EP2343715B1 - Method for producing a current sensor - Google Patents

Description

The invention relates to a method for producing a current detection device as used for example in electricity meters or energy meters.

For current detection or energy detection various types of electronic electricity meters are known, which replace the mechanical Ferraris counter increasingly in the industrial and household sectors and perform a current detection with mechanically and electrically differently constructed arrangements. In addition to current detection using measuring shunts, Rogowski coils or Hall elements, current transformers based on soft-magnetic toroidal cores, in particular toroidal cores, are also widely used as magnetic modules in electricity meters. A magnetic module (current transformer, transformer) provides galvanic isolation and provides a precise measure in the form of a signal voltage at a load resistor. The requirements for amplitude accuracy, phase accuracy and linearity are defined by IEC 62053, -21, -23 or formerly 1036 in Europe and ANSI C12.xx in the USA and are, for example, in the company brochure "VAC Current Transformers for Electronic Energy Meters" Vacuumschmelze, October 1998 refer. Current transformers for electronic energy meters are also generally known from the company brochure "Current transformers for electronic energy meters" of Vacuumschmelze 2002. Such energy converters using energy meters (also called watthour meter) serve as officially approved measuring means to be used by a consumer, the energy consumption representing electric power in terms of costs to the energy supply companies.

Common is a structure of so-called primary conductor forming busbars and a matching toroidal current transformer for detecting consumption currents. Pluggable electricity meters widely used in the USA and other countries have standardized rectangular connection lugs on the back, which are inserted into slots with suitable spring contacts when the electricity meter is mounted. These connections with a cross section of about 2.5 mm ax serve induction and recovery of the consumption current which at 110 V systems is a maximum of about 200-480 A _eff. As the width a of the cross section, for example, a = 19 mm is set at a maximum current of Imax = 320A _eff . Typically, the currents of the three phases of the AC mains are fed into the electricity meter, through a current sensing system, and out of the electricity meter again.

Further electricity meters are off US 3657651 and the intermediate literature US-2010 0090678 known.

The current transformer can now be designed so that a busbar, for example, the size of 19 x 2.5 mm can be pushed through an inner hole of the current transformer. The region of the busbar on which the current transformer is to be arranged can also have a round cross-section, so that the inner hole of the current transformer can be made smaller and, consequently, a smaller and cheaper annular band core can be used. Even with an otherwise identical production time of the core and the same winding time, the smaller the diameter of the core, the lower the consumption of high-quality magnetic material and the process steps of a heat treatment and a coating. The production of a suitable busbar is done by providing a U-shaped conductor arrangement with different Sections. A central connecting portion with a round cross-section serves as an element of the conductor for passing through the corresponding opening in the current transformer. Two connecting conductor sections with a rectangular cross-section serve to connect the current conductor in the form of the plug connections already known per se.

When mounting the current transformer on a one-piece primary conductor, it is now inevitable aufzustecken the inductive transducer on the primary conductor, including its connection contacts. Thus, the minimum inner diameter of the magnetic transducer in a one-piece primary conductor is inevitably determined by the size of the plug contact.

If the primary conductor is manufactured from several individual parts, it is possible to adapt the inner diameter of the inductive current transformer to the minimum possible from the electromagnetic design, but in this case an increased expenditure in assembling the primary current rail must be accepted. The conductor arrangement consists of three metal parts with mutually different cross sections, wherein the two ends of the round conductor are to be attached to the flattened surfaces of the rectangular connection conductor. Conventional joining methods in the production of busbars from, for example, three individual parts are brazing and welding processes. In both methods, it is imperative to protect the current transformer from the heat generated during the joining process, which requires complex constructions with cooling tongs between the joint and the current transformer.

Another disadvantage of these methods are the very limited possibilities of process control of the joining process. Safe control of the connection point is practically only possible by a destructive test.
To circumvent these disadvantages of the thermal joining method has been used for example in the DE 10 2004 058 452 proposed to perform the joining process in the form of a Kaltpressverschweißung. Although this method avoids the heat input during the joining process, the compounds of the individual parts of the primary conductor thus obtained have other disadvantages. Thus, only a fraction of the bonding area consists of cold-press welded material. The majority of the connection surface is merely positively connected with the result that an air gap in the micron range remains between the joining partners. This gap reduces the current carrying capacity of the connection point, with the result of possibly inadmissibly high heating of the joint when the conductor is loaded with the maximum current.

The compounds of such a conductor arrangement of three elements with each other at the connection points different cross-sections should allow a long life of, for example, about 10-15 years with great reliability, so that the production of the conductor arrangement must be performed very reliable process. For reasons of electrical conductivity, corresponding busbars or conductor arrangements are predominantly constructed from copper material. But problems arise both in brazing and welding in particular by the heating when creating the connection points, since the heat is transmitted through the conductor to the current transformer and can damage it.

The object of the invention is to provide a method for producing a current detection device, which provides a simple and cost-effective production with a secure connection and the lowest possible load of other components.
This object is achieved by a method for producing a current detection device according to claim 1 or by a current detection device according to claim 14. Embodiments and developments of the inventive concept are the subject of dependent claims.

A method according to the invention for producing a current detection device having a current conductor having a central portion and two end portions and having in the middle portion the shape of a rod and flats in its end portions, and a magnetic module for measuring a current flowing in the conductor over that of it generated magnetic field has the following steps:
Providing the magnetic module, the conductor and two copper sleeves, the conductor being in the form of a rod and made of aluminum or aluminum alloy, and wherein the sleeves fit on at least portions of the end portions of the conductor and are made of copper or copper alloy;
Applying the one sleeve to the conductor in at least a part of the one end portion;
Applying the other sleeve to the conductor in at least part of the other end portion;
Positioning the current conductor and the magnetic module relative to each other such that the conductor is in a position to the module in the region of its center portion such that it detects the magnetic field thereby resulting in current flow in the conductor,
Bending the conductor between the center section and the one end section,
Bending the conductor between the center section and the other end section,
Flattening of the conductor at the sleeve provided with the one end portion and
Flattening the conductor at the other end portion provided with the other sleeve,
wherein the order of application, bending, flattening and positioning steps is arbitrary provided that each application step takes place before the respective flattening step.

Fig. 1

den Ablauf eines ersten Beispiels eines erfindungsgemäßen Herstellungsverfahrens,

Fig. 2

den Ablauf eines zweiten Beispiels eines erfindungsgemäßen Herstellungsverfahrens,

Fig. 3

den Ablauf eines dritten Beispiels eines erfindungsgemäßen Herstellungsverfahrens,

Fig. 4

verschiedene beim Herstellen erhaltene Zwischenprodukte einschließlich einer komplett montierten Stromerfassungseinrichtung (Endprodukt),

Fig. 5

eine weitere beispielhafte Ausführungsform der Stromerfassungseinrichtung mit durchgestecktem Stromleiter und

Fig. 6

eine beispielhafte Ausführungsform der Stromerfassungseinrichtung mit angesetztem Stromleiter.

The invention will be explained in more detail with reference to the embodiments illustrated in the figures of the drawing. It shows:

Fig. 1

the sequence of a first example of a production method according to the invention,

Fig. 2

the sequence of a second example of a production method according to the invention,

Fig. 3

the sequence of a third example of a production method according to the invention,

Fig. 4

various intermediates obtained during manufacture, including a fully assembled current detection device (end product),

Fig. 5

a further exemplary embodiment of the current detection device with plugged current conductor and

Fig. 6

an exemplary embodiment of the current detection device with attached conductor.

The inventive method and the current detection device according to the invention provide as a conductor 1, a one-piece body made of aluminum or aluminum alloy, which are provided at its ends with sleeves 5 made of copper or copper alloy, which may be coated at least on their outer surfaces with a tin or tin alloy layer, wherein for the final shaping of the copper contact surfaces produced therewith, cold pressing is used. Thus, expensive copper as the conductor material is quantitatively reduced to a minimum, yet kept the size of the current detection device as low as possible and made with respect to the reliability of the conductor (eg, primary conductor) no compromise to an existing solid copper assembly. This is achieved by limiting the use of copper to the areas of the primary conductor where the properties to be achieved only with this material, such as very good corrosion resistance and minimal contact resistance, as well as virtually negligible creep, are required.

In the region of the contact rails of the primary conductor these material properties are indispensable, in all other areas of the primary conductor only a sufficiently low electrical resistance of the conductor is required to be realized with appropriate adjustment of the conductor cross-section with materials that have higher resistivities than copper. It is also an advantage of the invention that the reliability and optimum ampacity of a one-piece body of the primary conductor is accompanied by minimization of the size of the magnetic module due to optimum utilization of the conductor or feedthrough cross-section.

In Fig. 1 an exemplary sequence of a first production method according to the invention is shown. The end product of this manufacturing method is a current detection device such as a current transformer, a current sensor or the like. Such an end product is in Fig. 4F shown closer. The current detection device shown there comprises a one-piece, U-shaped, current conductor 1 of certain length, which has a central portion and two end portions and in the middle portion the shape of a rod with non-rectangular conductor cross-section and in its end portions flats (in the region of the sleeves 5) having rectangular conductor cross-section. Furthermore, a in the middle portion of the conductor 1 (also called its function according to the primary conductor) arranged magnetic module 2 is provided, which has a the conductor 1 receiving bushing 3. As shown, such a module can consist of at least one wound toroidal core and, in addition, may also include electronics such as a semiconductor circuit.

In the manufacturing method presented herein, according to Fig. 1 For example, in a step a) first, the magnetic module and in its central portion and at least one of the end sections straight and rod-shaped conductor, which in the present case consists of pure aluminum, but could also consist of an aluminum alloy or other suitable material apart from copper or copper alloy , and two sleeves made of copper or a copper alloy fitting on at least parts of the end portions of the conductor.

In a process step b), a heat treatment is carried out in which the sleeves are annealed, for example, at a temperature of 300 ° C to 600 ° C for 1 to 5 hours under inert gas.

In a method step c), a tin deposit of at least 3 μm is applied to at least the outer surfaces of the sleeves by electroplating or hot tinning. There are then starting products A as in Fig. 4 shown before. In the present example it is assumed that the conductor is provided as a generally straight, rod-shaped conductor with a round cross-section.

In a method step d) one of the sleeves is applied to the conductor in at least part of the one end portion of the conductor.

In a method step e), the other sleeve is applied to the conductor in at least part of the other end portion of the conductor.

In a method step f), the current conductor and the magnetic module are positioned, for example, by telescoping relative to each other such that the conductor is located with its center portion in the implementation of the module. This step leads to an intermediate C according to Fig. 4 ,

In a method step g), the current conductor is bent between the middle section and the one end section, for example by 90 °.

In a method step h), the current conductor is bent between the middle section and the other end section by, for example, 90 °. This results in an intermediate product E according to Fig. 4 in which, at two points 4 between the middle section and both end sections, a bend of 90 ° results in a U-shaped conductor. However, other forms would be equally possible if desired or required.

In a method step i), the conductor is flattened on the end provided with the one sleeve.

In a method step k), the current conductor is flattened on the other end section provided with the other sleeve. This results in the end product F according to Fig. 4 ,

The deformation carried out in steps i) and k) can be carried out, for example, by cold working (for example cold pressing). The sequence of the steps of the method can also be modified such that steps d) and e) only after step f) (see Intermediate B according to Fig. 4 ) or after the steps g) and h) (see Intermediate D according to Fig. 4 ) respectively. In addition, the order of the steps of the method may be modified such that steps i) and k) directly follow steps d) and e).

In Fig. 2 the sequence of a further exemplary manufacturing method according to the invention is shown. In this case, in a method step a) again the magnetic module and a straight and rod-shaped conductor formed in its middle section and at least one of the end sections and two sleeves provided on at least parts of the end sections of the conductor are provided.

In a process step b), a heat treatment is carried out in which the sleeves are annealed, for example, at a temperature of 300 ° C to 600 ° C for 1 to 5 hours under inert gas.

In a method step c), a tin deposit of at least 3 μm is applied to at least the outer surfaces of the sleeves by electroplating or hot tinning. There are then starting products as in Fig. 4A shown before. In the present example it is assumed that the conductor is provided as a generally straight, rod-shaped conductor with a round cross-section.

In a method step d) one of the sleeves is applied to the conductor in at least part of the one end portion of the conductor.

In a method step e), the current conductor is bent through 90 ° between the middle section and the one end section. In a method step f), the current conductor is flattened on the end provided with the one sleeve.

In a method step g), the current conductor and the magnetic module are positioned relative to each other such that the conductor is located with its center portion in the passage of the module, wherein the non-sleeve and non-bent end portion is guided through the magnetic module for positioning.

In a method step h), the other sleeve is applied to the conductor in at least part of the other end portion of the conductor.

In a method step i), the current conductor is bent by approximately 90 ° between the center section and the other end section.

In a method step k), the current conductor is flattened on the other end section provided with the other sleeve. This results in a final product according to Fig. 4F ,

The sequence of the steps of the method can also be modified such that step d) takes place after step e) and before step f) and / or that step h) takes place after step i) and before step k) and / or the steps d), e) and f) after step g) take place.

In Fig. 3 a further example of a manufacturing method according to the invention is shown. In this case, in a method step a), in turn, the magnetic module and a conductor formed in its center section and at least one of the end sections in a straight and rod-shaped fashion, as well as two provided at least parts of the end portions of the conductor suitable sleeves.

In a process step b), a heat treatment is carried out in which the sleeves are annealed, for example, at a temperature of 300 ° C to 600 ° C for 1 to 5 hours under inert gas.

In a method step c), a tin deposit of at least 3 μm is applied to at least the outer surfaces of the sleeves by electroplating or hot tinning. There are then starting products as in Fig. 4A shown before.

In a method step d), the current conductor and the magnetic module are positioned relative to each other such that the conductor is located with its center section in the passage of the module. After process step d) is an intermediate according to Fig. 4D in front.

In a method step e), a simultaneous application of the one sleeve onto the conductor takes place in at least a part of the one end section and the other sleeve on the conductor in at least one part of the other end section.

In a method step f), a simultaneous bending of the current conductor takes place between the middle section and the one end section by approximately 90 ° and between the center section and the other end section by approximately 90 °

In a method step g), a simultaneous flattening of the conductor takes place at the end provided with the one sleeve and at the one provided with the other sleeve other end section. This results in a final product according to Fig. 4F ,

The sequence of the steps of the method can also be modified such that step f) takes place before step e), whereby after step f) an intermediate product according to Figure 4D is present.

In Fig. 5 shows a further exemplary embodiment of a conductor of the current detection device. In this case, the current conductor 1 is carried out at its the sleeve 5 receiving end portions with a smaller diameter such that the diameter of the arrangement of conductor 1 and the applied sleeves 5, which are also designed with a smaller diameter, not in the region of the end portions of the conductor 1 is greater than in the middle section of the conductor. 1

In this way, the bushing 1 receiving the bushing 3 of the magnetic module 2 (see Fig. 4 ) are performed even with the smallest possible diameter, if one or both of the sleeves 5 are applied to the conductor 1 before the positioning of the conductor 1 and the magnetic module 2 relative to each other. By choosing the size of the diameter in the middle section of the conductor 1 and thus the outer diameter of the sleeves 5 while the current carrying capacity of the current measuring device can be determined.

In the exemplary embodiments explained above, it is thus provided that a current conductor 1 (primary conductor) with any desired, for example, circular cross-section and provided with a minimum cross section for a given cross section becomes. If pure aluminum or an aluminum alloy is used as the conductor material of the body, can be dispensed with a heat treatment of the conductor 1 entirely. In addition, pure aluminum or aluminum alloys are very inexpensive.

Furthermore, a sleeve is provided, for example, for each terminal end of the primary conductor whose inner diameter is greater than 0.5 mm greater than the outer diameter of the corresponding terminal end and whose length corresponds to at least the length of the later reshaped area. The wall thickness of the sleeve is at least 0.3 mm, the bottom of the sleeve has a minimum thickness of 2 mm. This sleeve is first subjected to adjusting the required for the following deformation microstructure as a heat treatment annealing between about 300 and 600 ° C for about one to five hours in a neutral inert gas. This prepared sleeve is then either galvanically or thermally provided at least on the outer surfaces with a tin pad a minimum thickness of greater than 3 microns.

It should be noted that tin plating at least this thickness during the molding of the pads of the primary conductor by cold pressing an extremely effective lubricant. This minimizes the forming work required for forming the primary conductor, improves the contour accuracy of the parts and allows the use of smaller and thus less expensive forming presses. It has also been found that this tin coating is retained after forming as a closed defect-free coating and thus ensures the required corrosion protection and the good electrical contactability of the pads on the finished primary conductor.

These two properties are an essential prerequisite for the production of the current transformer module described here. If a coating of the later connecting surfaces of the primary conductor forming copper sleeves with tin before the actual shape is not possible, the required for a secure and permanent contact coating would have to be applied subsequently either galvanically or by hot tin plating.

In the case of subsequent galvanic tinning, there would be the problem that the current transformer already located on the primary conductor would have to be protected from the entire process chemistry of electroplating in a very complex manner. If you were to perform the tinning as Heißverzinnung on the mounted current transformer assembly would again be the problem of thermal stress on the current transformer that would require comparable cumbersome measures with cooling tongs as in a production of the primary conductor of several items. Furthermore, it would also be virtually impossible to reliably comply with the required tight mechanical tolerances of the contact surfaces by a Heißverzinnungsvorgang.

When installing the conductor, the two ends of the conductor are bent at right angles according to the distance of the contact surfaces according to the ANSI standard. The correspondingly prepared primary conductor is then placed in a pressing tool and the two terminal contact surfaces of the primary conductor are formed either individually (for example in succession) or jointly (simultaneously) by cold extrusion from the ends of the primary conductor.

Since copper or copper alloys have a significantly higher yield strength than aluminum or aluminum alloys, it is impossible that the pushed over the conductor bar made of aluminum sleeve breaks during the forming. Rather, it forms a contact element whose core is surrounded by aluminum of a copper sheath, which has about half the wall thickness of the original sleeve at the usual diameter ratios of this application. In the region of the transition between the inner aluminum conductor and the outer copper jacket, cold welds sometimes occur, but always to a flat positive connection, so that optimum electrical contacting of the aluminum conductor with the copper jacket acting as a terminal surface is ensured.

Furthermore, according to this method, the outer contact surfaces of the sleeve are highly work hardened after forming and further coated surface with a closed tin layer, resulting in a very good corrosion protection results and on the other hand an optimal electrical contacting of the conductor is made possible to the on-site electrical installation.

This simplified manufacturing method assumes that the conductor cross-section of the contact surfaces of the ANSI standard (2.38 x 19 mm) is already given by the sum of the cross-sections of undeformed conductor and attached sleeve.

For example, a primary conductor for a current carrying capacity of about 200 A _rms common in the 110 V system can be made by using a 7 mm diameter pure aluminum rod-shaped conductor, tinned copper sleeves with an outer diameter of 7.7 mm, an inner diameter over both ends of 7.1 mm, a sleeve length of 35 mm can be pushed with a sleeve bottom thickness of 2 mm.

If there is a demand for a thicker and thus, of course, mechanically considerably more stable copper sheath, it is possible, for example, to assume a primary conductor bar of aluminum with a diameter of 7 mm whose two ends are tapered over a length of 35 mm to a diameter of 5.6 mm. About the rod ends then tinned copper sleeves are pushed with an outer diameter of, for example, 8.0 mm, an inner diameter of 6.0 mm and a sleeve length of 35 mm with a sleeve bottom thickness of 2 mm.

In the same way, it is also possible to carry out a cross-sectional adaptation of the primary conductor which is required for a possibly desired higher current-carrying capacity. If, for example, a current conductor is required for the current carrying capacity of approx. 320 A _rms, which is also used in the 110 V system, this can simply be made from a round rod made of pure aluminum with a diameter of 9.7 mm, whose two ends are over a length of 35 mm Diameter of 5.6 mm are tapered produce. About the rod ends here also tinned copper sleeves are pushed with an outer diameter of 8.0 mm, an inner diameter of 6.0 mm a sleeve length of 33 mm and a sleeve bottom thickness of 2 mm.

Regardless of the diameter variants described above takes place after mounting the tinned copper sleeves forming the contact surfaces by cold forming. In this process step, it comes to a positive and at least partially cohesive connection of the aluminum inner conductor with the mounted tinned copper sleeves. That's it Current transformer module in a ready-to-install state for the production of an electronic energy meter before.

An electronic circuit in the electricity meter detects the current and calculates the current (and possibly phase) the energy consumed as for example in US 4,887,028 is described.

Cost effective manufacture of a magnetic module for high quality current transformers involves the use of toroidal cores, particularly toroidal cores, and winding of the isolated cores with the corresponding secondary enameled copper wire based secondary winding. Cores suitable for this purpose are known, for example, from US Pat EP 1 131 830 and EP 1 129 459 , The EP 1 114 429 describes current transformers for such purposes.

It is also possible with the current conductor described other current measuring modules such as so-called Rogowski coils or Hall IC based systems use. In this case, the conductor either passes through an opening in the measuring module, as in the case of the magnetic toroidal-core current transformer, or as in FIG Fig. 6 shown the measuring module is arranged for example in a specially shaped loop 6 of the current conductor 1 such as is advantageous when using modules 7 with Rogowski coils or Hall elements. All solutions in common is the one-piece conductor 1, which leads either through the module or in the immediate vicinity of this.

Claims (18)

1. A method of manufacturing a current detection device with a current conductor (1) that has a central section and two end sections and has the shape of a rod in the central section and flattened areas in its end sections, and with a magnetic module (2) for measuring a current flowing in the current conductor (1) via the magnetic field generated in it, wherein the method comprises the steps:

   Making available the magnetic module (2), the current conductor (1) and two copper casings (5), wherein the current conductor (1) has the shape of a rod and consists of aluminum or an aluminum alloy, and wherein the casings (5) fit onto at least parts of the end sections of the current conductor (1) and consist of copper or a copper alloy;

   Placing the one casing (5) on the current conductor (1) in at least one part of the one end section;

   Placing the other casing (5) on the current conductor (1) in at least one part of the other end section;

   Positioning the current conductor (1) and the magnetic module (2) relative to one another in such a manner that the current conductor (1) is in such a position in the area of its central section relative to the module (2) that the latter detects the magnetic field produced during a current flow in the current conductor (1),

   Bending the current conductor (1) between the central section and the one end section,

   Bending the current conductor (1) between the central section and the other end section,

   Flattening the current conductor (1) on the one end section provided with a casing (5), and

   Flattening the current conductor (1) on the other end section provided with the other casing (5), wherein

   The placing, bending, flattening and positioning steps can be as desired in as far as each placing step takes place before the particular flattening step.
2. The method according to Claim 1 in which in addition the last flattening step and the last bending step take place after the positioning step.
3. The method according to Claim 1 or 2 in which in at least one flattening step a cold deformation of the casing (5) consisting of copper or a copper alloy is provided together with the end section of the current conductor (1) consisting of aluminum or an aluminum alloy, which end section is surrounded by the casing.
4. The method according to Claim 3 in which the cold pressing during the cold deformation is also provided.
5. The method according to one of the previous claims in which the flattening steps are designed in such a manner that they result in a rectangular cross section of the conductor.
6. The method according to one of Claims 1 to 5, in which the current conductor (1) is arranged in the area of the central section and adjacent to the module (2).
7. The method according to Claim 6 in which the magnetic module (7) comprises a Rogoffski coil or a Hall element that is arranged adjacent to the current conductor (1).
8. The method according to one of Claims 1 to 5, in which the current conductor (1) is arranged in the area of the central section and in a bushing of the module (2).
9. The method according to Claim 8, in which the magnetic module (2) comprises a non-slotted annular core provided with a winding or comprises a slotted annular core provided with a Hall element, wherein the current conductor (1) is run through the annular core.
10. The method according to one of the previous claims, in which at least one flattening step is such that the longer edge length of the rectangular cross section is greater at the ends of the current conductor (1) than the greatest diameter of the bushing of the module (2).
11. The method according to one of the previous claims, in which the current conductor (1) has a round cross section at least in the central section.
12. The method according to one of the previous claims, in which the bending steps are designed in such a manner that the current conductor (1) is bent by 90 ° between the central section and at least one end section.
13. The method according to Claim 12, in which the bending steps are designed in such a manner that a U-shaped conductor is formed.
14. The method according to one of the previous claims, in which the ends of the current conductor (1) are cold-upset before a flattening step.
15. The method according to one of the previous claims, in which the steps of the placing of the one casing (5) on the current conductor (1) in at least one part of the one end section and of the placing of the other casing (5) on the current conductor (1) in at least one part of the other end section and/or the steps of the bending of the current conductor (1) between the central section and the one end section and of the bending of the current conductor (1) between the central section and the other end section and/or the steps of the flattening of the current conductor (1) on the one end section provided with the one casing (5) and of the flattening of the current conductor (1) on the other end section provided with other casing (5) are carried out simultaneously.
16. The method according to one of the previous claims, in which the casings (5) are heat-treated before being placed on the current conductor (1).
17. The method according to one of the previous claims, in which the casings (5 are tin-plated on the current conductor (1 before the flattening step.
18. A current detection device with
    a current conductor (1) consisting of aluminum for an aluminum alloy that has a central section in the shape of a rod and two end sections with flattened areas, wherein it is bent between an end section and the central section,
    a magnetic module (2), wherein it is located in the area of the central section of the current conductor (1) in such a manner that the module (2) detects the magnetic field produced during current flow in the current conductor (1), and
    two casings (5) consisting of copper or a copper alloy that are placed at least on parts of the end sections of the current conductor (1) and cold-welded to them.

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