WO2018041463A1 - Method and device for welding joint partners - Google Patents

Abstract

The invention relates to a method and to a device for welding at least two joint partners (20, 22) to form a welding seam using both a laser beam and an electric arc beam (18), which are provided by a hybrid welding device (10). According to the invention, to achieve a better energy input in the joint region and an optimised welding process on the gap to be bridged between the joint partners to be welded, a single focal point (32) of the laser beam (18) is focused onto the joint region (26) and the focal point is adjusted relative to the displacement movement of the hybrid welding device (10) and transverse to and/or in the direction of displacement (11) of the hybrid welding device.

Description

 description

Method and device for welding joining partners

The invention relates to a method for welding at least two joining partners to form a weld by means of both laser and arc beam, which are provided by a hybrid welding device. The invention also relates to a hybrid welding apparatus comprising a laser and an arc welding apparatus, wherein laser radiation emitted by the laser can be imaged via at least one imaging optical system on the joining region of joining partners to be welded to form a weld seam.

Laser-arc hybrid welding is a welding process by means of which joining partners are welded by both laser beam welding and electric arc welding. In this case, both the laser beam and the arc is aligned with a weld zone, whereby a molten bath is generated, which solidifies to form a weld. By a suitable hybrid welding process the advantages of both methods are used.

Laser welding is used in industry in the field of higher laser power and primarily where material thicknesses of more than 3 mm have to be welded. Arc welding, in particular gas metal arc welding (MIG), which includes metal inert gas (MIG) welding and active gas (MAG) welding, provides high welding performance with low energy input. By means of the laser is a high welding speed and a reached large welding depth. The arc welding enables an increase of the A-measure and a good gap bridgeability. The combination of methods offers improved weld geometry, gap bridgeability, and coupling.

For laser welding imaging optics can be used, which produce a double focus. The double focus is fixed.

There is also the possibility that the foci having a fixed distance from one another are moved meander-like along the joining region in which the weld is produced (EP 0 823 304 A1).

Laser MSG hybrid methods are e.g. B. DE 10 2010 028 745 B4 or DE 11 2013 003 670 T5. In the corresponding method, a focus is imaged in the joining region by means of an imaging optic, which is moved together with the device.

The present invention has the object of developing a method and an apparatus of the type mentioned above so that an improved compared to the prior art energy input takes place in the joining area. Also, an optimization of the welding process to be bridged gap between the joining partners to be welded.

In terms of the method, the object is essentially achieved by imaging a single focus on the joining region of the laser beam and by adjusting the focus relative to the movement of the hybrid welding device and transversely to and / or in the direction of movement of the hybrid welding device.

In particular, it is provided that the focus is adjusted at least transversely to the direction of travel, with an adaptation to the gap width between the joining partners can be done. The focus is scanned to move to the joining area, wherein a movement can take place both in and across the direction of travel of the device. By changing the scan width, the resulting weld pool can be changed according to the seam formation and depth requirements. A controlled bridging of gap tolerances can be achieved. By integrating the scanner control in the hybrid welding device, a web-optimized welding of joining parts, in particular construction components, with different seam requirements is possible.

In particular, it is provided that the laser beam is moved to the joining region such that the focus moved to the joining region sweeps over a circular or circular surface whose diameter is greater than that of the focus. This results in a continuous "stirring process" in the melt with the consequence of a quiet welding behavior, since the outgassing of the melt can be actively adjusted.

It should be emphasized and invented that movement of the laser beam across the joining area is controlled or regulated as a function of the weld seam to be formed.

In particular, the distance between the joining partners in the joint area, ie in particular the distance from edges to be welded, is determined. Depending on the determined value, the deflection of the laser beam takes place transversely to the direction of travel of the hybrid welding device.

In particular, the invention provides that the distance is measured by means of a sensor which is moved synchronously with the hybrid welding device and is connected in particular to the hybrid welding device.

A hybrid welding device of the type mentioned above is characterized in particular by the fact that the imaging optics depicts a single focus and is designed such that the focus relative to the movement of the Hybrid welding device and is movable transversely and / or in the direction of travel of the hybrid welding device.

Additionally or alternatively, the invention is distinguished by the fact that scan width of the focus is regulatable or controllable transversely to the travel direction of the hybrid welding device as a function of the width of the weld to be joined and the gap to be joined.

Another feature of the invention provides that the imaging optics comprises at least one adjustable relative to the travel movement of the hybrid welding optical element, which is adjustable to an X and / or Y-axis. The partners to be joined themselves are aligned to a plane spanned by the X and Y axes.

The imaging optics comprises at least one parabolic reflector. In particular, it is provided that the imaging optics comprises at least two reflectors from the group simulation game, parabolic mirror, wherein preferably each reflector is adjustable relative to the movement of the hybrid welding device.

Further details, advantages and features of the invention will become apparent not only from the claims, the features to be taken these - alone and / or in combination - but also from the drawing to be taken preferred embodiments.

Show it:

1 is a schematic diagram of a hybrid welding device,

Fig. 2 is a schematic diagram of an arrangement for scanning moving a

 laser beam

3 is a schematic diagram of components to be welded, 4 shows a further basic illustration of an arrangement for scanning a laser beam,

Fig. 5 shows an alternative embodiment to that of Figs. 4 and

Fig. 6 is a schematic diagram of a welding operation with the

 Hybrid welding device according to FIG. 1.

With reference to the figures, in which the same reference numerals are used in principle for the same elements, the hybrid welding method according to the invention is to be explained, with which there is the possibility to adjust the energy input in the joining region of joining partners to be welded to the desired extent, with a controlled bridging gap tolerances is made possible.

For welding, a hybrid welding apparatus 10 is used, which can be seen purely in principle from FIG. The hybrid welding apparatus 10 includes a laser 12 and an arc welding apparatus 14. The arc welding apparatus 12 may be a metal arc welding apparatus having a consumable welding wire 16 tracked by a motor. At the same time, the wire feed supplies the welding point with protective or mixed gas via a nozzle. In that regard, reference is made to well-known techniques.

With the laser 12, a laser beam 18 is focused on the joint partners 20, 22 to be welded in the region of the joining region. The combination of laser welding and gas metal arc welding makes use of the advantages of both methods. High welding speeds are achieved with low energy input.

The hybrid welding device 10 is to be welded along the joint line or joining region 26, in which a weld seam is to be formed, in order to weld the joining partners 20, 22 - hereinafter referred to as workpieces for short. The hybrid welding apparatus 10 may further include a sensor 24 through which the width of the gap between the workpieces 20, 22 is determined to control the scanning motion of the laser beam 18 depending on the gap width, as explained below.

In order for the focused laser beam 18, i. In order to be able to scan the focus imaged in the region of the joining region 26 or the joint line to the joining region 26, according to FIG. 2 a parabolic mirror 28 is used on which the laser raw beam 30 impinges, in order then to be focused beam 18 on the region of the joint line to be focused, the focus in the direction of travel in front of the welding wire 16 on the joining region 26.

According to the illustration according to FIG. 3, the focused laser beam 18, that is to say the focus 32 transversely to the joint line 26, along which the hybrid welding device 10 is moved, scans the parabolic mirror 28 about the X-axis. and is moved. There is the possibility that the scan width is set as a function of the width of the gap 34 between the workpieces 20, 22. For this purpose, the gap width can be determined by means of the sensor 24 and the scan width of the focus 32 can be varied as a function of the gap width.

However, if the gap width is known, the corresponding data can also be entered into the control of the laser 12.

However, it is not only possible to move the laser beam back and forth in the X-direction, ie transversely to the joint line 26, but also in the direction of movement (arrow 11) of the hybrid welding device 10, as will be explained with reference to FIGS.

4, the laser beam 30 is deflected via a plane mirror 36 to a parabolic mirror 38, via which the raw beam 30 is focused onto the joining region. There is the possibility that the plane mirror 36 oscillates about the Y-axis and the parabolic mirror about the X-axis, wherein the Workpieces 20, 22 aligned to the XY plane, which is spanned by the X and Y axis, as is apparent from the figures in principle.

Thus, as shown in FIG. 6, the focused laser beam 18 and thus the focus 32 can be moved back and forth both transversely to the joint line 26 and in its longitudinal direction.

Instead of the plane mirror 36 this can also be replaced by a parabolic mirror 40, as is apparent from Fig. 5. For this purpose, a laser beam emitted by a fiber end 42 of a fiber laser is used on the parabolic mirror 40.

It should also be clarified with reference to FIG. 6 that the focus 32 is scanned to the joint line 26 in such a way that a circle is swept over, thereby enabling a continuous stirring process in the melt. This leads to a quiet welding behavior, since the outgassing of the melt can be actively adjusted.

The quasi circular movement of the focus should be symbolized by the round arrow 44 in FIG.

Suitable lasers are C0 ₂ lasers, disc and fiber lasers. The focus diameter should preferably be in the range of 0.1 mm to 0.5 mm. The scan width, ie the distance between the reversal points of the focus movement can be between 0.1 mm and 3.0 mm. The movement of the laser beam during scanning is preferably carried out with a frequency between 100 Hz and 1000 Hz. The power of the laser beam can be in the range of 1,000 watts and 1,200 watts.

In particular, all butt and overlap geometries, as well as all forms of fillet welds, come into consideration as seam geometries to be welded. Furthermore, the process is suitable for all weldable metals and non-ferrous metals.

Claims

Process and apparatus for welding joining partners Method for welding at least two joining partners (20, 22) to form a weld by means of both laser and arc beam (18) provided by a hybrid welding device (10), characterized in that  in that a single focus (32) is imaged by the laser beam (18) on the joining region (26) and that the focus is adjusted relative to the travel movement of the hybrid welding device (10) and transversely to and / or in the direction of travel (11) of the hybrid welding device. 2. The method according to claim 1,  characterized ,  in that the laser beam (18) is moved towards the joining region (26) in such a way that the focus (32) moved to the joining region covers a circular or circular surface whose diameter is greater than that of the focus. 3. The method according to claim 1 or 2,  characterized , that movement of the laser beam (28) is controlled or regulated transversely to the joining region (26) as a function of the weld seam to be formed. 4. The method according to at least one of the preceding claims, characterized  in that the distance between the joining partners (20, 22) is determined in their edges or regions to be welded, and as a function of the determined value deflection of the laser beam (28) transversely to the direction of travel (11) of the hybrid welding device (10). 5. The method according to at least one of the preceding claims,  characterized ,  the distance is measured by means of a sensor (24) moving synchronously with the hybrid welding device (10), in particular connected to the hybrid welding device. 6. hybrid welding arrangement (10), comprising a laser and an arc welding device (12, 14), wherein laser radiation emitted by the laser (28) via at least one imaging optics (28, 36, 38, 40) on joining region (26) of welding joining partners (20, 22) is formed to form a weld,  characterized ,  in that the imaging optics (28, 36, 38, 40) depicts a single focus (32) and is designed such that the focus is movable relative to the travel movement of the hybrid welding device (10) and transversely and / or in the direction of travel (11) of the hybrid welding device , 7. hybrid welding arrangement according to claim 6,  characterized , in that the scan width of the focus (32) is controllable or controllable transversely to the travel direction (11) of the hybrid welding device (10) as a function of the width of the weld to be joined by the partners (20, 22) or the gap extending between the joining partners. 8. hybrid welding arrangement according to claim 6 or 7,  characterized ,  in that the imaging optics comprise at least one optical element (28, 36, 38, 40) which can be displaced relative to the displacement movement of the hybrid welding device (10) and which is adjustable to an X and / or Y axis. 9. hybrid welding arrangement according to at least one of claims 6 to 8,  characterized ,  in that the imaging optics comprise at least one parabolic reflector (38, 40). 10. hybrid welding arrangement according to at least one of claims 6 to 9,  characterized ,  in that the imaging optics comprises at least two reflectors from the group of plane mirrors (36), parabolic mirrors (38, 40), wherein preferably each reflector is adjustable relative to the travel movement of the hybrid welding device (10).