METHOD FOR WELDING USING A WIRE-TYPE FILLER MATERIAL AND AT LEAST ONE LASER BEAM

Abstract

In a method for welding using a wire-shaped filler and at least one laser beam, the wire-shaped filler is advanced in the direction of the surface of the workpiece by a wire feed mechanism. The wire-shaped filler is successively fused during the feed movement thereof. The wire-shaped filler and the material are connected to an electrical voltage source and form an electrical circuit. The electrical voltage, the electrical current and/or the electrical resistance are measured and used as control variables for the wire feed movement and/or the power of the at least one laser beam. Use of the laser beam is modified when a predefined threshold value of the electrical voltage and/or of the electrical current are fallen short of or a predefined threshold value of the electrical resistance is exceeded.

Claims

1-9. (canceled)

10. A method for welding using a wire-shaped filler and at least one laser beam, which are directed at a surface of at least one workpiece to be processed, comprising: a wire-shaped filler being advanced in the direction of the surface of the workpiece by an accordingly designed wire feed mechanism, and wire-shaped filler being successively fused during the feed movement thereof in the area that is arranged directly above the particular surface, using the energy of the at least one laser beam, the wire-shaped filler and the material being connected to an electrical voltage source and forming an electrical circuit, the electrical voltage, the electrical current and/or the electrical resistance in the electrical circuit being measured and used as controlled variables for the wire feed movement and/or the power of the at least one laser beam, and the power with which the at least one laser beam is operated being reduced, or the at least one laser beam being switched off or not switched on, or the start, the stop or the abortion of the welding process being initiated, when a predefined threshold value of the electrical voltage and/or of the electrical current are fallen short of or a predefined threshold value of the electrical resistance is exceeded.

11. The method according to claim 10, wherein the at least one laser beam is switched off or not switched on when no electrical current flows in the electrical circuit or the electrical resistance has reached a value in the range of 10Ω to 1000Ω.

12. The method according to claim 10, wherein the first derivative of at least one of the control variables is determined in an electronic evaluation unit and, when the absolute value of the first derivative of the particular control variable exceeds a predefined threshold value, the power with which the at least one laser beam is operated is reduced or the at least one laser beam is switched off.

13. The method according to claim 10, wherein a first derivative of at least one of the control variables is determined in an electronic evaluation unit and, when the absolute value of the first derivative of the particular control variable exceeds a predefined threshold value, the wire feed is controlled.

14. The method according to claim 10, wherein the electrical voltage source is operated with a maximum electrical voltage of 48 V.

15. The method according to claim 10, wherein after the power with which the at least one laser beam is being operated has been reduced, or after the at least one laser beam has been switched off when carrying out a feed movement of the wire-shaped filler, either the power of the at least one laser beam is increased back to the normal operating power or the at least one laser beam is switched back on.

16. The method according to claim 10, wherein when a threshold value of the particular control variable(s) is fallen short or exceeded, the power with which the at least one laser beam is operated is reduced such that no fusion of wire-shaped filler occurs.

17. The method according to claim 10, wherein the power with which the at least one laser beam is operated or the at least one laser beam is reduced or switched off within no more than 100 ms.

18. The method according to claim 10, wherein after the power with which the at least one laser beam is being operated has been reduced, or after the at least one laser beam has been shut off, and a value of the particular control variable(s) which is above or below the particular threshold value has been reached, the power of the at least one laser beam is increased up to the normal operating power thereof, or the at least one laser beam is switched back on.

Description

[0024] FIG. 1 schematically shows an example of a device, which is suitable for carrying out the method according to the invention.

[0025] Wire-shaped filler 1 is moved by a wire feed mechanism 2 in the direction of a surface of a workpiece 3 through a wire guide 4. The wire guide is connected to a terminal of an electrical voltage source (not shown). The second terminal of the electrical voltage source is electrically conductively connected to the workpiece 3.

[0026] Moreover, a laser beam 5 is directed at the tip of the wire-shaped filler 1, which points in the direction of the workpiece surface, and material of the wire-shaped filler 1 is successively fused there, which is used for welding.

[0027] An electronic evaluation unit 6 is present between the connecting contacts of the electrical voltage source of the wire guide and the workpiece 3, which is designed to determine the electrical voltage, the electrical current and/or the electrical resistance in the electrical circuit and to use this as a controlled variable for the wire feed movement and/or for the power of the at least one laser beam 5, as is described in the general part of the description. For this purpose, the electronic evaluation and control unit 6 is connected via the lines 7 and 8 to the wire feed mechanism 2 or the laser radiation source or a controller of the laser radiation source (neither is shown) for influencing the wire feed movement or the power of the laser beam 5.