| 摘要 |
PROBLEM TO BE SOLVED: To enhance the casting performance of a socket portion while preventing the interfusion of foreign objects. SOLUTION: A cast iron pipe P is manufactured by centrifugal casting in which a mold 11 is provided with a core 17 having an inhibiting member 20 which is easily soluble or flammable by molten metal a. The thickness of the molten metal a is kept uniform in the circumferential direction and the foreign objects are separated and kept standing out on the inner face of the molten metal a by the time the molten metal a reaches the inhibiting member 20, with a position where the molten metal a commences to be poured into the mold 11 being 1,500 to 2,000 mm from the end face of the socket 1. This makes the inhibiting member effectively prevent the foreign objects from infiltrating into a socket forming portion, and in this state, the molten metal free from the foreign objects is poured into the socket forming portion so that the socket is formed without the interfusion of the foreign objects. Further, the molten metal a is rectified and there is no interfusion of the foreign objects caused by air entrainment. The inhibition of foreign object infiltration does not cause the deterioration of mechanical strength so that a socket of high precision is obtainable. COPYRIGHT: (C)2006,JPO&NCIPI
|
