Development of a Tool Holder with In-Built Sensors to Measure Symptoms of Tool Wear

Tool wear is a very complex phenomenon which can lead to machine down time, product rejects and can also cause problems to personnel. High cutting force, excessive cutting temperature and tool vibration of considerable magnitude form indications of tool wear. In this investigation, an attempt was made to design and fabricate a tool holder with in-built sensors that can sense signals of cutting force, cutting temperature and tool vibration that form the symptoms of tool wear during turning of AISI 4340 steel having a hardness of 46HRC using multicoated hard metal inserts with sculptured rake face. Cutting experiments were conducted to check the validity of the indications of the tool holder with in-built sensors and from the results it was observed that the indications of the tool holder with in-built sensors matched well with the indications of the dynamometer. This scheme is simple in construction, cost effective and holds promise as a means for tool condition monitoring during automated turning operations.