Haptic operating device for a motor vehicle

A haptic operating device for a motor vehicle has a base, a stationary central part connected thereto, a rotary knob which can be rotated about the stationary central part and which has a hollow design. A magnetorheological transmission device influences the rotational movement of the rotary knob in a controlled manner. The transmission device has two components which can be rotated relative to each other and one component of which is designed as a brake component that can be rotated relative to the base. The stationary central part is secured to the base by means of a support arm. The transmission device and the support arm are arranged adjacent each other and both are received radially within the rotary knob. The rotary knob is rotationally fixed to the rotatable brake component via a coupling device.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a haptic operating device for a motor vehicle comprising a magnetorheological transfer apparatus. The haptic operating device according to the invention serves for operation of/in motor vehicles.

Magnetorheological fluids have, for example, very fine ferromagnetic particles such as, e.g., carbonyl iron powder, distributed in an oil. Spherical particles with a diameter of 1 to 10 micrometers, said diameter being due to production processes, are used in magnetorheological liquids, with the particle size not being uniform. If a magnetic field is applied to such a magnetorheological fluid, the carbonyl iron particles of the magnetorheological fluid link along the magnetic field lines such that the rheological properties of the magnetorheological fluid (MRF) are significantly influenced as a function of the form and strength of the magnetic field.

WO 2012/034697 A1 has disclosed a magnetorheological transfer apparatus comprising two couplable components, the coupling intensity of which is able to be influenced. A channel with a magnetorheological medium is provided for the purposes of influencing the coupling intensity. A magnetic field is used to influence the magnetorheological medium in the channel. Rotary bodies are provided in the channel, acute angled regions containing the magnetorheological medium being provided at said rotary bodies. The magnetic field of the magnetic field generating device is able to be applied to the channel, or at least to a part thereof, in order to selectively link the particles and wedge these with the rotary body or release these. This magnetorheological transfer apparatus can also be used at a rotary knob for operating technical appliances. Such a magnetorheological transfer apparatus works and allows relatively high forces or torques to be transferred with, at the same time, a relatively small installed size. The entirety of the disclosure of WO 2012/034697 A1 is incorporated in this application.

WO 2017/001696 A1 has disclosed a haptic operating device in which a display is disposed at an operating knob. The required power and data cables can be supplied to the display through a hollow shaft. To this end, however, the bore in the hollow shaft must have a sufficiently large diameter. A further disadvantage of a hollow shaft is that the shaft must be sealed at both ends since the apparatus for influencing the rotational movement in controlled fashion is disposed in the interior. As a result of the seals at both ends of the shafts, the number of seals increases to two, as a result of which the base friction increases. A further disadvantage lies in the fact that there is a greater seal diameter and consequently a greater friction radius as a result of the greater shaft diameter; this likewise increases the base torque by a non-negligible amount. However, a particularly low base torque is very advantageous in many applications, and often required so that the required operating force remains low “in the idle state (base torque)”. Otherwise, the operator may show symptoms of fatigue. The entirety of the disclosure of WO 2017/001696 A1, too, is incorporated in this application.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to provide a haptic operating device with a magnetorheological transfer apparatus for a motor vehicle, by means of which a base torque in the idle state that is as low as possible is facilitated, with, in particular, a stationary central part being provided.

This object is achieved by a haptic operating device for a motor vehicle having the features as claimed. Preferred developments of the invention are the subject matter of the dependent claims. Further advantages and features of the present invention emerge from the general description and the description of the exemplary embodiments.

A haptic operating device according to the invention for a motor vehicle comprises a base plate or main body, wherein such a base plate may also be embodied as a holder in preferred configurations. The haptic operating device comprises a stationary central part connected to the base plate and a rotary knob with a hollow embodiment that is rotatable about the stationary central part and a magnetorheological transfer apparatus for targeted influencing of a rotational movement of the rotary knob. In particular, the magnetorheological transfer apparatus brakes a rotational movement of the rotary knob in a targeted fashion. The (magnetorheological) transfer apparatus comprises two components that are rotatable relative to one another, one component of which is embodied as a brake component (also referred to as rotary component) that is rotatable relative to the base plate. The stationary central part is fastened to the base plate by a carrier arm (or two or more carrier arms). The carrier arm is disposed adjacently to the transfer apparatus. The carrier arm and the transfer apparatus are received radially within the rotary knob. The rotary knob is rotationally conjointly coupled to the rotatable brake component by way of a coupling device. In particular, the transfer apparatus is completely received in the interior of the cavity of the rotary knob.

The haptic operating device according to the invention has many advantages. A significant advantage of the operating device according to the invention for a motor vehicle consists of the standing central part facilitating the arrangement of a stationary user interface that does not co-rotate with the rotary knob. The stationary central part is received radially within the rotary knob and adjacently to the transfer apparatus such that the stationary central part does not influence a rotational movement of the transfer apparatus.

The transfer apparatus and the central part are preferably received adjacent to one another and/or next to one another and radially within the rotary knob.

Particularly preferably, the carrier arm and the transfer apparatus are disposed next to one another. Therefore, the carrier arm is not disposed within the transfer apparatus but completely next to the latter. The carrier arm and the transfer apparatus do not penetrate one another.

The carrier arm and the transfer apparatus are preferably disposed in off-centered fashion with respect to one another and/or in off-centered fashion with respect to the rotary knob. This means that the axes of symmetry of the carrier arm and of the transfer apparatus are spaced apart from one another. Particularly preferably, the axes of symmetry are disposed radially within the rotary knob.

Preferably, the transfer apparatus is housed at least in part within the cavity of the rotary knob and, in particular, completely within said cavity. The transfer apparatus and the central part are housed adjacent to an one another but not nested in one another. Influencing within the meaning of the present invention is understood to mean, in particular, a braking of the rotational movement of the rotary knob.

In a simple configuration, another haptic operating device comprises in particular a base plate and a rotary knob with a hollow embodiment and a magnetorheological transfer apparatus for targeted influencing of a rotational movement of the rotary knob and, in particular, for braking said rotational movement. Here, the rotary knob is rotationally conjointly coupled to the transfer apparatus by way of a coupling device. The operating device may comprise a base plate, at which the magnetorheological transfer apparatus and the coupling device are disposed and/or fastened.

A base plate is provided in a further haptic operating device according to the invention. Moreover, this haptic operating device comprises a stationary central part and a rotary knob with a hollow embodiment that is rotatable about the central part, and a magnetorheological transfer apparatus for targeted influencing of a rotational movement of the rotary knob. Within the rotary knob, the transfer apparatus is received with a rotary component that is rotatable relative to the base plate and the rotary knob is rotationally conjointly coupled to the transfer apparatus by way of a coupling device.

In preferred configurations of all above-described operating devices, the rotary knob is rotationally conjointly coupled to the rotatable brake component by the coupling device in such a way that a spatial alignment of the rotary knob and of the rotatable brake component with respect to one another changes during the rotational movement of the rotary knob. Here, a spatial alignment also comprises an orientation in terms of angle such that different orientations in terms of angle are also different spatial alignments within the meaning of the present application.

Preferably, the coupling device comprises coupling means at the rotary knob and the rotatable brake component. Even further coupling means may be provided. By way of example, a further coupling means can be provided, the latter being in contact with the coupling means at the rotary knob on the one hand and being in contact with the coupling means at the brake component on the other hand. It is also possible that use is made of even more coupling means, which then, overall, bring about a coupling of the rotary knob with the rotatable brake component.

By preference, the coupling device comprises teeth, gear wheels, friction surfaces, belts, chains, gears and/or planetary gears and the like. In a simple configuration, the coupling device may be formed by two gear wheels or friction surfaces of friction wheels that are engaged in one another and bring about rotationally conjoint coupling.

Preferably, internal teeth are formed on an internal contour of the rotary knob and external teeth coupled to the internal teeth are formed on an external contour of the rotatable brake component. The coupling of the rotary knob with the rotatable brake component can be implemented by way of a direct engagement or, for example, by way of a coupling means such as a gear wheel or chain or the like.

Preferably, electrical cables are passed axially through the rotary knob. The electrical cables may comprise connection cables for the power supply, control cables and communication lines and more of same. A combination of all these cable types is also possible, as a result of which the passage opening must be correspondingly large. Possibly, a connector (contact) fixedly connected to the cable must be implemented during the assembly, requiring correspondingly large amounts of space.

In a preferred configuration, the central part comprises a carrier arm, the latter being connected (directly or indirectly) to the base plate at one end. Preferably, a carrier part is disposed at the other end of the carrier arm. The carrier arm preferably extends axially through the rotary knob. The carrier part can serve to carry various units and devices.

Preferably, the carrier arm is disposed off-center in relation to the rotary knob. In particular, the carrier arm (at least also) serves to guide the electrical cables. Electrical cables can be fastened to the carrier arm. It is also possible for the electrical cables or for some of the electrical cables to be guided through the hollow carrier arm. To this end, the carrier arm preferably has a cavity or at least one cavity.

Preferably, at least one illumination unit is received in the carrier part. Particularly preferably, at least one user interface is received in a carrier part. Such a user interface may comprise an operating panel, a display, a touch-sensitive display (touch display) with or without haptic feedback and/or at least one sensor. By way of example, a sensor such as a fingerprint sensor or a camera or the like can be provided at the user interface in order to register and recognize the fingerprint of a user. A camera, inter alia with a camera-based object recognition, can likewise be used to recognize the user. An operating panel can be embodied as a touch panel and can serve to input commands and gestures. The unit in the standing central part can be activated and/or deactivated when the user (e.g., hand; finger) approaches or moves away.

In all configurations, it is preferable for the rotary knob and the rotatable brake component to be separately rotatably mounted. Here, it is possible for the rotary knob and the brake component to be mounted by way of dedicated bearings such as sliding bearings or rolling bearings. However, it is also possible for the rotary knob and the rotatable brake component to be rotatably received in corresponding low-friction guides and consequently be mounted. In particular, the magnetorheological transfer apparatus, which can also be referred to as brake device in preferred configurations, is disposed within the rotary knob. The rotatable brake component and the rotary knob can be received nested in one another.

Preferably, one of the components of the transfer apparatus is formed as a stationary brake component. However, it is also conceivable that both components of the transfer apparatus each have a rotatable configuration.

Preferably, the stationary brake component is disposed radially on the inside and surrounded by the rotatable brake component. The rotatable brake component may form a closed brake housing.

In particular, the stationary brake component comprises a shaft that is connected to the base plate, the latter then being surrounded by the rotatable brake component in particular. The shaft can have a thin and solid embodiment and need not have a hollow embodiment. Preferably, no cables or lines are guided through the shaft.

By preference, the transfer apparatus has exactly one shaft output, which is sealed by way of exactly one contacting seal. In particular, the contacting seal is disposed between the rotatable brake component and the stationary brake component. The contacting seal can be embodied as a sealing ring and can be embodied, for example, as an O-ring, as a lip-type seal, a wiper ring or as a quad-ring.

In preferred configurations, the transfer apparatus has the shaft output on one side and a closed wall on the opposite side. Then, the rotatable brake component overall forms a closed brake housing with a shaft output.

It is possible and preferable in all configurations for the rotary knob to have a substantially sleeve-shaped embodiment.

Preferably, the rotary knob comprises two tubular parts that are axially displaceable with respect to one another, said tubular parts, in particular, being rotationally conjointly coupled to one another by way of coupling pins or guides or the like. In particular, the displaceable tubular parts are preloaded into the axially extended position by way of a preloading device.

Preferably, the rotary knob or a tubular part is mounted to the base plate by way of at least one bearing. In particular, the rotary knob and/or a tubular part of the rotary knob is axially displaceable (push/pull).

Preferably, the rotary knob and/or a part of the rotary knob is axially displaceable and provides haptic feedback in the region of the end position. Other pressure functions may also be integrated into the rotary knob such that a signal is triggered upon an axial actuation of the rotary knob and, in particular, haptic feedback is provided in return. Pulling the knob (pull) is also possible. Likewise, the entire operating element can be additionally displaced to the side (X and Y direction/movement).

Preferably, at least one sensor for detecting an axial actuation in the form of, e.g., an actuation sensor and/or a sensor for detecting an angle change or an absolute angle position is associated with the rotary knob.

It is preferable in all configurations for a difference between a clear internal diameter of the rotary knob and an external diameter of the transfer apparatus to be greater than 3 mm and less than 50 mm. Preferably, the difference lies between 10 mm and 30 mm.

In preferred configurations, an external diameter of the rotary knob is between 10 mm and 90 mm and in particular between 20 mm and 90 mm. A height of the rotary knob is preferably between 10 mm and 60 mm.

It is preferable in all configurations for the transfer apparatus to comprise a magnetic circuit and a magnetic field generating device with at least one electric coil and a gap between the stationary brake component and the rotatable brake component, the gap or channel between the two components of the transfer apparatus preferably being provided or equipped with a magnetorheological medium.

Particularly preferably, rotary bodies that serve in particular as magnetic field concentrators are disposed between the stationary brake component and the rotatable brake component or between the two components of the transfer apparatus that are rotatable relative to one another. In particular, the rotary bodies are surrounded by the magnetorheological medium. The functionality of influencing the rotational movement by way of rotary bodies in a gap or channel between two components of a magnetorheological transfer apparatus is described in WO 2012/034697 A1 and in WO 2017/001696 A1, and is used in a similar way or in the same way in a manner adapted to the structure present here.

A significant advance to the invention also consists of the fact that the base torque, low in any case, can be reduced even further since there is, regularly, a transformation of the rotational speed of the rotary knob. In a specific configuration, the ratio is between 3:1 and can, however, also become larger and reach or exceed 4:1, or it can be smaller than 2:1. The effective base torque at the transfer apparatus is reduced accordingly as a result, which once again significantly contributes to the ease of movement.

Further advantages and features of the present invention arise from the exemplary embodiments, which are explained below with reference to the attached drawing.

DESCRIPTION OF THE INVENTION

FIG. 1shows a schematic perspective exploded view of a haptic operating device200according to the invention for a motor vehicle, which comprises a main body210or base plate210. The receptacle210acan have an integral embodiment with the base plate or else it can be embodied as a separate part; it serves to receive the magnetorheological transfer apparatus1.

Here, the magnetorheological transfer apparatus1comprises a rotatable brake component3, which is formed by the principal part of the rotatable brake component3and the lower part3a. During the assembly, the two parts3,3aare pressed together and consequently form a closed housing or the rotatable brake component3overall. Received in the rotatable brake component3is the stationary brake component or component2, which is guided out of the rotatable component3via a stationary shaft212. The stationary shaft212is fastened to the base plate210or to the receptacle210a. By way of example, the shaft can be screwed to the receptacle210aor the base plate210by way of a screw such that the shaft212, and hence the stationary brake component2, is securely received at the base plate210. The rotatable brake component3and/or3ais rotatably received in relation to the base plate210or the receptacle210aby way of a rolling bearing30. A protective sleeve287made of a hard or hardened or coated (e.g., hard chrome coating) material is pushed over the shaft212consisting of a magnetically conductive material during the assembly. The seal46in the part3aacts on the protective sleeve287such that no grooves arise on the stationary shaft212, even during operation.

The rotatable brake component3or the upper part thereof has external teeth272on the external circumference, said external teeth meshing with the internal teeth271of the rotary knob202in the assembled state. As a result, a rotational movement of the rotary knob202is transferred to the rotatable brake component3.

Here, the rotary knob202substantially consists of two parts, specifically an upper tubular part281and a lower tubular part282, in which the inner teeth271are formed in this case.

The two tubular parts281and282are rotatably conjointly connected to one another. By way of example, this can be implemented by way of coupling pins283, which are inserted in corresponding receptacles in the tubular parts281and282. Springs284can be inserted into the coupling pins283, said springs consequently preloading the tubular parts281,282into a base position where they are axially spaced apart from one another. Instead of the coupling pins, which engage in pores, use can also be made of linear guides (recirculating ball guides, linear ball guides, profile guides . . . ).

The stationary central part260is disposed in the interior cavity261of the rotary knob202and connected to the base plate210. The standing central part260comprises a carrier arm263, which extends from the base plate210at one end to the upper end at which a carrier part264is formed. The carrier part264serves to carry the circuit board280and the illumination unit266disposed thereon. Here, the user interface267is disposed at the top; said user interface may provide an operating panel of the haptic operating device. By way of example, the operating panel can also be embodied as a display or as a touch sensitive display.

FIG. 2shows a side view of the haptic operating device200fromFIG. 1in an exploded view. The rotatable brake component3comprises a lower part3aand the upper part, which both overall are referred to as rotatable component3and which receive the stationary brake component2therein. Moreover, the rotary bodies11and the coil26including a coil holder26aare received in the interior of the rotatable brake component3. The remainder of the cavity is filled by a magnetorheological medium6(cf.,FIG. 4). The shaft212is sealed to the outside by the seal46, the latter interacting with the protective sleeve287that is applied to the shaft212.

When put together, the tubular parts281and282yield the rotary knob202, which has an embodiment with a hollow interior and which is formed in a sleeve-like manner. This means that the rotary knob202has a respectively open embodiment both at the upper and at the lower axial end and has no wall. At the upper axial end, and consequently at the end distant from the base plate210, the haptic operating device200is completed by the operating panel268, which, in particular, has a touch-sensitive or pressure-sensitive embodiment.

FIG. 3shows a perspective illustration of an exemplary embodiment of a haptic operating device200, as illustrated in an exploded view inFIGS. 1 and 2. The base plate210can have embodiments of different lengths and have different forms. In the illustration according toFIG. 3, the haptic operating device200is suitable to be received hovering above the background. By way of example, the rotary knob202with the user interface267can be illuminated by an illumination unit266. By way of example, a sensor275can be integrated on the surface. It is also possible that the surface of the user interface267is suitable, overall or in part, for recording images, for example, such that, e.g., a fingerprint can be recorded and recognized by the haptic operating device200following contact with a finger.

FIG. 4shows a very schematic cross-sectional view of a magnetorheological transfer apparatus1according to the invention, for influencing the force transfer between two components2and3. Here, a rotary body11is provided as a separate part4between the two components2and3inFIG. 4. Here, the rotary body11is embodied as a sphere14. However, it is likewise possible to embody rotary bodies11as cylinders or as ellipsoids, as rollers or as any other rotatable rotary bodies. Even rotary bodies that are not rotationally symmetric in the true sense, such as, e.g., a gear wheel or a rotary body11with a specific surface structure, can be used as a rotary body. The rotary bodies11are used not to bear one another but, instead, to transfer torque.

A channel5, filled with a medium6in this case, is provided between the components2and3of the magnetorheological transfer apparatus1. Here, the medium is a magnetorheological fluid20, which, e.g., comprises an oil as a carrier liquid, in which ferromagnetic particles19are present. Glycol, fat or viscous substances may also be used as a carrier medium, without being restricted thereto. The carrier medium may also be gaseous or the carrier medium can be dispensed with (vacuum). In this case, only particles that are able to be influenced by the magnetic field are filled into the channel.

The ferromagnetic particles19are preferably a carbonyl iron powder, the size distribution of the particles depending on the specific use. A particle size distribution of between one and ten micrometers is specifically preferred, with, however, larger particles of twenty, thirty, forty and fifty micrometers also being possible. Depending on the application, the particle size can also become significantly larger and even penetrate into the millimeter range (particle spheres). The particles may also have a special coating/cladding (titanium coating, ceramic, carbon cladding, etc.) so that they better endure the high pressure loads occurring depending on the application. The MR particles for this application case can be produced not only from carbonyl iron powder (pure iron) but also, e.g., from specific iron (harder steel).

The rotary body11is made to rotate about its axis of rotation12as a result of the relative movement17between the two components2and3and practically runs along the surface of the component3. At the same time, the rotary body11runs along the surface of the other component2such that a relative speed18is present there.

Strictly speaking, the rotary body11is not in direct contact with the surface of the component2and/or3and therefore does not roll directly thereon. The clear distance9from the rotary body11to one of the surfaces of the component2or3is 140 μm, for example. In a specific configuration of particle sizes between 1 μm and 10 μm, the clear distance lies, in particular, between 75 μm and 300 μm and, particularly preferably, between 100 μm and 200 μm.

In particular, the clear distance9is at least ten times the diameter of the typical mean particle diameter. Preferably, the clear distance9is at least ten times the size of a largest typical particle. On account of the lacking direct contact, a very low base friction/base force/base torque arises during the relative movement of the components2and3with respect to one another.

If a magnetic field is applied to the magnetorheological transfer apparatus1, field lines are formed depending on the distance between the rotary bodies11and the components2,3. The rotary body consists of the ferromagnetic material and, e.g., of ST37in this case. The steel type ST37has a magnetic permeability μr of approximately 2000. The field lines pass through the rotary body and concentrate in the rotary body. A high flux density in the channel5prevails at the entry and exit face, radial in this case, of the field lines at the rotary body. The field that is inhomogeneous and strong there leads to local and pronounced linking of the magnetically polarizable particles19. As a result of the rotational movement of the rotary body11in the direction of the wedge that is forming in the magnetorheological fluid, the effect is greatly increased and the possible brake or coupling torque is magnified to the extreme, far beyond the value that is normally generable in the magnetorheological fluid. Preferably, rotary bodies11and component2,3consist at least in part of ferromagnetic material, which is why the magnetic flux density becomes ever higher the smaller the distance is between rotary body11and component2,3. As a result, a substantially wedge-shaped region16forms in the medium, the gradient of the magnetic field in said wedge increasing strongly to the acute angle at the contact point or the region of smallest distance.

Despite the distance between rotary body11and component2,3, the rotary body11can be put into rotational movement by the relative speed of the surfaces with respect to one another. The rotational movement is possible both without and with an acting a magnetic field8.

When the magnetorheological transfer apparatus1is exposed to a magnetic field8of a magnetic field generating device7that is not illustrated here inFIG. 4, the individual particles19of the magnetorheological fluid20link along the field lines of the magnetic field8. It should be noted that the vectors, plotted inFIG. 4, only very schematically represent the region of the field lines that is relevant to influencing the MRF20. The field lines enter the channel5substantially perpendicular to the surfaces of the ferromagnetic components and need not extend in a straight line, especially in the acute angled region10.

At the same time, some material of the magnetorheological fluid20is also put into rotation at the circumference of the rotary body11such that an acute angled region10forms between the component3and the rotary body11. An equal acute angled region10arises between the rotary body11and the component2on the other side. By way of example, in the case of rotary bodies11configured in a cylindrical fashion, the acute angled regions10may have a wedge shape16. The further rotation of the rotary body11is impeded by the wedge shape16, and so the effect of the magnetic field on the magnetorheological fluid is increased since greater cohesion of the medium6arises within the acute angled region10as a result of the magnetic field acting there. As result, the effect of the magnetorheological fluid is amplified in the accumulated pile (the link formation in the fluid and hence the cohesion or the viscosity), making the further rotation or movement of the rotary body11more difficult.

Substantially greater forces or torques can be transferred by the wedge form16than would be possible with a comparable structure that only uses shear movement without a wedge effect.

The forces that are transferable directly by the applied magnetic field only represent a small portion of the forces transferable by the apparatus. The wedge formation and hence a mechanical force amplification can be controlled by way of the magnetic field. The mechanical amplification of the magnetorheological effect can go so far that the force transfer is even possible after an applied magnetic field has been deactivated if the particles were wedged.

It was found that a significantly greater effect of a magnetic field8of a given strength is obtained by the wedge effect of the acute angled region10. Here, the effect can be amplified multiple times. In one specific case, influencing of the relative speed of two components2and3with respect to one another that was approximately ten times stronger than in the prior art in the case of MRF couplings was observed. The possible amplification depends on different factors. Optionally, it can be amplified even further by a greater surface roughness of the rotary bodies11. It is also possible for outwardly projecting protrusions to be provided on the outer surface of the rotary bodies11, which can lead to an even stronger wedge formation.

The wedge action or the wedge effect is distributed in areal fashion on the rotary body11and the components2or3.

FIG. 5shows a cross section through an embodiment of a haptic operating device202. The haptic operating device200is assembled on a base plate210, which comprises a separate receptacle210afor the magnetorheological transfer apparatus1in this case. The transfer apparatus1comprises two components2,3, wherein the component2is embodied as a stationary brake component and screwed to the receptacle210a. In this case, the brake component2has an approximately mushroom-shaped form and comprises the shaft212and accommodates in the mushroom-shaped part the electrical coil26in a coil holder26aas a magnetic field generating device7. The electrical coil26is wound around the axis of symmetry of the stationary brake component2.

The rotatable brake component3comprises an upper part and a lower part3a, which are pressed together during the assembly. The plotted seal between the two parts of the rotatable brake component3serves to seal possible gaps.

Rotary bodies11, which are guided in corresponding receptacles of the stationary brake component2and the rotational brake component3, are received in the rotatable brake component3. The magnetic field8is plotted in exemplary fashion at one rotary body11and passes through the rotary body11, with the rotary bodies11being embodied as spheres14in this case. The spheres14are disposed in a gap5, which is filled with a magnetorheological medium and, in particular, with a magnetorheological fluid.

The rotary knob202has a larger internal diameter and, as visible inFIGS. 1 and 2, comprises internal teeth271on the internal circumference, said internal teeth engaging with external teeth272of the rotatable brake component3on the left-hand side in this case.

As a result, a clear interstice arises in this case on the right-hand side, the stationary central part260being disposed therein and extending from the base plate to above the rotatable brake component3. Above the rotatable brake component3, the stationary central part260forms a carrier part264, to which the illumination unit266, the user interface267and an operating panel168are applied.

The tubular parts281and282of the rotary knob202are coupled to one another by way of coupling pins283in this case. Springs284are disposed in the hollow coupling pins283, said springs preloading the two tubular parts in a base position axially spaced apart from one another.

The rotary knob202is mounted directly on the base plate210by way of a rolling bearing276. The transfer apparatus1or the rotatable brake component3is rotatably mounted on the base plate210or on the receptacle at210aby way of a bearing30, which is likewise embodied as a rolling bearing.

An angle sensor206detects an angular position of the rotary knob202. An actuation sensor204is activated in the case of an axial actuation of the rotary knob202, it not being possible to recognize said actuation sensor here inFIG. 5.

FIG. 6shows a schematic cross-section in a plan view, it being possible in this case to recognize the diameters of different sizes of the rotary knob202and of the transfer apparatus1. The transfer apparatus1is rotationally conjointly coupled to the rotary knob202by way of a coupling device270such that a rotation of the rotary knob202is directly converted into a rotation of the transfer apparatus1or into a rotation of the rotatable brake component3of the transfer apparatus1. Here, the coupling device270comprises internal teeth271at the rotary knob202and external teeth272at the rotatable brake component3. Here, the clear space for the stationary central part260is also recognizable, said stationary central part consequently being able to pass axially through the rotary knob202proceeding from the base plate, without impeding the rotational movement of the rotary knob or of the rotatable brake component. Electrical cables241can be passed through the inner cavity261of the stationary central part260in order to supply power to the user interface267, the illumination unit266or the operating panel268and in order to provide communication lines.

FIG. 7shows a modified embodiment of the haptic operating device200ofFIG. 5, with the actuation sensor204also been plotted in this case. In contrast to the exemplary embodiment according toFIG. 5, cylindrical or roller-shaped rotary bodies11are provided in the exemplary embodiment according toFIG. 7.

Moreover, a permanent magnet25is plotted in exemplary fashion; it can provide a permanent magnetic field. The magnetic field of the permanent magnet25can be influenced by the magnetic field of the electric coil26and can also be canceled in the case of appropriate polarity. It is also possible that the permanent magnet25is set by electrical pulses of the electrical coil26.

FIG. 8shows a schematic cross section in a plan view, wherein the haptic operating device200in this case once again comprises a rotary knob202and a transfer apparatus1with an external rotatable brake component3and an inner stationary brake component2. Electrical cables241can be guided to the operating panel, not recognizable here, through a stationary central part260. The maximum width available for the stationary central part260is a width that arises from a difference between the internal diameter285of the rotary knob202and the external diameter286of the transfer apparatus1.

In the illustration according toFIG. 8, the coupling device270can also be formed by friction surfaces on the outer surface of the rotatable brake component3and the inner surface of the rotary knob202.

FIG. 9shows a further variant, wherein the transfer apparatus1in this case has an outer rotatable brake component3again. The rotatable brake component3is rotatable about the central axis of symmetry of the transfer apparatus1and of the rotary knob202. In this case, the coupling device270comprises, e.g., a gear wheel273as a coupling means between the internal teeth of the rotary knob202and the external teeth of the transfer apparatus1. As a result, enough installation space is also available for stationary central part260.

FIG. 10shows another variant, in which the coupling device270comprises a belt274or a chain, by means of which the rotational movement is transferred from a central rotational shaft202ato the rotatable brake component3. In this configuration, the stationary brake component2surrounds the rotatable brake component3. In this configuration, the rotary knob202can be covered by a transparent pane, for example, at which the rotational shaft202ais attached centrally, the latter being guided into the inner cavity of the rotary knob202through the operating panel268, the belt274for coupling with the transfer apparatus1being disposed in said inner cavity. Sufficient installation space for the stationary central part260also arises in such a configuration. If use is made of capacitive or optical sensors, the user interface267can also be used for the input of data, even if the user interface267is covered by the e.g. transparent wall of the rotary knob202.

FIGS. 11a, 11band 11cillustrate possible embodiment variants for the dynamically generated magnetic field or the dynamically produced brake torque as a function of the rotational angle. Very different brake torques can be generated depending on the menu selection. Examples of menus in the case of motor vehicles include: air-conditioning level; temperature to the left or right; seat adjustment; volume. An operating menu can be chosen by pressing or pulling the operating element.

Here,FIG. 11ashows a variant in which a left end stop228and a right end stop229are generated. A high magnetic field or stop torque238is generated if the rotary knob202is rotated further, as a result of which the rotary knob202puts up a high resistance against a rotational movement.

A first latching point226, which corresponds to a first menu item225, is provided directly next to the left end stop228. Should the next menu item be selected, the rotary knob202must be rotated clockwise. To this end, the dynamically generated higher magnetic field or cogging torque239or the frictional torque thereof must be overcome before the next latching point226is reached. InFIG. 11a, a magnetic field that is constant in each case is generated for a certain angle range, in each case at the latching points226and at the regions lying therebetween, said magnetic field being substantially lower at the latching points than in the regions lying therebetween and being once again significantly lower than at the stops228,229.

An angle spacing237between individual latching points is dynamically modifiable and adapted to the number of available latching points or menu items.

FIG. 11bshows a variant in which the magnetic field does not increase abruptly at the end stops228,229but has a steep profile instead. Furthermore, ramp-like gradients of the magnetic field are provided on both rotational sides of the latching points226, as a result of which the rotational resistance increases in the corresponding rotational directions. Here, only three latching points226are made available by the same operating device200, the angle spacing237of said latching points being greater than in the example according toFIG. 11a.

FIG. 11cshows a variant in which a lower rotational resistance is present between the individual latching points226and in which a respectively elevated magnetic field239is only generated directly adjacent to the latching points226in order to facilitate latching of the individual latching points226and, the same time, to provide only a small rotational resistance between the individual latching points.

In principle, a mixture of the modes of operation and of the magnetic field curves ofFIGS. 11a, 11band 11cis also possible. By way of example, a correspondingly different setting of the magnetic field curve can be implemented in different submenus. Preferably, the current and hence torque changes are harmonious (smooth transitions, rounded, . . . ) such that a haptically good or comfortable operating feeling arises.

It is also possible in all cases that, e.g., in the case of a ripple (latching), switching is not carried out as previously between less and more current with the polarity (i.e., for example, +0.2 to +0.8 A=ripple), but, alternately, with a change in polarity, i.e., from +0.2 to +0.8 A and then the next ripple with −0.2 A to −0.8 A and then the next torque peak from +0.2 to +0.8 A, etc.

The preferably low-allow steel may keep a residual magnetic field. The steel is demagnetized (alternating field), preferably at regular intervals or when necessary.

If the rotary unit is not rotated, i.e., if the angle is constant, the current is preferably continuously reduced over time. The current can also be varied in speed-dependent fashion (angular speed of the rotary unit).

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