Verfahren und Vorrichtung zum Entgasen von mindestens zwei aufeinander gespannten, einen Beschichtungswerkstoff aufweisenden Blechen beim Laserschweißen

摘要

A method for degassing coated metal sheets in laser welding involves subjecting the stacked sheets to contact pressure from elements (6, 7) moving ahead of the laser beam so that the heat generated by the laser between the focus and the elements (6, 7) causes arching of the sheets to form a moving cavity in which the gas from the evaporating coating material is taken up and then expelled between the sheets. A method for degassing at least two coated metal sheets clamped over one another in laser welding, where the sheets are gripped by means of contact pressure from an element moving with the laser beam. In this method, the pressing elements (6, 7) move ahead of the laser beam (4) in such a way that the heat generated by the laser beam between the focus (5) of the beam and the elements (6, 7) causes arching (8) of one or all of the sheets (2, 3) to form an outward-pointing cavity in which the gases from the evaporating coating material are taken up and then passed out between the sheets (2, 3); this cavity moves in front of the laser beam in the welding/advance direction (arrow A). An independent claim is also included for a device for carrying out this method in which the contact elements (6, 7) are premounted at a distance (X and Y respectively) from the focus (5) of the laser beam (4).