1. Production of automobile aluminum alloy wheels
In order to fully demonstrate the superior performance of wheel hub and apply it to automobile production, aluminum alloy has become the preferred material for automobile wheel manufacturing, and the output of aluminum alloy has increased year by year. Through the analysis of the current production situation of automobile wheels in China, the traditional steel wheels are gradually being replaced and widely used in the automobile industry to meet the needs of lightweight development. The aluminum alloy wheel hub of automobile is helpful to improve the overall performance of the vehicle, promote the rapid development of the automobile industry, and meet the needs of automobile use. According to the understanding of the production situation of China’s automobile industry, China’s automobile aluminum consumption is low. However, from the actual development of China’s automobile industry, the demand for aluminum alloy materials is growing, which is more beneficial to the automobile industry and aluminum alloy wheel manufacturing industry. At present, in many famous automobile manufacturing industries, aluminum alloy wheels have replaced steel wheels, which optimizes the use performance of automobile wheels and promotes the development of aluminum alloy wheel industry.
2. Forming method of automobile aluminum alloy wheel hub
2.1 Low pressure casting method
The influence of low pressure casting on aluminum alloy comes from France. After World War II, Britain began to attach importance to the development of low pressure casting. Since China officially introduced scientific research equipment, half of the aluminum alloy castings have been obtained through low pressure casting, which has been widely used in wheel hub manufacturing. When aluminum alloy wheel hub is cast under low pressure, the liquid metal is filled and solidified under pressure. The casting has the characteristics of high output, few defects, relatively perfect quality, light weight, less waste and low cost.
2.2 Forging method
Compared with the casting method, the forging method has higher production cost, but has the advantages of fatigue resistance, corrosion resistance and high precision. As the forging process is relatively free, the proportion accuracy of machined parts is also high, and the forging process only accounts for less than half of the aluminum alloy wheels of the same specification. In addition, the forged aluminum alloy wheel hub surface is free of air holes, and can be coated, colored, bonded and other surface treatment.
2.3 Spinning method
Spinning method has more advantages than low pressure casting method, especially in the trend of increasing wheel size, low pressure casting technology can no longer meet the requirements of high-end passenger car wheels. Compared with the forging method, the rotary aluminum alloy wheel hub has the advantages of low cost, strong practicability, quality assurance, beautiful appearance, excellent performance and broad development prospects.
2.4 New casting spinning process
As we all know, the quality of aluminum alloy forged wheels is better than that of low-pressure cast wheels, but its cost is much higher than that of cast wheels. Therefore, combining these two advantages, it can be regarded as a successful technology and a new rotary casting process has been adopted. Low pressure casting technology is used to produce wheel hub casting blanks with low cost, good appearance and good quality, and then the edges of the blanks are heat treated. The process combines the advantages of low pressure casting and rotary casting, and has achieved good practical results.
2.5 Semi solid die forging
Semi solid forging is a new manufacturing process of aluminum alloy automobile wheels. Parts shrink and harden in a preformed mold to form usable aluminum alloy hubs. The process can not only reduce the processing amount, but also make the surface of the aluminum alloy hub smooth and waterproof. Compared with other production processes, the service life of parts has been greatly improved, which has become a new metal forming technology.
3. Production process flow of automobile aluminum alloy wheel hub
3.1 Development and design process
With the decline of China’s car prices, cars have become a hot product in China. The demand for cars also began to shift from practicality and cognition to the pursuit of aesthetics. People not only require excellent performance and convenient operation, but also require that the appearance of cars conform to their aesthetic taste and identity. Therefore, the appearance of the wheel hub has a great impact on the image of the vehicle. If the company does not have the ability to design and develop hubs, it will be difficult to obtain a long-term market position. Therefore, the design and development of wheel hub is the key to the development of enterprises.
3.2 Actual workshop production process
Aluminum alloy wheel manufacturing is a complex industry. First, high performance aluminum alloy is selected for necessary smelting treatment, and then a certain proportion of modifier is added to modify aluminum alloy. The current manufacturing method is casting. Once the finished product has good performance, stability, wide application and grinding formability, technicians must check the comfort of the tire surface to determine whether the size and width of the product meet the standards.
3.3 Machining of aluminum alloy wheel hub
When castings can be heat treated to eliminate quality processes, in order to maintain and manage more domestic vertical or horizontal single axis CNC machines, the processing sequence has changed from traditional vertical rough machining to new high-precision dual vertical CNC machining units. The main advantage of the latter is that it can meet environmental requirements and improve production efficiency. After treatment, the air tightness test can be carried out on the hydraulic pressure, which is more effective and more automatic than the former. This is the development trend and new trend of the air tightness detection technology. Due to technical limitations, most testing equipment is imported.
3.4 Cleaning and maintenance of aluminum alloy wheel hub
As an excellent material, aluminum alloy wheel hub has been recognized by the majority of consumers, but there are also many shortcomings. Although aluminum alloy has good quality and generous appearance, it is expensive. In addition to low strength, the surface may crack for a long time. If it is not found in time, it may lead to safety accidents. Therefore, consumers should reasonably choose tire types. In the subsequent cleaning process, do not directly use cold water, which will reduce the braking effect of the tire. Here, we introduce a common asphalt removal method, that is, wiping with active composite medical oil, which can achieve unexpected results. If the vehicle is wet or near the coast, clean the wheels to avoid salt corrosion near the aluminum surface. After cleaning, if necessary, wax the hub and maintain its lasting luster.