CONSTRUCTION SECURING MAIN PLATE OR HUB TO BOSS OF FAN IMPELLER AND PRODUCTION METHOD OF SECURING CONSTRUCTION

摘要

PURPOSE:To tighten a main plate to a boss of an impeller inseparably as an integral unit through an intermediate plate in strength to about an equal level to rivet tightening by the method of calking tightening. CONSTITUTION:A boss 14 placed with a turtle neck part 14b upward is set to a fixed mold 17 of a press machine, and a main plate 13 is fitted to the part 14b to both set an intermediate plate 15 to the protruded turtle neck part 14b through a mounting hole and fit a dowel 15b provided to the plate 15 to a dowel hole 13b formed to the plate 13. Then a press machine of movable type 18 equipped with an expander tool 18a is moved downward to expand a diameter of the part 14b as shown by a broken line. Then a press machine of movable type 19 is lowered to forcibly press the expanded turtle neck part 14b, and the part 14b, envelopes a part from an external end face to peripheral face of the plate 15 by a folded plastic worked part 16 to perform tightening by calking. In this way, the plate 13 and the boss 14 can be inseparably secured as an integral unit through the plate 15.