| 摘要 |
PURPOSE:To decrease the energy of the reflected light from a weld point with a shielding body and to prevent the burn in the outlet of an optical fiber for transmitting a laser beam by disposing the shielding body having a tapered through-hole between the outlet of the optical fiber and condenser lens. CONSTITUTION:The optical fiber 6 attached on the optical axis of the condenser lens 1 transmits the laser beam 4 and condenses the beam through the condenser lens 1 onto the irradiation point 2 of a work piece 7. The reflected light 5 having an inclination with the optical axis at the irradiation point is shielded or absorbed by the side wall of the tapered through-hole 9 having approximately the same angle as the spread angle theta of the laser beam 4 in the process of being condensed by the lens 1, by which the energy thereof is decreased and the generation of metallic vapor and spark is obviated. |
