More than 125 years ago, jewellery producer Heinrich Witzenmann generated the impulse for a new industrial sector when he invented the flexible metal tube. Today, flexible metal elements are found in a wide range of products and systems, and Witzenmann has earned the position of preferred development partner among leading companies. The latest developments relating to environmental standards in the commercial vehicle sector demonstrate the high level of development expertise of this technology leader.
Among the development strategies that have dominated the on-highway and off-highway sector in recent years is the fulfillment of the Tier 4 and Euro VI standards. The Witzenmann Group addressed this topic early on in close cooperation with customers, and is now able to offer series-tested components that promote reductions in nitrogen and soot particle emissions.
What will come after Tier 4 and Euro VI?
The final phases of these two ambitious policies will go into effect in 2014. It is widely agreed that the potential for reducing the nitrogen and soot particle content in emissions will have been exhausted when Tier 4 and Euro VI go fully into effect. Both technically and economically, there are no longer any development perspectives in this area. In fact, a further reduction in NOX would actually cause CO2 emissions to rise considerably. Policy makers are aware of this situation and are not expected to further tighten the applicable regulations. Instead, the next environmental goal is the reduction in CO2 emissions of all farm vehicles.
Targeting CO2 emissions
Emissions limits are already binding on passenger cars in Europe. For light commercial vehicles up to 3.5 t, they will be phased in in 2017 and 2020. In the on-highway and off-highway sector, setting standards is infinitely more complex due to the wide variety of vehicles and the different areas of application. However, experts believe that a concrete European regulation will go into force by 2016 at the latest. In Japan, this will occur in 2015 and the USA will react no later than 2017.
Engine-oriented solutions alone will not be enough
It is highly unlikely that engine technology developments alone would be able to achieve a reduction in fuel consumption and CO2 emissions while keeping pollutant emission levels constant. All-encompassing strategies and a variety of approaches will be needed here. Witzenmann has extensive experience in the design of flexible elements installed close to engines and uncoupled components that optimise the interaction of forces, temperatures and aggregates in the high-load range. To achieve the CO2 targets, Witzenmann Engineering offers a wide variety of development perspectives. For example, Research and Development is currently working on the design of return lines for use in thermal management systems, exhaust heat recovery and exhaust after-treatment. This research is highly promising, although it shares the fate of all forward-looking ideas. It can never be said with certainty how intensively the new concepts will be employed, if at all.
Downsizing at full pressure
One trend that may assert itself is downsizing. The technological challenge here is to be able to handle the raised operating pressures that all high-efficiency aggregates invariably exhibit. This results in very high demands on pressure-resistant piping and exhaust expansion chambers, in particular when they have a light-weight, thin-walled design. With its experience in multi-walled, flexible elements, the Witzenmann Group is pursuing promising approaches in this area.
In the future, the lower-volume engines will most likely be equipped with turbo chargers to raise their power outputs to the required levels. This could result in high-frequency vibrations, which in turn cause excessive noise emissions if they are transmitted into the exhaust system.
Here Witzenmann is working on an adaptation of its structure-borne noise decoupling elements from the passenger car sector.
New challenges in design
In the future, engines in commercial vehicles and construction machinery will probably have a more complex and compact design that is equipped with more auxiliary aggregates than today's models. The cramped installation space, which until now has been only a marginal issue in this sector, is expected to gain in importance in heavy duty vehicles.
In this area, too, Witzenmann can build on its experience in the passenger car sector. Ready-to-install components that are pre-formed and pre-assembled according to specific customer requirements will free up more space for commercial vehicle makers in the future.
Figure 1: Headquarters of the Witzenmann Group in Pforzheim
Figure 2: Production of flexible metal elements for commercial vehicles, large engines and construction machinery
Figure 3: 6-axis test stand
Figure 4: Laser welding
Figure 5: Clean room production at Witzenmann