METHOD AND DEVICE FOR WELDING TWO THERMOPLASTIC PARTS TO BE JOINED ALONG A WELD SEAM BY MEANS OF A LASER.

摘要

A system for welding two thermoplastic parts to be joined (8, 9) along a weld seam (3) by means of a laser works with a laser beam (2) which - is controlled in its beam direction (R) within a working area (A) by a control method using control data corresponding to the weld seam profile to be produced, - has in the region around its focal point (f) that brings about the welding a beam dimension, in particular a beam diameter (d), that in the joining plane (F) is smaller than the target width (B) of the weld seam (S) to be produced and also is dependent on the angle of incidence (W) of the laser beam (2) on the joining plane (F) and/or on the position of the focal point (f) in relation to the joining plane (F), - is moved in a first movement component in a main advancing direction (H) along the path of the weld seam (S) to be produced, - is moved in a second, oscillating movement component, overlaid on the first, to cover the weld seam width (B) transversely to the main advancing direction (H) with an oscillation amplitude swing (OAW), and - is set by a control method in its oscillation amplitude swing (OAW) in inverse dependence on the beam dimension in the joining plane (F), preferably the beam diameter (d), in such a way that the width of the beam area passed over by the laser beam (2) in the transverse direction with respect to the main advancing direction (H) corresponds to the target width (B) of the weld seam (S).