WO2011003826A1

WO2011003826A1 - Locking device for releaseably locking an adjustable part

Info

Publication number: WO2011003826A1
Application number: PCT/EP2010/059449
Authority: WO
Inventors: Georg Scheck; Sebastian Heinze; Alwin Macht; Hartmut Beyersdorfer
Original assignee: Brose Fahrzeugteile Gmbh & Co. Kg, Coburg
Priority date: 2009-07-10
Filing date: 2010-07-02
Publication date: 2011-01-13
Also published as: DE102009033469B3; DE102009033469B9

Abstract

The invention relates to a locking device for releaseably locking an adjustable part, in particular a motor vehicle part that can be displaced relative to a motor vehicle structure and that can be locked by the locking device within an adjustment range in a rest position reached by displacement, having at least one friction element (1) of the locking device and having at least one second friction element (2) of the locking device that is rotatable relative to the first friction element (1), a friction surface (10) of the first friction element (1) encompassing annularly in cross section the second friction element (2), and a circumferential second friction surface (20) of the second friction element (2) along the first friction surface (10) and opposite to the same, wherein the friction surface (20) of the second friction element (2) can slide along the associated friction surface (10) of the first friction element (1) under sliding friction conditions during a relative motion of the two friction elements (1, 2) initiated by displacing the adjustable part, and wherein the friction surface (20) of the second friction element (2) contacts the friction surface (10) of the first friction element (1) under static friction conditions in each rest position of the adjustable part. The second friction element (2) thereby contacts the first friction surface (10) in each rotary position relative to the first friction element (1) only in one or more partial regions (T, T1, T2) of the second friction surface (20), covering a total of no greater than 30% of the second friction surface (20).

Description

Locking device for releasably locking an adjustment part

description

The invention relates to a locking device for releasably locking an adjustment part, in particular a movable with respect to a motor vehicle structure motor vehicle part, which is locked by means of the locking device within a displacement range in a respective achieved by displacement rest position, according to the preamble of claim 1. Such a locking device comprises at least a first A friction element and a second friction element rotatable relative to the first friction element, which has a circumferential (outer) friction surface which is encompassed by an associated friction surface of the first friction element (ring-shaped in cross section), wherein during a relative movement of the two (triggered by displacement of the adjustment part) Friction elements, ie, a rotation of the two friction elements to each other, the second friction element (under Gleitreibungsbedingungen) with its friction surface along the associated friction surface of the first Reibelem Entes can slide and wherein in a respective rest position of the adjusting the second friction element with its friction surface (under static friction conditions) rests against the friction surface of the first friction element.

Under an annular in cross-section encompassing the second friction element by the friction surface of the first friction element is not only an annular Embracing understood as a special case, but the cross-sectionally annular contour of the first friction surface can be performed, for example, oval, polygonal or otherwise irregularly circulating. One of the two friction elements, for example the first friction element, is fixedly provided as a structure-side friction element on a structural component with respect to which the adjustment part is displaceable, in particular on a motor vehicle structure; and the other friction element, for example the second friction element, is associated with the adjustment part, eg a displaceable motor vehicle part, and is coupled thereto in such a way that it is rotated upon a displacement of that part. It depends on the function of the locking device on a relative movement of the two friction elements, without the specific assignment of the first and second friction element would be crucial on the one hand to a structural component and on the other hand to an adjustment.

In particular, one of the friction elements (for example the second friction element) may be coupled to the adjustment part (directly or indirectly via a driver) such that a (rotational) moment is introduced into the locking device as a result of a force or torque action on that part, which (possibly via a driver) on the rotatable (eg second) friction element of the locking device is transferable.

The (continuous) lockability of the adjustment by the associated locking device need not necessarily be provided in the entire, maximum possible adjustment of the corresponding part. So it may be sufficient if - depending on the application - the adjustment part, e.g. a displaceable motor vehicle part, can be locked only in a portion of its maximum adjustment range by means of the locking device in a respective displaced position. The area in which the locking device is effective is also referred to herein as a displacement area.

A motor vehicle part which can be locked in the displaced state (steplessly) can be a pivotable or foldable motor vehicle part, such as a motor vehicle door (side or rear door) or a closure flap (front or tailgate) of a motor vehicle. But it can also be provided by displaceable by moving motor vehicle part. By relocating a motor vehicle part with respect to the vehicle structure, in particular folding down of the motor vehicle part from the vehicle structure, in the case of a motor vehicle part in the form of a vehicle door access to the vehicle interior can be released or in the case of a motor vehicle part in the form of a shutter access to the vehicle engine or a trunk , In this case, it may be desirable not to fold the corresponding motor vehicle part down to its maximum possible pivoting position, but to make only a limited folding down into a partially folded-down position with a smaller folding angle compared to the completely folded-down position. This may be important, for example, if third-party vehicles are parked in the vicinity of a motor vehicle, which are not to be damaged when a motor vehicle part is folded down. For this purpose, the corresponding motor vehicle part should be lockable in its partially folded position by means of the locking device so that it is not already folded by a gust of wind or unintentional light touch, which could indeed have a collision with an adjacent vehicle result.

The locking device should thus on the one hand ensure sufficient ease of movement of a motor vehicle part, such as a vehicle door, when opening and closing and on the other hand sufficiently secure the corresponding motor vehicle part in a respective displaced state.

A locking device of this kind is known for example from WO 2009/007400 A1. In this case, according to a variant of the locking device described in WO 2009/007400 A1 a flowable additional medium is provided which can be brought in a relative movement of the friction between the friction surfaces to reduce the sliding friction, and which at a transition of the two friction elements in a rest position and so that static friction conditions from the space between the two friction elements is pressed in order to obtain the greatest possible static friction. The transport of the additional medium can take place via guide channels, which are formed on one of the two friction elements.

Furthermore, a generic locking device can also be used for coupling with an adjustment outside a motor vehicle, eg with a folding or tilting window of a building, a shutter, shutters of all kinds, eg on furniture or computers (notebooks), etc. The invention is based on the problem to provide a locking device of the type mentioned above, which is characterized by a reliable, reliable function with a simple structure. This problem is inventively solved by the provision of a locking device with the features of claim 1.

Thereafter, the second friction element in a respective rotational position with respect to the first friction element in each case only over one or more portions of the second friction surface with the first friction surface in contact, which cover a total of at most 30% of the second friction surface.

In other words, the friction surfaces of the two friction elements in each relative rotational position of the second friction element with respect to the first friction element only touch at most 30% of the friction surface of the second friction element. The active second friction surface is thus formed (only) by partial regions of the complete second friction surface (as a mating surface to the first friction surface of the first friction element) at a respective relative position of the two friction surfaces, which come into contact with the first friction surface when the locking device is used as intended can and make up at most 30% of the first friction surface. Although the remaining regions of the second friction surface are opposite to the first friction surface, which runs annularly in cross section in the manner of a mating surface; however, they are substantially spaced therefrom so that there is no contact under either sliding friction conditions or under static friction conditions.

Under the cross-sectional plane in which the first friction surface surrounds the second friction surface in an annular manner, in the present case a section perpendicular to the axis of rotation is understood, about which the two friction elements are rotatable relative to one another. The solution according to the invention makes it possible, with a simple design of the friction elements, to create free spaces between the mutually associated friction surfaces of the two friction elements without channels, pockets or other (concave) indentations being provided on one of the friction elements for this purpose. Because the mutual friction surfaces are only in partial contact with each other, free spaces between the two friction surfaces are formed outside of these subregions, where the two friction surfaces are spaced from each other. In addition, despite the reduced contact areas of the two friction surfaces because of the associated increased surface pressure at the existing contact areas under static friction conditions (ie in the resting state of the two friction elements) large holding forces can be achieved. The friction surfaces of the two friction elements can be designed such that the subregions of the second friction surface, which are in contact with the first friction surface in a respective rotational position of the second friction element with respect to the first friction element, at most 10% or even only at most 5% or 3% of make out second friction surface. In particular, it may be provided that the second friction surface bears against the first friction surface in a substantially line-like manner (or in a substantially point-like manner in cross section). In the case of a second friction surface formed by a circumferential lateral surface of the second friction element, this can be achieved, for example, in that the second friction surface has a different curvature than the first friction surface in the partial regions in which it is in contact with the first friction surface.

It can be provided on the one hand, that at least a portion of the second friction surface at each rotational position of the second friction element with respect to the first friction element is spaced from the first friction surface, e.g. in that, in each rotational position of the second friction element with respect to the first friction element, the same portion or the same portions of the second friction surface are in contact with the first friction surface.

On the other hand, it can be provided that, depending on the rotational position of the second friction element with respect to the first friction element different portions of the second friction surface with the first friction surface in contact, in particular in such a way that upon rotation of the second friction element with respect to the first friction element by 360 ° All areas of the second friction surface at least once in contact with the first friction surface. In order to be able to specify the area fraction of the subregions of the second friction surface over which the second friction surface rests against the first friction surface, it is necessary to define the boundaries of the second friction surface (in particular in the axial direction, which revolves as a lateral surface of the second friction element) , This may be particularly important if the second friction surface is not unique to other elements of the locking device, z. B. by discontinuities, is delimited. Preferably, the axial extent of the second friction surface is defined so that the axial extent of the second friction surface is limited by the axial limits of the partial regions, via which the second friction element bears against the first friction surface with the second friction surface.

According to one embodiment of the invention, the second friction surface is composed of Reibelementabschnitten, each of which at its the first

Friction surface opposite surface in cross-section convexly curved or rectilinearly extends, said friction element sections can be integrally formed in particular in one piece and thus connect seamlessly to each other. That is, the individual friction element sections need not be separately recognizable on the second friction element, but may in particular form a unitary, integrally formed friction element.

According to one embodiment of the invention, the mating surface of the second friction element is formed as a second friction surface exclusively from in cross-section convexly curved friction element sections. Alternatively it can be provided that the mating surface is composed of both in cross-section convexly curved and rectilinearly extending Reibelementabschnitten, wherein in particular in cross-section convex curved portions can be connected to each other via a rectilinearly extending portion. In particular, therefore, the counter surface may be free of concave shaped surface portions, such as channels or pockets.

At the transition between two Reibelementabschnitten with different curvature in cross section each discontinuity points may be formed on the mating surface.

According to a variant of the invention, the mating surface forms a surface which runs along the first friction surface and which is opposite to it and convexly curved in cross-section, for example in the form of an oval or elliptical surface of annular cross-section.

According to another embodiment of the invention, form the Reibelementabschnitte, of which the counter surface of the second friction element is formed in cross-section at least two circular sections with different radius of curvature. That in a respective rotational position of the second friction element with respect to the first friction element only a part of the counter surface of the second friction element is in contact with the first friction surface can be achieved for example by an eccentric bearing and / or an eccentric configuration of the counter surface with respect to the first friction surface or further by an eccentric design of the first friction surface with respect to the second friction surface.

According to a development of the invention, the second friction surface is formed by at least two curved Reibelementabschnitte over which they can each rest simultaneously on the first friction surface, in particular a system can be provided over at least two opposing curved Reibelementabschnitte. Furthermore, at least two sections of different curvature may also be under the said friction element sections. By the second friction surface with at least two spaced apart Reibelementabschnitten, in particular along the circumferential direction of spaced Reibelementabschnitten abuts the first friction surface, between these Reibelementabschnitten each free spaces between the two friction elements and their friction surfaces may be formed.

The spaced-apart Reibelementabschnitte can be arranged both in a cross-sectional plane, as well as lying in different cross-sectional planes. Furthermore, the second friction element may be multi-part, that is to say at least two parts, wherein the contact of the at least two friction element parts on the friction surface of the first friction element is controlled via elastic means.

In general, elastic means may be provided in order to clamp the two friction elements against each other in such a way that they are in contact with one another via their friction surfaces, in particular in such a way that only a part of the second friction surface is in contact with the first friction surface.

The locking device according to the invention is particularly advantageous when using a flowable additional medium, which in a relative movement of the

Friction elements between the friction surfaces can be brought and which can be pushed out of the area between the two friction surfaces when the two friction elements abut each other over their friction surfaces under static friction conditions. As a result, while ensuring a sufficiently large static friction at the same time the sliding friction is minimized. It can further be provided that in a free space forming region in which the first friction surface is not applied to the counter surface of the second friction element, the distance between the first friction surface and the counter surface is at least partially so small that there occurs a capillary effect, the an increase of the flowable additional medium (along the axis of rotation about which the two friction elements are rotatable relative to each other) causes; such a capillary effect of such a magnitude that the lubricant at typical operating temperature - based on the extension of the second friction element along the axis of rotation - under capillary action by at least 30%, in particular by more than 50%, rises.

Further details and advantages of the invention will become apparent in the following description of exemplary embodiments with reference to the figures.

Show it:

Figure 1A is a schematic cross-sectional view of two cooperating

Friction elements of a locking device;

Figure 1 B, a first embodiment of the arrangement of Figure 1 A;

Figure 1 C, a second embodiment of the arrangement of Figure 1 A;

Figure 2A shows a locking device on the basis of two friction elements of the in FIG

1A in a longitudinal section;

Figure 2B shows a first modification of the locking device of Figure 2A;

Figure 2C shows a second modification of the locking device of Figure 2A; Figure 3A shows another embodiment of two cooperating friction elements of a locking device in cross section; FIG. 3B shows a first development of the arrangement from FIG. 3A; FIG. 3C shows a second development of the arrangement from FIG. 3A; Figure 4A shows a further embodiment of a locking device with two cooperating friction elements in longitudinal section;

4B shows a cross section through the locking device of Figure 4A in the region of

friction;

Figure 5A is a modification of the locking device of Figure 4A with respect to

Inclination of the friction surfaces;

FIG. 5B shows a cross section through the locking device of FIG. 5A in the region of FIG

friction;

Figure 6 shows a modification of the locking device of Figure 4A with respect to

Embodiment of the friction surface of a friction element in longitudinal section; FIG. 7A shows a further embodiment of two cooperating friction elements of a locking device in cross-section, namely at a first temperature of a flowable additional medium which can be brought between the two friction elements; Figure 7B shows the arrangement of Figure 7A at a second temperature of the flowable

Additional medium;

Figure 8A is a longitudinal section through a further embodiment of a

Locking device with two cooperating friction elements, and that at a first temperature of a bringable between the two friction elements flowable additional medium;

8B, the locking device of Figure 8A at a second temperature of the flowable additional medium. Figure 9A is a cross-section through cooperating friction elements of a locking device, wherein one of the friction elements consists of two separate components; FIG. 9B shows a modification of the arrangement of FIG. 9A;

Figure 10 is an illustration of a known construction of a locking device with two cooperating friction elements in longitudinal section; Figure 11A is a perspective view of the lateral vehicle structure of a

Motor vehicle with an unfolded vehicle door;

Figure 11 B is a perspective view of the back of a motor vehicle with an opened rear door.

FIG. 11A shows a section of the lateral vehicle structure (body K) of a motor vehicle which, together with the roof area D of the motor vehicle, defines and encloses a door opening O through which a passenger can enter the interior of the motor vehicle. For closing the door opening O, a displaceable or deflectable motor vehicle part is provided in the form of a hinged side door S, which is shown in FIG. 1A in a partially folded-down position. The folding down of a side door S of a motor vehicle from the vehicle structure K into a partially folded-down position takes place, for example, regularly when a third vehicle is parked next to the motor vehicle, so that the side door S can not be opened arbitrarily wide without colliding with the third vehicle. It is then important that the side door S is locked in the partially unfolded position so that it is not already unfolded by a gust of wind or unintentional contact by a passer, as it could thereby collide with the adjacent third party vehicle. For this purpose, so-called locking devices are provided with which a side door S can be locked in a partially unfolded position.

The aim is to make such a locking device so that on the one hand allows a reliable locking of a motor vehicle door in partially unfolded position, but at the same time does not affect a desired ease of movement of the vehicle door when opening and closing. Different embodiments of locking devices, with which this goal can be achieved, will be described below with reference to Figures 1A to 9B. It should be further clarified with reference to FIG. 11B that locking devices of the type mentioned can be provided not only in side doors of a motor vehicle, but also, for example, in a rear door or tailgate H provided on the rear side R of a motor vehicle and serving to close a cargo space L. Further possible fields of use are trunk flaps, engine flaps, sliding doors, adjustable loading floors, roller blinds and other vehicle parts which are displaceable (deflectable) relative to a structural subassembly of the motor vehicle. In the following, it will be generally speaking in each case of deflectable motor vehicle parts, wherein in particular pivotable (hinged) but also displaceable motor vehicle parts are to be included.

Furthermore, the locking devices to be explained below can also be used for locking displaceable adjusting parts outside of motor vehicles, e.g. on buildings, furniture, implements, etc.

FIG. 10 shows in a longitudinal section the basic structure (eg known from WO 2009/007400 A1) of a locking device by means of which a deflectable motor vehicle part, such as a side door according to FIG. 1A or a rear door according to FIG. 11B or a sliding door, or another adjustment in a partially deflected position can be locked.

The locking device comprises a housing 5 with a housing lower part 51 and a housing upper part 52, which are fastened to each other by suitable fastening means, for example in the form of screws or rivets. In the housing 5, two friction elements 1, 2 are arranged, the mutually facing friction surfaces 10, 20 are engageable with each other to be able to lock by the thereby acting (static) static friction a deflectable motor vehicle part continuously in partially deflected position.

The first friction element 1 is formed by a portion of the inner wall of the housing 5, more precisely a portion of the inner wall of the housing base 51, which is rotationally symmetrical with respect to a housing axis A and the one to the housing bottom of the housing base 51 conically tapered friction surface 10 of the first friction element first defines or forms. Thus, the first friction element 1 is fixed to the housing by its with respect to the housing axis A rotationally symmetrical, conically tapered friction surface 10 an immediate Part of an annular circumferential inner side wall of the housing 5 forms. Alternatively, a housing-fixed first friction element, for example, also be realized in that a separate from the inner wall of the housing friction element is fixed in the interior of the housing.

The (disk-shaped) second friction element 2 is rotatably mounted on a shaft 3, which is rotatably mounted at its two ends 31, 32 in an associated bearing 53 and 54 of the housing 5 and the axis of rotation A coincides with the housing axis, with respect to the first friction element 1 is rotationally symmetrical. The second friction element 2 is also (apart from structuring its friction surface) substantially rotationally symmetrical with respect to that axis A and tapers - as well as the first friction element 1 - to the (bottom of the housing 51 provided) housing bottom. As a result, the second friction element 2 defines on its outer circumference a conical friction surface 20 which lies opposite the conical friction surface 10 of the first friction element 1 and can be brought into frictional engagement therewith.

In order to bring the friction surfaces 10, 20 of the two friction elements 1, 2 frictionally engaged with each other, an elastic element 4 in the form of a spring, more precisely designed as a compression spring coil spring is provided, which surrounds the shaft 3 and on the one hand to a widened end portion 32 of the shaft 3 and on the other hand on the second friction element 2 is supported, in such a way that it has the tendency to clamp the second friction element 2 against the first friction element 1 and thereby bring the two friction surfaces 10, 20 with each other. In other words, the effective direction Ri of the prestressed elastic element 4 applied forces or bias is such that it extends along the shaft 3 and the axis A and the second friction element 2 along that direction Ri against the first friction element. 1 braced. In order to continue to allow axial movement of the co-rotating mounted on the shaft 3 second friction element 2, so that it along the effective direction Ri of the bias of the elastic element 4 defined with the friction surface 10 of the first friction element 1 is engageable, the rotationally fixed mounting of second friction element 2 on the associated shaft 3 by means of interlocking form-fitting regions F2, F3 of the friction element 2 and the shaft 3, which allow axial mobility of the second friction element 2 along the axis A of the shaft 3 (and thus also coincides with the housing axis). Specifically form the Form-fitting regions F2, F3 here by way of example a tongue and groove connection with a provided on the second friction element 2 groove F2, which extends along the shaft axis A, and with an associated, projecting from the shaft 3 outwardly into the groove F2 in spring F3 in Form of a projection.

The form-locking region F3, which protrudes outwards from the shaft 3 in the form of a spring, engages in the assigned form-fit region F2 in the form of a groove of the second friction element 2 such that the second friction element 2-with the exception of an optionally present rotation angle play-is substantially non-rotatably mounted on the shaft 3 is supported, but can - under the action of the bias of the elastic element 4 - along the axis A limited shift, the (maximum) possible extent of displacement is limited by the fact that the second friction element 2 under the effect of the bias of the elastic Element 4 is pressed with its friction surface 20 against the associated friction surface 10 of the first friction element 1.

Due to its axially displaceable mounting, the second friction element 2 can be tracked (automatically) under the action of the prestressing of the elastic element 4 so that it is always defined with the associated friction surface 10 of the first friction element 1, even after a long period of operation of the locking device and associated wear is in an attack. The tracking takes place automatically under the action of the bias of the elastic element 4 and taking advantage of the axial displaceability of the second friction element 2 along the shaft 3. The material for the friction surfaces 10, 20 of the two friction elements 1, 2 is to be chosen so that the both friction surfaces 10, 20, when they are under the action of the bias of the elastic member 4 engaged with each other, generate a sufficiently large static static friction to lock by means of the locking device partially deflected with respect to the vehicle structure motor vehicle part in its deflected position can. Suitable combinations of materials for the two friction surfaces 10, 20 are further, for example, steel / plastic. In the present case, it should be assumed by way of example that of the two friction surfaces 10, 20, one (outer friction surface 10) made of steel and the other (inner friction surface 20) made of POM (polyoxymethylene). In addition to a reliable locking a deflected motor vehicle part, the parking brake should also allow the smoothest possible deflection of the corresponding motor vehicle part; that is, between the two Frictional surfaces 10, 20 of the friction elements 1, 2 acting friction forces should be as low as possible relative to each other in a relative movement of the two friction surfaces 10, 20. In other words, the sliding friction acting between the two friction surfaces 10, 20 during a relative movement should be significantly lower, if possible many times less than the (static) static friction acting between the two friction surfaces 10, 20, when the second Friction element 2 is clamped in rest position by the elastic member 4 against the first friction element 1.

The movement of the second friction element 2 during a deflection of an associated, to be locked by means of the parking brake motor vehicle part, for example a

Side door or a rear door of a motor vehicle, it is triggered by the fact that the shaft 3, on which the second friction element 2 is rotatably mounted, is coupled to that deflectable motor vehicle part, in such a way that a deflection of that motor vehicle part, so as a vehicle door, in a rotational movement of the shaft 3 is reacted about its axis A. For this purpose, the shaft 3 on the one hand attack directly on a pivot axis about which a deflectable motor vehicle part is pivoted, or it may be the shaft 3, a transmission upstream, via the one

Deflection of the corresponding motor vehicle part is converted into a rotational movement of the shaft. Such a transmission can then cause, for example, a defined ratio (for increased speeds of the second friction element) or also a directional deflection, for example, to be able to arrange the shaft 3 in a specific spatial direction.

As a result, therefore, the second friction element 2 via the associated shaft 3 with an associated, deflectable motor vehicle part, such as a vehicle door, to couple that deflection of that motor vehicle part has a rotational movement of the shaft 3 result.

The other, first friction element 1 is then to be fixed in such a way with respect to the vehicle structure, that it is not taken in a deflection of the motor vehicle part to be detected. This can be achieved, in particular, by the fact that the housing 5, on the inner wall of which the first friction element 1 is formed with its friction surface 10, is arranged structurally on the vehicle, for example on the frame of a vehicle door associated with the locking device.

As a result, a deflection movement of the deflectable motor vehicle part assigned to the locking device results in that the second friction element 2 is rotated by the shaft 3 about the axis A with respect to the first friction element 1, wherein the two conical friction surfaces 10, 20 slide against each other. The aim now is to limit the sliding friction forces occurring while at the same time ensuring the greatest possible static static frictional forces in such a way that no deflection of the said motor vehicle part is counteracted by excessive frictional forces. For this purpose, on the one hand contribute a suitable selection of the materials used for the two cooperating friction surfaces 10, 20, in particular by using such material pairings in which the static static friction is substantially greater, in particular by a multiple greater than the sliding friction.

Alternatively or additionally, the use of a (flowable) Zusatzbzw. Intermediate medium Z is provided, which is to bring during a movement of the second friction element 2 relative to the first friction element 1 between the mutually facing friction surfaces 10, 20 of the two friction elements 1, 2 and reduces the frictional forces acting. As a lubricant for reducing the frictional forces, a suitable oil, for example, fluorosilicone base oil with ester additives can be used, especially in combination with friction surfaces 10, 20, one of which is made of metal (steel) and the other of (thermoplastic ) Plastic (eg PA / polyamide or POM / polyoxymethylene).

The additional or intermediate medium Z in the form of a lubricant, ie consisting of a flowable material, is provided in the lower housing part 51, with a filling height such that it reaches at least as far as the underside of the second friction element 2 facing the housing bottom, but preferably the second friction element 2 surrounds total.

Thus, during a relative movement, ie a rotational movement, of the second friction element 2 with respect to the first friction element 1, a sufficient portion of the flowable additive or intermediate medium Z between the friction surfaces 10, 20 of the two friction elements 1, 2 can pass and thereby reduces the sliding friction accordingly can be provided along the friction surface 20 of the second friction element 2 guide channels, as described in WO 2009/007400 A1, in which the additional or intermediate medium Z is received and from which it during a rotational movement of the second friction element 2 between the two friction surfaces 10, 20 can pass. In this case, those channels, for example, as depressions (grooves or grooves) in the friction surface 20 of the second friction element 2 are formed in the Substantially along the shaft 3 and whose axis A extend, but - are inclined to that direction - according to the inclination of the friction surface 20.

In the resting state of the second friction element 2, that is, when about a deflected motor vehicle part is to be locked in the deflected position by means of the locking device, the additional or intermediate medium Z under the action of the biasing force of the elastic member 4 from the area between the abutting friction surfaces 10, 20 pushed out, so that the stiction is not affected. The type and amount of the additional medium Z to be provided is advantageously to be selected so that the second friction element 2 does not float under static friction conditions (resting state), ie the additional medium Z from the area of the mutually associated friction surfaces of the friction elements 1, 2, as described above. can be displaced to ensure reliable stiction at rest.

Overall, thus follows with reference to the figure 1 the following: Ends the deflection movement, which has led to the displacement of a locking device associated motor vehicle part, such as a vehicle door, so the shaft 3 does not continue and the second friction element 2 is the first friction element 1 stationary , wherein the mutual friction surfaces 10, 20 abut each other. Under the effect of the biasing force generated by the elastic element 4 then the intermediate medium Z located between the two friction surfaces 10, 20 is at least pushed away at the points at which the friction surfaces 10, 20 abut directly against one another. After a short transitional period, which is required for the pushing away of the intermediate medium Z, then the increased (dry) static friction between the two friction surfaces 10, 20 starts.

If later the corresponding motor vehicle part is moved again, for example in order to deflect it further or to fold it back into its original position, the static friction between the friction surfaces 10, 20 of the locking device must first be overcome for this purpose. As soon as the second friction element 2 is moved with its friction surface 20 again with respect to the first friction element 1 and its friction surface 10, that is, is rotated is - possibly by means of guide channels, which gradually during the rotational movement of the second friction element 2 all areas of Sweep over the friction surface 10 of the first friction element 1 - ensures that the friction surface 10 of the first friction element 1 continuously with intermediate medium Z is wetted over which then the friction surface 20 of the second friction element 2 can slide with reduced sliding friction.

When the locking device shown in Figure 10, the two friction elements 1, 2 with their friction surfaces 10, 20 substantially along the entire circumference of the locking device in contact when the two friction elements 1, 2 via their friction surfaces 10, 20 either under static friction conditions (in the rest position) or under sliding friction conditions (in a relative movement of the second friction element 2 with respect to the first friction element 1) abut each other. Exceptions to this are possibly only those (concave-shaped) areas of one or the other friction surface 10, 20, on which guide channels are formed, by means of which an additional medium Z is transportable, during a relative movement (sliding friction conditions) between the mutually associated friction surfaces 10, 20 to bring and drain in the rest position (static friction conditions) again.

A first embodiment of a locking device will now be described with reference to FIG. 1A, deviating from that principle in that only partial areas of the two friction surfaces 10, 20 are in contact with each other as intended, when the two friction elements 1, 2 over the friction surfaces 10, 20 under static friction conditions abut each other or slide under Gleitreibungsbedingungen relative to each other.

This embodiment of a locking device is based on the recognition that a defined static friction between the friction surfaces 10, 20 of the two friction elements 1, 2, which leads to the secure locking of a movable motor vehicle part, such as a motor vehicle door, is also achievable if the two Friction elements 1, 2 are only about portions of their friction surfaces 10, 20 in contact with each other. In this case, in particular, a surface pressure which is increased at the contact regions of the two friction surfaces 10, 20 and optionally a wedge effect occurring in the cross-sectional plane of the friction elements can be utilized, as will be explained in more detail below.

In a cross-sectional plane perpendicular to the axis of rotation D, with respect to which the two friction elements 1, 2 are rotatable relative to each other, as shown for example in Figures 1 A to 7B, are preferably at most 50%, in particular at most 30% or even at most 10% or only 3% to 5% of a respective friction surface 10 or 20 in contact of the respectively associated other friction surface 20 or 10, which in particular by a (by different curvatures of the two friction surfaces 10, 20 produced) substantially linear or in cross-section point-like contact of the two friction surfaces 10, 20 can be achieved.

In order to be able to specify the surface portion of the subregions of the second friction surface 20, via which the second friction surface 20 rests against the first friction surface 10, also without reference to the cross-sectional plane, it is necessary to define the boundaries G1, G2 of (as lateral surface of the second friction element 2 circumferential and opposite surface of the first friction surface 1) second friction surface 20, in particular in the axial direction to define or set. Here, the axial extent of the second friction surface 20 is defined such that the axial extent of the second friction surface 20 is limited by the axial boundaries G1, G2 of the subregions T, T1, T2, cf. FIGS. 2A-2C and 4A, 4B, 6, 8A and 8B, via which the second friction element 2 rests with the second friction surface 20 on the first friction surface 10. FIG. 1A shows, in a cross section perpendicular to the housing axis or rotational axis A, D of a locking device, as shown in FIG. 10, a first exemplary embodiment of an arrangement of two friction elements 1, 2 which, in the said cross-sectional plane, each have only partial areas T of their friction surfaces 10, 20 are in contact. The arrangement of Figure 1A starts - as well as the previously described with reference to Figure 10 known locking device - of two friction elements 1, 2, of which one friction element 1 as an outer (in the example fixed to the housing) friction element, the second, inner (rotatable in the embodiment mounted) friction element 2 in cross-section annularly surrounds, so that the radially inner surface of the first friction element 1 serves as its friction surface 10 and the radially outer surface of the second friction element 2 serves as a second friction surface 20, which faces the first friction surface 10 as a counter surface is or is opposite. In the exemplary embodiment of FIG. 1A, both friction surfaces 10, 20 run in cross section along a circular line, wherein the diameter of the first friction surface 10 is greater than the diameter of the second friction surface 20 (mating surface) ), so that between the friction surfaces 10, 20 of the two friction elements 1, 2, a clearance F is formed, which preferably extends in the axial direction (perpendicular to the cross-sectional plane of Figure 1A) along the entire length of the second friction element (2). The two friction surfaces 10, 20 may, for example, cylindrical surfaces or in axially tapered conical surfaces, corresponding to the arrangement of Figure 10, form.

However, in the present case, the second, inner friction element 2 in the case of FIG. 1A with its friction surface 20 is not arranged concentrically with respect to the first, outer friction element 1 and its friction surface 10, but rather off-center (eccentric).

Specifically, the housing axis A, which defines the center of the circle, on the circular line in the cross-sectional view, the first friction surface 10 extends, and the axis of rotation D of the second friction element 2, which in the embodiment forms the center of the limited by the second friction surface 20 circle from each other spaced, so that there is an eccentricity e corresponding to this distance in the storage of the second friction element 2 with respect to the first friction element 1. The said distance or the associated eccentricity e is selected such that the second inner friction element 2 in each friction layer bears in each case with a portion T of its friction surface 20 (as an active friction surface) against the associated friction surface 10 of the outer, first friction element 1 shown in Figure 1A.

Because of the cross-sectionally circular configuration of the two friction surfaces 10, 20, the mutual contact is punctiform in cross-section or in consideration of the extent of the friction elements 1, 2 along the housing axis A and axis of rotation D (perpendicular to the plane of the figure 1A). In actual systems, however, there is actually a two-dimensional contact of the two friction surfaces 10, 20 in a respective subregion T.

In general, in the following explanation of Figures 1A to 7B references to circles, circular sections, arcs, punctual installations, etc. in each case the cross-section of the friction elements 1, 2 such. As shown in Figures 1A to 1C and 3A to 3C respectively. In fact, the respective second friction element 2 is provided with an extent in the axial direction (perpendicular to the plane of the figures); However, for the sake of simplicity in the explanation of cross-sectional representations, as in Figures 1A to 1C, 3A to 3C, 4B, 5B, 6, 7A and 7B, not always expressly noted that the description of the respective geometry of the second friction element 2 relates specifically to its two-dimensional cross-sectional design and not to its actual three-dimensional shape. As a result of the wedge effect present in the cross-sectional plane according to FIG. 1A, if the two friction elements 1, 2 abut against each other via their friction surfaces 10, 20 in a subregion T, as shown in FIG. 1A, the static friction is reinforced (by wedging forces), even at a comparatively small contact surface of the two friction surfaces 10, 20 a sufficiently strong braking or locking action can be achieved.

The free space F formed between the two friction elements 1, 2 or their friction surfaces 10, 20 outside the partial area T is available for the transport of an additional medium Z, as shown in FIG. 10, so that the additional medium, on the one hand, during a rotational movement (sliding friction conditions) can be selectively brought between the friction surfaces 10, 20 of the two friction elements 1, 2 and on the other hand in the presence of static friction conditions (rest position of the friction elements 1, 2) from the portion T, in which the two friction surfaces 10, 20 abut each other, can be pushed out.

The free space F between the two friction elements 1, 2 or their friction surfaces 10, 20 (for a liquid transport in the circumferential direction U, to bring the additional medium between the contacting (active) areas of the friction surfaces 10, 20 and away from there) is present here without the formation of guide channels or other special receiving areas on one of the two friction surfaces 10, 20 created. Rather, the second, inner friction surface 20 in the cross section is continuously convexly curved and the associated first, outer friction surface in the cross section consistently concave curved.

In the embodiment of Figure 1A, a force on the second friction element 2, which defines this friction element 2 clamped against the first friction element 1, so that they rest with a portion T of their friction surfaces 10, 20 against each other, for example, generated by the gravitational force, especially in horizontal Position of the housing axis A and the axis of rotation D.

In contrast, in the exemplary embodiment of FIG. 1B, an elastic element 41, here in the form of a tension spring, is provided, which braces the two friction elements 1, 2 against one another in such a way that they abut each other over a portion T of their friction surfaces 10, 20. The elastic element 41 in the form of a tension spring acts for this purpose between the two friction elements 1, 2 and engages in the embodiment with a first spring end 41 a on a first friction element 1 associated (housing-side) abutment W1 and with a second spring end 41 b on an abutment W2 assigned to the second friction element 2, which is here arranged concentrically with respect to the axis of rotation D of the second friction element 2. By here as the elastic element 41, a spring with temperature-dependent spring constant or in any other way with respect to its spring characteristic temperature-controllable spring element is used, it can be ensured that temperature dependencies in the properties of an additional medium used (lubricant), z. B. of its viscosity can be compensated. Thus, it may be desirable to brace the two friction elements 1, 2 at lower temperatures with a comparatively greater spring force against each other, since with decreasing temperatures, the viscosity of the additional medium used, for. B. in the form of oil tends to increase and thus for a rapid displacement of the located between the friction surfaces 10, 20 in the subregion T additional medium in the transition from Gleitreibungs- to static friction conditions, a correspondingly greater spring force is advantageous.

In the embodiment of Figure 1 C, the two friction elements 1, 2 are braced against each other by means of a torsion spring 42 whose at least one spring coil on the second friction element 2 remote from the outside of the first friction element 1 and the corresponding housing 5 rotates and between the two friction elements , 2 acts. For this purpose, the elastic element 42 engages (with one spring end 42a, 42b) on the one hand on the first friction element 1 associated (fixed to the housing) abutment W1 and on the other hand on a second friction element 2 associated and rotatable together with this about the axis of rotation D abutment W2.

The second, inner friction element 2 associated abutment W2 is arranged on a lever arm 29 which is connected to a stationary, z. B. the first friction element 1 associated bearing point L1 is pivotally mounted and which is connected via further bearing means L2 with the second, inner friction element 2, so that the force acting on the lever-side abutment W2 spring force tends to have the second friction element 2 with a portion of his T To press friction surface 20 against the friction surface 10 of the first friction element 1. As a result, clamped in the embodiment of Figure 1 C, an elastic element 42, for. B. in the form of a torsion spring, the two friction elements 1, 2 via a lever arm 29 against each other, so that they in a portion T of their friction surfaces 10, 20th abut each other. By means of the lever arm 29 can thereby achieve a corresponding gain of the clamping torque.

In the locking devices of Figures 1A to 1 C occur - as well as in the case of the arrangement to be described below according to Figure 2A - depending on the

Rotary position of the second friction element 2 with respect to the first friction element 1 respectively different portions of the second friction surface 20 with the first friction surface 10 in

Contact, in the present case in such a way that upon rotation of the second

Friction element 2 with respect to the first friction element 1 by 360 ° reach all areas of the second friction surface 20 at least once with the first friction surface 10 into contact. The contact takes place (in each case essentially linear or in the

Cross-section point-like) always at the same location of the first friction surface 10th

FIG. 2A shows a longitudinal section through a locking device with a first friction element 1 formed by the inner surface of a housing 5, which defines a friction surface 10 that conically tapers in the axial direction, and a second friction element 2 rotatably mounted therein (on a shaft 3) at its outer

Surface is also a conically tapering, annular peripheral friction surface

20 defined. Both friction surfaces 10, 20 are each formed in a circular cross-section perpendicular to the housing axis A circular, so are each rotationally symmetrical.

Furthermore, an elastic element 4, here in the form of a compression spring, is provided which acts between the two friction elements 1, 2 - more precisely between the housing 5 and the second friction element 2 - and braces the two friction elements 1, 2 against each other.

The basic structure of this locking device corresponds to FIG. 10, so that reference is made to the explanations for FIG. 10 for further details, which apart from the special features described below also apply to the exemplary embodiment of FIG. 2A.

A significant difference between the locking device of Figure 10 and the locking device of Figure 2A is that according to Figure 10, the housing axis A, with respect to which the first friction element 1 is rotationally symmetrical coincides with the axis of rotation of the second friction element 2, with respect to which in turn the second Friction element 2 or its friction surface 20th is formed rotationally symmetrical, while in the embodiment of Figure 2A, the second friction element 2 is eccentrically mounted with respect to the housing axis A. In other words, is the axis of rotation D to which the rotationally symmetrical second friction element 2 or its likewise rotationally symmetric friction surface 20 with respect to the first friction element 1 and its rotationally symmetric friction surface 10, outside the housing axis A; but it runs in the embodiment parallel to the latter.

As a result, the two friction elements 1, 2 are pressed under the action of the elastic element 4 with their friction surfaces 10, 20 only in a portion T against each other, so that there contact between the two friction surfaces 10, 20 and outside of that portion T at least one space F (in the axial direction along the entire length of the second friction element 2). The eccentric mounting of the second friction element 2 with respect to the first friction element 1 or more precisely the (rotationally symmetric) second friction surface 20 with respect to the (rotationally symmetric) first friction surface 10 is achieved in that the second friction element 2 - by means of the shaft 3 and over the Shaft ends 31, 32 associated housing-side bearings 53, 54 - is mounted so that its axis of symmetry, which simultaneously forms the axis of rotation D, outside (and parallel to) the axis of symmetry (housing axis A) of the first friction element 1 and the associated friction surface 10.

As in the case of the locking device of FIG. 10, the housing 5 of the locking device, which is filled with a flowable additive or intermediate medium Z, consists of two housing parts 51, 52 (lower housing part and upper housing part), each of which has a bearing 53, 54 for the shaft 3 or more precisely a respective shaft end 31, 32 defined. According to a further difference from the arrangement of FIG. 10, in the present case the second friction element 2 is axially fixed (and not axially displaceable) to the shaft 3. A tracking of the second friction element 2 under the action of the elastic element 4, so that this presses with a portion T of its friction surface 20 against the associated friction surface 10 of the first friction element 1, is achieved here by the fact that the shaft 3 in the axial direction limited slidably in the housing-side bearings 53, 54 is mounted. This is in particular a certain clearance between the housing bottom 50 and the recorded in the local bearing 53 first shaft end 31 is provided.

Due to the conical design of the two friction elements 1, 2 (in the axial direction) causes here the spring element 4, which is provided for tracking the second friction element 2 with respect to the first friction element 1 in the axial direction, in addition, that the two friction elements 1, 2 in one Cross-sectional plane perpendicular to the housing axis A and rotational axis D are braced against each other. Furthermore, here wedge forces which reinforce the braking or holding force of the locking device at rest, considered both because of the conical design of the friction surfaces 10, 20 in the axial direction and because of the system of the two friction surfaces 10, 20 only in a partial area T in the Cross-sectional plane of the arrangement. As a result of the eccentric mounting of the second friction element 2 with respect to the axis of symmetry of the housing 5 (housing axis A) here also act comparatively large transverse forces at the bearings 53, 54, which must be formed sufficiently stable accordingly. FIG. 2B shows a further development of the locking device from FIG. 2A, according to which the second friction element 2 consists of a plurality of friction element parts 2a, 2b, 2c arranged one behind the other in the axial direction, which are each mounted rotatably with respect to the first friction element 1 or its friction surface 10, and Although in the exemplary embodiment on a common shaft 3. The individual Reibelemententeile 2a, 2b, 2c each eccentric with respect to the (defined by the shaft 3) axis of rotation (= housing axis A) are mounted so that each of the Reibelemententeile 2a, 2b, 2c only with a partial region T of its respective friction surface 20 bears against the friction surface 10 of the first friction element 1. The eccentricities e1, e2, e3, the displacement of the axes of symmetry S1, S2, S3 of the respective Reibelemententeiles 2a, 2b, 2c or of its respective friction surface 20 with respect to the axis of symmetry of the first friction element 1 and of its friction surface 10 (housing axis A) are present, in this case oriented in different directions (perpendicular to the housing axis A). This results in a multiple support of consisting of the Reibelemententeilen 2a, 2b, 2c second friction element 2 via the friction surfaces 20 on the friction surface 10 of the first friction element 1 in different spatial directions. This can be a symmetrical force introduction of the second Reibelemententeilen 2a, 2b, 2c reach in the first friction element 1, whereby - compared to the arrangement of Figure 2B - on the one hand one of the bearings of the shaft 3 can be omitted and on the other hand, the remaining bearing 54 of the shaft 3 is relieved.

Both in the embodiment of Figure 2A and in the embodiment of Figure 2B, the respective second friction element 2 may be designed as a sintered part.

In the case of the locking device of FIG. 2B, the second friction element 2 is concretely configured such that its friction element parts 2a, 2b, 2c form a unitary component (continuous in the axial direction). Alternatively, however, the individual friction element parts 2a, 2b, 2c can also be spaced apart in the axial direction. FIG. 2C shows a modification of the locking device from FIG. 2B, according to which the friction element parts 2a, 2b, 2c of a second friction element 2 arranged one behind the other in the axial direction are rotationally symmetrical with respect to a common axis of rotation D defined by a shaft 3 on which the second friction element 2 is mounted , are executed. Here, the (housing-side) friction surface 10 of the first friction element 1 is eccentric with respect to that axis of rotation D executed, in such a way that the friction surface 10 of the first friction element 1 is not rotationally symmetrical but eccentric with respect to that axis of rotation D is configured.

The design of the friction surface 10 of the first friction element 1, which is eccentric in cross-section, is realized in the exemplary embodiment such that in the circumferential direction (ie along the direction of rotation) spaced-apart, in particular mutually opposite, regions of the first friction surface 10 each have different distances a1, a2, b1, b2, d ≠ c2 from the axis of rotation D have. Specifically, in the present case three housing regions of different eccentricity are arranged one behind the other in the axial direction, to each of which a friction element part 2a, 2b, 2c of the second friction element 2 is assigned. Each of these Reibelemententeile 2a, 2b, 2c is due to the eccentric design of the first friction surface 10 (as a result of different distances of the first friction surface 10 of the rotation axis D of the second friction element 2) each with only a portion T of its respective friction surface 20 in contact with the This results in turn a mutual support along different spatial directions, which leads to a defined Support of the second friction element 2 on the first friction element 1 and a uniform force introduction from the second friction element 2 in the first friction element

1 leads. FIG. 3A shows a cross-section of a modification of the arrangement of FIG. 1A, the essential difference being that the second, inner friction element

2 not - as in the case of Figure 1A - is mounted eccentrically with respect to the friction surface 10 of the first outer friction element 1, but rather so non-rotationally symmetrical that only portions of the friction surface T 20 of the second friction element 2 (as an active friction surface) the friction surface 10 of the first, outer friction element 1 are in contact. In the present case, the axis of symmetry of the first friction surface 10 (housing axis A) and the axis of rotation D of the second friction element 2 coincide. Specifically, in the embodiment, there are two opposing portions T of the friction surface 20 of the second friction element 2, which form the active friction surface at a respective rotational position. For this purpose, the second friction element 2 present along one direction in the cross-sectional plane (perpendicular to the rotational or housing axis D, A) to such an extent that opposing portions T of the defined by the second friction member 2 friction surface 20 each with the friction surface 10 of first friction element 1 are in contact. Here, the friction surface 20 of the second friction element 2 is formed by a plurality of (on the friction surface 20 convex curved) Reibelementabschnitte 21, 22 in the form of circular segments or - sections of different diameters, which are arranged in the circumferential direction U one behind the other or alternate.

The exemplary embodiment involves two first friction element sections 21 with a comparatively smaller radius of curvature K1 (and thus comparatively greater curvature) and two intermediate second friction element sections 22 with a comparatively larger radius of curvature K2 (and correspondingly smaller curvature). Friction element sections 21 or 22 with the same radius of curvature K1 or K2 are in each case arranged opposite one another.

Only the first friction element sections 21 (with the comparatively small radius of curvature K1 and the correspondingly greater curvature) lie over a portion T of the friction surface 20 on the associated friction surface 10 of the first

Friction element 1 on. The associated with a respective first friction element 21 Part of the friction surface 20 forms in cross section in each case a circular arc (circular line section).

The second friction element sections 22 are each spaced from the friction surface 10 of the first friction element 1, so that free spaces F are formed, in which the mutually associated friction surfaces 10, 20 of the two friction elements 1, 2 are spaced from each other.

At the transition points between Reibelementabschnitten 21, 22 different curvature K1 and K2 are on the friction surface 20 of the second friction element 2 each (minor) discontinuities before, because the curvature of the second friction surface 20 there jump from the first curvature K1 to a second curvature K2 changes. However, each individual friction element section 21, 22, here in each case in the form of a circular section, is in each case convexly curved in each case.

Alternatively to an embodiment of the second friction element 2 from a plurality of circular sections, an elliptical or oval configuration of the second friction element 2 may be provided in cross-section. FIG. 3B shows a further development of the arrangement from FIG. 3A with a plurality of first and second friction element sections 21, 22 in the form of circular sections which have a different radius of curvature K1 or K2 and which are arranged one behind the other in the circumferential direction U. Again, only the Reibelementen- or circular sections 21 with comparatively small radius of curvature K1 and correspondingly greater curvature over a portion T of the friction surface 20 against the friction surface 10 of the first friction element 1 again.

In an embodiment of the second friction element 2 of a plurality of differently curved Reibelementabschnitte 21, 22, which are arranged one behind the other in the circumferential direction U, the free spaces F between the friction surfaces 10, 20 of the two friction elements 1, 2 are configured so that they have a so-called Form capillary gap in which a flowable additional medium Z provided on the bottom 50 of the corresponding housing 5 (see, for example, Figure 10) can rise under the action of the so-called capillary effect (capillarity). As a result, the targeted transport of flowable additional medium into the region between the mutually associated friction surfaces 10, 20 can be further improved. Advantageously, the size of the space formed as a gap F is to be chosen so that the flowable additional medium used at typical operating temperatures of the locking device due to the capillary effect by at least 30%, in particular by at least 50% or at least 80%, based on the axial extent of the second friction element 2 (expansion along the housing axis A, see Figure 10) rises.

Depending on the configuration of the second friction element 2, in particular its friction surface 20, it is not necessary - in the circumferential direction U - for a respective entire free space F to act as a capillary gap; but only parts of a respective free space F - because of a correspondingly small local distance between the two friction surfaces 10, 20 - be designed as a capillary gap.

FIG. 3C shows a further development of the arrangement of FIG. 3B, according to which, in addition to first and second friction element or circular sections 21, 22 with different (convex) curvature, additional third friction element sections / connecting sections 23 are provided, each between the first and second friction element sections 21, 22 and in the exemplary embodiment in each case define a section of the friction surface 20 that is straight in cross section.

As a result, not only - as in the case of FIGS. 3A and 3B - are friction element or circular sections 21 of the same curvature in contact with the friction surface 10 of the first friction element 1, but rather friction element or circular sections 21 in the subregions T1, T2. 22 different curvature, in this case both the first Reibelement- or circular sections 21 and the second Reibelement- or circular sections 22 of the second friction element 2. In the intermediate connecting sections 23, the second friction element 2, in contrast, in each case continuously from the friction surface 10 of the first friction element 1, so that here again corresponding free spaces F, possibly in the form of capillary gaps, are formed.

Such an arrangement can in particular also be used to selectively control the subregions T1, T2, via which the two friction surfaces 10, 20 abut one another, depending on the temperature, as will be explained below. In this connection, the insulator 200 indicated by dashed lines in FIG. 3C and consisting of a different material than the main body of the second friction element 2 can be used of the second friction element 2 be of importance, as will be explained in more detail below.

In the locking devices of FIGS. 3A to 3C, portions TA of the second friction surface 20 (eg, formed by the second friction element portions 22 in the case of FIGS. 3A and 3B and by the connection portions 23 in the case of FIG. 3C) are respectively related to each rotational position of the second friction element 2 of the first friction element 1 spaced from the first friction surface 10, since in each rotational position of the second friction element 2 with respect to the first friction element 1, the same portion or the same portions T, T1, T2 of the second friction surface 20 with the first friction surface 10 in contact. This contact takes place as a function of the rotational position of the second friction element 2 with respect to the first friction element 1 (respectively substantially linear or in cross-section point-like) at different points of the first friction surface 10. The same applies also in the preceding Figures 2B and 2C and the following FIGS. 4A to 9B.

In FIGS. 4A and 4B, a locking device is shown in longitudinal section (FIG. 4A) and in cross section (FIG. 4B), which is similar in construction and function to the arrangement of FIG. 3B.

According to FIGS. 4A and 4B, a rotationally symmetrical friction element 2 tapering conically along its axis of rotation D (which coincides with the housing axis A) is formed by a base body with a defined radius K2 (equal radius of curvature of the main body). On this main body of the second friction element 2 are on the outside, d. H. facing the friction surface 10 of the first friction element 1, sliding blocks 21 'are applied, each forming a circular section and the radius of curvature K1 is smaller than the radius K2 of the main body of the second friction element 2. Overall, there are three such Gleitböcke 21' present, along the Circumferentially U are spaced from each other and each rest over a portion T of the thus defined, the first friction element 1 opposite friction surface 20 on the friction surface 10 of the first friction element 1.

Again, there is the friction surface 10 of the first friction element 1 opposite mating surface (= friction surface 20) of the second friction element 2 from (in cross-section) convex shaped portions, each partially through the circular in cross-section body of the second friction element 2 and partly by the thereto formed (convexly curved on its outside) sliding blocks 21 'are formed. In each case, a free space F extends between two slide blocks 21 'since the base body of the second friction element 2, which is circular in cross-section, is spaced from the friction surface 10 of the first friction element 1 in the radial direction. If necessary, these free spaces F can again form capillary gaps.

A modification of the locking device of FIGS. 4A and 4B is shown in FIGS. 5A and 5B, the difference being that the friction surfaces 10, 20 of the two friction elements 1, 2 are inclined more strongly with respect to the axis of rotation D or housing axis A. Accordingly, the friction surfaces 10, 20 in the embodiment of Figures 4A and 4B are steeper than in the locking device of Figures 5A and 5B.

Finally, FIG. 6 shows a further modification of the locking device from FIGS. 4A and 4B, according to which a plurality of sliding blocks 21 "are arranged not only spaced from one another in the circumferential direction, but are also arranged one above the other in the axial direction in two rows.

FIG. 7A shows a cross-section of an arrangement related to FIG. 3C, according to which the second friction element 2 is provided with friction element or circular sections 21, 22 of different curvature, that is to say in FIG. H. Here with different radius of curvature K1 or K2, in each case with the friction surface 10 of the first friction element 1 can be brought into contact.

In the exemplary embodiment of FIG. 7A, in each case the same number, namely the two, is provided by the friction element sections 21 with greater curvature (ie comparatively smaller radius of curvature K1) and the friction element sections 22 with smaller curvature (ie comparatively larger radius of curvature K2). Frictional element sections 21 and 22 of the same curvature lie opposite each other - viewed in the cross-sectional plane. A special feature of the arrangement of Figure 7A is that the second friction element 2 in the cross-sectional plane, as shown in Figure 7A, has an anisotropy in the coefficient of thermal expansion. This can be achieved, for example, by introducing additives into the body of the second friction element 2 that justify anisotropy with regard to thermal expansion. In the case of a second friction element 2 made of plastic, for example, additives take the form along a specific spatial direction aligned fibers, z. As glass, carbon or Kevlar fibers, use, which are embedded in the plastic.

In the present case, it is assumed by way of example that the friction element 2 when heated along a spatial direction perpendicular to the direction of extension of the fibers 210 schematically indicated in FIG. 7A expands comparatively strongly and conversely contracts comparatively strongly when cooled along that direction.

Figure 7A shows the two friction elements 1, 2 at temperatures in a lower range of the usual operating temperatures, in particular by the temperature of the additional medium contained in the housing 5, z. In the form of oil. In this case, in the exemplary embodiment, initially the two friction element sections 21 (greater curvature) located opposite the direction of extension of the fibers 210 abut each other over a partial area T of the second friction surface 20 on the friction surface 10 of the first friction element 1, while the friction element sections 22 (smaller Curvature) each completely (but only slightly) from the first friction member 1 and its friction surface 10 are spaced. Now increases the temperature of the second friction element 2, z. B. by heating the housing 5 located in the additional medium, the second friction element 2 expands mainly along the direction perpendicular to the extension direction of the fibers 210, so that the two opposite to the extension direction of the fibers 210 Reibelement- or circular sections 22 according to Figure 7B in each case over a portion T of their friction surface with the friction surface 10 of the first friction element 1 come into abutment. Due to the concomitant deformation of the second friction element 2 as a whole and because of the simultaneous expansion of the first friction surface 10 defining housing 5 also along the direction of extension of the fibers 210 opposite Reibelement- or circular sections 21 each (slightly) from the friction surface 10 of the first Raised friction element 1.

In this case, it is advantageous if, at comparatively low temperatures, friction element sections 21 with comparatively large curvature (and correspondingly small radius of curvature K1) are brought into abutment with the first friction surface 10, as shown in FIG. 7A, while at comparatively larger temperatures, respectively the friction element or Circular portions 22 with comparatively smaller curvature (and correspondingly greater radius of curvature K2) are brought into contact with the first friction surface 10. Because the Reibelementabschnitte 21 larger curvature are basically better to a at low temperatures a comparatively larger viscosity exhibiting flowable additional medium such. As oil, in the transition from sliding to static friction from the respective portion T of the friction surfaces 10, 20 to displace by the two friction elements 1, 2 abut each other. As a result, the transition from the sliding to static friction is accelerated and causes a reliable locking at the end of an adjustment of the locking device associated adjustment part responsively under static friction conditions. A temperature-dependent installation of different (differently curved) Reibelement- or circular sections 21, 22 of the second friction element 2 on the associated friction surface 10 of the first friction element 1 can be achieved in a corresponding manner in the embodiment of Figure 3C, in particular by there anisotropy in terms of thermal expansion is provided. For this purpose, the insert 200 shown in dashed lines in FIG. 3C can serve, which consists for example of metal (steel) and which can be encapsulated by the material (plastic) of the second friction element 2.

By this insert 200 - viewed in the cross-sectional plane transverse to the axis of rotation D or housing axis A - from the first Reibelement- or circular sections 21 on the one hand and the second Reibelement- or circular sections 22 on the other hand differently spaced widely affect temperature-related changes in the extent of that Inserter 200 in the said cross-sectional plane on the first Reibelementabschnitte 21 on the one hand and the second Reibelementabschnitte 22 on the other hand different from.

Thus, in the embodiment of Figure 3C, the insert 200 in the local cross-sectional plane of the first Reibelementabschnitten 21 (with a relatively small radius of curvature K1 and correspondingly large curvature) further spaced than by the second Reibelementabschnitten 22 (with relatively larger radius of curvature K2 and correspondingly smaller curvature). A temperature-related change in the extent of the insert 200 (expansion with increasing temperature or contraction with decreasing temperature) therefore has a greater effect on the second friction element sections 22 than on the first friction element sections 21. The second friction element 2 can then be specifically configured, for example, so that at low temperatures, the first Reibelementabschnitte 21 (with large curvature) abut the associated friction surface 10 of the first friction element 1 and with increasing temperature due to the associated increasing expansion of the insert 200 and its Exposing to the second friction element sections 22 the latter come into contact with the friction surface 10 of the first friction element 1. For this purpose, in the example, in particular, an insert 200 can be used, which has a greater coefficient of thermal expansion than the material of the remaining regions of the second friction element 2.

FIG. 8A shows a further exemplary embodiment of a locking device, in which the friction surfaces 10, 20 of the first and second friction elements 1, 2 are each rotationally symmetrical (circular in cross section) and tapering conically in the axial direction (towards the housing bottom 50). The second friction element 2 consists of two friction elements 2a, 2b, which are spaced apart in the axial direction.

By these two friction element parts 2a, 2b made of different materials, for example made of different plastics or on the basis of the same plastic (such as POM), but with different additives (such as fibers or inserts), can be achieved that the two friction elements 2a, 2b show a different dependence of their respective extent, in particular in the radial direction R, on the temperature. In the present case, the two friction element parts 2a, 2b of the second friction element 2 also have a substantially different expansion in the radial direction R, namely the one (bottom closer) friction element part 2a a much smaller diameter than the other friction element part 2b. This is achieved here by the fact that the housing 5 forming the first friction surface 10 does not taper conically towards its base 50, but additionally has a step 11 between the two friction element parts 2a, 2b, so that there is a step between the two friction element parts 2a, 2b a sudden change of the inner cross section of the housing 5 takes place, in such a way that the distance of opposing portions of the first friction surface 10 (inner diameter of the housing) in the region of a friction element part 2a is significantly lower than in the region of the other friction element part 2b. Furthermore, in the present case, the two friction element parts 2 a, 2 b are designed so that the friction element part 2 b has a greater expansion in the radial direction R (ie larger diameter) a greater temperature dependence of its extent than the other, in cross-section smaller friction element part 2 a, which are achieved, for example For example, the friction element part 2b of larger (radial) extent may have a larger thermal expansion coefficient than the friction element part 2a of smaller (radial) extent.

In the embodiment, this is e.g. Concretely realized by the fact that the friction element part 2b of greater extent has an insert 200 with a large coefficient of thermal expansion, so that this friction element part 2b undergoes relatively larger expansion fluctuations in the radial direction R when the temperature changes than the other friction element part 2a smaller extent. As an alternative to using an insert 200 in one of the friction element parts 2a, 2b in order to influence its thermal expansion in the radial direction R, the two friction element parts 2a, 2b can also be produced selectively from materials (in particular plastics) with different coefficients of thermal expansion, which also results from the introduction of additives, eg Fibers, in at least one of the Reibelemententeile 2a, 2b is possible; The axial extent of the friction element parts 2a, 2b can also play a role here.

Another example of the use of different materials for the two friction element parts 2a, 2b, so that the friction element 2b with a greater extent in the radial direction R (larger diameter) has a greater temperature dependence of its extent than the other, smaller in cross section friction element part 2a, is the Using different starting materials for the two friction element parts 2a, 2b, for example POM for the friction member 2b with a larger expansion and carbon for the friction member 2a smaller dimension, with carbon even has a negative coefficient of thermal expansion in the relevant temperature ranges.

By using for a friction element part 2a a material (eg plastic, such as PA or POM, with carbon additives of suitable composition) whose thermal expansion is almost zero over the entire range of relevant operating temperatures, ie a material whose dimensions are in said range of operating temperatures are essentially constant, the arrangement can be so be configured that that friction element part 2a is always applied to the first friction surface 10 independent of temperature. The other friction element part 2b, whose dimensions are temperature-dependent, on the other hand, is in contact only with the first friction surface 10 in a subrange of the operating temperatures, eg at temperatures above a reference temperature.

Independently of this, the effect can be utilized that - even when using the same materials for both Reibelemententeile 2a, 2b - the cross section of the Reibelemententeiles 2b with greater expansion in the radial direction R varies more strongly with temperature changes than that of the Reibelemententeiles 2a smaller extent, so that also In this way, a temperature dependence in the system of one or the other friction element part 2a or 2b on the first friction surface 10 can be generated. As a result, according to the embodiment, the friction member parts 2a, 2b are dimensioned and arranged with respect to the associated first friction member 1 so that at relatively low temperatures, the friction member part 2a smaller radial expansion rests with its friction surface 20 on the associated friction surface 10 of the first friction element 1, while the friction element part 2b of greater radial extent with its friction surface 20 is slightly spaced from the friction surface 10 of the first friction element 1, compare FIG. 8A.

At higher temperatures, as shown in FIG. 8B, the friction element part 2b of greater radial extent in the radial direction R expands so strongly that it comes into contact with the associated friction surface 10 of the first friction element 1 via its friction surface 20. For this purpose, in particular the temperature-induced expansion change of the said friction element part 2b in the radial direction R is greater than that of the housing 5, which defines the first friction surface 10 on its inside.

Conversely, the temperature-induced expansion change of the other friction element part 2a smaller radial extent smaller than that of the first friction surface 10 defining the housing 5, so that that friction element part 2a with its friction surface 20 out of engagement with the friction surface 10 of the first friction element 1 device.

As a result, therefore, at comparatively low operating temperatures of the locking device, corresponding to the temperature of the additional medium Z used, the friction member part 2a of smaller extent is effective in that it is in contact with the friction surface 10 of the first friction element part 1 via its friction surface 20, as shown in FIG. 8A. This smaller friction element part 2a with a correspondingly larger (convex) curvature of its friction surface 20 is particularly suitable for displacing the additional medium Z during the transition from sliding to static friction conditions when the additional medium Z has a comparatively high viscosity at lower temperatures.

In contrast, at higher operating temperatures, according to FIG. 8B, the friction element part 2b of greater radial extent is effective in that it is in contact with the friction surface 10 of the first friction element via its friction surface 20.

The two Reibelemententeile 2a, 2b can be selectively configured, for example, that the Reibelemententeil 2a of smaller radial extension at operating temperatures below a mean operating temperature of for example 20 ⁰ C and the Reibelemententeil 2b greater radial expansion at operating temperatures above thereof respectively by bearing against the friction surface 10 of the first friction element 1 is effective. In a transition region around the average operating temperature, both friction element parts 2a, 2b can be effective at the same time.

Especially when using materials having different coefficients of thermal expansion for the friction element part 2a on the one hand and the other friction element part 2b on the other hand, different combinations of Reibelemententeile (eg the one or the other Reibelemententeil or both) can also be brought to the first friction surface 10 to the plant with temperature depending the two friction element parts 2a, 2b have the same dimensions, in particular a matching radial extent.

In the embodiment of Figures 8A and 8B, the friction elements 1, 2 are shown so that they are in contact with their entire friction surfaces 10, 20, corresponding to the arrangement in Figure 10. Of course, also here by an asymmetric or eccentric configuration or storage of the

Friction elements 1, 2 approximately corresponding to the arrangements in Figures 2A, 2B and 2C, be achieved, that the friction elements 1, 2 (depending on temperature) in each case only over portions of their friction surfaces 10, 20 come into contact. In the arrangement shown in FIG. 9A, the second friction element 2 consists of two separate components 102a, 102b arranged side by side in the cross-sectional plane of FIG. 9A, ie perpendicular to the axis of rotation D of the second friction element 2 and the axis of symmetry A of the first friction element 1 Gap L are separated from each other.

Through the gap L, the shaft 3 of the locking device, via which a drive torque in the second friction element 2 can be introduced, so that the two components 102a, 102b of the second friction element 2 are arranged on both sides of the shaft 3 and the rotational axis D defined thereby. The opposite boundary surfaces 24 of the two components 102a, 102b are in this case in each case formed in a straight line in cross section.

Both components 102a, 102b of the second friction element 2 are each formed by two Reibelementabschnitte 21 with curved (executed as a circular arc) outer

Contour formed over a rectilinear friction element section /

Connecting portion 23 are connected together. The two components 102a, 102b of the second friction element 2 can each be brought into contact with the associated friction surface 10 of the first friction element 1 via their (circular arc-like) curved friction element sections 2 in each case in a partial area T of their friction surface. Outside these subregions T there is in each case a free space F between mutually opposite friction surfaces 10, 20 of the two friction elements 1, 2.

In order to produce the desired contact between the friction surfaces 20 of the second friction element 2 and the friction surface 10 of the first friction element 1 in those portions T, the two components 102a, 102b of the second friction element 2 via (two) elastic elements 42, here in the form of one each Compression spring, so braced against each other that they each have the tendency to apply with a portion T of each curved friction element section 21 to the first friction surface 10. The elastic elements 42 are arranged on both sides of the shaft 3 and the axis of rotation D defined thereby and each act between the opposing boundary lines 24 of the two components 102a, 102b of the second friction element 2. In the present case, the second friction element 2 is the shaft introducing a drive torque 3 not directly rotatably in connection, but rather over a Driver 6, which is entrained at a displacement of the adjusting device associated adjusting part, for example in the form of a motor vehicle door, and a rotational movement of the shaft 3 associated therewith about the axis of rotation D. In the exemplary embodiment, the driver 6 has an elongated (rectangular) base body which extends along the gap L extending between the two components 102a, 102b of the second friction element 2 and has a recess 62 in the region of the spring elements 42 and (on its front sides) provided with actuating portions 65, via which the driver 6 can each act on an associated friction element-side stop 25 of the second friction element 2 to initiate the case of displacement of an associated adjustment part introduced drive torque in the friction element 2, more precisely, both components 102a, 102b ,

Depending on the direction of rotation of the shaft 3 and thus in dependence on the direction of the introduced torque M, the driver 6 (on each end face) respectively via one of two (frontal) actuating portions 65 with one of two stops

25 of the associated component 102a, 102b of the second friction element 2

Torque transmitting in conjunction; in the case of a clockwise acting

Torque M, as indicated in Figure 9A, with the characterized with "a" attacks 25th

In the Reibelementabschnitten 21, in which the marked with "a" are activated stops 25, the friction surface 20 is lifted at the caused by the shaft 3 and the driver 6 rotational movement of the second friction element 2 each slightly from the friction surface 10 of the first friction element 1; and the respective other friction element section 21 of a respective component 102a, 102b is looped in this case.

FIG. 9B shows a modification of the arrangement of FIG. 9A, the difference being essentially in the configuration of the driver 6, which according to FIG. 9B is arranged on one side with respect to the shaft 3 or the rotation axis D defined thereby. Accordingly, the two components 102a, 102b of the second

Friction element 2 braced here only by a spring element 42 against each other, which in each case acts in a recess 24a of the opposing boundary surfaces 24 of the components 102a, 102b. On the side of the shaft 3 or rotation axis D opposite that spring element 42, the two components 102a, 102b are abutted against each other via a substantially rigid (ie non-elastic) support bridge 26, which serves as an abutment for the elastic element 42.

Accordingly, in the present case, the driver 6 is operatively connected to each of the two components 102a, 102b of the second friction element 2 via only one actuating portion 65 and associated friction-element-side portion 25 so that a torque transmission is possible when the driver 6 is rotated together with the shaft 3 , Depending on the direction of rotation of the shaft 3 and thus of the driver 6, the latter thus acts via in each case only one actuating section 65 and a downstream friction element-side stop 25 on respectively only one of the two components 102a, 102b. The torque transmission between the two components 102a, 102b takes place via the support bridge 26.

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Claims

claims

1. Locking device for releasably locking an adjustment part, in particular a movable with respect to a motor vehicle structure motor vehicle part, which is locked by means of the locking device within a displacement range in a respective achieved by displacement rest position, with at least a first friction element (1) of the locking device, at least one relative to the first friction element (1) rotatable second friction element (2) of the locking device, a first friction surface (10) of the first friction element (1), which surrounds the second friction element (2) and a circumferential along the first friction surface (10) and second thereto Friction surface (20) of the second friction element (2), wherein during a triggered by displacement of the adjusting part

Relative movement of the two friction elements (1, 2) the second friction element (2) with the second friction surface (20) under Gleitreibungsbedingungen along the first friction surface (10) can slide and wherein in a respective rest position of the adjusting the second friction element (2) with its friction surface (20) under static friction conditions on the first friction surface (10), characterized in that the second friction element (2) in a respective rotational position with respect to the first friction element (1) each only one or more portions (T, T1, T2) of second friction surface (20) with the first friction surface (10) is in contact, which cover a total of at most 30% of the second friction surface (20).

2. Locking device according to claim 1, characterized in that the one or more subregions (T, T1, T2) cover a total of at most 10% of the second friction surface (20).

3. Locking device according to claim 2, characterized in that the one or more subregions (T, T1, T2) cover at most 5% of the second friction surface.

4. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) by a circumferential lateral surface of the second friction element (2) is formed.

5. Locking device according to one of the preceding claims, characterized in that a respective portion (T, T1, T2) of the second friction surface (20) through which it is in contact with the first friction surface (10) has a different curvature than the first friction surface (10).

6. Locking device according to one of the preceding claims, characterized in that the respective portion (T, T1, T2) of the second friction surface (20) on the first friction surface (1) is substantially linear.

7. Locking device according to one of the preceding claims, characterized in that in each rotational position of the second friction element (2) with respect to the first friction element (1) at least a portion (TA) of the second friction surface (20) from the first friction surface (10) is spaced ,

8. Locking device according to one of the preceding claims, characterized in that the second friction element (2) regardless of the rotational position with respect to the first friction element (1) respectively over the same subregion (T, T1, T2) or the same subregions (T, T1, T2 ) of the second friction surface (20) is in contact with the first friction surface (10).

9. Locking device according to one of claims 1 to 6, characterized in that the second friction element (2) in dependence on the rotational position relative to the first friction element (1) respectively over other portions (T) of the second friction surface (20) with the first friction surface (10) is in contact.

10. Locking device according to one of the preceding claims, characterized in that upon rotation of the second friction element (2) with respect to the first friction element (1) by 360 ° all areas of the second friction surface (20) at least once with the first friction surface (10) in Contact us.

1 1. Locking device according to one of the preceding claims, characterized in that the axial extent of the second friction surface (20) is limited by axial limits (G1, G2), which the subregions (T, T1, T2) over which the second friction surface (20) with the first friction surface (10) is in contact, in axial

Limit direction.

12. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) of Reibelementabschnitten (21, 21 ', 21 ", 22, 23) is composable, each of which at its first friction surface (10) opposite Surface in cross-section convexly curved or extends straight, and that in a respective rotational position of the second friction element (2) with respect to the first friction element (1) only at least a portion (T, T1, T2) of the second friction surface (20) with the first Friction surface (10) are in contact, so that outside the at least one subregion (T, T1, T2) at least one free space (F) between the two friction surfaces (10, 20) is formed, in which the two friction surfaces (10, 20) spaced apart from each other.

13. Locking device according to claim 12, characterized in that at least one free space (F) extends in the axial direction along the entire length of the second friction element (2).

14. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) at least partially from Reibelementabschnitten (21, 21 ', 21 ", 22), the convex at its the first friction surface (10) opposite surface in cross-section are curved.

15. Locking device according to claim 14, characterized in that the second friction surface (20) consists exclusively of friction element sections (21, 21 ', 21 ", 22), which are convexly curved on their surface opposite the first friction surface (10) in cross-section.

16. Locking device according to one of the preceding claims, characterized in that at the transition between two Reibelementabschnitten (21, 21 ', 21 ", 22, 23) of different curvature a point of discontinuity is formed.

17. Locking device according to one of the preceding claims, characterized in that the friction surface (20) of the second friction element (2) free of concave in cross section shaped areas, such as. e.g. Recesses, channels or pockets, is.

18. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) is rotationally symmetrical.

19. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) is elliptical, oval or polygonal in cross section.

20. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) by a circumferential, in the Cross-section through convexly curved counter surface to the first friction surface (10) is formed.

21. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) compared with the first friction surface (10), such a different symmetry that the second friction surface (20) in a respective rotational position only over at least one Part area (T, T1, T2) with the first friction surface (10) is in contact.

22. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) at least two

Friction element sections (21, 21 ', 21 ", 22, 23) with different curvature in cross-section, which are arranged in the circumferential direction (U) of the second friction element (2) one behind the other.

23. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) eccentric with respect to the first

Friction surface (10) is formed, so that the two friction surfaces (10, 20) only over at least a portion (T, T1, T2) of the second friction surface (20) are in contact.

24. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) is formed eccentrically with respect to the axis of rotation (D) about which the two friction elements (1, 2) are rotatable relative to each other, so that the two friction surfaces ( 10, 20) only over at least a portion (T, T1, T2) of the second friction surface (20) with each other in

Standing in contact.

25. Locking device according to one of the preceding claims, characterized in that the first friction surface (10) eccentrically with respect to the

Rotary axis (D) is formed around which the two friction elements (1, 2) to each other are rotatable, so that the two friction surfaces (10, 20) only over at least a portion (T, T1, T2) of the second friction surface (2) are in contact.

26. Locking device according to one of the preceding claims, characterized in that the second friction surface (20) in at least two spaced apart, curved Reibelementabschnitten (21, 21 ', 21 ", 22) of the second friction element (2) on the first friction surface (10 ) is present.

27. Locking device according to claim 26, characterized in that the two spaced Reibelementabschnitte (21, 21 ', 21 "; 22) of the second friction element (2) have a different curvature.

28. Locking device according to claim 26 or 27, characterized in that the at least two curved Reibelementabschnitte (21, 21 ', 21 ", 22) along the circumferential direction (U) of the second friction element (2) are spaced from each other.

29. Locking device according to one of claims 26 to 28, characterized in that between at least two curved Reibelementabschnitten (21, 21 ', 21 ", 22), via which the second friction element (2) with its friction surface (20) on the first friction surface (10) is applied, a free space (F) is formed, in which the two friction surfaces (10, 20) are spaced from each other.

30. Locking device according to one of claims 26 to 29, characterized in that the at least two Reibelementabschnitte (21, 21 ', 21 ", 22) in a plane perpendicular to the axis of rotation (D) to which the two friction elements

(1, 2) are mutually rotatable, are arranged one behind the other.

31. Locking device according to one of claims 26 to 30, characterized in that the at least two friction element sections (21, 21 ', 21 ",

22) are arranged one behind the other in the axial direction.

32. Locking device according to one of claims 26 to 31, characterized in that the Reibelementabschnitte (21, 21 ', 21 ", 22) are each formed by circular sections.

33. Locking device according to one of the preceding claims, characterized in that the second friction element (2) by at least two in the axial direction one behind the other arranged Reibelemententeile (2a, 2b, 2c) is formed.

34. Locking device according to one of the preceding claims, characterized in that the second friction element (2) at least two by means of an elastic element (41, 42) mutually braced components (102a, 102b) which in a cross-sectional plane perpendicular to the axis of rotation (D) of both

Friction elements (1, 2) are.

35. Locking device according to one of the preceding claims, characterized in that the first and second friction element (1, 2) are braced against each other such that the two friction elements (1, 2) via their friction surfaces (10, 20) in the at least one portion (T, T1, T2) are in contact with each other.

36. Locking device according to one of the preceding claims, characterized in that in the locking device, a flowable auxiliary medium (Z) is provided, which in a rotational movement of the two friction elements (1, 2) to each other in the sub-areas (T, T1, T2), in where the friction surfaces (10, 20) of the two friction elements (1, 2) abut each other, between those friction surfaces (10, 20) passes.

37. Locking device according to claim 36, characterized in that the flowable additional medium (Z) in at least one between the two Friction surfaces (10, 20) formed free space (F) is transportable to reach in the sub-areas (T, T1, T2) between the friction surfaces (10, 20).

38. Locking device according to claim 36 or 37, characterized in that in at least one free space (F), the distance between the first and the second friction surface (10, 20) is at least partially so small that the flowable additional medium (Z) in the free space rises under the effect of the capillary effect.

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