WO2019105694A1

WO2019105694A1 - Motor vehicle component

Info

Publication number: WO2019105694A1
Application number: PCT/EP2018/080390
Authority: WO
Inventors: Ulrich Strobel; Stephan Henzler
Original assignee: Brose Fahrzeugteile Gmbh & Co. Kommanditgesellschaft, Bamberg
Priority date: 2017-11-29
Filing date: 2018-11-07
Publication date: 2019-06-06
Also published as: DE102017128214A1

Abstract

The invention relates to a motor vehicle component, in particular a flap drive, comprising a drive element (6) that can be rotated about an axis of rotation (5), in particular a drive shaft, and a drive motor (7) for the motorized moving of the drive element (6). The motor vehicle component (1) has a brake assembly (9), which is coupled to the drive element (6). The brake assembly (9) forms a friction brake (10), which continuously brakes the drive element (6). According to the invention, the brake assembly (9) forms an additional brake (12) in addition to the friction brake (10), which additional brake brakes the drive element (6) in the manner of a magnetic hysteresis brake at least in the static state of the drive element (6).

Description

Motor vehicle component

The invention relates to a motor vehicle component, in particular a flap drive, according to the preamble of claim 1, a flap arrangement 5 with such a flap drive according to claim 18 and a method for operating a motor vehicle component according to claim 20.

Today's motor vehicles are equipped with a plurality of motor vehicle components that take over drive functions for adjusting elements. Examples le for this are damper actuators, window lift drives, Sitzverstellantriebe or the like. One of many requirements is that the adjusting element to be adjusted is held in any intermediate position, even if the associated drive motor is de-energized.

The known motor vehicle component (DE 10 2014 005 006 A1), from which the invention proceeds, is configured as a damper drive. The damper drive is used for the motorized adjustment of a tailgate of a motor vehicle between a closed position and an open position. The non-self-locking designed powertrain here is assigned a friction brake, which ensures 20 that the tailgate is held even when de-energized drive motor as mentioned above in any intermediate position. The friction brake acts constantly on the drive train, which allows a simple construction of the friction brake. A challenge in the known motor vehicle component is to achieve a good holding effect in each intermediate position 25 of the tailgate, regardless of whether the motor vehicle is parked in a flat position or on a slope.

Other brakes for damper actuators have also been proposed, such as hysteresis brakes, whose braking effect is due to the energy requirement 30 during the remagnetization of a ferromagnetic component (EP 2 543 808 A1). The operation of such a hysteresis brake results, for example, from DE 197 05 290 Al.

The invention is based on the problem of designing and developing the known motor vehicle component in such a way that an improved retaining effect is achieved with a low constructional outlay. It is essential first of all the fundamental consideration that the motor vehicle component has a brake assembly which operates according to different operating principles. First of all, it is assumed that the brake arrangement forms a friction brake, which constantly brakes the drive element.

It is also essential that the brake assembly forms, in addition to the friction brake, an additional brake which operates at least in the static state of the drive element in the manner of a magnetic hysteresis brake and thus brakes the drive element in addition to the friction brake, at least in the static state of the drive element. The additional brake is for this purpose of the basic structure of a hysteresis, this means that the brake assembly forms an additional brake with a permanent magnet excitation component and a ferromagnetic counter-component, which are rotatable relative to each other about the axis of rotation of the drive element. In this case, the exciter component is magnetized alternately around the axis of rotation.

In the static state, a magnetization of the countercomponent correspondingly alternating around the rotation axis takes place through the excitation of the excitation component stat, which preferably converts the countercomponent into its magnetic saturation. In the static state, this means that the magnetic interaction between the exciter component and the countercomponent generates a braking torque which must be overcome in order to reach the dynamic state, that is to say a relative rotation between the excitation component and the countercomponent. This results with the additional brake an additional braking effect in the static state, which improves the holding effect in the static state. In the dynamic state, however, an additional braking effect is not desirable. Here the construction of a hysteresis brake is particularly advantageous, since the hysteresis brake reduces or completely loses its effect at high speeds. The reason for this is that the hysteresis brake, as mentioned above, is based on the energy requirement during the remagnetization of the counter component. The frequency dependence of the magnetic permeability leads to a certain extent that the magnetic reversal can not follow the magnetic excitation by the excitation component, so that at high speeds a reduced or no braking effect occurs. This means in the present case that at correspondingly high rotational speeds, a selbstätige deactivation of the additional brake takes place, so that with a suitable design of the additional brake dynamic operation is not or only slightly hampered by the auxiliary brake, In this representation remain eddy current effects that can be avoided by known measures, unconsidered. Preferably, the effects of the friction brake and the additional brake add in the static state of the drive element. Accordingly, it is according to claim 2 such that the breakaway torque for the drive element from a breakaway torque generated by the friction brake! and composed of a breakaway torque generated by the auxiliary brake. In this case, the breakaway torque share generated by the additional brake at the breakaway torque is preferably at least 10%.

In the particularly preferred embodiment according to claim 6, the magnetic excitation field acting on the auxiliary brake is used twice, namely on the one hand for generating the braking effect of the hysteresis and on the other hand for generating the braking effect of the friction brake by the normal force for the friction brake back to the excitation field. This leads to a cost-effective and at the same time compact structural design of the brake assembly. The further preferred embodiments according to the Ansprings 7 and 8 relate to advantageous structural variants for the implementation of the above dual use of the exciter field.

The further preferred embodiments according to claims 10 to 12 relate to a preferred rated operation of the motor vehicle component, in which the drive motor is driven in a nominal speed range, in such a way that the pole change frequency on the counter component is greater than the magnetic limit frequency (s. "Electrical engineering in the Praxis ", Herbert Bernstein, De Gruyter Studium, 2016, p. 174, last paragraph) of the material of the countercomponent. This means that the relative rotation between the excitation component and the counter component due to the high rotational speeds no or only a small remagnetization of the negative component caused. The braking effect attributable to the additional brake can therefore be due at most to a remanent magnetization of the counter component and is therefore correspondingly low, in particular in the case of a soft magnetic design of the counter component. This is interesting insofar as with the proposed solution by a correspondingly high rated speed range, a above-mentioned deactivation of the additional brake takes place, which is triggered automatically upon reaching the dynamic range of the drive element. The auxiliary brake acts to a significant extent only in the static state of the drive element.

The particularly preferred embodiments according to claims 14 to 17 relate to preferred design variants for at least one of the friction surfaces, with which a particularly high wear resistance can be achieved. According to another teaching according to claim 18, which has independent significance, is a flap assembly of a motor vehicle with a flap and one of the flap associated », proposed according flap drive claimed as such, the flap drive is used to adjust the flap between a closed position and an open position by motor. On old versions of the proposed damper actuator may be referenced.

A particularly advantageous design of the flap assembly relates to claim 19, according to which the flap is held in each flap position by the combined braking action of the friction brake and the auxiliary brake in its static state. This means that the breakaway torque, which results from the addition of the braking effect of the friction brake with the braking effect of the auxiliary brake, is dimensioned correspondingly large. This can be easily achieved by the addition to the proposed additional brake, additional adjustment option for the braking effect in the static state without the motorized adjustment in the dynamic state is excessively obstructed.

According to another teaching according to claim 20, which also has independent significance, a method for the operation of a proposed according to the motor vehicle component, in particular a proposed

Flap assembly claimed as such.

Essential for the proposed method, the above-mentioned control of the drive motor is such that the prevailing on the counter component, the relative rotation between the excitation component and counter component backward pole change has a frequency above the magnetic cutoff frequency of the material of the counter component, so that the above-mentioned reduction of the braking effect the additional brake results. With the method according to the preamble, it is possible to generate an amplification of the braking effect of the brake arrangement in the static state of the drive element, while the dynamic state of the drive element is not or only insignificantly obstructed.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. In the drawing shows

1 shows the rear area of a motor vehicle with a motor vehicle component designed according to the preamble, designed as a flap drive,

2 shows the brake assembly of the motor vehicle component according to FIG. 1 in the view II, FIG.

Fig. 3 shows the brake assembly of FIG. 2, a) in the view purple and b) in the

View IIIb.

In the illustrated motor vehicle component 1 is a damper drive, which is associated with a flap 2 of a motor vehicle. The damper actuator 2 is used to adjust the flap 2 between a closed position and an open position.

The term "flap" is to be understood in the present context. It includes a tailgate, a trunk lid, a door, in particular a side door, a front hood o. The like. The term "flap" includes in a particularly wide interpretation also a sliding door. Other fields of application for the proposed motor vehicle component 1 are conceivable. 1, designed as a flap drive motor vehicle component 1 is configured in the manner of a spindle drive with which linear drive movements via the drive terminals 3, 4 to the flap. 2 allow it to slide out to adjust the flap 2 motor. With regard to the basic construction of such a spindle drive, reference may be made to the aforementioned patent application DE 10 2014 005 006 A1, which is based on the Applicant and which in this respect is the subject of the present application.

The motor vehicle component 1 has a drive element 6 rotatable about a rotation axis 5. Furthermore, the motor vehicle component 1 is equipped with a drive motor 7 for the motorized adjustment of the drive element 6. The drive element 6 can be any element which can be driven by a drive motor 7. In the illustrated preferred embodiment, the drive element is a drive shaft which is arranged in the drive train between the drive motor 7 and the spindle spindle nut transmission 8 of the spindle drive. In principle, however, the drive element 6 can also be the motor shaft of the drive motor 7, a gear shaft o, the like. The motor vehicle component 1 has a brake assembly 9, which is shown in Fig. 2 The brake assembly 9 is in a manner to be explained with the drive member 6, this braking, coupled.

The brake assembly 9 initially forms a friction brake 10, which brakes the drive element 6 constantly. The braking of the drive element 6 takes place here and preferably with respect to a drive housing 11 of the motor vehicle component 1, which is cylindrical in cylinder shape in FIG

It is essential that the brake assembly 9 in addition to the friction brake 10 forms an additional brake 12, at least in the static state of the

Drive element 6 operates in the manner of a magnetic hysteresis. As a result, at least in the static state of the drive element 6, the additional brake 12 brakes the drive element 6 in addition to the friction brake 10. For this purpose, the auxiliary brake 12 on the construction of a magnetic hysteresis. The auxiliary brake 12 brakes the drive element 6 at least in the static state of the drive element 6, ie when the drive element 6 is stationary, in addition to the friction brake 10. The construction of such a hysteresis brake has been explained in the introductory part of the description.

As has also been explained in the introductory part of the description, the brake assembly 9 is used to hold the drive member 6 in any intermediate position with de-energized drive motor 7. Since the drive element 6 is coupled via the spindle-spindle nut transmission 8 with the flap 2, this leads to a corresponding Hold the flap 2 in any intermediate position. It is assumed that the drive train between the two drive terminals 3, 4 is designed non-self-locking This means that the initiation of movement via the drive terminals 3, 4 in the drive train to a return drive of the spindle-Spindelmuttergetriebes 8 and preferably also of the drive motor From its static state, the drive element 6 can be brought into a dynamic state by applying a breakaway torque, in which the drive element 6 rotates about its axis of rotation 5. This on the

Drive element 6 to be applied breakaway torque is composed, here and preferably additive, from a Losbrechmo- generated by the friction brake 10 ment part and from a Losbrechmomentanteil generated by the additional brake 12. Here and preferably, it is such that the breakaway torque share generated by the additional brake 12 at the breakaway torque is at least 10%, preferably at least 20% and more preferably at least 25%. This means that adjustability of the breakaway torque results over a wide range with the proposed additional brake 12.

The illustration according to FIG. 2 shows that the friction brake 10 has two frictionally engaging elements 13, 14 with associated friction surfaces 13a, 14a, which are rotatable relative to each other about the rotation axis 5 and axially adjustable with respect to each other, wherein between the friction surfaces 13a, 14a of the two friction engagement elements 13 . 14 a normal force N acts, which generates a friction torque between the two friction engagement elements 13, 14. Here are the usual relationships for static friction in the static state and for sliding friction in the dynamic state application,

The structure of the auxiliary brake 12 is also shown in the illustration according to FIG. 2. The auxiliary brake 12 has a permanent-magnet exciter component 15 for generating an exciter field and a ferromagnetic counterpart component 16 which are rotatable relative to one another about the axis of rotation 5. The exciter component 15 provides at least two exciter magnets 17a-f, which are distributed in relation to the axis of rotation 5, here and preferably axially, which are distributed around the axis of rotation 5 and of alternating polarity. This is indicated in Fig. 3b) with an indication of the poles of the excitation gangue 17a-f. Between the excitation component 15 and the counter-component 16, a magnetic air gap 18 is arranged, wherein the excitation magnets 17a-f respectively excite a corresponding magnetic circuit 19a-f, which is closed via the air gap 18 and the counter-component 16. In the drawing, only the magnetic circuits 19a and 19d are indicated. In the static state, the exciting field generated by the excitation component 15 causes a corresponding magnetization of the counter-component 16, which is indicated in Fig. 3a) with an indication of the resulting poles. This can best be seen from a synopsis of FIGS. 2 and 3. Due to the ferromagnetic design of the counter-component 16, especially by the above magnetization, in the static state, a magnetic attraction between the excitation component 15 and the counter-component 16, which can be easily adjusted by an appropriate choice of the air gap 18 acts. The fact that the force of attraction between the excitation component 15 and the counterpart component 16 provides the normal force N for the friction brake 10 is interesting in the preferred embodiment shown in FIG. 2. In that regard, the pathogen component

15 as mentioned above used twice, namely on the one hand for the magnetization of the counter-component 16 with the resulting braking effect on the type of hysteresis, and on the other hand for the generation of Wormaikraft N, which is the cause of the emergence of the friction torque between the friction surfaces 13a, 14a

2 that the excitation component 15 is connected to one of the frictional engagement elements 13, while the countercomponent 18 is connected to the respective other frictional engagement element 14. The excitation component 15 and the counter-component 16 are supported by the normal force N on the friction surfaces 13a, 14a of the frictional engagement elements 13, 14, whereby the width of the air gap 18 is determined.

Here and preferably, the excitation component 15 is connected to the associated frictional engagement element 13 with the drive element, while the counter-component 16 is arranged fixed to the housing with the associated frictional engagement element 14 relative to the drive housing 11. This can also be provided vice versa. The above-mentioned, axial adjustability of the frictional engagement elements 13, 14 to each other results here and preferably by an axial adjustability of the drive element 6, The axial adjustability between the frictional engagement elements 13, 14 but also by a corresponding axial bearing of the frictional engagement elements 13, 14 at be the drive element 6.

In the preferred exemplary embodiment shown in FIG. 2, the friction surface 14a of the friction-type closing element 14 assigned to the counter-component 16 is formed separately from the surface of the counterpart component 16 forming the air pump If18. Alternatively or additionally, it can be provided that the friction surface 13a of the frictional engagement element 13 assigned to the excitation component 15 is formed separately from the surface of the excitation component 15 forming the air gap 18. This spatial separation of the surfaces in question allows a particularly simple variant formation by the respective surfaces can be realized separately from each other.

In principle, however, it may also be provided that the friction surfaces 13a, 14a simultaneously also provide the surfaces forming the air gap 18. This makes it possible to achieve an even more compact arrangement. In the illustrated preferred embodiment, the excitation component 15 is a one-piece component that is locally magnetized differently. The individual excitation magnets 17a-f are thus each realized in a correspondingly local magnetization of the exciter component 15. Alternatively, however, it may also be provided that the excitation component 15 is configured in several parts, the excitation magnets 17a-f being designed as separate units.

The counter component is preferably made of a soft magnetic material, which is in particular a nickel-iron alloy, a cobalt-iron alloy, a steel material, in particular with a low carbon content, o. The like. A soft magnetic material has a comparatively Low remanence magnetization, so that the above-mentioned deactivation of the additional brake in the dynamic state of the drive element 6 is particularly clear.

The mode of operation of the proposed motor vehicle component is of particular importance in the present case. The motor vehicle component 1 is assigned a drive control 20, wherein the drive control 20 drives the drive motor 7 in a nominal speed range such that the pole change on the countercomponent 16, which is due to the relative rotation between the excitation arrangement 15 and the counterpart component 16, has a frequency above the magnetic limit frequency of the Material of the counter component 16 has. This means that the remagnetization of the counterpart component 16 can no longer follow the fast pole change produced by the exciter component 15, so that the braking effect of the additional brake 12 is significantly reduced or completely eliminated. This corresponds to the above-mentioned deactivation of the auxiliary brake 12 in the dynamic state of the drive element. 6

Depending on the design, it can be achieved with the above control of the drive motor 7 that the braking torque generated by the auxiliary brake 12 is less than 30% of the braking torque generated by the auxiliary brake 12 in the static state in the dynamic state of the drive element 6 at drive element 6 rotating in the rated speed range. Depending on the design can be achieved with the above control of the drive motor 7 further, that in the dynamic state of the drive element 6 at Nenndrehzahlbareich rotating drive element 6, the braking torque generated by the additional brake 12 is less than 10% of the braking torque generated by the friction brake 10.

Furthermore, the design may be such that the magnetic attraction between the excitation component 15 and the counter-component 16 is less in the static state, preferably at least 20% less, than in the dynamic state with the drive element 6 rotating in the nominal rotational speed range. This means that the normal force N, which is the cause of the friction torque of the friction brake 10, correspondingly decreases, so that the friction torque generated by the friction brake 10 decreases accordingly. As a result, a deactivation of the braking torque generated by the friction brake 10 in the dynamic state of the drive element 6 is at least to a certain extent recorded.

The dargesteiite in Fig. 2, constructive design of the brake assembly 9 allows the flexible use of the brake assembly 9 for a variety of applications. One reason for this is that the friction brake 10 and the additional brake 12 have a common housing 21, which is otherwise configured separately from the motor vehicle component 1, so that the friction brake 10 arranged in the housing 21 and the auxiliary brake 12 arranged in the housing 21 are common In principle, however, it can also be provided that the housing 21 of the brake assembly 6 is provided by an already provided housing of the motor vehicle component 1, in particular by the housing of the drive motor 7. It follows from the above explanations that in the illustrated preferred embodiment, the air gap 18 is determined by the fact that the excitation component 15 and the counter-component 16 are supported on one another via the friction surfaces 13a, 14a. However, this also means that it depends on a particularly low wear of the friction surfaces 13a, 14a. In order to reduce the wear between the friction surfaces 13a, 14a, it is preferably provided that at least one of the friction surfaces 13a, 14a, here and preferably both friction surfaces 13a, 14a, are provided with a coating. In terms of a simple production of the coating, it is preferably such that the relevant component, which has the respective friction surface 13a, 14a, is completely provided with the coating. In a preferred embodiment, it is provided that the coating has been applied to a base area in the CVD or PVD coating method. In particular, the coating is a DLC layer.

Alternatively, it can be provided that the coating has been applied to a base area in a galvanic coating process. In a particularly preferred embodiment, the coating is then a zinc / nickel coating, which further preferably has a PTFE additive.

A particularly good bond between the coating and the base surface can be achieved by applying the coating to the relevant base area in a chemical coating process. In this context, a nickel coating has proven in which, more preferably, the phosphorus content is less than 5% vol and in particular between 3% vol and 5% vol.

Alternatively, the coating may be formed as an anti-friction coating, wherein the Giteitlack particular has a ceramic portion and / or a molybdenum disulfide portion. A particularly hard coating can be achieved in that the coating is formed as a manganese-chromium-nitrite coating.

As an alternative to the above coatings, it may be provided that at least one frictional engagement element 13, 14 consists at least partly of a ceramic material or of a glass-metal material. A likewise preferred alternative for increasing the wear resistance of the friction surfaces 13a, 14a is that at least one of the friction surfaces 13a, 14a has a structured surface topology such that a mostly dust-like friction surface abrasion can be deposited in recessed surface areas.

According to a further teaching, which has independent significance, a flap assembly of a motor vehicle is claimed with a flap 2 and a proposed motor vehicle component 1 designed as a flap drive, the flap being connected by the flap drive between a motor vehicle component 1

Closed position and an open position is adjustable by motor. Reference may be made to all statements on the proposed motor vehicle component 1. In a particularly preferred embodiment, the arrangement is such that the flap 2 is held in each flap position by the combined braking action of the friction brake 10 and the auxiliary brake 12 in its static state. In this case, a vote of the above breakaway torque on the flap weight, a possibly provided, acting on the flap 2 spring arrangement and other possibly provided force effects on the flap 2 make.

According to another teaching, which also has independent significance, a method for the operation of a proposed motor vehicle component 1 as such is claimed.

It is essential according to the proposed method, that the drive motor 7 is controlled such that the prevailing on the counter-component 16, the relative rotation between the excitation component 15 and counter component 16 going back pole change of the excitation field of the excitation component 15 is a frequency above the magnetic limit frequency of the material Counter-component 16 has. Also in this respect may be made to all the above comments on the proposed motor vehicle component 1.

Claims

claims

1. motor vehicle component, in particular damper drive, with a about a rotational axis (5) rotatable drive element (6), in particular a drive shaft, and a drive motor (7) for the motorized adjustment of the drive element (6), wherein the motor vehicle component (1) a brake assembly (9), which is coupled to the drive element (6), wherein the brake assembly (9) forms a friction brake (10) which brakes the drive element (6) constantly,

characterized,

the brake arrangement (9) forms, in addition to the friction brake (10), an auxiliary brake (12) which operates in the manner of a magnetic hysteresis brake at least in the static state of the drive element (6) and brakes the drive element (6) in addition to the friction brake (10) ,

2. Motor vehicle component according to claim 1, characterized in that the drive element (6) located in its static state by applying a breakaway torque of the static state can be brought into a dynamic state and that the breakaway torque for the drive element (6) from a from the friction brake (10) eiseugten breakaway torque and from a portion of the auxiliary brake (12) generated breakaway torque component composed.

3. Motor vehicle component according to claim 2, characterized in that the auxiliary brake (12) generated breakaway torque on the breakaway torque at least 10%, preferably at least 20%, more preferably at least 25%.

4. Motor vehicle component according to one of the preceding claims, characterized in that the friction brake (10) has two about the rotational axis (5) rotatable relative to each other and axially adjustable friction frictional elements (13, 14) with friction surfaces (13a, 14a) that between the friction surfaces (13a, 14a) of the two friction engagement elements (13, 14) a normal force (N) acts, which generates a friction torque between the two friction engagement elements (13, 14).

5, motor vehicle component according to one of the preceding claims, characterized in that the auxiliary brake (12) has a permanent magnet exciter component (16) and a ferromagnetic counter component (17) which are rotatable relative to each other about the axis of rotation (5) that the excitation component (16 ) at least two relative to the axis of rotation (5) in particular axially magnetized exciter magnets (17a-f) provides that are distributed about the axis of rotation (5) and of alternating polarity, preferably that between the excitation component (16) and the counter component (17) a magnetic air gap (18) is arranged and that the excitation magnets (17a-f) each excite a magnetic circuit (19a-f) which is closed via the air gap (18) and the counter-component (17),

6, motor vehicle component according to claims 4 and 5, characterized in that a magnetic attraction force between the excitation component (16) and the counter-component (17) acts, which provides the normal force (N) for the friction brake (10)

7, motor vehicle component according to claims 4 and 5 and optionally, according to claim 6, characterized in that the excitation component (15) with one of the Reibschlusselemente (13, 14) is connected and that the counter component (16) with the other of the frictional engagement elements (13, 14) is connected.

8, motor vehicle component according to claims 4 and 5 and optionally according to claim 6 or 7, characterized in that the excitation component (15) and the counter component (16) with the normal force (N) on the friction surfaces (13a, 14a) of the frictional engagement elements (13, 14) support each other, whereby the width of the air gap (18) is determined.

9, motor vehicle component according to claim 5 and optionally according to any of arrival claims 6 to 8, characterized in that the counter-component (16) is made of a soft magnetic material, preferably, that the counter-component (16) made of a nickel-iron alloy , a cobalt-iron alloy, a steel material, in particular with a low carbon content, o. The like. Is configured.

10, motor vehicle component according to claim 5 and optionally according to one of claims 8 to 9, characterized in that the motor vehicle component has a drive control (20) and that the drive control (20) drives the drive motor (7) in such a rated speed range that the on Having the counter component (16), on the relative rotation between the exciter assembly (15) and the counter component (16) due to the pole change a frequency above the magnetic limit frequency of the material of the counter component (16).

1 1. Motor vehicle component according to claim 10, characterized in that in the dynamic state at the rated speed range rotating drive element (6) of the auxiliary brake (12) generated braking torque is less than 10% of the friction brake (10) generated braking torque.

12. motor vehicle component according to claim 10 or 11, characterized in that the magnetic attraction between the excitation component (15) and the counter-component (16) in the static state less, preferably at least 20% less than in the dynamic state at the nominal speed range rotating drive element ( 6)

13. Motor vehicle component according to one of the preceding claims, characterized in that the friction brake (10) and the auxiliary brake (12) have a common housing (21) which is otherwise configured separately from the motor vehicle component (1), so that in the Housing (21) arranged friction brake (10) and arranged in the housing (21) additional brake (12) as a brake assembly (22) are manageable.

14. Motor vehicle component according to claim 4 and optionally according to one of claims 5 to 13, characterized in that at least one of the friction surfaces (13a, 14a), preferably both friction surfaces (13a, 14a) are provided with a coating, preferably, that the component in question is completely provided with the coating.

15. Motor vehicle component according to claim 14, characterized in that the coating in the CVD or PVD coating method to a

Base has been applied, and / or that the coating in one galvanic coating method has been applied to a base surface, and / or that the coating has been applied to a base area in a chemical coating process, and / or that the coating is formed as a bonded coating.

16. Motor vehicle component according to one of the preceding claims, characterized in that at least one of the frictional engagement elements (13, 14) consists at least partly of a ceramic material or of a glass-metal material.

17. Motor vehicle component according to one of the preceding claims, characterized in that at least one of the friction surfaces (13a, 14a) each having a structured surface topology such that a Reibflächenabrieb can be deposited in recessed surface areas.

18. A car wing assembly of a motor vehicle with a flap (2) and a flap (2) associated flap drive according to one of the preceding claims, with which the flap (2) between a closed position and an open position is adjustable by motor.

19, flap assembly according to claim 18, characterized in that the flap (2) in each flap position by the combined braking action of the friction brake (10) and the auxiliary brake (12) is kept in its static state.

20. A method for operating a motor vehicle component, in particular a damper drive, according to claim 5 and optionally according to one of claims 6 to 17, characterized in that the drive motor (7) is driven such that on the counter component (16) prevailing, Having on the relative rotation between the excitation component (15) and counter component (16) going back pole change a frequency above the magnetic limit frequency of the material of the counter component (16).