| 摘要 |
PURPOSE:To prevent weld cracking of materials ot be welded by preheating and post heating said materials before and after laser welding. CONSTITUTION: A laser beam 2 from a laser oscillator 1 passes through a welding head 3, by which the beam is condensed and is irradiated to the surface of materials 4 to be welded. A control device 6 for laser output preheats the materials 4 for the present time alone while receiving the signal from a plasma detector 5. The device 6 controls the oscillator 1 to increase the laser output to the extent that laser welding is accomplished according to the signal from the detector 5. The device 6 controls the oscillator 1 to perform the post heating similar to preheating upon completion of welding. |
