When it comes to making cars, the eco-friendliness of the vehicle is assessed and regulated by strict consumption and emissions parameters. Car manufacturers have to meet these requirements by using increasingly complex technological systems – all of which must work safely and reliably under any operating conditions. One area of major potential in this area is the engine control unit. For example, the innovative Camtronic system provides additional ways to optimize the combustion process by means of load-dependent valve stroke switching using a supporting camshaft with two adjustable cam components. Depending on the driving style, fuel consumption can be reduced by 3.5% - 10%. Due to their required functionality, the cam components of the Camtronic system are designed as pipe-shaped components with comparatively thin walls. As a result, conventional hardening processes offer limited usefulness because of the high heat loads they produce and the fact that this heat exposure can cause component deformation. The project partners at Daimler, who joined forces with the Steinbeis Transfer Center for Laser Processing and Innovative Manufacturing Technology, were presented with the Steinbeis foundation’s 2014 Transfer Award for their project which looked at the laser hardening of Camtronic camshafts.
Laser hardening is ideal for components that are exposed to high stresses and require a high level of functional integration. Compared to induction hardening, it exposes the component to up to 90% less thermal stress for comparable hardening depths. With this in mind, Daimler and the Steinbeis Transfer Center for Laser Processing and Innovative Manufacturing Technology worked together to develop a laser hardening process for cam pieces. It was a natural fit – the project partners shared positive experiences from past collaborative work, and the Steinbeis experts at Pforzheim University of Applied Sciences had already acquired significant know-how in controlled laser beam hardening.
Based on preliminary feasibility studies, the transfer project covered precisely adapted process developments in the use of laser hardening for Camtronic cam components. As part of the project, the partners also took first steps in introducing the process in large-scale series production. This included a draft concept for the future production facility, support in implementing a suitable laser hardening optical system, and further evaluations of the optical system and other important facility components. Following this project, which was awarded the Steinbeis Foundation’s Transfer Award - Löhn Award for outstanding transfer projects, the Daimler and Steinbeis partners plan to continue their work with new applications for laser beam hardening and to investigate the further potential this new technology could bring.
Professor Dr.-Ing. Roland Wahl
Steinbeis Transfer Center for Laser Processing and Innovative Manufacturing Technology (Pforzheim)
su0775@stw.de