A SYSTEM FOR MONITORING CUTTING-TOOL SPONTANEOUS FAILURE BASED ON STRESS ESTIMATION

Cutting tool spontaneous failure such as, edge fracture and chipping are common phenomena in the metal cutting process, especially when difficult workpiece materials which have poor cutibility are met in the machining process. The tool failures are often caused by high mechanical and thermal stresses acting in it. Monitoring stresses acting in a cutting edge during machining process can provide more reliable means to monitor and to predict tool spontaneous failure. In this paper, The design and implementation of a real time monitoring system has been introduced intending to monitor the spontaneous failure of a cutting tool in a turning process. The system is based on a VME computer system and a real time kernel. The system includes a high speed data acquisition subsystem and a graphic presentation subsystem. The strategy for monitoring is based on the estimation of stresses acting in a cutting tool. On-line stress estimations are obtained according to in-process measured cutting forces, load functions and cutting parameters and cutting tool geometry.