Lightweight is one of the direction of the development of the automotive industry. In order to achieve energy saving, reduce emissions, improve vehicle speed, reduce the cost of the purpose, since the 20th century, 90 years, the use of plastic made of functional parts in the growing use of cars. The easy molding of plastic makes it more and more used to manufacture complex components such as intake manifolds and fuel tanks for the engine, thus playing an important role in advancing the progress of automobile manufacturing technology.
1, plastic intake manifold features
All along, the domestic engine intake manifolds are mostly made of aluminum alloy. In foreign countries, plastic intake manifold has been more widely used, for example, in the BMW, Hyundai, Nissan and other high-end cars, are using plastic intake manifold.
As the shape of the intake manifold complex, so in the past often made of aluminum alloy casting, but the rough wall, the use of air resistance is great, resulting in large noise, fuel combustion is not sufficient, exhaust emissions. Therefore, in recent years, plastic intake manifold has been the people's attention. Compared with the traditional aluminum alloy intake manifold, the weight of the plastic intake manifold is reduced by 50%. At the same time, the plastic intake manifold airway is smooth, the air flow resistance is small, improves the engine power performance and the exhaust function, enhances the fuel efficiency, the fuel consumption can be reduced by 6% ~ 8%. In addition, the plastic intake manifold vibration and noise reduction better.
2, plastic intake manifold technology and market development status
Plastic intake manifold was born in 1972. Since the 1980s, Europe began to use the fusion method to produce intake manifolds. The intake manifolds so made are not only costly but also have a certain scrap rate because of the material PA66 (or PA6) is reinforced by glass fiber, its processing temperature reaches 250 ℃ ~ 260 ℃, although the contact time with the core in the mold only a few minutes, but some of the core is still inevitably melted, so that the manifold wall size is difficult controlled. With the glass fiber reinforced PA66 welding technology matures, the world's most car manufacturers began to use vibration friction welding process to produce intake manifold, respectively, injection molding two or more manifold parts, and then they are welded into one. This technology was born, greatly promoted the intake manifold plastic process.
Automotive engine parts of the material performance requirements are higher, requiring -40 ℃ ~ 150 ℃ repeated changes in the temperature range, with excellent heat aging, fuel resistance, resistance to various lubricants, chemical resistance, Impact, but also should have good resistance to vibration and audio attenuation, therefore, nylon has become the preferred material. However, due to the requirements of the parts around the engine at work to withstand the high temperature of 220 ℃, and at this temperature can still maintain high modulus, high strength, at -40 ℃ is still good mechanical properties and fragmentation without toughness , So glass fiber reinforced nylon is not the best material. At present, foreign has been used PPA resin (poly (o-phenylene units) through the molding method to produce the intake manifold, and has been applied to the Corvette, Cameroon, Firebird and other models of LS1 and LS6 engine in. This type of intake manifold is designed in three sections and is bolted to the engine. In high temperature and high humidity, PPA tensile strength than PA6 increased by 20%, higher than the PA66. In addition, the flexural (flexural) modulus of PPA is 20% higher than that of nylon, and it is more resistant to longer tensile elongation. PPA is resistant to gasoline, grease and coolant. Most importantly, in terms of weight reduction, the general use of cast aluminum manufacturing intake manifold weight of 26lb, and the use of PPA resin molded into three pieces of the same type of intake manifold only 11lb, can produce more 25% of the airflow.
At present, Europe and the United States in the plastic intake manifold research and development ahead of Japan. In 2000, plastic intake manifolds in the European intake manifold market share has reached 60% of the proportion, while in North America and Japan is relatively low, but its faster growth. It is expected that in 2006, plastic intake manifold in the European market share will increase to 90%, Japan and the United States will reach 60% to 70%.
3, plastic intake manifold to bring the market opportunities
The technological progress of plastic intake manifolds depends not only on the development of new materials, but also on the continuous improvement of processing methods. With the progress of welding technology, driven and promoted the development of the corresponding materials. For example, semi-crystalline polymer poly-phthalamide is a very interesting new material for intake manifolds, and its performance is between the general engineering plastics and specialty engineering plastics, but the price is relatively high. Belgium Solvay High Performance Polymers has introduced a 35% glass fiber reinforced grade AmodelA-6135HSL with a much higher tensile strength than PA66 in high temperature and high humidity environments with better rigidity and excellent tensile resistance , Thereby reducing the air leakage at the intake manifold gasket. The chemical resistance of this new type of resin is also significantly better than nylon, including coolants, fuels, lubricants, oils and other vehicles used in the fluid. The material has been used to make the intake manifold known as LSX, which replaces the existing standard nylon intake manifold. In 2004, three companies had adopted LSX on their new sedans. It is said that the LSX intake manifold is about 25% lighter than the existing standard nylon intake manifold and can increase the power of the usual 360 horsepower engine by 20 horsepower.
1, the advantages of plastic fuel tank
The car fuel tank is the only part of the car to store fuel, is an important function and safety components. As consumer demand for cars is increasing, such as comfortable interior space, smooth driving, and large rear containers, the result is that the place where the tank is filled is often a complex, limited space The shape of the fuel tank becomes very complicated.
The traditional fuel tank is made of metal, but the disadvantage of metal is that it is difficult to create a complex shape, even if it can be made also need a lot of processing processes, thereby increasing the manufacturing cost. Compared with the metal, plastic because of its light weight, free molding, corrosion resistance and other advantages, it is increasingly used in the manufacture of fuel tanks. Plastic fuel tank is characterized by:
●Since the relative density of plastic is only about 1/7 of that of metal, the weight can be reduced by about 1/3 to 1/2 compared with the same volume of metal fuel tank.
●With the metal fuel tank is not the same, plastic fuel tank with a blow molding method, can be made of complex shape of the shape of the structure, so the overall layout of the car has been determined to take full advantage of the remaining space, as much as possible to expand the fuel The volume of the tank, thereby increasing the fuel storage capacity.
●metal fuel tank in the event of fire is easy to explode, and plastic fuel tank due to the use of high molecular weight polyethylene material, its thermal conductivity is very low, only 1% of the metal. At the same time, high molecular weight polyethylene is both elastic and rigid, in the -40 ℃ ~ 60 ℃ environment, still has excellent impact resistance and mechanical properties. So when there is impact or friction is not easy to produce sparks. Even if the car accidentally ignited, and will not be due to plastic fuel tank explosion and explosion.
●plastic fuel tank is not afraid of salt and alkali erosion. Especially in the winter, some pavement to prevent salt from freezing, the car through the metal fuel tank is easy to be corroded, and plastic fuel tank is no such worries.
●manufacturing process is simple. Plastic fuel tank is generally made of high-molecular-weight polyethylene substrate, supplemented by adhesive or barrier material, blown into single or multi-layer composite structure. Compared with the metal fuel tank, plastic fuel tank production process is simple, high efficiency, short production cycle. In addition, the plastic fuel tank, including accessories can be a molding, in order to achieve the main and accessories integration, the cost can be reduced by 1/3.
●Small fuel leakage. In the 40 ℃ environment, the average fuel leakage of plastic fuel tank maximum of not more than 20g / 24h, for multi-layer composite structure of the plastic fuel tank, the average fuel leakage is less than 2g / 24h. Due to the high stability of high molecular weight polyethylene, plastic fuel tank life of up to 10 years.
2, plastic fuel tank technology and market progress
The world's first car plastic fuel tank by the German Volkswagen car company, BASF company and Kautex company in the 20th century, 60 years jointly developed and applied to the Porsche sports car. As Europe is the birthplace of plastic fuel tanks, its market covers a wide range of plastic fuel tanks, including single and multi-layer composite structure of the plastic fuel tank. In the United States and Japan, because of its control standards for the emission of automotive pollutants in Europe, coupled with the commercialization of plastic fuel tank later than in Europe, so at the start when the use of multi-layer co-extrusion technology to produce plastic fuel tank. By 2001, the global production of plastic fuel tank is about 31 million.
China's auto plastic fuel tank technology development process is basically a replica of Europe. In China, the development of plastic fuel tank started in Jiangsu Yangzhou Plastic Factory. In 1987, the plant introduced plastic fuel tank production equipment and technology from Krupp Kautex and Volkswagen in Germany to provide plastic fuel tanks for the Santana sedan of Shanghai Volkswagen Co., Ltd. and the Peugeot 505 sedan of Guangzhou Peugeot Automobile Co., Ltd. After 15 years of development, in the Chinese passenger car market, the plastic fuel tank market share has reached 44%. At the same time, plastic fuel tank manufacturers in addition to Yangzhou Yap Automotive Plastic Parts Co., Ltd. (YAPP), also includes Changchun Clivia - Kautex company, TI (Tianjin), Yachiyo company.
In recent years, with the increasing demand for environmental protection in the world, automobile exhaust emission standards are increasingly stringent, and improve the anti-permeability of plastic fuel tank performance as a vehicle exhaust emissions standards of the most direct, most effective and most important way The Therefore, on the basis of single-layer blow molding technology, three techniques have been developed to improve the anti-permeability performance: vulcanization / fluorination technology, SELAR (R) technology and multilayer coextrusion technology. From the control of production process, the stability of product quality and meet the requirements of new exhaust emission regulations, multi-layer co-extrusion technology is the mainstream of plastic fuel tank development direction. In order to meet the requirements of the vehicle zero emission standards, the possible development trend of the plastic fuel tank system will be reflected in the following aspects: COVER technology - including multi-layer construction cover, multi-layer fuel tank assembly, fuel tank top surface and fuel Box sub-surface completely sealed, etc .; SIB technology; PEEMBLOK AS6-5 / 6 structure; thermoforming technology.
With the implementation of the new standard of automobile fuel economy, the reduction of automobile weight will become one of the key directions for automobile development in the future, so the development of plastic fuel tank is completely consistent with the development direction of automobile. At present, the German Santana sedan has all been used plastic fuel tank. In addition, the Italian Fiat company in 1994 as early as in all its new car using a plastic fuel tank. Plastic fuel tank in the application of the proportion of the car: the United States for 25%, Europe up to 75%. In China, almost all of the new models are put into use plastic fuel tank, such as: Changan Ford's Mondeo car, Guangzhou Honda's Fit car, Beijing's modern Avante XD car and Shanghai Volkswagen and FAW-Volkswagen PQ35 car.