| 摘要 |
PURPOSE:To cast a multilayered pipe having uniformly walled materials over the longitudinal direction centrifugally, easily and surely by providing an inside circumferential projecting part in the end part on the casting side of a rotary mold and dropping the molten metal for the 2nd and subsequent layers onto this projecting part. CONSTITUTION:In the stage of centrifugal casting of a multilayered pipe, an inside circumferential projecting part 4 which is unified with the wall thickness of a rotary mold 1 is provided in the end part on the casting side of the mold 1. The wall thickness (a) of the part 4 is made roughly equal to the wall thickness t1 of the 1st layer 5, and its longitudinal size (b) is formed to the sufficiently long size extending to the front side of the falling point of molten metal from the end part of the casting. When the molten metal for the 2nd layer falls onto the part 4 from a hopper 3 after casting of the last layer 5, it moves slowly thereafter onto the layer 5. Hence, the erosion phenomenon of the layer 5 by the charging of the 2nd layer is effectively prevented. For casting of the multilayered pipe of >=3 layers, all required is to increase the sizes (a), (b) of the inside circumferential projecting part and to provide plural stepped parts. |
