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.

我們要分析汽車變速器殼體模具變形產生的原因。

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

薄壁類殼體鑄件，內腔有較大的空間，致使鑄件結構不連續。由于鑄件結構的特殊性，容易在浸涂和振實過程中產生變形。據保麗龍雕刻機、泡沫雕刻機小編了解，有的企業廢品率高達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，如何解決汽車變速器殼體模具變形缺陷。

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

由于鑄件變形是模型在成型﹑干燥﹑組裝﹑涂覆和振實裝箱等過程操作不妥和控制不嚴所致；如在泡沫模型在出模過程的操作控制﹑干燥時的擺放位置和涂料涂敷的操作都要有嚴格操作工藝和控制措施﹑振實裝箱時型砂在不同方向施加給泡沫模型的力大小不一致而導致。

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.

通過分析，認為對泡沫模樣的預發泡的密度和粒度進行嚴格的質量控制﹑要求使用高強度低密度的發炮珠粒進行成型；其次對涂料的配制工藝進行改進增加涂料對泡沫模樣的抗變形能力和附著力；提高泡沫模樣的強度；同時在泡沫模樣殼體上口增加支撐筋，利用支撐筋對泡沫模樣的反作用力來平衡浸涂和振實中涂料和型砂對模型的作用力，從而起到防止變形作用。

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.

保麗龍雕刻機、泡沫雕刻機小編建議，我們可以根據消失模鑄造原理和變速器殼體鑄件的結構特性，通過增設支撐肋、控制EPS泡沫塑料密度、采用合理的澆注系統和造型工藝等措施，來預防變速器殼體變形、夾渣、鐵包砂、冷隔等缺陷的額產生，降低成品的廢品率，提高鑄件產品的合格率

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