| 摘要 |
PURPOSE:To prevent generation of a cold junction, penetrator, etc. and to perform sure welding in the stage of using a high-frequency voltage and a laser beam in combination in welding wedge shaped welding surfaces by controlling the incident angle, beam diameter, diverging angle, etc. of the laser beam. CONSTITUTION:The wedge shaped ends 2 of a tubular body 1 formed by forming a steel plate into a pipe shape are heated by the current conducted to contactors 4a, 4b from a high-frequency power source 4. On the other hand, a laser beam LB is radiated from a laser oscillator to said part to heat and melt the ends thereby welding the same. When the beam LB adjusted in a beam diameter D and a diverging angle alpha by beam shape converters 6, 7 and an objective mirror 8 is projected toward the single Vee groove, the laser beam is multiple-reflected by PL1-PR1 to form a final heating zone Hz and a melt zone Mz. The projecting angle between the beam LB and the inside surface of the single V groove increases sharply when the number of reflection increases. The position of the zone Hz and the zone Mz is thus controlled by changing the angle alpha. |
