Sand Casting / 砂型铸造

Sand casting is used to make large parts. Molten metal is poured into a mold cavity formed out of sand. The cavity in the sand is formed by using a pattern, which is typically made out of wood, sometimes metal. The cavity is contained in an aggregate housed in a box called the flask. Core is a sand shape inserted into the mold to produce the internal features of the part such as holes or internal passages. Cores are placed in the cavity to form holes of the desired shapes.
砂型铸造用于生产大的零件。将熔化的金属倒入由型砂做成的铸模的型腔中。型砂中的型腔是由模型形成的,模型一般是木制的,有时也采用金属制成。型腔位于一个称作砂箱的盒子中。型芯是一种砂型,可以将型芯插入到铸模中以得到零件的内部特性,比如孔或内部通道。将型芯放入到型腔中可得到预期形状的孔。

In a two-part mold, which is typical of sand casting, the upper half, including the top half of the pattern, flask, and core is called cope and the lower half is called drag. The parting line or the parting surface is a line or surface that separates the cope and drag. The drag is first filled partially with sand, and the core print, the cores, and the gating system are placed near the parting line. The cope is then assembled to the drug, and the sand is poured on the cope half, covering the pattern, core and the gating system. The sand is compacted by vibration and mechanical means. Next, the cope is removed from the drug, and the pattern is carefully removed. The object is to remove the pattern without breaking the mold cavity. This is facilitated by designing a draft, a slight angular offset from the vertical to the vertical surfaces of the pattern.
两箱造型是砂型铸造的一种典型结构,上半部分包括模型、砂箱和型芯的顶部,称为上型箱,下半部分则称为下型箱。分型线或分型面是将上、下两型箱分开的线或面。先将下型箱装上部分型砂,安放好型芯座、型芯,浇通系统应放置在分型线附近。之后将上、下型箱装配在一起,型砂注入上型箱,覆盖模型、型芯和浇道系统。通过振动和机械方法将型砂紧实。下一步,将上型箱从下型箱上移开,小心地移走模型,目的是在移走模型时不破坏型腔。这可以通过设计一个拔模斜度,使它与模型的垂直面之间有一个小小的角度偏移量,便可容易地实现。

Sand castings generally have a rough surface sometimes with surface impurities, and surface variations.
砂型铸造生产的表面一般较粗糙,有时表面会掺有杂质,并且可能会有表面变化。