Patent ID: 8297339

Claim:
A semi-molten or semi-solid molding method using a molding die in order to cast, with semi-molten or semi-solid metal, a scroll member having a tabular panel, a spiral section projecting from one surface of the panel, and a columnar part projecting from an other surface of the panel on a side opposite to the surface from which the spiral section is projected, the semi-molten or semi-solid molding method comprising: filling a cavity formed inside of the molding die with the semi-molten or semi-solid metal from a section for forming the columnar part via a runner that forms a channel, the cavity forming a space for casting the scroll member, at least one of an angle of intersection θ 1 between the runner and the section for forming the columnar part being set such that 97°≦θ 1 ≦135° and a ratio R/√S being set such that 0.12≦R/√S≦0.96, where R is a radius of curvature of a chamfered section in which the runner intersects the section for forming the columnar part, and √S is the square root of a cross-sectional area S of the section for forming the columnar part.