Spindle arrangement for a closure element of a motor vehicle

Abstract

The invention relates to a spindle arrangement for a closure element (2), in particular a tailgate, of a motor vehicle (3), wherein the spindle arrangement (5) has a spindle unit (6) with a threadless or threaded spindle (8) having an axially extending geometric spindle axis (7) and with a threadless or threaded spindle guide bush (9), in which the spindle (8) is guided, for performing in particular linear adjustment movements along the geometric spindle axis (7) between a spindle-side connection (10) and a spindle guide bush-side connection (11), wherein the spindle (8) is coupled to the spindle-side connection (10) in an axially fixed manner and the spindle guide bush (9) is axially secured on a spindle guide tube (12) radially in the interior of said spindle guide tube (12), which is coupled to the spindle guide bush-side connection (11) in an axially fixed manner. It is proposed that in the event of an axial movement of the spindle (8) relative to the spindle guide tube (12) in at least one movement direction, if the spindle (8) accelerates relative to the spindle guide tube (12) in excess of a predefined threshold value, a braking device (13) is activated which brakes the axial movement.

Description

[0001] Spindle arrangement for a closure element of a motor vehicle

[0002] The present invention relates to a spindle arrangement for a closure element, in particular a tailgate, of a motor vehicle according to the preamble of claim 1 and to a drive arrangement for a closure element, in particular a tailgate, of a motor vehicle according to claim 16.

[0003] The drive assembly in question is used for the motorized adjustment of any locking element of a motor vehicle. Such locking elements can be, for example, tailgates, trunk lids, engine hoods, cargo floor, and even doors of a motor vehicle.

[0004] The known prior art (DE 10 2017 102 173 A1), from which the invention is based, relates to a spindle assembly for a tailgate of a motor vehicle, comprising a spindle unit with a threadless spindle and a threadless spindle guide bushing in which the spindle is guided. The spindle unit allows the execution of linear adjustment movements along the geometric spindle axis between two connections via which the spindle assembly is connected to the motor vehicle. The spindle is axially fixedly coupled to one connection, and the spindle guide bushing is axially fixed to the other connection via a spindle guide tube.

[0005] The spindle assembly is located on one side of the tailgate and forms the passive side of an active / passive system. The active side, i.e. the driven side, is formed by a motorized spindle drive, i.e. one with an electric drive motor, on the other side of the tailgate. The spindle assembly, which is designed here as a gas pressure element, compensates for the weight of the tailgate, which can be considerable. The aim is generally to ensure that the tailgate is always close to equilibrium or is forced in the opening direction in order to optimally support the spindle drive on the other side of the tailgate. One challenge with such an active / passive system is that unlinking the active side can cause the tailgate to fall uncontrollably.The invention is based on the problem of designing and developing the known spindle arrangement in such a way that an uncontrolled falling of the tailgate is prevented.

[0006] The above problem is solved by the features of the characterising part of claim 1.

[0007] The fundamental idea is that, if necessary, as soon as the active side is unhooked, for example, and the entire or majority of the weight of the locking element is applied to the passive side, a braking device is immediately activated to slow the fall and lower the locking element slowly in a controlled manner, or preferably even to hold it in one position. The braking device switches to a corresponding braking state when two components of the drive assembly experience a certain relative acceleration resulting from the weight of the locking element. The locking element then sinks a small distance at most, but is then immediately caught.

[0008] In particular, it is proposed that, in the case of an axial movement of the spindle relative to the spindle guide tube in at least one direction of movement, if the acceleration of the spindle relative to the spindle guide tube exceeds a predetermined threshold value, a switchable braking device is activated which causes the axial movement to be decelerated.

[0009] Claim 2 specifies the activation of the braking device, namely through an axial displacement of a switching element inside the spindle guide tube. The switching element can be formed by the existing spindle guide bushing or be designed separately, i.e., as a separate component (claim 3).

[0010] According to claims 4 to 8, the axial displacement of the switching element relative to the spindle guide tube occurs from an initial position to a braking position, in which the switching element acts on the spindle with a higher normal force than in the initial position. This occurs primarily due to inertia, i.e., due to the switching element's own mass inertia. Thus, the switching element initially follows the movement of the spindle relative to the spindle guide tube and then (in an emergency), if the acceleration is sufficiently large, pushes due to inertia into a position in which it decelerates the movement of the spindle relative to the spindle guide tube.

[0011] Claims 9 to 11 relate to a counter element that interacts with the switching element when the latter is displaced. In particular, the switching element can move against and preferably into the counter element due to inertia and is thereby deformed or tilted in such a way that it slows down the movement of the spindle relative to the spindle guide tube.

[0012] Claim 12 defines that the braking device can also be deactivated again, whereby the spindle arrangement can then be used again in normal operation.

[0013] Claim 13 relates to a magnet integrated into the switching element. This magnet can interact with the spindle, for example, in such a way that the switching element is magnetically repelled by the spindle in the radial direction, thereby reducing the friction between the spindle and the switching element. This reduces frictional wear on the switching element. Conversely, a magnetic attraction between the spindle and the switching element can exert an additional braking force on the spindle.

[0014] In claim 14, a plastic material is specified as a particularly preferred material for the switching element and / or the counter element, with which in particular optimal deformability and friction effect can be achieved.

[0015] Claim 15 relates to a tubular housing that radially surrounds the spindle unit and optimally protects the individual components from the environment.

[0016] According to a further teaching according to claim 16, which has independent significance, a drive arrangement for a closure element, in particular a tailgate, of a motor vehicle is claimed, with a proposed spindle arrangement, in particular in the form of a gas pressure element, and a motor drive for adjusting the closure element, in particular a spindle drive, wherein the spindle drive preferably has a feed gear in the form of a spindle-spindle nut gear with a drive spindle having an axially extending geometric spindle axis and a spindle nut in meshing engagement therewith for carrying out in particular linear drive movements along the geometric spindle axis between a spindle-side drive connection and a spindle nut-side drive connection,The drive spindle is axially fixed to the spindle-side drive connection, and the spindle nut is axially fixed to the drive spindle guide tube radially inside a drive spindle guide tube, which is axially fixed to the spindle nut-side drive connection. The spindle assembly then represents, in particular, the passive side, and the motor drive, in particular, the active side of the drive assembly.

[0017] Reference may be made to all statements regarding the proposed spindle arrangement.

[0018] In the following, the invention is explained in more detail with reference to a drawing which merely represents exemplary embodiments. In the drawing,

[0019] Fig. 1 shows the rear area of ​​a motor vehicle with a proposed drive arrangement, which is equipped with a proposed spindle arrangement,

[0020] Fig. 2 a sectional view of the proposed drive arrangement with a conventional spindle drive as the active side (shown on the left) and a proposed spindle arrangement as the passive side (shown on the right),

[0021] Fig. 3 shows an exemplary embodiment of a braking device of the spindle arrangement according to Fig. 2 a) in an exploded view, b) in a sectional view in the deactivated state and c) in a sectional view in the activated state and

[0022] Fig. 4 shows further exemplary embodiments of the braking device of the spindle arrangement according to Fig. 2. The proposed drive arrangement 1 serves for the motorized adjustment of a closure element 2 of a motor vehicle 3. The closure element 2 can be adjusted by means of the drive arrangement 1 in an opening direction and / or in a closing direction of the closure element 2.

[0023] The closure element 2 is here and preferably a tailgate of the motor vehicle 3. The proposed drive arrangement 1 can be used particularly advantageously in the “tailgate” application, since tailgates have a comparatively high weight.

[0024] In principle, the proposed drive arrangement 1 can also be applied to other types of closure elements 2 of a motor vehicle 3. These include trunk lids, hoods, or the like, but also doors. All statements apply accordingly to other closure elements 2.

[0025] As Fig. 1 shows, the proposed drive arrangement 1 here and preferably has exactly one motor drive, here in the form of a spindle drive 4, and exactly one spindle arrangement 5, here in the form of a gas pressure element.

[0026] The gas pressure element here is preferably a gas spring, in particular a gas compression spring. Here and preferably, the gas spring preloads the closure element 2 in its opening direction. The gas spring can in principle also be a gas tension spring. It is also conceivable for the gas pressure element to be a gas damper, i.e., one without a spring effect. In this case, but also in principle in the case of a gas spring, the gas pressure element can additionally have a spring arrangement that generates a spring force parallel or coaxial to its direction of action. In the exemplary embodiments described here, a gas spring is provided as the gas pressure element by way of example. However, the relevant statements apply equally to the other gas pressure elements mentioned.

[0027] The proposed drive arrangement 1 can in principle also have more than one motor drive and / or more than one spindle arrangement 5. In the closure element arrangement 2 shown in Fig. 1, which in addition to the closure element 2 of the motor vehicle 3 also has the drive arrangement 1, the motor drive is arranged on a first side of the closure element 2, on the left side in the illustration in Figs. 1 and 2, and the spindle arrangement 5 is arranged on an opposite, second side of the closure element 2, on the right side in the illustration in Figs. 1 and 2.

[0028] The motor drive, which here forms the active side of an active / passive system, is designed to open and close the closure element 2. For this purpose, the drive has an electric drive motor and a feed gear connected downstream of it.

[0029] The spindle assembly 5, here and preferably the gas pressure element or gas spring, which forms the passive side of the active / passive system, does not have its own drive, but rather provides a spring function. Thus, the spindle assembly 5 is intended to absorb part of the weight of the closure element 2 and thereby keep the closure element 2, when opened, close to equilibrium or urge it in the opening direction.

[0030] The embodiment shown in the figures and preferred in this respect relates to a spindle arrangement 5, here and preferably in the form of a gas pressure element, for a closure element 2, in particular a tailgate, of a motor vehicle 3, wherein the spindle arrangement 5 comprises a spindle unit 6 with a threadless or threaded spindle 8 having an axially extending geometric spindle axis 7 and a threadless or threaded spindle guide bush 9, in which the spindle 8 is guided, for carrying out in particular linear adjustment movements along the geometric spindle axis 7 between a spindle-side connection 10 and a spindle guide bush side connection 11, wherein the spindle 8 is axially fixedly coupled to the spindle-side connection 10 and the spindle guide bush 9 is radially inside a spindle guide tube 12, which is axially fixedly coupled to the spindle guide bush side connection 11,is axially secured to the spindle guide tube 12. The spindle assembly 5 is connected to the body of the motor vehicle 3 via the spindle-side connection 10 and to the closure element 2 of the motor vehicle 3 via the spindle guide bushing-side connection 11.

[0031] "Threaded" here means that the spindle 8 has an external thread and / or the spindle guide bushing 9 has an internal thread. Thus, it is conceivable that the spindle 8 forms a gear with the spindle guide bushing 9, in which the spindle 8 meshes with the spindle guide bushing 9, so that a linear adjustment movement of the spindle guide bushing 9 leads to a rotation of the spindle 8. However, it is also conceivable that the spindle 8, especially if it is threadless, as in this case, can only be moved linearly in the spindle guide bushing 9.

[0032] The terms "axial" and "radial" here always refer to the geometric spindle axis 7, i.e. axial refers to the direction along the geometric spindle axis 7, radial the direction orthogonal to the geometric spindle axis 7.

[0033] "Axially secured" means that a movement of the spindle guide tube 12 relative to the spindle 8 is transferable to the spindle guide bushing 9, so that the latter follows the movement of the spindle guide tube 12 relative to the spindle 8. For this purpose, the spindle guide bushing 9 does not have to be completely axially immobile relative to the spindle guide tube 12, but rather should even exhibit, within specified limits, axial mobility relative to the spindle guide tube 12, which will be explained in more detail below.

[0034] It is now essential that, during an axial movement of the spindle 8 relative to the spindle guide tube 12 in at least one direction of movement, the exceeding of the acceleration of the spindle 8 relative to the spindle guide tube 12 beyond a predetermined threshold value activates a switchable braking device 13 which causes a braking of the axial movement.

[0035] Such a direction of movement is, in particular, the direction resulting from the retraction movement of the spindle assembly 5, i.e., when, for example, by adjusting the closure element 2 in its closing direction, the spindle-side connection 10 and the spindle guide bushing-side connection 11 are moved toward each other. This application, for example, is the basis for Fig. 3, to prevent an uncontrolled fall of the closure element 2, for example, when the active side is disengaged and the weight of the closure element 2 rests predominantly or entirely on the passive side. In this case, a sudden adjustment of the closure element 2 in its closing direction activates the switchable braking device 13.

[0036] However, applications are also conceivable in which the said direction of movement of the axial movement of the spindle 8 relative to the spindle guide tube 12 can also be the opposite direction, i.e. the direction resulting from the extension movement of the spindle arrangement 5, i.e. when the spindle-side connection 10 and the spindle guide bush-side connection 11 are moved away from one another by an adjustment of the closure element 2 in its opening direction. Fig. 4a) shows an embodiment in which a sudden adjustment of the closure element 2 in its opening direction activates the switchable braking device 13. Fig. 4b) shows an embodiment in which both a sudden adjustment of the closure element 2 in its closing direction and a sudden adjustment of the closure element 2 in its opening direction activate one and the same switchable braking device 13.

[0037] 'Activated' in this case means that the braking device 13 automatically switches from its initial state to a braking state when the threshold value is exceeded, in which it then brakes the axial movement. Here and preferably, as will be explained in more detail later, the braking device 13 can also be returned from the braking state to the initial state, in which it then releases the axial movement, i.e., no longer brakes or at least brakes to a lesser extent.

[0038] In all the exemplary embodiments shown here, however, the braking effect generated is so strong that movement of the closure element 2 is slowed down and preferably stopped. The braking device 13 here and preferably comprises a switching element 14 in which the spindle 8 is guided, in particular a bush-shaped switching element 14. The switching element 14 is axially secured radially inside the spindle guide tube 12 and has axial play therewith. Activating the braking device 13 here consists in an axial displacement of the switching element 14 relative to the spindle guide tube 12.

[0039] 'Axially subject to play' means that the switching element 14, as previously indicated, is axially movable relative to the spindle guide tube 12 within specified limits that define the axial play, preferably over a maximum of 10 mm, more preferably over a maximum of 5 mm, more preferably over a maximum of 2 mm. This axial mobility preferably enables the switching of the braking device 13 from the inactive to the active state, i.e., to the braking state, and / or from the active to the inactive state, i.e., to the initial state.

[0040] Here and preferably, the switching element 14 is formed by the spindle guide bush 9, i.e., the component that guides the spindle 8 during its axial movement in normal operation is simultaneously a component of the braking device 13. Alternatively, it is also conceivable that the switching element 14 is designed separately from the spindle guide bush 9.

[0041] Furthermore, it is preferably provided here that the activation of the braking device 13 consists in an inertia-related axial displacement of the switching element 14 relative to the spindle guide tube 12 from an initial position into at least one of possibly several braking positions, in which braking position the switching element 14 acts on the spindle 8 with a higher normal force than in the initial position, so that the frictional force, in particular sliding friction force and / or static friction force, and thus the braking effect, between the switching element 14 and the spindle 8 is higher in the at least one braking position than in the initial position.

[0042] "At least one of possibly several braking positions" means that, as previously explained, an application is also conceivable in which, as in Fig. 4b), the braking device 13 can be activated in both the one direction of movement and the other direction of movement from one and the same starting position by moving the switching element 14 into a respective braking position. In this case, the switching element 14 can then assume two braking positions: one when moved in one direction of movement, and the other when moved in the other direction of movement. In each of these braking positions, a higher normal force acts on the spindle 8 than in the starting position, whereby the normal force can be the same or different in both braking positions. The starting position of the switching element 14 is then located, in particular, axially between the two braking positions.

[0043] The "normal force" here refers to the force with which the switching element 14 presses perpendicularly onto the radial surface of the spindle 8.

[0044] The displacement of the switching element 14 relative to the spindle guide tube 12 mentioned here is, as mentioned, possible due to the axial play between the switching element 14 and the spindle guide tube 12. The displacement thus preferably occurs over a distance of a maximum of 10 mm, more preferably a maximum of 5 mm, and more preferably a maximum of 2 mm.

[0045] The displacement occurs particularly due to inertia, i.e. due to the inherent inertia of the switching element 14. Thus, when the spindle arrangement 5 is adjusted, as shown in Fig. 3, for example during a retraction movement, the switching element 14 is generally urged by the spindle 8 relative to the spindle guide tube 12 towards a position in which it can decelerate the movement of the spindle 8 relative to the spindle guide tube 12. If the acceleration of the spindle 8 relative to the spindle guide tube 12 exceeds the predetermined threshold value, the switching element's own inertia leads to a displacement into said position. If, on the other hand, the acceleration remains below the threshold value, the switching element 14 does not move, at least not to the extent that it can decelerate the movement of the spindle 8 relative to the spindle guide tube 12.

[0046] Furthermore, it is preferably provided here that the normal force and / or the frictional force increases, in particular continuously, with increasing displacement of the switching element 14 relative to the spindle guide tube 12 from the starting position to the braking position. Here and preferably, the displacement of the switching element 14, which occurs during the activation of the braking device 13, i.e. when the acceleration of the spindle 8 relative to the spindle guide tube 12 exceeds the predetermined threshold value, is accompanied by an increase in a radially inwardly directed load on the switching element 14, in particular on an axial section 15 of the switching element 14. As a comparison of Fig. 3a) with Fig. 3b) shows, it is preferably the case that the displacement of the switching element 14 from the starting position (Fig. 3a)) into the at least one braking position (Fig.3b)) is accompanied by a radially inwardly directed deformation of the switching element 14, in particular of the axial section 15 of the switching element 14, and / or a tilting of the switching element 14.

[0047] An increase in a radially inwardly directed load on the switching element 14 results from the fact that the switching element 14 is subjected to increasingly greater radial external loads during its displacement and is thus pressed increasingly radially inward.

[0048] The radially inward deformation of the switching element 14 can consist of a reduction in the cross-section, in particular the inner cross-section, of the switching element 14, in particular of the axial section 15 of the switching element 14. In principle, the switching element 14 can also become tilted, i.e., tilted relative to the geometric spindle axis 7.

[0049] Due to the radial load or deformation or tilting of the switching element 14 or axial section 15, the normal force with which the switching element 14 presses on the spindle 8, i.e. the radial contact pressure of the switching element 14, and thus the braking effect is increased.

[0050] As previously explained, it is conceivable that the braking device 13 is only activated upon an axial movement of the spindle 8 relative to the spindle guide tube 12 in one direction of movement (Fig. 3c)). Alternatively, it is conceivable that the braking device 13 is only activated upon an axial movement of the spindle 8 relative to the spindle guide tube 12 in the other direction of movement (Fig. 4a)). It is also conceivable that the braking device 13 is activated both upon an axial movement of the spindle 8 relative to the spindle guide tube 12 in one direction of movement and upon an axial movement of the spindle 8 relative to the spindle guide tube 12 in the other direction of movement (Fig. 4b)).Accordingly, it is preferably provided here that the displacement of the switching element 14, which takes place during the activation of the braking device 13, takes place during an axial movement of the spindle 8 relative to the spindle guide tube 12 in a first direction of movement which results from the retraction movement of the spindle arrangement 5 (Fig. 3c) and 4b)), and / or that the displacement of the switching element 14, which takes place during the activation of the braking device 13, takes place during an axial movement of the spindle 8 relative to the spindle guide tube 12 in a second direction of movement which results from the extension movement of the spindle arrangement 5 (Fig. 4a) and 4b)).

[0051] Furthermore, as shown in perspective in Fig. 3a), it is preferably provided here that the switching element 14 has at least one tab 16 extending axially from the switching element 14, wherein it is preferably provided that the at least one tab 16 forms the axial section 15 of the switching element 14 and / or the displacement of the switching element 14 from the starting position into the at least one braking position is accompanied by a radially inwardly directed deformation of the at least one tab 16. In the illustrated and thus preferred embodiments, two tabs 16 are provided in each case, here radially opposite one another. However, only one tab 16 or a larger number of tabs 16 can also be provided.

[0052] Furthermore, it is preferably provided here that a counter element 17 is arranged in the spindle guide tube 12, which counter element interacts with the switching element 14 in such a way that the switching element 14 can be guided axially into the counter element 17 at least in sections, in particular with its axial section 15, preferably that with increasing axial path that the switching element 14 axially immerses into the counter element 17, the normal force and / or the friction force increases, in particular continuously.

[0053] Thus, as mentioned, the switching element 14 can move into a position that produces a braking effect. This preferably occurs when the switching element 14 moves against and preferably into the counter element 17, or even further into the counter element 17 than before, and is thereby deformed or tilted in such a way that it slows down the movement of the spindle 8 relative to the spindle guide tube 12. As already explained, the displacement of the switching element 14 occurs particularly due to inertia. Then, upon adjustment of the spindle arrangement 5, as shown in Fig. 3, for example during a retraction movement, the switching element 14 is generally urged by the spindle 8 relative to the spindle guide tube 12 in the direction of the counter element 17. When the acceleration of the spindle 8 relative to the spindle guide tube 12 exceeds the predetermined threshold, its own mass inertia preferably leads to a displacement into the counter element 17, or in this case even further into the counter element 17.If, however, the acceleration remains below the threshold value, the switching element 14 does not shift, at least not further into the counter element 17.

[0054] The counter element 17 is here and preferably an annular body, i.e., a circumferential body, in particular with an annular portion pointing axially toward the switching element 14, into which the switching element 14 can engage to generate the braking effect, or can engage even further here. In the initial position of the switching element 14, the counter element 17 is arranged, in particular, directly adjacent to the switching element 14, preferably axially overlapping with the switching element 14, and is brought into a larger axial overlap during the displacement of the switching element 14 from the initial position to the respective braking position.

[0055] The switching element 14 is axially acted upon and accelerated by the spindle 8, preferably via a friction effect existing between the switching element 14 and the spindle 8, in particular static friction and sliding friction, ie the spindle 8 drives the switching element 14 from the starting position out to and / or into the counter element 17, whereby the counter element 17 exerts a radial force on the axial section 15 of the switching element 14 which plunges into the counter element 17 and which is then in the respective braking position, or increases it compared to the starting position.

[0056] In addition to or as an alternative to the friction-based axial loading of the switching element 14 by the spindle 8, it can also be provided that the switching element 14 is axially loaded by the spindle 8 from the starting position via a magnetic attraction existing between the switching element 14 and the spindle 8 and is accelerated in this way for at least a first part of the displacement. As the displacement continues, the switching element 14 is then also axially loaded via the friction effect existing between the switching element 14 and the spindle 8 because it is then pressed radially against the spindle 8 by the counter-element 17. By providing a magnetic attraction, additional permanent braking can be achieved and / or frictional wear on the switching element 14 can be reduced.

[0057] Furthermore, it is preferably provided here that the counter element 17 has an inner surface 18 which runs obliquely relative to the geometric spindle axis 7 and along which the switching element 14 is guided during the displacement of the switching element 14, and / or that the switching element 14, in particular the axial section 15 and / or the at least one tab 16, has an outer surface 19 which runs obliquely relative to the geometric spindle axis 7 and along which the counter element 17 slides during the displacement of the switching element 14.

[0058] The switching element 14 interacts with the spindle 8 by means of the counter-element 17, preferably in the manner of a collet connection, i.e. the axial section 15 of the switching element 14 can be radially narrowed by means of the counter-element 17 in the manner described above. In principle, it is also conceivable for the switching element 14 as a whole, i.e. over its entire axial extent, to be radially narrowed by means of the counter-element 17. For this purpose, the axial section 15 of the switching element 14 here and preferably, as mentioned, has at least or exactly one, in particular at least or exactly two, tabs 16 which extend axially from the switching element 14 and which - at least in the unassembled state of the switching element 14 - are radially displaceable, in particular pivotable.In the assembled state, according to one embodiment, the tabs 16 can already bear radially against the spindle 8 in the starting position of the switching element 14 and thus, in contrast to the unassembled state, can no longer be pivotable; in this case, the braking effect is increased exclusively by increasing the contact pressure of the switching element 14 or axial section 15 on the spindle 8. Here and preferably, however, the tabs 16 are still radially spaced from the spindle 8 in the starting position of the switching element 14, even in the assembled state of the switching element 14, i.e. when the latter is pushed onto the spindle 8 as intended, and are thus still radially displaceable, in particular pivotable, and only come into (frictional) contact with the surface of the spindle 8 during the displacement of the switching element 14.

[0059] Here and preferably, it is further the case that during an axial movement of the spindle 8 relative to the spindle guide tube 12 in the at least one direction of movement, the exceeding of a force acting from the counter element 17 on the switching element 14, in particular on the axial section 15 of the switching element 14, which exceeds the predetermined threshold value, causes a braking of the axial movement.

[0060] Furthermore, it is preferably provided here that after the braking device 13 has been activated, it can be deactivated by a movement of the spindle 8 relative to the spindle guide tube 12 that is opposite to the previous movement of the spindle 8 relative to the spindle guide tube 12 that caused the activation. As already indicated above, the braking device 13 can therefore preferably be returned from the braking state to the initial state, in which it then releases the axial movement, i.e. no longer or at least less braking. Accordingly, here and preferably, the switching element 14, after being moved into the respective braking position, can be returned to its initial position in the opposite direction relative to the spindle guide tube 12, in particular by a movement of the spindle 8 relative to the spindle guide tube 12 that is opposite to the previous movement.

[0061] A preferred magnetic effect 20 has already been described above. This is achieved here and preferably by integrating, in particular embedding, a magnet 20 into the switching element 14 and by designing the spindle 8 in sections or entirely as a magnetic body, in particular in sections or entirely as a metal body, in particular a magnetized metal body.

[0062] The switching element 14 and / or the counter element 17 is here and preferably made of a plastic material. Furthermore, it is here and preferably provided that the spindle arrangement 5 has a tubular housing 21 radially enclosing the spindle unit 6, comprising a first housing tube, in particular an inner housing tube 22, and a second housing tube, in particular an outer housing tube 23, which is telescopically extendable with the first housing tube. Preferably, the spindle-side connection 10 is axially fixedly coupled to one housing tube, in particular the second housing tube, and the spindle guide bush-side connection 11 is axially fixedly coupled to the other housing tube, in particular the first housing tube.

[0063] Also proposed is a drive arrangement 1 for a closure element 2, in particular a tailgate, of a motor vehicle 3, comprising a proposed spindle arrangement 5, in particular in the form of a gas pressure element, and a motor drive for adjusting the closure element 2, in particular spindle drive 4, wherein the spindle drive 4 preferably comprises a feed gear in the form of a spindle-spindle nut gear 24 with a drive spindle 25 having an axially extending geometric spindle axis 7 and a spindle nut 26 meshing therewith for executing in particular linear drive movements along the geometric spindle axis 7 between a spindle-side drive connection 27 and a spindle nut-side drive connection 28, wherein the drive spindle 25 is axially fixedly coupled to the spindle-side drive connection 27 and the spindle nut 26 is radially arranged inside a drive spindle guide tube 29,which is axially fixed to the spindle nut-side drive connection 28, is axially fixed to the drive spindle guide tube 29.,

[0064] Reference may be made to all statements relating to the proposed spindle arrangement 5.

Claims

Patent claims 1. Spindle arrangement for a closure element (2), in particular a tailgate, of a motor vehicle (3), wherein the spindle arrangement (5) comprises a spindle unit (6) with a threadless or threaded spindle (8) having an axially extending geometric spindle axis (7) and a threadless or threaded spindle guide bush (9), in which the spindle (8) is guided, for carrying out in particular linear adjustment movements along the geometric spindle axis (7) between a spindle-side connection (10) and a spindle guide bush-side connection (11 ), wherein the spindle (8) is axially fixedly coupled to the spindle-side connection (10) and the spindle guide bush (9) is axially secured radially in the interior of a spindle guide tube (12), which is axially fixedly coupled to the spindle guide bush-side connection (11 ), on the spindle guide tube (12), characterized in that upon axial movement of the spindle (8) relative to the spindle guide tube (12) in at least one direction of movement, the exceeding of the acceleration of the spindle (8) relative to the spindle guide tube (12) beyond a predetermined threshold value activates a switchable braking device (13) which causes the axial movement to be decelerated.

2. Spindle arrangement according to claim 1, characterized in that the braking device (13) has a switching element (14) in which the spindle (8) is guided, in particular a bush-shaped switching element (14), that the switching element (14) is axially secured radially in the interior of the spindle guide tube (12) and is subject to axial play thereto, and that the activation of the braking device (13) consists in an axial displacement of the switching element (14) relative to the spindle guide tube (12).

3. Spindle arrangement according to claim 2, characterized in that the switching element (14) is formed by the spindle guide bush (9) or is designed separately from the spindle guide bush (9).

4. Spindle arrangement according to claim 2 or 3, characterized in that the activation of the braking device (13) results in an inertia-related axial displacement of the switching element (14) relative to the spindle guide tube (12) from an initial position into at least one braking position, in which braking position the switching element (14) acts on the spindle (8) with a higher normal force than in the initial position, so that the frictional force, in particular sliding friction force and / or static friction force, between the switching element (14) and the spindle (8) is higher in the at least one braking position than in the initial position.

5. Spindle arrangement according to claim 4, characterized in that the normal force and / or the frictional force increases with increasing displacement of the switching element (14) relative to the spindle guide tube (12) from the starting position to the braking position, in particular continuously.

6. Spindle arrangement according to one of claims 2 to 5, characterized in that the displacement of the switching element (14) is accompanied by an increase in a radially inwardly directed load on the switching element (14), in particular on an axial section (15) of the switching element (14), preferably in that the displacement of the switching element (14) from the starting position into the at least one braking position is accompanied by a radially inwardly directed deformation of the switching element (14), in particular on the axial section (15) of the switching element (14), and / or a tilting of the switching element (14).

7. Spindle arrangement according to one of claims 4 to 6, characterized in that the displacement of the switching element (14) takes place during an axial movement of the spindle (8) relative to the spindle guide tube (12) in a first direction of movement which results from the retraction movement of the spindle arrangement (5), and / or that the displacement of the switching element (14) takes place during an axial movement of the spindle (8) relative to the spindle guide tube (12) in a second direction of movement which results from the extension movement of the spindle arrangement (5).

8. Spindle arrangement according to one of the preceding claims, characterized in that the switching element (14) has at least one tab (16) extending axially from the switching element (14), preferably that the at least one tab (16) forms the axial section (15) of the switching element (14) and / or the displacement of the switching element (14) from the Starting position into the at least one braking position is accompanied by a radially inwardly directed deformation of the at least one tab (16).

9. Spindle arrangement according to one of claims 2 to 8, characterized in that a counter element (17) is arranged in the spindle guide tube (12), which interacts with the switching element (14) in such a way that the switching element (14) can be guided axially into the counter element (17) at least in sections, in particular with its axial section (15), preferably that with increasing axial path that the switching element (14) axially immerses into the counter element (17), the normal force and / or the frictional force increases, in particular continuously.

10. Spindle arrangement according to claim 9, characterized in that the counter element (17) has an inner surface (18) which runs obliquely relative to the geometric spindle axis (7) and along which the switching element (14) is guided during the displacement of the switching element (14), and / or that the switching element (14), in particular the axial section (15) and / or the at least one tab (16), has an outer surface (19) which runs obliquely relative to the geometric spindle axis (7) and along which the counter element (17) slides during the displacement of the switching element (14).

11. Spindle arrangement according to claim 9 or 10, characterized in that during an axial movement of the spindle (8) relative to the spindle guide tube (12) in the at least one direction of movement, the exceeding of a force acting from the counter element (17) on the switching element (14), in particular on the axial section (15) of the switching element (14), which exceeds a predetermined threshold value, causes a braking of the axial movement.

12. Spindle arrangement according to one of the preceding claims, characterized in that after activation of the braking device (13), this can be deactivated by a movement of the spindle (8) relative to the spindle guide tube (12) opposite to the previous movement of the spindle (8) causing the activation relative to the spindle guide tube (12), preferably in that the switching element (14) after its displacement into the respective braking position in the opposite direction relative to the spindle guide tube (12), in particular by a movement opposite to the previous movement. set movement of the spindle (8) relative to the spindle guide tube (12), can be returned to its initial position.

13. Spindle arrangement according to one of claims 2 to 12, characterized in that a magnet (20) is integrated, in particular embedded, in the switching element (14) and that the spindle (8) is designed to be partially or completely magnetic, in particular partially or completely as a metal body, in particular a magnetized metal body.

14. Spindle arrangement according to one of claims 2 to 13, characterized in that the switching element (14) and / or the counter element (17) is made of a plastic material.

15. Spindle arrangement according to one of the preceding claims, characterized in that the spindle arrangement (5) has a tubular housing (21) radially enclosing the spindle unit (6) with a first housing tube, in particular inner housing tube (22), and a second housing tube, in particular outer housing tube (23), which can be telescoped with the first housing tube, preferably in that the spindle-side connection (10) is axially fixedly coupled to one housing tube, in particular the second housing tube, and in that the spindle guide bush-side connection (11) is axially fixedly coupled to the other housing tube, in particular the first housing tube.

16. Drive arrangement for a closure element (2), in particular a tailgate, of a motor vehicle (3) with a spindle arrangement (5) according to one of the preceding claims, in particular in the form of a gas pressure element, and a motor drive for adjusting the closure element (2), in particular a spindle drive (4), wherein the spindle drive (4) preferably comprises a feed gear in the form of a spindle-spindle nut gear (24) with a drive spindle (25) having an axially extending geometric spindle axis (7) and a spindle nut in meshing engagement therewith (26) for carrying out in particular linear drive movements along the geometric spindle axis (7) between a spindle-side drive connection (27) and a spindle-nut-side drive connection (28), wherein the drive spindle (25) is connected to the spindle-side drive connection (27) is axially fixedly coupled and the spindle nut (26) is radially inside a drive spindle guide tube (29) which is connected to the spindle nut-side drive connection (28) is axially fixed, is axially fixed to the drive spindle guide tube (29).

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