Numerical simulation of mold filling and solidification process of cylinder head in rapid sand casting

With the development of economy, China’s automobile industry has developed rapidly, but it is facing the problems of unreasonable industrial structure, low technical level and weak independent R & D ability. One of them is the lack of rapid manufacturing capacity. Rapid prototyping technology, using the principle of material accumulation manufacturing, can realize the manufacturing of complex shape parts. The rapid sand casting technology (QC), which combines rapid prototyping manufacturing technology with traditional sand casting technology, is an ideal process to quickly obtain complex metal parts (SLA) rapid prototyping technology is combined with traditional sand casting technology to form rapid sand casting technology based on SLA prototype. This technology has short manufacturing cycle and is suitable for single piece and small batch production, especially for new product development in automobile industry.

Numerical simulation technology can optimize and improve process, improve product quality and shorten product development cycle. In the rapid sand casting technology based on SLA prototype, One of the core problems is sand casting Therefore, a rapid sand mold casting process CAD / CAE system based on SLA prototype is developed. Its CAD subsystem is used to design the sand mold CAD model quickly and accurately, and its CAE subsystem is used to analyze and verify the sand mold design.

(1) The sand casting process CAD / CAE system based on SLA prototype can effectively realize the sand casting process design of complex parts such as automobile engine cylinder head and improve the design and development efficiency.

(2) The single side bottom casting gating system can realize sequential solidification. In the solidification stage, the outer wall of the cylinder head solidifies first, followed by the internal solidification of the sand casting. The riser feeds the thick part at the upper part of the cylinder head well, and the inner sprue feeds the thick part at the lower end of the cylinder head. There is no obvious isolated liquid phase area in the whole sand casting. There is only uniform distribution in the sand casting The porosity is generally less than 10%, and the quality of sand castings is good.

The internal and external shape of the engine cylinder cover is complex, there are many curved surface structures, and there are many isolated hot spots inside. Sand casting requires high precision and is difficult. Taking an engine cylinder head as an example, this paper first introduces its rapid sand casting process, completes the sand casting process design with the help of the sand casting process CAD subsystem, and then simulates the filling and solidification process with the CAE subsystem based on ProCAST.