| 摘要 |
PURPOSE:To prevent the generation of blow hole inside welding zone by moving in the feeding direction of the body to be worked under vibrating the focus of converged laser beam in the plate thickness direction of the body to be worked. CONSTITUTION:A laser beam 10 is deflected vertically to the lower part by reflection mirror 6 and becomes a converged laser beam 11 by a condensing lens 8. In this case, the focus position is set to the position (a) coming in slightly under the lower part than the upper face of the bodies 1a, 1b to be worked. The converged laser beam 11 is irradiated on the bodies 1a, 1b to be worked with reciprocally moving the condensing lens 8 in the upper and lower directions by operating an agitator 9 on starting of welding. In this case, a working gas is fed as well from a feeding port 3 simultaneously with the vibration. The focus position (a) is moved further to the position in the lower direction (b) from the position coming slightly under from the upper face of the bodies 1a, 1b to be worked and returns to the original position (a). Namely due to the feeding motion in welding being combined in addition to the vertical movement of the focus position, the locus of the focus becomes in a saw edge shape 12. The weld without any defect is thus performed by giving a vibration stirring to a molten metal 13 and by expelling the bubbles, etc. of the inner part to the external part. |
