| 摘要 |
<p>PURPOSE:To reduce the time up to freezing and hardening of a mold, reduce the consumption of a refrigerant and improve productivity by flowing the refrigerant through the hydrous sand filled in the mold by blowing thereby freezing and hardening the same. CONSTITUTION:Hydrous sand S in a blowing head 3 is filled in a product cavity 1 by blowing, and an ejector 7 for ejecting a refrigerant such as liquid nitrogen into a product cavity 1 is carried into between the head 3 and metal molds 2. When the liquid nitrogen is ejected from the ejector 7 into the cavity 1, the water of the hydrous sand S solidifies and the entire part of the sand S freezes and hardens quickly and surely. Thence, an elevating table 4 or the like is lowered, the molds 2, 2 are opened, the frozen and hardened core is removed, and is set into other master mold in a frozen state, thereafter, molten metal is poured. Thereby, the defect-free casting product is obtained.</p> |
