A spot welding system includes a spot welding gun, a robot, and a tip dresser that polishes a face of electrode. The tip dresser includes a blade that cuts the face of the electrode and a blade driving motor that rotates the blade. A dresser control section of a control device detects torque of the blade driving motor. When the torque of the blade driving motor exceeds a predetermined torque upper limit value, the dresser control section carries out speed reduction control that reduces the rotation speed of the blade driving motor.

A weld wheel cleaning system is provided to clean or remove a layer of embedded material and other debris produced from welding from the working surface of a weld wheel. Such a weld wheel cleaning system includes a cleaner with an abrasive material positioned on an outer surface of the cleaner. The cleaner is positionable adjacent to the weld wheel such that the abrasive material is aligned with the working surface of the weld wheel. An actuator can be used to selectively actuate the cleaner with a force sufficient to remove the layer of embedded material from the working surface of the weld wheel with the abrasive material. The debris from the cleaner can be removed by a vacuum.

Spot welding electrodes with generally dome shaped welding faces are provided with surface features for welding both aluminum alloy sheet assemblies and steel sheet assemblies. A raised circular plateau is formed on the central axis of the dome and, in one embodiment, a suitable number of round bumps are formed in concentric spacing from adjacent the circumference of the plateau toward the circular edge of the welding face. For welding steel workpieces the plateau mainly serves as the engaging feature of the electrode. Both the plateau and concentric bumps are used in penetrating light metal surfaces for suitable current passage. In another embodiment, the domed surface is shaped with concentric terraces for engagement with the workpieces.

Provided is a shaping device for a roller electrode for seam welding that prepares shapes for a first roller electrode and a second roller electrode attached to an arm of a robot. This shaping device is provided independently from the robot and disposed within rotational range of the arm, and is provided with a first roller and a second roller that are disposed on a line orthogonal to a line joining the rotational centers of the first and second roller electrodes and are in contact with the outer circumferences of the first and second roller electrodes.

A rotary cutter includes a pair of recessed receivers which receive the respective tip ends of a pair of electrode tips, and a through portion which runs through in a rotation axis direction and provides an opening that communicates with each of the recessed receivers. A cover case covers the lower recessed receiver of the rotary cutter and has a notch which is associated with the lower recessed receiver. Over the upper recessed receiver of the rotary cutter, a cover plate is fixed to cover the upper recessed receiver. An electrode tip insertion hole is cut through a center portion of the cover plate.

A welding electrode for resistance spot welding includes a weld face comprising rings of ridges that project outwardly from a base surface of the weld face. The rings of ridges are positioned on the weld face to contact and impress into a sheet metal workpiece surface during resistance spot welding. If the welding electrode is used during resistance spot welding of light metal alloy workpieces, such as those of aluminum alloy or magnesium alloy, the rings of ridges on the weld face can contribute to improved welding performance.

A method for welding a plurality of aluminum to aluminum welds and a plurality of steel to steel welds using the same welder includes providing a resistance spot welder with a pair of weld electrodes having an electrode face radius of curvature in the range between 20 mm and 40 mm. The series of aluminum to aluminum welds is first made, and then, after completing the aluminum to aluminum welds, the series of steel to steel welds are made. After completing the steel to steel welds the weld electrodes are cleaned by an abrasive to remove any buildup or contamination of aluminum on the electrodes. In the event the electrodes have mushroomed, then dressing of the electrodes is provided and then the abrasive cleaning is performed to restore the surface texture.

A spot welding system includes a plurality of robots each including a spot welding gun and an inspection management device for managing an electrode inspection to be executed in each of the robots, for inspecting electrodes of the spot welding gun. Each robot includes an inspection execution unit for selectively executing one of different electrode inspections. The inspection management device includes an inspection instruction unit for instructing an electrode inspection to be executed in each of the robots.

An electrode tip tester for spot welding comprises a main body, a test block connected to the main body and including a first hole and a second hole facing each other, a camera, a first light source disposed between the first hole and the second hole, a second light source disposed between the first hole and the second hole, a mirror disposed between the upper and lower holes in the test block, and a controller determining at least one of whether there the electrode tip has a defect or damage or the diameter of the electrode tip based on the first image and the second image.

A head for a swing arm assembly is provided for a spot welding machine. The head can accommodate a tip dresser or a tip exchanger.