2014 Award Winners
Award-winning project: Laser hardening of Camtronic camshafts
Project partners: Daimler AG, Stuttgart | Steinbeis Transfer Center for Laser Processing and Innovative Manufacturing, Pforzheim
In the automotive industry, the environmental performance of vehicles is assessed and regulated on the basis of specific fuel consumption and emissions data. Manufacturers must meet these requirements through increasingly complex technological systems, which must nevertheless operate safely and reliably under all operating conditions.
Engine management offers an approach with considerable potential. The innovative Camtronic system further enhances the scope for optimising the combustion process through load-dependent valve lift switching via a carrier camshaft with two sliding cam segments. Depending on the driving profile, this enables fuel savings in the range of 3.5 %–10 %.
Due to their function, the cam segments of the Camtronic system are designed as tubular components with comparatively thin walls; consequently, conventional hardening processes reach their limits here due to the intense thermal stress they exert and the resulting component distortion. The characteristics of laser hardening are ideally suited to highly stressed components with a high degree of functional integration, as it exerts up to 90 % less thermal stress on the component than, for example, induction hardening, whilst achieving a comparable hardening depth. The decision by Daimler AG and the Steinbeis Transfer Centre for Laser Processing and Innovative Manufacturing to jointly develop laser hardening for camshaft segments was based on positive experiences from previous projects and the fact that the Steinbeis experts at Pforzheim University already possessed in-depth expertise in controlled laser beam hardening.
Following preliminary fundamental feasibility tests, the transfer project carried out comprised the precisely tailored process development for the application of laser hardening to the Camtronic camshaft segments. The collaboration also included implementation work to introduce the process into large-scale series production, comprising the development of a machining concept for the future production line, support in realising a suitable hardening optical system, and evaluations of the optical system and other key plant components.
Following this project, which was awarded the Steinbeis Foundation’s Transfer Prize – the Löhn Prize – the collaboration between partners Daimler AG and Steinbeis will continue with new applications of laser beam hardening in order to tap into further potential with this new technology.