A welding electrode may comprise a welding electrode body and a welding electrode cap that is connected or connectable to the welding electrode body for making contact between the welding electrode and a component for producing a welded connection. The problem of achieving an efficient heating of the sandwich sheet to be welded in a compact layout with the fewest possible modifications of the welding electrodes used heretofore is solved in that an electrically conductive resistance element integrated, or which can be integrated, in the welding electrode and which is connected or connectable in an electrically-conductive manner to the welding electrode body and the welding electrode cap is provided for the heating of the component. Furthermore, a method and a device with the welding electrode and a use are disclosed.

A welding electrode may comprise a welding electrode body and a welding electrode cap that is connected or connectable to the welding electrode body for making contact between the welding electrode and a component for producing a welded connection. The problem of achieving an efficient heating of the sandwich sheet to be welded in a compact layout with the fewest possible modifications of the welding electrodes used heretofore is solved in that an electrically conductive resistance element integrated, or which can be integrated, in the welding electrode and which is connected or connectable in an electrically-conductive manner to the welding electrode body and the welding electrode cap is provided for the heating of the component. Furthermore, a method and a device with the welding electrode and a use are disclosed.

A resistance spot welding method comprises: performing test welding; and performing actual welding after the test welding, wherein the test welding is performed under each of two or more welding conditions. In the test welding, for each of the welding conditions, an electrode force parameter from when electrode force application to parts to be welded starts to when a set electrode force is reached before start of current passage and a time variation curve of an instantaneous amount of heat generated and a cumulative amount of heat generated are stored. In the actual welding: electrode force application to the parts to be welded is performed under each of the same conditions as in the test welding before start of current passage, and a corresponding electrode force parameter and the parameter stored in the test welding are compared for each of the welding conditions to set a target of a time variation curve of an instantaneous amount of heat generated and a cumulative amount of heat generated in the actual welding; and adaptive control welding is performed to control a current passage amount according to the target.

The present invention relates micro resistance welding apparatus and to a method of welding. In particular, the present invention relates to small scale or micro welding apparatus and to a method of micro resistance welding using a controlled sequence of current, voltage and/or power signal profile for an electric arc. The invention provides a welding apparatus comprising: a controller supplying a controlled drive current to a weld head circuit in which the controller supplies said controlled drive current in dependence upon electrical feedback from the weld head circuit and in which the controlled drive current is defined by a sequence of segments and for each segment the welding apparatus operates in a mode defined by setting one of a predetermined current target, a predetermined voltage target or a predetermined power target; and at least two of the segments are operated in a different mode from one another. The invention also provide a method of operating such an apparatus.

A spatter production information storage unit stores spots where spatter has been produced. For the spots where spatter has been produced, a comparison information generation unit acquires weld design information stored in a design information storage unit and weld instruction information stored in an instruction information storage unit, compares both pieces of information, and generates comparison information. An image information output unit outputs the generated comparison information to a display device. The display device displays the comparison information on a screen so as to allow checking by an operator. Hence, it is possible to check, on the screen, comparison information for weld instruction information and weld design information highly likely as a cause for spatter being produced, and to efficiently perform the task of analyzing the causes for spatter being produced.

A spatter production information storage unit stores spots where spatter has been produced. For the spots where spatter has been produced, a comparison information generation unit acquires weld design information stored in a design information storage unit and weld instruction information stored in an instruction information storage unit, compares both pieces of information, and generates comparison information. An image information output unit outputs the generated comparison information to a display device. The display device displays the comparison information on a screen so as to allow checking by an operator. Hence, it is possible to check, on the screen, comparison information for weld instruction information and weld design information highly likely as a cause for spatter being produced, and to efficiently perform the task of analyzing the causes for spatter being produced.

A high frequency power supply system provides highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactors with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

The method for the production of a resistance spot welded joint according to the present invention can suppress the occurrence of spatter and can stably ensure nugget diameter in the spot welding of steel sheets in which a material having a high electrical resistance is present on the surface layer thereof. The method for the production of a welded joint according to the present invention is characterized by a tip diameter of the electrode, which is the diameter of a circle which is equivalent in area to a region in which a surface region of a tip surface of the electrode having a radius of curvature of 40 mm or more is projected onto a surface perpendicular to a direction of pressure of the electrode, is 8.0 mm or more, the method including a preliminary conduction step of applying a direct current Ia(t) (kA) for a conduction time ta seconds so as to satisfy formulas (1) and (2) below while pressing the electrode with a pressure of 5.5 kN or more, and a main conduction step of energizing with direct current while pressing the electrode with a pressure of 5.0 kN or more after the preliminary conduction step, wherein the current Ia(t) is continuously supplied for 80% or more of ta.

[Math 1]

Ia(t)6.0 (kA) formula (1)

0.5(kA.Math.s).sub.0.sup.taI.sub.a(t)dt2.0(kA.Math.s) formula (2)

A resistance weld shielding control system includes a computer that is executed to control a fixture to receive and hold at least one part to be welded. The computer also controls one or more electrodes to apply electrical energy to the part for welding the at least one part, and controls a gas delivery system to direct an inert gas onto the part for shielding the part from the ambient atmosphere via a nozzle. The nozzle is configured in the fixture such that the fixture holds the nozzle in a fixed physical relationship to the part.

A resistance weld shielding control system includes a computer that is executed to control a fixture to receive and hold at least one part to be welded. The computer also controls one or more electrodes to apply electrical energy to the part for welding the at least one part, and controls a gas delivery system to direct an inert gas onto the part for shielding the part from the ambient atmosphere via a nozzle. The nozzle is configured in the fixture such that the fixture holds the nozzle in a fixed physical relationship to the part.