Supplier Hirschvogel Automotive Group stresses on lower billet weight to reduce CO₂ levels

Hirschvogel Automotive Group, de- velopment partner and production specialist for the automotive industry, showcased its know-how in achieving resource-saving mobility with reduced CO₂ emission at the IAA in Frankfurt last year. The supplier laid stress on the fact that lightweight components and material savings attained by a lower billet weight can make a considerable contribution to reducing CO₂ levels. In order to achieve material savings, Hirschvogel has developed hollow shafts for transmissions and powertrain; optimum lightweight design is obtained through the use of forged aluminium with maximum strength values. Says Dr. Hans-Willi Raedt, director of research and development at the Hirschvogel Umformtechnik GmbH, "The link between material, design and production competence leads to optimum lightweight design".

The Hirschvogel Aluminium GmbH in Marksuhl, Thuringia, is supplying forged aluminium knuckles for the new Mercedes-Benz C-Class (W204). This new part replaces the casting found in the previous vehicle generation of the C-Class. Even as early as the pre-development phase, it became clear that a knuckle with higher mechanical properties would be needed for the new generation of the Mercedes-Benz C-Class. A tensile strength of greater than 360 MPa has been achieved. The yield stress exceeds 340 MPa, and the elongation lies at greater than 10 per cent.

In spite of the higher strength requirements demanded of the part, the newly developed forged component was much lighter than the weight specification for a cast part. This was made possible through the joint development efforts between the DaimlerChrysler AG and the developers at the Hirschvogel plants in Denklingen and Marksuhl. The knuckles are being produced fully-automatically on a new group of presses at the Hirschvogel Aluminium GmbH, based in Marksuhl, Germany.

Hirschvogel showcased a 2-litre, four-cylinder diesel engine at Frankfurt, and which it claims is also the first model to use balancer shafts with roller bearings. The use of balancer shafts with roller bearings has led to reduction in friction, increase in efficiency and thus lower consumption. An induction hardening steel with stringent cleanliness requirements is forged in an automated process (component design and forging simulations using FEM were carried out simultaneously in order to generate an optimum part). The part is finish-machined by the Hirschvogel Komponenten GmbH. Extremely good roundness and minimum unevenness values are generated at the roller-bearing sites. While these properties are checked by means of Fourier Analyses, the end product is supplied ready-for-assembly with needle bearings. This clearly illustrates how enhancements in engine efficiency have an effect on components.

The Hirschvogel Umformtechnik GmbH, located in Denklingen, Upper Bavaria, Germany. Headquarters of the Hirschvogel Automotive Group, more than 1,500 employees produce approximately 135,000 tonnes of forged and extruded parts made from steel. The company has three subsidiaries in Germany. In Marksuhl (near Eisenach), the Hirschvogel Aluminium GmbH produces sophisticated chassis components from high quality aluminum materials. Another steel forge, the Hirschvogel Eisenach GmbH, is likewise located in Marksuhl. In Schongau (Upper Bavaria), both steel and aluminum parts are then processed into ready-for-assembly components at the Hirschvogel Komponenten GmbH.