ROBOT FOR ARC WELDING

PURPOSE:To provide a titled robot which recognizes direcly a weld line by a TV camera near a welding torch and guides exactly the torch by providing a filter which allows passage of only the specific wavelength in the reflected light of the laser light irradiated to a weld zone in a narrow band. CONSTITUTION:A laser light source 11 moves together with a welding torch 4 and a welding wire 3 in a weld line direction while irradiating the part near the weld zone. A TV camera 6 and a motor 14 move in the same direction as well. The motor 14 runs in synchronization with the pulsation of welding current and when the welding current decreases, said motor positions the light transmission hole 15 of a perforated disc 13 to the front of the image pickup lens of the camera 6. The video near the weld point is passed through the hole 15 and a filter 12 and only the wavelength of the laser illuminating light passes through the filter in the narrow band and is made incident to the camera 6. The central position of the weld line, the fluctuation in the shape of a groove 2, etc. are thus known directly. The difference between the taught weld line and the actual weld line is then recognized and the teaching is corrected so that the position of the torch 4 is corrected by a control means 15.