What Sound Can Be Expected From a Worn Tool?

Abstract

This paper describes an electronic-mechanical system which utilizes sonic signals to detect the degree of cutting edge wear in metalworking tools and automatically trigger a cutting edge change. A packaged electronic unit reads out sonic vibrations from an instrumented machine-tool workpiece cutting-tool system to determine degree of cutting edge wear during a turning cut. At a predetermined comparative sonic ratio, the electronic unit commands stoppage of the machine tool feed, retraction of the tool and automatic index of the cemented carbide insert to the next good cutting edge. The latter function is performed by a prototype mechanical device. The paper describes the system and cites data generated during use of the sonic detection system with five grades of cemented carbide cutting AISI 1045 steel. Results under varying cutting conditions are reported. The authors speculate on the possibility of combining such a wear detection and cutting edge indexing arrangement with a computer to provide a complete system for optimum productivity and economy in a completely automatic operation.