Abstract
In high-precision machining, knowing the precise diameter and length of the cutting tools and the correct setting of the coordinate system are very important. In general, the relative distance between the cutting edge and workpiece has to be measured using two measuring instruments in numerically controlled machine tools such as machining centers (MCs). The machining accuracy is affected by indirect errors in the measuring instrument and the error in the relative distance between the cutting edge and the workpiece. In order to eliminate this problem, this paper proposes an on-machine measurement system. This system uses an acoustic emission (AE) technique to precisely detect the cutting edge position when the cutting tool is in contact with the workpiece in real cutting conditions. This measurement system is installed into MCs and evaluated with different feed speeds and approach directions of the cutting tool with respect to the workpiece. Through this system, we successfully minimized the contact depth of the cutting edge and the workpiece, which also facilitated detection of the cutting edge position. The responsiveness of AE signals and measurement system were investigated and found to be suitable with few limitations.
