| 摘要 |
PURPOSE:To set a condition maximizing machining speed, improve the machining yield and stabilize the quantity of products by providing a photosensor to detect a blue light emission and easily setting the surface of a material to be machined using a range in which the blue light emission is detected. CONSTITUTION:A switching valve 8d is actuated by a numerical controller 11 to switch a cutting auxiliary gas 8b to an inert gas 8c. While the inert gas is ejected, a machining torch 6 is moved vertically within about 1/5 of the light emitting range stored in the numerical controller 11 to regulate the height of a boundary at which the light emitting caused by the irradiation of a laser beam 1a changes its color from blue to orange to be equal to the height of the machining torch 6 when the level of an output signal 18a from the photosensor 18 changes. Then, while the height of the machining torch 6 at the time when the level of the output signal 18a changes is newly stored, a servomotor 9a is moved to the height to move the machining torch 6 and the machining is restarted switching the inert gas 8c to the cutting auxiliary gas 8b. |
