The present disclosure relates to a spindle drive for a closure element of a motor
vehicle.
Vehicles may include a spindle drive configured for use in all types of adjustment or closure elements of a motor vehicle. Exemplary closure elements are tailgates, boot lids, side doors, bonnets or the like.
One challenge here is that drive connectors and the drive housing of a spindle drive are usually plastic components, as a result of which the latter melt in the case of a fire and the drive spring may be released. This is prevented to some extent in that the drive connector is configured with a metal portion which is connected to the spindle guide tube and thus secures the drive spring. However, this is complex in terms of production technology.
The present disclosure attempts to provide a spindle drive in which the drive spring is secured in a stable manner while achieving low production costs.
As one example, radially enlarging the spindle guide tube at one end and securing the drive spring by means of this radial enlargement may address the problem of unintentional movement of the drive spring.
In one or more embodiments, the spindle guide tube on the side thereof that faces the first drive connector has a tube end portion having a tube end edge, that the tube end portion across at least part of the circumference thereof is radially enlarged, in particular bent open, in such a manner that the tube end edge, proceeding from the drive longitudinal axis, has an outer end edge radius which is larger than the first external radius, and that the enlarged tube end portion secures the drive spring in relation to a movement along the drive longitudinal axis.
100081 This approach makes possible a plurality of solutions for securing the drive spring that are cost-effective in terms of production technology. The term “securing” means that the enlarged tube end portion, at least in many cases in which, depending on the design embodiment, some or else all surrounding components, such as the plastics components, break off or melt, supports the drive spring directly or indirectly and prevents any further expansion.
In another embodiment, the drive spring in the assembled state is additionally axially supported directly or indirectly on the enlarged tube end portion. During the operation of the spindle drive, the drive spring in this instance at times, may exert a spring force on the enlarged tube end portion. Accordingly, the tube end portion in this instance serves not only for securing the drive spring, but also for fastening the latter during the normal operation.
As an example, the enlarged tube end portion, may be enlarged in a completely encircling manner, or only in portions, depending on the requirement.
In another embodiment, a securing element is provided and the securing element set may include at least one securing element. A relatively simple construction results when the securing element is disposed about the spindle guide tube. As an example, the tube end portion may be enlarged only slightly and that the securing radius is increased by means of the securing element.
In another embodiment, the drive spring in the axial direction contacts directly the enlarged tube end portion. Depending on a radius of the drive spring, the tube end portion may be correspondingly enlarged for this purpose; no further securing element is required for this purpose.
In one or more embodiments, the tube end portion may include a bend portion which may have different bending angles.
In one or more embodiments, the first drive connector may include a connector portion connected to the spindle guide tube.
As an example, the securing element, of the first drive connector and the second drive connector may be formed of a plastic material.
In another embodiment, the tube portion is enlarged in such a manner that a maximum external tube radius in the tube portion is smaller than a minimum winding radius of the drive spring.
Reference may be made to all embodiments pertaining to the first teaching according to the proposal. The embodiments pertaining to the tube end portion apply in analogous manner to the tube portion; however, the tube end edge can in principle be disposed in an arbitrary manner, for example also be bent inward again.
In one or more embodiments, the tube portion is radially enlarged, and the spindle guide tube is simultaneously connected directly to the drive connector.
The invention will be explained in more detail hereunder by means of a drawing which illustrates only exemplary embodiments. In the drawing
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
The term “closure element” in the present context is to be understood as being comprehensive. The term includes tailgates, trunk lids, hoods, side doors, sliding doors, elevating roofs, sliding windows, etc.
The spindle drive being discussed is however used primarily in tailgates and trunk lids in motor vehicles. Said spindle drive typically serves for the motorized adjustment of the closure element between an open position and a closed position.
The known spindle drive (DE 10 2014 105 956 A1), from which the invention proceeds, has a spindle/spindle nut gear mechanism having a spindle, a spindle nut and a spindle guide tube. Furthermore, said spindle drive has drive connectors for discharging driving movements, one of said drive connectors being assigned to the spindle and one being assigned to the spindle guide tube. The spindle guide tube, owing to the cylindrical shape thereof, usually has a mostly constant external radius. The drive connector that is assigned to the spindle guide tube, on said external radius, by way of a connector portion is inserted into the spindle guide tube and crimped to the latter. In addition to the spindle/spindle nut gear mechanism and a drive unit for driving the spindle/spindle nut gear mechanism the known spindle drive has a drive spring which preloads the drive connectors away from one another and thus supports the drive unit. This drive spring is usually conceived to match the weight of the tailgate and is designed so as to be correspondingly strong.
Drive springs of this type, in particular in the case of a fire, can become a risk when said drive springs are released from the remaining part of the spindle drive and abruptly relax. It is known for these drive springs to be secured by a housing of the spindle drive and/or the drive connectors. To some extent, further securing elements are also used herein.
The assembly illustrated in
As can be derived from
The spindle 6 meshes with the spindle nut 7. The spindle 6 herein may be driven by the drive unit 4. However, it is likewise conceivable that the spindle nut 7 is driven instead. In this way, the spindle/spindle nut gear mechanism 5 presently and preferably converts rotary driving movements of the drive unit 4 into linear driving movements of the spindle 6 or of the spindle nut 7.
The spindle guide tube 8 is connected in an axially fixed manner to the spindle nut 7 and is adjustable in a telescopic manner along the drive longitudinal axis 9 relative to the spindle 6. The spindle 6 in the spindle guide tube 8 runs in a spindle-guiding region 12 of the spindle guide tube 8. The spindle-guiding region 12 presently and preferably does not comprise the entire spindle guide tube 8. In principle however, it would also be conceivable for the spindle guide tube 8 to be relatively short in comparison to the spindle 6, and for the spindle 6 to be able to project from the spindle guide tube 8 on both sides. In this instance, the spindle-guiding region 12 could comprise the entire spindle guide tube 8. In either case, the spindle-guiding region 12 is the region in which the spindle 6 can be situated within the spindle guide tube 8.
The spindle drive 1 has drive connectors 13, 14 for discharging the driving movements. The drive connectors 13, 14 by means of the drive unit 4 are adjustable relative to one another along the drive longitudinal axis 9 between a retracted state (
A first drive connector 13 of the drive connectors 13, 14 is connected in an axially fixed manner to the spindle guide tube 8. A second drive connector 14 of the drive connectors 13, 14 is connected in an axially fixed manner to the spindle 6. The drive connectors 13, 14 are thus adjusted relative to the spindle nut 7 and the spindle guide tube 8 by the telescopic adjustment of the spindle 6.
Furthermore provided is a drive spring 15, presently and preferably a helical spring and/or a compression spring, such as a helical compression spring. The drive spring 15 likewise serves for generating the driving movements along the drive longitudinal axis 9. To this end, the drive spring 15 acts on the drive connectors 13, 14 and preloads the latter, for example, away from one another.
The spindle guide tube 8, along at least one axial portion of the spindle-guiding region 12, for example, along the entire spindle-guiding region 12, proceeding from the drive longitudinal axis 9 has a first external radius a. It is provided here that the spindle guide tube 8 is round in the cross section. In this case, the external radius a is not dependent on an angle. In principle however, it would also be conceivable for the spindle guide tube 8 to have a different cross section. In this case, the external radius a may be the maximum radius of the spindle guide tube 8 in the spindle-guiding region 12. The spindle guide tube 8 may be in at least 50%, or at least 90%, of the axial extent of the spindle-guiding region 12, has a constant external radius a. Since the spindle 6 may be guided in the spindle-guiding tube 8 by way of a guide contour 16, and the spindle guide tube 8 may include a constant wall thickness, it is also obvious that the external radius a presently and preferably has to be constant in substantial parts of the spindle-guiding region 12.
As an example, the spindle guide tube 8 on the side thereof that faces the first drive connector 13 has a tube end portion 17 having a tube end edge 18. The tube end edge 18 is the material end of the spindle guide tube 8 on the end side. It is furthermore significant that the tube end portion 17 across at least part of the circumference thereof is radially enlarged, in particular bent open, in such a manner that the tube end edge 18, proceeding from the drive longitudinal axis 9, has an outer end edge radius e which is larger than the first external radius a, and that the enlarged tube end portion 17 secures the drive spring 15 in relation to a movement along the drive longitudinal axis 9. This can best be seen in the lower enlargement in
The tube end portion 17 extends from the beginning of the enlargement to the tube end edge 18. The outer end edge radius e, in terms of the same angular position about the drive longitudinal axis 9, is larger than the first external radius a. The outer end edge radius e, presently and preferably, is also constant at all angular positions about the drive longitudinal axis 9.
As has already been mentioned at the outset, the securing of the drive spring 15 serves to prevent that the drive spring 15, in particular in the case of an emergency such as a fire, does not perform any undesirable axial movement. The securing action here may be indirect. It may also be the case that the securing is associated with a transmission of force between the drive spring 15 and the tube end portion 17 only when other parts of the spindle drive 1 have broken off or have melted, or the like. This can best be explained by means of
In one or more embodiments, that the drive spring 15 in the assembled state is axially supported directly or indirectly on the enlarged tube end portion 17. As opposed to pure securing, supporting means that a force is actually transmitted from the drive spring 15 to the tube end portion 17. It is not necessary for this always to be the case here; the drive spring 15 in the deployed state of the spindle drive 1 could be relaxed, for example, but the drive spring 15 in the deployed state of the spindle drive 1 preferably also introduces a force, which is in particular not insignificant, into the drive connectors 13, 14.
Additionally or alternatively it can be provided that the enlarged tube end portion 17 secures the drive spring 15 in relation to a movement of the nearest spring winding 19 thereof and/or of a nearest spring end 20 in the axial direction past the tube end edge 18. In principle however, it would also be conceivable to secure the next to last spring winding, for example. The enlarged tube end portion 17 may secure the drive spring 15 in relation to being abruptly released, thus in relation to the drive spring 15 leaving the remaining spindle drive 1, which is not envisaged in this way.
In that the drive spring 15 is supported directly or indirectly on the enlarged tube end portion 17, the transmission of force is ensured during the opening procedure. Indirect support here means that a further separate element, by way of which the force is transmitted from the drive spring 15 to the enlarged tube end portion 17 during the opening procedure, is situated between the drive spring 15 and the enlarged tube end portion 17. In the case of a direct support, no further separate element is provided between the drive spring 15 and the enlarged tube end portion 17.
The enlarged tube end portion 17 may be enlarged across the entire circumference thereof. The tube end portion 17 may be evenly enlarged across the entire circumference thereof. Additionally or alternatively, the enlarged tube and portion 17 is enlarged radially in portions. It can be provided here on the one hand, that only one half of the circumference of the tube end portion 17 is enlarged for example, or that the tube end portion 17 is indeed completely enlarged across the entire circumference but for de-stressing is split into a plurality of circumferential portions. However, the enlarged tube end portion 17 may form a continuous enlarged collar. Alternatively, the enlarged tube end portion 17 include at least two, or at least three, or at least four, enlarged circumferential portions.
As is shown in
The securing element 22 may be disposed axially between the drive spring 15 and the enlarged tube end portion 17 and at least partially, for example completely, encircles the spindle guide tube 8. The securing element 22 may be formed from a fireproof material and/or a metal. The securing element 22 can contact directly the drive spring 15 and/or the enlarged tube end portion 17. The securing element 22 may be designed in the shape of a disk having a centric receptacle for the spindle guide tube 8. In this way, said spindle guide tube 8 during assembling can be very easily pushed over the spindle guide tube 8 prior to the enlargement of the tube end portion 17, for example, or else be pushed over the spindle guide tube 8 from the other end after the enlargement.
It can be seen in the exemplary embodiment according to
As can be derived from
The tube end portion 17 may include a bend portion 23 in which the wall of the spindle guide tube 8 has a curved profile, and as an example straight securing portion 24 which adjoins the bend portion 23, runs in the radial direction so as to be transverse to the drive longitudinal axis 9 and secures the drive spring 15 in relation to a movement along the drive longitudinal axis 9.
The first drive connector 13 presently and preferably has a connector portion 26. The connector portion 26 may be connected directly to the spindle guide tube 8. The connector portion 26 may protrude into the spindle guide tube 8 and from the inside is connected in a materially integral and/or form-fitting and/or force-fitting manner to the spindle guide tube 8.
The securing element 22, or the at least one drive spring 15 and/or the spindle guide tube 8 may be formed from metal. Additionally or alternatively, the first drive connector 13 and/or the second drive connector 14 can be configured from a plastics material.
Proposed according to a further teaching, which is of independent significance, is a spindle drive 1 for a closure element 2 of a motor vehicle 3, in which likewise are provided a drive unit 4 and a spindle/spindle nut gear mechanism 5 which in drive-operation terms is disposed downstream of the drive unit 4 and has a spindle 6, a spindle nut 7 and a spindle guide tube 8 for generating driving movements along a drive longitudinal axis 9.
The spindle 6 meshes with the spindle nut 7, and the spindle guide tube 8 is connected in an axially fixed manner to the spindle nut 7. The spindle guide tube 8 is adjustable in a telescopic manner along the drive longitudinal axis 9 relative to the spindle 6. The spindle 6 in the spindle guide tube 8 runs in a spindle-guiding region 12 of the spindle guide tube 8.
The spindle drive 1 has drive connectors 13, 14 for discharging the driving movements. The drive connectors 13, 14 by means of the drive unit 4 are adjustable relative to one another between a retracted state and a deployed state along the drive longitudinal axis 9. A first drive connector 13 of the drive connectors 13, 14 is connected in an axially fixed manner to the spindle guide tube 8. A second drive connector 14 of the drive connectors 13, 14 is connected in an axially fixed manner to the spindle 6.
Furthermore provided is a drive spring 15, in particular a helical compression spring, for generating driving movements along the drive longitudinal axis 9. The drive spring 15 acts on the drive connectors 13, 14.
Proceeding from the drive longitudinal axis 9, the drive spring 15 has at least one spring winding 19, such as an end winding, having an inner winding radius w. The spindle guide tube 8 along at least one axial portion of the spindle guiding region 12, proceeding from the drive longitudinal axis 9, has a first external radius a.
It is significant according to this further teaching that the spindle guide tube 8 on the side thereof that faces the first drive connector 13 has a tube portion 27, that the tube portion 27 is at least partially radially enlarged, in particular bent open, that the tube portion 27 in the enlarged region has a maximum external tube radius r which is smaller than the inner winding radius w, that the spindle drive 1 has a securing assembly 21 having a securing element 22, that the securing element 22 on the drive spring side of the tube portion 27 is disposed about the spindle guide tube 8, and that the securing element 22 by way of the tube portion 27 secures the drive spring 15 in relation to a movement along the drive longitudinal axis 9.
All embodiments pertaining to the tube end portion 17 apply in analogous manner to the tube portion 27. However, the tube end edge 18 here can be disposed in an arbitrary manner. Said tube end edge 18, in particular following the tube end portion 27, can again be bent inward.
Reference in terms of the second teaching may be made to all embodiments pertaining to the first teaching, and vice versa.
The drive connectors 13, 14 can in each case be coupled to an articulated counterpart on the motor vehicle. At least the first drive connector 13, or both drive connectors 13, 14, has/have a bearing portion 28 for coupling to the articulated counterpart, in particular a ball socket or a ball head, and a connector portion 26 which is connected directly to the spindle guide tube, and a connection portion 29 which connects the bearing portion 28 to the connector portion 26. As has already been indicated, the drive connector 13, or as an example, both drive connectors 13, 14, respectively, is/are at least partially, formed from plastics material. Additionally or alternatively, the drive connector 13, or both drive connectors 13, 14, can be integrally configured.
Proposed according to yet one further teaching is a spindle drive 1 for a closure element 2 of a motor vehicle 3, wherein are provided a drive unit 4 and a spindle/spindle nut gear mechanism 5 which in drive-operation terms is disposed downstream of the drive unit 4 and has a spindle 6, a spindle nut 7 and a spindle guide tube 8 for generating driving movements along a drive longitudinal axis 9.
The spindle 6 meshes with the spindle nut 7. The spindle guide tube 8 is connected in an axially fixed manner to the spindle nut 7 and is adjustable in a telescopic manner along the drive longitudinal axis 9 relative to the spindle 6. The spindle 6 in the spindle guide tube 8 runs in a spindle-guiding region 12 of the spindle guide tube 8.
The spindle drive 1 has drive connectors 13, 14 for discharging the driving movements. The drive connectors 13, 14 by means of the drive unit 4 are adjustable relative to one another along the drive longitudinal axis 9, wherein a first drive connector 13 of the drive connectors 13, 14 is connected in an axially fixed manner to the spindle guide tube 8, and wherein a second drive connector 14 of the drive connectors 13, 14 is connected in an axially fixed manner to the spindle 6.
The spindle drive 1 furthermore has a drive spring 15, in particular a helical compression spring, for generating driving movements along the drive longitudinal axis 9. The drive spring 15 acts on the drive connectors 13, 14.
The spindle guide tube 8 along at least one axial portion of the spindle-guiding region 12, proceeding from the drive longitudinal axis 9, has a first external radius a.
It now is significant according to this teaching that the spindle guide tube 8 on the side thereof that faces the first drive connector 13 has a tube portion 27, that the tube portion 27 is at least partially radially enlarged, in particular bent open, that the tube portion 27 secures the drive spring 15 in relation to a movement along the drive longitudinal axis 9, that the first drive connector 13 has a bearing portion 28 for coupling to the articulated counterpart, in particular a ball socket or a ball head, and a connector portion 26 which is connected directly to the spindle guide tube 8, and a connection portion 29 which connects the bearing portion 28 to the connector portion 26, and that the drive connector 13 is integrally configured.
Reference in terms of the third teaching may be made to all embodiments pertaining to the first two teachings, and vice versa.
In one or more embodiments, the spindle guide tube 8, in the axial direction toward the drive connector 13, behind the tube portion 27 has an end portion which has an external end radius which is smaller than the maximum external tube radius r.
The following is a list of reference numbers shown in the Figures. However, it should be understood that the use of these terms is for illustrative purposes only with respect to one embodiment. And, use of reference numbers correlating a certain term that is both illustrated in the Figures and present in the claims is not intended to limit the claims to only cover the illustrated embodiment.
1 spindle drive
2 closure element
3 motor vehicle
4 drive unit
5 spindle/spindle nut gear mechanism
6 spindle
7 spindle nut
8 spindle guide tube
9 drive longitudinal axis
10 electric drive motor
11 intermediate gearbox
12 spindle-guiding region
13 first drive connector
4 second drive connector
5 drive spring
16 guide contour
17 tube end portion
18 tube end edge
19 spring winding
20 spring end
21 securing element assembly
22 securing element
23 bend portion
24 securing portion
25 angle
26 connector portion
27 tube portion
28 bearing portion
29 connection portion
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
Number | Date | Country | Kind |
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10 2020 111 986.0 | May 2020 | DE | national |
This application is the U.S. National Phase of PCT Application No. PCT/EP2021/061419 filed on Apr. 30, 2021, which claims priority to German Patent Application No. DE 10 2020 111 986.0, filed on May 4, 2020, the disclosures of which are hereby incorporated in their entirety by reference herein.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/061419 | 4/30/2021 | WO |