Casting is one of the oldest metal forming methods. About 15% ~ 20% of automobile parts are produced by different casting methods. These castings are mainly the key components of power system and important structural components. At present, European and American automobile industry developed countries have advanced automobile casting production technology, good product quality, high production efficiency and small environmental pollution. The raw and auxiliary materials for casting have been serialized and standardized, and the whole production process has been mechanized, automated and intelligent. Digital technology is widely used in these countries to improve the level of casting process design. The scrap rate of castings is about 2%~5%. Compared with it, although the output of automobile castings in China is large, most of them are black castings with low added value and technical content and relatively simple structure, which are far behind the level of foreign countries. This paper mainly discusses the development direction of Automobile Casting and automobile technology from the development demand of automobile energy saving and environmental protection.
With the increasing requirements of energy saving and environmental protection of automobile and the reduction of production cost, the advantages of casting forming are fully utilized. The casting forming of integrated parts is realized by reasonable design and structural optimization, which can effectively reduce the weight of parts and unnecessary processing process, So as to realize the lightweight and high performance of parts.
The figure shows the integrated bridge shell developed by an automobile group to replace the new products of welded bridge shell and cast bridge shell with half axle casing, realize the integrated casting of castings and make full use of the advantages of casting forming. At present, the main form of casting integral bridge shell is to press seamless steel tube into the two ends of the bridge shell as the axle shaft sleeve, and fix the axle shell assembly with pins. In order to further improve the strength, rigidity and simplify the technological process of the bridge shell, an integrated bridge shell is developed, which is directly cast on the bridge shell with half axle casings (the parts on both sides of the bridge shell in Fig. 1). Its characteristics are reducing the processing difficulty, reducing the cost more, the structure of the bridge shell tends to be simple, and the rigidity of the bridge shell is better, which can be made into a complex and ideal shape, the wall thickness can be changed, and the ideal stress distribution can be obtained, Its strength and rigidity are large, and it works reliably. As a result of the integration of the half shaft sleeve, the casting size is significantly increased, the casting length is 258mm, and the weight of a single piece is more than 200 kg. According to the characteristics of this integrated casting, the enterprise has established a special production line to ensure production.
The development trend of Automobile Casting integration is more obvious in non-ferrous alloy casting. In order to make full use of the casting process to realize the production characteristics of complex structure castings, there are integrated design high-pressure castings such as door inner panel, seat frame, instrument panel frame, front-end frame and firewall, whose size is significantly larger than the castings currently produced, and it needs a die-casting machine of 4000 ~ 5000 t or even larger tonnage for production.
