Approximately 15% to 20% of the auto parts are castings produced by different casting methods. These castings are mainly key components of the power system and important structural components. At present, Europe and the United States automobile industry developed countries, automobile casting production technology is advanced, product quality is good, high production efficiency, environmental pollution. Casting raw and auxiliary materials have been formed series and standardization, the entire production process has been achieved mechanization, automation and intelligence. These countries generally use digital technology to improve the level of casting process design, casting scrap rate of about 2% to 5%, and has established a multinational service system and network technology support. In contrast, although China's automobile castings larger output, but most of them are low value-added and low technical content, the structure is relatively simple black castings, and the gap between foreign level. This article mainly discusses the development direction of automobile casting and automobile technology from the development demand of automobile energy saving and environmental protection.
1. The direction of development of automotive castings
1.1 integrated design of automotive castings
With the automotive energy saving and reduce the cost of production requirements continue to increase, make full use of the advantages of casting, the original stamping, welding, forging and casting forming several parts, through a reasonable design and structural optimization, to achieve integrated parts casting Forming, can effectively reduce the weight of parts and reduce the unnecessary processing of the process, in order to achieve the weight of parts and high performance.
The development trend of automobile casting integration is more obvious in the development of nonferrous alloy castings. In order to make full use of the casting process to achieve the characteristics of the production of complex structural castings, there have been integrated design of the door panels, seat skeleton, dashboard skeleton, front frame and firewall integrated design of high-pressure castings, the size is significantly larger than the current production Casting, the need for 4 000 ~ 5 000 t or even larger tonnage die-casting machine for production.
1.2 The weight of automotive castings
To ensure the strength and safety of the car under the premise of the car as much as possible to reduce the quality of the preparation, to achieve lightweight, thereby enhancing the vehicle's power, reduce fuel consumption and reduce exhaust pollution. The quality of the vehicle is reduced by 100 kg and the fuel consumption per 100 km can be reduced by 0.3 to 0.6 L. If the vehicle weight is reduced by 10%, the fuel efficiency can be increased by 6% to 8%. With the needs of environmental protection and energy conservation, the weight of the car has become the world's automobile development trend, the weight of automotive castings has become one of the important direction of development of automotive castings.
2. The development direction of automobile casting technology
Production technology of thin – walled complex structure castings
With the development of the automobile industry and the demand for energy saving and emission reduction, the weight of automobile parts is becoming more and more lightweight. Through thin-walled design, it is an important development direction of engine block. FAW Casting Co., Ltd. for the FAW Volkswagen production cast iron cylinder, for example, the early production of 06A cylinder wall thickness 4.5mm ± 1.5 mm, EA111 cylinder wall thickness 4 mm ± 1 mm, the current mass production EA888Evo2 cylinder wall thickness 3.5 mm ± 0.8 mm, the next generation EA888Gen.3 cylinder product structure is more complex, the wall thickness of only 3mm ± 0.5 mm, is the thinnest gray cast iron cylinder. In the mass production, there are some problems such as broken core, drift core and wall thickness fluctuating. However, by controlling the quality of sand core and sand, But can not meet the EA888Gen.3 cylinder production requirements, must be used as a whole group of core pouring process.
2.2 Aluminum-magnesium alloy large-scale structural parts manufacturing technology
With the increasing demand for energy saving, environmental protection and cost reduction, aluminum-magnesium alloy large-scale structural casting has become an important development trend, and its manufacturing technology has become the current development hotspot. At present, the main production technology of aluminum-magnesium alloy large-scale structural parts is high-pressure casting, extrusion casting and low-pressure casting. As the high-pressure casting production efficiency, product quality has become the main production process, its manufacturing technology development focused on the high-pressure casting process is easy to curl, casting easy to form pores, can not heat treatment problems.
2.3 Casting Precision Casting Technology
Commonly referred to as the precise casting of automotive casting mainly refers to the elimination of Mold and investment casting technology. With the development of automobile casting forming technology, casting precision forming is a kind of casting forming method. Castings produced by this type of forming method can be used directly without cutting or cutting. With the improvement of casting size precision, casting precision forming technology has been developed rapidly in recent years, and a series of new casting methods have been developed such as precision sand casting, Lost Foam Casting, Controlled Pressure Casting and Pressure Casting. The Cosworth casting method was developed by the UK using a combination of zirconium sand core and controlled by an electromagnetic pump. It has been successfully used for mass production of aluminum alloy cylinders and has appeared in many process variants such as low pressure casting instead of electromagnetic Pump casting and other processes. The use of this type of casting method can produce wall thickness of 3.5 ~ 4.0 mm aluminum alloy cylinder, is the current precision sand casting on behalf of the process.
In the high-pressure casting process developed on the basis of vacuum casting, oxygenated die-casting, semi-solid metal rheological or thixotropic die-casting process, designed to eliminate casting defects, improve internal quality and expand the scope of die casting applications. In the process of extrusion casting, the melt is filled and solidified under pressure, and has the advantages of smooth, no metal splashing, less loss of metal liquid oxidation, energy saving, safe operation and defects of casting hole. High-performance aluminum alloy casting the development and application of a wide range of applications.
The continuous growth of automobile production requires the casting production to high quality, excellent performance, near net shape, multi-species, low consumption, low cost direction. As a vehicle about 15% to 20% of the parts are castings. This requires the casting industry to continue to use a variety of new technologies, new materials to enhance the overall level of casting. Casting precision casting technology can meet the above requirements of automotive castings, and its applications will also cover the different casting processes of automotive castings.
In order to meet the increasingly demanding environmental regulations, cars are moving towards light weight. Reduced vehicle weight by 10%, fuel consumption can be reduced by 5.5%, fuel economy can be increased by 3% to 5%, while reducing emissions by about 10%. Application of aluminum and magnesium and other nonferrous alloy castings, the development of large complex structure of integrated castings and extensive application of precision casting molding technology is to achieve the main way to reduce the weight of automotive castings. And therefore requires extensive use of digital technology on the basis of high-performance casting materials, automation equipment, such as a wide range of means to achieve the development and production of automotive castings to meet the needs of modern automotive industry.
Link to this article：Automobile Casting Process Knowledge And Technology Development Trend
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