| 摘要 |
PURPOSE:To make deburring work of the external circumference of a ring part after molding unnecessary by improving deaeration even if a square-tubular material is used for a core metal of a ring part, by making a material to be poured through a gate of a molding die join at a connecting with a core metal of a spoke at the core metal of the ring part. CONSTITUTION:A molding material branches into an A route and a B route at a connecting part between a core metal 12a of a ring part and a core metal 12b1 of a spoke part after coating of the external circumference of the core metal 12b1 of one side spoke part, coat the metal 12a of the ring part respectively, which are made to join at a connecting part between a core metal 12b2 of the other side spoke part and the core metal 12a of the ring part and a coating layer 13 is formed further on the external circumference of the core metal 12b2 of the spoke part. In this instance, it becomes that air is discharged along the external circumference of the core metal 12b2 of of the spoke part through a forming cavity 19 of a coating layer 13 on the external circumference of the core metal 12b2 of the spoke part, and as removal of the air is performed sufficiently due to a matter that the part is a place through which air is liable to be discharged from a point of view of accuracy of a mold 14, there exist little possibility that a weld mark becomes conspicuous. |
