| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a molding die capable of molding a magnet rotor that is sufficiently low in coaxiality and makes it possible to considerably reduce vibration and abnormal noise during rotation. <P>SOLUTION: The molding die is for a magnet rotor R obtained by annularly injection molding a bond magnet 5 having a predetermined thickness on the circumference of a metal cylindrical boss 4. A movable die 2 forms a cylindrical cavity space S closed at both ends when a fixed die is joined therewith and its plane 22a has a center pin 24. The outside diameter of the tip 242 of the center pin is smaller than the inside diameter of the boss 4 and the outside diameter of the body portion 243 is larger than the inside diameter of the boss 4. The tip portion 241 of the center pin is formed in a tapered shape and is gradually increased in outside diameter as it goes from the tip 242 to the body portion 243. The center pin is so provided that its central axis agrees with the central axis of the cavity space S. With the boss 4 fit on the tip portion 241 of the center pin 24, the boss 4 is pressed and moved from the tip portion 241 to the body portion 243 of the center pin 24 by the fixed die 1 joined with the movable die 2. <P>COPYRIGHT: (C)2008,JPO&INPIT |
