1. Field of science and technology
   This project belongs to the design and development innovation of automobile parts and systems. It is a key technological innovation project for SAIC General Motors to fulfill its green social responsibilities of energy conservation and emission reduction, implement the company's "green future" sustainable development strategy, and promote the development of automobile door cover systems towards lightweight, green and energy-saving. The results have reached the international advanced level.

2. Research content and innovation points
   Fuel consumption and emission issues will restrict the sustainable development of the automobile industry. Vehicle lightweight is of great significance for saving fuel, reducing emissions, and improving performance. It is the main direction of technological development in the modern automobile industry.
   The weight reduction of automobile subsystems has a significant impact on performance. The weight reduction of the automobile is 10%: fuel consumption is reduced by about 6-8% under no-load conditions, and fuel consumption per 100 kilometers is reduced by 0.7 liters; emissions and pollution are reduced by 2mpg; acceleration from 0 to 100kph The time required is reduced by 0.5 seconds; the braking safety distance is increased by 3 meters; the payload and traction are increased by 150Kg.
   This project takes the automobile door cover system as an example to carry out the overall planning and innovative practice of door cover lightweight from three ways: lightweight materials, lightweight design, and lightweight manufacturing.

1)Innovation in lightweight materials

• 0.8mm thin aluminum alloy front cover: Breaking through the limit of engine cover thickness of international automobile companies, reducing weight by 50%, and promoting it to GM for global application;
• Independent development of aluminum alloy lifting doors: the first in China, breaking through the technical blockade of international automobile companies and reducing weight by 40%;
• Stamped magnesium alloy plate trunk lid: The first mass-produced body part in the automotive industry to be formed from magnesium alloy rolled plate, which reduces weight by 75%. It won the 2013 Best Application Award awarded by the International Magnesium Industry Association;
• Non-metallic materials: Plastic tailgates and fenders, carbon fiber materials and other projects will be launched soon.

2)Innovation in lightweight design

• Thinning: The application of 0.5mm ultra-thin steel plate on the front cover is the first in the industry, and the design quality and efficiency have reached the world-class level;
• Smaller: Lightweight and lean design of the second generation typical section of the door, innovative application of topology optimization in lightweight of the back cover, and other research contents have reached the international advanced level;
• Integration: represented by new door module technology, single-rail anti-pinch swing window machine system, low-cost intelligent trunk lid opening drive system, etc.; obtained invention patents.

3)Exploration and practice of lightweight manufacturing

• Lightweight material forming process: For example, innovative application of vacuum plastic forming (QPF) technology in aluminum alloy and magnesium alloy back covers;
• Lightweight material connection technology: For example, the first case of spot welding of 0.5mm ultra-thin steel plate; the first case of spot welding of aluminum plate; laser brazing; punching and riveting of thin plates.

3. Application and promotion
   The research results of this project have been successfully applied to SAIC GM's independently developed Chevrolet New Sail, Buick New GL8, Buick New LaCrosse, and other models jointly developed with GM, and will be further promoted in subsequent projects. The project has created considerable economic benefits for the company. For example, from 2011 to August 2015, the ultra-thin aluminum alloy front cover applied to Buick GL8 and New LaCrosse achieved new output value: 545 million yuan, new profit: 115 million yuan, new tax revenue: 100 million yuan, saving money: 168 million yuan.
   In terms of scientific value, through this project, we have mastered core technologies and owned independent intellectual property rights, improved the competitiveness of enterprises and products, and expanded the market share of products. The local suppliers cultivated by the project, the patents applied, and the papers published have played a positive role in improving my country's independent development capabilities and international competitiveness for lightweight automotive subsystems.
   The following scientific and technological achievements have been achieved:

1. Obtained 1 invention patent and 11 utility model patents;
2. Published 2 papers;
3. Received 13 scientific and technological awards (1 international award, 1 national award, 1 provincial and municipal award, and 10 enterprise awards).