Welding Electrode and Method for Electrically Welding a Ball

Abstract

A welding apparatus includes a welding electrode, where the welding electrode has a concavely formed end-face region and where the welding electrode has a magnet such that a spherical dome-shaped portion of a magnetically attractable ball which is located in an effective range of the magnet is drawable against the concavely formed end-face region.

Claims

1.-11. (canceled)

12. A welding apparatus, comprising: a welding electrode, wherein the welding electrode has a concavely formed end-face region and wherein the welding electrode has a magnet such that a spherical dome-shaped portion of a magnetically attractable ball which is located in an effective range of the magnet is drawable against the concavely formed end-face region.

13. The welding apparatus according to claim 12, wherein the magnet is a permanent magnet.

14. The welding apparatus according to claim 12, wherein the magnet is an electromagnet.

15. The welding apparatus according to claim 12, wherein the magnet is disposed symmetrically with respect to a central longitudinal axis of the welding electrode.

16. The welding apparatus according to claim 12, wherein the welding electrode has a plurality of magnets which are disposed symmetrically with respect to a central longitudinal axis of the welding electrode.

17. The welding apparatus according to claim 16, wherein the welding electrode has a permanent magnet disposed in a middle of the plurality of magnets and electromagnets disposed radially to the permanent magnet.

18. A method for welding, comprising the acts of: capturing a magnetically attractable ball by the welding electrode of the welding apparatus according to claim 12; pressing the magnetically attractable ball against a component; and flowing a welding current from the welding electrode via the magnetically attractable ball to the component and partially melting the magnetically attractable ball in a region of contact with the component by the welding current.

19. The method according to claim 18, wherein the welding current flows into the magnetically attractable ball from the concavely formed end-face region of the welding electrode.

20. The method according to claim 18, wherein the magnetically attractable ball is a steel ball.

21. The method according to claim 18, wherein the component is a ball.

22. The method according to claim 21, wherein the ball is attached to a vehicle component or a vehicle body component.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0016] The single FIGURE shows the basic principle of a welding electrode according to the invention in a schematic representation.

DETAILED DESCRIPTION OF THE DRAWING

[0017] The FIGURE shows a welding electrode 1, which has a concavely formed end-face region 2. The welding electrode 1 has a central longitudinal axis 3. The welding electrode 1 also has a magnet 4, which is arranged in the middle or symmetrically with respect to the central longitudinal axis 3. An end face 5 of the magnet forms part of the concavely formed end-face region 2. However, this does not necessarily have to be the case. The magnet 4 may also be set back slightly. i.e., integrated further into the welding electrode 1.

[0018] A magnetically attractable ball 6 lies against the concavely formed portion 2. The ball 6 is attracted by the magnet 4. If the end face 5 of the magnet 4 forms part of the concavely formed end-face region, the ball 6 can lie directly against the end face 5 of the magnet 4. If the magnet 4 is set back further, i.e., is integrated further into the welding electrode 1, the ball 6 does not lie directly against the magnet 4.

[0019] The magnet 4 may be for example a permanent magnet. As an alternative to this, the magnet 4 may also be a switchable electromagnet.

[0020] By means of such a welding electrode, a ball can be simply picked up. For example, the welding electrode need only be held in a ball storage container, which has the effect that a ball jumps out of the ball storage container onto the welding electrode and is attracted by the magnet 4 such that the ball 6 is automatically centered with respect to the concavely formed end-face region.

[0021] After the picking up of the ball by means of the welding electrode 1, the ball 6 is brought or moved up to another component to which the ball 6 is to be welded. Here, the other component is a ball 7, which has been welded onto a metal sheet 8.

[0022] The welding electrode 1 is connected via a power line 9 to a welding unit 10, which generates an electrical welding voltage. In the case of the exemplary embodiment shown here, a second welding electrode 11 is provided, which is pressed from an underside of the metal sheet 8 against the metal sheet 8. The second welding electrode 11 is likewise connected to the welding unit 10 via an electrical line 12. When the ball 6 is pressed against the ball 7 and the welding unit is switched on, i.e., a welding voltage is applied, a welding current flows from the welding electrode 1 via the ball 6 to be welded, the ball 7, the metal sheet 8 and the welding electrode 11 back to the welding unit 10.