FASTENING ELEMENT

Abstract

The invention relates to a fastening element (10) for connecting to a component (12), wherein the fastening element (10) comprises a flange with drive structures, wherein a connection region is formed on the flange, through the fusing of which the fastening element (10) can be fastened to the component (12) by friction welding, wherein the fastening element (10) comprise a shaft which is arranged on the side of the flange opposite the connection region. The fastening element (10) further comprises a guide region between shaft and connection region in the axial direction, which comprises a guide surface, which comprises at least one segment of an outer surface, which is associated with a cone which broadens in the direction of the connection region. The invention is characterized in that the guide region has a flat surface on the end thereof facing towards the shaft, wherein the extension of the flat surface in a radial direction is greater than the diameter of the shaft.

Claims

1. Fastening element for connecting to a component, which fastening element comprises a flange with drive structures, wherein a connecting region is integrally formed on the flange, through the fusing of which the fastening element can be fastened to the component by friction welding, wherein the fastening element comprises a shaft which is arranged on the side of the flange opposite the connection region; the fastening element further comprises a guide region between the shaft and the connection region in the axial direction, which connection region comprises a guide surface, which comprises at least one segment of an outer surface, which is associated with a cone which broadens in the direction of the connection region characterized in that the guide region has an axial pressure surface on its end facing the shaft, wherein the extension of the axial pressure surface in a radial direction is greater than the diameter of the shaft.

2. Fastening element according to claim 1 characterized in that the guide region is arranged between the shaft and the flange.

3. Fastening element according to claim 1 characterized in that the flange comprises the guide region.

4. Fastening element according to claim 1 characterized in that the guide region is arranged between the connection region and the flange.

5. Fastening element according to claim 1 characterized in that the guide surface comprises a completely circumferential outer surface of the associated cone.

6. Fastening element according to claim 1 characterized in that the cone forms an angle of more than 35, in particular of between 35 and 65, with the axis of the fastening element.

7. Fastening element according to claim 1 characterized in that the flat pressure surface is normal to the shaft axis.

8. Fastening element according to claim 1 characterized in that the connection region is designed such that it defines a contact surface.

9. Fastening element according to claim 8 characterized in that the contact surface is plane-parallel to the axial pressure surface.

10. Tool for fastening a fastening element according to claim 1, wherein said tool comprises a drive recess for transmitting a rotary movement and a pressure piece which is partially hollow and which has a frustum-shaped recess on its end facing the fastening element which recess forms a guide surface on the tool side.

11. Tool according to claim 10 characterized in that said pressure piece has an annular axial pressure surface in the inner area of the frustum-shaped recess.

12. Fastening system comprising a fastening element for connecting to a component, which fastening element comprises a flange with drive structures, wherein a connecting region is integrally formed on the flange, through the fusing of which the fastening element can be fastened to the component by friction welding, wherein the fastening element comprises a shaft which is arranged on the side of the flange opposite the connection region; the fastening element further comprises a guide region between the shaft and the connection region in the axial direction, which connection region comprises a guide surface, which comprises at least one segment of an outer surface, which is associated with a cone which broadens in the direction of the connection region characterized in that the guide region has an axial pressure surface on its end facing the shaft, wherein the extension of the axial pressure surface in a radial direction is greater than the diameter of the shaft and a tool that comprises a drive recess for transmitting a rotary movement and a pressure piece which is partially hollow and which has a frustum-shaped recess on its end facing the fastening element which recess forms a guide surface on the tool side, characterized in that said pressure piece has an annular axial pressure surface in the inner area of the frustum-shaped recess, and further characterized in that the pressure piece and the axial pressure surface, which latter is in the form of a flat pressure surface, are adapted to each other in such a way that the pressure force required for the setting process is transmitted and the tool-side guide surface and the fastening element-side guide region are adapted to each other so as to enable the pressure piece and the flat pressure surface to abut on one another, and the guide region and the guide surface to be brought into contact with one another by an eccentric position of the inserted fastening element.

13. Fastening system according to claim 12 characterized in that in the fastening element the guide region is arranged between the shaft and the flange.

14. Fastening system according to claim 12 characterized in that in the fastening element the flange comprises the guide region.

15. Fastening system according to claim 12 characterized in that in the fastening element the guide region is arranged between the connection region and the flange.

16. Fastening system according to claim 12 characterized in that in the fastening element the guide surface comprises a completely circumferential outer surface of the associated cone.

17. Fastening system according to claim 12 characterized in that in the fastening element the cone forms an angle of more than 35, in particular of between 35 and 65, with the axis of the fastening system.

18. Fastening system according to claim 12 characterized in that in the fastening element the flat pressure surface is normal to the shaft axis.

19. Fastening system according to claim 12 characterized in that in the fastening element the connection region is designed such that it defines a contact surface.

20. Fastening system according to claim 19 characterized in that in the fastening element the contact surface is plane-parallel to the axial pressure surface.

Description

[0031] Additional advantages, features and possible applications of the present invention may be gathered from the description which follows, in connection with the embodiments illustrated in the drawings.

[0032] Throughout the description, claims and drawings, those terms and associated reference signs are, used as are listed in the List of Reference Signs below. In the drawings,

[0033] FIG. 1 is a view of a friction element which can be connected to a component via a rotary movement and the application of an axial force;

[0034] FIG. 2 is a view of another embodiment of a friction element according to the invention;

[0035] FIG. 3a is a cross-sectional view of a fastening element of FIG. 1;

[0036] FIG. 3b is a view of the fastening element completely received in the drive tool;

[0037] FIG. 4 is a view of an embodiment in which a drive tool is provided which comprises a pressure piece that is provided radially outside the drive means;

[0038] FIG. 5a is a cross-sectional view of a fastening system before a fastening element is completely received in a tool, and

[0039] FIG. 5b is a cross-sectional view of a fastening system after a fastening element has been completely received in a tool.

[0040] FIG. 1 is a view of a fastening element 10 according to the invention which can be connected to a component 12 by means of a rotary movement and the application of an axial force F. The fastening element 10 comprises a flange 14 with drive means thereon for transmitting a rotary movement from a tool to the fastening element 10, The drive means are provided in the form of an external hexagon drive. In the direction of the shaft 16, a guide region 18 follows after the flange 14. The guide region 18 is frustum-shaped and offset from the flange 14. On its end facing the shaft, the frustum has a flat surface 20 which constitutes an annular surface. The contact pressure required for the friction welding connection is, transmitted from the flat surface 20 to the fastening element 10. A frictional connection can thus be achieved between the fastening element 10 and the component 12 through the fusing of a connection region 22. The conical guide surface 24 acts to center the fastening element 10 on associated guide surfaces of a drive tool (not shown) during the fastening process. This ensures uniform rotation of the fastening element 10 about its axis and ensures shock-free running of the fastening element 10 during the friction welding process.

[0041] The way the fastening element 10 cooperates with the tool will now be described with reference to the next Figures.

[0042] FIG. 2 is a view of another embodiment of a fastening element 30 according to the invention. In this embodiment, the connection region 32 fleshly transitions into the flange 24. On the one side of the flange 34. the fastening element has a connection region 36 and, on the side opposite the connection region, a shaft 38. The drive means are provided in the form of toothing 35. A cross-sectional view of this embodiment of the fastening element 30 will now be described in more detail with reference to FIGS. 3a and 3b. The required contact pressure forces are transmitted via the flat annular axial pressure surface 37.

[0043] FIG. 3a is a cross-sectional view of a fastening element 30 of FIG. 1. The fastening element 30 has drive means 35 which are formed in the flange 34 as recesses. Respective associated drive means 52 for transmitting the rotary movement are integrally formed on the drive tool 50. The drive tool 50 also has a pressure piece 54.

[0044] The pressure piece 54 is used to transmit the contact pressure to the fastening element 30. For this purpose, the fastening element 30 has an annular axial pressure surface 56 which transitions into a conical guide surface 58. In the feeding operation, the fastening element 30 is first clasped by the drive means 35 and then its guide region 32 is inserted into a matching recess in the pressure piece 54. The annular axial pressure surface 56 thus presses down on the axial pressure surface 37, which is formed as an annular surface around the shaft, in the fastening direction. During rotation, the fastening element 30 is centered via the guide surfaces 34 and the corresponding conical guide surface 58 of the drive tool 50. This ensures smooth running of the fastening element 30 without any wear due to the high contact pressures since no contact pressure is exerted on the conical guide surface 58 of the drive tool 50.

[0045] The fastening element 30 is thus first guided by the drive portion of the drive tool 50 and its axial pressure surface 37 is then made to contact the annular axial pressure surface 56 of the pressure piece 54.

[0046] FIG. 3b is a view of the fastening element completely accommodated within the drive tool 50. Once the axial pressure surfaces 37 of the fastening element abut on the axial pressure surface 56 of the pressure piece 54, the drive means 52 will be spaced from the drive means 35 of the fastening element. This will prevent jamming of the fastening element 30 with the drive means 52 as the fastening element 30 is balanced and/or centered by the pressure piece 54. The corresponding guide surfaces 34, 58 have so much play that there will be no axial forces acting on the guide surface 34 of the fastening element 30 if it is in an ideal centric and straight position.

[0047] The corresponding axial pressure surfaces 37 of the fastening element 30 and the axial pressure surface 56 of the drive tool 50 reliably transmit the axial force F required for the frictional welding process, with the guide surface 58 of the drive tool 50 together with the corresponding guide surface 34 ensuring a stable position during insertion.

[0048] FIG. 4 is a view of an embodiment in which the axial pressure surface 90 is provided radially outwardly of the drive means 84. The fastening element 80 has a guide region 82 which is arranged between the flange 86 with the drive means 84 and the connection region 88.

[0049] This design allows the entire area which is radially inwardly of the annular axial pressure surface 90 of the centering element 82 to be designed freely without having to ensure the stabilization of the element. Consequently, in particular with such a design, premounted elements, e.g. a fastening element 80 in the present case, can be mounted on a component with a nut 92, which still allows a stable attachment ensuring smooth running.

[0050] FIG. 5a is a view of a fastening system 100 comprising a fastening element 102 as well as a tool 104 for attaching a fastening element 102. As already described before, the fastening element comprises a flange 106 having drive structures 108. A connection area 110 is integrally formed on the flange 106 through the fusing of which the fastening element 102 can be connected to its surface. Between its shaft 112 and its connection area 110, the fastening element 102 has a guide region with a guide surface 114. The fastening element 102 further comprises an axial pressure surface 116. This axial pressure surface 116 cooperates with an axial pressure surface 118 of the tool 104 so as to transmit the contact pressure from the tool to the fastening element 102. The guide surface 114 of the fastening element 102 is arranged so as to be parallel to the guide surface 120 of the tool. The guide surface 120 of the tool is designed as a conical recess and thus adapted to correspond to the conical guide surface 114 of the fastening element 102.

[0051] As may be seen in FIG. 5b, which is a cross-sectional view of the fastening element 102 fully inserted, the pressure force is transmitted via the axial pressure surfaces 116, 118 which come to lie on one another, with a small distance remaining between the guide surfaces 120, 114 which distance will not affect the transmission of the axial pressure but will act to keep any tipping of the fastening element 102 from its rotational axis within narrow limits. Particularly secure and high-quality fastening is thus achieved.