Increasingly stringent exhaust emissions and noise limit values require innovative and environmentally-friendly technologies that safe the mobility of the future. The use of electric motors will increase in automotive powertrains, but mainly as a hybrid drive, i.e. in combination with a combustion engine. Due to the constantly increasing number of vehicles, especially in the growth regions in Asia, the combustion engine will remain the most important drive type for the next decades. The increasing use of alternative fuels and refinements in the combustion process will also further reduce emissions.
Eberspächer is working on groundbreaking products which will reduce emissions further. Already developed to series production readiness, lightweight systems with reduced material thicknesses and new system solutions enable CO2 savings. CO2 emissions can also be reduced with “ActiveSilence". Heat recovery offers the greatest savings potential for carbon dioxide emissions. In addition, we plan to further reduce the emission of particulates and NOx through innovative solutions such as close-coupled SCR systems and particulate filters for gasoline engines.
Eberspächer offers various technologies for noise attenuation. Muffler volume/weight can be reduced by simple self-controlled valves (passive valve) as well as active (electrically) controlled valves. The greatest potential for noise damping, as well as with sound design is offered by the Eberspächer ActiveSilence System.
Today's engines are becoming ever more efficient – by measures such as downsizing (fewer cylinders) and downspeeding (lower rotational speed) – and the sound they generate is changing as a result. At the same time, changes in the law are demanding reductions in noise emissions of vehicles on the road. The two factors are leading to larger and more complex exhaust systems. ActiveSilence®-systems from Eberspächer are an efficient, environmentally friendly alternative to conventional mufflers. They eliminate unwanted, non-compliant noise, so ensuring a pleasant in-vehicle acoustic experience and acceptable levels of emissions to the outside world.
The technology behind the system is Active Noise Cancellation. In this, a counter-noise overlays and neutralizes the unwanted sound waves. The principle behind ActiveSilence® is simple, but its application is complex. A control unit computes the signal for the counter-noise based on data from the engine electronics. A microphone continuously records the tailpipe noise and relays the measured data to the control unit. After exact calculation of the frequency, a precisely computed counter-noise overlays and neutralizes the unwanted sound waves.
Benefits of the ActiveSilence® exhaust system: The muffler takes up less space – in a car delivering savings of up to 60 percent which can be used for other components. And the system is as much as 30 percent lighter than a conventional exhaust system. Thanks to the system's lighter weight and lower exhaust gas back pressure, the vehicle's CO2 emissions are also cut. Moreover, the number of exhaust system variants is significantly reduced because the requirements of different vehicle models are met in the software design rather than in the product design. This helps conserve valuable resources in all areas.
To implement new product ideas, Eberspächer relies on continuous improvement in all technology and production areas. This range from modern production lines and technologies in welding and forming processes to new and alternative materials for the development and manufacturing of exhaust systems: Innovations soon to be industrialized and offering new powerful solutions for exhaust technology.