| 摘要 |
<p>PURPOSE: To obtain a material having beads only to the outer surface of a hollow pattern by covering the contour at the one side of a foaming plastic pattern with a refractory forming member buried in a casting body. CONSTITUTION: When pouring molten iron into a casting sprue 11, the material of the foaming plastic pattern 3 is decomposed and made gaseous and sucked out through a negative pressure introducing pipe 14. In the casting process, the refractory forming member 2 (contg. a heat insulating layer 8 depending on the situation) is made into a constitutional element of the casting body to be cast. Therefore, the casting body comes to finally posses a space possessed with the foaming plastic pattern 3 at the initial stage. The contour 15 of the outer surface in the foaming plastic pattern is the contour of the outer surface in the casting body or becomes this contour. Therefore, the contour 16 of the inner surface in the casting pattern 1 of the inner surface of the forming member 2, is constituted as the contour 16 of the inner surface in the casting body to be cast.</p> |
