BE1030038B1 - Steer-by-wire steering column for a motor vehicle - Google Patents

Abstract

The present invention relates to an adjustable steer-by-wire steering column (1) for a motor vehicle, comprising a casing unit (5) in which a steering spindle (51) is rotatably mounted about a longitudinal axis (L) running in the longitudinal direction, and the one outer casing (53), an intermediate casing (54) and an inner casing (55), the intermediate casing (54) being accommodated in the outer casing (53) and the inner casing (55) being telescopically adjustable in the intermediate casing (54), the casing unit (5) has an electromotive feedback actuator (6) which is designed to generate and introduce a feedback torque into the steering spindle (51), and the jacket unit (5) has an adjustment drive (8) which has a motor drive unit (81). and is designed for the relative adjustment of the outer shell (53), intermediate shell (54) and inner shell (55). In order to enable improved stowage and to provide a more compact design in the operating area, the invention proposes that the feedback actuator (6) be attached to the intermediate casing (54).

Description

t BE2022/5628

Steer-by-wire steering column for a motor vehicle

State of the art

The invention relates to an adjustable steer-by-wire steering column for a motor vehicle, comprising a jacket unit in which a steering spindle is mounted so that it can rotate about a longitudinal axis running in the longitudinal direction, and which has an outer jacket, an intermediate jacket and an inner jacket has, wherein the intermediate shell is telescopically adjustable in the outer shell and the inner shell in the intermediate shell, the shell unit having an electromotive feedback actuator which is designed to generate and introduce a feedback torque in the steering spindle, and the shell unit has an adjustment drive , which has a motorized drive unit and is designed for the relative adjustment of the outer jacket, intermediate jacket and inner jacket.

The steering column includes a steering spindle on which a steering handle, for example a steering wheel for manual input of steering commands by rotating the steering spindle, is attached to steer a motor vehicle in the operating position relative to the direction of travel. The steering spindle is mounted in a casing unit so that it can rotate about a longitudinal axis running in the longitudinal direction. In steer-by-wire steering systems, an angle of rotation and/or a torque of a steering command introduced into the steering shaft is detected by means of an electric rotary sensor, and an electric control signal generated from this is sent to a steering actuator, which uses an electric actuator to set a corresponding Adjusts the steering angle of the steerable wheels. In autonomous driving with self-driving vehicles, in which no manual

steering input, the electric steering control signals can be supplied by an electronic

Control unit are provided.

To create a realistic driving experience, the casing unit has an electromotive

feedback actuator on. From an actual current driving situation, parameters such as vehicle speed, steering angle, steering reaction torque and the like are recorded or calculated in a simulation, and a feedback signal is formed from these variables, with which the feedback actuator is controlled. Depending on the feedback signal, this generates a restoring torque corresponding to the real reaction torque, which is fed into the steering wheel as a feedback torque via the steering spindle. Such "force feedback" systems give the driver the impression of a real driving situation, as with a conventional, mechanically coupled steering system, which facilitates an intuitive reaction.

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A generic steering column of the type mentioned is for example from

EP 3 341 262 B1. This has an inner shell from which the steering shaft with the

Steering handle protrudes backwards toward the driver's position, which is accommodated in a longitudinally telescopically adjustable manner in an intermediate casing, which in turn is accommodated in a telescopically adjustable manner in an outer casing. For comfort adjustment, the steering wheel can be adjusted back and forth within an operating range into an optimal operating position relative to the driver's position in the longitudinal direction, preferably by a linear motorized adjustment drive. To stow the steering column in autonomous driving mode, when there is no manual steering intervention, the intermediate casing and the inner casing can be retracted into the outer casing as far as possible by means of the adjustment drive, whereby the casing unit is shortened as much as possible in the longitudinal direction. As a result, the steering wheel can be stowed in a stowed position outside of the operating position in order to release the operating area in the vehicle interior for other uses. The generic multiple telescopic arrangement enables an advantageous shortening of the shell unit. Due to the fact that the feedback actuator is fixed to the outer jacket, the installation space required in the stowed position and in particular within the operating area is relatively large even when the jacket unit is fully retracted.

A steer-by-wire steering column of the type mentioned above is known from DE 10 2019 200 908 A1.

In view of the problems explained above, it is an object of the present invention to enable improved stowage and to provide a more compact design in the operating area.

Presentation of the invention

This object is achieved according to the invention by the steering system with the features of claim - claim 1. Advantageous developments result from the dependent claims.

In an adjustable steer-by-wire steering column for a motor vehicle, comprising a jacket unit, in which a steering shaft is rotatably mounted about a longitudinal axis running in the longitudinal direction, and which has an outer jacket, an intermediate jacket and an inner jacket, wherein the Intermediate shell in the AuBenmantel and the inner shell in the intermediate shell is accommodated telescopically adjustable, the shell unit an electric motor

> BE2022/5628

Has a feedback actuator which is designed to generate and introduce a feedback torque into the steering spindle, and the jacket unit has an adjusting drive which has a motorized drive unit and is designed for the relative adjustment of the outer jacket,

Intermediate casing and inner casing, the invention provides that the feedback actuator is attached to the intermediate casing.

In the following, the terms "longitudinal" and "axial" are synonymous to designate the

used longitudinally. In the installation position, the longitudinal direction points from back to front with respect to the direction of travel, the steering wheel being attachable at the rear end of the inner casing, and the intermediate casing and the outer casing being arranged at the front with respect to the inner casing. Inside-. The intermediate and outer jackets are collectively referred to as the jackets for short.

According to the invention, the feedback actuator is fixed to the intermediate jacket tube, preferably on the face side in the front end area. Correspondingly, it can be adjusted in the longitudinal direction together with the intermediate jacket relative to the outer jacket. As a result, a smaller construction volume of the outer jacket can be realized. In particular, because the feedback actuator is no longer arranged on the front side on the outer shell, as in the prior art mentioned at the outset, a shortened axial overall length of the shell unit can be achieved. The feedback actuator can advantageously be attached coaxially to the intermediate casing, with it not protruding radially or less radially outwards from the outer casing as seen from the longitudinal axis, so that a slimmer one that saves additional space Execution of the jacket unit and thus the entire steering column is made possible. This results in improved and expanded options for utilizing the space available in the vehicle interior for stowage of the steering column. Alternatively, due to the more compact design with the same volume, increased safety functions, for example larger

Crumple zones are provided.

An advantageous development provides that the outer jacket has a continuous through-opening in the longitudinal direction, from which the intermediate jacket can be adjusted forwards and backwards with respect to the longitudinal direction. The intermediate casing is mounted in the through-opening so that it can be displaced longitudinally. The outer shell is shorter in the longitudinal direction than the intermediate shell, at least in the area of the through-opening, and thus extends only over an axial section of the intermediate shell. In contrast to the prior art, in which the intermediate casing only protrudes backwards out of the outer casing and accordingly can only be extended backwards out of the outer casing, the intermediate casing according to the invention penetrates the lengthwise between a front and a rear end the through-opening is completely open in the outer shell

' BE2022/5628 and protrudes axially in both directions, i.e. forwards and backwards, from the through hole. As a result, the intermediate casing can be moved forwards and backwards out of the through opening with respect to the longitudinal direction. Thus, the intermediate coat is not as in

State of the art can only be moved in one direction to the rear, but longitudinally in both directions to the front and to the rear beyond the outer casing. By compared to

State of the art shorter outer shell, space can be saved, and there are expanded design possibilities for the integration of the steering column.

In the above embodiment, the feedback actuator is on one side axially in front of the

Outer shell arranged, and the inner shell is on the other side to the rear from the outer shell. This arrangement has the advantage that the transverse forces and moments occurring during the steering input can be effectively absorbed by the outer jacket and supported on the vehicle body with a reduced installation space requirement.

Provision can preferably be made for the motorized drive unit of the adjustment drive to be attached to the outer casing. The adjusting drive has at least one linear drive which acts on the casings in the longitudinal direction. This can preferably be done in a manner known per se

Way be designed as a spindle drive, in which a in a spindle nut and a threaded spindle axially engaging therein are driven by a motor drive unit to rotate relative to each other. Depending on the design, the spindle nut supported axially on the drive unit is driven in rotation in a plunger spindle drive, and the threaded spindle that is rotationally fixed relative to it is moved linearly, or in the case of a rotary spindle drive, the threaded spindle supported axially on the drive unit is driven in rotation and the threaded spindle relative to it rotationally fixed spindle nut is moved linearly. In any case, the drive unit has an electric motor and gearing means for transmitting the motor torque to the spindle drive. In the case of the invention, it is advantageous that the adjustment drive can act axially on both sides of the outer casing, directly or indirectly, on the intermediate casing, resulting in expanded design possibilities for optimized use of the installation space. It is conceivable to also use other types of linear adjusting drives, for example toothed belt, belt or rack and pinion drives or the like.

It can be provided that the adjusting drive is arranged between the outer shell and the inner shell in terms of effect. Because the adjustment drive acts directly on the inner casing, for example, the operating position of the steering wheel mounted thereon can be set directly relative to the outer casing. In order to enable a controlled adjustment of the inner casing relative to the intermediate casing, it can be temporarily fixed axially relative to the outer casing, for example by means of a blocking or locking device. The

> BE2022/5628 adjusting drive acting on the inner casing can thus also be used to move the intermediate casing relative to the outer casing. For this purpose, the inner casing is fixed axially relative to the intermediate casing, and the fixing of the intermediate casing on the outer casing is released, so that it can be moved forward together with the inner casing by the adjusting drive into the stowed position, or vice versa out of the stowed position to the operating position. For example, the locking device can be designed to be switchable in such a way that it selectively locks the intermediate jacket axially on the outer jacket or on the inner jacket. An actuation sequence can be specified, so that, for example, the inner casing, which is extended to the rear in the operating position, is first fully retracted forwards into the intermediate casing locked with the outer casing when stowed, and then the intermediate casing is unlocked from the outer casing by switching the locking or locking device and the inner shell is locked to the intermediate shell so that the intermediate shell can be moved relative to the outer shell. A benefit of this

The arrangement is that a single adjustment drive is sufficient for stowing and adjusting the steering column _.

A further possibility is that the adjustment drive has a stowage drive which is functionally arranged between the outer shell and the intermediate shell. This

The stowage drive can be designed as a separate linear drive, which is preferably used exclusively to move the intermediate casing together with the feedback actuator attached thereto and the actuating unit formed from the inner casing and the steering spindle relative to the

To bring Benmantel from the operating to the stowed position, or vice versa. The stowage drive is preferably provided in addition to an adjustment drive which is functionally located between the outer shell and the inner shell or between the intermediate shell and the

Inner shell is arranged, which is then used exclusively for adjusting the inner shell relative to the outer or intermediate shell.

In principle, the adjustment and stowage drive can be designed in the same way, for example as a

spindle drives. However, it can be advantageous for the stowage drive to be more powerful in order to be able to move the greater inertial mass of the intermediate casing including the feedback actuator and inner casing as quickly as possible between the operating and stowage positions. The adjustment drive for adjusting the operating position can then be designed to be relatively small and light.

This advantageously enables optimization of the weight, installation space and energy requirement.

° BE2022/5628

It is expedient that an electrical rotation sensor is provided for detecting the rotation of the steering shaft relative to the jacket unit. The rotation sensor can preferably have a rotation angle sensor and/or a torque sensor, with which the angle of rotation of the steering spindle introduced and the manual torque applied in the process are recorded when a steering command is entered manually. These measured variables are used to control the steering actuators to generate a steering angle of the steerable wheels, and also to control the feedback actuator.

It can be advantageous for an energy absorption device to be arranged between the outer jacket and the intermediate jacket. If, in the event of a crash, a body hitting the steering wheel exerts a high longitudinal force on the steering spindle that exceeds a predetermined limit value, the jackets are pushed together like a telescope. In the energy absorption device, which is coupled between the jackets, the kinetic energy introduced by the relative movement is absorbed and converted into deformation work, so that the body hitting the steering wheel is braked in a controlled manner and the risk of injury is reduced.

The energy absorption device can have an energy absorption element arranged directly or indirectly between the outer shell and the intermediate shell. A deformation section of the energy absorbing element is caused by the relative movement between

In the event of a crash, the benmantel and actuating unit are plastically deformed with the absorption of kinetic energy, for example by bending over a bending lug, separating a tearing lug, widening a slit or the like. Friction elements can also be provided which convert kinetic energy into frictional heat. Such and other energy absorption elements and combinations thereof are known in principle from the prior art.

An advantageous embodiment can provide that the energy absorption device is arranged between the adjustment drive and the outer casing. For example, an energy absorption element, as described above, can be integrated between the drive unit of the adjustment drive and the outer casing. As a result, an optimized use of space can take place, and the constructive possibilities are expanded.

It is also conceivable and possible to integrate an energy absorption device into the adjustment drive, for example by means of a deformable device or one that can be displaced with energy absorption

Threaded spindle or spindle nut.

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An advantageous embodiment provides that the outer shell is held by a support unit. The support unit is used to mount the steering column in the motor vehicle and has connecting means for fastening the steering column to a vehicle body and holds the outer casing fixed to the vehicle body at least in the longitudinal direction. Due to the arrangement according to the invention, the intermediate casing together with the feedback actuator can be adjusted relative to the support unit. This expands the design options and enables improved use of the installation space.

Provision can be made for the jacket unit to be adjustable in a vertical direction transverse to the longitudinal axis relative to the support unit. To adjust the height, the casing unit can, for example, be pivotably mounted about a pivot axis lying transversely to the longitudinal axis, so that the steering wheel attached to the rear end of the steering spindle can be adjusted in height relative to the

Driver's position can be adjusted. The height can be adjusted manually. In particular for automated stowage of the steering column during autonomous driving, it is advantageous for an electromotive height adjustment drive to be arranged between the casing unit and the support unit, by which the casing unit can be moved up or down relative to the support unit.

A height adjustment drive can be implemented, for example, by an electric motor-driven spindle drive, as described above for the longitudinal adjustment. In order to fix the vertical position, it can be provided that the jacket unit can be releasably clamped to the support unit by means of a clamping device, as explained above for the longitudinal adjustment.

It is possible for an energy absorption device to be arranged between the outer casing and the support unit. In the event of a crash, when a high force is exerted on the jacket unit via the steering spindle, this can absorb kinetic energy when the jacket unit moves relative to the support unit. The energy absorption device can be effective in the longitudinal and/or vertical direction and can in principle be constructed in a similar way to that described above for the energy absorption device arranged between the outer jacket and the intermediate jacket.

Provision can be made for the carrying unit to have a storage housing. The stowage housing includes connection means for connection to the vehicle body, and has a

Storage space that extends forward from the front end of the outer shell in the longitudinal direction. The intermediate casing, which protrudes forward from the outer casing when stowed away, can be accommodated in the storage space with the feedback actuator attached to it.

In addition, it can have an energy-absorbing crumple zone and/or allow the receiving unit to be immersed in an energy-absorbing manner. In this case, the stowage housing

3 BE2022/5628 have a bulge or depression formed forward relative to the bulkhead that delimits the vehicle interior at the front, which bulge or depression has the storage space. This allows the retracted intermediate jacket to be stowed outside the vehicle interior.

The outer jacket, the intermediate jacket and the inner jacket can each have a jacket tube or be designed as a jacket tube. The casing pipes can be of known type

way be nested and guided. As already mentioned above, the

The outer jacket tube is shorter than the intermediate jacket tube, with the intermediate jacket tube preferably passing through a through opening in the outer jacket and protruding axially in both directions out of the outer jacket tube and being movable. In other words, it forms

Outer jacket pipe a kind of pipe sleeve, which surrounds the intermediate jacket pipe and into both

Directions on it is axially movable back and forth. An advantage of the tubular shells is the high rigidity of the telescope assembly with a compact design. In addition, the production from pipe sections can be carried out efficiently and inexpensively.

Provision can be made for the casing tube to have a round or non-round cross section. The tube cross-section can be round, non-round or polygonal. In this case, the inner cross-section of the respectively outer jacket tube is adapted to the outer cross-section of the jacket tube accommodated on the inside in order to form a telescopic guide. A linear sliding or rolling element guide can be arranged between the jacket tubes. By adapting the tube cross section, an advantageously high rigidity and natural frequency of the jacket unit can be achieved.

Description of the drawings

Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. Show in detail:

FIG. 1 shows a schematic representation of a steer-by-wire steering system,

FIG. 2 shows a steering column according to the invention in a schematic perspective view,

FIG. 3 shows a side view of the steering column according to FIG. 2 in the operating position,

FIG. 4 shows a side view of the steering column according to FIG. 2 in the stowed position.

Embodiments of the invention

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

The directional information relates to the normal direction of travel of a vehicle, not shown in detail, with the longitudinal direction forwards being indicated in the figures as direction V with an arrow, and correspondingly backwards in the opposite direction H.

Figure 1 shows schematically a steer-by-wire steering system 1, which is an inventive

Includes steering column 2, which is connected to an electric steering drive 4 via an electric control line 3.

The steering drive 4 includes a servomotor 41 which is connected to the control line 3 and introduces a steering actuating torque into a steering gear 42 . There the steering actuating torque is converted into a translational movement of tie rods 45 via a pinion 43 and a toothed rack 44, whereby a steering angle of the steered wheels 46 is effected in a manner known per se by pivoting steering knuckles. Alternatively, the steered

Wheels 46 can be connected to individually controllable electric actuators in order to implement single-wheel steering.

The steering column 2 has a casing unit 5 in which a steering spindle 51 is mounted so as to be rotatable about a longitudinal axis L pointing from the back to the front in the longitudinal direction. A steering wheel 52 is attached to the rear end.

The shell unit 5 has a feedback actuator 6, which has an electric motor drive, not shown here, which is connected to the steering spindle 51 for coupling in a feedback moment.

The shell unit 5 is held by a support unit 7 which has connecting means for attaching the steering column 2 to a vehicle body, not shown.

In Figure 2, the steering column 2 is separately in a perspective view in an extended

Operating position shown, and in Figure 3 in a side view. Figure 4 shows a view like

Figure 3 with the steering column 2 in the stowed position.

At its rear end region, the steering shaft 51 has a fastening section 510 to which the steering wheel 52 can be attached.

The jacket unit 5 has an outer jacket 53, an intermediate jacket 54 and an inner jacket 55, which are arranged such that they can be adjusted telescopically in the longitudinal direction, as indicated by the double arrow. The casings 53, 54, 55 each have a casing tube which has a polygonal cross-section in the case of the intermediate casing 54 and is round in the case of the inner casing 55.

According to the invention, the feedback actuator 7 is attached to the intermediate casing 54 at the front on the face side.

A linear adjustment drive 8 , which is designed as a plunger spindle drive in the example shown, has an electromotive drive unit 81 which is attached to the outer casing 53 . The drive unit 81 has a longitudinally supported spindle nut 82, which is supported in the longitudinal direction and can be driven in rotation about a spindle axis parallel to the longitudinal axis L

Area of the inner shell 55 is connected.

It can be seen in FIGS. 3 and 4 that the outer jacket 53 is significantly shorter than the intermediate jacket 54, viewed in the longitudinal direction.

Benmantel 53 continuous passage, so that it can be moved forwards and backwards from the outer shell 53 out.

FIG. 3 shows an adjustment state in the operating position, in which the intermediate jacket 54 is extended to the rear, to the right in the drawing, out of the outer jacket 53, and the inner jacket 55 is also extended out of the intermediate jacket 54 to the rear. The steering wheel 51 attached to the attachment section 510 is in this operating position

Input of manual steering commands in an operating area accessible from the driver's position. The feedback actuator 6 is on the intermediate shell 54 in front of the front end of the Au-

Benmantels 53 arranged.

By adjusting the inner shell 8 55 to the rear, in the drawing to the left, are retracted into the intermediate shell 54, and the intermediate shell 54 is through the

The passage of the outer casing 53 is retracted forwards, as indicated by the arrow in FIG. 3, until the stowed state shown in FIG. 4 is reached.

The outer casing 53 is supported and fixed on the support unit 7 in the longitudinal direction. This can have a stowage housing 71 which is shown schematically in a box shape in FIGS. 3 and 4 and encloses a stowage space 72 . During stowage, the intermediate jacket 54 together with the feedback actuator 6 attached to it at the front can dip into this until the stowage position shown in FIG. 4 is reached.

A locking device (not shown here) can be provided, through which the intermediate jacket 54 can be locked to the outer jacket 53 in the longitudinal direction, so that the inner jacket 55 alone can be adjusted by means of the adjustment drive 8 to adjust the operating position. For stowage, the inner casing 55 can be locked with the intermediate casing 54 in the retracted state, and the intermediate casing 54 can be unlocked from the outer casing 53 so that it can be moved into the stowed position.

Alternatively, a stowage drive can also be provided, which can include a linear drive acting between the outer jacket 53 and the intermediate jacket 54, for example also a motorized spindle drive.

LIST OF REFERENCE NUMERALS 1 steering system 2 steering column (input unit) 3 control line 4 steering drive 41 servomotor 42 steering gear 43 pinion 44 toothed rack 45 tie rod 46 wheel 5 jacket unit 51 steering spindle 510 fastening section 52 steering wheel 53 outer jacket 54 intermediate jacket 55 inner jacket 6 feedback actuator 7 support unit 71 storage housing 72 storage space 8 adjustment drive 81 drive unit 82 spindle nut 83 threaded spindle

L longitudinal axis

V direction forward

H backward direction

Claims (15)

PATENT CLAIMS 1. Adjustable steer-by-wire steering column (1) for a motor vehicle, comprising a casing unit (5) in which a steering spindle (51) is rotatably mounted about a longitudinal axis (L) running in the longitudinal direction, and the an outer shell (53), an intermediate shell (54) and an inner shell (55), the intermediate shell (54) being telescopically received in the outer shell (53) and the inner shell (55) in the intermediate shell (54). is, wherein the casing unit (5) has an electromotive feedback actuator (6) which is designed to generate and introduce a feedback torque into the steering spindle (51), and the casing unit (5) has an adjusting drive (8). , which has a motor drive unit (81) and is designed for the relative adjustment of the outer shell (53), intermediate shell (54) and inner shell (55), characterized in that the feedback actuator (6) on the intermediate shell (54) is attached. 2. Steering column according to claim 1, characterized in that the outer jacket (53) has a continuous through opening in the longitudinal direction, from which the intermediate jacket (54) can be adjusted forwards and backwards with respect to the longitudinal direction. 3. Steering column according to one of the preceding claims, characterized in that the motor drive unit (81) of the adjusting drive (8) is attached to the outer casing (53). 4. Steering column according to one of the preceding claims, characterized in that the adjusting drive (8) is arranged operatively between the outer jacket (53) and the inner jacket (55). 5. Steering column according to one of the preceding claims, characterized in that an adjusting drive (8) has a stowage drive which is operatively arranged between the outer casing (53) and the intermediate casing (54). 6. Steering column according to one of the preceding claims, characterized in that an electrical rotation sensor is provided for detecting the rotation of the steering shaft (51) relative to the casing unit (5). 7. Steering column according to one of the preceding claims, characterized in that an energy absorption device is arranged between the outer jacket (53) and the intermediate jacket (54). 8. Steering column according to one of the preceding claims, characterized in that the outer jacket (53) is held by a support unit (7). 9. Steering column according to claim 8, characterized in that the casing unit (5) is adjustable in a vertical direction transverse to the longitudinal axis (L) relative to the support unit (7). 10. Steering column according to one of the preceding claims 8 to 9, characterized in that between the outer casing (53) and the support unit (7) a motorized height adjustment drive is attached. 11. Steering column according to one of the preceding claims 8 to 10, characterized in that an energy absorption device is arranged between the outer jacket (53) and the support unit (7). 12. Steering column according to one of the preceding claims, characterized in that the support unit (7) has a storage housing (71). 13. Steering column according to one of the preceding claims, characterized in that the outer shell (53), the intermediate shell (54) and the inner shell (55) each have a jacket tube or are designed as a jacket tube. 14. Steering column according to claim 13, characterized in that the jacket tube has a round, polygonal or non-round cross-section. 15. Steering column according to one of claims 1 to 5, characterized in that the energy absorption device is arranged between the adjustment drive (8) and the outer jacket (53).