Tool condition monitoring in end milling using a torque-based sensorized toolholder

Abstract

The automation of metal-cutting processes needs robust sensing systems and monitoring methods, able to detect the tool condition on-line. In milling operations, powerful tool-monitoring solutions are based on cutting force measurement, performed by using sensorized toolholders. This paper deals with a particular application of this method, consisting of acquiring the cutting torque signal in end milling by means of a commercial low-cost rotating dynamometer, usually applied in other machining operations. The dynamometer is directly integrated into a toolholder body, properly modified in order to obtain the needed specifications. The proposed solution is not invasive and, therefore, avoids a strong reduction in mechanical properties of the tool and the toolholder set. Preliminary cutting tests were performed in order to detect if the acquired signal can be successfully used to recognize on-line the status of the cutting tool. On-line threshold-based monitoring strategies were also proposed, and significant indicators were considered for tool condition monitoring in milling.