US 2017/0291248 A1 · WELDING ELECTRODE FOR USE IN A RESISTANCE SPOT WELDING WORKPIECE STACK-UPS THAT INCLUDE AN ALUMINUM WORKPIECE AND A STEEL WORKPIECE

Abstract

A welding electrode is disclosed that includes an electrode welding shell and a blind adapter that are joined together to cooperatively define an internal cavity. The electrode welding shell and the blind adapter may be integrally formed or they may be distinct components that are attached together. The presence of the internal cavity defined by the electrode welding shell and the blind adapter reduces the thermal mass of the welding electrode and slows the rate of conductive heat transfer from the weld face to a cooling fluid, which allows in the center of the weld face to retain heat for a longer duration once current flow through the welding electrode is terminated, thereby positively affecting the spot welding process for particular types of workpiece stack-ups including those that include an aluminum workpiece and an overlapping adjacent steel workpiece.

Claims20

Dependent claims

A welding electrode for use in spot welding operations, the welding electrode comprising:

an electrode welding shell that includes a front end wall and a peripheral side wall, the front end wall exteriorly comprising a weld face and the peripheral side wall extending rearwards from the front end wall;
and
a blind adapter joined to the peripheral side wall such that the electrode welding shell and the blind adapter cooperate to define an internal cavity, the blind adapter having an axially closed front wall surrounded by a rearward portion of the peripheral side wall of the electrode welding shell, the axially closed front wall of the blind adapter having an exterior front surface that partially defines the internal cavity.

A welding electrode for use in spot welding operations, the welding electrode comprising:

an electrode welding shell that includes a front end wall and a peripheral side wall, the front end wall exteriorly comprising a weld face and the peripheral side wall extending rearwards from the front end wall to a back end;
and
a blind adapter that includes an axially closed front wall and a peripheral side wall that extends away from the axially closed front wall to define an internal recess, the peripheral side wall of the blind adapter being joined to the peripheral side wall of the electrode welding shell such that the peripheral side wall of the blind adapter and the peripheral side wall of the electrode welding shell overlap and the axially closed front wall of the blind adapter is surrounded by the peripheral side wall of the electrode welding shell, wherein an exterior front end surface of the axially closed front wall of the blind adapter cooperates with an interior surface of the peripheral side wall of the electrode welding shell and an interior back surface of the front end wall of the electrode welding shell to define an internal cavity, and wherein a part of the internal recess of the blind adapter proximate the axially closed front wall serves as a cooling pocket when an electrode shank adapter is supported in the internal recess of the blind adapter.

A method of resistance spot welding a workpiece stack-up that comprises an aluminum workpiece and an adjacent overlapping steel workpiece, the method comprising:

contacting an aluminum workpiece surface of the workpiece stack-up with a first weld face of a first welding electrode, the first welding electrode comprising an electrode welding shell, which includes the first weld face, and a blind adapter joined to the electrode welding shell at one end and further joined to an electrode shank adapter at another end, wherein the electrode welding shell and the blind adapter cooperate to define an internal cavity, and wherein blind adapter and the electrode shank adapter cooperate to define a cooling pocket;
contacting a steel workpiece surface of the workpiece stack-up with a second weld face of a second welding electrode;
passing electrical current between the first weld face of the first welding electrode and the second weld face of the second welding electrode to create a molten aluminum weld pool within the aluminum workpiece that wets an adjacent faying surface of the steel workpiece;
introducing a flow of cooling fluid into the cooling pocket through the electrode shank adapter to extract heat away from the first weld face of the first welding electrode during passage of the electrical current between the first and second weld faces of the first and second welding electrodes;
and
terminating passage of electrical current between the first weld face of the first welding electrode and the second weld face of the second welding electrode to allow the molten aluminum weld pool to solidify into a weld joint that bonds the aluminum and steel workpieces together.

3 more elements

Dependencies are inferred from the claim text.

Welding electrode for use in a resistance spot welding workpiece stack-ups that include an aluminum workpiece and a steel workpiece

Life of this patent

Welding electrode for use in a resistance spot welding workpiece stack-ups that include an aluminum workpiece and a steel workpiece

Life of this patent

Abstract

Claims20