摘要:
During welding with high output power, the gaps between the pieces being joined may not exceed a maximal gap width. A process for laser beam welding is provided, which on the one hand ensures maintaining (not exceeding) a maximal gap width between the sheets and on the other hand makes possible a maximal utilization of the achievable welding speed. The sheets, prior to welding, are first spot welded, wherein they are clamped only during this spot welding in order to ensure the maintenance of a maximum gap width.
摘要:
In coated sheets the coating material often has a significantly lower melting point than the material of the sheet. Accordingly, when welding together this type of sheets, there may occur explosion-like evaporation of coating material, which significantly compromises the quality of the joint. For improving the joining quality it has already been proposed to provide a narrow gap between the sheets, through which the vaporized coating material can escape. The present invention provides a process and a device for simple and reliable checking the spacing of the sheets. This is done by a process and a device in which on at least one side of a first sheet topographical changes are produced projecting from the surface, the first sheet is positioned and clamped relative to a second sheet with the topographical changes projecting from the surface defining a minimal spacing between the two sheets through which spacing, during welding, vaporized products can escape, and wherein it is checked whether the two sheets are in contact with each other via the topographical changes projecting from the surface.
摘要:
A method for welding two metal parts from aluminum alloys with the steps: melting of the metal parts to be joined in a weld region through an energy input by means of a laser beam with the formation of a weld seam, smoothing the surface of the weld seam through a further energy input with partial melting of the weld seam in the region of the surface, wherein the further energy input is a defocused laser beam, of which the focal point is positioned in the beam direction in front of or behind the surface of the weld seam, wherein the defocused laser beam and the surface normal of a surface of the two metal parts to which the laser beam is applied, incorporate an angle of greater than or equal to 5 degrees, and a connecting arrangement welded with this method.
摘要:
A method for welding two metal parts from aluminium alloys with the steps: melting of the metal parts to be joined in a weld region through an energy input by means of a laser beam with the formation of a weld seam, smoothing the surface of the weld seam through a further energy input with partial melting of the weld seam in the region of the surface, wherein the further energy input is a defocused laser beam, of which the focal point is positioned in the beam direction in front of or behind the surface of the weld seam, wherein the defocused laser beam and the surface normal of a surface of the two metal parts to which the laser beam is applied, incorporate an angle of greater than or equal to 5 degrees, and a connecting arrangement welded with this method.
摘要:
In many cases, the coating material of coated sheet metal has a significantly lower boiling point than the sheet metal material. Thus, an explosive vaporization of coating material can occur when sheet metal of this type is joined by welding, negatively affecting the quality of the connection. To improve the connection quality, narrow gaps are created by means of spacers, allowing the vaporized coating material to escape through said gaps. The spacers are created e.g. by the laser radiation of the sheet metal. The aim of the invention is to reduce the variations in distance between the sheet metal sheets by the appropriate shaping of the spacers. This is achieved by a method, in which the laser beam executes a movement comprising transverse and longitudinal components through and/or around the center of its processing surface. This creates a topographical modification with a spherical form, i.e. with an apex radius that is greater than the height of said topographical modification.
摘要:
The application of anti-corrosion base coating by cataphoretic painting (KTL) is well known in manufacturing automobile body parts. However, the cataphoretic paint can penetrate only incompletely or possibly not at all into the gap in the contact areas of the components joined to each other. This type of gap is conventionally sealed following cataphoretic painting, in order to ensure corrosion protection for the entire assembly. The present invention makes it possible to dispense with the sealing in the production of an assembly of joined conductive components and nevertheless to ensure a sufficient corrosion protection. By introducing topographic changes in the components projecting from their surface in the known contact areas and then joining these components, they are spaced apart by the projecting topographic changes in such a manner that during cataphoretic painting the paint wets the entire surface of the assembly.
摘要:
With many coated plates, in particular zinc (galvanized) and organic coated sheet metal as are employed in the automobile industry, the coating material has a significantly lower boiling point than the melting point of the sheet metal material. Therefore in the case of laser welding of this type of sheet metal with zero gap in the overlap abutment area to a explosion like vaporization of coating material, which take along or entrain molten sheet metal material and strongly damage the quality of the joint. For improving the connection it has already been proposed that no gap be provided between the sheets, but rather these are positioned directly over each other and then first by means of first laser beam to warm until vaporization of the coating and subsequently to weld the uncoated sheets by means of a second laser beam. The disadvantage therein is above all the elaborate apparatus set up or complexity for the two required optical systems. The task of the present invention is thus comprised therein, to reduce the apparatus complexity and at the same time to at least maintain the work quality, preferably to improve it. The task is solved by a process in which by means of a signal laser beam first all plates can be uncoated and thereafter the plates are welded along the uncoated area with the same laser beam.
摘要:
With many coated sheets, in particular zinc-coated sheets as used in the automobile industry, the coating material has a much lower boiling point than the material of the sheet. On welding said sheets together the above leads to explosive evaporation of coating material which seriously affects the quality of the connection. In order to improve the quality of the connection it has already been disclosed that narrow gaps between the sheets can be produced by means of spacers, through which the coating material can escape. The spacers can be produced for example, by means of laser bombardment of the sheets. A disadvantage is the relatively long time necessary for machining, which causes large costs in particular for serial production. The aim of the invention is to reduce the time necessary for machining the sheets whilst at least maintaining, preferably improving the quality of the machining. Said aim is achieved, by means of a method, whereby the laser beam is deflected onto the surface by means of a scanner device. A scanner device is a particularly rapid and flexible beam-diverting device. The above permits a reduction in the machining time by a factor of 10 without reducing the quality of the machining.
摘要:
A laser weld seam with reduced end crater and a process for production thereof are provided. The seam end is provided at a location, which exhibits a excessive material relative to the surrounding surface or thereby, that the seam towards the seam end exhibits a counter-running direction change of its preferred direction, which is designed in such a manner, that as a consequence of the interaction between cooling forward and counter-running seam a backfill of the melt towards the seam end occurs.
摘要:
The application of anti-corrosion base coating by cataphoretic painting (KTL) is well known in manufacturing automobile body parts. However the cataphoretic paint can penetrate only incompletely or possibly not at all into the gap in the contact areas of the components joined to each other. This type of gap is conventionally scaled following cataphoretic painting, in order to ensure corrosion protection for the entire assembly. The present invention makes it possible to dispense with the sealing in the production of an assembly of joined conductive components and nevertheless to ensure a sufficient corrosion protection. By introducing topographic changes in the components projecting from their surface in the known contact areas and then joining these components, they are spaced apart by the projecting topographic changes in such a manner that during cataphoretic painting the paint wets the entire surface of the assembly.