Method of manufacturing turbine frame for VGS turbocharger, turbine frame manufactured by the method, exhaust gas guide assembly for VGS turbocharger using the turbine frame, and VGS turbocharger in which the exhaust gas guide assembly is incorporated

摘要

A novel method of manufacturing a turbine frame for rotatably holding adjustable blades in a VGS turbocharger is provided, which method is capable of manufacturing the turbine frame while almost eliminating a time-consuming cutting operation, whereby mass production of the turbine frame and the like can be realized. The method includes: a blank which is punched out from a metal material having a substantially constant thickness in such a manner as to integrally include a boss forming portion (24a) and a flange forming portion (23a) is used as a shaped material (W) serving as an original member for the turbine frame; when the shaped material (W) is processed, the boss forming portion (24a) is formed into a projecting state by a press forging tool; receiving holes for rotatably holding the respective adjustable blades are formed in the flange forming portion (23a) by punching; and when the shaped material (W) is processed, some or all of the manufacturing processes are carried out in a warm condition.