A method of manufacturing a terminal-formed electric wire includes a welding member placing process in which at least one welding member formed of metal having a melting point lower than that of a plurality of metal strands included in a core wire is arranged to the core wire of at least a terminal-forming target portion of the electric wire, and a terminal forming process in which the exposed terminal-forming target portion is interposed between first and second electrodes having a shape corresponding to a desired terminal shape, at least the welding member in the terminal-forming target portion is melted by electrically conducting the first and second electrodes while pressing the terminal-forming target portion with the first and second electrodes, and the melted metal is then solidified, so that the terminal-forming target portion is formed as a terminal portion having a desired terminal shape.

In a resistance spot welding method, test welding and actual welding in which a current pattern is divided into two or more steps are performed. In the test welding, a constant current of a different value is passed in each step, and a time variation of an instantaneous amount of heat generated per unit volume and a cumulative amount of heat generated per unit volume are stored as a target value. In the subsequent actual welding, when a time variation amount of an instantaneous amount of heat generated per unit volume deviates during any step from the results of the test welding, a current passage amount is controlled to compensate for the difference during a remaining welding time in the step. In the test welding, 0.3×I.sub.x≦I.sub.a<I.sub.x, where I.sub.a is the current in the first step, and I.sub.x is the current in second and subsequent steps.

An electrical connector for removably engaging a welder to a spot welding tool having a first arm in a pivoting engagement to a second arm. The connector features an electrically conductive member engaged to or forming a powered translating shaft of a welder which is surrounded by a housing. The connector engages within a passage formed in a coupling to communicate forward and rearward movement and electric current to a first arm of a spot welding tool.

A system is for bonding a cover sheet to a core to form or repair a dual wall structure. The system includes a cover sheet probe and an inner pedestal probe. A three dimensional contoured tip of the cover sheet probe abuts against a three dimensional contoured outer surface of the cover sheet opposite a pedestal of the core. The pedestal abuts the inner surface of the cover sheet. The inner pedestal probe may be coupled to the core to create a conductive electrical path from the cover sheet probe through at least part of the structure. A flow of electric power is controlled and supplied to the cover sheet probe to heat a junction between the area of the cover sheet abutting the pedestal and the pedestal. A heated area is created in the junction and fixedly couples the coversheet and the pedestal.

The resistance spot welding method includes performing actual welding to squeeze, by a pair of electrodes (14), a sheet combination with a sheet thickness ratio of more than 3 in which a thin sheet (11) is overlapped on at least one face of two or more overlapping thick sheets (12, 13), and passing a current while applying an electrode force to join the sheet combination, wherein in the actual welding, a pattern of the current and the electrode force is divided into two or more steps including a first step and a second step to perform welding, and an electrode force F1 in the first step and an electrode force F2 in the second step satisfy a relationship

F1>F2.

A resistance welding device is configured for use in combination with a resistance welder having a translating welding electrode. A first arm of the welding device is in a translating rotational engagement with a second arm thereof. The first arm of the device is engageable to a translating electrode from the resistance welder. Translation of the welding electrode of the resistance welder moves first and second electrodes to contact metal therebetween and spot weld the metal.

An electrostatic energy storage welding machine for performing resistance welding while applying pressure to an object to be welded includes: a pair of welding electrodes; an energy storage section including a plurality of energy storage parts; an individual charge circuit for individually charging respective energy storage parts; an individual discharge circuit for individually discharging the respective energy storage parts; a voltage monitor circuit individually monitoring voltages of the respective energy storage parts; an individual voltage stabilization control section for performing control to further charge an energy storage part having deviation in performance in an individual manner to stabilize a voltage of that energy storage part and thereby achieve a set voltage; and an output circuit for outputting power produced by the set voltage stabilized through individual charging and electric current through individual discharging in the energy storage section to apply the electric current between the welding electrodes.

A sealing method that uses an electrostatic energy storage welding machine which includes an energy storage section including a plurality of energy storage parts is provided. A method of sealing a liquid inlet port of a power storage device includes burring in advance a through-hole of the liquid sealing port to raise a hole edge of the through-hole into a form of a projection, wherein the liquid sealing port of the power storage device to be sealed with electrolyte contained therein corresponds to an object to be welded; placing a spherical body that is a lid body on the projection; and performing resistance welding between the projection and the spherical body to seal the liquid inlet port.

A method of resistance spot welding a workpiece stack-up that includes an aluminum workpiece and an adjacent overlapping steel workpiece is disclosed. The method uses a first welding electrode positioned proximate the aluminum workpiece and a second welding electrode positioned proximate the steel workpiece to effectuate the spot welding process. In an effort to positively affect the strength of the ultimately-formed weld joint, external heat may be supplied to the first welding electrode by an external heating source disposed in heat transfer relation with the first welding electrode either before or after, or both before or after, an electrical current is passed between the first and second welding electrodes to create a molten aluminum weld pool within the aluminum workpiece.

A method of resistance spot welding workpiece stack-ups of different combinations of metal workpieces with a single weld gun using the same set of welding electrodes is disclosed. In this method, a set of opposed welding electrodes that include an original shape and oxide-disrupting structural features are used to resistance spot weld at least two of the following types of workpiece stack-ups in a particular sequence: (1) a workpiece stack-up of two or more aluminum workpieces; (2) a workpiece stack-up that includes an aluminum workpiece and an adjacent steel workpiece; and (3) a workpiece stack-up of two or more steel workpieces. The spot welding sequence calls for completing all of the aluminum-to-aluminum spot welds and/or all of the steel-to-steel spot welds last.