PURPOSE: To permit easy parting of spiral parts by forming the outside peripheral surfaces of split forming dies and the inside peripheral surface of a holder which are engaged with each other into tapered shapes and fitting the spiral rugged parts provided on the above-mentioned respective peripheral surfaces freely slidably into the line length direction thereof.
CONSTITUTION: The outside peripheral surfaces of forming dies x1...x8 split radially and the inside peripheral surface of a holder (y) holding the same are formed into tapered shapes to form sockets and spigots II, IO of rugged combinations at an angle on the respective peripheral surfaces with a device for forming spiral parts. The dies (x) are pushed into the holder (y) by cooperation of a punch and die holder to forge a blank material and thereafter the product is separated from the dies (x) by a forming die knock-out and is removed to the outside of the dies by a product knock-out in the stage of forming. The spiral parts are thus easily parted after forging.
SUZUKI KENJI
IIFUSHI JIYUNICHI
MASUMOTO MASANORI
SANNOMIYA KANAE
OKAZAKI YOUICHIROU
ISHIZUKA TADAYUKI
