Arc welding device and method

Abstract

A plasma ejection unit (21) of an arc welding device includes a plasma torch (26), a copper plate (27), a container (28), and a gas supplying unit (29). Plasma gas inside the container (28) is pressurized by argon gas supplied from the gas supplying unit (29), and ejected from first to eighth ejection ports. The plasma gas ejected from the first to eighth ejection ports is concentrated in a concentration area (CA) between vehicle body plates (16-17) to form through holes (40) in the vehicle body plates (16-17), and is separated. The air pressures, in eight areas, of the plasma gas reaching a vehicle body plate (18) are approximately one-eighth of the air pressure of the plasma gas in the concentration area (CA). Accordingly, while the through holes (40) are formed in the vehicle body plates (16-17), no through hole is formed in the vehicle body plate (18).

Dependencies are inferred from the claim text.