TOOL WEAR MONITORING AT TURNING

A new method for automatic tool wear monitoring at turning has been developed based on the analysis of the continuous acoustic emission (machining noise) generated by the tool during machining. Different wear types (wear of tool flank face and tool chipping) result in changes in the different characteristic values of the noise signal. In case of a uniform abrasion of the insert, e.g., flank face or crater wear, an increased mean signal level is observed, whereas for microbreakage at the edge, an increase of the crest factor with nearly constant mean signal level is found. The burst-like signals from collision between chip and tool and from chip breakage have to be eliminated from analysis to avoid the distortion of the signal parameters of the continuous acoustic emission. This method should be well suited especially for monitoring of finishing processes (small depth of cut).