Method of machining plate materials with a plasma cutter and plasma torch

摘要

The present invention relates to a method of machining plate materials with a plasma cutter and plasma torch. This method is one in which the density of a magnetic flux formed in the range between the vicinity of the surface of an electrode material 3 fixed to the front end of the electrode and the vicinity of the nozzle opening 1b of a nozzle 1 is between 10 and 200 gauss. The magnetic flux is generated by a magnetization apparatus 4 disposed in the vicinity of the electrode 2 of a plasma torch 100. A workpiece 26 is cut by a plasma arc emitted from a nozzle, the diameter d of which is 1.5 mm or less. The plasma torch 100 for use in this method is equipped with a magnetization apparatus 4 in the vicinity of the electrode 2 and the nozzle diameter d is 1.5 mm or less. The above magnetization apparatus 4 is disposed on the same axis as the axis center of the nozzle opening 1b. Thus, even if a voltage drop results from the fact that the nozzle diameter of the plasma torch is made very small, the present invention is free from the double-arc phenomenon and the unstable arc phenomenon, thereby enabling a plasma arc to be stabilized. As a result, stable machining quality and a high- precision machined shape can be obtained.