WO2020025284A1

WO2020025284A1 - Electromotively adjustable steering device

Info

Publication number: WO2020025284A1
Application number: PCT/EP2019/068658
Authority: WO
Inventors: Renee Dietzel; Frank Gömmel
Original assignee: Brose Fahrzeugteile Gmbh & Co. Kommanditgesellschaft, Coburg
Priority date: 2018-07-31
Filing date: 2019-07-11
Publication date: 2020-02-06
Also published as: DE102018212738A1

Abstract

The invention relates to an electromotively adjustable steering device (6) of a land-bound motor vehicle (2), having a steering column (10), to which a steering wheel (8) is attached for conjoin rotation, and having an electromotive drive (18), which has an electric motor (30) and a variable-length component (24). The variable-length component (24) is driven by means of the electric motor (30) and is attached to the steering column (10) by means of a fastening device (22). The variable-length component (24) extends from the fastening device (22) in the direction of the steering wheel (8). The invention furthermore relates to a land-bound motor vehicle (2).

Description

description

Steering device adjustable by electric motor

The invention relates to an electromotively adjustable steering device of a land-based motor vehicle, with a steering column to which a steering wheel is connected in a rotationally fixed manner. The invention further relates to a land-based motor vehicle.

Motor vehicles usually have front wheels, by means of which a desired direction of the motor vehicle is set. For this purpose, the front wheels are usually coupled to a steering device that has a steering wheel. The driver of the motor vehicle uses the steering device to set the desired direction. For this purpose, a steering wheel rim of the steering wheel is rotated so that the front wheels point in the desired direction. The steering wheel rim itself is usually positioned at chest height in front of the driver of the motor vehicle, so that the driver can grasp the steering wheel rim comparatively easily.

During operation, it should be possible for the driver to be able to exert a comparatively large force on the steering wheel rim, in particular if steering assistance fails. Therefore, the steering wheel rim should usually be at a distance of approx. 35 cm in front of the driver's chest. At such a distance, the comfort for the driver is also increased. Since motor vehicles are not always moved by drivers of the same size, it is necessary to adjust the position of the steering wheel appropriately. In particular, an inclination of the steering wheel and the complete steering column is set. A change in length is also known, that is to say a longitudinal adjustment of the steering column along its course. Here, for example, a lock is released manually and the steering wheel and the steering column are pivoted in a suitable manner. To increase comfort, such an adjustment is carried out increasingly electrically. Also Security is increased because a position of any airbag of the steering device can be ideally adjusted. Here, the steering device has one or more electric motor drives, by means of which the steering column is suitably moved. For reasons of space, the electric motor and / or an electric motor gear unit having the electric motor is usually relatively far apart from the steering wheel.

The invention is based on the object of specifying a particularly suitable electromotively adjustable steering device of a land-based motor vehicle and a particularly suitable land-bound motor vehicle, in particular increasing safety and expediently reducing the weight and / or the manufacturing costs.

With regard to the steering device, this object is achieved according to the invention by the features of claim 1 and with respect to the motor vehicle by the features of claim 7. Advantageous further developments and refinements are the subject of the respective subclaims.

The electric motor-adjustable steering device is part of a land-bound motor vehicle. When used as intended, the land-based motor vehicle is thus moved ashore. In this case, the motor vehicle is expediently independent of a lane, but is particularly preferably moved along a lane which is made, for example, of asphalt / tar. The land-bound motor vehicle expediently comprises a number of wheels which stand on a floor and by means of which contact with the land is realized. The land-based motor vehicle is preferably a passenger vehicle (passenger car) or a commercial vehicle, such as a truck or a bus. During operation, in particular by a driver of the land-bound motor vehicle, the steering motor is used to set a direction in which the land-bound motor vehicle is moved during operation. The electric motor-adjustable steering device is suitable for this, in particular provided and set up. In other words, the electromotively adjustable steering device serves for the control movement of the land-based motor vehicle and in particular for the selection and / or setting of a direction of movement / direction of movement. For this purpose, the steering device which can be adjusted by an electric motor is expediently coupled to wheels of the land-based motor vehicle. In particular, the electromotively adjustable steering device comprises a toothed rack or is provided to be coupled to a toothed rack. In the assembled state, the rack is connected to at least one of the wheels of the land-bound motor vehicle, preferably two of the wheels, in particular the front wheels, so that a steering angle of the wheels is changed when the rack is shifted by a certain range. For example, the electric motor-adjustable steering device is coupled or provided with a pinion, which is operatively connected to the toothed rack, if any. For example, the electric motor-adjustable steering device includes a steering support, in particular a so-called power steering unit. Alternatively, the pinion is driven by an electric motor, which is controlled in the case of example on the basis of electrical signals. The electrical signals are generated at least in part by means of the electromotively adjustable steering device.

The electric motor-adjustable steering device has a steering column and a steering wheel connected to it in a rotationally fixed manner. For example, the steering column section is coupled to the possible pinion or a sensor for recording the position of the steering wheel rim. The steering column is expediently mounted rotatably about an axis of rotation. The steering wheel is thus also rotatably mounted about the axis of rotation by means of the steering column. The steering wheel includes, for example, a hub which is surrounded on the circumference by a steering wheel rim. The steering wheel rim is connected to the hub by means of a number of spokes, for example, and is preferably in one piece with the hub. The steering wheel, expediently the steering wheel rim, is suitable, in particular provided and set up, to be operated at least temporarily by a driver of the motor vehicle. By turning the steering wheel about the axis of rotation, a control movement is carried out during operation, so that at least one setting is preferably made by means of the steering wheel Wheel of the motor vehicle takes place. The axis of rotation is preferably arranged essentially parallel to a direction of travel of the motor vehicle, and is inclined, for example, relative to a horizontal plane to increase comfort.

The electric motor-adjustable steering device further comprises an electric motor drive, which is a linear drive, for example. The electric motor drive makes it possible to adjust the steering column and the steering wheel along the longitudinal direction of the steering column, in particular along the axis of rotation. The electric motor drive is suitable for this, in particular it is provided and set up. For example, the electromotively adjustable steering device comprises a further electromotive drive, by means of which the steering column is pivoted and / or the steering column is moved along a further direction, in particular essentially vertically. In other words, the further electromotive drive is used for height adjustment.

The electric motor drive comprises an electric motor, which is in particular a rotating electric motor. For example, the electric motor is designed to be brushless and, for example, a brushless DC motor (BLDC). However, the electric motor is particularly preferably a brushed commutator motor. In addition, the electromotive drive comprises a variable-length component which is driven by the electric motor. For example, the variable-length component is mechanically coupled to the electric motor directly or via a gear, for example a worm gear. The length of the variable-length component is changed during operation of the electric motor. In particular, the length of the variable-length component is set by means of the electric motor. The variable-length component is, for example, just a single element. However, the variable-length component particularly preferably comprises a plurality of individual elements which interact appropriately with one another. In other words, a variable-length component is understood in particular to mean a variable-length assembly. The variable-length component is connected to the steering column by means of a fastening device. In this case, in particular an end of the variable-length component or a section of the variable-length component which is moved with respect to the electric motor when the electric motor is in operation is connected to the steering column. The remaining end of the variable-length component is particularly attached to the electric motor and thus stabilized with respect to this. In the assembled state, the electric motor and / or this section of the variable-length component, that is to say the section of the variable-length component, the distance of which changes when the length changes to the section connected to the steering column, is expediently fixed in particular on the body side. It is thus possible to adjust the position of the steering column and thus also of the steering wheel along the extent of the steering column, that is, along the longitudinal axis, when the electric motor is in operation. At least, however, the variable-length component is arranged and connected to the electric motor and the steering column in such a way that when the length of the variable-length component changes, the steering column is adjusted along its longitudinal direction.

The variable-length component extends from the fastening device in the direction of the steering wheel. In other words, in particular the end or section of the variable-length component connected to the steering column forms the end of the variable-length component that is most distant from the steering wheel. In other words, the section of the variable-length component, which is moved with a change in length with respect to the section of the variable-length component connected to the steering column, is displaced in the direction of the steering wheel and there is expediently held there in the assembly state in a body-like manner.

Due to such positioning of the variable-length component, when the steering wheel is subjected to a force along the longitudinal axis away from the driver, in particular in the direction of any wheels or a front of the land-based motor vehicle, only a tensile load is exerted on the variable-length component. Such action of force occurs particularly in the event of an accident of the land-based motor vehicle. With a comparatively large For example, there is a plastic deformation of the length-modifiable component in which it is elongated. However, stabilization continues. If the length-modifiable component is oriented differently, on the other hand, it is compressed when the force is applied, so that it buckles, for example. This involves tearing off and / or uncontrolled deformation of the variable-length component. Due to the extension in the direction of the steering wheel and essentially only the suspension of tensile forces, it is possible to manufacture the variable-length component more delicately and thus with less weight. In particular, a tensile strength is greater than the strength with regard to a correspondingly acting pressure. Manufacturing costs are also reduced in this way. In summary, in particular due to the arrangement, a possible kinking of the length-variable component, which is in particular comparatively long and thin, is to be avoided by loading it under tension.

In summary, with such an arrangement, it is not necessary to manufacture the variable-length component in a comparatively robust manner, which reduces manufacturing costs and the weight. Also, if the variable-length component is torn off or if the variable-length component is destroyed, the latter is essentially pulled apart, and no elements thereof reach an interior of the motor vehicle. This also increases security. Since the variable-length component has a comparatively low weight, it is possible to use a comparatively low-power electric motor, so that manufacturing costs are further reduced. Required installation space is also reduced.

For example, the steering device which can be adjusted by an electric motor comprises a further such electric motor drive, which is in particular identical in construction to the electric motor drive. In this way, a comparatively quick adjustment is made possible. In this way, only a fraction of the force acting in the event of an accident can be absorbed by means of the variable-length components. Advantageously, the electromotively adjustable steering device additionally comprises a further drive, by means of which the Axis of rotation can be pivoted, in particular with respect to a horizontal. Comfort is thus further increased.

For example, the steering device that can be adjusted by an electric motor is used when the motor vehicle is driving completely autonomously. Here, the electric motor drive and / or further components of the electric motor-adjustable steering device are suitably adapted so that the steering wheel can be moved comparatively far from the driver during autonomous locomotion, which increases comfort.

For example, the variable-length component is pivoted with respect to the steering column, in particular the axis of rotation. This makes it possible to apply a comparatively large force to adjust the steering column by means of the variable-length component. However, the length-variable component is particularly preferably arranged parallel to the steering column, that is to say parallel to the axis of rotation. In this way, a size is reduced. Assembly is also simplified. It is thus possible, in particular, to mount the steering device adjustable by an electric motor as a module in the land-based motor vehicle. In an alternative to this, the variable-length component is pivotally mounted with respect to the steering column, preferably by means of a housing. With certain settings, the variable-length component is parallel to the steering column, for example, or at least approximately parallel. In other words, the variable-length component is arranged parallel to the steering column only in certain settings. In this way, utilization of an installation space is improved.

For example, the electric motor is arranged on the side of the fastening device opposite the steering wheel. A choice of the position of the electric motor is thus comparatively free. The variable-length component is suitably driven via a suitable gear or other components, for example deflection rollers. However, the electric motor is particularly preferably arranged between the fastening device and the steering wheel, expediently in a region of one end of the variable-length component. Here, the electric motor is moved away from the longitudinal axis of the steering column, for example. puts. However, the electric motor is located between the fastening device and the steering wheel along the direction of the longitudinal axis. This enables a comparatively simple and inexpensive connection of the electric motor to the variable-length component. Any mechanical losses for the operation of the variable-length component are also reduced. Since the variable-length component is only subjected to comparatively low loads and has a comparatively low weight, a comparatively low-power electric motor is also sufficient for operation, so that it is also arranged in the comparatively small installation space between the fastening device and the steering wheel can be.

For example, the variable-length component comprises or is formed by means of a spindle. The spindle itself expediently comprises a threaded rod or the like on which a nut, in particular a spindle nut, is placed. In particular, the nut is connected to the steering column, in particular by means of a suitable device, such as a cover cap. The threaded rod is driven in particular by means of the electric motor and expediently rotatably mounted. However, longitudinal movement of the threaded rod is preferably prevented. When the threaded rod rotates, the nut is displaced and the length of the variable-length component is set. This increases robustness and reliability. In particular, self-locking is thus also realized, so that an adjustment of the steering column along the longitudinal axis is not possible when the electric motor is not operated.

For example, the spindle nut is arranged within a U-shaped carrier, expediently between the two mutually parallel legs of the carrier. The electric motor is suitably attached to the carrier and is preferably arranged substantially perpendicular to all of the legs of the carrier. The threaded rod is preferably arranged perpendicular to the two parallel legs and extends through them. The spindle nut is arranged between the two mutually parallel legs of the carrier and is placed on the threaded rod. The spindle nut is preferred directly driven by the electric motor. The electric motor is suitably arranged between the spindle nut and the leg of the carrier perpendicular to the two legs of the carrier and is protected in this way. A comparatively compact electromotive drive is thus provided.

For example, the variable-length component is firmly attached to the steering column by means of the fastening device. Thus, when the steering wheel and thus also the steering column rotate, the variable-length component is also pivoted. However, the fastening device particularly preferably comprises a bearing. The bearing itself expediently has an inner ring and an outer ring which are rotatable relative to one another. For example, a plain bearing is formed between the rings. Alternatively, there are rolling elements in between, such as balls or cylinders in particular, which reduces friction. The inner ring is expediently fastened to and placed on the steering column. The length-variable component is preferably fastened to the outer ring, for example directly or indirectly by means of a further fastening means. Because of the bearing, the length-variable component is not pivoted when the steering wheel and thus also the steering column are rotated, so that a comparatively simple construction can be used. The probability of damage to the electric motor drive is also reduced. For example, the steering column is additionally supported by means of the fastening device, that is to say the bearing. At least, however, the steering column is expediently stabilized by means of the fastening device. The robustness of the electric motor-adjustable steering device is thus increased.

The electromotively adjustable steering device preferably comprises a sleeve which is designed, for example, in the manner of a hollow cylinder. The steering column is at least partially arranged within the shell. In particular, the shaft is positioned concentrically with the steering column. The casing preferably guides the steering column, in particular along the longitudinal axis of the steering column. In the assembled state, the casing is expediently fastened to a body of the motor vehicle and / or a dashboard, in particular rigidly. So- with an assembly is simplified. For example, when the axis of rotation is pivoted with respect to the horizontal direction, the casing is also pivoted. For this purpose, the possible drive is suitably connected to the casing. The electric motor and / or the variable-length component is particularly preferably attached to the casing. In this case, the section of the variable-length component is fastened to the sleeve, which is expediently not moved with respect to the electric motor when the electric motor is in operation. Because of the cover, a construction is simplified and in particular an assembly of the electromotive adjustable steering device as a module is made possible. Suitably, the casing is solid on the body side in the assembled state. For example, the cover is suitable, expediently provided and set up to be attached to the body. The land-based motor vehicle is suitable, in particular provided and set up, for being moved on land. Here, the motor vehicle can be moved independently of geographic conditions, such as rails. In particular, however, the motor vehicle is moved along a roadway which is made in particular from an asphalt, concrete or tar. The land-based motor vehicle comprises one wheel, advantageously several wheels. The land-based motor vehicle stands up on a floor in particular by means of the wheels.

Furthermore, the land-based motor vehicle comprises an electric motor-adjustable steering device with a steering column to which a steering wheel is connected in a rotationally fixed manner. The electromotively adjustable steering device further comprises an electromotive drive which has an electric motor and a variable-length component which is driven by means of the electric motor. The variable-length component is connected to the steering column by means of a fastening device and extends from the fastening device in the direction of the steering wheel. The electric motor drive makes it possible to adjust the steering wheel and the steering column, in particular with respect to a dashboard and / or a body of the motor vehicle, along the longitudinal axis of the steering column.

The distance between the steering wheel and the dashboard is suitably set by means of the electric motor drive.

The electric motor-adjustable steering device is operatively connected to the wheel or to several of the wheels, if these are present. In this case, a direction of the wheel is set in particular as a function of the steering wheel.

Advantageously, when the steering wheel is rotated about the longitudinal axis of the steering column, which is in particular an axis of rotation about which the steering column is rotatably mounted, the wheel is rotated about a vertical or at least substantially vertical axis. A rack is suitably connected to the wheel, into which a pinion engages, which is connected at the end to the steering column. In other words, there is a mechanical coupling between the wheel and the steering wheel by means of the steering column, the pinion and the rack. The land-bound motor vehicle preferably includes a steering support, which has an electric motor, for example. In particular, operation of the steering wheel is detected by means of this and the rotational movement of the steering column about the axis of rotation is supported. In a further alternative, no mechanical coupling is realized between the wheel and the steering device that can be adjusted by an electric motor. Here, a sensor detects a rotational movement of the steering wheel about in particular the axis of rotation. The sensor data are transmitted in particular to a further drive, which expediently has an electric motor. The wheel is influenced by the electric motor, in particular pivoting about the possible vertical axis. The advantages and developments mentioned in connection with the electromotively adjustable steering device can also be applied analogously to the land-based motor vehicle and vice versa. An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. In it show:

1 schematically shows a land-based motor vehicle with an electromotive adjustable steering device, and

2 schematically simplifies the steering device which can be adjusted by an electric motor.

Corresponding parts are provided with the same reference symbols in all the figures.

1 shows a land-based motor vehicle 2 with two front wheels 4, only one of which is shown. The motor vehicle 2 has an electromotive adjustable steering device 6 with a steering wheel 8 and a steering column 10. The steering wheel 8 is non-rotatably connected to the steering column 10, which is partially arranged within a shell 12. The steering column 10 and thus also the steering wheel 8 are mounted rotatably about an axis of rotation 14 by means of the sleeve 12. The casing 12 is fastened to a dashboard 16, which in turn is fastened to a body of the land-based motor vehicle 2 (not shown in more detail). The casing 12 is thus held in place on the body side by means of the dashboard 16. The steering column 10 is in operative connection with the front wheels 4 by means of a toothed rack (not shown in more detail) again drives the rack in the transverse direction. A steering angle of the front wheels 4 is set by means of the toothed rack, so that a direction of movement of the land-based motor vehicle 2 is changed.

To increase comfort, the steering wheel 8 and also the steering column 10 can be adjusted in a longitudinal direction 20 with respect to the casing 12 by means of an electromotive drive 18. The longitudinal direction 20 is in this case parallel to the extension of the steering column 10, that is to say its longitudinal axis, and also the axis of rotation 14. It is thus possible to space the steering wheel 8 from the casing 12 or towards it move depending on the anatomical conditions of the driver of the land-based motor vehicle 2.

FIG. 2 shows the steering device 6, which can be adjusted by an electric motor, in a schematically simplified manner. The casing 12 is essentially hollow cylindrical and is arranged concentrically with the cylindrical steering column 10. The steering column 10 extends here, for example, as shown in Figure 2, through the shell 12. The steering wheel 8 is connected in a rotationally fixed manner to one of the ends of the steering column 10.

The steering column 10 is also guided in the longitudinal direction 20 by means of the sleeve 12 by means of guide rails (not shown). A fastening device 22 is connected to the steering column 10 within the casing 12 and comprises a bearing, not shown, namely a ball bearing. An inner ring of the ball bearing is attached to the steering column 10 in a rotationally fixed manner. An outer ring of the ball bearing is connected to one end of a component 24 of the electromotive drive 18 which can be steered. The variable-length component 24 is a spindle with a threaded rod 26, on which a spindle nut 28 is placed. The spindle nut 28 is fastened to the fastening device 22, namely to the outer ring of the ball bearing.

The threaded rod 26 extends from the fastening device 22 in the longitudinal direction 20 towards the steering wheel 8, that is to say from the fastening device 22 in the direction of the steering wheel 8. The length-variable component part 24 is thus arranged parallel to the steering column 10. A sleeve 29 is connected to the spindle nut 28, within which the part of the threaded rod 26 which projects through the spindle nut 28 is arranged. The length of the sleeve 29 is constant, and the threaded rod 26 is at least partially supported by the sleeve 29. The sleeve 29 is located on the side of the spindle nut 28 opposite the steering wheel 8.

At the free end offset from the steering wheel 8, an electric motor 30 in the form of a brushless DC motor (BLDC) and a gear 32 are arranged and on attached to the shell 12, for example directly or by means of components, not shown. The electric motor 30 is thus located in the longitudinal direction 20 between the fastening device 22 and the steering wheel 8. The gear 32 is mechanically coupled to the threaded rod 26. When the electric motor 30 is energized, the gear 32 is driven and the threaded rod 26 is set in a rotational movement. Here, the threaded rod 26 is not movable in the longitudinal direction 20 due to the connection of the electric motor 30 to the sleeve 12. As a result, the spindle nut 28 is moved in the longitudinal direction 20 and consequently also the fastening device 22. Thus the steering column 10 and the steering wheel 8 are also adjusted in the longitudinal direction 20 with respect to the sleeve 12.

When a force is exerted on the steering wheel 8 in the longitudinal direction 20 towards the sleeve 12, as is the case in particular in the event of an accident, essentially only a tensile force acts on the variable-length component 24, in particular the threaded rod 26, which is located between the spindle nut 28, which is connected to the steering column 10, and the electric motor 30, which is connected to the casing 12. In other words, the threaded rod 26 is only elongated and not compressed. This prevents an uncontrolled movement of the variable-length component 24, as is the case, for example, when the threaded rod 26 is compressed. Only a comparatively filigree design is sufficient to compensate for the tensile forces, so that the weight of the component 24 that can be steered is reduced. A required driving force is thus also reduced, which is why a comparatively inexpensive electric motor 30 can be used.

In summary, the comparatively small-sized electric motor drive 18 makes it possible to move it in the direction of the steering wheel 8 and thus in the direction of the vehicle interior. The variable-length component 24 is thus partially arranged between the fastening device 22 and the steering wheel 8 and extends from the fastening device 22 in the direction of the steering wheel 8. Thus, the electromotive drive 18 is only subjected to a train in the event of an accident, which is why it is designed to be comparatively small. that can. This creates weight and cost advantages. Is also a hen an electromotive drive 18 enables, which can also be used for example in another area, for example as a seat adjustment. Therefore, special design and development of the electric motor 30 is not required, and existing products can be used.

The invention is not restricted to the exemplary embodiment described above. Rather, other variants of the invention can also be derived from this by the person skilled in the art without departing from the subject matter of the invention. In particular, all of the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the subject matter of the invention.

LIST OF REFERENCE NUMBERS

2 land vehicle

4 front wheel

6 electric steering device

8 steering wheel

10 steering column

12 case

14 axis of rotation

16 dashboard

18 electric motor drive

20 longitudinal direction

22 fastening device

24 variable length component

26 threaded rod

28 spindle nut

29 sleeve

30 electric motor

32 gears

Claims

Expectations

1. Electric motor-adjustable steering device (6) of a land-based motor vehicle (2), with a steering column (10) to which a steering wheel (8) is non-rotatably connected, and with an electromotive drive (18), which is an electric motor (30) and a has a variable-length component (24) which is driven by means of the electric motor (30) and which is connected to the steering column (10) by means of a fastening device (22), the variable-length component (24) moving away from the fastening device (22) extends in the direction of the steering wheel (8).

2. Electromotively adjustable steering device (6) according to claim 1,

characterized,

that the variable-length component (24) is arranged parallel to the steering column (10).

3. Electromotively adjustable steering device (6) according to claim 1 or 2, characterized in that

that the electric motor (30) is arranged between the fastening device (22) and the steering wheel (8).

4. Electromechanically adjustable steering device (6) according to one of claims 1 to 3,

characterized,

that the variable-length component (24) comprises a spindle.

5. Electrically adjustable steering device (6) according to one of claims 1 to 4,

characterized,

that the fastening device (22) comprises a bearing.

6. Electromotive adjustable steering device (6) according to one of claims 1 to 5,

marked by

a sleeve (12) within which the steering column (10) is partially arranged and by means of which the steering column (10) is guided, the electric motor (30) being fastened to the sleeve (12).

7. land-based motor vehicle (2), in particular passenger cars, with a wheel (4), and with an electromotively adjustable steering device (6) according to one of claims 1 to 6, which is in operative connection with the wheel (4).