Spindle drive for a closure element of a motor vehicle

Abstract

The invention relates to a spindle drive for a closure element (2) of a motor vehicle (3), wherein a drive unit (4) and a downstream spindle / spindle nut mechanism (5), comprising a spindle (6), a spindle nut (7) and a spindle guide tube (8), for producing drive movements along a drive longitudinal axis (9) are provided, wherein the spindle drive (1) has drive connections (13, 14) for passing out the drive movements and being adjustable with respect to one another, wherein a first drive connection (13) is connected to the spindle guide tube (8) in an axially fixed manner, wherein a second drive connection (14) is connected to the spindle (6) in an axially fixed manner, wherein a drive spring (15) for producing drive movements along the drive longitudinal axis (9) is provided which acts on the drive connections (13, 14), wherein the spindle guide tube (8) has a first outer radius (a) along at least one axial portion. It is proposed that the spindle guide tube (8) has, on its side facing the first drive connection (13), a tube end portion (17) with a tube end edge (18), that the tube end portion (17) is widened radially over at least part of its circumference in such a way that the tube end edge (18) has an outer end edge radius (e) which is greater than the first outer radius (a), and that the widened tube end portion (17) secures the drive spring (15) against a movement along the drive longitudinal axis (9).

Description

[0001] The invention relates to a spindle drive for a locking element of a motor vehicle according to the preamble of claim 1.

[0002] The term "closing element" is to be understood in a comprehensive manner in this context. This includes tailgates, trunk lids, hoods, side doors, sliding doors, pop-up roofs, sliding windows, etc.

[0003] The spindle drive in question is primarily used in tailgates and trunk lids of motor vehicles. It typically serves to adjust the locking mechanism between an open and a closed position using a motor.

[0004] The known spindle drive (DE 10 2014 105 956 A1), from which the invention is based, comprises a spindle-spindle nut drive with a spindle, spindle nut, and spindle guide tube. It also has drive connections for transmitting drive movements, one of which is associated with the spindle and one with the spindle guide tube. Due to its cylindrical shape, the spindle guide tube typically has a substantially constant outer radius. The drive connection associated with the spindle guide tube is inserted into the spindle guide tube with a connecting section and crimped to it. In addition to the spindle-spindle nut drive and a drive unit for driving the spindle-spindle nut drive, the known spindle drive has a drive spring that biases the drive connections away from each other and thus supports the drive unit.This drive spring is typically designed to support the weight of the tailgate and is correspondingly robust. Such a spindle drive is also known from US 2014 / 137477 A1.

[0005] Such drive springs can become a hazard, especially in the event of a fire, if they detach from the spindle drive and suddenly release. It is known to secure these drive springs via a housing of the spindle drive and / or the drive connections. In some cases, additional securing elements are also used.

[0006] One challenge here is that the drive connections and the drive housing are usually made of plastic components, which means that in the event of a fire they can melt away and still release the drive spring. This is sometimes prevented by designing the drive connection with a metal section that is connected to the spindle guide tube, thus securing the drive spring. However, this is complex from a production standpoint.

[0007] The invention is based on the problem of designing and further developing the known spindle drive in such a way that stable protection of the drive spring is achieved at low production costs.

[0008] The above problem is solved in a spindle drive according to the preamble of claim 1 by the features of the characterizing part of claim 1.

[0009] The essential principle is to radially widen the spindle guide tube at one end and to secure the drive spring by means of this radial widening.

[0010] Specifically, it is proposed that the spindle guide tube is made of metal, that the spindle guide tube has a tube end section with a tube end edge on its side facing the first drive connection, that the tube end section is radially expanded, in particular bent, over at least part of its circumference such that the tube end edge has an outer end edge radius starting from the drive longitudinal axis, which is larger than the first outer radius, that the expanded tube end section secures the drive spring against movement along the drive longitudinal axis, and that the first drive connection has a connection section that is directly connected to the spindle guide tube.

[0011] This approach enables several cost-effective solutions for securing the drive spring. The term "secure" means that the expanded pipe end section, at least in some cases where some or, depending on the design, all surrounding components, especially the plastic components, break off or melt away, directly or indirectly supports the drive spring and prevents further expansion.

[0012] In a particularly preferred embodiment according to claim 2, the drive spring, in the assembled state, is additionally supported directly or indirectly axially against the flared pipe end section. During operation of the spindle drive, the drive spring then sometimes, preferably always, exerts a spring force on the flared pipe end section. Accordingly, the pipe end section serves not only to secure the drive spring but also to fasten it during normal operation.

[0013] Claim 3 relates to preferred embodiments of the expanded pipe end section, which may be expanded completely around the circumference or only in sections, depending on requirements.

[0014] In the embodiments of claims 4 and 5, a locking element arrangement is provided, comprising at least one locking element. A particularly simple design results when the locking element is arranged around the spindle guide tube. This makes it possible, in particular, to widen the tube end section only slightly and to increase the locking radius by means of the locking element.

[0015] Alternatively, according to claim 6, the drive spring can be in direct axial contact with the flared pipe end section. Depending on the radius of the drive spring, the pipe end section must be flared accordingly; no further securing element is required for this.

[0016] Claim 7 relates to preferred radii of the drive spring, the pipe end edge and the locking element in relation to each other.

[0017] In principle, the pipe end section can have a bent section which can have different bending angles. Corresponding embodiments are the subject of claim 8.

[0018] Preferred connections between the drive connection and the spindle guide tube are the subject of claim 9.

[0019] Claim 10 relates to preferred materials of the locking element, the drive spring, the first drive connection and the second drive connection.

[0020] Another teaching, which is not the subject of the invention, is also based on the concept of the first teaching. Here, instead of the pipe end section, a theoretically arbitrary pipe section of the spindle guide tube is radially expanded. However, the pipe section is expanded in such a way that the maximum outer radius of the pipe in this section is smaller than the minimum coil radius of the drive spring.

[0021] Reference may be made to all explanations relating to the first proposed teaching. The explanations regarding the pipe end section apply accordingly to the pipe section; however, the pipe end edge can, in principle, be positioned arbitrarily, for example, even bent inwards again.

[0022] In another spindle drive, which also implements the concept of the first two teachings but is not the subject of the invention, the pipe section is likewise radially expanded, and at the same time the spindle guide tube is directly connected to the drive connection. Reference may again be made to all the details relating to the first two teachings.

[0023] The invention will now be explained in more detail with reference to a drawing that merely illustrates exemplary embodiments. The drawing shows Fig. 1 shows a schematic perspective view of the rear of a motor vehicle with a proposed spindle drive; Fig. 2 shows a sectional view of the proposed spindle drive according to Fig. 1 in a) a retracted position and b) an extended position and Fig. 3 in an enlarged view a detail of the proposed drive according to Fig. 1 , wherein the embodiment of Figur 3a ) does not belong to the claimed item.

[0024] The in Fig. 1 The illustrated arrangement shows a single spindle drive 1, which serves for the motorized adjustment of a locking element 2, here a tailgate, of a motor vehicle 3. In principle, however, all other locking elements 2 mentioned in the introductory part of the description, in particular tailgates, can also be advantageously adjusted by means of the spindle drive 1. All descriptions relating to a tailgate apply equally to all other conceivable locking elements 2.

[0025] How Fig. 2 As can be seen, the spindle drive 1 comprises a drive unit 4 and a spindle-spindle nut gearbox 5 downstream of the drive unit 4, comprising a spindle 6, spindle nut 7, and spindle guide tube 8 for generating drive movements along a longitudinal drive axis 9. The drive unit 4 preferably includes an electric drive motor 10 and an intermediate gearbox 11 connected between the electric drive motor 10 and the spindle-spindle nut gearbox 5.

[0026] The spindle 6 meshes with the spindle nut 7. Here, and preferably, the spindle 6 is driven by the drive unit 4. However, it is equally conceivable that the spindle nut 7 is driven instead. The spindle-spindle nut drive 5 thus converts, here and preferably, rotary drive movements of the drive unit 4 into linear drive movements of the spindle 6 or the spindle nut 7.

[0027] The spindle guide tube 8 is axially fixed to the spindle nut 7 and is telescopically adjustable along the drive longitudinal axis 9 relative to the spindle 6. The spindle 6 runs within a spindle guide section 12 of the spindle guide tube 8. Here, and preferably, the spindle guide section 12 does not encompass the entire spindle guide tube 8. The spindle guide section 12 is the area within which the spindle 6 can be located within the spindle guide tube 8.

[0028] The spindle drive 1 has drive connections 13, 14 for transmitting the drive movements. The drive connections 13, 14 are connected to each other by means of the drive unit 4 along the longitudinal drive axis 9 between a retracted state ( Fig. 2a )) and an extended state ( Fig. 2b Adjustable. As in Fig. 1 As shown, one of the drive connections 13 is preferably connected to a motor vehicle body of the motor vehicle 3 and the other of the drive connections 14 is connected to the locking element 2 of the motor vehicle 3.

[0029] A first drive connection 13 of the drive connections 13, 14 is axially fixed to the spindle guide tube 8. A second drive connection 14 of the drive connections 13, 14 is axially fixed to the spindle 6. The drive connections 13, 14 are thus adjusted by the telescopic adjustment of the spindle 6 relative to the spindle nut 7 and the spindle guide tube 8.

[0030] Furthermore, a drive spring 15, which is preferably a helical spring and / or a compression spring, in particular a helical compression spring, is provided. The drive spring 15 also serves to generate the drive movements along the longitudinal axis 9 of the drive. The drive spring 15 acts on the drive connections 13, 14 and, in particular, pre-tensions them away from each other.

[0031] The spindle guide tube 8 has a first outer radius a along at least one axial section of the spindle guide area 12, here and preferably along the entire spindle guide area 12, extending from the drive longitudinal axis 9. It is provided here that the spindle guide tube 8 has a round cross-section. In this case, the outer radius a is independent of the angle. However, it would also be conceivable for the spindle guide tube 8 to have a different cross-section. In this case, the outer radius a is preferably the maximum radius that the spindle guide tube 8 has in the spindle guide area 12. Here and preferably, the spindle guide tube 8 has a constant outer radius a over at least 50%, and more preferably at least 90%, of the axial extent of the spindle guide area 12.Since the spindle 6 is guided here and preferably with a guide contour 16 in the spindle guide tube 8 and this preferably has a constant wall thickness, it is also evident that the outer radius a must be constant here and preferably in essential parts of the spindle guide area 12.

[0032] It is essential that the spindle guide tube 8 has a tube end section 17 with a tube end edge 18 on its side facing the first drive connection 13. The tube end edge 18 is the end face of the material of the spindle guide tube 8. Furthermore, it is essential that the tube end section 17 is radially expanded, in particular bent, over at least part of its circumference such that the tube end edge 18 has an outer end edge radius e extending from the drive longitudinal axis 9, which is larger than the first outer radius a, and that the expanded tube end section 17 secures the drive spring 15 against movement along the drive longitudinal axis 9. This is best illustrated by the lower magnification in Fig. 2 as well as in various versions Fig. 3 to be taken.

[0033] The pipe end section 17 extends from the beginning of the widening to the pipe end edge 18. The outer end edge radius e is larger than the first outer radius a, relative to the same angular position about the drive longitudinal axis 9. Here, and preferably, the outer end edge radius e is also constant in all angular positions about the drive longitudinal axis 9.

[0034] As explained in the introduction, securing the drive spring 15 serves to prevent it from undergoing unwanted axial movement, particularly in an emergency such as a fire. This securing can be indirect. It is also possible that securing only involves force transmission between the drive spring 15 and the pipe end section 17 if other parts of the spindle drive 1 have broken off, melted away, or similarly damaged. This can best be determined by examining… Fig. 3a ) explain, which, however, shows a non-inventive embodiment. There, the drive spring 15 is supported against the drive connection 13. Although the gaps shown there are only for better identification of the individual parts, it is quite conceivable that no force is transmitted between the drive spring 15 and the flared pipe end section 17 during normal operation, since this force is completely derived from the drive connection 13. If the drive connection 13 breaks off, however, the pipe end section 17 continues to secure the drive spring 15. All descriptions regarding the operation of the spindle drive 1 refer to a mounted state of the spindle drive 1 on the motor vehicle 3.

[0035] Here, and preferably, it is provided that the drive spring 15, in the assembled state, is directly or indirectly axially supported against the flared pipe end section 17. In contrast to mere securing, this support means that a force is actually transmitted from the drive spring 15 to the pipe end section 17. It is not necessary that this is always the case; for example, the drive spring 15 could be relaxed when the spindle drive 1 is extended. Preferably, however, the drive spring 15 also transmits a force, particularly a significant one, to the drive connections 13, 14 when the spindle drive 1 is extended.

[0036] Additionally or alternatively, the flared pipe end section 17 can secure the drive spring 15 against axial movement of its nearest spring coil 19 and / or a nearest spring end 20 past the pipe end edge 18. In principle, it would also be conceivable, for example, to secure the penultimate spring coil. Here, and preferably, the flared pipe end section 17 secures the drive spring 15 against sudden release, i.e., against the drive spring 15 leaving the rest of the spindle drive 1, which is not intended.

[0037] By bearing directly or indirectly against the flared pipe end section 17, the drive spring 15 ensures force transmission during the opening process. Indirect bearing means that a separate element is located between the drive spring 15 and the flared pipe end section 17, through which the force is transmitted from the drive spring 15 to the flared pipe end section 17 during the opening process. Direct bearing involves no separate element between the drive spring 15 and the flared pipe end section 17.

[0038] Here, and preferably, the expanded pipe end section 17 is expanded over its entire circumference. Preferably, the pipe end section 17 is expanded uniformly over its entire circumference. Additionally or alternatively, the expanded pipe end section 17 is expanded radially in sections. It can be provided, for example, that only half of the circumference of the pipe end section 17 is expanded, or that the pipe end section 17 is expanded completely over its circumference but is divided into several circumferential sections for stress relief. Here, and preferably, the expanded pipe end section 17 forms a continuous expanded collar. Alternatively, the expanded pipe end section 17 preferably has at least two, more preferably at least three, and even more preferably at least four expanded circumferential sections.

[0039] As in Fig. 3 As shown, the spindle drive 1 can be provided with a locking element arrangement 21, comprising at least one locking element 22, located between the drive spring 15 and the flared pipe end section 17. The locking element arrangement 21 preferably provides continuous securing, and in particular continuous support, of the drive spring 15 in the radial direction via refractory materials and / or metal. Thus, preferably, if all non-refractory and / or non-metallic materials are disregarded, a continuous connection is created between the drive spring 15 and the flared pipe end section 17. In particular, it can be provided that only refractory materials and / or metal are arranged between the drive spring 15 and the flared pipe end section 17 in the axial direction.If the safety element 21 is designed, as preferred, from a fire-resistant material and / or metal, the latter is therefore in the . Fig. 3b ) and c) the case. If the drive connection 13 is made of plastic, as is also preferred, then as in Fig. 3a ) between the drive spring 15 and the flared pipe end section 17, a plastic component is also arranged in the axial direction. The term "fire-resistant" here means that the corresponding material is at least more fire-resistant than the drive connection 13 and / or a plastic part of the spindle drive 1.

[0040] Here, and preferably, the locking element 22 is arranged axially between the drive spring 15 and the flared tube end section 17 and at least partially, and in particular completely, circumferentially around the spindle guide tube 8. Preferably, the locking element 22 is made of a refractory material and / or a metal. The locking element 22 can be in direct contact with the drive spring 15 and / or the flared tube end section 17. Here, and preferably, the locking element 22 is designed in a disc shape with a central receptacle for the spindle guide tube 8. This allows it, for example, to be easily slid over the spindle guide tube 8 during assembly, either before the tube end section 17 is flared or after flared, from the other end, over the spindle guide tube 8.

[0041] In the exemplary embodiment according to Fig. 2 It can be seen that the drive spring 15 can alternatively be in direct contact with the flared pipe end section 17 in the axial direction.

[0042] How Fig. 3 As can be seen, the drive spring 15 here, and preferably, comprises a spring wire having at least one spring coil 19, in particular an end coil, with an inner coil radius w extending from the drive longitudinal axis 9. Here, and preferably, no spring wire is arranged within the inner coil radius w along the entire drive spring 15, so that this is the overall minimum spring radius. Here, and preferably, the outer end edge radius e is smaller than the inner coil radius w of the at least one spring coil 19. Additionally or alternatively, the locking element 22 can have an inner radius i extending from the drive longitudinal axis 9 that is smaller than the outer end edge radius e. Additionally or alternatively, the locking element 22 can have an outer radius s that is larger than the inner coil radius w.Thus, the drive spring 15 can preferably be moved past the flared pipe end section 17, assuming the locking element 22 is disregarded.

[0043] The pipe end section 17 here and preferably has a bending section 23 in which the wall of the spindle guide tube 8 has a curved profile, and a securing section 24 adjoining the bending section 23, extending in a radial direction transverse to the drive longitudinal axis 9, in particular straight, which secures the drive spring 15 against movement along the drive longitudinal axis 9.

[0044] The Fig. 3a) und 3c ) show that the locking section 24 is bent over the bending section 23 here, and preferably by an angle 25 of approximately 90°. Alternatively, the locking section 24 can be bent over the bending section 23 by less than 90° or by more than 90° from the spindle guide tube 8. The locking section 24 terminates here, and preferably at the tube end edge 18, so that the tube end section 17 consists only of the bending section 23 and the locking section 24. The angle 25 is in Fig. 3 marked.

[0045] Here, the first drive connection 13 has a connection section 26. The connection section 26 is directly connected to the spindle guide tube 8. Preferably, the connection section 26 projects into the spindle guide tube 8 and is connected to the spindle guide tube 8 from the inside by a material-fit and / or form-fit and / or force-fit connection. Fig. 3aFigure 1 shows an embodiment not according to the invention. There, the connecting section 26 engages behind the expanded pipe end section 17 and, in particular, engages with it in a form-fitting manner.

[0046] The locking element 22 or the at least one drive spring 15 is preferably made of metal. Additionally or alternatively, the first drive connection 13 and / or the second drive connection 14 can be made of a plastic material.

[0047] According to a further teaching, which has independent significance, a spindle drive 1 for a locking element 2 of a motor vehicle 3 is proposed, in which a drive unit 4 and a spindle-spindle nut gearbox 5 with spindle 6, spindle nut 7 and spindle guide tube 8, which is connected downstream of the drive unit 4, are provided for generating drive movements along a drive longitudinal axis 9.

[0048] The spindle 6 meshes with the spindle nut 7, and the spindle guide tube 8 is axially fixed to the spindle nut 7. The spindle guide tube 8 is telescopically adjustable along the drive longitudinal axis 9 relative to the spindle 6. The spindle 6 runs within a spindle guide section 12 of the spindle guide tube 8.

[0049] The spindle drive 1 has drive connections 13 and 14 for transmitting the drive movements. The drive connections 13 and 14 are adjustable relative to each other along the longitudinal drive axis 9 between a retracted and an extended position by means of the drive unit 4. A first drive connection 13 of the drive connections 13 and 14 is axially fixed to the spindle guide tube 8. A second drive connection 14 of the drive connections 13 and 14 is axially fixed to the spindle 6.

[0050] Furthermore, a drive spring 15, in particular a helical compression spring, is provided to generate drive movements along the longitudinal drive axis 9. The drive spring 15 acts on the drive connections 13, 14.

[0051] Starting from the longitudinal axis 9 of the drive, the drive spring 15 has at least one spring coil 19, in particular an end coil, with an inner coil radius w. The spindle guide tube 8 has a first outer radius a along at least one axial section of the spindle guide area 12, starting from the longitudinal axis 9 of the drive.

[0052] Essential according to this further teaching is that the spindle guide tube 8 has a tube section 27 on its side facing the first drive connection 13, that the tube section 27 is at least partially radially expanded, in particular bent open, that the tube section 27 has a maximum outer tube radius r in the expanded area, which is smaller than the inner winding radius w, that the spindle drive 1 has a locking arrangement 21 with a locking element 22, that the locking element 22 is arranged around the spindle guide tube 8 on the drive spring side of the tube section 27, and that the locking element 22 secures the drive spring 15 against movement along the drive longitudinal axis 9 via the tube section 27.

[0053] All statements regarding pipe end section 17 apply accordingly to pipe section 27. However, the pipe end edge 18 can be positioned arbitrarily here. In particular, it can be bent inwards again following pipe section 27.

[0054] Reference may be made to all statements concerning the first doctrine with regard to the second doctrine and to each other.

[0055] The drive connections 13, 14 can each be coupled to a counter-joint component on the vehicle side. At least the first drive connection 13, and preferably both drive connections 13, 14, has a bearing section 28 for coupling with the counter-joint component, in particular a ball socket or a ball head, as well as a connection section 26 directly connected to the spindle guide tube and a connecting section 29 connecting the bearing section 28 to the connection section 26. As already indicated, the drive connection 13, and in particular both drive connections 13, 14, are at least partially, and preferably completely, made of plastic. Additionally or alternatively, the drive connection 13 or both drive connections 13, 14 can be formed in one piece.

[0056] According to yet another teaching, a spindle drive 1 for a locking element 2 of a motor vehicle 3 is proposed, wherein a drive unit 4 and a spindle-spindle nut gearbox 5 with spindle 6, spindle nut 7 and spindle guide tube 8, which is connected downstream of the drive unit 4, are provided for generating drive movements along a drive longitudinal axis 9.

[0057] The spindle 6 meshes with the spindle nut 7. The spindle guide tube 8 is axially fixed to the spindle nut 7 and is telescopically adjustable along the drive longitudinal axis 9 relative to the spindle 6. The spindle 6 runs within a spindle guide section 12 of the spindle guide tube 8.

[0058] The spindle drive 1 has drive connections 13, 14 for transmitting the drive movements. The drive connections 13, 14 are adjustable relative to each other along the longitudinal drive axis 9 by means of the drive unit 4, wherein a first drive connection 13 of the drive connections 13, 14 is axially fixed to the spindle guide tube 8 and wherein a second drive connection 14 of the drive connections 13, 14 is axially fixed to the spindle 6.

[0059] Furthermore, the spindle drive 1 has a drive spring 15, in particular a helical compression spring, for generating drive movements along the longitudinal drive axis 9. The drive spring 15 acts on the drive connections 13, 14.

[0060] The spindle guide tube 8 has a first outer radius a along at least one axial section of the spindle guide area 12 starting from the drive longitudinal axis 9.

[0061] Essential to this teaching is that the spindle guide tube 8 has a tube section 27 on its side facing the first drive connection 13, that the tube section 27 is at least partially radially expanded, in particular bent open, that the tube section 27 secures the drive spring 15 against movement along the drive longitudinal axis 9, that the first drive connection 13 has a bearing section 28 for coupling with the counter-joint part, in particular a ball socket or a ball head, as well as a connection section 26 directly connected to the spindle guide tube 8 and a connecting section 29 connecting the bearing section 28 to the connection section 26, and that the drive connection 13 is designed in one piece.

[0062] Reference may be made to all statements concerning the first two doctrines with regard to the third doctrine, and mutually to each other.

[0063] Here, and preferably in the last two teachings, it is provided that the spindle guide tube 8 behind the tube section 27 in the axial direction to the drive connection 13 has an end section which has an end outer radius that is smaller than the maximum tube outer radius r.

Claims

1. Spindle drive for a closure element (2) of a motor vehicle (3), wherein a drive unit (4) and a spindle-spindle nut mechanism (5) arranged on the drive-output side of the drive unit (4), comprising a spindle (6), a spindle nut (7) and a spindle guide tube (8), are provided for producing drive movements along a drive longitudinal axis (9), wherein the spindle (6) meshes with the spindle nut (7), wherein the spindle guide tube (8) is connected to the spindle nut (7) in an axially fixed manner and is adjustable telescopically with respect to the spindle (6) along the drive longitudinal axis (9), wherein the spindle (6) runs in the spindle guide tube (8) in a spindle-guiding region (12) of the spindle guide tube (8), wherein the spindle drive (1) has drive connectors (13, 14) for outputting the drive movements, wherein the drive connectors (13, 14) are adjustable with respect to one another along the drive longitudinal axis (9), between a retracted state and a deployed state, by means of the drive unit (4), wherein a first drive connector (13) of the drive connectors (13, 14) is connected to the spindle guide tube (8) in an axially fixed manner, wherein a second drive connector (14) of the drive connectors (13, 14) is connected to the spindle (6) in an axially fixed manner, wherein a drive spring (15), in particular a helical compression spring, is provided for producing drive movements along the drive longitudinal axis (9), wherein the drive spring (15) acts on the drive connectors (13, 14), wherein, starting from the drive longitudinal axis (13, 14), the spindle guide tube (8) has a first outer radius (a) along at least one axial portion of the spindle-guiding region (12), wherein the spindle guide tube (8) has, on its side facing the first drive connector (13), a tube end portion (17) with a tube end edge (18) which is widened radially, in particular bent open, over at least part of its circumference in such a way that, starting from the drive longitudinal axis (9), the tube end edge (18) has an outer end edge radius (e) which is larger than the first outer radius (a), characterized in that the spindle guide tube (8) is made of metal, in that the widened tube end portion (17) secures the drive spring (15) against a movement along the drive longitudinal axis (9), and in that the first drive connector (13) has a connection portion (26) which is connected directly to the spindle guide tube (8).

2. Spindle drive according to Claim 1, characterized in that, in the assembled state, the drive spring (15) is axially supported directly or indirectly on the widened tube end portion (17), and / or in that the widened tube end portion (17) secures the drive spring (15) against a movement of its nearest spring turn (19) and / or of a nearest spring end (20) past the tube end edge (18) in the axial direction, and / or in that the widened tube end portion (17) secures the drive spring (15) against sudden release.

3. Spindle drive according to Claim 1 or 2, characterized in that the widened tube end portion (17) is widened over its entire circumference, and / or in that the widened tube end portion (17) is radially widened in some section or sections, preferably in that the widened tube end portion (17) has at least two, more preferably at least three, even more preferably at least four, widened circumference sections.

4. Spindle drive according to one of the preceding claims, characterized in that the spindle drive (1) has a securing element assembly (21), which is arranged between the drive spring (15) and the widened tube end portion (17) and comprises at least one securing element (22), preferably in that the securing element assembly (21) enables a continuous securing effect on, in particular continuous support for, the drive spring (15) in the radial direction by means of fire-resistant materials and / or metal, more preferably in that only fire-resistant materials and / or metal are / is arranged between the drive spring (15) and the widened tube end portion (17) in the axial direction.

5. Spindle drive according to Claim 4, characterized in that the securing element (22) is arranged axially between the drive spring (15) and the widened tube end portion (17) and at least partially, in particular completely, around the spindle guide tube (8), and / or in that the securing element (22) is made of a fire-resistant material and / or a metal, and / or in that the securing element (22) is in direct contact with the drive spring (15) and / or the widened tube end portion (17).

6. Spindle drive according to one of Claims 1 to 3, characterized in that the drive spring is in direct contact with the widened tube end portion in the axial direction.

7. Spindle drive according to one of the preceding claims, characterized in that a spring wire of the drive spring (15) has at least one spring turn (19), in particular end turn, with an inner turn radius (w) starting from the drive longitudinal axis, and in that the outer end edge radius (e) is smaller than the inner turn radius (w) of the at least one spring turn (19), and / or, starting from the drive longitudinal axis (9), the securing element (22) has an inner radius (i) which is smaller than the outer end edge radius (e), and / or the securing element (22) has an outer radius (s) which is larger than the inner turn radius (w).

8. Spindle drive according to one of the preceding claims, characterized in that the tube end portion (17) has a bent portion (23), in which a wall of the spindle guide tube (8) has a bent profile, and a securing portion (24), in particular a straight securing portion, which adjoins the bent portion (23), extends transversely to the drive longitudinal axis (9) in the radial direction, and secures the drive spring (15) against a movement along the drive longitudinal axis (9), preferably in that, starting from the spindle guide tube (8), the securing portion (24) is bent over the bent portion (23) through less than 90 degrees, or through about 90 degrees, or by more than 90 degrees, more preferably in that the securing portion (24) ends at the tube end edge (18).

9. Spindle drive according to one of the preceding claims, characterized in that the connection portion (26) projects into the spindle guide tube (8) and is connected in a materially integral and / or form-fitting and / or force-fitting manner to the spindle guide tube (8) from the inside, and / or in that the connection portion (26) fits behind the widened tube end portion (17) and, in particular, is in form-fitting engagement with the latter.

10. Spindle drive according to one of the preceding claims, characterized in that the securing element (22) and / or the at least one drive spring (15) are / is made of metal, and / or in that the first drive connector (13) and / or the second drive connector (14) are / is made of a plastics material.

11. Spindle drive according to one of the preceding claims, characterized in that the drive connectors (13, 14) can each be coupled to a mating joint component on the motor vehicle, in that at least the first drive connector (13) has a bearing portion (28) for coupling to the mating joint component, in particular a ball socket or a ball head, as well as a connection portion (26) connected directly to the spindle guide tube (8), and a linking portion (29) linking the bearing portion (28) to the connection portion (26), in that the first drive connector (13) is made, in particular completely, of plastic, and / or is of integral design.

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