CN114514150A

CN114514150A - Locking device and steering column with locking device

Info

Publication number: CN114514150A
Application number: CN202080071269.2A
Authority: CN
Inventors: 罗伯特·加莱尔; 塞巴斯蒂安·福特
Original assignee: ThyssenKrupp AG; ThyssenKrupp Presta AG
Current assignee: ThyssenKrupp AG; ThyssenKrupp Presta AG
Priority date: 2019-10-11
Filing date: 2020-10-06
Publication date: 2022-05-17
Anticipated expiration: 2040-10-06
Also published as: DE102019215681A1; WO2021069405A1; CN114514150B

Abstract

The invention relates to a locking device (1; 29) for a steering column (3) of a steer-by-wire system of a motor vehicle, the steering column comprising a steering shaft (2), the locking device comprising a catch star (8) with a plurality of protrusions (6) and recesses (7), wherein the detent star (8) can be coupled to the steering shaft (2) in a rotationally fixed manner, the locking device comprises a locking element (9; 30) which can be moved relative to the locking star (8) and an adjustment drive (10; 31), the adjustment drive is designed such that the locking element (9; 30) is switched between a blocking position and a release position, in the blocking position the rotation of the steering shaft (2) is blocked and in the release position the rotation of the steering shaft (2) is released, wherein the actuating drive (10; 31) comprises at least one first electromagnetic actuator (11; 34) and at least one second electromagnetic actuator (12; 35). The invention also relates to a steering column (3) for a motor vehicle.

Description

Locking device and steering column with locking device

Technical Field

The invention relates to a locking device for a steering column of a steer-by-wire system of a motor vehicle, comprising a steering shaft, comprising a detent star having a plurality of projections and recesses, wherein the detent star can be coupled in a rotationally fixed manner to the steering shaft, comprising a detent element which can be moved relative to the detent star, and an adjustment drive which is designed to switch the locking element between a blocking position, in which the rotation of the steering shaft is blocked, and a release position, in which the rotation of the steering shaft is released. The invention also relates to a steering column for a motor vehicle.

Background

A steering column for a motor vehicle has a steering shaft, to the end of which, which faces the driver in the driving direction, is situated at the rear, for the introduction of steering commands by the driver. The steering shaft is mounted in the steering column so as to be rotatable about its longitudinal axis. In contrast to conventional steering systems, the steering system of a steer-by-wire system does not have a mechanical steering force/torque transmission or a mechanical coupling between the steering column and the steering gear and thus the wheels of the motor vehicle.

By mechanically decoupling the steering column from the steering gear and thus from the vehicle wheels, the driver does not at all obtain haptic feedback information, which can contribute to conveying the driving sensation or impression of the current vehicle condition to the driver. In particular, the mechanical decoupling results in the driver being able to rotate the steering wheel without hindrance by an infinite steering angle, i.e. any number of steering wheel rotations can be performed. This does not correspond to a customary steering operation of the vehicle and may therefore lead to confusion for the driver. Driver errors in steering operations, particularly during driving, can lead to safety-critical situations. Any form of confusion or distraction of the driver should be avoided.

In order to improve driving safety, locking devices for steering columns of steer-by-wire systems, which comprise a steering shaft, are used to provide the driver of the motor vehicle with a haptic feedback in the form of a significantly increased or insurmountable steering resistance in certain situations. This occurs, for example, when the steering gear or the wheels have reached a maximum steering angle. The driver also expects a haptic feedback if one or both wheels of the motor vehicle, which are operatively connected to the steering gear, hit an obstacle, in particular a ground stone, a curb or a curb, during the steering process. Common to both cases is that the wheels cannot be steered further in the direction of the steering movement. The desired tactile feedback may be such that the steering resistance has to be increased significantly, precisely when the wheel is unable to continue to steer in the direction of the corresponding steering movement. This type of haptic feedback is also referred to as an analog stop.

In order to increase the steering resistance as the case may be, the prior art discloses applying a corresponding torque to the steering shaft that acts counter to the direction of the steering movement. However, this requires a correspondingly powerful electric motor which must be correspondingly designed to be large in size and therefore requires a relatively large installation space and is costly.

DE 102016206610 a1 discloses a steer-by-wire device for a motor vehicle having a locking device. The locking device has a gear-like latching star which is connected to the steering shaft in a rotationally fixed manner, a latching element which can be engaged with the latching star, and an adjustment drive which can move the latching element.

A disadvantage of this known steering wheel lock is the relatively long switching time of the movement mechanism. The term "switching time" is understood to mean the time period required to switch from one state to another. In combination with the locking means, this means the length of time for which the catch element is moved from the blocking position to the release position or vice versa. In order to return the detent element into its starting position along the adjustment path, a correspondingly pretensioned return spring is provided. Although an improved dynamics of the kinematic mechanism and thus a shorter switching time can be achieved by increasing the spring force of the restoring spring, in particular by increasing the spring constant or the spring deflection. However, in order to overcome the increased spring force, a correspondingly more powerful electric motor must be provided, which is therefore more space-intensive and more costly.

DE 60303081T 2 discloses a locking device with a fixed and variable mechanical end-of-travel stop. However, this known locking device is comparatively complex in its construction and requires construction space.

Other locking devices are disclosed by FR 2908101B 1 and DE 102004037617 a 1.

When a rotation direction change is detected using a sensor in the simulated stop, the steering column is then released as quickly as possible. In other words: the catch element of the locking device is moved from the blocking position into the release position in the shortest possible switching time, so that the steering wheel or the steering shaft does not remain blocked after a rotational direction switch has been detected.

The detection of the position of the steering wheel is a safety-relevant function and therefore should be ensured reliably or in a fail-safe manner (ASIL D).

In view of the above-mentioned drawbacks of the known locking devices, it is an object of the present invention to provide a locking device which achieves a short switching time by means of a relatively simple construction, has a compact construction and is reliable.

Disclosure of Invention

The object on which the invention is based is achieved by a locking device for a steering column of a steer-by-wire system for a motor vehicle, comprising a steering shaft, having the features of claim 1, and by a steering column for a motor vehicle having the features of claim 10. Advantageous developments emerge from the dependent claims.

According to the invention, it is proposed for a locking device of the type mentioned at the outset that the actuating drive comprises at least one first electromagnetic actuator and at least one second electromagnetic actuator. Short switching times can be achieved by means of two electromagnetic actuators. The electromagnetic actuator can be supplied with electrical energy in each case, so that it generates a high magnetic force and thus acts on the catch element with a high actuating force.

The plurality of projections and recesses are arranged alternately in the circumferential direction and can form teeth, for example.

Preferably, the locking device is not just a steering wheel lock which fixes or blocks the steering shaft in the direction of rotation in the event of the driver of the vehicle leaving the vehicle. In contrast, as described above, the locking device serves to provide the driver of the motor vehicle with a haptic feedback in the form of a significantly increased or insurmountable steering resistance in certain situations, in order to simulate a mechanical coupling between the steering column and the steering gear, which is omitted in the context of a steer-by-wire system.

The electromagnetic actuators may each be configured as an electromagnet, comprising a coil and an iron core arranged in the coil. In order to guide and reinforce the magnetic field generated during the energization, that is to say during the supply of electrical energy, the respective core can have a shaping. The control unit is used to selectively energize the coils in order to generate a changing magnetic field during normal operation, in order to move the catch element into the blocking position or the release position, depending on the situation.

Furthermore, the profile can be designed as a mechanical stop for the pivoting movement of the detent element. The mechanical stop on the forming section contributes to the magnetization process of the iron element interacting with the electromagnetic actuator. This is because the mechanical stop causes an impact or pulse which facilitates or simplifies the orientation of the magnetic domains, also called white regions (Weiss-bezier). The orientation of the magnetic domains in the almost parallel direction is a fundamental, metal-based magnetization effect on the crystallographic plane.

Advantageously, the first electromagnetic actuator is designed to move the catch element from the blocking position into the release position, and the second electromagnetic actuator is designed to move the catch element from the release position into the blocking position. Conversely, the direction of movement may also be defined in the opposite direction.

In a particularly advantageous manner, the two electromagnetic actuators are each designed in such a way that the latching element is moved away or pushed away or repelled. Moving the catch element away from it provides the advantage of a very fast switching time, since the gap between the electromagnetic actuator and the catch element is very small or almost non-existent. Thereby, the efficiency at the start of the handover procedure is very high. Thus, when the latching element has to be accelerated in order to transfer it from one state into the other, a correspondingly large force can be provided precisely. It is also conceivable for the two electromagnetic actuators to each be designed such that the latching element is moved or attracted thereto. In both cases, both electromagnetic actuators are designed to act on the catch element in the same manner. This enables the use of simpler and therefore less costly control of the individual actuators.

Alternatively, the first electromagnetic actuator may be configured such that the catch element is moved away or pushed away or repelled from it, while the second electromagnetic actuator is configured such that the catch element is moved or attracted to it, i.e. just when the first electromagnetic actuator moves or pushes away or repelles the catch element away from it. Preferably, this is done during the switching cycle, that is to say when switching between the release position and the blocking position. In other words, two actuators act simultaneously or two movements occur simultaneously.

It is also conceivable to counteract or counteract this, rather the first electromagnetic actuator can be designed such that the catch element is moved or attracted towards it, while the second electromagnetic actuator is designed such that the catch element is moved away or pushed away or repelled, i.e. precisely when the first electromagnetic actuator attracts the catch element towards it. Preferably, this is done during the switching cycle, that is to say when switching between the release position and the blocking position. In other words, two actuators act simultaneously or two movements occur simultaneously.

In both cases, both electromagnetic actuators are designed to act on the catch element in different ways. The action modes of the two electromagnetic actuators are mutually complementary. One actuator pushes or pulls and the other actuator pulls or pushes. Particularly good kinetics and therefore particularly short switching times can be achieved thereby.

In a preferred embodiment, the latching element is configured to be pivotable about a pivot axis. Such pivotable latching elements are also referred to as locking/pivoting levers or handles. In contrast to axially displaceable latching elements, particularly short switching times can be achieved in this way. Furthermore, a position-saving or space-saving and compact locking device can thus be achieved.

In a particularly preferred embodiment, the latching element is designed such that its pivot axis extends through its center of mass. External (disturbing) forces acting on the center of gravity of the mass, which may be caused, for example, by vibrations or other environmental influences, do not introduce torques into the detent element. This improves the reliability and operational safety of the locking element. Furthermore, a relatively smooth latching element is thereby provided, i.e. requiring a low adjustment force.

The detent element can comprise at least one form-fitting unit which engages into the detent star and at least one fitting unit which is fixedly connected to the form-fitting unit. The form-fitting unit extends from the center of mass as far as the open or free end of the latching element facing the latching star and is of leg-like design. The form-fitting unit is fitted to the latching star in such a way that it can be brought into engagement with the latching star. By "engaging" is meant herein that the form-fitting unit is brought or inserted or moved, in particular pivoted, into one of the recesses of the latching star, so that the rotation of the steering shaft is blocked. The rotation of the steering shaft is blocked to the extent that a rotational movement is possible only in the intermediate space defined by two successive projections of the locking star. The intermediate space corresponds to the recess.

The mating unit extends from the center of mass as far as the open or free end of the latching element facing the actuating drive and is of leg-like design. The engagement unit interacts with the servo drive in such a way that it can be moved back and forth, in particular pivoted, by the electromagnetic actuator.

The locking star of the locking device according to the invention can be a separate component which is fixed to the steering shaft. Alternatively, the locking star can be a molded part which is formed integrally with the steering shaft and which is produced, for example, in particular by cutting or by a cold forming process.

The form-fitting unit and the fitting unit can be made of different materials or of the same material. By the fixed connection of the form-fitting unit to the fitting unit, the two units can be moved in a fixed orientation relative to one another or synchronously with one another. In other words: the movement of the fitting unit caused by the adjustment drive results in a corresponding movement of the form-fitting unit. The fixed connection can be achieved by force fit, form fit or material fit. Combinations of these connection techniques are also contemplated. Alternatively, the form-fitting unit and the fitting unit can also be designed as one piece.

The form-fitting unit can be hook-shaped. The hook shape is implemented in such a way that the form-fitting unit has an undercut on the open end facing the latching star, which is complementary to the convex shape of the latching star.

The locking device may have a permanent magnet or a permanent magnet. This can be designed such that the latching element remains in the last position occupied when it is not actuated. This is achieved by a corresponding positioning of the permanent magnet relative to the pivotable latching element. More precisely, the position of the permanent magnet is selected such that the magnetic field of the permanent magnet acts on the latching element such that the magnetic force can fix the latching element against external disturbing influences or disturbing forces. In this way, the catch element can be held or fixed magnetically in the last position assumed, i.e. either in the blocking position or in the release position, even when electromagnetic actuation is not taking place, for example when the current in the onboard power supply system of the vehicle is interrupted and therefore when the electromagnetic actuator is deactivated. In this way, a clear and thus reliable operating state of the locking device is always ensured even in or after an operating fault.

It is also conceivable to configure the permanent magnet such that, if the last position assumed does not correspond to the standard position when no actuation has taken place, the catch element is brought into the previously determined position (default position or standard position), i.e. either in the blocking position or in the release position, or, if the last position assumed corresponds to the standard position, is held in the previously determined position (default position or standard position). This ensures a specific and thus reliable operating state of the locking device even in the event of or after an operating fault.

In the case of a permanent magnet which is designed to move the detent element into the blocking position when no actuation takes place and the detent star is in an angular position in which the detent element cannot be brought into engagement with the detent star at the time of the interruption of the current, the locking device is briefly in an unstable state because the detent element strikes the front of the projection of the detent star at the end face. However, a small change in the angle of the detent star is sufficient to move the detent element into engagement with the detent star again and thus to transfer the locking device into a stable and reliable state.

Additionally or alternatively, the permanent magnet may be configured to magnetize an iron element for cooperation with the electromagnetic actuator. This is necessary in particular for embodiments which do not provide for an attracting movement of the catch element with the electromagnetic actuator, but rather a repelling movement of the catch element from the electromagnetic actuator. This is because the magnetization of the ferrous element generates magnetic poles in the ferrous element, which is imperative for the generation of a repulsive force due to the opposite polarity.

To further improve the dynamics of the locking mechanism, the adjustment drive may comprise more than one first and second electromagnetic actuator. In particular, the actuating drive may comprise two first electromagnetic actuators and two second electromagnetic actuators. This results in a greater actuating force acting on the latching element. This enables a shorter switching time.

Furthermore, redundancy of the electromagnetic actuators is thereby provided, which improves the reliability and operational or fail-safe of the locking device. Since the additional first electromagnetic actuator and the additional second electromagnetic actuator may be used as a substitute for the first electromagnetic actuator or the second electromagnetic actuator, respectively, in the event of a failure of the first electromagnetic actuator or the second electromagnetic actuator, respectively.

Furthermore, according to the invention, a steering column for a motor vehicle is provided, comprising a steering shaft bearing unit in which a steering shaft is rotatably supported, wherein the steering shaft can be coupled to a steering wheel, and comprising a locking device which is formed as described above, wherein all features can be combined with one another.

Preferably, the steering column is free of a steering wheel lock, that is to say the steering column does not have a steering wheel lock which fixes or blocks the steering shaft in the direction of rotation in the event of the driver of the vehicle leaving the motor vehicle, in particular in the event of an unintentional start of the motor vehicle.

Drawings

Advantageous embodiments of the invention are explained in detail below with the aid of the figures. In detail show

Figure 1 shows an embodiment of the locking device according to the invention in a perspective view,

figure 2 shows the locking device of figure 1 in a detailed view,

figure 3 shows the locking device of figure 1 in a top view,

figure 4 shows the locking device of figure 1 in a top view,

figure 5 shows a further embodiment of the locking device according to the invention in a top view,

figure 6 shows the locking device of figure 5 in a top view,

fig. 7 shows an embodiment of a steering column according to the invention in a perspective view, and

fig. 8 shows the steering column of fig. 7 in a perspective detail view.

Detailed Description

In the different figures, identical components are provided with the same reference numerals throughout and are therefore generally named or referred to, respectively, only once.

Fig. 1 shows an embodiment of a locking device 1 according to the invention in a perspective view. The locking device 1 is in its release position.

The locking device 1 is provided on a steering column 3 including a steering shaft 2 of a steer-by-wire system of a motor vehicle. Specifically, the locking device 1 is fixed on the end of the steering column 3 facing away from the steering wheel, which is not shown in the drawings, to the steering column 3 via an opening 4 for receiving a screw, which is also not shown in the drawings. The locking device 1 is surrounded by a housing element 5. For a better view of the locking device 1, the housing element 5 is shown in cross section.

The locking device 1 comprises a detent star 8, a detent element 9 and an adjusting drive 10, the detent star 8 being fixedly connected to the steering shaft 2 and having a plurality of projections 6 and recesses 7, the detent element 9 being movable relative to the detent star 8. The projections 6 and the recesses 7 are formed on the latching star in circumferential sections and are arranged alternately in the circumferential direction.

The latching star 8 is designed like a gear wheel. The projections 6 of the detent star 8 are designed as detent planets with tooth flanks oriented perpendicularly or normal to the outer circumferential surface of the detent star 8. The recesses 7 of the detent star 8 are designed as detent tooth grooves, which are each formed by two detent stars that are successive in the circumferential direction of the detent star 8.

The adjustment drive 10 is designed to move the catch element 9 back and forth between a position blocking the rotation of the steering shaft 2 (blocking position) and a position releasing the rotation of the steering shaft 2 (releasing position), in other words, the catch element 9 can be switched between the blocking position and the releasing position by the adjustment drive 10.

Fig. 2 shows the catch element 9 and the adjustment drive 10 of the locking device 1 in schematic detail. For better overview, the housing element 5 is not shown. The locking device 1 is in its release position.

The actuator 10 includes a first electromagnetic actuator 11 and a second electromagnetic actuator 12. The

electromagnetic actuators

11, 12 are electromagnets, respectively.

The first electromagnetic actuator 11 comprises a coil 13, a core 14 arranged within the coil 13, a connecting element 16 having an opening 15. The actuator 11 is connected in a positionally fixed manner to the housing element 5 (not shown in fig. 2) of the locking device 1 via a connecting element 16. The core 14 has two formations 17 at right angles to the longitudinal axis of the core, so that the core 14 is configured in a U-shape. The forming portions 17 constitute open end portions of the core 14, respectively. The formation 17 serves as an "extension" of the plunger 14 and as a displacement limitation or mechanical stop for the pivoting movement of the catch element 9 in the direction of the first electromagnetic actuator 11.

Similarly, the second electromagnetic actuator 12 comprises a coil 18, a core 19 arranged in the coil 18 and a connecting element 21 having an opening 20. The actuator 12 is connected in a positionally fixed manner to the housing element 5 (not shown in fig. 2) of the locking device 1 via a connecting element 21. The core 19 comprises two profiles 22 which are formed at right angles to the longitudinal axis of the core and are therefore U-shaped. The forming portions 22 respectively constitute open end portions of the core 19. They serve as "extensions" of the plunger 19 and as displacement limits or mechanical stops for the pivoting movement of the catch element 9 in the direction of the second electromagnetic actuator 12.

The

coils

13, 18 are each electrically connected to a power supply and can be selectively energized or switched on by a control unit not shown in the figures. As a result, magnetic fields having a polarity corresponding to the electrical throughflow are generated in each case. The

cores

14, 19 arranged in the

coils

13, 18, respectively, guide and intensify the respective magnetic field.

The first electromagnetic actuator 11 is designed in such a way that the blocking element 9 is moved from the blocking position into the release position. The second electromagnetic actuator 12 is configured in such a way that the blocking element 9 is moved from the release position into the blocking position.

The

electromagnetic actuators

11, 12 are each designed such that the latching element 9 is moved away from it, pushed away or repelled.

The catch element 9 is designed as a lever or a catch lever, which can be pivoted about a pivot axis 23. The pivot axis 23 of the catch element 9 extends through its center of mass.

The locking element 9 comprises a form-fitting unit 24 of sintered material which engages into the locking star 8 and a fitting unit 25 of plastic which is fixedly connected to the form-fitting unit 24. The mating unit 25 can be actuated by means of the

electromagnetic actuators

11, 12. By the fixed connection of the form-fitting unit 24 to the fitting unit 25, the two units can be moved in a fixed orientation relative to one another or synchronously with one another. The center of mass of the catch element 9 is located in the region of the connection fitting unit 25 and the form-fitting unit 24. The pivot axis 23 of the latching element 9 extends through the connection region.

The form-fitting unit 24 of the latching element 9 is designed in the form of a hook. The open end of the form-fitting unit 24 is designed to form-fit or form-fit with the projections 6 designed as latch stars. When the form-fitting unit 24 is engaged in the locking star 8, a pair of action surfaces is formed between one of the tooth surfaces of the locking star oriented perpendicularly or normal to the outer circumferential surface of the locking star 8 and the form-fitting unit 24 configured complementarily to the tooth surface.

The mating unit 25 of the locking element 9 is connected in a material-locking manner to two iron elements 26, which are each embedded in the mating unit 25 or are surrounded by the mating unit 25. The ferrous element 26 is configured to magnetically interact with the

electromagnetic actuators

11, 12, respectively. The end-side surfaces of the

profiles

17, 22 are in each case in active confrontation with the end-side surfaces of the two iron elements 26 lying opposite one another.

The repelling movement of the iron elements 26 carried by the catch element 9 away from the stationary

electromagnetic actuators

11, 12 is a result of the fact that the magnetized end faces of the

profiles

17, 22 on the one hand and the magnetized end faces of the two iron elements 26 on the other hand have the same polarity.

The locking device 1 also has a permanent magnet 27. The permanent magnet 27 has an opening 28 for guiding a bolt for fastening to the housing element 5 therethrough. Furthermore, the permanent magnet 27 has two right-angled formations. Accordingly, the permanent magnet 27 is U-shaped. The permanent magnet 27 is arranged outside the pivotably supported fitting unit 25 in the radial direction thereof.

The poles of the respective ferrous elements 26 are generated by magnetization induced or caused by the permanent magnets 27. The first open end of the U-shaped permanent magnet 27 forms a magnetic north pole and the second open end of the U-shaped permanent magnet 28 forms a magnetic south pole. The permanent magnets 27 are arranged in direct spatial proximity to the ferrous elements 26. A magnetic field is formed in direct spatial proximity to the permanent magnet 27. By introducing the iron element 26 into the magnetic field of the permanent magnet 27, the magnetic domains of the iron element 26 are oriented substantially parallel to the magnetic field. This is called magnetization. In normal operation, the mechanical abutment of the ferrous elements 26 of the mating unit 25 with respect to the shaped

portions

17, 22 generates impacts or pulses that promote or simplify the orientation of the magnetic domains.

The permanent magnet 27 fulfils another function in addition to the magnetization of the ferrous element 26. Specifically, the permanent magnet 27 serves to magnetically hold the latching element 9 in the last position assumed, that is to say either in the blocking position or in the release position, when electromagnetic actuation does not take place, for example when the current is interrupted and therefore when the

electromagnetic actuators

11, 12 are deactivated. A clearly defined and reliable operating state of the locking device 1 is therefore always ensured.

Fig. 3 and 4 clearly show the release position and the blocking position of the locking device 1 in comparison.

Fig. 3 shows the locking device 1 in a top view. The locking device 1 is in its release position.

The coil 13 of the first electromagnetic actuator 11 is energized by a control unit, not shown in the figures, so that the engagement unit 25 of the catch element 9 is repelled by the first electromagnetic actuator 11. Thereby, the engaging unit 25 is pivoted counterclockwise about the pivot axis 23 and until the iron element 26 of the engaging unit 25 abuts on the forming section 22. The pivoting movement of the engagement unit 25, due to the fixed connection to the form-fitting unit 24, in turn leads to a counterclockwise pivoting movement of the form-fitting unit 24 about the pivot axis 23, i.e. out of engagement with the detent star 8.

Fig. 4 shows the locking device 1 in a top view. Unlike fig. 1 to 3, the locking device 1 is in its blocking position.

The coil 18 of the second electromagnetic actuator 12 is energized by a control unit, not shown in the figures, in such a way that the engagement unit 25 of the catch element 9 is repelled by the second electromagnetic actuator 12. Thereby, the engaging unit 25 is pivoted clockwise about the pivot axis 23 and until the iron element 26 of the engaging unit 25 abuts on the forming section 17. Due to the fixed connection with the form-fitting unit 24, the pivoting movement of the fitting unit 25 causes the form-fitting unit 24 to pivot about the pivot axis 23 in the clockwise direction into engagement with the detent star 8.

Fig. 5 and 6 show a comparison of the release position and the blocking position of a further embodiment of the locking device 29 according to the invention.

Fig. 5 shows the locking device 29 in a top view. The locking device 29 is in its release position.

The basic construction of the locking device 29 corresponds to the construction of the locking device 1 of fig. 1 to 4. The locking device 29 likewise comprises a locking star 8, which is connected in a rotationally fixed manner to the steering spindle 2 and has a plurality of projections 6 and recesses 7, a locking element 30, which is movable relative to the locking star 8, and an adjusting drive 31.

The latching element 30 is designed as a lever or a locking lever, which can be pivoted about a pivot axis 23, wherein the pivot axis 23 extends through the center of mass of the latching element 30. The latching element 30 comprises a form-fitting unit 32 which engages into the latching star 8 and a fitting unit 33 which is fixedly connected to the form-fitting unit 32.

The adjustment drive 31 includes a first electromagnetic actuator 34 and a second electromagnetic actuator 35. The

electromagnetic actuators

34, 35 are electromagnets, respectively. The adjustment drive 31 can reciprocate or switch the catch element 30 between the blocking position and the release position.

In contrast to the form-fitting unit 24 and the fitting unit 25, both the form-fitting unit 32 and the fitting unit 33 are made of magnetizable material, and both the form-fitting unit 32 and the fitting unit 33 are actuatable. That is, the fitting unit 33 can be actuated by the first electromagnetic actuator 34, and the shape fitting unit 32 can be actuated by the second electromagnetic actuator 35.

The first electromagnetic actuator 34 includes a coil 36 and a core unit 37 having an opening. The core unit 37 is fixedly connected to the housing element 5 by means of fixing bolts 38 which pass through the openings. The core unit 37 has a base 39, an inner or middle leg 40 and two outer legs 41.

Legs

40, 41 are respectively molded onto base 39 and are equidistant from each other. The base 39 and the

legs

40, 41 are integrally or one-piece formed. The inner leg 40 is arranged inside the coil 36 and thus functions in a narrow sense as an iron core of the first electromagnetic actuator 34. The two outer legs 41 of the core unit 37 are arranged outside the coil 36 or are guided around the coil 36. The outer leg 41 also serves as an iron core of the first electromagnetic actuator 34 by forming the outer leg 41 as a unit integrally with the inner leg 40.

The three

legs

40, 41 respectively form open ends of the core unit 37. They are oriented or directed from the base 39 in such a way that they respectively match the surface shape of the mating unit 33. They therefore act as displacement limits or mechanical stops for the pivoting movement of the mating unit 33 of the latching element 30. The end side surfaces of the

legs

40, 41 each form a functional surface pair with a surface region of the mating unit 33 arranged opposite to them.

The coil 36 of the first electromagnetic actuator 34 is energized by a control unit, not shown in the figures, in such a way that the engagement unit 33 of the catch element 30 is repelled by the first electromagnetic actuator 34. Thereby, the fitting unit 33 pivots counterclockwise about the pivot axis 23. The pivoting movement of the mating unit 33, due to the fixed connection with the form-fitting unit 32, causes a pivoting movement of the form-fitting unit 32, i.e. a disengagement from the engagement with the latching star 8.

Fig. 6 shows a top view of the locking device 29. The locking device 29 is in its blocking position.

Similarly to the structure of the first electromagnetic actuator 34, the second electromagnetic actuator 35 has a coil 42 and an iron core unit 43 with an opening. The core unit 43 is fixedly connected to the housing member 5 by a fixing bolt 44 passing through the opening. The core unit 43 has a base 45, an inner or middle leg 46 and two outer legs 47.

Legs

46, 47 are respectively molded onto base 45 and are equidistant from each other. The base 45 and the

legs

46, 47 are constructed in one piece or integral. The inner leg 46 is arranged inside the coil 42 and thus functions as an iron core of the second electromagnetic actuator 35 in a narrow sense. The two outer legs 47 of the core unit 43 are arranged outside the coil 42 or are guided around the coil 42. The outer leg 47 also serves as the iron core of the second electromagnetic actuator 35 by forming the outer leg 47 as a unit integrally with the inner leg 46.

The three

legs

46, 47 form the open ends of the core unit 43, respectively. They are oriented or directed from the base 45 in such a way that they each match the surface shape of the form-fitting unit 32. They therefore serve as displacement limits or mechanical stops for the pivoting movement of the positive-locking unit 32 of the latching element 30. The end side surfaces of the

legs

46, 47 each form a functional surface pair with the surface region of the form-fitting unit 32 lying opposite them.

The coil 42 of the second electromagnetic actuator 35 is energized by a control unit, not shown in the figures, in such a way that the form-fitting unit 32 is repelled by the second electromagnetic actuator 35. Thereby, the form-fitting unit 32 pivots about the pivot axis 23 in the clockwise direction. The pivoting movement of the form-fitting unit 32 moves the form-fitting unit 32 into engagement with the latching star 8.

Fig. 7 shows a steering column 3 for a motor vehicle, which has a rotatably mounted steering shaft 2, to the end of which, facing the driver of the motor vehicle, not shown in the drawing, a steering wheel, also not shown in the drawing, can be attached. Furthermore, the steering column 3 comprises a bearing unit 48 which can be mounted on the body of the vehicle, a housing unit 49 which is fixed to the bearing unit 48 and has an adjusting unit 50, and a height adjusting device 51 and a longitudinal adjusting device 52.

Furthermore, the steering column 3 comprises a locking device 1 shown in fig. 1 to 4, which locking device 1 is enclosed by a housing element 5. Alternatively, a locking device 29 shown in fig. 5 and 6 may also be provided. The

locking device

1 or 29 is arranged at the axial end of the steering column 3 facing away from the steering wheel, which is not shown in the figures. This arrangement can also be seen in fig. 1.

The other housing element 53 is arranged directly adjacent to the housing element 5 in the axial direction.

Fig. 8 shows a detail of the steering column 3. The housing member 53 is shown in cross-section. The feedback actuator 54 is surrounded by a housing element 53.

In a steer-by-wire system, the feedback actuator 54 is used to provide or simulate mechanical information to the vehicle operator, particularly vibration and mechanical resistance during steering, preferably mechanical steering resistance. The feedback actuator 54 comprises an electric motor, wherein the electric motor has a stator 55 and a rotor 56, the stator 55 being received in the housing element 53 in a rotationally fixed manner, the rotor 56 being connected to the steering shaft 2 in a rotationally fixed manner.

Description of the reference numerals

1 locking device

2 steering shaft

3 steering column

4 opening

5 housing element

6 convex

7 concave part

8-latch star

9 latching element

10 adjustment drive

11 first electromagnetic actuator

12 second electromagnetic actuator

13 coil

14 iron core

15 opening

16 connecting element

17 forming part

18 coil

19 iron core

20 opening

21 connecting element

22 forming part

23 pivoting axis

24 form-fitting unit

25 mating unit

26 iron element

27 permanent magnet

28 opening

29 locking device

30 latching element

31 adjustment drive

32 form-fitting unit

33 mating unit

34 first electromagnetic actuator

35 second electromagnetic actuator

36 coil

37 iron core unit

38 fixing bolt

39 base part

40 inner leg

41 outer leg

42 coil

43 iron core unit

44 fixing bolt

45 base

46 inner leg

47 outer leg

48 support unit

49 housing unit

50 adjusting unit

51 height adjusting device

52 longitudinal adjustment device

53 housing element

54 feedback actuator

55 stator

56 rotor

Claims

1. A locking device (1; 29) for a steering column (3) of a steer-by-wire system of a motor vehicle, the steering column comprising a steering shaft (2), the locking device comprising a catch star (8) with a plurality of protrusions (6) and recesses (7), wherein the detent star (8) can be coupled to the steering shaft (2) in a rotationally fixed manner, the locking device comprises a locking element (9; 30) which can be moved relative to the locking star (8) and an adjustment drive (10; 31), the adjustment drive is designed such that the locking element (9; 30) is switched between a blocking position and a release position, in the blocking position the rotation of the steering shaft (2) is blocked and in the release position the rotation of the steering shaft (2) is released, the adjusting drive (10; 31) comprises at least one first electromagnetic actuator (11; 34) and at least one second electromagnetic actuator (12; 35).

2. Locking device (1; 29) according to claim 1, characterized in that the first electromagnetic actuator (11; 23) is designed to move the catch element (9; 30) from the blocking position to the release position and the second electromagnetic actuator (12; 35) is designed to move the catch element (9; 30) from the release position to the blocking position.

3. Locking device (1; 29) according to claim 1 or 2, characterized in that the first and second electromagnetic actuators (11, 12; 34, 35) are each configured to move the catch element (9; 30) away from it or to attract it.

4. Locking device (1; 29) according to claim 1 or 2, characterized in that the first electromagnetic actuator (11; 23) is configured to move the catch element (9; 30) away therefrom and the second electromagnetic actuator (12; 35) is configured to attract the catch element (9; 30) towards it, i.e. exactly when the first electromagnetic actuator (11; 23) moves the catch element (9; 30) away therefrom, or vice versa, respectively.

5. Locking device (1; 29) according to one of the preceding claims, characterized in that the catch element (9; 30) is pivotable about a pivot axis (23).

6. Locking device (1) according to claim 5, characterized in that the pivot axis (23) of the catch element (9; 30) extends through its center of mass.

7. Locking device (1; 29) according to one of the preceding claims, characterized in that the latching element (9; 30) comprises at least one form-fitting unit (24; 32) which engages into the latching star (8) and at least one fitting unit (25; 33) which is fixedly connected to the form-fitting unit (24; 32).

8. Locking device (1; 29) according to one of the preceding claims, characterized in that the locking device (1; 29) has a permanent magnet (27), the permanent magnet (27) being configured to hold the catch element (9; 30) in the last occupied position when no actuation takes place and/or being configured as a magnetised iron element (26) to cooperate with an electromagnetic actuator (11; 12).

9. Locking device (1) according to one of the preceding claims, characterized in that the adjustment drive (10; 31) comprises two first and two second electromagnetic actuators (11, 12; 34, 35).

10. Steering column (3) for a motor vehicle, comprising a steering shaft bearing unit in which a steering shaft (2) is rotatably supported, wherein the steering shaft (2) can be coupled to a steering wheel, and wherein the steering column (3) comprises a locking device (1; 29) according to one of claims 1 to 9.