As the core part of diesel engine, the engine block carries all parts of the engine. Its working environment is bad. It bears not only oil pressure and water pressure, but also regular high frequency vibration and impact produced by other parts. Therefore, the quality of engine block blank directly affects the performance and reliability of diesel engine. Blowhole defect is the main common defect of diesel engine block casting. In this paper, taking a medium speed diesel engine block as an example, according to the structural characteristics of the casting, the horizontalscheme of the engine block is proposed. The measures of optimizing the main sand core design, reasonably designing the sand core exhaust and the exhaust passage of the mold are adopted to solve the casting defects of blowholes. The casting practice shows that this method can produce qualified castings.
For the gray cast iron body of medium speed diesel engine with water channel inner cavity, the horizontal pouring process scheme is easy to operate and the sand core positioning is accurate. The key of the casting process is the design of the gating system and the exhaust system. The results show that the temperature field of molten metal in the mold tends to be reasonable, which is conducive to the feeding of the casting; the reasonable design of the exhaust passage of the mold can improve the filling capacity of the molten iron; adopting the weight reduction, hollowing out the main sand core and designing the sand core exhaust channel can effectively solve the exhaust problem of the main sand core, and the qualified castings are produced.