TRANSMUTATION CONTROL METHOD AND APPARATUS FOR CONDENSING DIAMETER IN FIBER LASER BEAM MACHINE

PROBLEM TO BE SOLVED: To provide an optimum machining method in a fiber laser beam machine, in which specific machining performance can be maintained regardless of change in a beam quality constant in the fiber laser beam machine, and also to provide an apparatus for the method. SOLUTION: A fiber laser beam machine is equipped with a condensing optical system in which a collimator lens 13 for collimating a laser beam 7 emitted from a transmission optical fiber 11 from a fiber laser oscillator is installed movably in the optical axis direction and in which a condensing lens 21 for condensingly irradiating a workpiece with the collimated laser beam is installed movably in the incident optical axis direction. In the fiber laser beam machine, the transmutation control method for a condensing diameter is such that the collimator lens and the condensing lens are moved in the optical axis direction, thereby making a condensing diameter in the condensing lens variable, and making a specific machining performance maintainable regardless of change in the beam quality constant in the fiber laser beam machine. COPYRIGHT: (C)2010,JPO&INPIT