| 摘要 |
PURPOSE:To improve the quality of a cut surface by moving the irradiation point of a laser beam, cutting a work and further irradiating the entire part or a part of the cutting route thereof with the laser beam. CONSTITUTION:The optical path of the laser beam 2 is disposed therein with 1st, 2nd partial reflecting mirrors 3a, 3b in series. The inclination angle of the reflecting mirror 3a is set at 45 deg. and the inclination angle of the reflecting mirror 3b is set at 45 deg.+alpha. The work 6 is first irradiated with the 1st laser beam 2a and is thereby cut. The 2nd laser beam 2b is then made incident to a condenser lens 4 via the partial reflecting mirror 3b and the entire part of a part of the cut surface is irradiated with this beam. An assist gas is ejected from a nozzle hole 5 at this time. Since the cutting route is irradiated again with the laser beam 2b, the aggregate sticking to the cut surface is surely removed. The quality of the cut surface is, therefore, improved. |
