PURPOSE: To gouge a narrow and deep J groove of high accuracy on the end of a work piece, by butting a waste plate to the end face of the work piece, and preparing a U groove in the butt part thereof then removing the waste plate.
CONSTITUTION: A waste plate 13 is spot-welded to the side end face 12 of a work piece 4, and while compressed air is injected along the butt part 14 thereof, a carbon electrode 3 is moved, by which a U groove is worked with the butt part 14 as an approximate center. In this stage, the electrode 3 is tilted by 5W 25° from the perpendicular direction to either right or left an arrow A of the advancing direction in said butt part 14, by which a narrow and deep groove having a small angle θ and a curved surface (r) can be formed. The melt is blown to the front of the arc by inclining the electrode backward at 45W60° in the arrow A of the advancing direction, whereby the generation of shear droops is prevented. The above-mentioned gouging is accomplished efficiently with an automatic gouging device provided with a holder B for regulating the angle of an electrode which holds the electrode inclinedly at an angle β to right or left and at an angle α in the advancing direction.
OKUYA SENNOSUKE
YASUDA HARUO
MIZUTANI TAKAYUKI
IBIDEN ENGINEERING KK