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 welding determination device includes: a measurement unit configured to measure temperature of a joint portion between strip-shaped sheets (for example, steel strips (2)) to be joined by seam welding; and a determination unit configured to, based on measurement results by the measurement unit, calculate an average temperature T.sub.ave of the joint portion and a temperature difference T that is a difference between a maximum value and a minimum value among temperature of the joint portion and, when the average temperature T.sub.ave is less than or equal to a first threshold value and the temperature difference T is more than or equal to a second threshold value, determine that a joining defect due to ineffective current has occurred at the joint portion.

A spot-welding system including a spot-welding gun including a movable part including a movable electrode, and a drive part that drives the movable part, a controller that controls the drive part, an applied pressure sensor that measures an applied pressure from the movable electrode of the spot-welding gun, and an own-weight calculator that calculates an own weight of the movable part based on the applied pressure detected by the applied pressure sensor in two different postures of the spot-welding gun that places the movable electrode in different movement directions. . The controller superimposes a dither signal onto a control signal so as to control the drive part in measuring the applied pressure for use in calculating the own weight of the movable part by the own-weight calculator, and after the own weight is calculated, the controller corrects the control signal based on the calculated own weight.

A welding quality inspection apparatus for inspecting the welding quality of a plurality of welding parts formed on the material through the upper electrode and the lower electrode of the welding gun includes a position detection unit for detecting a position of the upper electrode, a control unit generating a position table based on a signal detected by the position detection unit during a total welding time of welding the plurality of welding parts of the material, generating first position data for a first welding time and second position data for a second welding time of a spot welding time of each of the welding parts based on the position table, checking whether the welding parts are defective by using the first position data, the second position data, and reference data, and generating result data based on whether the welding parts are detective, and an output unit for outputting the result data.

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.

Resistance spot rivet welding systems, subsystems, and methods of use thereof are provided.

Resistance spot rivet welding systems, subsystems, and methods of use thereof are provided.

Provided is a welding management system that appropriately manages welding. The welding management system (100) includes a plurality of local magnetic sensors (10a to 10f) provided around a target joining position (K) and a correction magnetic sensor (20) curved to surround the target joining position (K). A data processing unit (30) generates information of a joining state of the target joining position (K) based on a difference between a detection value of each of the plurality of the local magnetic sensors (10a to 10f) and a detection value of the correction magnetic sensor (20).

Provided is a welding management system that appropriately manages welding. The welding management system (100) includes a plurality of local magnetic sensors (10a to 10f) provided around a target joining position (K) and a correction magnetic sensor (20) curved to surround the target joining position (K). A data processing unit (30) generates information of a joining state of the target joining position (K) based on a difference between a detection value of each of the plurality of the local magnetic sensors (10a to 10f) and a detection value of the correction magnetic sensor (20).