At the beginning of 2018, the first domestic urban bus project adopting "all aluminum body + all aluminum chassis" successfully passed the road test of China First Automobile Co., Ltd. (hereinafter referred to as "FAW"). The project is jointly developed by Zhongwang group and FAW, which not only makes up the blank of aluminum alloy in chassis application, but also makes Zhongwang become the first aluminum processing enterprise in China that can independently design and manufacture "all aluminum body + all aluminum chassis", which is another major innovation in the field of new energy market.
According to the person in charge of Zhongwang project, Zhongwang and FAW jointly completed the structural design and strength analysis of the whole vehicle, as well as material test, process evaluation, processing and manufacturing, sample vehicle trial production, etc. The whole body adopts the welding and riveting structure, in which the welding is strictly controlled by the high-speed rail welding standard to ensure that the accuracy of the body is higher than that of the steel car. "
This 12 meter urban bus body lightweight and chassis performance improvement project mainly studies the "aluminum instead of steel" vehicle used for urban public transport, providing technical reference for other FAW models to adopt all aluminum body and all aluminum chassis structure.
Control the safety of all aluminum passenger cars with high-speed rail welding standards
At present, major domestic and foreign automobile manufacturers, such as Volvo, Scania, Alexander Dennis, BYD, etc., have mass-produced all aluminum buses in the UK, Finland, Malaysia and other countries, as well as in Hong Kong, Shenzhen and other regions of China. But this kind of all aluminum bus is only the framework of all aluminum body, excluding the chassis part.
The city bus project that Zhongwang cooperates with FAW is the first bus with all aluminum body and all aluminum chassis structure in China, which has great technical difficulty and high process requirements. According to relevant R & D personnel of Zhongwang, one of the major challenges of the project is the industry-wide problem of weight reduction objectives and safety indicators changing from one to the other. For this, the project team has achieved the modularization and integration of the structure to the greatest extent through multiple design and analysis, and completed the design scheme in 8 months. After the completion of the assembly and preliminary running in of the whole vehicle, the maturity of this technology has been verified after six months of testing of the vehicle's power, economy, long-distance limit road conditions, etc.
According to the project leader of FAW, the difficulty in the design of all aluminum structure lies in how to meet the requirements of performance indexes such as the rigidity and strength of the whole vehicle and realize lightweight. In the design process of this project, we fully draw lessons from the design scheme of aluminum underframe of motor car, adopt steel aluminum riveting safety structure locally, form lightweight aluminum alloy structure frame, realize the weight reduction of up to 20% compared with steel structure vehicle, and meet all performance requirements of vehicle. This technology reduces the fuel consumption rate of the whole vehicle by about 10%, the operating cost in the life cycle by 40000 yuan, the comprehensive cost of all aluminum bus is lower than that of steel bus, and the lightweight achievements are outstanding. "
It is understood that for passenger cars with aluminum profiles, first of all, the chassis structure of the body should meet the requirements of the bending and torsional stiffness of the whole vehicle and the fatigue durability test of the whole vehicle, so as to ensure the safety of passengers. In particular, aluminum body structural parts, involving metal connection technology, deep stamping technology, technical difficulty is relatively high. Now, using aluminum as the chassis structure puts forward higher requirements for technology.
Being able to overcome the above technical problems "depends on Zhongwang's technology accumulation in connection technology, especially its rich production experience in welding. It adopts high-speed rail welding standards to strictly control the deformation through specific process methods, so as to ensure that the accuracy of the car body is higher than that of the steel car." Said the head of Zhongwang project.
According to the person in charge, in the passenger car project of "all aluminum body + all aluminum chassis" cooperated with FAW, Zhongwang not only provided all aluminum materials, but also jointly completed structural optimization design, material test, process evaluation, sample car trial production, etc. In addition to meeting the same safety index of the steel vehicle, the car body framework is more than 1200kg, accounting for 10.4% of the weight of the whole vehicle; the comprehensive energy consumption performance of the whole vehicle is improved, and a large amount of operation cost is saved; the chassis is made of aluminum alloy structure, with high corrosion resistance, the electrophoresis process of the traditional steel chassis is reduced, and the economy of the whole vehicle is further improved; and the body chassis parts realize 100% material feasibility Recycling.
So far, in the process of upgrading to "lightweight comprehensive solution supplier", Zhongwang has overcome another "problem" -- design, development and manufacture of the first "all aluminum body + aluminum alloy chassis structure" urban bus in China.
Zhongwang strength promotes the application of bus aluminum
According to China's fuel consumption limit for passenger cars, the average fuel consumption of passenger cars produced in China will be reduced to 5 L / 100km by 2020. In addition, according to the plan, the total carbon emission of automobile industry is prior to the national commitment and industrial scale, and reaches the peak in 2028.
The increasingly strict emission standards put forward higher requirements for automobile manufacturers, and also provide development opportunities for lightweight automobile materials. Aluminum alloy with its superior strength, lightweight characteristics, flexible design, high corrosion resistance, high recycling rate and other characteristics, has been recognized as the first choice of new energy bus body by many bus enterprises and bus companies.
The lightweight of passenger car is a systematic project which integrates design, manufacturing, material technology and so on. From the beginning of design, Zhongwang paid attention to structural optimization, carried out material test and process evaluation continuously, and finally provided aluminum alloy materials with better performance to manufacture all aluminum passenger cars.
However, the all aluminum bus has the advantages that the traditional steel car body can't compare with, which also means that it has a significant improvement in the difficulty of the car body processing technology. Zhongwang strictly controls the accuracy and safety of the bus body with the high-speed rail welding standard to ensure that the accuracy of the car body is higher than that of the steel car, and at the same time better realizes the goal of lightweight.
FAW chose to cooperate with Zhongwang in the research and development of "all aluminum body + all aluminum chassis" bus project, because Zhongwang not only has strong research and development ability, but also has professional qualification and manufacturing experience of aluminum alloy bus body.
At present, Zhongwang has obtained a number of international certification qualifications in railway, automobile, ship, aviation and other industries. Among them, Liaoning Zhongwang Special Vehicle Manufacturing Co., Ltd. has obtained license plates to produce and sell multiple all aluminum commercial vehicles, and has production lines for semi trailers and oil tank vehicles. The first production line of the new plant of Zhongwang Tianjin factory produces 13mm to 300mm thick aluminum alloy medium and thick plates, and relevant products can be used for automobiles, railcars and special car bodies. This is one of the leading aluminum rolling production bases of global equipment and supporting facilities, which shows the strength of Zhongwang in the field of new energy vehicles.
"Zhongwang has accumulated very professional and rich experience in the design and manufacturing of all aluminum passenger cars." As early as 2012, Zhongwang cooperated with BYD Automobile Industry Co., Ltd., a domestic new energy vehicle manufacturer, to provide all aluminum body frame profiles for it, said the project leader of Zhongwang automobile. In 2015, Zhongwang successfully designed, manufactured and developed all aluminum body new energy electric bus for brilliance bus (Dalian). The framework of the bus is welded with 6 series alloy, and the skin is welded with 5 series sheet metal. It has the advantages of light weight, high strength, corrosion resistance and strong vibration absorption. This cooperation also marks that Zhongwang has further developed mature aluminum alloy chassis technology in the field of passenger car body, laying a solid foundation for subsequent various new energy transportation products.
Extended reading The market share of all aluminum passenger cars will be further increased
According to the research of the European aluminum industry association, for every 100 kg of weight loss, the fuel consumption is reduced by 0.4 L / 100 km, and the carbon dioxide emission is reduced by 1 kg. It has become a trend in the future to improve the power performance, reduce fuel consumption and reduce emission pollution by reducing the vehicle's servicing quality.
All aluminum body buses made of light aluminum materials have been used in developed countries such as Europe, Japan, Singapore, etc. in China, public buses in Shenzhen, Hangzhou, Fuzhou, Qingdao, Beijing and other cities have been vigorously promoted since 2013. At present, 20 provinces and cities in China have made it clear that the public transport system will be fully electrified in 2020, and many provinces and cities have issued plans for the electrification of road buses.
"The demand for lightweight electric buses is more urgent." According to Pei Zhihao, senior consultant of passenger car branch of China highway society, the electric power consumption of electric vehicles mainly depends on the body mass. "Compared with traditional liquid fuel, the unit specific energy of power battery is relatively low. If you want to ensure sufficient endurance mileage, the battery often accounts for 30% - 40% of the total vehicle weight.". In this case, the importance of lightweight body materials is self-evident. "
For domestic automobile enterprises, lightweight has become the only way for them to compete for market share. CITIC Securities research pointed out that the rapid development of new energy bus in the past few years, with the accelerated decline of subsidies, the survival of the fittest in the industry will also accelerate, leading enterprises with core technology competitiveness and market driving force are expected to benefit from the increase of concentration and market share.
The sales data also shows that the new energy bus market is steadily improving in 2017. According to the statistics of China Association of automobile industry, the sales volume of new energy buses in November 2017 was 18662, with a month on month growth of 62.4%; the total sales volume of new energy buses from January to November exceeded 70000. CAAC expects to sell 100000 new energy buses in 2018.
Although car companies and aluminum companies have increased investment in research and development of new energy and lightweight technology, aiming to seize the opportunity in a new round of industry competition. However, lightweight is a system engineering. Only through the continuous optimization of the structural system, matching with appropriate materials, and properly controlling the cost, can lightweight vehicles be truly accepted by the market.
Zhongwang, which has been in the field of new energy vehicles for a long time, is at the forefront of the industry in terms of technology, technology, products, structural optimization, cost control and so on. Its R & D and production of all aluminum body in white for passenger cars, all aluminum body for buses and other five products have been quantitatively produced and put into the market, and received positive feedback.
Industry insiders predict that the new energy vehicle market will usher in an explosion of production and sales in 2018. In the face of a new round of development opportunities, Zhongwang constantly improves the proportion of high value-added products in the field of lightweight, and transforms its scale advantages into products and technical advantages with higher barriers. Lu Changqing, chairman of Zhongwang, also said: "Zhongwang attaches great importance to industrial cooperation and the development of new energy vehicles, and has prepared sufficient resources for this, so as to make the necessary investment and capacity construction in time."