BEVELING POSITION DETECTING DEVICE

PURPOSE:To detect a beveling position accurately by calculating a distance between a calculated assuming datum line and a center position of a bright portion and thus forming to obtain a shoulder portion based on a variation of this distance. CONSTITUTION:A light-source 3 irradiates so as to cross a beveling 2 and an image-taking device 5 takes a slit photo-image 4' of an irradiated slit light 4. The signal is fed to a signal processing circuit 20a and stored in a video- memory 6 after being converted by an A/D converter 5'. Then the photo-image signal is binaryfied at a binaryfication circuit 8 and fed to a noise removing circuit 9 inevery scanning line, where the width of a bright portion is calculated and output to an averaging circuit 11 after the bright portion is converted to the dark portion as noise. The circuit 11 outputs the input signal to a linearization circuit 12 and the circuit 12 calculates an assuming detum straight line. And, by outputting those data to a shoulder detecting circuit 13, the circuit 13 obtains the shoulder portion of a steel plate 1. The obtained locations of the both shoulders are fed to a welding position detecting circuit 14 and are judged correctly. And a welding torch drive control operating circuit 15 calculates a necessary amount to move for a welding torch 17.