Verfahren und Vorrichtung zum Verschweissen von verzinkten Stahlblechen mittels Laserstrahlen

摘要

The invention concerns welding of metal (esp. galvanised steel), sheets (1, 2), according to which clamping forces are applied by means of an accompanying clamping element (5), to the sheets in the immediate vicinity of welding spot of the laser beam used for joining these sheets. The focus (4) of the laser beam is preceded by directed deformation of the top sheet (1) until it makes line contact with the bottom sheet (2) for subsequent welding. An oscillatable piezoelement (8) is located between the clamping unit (6) and the clamping element (5) for producing an intermittent pressure on the latter during the clamping process. The directed deformation of the top sheet with plastic and elastic constituents is used to reduce the gap between the sheets. The intermittent line contact between sheets produced by the oscillating piezoelement leaves side pockets for escaping gas. The stroke of the piezoelement (8) is about 0.3 mm, while the forces exerted by it lie within the kN range.