PURPOSE: To prevent an electrode from being consumed due to heating by moving an arc in a shape of a ring, and to improve the work efficiency, by forming a supporting cylinder side electrode of a non-transfer type plasma torch, in a shape of a cylinder.
CONSTITUTION: A voltage from a plasma power source 15 is impressed between an outer cylinder nozzle 1 and the same cylinder electrode 9 through power lines 17a, 17b, and an arc 22a is generated between them. In this case, since the electrode is shaped like a ring, the arc rotates and moves on the surface of the cylindrical electrode 9 due to a tip effect, etc. of the arc 22a. Accordingly, an arc point does not stop at the same position, and also, since the electrode tip is shaped like a ring, an electrode area of an arc generation point increases, a life is extended remarkably, and it becomes scarcely necessary to replace the electrode.
FUJIMURA HIROSHI
KONO TAKAYUKI
OBA SHINSUKE
