| 摘要 |
PURPOSE:To fill the circumference of a through hole with a hard material, by a method wherein a cave part on the inside of a molding tool is covered with a slide core, a soft material is cast, then the hard material is cast into the said soft material, the slide core is opened at the time of a rise of inner pressure and the hard material is cast further. CONSTITUTION:Split molds 21, 22, 23 are combined with one another and a cavity 25 and cave part 26 corresponding to an external form of a mud guard 7 are formed. A slide core 3 movable in e vertical direction is provided on the cave part 26. When the front of the cave part 26 is closed with a main body 30, a core pin 31 is in a pin hole 231 of the split mold 23. A soft material for skin layer molding is injected within the cavity through an injection hole 24. Then a hard material 11 is cast into the soft material 12 and the inside of the cave part 26 is filled with the soft material 12 and hard material 11 which is in the soft material 12. Therefore, the cave part 26 becomes a state where the hard material is surrounded by the soft material, in the cave part 26. |
