REEZAYOSETSUHOHOOYOBISONOSOCHI

摘要

PURPOSE:To condense exactly a laser for working to a weld point and to perform welding with high accuracy by detecting the change in a weld line and the inside diameter of a pipe by a laser for detection and controlling a laser for working according to the detected information. CONSTITUTION:A laser 2 for detection from a laser oscillator 1 for detection is first condensed through a reflecting mirror 4 and a condensing system 11 to the inside circumferential surface of a pipe 7. Then the laser 2 is reflected there are returns to the direction where the laser is irradiated. A part of the laser is reflected by a dichroic mirror 3 and enters a detector 16. If the spot position of the laser 2 strikes the inside circumferential surface of the pipe, the laser is detected in a detector 16 by the reflection thereof but if said position strikes a notch part 20a, the laser is not detected. A mechanism 15 for moving the condensing system is actuated via a control device 19 by the signal from the detector 16. More specifically, the device 19 is inputted with the laser 2 and feeds a signal to the mechanism 15 after making prescribed calculation to move laterally a support 12 for the condensing system thereby controlling the position of the weld line so as to come to the condensing point of the laser 2. Said device stores the pipe and a condensing lens 5 and thereafter irradiates a laser 8 for working. Welding is thus accomplished.