This spot welding method is a method for joining workpieces being a layered body of three or more metal sheets by supplying welding current. The welding current has a pulse-like waveform wherein a peak state in which the current reaches or is maintained to be within a set peak current range and a non-peak state in which the current is lowered from the peak current range to a set bottom current, and is then increased toward the peak current range again are alternately achieved. In the non-peak state, in the case where an effective value Irms of the welding current is lowered, and reaches a predetermined effective value target range, a current control process for increasing the welding current toward the peak current range is started.

A bonding system is used for bonding a cover sheet to a core to form or repair a dual wall structure. The bonding system includes a plurality of bonding probes and controller circuitry. The bonding probes include a three dimensional (3D) contoured tip configured to align with a predetermined area of a 3D contoured cover sheet of a dual wall structure. The controller circuitry comprises processor circuitry and sensor circuitry. The sensor circuitry provides a location of an area of the 3D contoured cover sheet for bonding. The processor circuitry identifies a bonding probe having a contacting area that aligns with the 3D contour of the cover sheet in the location provided by the sensor circuitry.

The present invention relates to methods and apparatus for detection of fire states in the presence of welding activities. In some examples, the welding detection system may algorithmically calculate a risk of a fire state developing. In some embodiments, the welding fire detection and prevention system may communicate warning states to users, supervisors, equipment and/or building monitoring systems.

A system and method to correct for height error during a robotic additive manufacturing process. One or both of an output current, output voltage, output power, output circuit impedance and a wire feed speed are sampled during an additive manufacturing process when creating a current layer. A plurality of instantaneous contact tip-to-work distances (CTWD's) are determined based on at least one or both of the output current, output voltage, output power, output circuit impedance and the wire feed speed. An average CTWD is determined based on the plurality of instantaneous CTWD's. A correction factor is generated, based on at least the average CTWD, which is used to compensate for any error in height of the current layer.

A no-indentation welding monitoring device may include a pressing force measuring device for measuring a pressing force for pressing a welding target of a welding tip of a welding gun, a voltage measuring device for measuring a voltage applied to the welding tip of the welding gun, and a monitor device for digitizing a welding quality by use of the pressing force and the voltage transmitted from the pressing force measuring device and the voltage measuring device.

To provide a spot welding system of high reliability which, when an abnormality such as a spot missing in spot welding occurs, is capable of more precisely and accurately detecting this immediately. Provided are a robot-side system having a robot and a robot-side control unit which controls driving of the robot; and a welder-side system having a welding gun mounted to the robot, and a welder-side control unit, in which the robot-side system includes: a storage unit which stores in advance a required welding time needed in a sport welding operation of one location or a plurality of spot welding operations; a welding time measurement unit which measures an actual time from when a welding start command is outputted until receiving a welding completion command; and a comparative determination unit which determines quality by comparing the required welding time stored in the storage unit and the actual welding time measured by the welding time measurement unit.

Disclosed is a nut welding automation system configured to automatically weld different types of nuts to holes formed in a metal-processed product using a robot. The system may reduce an error rate with respect to products by preventing omission of a nut or welding of a wrong type nut so that reliability in administration of the welding process may be secured and overall productivity may be improved.

A resistance welding apparatus includes a welding controller configured to control a welding tool. The welding controller has an assignment device including a parametrization device. The assignment device is configured to read out a current point to be welded from a list of points to be welded, to read out a first setpoint curve from a record of a database assigned to the current point to be welded, and to assign the first setpoint curve to the first regulator and the parametrization device is configured to read out the first value from the record of the point to be currently welded and to parametrize a first parameter of the first regulator with the first value. The welding controller further includes the first regulator configured, using a first parameter, to regulate a temporal profile of an electric current at the current point to be welded in accordance with the first setpoint curve.

A resistance spot welding method able to form a welded joint having delayed fracture resistance, includes, in order, applying a pressing force P1 (kN) to the plurality of steel sheets by welding electrodes while supplying a supplied current I1 (kA), while applying the pressing force P1, supplying a current Ic (kA) during a cooling time tc (s), repeating two times or more a pressure force raising and lowering cycle of supplying a supplied current I2 (kA) to the welding electrodes while applying a pressing force P2 (kN) to the plurality of steel sheets by the welding electrodes during a pressing time tf (s), then immediately applying a pressing force P3 (kN) during a pressing time ti (s), applying the pressing force P2 during the pressing time tf, and releasing the pressing force and ending the supply of current, satisfying 0Ic<I1, 0.3I2/I1<1.0, P2/P12, tf0.2, P3<P2, and ti0.2.

An expulsion sensing device includes a spot welding device 2 that pressurizes, via a pair of electrodes 33 and 34, a workpiece W in which a plurality of metal plate members is superposed and welds the workpiece W by passing electricity between the pair of electrodes 33 and 34 while maintaining a predetermined pressurizing force, an operation control unit 42 that detects an interelectrode distance between the pair of electrodes 33 and 34 at predetermined time intervals, a calculation unit 51 that detects a temporal change rate of the detected interelectrode distance, and a determination circuit unit 52 that determines occurrence of expulsion when the detected change rate in an approaching direction of the pair of electrodes 33 and 34 is equal to or more than a predetermined threshold