Semi-finished electrical conductor for electrical machine

Abstract

One aspect of the invention relates to a semi-finished power conductor for an electric machine, comprising a first and a second conductive trace 1, 2, which respectively comprise a first and a second free edge 1s, 2s opposite each other and a first and a second longitudinal face 1i, 2i, and comprising welding surface portions 10Si, 20Si facing each other with a gap J of less than 0.6 mm, the first trace 1 further comprises a protection section 10p comprising a protection surface 10pi facing the gap J and extending from a flat surface of the second face 1i at least as far as a plane P extending from an edge angle between the free edge 2s of the second trace 2 and the solder surface portion 20Si, the plane P being parallel to the solder surface portion 10Si of the first trace 1.

Description

Technical Field

[0001] The technical field of the invention is that of electric power conductors for rotating electrical machines in the motor vehicle field.

[0002] In particular, the invention relates to semi-finished power conductors. Background Art

[0003] The electric machine comprises a rotor and / or stator active windings connected to various power electronic components located inside an electronic housing, which is fixed in the electric machine or outside the electric machine. These components perform the function of a reversible AC / DC power converter. When the rotating electric machine is in an alternator operating mode, the above-mentioned converter rectifies the AC phase voltage generated by the electric machine in the alternator mode to produce a single DC supply voltage (usually 48 volts), which supplies power to the on-board power supply network of the motor vehicle. Conversely, as is well known to those skilled in the art, when the rotating electric machine is in a motor / starter operating mode, the converter provides a phase voltage, which supplies power to the stator windings of the rotating electric machine.

[0004] Thus, wires enable the electronic housing to be connected to the battery voltage or the windings (which in some cases may in particular have traces of rectangular cross-section). However, the volume and cost of these wires need to be minimized while maintaining the quality of the connector.

[0005] For example Figure 1As shown in , such a conductor requires connecting a first conductive trace 1 to a second trace 2 for a positive voltage line + of, for example, 48V or a ground line -. The first trace or the second trace can, for example, be a trace of a winding output or a connector, and correspondingly, the second trace or the first trace can be a trace of a power electronic component connected to the electronic housing. The connection of the two traces 1, 2 needs to be performed at the free edge of each of the two traces 1, 2 by welding a portion of each trace 1, 2 to each other. A fast, cheap and very high-quality means of connection is laser welding. However, such laser welding requires a very small gap between the two surfaces 10Si, 20Si of the welded part, for example less than 0.6mm. One of the solutions is to mount the two welded parts to fit tightly, but this solution is very difficult to achieve due to the manufacturing and assembly tolerances on the two traces and the manufacturing and assembly tolerances on the components supporting the traces. In this example, a housing 3 supports the first track 1, the housing 3 is particularly overmolded onto a portion of the first track 1, a heat sink 5 made of aluminum comprises an opening, a portion of the first track 1 including the welding portion passes through the opening and is assembled with the first housing 3, and a second housing 4 made of plastic encapsulates at least a portion of the second track 2, for example by overmolding. In this example, an electrically insulating thermal adhesive is located between the heat sink 5 and the second track 2. The two housings 3, 4 and the heat sink 5 each have manufacturing and assembly tolerances, but also tolerances that control their relative expansion, indicating a positive gap of less than 0.6 mm for laser welding.

[0006] However, this gap still allows the laser beam transmitted by the laser welding device to pass between the two surfaces 10Si, 20Si, thereby potentially damaging the components facing the gap (below), for example a portion of the housing 3 overmolded onto the first trace 1 may be positioned facing the laser beam. The laser beam will then effectively heat this portion of the housing to the point where it burns and thus damages it on the one hand and produces fumes that may hinder the correct operation of the laser welding on the other hand. Therefore, one of the solutions is to eliminate any plastic components in the vicinity of the first trace 1 below the focal plane for the laser welding. In Figure 1In order to avoid damaging the positioning lugs or any other equipment located below the focal plane, a metal shield 9 has been bonded to the housing 3, a part of the shield being positioned facing the gap so as to absorb the light beam passing through the gap during the assembly phase by laser welding. Thus, this shield 9 absorbs the energy of the laser beam passing through the gap between the two metal traces to be welded together. However, this metal shield 9 introduces many limitations during the manufacturing process regarding assembly and regarding the ability to withstand environmental tests, even if its function is only to provide protection during the laser welding operation. In particular, it requires a step of adhesively bonding the metal shield 9 to the housing 3, which may result in adhesive overflow, electrical bonding of the metal shield 9, and defects in protecting the metal shield 9 or obtaining a metal material resistant to salt spray.

[0007] Therefore, there is a need to find a solution to the problem of light beams passing through gaps that is less restrictive than the metal shielding solution. Summary of the invention

[0008] The present invention provides a solution to the above-mentioned problems by making it possible to have a connector whose traces are improved so as to reduce separation at their connection ends.

[0009] One aspect of the present invention relates to a semi-finished power conductor for an electric machine, comprising:

[0010] A first conductive trace and a second conductive trace, comprising a first free edge and a second free edge, respectively, each trace comprising:

[0011] a first longitudinal surface and a second longitudinal surface opposite to each other,

[0012] a connecting portion comprising welding sections extending from the free edge and each comprising a corresponding welding surface portion of the second face, the surface portions facing each other with a gap J of less than 0.6 mm,

[0013] The first bent portion extends from the connecting portion and includes a bent portion forming a concave surface on a side of the first face.

[0014] The connecting portion of the first trace includes a protection section between the welding section and the first bent portion, the protection section including a protection surface, the protection surface facing the gap J and extending from a flat surface portion of the second face of the connecting portion at least as far as a plane P, the plane P passing through an edge corner between the second free edge and the surface of the welding portion of the second trace, the plane P being parallel to the welding surface portion of the first trace.

[0015] By means of the invention, the fact of having a protection section comprising a protection surface positioned facing the gap J makes it possible to absorb the energy of the laser beam passing through the gap J during welding. Furthermore, it makes it possible to avoid adding additional protection components, such as metal shields. Finally, it allows to assemble and form a housing having a protected portion between the connection end and the protection section.

[0016] In addition to the features just mentioned in the preceding paragraph, the connector according to one aspect of the invention may have one or more of the following additional features, taken alone or in any technically possible combination:

[0017] According to one embodiment, the protection section forms a recess on the first face and a protrusion on the second face, thereby forming a protection surface on the side opposite to the recess. This makes it possible to add only the step of deforming the first trace in order to form this portion without modifying the rest of the trace.

[0018] According to one example, the first trace includes punched holes forming protrusions and recesses.

[0019] According to a variation of this embodiment, the protection section extends from the connection end, and the protection surface is a bent portion formed on the side of the second face, and an intermediate section including two surfaces parallel to the plane P extends from the bent portion until the welding section. According to one example, the bent portion in the bent portion includes a portion on the side of the connection end facing the gap J. Compared with the aforementioned embodiment, this embodiment has a disadvantage in that the position of the bent portion in the protection section is changed during the method of manufacturing the first trace, and a second bent portion extending from the protection section and a third bent portion extending from the parallel section are added, and the protection surface of the protection section is formed between them.

[0020] According to one embodiment, the wire includes a first plastic housing enclosing at least a first bent portion of a first trace.

[0021] According to one example, the first housing includes a portion overmolded on the protection section on the same side as the second face. This makes it possible to well maintain the first trace, thereby improving the efficiency of welding.

[0022] According to one example of this embodiment and including examples of a protrusion and a recess, a first portion of the protrusion is covered by the overmolded portion of the housing and a second portion of the protrusion includes a protective surface.

[0023] According to an example of this embodiment, the wire further includes:

[0024] an aluminum heat sink including an opening through which the connection portion of the first trace passes, and the aluminum heat sink is assembled with the first housing,

[0025] A second plastic housing encapsulates at least the first bent portion of the second trace, such as by overmolding, and the second housing is fixed to the heat sink.

[0026] According to one example, an electrically insulating thermal adhesive is located between the second trace and the heat sink in order to adhesively bond them together. This makes it possible to improve the transfer of heat from the second trace to the heat sink.

[0027] According to a variation of this embodiment, the wire comprises a single housing overmolded over the two traces.

[0028] According to one embodiment, the protection zone is closer to the first curved portion than to the first free edge. This makes it possible to reduce the power of the laser beam on the protection zone.

[0029] According to a variant of this embodiment, the protection zone is closer to the first free edge than to the first curved portion. This makes it possible, for example, to increase the coverage area of ​​the portion of the housing overmolded between the first curved portion and the protection surface on the second face of the track.

[0030] According to one embodiment, the first free edge and the second free edge each lie in planes parallel to each other, separated by a distance of less than 0.5 mm.

[0031] According to one embodiment, the connecting portion of the second track is completely formed by the soldering section.

[0032] According to one embodiment, the first connecting portion comprises an intermediate section comprising two flat surfaces each parallel to the plane P and extending from a welding section as far as the protection section, the two welding sections being longitudinally delimited relative to each other by a gap J less than 0.6 mm therebetween.

[0033] A second aspect of the invention relates to a method for manufacturing a semi-finished wire according to the first aspect of the invention, with or without the various combined features or according to only one of the embodiments described above, the method comprising the following steps:

[0034] bending the initially planar first and second traces to form curved portions of the first and second traces, respectively,

[0035] deforming the first trace between the first free edge and the curved portion to form a protection section of the connecting portion such that the protection surface extends obliquely relative to a portion of the planar surface of the second face of the connecting portion, and

[0036] The second trace is positioned relative to the first trace such that the two welding surface portions face each other with a gap of less than 0.6 mm.

[0037] According to one example, the wire according to an embodiment includes a housing, and the method further includes inserting the first trace into the first housing or overmolding the first housing over the first trace.

[0038] According to one example, the wire according to an embodiment including a heat sink and a second housing, the method further comprising:

[0039] the step of inserting the second trace into the second housing or the step of overmolding the second housing over the second trace, and

[0040] The step of adhesively bonding the planar surface of the second side of the second trace to the planar surface of the heat sink using an electrically insulating thermal adhesive.

[0041] The positioning step includes the sub-step of inserting the connecting portion through the opening in the heat sink until the heat sink is assembled with the first housing.

[0042] A third aspect of the invention relates to a method for producing a voltage conductor from a semi-finished conductor according to the first aspect of the invention, the semi-finished conductor having or not having the various combined features or according to only one of the embodiments described above, the method comprising the following steps:

[0043] positioning a laser welding device to transmit a laser beam directed in line with and facing the first and second free edges of the first and second traces,

[0044] Laser welding, wherein a welding device converts electrical energy into a laser beam, causing the beam to move relative to the semi-finished wire so that the beam travels along a plurality of paths from a first free edge to a second free edge, and vice versa, through a gap J, the beam on each path heating a first trace at the first free edge, heating a protection section through the gap J at a protection surface, and heating a second trace at a second free edge, repeating the plurality of paths until the first trace and the second trace are melted at the free edge to a limited depth along the traces.

[0045] A fourth aspect of the present invention relates to a power conductor for a motor, comprising:

[0046] A first conductive trace and a second conductive trace, the first conductive trace and the second conductive trace being welded to each other via a molten bond of the laser welding type connecting the first trace to the second trace, the first trace and the second trace further comprising:

[0047] a first longitudinal surface and a second longitudinal surface opposite to each other,

[0048] a first curved portion including a curved portion forming a concave surface on one side of the first face, and

[0049] The first plastic housing encloses at least the first bent portion of the first trace.

[0050] The first trace includes a connecting portion extending between the welding area and the first bend portion, the connecting portion including a protection segment on the same side as the second face, the protection segment including a protection surface facing the welding area in a direction parallel to a plane extending side by side with a surface of a middle segment of the connecting portion extending from the welding area.

[0051] According to one example, the electrically insulating thermal lug is located in an opening of the heat sink surrounding a portion of the first track. This makes it possible to improve the transfer of heat from the first track to the heat sink.

[0052] A fifth aspect relates to a connector comprising the wire according to the first aspect of the invention according to an embodiment comprising a first housing.

[0053] The invention and its various applications will be better understood by reading the following description and examining the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings are presented by way of indication and do not limit the invention.

[0055] Figure 1 A schematic cross-sectional view of a semi-finished wire according to the prior art is given.

[0056] Figure 2A A cross section of a portion of a semi-finished wire according to one example of a first embodiment of the present invention is depicted.

[0057] Figure 2B Depicted Figure 2A A magnified view of a portion of .

[0058] Figure 3 is based on Figure 2A Schematic diagram of a cross section of a semi-finished wire with a welding device before welding according to an example of a first embodiment of the present invention.

[0059] Figure 4 is a schematic diagram of a finished wire including a soldering pad connecting two traces to each other. DETAILED DESCRIPTION

[0060] The drawings are presented by way of indication and do not limit the invention.

[0061] Figure 2A is a schematic cross-sectional view of a first embodiment of a semi-finished power conductor according to the first aspect of the invention. The semi-finished power conductor may be a semi-finished power conductor of an internal power connector, such as a DC voltage connector for an electronics housing of an electric machine of a motor vehicle.

[0062] The semi-finished power conductor comprises a first conductive track 1, which in this case is positive, for example intended to be connected to a 48 volt battery terminal, and an identical second conductive track 2, which is arranged relative to each other in such a way as to be connected by laser welding. In the following, faces, or surfaces, or regions, or parts or sections of the first track 1 contain the number "1" in their reference, and faces, or surfaces, or regions, or parts or sections of the second track 2 contain the number "2" in their reference.

[0063] Each of the first and second tracks 1, 2 comprises a first longitudinal face 1e, 2e (also called an outer face) and a second longitudinal face 1i, 2i (also called an inner face), with the letter "e" in their reference. Each track also comprises two longitudinal edges (not marked), each longitudinal edge connecting the first face 1e, 2e to the corresponding second face 1i, 2i.

[0064] Each of the first track 1 and the second track 2 comprises a first free edge 1s and a second free edge 2s, which likewise connect the first face 1e, 2e to the second face 1i, 2i and to two longitudinal edges. Figure 2A In the figure, the two free edges 1s, 2s are depicted as being aligned in the same plane, but depending on manufacturing tolerances, they may be offset relative to each other, for example by 0.5 mm. In other words, the first free edge 1s and the second free edge 2s are each located in planes parallel to each other (giving or taking a manufacturing angle tolerance of, for example, 1°), separated by a distance of less than 0.5 mm.

[0065] The first track 1 includes at least a first curved portion forming a curved portion 11 and a connecting portion 10 extending from the first curved portion 11 to a first free edge 1s. The boundary between the curved portion 11 and the connecting end of the connecting portion 10 is formed by the end of the curvature of the curved portion, which forms a surface concave on the first face 1e side.

[0066] The second track 2 includes at least a first curved portion forming a curved portion 21 and a connecting portion 20 extending from the first curved portion 21 to a second free edge 2s. The boundary between the curved portion 21 and the connecting end of the connecting portion 20 is formed by the end of the curvature of the curved portion, which forms a surface concave on the first face 2e side. In the figure, the dotted line indicates the connecting end of the connecting portion 20.

[0067] The connecting portion 10 of the first trace 1 includes a welding section 10S extending from a first free edge 1s, the welding section 10S including a welding surface portion 10Si, the welding surface portion 10Si facing the portion of the welding surface 20S of the second face 2i of the welding section 20S of the second trace 2 extending from the second free edge 2s. Each welding section 10S, 20S is defined from the corresponding free edge 1s, 2s to the bending portion of the second trace 2. Each welding surface portion 20S and 10S faces each other with a gap of less than 0.6mm. In the case where the two free edges 1s and 2s are not aligned in the same plane, one of the two welding surface portions 20S, 10S is longer than the other. In this example, the two welding surface portions 10Si, 20Si are parallel to each other, but they can be slightly inclined.

[0068] The connection portion 10 of the first track 1 further includes a protection section 10p between the soldering section 10S and the connection end, and the protection section 10p includes a protection surface 10pi facing the gap J. Figure 2A part of Figure 2B As can be seen in FIG. 1 , the protection surface 10pi extends from the flat surface of the second face 1i of the connection portion 10 at least as far as a plane P extending from the edge corner between the second free edge 2s and the soldering surface portion 20Si of the soldering section 20S of the second track 2. The plane P is parallel to the soldering surface portion 10Si of the first track 1. In this particular case, it extends into the soldering surface portion 20Si of the soldering section 20S of the second track 2 because it is parallel to the soldering surface portion 10Si.

[0069] In this example, the connecting portion 10 also includes a middle section 10m, such as Figure 2B As shown, the middle section 10m extends from the welding section 10S to the protection section 10p. The dotted line represents the boundary between the welding section 10S and the middle section 10m. Therefore, the middle section 10m includes a portion of the second face 1i of the bend of the first bend portion 21 facing the second track 2, and includes a flat surface from which the protection surface 10pi extends.

[0070] The first connection portion 10 of the first track 1 extends along a first measuring length from the first curved portion 11 to the first free edge 1s. In this example, the length of the connection portion 20 of the second track 2 is much shorter than the length of the connection portion 10 of the first track 1. Specifically, the connection portion 20 of the second track 2 corresponds to the welding section 20S in this example. In other words, in this example, the connection portion 20 of the second track 2 is completely formed by the welding section 20S.

[0071] The first trace 1 and / or the second trace 2 may also each include a plurality of bends and straight portions (not shown) forming different bend regions.

[0072] In this example, the protection section 10 p is formed using a punch and thus includes a recess 12 e on the first face 1 e and a protrusion 12 i forming a protection surface 10 pi on the side opposite to the recess.

[0073] The semi-finished conductor also comprises a first electrically insulating housing 3 accommodating at least a portion of the first curved portion 11 of the first track 1. The first housing 3 in this example is overmolded on the first curved portion 11 of the first track 1. In this particular example, in this example, the first housing 3 comprises a portion 30 overmolded on the protective section 10p on the same side as the second face 1i of the first track 1. This portion of the housing 1 makes it possible to achieve a better retention of the first track 1 and thus improve the manufacturing tolerances. Thus, in this example, the first portion of the protrusion is covered by the overmolded portion of the housing 3 and the second portion of the protrusion comprises an uncovered protective surface 10pi so that it can face the gap J and is opposite to the gap J.

[0074] In this example, the semi-finished wire also includes an aluminum heat sink 5, which includes an opening through which the connecting portion 10 of the first track 1 passes and which is mated with the first housing 3. The wire also includes an electrically insulating thermal adhesive between the heat sink 5 and the second track 2 to dissipate heat from the second track 2.

[0075] In this example, the semi-finished conductor also comprises a second electrically insulating housing 4 (partially shown) fitted with a heat sink 5. In particular, the second electrically insulating housing is a unit of the electronic housing of the motor, housing the second track 2 (which may be inserted into or overmolded by the second housing).

[0076] A second aspect of the invention relates to the production of a semi-finished wire according to the first aspect of the invention.

[0077] The method comprises the steps of bending the first and second tracks, which are initially planar, to form the bent portions 11, 21, respectively, of the first and second tracks 1, 2. The second track 2 is thus formed and comprises a connecting portion forming a welding section, while the manufacture of the first track 1, in particular the manufacture of the connecting portion 10, is not completed.

[0078] The method further comprises a step of deforming the unfinished first trace between the first free edge 1s and the curved portion 11, thereby forming a protective section 10p comprising a protective surface 10pi and thus forming a connecting portion 10. The protective surface 10pi extends obliquely relative to a portion of the flat surface of the second face 1i of the middle section 10m of the connecting portion 10. The deformation is such that the end of the protective surface 10pi is located at a distance of at least 0.6 mm from the flat surface portion of the second face 1i, from which the end of the protective surface 10pi extends. The distance is measured perpendicularly to the flat surface portion of the second face 1i of the middle section 10m.

[0079] The method further comprises the step of positioning the second track 2 relative to the first track 1 such that the two welding surface portions 10Si, 20Si face each other with a gap of less than 0.6 mm.

[0080] In this embodiment, the method further comprises the step of inserting the first trace into the first housing or overmolding the first housing 3 onto the first trace 1 before the positioning step.

[0081] In this example, the method further comprises the steps of inserting the second trace 2 into the second housing 4, in this particular example of overmolding the second housing 4 over the second trace 2, and adhesively bonding the planar surface of the second face 2i of the second trace 2 to the planar surface of the heat sink 5 using an electrically insulating thermal adhesive. The positioning step comprises the sub-step of inserting the connection portion 10 through the opening in the heat sink 5 until the heat sink 5 is assembled with the first housing 3.

[0082] The welding section 10S and the intermediate section 10m have the same cross section, and in particular here have the same cross section as the cross section of the first curved portion 11. The protection section 10p may also have the same cross section as the welding section 10S and the intermediate section 10m. In another example, the protection section 10p may have a different cross section, due to the deformation it undergoes, for example by stamping. Preferably, the protrusion 12i has a width (measured between the two longitudinal edges) that is equal to or greater than the width of the welding surface portion 10Si. This makes it possible to capture the Figure 3 All beams of the laser device in the gap J are depicted.

[0083] In with Figure 2A In the same way, the semi-finished wire is depicted in cross section. Figure 3In the figure, a laser welding device 7 can be seen, which is positioned in such a way as to transmit a laser beam 70 oriented in line with and facing each free edge 1s, 2s. The welding device 7 converts electrical energy into a laser beam, making the beam movable relative to the semi-finished wire. The beam 70 travels along a plurality of paths from the first free edge 1s to the second free edge 2s and vice versa, crossing the gap J, the beam 70 being schematically indicated by three arrows at three locations. The beam 70 on each path between the first and second tracks 1, 2 heats the first track 1 at the first free edge 1s, heats the protection section 10p when it crosses the gap J and irradiates the protection surface 10pi, and finally heats the second track 2 at the second free edge 2s, until at least a portion of the welding sections 10S, 20S of the first and second tracks 1, 2 have melted, so as to fuse these together. This portion of the welding section 10S, 20S extends downward from the respective free edge 1s, 2s to a limited depth. The protection section 10 p may show traces of heating on its protection surface 10 pi , but is not completely melted to a molten state like the welding sections 10S, 20S.

[0084] Another aspect of the invention relates to a method for manufacturing a voltage conductor from an unfinished conductor according to the first aspect described above. The method comprises a step of positioning a laser welding device 7 so as to transmit a laser beam 70 directed in line with and facing each free edge 1s, 2s. The method then comprises a laser welding step, in which the welding device 7 converts electrical energy into a laser beam so that the beam is movable relative to the unfinished conductor so that the beam travels along a plurality of paths from the first free edge 1s to the second free edge 2s, and vice versa, through the gap J. During this welding step, the beam 70 on each path (from the first trace to the second trace and vice versa) heats the first trace 1 at the first free edge 1s, heats the protection section 10p by heating the protection surface 10pi, and heats the second trace 2 at the second free edge 2s. The beam forms as many paths as necessary until at least a portion of the welding sections 10S, 20S of the first and second traces 1, 2 melts to the extent that both portions are melted.

[0085] Figure 4 A wire is depicted in which the welding step has been completed. The wire is identical to the unfinished wire except that it comprises a weld 6 welding the first track 1 to the second track 2 at part or indeed the entirety of the welding section 10S, 20S of the semi-finished wire.

[0086] Unless stated otherwise, identical elements appearing in different drawings are provided with a single reference numeral.

Claims

1. A semi-finished power conductor for a motor, comprising: A first conductive trace (1) and a second conductive trace (2), wherein the first conductive trace (1) and the second conductive trace (2) respectively comprise a first free edge (1s) and a second free edge (2s), and each trace (1, 2) comprises: a first longitudinal surface (1e, 2e) and a second longitudinal surface (1i, 2i) opposite to each other, A connecting portion (10, 20) comprising a welding section (10S, 20S) extending from said free edge (1s, 2s) and comprising a welding surface portion (10Si, 20S) of the respective second face (1i, 2i) 20Si), the welding surface parts face each other with a gap J less than 0.6mm, A first bent portion (11, 21) extending from the connecting portion (10, 20) and comprising a bent portion, the bent portion forming a surface concave on one side of the first surface (1e, 2e), characterized in that the connecting portion (10) of the first trace (1) comprises a protection segment (10p) between the welding section (10S) and the first bent portion (11, 21), the protection segment (10p) comprising a protection surface (10pi), the protection surface (10pi) facing the gap J and extending from the flat surface of the second surface (1i) of the connecting portion (10) at least to a plane P, the plane P passing through an edge corner between the second free edge (2s) and a welding surface portion (20Si) of the welding section (20S) of the second trace (2), the plane P being parallel to the welding surface portion (10Si) of the first trace (1).

2. The semi-finished wire according to claim 2, characterized in that: The protection section (10p) includes a recess (12e) and a protrusion (12i), and the protrusion (12i) forms the protection surface (10pi) on a side opposite to the recess (12e).

3. The semi-finished wire according to claim 2, characterized in that: The first track (1) includes punched holes forming the protrusions (12i) and the recesses (12e).

4. The semi-finished conductor according to any one of the preceding claims, characterized in that The protection zone (10p) is closer to the first curved portion (11) than to the free edge (1s).

5. The semi-finished conductor according to any one of the preceding claims, characterized in that The free edge (1s) of the first track (1) and the free edge (2s) of the second track (2) each lie in planes parallel to each other, separated by a distance of less than 0.5 mm.

6. The semi-finished conductor according to any of the preceding claims, comprising a first plastic housing (3), in particular an overmolded first plastic housing, which at least partially surrounds the first curved portion (11) of the first track (1) up to the abutment end of the connecting portion (10).

7. Semi-finished conductor according to claim 6, wherein the first shell (3) comprises a portion overmolded onto the protection section (10p) on the same side as the second face (1i).

8. Semi-finished wire according to claim 2 or 3, wherein a first portion of the protrusion (12i) is covered by an overmolded portion of the housing and a second portion of the protrusion (12i) comprises the protective surface (10pi).

9. The semi-finished conductor according to claim 7 or 8, characterized in that: The semi-finished wire also includes: An aluminum heat sink (5) comprising an opening through which the connecting portion (11) of the first trace passes, and the aluminum heat sink (5) is assembled with the first housing (3) A second plastic housing (4) encapsulates at least the first bent portion (21) of the second track (2), for example by overmolding, and the second housing (4) is fixed to the heat sink (5).

10. The semi-finished conductor according to any one of the preceding claims, characterized in that The connection portion (20) of the second track (2) is completely formed by the welding section (20S), and the first connection portion (10) includes an intermediate section, which includes two flat surfaces, each of which is parallel to the plane P and extends from the welding section (10S) to the protection section (10p), and the two welding sections (10S, 20S) are longitudinally delimited relative to each other by a gap J of less than 0.6 mm between them.

11. A method for manufacturing a semi-finished wire according to any one of claims 1 to 10, comprising the following steps: bending first and second traces which are initially planar to form curved portions (11, 21) of the first and second traces (1, 2), respectively, deforming the first trace between the free edge (1s) and the bent portion (11) to form the protection section (10p), the protection section (10p) comprising a protection surface (10pi) extending obliquely relative to a portion of the flat surface (10si) of the second face (1i) of the connecting portion (10), and The second track (2) is positioned relative to the first track (1) so that the two welding surface portions (10Si, 20Si) face each other with a gap of less than 0.6 mm.

12. A method for producing a voltage conductor from a semi-finished conductor according to any one of the preceding claims, characterized in that The method comprises the following steps: positioning a laser welding device (7) to emit a laser beam (70) directed in line with and facing the first free edge (1s) and the second free edge (2s) of the first track (1) and the second track (2), Laser welding, wherein a welding device (7) converts electrical energy into a laser beam so that the laser beam can be moved relative to the semi-finished wire so that the laser beam travels along a plurality of paths from the first free edge (1s) to the second free edge (2s) and vice versa, through a gap J, the laser beam (70) on each path heating the first track (1) at the first free edge (1s), heating the protection section (10p) through the gap J, and heating the second track (2) at the second free edge (2s) until the first track (1) and the second track (2) have melted to a limited depth along the tracks (1, 2) at the free edges (10s, 20s).

13. A power conductor for a motor, comprising: A first conductive track (1) and a second conductive track (2), the first conductive track (1) and the second conductive track (2) being welded to each other via a molten bonding area (6) of the laser welding type connecting the first track to the second track, the first track (1) and the second track (2) further comprising: a first longitudinal surface (1e, 2e) and a second longitudinal surface (1i, 2i) opposite to each other, a first curved portion (11, 21) comprising a curved portion forming a concave surface on one side of the first face (1e, 2e), Characterized in that the first trace includes a connecting portion (10) extending between the welding area (6) and the first bent portion (11), and the connecting portion includes a protection segment (10p) on the same side as the second surface (1i), and the protection segment includes a protection surface (10pi), and the protection surface (10pi) faces the welding area (6) in a direction parallel to a plane extending side by side with the surface of the middle section of the connecting portion (10) extending from the welding area (6).

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