| 摘要 |
PURPOSE:To make possible the saving of the time and expense at the making of sand molds by penetrating sprue holes and vent holes in an upper die, freely removably fitting a fired mold to this, and pouring motlen metal by keeping the lower mold and upper mold surfaces at the pouring at the specific temperature. CONSTITUTION:A lower mold 6 is constituted by guide pins 1, clamping rings 2, cross gate channels 3, vent channels 4 and a concave cavity part 5. If necessary, a concave cavity part 9 is concavely engraved in the plate surface. An upper mold 14 has the sprue holes 10 and vent holes 11 penetrated in the positions corresponding to the cross gate channels and vent channels of the lower mold. A sand mold 13 of a cylindrical shape is freely removably fitted to the top edge of the inside walls of the sprue holes and vent holes and the mold registration is performed. Prior to this, a layer of coat is made on the entire plate surface of the lower mold and upper mold, and at this time, the temperature of the upper and lower mold surfaces is prevented from lowering to <=50 deg.C by a portable burner. The sand mold is fixed by members 15 and, for example, an Si base Alalloy is melted to molten metal of 750 deg.C which is then poured in 15 seconds. After 5 minutes, the casting is removed from the mold, whereby the casting is obtained. |
