| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a laser beam machine and laser cutting method capable of high-speed, stable and excellent cutting in a wide machining area from the near to the far positions and also capable of steady cutting even for a thick plate. SOLUTION: In a laser beam machine 21 with a variable optical path length having a collimation lens 9, a divergent lens 13, which divergently expands a laser beam made incident on the condensing lens 11 of a laser machining head 7a, 7b, is provided on the optical axis inside the laser machining head. In addition, the divergent lens is provided freely movably forward and backward on the optical axis, and a thick plate is cut in a state where the divergent lens 13 recedes from the optical axis.</p> |
