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.

The spot welding method of the present invention has steps of preliminary conduction, first conduction, second conduction, and third conduction: Preliminary conduction: Conduction method aimed at improving closeness of contact surfaces of steel sheets and reducing sheet gaps by gradually increasing the welding current (for example, upslope conduction). If rapidly applying current, current would be locally carried and that part would melt resulting in expulsion, so this is a conduction method gradually running current (for example upslope conduction) to avoid local heating. First conduction: Conduction method running a constant welding current and using the heat generated by the electrical contact resistance between steel sheets to cause the formation of a nugget when preliminary conduction results in close contact surfaces between the steel sheets. Second conduction: Conduction method making the current lower than the first conduction to suppress inside expulsion while making the nugget grow in the diametrical direction. Third conduction: Conduction method making the current higher than the second conduction and making the nugget grow not only in the diametrical direction, but also mainly in the sheet thickness direction when the nugget size becomes a certain extent of size at the second conduction step.

The spot welding method of the present invention has steps of preliminary conduction, first conduction, second conduction, and third conduction: Preliminary conduction: Conduction method aimed at improving closeness of contact surfaces of steel sheets and reducing sheet gaps by gradually increasing the welding current (for example, upslope conduction). If rapidly applying current, current would be locally carried and that part would melt resulting in expulsion, so this is a conduction method gradually running current (for example upslope conduction) to avoid local heating. First conduction: Conduction method running a constant welding current and using the heat generated by the electrical contact resistance between steel sheets to cause the formation of a nugget when preliminary conduction results in close contact surfaces between the steel sheets. Second conduction: Conduction method making the current lower than the first conduction to suppress inside expulsion while making the nugget grow in the diametrical direction. Third conduction: Conduction method making the current higher than the second conduction and making the nugget grow not only in the diametrical direction, but also mainly in the sheet thickness direction when the nugget size becomes a certain extent of size at the second conduction step.

A wire welding and grinding station (100) comprises a wire welder (112), an AC electrical motor (114) for powering a metal grinder (116), and an AC power supply (110) for supplying electrical power to both the wire welder (112) and the electrical AC motor (114). The station (100) further comprises a soft start module (118) to reduce inrush current demanded by the electrical AC motor (114) while starting. The use of the soft start module (118) allows using a battery (102) as power supply and the use of a battery as power supply has the advantage of practical movability and stable welding currents.

A wire welding and grinding station (100) comprises a wire welder (112), an AC electrical motor (114) for powering a metal grinder (116), and an AC power supply (110) for supplying electrical power to both the wire welder (112) and the electrical AC motor (114). The station (100) further comprises a soft start module (118) to reduce inrush current demanded by the electrical AC motor (114) while starting. The use of the soft start module (118) allows using a battery (102) as power supply and the use of a battery as power supply has the advantage of practical movability and stable welding currents.

A resistance spot welding device for welding at least two overlapping steel sheets held between a pair of welding electrodes is provided. The resistance spot welding device includes the pair of electrodes, an electrode force gauge that measures an electrode force, and a controller that controls an electric current supply to the electrodes according to the electrode force measured by the electrode force gauge. The controller controls the electric current such that the electrode force F measured by the electrode force gauge after the start of the electric current supply is adjusted to a prescribed value.

Provided is a resistance spot welding method. The resistance spot welding method for joining a sheet set including a plurality of lapped steel sheets includes: holding the sheet set between a pair of electrodes; and energizing the sheet set under application of electrode force to thereby join the steel sheets together. At least one of the plurality of lapped steel sheets is a surface-treated steel sheet including a metal coating layer on a surface thereof. The energizing includes: a primary energizing step of performing energization to form a nugget portion; a non-energizing step in which, after the primary energizing step, the energization is suspended for an energization suspension time Tc (cycles); and a secondary energizing step of, after the non-energizing step, performing energization for reheating while the nugget portion is prevented from growing. During the energizing, the relations of a particular formula are satisfied.

A computer-implemented method for reducing spot welds in a parameterized workpiece model includes generating a new design space (DS) from an original spot weld DS. The new DS includes a plurality of spot weld locations from the parameterized workpiece model with the original spot weld DS. The new DS is optimized to have a fewer number of spot weld locations than the original DS. The processor identifies a plurality of offending spot weld locations of the remaining spot weld locations in the new DS and a plurality of conforming spot weld locations of the remaining spot weld locations. The processor removes all but one optimized extension candidate from processor-selected groupings of welds while enforcing a minimum distance requirement. The processor outputs an inter-distance constrained parameterized workpiece model with an optimized extension candidate in each of the plurality of extended DSs to an operatively connected output processor.

A computer-implemented method for reducing spot welds in a parameterized workpiece model includes generating a new design space (DS) from an original spot weld DS. The new DS includes a plurality of spot weld locations from the parameterized workpiece model with the original spot weld DS. The new DS is optimized to have a fewer number of spot weld locations than the original DS. The processor identifies a plurality of offending spot weld locations of the remaining spot weld locations in the new DS and a plurality of conforming spot weld locations of the remaining spot weld locations. The processor removes all but one optimized extension candidate from processor-selected groupings of welds while enforcing a minimum distance requirement. The processor outputs an inter-distance constrained parameterized workpiece model with an optimized extension candidate in each of the plurality of extended DSs to an operatively connected output processor.

A series of many electrical resistance spot welds is to be formed in members of an assembled, but un-joined, body that presents workpiece stack-ups of various combinations of metal workpieces including all aluminum workpieces, all steel workpieces, and a combination of aluminum and steel workpieces. A pair of spot welding electrodes, each with a specified weld face that includes oxide-disrupting features, is used to form the required numbers of aluminum-to-aluminum spot welds, aluminum-to-steel spot welds, and steel-to-steel spot welds. A predetermined sequence of forming the various spot welds may be specified for extending the number of spot welds that can be made before the weld faces must be restored. And, during at least one of the aluminum-to-steel spot welds, a cover is inserted between the weld face of one of the welding electrodes and a side of a workpiece stack-up that includes the adjacent aluminum and steel workpieces.