| 摘要 |
PURPOSE: To prevent machining defects which tend to be caused at the time of transition from piercing to cutting on a hard-to-work material such as thick soft steel because of heat accumulation on a work at the time of piercing and because of the unsmooth flow of molten metal at the start of cutting. CONSTITUTION: A machining command part 100, receiving a command based on a program for working from a program analysis part 18, outputs a machining command for operating a laser generator 6 and a laser beam machine 9. In addition, receiving a command outputted from a preliminary machining command part 200, the machining command part in cooperation with that part 200 forms a command for a prelimirnary machining and outputs it after a command for piercing. Cutting is performed for a short distance after piercing, under the machining conditions of a low speed and a low output; a groove to flow a molten metal is formed while heat accumulation is reduced; the irradiation of a laser beam is once stopped after that; a machining position is returned to a piercing position; and since the cutting is resumed with the irradiation of a laser beam under the original machining conditions, the flow of the molten metal is smooth. |
