| 摘要 |
<p>The cone of a laser beam is focused straight above the joining line and the image of the weld zone is digitized. This image is compared with a reference image and the weld head is displaced immediately. A method for the fabrication of a tubular metal envelope comprises the following steps:- a) the permanent surveillance, by means of an image taker (72), of the weld zone (74) in which the cone (64) of the laser beam (42) is focused straight above the joining line (46) of the edges (32, 34) of the metal ribbon (26); b) digitizing the image of the weld zone (74) furnished by the image taker (72); c) comparing the image of the weld zone (74) with the record of a reference image of the same weld zone (74); and d) ordering the displacement of the welding head (56) immediately when a difference greater than a determined threshold has been detected between the image provided by the image taker (72) and the reference image. The device used to put this method into service is also claimed.</p> |
