METHOD AND DEVICE FOR PROCESSING AN ELECTRIC CONDUCTOR

Description

[0001] The subject matter relates to a method and a device for processing an electrical conductor. In particular, the subject matter relates to a method for processing a conductor end, in particular for preparing a conductor end for subsequent welding to a connecting part. Furthermore, the subject matter relates to a method for welding a conductor to a connecting part.

[0002] The welding of stranded conductors to connecting parts, such as flat parts, cable lugs, terminal sleeves, or the like, is well known. The most common welding processes include resistance welding, friction welding, and laser welding. Especially with laser welding, the end face of the stranded conductor must be as flat as possible to ensure a butt weld between the conductor end and a connecting part.

[0003] A conductor to be welded within the meaning of this application is a stranded conductor. This is formed from a plurality of strands. The strands can be untwisted, twisted, stranded, woven, or otherwise arranged in an ordered or random manner. In particular, a braided conductor made of strands can also be used. The stranded conductor can have a flat or round conductor cross-section.

[0004] To prepare for the welding process, a cable is preferably stripped at one end, leaving a bare conductor. Alternatively, the cable can be stripped in the middle, leaving the insulation on both sides of the stripped areas. If the conductor is then severed in the stripped area, a bare conductor end is also present.

[0005] The stranded wire ends located in the stripped area must be shaped to a desired cross-sectional profile for the subsequent welding process, especially for a butt joint. This profile is often congruent with the profile of the connecting part to be welded. This can be a polygonal, particularly rectangular or square profile.

[0006] In conventional processes, the strands are compacted at the conductor end, meaning they are mechanically pressed together, reducing or eliminating gaps between the strands. This process creates a disordered strand pattern at the end face to be welded, meaning the individual strands protrude or recede from an imaginary end face by varying distances. Thus, a flat end face that could be welded using laser welding is not formed.

[0007] The different protruding individual strands result in only small, discontinuous contact areas between the strand ends and the connecting part in a butt joint, as only some of the strands protrude far enough to come into contact with the connecting part. As only a few strands are in direct contact with the connecting part, a subsequent laser welding process may result in insufficient material being available to weld to create a continuous weld seam. In addition, direct contact only occurs between individual strands and the connecting part, and the cross-sectional area of ​​the weld seam is reduced and undefined compared to the cross-sectional area of ​​the connecting part. This is disadvantageous both in terms of the long-term mechanical stability of the connection and in terms of the electrical contact resistance.In particular, due to increased electrical contact resistance, there is increased Joule losses and thus increased heat input, which can ultimately lead to damage to the weld seam.

[0008] To create a continuous laser weld seam with a sufficiently large joining surface, it is therefore necessary to deburr the end face of the compacted strands using suitable manufacturing processes. Today, this is done by milling, sawing, or punching the already compacted strands at the conductor end, creating a flat end face. This flat end face provides a sufficiently large and reliable joining surface to enable welding to a connecting component.

[0009] A disadvantage of the known method is the multi-step conductor preparation process involving various tools. The conductor must be provided bare, meaning that in the case of a cable, the conductor end must be stripped with a first tool. The strands must then be compacted at one end face with a second tool. In a subsequent processing step, the end face must be deburred with a third tool, as described above, to create a flat joining surface. These multiple steps involving the various tools result in significant additional costs for a laser weld compared to, for example, a resistance weld.

[0010] US 2010 / 0270275 A1 relates to a method for welding an electrode and a cable core together by irradiation with a laser beam.

[0011] The object was now to prepare a conductor end for laser welding with as few work steps as possible.

[0012] It has been recognized that the laser beam source can be used to carry out both the compaction step and the end face preparation step, so that two different tools do not have to be used to process the conductor end, as was previously the case, but that the conductor end can be completely prepared for welding and, if necessary, subsequently welded using a single tool.

[0013] In this context, it is therefore proposed to provide a bare conductor end of a stranded conductor. A conductor end is an area at the front end of the conductor. If the conductor is in a cable, the insulation at the cable end can be removed, leaving the bare conductor on the stripped cable.

[0014] It is further proposed that the strands of the bare conductor end are at least partially encompassed by gripping jaws in a circumferential manner. Gripping jaws can be moved relative to one another, towards one another, and away from one another. Gripping jaws can be designed in the form of gripping arms, side shifters, or the like. Gripping jaws can be multi-part, in particular two-, three-, or four-part. The gripping jaws can be part of a gripping device. The gripping jaws can, as will be shown below, be part of a laser welding device and, for example, be combined in a device together with a laser beam source. The gripping jaws encompass the conductor end at least partially, preferably completely, circumferentially. The gripping jaws encompass the strands of a frontal conductor end, which was provided bare, in order to subsequently compact the strands.When gripping, the gripping jaws preferably grasp all strands of the conductor end. When gripping, the strands are preferably gripped in a ring shape.

[0015] The gripping jaws are then moved towards each other so that the strands located between the gripping jaws are mechanically compressed in a radial direction. The strands are pressed together so that gaps between the strands are reduced, minimized, and in particular eliminated. The gripping jaws at least partially compact the encircling strands, with compaction levels of over 90% being possible. In the non-compacted state, there are gaps between the strands that are filled with air, for example. Compacting moves the strands towards each other and the gaps are reduced. The ratio between material of strands and material without strands can be understood as the degree of compaction. This is preferably over 90%, more preferably over 95%.

[0016] As already explained at the beginning, a laser beam source is already provided for laser welding. This laser beam source can now be used to weld the compacted strands together in the area of ​​the gripping jaws through the gripping jaws. The laser beam source can thus already be used to at least partially join the compacted conductor ends together in a material-to-material bond. The strands can be at least partially melted at least on their surfaces by the laser beam source through the gripping jaws, so that the strands are at least partially welded together at least on their surfaces. This creates a weld node while the strands are still pressed together by the gripping jaws.Because the laser beam source welds the strands together through the gripping jaws, the strands are spatially fixed relative to each other by the gripping jaws, resulting in a flat weld pattern. The relative arrangement of the strands is fixed. This arrangement remains unchanged even when the gripping jaws are removed.

[0017] According to one embodiment, it is proposed that the gripping jaws, at least in welding areas, be formed from a material that is at least partially translucent to a laser beam emerging from the laser beam source. A welding area can be an area in which the strands are welded while being encompassed by the gripping jaws. The gripping jaws can be designed such that, at least in the welding areas, they are formed from a material that is translucent to the laser beam. The laser beam source can be adjusted such that a focal point on the strands lies behind the gripping jaws, thus ensuring that the required welding temperature is reached on the strands.

[0018] The strands are welded together through the gripping jaws, in particular through the translucent material, and form a welded node, which can then be processed as will be described below.

[0019] The term "through the gripper jaws" can also be understood to mean that window-like recesses are provided in the gripper jaws within the welding areas. These window-like recesses can be continuous recesses. The gripper jaws are then provided with a recess through which the laser beam from the laser beam source can directly impinge on the strands. This means that the laser beam does not have to pass through the material of the gripper jaws, but impinges directly on the strands. In both cases, a material bond is created between the strands in the welding area.

[0020] According to one embodiment, it is proposed that the gripping jaws grip the conductor end at one end. The end is thus mechanically fixed by the gripping jaws, and the laser beam from the laser beam source can at least partially weld the strands together through the gripping jaws, as described above. At the end, the strands are fixed to one another by the gripping jaws, and a reliable weld seam can be formed.

[0021] As already explained, the gripping jaws can grip around the strands. The gripping jaws can grip around the strands in a ring shape, preferably in a closed ring. The recesses or the translucent material can be arranged on the circumferential surface of the gripping jaws. The laser beam can strike the strands in a radial direction through the gripping jaws and weld them together at least partially. In particular, at least the peripheral strands, i.e. the strands located on the outer surface of the stranded conductor, are welded together. However, it is also preferred that the strands located further inside can also be at least partially welded together due to the energy input by the laser beam. The strands can also be welded together at the end faces.

[0022] According to one embodiment, it is proposed that the strands are compacted into a polygonal, in particular rectangular, cross-sectional profile using the gripping jaws. The stranded conductor can also be a round conductor. With the help of the gripping jaws, the cross-sectional profile of the stranded conductor can be changed in the region of the gripping jaws. In particular, a polygonal, preferably rectangular or square cross-sectional profile can be produced. It is preferred if the cross-sectional profile achieved by compacting is geometrically similar or congruent to the cross-sectional profile of the connecting part to be welded. In particular, in the case of a butt joint, the cross-sectional profiles of the adjoining surfaces that are welded together can be geometrically similar or congruent to one another.

[0023] According to one embodiment, it is proposed that the compacted strands are welded together with the aid of the laser beam source on opposing jaws of the gripping jaws through the gripping jaws. As already explained, the laser beam can impinge on the strands in a radial direction. In order to ensure that the weld node is as compact as possible, it is proposed that the laser beam welds the strands through the gripping jaws not only on one side of the gripping jaws, but also on opposite sides of the gripping jaws. It is also preferred that a welding area is provided on each gripping jaw, so that the strands are at least partially welded together on all side surfaces of the compacted weld node.

[0024] According to one embodiment, it is proposed that at least two welding areas be arranged on the gripping jaws, spaced apart from one another in the longitudinal direction of the stranded conductor. The conductor extends along a longitudinal axis and has a longitudinal direction. Starting from the end face, the conductor extends in the longitudinal direction. The welding areas on the gripping jaws can be provided on a gripping jaw, spaced apart from one another in this longitudinal direction. At least two spaced-apart welding areas are proposed. The additional welding areas achieve increased mechanical stability of the weld node after welding.

[0025] As already explained, the strands are to be compacted by the gripping jaws. This compaction can be optimized by exciting the gripping jaws with vibrations after gripping, during the compaction process. The vibration of the gripping jaws, particularly with high-frequency vibrations, can break up the loose connections between the strands, whether random, ordered, twisted, or stranded. The vibrations lead to the strands being brought into an optimized order relationship with one another, so that gaps between the strands are reduced, minimized, or eliminated. The vibration excitation also leads to the strands being more easily plastically deformed, so that the compacted area of ​​the strands is plastically deformed, forming a compacted node that is subsequently suitable for laser welding.

[0026] According to the invention, the compacted, welded strands are deburred on their ends after welding using a laser beam source. As already explained at the beginning, due to the arrangement of the strands within the stranded conductor (e.g., loose, random, ordered, twisted, or stranded), when these strands are compacted, their strand ends protrude differently from an imaginary end face. To achieve a flat end face, it is proposed to deburr the welded strands with the laser beam source. In this process, the laser of the laser beam source removes the strand material that protrudes beyond the imaginary end face, and an actual end face is created on the imaginary end face. Laser deburring as such is known and will therefore not be described in detail.

[0027] It is particularly advantageous if welding and deburring are carried out using the same laser beam source. As already explained at the beginning, it is particularly advantageous if compacting and deburring could take place in one and the same tool. The same laser beam source can be used for this. It is possible to refocus the laser beam from this laser beam source according to the respective requirements. Laser beam sources with more than one, preferably two or three, focus points that can be variably adjusted are known. It is therefore conceivable that a first focus point is selected for welding the compacted strands and a second focus point is selected for the subsequent deburring. One and the same laser beam source can thus be used for two different process steps, which is very advantageous for the process.

[0028] According to one embodiment, it is proposed that an end face of the stranded conductor has a flatness of a maximum of 1 mm, preferably a maximum of 0.5 mm, after deburring. Flatness is a measure of the deviation of a surface from a reference plane. The reference plane is preferably perpendicular to the longitudinal axis of the conductor. A maximum deviation of the end face from the reference plane is 1 mm with a maximum flatness of 1 mm. The flatter the end face, the easier it is to apply to the connecting part and butt weld it to this. In particular, in butt joints, the deburred end face is applied to the connecting part and then welded to the connecting part. The high flatness of the end face results in a large contact area.On the one hand, this favors the welding process, as it is very even, and on the other hand, the welded area is sufficiently large to keep the transition resistance at the weld node as low as possible.

[0029] According to one embodiment, it is proposed that the strands are encompassed by a cutting device before compacting and are severed substantially flatly at one end face.

[0030] In addition to deburring, preferably laser deburring after compaction and welding, it is also possible to produce a flat end face prior to actual welding. For this purpose, it is proposed that a conductor be bare in one area. For this purpose, a cable can be freed of insulation in an end area or a middle area, as already described. The conductor is then gripped by gripping jaws. These can be gripping jaws of a cutting device or the gripping jaws mentioned above. The gripping jaws can be spaced apart from one another in the longitudinal direction so that two adjacent areas with a gap are formed by the gripping jaws in the longitudinal direction of the conductor, and cutting can be carried out along this gap. It is also possible for the gripping jaws to grip the conductor and for a cut to be made on one end face of the gripping jaws.

[0031] In both of the above-mentioned cases, it is proposed that the individual strands be subjected to mechanical vibrations during the gripping process. For this purpose, the cutting device is subjected to vibrations, particularly ultrasound, before the strands are separated, so that existing twists and interlacing of the individual strands are released and they are "vibrated" into a new position. The behavior of the strands during vibration excitation is preferably the same during cutting and compacting, so the respective descriptions can be used interchangeably.

[0032] The pressed, compacted strands are severed with a cutting device, creating a flat separation surface. The separation is performed in such a way that a substantially flat end face with the aforementioned flatness is created.

[0033] The gripping jaws of the cutting device can also be used as gripping jaws of the welding device described above. After cutting, the strands can be welded immediately as described above. It is also possible to release the gripping jaws of the cutting device and apply the gripping jaws described above. In this case, however, compaction is not absolutely necessary, as this can already be done beforehand, as described above.

[0034] By unbraiding and untwisting the strands before cutting, they are already in their final position and will not shift after cutting. This ensures that the flat end surface achieved by cutting is retained after cutting. If the strands are then welded immediately or shortly thereafter, as described above, the relative position of the strands is fixed.

[0035] In other words, it is technically possible to first create a flat end face with a given flatness using a cutting device and then weld the compacted strands of the conductor end, thus fixing their position relative to one another. On the other hand, it is also technically possible to first compact and weld the strands, fixing their position relative to one another, and then create a flat end face. In both cases, the strands are welded to one another through the gripping jaws in the manner described above.

[0036] For example, the stranded conductor is a stranded braid or a multi-stranded conductor. A multi-stranded conductor can, as described above, be formed from ordered, random, twisted, braided, or stranded strands.

[0037] According to one embodiment, it is proposed that after welding, the stranded conductor is butt-welded to a connecting part with its welded conductor end using a laser beam source. As already explained above, the end face of the stranded conductor is flat due to the cutting and subsequent welding or the welding and subsequent deburring. This flat end face is used to enable welding to a connecting part in a butt joint. The flat end face is pressed against the connecting part and then welded using a laser beam source.

[0038] Preferably, the same laser beam source is used that was previously used at least for welding, but preferably also for deburring. As already explained above, the laser beam source can be multifocal. This means that the laser beam source has a laser that can be adjusted for different applications with different focal points. A different focal point can thus be selected for welding than for the previous welding and / or deburring. However, it is advantageous to use exactly the same laser that was previously used for welding and, if necessary, deburring. This allows the entire welding process, including preparation of the stranded conductor, to be performed in one tool.

[0039] According to one embodiment, it is proposed that the laser beam source be set to be multifocal. In this context, it should be mentioned again that the welding of the strands can be performed with a different focus than the optional deburring and the optional butt welding to the connecting part. Different settings on the same laser beam source make it possible to use it for the various applications mentioned, thus enabling welding to be performed in the same tool.

[0040] A further aspect is a processing device according to claim 13. The processing device has a provision device with which a bare conductor or a bare conductor end can be made available. The bare conductor end can then be grasped by means of gripping jaws. In this case, at least partial, preferably completely circumferential grasping is proposed. With the help of the gripping jaws, the strands can be at least partially compacted. The compacted strands are then welded together using a laser from a laser beam source, so that a compact weld node is created. During welding, the laser from the laser beam source is directed through the material of the gripping jaws or through recesses in the gripping jaws onto the strands. A laser beam source deburrs the end faces of the welded strands.

[0041] The subject matter is explained in more detail below using a drawing showing exemplary embodiments. The drawing shows: Fig. 1a, b shows a conductor end with strands according to the prior art in the unprocessed state; Fig. 2a, b shows a conductor end of a stranded conductor in the processed state according to the prior art; Fig. 3a, b shows the processing of a stranded conductor according to an embodiment; Fig. 4a-c shows the processing of a stranded conductor according to a further embodiment; Fig. 5 shows a view of a processed stranded conductor according to an embodiment; Fig. 6a, b shows the deburring of a stranded conductor after welding according to an embodiment; Fig. 7a-d shows the cutting of a stranded conductor before welding according to an embodiment; Fig. 8 shows the butt welding of a stranded conductor to a connection part according to an embodiment.

[0042] Fig. 1a shows a view of a conductor end 2 of a cable 4. The conductor end 2 has a compacted region 6. In the compacted region 6, the strands 8 of the conductor end 2 are compacted, in particular in such a way that a cross-sectional profile of the conductor end 2 is rectangular. The compacted region 6 was produced, in particular, by resistance welding.

[0043] In the Fig. 1b It can be seen that an end face 6a of the compacted area 6 is formed from less far and further protruding strand ends of the strands 8. The flatness of the end face 8 is 2 to 3 mm. This is necessary for subsequent butt welding, as in Fig. 8 shown is not suitable.

[0044] The uneven end face 6a is created by the strands being moved toward each other during the compaction of the compacted area 6. Due to the structure of the conductor end 2, the strands 8 are usually twisted, stranded, or interwoven in some other way. Compaction alters this structure, so that the positional relationship of the strands 8 to each other is altered. This results in the strands 8 protruding further and less far from the end face 6a.

[0045] In order to prepare the end face 6a for welding, the end face 6a is welded as shown in the Fig. 2a shown, after resistance spot welding, they are post-processed, especially by cutting or milling. As shown in the Fig. 2b As can be seen, this achieves a flatness of the end face 6a of 0.5 mm or less. Such an end face 6a is suitable for subsequent butt welding. However, the known methods require a variety of tools to prepare the end face 6a in the manner shown.

[0046] According to the invention, it is now proposed to prepare the conductor end 2 by means of laser welding, as in the Fig. 3a, b is shown.

[0047] Fig. 3a shows a plan view of an end face 6a of a conductor end 2. On the circumference of the conductor end 2, gripping jaws 10 are moved towards one another in a radial direction towards the center of the conductor end 2, thus compacting the conductor end 2. A compacted region 6 is created. The gripping jaws 10 can be vibrated, in particular with an ultrasonic vibration, in order, on the one hand, to move the strands 8 of the conductor towards one another and thus dissolve their spatial arrangement relative to one another, and on the other hand, to facilitate plastic deformation of the strands 8 relative to one another. The gripping jaws 10 are shaped relative to one another in such a way that the end face 6a preferably has a rectangular cross-sectional profile, as shown. Other shapes are conceivable and included.

[0048] After compaction by the gripping jaws 10, the strands 8 are welded together by means of a laser beam 12 from a laser beam source (not shown). The laser beam 12 penetrates the gripping jaws 10 and thus directly impinges on the circumferential strands 8 in the region of the end face 6, particularly in the compacted area 6. The strands 8 are welded together.

[0049] After welding, the gripping jaws 10 are moved apart in a radial direction away from the center of the conductor end 2, as shown in Fig. 3b It can be seen that the end face 6a has a smaller cross-sectional profile than the conductor end 2. The strands 8 are welded together in the compacted area 6, particularly at the end face 6a.

[0050] The welding of the strands 8 to each other through the gripping jaws 10 is in a preferred embodiment in the Fig. 4a-c shown again. Fig. 4a shows the gripping jaws 10 and the front face 6a according to the Fig. 3a .

[0051] In a top view, which is Fig. 4b As shown, it can be seen that at a conductor end 2 in a compacted area 6, the gripping jaws 10 rest on the strands 8. The cable 4 or the conductor 2 extends in a longitudinal direction 14. Starting from an end face 6a in the longitudinal direction 14 spaced from the end face 6a, welding areas 16 can be provided in the gripping jaws 10. It is possible for one welding area 16 or several welding areas 16 to be provided in the gripping jaws 10 at a distance from one another in the longitudinal direction 14. The laser beam 12 penetrates the gripping jaws 10 in the welding areas 16 and strikes the strands 8 of the conductor end 2.

[0052] The welding areas 16 can be formed by recesses in the material of the gripping jaws 10. It is also possible for the welding areas 16 to be formed by a translucent material through which the laser beam 12 can pass.

[0053] Fig. 4b shows a side view and Fig. 4c shows a top view of a conductor end 2. In the Fig. 4c is according to the Fig. 4b A top view shows that welding areas 16 are provided at a front end of the conductor end 2 in the gripping jaws 10. One or more welding areas 16 can also be provided in the top view. The arrangement of the welding areas 16 relative to the longitudinal direction 14 can be spaced apart from one another.

[0054] It can be seen that welding areas 16 are provided in both a side view and a top view. This preferably applies to both side views, as well as to a top view and a bottom view, so that the welding areas 16 preferably lie circumferentially, but not necessarily completely circumferentially, against the strands 8 of the conductor end 2 in the compacted area 6.

[0055] It is now proposed that, as in the Fig. 6a shown, preferably with the same laser beam 12, the strands 8 are removed from the end face 6. This laser deburring results in the end face 6a, as shown in the Fig. 6b shown, has a flatness of less than 1 mm, preferably less than 0.5 mm. This end face 6a is suitable for butt welding with a connecting part according to Fig. 8 .

[0056] As an alternative to laser deburring according to the Fig. 6a, b A cutting process is also conceivable. Such a process is available in the Fig. 7a-d Preferably, the cutting process is carried out before welding according to the Fig. 3 and 4 carried out.

[0057] As in the Fig. 7a As can be seen, the cable 4 is stripped either in a central area or at the end face, leaving the bare strands 8 exposed. Press jaws 20a, b are applied to these bare strands 8. The press jaws 20a, b are spaced apart from one another in the longitudinal direction 14. This can be a gap 22 through which a cutting edge can pass. This can be done using a knife, a laser, or another cutting method.

[0058] Fig. 7c shows the pressing jaws 20a in a cross-section perpendicular to the longitudinal direction 14. The pressing jaws 20a are pressed against each other and the strands 8 are fixed to each other by side sliders 24. The strands thus fixed can be severed with a cutting device so that, as in Fig. 7d shown, at least one, preferably two flat end faces 6a are formed. At this conductor end 2, the method according to Fig. 3 and 4 be performed.

[0059] The conductor end 2 of the cable 4 is then connected with its end face 6a to a connecting part 26, as shown in the Fig. 8 shown, butt-welded. With this butt-welding, the welding is also carried out using the laser beam 12. The conductor end 6 is placed butt-welded onto a surface of a connecting part 26. The laser beam 12 then moves along the interface between the end face 6a and the surface of the connecting part 26. Because the end face 6a has the described flatness, the laser beam 12 has a sufficiently large contact surface to almost completely weld the strands 8 to the surface of the connecting part 26.

[0060] When welding the strands together in the compacted area 6, during laser deburring according to the Fig. 6 , as well as when welding according to the Fig. 8 A single laser beam source can be used. This can be multifocal, allowing the appropriate focus to be set for each application. List of reference symbols

[0061] 2Conductor end 4Cable 6Compacted area 6aEnd face 8Strands 10Gripper jaws 12Laser beam 14Longitudinal direction 16Welding area 18Welding node 20a,bPress jaws 22Gap 24Side shift 26Connector

Claims

1. Method of processing an electrical conductor in which, - a bare conductor end (2) (2) of a stranded conductor is provided, - the strands (8) of the bare conductor end (2) (2) are gripped at least partially circumferentially by gripping jaws (10), - the strands (8) are at least partially compacted in the region of the conductor end (2) (2) by the gripping jaws (10), and - the compacted strands (8) are welded together with the aid of a laser beam source in the region of the gripping jaws (10), through the gripping jaws (10), characterised in - that the compacted strands (8) welded to one another are deburred on a front face after welding with the aid of a laser beam source.

2. Method according to claim 1, characterised in - that the gripping jaws (10) are formed, at least in welding regions (16), from a material which is at least partially translucent for a laser beam (12) emerging from the laser beam source, and the compacted strands (8) are welded to one another in the welding regions (16) through the gripping jaws (10), and / or - that the gripping jaws (10) have through recesses at least in welding regions (16) and the compacted strands (8) are welded to one another in the welding regions (16) through the gripping jaws (10).

3. Method according to one of the preceding claims, characterized in - that the gripping jaws (10) grip around the conductor end (2) at a front face.

4. Method according to one of the preceding claims, characterized in - that the compacted strands (8) are welded together by means of the laser beam source at a perimeter of the gripping jaws (10), through the gripping jaws (10) and / or - that the compacted strands (8) are welded together with the aid of the laser beam source at mutually opposite jaws (10) of the gripping jaws (10), through the gripping jaws (10).

5. Method according to one of the preceding claims, characterised in - that the strands (8) are compacted with the aid of the gripping jaws (10) to form a polygonal, in particular rectangular, cross-sectional profile.

6. Method according to one of the preceding claims, characterized in - that at least two welding regions (16) are arranged in the gripping jaws (10) spaced apart from one another in the longitudinal direction of the stranded conductor.

7. Method according to one of the preceding claims, characterized in - that the gripping jaws (10) are vibrationally excited after gripping, in particular with high-frequency vibrations.

8. Method according to one of the preceding claims, characterised in - that a front face (6a) of the stranded conductor after deburring has a evenness of at most 1 mm, preferably at most 0.5 mm.

9. Method according to one of the preceding claims, characterized in - that the strands (8) are embraced by a cutting device prior to compacting and are cut off substantially flat at a front face and / or - that the strands (8) are vibrationally excited by the cutting device prior to cutting and are thereby at least partially untwisted relative to one another.

10. Method according to one of the preceding claims, characterized in - that, after welding, the stranded conductor is butt-welded with its welded conductor end (2) to a connecting part by means of a laser beam source.

11. Method according to claim 10, characterized in - that the welding of the strands (8) and the butt welding to the connecting part (26) are carried out with the aid of the same laser beam source and / or - that the welding of the strands (8) and the deburring are carried out with the aid of the same laser beam source.

12. Method according to claim 10, characterized in - that the laser beam source is adjusted multifocally in such a way that a focus of the laser beam source is adjusted differently from each other during the welding of the strands (8), during the optional deburring and during the optional butt welding to the connecting part.

13. Processing device for stranded conductors comprising: - a supply device arranged for supplying a bare conductor end (2) of a stranded conductor, - gripping jaws (10) arranged for at least partially circumferentially gripping the strands (8) of the bare conductor end (2) in such a way that the strands (8) are at least partially compacted in the region of the conductor end (2) by the gripping jaws (10), and - a laser beam source arranged for welding together the compacted strands (8) of the gripping jaws (10), through the gripping jaws (10) characterized in - that the laser beam source deburrs the welded strands (8) at a front face.

14. Processing device according to claim 13, characterized in - that the gripping jaws (10) are formed from a material which is translucent, at least in parts, to a laser beam from the laser beam source.

15. Processing device according to claim 13 or 14, characterized in - that the laser beam source is multifocal, such that the laser is adjustable with a different focus during successive working steps.