Method of and apparatus for machining workpieces with a laser beam

摘要

PCT No. PCT/DE92/00115 Sec. 371 Date Aug. 19, 1993 Sec. 102(e) Date Aug. 19, 1993 PCT Filed Feb. 19, 1992 PCT Pub. No. WO92/14578 PCT Pub. Date Sep. 3, 1992.A method of machining workpieces with a laser beam wherein the machining process, in particular the melting depth or the through-melting distance is monitored by detecting an optical and/or acoustical signal created by an unshielded laser-induced plasma or vapor. In order to receive monitoring date which as much as possible is independent of signal variations in the process the signals are subjected to a frequency analysis and the average amplitudes (Ax, Ay) of two different frequency bands (x, y) of the analyzed frequencies are used with a predetermined calculation function to determine a rating value (B).