| 摘要 |
<p>A laser beam machining method capable of preventing the occurrence of a notch portion (burn-through) at a machining terminating point on a product even when a work is machined into a shape in which a machining starting point and machining terminating point agree with each other, and an apparatus used therefor. A boring and periphery machining operations are started with a boring operation at a point P, and a cutting operation is then carried out from the point P to a point Q. A periphery machining operation is started at the point Q, and this cutting operation is carried out along a path 40 up to a point R. At the point R, the machining conditions are changed, and the laser beam reaches a point S, at which the periphery machining operation is completed. In order to carry out this boring and periphery machining operations, a CNC (10) subtracts a very short distance ΔL1 between the points Q, S from a one-round machining path which starts at the point Q, to generate the machining path 40, which is then stored in a memory. This very short distance ΔL1 is set to such a level that permits the portion of the work which is on the inner side of the periphery thereof to be removed speedily at the time of completion of the periphery machining operation. Since the machining finishing point S is set by subtracting the very short distance ΔL1 from a one round machining path without having the starting and finishing points Q, S of the periphery machining operation agree with each other, the occurrence of a notch portion, which is encountered in a machining operation in which the starting and finishing points Q, S agree with each other, can be avoided.</p> |
