EP3769370A1

EP3769370A1 - Method for establishing a connection between an electric connection element for a motor vehicle electrical system and a cable of the motor vehicle electrical system

Info

Publication number: EP3769370A1
Application number: EP18826264.6A
Authority: EP
Inventors: Rene MATHEWS; Kai Moldenhauer
Original assignee: Auto Kabel Management GmbH
Current assignee: Auto Kabel Management GmbH
Priority date: 2018-03-21
Filing date: 2018-12-14
Publication date: 2021-01-27
Also published as: US11942748B2; WO2019179650A1; US20210044071A1; CN111886756A; DE102018111853A1; MX2020009741A

Abstract

The invention relates to a method for establishing a connection between an electric connection element for a motor vehicle electrical system and a cable of the motor vehicle electrical system, in which method: the cable (2) is provided with a metal stranded conductor (4); then the metal stranded conductor is mechanically compressed such that a planar region is formed, an integral connection being formed between strands of the stranded conductor (4) during said compression; and subsequently the connection element is integrally bonded to the planar region.

Description

A method for establishing a connection between an electrical connection element for a motor vehicle electrical system and a cable of the

Vehicle electrical system

The subject matter relates to a method for producing a connection between an electrical connection element for a motor vehicle electrical system and a cable of the motor vehicle electrical system. The subject matter further relates to a cable as well as the use of such a cable.

In a motor vehicle electrical system, it is necessary, starting from a

Main power line, which is directly connected to the positive pole of the battery to realize electrical outlets to consume. Due to the large number of electrical consumers to be connected in a vehicle electrical system is a wide

Branching of the wiring system required. Some consumers need great power from the battery, and thus need to use cables with large ones

Cable cross-sections are connected to the distribution network. Groups of consumers often need to be secured by a common fuse, on the other hand, it is also necessary, starting from the main power line to provide a plurality of each hedged strands.

The tap of electrical energy from the main energy line is not readily possible. On the one hand, such a tap is each connected to a transition resistance and thus ohmic losses and on the other hand there is an increased risk of corrosion at the taps.

The automotive industry is increasingly using shaped tubes instead of round cables

Aluminum flat cables. This is especially true for battery lines, especially the B + line, where high currents flow. It is also possible with a small one

Space, so narrow and inaccessible areas to realize large cable cross-sections and also to increase the current carrying capacity of the battery cables. However, round conductors are still used for contacting electrical consumers. This is mainly for the reason that the electric

Consumers usually have to be contacted via flexible lines. When installing the connecting lines between the rigid battery line and electrical consumers, it is often necessary that the lines must be threaded into tight spaces, which is easier with the help of round conductors than with rigid flat conductors. For the realization of e.g. Transfer points with bolt, which are also the subject of the invention are currently additional

Partial elements are required on which the bolts can be welded, so that ultimately a contact element (such as a cable lug) can connect.

In addition, when using aluminum cables, the electrical tap is always exposed to the risk that by oxidation of the aluminum conductor of the

Contact resistance is large and the electrical power loss leads to this contact resistance to an undesirable heating of the line.

Based on these problems, the object was the object of providing a method available with which a tap on a stranded conductor is particularly easy to implement.

This object is achieved by a method claim 1.

Especially in motor vehicle electrical systems preferably in those in which the battery in the rear of the vehicle and the prime mover, in particular the starter of the internal combustion engine, but also possibly an electric motor for the drive, are arranged in the engine compartment, the main battery line runs from the rear to the front of the vehicle. This can be done by an underground installation of the battery cable or by an interior installation of the battery cable. Along this

Battery string can be realized with the help of the subject terminal console a plurality of electrical outlets in a particularly simple manner.

In particular, if the battery string is formed from an aluminum conductor, in particular an aluminum stranded conductor, it is problematic to arrange connection consoles on such conductors. With the help of the objective solution it is possible in a non-insulated area, in particular in a center region of the cable remote from the cable ends, but also at at least not insulated end of a cable to establish a connection between a connection element and the cable.

In the first instance, the cable is provided with a metallic stranded conductor. In this case, the cable may be provided with an insulation or not. In the first case, the isolation can be removed first. The non-insulated region of the cable, that is to say the bare strands of the stranded conductor, which forms the core of the cable, can be led to a compression device.

Thereafter, first the metallic stranded conductor is mechanically compacted. Here, the strands of the stranded conductor are pressed together. As far as possible a connection between cavities between the strands is prevented. The strands are bonded together during compression. The result is preferably a material bond on the outer lateral surfaces of the strands. By compacting a flat area is formed. The area can also be considered as a connection area. In the area of the area, the strands are connected to each other by means of material connection. It forms a compact area in which the stiffness of the stranded wire compared to the non-compacted stranded wire is substantially increased.

After the compaction has been completed, the area can be considered

Connection area for connecting a connection element serve. One

Connecting element can thereby another cable, e.g. a flat conductor or a

Round conductor, each made of solid material or stranded wire, a connecting bolt, a tap, a contact eye or sleeve or the like. The connection element can be materially connected to the areal area.

It is also proposed to compact a stranded aluminum or Kupferlitzenleitung (eg round cable, braid), for example by welding, for example ultrasonic welding and then a connection element (eg a threaded bolt) aufzuschweißen on the resulting surface (eg by means of friction welding). Optional can welded on both surfaces (from above and below) a connecting element. The previously necessary terminal can thus be omitted and a process step can be saved. Furthermore, the required space is reduced, weight saved and consequently reduced production costs.

As the base material of the connecting element, for example, aluminum can be used. In order for a nut to be bolted with sufficient torque, the use of a harder material (e.g.

Copper alloy) conceivable for the connection element. However, the use of aluminum as a base material has the advantage that the corrosion resistance of the component and thus the interface between the strands and the connection element and ultimately the entire system increases significantly. Corrosion resistance can be further enhanced by additional coating of the terminal (e.g., nickel).

It is also proposed that the areal area be compacted with a degree of compaction of between 70% and 100%, in particular with a degree of compaction of between 85% and 95%. Such a high compression leads to the desired strength of the flat area, so that there a connection element can be welded. The material in the area flows under the load of the

Welding tool not to the extent that welding is impossible.

In addition, the strands form a nearly flat contact surface in this compacted state.

It is also proposed that the areal area is compressed by welding the strands of the stranded conductor, in particular that the areal area is compacted by means of ultrasonic welding or by means of resistance welding. By welding the strands with each other is achieved that they do not move against each other during subsequent connection with the connection element and absorb welding energy. In resistance welding and concomitant compaction, the surfaces which are attached to the

Apply tools, smooth. It is also proposed that the surface used for welding of the welding tool used during compaction is profiled in a relief-like manner. As a result, areas are formed in the planar area, which are highly compacted and areas that are less compacted. The profile ensures that, at least in the higher compacted areas, the strands are welded together sufficiently well.

It is also proposed that a relief-shaped profile embossed in the planar area when welding takes place at an angle to the longitudinal axis of the strands of the stranded conductor. Due to the angled course, in particular substantially perpendicular to the longitudinal axis of the strands or of the cable, it is achieved that the areal area is sufficiently compacted over its entire width. It is also achieved that external strands are included in the step of compacting and not protrude as loose strands of the flat area and are not connected to the area. A fraying of the area is thus avoided.

It is also proposed that the profile is strip-shaped or latticed. Both forms offer the advantage of connecting all the strands with the flat area.

It is also proposed that the profile by an anvil and / or a

Sonotrode the welding tool is introduced into the flat area. As a result, a profiling of the area is achieved already in the step of compacting.

It is also proposed that the profile be introduced on both sides of the area. As a result, a particularly good compaction is achieved in the areas in which the profile protrudes into the planar area. In addition, the strands are equally compressed on both sides of the flat area.

It is also proposed that the profile be inserted by complementary contours on the surfaces used for welding during compression

Welding tool is introduced and / or the profile by congruent contours on the surfaces used for welding of the compression used Sweat ßwerkzeugs is introduced. It may be useful to make the projecting into the flat area in areas adjacent to each other, so that thereby a particularly high compression is achieved. On the other hand, with a complementary profiling, a uniform compaction along the entire area can be achieved.

It is also proposed that in the area of a continuous

Recess is formed and the connection element is arranged in the recess. In this case, an annular, sleeve-shaped and / or rivet-like

Connection element can be arranged in the recess. The recess may e.g. be formed by punching correspondingly large holes in the area. In particular, the connection element is annular.

It is also proposed that the connecting element is connected on both sides of the flat area cohesively with the strands. In this case, e.g. be achieved by a compound on both sides of the recess, a particularly good connection between the flat area and the connection element.

Another object is a cable with a metallic stranded conductor produced by a method described herein.

It is proposed that the cable has an insulation of the stranded conductor, that the planar region is arranged in a stripped region arranged between two insulation sections of the insulation and that the connection element is connected in a materially bonded manner to the conductor in the planar region. Then, a tap can be realized in a central region of the cable. It is understood that the

Isolation can also be removed at a front end and the area lies in the end region of the stranded conductor.

It is also proposed that in the insulation sections the insulation

Completely encloses stranded conductor. It is also proposed that the stranded conductor is a round conductor and / or that the stranded conductor is formed from aluminum or an alloy thereof or from copper or an alloy thereof.

It is also proposed that the connecting element made of aluminum or

Alloys thereof is formed and / or that the connection element made of copper or alloys thereof, steel or stainless steel is formed and / or that the

Tinned and / or nickled connection element. Preferably, the transition between the stranded conductor and the connection element is sorted.

It is also proposed that the connecting element is annular sleeve-shaped and is connected on both sides of the planar region of radially outwardly facing collar with the flat region cohesively. The collar can be materially connected to the surface region facing the area with the flat area.

It is also proposed that the connection element and the stranded conductor are sheathed with insulation, in particular over the insulation of the stranded conductor also, are preferably encapsulated.

The areal area preferably lies between the ends of the cable and is preferably arranged in a middle area of the cable. In particular, the area lies away from the distal ends of the cable. Due to the cohesive arrangement of the connection element on the conductor, a high current flow with low electrical losses is possible.

In particular, the conductor of the electric cable is insulated and in the area of the area the conductor is free of the insulation. Thus, the area between two isolated areas of the conductor. If a plurality of stripped regions are provided, one or more connection elements can be provided along the path of the cable, via which electrical taps are possible. In particular, when the cable is one of the main battery string, thus a variety of electrical taps on the battery string can be made possible without affecting the conductance of the battery line as such by otherwise necessary interruptions negative. The Taps do not lead to increased electrical power loss along the cable, since the cable is not interrupted by the taps.

Due to the material connection with the connection element, the cable remains intact and its conductance is essentially unaffected. So it is possible to lead a one- or two- or multi-piece cable from the battery to the engine compartment, in particular to the starter or the electric motor in the engine compartment, which is not or only marginally affected by taps in its electrical conductivity of each section. The insulation of the cable is such that it completely encloses the conductor in the insulation sections. The isolation is

preferably made of a non-conductor, in particular a plastic, such as

For example, PVC or silicone formed.

Preferably, the cable is rigid and thus not plastically deformable due in particular to its own weight. It is also suggested that the conductor is formed of aluminum or an alloy thereof. In particular E aluminum, such as aluminum 99.5 can be used for the conductor.

Depending on the use of the material of the conductor, the connecting element is preferably formed from an electrically similar, in particular the same metallic material. For example, if the conductor is formed of copper or an alloy thereof, the terminal may also be formed of copper. By using an electrically similar or the same metal for the connection element as well as the conductor a sorted connection between the connection element and conductor is ensured. Contact corrosion is thus prevented or reduced to a minimum.

A particularly good connection between the connection element and the conductor is possible if this is produced by means of ultrasonic welding. Ultrasonic welding breaks up any existing aluminum oxide layer on the conductor and the resulting welding knot is largely free of aluminum oxide. As a result, the contact resistance is in the range of

Welding node compared to conventional welding processes reduced. According to one embodiment, it is proposed that the connecting element by means of friction welding, in particular rotational friction welding or

Reibpunktschweißen, but also by means of arc welding, is connected to the flat area. The friction welding of the connection element to the conductor can also break up any existing aluminum oxide layer on the strands of the conductor and the contact resistance between the flat part and the

Connection bolts are kept small.

The article will be explained in more detail with reference to drawings showing an exemplary embodiments. In the drawing show:

Fig. La a cross section of a cable;

Fig. Lb is a view of a stripped cable;

Figure lc is a view of a stripped, compressed cable.

FIG. 2 is a view of a cable according to FIG. 1; FIG.

3a shows a view of a connecting bolt according to an embodiment;

Fig. 3b is a view of a connecting bolt according to another

Embodiment;

Fig. 3c is a view of a connecting bolt according to another

Embodiment;

Fig. 3d shows a view of a connecting bolt according to another

Embodiment;

4 shows a view of a bolt according to FIG. 3b; Fig. 5a -c plan views according to embodiments;

Fig. 6a, b views according to an embodiment;

Fig. 7a, b views according to an embodiment;

FIG. 1 a shows an electrical cable 2 with a metallic stranded conductor 4 and an insulation 6.

The metallic conductor 4 is preferably a stranded conductor and in particular resistant to bending. The conductor 4 is preferably a round conductor. The material of the strands of the conductor 4 is preferably aluminum, in particular aluminum 99.5. The bending stiffness of the cable 2 arises when the cable 2 due to its own

Weight does not plastically deform. It's a bigger force than that

Weight force necessary to plastic deformation of the cable. 2

bring about.

The insulation 6 is preferably made of PVC or silicone.

As shown in Figure lb, the cable 2 may be stripped in a central region, that is, away from its respective distal ends, so that a stripped region 8 is formed. In the stripped area 8, the conductor 4 is free of the insulation 6.

After the stripped area 8 has been produced, the cable 2

or its conductor 4 are compressed. During compaction, the flat area 10 can be formed by a corresponding tool. The areal area 10 preferably has a width that is greater than the diameter of the conductor 4 by a factor of at least 2, preferably between 2 and 5, and at least by the factor 2, preferably the factor 5 to 10, is smaller than the diameter of the conductor 4. The height is shown in Fig. Lc. In Fig. Lc, the area 10 is shown. FIG. 2 shows a view of a cable 2 according to FIG. 1c. It can be seen that the conductor 4 is a round conductor and is flat in the area 10. The flat area 10 is located in the stripped area 8, which is remote from the distal ends of the cable 2.

When compacting a cohesive connection between the strands of the conductor 4 can be formed directly. The strands are pressed together and simultaneously welded together. In this case, the pressing tool can simultaneously be a welding tool, in particular an ultrasonic tool.

Figure 3a shows a connection element as a connection pin 12, therefore, all other connection elements are meant below and the description applies as far as meaningful for other connection elements. The one shown in FIG. 3a

Terminal bolt 12 is cylindrical and formed of a solid material. In particular, the connecting bolt 12 may be formed of stainless steel. However, it is also possible to form the terminal bolt 12 made of copper, aluminum or alloys thereof. The terminal bolt 12 can be formed by turning or cutting a rod.

FIG. 3b shows a connecting bolt 12, which has a terminal at its one end

Terminal lug 14, to which, for example, a clamping element of an electrical connection can be clamped. In particular, can

For example, a terminal in the form of a battery terminal to the

Terminal lug 14 are clamped.

FIG. 3 c shows a connection bolt 12, in which one end is provided with a thread 16. To such a connection bolt 12, for example, an electrical connection can be screwed.

FIG. 3d shows a further connecting bolt 12, which has an opening 18, in particular in the form of a bore, at its end. Through this opening 18, for example, a screw connection can be made with an electrical connection in which a screw is pushed through an opening 18 and / or bolted there.

FIG. 4 shows a connection bolt according to FIG. 3b in a view. It can be seen that the cylindrical bolt 12 in the region of the terminal lug 14 has a smaller radius and is formed, for example, for receiving a clamping element.

5a shows a top view of a cable 2. It can be seen that in the area 10 a relief-shaped profile 20 is embossed. In this case, the regions of the profile 20 extend with an increased compression substantially perpendicular to the longitudinal axis 2a of the cable 2. The profile 20 can be provided on both sides on the flat region 10 and be uniform.

Fig. 5b shows a cable 2, in which the profile 20 has been impressed by mutually complementary tools on both sides of the area 10. The dashed lines are on the side of the area 10 facing away from the plane of the drawing.

FIG. 5 c shows a cable 2 in which the profile 20 has been embossed as a lattice structure in the region 10.

By the profile 20, the strands of the line 4 are highly compressed and it comes to a material connection at least in the region of the profile. This makes it possible, directly on the line 4 and its strands after the compression to weld a connecting bolt 12 or another connection element.

FIGS. 6 a, b show a connection bolt 12, which is welded directly onto the flat area 10 in the areal area 10. Due to the profile of the area is suitable for this and sufficiently compacted that the connecting bolt, for example. can be applied by rotary friction welding or ultrasonic welding.

The Figs. 7a, b show a flat region 10 in which an opening 22 has been introduced during compaction or thereafter, in particular punched. In this opening 22, a sleeve 12b can be inserted as another possible connection element. The outer flanges of the sleeve 12 b can then be welded to the strands of the conductor 4 in the area 10. The sleeve 12b may also have a flange on only one side so that it can only be welded to the flange on one surface of the flat region 10.

Claims

Patent claims

1. A method for establishing a connection between an electrical

Connection element for a vehicle electrical system and a cable of

Motor vehicle electrical system in which,

the cable is provided with a metallic stranded conductor,

First, the metallic stranded conductor is mechanically compressed so that forms a flat area, wherein during the compaction a cohesive connection between strands of the stranded conductor is formed and then the connection element is integrally bonded to the sheet-like region.

2. The method according to claim 1,

characterized,

that the areal area is compacted with a degree of compaction of between 70% and 100%, in particular with a degree of compaction of between 85% and 95%.

3. The method according to any one of the preceding claims,

characterized,

that the areal area is compressed by welding the strands of the stranded conductor, in particular that the areal area by means of

Ultrasonic welding or compacted by resistance welding.

4. The method according to any one of the preceding claims,

characterized,

that the surface used for welding of the welding tool used in the compression is profiled in a relief-like manner.

5. The method according to any one of the preceding claims,

characterized, a relief-shaped profile embossed in the planar area during welding runs at an angle to the longitudinal axis of the strands of the stranded conductor.

6. The method according to any one of the preceding claims,

characterized,

that the profile is strip-shaped or latticed.

7. The method according to any one of the preceding claims,

characterized,

that the profile by an anvil and / or a sonotrode of

Welding tool is introduced into the flat area.

8. The method according to any one of the preceding claims,

characterized,

that the profile is introduced on both sides of the area.

9. The method according to any one of the preceding claims,

characterized,

that the profile is introduced by complementary contours on the surfaces used for welding of the welding tool used in the compression and / or the profile by congruent contours on the surfaces used for welding during the compression

Welding tool is introduced.

10. The method according to any one of the preceding claims,

characterized,

in that a continuous recess is formed in the areal area and the connection element is arranged in the recess.

11. The method according to any one of the preceding claims,

characterized,

that the connection element is annular.

12. The method according to any one of the preceding claims,

characterized,

that the connection element is connected on both sides of the flat area cohesively with the strands.

13. Cable with a metallic stranded conductor prepared by a method according to any one of the preceding claims.

14. Cable according to one of the preceding claims,

characterized,

in that the cable has an insulation of the stranded conductor, that the planar region is arranged in a stripped region arranged between two insulation sections of the insulation, and that the connection element in the planar region is bonded to the conductor.

15. Cable according to one of the preceding claims,

characterized,

that in the insulation sections, the insulation completely surrounds the stranded conductor.

16. Cable according to one of the preceding claims, characterized in that the stranded conductor is a round conductor and / or that the stranded conductor made of aluminum or an alloy thereof is formed and / or that the stranded conductor is formed of solid material.

17. Cable according to one of the preceding claims, characterized in that the connecting element made of aluminum or alloys thereof is formed and / or that the connecting element made of copper or alloys thereof, steel or stainless steel is formed and / or that the connection element tinned and / or undersized is.

18. Cable according to one of the preceding claims, characterized in that the connecting element is connected by means of ultrasonic welding to the flat area.

19. Cable according to one of the preceding claims, characterized in that the connecting element by means of friction welding, in particular

Rotational friction welding is connected to the flat area.

20. Cable according to one of the preceding claims, characterized in that the connection element is annular sleeve-shaped and is connected on both sides of the planar region of radially outwardly facing collar with the flat region cohesively.

21. Cable according to one of the preceding claims, characterized in that the connecting element and the stranded conductor with an insulation, in particular to over the insulation of the stranded conductor also sheathed, are preferably encapsulated.

22. Use of a cable according to one of the preceding claims in a power line, in particular in a motor vehicle battery line.