Ultrasound takes cutting to the next level
The ultrasonic vibration system Perma Vib from Fraunhofer-IWU for drilling and milling tools is primarily intended to perfect the machining of steel and aluminum.
In the machining of fiber-reinforced plastics and ceramics, typical defects such as fiber tears, delamination and chipping of the tool or workpiece still occur to this day. The efficiency of machining metallic materials is limited by poor chip removal and burr formation.
Improved component quality and easy retrofitting
"The Perma Vib system, which we developed together with four industrial partners, is changing that," says Martin Hamm, a scientist at Fraunhofer-IWU. "The system uses ultrasound to cause a vibration of the tool and thus reduces the forces that have to be applied for machining by up to 40 %. This results in smaller chip sizes, improved chip removal and component quality, while at the same time reducing tool wear by up to 50 %. In addition, existing machine tools can be retrofitted with the system easily, because it can be integrated as a module in any machining center. "Perma Vib is unrivalled in this field," continues Hamm. "The few similar products that are on the market require the purchase of special machines and are therefore only suitable for machining smaller components.”
Perma Vib is designed as a tool holder with shrink chuck, which is inserted into the machine spindle instead of the conventional tool holder. Inside, it has a piezoceramic transducer that translates a high-frequency alternating electrical voltage into fast movements. Thus, the conventional forward and cutting movements are superimposed by a longitudinal vibration. The geometry of the system amplifies the vibration amplitude. At the tool tip, values in the two-digit micrometer range are achieved in this way. However, the housing is decoupled from the vibrations, protecting the spindle and bearing from unwanted vibrations.
Perma Vib's control and power supply is independent of the power supply and control of the respective machining center by using an external supply unit installed outside the working area. "In this way, no modifications have to be made to the machine," explains Hamm. "This guarantees maximum flexibility”.
Ultrasonic technology in machining - systems and fffects
Interested parties could experience the use of Perma Vib at the event "Ultrasonic Technology in Machining - Systems and Effects" on November 22. The ultrasonic vibration systems were at the focus of the 4th "Production Technology Conference" at the Fraunhofer-IWU test field. Participants had the opportunity to get to know the technical details of the adaptronic components in practice during live demonstrations in a close circle of experts. Keynote speeches by high-ranking representatives from industry provided an insight into the latest development trends in machining.
The Perma Vib vibration system was developed in cooperation with the industrial partners Devad GmbH, EAAT GmbH, Parker Hannifin Manufacturing Germany GmbH & Co. KG and Tixbo Automotive GmbH. The project was supported by the Federal Ministry of Education and Research within the framework of the program "Zwanzig20 — Partnership for Innovation".