An apparatus for manufacturing a resin fan that includes a multitude of blades arranged radially from center of the fan and held securely between a first circular plate and a second circular plate aligned at the center of the fan with each other, said resin fan being molded on a two-stage molding process including a primary forming mold and a secondary forming mold, wherein
- (1) said resin fan is molded into a particular shape in the following way in which
- (a) said blades are bent at a bend and the bend has a convex surface;
- (b) each of said blades is molded such that it has a height of H01 on an outer peripheral edge thereof, said height increasing gradually toward an inner peripheral edge and that each of said blades has a height of H02 that is greater than H01 on the inner peripheral edge thereof;
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- (c) said first circular plate includes a first central opening portion;
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- (2) with each of the molds being closed, said primary forming mold is the mold on which a semi-molded article including said first circular plate and said blades united together into one unit is to be molded,
- the apparatus comprises:
- (a) a first circular plate forming mold for molding an outer side and an outer peripheral edge of said first circular plate;
- (b) a first mold for molding the first central opening portion of said first circular plate;
- (c) a blade forming mold for molding said blades on an inner side of said first circular plate;
- and further includes:
- (d) means for moving said blade forming mold, said first circular plate forming mold, and said first mold to a molding position in which said semi-molded article is to be molded by being brought closer to each other and to a non-molding position by being brought away from each other;
- (3) with all of the molds being closed, said secondary forming mold is the mold on which said resin fan is to be molded by uniting said semi-molded article and said second circular plate together, and includes the molds described below:
- (a) said first mold;
- (b) a second mold for molding an outer side and an outer peripheral edge of said second circular plate;
- (c) a third mold for molding an inner side of said second circular plate by being inserted into a corresponding gap formed between any two of the multitude of blades that are adjacent to each other and disposed radially in close proximity of a circumference of said first mold so that said third mold can engage closely a lateral wall of one blade located in said corresponding gap and that said third mold can engage a lateral wall of another of the multitude of blades located in said corresponding gap;
- (d) means is provided for moving said second mold and said first mold to a molding position in which said fan is to be molded from said semi-molded article by bringing those two molds closer to each other and for moving said second mold and said first mold to a non-molding position by bringing those two molds away from each other;
- (e) means is provided for opening and closing said third mold so that said third mold can be moved to a first position located on a centrifugal side by being brought closer to said first mold and that said third mold can be moved to a second position located radially away from said first mold, said third mold having the structure in which in said first position, said third mold is inserted into the corresponding gap formed between said any two adjacent blades so that it can mold the inner side of said second circular plate;
- (f) said first mold has a recessed portion that engages the forward end of said third mold by being fitted into said forward end;
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- (g) said third mold is inserted into said corresponding gap and has a projecting portion that allows it to engage said first mold by allowing its forward end to be fitted into said recessed portion on said first mold;
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- (4) two composite molds are provided, each of said composite molds having the functions provided by combining said first circular plate forming mold with said first mold, and means is provided for allowing each composite mold to move to the position that corresponds to said blade forming mold and to the position that corresponds to said second mold, the movement of each composite mold occurring alternately between those two positions.