METHOD OF ESTIMATING NUGGET DIAMETER IN RESISTANCE WELDING AND CONTROL METHOD OF RESISTANCE WELDING

摘要

PROBLEM TO BE SOLVED: To estimate the diameter of a nugget which is formed in spot welding, with extreme accuracy during the welding. ;SOLUTION: In this estimation method of a nugget diameter in resistance welding, an inter-electrode displacement is measured at the time of thermal expansion during a current-carrying time for welding a regression line is determined from the inter-electrode displacement, an intersection is determined between this regression line and the zero-inclination line which into contact with the point where the displacement saturates; and the nugget diameter is calculated from a pre-determined multiple regression expression on the basis of time from the start of the energization to the intersection, the inclination of the regression line, and the intercept value of the regression line.;COPYRIGHT: (C)2000,JPO