VARIABLE BLADE MANUFACTURING METHOD FOR A VGS TYPE TURBO CHARGER

A manufacturing method based on a plastic working technique which can eliminate cutting and welding as much as possible in manufacturing an adjustable blade incorporated in a VGS turbocharger is provided. The present invention is characterized in that: a blank is punched out from a metal material having a substantially constant thickness to be a shaped material (W) as a starting form for an adjustable blade (1); thereafter, the shaped material (W) is compressed between a pair of opposed dies to form a blade portion (11), a shaft portion (12) and the like having desired shapes; thereafter a non-product portion protruding from a product portion is trimmed; then the shaft portion (12) is rolled by pressing the shaft portion (12) of the shaped material (W) against a pair of dies to have a desired diametrical thickness and a near net shape having a shape and dimensions thereof made close to the aimed at adjustable blade; and in finishing the vane height corresponding to a blade width of the adjustable blade (1), the shaped material (W) having the near net shape is pressed by a pair of opposed dies, so that an accuracy of a vane height in a completed state can be achieved.