Supplement
1. Supplementary Texts
High-level Gasoline-Ethanol BlendE85(Unit 1)
E85 is a high-level gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season. The ethanol content is adjusted according to the local climate to maximize engine performance. It is considered an alternative fuel under the Energy Policy Act of 1992 (EPAct).
It can be used in flexible fuel vehicles (FFVs), which are commonly available from domestic and foreign automakers. Motorists will see little difference when using E85 versus gasoline. E85 has about 27% less energy per gallon than gasoline (mileage penalty lessens as ethanol content decreases). But because ethanol is a high-octane fuel, it offers increased vehicle power and performance.
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Euro 5 and Euro 6 - Emissions From Light Duty Vehicles(Unit 1)
New emission limits (Euro 5 and Euro 6) have been introduced for cars and light commercial vehicles with respect to a number of pollutants, especially nitrogen oxides and particulate pollutants. The new standard known as Euro 5 applies as of 1 September 2009 for the approval of vehicles and as of 1 January 2011 for the registration and sale of new types of cars and vans sold in the EU market.
This will also make the introduction of particle filters for diesel cars obligatory. Euro 6 will set even lower emission limits. It will be binding for the type approval of vehicles as of 1 September 2014 and for the registration and sale of new types of cars and vans as of 1 September 2015.
Ecotec DOHC Four-Cylinder Engine( Unit 2)
Bringing the popular concept car to life, GM announced production of the Pontiac Solstice roadster as a 2006 model. The vehicle is expected in dealer showrooms in fall 2005.
First shown as a concept at the 2002 North American International Auto Show (NAIAS) in Detroit, the Solstice immediately gained a huge following, both inside and outside of General Motors. Designed from the ground up in less than four months, the 2002 Solstice concept car promised thrilling, open-air driving freedom in the spirit of the great roadsters of the past.
Built on GM's new Kappa architecture, the production model remains true to the original Solstice concept, including rear-wheel drive, two-passenger seating and a reverse hinged clamshell hood that opens to reveal a sophisticated double overhead cam variable-valve four-cylinder engine.
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Chassis(Unit 2)
Strong response to the 2002 Solstice concept vehicle helped put the sports car on the fast track to production. But while the concept was designed with production-style elements, there was no compact rear-wheel-drive platform at GM on which to build it. Creating a production version of the concept vehicle required marrying the Solstice's curvaceous design to an entirely new performance body-chassis architecture.
The robust Kappa architecture features state-of-the-art, full-length hydroformed frame rails and a stamped steel structural tunnel to provide a solid structure to enhance vehicle handling.
Solstice's power is created by a new 2.4-liter variable-valve version of the Ecotec DOHC four-cylinder engine, producing about 170 horsepower. Its twin-cam, multi-valve design provides stirring, high-revving performance, while the engines lightweight, all-aluminum construction helps optimize the vehicles front-to-rear balance. At the start of production, Solstice will be offered with a close-ratio Aisin five-speed manual transmission.
Faithfulness to the concept can be seen in Solstices proportions, which are comparable in terms of overhangs, wheelbase and track width. Independent front and rear suspensions that feature independent SLA designs with forged aluminum upper and lower control arms contribute to responsive handling. Monotube shock absorbers and coil springs contribute to uncompromised handling response and sporty driving characteristics while the wheels-at-the-corners wide stance enhances handling. Eighteen-inch wheels and tires are standard, as are four-wheel disc brakes.
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Aspects of Lightweight Design with Door Frames as an Example(Unit 3)
Klaus Maier, Gerald Widegger
For a number of premium-class vehicles, George Fischer Automotive manufactures innovative door inner frames and door frames using aluminum and magnesium pressure die casting methods. Mercedes-Benz, Aston Martin and Porsche demonstrate that a rear door frame, for instance, can be about 30 % lighter than a comparable sheet-steel component. Lightweight design is regarded as a proven method of reducing fuel consumption and, along with it, the CO2 emissions of passenger cars.
According to a rule of thumb, every 100 kg of vehicle weight reduction results in savings of between 0.3 and 0.5 l of fuel every 100km. This corresponds to a reduction of between 8 and 11 g of CO2 per km. The vehicle bodywork, chassis and power train are regarded as those areas with promising weight-saving potentials. Essentially, the selection of materials and production methods depend upon the number of units to be produced and the technical requirements. Taking as examples the door inner frames for the Mercedes-Benz S-Class, George Fischer demonstrates what influence these inputs have in practice. The tailor-made door frames feature minimum mass, economic efficiency and high functionality.
An upper frame section comprising an aluminum profile is welded onto the one piece aluminum diecast frame. The few MIG welding seams result in minimum component distortion and thus very tight tolerances. This facilitates the assembly work and promises efficient inner-frame sealing between the door’s wet and dry compartments. Georg Fischer selected AlMg5Si2Mn as the material for the door inner frame. Aluminum alloys can be optimized to fulfill a variety of different material requirements, for instance with respect to elongation, tensile strength and deformability (ductility). The experts for light metal at Georg Fischer decided on the “naturally hardening” alloy because it does not require heat treatment.
Georg Fischer produces the front and rear door frames for the Porsche Panamera using the aluminum pressure die casting method
At a length of maximum 1281 mm, the Aston Martin door inner frames made from magnesium are of above-average size
Excellent production properties result from these highly complex casting and processing procedures. The aluminum alloy AlMg5Si2Mn with 5 % magnesium and 2 % silicon and manganese content is easy to stamp and weld. The die cast inner frame for the front doors is longer than 90 cm, maintains tolerance in the 1/10 millimeter range. Wall thicknesses of only 2.2 to 3.5 mm result in a component weight of only about 3.7 kg. Among other things, the inner frame’s economic efficiency results from the moderate number of units produced. The figure here is just under 1500 inner frames produced every day. This means that the unit cost for the aluminum die cast part is lower than that of a new aluminum-sheet component and practically the same as that of a comparable sheet-steel part.(2253 characters)
Notes:
pressure diecastingлитьеподдавлением
Technical Advancement (Unit 3)
Back in the 1990s, when aerospace manufacturers started to build airframe components of business jets and commercial airliners from polymer composite materials, many industry observers felt that it would be only a few years before large-volume automakers would begin to follow suit. After all, the lightweight but strong and stiff composites of fiber-reinforced resin had already made the transition from military aircraft structures to civilian ones, and racecars and exotic sports car prototypes featuring mass-efficient carbon-fiber bodies had started to appear. Yes, composites were still too expensive, but many experts believed that continued technical advancement would in due time yield low-cost, mass-produced auto chassis and bodies that could save fuel while enabling new designs that were never previously possible.
More than a decade later, however, car structures are still made primarily of steel and other metals, and are likely to stay so for the foreseeable future. Plastics—reinforced and not—have found much greater application in interiors and some non-primary structural applications such as body panels and pickup truck boxes made of reinforced sheet molding compound (SMC), but the OEMs, having sunk large quantities of capital in metal-part fabrication and assembly plants as well as paint operations, have retained what critics call a "steel mentality." In fact, between 2001 and 2007 utilization of thermoset composites—resins that harden permanently at high temperatures—has declined significantly in the automotive sector, according to data collected by theAutomotive Composites Alliance, an industry consortium.
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Composites Save Weight (Unit 3)
Potential weight savings offered by structural composite materials are significant, reported Joseph Carpenter, Jr., Manager of the lightweight materials technology area development at theU.S. Department of Energy's Office of Vehicle Technologies, at a federal workshop held on the topic last year. Estimates of the relative weight savings and costs that could be achieved by replacing steel with current carbon-fiber-reinforced polymer composites (CFRPCs) range from 50 to 60% at two to ten times the cost. Substituting glass-fiber-reinforced polymer composites (GFRPCs) for steel could cut weight by a quarter to a third with a comparatively modest— 50%—cost rise.
Nevertheless, composites researchers continue to believe that further work on cheaper fibers, new resin systems such as liquid crystal polymers, and automated processing equipment will eventually cut costs and improve the final product enough to make polymer composites attractive forwidespread use in auto bodies and chassis.
Other potential benefits deriving from the adoption of structural composites are manifold. Improved crash safety could result when engineers take advantage of the materials' higher specific energy absorption. Simpler assembly operations should be achievable because composites enable significant parts consolidation. Production tooling costs for the polymer materials are lower compared with those of steel fabrication tools. Polymer composite structures could offer better long-term durability than metal ones as well as superior environmental sustainability through enhanced end-of- life recyclability.
Laser Welding(Unit4)
Many variants of laser technology are currently used in production processes including cutting, welding, marking, surface engineering and direct parts fabrication. The range of applications covers metals, plastics, semiconductors and ceramics on a scale from sub-micron to several metres. Many industries, including the automotive, shipbuilding and aerospace sectors are using laser welding and laser cutting technology.
The laser beam welding is mainly used for joining components that need to be joined with high welding speeds, thin and small weld seams and low thermal distortion. The high welding speeds, an excellent automatic operation and the possibility to control the quality online during the process make the laser welding a common joining method in the modern industrial production. The application range covers finest welding of non-porous seams in medical technology to precision spot welding in electronics or the jewelry industry, to deposit welding in tool and mold-making and welding complete car bodies in automobile construction. However, new and efficient production processes are often not possible without the advantages of laser technology. Thus, diverse sheet thicknesses and qualities are turned into tailored blanks by welding and resistance spot welding is replaced by laser seams.
Welding method
There are two main processes: heat conduction welding and deep penetration welding
High Speed Laser Welding for Automobile Exhaust Components (Unit 4)
Keng H. Leong and Donna J. Holdridge
Argonne National Laboratory and Maryann G. Seibert and David E. Nelson,
AC Rochester Division of General Motors
Arc welding has been the traditional technique for the joining of many automobile parts and
components of steel. The advent of laser beam welding with its rapid speed and relatively low
thermal distortion has resulted in the erosion of gas metal arc welding (GMAW) and gas
tungsten arc welding (GTAW) dominance. The faster joining speed that can be achieved with
laser beam welding is particularly suited to the high-production rate requirements in the
automobile industry.
Some automotive exhaust components use 409 stainless steel and are currently arc welded.
Welding speeds obtained with GMAW or GTAW are usually <2.5 cm/s. Weld speeds that can
be achieved with high power laser beam welding can be significantly higher. Consequently,
higher production rates can often be expected. This work provides preliminary data on weld
speeds that can be achieved for two weld configurations subject to the constraints of material fit up requirements.