MANUFACTURING METHOD FOR VARIABLE CAPACITY EXHAUST GAS TURBINE

摘要

Provided is a manufacturing method for a variable capacity exhaust gas turbine whereby, with variable capacity exhaust gas turbine component members produced using casting or other element molding and with which the final finished product is obtained using machining, the gap in a tongue section to allow an exhaust gas stream to flow smoothly into an inner circumferential scroll section can be formed at a minimum, and mounting of a cover section near a ring can be accomplished with high precision. The method is characterized in that: the component members are comprised of a cover section and a reduced-diameter plate section extending the inner diameter side in the direction of a plane perpendicular to the shaft following the gap between a bearing housing and the turbine rotor; the cover section and the reduced-diameter plate section are integrally formed using either casting, injection molding, or cold casting; a molded surface of the cover section is protruded to form a protrusion corresponding to the tongue section that is in the exhaust gas path in the turbine housing and that is formed in an intake equivalent portion of the inner circumferential scroll section of the cover section; and the protrusion undergoes cutting, and the cut surface and the tongue section are assembled maintaining the gap value therebetween.