LASER BEAM MACHINING HEAD AND CUTTING/WELDING METHOD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a laser beam machining head capable of forming a parallel laser beam with a small diameter and cutting even a thick plate with a constant kerf width, and capable of welding satisfactorily even a narrow grooved thick plates. SOLUTION: A converged laser beam 4 contracted by a converging optical system 3, which converges a laser beam 2 introduced froma an optical fiber 1 and emits, is formed into a parallel laser beam 12, which is a parallel ray with a long focus, by a parallel ray optical system 11 composed of flat-concave lenses or both concave lenses, and this parallel laser beam 12 is made to emit toward a member 5 to be machined.