2012 Lightweighting Special: Brose's lighter, stronger agenda

The Brose Group, the German auto supplier, makes door and seat systems as well as electric motors. In February 2011, the company opened a production facility at Hinjewadi, near Pune, which can currently make about 600,000 window regulators per year. The facility was opened with the aim of catering to both local and export markets.

Brose India has said officially that it plans to treble its India production capacities by 2014. In calendar 2012, the company plans to commence production of the first manual seat height adjuster and in the first quarter of 2014, the company expects to begin series production of side door latches at its Pune plant.

The company has gone on record to say that its focus will be increasingly on weight reduction and improving efficiency.In an interview to Autocar Professional, Rajesh Kulkarni, vice-president, global services India, spells out his company’s lightweighting agenda.

What steps has Brose initiated to reduce the weight of automotive components?

Development activities at Brose have focused for many decades on reducing the vehicle weight in all product areas. With new materials and manufacturing processes as well as increased functional integration, the Brose Group has reduced the weight of its door, closure and seat systems along with its adjuster drives by 30 percent to 50 percent over the last 10 years. At the same time, functionality has been increased without detriment to safety and comfort.

Have you implemented any innovative ideas to enable lightweight manufacturing?

Our expertise in lightweight design is constantly being developed in all product areas and our focus is always on saving weight and maintaining or increasing functionality. The deciding factor in this regard is that our components are always developed under consideration of the overall system. This means that our components are consistently designed using materials optimised for the function in an intelligent combination and corresponding joining technologies so as to achieve a maximum weight saving for the entire system.

An example of this is our concept for the rear seat, which we presented at the IAA in Frankfurt in 2011. Just by employing intelligent composite design and laser welding, i.e. by designing new interfaces allowing screws to be dispensed with, for example, the weight of the seat rails has been reduced by some 75 percent, even though the same materials are used. New composites, like fibre-reinforced thermoplastics in the seat pan, reduce the weight of these parts by approximately 50 percent. Partially reducing the wall thickness of a transverse bar leads to a weight saving of around 30 percent compared to other components on the market. Brose has been able to design the folding function of the rear seat nearly 50 percent lighter by using innovative fibre-reinforced plastics. In the entire system, that is to say the complete rear seat, these lightweight components achieve a weight saving of 15 percent against commercially available rear seat structures.



How does Brose plan to progressively reduce weight in components/vehicles?

Primarily by using new materials combined with new production processes. This includes door and seat concepts with new materials and procedures along with the increased integration of functions as well as innovations in our drives division.

We achieve weight savings, for example, by using small, efficient drives in HVAC blower modules, power steering, dual clutch transmissions or in engine cooling. Thus our new generation of brushless cooling fan modules in the power range of 200 to 450 watts combines minimal use of resources with maximum performance in cooling, acoustics, package space and weight. Compared to conventional systems, the module is not only lighter and more efficient, its effectiveness has also been optimised. The length has been reduced by 15mm and the weight by about 700 grams, pursuing a holistic sustainable approach which begins already with the saving of energy in production.

Due to the process of physical foaming, the frame enables plastics to be used sparingly thus lowering energy consumption in production by as much as 30 percent and the use of resources by five percent. In addition, wired components are assembled without solder.

The electronic control unit for infinitely variable speed regulation is fully integrated in the drives. An intelligent circuit design optimises the drives at the load point, achieving a degree of effectiveness exceeding 80 percent. This results in energy consumption during operation at full load being reduced by around 40 percent. Even in the upper power ranges – cooling fan modules of 850 to 1,000 watts – we contribute to reducing fuel and emissions with efficient drives by implementing extremely efficient drives with degrees of effectiveness exceeding 80 percent and whose weight has been reduced by 1kg to 2,650 grams.

All Brose drives – ranging from 200 to 1,000 watts – can be fitted on the frame without any adjustment necessary. This saves automakers’ tooling costs and streamlines the design of variants. One more aspect which complements lightweight design is higher vehicle efficiency by the increasing electrification of components. An example of this is electromechanical steering. The fact that it is only activated when necessary gives it a decisive advantage over the conventional hydraulic solution. This saves energy, lowers fuel consumption and reduces carbon dioxide emissions by up to seven grams per kilometre. Our power steering motors are supplied in the power ranges 250 to 1,000 watts and can be fitted in all classes of vehicle with a minimum of adjustment. Our motor concept also results in a high power density.

Is Brose using any high-performance engineering plastics to replace metal parts?

The importance of plastics is growing increasingly in all product areas of Brose, for cooling fan modules, lightweight seat pans or door systems. In view of this, we also support research and regularly donate the prizes awarded annually to six scientists in three different areas by the Scientific Alliance of Polymer Technology (WAK), to which some 30 prestigious international experts specialising in plastics technology belong.

Of course, with all these activities the cost aspect has to be considered. We select the most economical and most suitable material for production purposes depending on the technical function and the stress it is exposed to. Our door systems are an example of this. In view of the increasing pressure on prices and the multitude of variants available for new models, the modular design plays a significant role in the automobile industry. All principal door functions are combined on a module carrier and form a pre-tested and ready-to-fit unit, which is delivered just-in-sequence to the automobile manufacturers’ assembly line. Having produced more than 120 million door systems, Brose is the most experienced manufacturer in series production and is world market leader in this area.

Which material provides the most benefit for the OEM and the greatest efficiency in the specific project?

These are the deciding criteria when selecting material for the module carrier. We, therefore, keep the necessary resources and processes for the development, manufacture and supply of the different door system variants to hand.

From the classic steel module through the use of lightweight metal alloys to concepts of glass and carbon fibre reinforced plastic door systems. The latter offer high potential since besides a weight saving of 55 percent against steel and about 30 percent against aluminum, they are a long term cost-efficient alternative for long-term use in vehicles. For this reason, carbon fibre reinforced door systems are also well suited for use in electric vehicles.

Do you work in conjunction with OEMs to reduce component weight? And can you describe any particular project?

All our on-going development projects give priority to saving weight saving while at the same time maintaining or improving functionality. Our cooperation with various universities, above all with regard to new materials and production technologies, as well as with our customers to tailor projects to their individual requirements, in this regard, is necessary.