Resistance Spot Welding Electrode and Use of the Electrode

Abstract

A resistance spot welding electrode for forming dissimilar welded lap joints in crash-relevant structural components of the automotive industry made of high-strength materials. The resistance spot welding electrode includes a cap having, at an end portion of the electrode in contact with materials to be welded together during welding, a non-axially symmetrical contact area in order to form, between the materials being welded, a weld nugget with an essentially similar non-axially symmetrical shape.

Claims

1. A resistance spot welding electrode for dissimilar welded lap joints in crash-relevant structural components of the automotive industry made of high-strength materials, wherein the resistance spot welding electrode includes a non-axially symmetrical cap having at an end of the electrode configured during welding to be in contact with materials to be welded together, a non-axially symmetrical contact area in order to achieve a weld nugget between the materials with an essentially similar non-axially symmetrical shape.

2. The resistance spot welding electrode according to claim 1, wherein the resistance spot welding electrode is positioned so that a part of the non-axially symmetrical cap, which is essentially parallel with a longest dimension of the structural components to be welded, is positioned close to an opposite edge of structural components in a cross direction.

3. The resistance spot welding electrode according to claim 1, wherein the resistance spot welding electrode is positioned so that a part of the non-axially symmetrical cap, which is essentially parallel with a longest dimension of the structural components to be welded, is positioned close to a first edge of structural components in the cross direction.

4. The resistance spot welding electrode according to claim 1, wherein the non-axially symmetrical cap has a web width not smaller than 1.5 mm and not greater than 5 mm.

5. The resistance spot welding electrode according to claim 1, wherein a ratio of a web length to a web width in the non-axially symmetrical cap is bigger than 2.0, but smaller than 6.0.

6. The resistance spot welding electrode according to claim 1, wherein the orientation of a web length is 75-90 to the component longitudinal direction.

7. The resistance spot welding electrode according to claim 1, wherein the non-axially symmetrical cap has a modified or unmodified C, T, L or S shape.

8. The resistance spot welding electrode according to claim 1, wherein the non-axially symmetrical cap has a modified or unmodified crescent, clamp or bracket shape.

9. The resistance spot welding electrode according to claim 1, wherein the non-axially symmetrical cap has a modified or unmodified combination of a classical point with a web.

10. The resistance spot welding electrode according to claim 1, wherein the non-axially symmetrical cap has a modified or unmodified W or H shape.

11. A method of welding with a resistance spot welding electrode including: positioning a non-axially symmetrical cap having, at an end of the non-axially symmetrical electrode configured to be in contact with materials to be welded together, a non-axially symmetrical contact area; and engaging the resistance spot welding electrode to weld high strength materials, such as carbon steel or stainless steel with a yield strength greater than 400 MPa, wherein the carbon content is more than 0.15 weight % in the resulting dissimilar weld nugget.

12. A method of welding with a resistance spot welding electrode including: positioning a non-axially symmetrical cap having, at an end of the resistance spot welding electrode configured to be in contact with materials to be welded together, a non-axially symmetrical contact area; and engaging the resistance spot welding electrode to weld high strength aluminium alloys.

13. The method of claim 11, wherein the welded materials form crash-relevant parts for automobiles, crash-relevant parts for trucks, railway construction parts, battery packs for battery electric vehicles, hybrid and pressure resistance tanks, or white good products.

14. (canceled)

15. The resistance spot welding electrode according to claim 4, wherein the non-axially symmetrical cap has a web width not smaller than 2.5 mm and not greater than 3.5 mm.

16. The resistance spot welding electrode according to claim 5, wherein a ratio of a web length to a web width in the non-axially symmetrical cap is bigger than 2.5 but smaller than 6.0.

17. The method of claim 12, wherein the welded materials form crash-relevant parts for automobiles, crash-relevant parts for trucks, railway construction parts, battery packs for battery electric vehicles, hybrid and pressure resistance tanks, or white good products.

Description

[0024] The present invention is illustrated in more details referring to the following drawings where

[0025] FIG. 1 shows one preferred embodiment of the invention schematically seen from the top view,

[0026] FIG. 2 shows another preferred embodiment of the invention schematically seen from the top view,

[0027] FIG. 3 shows still another preferred embodiment of the invention schematically seen from the top view,

[0028] FIG. 4 shows further another preferred embodiment of the invention schematically seen from the top view,

[0029] FIG. 5 shows one another preferred embodiment of the invention schematically seen from the top view.

[0030] FIG. 1 illustrates the end of a resistance spot welding electrode cap 1 which is during welding in contact with the materials to be welded and has a shape of a modified C letter rotated 180 degrees. The cap 1 is non-axially symmetrical in the vertical direction. In FIG. 1 it is illustrated for the cap 1 the web width w, the web length l and the radius r in the geometrical transition zone. The cap 1 is positioned to a welded component so that the longitudinal direction of the welded component is illustrated by an arrow 2.

[0031] FIG. 2 illustrates the end of a resistance spot welding electrode cap 6 which is during welding in contact with the materials to be welded and has a shape of an unmodified L letter rotated 180 degrees. The cap 6 is non-axially symmetrical in the vertical direction. In FIG. 2 it is illustrated for the cap 6 the web width w and the web length. The cap 6 is positioned to a welded component so that the longitudinal direction of the welded component is illustrated by an arrow 7.

[0032] FIG. 3 illustrates the end of a resistance spot welding electrode cap 11 which is during welding in contact with the materials to be welded and has a shape of an unmodified T letter. The cap 11 is non-axially symmetrical in the vertical direction. In FIG. 3 it is illustrated for the cap 11 the web width w and the web length. The cap 11 is positioned to a welded component so that the longitudinal direction of the welded component is illustrated by an arrow 12.

[0033] FIG. 4 illustrates the end of a resistance spot welding electrode cap 16 which is during welding in contact with the materials to be welded and has a shape of an unmodified W letter rotated 90 degrees. The cap 16 is non-axially symmetrical in the vertical direction. In FIG. 4 it is illustrated for the cap 16 the web width w and the web length. The cap 16 is positioned to a welded component so that the longitudinal direction of the welded component is illustrated by an arrow 17.

[0034] In accordance with FIG. 5 the end of a resistance spot welding electrode cap 21 which is during welding in contact with the materials to be welded is a shape of a modified combination of a non-axially symmetrical area 22 and an axially symmetrical area 23. The cap 21 is non-axially symmetrical in the vertical direction and, therefore, in order to achieve a desired weld nugget in accordance with the invention the cap 21 is positioned during welding in the transverse direction to the material to be welded. In FIG. 5 it is illustrated for the cap 21 the web width w and the web length as well as the distance d between the traditional, prior art axially symmetrical area and the non-axially symmetrical area. The cap 21 is positioned to a welded component so that the longitudinal direction of the welded component is illustrated by an arrow 24.