Sophisticated PCD tool concepts for machining aluminium
Economic, high-precision machining of forged aluminium parts
Highest precision and economical production – these aspects are the focus when Carl Hirschmann GmbH machines forged parts made of aluminium for sports vehicle chassis. Well thought-out, multi-stage combination tools from MAPAL have proven their worth here. The shape-adapted PCD cutting edges are particularly impressive. Those responsible at Carl Hirschmann are also impressed by the all-round support provided by their development partner MAPAL.
„We have developed from a trading company founded in 1957 into an international technology leader in the manufacture of heavy-duty plain bearings, rotary indexing tables and clamping systems“, said Rainer Harter, Technical Managing Director of Carl Hirschmann GmbH in rural Fluorn-Winzeln in the Black Forest. Thanks to its expertise, diligence and the ability to innovate, the original license manufacturer has developed into a manufacturer of top-quality products.
Carl Hirschmann‘s core products include support and guide joints, for example for the longitudinal, transverse or triangular control arms in the axle structures of high-end sports vehicles. Multidisciplinary expertise is required to produce these cutting-edge components. Carl Hirschmann has earned an excellent reputation in this field and supplies well-known sports car manufacturers.
Development partner for car manufacturers
„Due to the extensive experience we have gained in axle components for sports vehicles, our customers involve us in the development and production of complete axle assemblies as a partner,“ said Rainer Harter. As is customary in the industry, the experts from Carl Hirschmann receive a comprehensive specification sheet containing all the information on the installation space as well as the requirements and specifications from the customer. To this end, Carl Hirschmann and the customer jointly develop an optimally-suitable assembly - for whose manufacture and delivery Carl Hirschmann then accepts overall responsibility. This includes all process steps from the procurement and machining of all external components, which includes in particular the aluminium forgings, to the just-in-time delivery of complete and tested assemblies to the customer‘s production line. To this end, Carl Hirschmann has networked its IT systems directly with those of its customers so that call-offs can be imported directly from the production planning system run by the customer, a sports car manufacturer, into the company‘s own ERP system.
Forged aluminium strut mounts for connecting the spring strut rod end of a vehicle axle to the chassis.
The challenge of precision machining
In addition to technical perfection, the cost-effectiveness of the process plays an essential role in component machining. And this, in turn, requires the smooth supply of well-thought-out high-performance tools. Carl Hirschmann has brought tool manufacturer MAPAL on board for just this purpose.
„The axle structures in top sporting vehicles must be as light as possible and withstand the enormous dynamic loads. This means that lightweight designs are required for these safety parts, right to the limit of what is feasible - with the corresponding demands on machining,“ said Thomas Kuner, Technical Advisor at MAPAL in Aalen. The forged parts are therefore made of high-strength aluminium alloys. These workpiece materials are long-chipping and difficult to machine. The machining must also be extremely precise because of the tight tolerances required. A maximum deviation of ± 5 μm is permitted in critical areas such as the seat of the bearing shells.
Close tolerances of up to ± 5 µm must be maintained when machining the dome bearing. Extremely tight tolerance specifications also apply to the fine thread.
In order to manufacture economically despite this, Carl Hirschmann uses customised stepped and combination tools from MAPAL, which the tool manufacturer equips with various shape-adapted blades. High-precision calottes, slots, threads or undercuts can be produced with comparatively few feed movements. This is much quicker than the time-consuming „multipass milling“ with standard tools. The preferred tool cutting material is polycrystalline diamond (PCD). The cutting edges are usually brazed in.
PCD multi-stage tool (l) is used to pre-machine the calotte, and to drill out and circularly mill the fine thread. The fine boring tool (r) machines the seat of the bearing shell. In the centre you can see the ring-shaped concentricity control point.
Thanks to the sophisticated step and combination tools, Carl Hirschmann can implement numerous different machining processes without changing tools. Another advantage of combination tools is the fact that there are fewer alignment deviations as a result of tool changes. „We also achieve the best combination of dimensional accuracy and tool life with PCD tools“, said Thomas Maier, Milling Team Leader. In addition, the cutting edges are convincing due to their reliability. „This is even more important for us because we have to meet just-in-time delivery deadlines to our customers“, Thomas Maier explained. The demands on the stability of the production processes are therefore correspondingly high.
Entwicklungspartnerschaft mit MAPAL
„Bezüglich der Entwicklung und Lieferung solcher Werkzeuge arbeiten wir schon seit 2013 eng mit MAPAL zusammen“, erläutert Thomas Maier. Hierbei schauen sich die Experten beider Unternehmen die jeweiligen Spezifikationen der angeforderten Baugruppen und Bauteile genau an und definieren, mit welchen Werkzeugauslegungen, Schneidengeometrien und NC-Strategien sie die gewünschten Ergebnisse so effizient und wirtschaftlich wie möglich erreichen. „Dabei bringt sich MAPAL dank des weitreichenden Prozessverständnisses jederzeit gewinnbringend ein“, bestätigt Thomas Maier.
Mit dem Erfolg zufrieden: Thomas Maier (Teamleiter Fräsen, Carl Hirschmann), Rainer Harter (Technischer Geschäftsführer, Carl Hirschmann) und Thomas Kuner (Technischer Berater, MAPAL) (v. l.).
Gute Erfahrungen auch beim Support
„Ein wesentlicher Bestandteil der Versorgung mit Werkzeugen ist für uns auch der von MAPAL geleistete Support“, bekräftigt Thomas Maier. Dieser umfasse zusätzlich zur Zusammenarbeit bei der Entwicklung auch alle anderen Aspekte wie die Lieferzeiten bei Neu- oder Nachbestellungen, die Standzeiten beziehungsweise die Standmengen der Werkzeuge und der Schneiden sowie die Reaktionsschnelligkeit bei der Instandhaltung, der Wiederaufbereitung und der Reparatur von Werkzeugen. „Wir fühlen uns bei MAPAL rundum gut aufgehoben“, bilanziert Thomas Maier.
At the automotive supplier Schabmüller, MAPAL has already been responsible for tool management. Now, the tool manufacturer from Aalen has also taken over the CAD/CAM programming of the components, including simulation.
