| 摘要 |
PURPOSE:To obtain an impeller at a low cost with a less stage in the stage of extruding and forging radially vanes by using punches, by giving twist to the punches to incline the vanes in the stage of drawing the punches forced into the blank material in a bottom die. CONSTITUTION:A blank material 3 for an impeller 3 is fitted into a bottom die 9, and a top die 12 is lowered to force radially projected punches 11 into the material 3, thereby radially extruding respective vanes and yielding an impeller 4 arranged alternately with large and small plane vanes. Shaft grooves for twisting are provided at the top end in a shaft part. The impeller 4 is then fixed together with the die 9 by means of a chuck 10, and the die 12 is moved and rotated to twist the punches 11 while drawing the same from the impeller 4, by which the vanes 6 are inclined in the same direction and the impeller 5 is obtd. The chuck 14 of the die 12 is fitted in the shaft grooves in this stage to twist the shaft part to the same degree as for the vanes. Mass production of the impeller having an intricate shape is thus made possible. |
