METHOD FOR INSPECTING WELDING WHEREBY NUGGET DIAMETER OF SPOT-WELDING PORTION IS MEASURED

摘要

PURPOSE:To reduce the weight of a non-destructive inspection device and achieve further miniaturization and cost reduction of the inspection device which measures the nugget diameter of a welding portion without destructing the nugget by means of insertion of an inspecting chisel between two spot- welded metal plates. CONSTITUTION:A chisel 1 having a V-groove at its end and a vibrator for vibrating the chisel 1 are provided, and the chisel is inserted between two spot- welded metal plates by means of vibration that the chisel receives from the vibrator, and a nugget is held in the V-groove. When the V-groove abuts on the nugget and the forward movement of the chisel 1 is stopped, the distance (c) from the apex B of the angle of the V-groove to the center O of the nugget is calculated according to the distance (b) from a predetermined reference line of the chisel 1 to the apex B of the angle of the V-groove and the amount (a) of movement obtained by measuring the distance from the apex B to the center O of the nugget, and the diameter of the nugget is measured from this (c) value and the angle theta of the v-groove.