Variable blade manufacturing method and variable blade in VGS type turbo charger

A method of manufacturing an adjustable blade for a VGS turbocharger,

• the adjustable blade including a shaft portion serving as a center of rotation and a blade portion for substantially adjusting the flow rate of exhaust gas, the adjustable blade being incorporated in the VGS turbocharger,
• wherein the exhaust gas discharged from an engine at a relatively low flow rate is suitably throttled to increase the velocity of the exhaust gas so that an exhaust turbine wheel is rotated by energy of the exhaust gas and a compressor directly coupled to the exhaust turbine wheel feeds more air into the engine than is fed into it by natural suction, and thereby a high output power of the engine is obtained at low rotational speeds, wherein:
• in manufacturing the adjustable blade (1), the adjustable blade (1) is integrally provided with the blade portion (11) and the shaft portion (12) and a starting material thereof is a metal shaped material providing starting form for the adjustable blade;
• the shaped material is made to have such a near net shape by applying a processing operation to the shaped material or the shaped material is originally formed to have such a near net shape in a stage of obtaining the shaped material that the shape and dimensions thereof are made close to those of the aimed at adjustable blade;
• and
• in finishing a vane height corresponding to a blade width of the adjustable blade, the shaped material having the near net shape is pressed between a pair of opposed dies, and thereby an accuracy of the vane height in a finished state is achieved.

A method of manufacturing an adjustable blade for a VGS turbocharger,

• the adjustable blade including a shaft portion serving as a center of rotation and a blade portion for substantially adjusting the flow rate of exhaust gas, the adjustable blade being incorporated in the VGS turbocharger,
• wherein the exhaust gas discharged from an engine at a relatively low flow rate is suitably throttled to increase the velocity of the exhaust gas so that an exhaust turbine wheel is rotated by energy of the exhaust gas and a compressor directly coupled to the exhaust turbine wheel feeds more air into the engine than is fed into it by natural suction, and thereby a high output power of the engine is obtained at low rotational speeds,
• the method of manufacturing the adjustable blade (1) comprising:
• using a blank punched out from a metal material having a substantially constant thickness as a shaped material which provides a starting form for the adjustable blade;
• thereafter, compressing the shaped material between a pair of opposed dies so as to form the blade portion, and the shaft portion to have desired shapes;
• then trimming a non-product portion of the shaped material protruding from a product portion of the shaped material;
• thereafter, pressing the shaft portion of the shaped material against a pair of dies so that the shaft portion is rolled to have a desired diametrical thickness and a near net shape having a shape and dimensions thereof which are made close to those of the aimed at adjustable blade;
• and
• finishing a vane height, which corresponds to a blade width of the adjustable blade, by pressing the shaped material having the near net shape between a pair of opposed dies so as to achieve an accuracy of the vane height in a completed state.