负压又称真空,在铸造生产中早以得到应用,如真空吸铸、真空压铸等特种铸造工艺均获得很好的效果,被广泛采用。近二十年来,它在造型和靠芯方面的应用也得到迅速发展。如真空造型(V 法造型),改变了砂型铸造的传统的造型方法,简化各造型工艺,改善了造型工艺方法改善了铸型性能,在大平面扁平形铸件的铸造方面取得了显著的工艺效果。又如西 Negative pressure, also known as vacuum, is used as early as possible in casting production. Special casting processes such as vacuum suction casting and vacuum die-casting have achieved good results and are widely used. In the past two decades, its application in modeling and relying on the core has also been rapidly developed. Such as vacuum modeling (V method), changing the traditional molding method of sand casting, simplifying each molding process, improving the molding process method to improve the mold performance, and achieving remarkable process effect in casting large flat flat castings . Another example is the west