| 摘要 |
PURPOSE:To simplify a metal mold, prolong the service life, and making a blade piece thin and cut cost by forming a convex part in the vicinity of the outside of the dividing line formed onto a disc and inserting the blade piece into the groove and collapsing the convex part, thus fixing the disc and the blade piece. CONSTITUTION:In order to form the groove 4a on a disc 4, the inside countour 4e on the disc 4 and the projection 4b are allowed to coincide with the outside contour 4f and the cut part 4c, respectively, and since the dimension for puching- out a hole 4g is small, a metal mold can be formed integrally and the strength can be increased, and the life can be prolonged. Further, the width of the groove is not restricted as in the formation of the punched groove nearly in the width for the formation of the groove 4a on the disc 4, purpose can be achieved even if a blade piece 3 is made thin, and the blade piece 3 of a multiblade fan can be made thin, and the gap between the blade pieces 3 and 3 can be increased, and the performance can be improved, and noise can be reduced. Further, cost cut is permitted by making the blade piece 3 thin.
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