压实式造型机 利用气压或液压通过压头或模样对砂箱内的型砂施加压力来紧实型砂。其压强一般为0.25～0.4兆帕。这种造型机﹐使远离施压面的砂型紧实度差。20世纪50年代初出现了高压造型机﹐砂型平面上的压强在 0.7兆帕以上。高压造型机的压头分为平压头﹑成形压头和多触头压头等几种结构形式。其中以高压多触头造型机应用最为广泛。高压多触头造型机压头分割成许多可上下运动的小方块──触头﹐通过液压缸可获得很大的压实力。压实时﹐各触头按其下面的模样高度(即受压砂层厚度)施加相应的压力﹐使砂型获得很高的﹑均匀的紧实度和硬度。这类造型机都设有微震震击机构﹐能够适应复杂模样的造型。高压多触头造型机多采用四立柱结构﹐有单工位式和双工位式。为了适应中小批量铸件的生产﹐这种造型机多附有模板快换装置﹐更换模板时﹐造型机不必停机。采用高压多触头造型﹐砂型铸造能浇出薄壁﹑尺寸精确﹑表面光洁的铸件。
The compaction molding machine uses air pressure or hydraulic pressure to apply pressure to the molding sand in the sand box through the pressure head or pattern to compact the molding sand. Its pressure is generally 0.25-0.4 megapascals. This type of molding machine results in poor compaction of the sand mold away from the pressure surface. In the early 1950s, high-pressure molding machines emerged, and the pressure on the sand mold surface was above 0.7 megapascals. The pressure head of high-pressure molding machine is divided into several structural forms, including flat pressure head, forming pressure head, and multi contact pressure head. Among them, high-voltage multi contact molding machines are the most widely used. The high-pressure multi contact molding machine divides the pressure head into many small blocks that can move up and down - the contact head, which can obtain a large compaction force through a hydraulic cylinder. During compaction, each contact applies corresponding pressure according to its lower pattern height (i.e. the thickness of the compressed sand layer) to achieve high and uniform compaction and hardness of the sand mold. These types of molding machines are equipped with micro shock mechanisms, which can adapt to complex shapes. High voltage multi contact molding machines often adopt a four column structure, with single station and double station versions. In order to adapt to the production of small and medium-sized castings, this type of molding machine is often equipped with a template quick change device. When replacing the template, the molding machine does not need to be stopped. Adopting a high-pressure multi contact design, sand casting can produce thin-walled, accurately sized, and smooth surface castings.
