Requirements for Die Casting Equipment for New Energy Automobile Die Casting Parts

1. Features of die casting
Die casting is a special casting method with less cutting or no cutting that has developed rapidly in modern metal processing technology. It is a process that a mold is filled with molten metal (metal molds with complex shapes) under high pressure and high speed, and the die casting part is formed by crystallizing and solidifying under high pressure. High pressure and high speed are the main characteristics of die casting. The commonly used pressure is tens of megapascals; the filling speed (inner gate speed) is about 16 to 80 m/s, and the time for molten metal to fill the mold cavity is extremely short, about 0.01 to 0.2 second. In 1964, the Japan Die Casting Association defined die casting as a casting method that presses molten alloy to a precision mold at a high temperature, and mass-produces parts with high precision and excellent casting surface in a short time. It is called die casting in the United States, while it is known as pressure die casting in the United Kingdom. The Japanese term that is most familiar to the general staff in China is called Die Casting. Castings made by die casting are called die castings.
 
2. The analysis of the development trend of new energy vehicles
In 2018, the cumulative sales of passenger vehicles were 28.081 million, a year-on-year increase of negative 2.8%. However, promoted by policies like double points, the sales of new energy passenger vehicles (pure electric and plug-in hybrids) increased by 82% year-on-year, reaching 105.3 million vehicles. Starting from 12,000 vehicles in 2013, sales have increased by 100 times in 5 years, and the growth rate is rapid. Moreover, new energy vehicles are mainly affected by factors such as policies, maturity of product technology, market supply conditions, and consumer wishes. It was expected in 2019 that the scale of the new energy passenger vehicle market increased by 40%, reaching 1.47 to 1.5 million vehicles. According to Medium and Long-term Development Plans for the Automobile Industry from the Ministry of Industry and Information Technology, the production of new energy vehicles will reach 7 million by 2025, and the average fuel consumption of new vehicles by 2025 will reduce to 4.0 liters per 100 kilometers.
 
3. Applications of die castings on new energy vehicles
The development of die casting parts for new energy vehicles must be the general trend due to the rapid development of new energy vehicles and the gradual shrinkage of traditional fuel vehicles. The data shows that the average amount of aluminum used in bicycles abroad is between 160 to 180 kg, and the average Chinese brand is from 80 to 90 kg. It was estimated that the average aluminum consumption in bicycles in China would reach 190 kg by 2020, and it would exceed 250 kg by 2025.
 
In recent years, aluminum used for automobiles has been mainly concentrated in the drive system, gearbox, transmission system, braking system and other parts. In the future, with the further improvement of applications of aluminum alloys, its application in the automotive field will gradually extend to the hood, fenders, doors, rear compartment, roof, body and other large parts that are now mainly made by steel castings. Automotive aluminum is expected to continue to grow in the future. Automotive aluminum is mainly used in the automotive industry in three forms such as die casting, extrusion casting and calendering, among which die castings account for about 80%.
 
At present, die casting parts for new energy vehicles which are developed or applied are battery brackets, shock absorption, rear A pillars, D pillars, door frames, seats, rear axles, rear longitudinal beams, etc.
 
4. Equipment requirements for new energy automobile die castings
It can be seen from the above that the newly added die casting parts for new energy vehicles are body structural parts with large dimensions and high technical requirements. The equipment is  a large-scale die casting machine above 4000T. At present, the demand for these large-scale die casting machines is great. The unit price of large-scale die casting machines is relatively high. More rigorous and comprehensive requirements are put forward for the function selection and peripheral configuration of the equipment, meeting requirements for process adaptability and Chinese manufacturing in 2025. An expandable plan for the functions and performance of the die casting machine is required.
 
(1) Take the DCC5000 die casting unit for the die-cast battery case of a new energy automobile as an example to analyze the configuration requirements. The IMPRESS-PLUS series for a new energy battery shell is selected for a certain customer.
 
Configuration of DCC5000 cold chamber die casting machines 

 
4.1 Intelligent real-time injection systems
1) Real-time control of the injection process
2) Adopting dual throttle control at outlets and inlets and free setting
3) 10 settings for positions and speeds
4) Having the function of uniform acceleration and braking at the end of injection
5) Curve display and being able to store 8000 curves
 
4.2 Intelligent quality monitoring systems
1) Realize online monitoring of parameters of multiple key products such as low speeds, high speeds, material cake thickness, high-speed switching points, casting pressure, pressure building time, cycle periods, etc.
2) There is powerful parameter storage capacity, and more than ten thousand key parameters can be stored.
3) The robot can realize the sorting function of defective products through the detection data.
4) The system automatically keeps change records of key production parameters to achieve good GMP production practices.
 
4.3 Intelligent process auxiliary systems
1) They can realize the input of relevant die casting characteristic parameters and automatically generate die casting process parameter schemes.
2) Assist the process personnel to quickly complete process debugging, which has simple operation and high efficiency.
 
4.4 Intelligent mold adjustment systems
1) The system can show the amount of the clamping force; just set the required clamping force to start the intelligent mold adjustment, and the machine can automatically adjust to the set value, shortening the mold's change time.
2) Timely control the stress conditions of core parts such as mold plates and big cylinders so as to detect and judge whether there is overloading, effectively avoiding major mechanical failures of the equipment.
 
The above settings take into account the real-time control system, vacuum die casting and extrusion functions. In order to expand the consideration of the number of core-pulling oil valves and the configuration of the MES interface, it is of reference significance for customers in the die casting industry relating to this subject.
 
5. Conclusion
It is imperative for the increase of scale and quantity of new energy vehicles. At present, equipment manufacturers are ready to cope with the explosive growth of new energy vehicles, so entrepreneurs who have market and technical capabilities for large-scale die casting can act.