Development of an active clamping system for noise and vibration reduction

Noise emissions of up to 110 dB(A) occur during the machining of composite boards. Vacuum clamping systems are predominantly used for machining particle boards on woodworking machining centers. These clamping systems enable a good accessibility to the workpiece edges during milling. As a result to this clamping method the boards have non-clamped areas. Consequently they vibrate over a wide frequency domain during machining. The quality of the particle board edges is reduced and a high noise level is induced by these vibrations. An active clamping system based on piezo-stack actuators has been designed and implemented to reduce these vibration amplitudes. All required steps of its development, the localization of the vibrations and the noise emission, the mechanical and control design and the system integration into the machine table, are presented in this paper. The achieved results of this research demonstrate the significance of active systems in machine tools. (C) 2010 CIRP.