Connecting Element

Abstract

The invention relates to a connecting element (10, 30) for connecting at least two components that are positioned one on top of the other, comprising a shaft (14, 34) and a head (12, 32), which is provided with a drive (38), the shaft (14, 34) being formed from a base material and ending at the exposed shaft end thereof that is opposite the head (12, 32). The invention is characterised in that a tip (16, 40) made of plating material is applied to the exposed shaft end, which plating material is different from the base material.

Claims

1. Connecting element (10, 30, 50) for connecting at least two components that are positioned the one on top of the other, comprising a shaft (14, 34, 56) and a head (12, 32), which is provided with a drive (38), the shaft (14, 34, 36) being formed from a base material and ending at its exposed end that is opposite the head (12, 32), and a tip region (16, 40, 52) made of a plating material (36) is applied to the exposed shaft end, which plating material (36) is different from the base material.

2. Connecting element according to claim 1, wherein the plating material (36) is a material that is hardenable or harder than the base material.

3. Connecting element according to claim 1, wherein the tip region is formed as a tip (16, 40, 52).

4. Connecting element according to claim 1, wherein the base material is an acid-resistant stainless steel, or a non-ferrous metal alloy.

5. Connecting element according to claim 1, wherein the plating material at the tip is formed into its final tip shape by rolling or pressing.

6. Connecting element according to claim 1, wherein the plating material at the tip is formed into its final tip shape by machining.

7. Connecting element according to claim 1, wherein the connecting element (30) is a self-tapping screw.

8. Connecting element according to claim 6, wherein at least in at least part of its tapping region, the self-tapping screw (30, 50) exhibits a thread (42, 58) made of plating material.

9. Connecting element according to claim 1, wherein the connecting element is a friction welding element.

10. Connecting element according to claim 1, wherein the tip (16, 40) is of a rounded, an acute-angled or an obtuse-angled design.

11. Method for producing a connecting element (10, 30) comprising forming a shaft (14, 34, 56) and a head (12, 32), which is provided with a drive (38), the shaft (14, 34, 36) being formed from a base material and ending at its exposed end that is opposite the head (12, 32), and a tip region (16, 40, 52) made of a plating material (36) is applied to the exposed shaft end, which plating material (36) is different from the base material, and at least at the exposed end of the shaft, a plating material is weld-cladded onto the base material of the shaft (14, 34, 56) so as to allow the tip (16, 40) of the connecting element to be formed from the plating material.

12. Method according to claim 11, wherein the exposed shaft end made of base material is cylindrical and has a circular end surface.

13. Method according to claim 11, wherein after the tip region has been weld-cladded onto the exposed shaft end, the tip is mechanically formed, for example by means of a forming or a machining process.

14. Method according to claim 12, wherein in addition to the tip, further functional structures are weld-cladded onto the shaft.

15. Method according to claim 14, wherein the functional structure is a self-tapping thread.

16. Method according to claim 14, wherein the thread is produced by rolling a thread on the screw shaft after the plating material has been deposited on the screw shaft.

17. Method according to claim 14, wherein the thread is produced by applying the plating material in a helical pattern on the shaft in such a manner that the thread is completed once the plating material has been deposited.

18. Method according to claim 14, wherein the plating material is deposited in the form of beads or over the entire surface.

19. Method according to claim 16, wherein the weld beads extend parallel to the screw axis or in spirals around the screw shaft.

20. Method according to claim 14, wherein before weld-cladding the plating material onto the shaft, grooves are made in the base material of the screw shaft in which the weld-cladding is then performed.

21. Method according to claim 14, wherein the weld-cladding is performed by means of laser cladding, arc welding or plasma powder deposition welding.

Description

[0053] In the drawings,

[0054] FIG. 1 is a schematic sectional view of a friction pin according to the invention;

[0055] FIGS. 2a to 2c are a schematic sectional view each of a self-tapping screw according to the invention, and

[0056] FIG. 3 is a schematic sectional view of a self-tapping and hole-drilling screw according to the invention.

[0057] The view of FIG. 1 shows a connecting element 10 for penetrating panel materials, comprising a head 12 and a shaft 14. The head 12 has a drive. The shaft 14 has a point formed thereon by weld cladding, in particular by laser cladding. The weld cladded tip is made of a harder material than the shaft 14 and also than the head 12, which are preferably both made of the same first material. As a result, when screwed in under rotation and with pressure, the connecting element 10 shown is capable of penetrating component layers that are harder than the first material. Nevertheless, after penetration of the component layers to be connected, a friction-welded joint can be produced between the component layers and the specially adapted connecting element.

[0058] The shaft 14 and the head 12 can be ideally designed with regard to corrosion resistance, whereas the tip can only be designed with hardness in mind.

[0059] FIGS. 2a to 2c are schematic sectional views each of the production of a self-tapping screw 30 having a hole-forming tip 40, with the tip 40 and the thread 42 being formed of a plating material different from the base material of the shaft 34 and the head 32 of the screw.

[0060] The view of FIG. 2a is the base element 35 of the bolt comprising the head 32 and the shaft 34, both made of the base material. A drive 38 made in the head 32 is used to transfer a rotary movement to the connecting element 30. The base element 35 produced in this way is coated with a plating material in an additional step, as is shown in FIG. 2b.

[0061] The plating material is a harder material than the base material. In this case, the base material is stainless steel, whereas the plating material is tempered steel. The latter can be additionally hardened. Another hardening step can involve the selective heating of the tip and the thread, for example.

[0062] The plating material is preferably deposited by means of powder deposition welding.

[0063] As seen in FIG. 2b, the plating material 36 is applied both in the region of the thread 42 and in the region of the tip.

[0064] Next, the connecting element is subjected to a rolling step in which both the tip and the thread are formed.

[0065] The finished rolled screw 30 is shown in FIG. 2c.

[0066] In this way, a connecting element can exhibit a hole-forming tip as well as a self-tapping thread which are both made of a material which is harder than that used for the shaft. The material properties of the individual regions can thus complement each other.

[0067] FIG. 3 is a schematic view of another embodiment of a screw 50 according to the invention. The screw 50 has a drill tip 52 which cuts a hole in a component.

[0068] It is manufactured substantially in the same manner as described with reference to FIG. 2a, 2b. The drill tip 52 is produced by weld cladding a plating material 54 onto the tip region of the free end of the base element 56 made of the base material.

[0069] The plating material 54 in the tip region of the screw 50 is not rolled, but molded using cold forming so as to produce a drill tip 52. This allows a hard drill tip 52 to be produced which is reliably connected to a base element of the shaft.

[0070] As is further seen in FIG. 3, at least part of the thread 58 can also be formed from the plating material 54. The plating material 54 can be applied in a single step together with the weld cladding of the plating material in the tip region. The final formation of the thread is achieved by the rolling process following the production of the drill tip 52.