| 摘要 |
PURPOSE:To always detect the sound of processing under a constant condition and to surely detect the processing state with a simple means by discriminating the processing state of a body to be machined by the output signal of an acoustic-electric transducer. CONSTITUTION:The laser beam sent from a processing energy source 1 is projected to the body 3 to be machined to carry out boring, and the processing sound is detected by the acoustic electric transducer 4 and is made into an electric signal Sa through an amplifier 5. The signal Sa is sampled by a gate sampling circuits 7, 8 and is inputted to an adder circuit 11, which adds a sampling signal Si to a sample/hold signal Sh to send a signal to an error amplifier 12. The amplifier 12 compares the signal sent from the adder circuit 11 with a reference signal to send an error signal Se to a control circuit 13, and a polarity discriminating circuit 14 sends the signal showing polarity to the control circuit 13. The control circuit 13 sends a control signal to a driving device 15 so that the magnitude of the error signal Se becomes zero, and drives a convergence lens system 2 to converge the laser beam to the optimum processing position. |
