MANUFACTURING METHOD FOR VARIABLE VANE IN VGS(VARIABLE GEOMETRY SYSTEM) TYPE TURBOCHARGER AND VARIABLE VANE MANUFACTURED BY SAME METHOD

摘要

PROBLEM TO BE SOLVED: To provide a new manufacturing method greatly suppressing shaft extension caused by a rolling while supposing that the shaft part of a preform to be an original form of a variable vane is formed by the rolling. SOLUTION: The metal preform to be the original form of the variable vane 1 is used as a starting material and the shaft part formed part of the preform is rolled and formed into the shaft part 12. The shaft part 12 is provided with a fitting part 16 to be turnably fitted into a receiving hole 25 in a turbine frame positioned in the outer circumference of an exhaust turbine T. The variable vane is characterized in that the fitting part 16 is provided with a rolling required part 17 and non-rolling part 18 having a slightly narrower diameter than that of the rolling required part 17 and that the rolling of the shaft part 12 is performed in the rolling required part 17 alone.