Welding electrode, method, and device for welding sandwich panels

A welding electrode comprising:

• a welding electrode body;
• a welding electrode cap that is connected or connectable to the welding electrode body and is configured to make contact with a component to produce a welded connection;
• and
• an electrically conductive resistance element for heating the component, wherein the electrically conductive resistance element is integrated or configured to be integrated in the welding electrode, wherein the electrically conductive resistance element is connected or connectable in an electrically conductive manner to the welding electrode body and the welding electrode cap.

A method for resistance welding a metallic component to a sandwich sheet that comprises a thermoplastic layer disposed between two metallic cover layers, the method comprising:

• heating a region of the sandwich sheet to be welded such that the thermoplastic layer softens;
• displacing the softened thermoplastic layer in the region by pressing together the two metallic cover layers;
• and
• welding the two metallic cover layers and the metallic component together by a flow of electric current in a first circuit through a first welding electrode disposed on a side of the sandwich sheet and a second welding electrode disposed on a side of the metallic component,
• wherein the first welding electrode comprises a welding electrode body, a welding electrode cap that is connected or connectable to the welding electrode body and is configured to make contact with the metallic component to produce a welded connection, and an electrically conductive resistance element for heating the metallic component, wherein the electrically conductive resistance element is integrated or configured to be integrated in the first welding electrode, wherein the electrically conductive resistance element is connected or connectable in an electrically conductive manner to the welding electrode body and the welding electrode cap,
• wherein heating the region of the sandwich sheet to be welded is performed by way of a current flow in a second circuit comprising the welding electrode body, the electrically conductive resistance element, and the welding electrode cap of the first welding electrode.

A device for resistance welding a metallic component to a sandwich sheet that comprises a thermoplastic layer disposed between metallic cover layers, the device comprising:

• a first welding electrode positionable on a side of the sandwich sheet, wherein the first welding electrode comprises a welding electrode body, a welding electrode cap that is connected or connectable to the welding electrode body and is configured to make contact with the metallic component to produce a welded connection, and an electrically conductive resistance element for heating the metallic component, wherein the electrically conductive resistance element is integrated or configured to be integrated in the first welding electrode, wherein the electrically conductive resistance element is connected or connectable in an electrically conductive manner to the welding electrode body and the welding electrode cap;
• a second welding electrode positionable on a side of the metallic component;
• a first circuit configured to pass a welding current across the first and second welding electrodes;
• and
• means for displacing the thermoplastic layer of the sandwich sheet from a region of the sandwich sheet to be welded,
• wherein a second circuit comprises the welding electrode body, the electrically conductive resistance element, and the welding electrode cap of the first welding electrode, wherein the region of the sandwich sheet to be welded can be heated by passing current through the second circuit.