Method and apparatus for manufacturing a compressor rotor

A plurality of tread portion divided metal molds 12 surrounding a profile portion 11a of a compressor rotor 11 to allow pitch. A pair of Endmetallformen 14 and 15 surrounds both ends of the rotor. A helical core 16 is attached to a Endmetallform 14 to be helically guided by the profile section of the rotor. A rotor-shaped cavity 13 is formed in the interior through the tread portion and the split metal molds Endmetallformen. Hot metal is pressurized and injected into the cavity and solidified therein. Subsequently, the Endmetallform 14 with the helical core extracted by rotating it along a helical line.