Patent ID: 10519850

Abstract:
An object is to provide a turbine housing with a simple structure whereby it is possible to reduce flow resistance of exhaust gas and improve efficiency of a turbocharger. A turbine housing made by casting has an opening part formed on a hub side of a scroll part, the opening part having a radius R2 which satisfies a relationship R1<R2, provided that R1 is a radial directional distance from an axis of a turbine wheel to a tip of a shroud part and R2 is a radial directional distance from the axis to an inner peripheral edge of a hub-side wall surface of the scroll part. A roughness of a flow-path surface in a region A is smaller than in a region B, provided that the region A is a predetermined range from the tip of the shroud part and the region B is a predetermined range adjacent to the region A, among flow-path surfaces of the shroud part and the scroll part facing a scroll flow path on an outer side, in a radial direction, of the tip of the shroud part.