the first toothing, and a second, sleeve-like steering spindle part with an inner side and an outer side opposite it, wherein the second steering spindle part has, on its inner side, at least partially, toothing corresponding to the second toothing and the toothing of the second steering spindle part is in engagement with the second toothing in the assembled state, wherein the second steering spindle part, due to the aligned arrangement of the first and second toothing, serves as an aid for determining the correct mounting position of the steering handle on the steering spindle, and wherein at least one positioning means is arranged on the second steering spindle part by means of which the steering handle can be easily aligned and positioned during assembly on the steering spindle.

[0012] The two-part design of the steering spindle has proven particularly advantageous, consisting of a first steering spindle section and a second steering spindle section that can be connected to the first. The second steering spindle section is designed in the form of a sleeve and, depending on the type of steering system in the vehicle, has at least one positioning element to position the steering handle relative to the steering spindle. Since the positioning element is not, as is usually the case, part of the steering spindle head but is located on the second steering spindle section, the first steering spindle sections can be identical or of the same design, regardless of the type of steering system installed in the vehicle. Therefore, only the second steering spindle sections differ, as they can have different positioning elements.In a steer-by-wire steering system, the second steering spindle part can have at least one positioning feature in the form of a poka-yoke, while in a mechanical steering system, the second steering spindle part can have at least one positioning feature in the form of a line marking. By simply replacing the second steering spindle part, the steering spindle can be used for a wide variety of steering systems. Conversely, the second steering spindle part can also be designed to allow the mounting of a single steering wheel hub; that is, the second steering spindle part has different positioning features, namely at least one line marking and at least one poka-yoke feature. Using different positioning features provides a standardized steering wheel interface to which various types of steering wheels can be mounted.

[0013] According to the invention, the first steering spindle section has an end facing away from the steering wheel or steering gear and an opposite end facing the steering wheel, the latter being designed as a stepped connecting section. The steering wheel-facing end of the first steering spindle section is also referred to as the steering spindle head and serves to attach the steering handle. The stepped connecting section consists of a first connecting section with a first outer diameter and a first toothed section, the first connecting section being designed such that the steering handle hub or the steering wheel hub can be attached to it. For this purpose, the first toothed section is designed as a longitudinal toothing or tooth-like longitudinal profile or as a straight toothing in the direction of the longitudinal axis of the steering spindle.The toothing of the first connecting section creates a positive connection between the steering wheel hub and the steering spindle, by means of which the torque can be transmitted from the steering wheel to the steering spindle.

[0014] Furthermore, the first steering spindle section has a second connecting section adjoining the first connecting section in the direction of the steering handle. This second connecting section has a second outer diameter and a second set of teeth, to which the second steering spindle section can be attached. The special feature is that the second set of teeth is aligned with the first set of teeth; that is, the second set of teeth is also designed as a longitudinal toothing or tooth-like longitudinal profile, or as a straight toothing in the direction of the longitudinal axis of the steering spindle. Due to the aligned arrangement of the two sets of teeth, the number of teeth or grooves of the first set of teeth in the first connecting section and the number of teeth or grooves of the second set of teeth in the second connecting section are identical or have the same pitch. Advantageously, the steering spindle's teeth are designed as splined or fine teeth.In particular, a fine toothing is used, for example a 1x66 toothing.

[0015] The first connecting section preferably features fine teeth with block teeth and a conical seat. The conical seat is understood to be a cone, preferably opening or widening, located on the side of the connecting section of the first steering spindle part facing away from the steering wheel, which transitions from the first connecting section into the steering spindle body. The conical seat forms an axial stop for the steering handle when it is axially slid onto the steering spindle. The positive-locking connection between the steering handle and the steering spindle creates a particularly good, backlash-free, and secure connection. This type of steering spindle-steering wheel hub connection is also particularly well-suited for backlash-free torque transmission.

[0016] Furthermore, it is advantageous to have a first and second set of teeth on the cylindrical surface of the steering spindle head or on the cylindrical surface of the connecting section of the steering spindle. The first and second sets of teeth have longitudinal teeth in the direction of the longitudinal axis or a tooth-like longitudinal profile comprising a plurality of teeth, in particular block teeth, wherein the number of teeth of the first and second sets of teeth is the same due to the aligned arrangement. Because of the aligned arrangement and the identical number of teeth of the first and second sets of teeth, the second steering spindle part can be attached circumferentially at the position of the second set of teeth that corresponds circumferentially to the position of the first set of teeth; that is, with respect to the first tooth profile, the second steering spindle part can be attached in the same position or orientation on the second tooth profile from a rotational perspective.Thus, by rotating the second steering spindle part, the exact mounting position for the subsequent mounting of the steering handle on the steering spindle can be determined.

[0017] According to the invention, a second steering spindle part is provided, which is tubular or hollow cylindrical, or in the form of a sleeve, and has an inner surface and an outer surface opposite it. The second steering spindle part has, on its inner surface, at least partially, a toothed section around its circumference corresponding to the second toothed section, in order to attach the second steering spindle part to the second connecting section. Thus, in the assembled state, the internal toothed section of the second steering spindle part engages with the external toothed section of the second connecting section. The internal toothed section of the second steering spindle part extends circumferentially over at least a portion of the inner surface. Furthermore, at least one positioning means is arranged on the second steering spindle part, by means of which the steering handle can be aligned during assembly on the steering spindle.

[0018] The second steering spindle section initially serves as an aid to determine the exact mounting position for the steering handle on the steering spindle and then to attach the steering handle in the correct position. For this purpose, the second steering spindle section is axially slid onto the second connecting section and rotated circumferentially until it is rotationally aligned with the first steering spindle section. This means that, due to the aligned arrangement of the first and second teeth of the connecting section in the circumferential or rotational direction of the steering spindle, the second steering spindle section can be attached in the same number of positions as the steering handle on the teeth of the first connecting section. The second steering spindle section is therefore a pre-centering aid, which makes attaching the steering handle to the steering spindle particularly convenient and easy during the subsequent assembly process.The steering spindle head can be mounted on it. The positioning means on the second steering spindle part clearly and, above all, unmistakably define the mounting position for the steering handle on the steering spindle.

[0019] Advantageously, the first and second steering spindle parts are made of different materials. The first steering spindle part is preferably made of metal, especially steel, and the second steering spindle part of plastic. Manufacturing the first steering spindle part from metal ensures backlash-free torque transmission between the steering handle or steering wheel hub and the first steering spindle part. Furthermore, the manufacturing of the first steering spindle part, particularly the steering spindle head with its external teeth, achieves a reliable and permanently stable torque transmission between the steering handle and the steering spindle. In contrast, the second, sleeve-like steering spindle part is made of plastic.Manufacturing the second steering spindle part from plastic has the advantage that, on the one hand, complex geometries can be created, and on the other hand, the second steering spindle part can be produced cost-effectively.

[0020] It is further advantageous that the at least one positioning means is designed in the form of a positioning recess, in particular a line marking, or in the form of a positioning nose or element projecting from the outside of the second steering spindle part, e.g., in the form of a poka-yoke feature. In a preferred embodiment, the positioning recess is slot-shaped or groove-shaped. Preferably, the positioning recess extends from the top of the second steering spindle part to the underside of the second steering spindle part and is located on the steering wheel side or on the end face of the second steering spindle part in the direction of the steering handle. The slot- or groove-shaped positioning recess is a so-called line marking, which is generally used in conventional, mechanical steering systems.

[0021] Alternatively or additionally, at least one positioning lug can be arranged on the second steering spindle section, by means of which the steering handle can be rotationally aligned during assembly on the steering spindle. The positioning lug is located on the outer surface of the second steering spindle section. Furthermore, the at least one positioning lug is attached to the side of the second steering spindle section facing away from the steering wheel or the steering gear, and is preferably located at the edge of the second steering spindle section. Advantageously, the at least one positioning lug is preferably wedge-shaped, ramp-shaped, or in the form of an inclined plane that rises towards the side of the second steering spindle section facing away from the steering wheel. However, the shape of the positioning lug is not limited to this form; rather, the positioning lug can also be pin-shaped, bolt-shaped, cuboid-shaped, etc.

[0022] In a further advantageous embodiment, two or more positioning means are provided, wherein at least one positioning means is designed as a positioning recess and at least one positioning means as a positioning nose or positioning element. If two different positioning means are provided, they are arranged in alignment with each other in the longitudinal direction of the steering spindle, i.e., the at least one positioning recess and the at least one positioning nose are arranged opposite each other in the axial direction of the second steering spindle part. The respective positioning recess is positioned on the steering wheel side, and the positioning nose associated with the positioning recess is positioned on the side facing away from the steering wheel.By using two different positioning means, a universal steering wheel interface is provided that meets the requirements of both mounting situations; the steering wheel hub of a conventional, mechanical steering system as well as the steering wheel hub of a steer-by-wire steering system can be mounted on the steering spindle.

[0023] In a further preferred embodiment, a locking mechanism is provided for a slip-proof connection between the second steering spindle part and the connecting section. The locking mechanism comprises at least one detent element and at least one detent recess corresponding to the detent element. The locking mechanism prevents the second steering spindle part from shifting along the connecting section in the direction of the longitudinal axis. The locking mechanism ensures that the second steering spindle part is held securely against removal after assembly onto the first steering spindle part. In other words, after being axially slid onto the first steering spindle part, the locking mechanism secures the second steering spindle part against longitudinal displacement, thus forming a kind of pull-off or removal lock.

[0024] Particularly preferably, the at least one locking element is designed in the form of a spring-loaded locking hook or locking lug, or as a type of clip, and is arranged on the second steering spindle part. Advantageously, the locking hook snaps into the locking recess associated with it as soon as the second steering spindle part has been axially pushed onto the first steering spindle part. Furthermore, the at least one locking recess is groove-shaped and preferably incorporated into the cylindrical surface between the first and second connecting sections. The groove-shaped locking recess can extend circumferentially over a partial section of the first steering spindle part. Alternatively, it would also be conceivable for the groove-shaped locking recess to extend around the entire circumference of the first steering spindle part or to be designed as a continuous groove extending around the circumference of the connecting section.

[0025] According to the invention, a method for mounting a steering handle on a steering spindle is further provided, comprising a steering spindle according to the above features, in which the second steering spindle part is first mounted on the second connecting section of the first steering spindle part or axially slid onto it, before the rotational alignment of the second steering spindle part relative to the first steering spindle part is carried out with the aid of the second steering spindle part, wherein for this purpose the second steering spindle part is rotated into a position in which the at least one positioning means on the second steering spindle part is aligned and positioned in such a way that the steering handle only needs to be axially slid onto the steering spindle during the subsequent assembly.The assembly process begins with the second steering spindle section, which serves as an aid for centering and positioning the steering handle on the steering spindle, being axially slid onto the first steering spindle section. Even after the second steering spindle section is slid onto the first and the internal teeth of the second steering spindle are engaged with the second teeth of the second connecting section of the first steering spindle, the second steering spindle section can be rotated into alignment by applying a certain amount of force. Following the rotational alignment of the second steering spindle section, the steering handle can be slid onto the steering spindle head or the connecting section of the first steering spindle section.By pre-centering using the second steering spindle part on the one hand, and by conveniently finding the correct mounting position for the steering handle using the second steering spindle part on the other hand, it is ensured that the steering handle can be mounted on the steering spindle in a simple and relatively comfortable way.

[0026] Further advantages, features and details of the invention will become apparent from the following description of the figures.

[0027] The invention will be explained in more detail below with reference to an exemplary embodiment in conjunction with the schematic drawing. The drawing shows... Fig. 1 a perspective view of the connecting section of the first steering spindle part of the steering spindle according to the invention, Fig. 2 a perspective view of the second steering spindle part of the steering spindle according to the invention, Fig. 3 another perspective view of the second steering spindle part according to Fig. 2, Fig. 4 a perspective view of the steering spindle according to the invention in the assembled state, Fig. 5 a sectional view of the steering spindle according to the invention Fig. 4, Fig. 6 a sectional view of a detailed view of the locking mechanism between the first and second steering spindle parts and Fig. 7 a perspective detail view of the external gearing of the connecting section and the internal gearing of the second steering spindle part.

[0028] In Fig. Figure 1, referenced as numeral 1, shows a steering spindle for a steering system, in particular a mechanical steering system or a steer-by-wire steering system or a steer-by-wire system without a mechanical fallback, of a motor vehicle. A motor vehicle can be understood to be any known vehicle in which the vehicle's wheels are steered by means of a steering handle. Examples include passenger cars, trucks, buses, agricultural and forestry tractors, construction vehicles, etc.

[0029] The steering spindle 1 is essentially designed in two parts and consists of a first steering spindle part 10 and a second steering spindle part 20 that can be connected to the first steering spindle part 10. The first steering spindle part is designed as a steering shaft or hollow shaft or cylindrical steering spindle body and extends in the longitudinal direction of the steering spindle 1 or along the longitudinal axis L.

[0030] In conventional steering spindles, the steering spindle head is located at the steering wheel-side end of the spindle. This head allows the steering handle to be engaged in a positive-locking, backlash-free, and torque-transmitting manner. To attach the steering handle to the steering spindle head, the head of conventional steering spindles has a radially centered threaded bore. A screw is inserted into this bore to fix the steering handle, e.g., a steering wheel, to the steering spindle head.

[0031] The special feature of the first steering spindle part 10 is that it consists of a steering spindle body 11 and a connecting section 12 adjoining it on the steering wheel side, the connecting section 12 being stepped. The connecting section 12 is therefore an end section serving as the steering spindle head. According to the Fig. 1, Fig. 4 and Fig. The connecting section 12 comprises a first connecting section 12.1 with a first outer diameter d1, wherein the first connecting section 12.1 connects longitudinally to the steering spindle body 11 on the steering wheel side, and a second connecting section 12.2 with a second outer diameter d2, wherein the second connecting section 12.2 connects longitudinally to the first connecting section 12.1 on the steering wheel side. The transition between the steering spindle body 11 and the first connecting section 12.1 is conically shaped and simultaneously provides a stop or contact surface for mounting the steering handle. The section between the steering spindle body 11 and the connecting section 12 tapers towards the connecting section 12. The conical design of the transition forms a type of conical seat 50 for mounting the steering handle on the steering spindle 1.

[0032] Furthermore, the outer diameter d1 of the first connecting section 12.1 is larger than the outer diameter d2 of the second connecting section 12.2, thus achieving the stepped design of the connecting section 12. Here, too, the step between the first and second connecting sections 12.1, 12.2 forms a stop surface against which the second steering spindle part 20 can rest when assembled. Both the cylindrical surface of the first connecting section 12.1 and the cylindrical surface of the second connecting section 12.2 have a toothed section 14, or external toothed section, respectively. Accordingly, the first connecting section 12.1 has a first external toothed section 14.1 and the second connecting section 12.2 has a second external toothed section 14.2, with the profile of both toothed sections 14, 14.1, 14.2 extending longitudinally. As can be seen from the Fig. 1 and Fig. As can be seen in Figure 4, it is therefore a straight-toothed profile which extends in the direction of the longitudinal axis L, or a toothing in the form of a longitudinal toothing or in the form of a tooth-like longitudinal profile.

[0033] It is of great importance that the teeth 14.1 of the first connecting section 12.1 and the teeth 14.2 of the second connecting section 12.2 are aligned with each other, i.e., despite the height difference between the two connecting sections 12.1 and 12.2, each tooth of the first tooth 14.1 is longitudinally associated with a tooth of the second tooth 14.2, with the respective aligned teeth forming a tooth pair. The teeth of a tooth pair share a common center line in the longitudinal direction, which extends parallel to the longitudinal axis L.

[0034] The aligned arrangement of both toothed sections 14.1 and 14.2 is essential to enable pre-centering of the steering spindle section for the subsequent assembly of the steering handle using the second steering spindle section. For pre-centering, the second steering spindle section 20 is axially slid onto the second connecting section 12.2 and then secured in the position corresponding to the mounting position of the steering handle on the first connecting section 12.1. In other words, during rotational alignment, the second steering spindle section 20 follows the first toothed section 14.1 on the second toothed section 14.2, allowing the second steering spindle section 20 to be secured in the same position relative to the tooth profile, i.e., with the same number of teeth, as if it were attached to the first connecting section 12.1. This ensures optimal and convenient alignment of the second steering spindle section 20 relative to the steering spindle 1.Due to the positioning means 30, which are attached to the second steering spindle part 20, the steering handle can subsequently be attached simply and, above all, quickly. This is because the rotary alignment no longer needs to be carried out during the assembly of the steering handle, but is instead performed beforehand in a simple manner using the second steering spindle part 20.

[0035] The positive-locking connection between the steering handle hub and the first connecting section 12.1 is preferably created by a fine toothing, in particular a fine toothing with block teeth. The steering handle hub, not shown in the figures, has a corresponding internal toothing that meshes with the external toothing 14.1 of the first connecting section 12.1. A fine toothing, for example a 1x66 tooth pattern, is particularly preferred. Furthermore, the shaft-hub connection between the first steering spindle part 10 and the steering handle hub is made of metal, in particular steel or light metal, e.g., aluminum or magnesium, to ensure reliable and permanently stable torque transmission.

[0036] In the Fig. 2 and Fig. Figure 3 shows the second steering spindle part 20, which is designed in the form of a sleeve or is tubular or hollow cylindrical. The second steering spindle part 20 is preferably made of plastic. The advantage of plastic is that complex geometries can be produced and the manufacturing of the components is cost-effective. The second steering spindle part 20 has a wall 28, wherein the wall 28 has an inner surface 22 and an outer surface 24 opposite it. A toothed section 26, in particular an internal toothed section, is provided on the inner surface 22 of the second steering spindle part 20, which engages with the second toothed section 14.2 in the assembled state.

[0037] In a preferred embodiment, as in Fig. As shown in Figure 3, the internal toothing 26 of the second steering spindle part 20 is arranged at least partially along the inner circumference, i.e., the internal toothing can be designed as a toothed section in the circumferential direction. If the internal toothing 26 is designed as a toothed section, it has, depending on the embodiment, fewer teeth, in particular block teeth, than the second toothing. As shown in the Fig. 3 and Fig. As shown in Figure 7, the toothed section here has approximately ten teeth as an example. However, depending on the embodiment, the toothed section can also have more or fewer teeth. Particularly preferably, two opposing, internal toothed sections are provided on the second steering spindle part. The internal toothing of the second steering spindle part 20 can, however, also be circumferential.

[0038] Furthermore, the second steering spindle part 20 comprises at least one positioning means 30, wherein this is in the form of a positioning recess 32, in particular a line marking, or a positioning nose 34 projecting from the outside of the wall 28, such as a Poka-Yoke feature. Fig. Figure 2 shows that the second steering spindle part 20 has two positioning means 30, namely a positioning recess 32 in the form of a line marking and a positioning lug 34, which is designed as a poka-yoke feature. The inclusion of these two different positioning means ensures that the steering spindle 1 is universally applicable and can accommodate both steering wheels of a conventional mechanical steering system and steering wheels of a steer-by-wire steering system.

[0039] In Fig. Figure 2, referenced by numeral 32, shows a first positioning means in the form of a slot-shaped positioning recess, in particular a line marking. The line marking is radially integrated into the second steering spindle part 20 on the side facing the steering wheel and is preferably designed as a through-hole or slot, i.e., the line marking extends from the outer surface 24 to the inner surface 22. Preferably, the line marking is open towards the steering wheel so that a counterpart of the steering handle can be aligned with it. In addition to the line marking, a further second positioning means is provided in the axial direction or longitudinal direction, opposite the line marking. The second positioning means is designed in the form of a positioning lug 34 and is arranged on the outer surface 24.

[0040] The positioning nose 34 projects outwards from the outer surface of the second steering spindle part 20. The shape of the positioning nose 34 can be designed depending on the counterpart on the steering handle. In the present embodiment, the positioning nose 34 is ramp- or wedge-shaped. Preferably, the slope of the positioning nose 34 increases towards the side of the second steering spindle part 20 facing away from the steering wheel, thus enabling the steering handle to be easily slid axially onto the steering spindle.

[0041] To ensure a secure hold after the second steering spindle part 20 is mounted on the first steering spindle part 10, the steering spindle 1 is equipped with a locking mechanism 40 in the form of a pull-off or removal safety device. The locking mechanism 40 prevents the second steering spindle part 20 from unintentionally detaching from the first steering spindle part 10 in its mounted position. For this purpose, the second steering spindle part 20 is provided with a detent element 42, in particular a detent lug or detent hook, which engages in a suitable detent recess 44. An example is shown in Fig. Figure 6 shows a locking element 42 in the form of a clip or spring-loaded locking hook. The locking hook in Fig.In its assembled state, the locking element 6 engages in a groove-shaped locking recess 44, which is provided in the cylindrical surface between the first and second connecting sections 12.1, 12.2. The locking element 42 is designed such that it can engage in the groove-shaped locking recess 44 and secures the second steering spindle part 20 against longitudinal displacement along the longitudinal axis L in its assembled state. The second steering spindle part 20 can only be released from the first steering spindle part 10 when a certain axial force is applied.

[0042] The steering handle is mounted to the two-part steering spindle 1 in stages. First, the second steering spindle part 20 is axially slid onto the second connecting section 12.2. This engages at least one internal toothed section with the external toothing 14.2 of the second connecting section 12.2. By manually rotating the second steering spindle part 20 relative to the first steering spindle part 10, it can be pre-centered to achieve the correct rotational alignment of the two components. The correct circumferential position of the second steering spindle part 20 is reached when at least one positioning means 30 is aligned relative to the first steering spindle part 10 such that, in the subsequent step of mounting the steering handle to the steering spindle 1, the steering handle only needs to be axially slid onto it.The major advantage is that the steering wheel no longer needs to be aligned with the steering spindle 1 in the direction of rotation, as the alignment is already achieved beforehand by means of the second steering spindle part 20. The steering handle and the steering spindle 1 can therefore be assembled conveniently and, above all, always in the correct position relative to each other, since the mounting position of the steering handle is predetermined.

[0043] For example, it is provided that the first and / or second toothing 14.1, 14.2 is a straight-toothed fine toothing with teeth, in particular block teeth.

Claims

[1] Steering spindle (1) for a steering system of a motor vehicle, which is rotatably mounted in a steering column about a longitudinal axis (L) and can be connected in a rotationally fixed manner to a steering handle that can be operated by a vehicle driver, wherein the steering spindle (1) is designed in two parts, comprising a first steering spindle part (10) with a stepped connecting section (12) pointing towards the steering handle, wherein the connecting section (12) has a first connecting section (12.1) with a first outer diameter (d1) and a first toothing (14.1) which, in the assembled state, is in engagement with a hub or coupling part of the steering handle, and a second connecting section (12.2) adjoining the first connecting section (12.1) in the direction of the steering handle, with a second outer diameter (d2) and a second toothing (14.2), wherein the first outer diameter (d1) is larger than the second outer diameter (d2) and wherein the second toothing (14.2) is aligned with the first toothing (14.1), and a second, sleeve-shaped steering spindle part (20) with an inner side (22) and an outer side (24) opposite it, characterized by , that the second steering spindle part (20) has, on its inner side (22), at least partially circumferentially, a toothing (26) corresponding to the second toothing (14.2), and the toothing (26) of the second steering spindle part (20) is in engagement with the second toothing (14.2) in the assembled state, wherein the second steering spindle part (20) serves as an aid for determining the correct assembly position of the steering handle on the steering spindle (1) due to the aligned arrangement of the first and second toothing (14.1, 14.2). and wherein at least one positioning means (30) is arranged on the second steering spindle part (20) by means of which the steering handle can be easily aligned and positioned during assembly on the steering spindle (1). [2] Steering spindle (1) according to one of the preceding claims, characterized by , that the first and / or second toothing (14.1, 14.2) is a fine toothing with teeth and a conical seat (50). [3] Steering spindle (1) according to claim 1 or 2, characterized by , that the first toothing (14.1) and the second toothing (14.2) have the same number of teeth or the same pitch due to the aligned arrangement. [4] Steering spindle (1) according to any one of claims 1 to 3, characterized by , that the mounting position of the steering handle on the first connecting section (12.1) corresponds to the mounting position of the second steering spindle part (20) on the second connecting section (12.2), wherein the second steering spindle part (20) can be attached to the second connecting section (12.2) in the same position with respect to the number of teeth as the steering handle on the first connecting section (12) following the direction of rotation (R) of the first toothing (14.1). [5] Steering spindle (1) according to one of the preceding claims, characterized by, that at least one positioning means (30) is formed in the form of a positioning recess (32) or in the form of a positioning nose (34) projecting from the outside (24) of the second steering spindle part (20). [6] Steering spindle (1) according to one of the preceding claims, characterized by , that two or more positioning means (30) are provided and at least one positioning means (30) is designed as a positioning recess (32) and at least one positioning means (30) is designed as a positioning nose (34). [7] Steering spindle (1) according to one of the preceding claims, characterized by, that a locking mechanism (40) is provided for a displaceable connection between the second steering spindle part (20) and the connecting section (12), wherein the locking mechanism (40) is formed at least from a detent element (42) and at least one detent recess (44) corresponding to the detent element (42), and wherein the locking mechanism (40) prevents displacement of the second steering spindle part (20) on the connecting section (12) in the direction of the longitudinal axis (L). [8] Steering spindle (1) according to claim 6, characterized by , that the at least one detent element (42) is designed in the form of a spring-elastic detent hook or detent nose or as a type of clip and is arranged on the second steering spindle part (20) and the at least one detent recess (44) is designed in a groove shape. [9] Steering spindle (1) according to one of the preceding claims, characterized by, that the first steering spindle part (10) is made of metal and the second steering spindle part (20) is made of plastic. [10] Method for mounting a steering handle on a steering spindle (1), comprising a steering spindle (1) according to any one of claims 1 to 9, in which the second steering spindle part (20) is first mounted or axially slid onto the second connecting section (12.2) of the first steering spindle part (10), before the rotational alignment of the second steering spindle part (20) relative to the first steering spindle part (10) is carried out with the aid of the second steering spindle part (20), in which the second steering spindle part (20) is rotated into a position in which the at least one positioning means (30) on the second steering spindle part (20) is aligned and positioned such that the steering handle only needs to be axially slid onto the steering spindle (1) during the subsequent assembly.

Images