DE102022133275B4 - Length-adjustable control unit and steer-by-wire system - Google Patents

Abstract

The invention relates to a length-adjustable operating unit (1) for influencing a direction of travel of a motor vehicle (2) by a user, comprising a telescopic extension device (4) with a guide tube (5), in or on which at least a first extension tube (6) is guided relative to the guide tube (5) and can be displaced in translation by means of a rotatable spindle (8) or spindle nut (16), wherein the telescopic extension device (4) can be coupled on the one hand to a steering means (7) which can be subjected to torque via an output shaft (9) of a transmission arrangement (10) to a first force feedback actuator (11) which is coupled to a first input shaft (12) of the transmission arrangement (10) and can be subjected to torque by at least one second force feedback actuator (13) which is coupled to a second input shaft (14) of the transmission arrangement (10), wherein the first force feedback actuator (11) and the second Force feedback actuator (13) are arranged in the first extension tube (6).

Description

The present invention relates to a length-adjustable operating unit for influencing a driving direction of a motor vehicle by a user according to the preamble of patent claim 1. The invention further relates to a steer-by-wire system with such a length-adjustable operating unit.

Electric steering devices are used - among other things in motor vehicles - to receive a driver's directional request and translate it into corresponding movements of one or more wheels. In contrast to purely mechanical steering devices, electric steering devices are divided into electrically assisted steering devices and fully electric steering devices, so-called "steer-by-wire" steering devices. These steer-by-wire steering devices in particular have the advantage that the control unit can be positioned relatively freely within the vehicle, independent of mechanical connecting components, which, in addition to saving costs when distinguishing between, for example, right- and left-hand drive vehicles, also leads to improved accident behavior due to the lack of a steering column. Furthermore, the control unit can be put into a stowed position, which is also used, for example, for fully automatic steering or driving.

A steer-by-wire steering system in the sense of the present invention is a steering system which essentially consists of a so-called hand wheel actuator (HWA), for example the actuators around the commanding vehicle steering wheel, and a road wheel actuator (RWA), i.e. the actuators acting on the steering mechanism connected to the vehicle wheels. The steering signal is transmitted from the HWA to the RWA by wire.

Such systems are basically known from the state of the art. For example, the EN 10 2015 224 602 A1 an adjustable steering column for a steer-by-wire steering device of a motor vehicle, comprising an actuating unit which comprises a steering spindle mounted in a casing unit so as to be rotatable about a longitudinal axis, wherein the casing unit has a first casing tube in which at least one second casing tube is arranged in a rotationally fixed manner with respect to the longitudinal axis and is mounted so as to be axially displaceable in a telescopic manner, wherein an actuating drive is connected to the first and second casing tubes, by which the second casing tube can be axially extended and retracted relative to the first casing tube, and which comprises a spindle drive with a threaded spindle arranged parallel to the longitudinal axis, which can be driven in rotation by an electric actuator, which is supported on one casing tube and which is screwed into a spindle nut which is attached to the other casing tube so as to be rotationally fixed, wherein the threaded spindle extends within the first casing tube and the spindle nut is attached to the second casing tube

The EN 10 2018 212 696 B3 Furthermore, an adjustment drive for a motor-adjustable steering column for a motor vehicle is known, comprising a motor drive unit and an external threaded spindle, which has an external thread and a coaxial internal thread, into which an internal threaded spindle engages, wherein the external threaded spindle and the internal threaded spindle can be driven by the drive unit relative to one another about an axis. In order to provide an adjustment drive that requires a lower drive torque and offers an optimized free adjustment path, the EN 10 2018 212 696 B3 that the external thread of the external threaded spindle engages a drive nut, whereby the drive nut or the internal threaded spindle can be driven in rotation by the drive unit and is supported in the direction of the axis relative to the drive unit.

From the EN 10 2018 116 617 A1 a steering system of a motor vehicle is known. The steering wheel unit has a steering movement sensor arranged in the area of a steering wheel shaft of the steering wheel for detecting the steering wheel position, as well as first and second force generating means. The first force generating means are used to adjust the height and inclination of a steering column connected to the steering wheel, while the second force generating means are designed to apply a mechanical feedback force to the steering wheel to the driver about the current steering and/or driving state. The steering wheel unit also comprises a first and a second electric motor, wherein the first and the second electric motor can be mechanically connected on the one hand to the first force generating means for adjusting the steering column, and on the other hand can be connected to the second force generating means for applying a mechanical feedback force to the steering wheel to a driver.

The EN 10 2017 207 272 A1 describes a steering handle for inputting a driver-side steering command into a steer-by-wire vehicle steering system comprising a rotatably mounted base body for actuation by the driver. A receptacle is formed on the base body in which a transmission is arranged, wherein an input element of the transmission can be coupled to an electric motor and an output element of the transmission is coupled to the base body.

With regard to the further development towards autonomous driving, the driver of the vehicle would like to be given the opportunity to retract the steering wheel almost completely towards the dashboard during autonomous driving in order to achieve an improved comfort area without a steering wheel that may be perceived as annoying, which also allows completely new design concepts for the passenger compartment.

Such new designs of the passenger compartment in autonomously driving motor vehicles often result in special requirements for the retractable steering wheel, in particular with regard to the required travel distance, which is usually much greater than the travel distance for an extendable steering column in a non-autonomously driving automobile.

It is the object of the invention to realize a length-adjustable control unit with a particularly compact structure. It is also the object of the invention to provide an improved steer-by-wire system.

This object is achieved by a length-adjustable operating unit for influencing a direction of travel of a motor vehicle by a user, comprising a telescopic extension device with a guide tube, in or on which at least a first extension tube is guided relative to the guide tube and can be translated by means of a rotatable spindle or spindle nut, wherein the telescopic extension device can be coupled on the one hand to a steering means which can be subjected to torque via an output shaft of a transmission arrangement with a first force feedback actuator which is coupled to a first input shaft of the transmission arrangement and which can be subjected to torque with at least one second force feedback actuator which is coupled to a second input shaft of the transmission arrangement, wherein the first force feedback actuator and the second force feedback actuator are arranged in the first extension tube. This makes it possible to provide an arrangement of the force feedback actuators which is optimized for installation space.

It goes without saying that the telescopic extension device can also have more than just a first extension tube. For example, a second or a third extension tube can also be present, which are then arranged telescopically between the guide tube and the first extension tube.

The first extension tube preferably has an outer surface which essentially has a rectangular cross-sectional contour. The first extension tube is most preferably cuboid-shaped and is aligned with its cross-sectionally wide side perpendicular to the direction of gravity when installed in a motor vehicle. The first extension tube can preferably be designed in several parts. It is further preferred that the first extension tube is formed from one or more shaped sheet metal parts.

Corresponding to the first extension tube, the guide tube can preferably have an inner surface that has a substantially rectangular cross-sectional contour, so that the first extension tube is accommodated in the guide tube in a translationally displaceable manner so that it cannot twist or tilt. In this context, it is also preferred that the guide tube is cuboid-shaped.

According to an advantageous embodiment of the invention, it can further be provided that the first extension tube has a base element and a cover element and the first force feedback actuator and/or the second force feedback actuator are/is fixed to the base element or the cover element, whereby the mountability of the force feedback actuators in the first extension tube can be improved.

According to a further preferred development of the invention, it can also be provided that the first force feedback actuator and/or the second force feedback actuator are designed as an electric motor or geared motor. Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the first force feedback actuator and/or the second force feedback actuator are designed as a brake, preferably as a friction brake, most preferably as a magnetorheological friction brake.

In this context, it can be provided that the first force feedback actuator and the second force feedback actuator are designed to be substantially identical, whereby the manufacturing costs can be reduced due to increased uniformity.

However, it can also be provided that the first force feedback actuator and the second force feedback actuator are designed differently from one another. In principle, this also allows a redundant system to be defined, which has the advantage that the probability of failure of two different force feedback actuators (“technology diversity”) is lower than that of two identical ones. Furthermore, for example, by combining an electric motor and a brake, optimized controls for the control unit and optimized or new force feedback "experiences" for the user can be realized. The electronics can also be designed more inexpensively, since a brake can be electrically controlled in a single phase, while a motor requires multi-phase control.

According to another particularly preferred embodiment of the invention, it can be provided that at least one first control device for supplying current to one of the force feedback actuators is arranged in the first extension tube, which also contributes to a compact design of the operating unit. Furthermore, the entire force feedback actuator system can be integrated and prefabricated in the first extension tube, which is particularly favorable in terms of assembly. In this context, it would of course also be conceivable for a first control device for supplying current to the first force feedback actuator and a second control device for supplying current to the second force feedback actuator to be arranged in the first extension tube.

According to a further preferred embodiment of the invention, at least one energy absorption element is connected to the spindle or the spindle nut, which in the event of an accident converts energy acting on the steering means in the axial retraction direction of the telescopic extension device into elastic and/or plastic deformation of the energy absorption element. Such energy absorption elements, also known as crash elements, are used in safety steering columns to enable the steering wheel (or the casing tube connected to the steering wheel) to be pushed away over a predefined path in the event of an accident. This means that when the steering wheel is extended in the event of a crash, for example, the impact on the driver's head is further mitigated and injuries are minimized.

Particularly preferably, at least one energy absorption element is provided within the extension tube. It is of course also possible for several energy absorption elements to be present in a series connection and/or parallel connection in order to increase the energy absorption capacity. It is advantageous for the majority of energy absorption elements to be designed essentially identically, which in particular brings cost advantages due to increased uniformity.

In principle, the energy absorption element can have any spatial shape that can be positioned within the extension tube and can be deformed, in particular compressed, in the event of a crash in the axial direction. It is advantageous if the outer contour of the energy absorption element rests at least partially against the inner surface of the extension tube.

According to an advantageous embodiment of the invention, it can be provided that the energy absorption element is designed as a hollow cylindrical body which surrounds the spindle in the axial direction at least in sections.

In this context, it is particularly preferred that the energy absorption element is made of a plastic, particularly preferably a glass fiber reinforced plastic. It may also be preferred that the energy absorption element is made of a porous material based on plastic or metal, which can further improve the energy absorption capabilities.

Furthermore, the invention can also be further developed in such a way that an actuator is fixed in or on the guide tube, which drives the spindle, which can also contribute to a compact structure and simplified assembly. The spindle is preferably gear-coupled to a spindle nut that is fixed in a rotationally fixed manner on or in the first extension tube, so that rotation of the spindle causes a translational relative movement between the guide tube and the extension tube. In principle, it would of course also be possible for the spindle nut to be driven by the actuator, while the spindle is designed to be rotationally fixed.

According to the invention, it is also provided that the gear arrangement has a rotatable central wheel that is arranged coaxially to a rotation axis of the steering means and can be connected to it in a rotationally fixed manner, and the central wheel is in engagement with a first gear wheel that can be subjected to torque by the first force feedback actuator and with a second gear wheel that can be subjected to torque by the second force feedback actuator. This ensures that both force feedback actuators are always coupled to the steering means, so that, for example, if one force feedback actuator fails, torque can be applied via the other.

In a further preferred embodiment of the invention, it is provided that the central wheel is made of a plastic, which can lead to advantages in terms of gear noise, weight and costs compared to a metallic design. In a further preferred embodiment, the central wheel can also be made as an internally toothed ring gear. Other gears can also be made of plastic.

It is also preferred that the gear arrangement is arranged in or on the first extension tube, so that the force feedback actuator can be completely prefabricated on or in the first extension tube.

According to the invention, the axis of rotation of the steering means is inclined relative to an axis of rotation of the first gear and/or the second gear, whereby an ergonomically particularly favorable position of the steering means can be provided for the user and a compact structure of the control unit and the entire front end with dashboard can also be realized. This inclination of the axis of rotation of the steering means is also referred to as offset.

In this context, it may be further preferred that the rotation axis of the steering means and the rotation axes of the gears are arranged parallel to the axis and in a radial plane on a triangular contour, so that the steering means can be positioned above the gears in the direction of gravity, which may help to provide a greater degree of legroom for the user when the control unit is installed. Alternatively, it would also be possible for the rotation axis of the steering means and the rotation axes of the gears to be arranged parallel to the axis and in a radial plane on a straight line, which generally allows more compact control units to be realized in terms of installation height.

The spindle and the axis of rotation of the steering device can be aligned coaxially or axially parallel to each other.

According to a further preferred embodiment of the subject matter of the invention, the central wheel can be penetrated by a hollow steering shaft which extends at least partially in the axial direction through the first extension tube, which can also have a positive influence on a compact design of the control unit. It is also possible to route electrical lines to the steering wheel or its control/display elements through this hollow shaft. In this case, it is then particularly preferred that the hollow steering shaft is rotatably mounted in a sleeve fixed to the first extension tube via two axially spaced steering shaft bearings in a tilt-resistant manner. Furthermore, the spindle can then also penetrate the sleeve axially at least partially.

Finally, the object of the invention can also be achieved by a steer-by-wire system having an operating unit according to one of claims 1-7.

The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

• 1 eine erste Ausführungsform einer längenverstellbaren Bedieneinheit in einem teleskopierten Betriebszustand in einer perspektivischen Ansicht,
• 2 eine erste Ausführungsform einer längenverstellbaren Bedieneinheit in einem teleskopierten Betriebszustand in einer ersten perspektivischen Längsschnittansicht,
• 3 eine Detailansicht auf das erste Auszugsrohr mit den Kraftrückkopplungsaktuatoren und der Getriebeanordnung in einer perspektivischen Darstellung,
• 4 eine erste Ausführungsform einer längenverstellbaren Bedieneinheit in einem teleskopierten Betriebszustand in einer zweiten perspektivischen Längsschnittansicht,
• 5 eine erste Ausführungsform einer längenverstellbaren Bedieneinheit in einem teleskopierten Betriebszustand in einer Längsschnittaufsicht.
• 6 eine zweite Ausführungsform einer längenverstellbaren Bedieneinheit in einem eingerückten Betriebszustand in einer perspektivischen Ansicht,
• 7 eine zweite Ausführungsform einer längenverstellbaren Bedieneinheit in einem eingerückten Betriebszustand in einer Längsschnittansicht,
• 8 eine zweite Ausführungsform einer längenverstellbaren Bedieneinheit in einem eingerückten Betriebszustand in einer geöffneten perspektivischen Ansicht,
• 9 eine zweite Ausführungsform einer längenverstellbaren Bedieneinheit in einem eingerückten Betriebszustand in einer ersten perspektivischen Längsschnittansicht,
• 10 eine erste Ausführungsform einer längenverstellbaren Bedieneinheit in einer Rückansicht,
• 11 eine Detaildarstellung der Getriebeanordnung in einer Frontalansicht,
• 12 zwei Detaildarstellungen von Ausführungsformen der Lenkmittelanbindung an die Getriebeanordnung in jeweils einer Seitenansicht,
• 13 eine dritte Ausführungsform einer längenverstellbaren Bedieneinheit mit einer ersten Ausführungsvariante eines Energieabsorptionselements in einem eingerückten Betriebszustand in einer perspektivischen Ansicht,
• 14 eine vierte Ausführungsform einer längenverstellbaren Bedieneinheit mit einer zweiten Ausführungsvariante eines Energieabsorptionselements in einer perspektivischen Ansicht,
• 15 eine fünfte Ausführungsform einer längenverstellbaren Bedieneinheit mit einer drittem Ausführungsvariante eines Energieabsorptionselements in zwei perspektivischen Ansichten,
• 16 ein Kraftfahrzeug mit einem Steer-by-wire-System in einer schematischen Blockschaltdarstellung.

It shows:

• 1 a first embodiment of a length-adjustable operating unit in a telescoped operating state in a perspective view,
• 2 a first embodiment of a length-adjustable operating unit in a telescopic operating state in a first perspective longitudinal sectional view,
• 3 a detailed view of the first extension tube with the force feedback actuators and the gear arrangement in a perspective view,
• 4 a first embodiment of a length-adjustable operating unit in a telescopic operating state in a second perspective longitudinal sectional view,
• 5 a first embodiment of a length-adjustable control unit in a telescopic operating state in a longitudinal sectional view.
• 6 a second embodiment of a length-adjustable operating unit in an engaged operating state in a perspective view,
• 7 a second embodiment of a length-adjustable operating unit in an engaged operating state in a longitudinal sectional view,
• 8th a second embodiment of a length-adjustable operating unit in an engaged operating state in an open perspective view,
• 9 a second embodiment of a length-adjustable operating unit in an engaged operating state in a first perspective longitudinal sectional view,
• 10 a first embodiment of a length-adjustable control unit in a rear view,
• 11 a detailed view of the gear arrangement in a front view,
• 12 two detailed representations of embodiments of the steering connection to the gear arrangement, each in a side view,
• 13 a third embodiment of a length-adjustable operating unit with a first embodiment of an energy absorption element in an engaged operating state in a perspective view,
• 14 a fourth embodiment of a length-adjustable operating unit with a second embodiment of an energy absorption element in a perspective view,
• 15 a fifth embodiment of a length-adjustable operating unit with a third embodiment of an energy absorption element in two perspective views,
• 16 a motor vehicle with a steer-by-wire system in a schematic block diagram.

The 1-5 show a first embodiment of a length-adjustable operating unit 1 for influencing a driving direction of a motor vehicle 2 by a user, comprising a telescopic extension device 4 with a guide tube 5, in or on which at least a first extension tube 6 is guided relative to the guide tube 5 and can be displaced in translation by means of a rotatable spindle 8, which runs axially at least in sections in the first extension tube 6. As can be seen from the 1 As can be clearly seen, the first extension tube 6 and the guide tube 5 are cuboid-shaped, with the extension tube 6 being guided within the guide tube 5 in a translationally displaceable manner.

Such an operating unit is provided for a steer-by-wire system 50 of a motor vehicle 2, as is also shown by way of example in the 16 can be seen. The steering movements of the steering device 7 are transmitted electrically (“by-wire”) to an RWA 51 (road wheel actuator), which then actuates the vehicle wheels accordingly.

The telescopic extension device 4 can be coupled on the one hand to a steering means 7, which can be subjected to torque via an output shaft 9 of a gear arrangement 10 with a first force feedback actuator 11, which is coupled to a first input shaft 12 of the gear arrangement 10, and can be subjected to torque with a second force feedback actuator 13, which is coupled to a second input shaft 14 of the gear arrangement 10.

The first force feedback actuator 11 and the second force feedback actuator 13 are arranged in the first extension tube 6. The first force feedback actuator 11 and the second force feedback actuator 13 are designed as identical electric motors in the embodiment shown. In principle, it would also be conceivable for the first force feedback actuator 11 and the second force feedback actuator 13 to be designed differently from one another, for example one of the actuators as an electric motor and the other as a magnetorheological friction brake.

Furthermore, a first control device 18 for supplying current to the first force feedback actuator 11 and a second control device 19 for supplying current to the second force feedback actuator 13 are arranged in the first extension tube 6. This can also be clearly seen from a summary of the 4 , 5 and 10 recognize.

The first extension tube 6, which is made of several parts and formed from a sheet metal, has an outer surface which essentially has a rectangular cross-sectional contour. 3 It is also clearly visible that the first extension tube 6 has a base element 61 and the first force feedback actuator 11 and the second force feedback actuator 13 are fixed to the base element 61. The base element 61 has a first wall section 64 which extends essentially at right angles from a base plate 63 and to which the first force feedback actuator 11 and the second force feedback actuator 13 are fixed or their axial position is defined.

In the 2 it is shown that an actuator 15 is fixed in or on the guide tube 5, which drives the spindle 8. The spindle 8 is gear-coupled to a spindle nut 16 fixed on or in the first extension tube 6, so that a rotation of the spindle 8 causes a translational relative movement between the guide tube 5 and the extension tube 6. The spindle 8 and the axis of rotation 21 of the steering means 7 can be aligned coaxially or axially parallel to one another.

The gear arrangement 10, like the force feedback actuators 11, 13 and the control devices 18, 19, is arranged in or on the first extension tube 6. The gear arrangement 10 has a rotatable central wheel 20 that is arranged coaxially to a rotation axis 21 of the steering means 7 and can be connected to it in a rotationally fixed manner. The central wheel 20 is thereby in engagement with a first gear 22 that can be subjected to torque by the first force feedback actuator 11 and with a second gear 23 that can be subjected to torque by the second force feedback actuator 13.

In the 6-9 a further embodiment of an operating unit is shown in which the guide tube 5 has an inner surface which has a substantially trapezoidal cross-sectional contour and that the extension tube 6 has a has a corresponding outer surface, which also has a substantially trapezoidal cross-sectional contour.

In this second embodiment of an operating unit 1, the central wheel 20 is penetrated by a hollow steering shaft 29, which extends at least partially in the axial direction through the first extension tube 6. The hollow steering shaft 29 is rotatably mounted in a sleeve 30 fixed to the first extension tube 6 via two axially spaced steering shaft bearings 31. The spindle 8 extends axially through the sleeve 30 at least partially. An energy absorption element 32 is fixed to the sleeve 30 and is supported on the actuator 15 in the axial direction.

Based on 11 It is easy to understand that the rotation axis 21 of the steering means 7 and the rotation axes 24, 25 of the gears 22, 23 can be arranged in a radial plane 26 on a triangular contour 28. This allows the steering means 7 to be moved upwards against the direction of gravity, which allows the user more legroom when the control unit 1 is installed.

In the 12 Two possible configurations of the steering means connection to the gear arrangement 10 are shown, in which the lower figure b shows an embodiment in which the axis of rotation 21 of the steering means 7 is inclined relative to an axis of rotation 24,25 of the first gear 22 and the second gear 23. This is sometimes also referred to as offset. In contrast to this, the axis of rotation 21 of the steering means 7 and the axes of rotation 24,25 of the gears 22,23 are arranged axially parallel in the embodiment of figure a (above).

The 13-15 show further embodiments of operating units with different energy absorption elements 32, which are sometimes also referred to as crash elements.

In the 13 a plate-shaped energy absorption element 32 with a rib structure is shown, which is supported on the one hand on the guide tube 5 and on the other hand on the first extension tube 6.

In the embodiments of the 14-15 An energy absorption element 32 is fixed to the spindle nut 16, which is supported on the first extension tube 6 in the axial direction. The 15 The energy absorption element 32 shown is guided axially through the guide 65, which is formed by means of a punching and bending of the cover element 62.

The invention is not limited to the embodiments shown in the figures. The above description is therefore not to be regarded as restrictive, but as explanatory. The following patent claims are to be understood in such a way that a named feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. If the patent claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a ranking.

List of reference symbols

1

Control unit

2

Motor vehicle

4

Extractor

5

Guide tube

6

Extension tube

7

Steering means

8th

spindle

9

Output shaft

10

Gear arrangement

11

Force feedback actuator

12

Input shaft

13

Force feedback actuator

14

Input shaft

15

Actuator

16

Spindle nut

18

Control device

19

Control device

20

Central wheel

21

Rotation axis

22

gear

23

gear

24

Rotation axis

25

Rotation axis

26

Radial plane

28

Triangle contour

29

Hollow steering shaft

30

Sleeve

31

Steering shaft bearing

32

Energy absorption element

50

Steer-by-wire system 51 RWA

61

Floor element

62

Cover element

63

Base plate

64

Wall section

65

guide

Claims (8)

Length-adjustable operating unit (1) for influencing a driving direction of a motor vehicle (2) by a user, comprising a telescopic extension device (4) with a guide tube (5), in or on which at least a first extension tube (6) is guided relative to the guide tube (5) and can be displaced in translation by means of a rotatable spindle (8) or spindle nut (16), wherein the telescopic extension device (4) can be coupled on the one hand to a steering means (7) which can be subjected to torque via an output shaft (9) of a transmission arrangement (10) to a first force feedback actuator (11) which is coupled to a first input shaft (12) of the transmission arrangement (10) and can be subjected to torque by at least one second force feedback actuator (13) which is coupled to a second input shaft (14) of the transmission arrangement (10), wherein the first force feedback actuator (11) and the second Force feedback actuator (13) are arranged in the first extension tube (6), and wherein the gear arrangement (10) has a rotatable central wheel (20) which is arranged coaxially to a rotation axis (21) of the steering means (7) and can be connected to it in a rotationally fixed manner, and the central wheel (20) is in engagement on the one hand with a first gear (22) to which torque can be applied by the first force feedback actuator (11) and on the other hand with a second gear (23) to which torque can be applied by the second force feedback actuator (13), characterized in that the rotation axis (21) of the steering means (7) is inclined with respect to a rotation axis (24, 25) of the first gear (22) and/or the second gear (23). Length-adjustable control unit (1) according to Claim 1 , characterized in that the first extension tube (6) has a base element (61) and a cover element (62) and the first force feedback actuator (11) and/or the second force feedback actuator (13) are fixed to the base element (61) or the cover element (62). Length-adjustable control unit (1) according to Claim 1 or 2 , characterized in that the first force feedback actuator (11) and/or the second force feedback actuator (13) are designed as electric motors. Length-adjustable operating unit (1) according to one of the preceding claims, characterized in that at least one energy absorption element (32) is connected to the spindle (8) or the spindle nut (16), which in the event of an accident converts energy acting in the axial retraction direction of the telescopic extension device (4) with respect to the steering means (7) into elastic and/or plastic deformation of the energy absorption element (32). Length-adjustable operating unit (1) according to one of the preceding claims, characterized in that at least one first control device (18) for supplying current to at least one of the force feedback actuators (11, 13) is arranged in the first extension tube (6). Length-adjustable operating unit (1) according to one of the preceding claims, characterized in that an actuator (15) is fixed in or on the guide tube (5), which drives the spindle (8) of a spindle drive or the spindle nut (16) of a spindle drive. Length-adjustable control unit (1) according to one of the previous Claims 1 - 6 , characterized in that the central wheel (20) is penetrated by a hollow steering shaft (29) which extends at least partially in the axial direction through the first extension tube (6) Steer-by-wire system (50) of a motor vehicle (2) comprising a length-adjustable operating unit (1) according to one of the Claims 1 - 7 .

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