The automobile gearbox shell is made of a large class of shell castings by using the EPS polyfoam foam EPC casting process. It was processed by numerical control Dragon carving machine and foam engraving machine in the early stage, and then cast into it. In the molding process of the automobile transmission housing mold, there will be casting deformation, slag inclusion, ladle sand, cold shut defects and so on. How to solve these problems and improve the yield has become a problem in the industry.

我们要分析汽车变速器壳体模具变形产生的原因。

First of all, we want to analyze the causes of the deformation of the automobile transmission housing die.

薄壁类壳体铸件，内腔有较大的空间，致使铸件结构不连续。由于铸件结构的特殊性，容易在浸涂和振实过程中产生变形。据保丽龙雕刻机、泡沫雕刻机小编了解，有的企业废品率高达15%左右。

There is a large space in the inner cavity of thin-walled shell casting, which results in the discontinuity of casting structure. Due to the particularity of casting structure, it is easy to produce deformation in the process of dip coating and vibration compaction. According to Xiaobian engraving machine and foam engraving machine, some enterprises have a reject rate of about 15%.

其次，如何解决汽车变速器壳体模具变形缺陷。

Secondly, how to solve the deformation defects of the automobile transmission housing die.

由于铸件变形是模型在成型﹑干燥﹑组装﹑涂覆和振实装箱等过程操作不妥和控制不严所致；如在泡沫模型在出模过程的操作控制﹑干燥时的摆放位置和涂料涂敷的操作都要有严格操作工艺和控制措施﹑振实装箱时型砂在不同方向施加给泡沫模型的力大小不一致而导致。

The deformation of the casting is caused by improper operation and poor control in the process of molding, drying, assembling, coating and vibrating packing. For example, the operation and control of the foam model during the mold production, the placement of the dry place and the operation of the coating must be strictly controlled by operation and control measures, and the force of the molding sand applied to the foam model in different directions is inconsistent. Lead to.

通过分析，认为对泡沫模样的预发泡的密度和粒度进行严格的质量控制﹑要求使用高强度低密度的发炮珠粒进行成型；其次对涂料的配制工艺进行改进增加涂料对泡沫模样的抗变形能力和附着力；提高泡沫模样的强度；同时在泡沫模样壳体上口增加支撑筋，利用支撑筋对泡沫模样的反作用力来平衡浸涂和振实中涂料和型砂对模型的作用力，从而起到防止变形作用。

Through analysis, it is considered that strict quality control is required for the density and granularity of pre foaming of foam pattern, and the use of high strength and low density gun pellets is required for molding. Secondly, the coating process is improved to increase the anti deformation ability and adhesion of the coating to foam pattern, enhance the strength of foam pattern, and increase the supporting rib on the upper side of the foam pattern shell. The reaction force between the support and the foam pattern is used to balance the effect of the coating and the molding sand on the model, so as to prevent deformation.

保丽龙雕刻机、泡沫雕刻机小编建议，我们可以根据消失模铸造原理和变速器壳体铸件的结构特性，通过增设支撑肋、控制EPS泡沫塑料密度、采用合理的浇注系统和造型工艺等措施，来预防变速器壳体变形、夹渣、铁包砂、冷隔等缺陷的额产生，降低成品的废品率，提高铸件产品的合格率

According to Xiaomian's engraving machine and foam engraving machine, we can prevent the transmission volume deformation, slag inclusion, iron sand and cold separation defects and reduce the reject rate of finished products by adding support rib, controlling the density of EPS foam plastics, adopting reasonable gating system and molding process, according to the principle of EPC and the structural characteristics of the transmission housing castings. To improve the qualified rate of casting products