| 摘要 |
PURPOSE:To extract a die material after molding and curing resin, and to form the air duct functioning as a hollow easily by using a high molecular material, a thermal expansion coefficient thereof is larger than a resin material for molding and the difference of the thermal expansion coefficient thereof is within a predetermined range, as the die material of the air duct. CONSTITUTION:The coils 2 molded with the resin 3 for molding are arragned into a resin casting die 1, and the duct die material 7 is disposed between the resin 3 for the molding. The duct die material 7 is made of the high molecular material, the thermal expansion coefficient thereof is larger than the resin 3 material for molding and a range of the difference of the thermal expansion coefficient thereof is within 10X10<-6>-100X10<-6>/ deg.C. The duct die material 7 is extracted after the resin is molded and cured, and the hollow air duct is easily formed. When a hollow section of the duct is square-shaped, t/2-t/10 is given as the curvature of angular sections to the width t of the air duct. Accordingly, frictional pressure at the time when extracting the die material 7 is minimized, and the material is easily extracted. |
