In the 21st century, the society and economy are developing rapidly, and there are extremely high requirements and standards for weight reduction and emission reduction in the process of driving. At present, the lightweight of automobiles has become an inevitable trend in the development of the times. In the process of vehicle design, the application of aluminum alloy cast rotary wheels can effectively reduce the actual weight of the automobile and improve the fuel efficiency of the automobile. Body weight reduction can greatly optimize vehicle fuel economy and enhance the stability of vehicle driving control. With the development of technology, the application of light alloy wheels in the automobile field has become more extensive. For the current lightweight of automobiles in my country, automobile material processing is the key issue among them. Currently, the low-density, high-strength, lightweight materials used in the market are widely used in wheel hubs, which can greatly reduce the weight of the vehicle and realize the lightweight of the wheel hub structure. At the same time, it can save materials used in production and contribute to energy saving and environmental protection. The current composite materials used in vehicle wheels include: polymer materials, magnesium alloy materials, etc. However, due to the actual large-scale production of such materials, there are certain technical problems, and the cost of applying such materials is relatively high. It is difficult to put into practical application well. The application design of aluminum alloy materials in cast rotary wheels has significant advantages such as high strength, light weight, good stability, and moderate price. Moreover, the application of aluminum alloy materials can achieve recycling, which has certain advantages in terms of energy saving, emission reduction and energy consumption control of current vehicles in my country. Therefore, the design and application of aluminum alloy materials in cast rotary wheels is a major trend in the market, and aluminum alloy materials have become the material of choice for the design and manufacture of most automobile wheels on the market. This paper conducts research on the production design of automotive wheel aluminum alloy B356. Through the analysis of the process and equipment of B356, optimization and improvement measures are proposed, so that the finally developed B356 has higher toughness and strength.

1  Technical Research on Cast Spin Forming of Aluminum Alloy Wheels

1.1  Process development of casting aluminum alloy
Aluminum alloy materials are widely used in the process. As a kind of non-ferrous metal structural material, aluminum alloy can be used in equipment and parts manufacturing in aerospace, civil industrial enterprises, automobile enterprises, machinery enterprises and other fields. At present, aluminum alloy materials have been widely used in various fields in my country. Among them, the cast aluminum alloy has the advantages of high strength, light weight and easy use in the field of casting in the actual application process, and has extremely high comprehensive mechanical properties. The application of aluminum alloy materials in the production of automobile wheels can effectively reduce the weight of the car body, and at the same time can meet the requirements of the strength and safety performance of the vehicle, and has good plasticity.

1.2  Practical application of aluminum alloy wheels
The design and application of aluminum alloy materials in vehicle wheels first began in the 1970s. With the development of the automobile industry, the production of aluminum alloy wheels has been more and more widely used in the industry. Currently, there are many methods for forming aluminum alloy wheels, and different methods have different advantages after production is completed. At this stage, the more commonly used aluminum alloy wheel forming methods on the market in my country mainly include: gravity casting, low pressure casting, squeeze casting, and liquid die forging. The casting method of aluminum alloy wheels has been verified and researched for many times and has been improved to a certain extent, and the performance of the vehicle has been greatly improved. However, there is still a certain gap compared with the reliability and light weight of forged wheels. At present, forged wheels are used in the wheel design of some high-end automobiles. However, due to the high cost of forged wheels, in order to save costs, most vehicle manufacturers on the market still use cast-shaped wheels. At present, in order to meet the basic energy consumption and performance requirements of vehicles, aluminum alloy wheels are moving towards a trend of lighter weight, higher toughness and higher strength.

2 Research on the weight reduction design of aluminum alloy cast rotary wheel hub

2.1  Aluminum alloy casting spinning process
The hot spinning process of casting billet rim mainly uses the partial continuous rotation of the revolving cast billet, which is compressed by rotating rollers to make it shape. In this process, when spinning, only the rim is deformed, and the outer edge of the hub and the spokes can fix it. The blank is clamped on the mandrel, and the main shaft drives the blank to rotate. At this time, the system can automatically control the running track and direction of the rotating wheel according to the preset program. By squeezing the blank, the blank and the mold surface only fit together to realize the casting of the rim. Considering that the aluminum alloy material used in this article has poor room temperature plasticity, it should be processed in a hot state during processing. By analyzing the mechanical properties of aluminum alloys at different temperatures
It can be seen from the analysis that the temperature gradually decreases, at this time the strength of the aluminum alloy material gradually increases, and the plasticity decreases accordingly. On the contrary, the temperature increases, the strength of the material decreases, and the plasticity increases. By comparing the changes of aluminum alloy materials at different temperatures, it is finally concluded that in order to satisfy the plasticity and material strength of aluminum alloy materials, when the spinning temperature range is 370 to 400¡ãC, the plasticity and material strength of aluminum alloy are the best. At the same time, the hot spinning of aluminum alloy wheel cast blanks has defects in practical applications. Since the hot spinning process of the wheel cast blanks is highly operability and requires multiple numerical control processing and other technological processes, if the temperature of the material is too low or the material is piled up, it will affect the performance of the final product. If this is over
When the temperature of the material is too low, it will seriously affect the plasticity of the material. If the material has a large area of ​​bulge at this time, it will cause the product to crack and even affect the size and accuracy of the material.

2.2  Hot spinning process of aluminum alloy wheel casting billet
The factors that have the greatest influence on the hot spinning forming of aluminum alloy wheel cast blanks are mainly due to the parameters of spinning forming temperature and spinning process. The forming angle of the rotating wheel is an important process affecting the aluminum alloy wheel hub. The larger the parameter, the higher the uplift of the forming angle of the rotating wheel. At this time, the metal will assume an unstable state. The aluminum alloy material is very easy to swell during processing, so when taking the value of the rotational forming angle, the maximum value should not be taken. But at the same time, it should also be noted that the value of the rotational forming angle cannot be too small. If the value is too small, it will also affect the spinning force. In order to ensure a good shape of the rotary wheel. The feed rate setting should be considered comprehensively in conjunction with the wall thickness reduction rate. If this value is set too large, it will cause the material to peel and the surface will bulge, and if the value is set too small, it will cause a series of deformation problems. Therefore, the feed rate of the thinning and spinning of aluminum alloy wheels should be controlled within the range of 0.5 to 2mmr-1 to reduce the impact on the material. At the same time, when setting the pass thinning rate, it should be controlled to keep it between 20% and 50%, and it is best to control the thinning rate between 20% and 30%. The control of the multi-rotating wheel offset is also an important factor affecting the quality of the hub. If the multi-rotating wheel's offset is too large, the metal swelling is likely to occur during actual work, causing the surface of the material to peel and fold. If the pitch is too small, the protrusion of the material in front of the wheel is likely to occur, which will cause material accumulation, which will have a very serious impact on the surface material of the aluminum alloy wheel, and cause the size of the aluminum alloy wheel to be inaccurate. Generally, when designing the staggered pitch of multi-rotating wheels, it is best not to exceed half of the diameter of the rotating wheels.

2.3  Analysis of the selection of hot spinning process for casting billets
Because the hot spinning forming process of aluminum alloy wheel hub casting blank involves extensive physical knowledge and geometric knowledge, and the realization process is more complicated. There are many factors that can affect the final result in the hot spinning process of casting billets. If a single method is used to study the wheel casting and spinning process, it is very likely to cause excessive capital consumption. The research time is long and the results are not accurate enough. Taking into account the process of wheel casting and the investment of materials and capital, the application of numerical simulation technology can formulate the process of wheel casting and can effectively realize the accuracy of the casting billet value. In actual application, numerical simulation can be carried out through the hot spinning process of aluminum alloy wheel hub casting billet to determine the wheel track and billet
The parameter setting of the process steps such as the opening angle of the material can realize the optimized design of the hot spinning process of the casting billet. And in the application process can greatly shorten the time consumed by the project.

3  Conclusion
In summary, using low-pressure casting production technology, the final wheel hub size is larger, and the load is higher, and the weight is difficult to meet the current standard requirements for vehicle lightweight in my country. The design of aluminum alloy cast-rotating wheel hub does not have to be constrained by the size set by the vehicle after being formed. It has excellent plasticity, beautiful appearance, and meets the requirements of current vehicle design. The aluminum alloy cast rotary wheel design can effectively reduce the vehicle's own weight and meet the current lightweight requirements of vehicle wheels. In the actual production process of vehicle wheels, the application of casting and spinning is more conducive to saving the cost of automobile manufacturers, more economical and applicable, and more advantageous in market competition. The design and production of aluminum alloy cast rotary wheels has broad market development prospects, and it is also an inevitable trend in my country's vehicle wheel manufacturing. Therefore, relevant vehicle manufacturers should carry out research on this technology. Through in-depth analysis and research, the hot spinning technology of cast aluminum alloy can be optimized in the actual production process, and further promote the market competition and healthy development of my country's automobile industry. .