| 摘要 |
PURPOSE:To make a mold easily without using any binder by packing molding sand contg. water into a metallic mold pattern box cooled with a refrigerant, parting the same in the state of the hardened surface thereof and acting the refrigerant upon the removed mold thereby freezing the same down to the inside. CONSTITUTION:Liquid N2 is injected 2 onto the outside surface of a metallic mold pattern box 2 sandwiched between a base plate 1 and a blowing head 8, whereby the box 2 is cooled down to a certain temp. In this state, compressed air is supplied into the head 8, and molding sand 9 contg. a proper amt. of moisture is blown through a blow port 8a into the cavity of the box 2, whereby it is packed. Upon completion of the blowing, the base plate 1 is lowered to detach the box 2 from the bottom surface of the head 8, and in this state the molding sand is held in the box 2 for a prescribed time. Next, the box 2 is opened, and the molding sand of the hardened surface is removed from the box 2, after which this mold is put in a refrigerating chamber and is hardened down to the inside, whereby the frozen mold permitting pouring of molten metal is produced. |
