Lightweight construction concepts continue to gain ground in the automotive industry – each gram less is an active contribution towards reducing CO2. At the International Motor Show, various companies will present interesting new concepts.
(Compact exhaust system for front engines – all functional units are housed in the engine compartment)
A study prototype of a compact exhaust system for front engines houses all functional units in the engine compartment. Some years ago, Eberspaecher produced a comparable system for small cars with rear engines. As the functions are concentrated in one component, there are no long connecting pipes running under the underfloor of the vehicle. This makes the system significantly lighter – in a four-cylinder engine, in comparison with a series produced system, a weight saving of up to 40% is possible. And it creates space: Due to the operating temperatures and movements of the pipes, in a conventional design other components have to be installed apart.
The exhaust system is particularly suitable for use in downsizing concepts with three and four-cylinder engines. Due to the reduced number of cylinders it can be integrated in the otherwise overcrowded engine compartment. It also offers decisive advantages for alternative drive concepts such as plug-in hybrids. As the exhaust pipe is not blocking the space in the underfloor, valuable installation room is freed up for the battery or for induction loops for cable-free supercharging.
A further advantage is the silencing: as the acoustic standards, especially in otto engines, are more demanding due to the reduced length of the exhaust system branch, the »ActiveSilence« technology is used. From a technical aspect, ActiveSilence is based on the anti-sound principle: a mirror-inverted image is produced of the undesired sound waves via a loudspeaker. If these waves, traveling in the opposite direction, are superimposed over one another exactly, they cancel each other out. Using this system, the exhaust gas back pressure can be reduced by up to 75% compared with conventional technologies. In addition, the component scores by virtue of its design: the new type of muffler has a volume of up to 60% lower and weighs up to 40% less than traditional systems.
(Weight-optimized exhaust system for e-vehicle with range extender – for the Chevrolet Volt the technology is already in large-scale production)
Another topic is reducing wall thicknesses and weight of an exhaust system using the series production system for the Chevrolet Volt: the electric vehicle is equipped with a combustion engine designed to extend its range, a so-called range extender.
(The exhaust system with reduced wall thickness in the Audi A4 diminishes weight by a further ten percent)
For this, Eberspaecher has developed a weight-optimized exhaust system. The catalytic converter, centre muffler and pipes are arranged conventionally. The system becomes lightweight thanks to reduced material use. The pipes are one millimetre thick – 1.2 to 1.5 millimetres is normal. As a result, a 20% weight saving can be achieved in relation to traditional pipes. »In the exhaust system for the Chevrolet Volt we succeeded in minimizing the wall thicknesses and optimizing durability – the series-produced exhaust system proves our competence in both design and manufacture«, says Thomas Nording, »Eberspaecher is also a series supplier for the sister model Opel Ampera which will be launched later this year«.
In addition, at IAA Cars Eberspaecher will show how the weight of an exhaust system can be significantly reduced by the use of innovative, light materials.
(Plastic actuator for the exhaust system – using the example of ActiveSilence technology, Eberspaecher will show how groundbreaking materials are continuing to save weight)
Using the example of ActiveSilence, the developers have explored various options: as the exhaust gas does not flow directly through the actuator, it is also possible to use materials that are less temperature stable. Alongside the standard version in steel, the company will show a plastic version with a weight saving of 35% (in relation to the housing). Furthermore, there will be study prototypes made of aluminium (37% weight saving), titanium (26%) and carbon with a 40% reduction in weight.