Steering shaft for a motor vehicle steering system, steering system for a motor vehicle, and motor vehicles

Abstract

Steering shaft (10) for a steering system (12) of a motor vehicle, comprising at least two first steering shaft elements (14, 16) via which a steering wheel (18) can be mechanically connected to a steering gear (20) of the steering system (12), comprising at least one first joint (48) via which the steering shaft elements (14, 16) are connected to each other in a torque-transmitting manner and pivotable about a pivot axis (50) relative to each other, comprising at least one locking element (52) which secures the steering shaft elements (14, 16) relative to each other against pivoting movements about the pivot axis (50) both in a first pivoting direction (54) and in a second pivoting direction (56) opposite to the first pivoting direction (54) and which, as a result of an accident-related force application, releases the first steering shaft elements (14, 16) for a pivoting movement relative to each other about the pivot axis (50) in at least one of the pivoting directions (54, 56),and with at least one further steering shaft element (26), which is connected to the first steering shaft elements (14, 16) via at least one second joint (30) in a torque-transmitting manner and pivotable about a second pivot axis (32) relative to the first steering shaft elements (14, 16), characterized by at least one shaft element (72) connected to the further steering shaft element (26) in a torque-transmitting manner and provided in addition to the steering shaft elements (14, 16, 26), wherein the further steering shaft element (26) and the shaft element (72) are telescopically slidable into one another, and wherein at least one of the first steering shaft elements (14, 16) has two steering shaft parts (68, 70) rotatable about a pivot axis (36), torque-transmitting, and telescopically slidable into one another.

Description

[0001] The invention relates to a steering shaft for a steering system of a motor vehicle, in particular a passenger car, according to the preamble of claim 1. Furthermore, the invention relates to a steering system for a motor vehicle, in particular for a passenger car, and to a motor vehicle.

[0002] US Patent 5,853,194 A discloses an arrangement of steering shafts that are rotatable together to transmit steering torques in a vehicle steering column. The shafts are connected to each other via a joint.

[0003] Furthermore, WO 99 / 03716 A1 discloses a steering column arrangement for motor vehicles with an energy absorption element and a telescopically collapsible steering spindle mounted in sleeve tube parts.

[0004] From GB 2482161 A, a steering linkage is known which has two universal joints. Furthermore, a connection is provided by which a lower and an upper section of the steering linkage are connected to each other. The connection is designed to break in a frontal impact.

[0005] Furthermore, DE 10 2012 014 762 A1 discloses a motor vehicle with an instrument panel and a steering wheel mounted on a steering column. The steering wheel is movable relative to the instrument panel and can be shifted longitudinally along the steering column towards the instrument panel from a first position to a second position. JP 2003 182 594 A discloses a steering shaft for a motor vehicle steering system. EP 2 429 876 B1 discloses a steering column for a motor vehicle. Additionally, DE 21 50 789 A discloses a safety steering column for motor vehicles.

[0006] The object of the present invention is to create a steering shaft, a steering system and a motor vehicle in such a way that a particularly advantageous accident behavior can be achieved.

[0007] This problem is solved according to the invention by a steering shaft with the features of claim 1, by a steering system with the features of claim 6, and by a motor vehicle with the features of claim 7. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0008] A first aspect of the invention relates to a steering shaft for the steering system of a motor vehicle, in particular a passenger car. The steering shaft comprises at least two first steering shaft elements, via which a steering wheel can be mechanically connected to a steering gear. The steering shaft also has at least one joint, via which the first steering shaft elements are connected or coupled to each other in a torque-transmitting manner and pivotable about a pivot axis relative to each other. Preferably, the first steering shaft elements are designed separately from each other and pivotable relative to each other via the joint, and thus articulated together.The aforementioned pivot axis is defined or predetermined by the joint, for example, by connecting at least two joint components of the joint in such a way that the joint components, and with them the first steering shaft elements, can pivot relative to each other about the pivot axis. One of the joint components is, for example, rotationally fixed to one of the first steering shaft elements, while the other joint component is rotationally fixed to the other of the first steering shaft elements. In particular, it is conceivable that one joint component is formed integrally with one of the first steering shaft elements and / or the other joint component is formed integrally with the other first steering shaft element. Alternatively, it is conceivable that the respective joint component and the respective associated first steering shaft element are designed as separate components that are at least rotationally fixed to each other.The joint components are designed separately and connected to each other by a pivot. The pivot axis is a virtual or imaginary axis around which the steering shaft elements can be pivoted relative to each other.

[0009] The characteristic that the first steering shaft elements are connected to each other via the joint in a torque-transmitting manner means that torques can be transmitted between the first steering shaft elements via the joint. For example, a torque transmitted via the steering wheel to one first steering shaft element can be transmitted from that first steering shaft element to the other first steering shaft element via the joint. The torque can then be transmitted from the other first steering shaft element to the steering gear, thus enabling the steering of the vehicle's steerable wheels, particularly the front wheels. In this way, torques applied to the steering wheel can be transmitted from the steering wheel via the steering shaft and thus via the first steering shaft elements to the steering gear.The first steering shaft elements are rotatable about at least one, in particular a common, axis of rotation, or about individual axes of rotation, in particular simultaneously or jointly. Thus, if, for example, the steering wheel is rotated around a steering wheel axis around a body structure, in particular a self-supporting body, of a motor vehicle (e.g., a passenger car), the first steering shaft elements are thereby rotated about the axis of rotation or about the individual axes of rotation, in particular relative to the body structure. The first steering shaft elements and the steering wheel rotate together or simultaneously. As a result, the wheels are pivoted relative to the body structure and thus steered. This allows, for example, cornering and / or changes of direction of the motor vehicle.

[0010] In other words, the fully assembled vehicle has wheels and a steering system, which includes the steering shaft. The wheels are rotatably mounted to the body and can pivot around a steering axis relative to the body, thus enabling steering. By steering or pivoting the wheels around the steering axes, lane changes, changes of direction, and / or cornering of the vehicle can be achieved. In the fully assembled vehicle, the steering wheel is mechanically connected to the steering gear via the steering shaft and thus via the first steering shaft components, so that torques applied to the steering wheel can be transmitted from the steering wheel to the steering shaft and from the steering shaft to the steering gear.The aforementioned torques are applied, for example, by a person, in particular by the driver of the motor vehicle, to the steering wheel in order to turn the steering wheel relative to the body and thereby steer the wheels.

[0011] In particular, the steering shaft according to the invention can be designed as an intermediate steering shaft. The steering system comprises, for example, a steering column on which, for example, the steering wheel is rotatably mounted. In particular, the steering wheel can be fixedly connected to the steering column. In the fully manufactured state of the motor vehicle, the steering column can be mechanically connected to the steering gear via the intermediate steering shaft, in particular such that the aforementioned torques exerted on the steering wheel can be transmitted from the steering wheel first to the steering column, from the steering column to the intermediate steering shaft, and from the intermediate steering shaft to the steering gear.

[0012] In order to achieve particularly advantageous crash behavior of the steering shaft and thus of the motor vehicle as a whole in a particularly space-saving manner, the invention provides that the steering shaft has at least one locking element. The locking element secures the first steering shaft elements relative to each other against pivoting movements around the pivot axis, both in a first pivoting direction around the pivot axis and in a second pivoting direction opposite to the first pivoting direction and also around the pivot axis.This means that the joint itself defines, specifies, or forms the pivot axis, so that the first steering shaft elements can pivot relative to each other in opposite directions around the pivot axis, especially if the locking element is not yet provided or installed, without causing damage or destruction to the first steering shaft elements or the joint. However, the locking element secures the first steering shaft elements relative to each other in such a way that both pivoting of the first steering shaft elements relative to each other around the pivot axis in the first direction and pivoting of the first steering shaft elements relative to each other around the pivot axis in the second direction are prevented by the locking element.In other words, when the steering shaft is fully manufactured, in which the first steering shaft elements are connected to each other via the joint in a torque-transmitting manner and are pivotable relative to each other about the pivot axis, and the locking element is provided, i.e., mounted, the first steering shaft elements cannot be pivoted relative to each other about the pivot axis in the pivot directions without damaging or destroying the locking element.

[0013] Furthermore, according to the invention, the locking element releases the first steering shaft elements for a pivoting movement about the pivot axis in at least one of the pivot directions and relative to each other as a result of an accident-induced force. Thus, if, for example, a force acting on the steering shaft, particularly on the first steering shaft elements, resulting from an accident, especially a frontal impact, is sufficiently high and particularly high enough to exceed a threshold value, the first steering shaft elements are pivoted about the pivot axis in at least one of the pivot directions relative to each other, such that the locking element is damaged or destroyed and, for example, at least deformed and / or broken.This means that, as a result of an accident-induced force, the locking element releases the first steering shaft elements relative to each other, thereby destroying and / or damaging the locking element. This allows the locking element to pivot around the pivot axis in at least one of the pivot directions. In other words, any pivoting of the first steering shaft elements relative to each other around the pivot axis will result in the destruction and / or damage of the locking element. The aforementioned threshold can be set or predetermined by the design of the locking element. In other words, the threshold can be influenced or set by selecting the appropriate geometry of the locking element and / or the appropriate material from which the locking element is manufactured.In this way, it is possible to adjust the steering shaft's crash behavior as needed in a space-saving manner.

[0014] By pivoting the first steering shaft elements relative to each other around the pivot axis, the joint is flexed or bent. Therefore, this pivoting of the first steering shaft elements relative to each other around the pivot axis is also referred to as bending or buckling of the joint. This occurs, for example, as a pivoting of the joint components, and thus of the first steering shaft elements, relative to each other, without causing or necessarily causing damage to the joint or the joint components themselves. The threshold value above which the first steering shaft elements pivot relative to each other around the pivot axis, thereby damaging or destroying the locking element, is also referred to as the buckling or bending force. The buckling force can be adjusted as needed by appropriately designing a single component in the form of the locking element, thus in a particularly simple manner.Furthermore, the buckling force can be kept particularly low or adjusted to a very low level, resulting in especially favorable crash behavior. Additionally, the telescopic length or telescoping of the steering shaft can be kept particularly short, thus minimizing the installation space required for the steering shaft. This allows for particularly easy installation of the steering shaft. Since the joint and the locking element enable advantageous bending or buckling of the joint and thus of the steering shaft in the event of an accident, the telescoping is either unnecessary or only minimally required to achieve favorable crash behavior. Therefore, the telescoping serves primarily, or at least predominantly, assembly and tolerance compensation functions.The telescoping function of the assembly means, for example, that it is used during the installation of the steering shaft or steering system to allow for easy installation even in confined spaces. The tolerance compensation function means that the telescoping is used to compensate for manufacturing and / or assembly-related tolerances, particularly during vehicle operation. Since the telescoping is not used, or only used to a minor extent, to prevent excessive intrusion of the steering gear, especially into the vehicle's interior, the telescopic length can be kept particularly short.At the same time, excessive intrusions into the steering gear can be avoided, as the locking element allows for advantageous and required bending of the joint and thus of the first steering shaft elements.

[0015] The invention is based in particular on the following insight: Conventional intermediate steering shafts, as a connection between a steering column and a steering gear, typically have a telescoping section. This section is used both for assembly and, in the event of an accident, to decouple the steering gear, which is subjected to accidental loads, from the steering column and thus from the steering wheel. This means that the telescoping section is conventionally used to prevent excessive intrusion of the steering column and steering wheel.

[0016] Furthermore, it is conceivable to equip a steering shaft, for example, designed as an intermediate steering shaft, with at least one predetermined bending point, which is formed, for instance, by a so-called corrugated tube. If a load acting on such a steering shaft due to an accident exceeds a certain level, the shaft bends in a defined manner at the predetermined bending point. Such conventional steering shafts have the following disadvantages: The telescopic length, also simply referred to as the length, is usually limited by geometry, as the respective positions of the universal joints are predetermined for space reasons, and a residual overlap of the telescopic sections must be maintained for normal operation. The telescopic sections are partially nested within each other in an initial state and can be further inserted from this initial state.The telescopic sections can be pushed into one another, for example, a distance referred to as the aforementioned telescopic length. Since the telescopic length is limited, the maximum retraction of the steering gear is also limited. This means that the distance by which the steering gear can be moved backwards in the longitudinal direction of the vehicle during an accident without causing excessive rearward movement or displacement of the steering wheel is limited. Consequently, appropriate bodywork measures should be implemented to prevent or limit excessive compression in the event of an accident. However, these measures may conflict with the desire for the softest possible suspension in the event of a crash.

[0017] The disadvantage of designed kinks on intermediate steering shafts is that such a kink only fails under very high loads. In other words, an intermediate steering shaft designed with such a kink only buckles under very high loads, as these loads cannot be arbitrarily low. This is because sufficiently high torques must be transmitted through the kink during normal operation without damaging or destroying the steering shaft.

[0018] The steering shaft according to the invention avoids the aforementioned disadvantages and problems. On the one hand, the steering shaft according to the invention enables a particularly advantageous decoupling of the steering gear from the steering column or the steering wheel, so that, for example, in an accident, especially a frontal collision, the steering gear can be moved a considerable distance rearward in the longitudinal direction of the vehicle without causing excessive rearward displacement or relocation of the steering wheel. At the same time, undesirable body modifications can be avoided, so that the body does not need to be designed with excessive rigidity. Consequently, particularly high accident-related energies can be absorbed by means of deformation of the body.Furthermore, for example, the telescopic length of a steering shaft can be kept particularly short, thus minimizing the installation space required for the steering shaft. Consequently, the steering shaft can be easily installed.

[0019] Furthermore, the steering shaft according to the invention can be easily assembled, for example, by mounting the steering shaft in a state in which the first steering shaft elements are pivotable relative to each other about the pivot axis and are therefore not yet secured against pivoting relative to each other about the pivot axis by the locking element. After the steering shaft has been mounted, the locking element is mounted or arranged such that it fixes the joint and thus secures it against bending about the pivot axis in the pivot directions. In the previously described state in which the joint can still be bent, the first steering shaft elements can be pivoted relative to each other about the pivot axis for assembly purposes, so that the steering shaft can be bent or flexed about the pivot axis for assembly purposes.Subsequently, the joint is fixed by means of the locking element, thus forming a rigid or fixed joint. If an accidental force is applied, the locking element may fail under force and / or displacement, thereby releasing the joint into flexion.

[0020] Consequently, if the steering gear is displaced backwards in an accident, the steering shaft can bend or flex about its pivot axis, so that the steering gear subjected to the accident can no longer transmit any or only a minimal force to the steering column or steering wheel. This prevents excessive backward displacement of the steering column and steering wheel. In other words, the steering shaft according to the invention can yield to or evade a force applied to it, for example, in an accident, by the locking element failing under this force and releasing the joint. If, for example, the steering gear is then displaced further backwards, this causes the joint to flex, that is, the first steering shaft elements to pivot relative to each other about their pivot axis.This allows the steering gear to be moved backwards in the longitudinal direction of the vehicle, while preventing excessive backward movement of the steering column and steering wheel in the longitudinal direction of the vehicle.

[0021] To enable a simple and space-saving change in the length of the steering shaft, it is provided that at least one of the first steering shaft elements has two steering shaft parts that are rotatable about an axis of rotation, torque-transmitting, and in particular rotationally fixed to one another, and that can be telescopically slid into one another. This allows, for example, a steering column adjustment to be implemented, within which the steering wheel can be moved in the longitudinal direction of the steering shaft parts, in particular relative to the body.

[0022] The steering shaft components are rotatable about a common steering shaft component axis of rotation, such that the steering shaft components rotate together or simultaneously about this axis, particularly when the steering wheel is turned relative to the vehicle body. The steering shaft component axis of rotation coincides, for example, with the longitudinal direction of the respective steering shaft component. In particular, it is conceivable that the steering shaft component axis of rotation coincides with the axis of rotation about which at least one steering shaft component is rotatable, especially relative to the vehicle body, when the steering wheel is turned relative to the vehicle body.

[0023] The feature that the steering shaft sections can be telescopically slid into one another is also referred to as the telescoping of the steering shaft sections or of at least one steering shaft element. In this telescoping mechanism, the steering shaft sections are each arranged at least partially within one another and can be slid into one another, particularly along the axis of rotation of the steering shaft section. The telescoping mechanism can be used during steering shaft assembly to at least temporarily slide the steering shaft sections into one another. This allows for a reduction in the length of the steering shaft, thus simplifying assembly. After assembly or pre-assembly, the steering shaft sections can, for example, be pulled or pushed apart again using the telescoping mechanism and fixed relative to each other.

[0024] Furthermore, the telescoping mechanism can be used, for example, to move the steering wheel towards or away from a seat, allowing it to be positioned as needed within the vehicle's interior. The steering shaft components can be extended telescopically by a distance also referred to as the telescopic length, and then, for example, pulled apart or extended again.

[0025] For example, one of the steering shaft sections is rotationally fixed to one of the previously described joint sections, and it is conceivable that the steering shaft section is formed integrally with the joint section. This allows the telescoping of the steering shaft sections to be located in or very close to the joint. Since particularly advantageous crash behavior can already be ensured by means of the joint and the locking element, the telescoping of the steering shaft sections does not need to be used, or not primarily used, to achieve advantageous crash behavior. Therefore, the telescoping length of the steering shaft sections can be significantly shorter than that of conventional steering shafts. In particular, the telescoping length of the steering shaft sections can be kept short because assembly considerations are not relevant to the design.Furthermore, the telescopic length can be kept particularly short, for example by placing the pivot axis of the steering column adjustment as close as possible to an upper universal joint and / or by using soft bearings, for example for the steering gear.

[0026] The steering shaft has at least one further steering shaft element, which is connected to the first steering shaft elements via at least one second joint, transmitting torque and pivoting about a second pivot axis relative to the first steering shaft elements. Preferably, the pivot axes run parallel to each other, with the pivot axes being spaced apart from each other along a direction perpendicular to the pivot axes. The respective pivot axis, as mentioned above, runs, for example, perpendicular to a first plane. The respective pivot axis runs, for example, perpendicular to a second plane. The respective pivot axis and the respective pivot axis are arranged relative to each other such that the planes are perpendicular to each other.

[0027] Regarding the second joint, the first joint is an additional joint which, in combination with the locking element, enables particularly advantageous crash behavior and a particularly small installation space requirement for the steering shaft. If, for example, the steering shaft is fundamentally designed as a two-joint steering system with two conventional joints, then the first joint is an additional, third joint. If, for example, the steering shaft is fundamentally designed as a three-joint steering system with three joints, then the first joint is an additional, fourth joint. The idea of ​​the invention is therefore to supplement conventional steering shafts with at least one further, additional joint and to prevent bending of the additional joint by means of the locking element in a normal state.However, if an accident occurs that deviates from the normal state, in which a force is applied to the steering shaft, the locking element, by destroying or damaging itself, releases the additional joint, allowing the steering shaft to yield to or evade the force. This prevents excessive steering wheel intrusion.

[0028] Furthermore, at least one additional shaft element is provided, which is connected to the further steering shaft element in a torque-transmitting manner and is provided in addition to the steering shaft elements, wherein the further steering shaft element and the shaft element can be telescopically slid into one another. This allows, for example, a particularly advantageous steering column adjustment to be realized, within which the steering wheel can be moved relative to the aforementioned seat assembly.

[0029] To achieve particularly advantageous crash behavior, a preferred embodiment of the invention provides that the safety element is designed as a sleeve, separate from the first steering shaft elements and separate from the joint. This sleeve is partially arranged on each of the first steering shaft elements and thus extends from one of the first steering shaft elements, across the joint, to the other first steering shaft element, in particular continuously. The sleeve is therefore also arranged on or above the joint. This allows, for example, the aforementioned buckling force, at which the sleeve fails and the first steering shaft elements pivot relative to each other about the pivot axis, to be adjusted particularly precisely, simply, and cost-effectively.

[0030] In order to achieve a particularly advantageous accident behavior in a particularly cost-effective manner, it is provided in a further embodiment of the invention that the safety element is formed in one piece.

[0031] Another embodiment is characterized in that the locking element is made of a plastic and / or a metallic material, in particular steel. This allows the buckling force to be adjusted in a particularly targeted and efficient manner.

[0032] In a particularly advantageous embodiment of the invention, the first steering shaft elements are secured by the locking element in a position in which they run in a straight line, i.e., along an imaginary straight line. This means that the first steering shaft elements, or rather their respective longitudinal directions, enclose an angle of 180 degrees and 0 degrees, respectively. In other words, the longitudinal directions of the first steering shaft elements coincide. Put another way, one first steering shaft element follows the other first steering shaft element in a straight line, so that both first steering shaft elements run along an imaginary straight line. This position, in which the first steering shaft elements are fixed relative to each other by means of the locking element, is also referred to as the straight position.In the straight position, the joint is not bent.

[0033] Alternatively, it has proven particularly advantageous if the first steering shaft elements, or rather their longitudinal directions, in the aforementioned position in which the first steering shaft elements are secured relative to each other by means of the locking element, enclose an angle other than 180 degrees, and preferably an obtuse angle. In this case, the steering shaft is cranked and requires more installation space compared to the straight position, especially during a so-called "rotation," in which the first steering shaft elements are rotated together or simultaneously by turning the steering wheel.However, a bending direction, coinciding with one of the directions of rotation, is then predetermined or defined. This direction is the direction into which the first steering shaft elements are pivoted relative to each other in an accident, particularly a frontal collision, thereby destroying or damaging the safety element. If the first steering shaft elements do not run in a straight line, but instead form an angle other than 180 degrees or 0 degrees, then the steering shaft is cranked. This means that the steering shaft has a bend that allows the aforementioned bending direction to be defined or predetermined.

[0034] Finally, it has proven particularly advantageous to have at least one or more actuation elements. By means of the respective actuation element(s), the locking element can be converted from a locking state securing the first steering shaft elements to a release state releasing them in the event of an accident-induced force application. This means, for example, that in the event of an accident-induced force application, a force is exerted or transmitted from the actuation element to the locking element.The locking element is moved from the locked state to the released state by means of force, in particular by moving the locking element relative to the first steering shaft elements, especially by displacing it, and / or deforming it and / or destroying it.

[0035] The actuating element can have at least or exactly one strut, in particular with a pivot bearing, wherein, in the event of an accident-related retraction of the steering gear, the strut causes a relative movement of the locking element, in particular relative to the first steering shaft elements. This causes the locking element to move from the locked state to the released state. In the locked state, the locking element is, for example, at least partially arranged on both first steering shaft elements and on the joint, thereby securing the first steering shaft elements. In the released state, however, the locking element is, for example, no longer arranged on at least one of the first steering shaft elements and, for example, no longer on the joint, thereby releasing the first steering shaft elements.

[0036] A second aspect concerns a method for assembling a steering shaft according to the invention. In this method, at least a first assembly step is carried out while the steering shaft is in an assembly state in which the securing of the steering shaft elements relative to each other against pivoting movements about the pivot axis, both in the first and second pivoting directions, is prevented by means of the locking element. This allows the steering shaft elements to be pivoted relative to each other as required, making the steering shaft particularly easy to assemble.

[0037] After carrying out the second assembly step, the locking element is mounted in such a way, in particular on and / or at the steering shaft elements, that the locking element secures the steering shaft elements relative to each other.

[0038] A third aspect of the invention relates to a steering system for a motor vehicle, in particular for a passenger car. The steering system according to the invention comprises a steering wheel, a steering gear, and a steering shaft according to the invention, via which the steering wheel is mechanically connected to the steering gear. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the third aspect of the invention, and vice versa.

[0039] A fourth aspect of the invention relates to a motor vehicle, preferably designed as a passenger car, which has a steering shaft and / or a steering system according to the invention.

[0040] The invention also includes further developments of the inventive method, the inventive steering system, and the inventive motor vehicle, which have features already described in connection with the further developments of the inventive steering shaft. For this reason, the corresponding further developments of the inventive steering system and the inventive motor vehicle are not described again here.

[0041] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 A schematic side view of a steering shaft according to the invention for a motor vehicle in normal operation and thus during operation of the motor vehicle; and Fig. 2 A schematic side view of the steering shaft in an accident state.

[0042] The embodiment described below represents a preferred embodiment of the invention. In this embodiment, the described components each constitute individual features of the invention, which can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiment can also be supplemented by other features of the invention already described.

[0043] In the figures, identical reference symbols denote functionally equivalent elements.

[0044] Fig. Figure 1 shows a schematic side view of a steering shaft 10 for a steering system 12 of a motor vehicle, preferably a passenger car. The steering shaft 10 has a first steering shaft element 14 and a second steering shaft element 16, via which in Fig. Figure 1, a particularly schematic representation of the steering wheel 18, is mechanically connectable to a steering gear 20 of the steering system 12. In its fully assembled state, the motor vehicle comprises the steering system 12, which includes, for example, the steering shaft 10, the steering wheel 18, and the steering gear 20. The motor vehicle also has a body, for example, a self-supporting structure, and an interior enclosed by the body, in which persons such as the driver can be located. Furthermore, the motor vehicle includes wheels (not shown in the figures), for example, front wheels, which are designed as steerable wheels. Thus, the wheels can be pivoted about their respective steering axes relative to the body and thereby steered.By pivoting or steering the wheels relative to the vehicle body, the driver can, for example, change lanes, change direction, and / or steer the vehicle around curves. To pivot the wheels relative to the vehicle body, the driver applies torque to the steering wheel 18. This causes the steering wheel 18 to rotate about a steering wheel axis 22 relative to the vehicle body. Turning the steering wheel 18 rotates the steering shaft 10, and thus the steering shaft elements 14 and 16, together or simultaneously relative to the vehicle body. Furthermore, the respective torque applied to the steering wheel 18 is transmitted from the steering wheel 18 to the steering shaft 10, from the steering shaft 10 to the steering gear 20, and finally from the steering gear 20 to the wheels. This is how the wheels are steered.

[0045] The steering system 12 comprises, for example, a steering column 24, to which the steering wheel 18 can be connected, in particular in a rotationally fixed manner. Furthermore, the steering shaft 10 comprises a third steering shaft element 26 and a fourth steering shaft element 28. Fig. 1 it can be seen that the steering shaft element 26 is connected to the steering shaft element 14 via a first joint 30 of the steering shaft 10 in a torque-transmitting manner and is pivotable about a first pivot axis 32 relative to the steering shaft element 14. Fig. Figure 1 shows the steering shaft 10 in a normal state, in which no accident-related force has been applied to the steering shaft 10. The steering shaft 10 assumes this normal state, for example, during normal operation of the motor vehicle. The steering shaft element 26 is rotatable about a first axis of rotation 34 relative to the body, while the steering shaft element 14 is rotatable about a second axis of rotation 36 relative to the body. Since the joint 30 is flexed and not extended in the normal state, the steering shaft elements 14 and 26, or rather their respective longitudinal directions of extension coinciding with the respective axes of rotation 34 and 36, do not form an imaginary straight line, but rather the steering shaft elements 14 and 26 enclose an angle other than 180 degrees and 0 degrees, respectively, and preferably an obtuse angle.The longitudinal direction of the steering shaft element 14 coincides with the axis of rotation 36, while the longitudinal direction of the steering shaft element 26 coincides with the axis of rotation 34. From . Fig. 1 It can be seen that because the joint 30 is bent and not extended, the longitudinal extension directions of the steering shaft elements 14 and 26 or the axes of rotation 34 and 36 run obliquely to each other and thus enclose an angle different from 180 degrees or 0 degrees respectively.

[0046] Furthermore, the steering shaft 10 has a second joint 38, via which the steering shaft elements 16 and 28 are connected to each other in a torque-transmitting manner and pivotable about a second pivot axis 40 relative to each other. The pivot axes 32 and 40 run parallel to each other and are spaced apart, in particular along a direction perpendicular to the pivot axes 32 and 40. The pivot axes 32 and 40 thus run perpendicular to a common first plane. The steering shaft element 16 is rotatable about a rotation axis 42 relative to the assembly, and the steering shaft element 28, which belongs, for example, to the steering gear 20, is rotatable about a rotation axis 44 relative to the assembly. Fig. The assembly shown schematically in Figure 1, designated by 46, is rotatable. The joint 38 is also bent and therefore not straight, so that the steering shaft elements 16 and 44, or rather their longitudinal directions, do not run along an imaginary straight line, but rather the steering shaft elements 16 and 28, or rather their longitudinal directions, form an angle other than 180 degrees and 0 degrees, respectively. The longitudinal direction of the steering shaft element 16 coincides with the axis of rotation 42, while the longitudinal direction of the steering shaft element 28 coincides with the axis of rotation 44. Thus, the longitudinal directions, or rather the axes of rotation 42 and 44, do not run along an imaginary straight line, but rather the longitudinal directions, or rather the axes of rotation 42 and 44, form an angle other than 0 degrees and 180 degrees, and preferably an obtuse angle.Overall, it can be seen that the axes of rotation 34 and 36 run at an angle to each other and therefore do not coincide, and the axes of rotation 42 and 44 also run at an angle to each other and do not coincide.

[0047] For example, the steering wheel axis 22 also runs at an angle to the axis of rotation 34. The steering wheel axis 22 and the respective axes of rotation 34, 36, 42, and 44 are each perpendicular to a second plane, which in turn is perpendicular to the first plane. If the steering wheel 18 is now turned by the driver of the vehicle around the steering wheel axis 22 relative to the vehicle body, the steering shaft elements 14, 16, 26, and 28 are thereby turned together, or simultaneously, around their respective axes of rotation 34, 36, 42, and 44 relative to the vehicle body. As a result, the wheels are pivoted relative to the vehicle body and thus steered.

[0048] To achieve particularly advantageous crash behavior of the steering shaft 10, and thus of the vehicle as a whole, in a space-saving manner, the steering shaft 10 has a third joint 48 in addition to the joints 30 and 38. The steering shaft elements 14 and 16 are connected to each other via the joint 48 in a torque-transmitting manner and are pivotable relative to each other about a third pivot axis 50, with the pivot axis 50 running parallel to the pivot axes 32 and 40 and thus perpendicular to the first plane. With respect to a torque flow from the steering wheel 18 to the steering gear 20, the joint 48 is arranged between the joints 30 and 38.A locking element 52 is assigned to the joint 48, which secures the steering shaft elements 14 and 16 relative to each other against pivoting movements around the pivot axis 50, both in a first pivoting direction illustrated by an arrow 54 and in a direction opposite to the first pivoting direction. Fig. The second pivot direction, illustrated by arrow 56, is secured. This means that the locking element 52 prevents or avoids bending of the joint 48. In other words, the locking element 52 secures the joint 48 against bending, so that in the normal state the steering shaft elements 14 and 16 cannot pivot about the pivot axis 50 relative to each other without destroying or damaging the locking element 52.

[0049] As a result of an accident-related force acting, for example, from the steering gear 20 on the steering shaft 10 and in particular on the steering shaft elements 14 and 16, the locking element 52 releases the steering shaft elements 14 and 16 for a pivoting movement relative to each other about the pivot axis 50 in at least one of the pivot directions, thereby destroying or damaging the locking element 52.

[0050] In the embodiment illustrated in the figures, the locking element 52 is designed as a sleeve separate from the steering shaft elements 14, 16, 26 and 28 and separate from the joints 30, 38 and 48, which is partially arranged on the steering shaft elements 14 and 16 and thus extends continuously from the steering shaft element 14 over the joint 48 to the steering shaft element 16 or vice versa.The locking element 52, which, for example, at least partially, in particular at least predominantly or completely, surrounds the respective length ranges of the steering shaft elements 14 and 16 and the joint 48 in the circumferential direction of the respective steering shaft elements 14 and 16, interacts, for example, with the steering shaft elements 14 and 16, in particular in a positive-locking manner, such that the steering shaft elements 14 and 16 cannot be pivoted about the pivot axis 50 relative to each other without damage or destruction of the locking element 52, that is to say, that the joint 48 cannot be bent without destruction or damage of the locking element 52, in particular starting from a position of the steering shaft elements 14 and 16 relative to each other.

[0051] The locking element 52 is, for example, formed in one piece. Furthermore, it is conceivable that the locking element 52 is made of a plastic and / or a metallic material.

[0052] In the embodiment illustrated in the figures, the aforementioned position in which the steering shaft elements 14 and 16 are secured relative to each other by means of the locking element 52 is a so-called straight position, in which the joint 48 is extended. As a result, the steering shaft elements 14 and 16 run along an imaginary straight line that coincides with the axes of rotation 36 and 42. In other words, in the embodiment illustrated in the figures, the steering shaft elements 14 and 16 are secured by means of the locking element 52 in such a way that the longitudinal directions of the steering shaft elements 14 and 16, and thus the axes of rotation 36 and 42, coincide.

[0053] Alternatively, it is conceivable that the joint 48 is bent in the aforementioned position, so that the longitudinal extension directions of the steering shaft elements 14 and 16 or the axes of rotation 36 and 42 run obliquely to each other in the position in which the steering shaft elements 14 and 16 are secured relative to each other by means of the locking element 52 and thus enclose an angle different from 180 degrees or from 0 degrees and preferably obtuse.

[0054] Out of Fig. Figure 1 shows that the locking element 52 has a receiving chamber 58 in which the joint 48 is received. Furthermore, the locking element 52 has through-openings 60 and 62, each of which opens into the receiving chamber 58. The steering shaft element 14 passes through the through-opening 62, and the steering shaft element 16 passes through the through-opening 60.

[0055] The joint 48 comprises, for example, a first joint part 64 associated with the steering shaft element 14 and a second joint part 66 associated with the steering shaft element 16. The joint part 64 is, for example, rotationally fixed to the steering shaft element 14. In particular, the joint part 64 can be formed integrally with the steering shaft element 14. The joint part 66 is, for example, rotationally fixed to the steering shaft element 16, and can also be formed integrally with the steering shaft element 16. The joint parts 64 and 66 are formed separately from one another and are articulated to each other in such a way that the joint parts 64 and 66, and thus the joint 48, define or specify the pivot axis 50.

[0056] If, for example, a frontal collision of the vehicle results in an accident-related force acting on the steering shaft 10 via the steering gear 20, and in particular on the steering shaft elements 14 and 16, and this accident-related force exceeds a level that can be specified or adjusted, for example by the design of the locking element 52 and is also referred to as a threshold value, then the steering shaft elements 14 and 16 are pivoted relative to each other about the pivot axis 50 in at least one of the pivot directions by the accident-related force, destroying or damaging the locking element 52. This means that the joint 48 is bent from its position, so that the steering shaft 10 is bent or kinked from its position. Fig. Figure 2 shows that the locking element 52 is deformed, in particular bent, by the force applied in the accident or by the pivoting of the steering shaft elements 14 and 16 relative to each other caused by the force applied in the accident. As a result, the steering gear 20 can be displaced or moved backward in the longitudinal direction of the vehicle due to the accident without excessive backward displacement of the steering wheel 18 or the steering column 24. Thus, the backward displacement of the steering gear 20 due to the accident can be at least substantially decoupled from a backward displacement of the steering wheel 18 due to the accident. It has also proven particularly advantageous if, for example, the steering shaft element 14 has a telescoping T (not shown in detail) in a region B.The telescoping T comprises two steering shaft sections 68 and 70 of the steering shaft element 14, which are rotatable together or simultaneously about the axis of rotation 36, torque-transmitting, and, for example, rotationally fixed to one another and telescopically slide into one another. The steering shaft sections 68 and 70 can be pushed into and pulled apart along the axis of rotation 36. For example, the steering shaft section 68 is rotationally fixed to the joint section 64, and the steering shaft section 68 can be formed integrally with the joint section 64. The steering shaft section 70 is, for example, rotationally fixed to a joint part of the joint 30, and the steering shaft section 70 can be formed integrally with the joint part of the joint 30. In the telescoping T, the steering shaft sections 68 and 70 can be pushed into one another by a distance also referred to as the telescopic length, whereby the telescopic length can be kept particularly short.The telescoping T allows, for example, steering column adjustment.

[0057] Furthermore, it is conceivable that the steering shaft 10 has at least one shaft element 72, which is connected to the steering shaft element 26 in a torque-transmitting manner and is provided in addition to the steering shaft elements 14, 16, 26 and 28, wherein, for example, the steering shaft element 26 and the shaft element 72 are telescopically or telescopically slid into one another, particularly along the axis of rotation 34. This allows, for example, a particularly advantageous steering column adjustment to be realized, within which the steering wheel 18 can be moved relative to a seating unit external to the vehicle, such as a driver's seat. This allows, for example, the steering wheel 18 to be moved towards and away from the driver's seat, so that the steering wheel 18 can be positioned within the interior as required.

[0058] Out of Fig. 2 It can be seen that, for example, the steering shaft element 26 and the shaft element 72 are rotatably mounted on the structure 46 about the axis of rotation 34. In particular, it is conceivable that the steering wheel axis of rotation 22 coincides with the axis of rotation 34.

[0059] Furthermore, it is from Fig. 2. It can be seen that, for example, the steering shaft 10 also bends at the joint 30 when subjected to a force in an accident, so that the steering gear 20 can be displaced a particularly large distance to the rear in the longitudinal direction of the vehicle without excessive rearward displacement of the steering wheel 18. This allows for advantageous accident behavior to be achieved in a space-saving manner.

[0060] The joint 48 can also be used to facilitate the simple assembly of the steering shaft 10. For example, the steering shaft 10 is assembled in a state where the steering shaft elements 14 and 16 are not yet secured relative to each other about the pivot axis 50 by means of the locking element 52, but can still pivot relative to each other about the pivot axis 50. After the steering shaft 10 has been assembled, the locking element 52 is installed, specifically such that the locking element 52 secures the steering shaft elements 14 and 16 against pivoting movements about the pivot axis 50 in both directions relative to each other. The use of the joint 48 and the locking element 52 allows for the transmission of particularly high torques between the steering shaft elements 14 and 16.On the other hand, the locking element 52 can be designed such that the threshold value described above is particularly low, so that the steering shaft elements 14 and 16 pivot relative to each other in at least one of the pivot directions even with a sufficiently low force applied about the pivot axis 50, thereby destroying or damaging the locking element 52.

Claims

[1] Steering shaft (10) for a steering system (12) of a motor vehicle, comprising at least two first steering shaft elements (14, 16) via which a steering wheel (18) can be mechanically connected to a steering gear (20) of the steering system (12), comprising at least one first joint (48) via which the steering shaft elements (14, 16) are connected to each other in a torque-transmitting manner and pivotable about a pivot axis (50) relative to each other, comprising at least one locking element (52) which secures the steering shaft elements (14, 16) relative to each other against pivoting movements about the pivot axis (50) both in a first pivoting direction (54) and in a second pivoting direction (56) opposite to the first pivoting direction (54) and as a result of an accident-related force application, the first steering shaft elements (14, 16) are prevented from pivoting about the pivot axis (50) in at least one of the pivoting directions (54, 56) relative to each other. releasesand with at least one further steering shaft element (26), which is connected to the first steering shaft elements (14, 16) via at least one second joint (30) in a torque-transmitting manner and pivotable about a second pivot axis (32) relative to the first steering shaft elements (14, 16), , characterized by at least one shaft element (72) connected to the further steering shaft element (26) in a torque-transmitting manner and provided in addition to the steering shaft elements (14, 16, 26), wherein the further steering shaft element (26) and the shaft element (72) are telescopically slidable into one another, and wherein at least one of the first steering shaft elements (14, 16) has two steering shaft parts (68, 70) rotatable about an axis of rotation (36), torque-transmitting, and telescopically slidable into one another. [2] Steering shaft (10) Claim 1, characterized by, that the locking element (52) is designed as a sleeve (52) which is separate from the first steering shaft elements (14, 16) and separate from the first joint (48), which is partially arranged on the first steering shaft elements (14, 16) and thus extends continuously from one of the first steering shaft elements (14, 16) over the first joint (48) to the other first steering shaft element (16, 14). [3] Steering shaft (10) according to claim 1 or 2, characterized by , that the locking element (52) is formed in one piece. [4] Steering shaft (10) according to one of the preceding claims, characterized by , that the locking element (52) is made of a plastic and / or a metallic material. [5] Steering shaft (10) according to one of the preceding claims, characterized by, that the first steering shaft elements (14, 16) are secured by means of the locking element (52) in a position in which the steering shaft elements (14, 16) run in a straight line or enclose an angle other than 180 degrees. [6] Steering (12) for a motor vehicle, comprising a steering wheel (18), a steering gear (20) and a steering shaft (10) according to any one of claims 1 to 5 via which the steering wheel (18) is mechanically connected to the steering gear (12). [7] Motor vehicle, with a steering shaft (10) according to any one of claims 1 to 5 and / or with a steering system (12) according to claim 6.

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