Rapid sand casting technology of engine cylinder head based on numerical simulation

China’s automobile industry is booming and has become the pillar industry of national economic development. However, China’s automobile industry still faces the problems of unreasonable industrial structure, low technology level and weak independent R & D capability. Among them, one of the key points restricting the improvement of independent R & D capability is the lack of rapid manufacturing means and related common technology development platform [5] [6]. Automobile parts have the characteristics of complex structure, large load, high dimensional accuracy requirements and poor working conditions. And driven by the rapid development of the global economy, it also requires its products to be updated quickly and the production cycle is short, so as to adapt to the flexible market demand. Although our country is the largest casting production country, but due to the relatively backward casting conditions, the current situation of the casting mold is difficult to adapt to the current situation, so it puts forward the urgent problems to be solved for China’s casting industry.

As the most complex and key part of engine, the cylinder head of automobile engine needs the corresponding professional casting technology to develop and produce. For the development of cylinder head, the traditional method is trial production and improvement of wood mold and metal mold, with long research and development cycle and high cost. Generally, the traditional development cycle of cylinder head is 6-8 months, and the development cost of cylinder head gravity mold is about 1 million / pair. This traditional development method seriously restricts the improvement of the enterprise’s R & D ability, and brings huge R & D cost, which is not suitable for the reality of fast upgrading of automobile engine and urgent need to realize industrialization of key parts. Sand casting is the most widely used casting technology in the foundry industry.

Rapid sand casting technology is to use rapid prototype parts to replace the traditional metal pattern or wood pattern, and then use the rapid casting process CAD system to design the mold and combine the traditional casting process to quickly produce the casting. Among them, SLA technology is a relatively mature UV curing prototype technology. Using SLA prototype to make pattern and core box, combining with the traditional technology of parting and assembly of sand mold to make mold, this forms a complete method of producing and processing rapid sand mold. Because SLA pattern and core box can be reused in the rapid sand casting process based on SLA prototype, which reduces the cost and improves the quality of castings, the rapid sand casting process based on SLA prototype is particularly suitable for the cylinder block, cylinder head, intake and exhaust manifold and other automobile castings with complex shape and requiring sand core molding. However, due to the following reasons: (1) SLA prototyping and optimization work is very professional; (2) the core problem of SLA based sand mold rapid casting is the establishment of mold (module) CAD model. The realization of this process should not only adapt to the characteristics of SLA process, but also be based on casting process knowledge, experience and principles. At present, the modeling function of casting CAE software is limited, and there are some deficiencies in data sharing between CAD and CAE. These factors make the establishment of mold CAD model become a professional technical work, which is difficult for the general technologists.