| 摘要 |
PURPOSE:To improve the productivity of casting in the production of a drum-in- disc brake rotor by providing a recess on the inside surface of a casting cavity and fitting the inside core print of a core therein during charging of molten metal. CONSTITUTION:In the casting of a drum-in-disc brake rotor, a mold is constituted of a cope 13, a drag 14, and a core body 6 having a core print 5 for an outside circumferential part and a core print 9 for an inside circumferential part. In this case, a recess 10 permitting fitting of the core print 9 is beforehand formed on the top surface of a cavity 2a for forming the disc part of the cope 13. When molten metal is charged into such mold, the inner end side of the core body part 6 is moved upward by the buoyancy of the molten metal, thus forcing the core print 9 to fit into the recess 10. On ascending of the surface of the molten metal, the molten metal fills the entire part of the cavity but it does not enter the inside of the recess 10, thus the good drum-in-disc brake rotor having no fins at the vent port in the disc part of the casting is cast. |
