| 摘要 |
PURPOSE:To reduce the loss owing to heat conduction and improve cutting efficiency by so setting laser beam radiation position that the radiation preheating part approaches to the cutting part in cutting a revolving metal pipe through laser beam radiation. CONSTITUTION:A laser beam A is set to a metal pipe 1 and while jet-form oxygen 3 is being blown from a nozzle 2, a condensed laser beam 4 is radiated. Then, the oxidation reaction heat with the oxygen 3 is added to the high density energy of the beam 4, by which the pipe 1 is burnt and melted. The product of combustion is blown off as slag 5 by the kinetic energy of the jet oxygen 3. At this time, the distance between the portion below the radiation part of the through-beam 4 and the cutting part E is made sufficiently smaller as compared to the inside diameter of the pipe and the time that the beam reaches the cutting part E is made shorter with the beam A of this invention as compared to conventional laser beam C owing to the rotation of the pipe 1, whereby the heat conduction of preheating is reduced. Hence, the pipe may be cut at high energy. |
