Spot welding system and spot welding method and nugget diameter estimation system and nugget diameter estimation method

摘要

A welding spot is held between electrodes either biased with a controlled pressure, having a controlled voltage applied thereacross, and variations of an inter-electrode distance are detected for a welding quality control, in which the distance variations are time-integrated, a nugget size is estimated on a basis of the integration, and a decision is made of a conformity of welding quality based on an estimated nugget size.