| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal casting apparatus by which high speed and highly precise casting can be performed. SOLUTION: A molten metal holding furnace 1 constituted of a molten metal waiting vessel 2 and a molten metal pouring vessel 20, is provided so as to control to open/close a replenishing hole 14 formed between the molten metal pouring vessel 20 and the molten metal waiting vessel 2 with a molten metal shut-off valve 15. A molten metal holding means, in which the molten metal shut-off valve 15 is shifted to the opening position when the molten metal quantity in the molten metal pouring vessel 20 is less than a reference quantity and this shut-off valve 15 is shifted to the closing position when the molten metal exceeds the reference quantity, is arranged and further, a supplying pressure control means, with which the force-feed of the molten metal into a cavity is performed with both of sucking and pressurizing. Therefore, the reduction and replenishment of the molten metal quantity in the molten metal pouring vessel is repeated by the quantity needed to one time of casting, and the charging time for replenishing into the molten metal pouring vessel is not needed as the conventional apparatus and also, the pressure variation in the molten metal pouring vessel can be reduced and the force-feed of the molten metal into the cavity can be performed at a constant pressure. Further, since the back pressure in the cavity is not generated by performing both of sucking and pressurizing and the molten metal can be quickly and densely filled into the cavity, the casting having high preciseness and high density can be performed at high speed.
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