| 摘要 |
PURPOSE:To make two metal plates sufficiently melted for welding, in laser butt welding of two plates with different thickness, by enlarging energy density of the base metal plate having larger thickness and thereby eliminating relative energy, shortage due to difference in thickness. CONSTITUTION:In butt welding in a state where two metal plates 1, 2 each with a different thickness are shifted on one side of their surfaces against each other, the difference in thickness of the two plates 1, 2 is detected by a means 10 for detecting such difference, the signal of this detection is sent to a controller 12, and a computed control signal is sent to a motor 13 for rotating a lens. The condensing lens 7 is inclined for a preset angle corresponding to the difference in thickness by the rotation of the motor 13A. The energy density of the laser beam 4, by which the plate 1 with a larger thickness is irradiated through the inclination of this condensing lens 7, becomes larger than the plate 2 with a smaller thickness. Then, sufficiently melted, both plates 1, 2 shows no acute angled difference in level. Consequently, a formed product to be press- formed is free from the problem of galling because of the absence of acute angled difference in level. |
