Mounting structure for variable nozzle mechanism

Provided is a variable-throat exhaust turbocharger in which a nozzle assembly including a nozzle mount and nozzle vanes has a firm support structure without affection by a thermal deformation of a turbine casing and an external force exerted to the turbine casing, and a scroll portion is formed in a substantially opened configuration so that the nozzle assembly can be simply formed in order to reduce the number of mold cores for a scroll during casting of the turbine casing, and thereby it is possible to enhance the productivity of the turbine casing.