EP3994767A1

EP3994767A1 - Electrical connection between an electrical conductor and a contact element

Info

Publication number: EP3994767A1
Application number: EP20734768.3A
Authority: EP
Inventors: Karl Fröschl
Original assignee: Gebauer and Griller Kabelwerke GmbH
Current assignee: Gebauer and Griller Kabelwerke GmbH
Priority date: 2019-07-03
Filing date: 2020-07-01
Publication date: 2022-05-11
Anticipated expiration: 2040-07-01
Also published as: CN114080737A; US20220328985A1; JP2022540058A; EP3761452A1; EP3994767B1; WO2021001434A1

Abstract

The invention relates to a method for producing an electrical connection between an electrical conductor (5), which comprises a plurality of individual wires (9), and a contact element (2), wherein: the electrical conductor (5) is arranged in a contact portion (4) of the contact element (2), and the contact portion (4) and the electrical conductor (5) are subsequently pressed together such that the contact portion (4) surrounds the electrical conductor (5); a plurality of mutually spaced elongate welded connections (14) between the contact portion (4) and the electrical conductor (5) are produced by means of laser irradiation of the contact portion (4), or by means of laser irradiation of the electrical conductor (5) through an opening (17) in the contact portion (4); the elongate welded connections (14) extend in an irradiation direction from an irradiated region (13) of the contact portion (4), or from an irradiated region (13) of the electrical conductor (5), through the entire cross section of the pressed electrical conductor (5) to a region of the contact portion (4) opposite the irradiated region (13), such that the electrical conductor (5) is connected to said region of the contact portion (4); and the irradiated regions (13) are arranged in the form of a grid.

Description

Electrical connection between an electrical conductor and a contact element

FIELD OF THE INVENTION

The invention relates to a method for producing an electrical connection between an electrical conductor comprising a plurality of individual wires and a contact element, the electrical conductor being arranged in a contact section of the contact element and subsequently the

Contact section and the electrical conductor are pressed together so that the contact section engages around the electrical conductor.

The invention also relates to a corresponding device for establishing an electrical connection and to a

A unit made up of several individual wires

electrical conductor and a contact element.

The contact element is formed, for example, by a cable lug, such as a crimp cable lug, or a cable sleeve, such as a crimp sleeve.

STATE OF THE ART

There are known connection methods for electrically connecting an electrical cable to a contact element, in which a cable crimping section which is provided on the contact element is brought into press contact with an electrical conductor of the electrical cable. With such a

Crimp contact connections are made when the conductor of the

electrical cable is made up of several individual wires, the conductor wires, which are located on the outer circumference, brought into direct contact with the contact element and for this a power line is easy to achieve. The individual wires that are arranged in the center of the conductor can be connected to the Contact element can only be brought into conductive contact via the individual wires that are located on the outer circumference.

In order to establish a corresponding cross contact between the individual wires lying inside the conductor to other individual wires and on to the contact element, it was proposed in DE 10358153 A1 to laser weld the individual wires to one another and to the contact element in addition to crimping. It is provided there that several areas of the conductor are welded one after the other and overlapping. During the first welding step a

rapid heating through the application of the laser beam and explosive distribution of material within the conductor. One subsequently welded area

covers the area that was welded first and uses the resulting increased temperature by preventing rapid heating by the laser beam during the second and subsequent welding steps. The

Material gradually melts, making an explosive

Spreading can be prevented. Downside to this

However, the process is that the first welding step can still lead to explosive distribution.

DE 10 2013 010981 B3 shows a method and a

Device for connecting an electrical conductor to a contact part, wherein the device for pressing one or more openings are provided through which a

Laser beam of a laser welding device can pass through. A specific arrangement or mode of action of laser beams is not disclosed in DE 10 2013 010981 B3.

From US 2016/126642 A1 a crimped contact element is known that encloses a bundle of aluminum wires. In a transition section where there are no aluminum wires, tabs of the contact element are by means of

Point-shaped laser welding connected to one another, which, however, should prevent the entry of liquid into the contact element, and not the production of an electrical one Connection between the individual wires of an electrical

Conductor and the contact element is used.

OBJECT OF THE INVENTION

It is therefore an object of the invention to overcome the disadvantages of the prior art and a method

to propose at what the risk of explosive

Distribution is reduced and a transverse conductivity between individual wires can still be established.

DISCLOSURE OF THE INVENTION

This object is achieved by a method according to claim 1. The starting point for this is a method for producing an electrical connection between an electrical conductor comprising several individual wires and a contact element, the electrical conductor being arranged in a contact section of the contact element and then the

According to the invention it is provided that by means of a

Laser irradiation of the contact section, or by means of laser irradiation of the electrical conductor through an opening in the contact section, several spaced apart

elongated welded connections are made between the contact section and the electrical conductor, the elongated welded connections extending in an irradiation direction from an irradiated area of the contact section, or from an irradiated area of the electrical conductor, through an entire cross section of the pressed electrical conductor up to an area of the Contact portion, which is opposite to the irradiated area, extend so that the electrical conductor with this area of the contact portion is connected, wherein the irradiated areas are arranged in a grid shape.

By making several elongated

Welded connections, each extending from the surface of the contact portion through this and further into the interior of the conductor, or by the production of a plurality of elongated welded connections, each extending from the

Surface of the electrical conductor extend into the interior of the conductor - in the event that there is an opening in the

Contact section exposes the surface of the electrical conductor for laser irradiation, the elongated

However, welded joints are spaced apart, the energy input is reduced compared to conventional welding processes because the material between the elongated

According to the invention, welded connections should not be melted.

The deeper the elongated welded connections reach into the conductor, the more individual wires are connected to the elongated welded connections and the better it is

Transverse conductivity. The invention therefore provides that the laser irradiation is carried out in such a way that the elongated welded connection extends in the irradiation direction through the entire cross section of the pressed electrical conductor. The elongated welded connections thus extend in their longitudinal direction in a first variant of FIG

Invention where the laser radiation on the contact element

impinges, from the irradiated area of the contact portion through the conductor to that area of the around the conductor

guided around contact portion, which is opposite to the irradiated area. Then the individual wires captured by this welding connection are even in two places with the

Contact section connected.

In a second variant of the invention, where the contact element has an opening through which the laser radiation

passes through and on the surface of the electrical conductor occurs, the elongated welded connections extend from the irradiated area of the electrical conductor through the conductor to that area of the contact section passed around the conductor which is opposite the irradiated area. Then the individual wires captured by this welded connection are at at least one point with the

Contact section connected.

By varying the energy introduced into the material by the laser and / or through the duration of the laser irradiation, it is possible to set how deep the laser penetrates the material.

Elongated welded connections according to the present invention have a greater extent in their longitudinal direction, that is to say in the direction of irradiation, than in the width direction. The length is preferably a multiple of the average width or its diameter, in particular the elongate welded connections can be rod-shaped, that is to say one

have approximately constant diameter over their length.

Such elongated, in particular rod-shaped,

Welded connections can be made by deep laser welding

can be produced, where high beam intensities in the melt in the direction of radiation create a vapor capillary deep into the workpiece. As a result, the material is also melted in depth, the melting zone is usually more deep than wide.

The energy of the laser beam is determined according to the desired penetration depth of the laser beam in the area of the

Contact section, which is opposite to the irradiated area, metered. The laser beam should not completely penetrate this opposite area of the contact section and exit to the outside, since this would represent a quality defect. A typical power of a laser for the method according to the invention is 1-15 kW. The power requirement depends on the

Material of the electrical conductor and of the contact section. The power requirement also depends on the diameter of the elongated welded connection, the length of the elongated welded connection, i.e. the penetration depth, and the

Puncture speed.

The irradiated area is after the laser irradiation in the first variant of the invention on the surface of the

Contact section, or in the second variant of the invention on the surface of the electrical conductor, usually visible as an approximately round area, corresponding to the

Diameter of the laser beam and that around it

melted material of the contact area or the electrical conductor. The irradiated areas are therefore located in the first variant of the invention on the surface of the contact section, and in the second variant on the surface of the electrical conductor. Since the electrical conductor comprises several individual wires, the irradiated areas are located on the surface of the individual wires.

Due to the concentration of the molten material per so-called laser puncture, i.e. per area of the later elongated welded joint, in a very narrow area, only little is achieved relative to conventional welding methods

Material liquefies, which creates the risk of explosive

Distribution of material decreased.

One design variant provides that the elongated

Welded joints over a large part of their length, measured in the direction of irradiation, normal to

Irradiation direction are spaced from each other. in the

Ideally, the elongated welded connections are spaced from one another over their entire length.

One embodiment of the invention provides that several elongated welded connections, preferably all of them, are made over time successively produced by the same source of laser irradiation. With a source, that is to say a laser, all desired irradiated areas can be reached from a source, for example by appropriate optical deflections (eg mirrors, etc.), without the contact element having to be moved relative to the source.

However, because it can be carried out more quickly, it is preferred if several elongate welded connections are made simultaneously, in particular by the same source of laser irradiation. With a source, for example, the laser beam can be divided into all desired irradiated areas again by appropriate optical deflections.

The invention provides that several elongated

Welded connections grid-like, so in regular

spaced apart irradiated areas. The irradiated areas, usually as small approximately circular spots on the surface of the

Contact area or the electrical conductor visible, are therefore at a distance from one another on the surface of the

Arranged contact area or the electrical conductor.

Due to the regular arrangement, a regular

Penetration of the conductor, and thus connection of the

Single wires of the conductor, to be ensured with elongated welded connections. The irradiated areas are therefore arranged according to a grid on the surface of the contact area or the electrical conductor. The fact that the individual wires of the electrical conductor are usually also twisted and change their position in the conductor cross-section over their length also contributes to the contacting of all individual wires.

Examples of a grid-like arrangement of the irradiated areas are, for example, several irradiated areas that lie on a line and thus form a row, with two or more such rows transverse, in particular normal, to the

The individual wires of the electrical conductor are arranged in the longitudinal direction and in the longitudinal direction of the individual wires are arranged at a constant distance from one another. Adjacent rows have the same number of irradiated areas, for example, or differ by one irradiated area.

With the grid-like arrangement of the irradiated areas, it can be provided that one irradiated area is offset from another irradiated area normal to the longitudinal direction of the individual wires, so that the projection of all elongated wires

Welded joints on a cross-sectional area of the

electrical conductor in the field of elongated

Welded connections, result in a continuous welded surface in the transverse direction of the electrical conductor. This ensures that not only one and the same single wire from different, in the longitudinal direction of the

Single strands of consecutive elongated

Welded connections is contacted and not other adjacent individual wires. It is also ensured that everyone

Single wires at least once in an elongated one

Welded connection are included.

In the first variant of the invention, the laser beam usually hits the surface of the contact section on the

Contact section on, or in the second variant of the

Invention normal to the surface of the electrical conductor, specifically normal to the surface of its individual wires, on the electrical conductor. To that extent are with this

Design variant, the irradiated areas at the same time offset from one another normal to the direction of irradiation.

A possible grid-like arrangement with one another

Staggered irradiated areas consists for example of several rows of irradiated areas, the rows running transversely, in particular normal, to the longitudinal direction of the individual wires and adjacent rows being offset to one another transversely, in particular normal, to the longitudinal direction of the individual wires. The irradiated areas of the first, third, etc. row can then be aligned with one another as seen in the longitudinal direction of the individual wires, as can the irradiated areas of the second, fourth, etc. row. Adjacent rows, which are offset from one another, can also be aligned in the longitudinal direction of the

The individual wires overlap as seen.

It can be provided that the degree of compression of the

Individual wires in a longitudinal area of the contact element in which there are no irradiated areas is less than in a longitudinal area of the contact element where there are irradiated areas.

The degree of crimping indicates the ratio of conductor cross-section after crimping (or crimping) to conductor cross-section before crimping (or crimping). A compression rate of 100% means that the conductor cross-section has not been reduced at all by the compression (or crimping), but has remained the same. A crimping degree of 80% means that the conductor cross-section increases as a result of the crimping (resp.

Crimping) to 80% of the original conductor cross-section.

It can now be provided that the contact section is divided into two longitudinal areas transversely to the longitudinal direction of the individual wires. In one longitudinal area the conductor is only pressed, in the other longitudinal area the conductor is pressed and additionally irradiated with the laser according to the invention. In the longitudinal area where the laser is also used, it is advantageous if there are as many spaces as possible between the individual wires, that is to say an open one

Rope structure is ensured when building a

Melt pressure as part of the laser welding process as

Ventilation channel acts. This measure stabilizes the laser welding process, that is, for example, if there is an emulsion residue between the pressed wires, this can lead to an emulsion when the energy is introduced

Evaporation of this emulsion come that the

Laser welding result negatively influenced. If you now make sure that the loose rope structure creates a kind of

If there is a chimney effect, then the evaporation has this Emulsion residue does not have a negative impact on the result.

One possibility to produce a different degree of compression is that the different

Degree of compression by a compression tool with a

stepped support surface is produced. The length of the two steps corresponds to a longitudinal section of the

Contact section. The different heights of the support surface relative to the contact section of the contact element have the effect that the conductor is compressed to different degrees in the two longitudinal sections of the contact element.

Another way to get a different one

To produce degree of compression consists in that the

different degrees of compression is produced by a contact section with cable lug claws of different lengths in the transverse direction. That longitudinal section, which is more

should be pressed together, then has longer

Cable lug claws, i.e. more material that is pressed towards the conductor during pressing. In this way, a different height or compression of the conductor can be achieved even with a flat contact surface of the pressing tool.

It is also not ruled out simultaneously tiered

Use contact surfaces and different long cable lug claws.

With regard to an open rope structure of the individual wires, it is advantageous if the degree of compression of the individual wires in a longitudinal area of the contact element where the irradiated areas are located is greater than 70%.

In order to avoid unnecessary processing steps, such as bringing the pressed conductor to a welding station, it can be provided that the laser irradiation in that

Tool takes place in which the pressing takes place. In particular, it can be provided that the position of the pressed electrical conductor between pressing and

Laser irradiation is not changed. The pressed

electrical conductor remains in the after pressing

Tool and is also welded there with the laser.

It can be provided that the production of an elongated welded connection takes less than 100 ms, in particular less than 80 ms, e.g. around 60 ms. Depending on the power of the laser, there is a range of 20 to 100 ms for creating an elongated welded joint.

It can be provided that the contact section is provided with a nickel coating, at least in the area where it touches the electrical conductor. The nickel layer on the one hand causes corrosion protection between the conductor and the contact section and on the other hand increases the

Energy absorption during laser welding.

In one embodiment of the invention it is provided that the diameter of an irradiated area is between 0.4 and 0.8 mm, in particular between 0.5 and 0.7 mm, preferably 0.6 mm.

In one embodiment of the invention it is provided that the grid constant of the irradiated areas is between 0.8 and 1.2 mm, in particular between 0.9 and 1.1 mm, preferably 1 mm. The grid constant gives the constant distance between two irradiated areas in a certain

Direction of the grid forward. The grid constant will therefore be greater than a diameter of an irradiated area in order to allow the elongated welds from one another

are spaced. The greater the grid constant compared to the diameter of the irradiated areas, the greater the distance between the elongated welds.

The diameter of an elongated weld joint is usually slightly larger than the diameter of the irradiated one Area. In particular, it can be provided that the largest diameter of an elongated welded connection is 0.7 to 0.9 mm, in particular around 0.8 mm.

An apparatus for performing the invention

Method, that is to say for producing an electrical connection between an electrical conductor comprising several individual wires and a contact element, comprises a pressing tool with which the electrical conductor arranged in a contact section of the contact element is connected to the contact element

can be pressed so that the contact portion the

encompasses electrical conductor, and is characterized in that a device for laser irradiation is provided which is designed to produce a plurality of elongated welded connections spaced apart from one another between the contact section and the electrical conductor, the elongated welded connections each extending in an irradiation direction from an irradiated area of the contact section , or from an irradiated area of the electrical conductor in an opening in the contact section to an area of the contact section which is opposite the irradiated area, so that the electrical conductor is connected to this area of the contact section, the

irradiated areas are arranged in a grid.

The device can be designed so that one or more variant embodiments of the method according to the invention can be carried out with it. In particular, the device can be designed so that the position of the pressed

electrical conductor is not changed between pressing and laser irradiation.

The invention also comprises one according to the method according to the invention or with the device according to the invention

Unit produced from a number of individual wires

comprehensive electrical conductor and a contact element, wherein the electrical conductor is arranged in a contact section of the contact element and the contact section and the electrical conductor are pressed together so that the contact section engages around the electrical conductor and an electrical connection between the electrical conductor and

Contact element exists. The unity is through it

characterized in that several spaced apart

elongated welded connections are present between the contact section and the electrical conductor, the

Elongated welded connections in an irradiation direction each extend from an irradiated area of the contact section, or from an irradiated area of the electrical conductor in an opening in the contact section, to an area of the contact section which is opposite the irradiated area, so that the electrical conductor connects to this area of the contact portion is connected, the

irradiated areas are arranged in a grid.

The unit can, a variant of the

According to the method according to the invention, be designed so that the elongated welded connections are spaced from one another over a large part of their length normal to the direction of irradiation.

The unit can, a variant of the

According to the method according to the invention, be designed so that at least one irradiated area is offset from another irradiated area normal to the longitudinal direction of the individual wires, so that the projection of all elongated

Welded joints on a cross-sectional area of the

electrical conductor in the field of elongated

Welded connections, result in a continuous welded surface in the transverse direction of the electrical conductor.

The unit can, a variant of the

According to the method according to the invention, be designed so that the diameter of an irradiated area is between 0.4 and 0.8 mm, in particular between 0.5 and 0.7 mm, preferably 0.6 mm. The unit can, a variant of the

According to the method according to the invention, be designed so that the grid constant of the irradiated areas is between 0.8 and 1.2 mm, in particular between 0.9 and 1.1 mm, preferably 1 mm.

The unit can, a variant of the

According to the method according to the invention, be designed so that the largest diameter of an elongated welded joint is 0.7 to 0.9 mm, in particular around 0.8 mm.

The invention can be used to produce a so-called B crimp form or heart crimp form, as is known from the prior art. The invention can

can of course also be used for other types of crimp molds or compression molds.

The invention makes it possible in particular to use individual wires made of aluminum or an aluminum alloy. The use of aluminum for the strands leads

is known to cause the

Individual wires form an oxide layer and thus there are no stable resistance ratios over the service life of the conductor. By the elongated according to the invention

Welded connections, however, establish a material connection and thus electrical contact between the individual wires and the contact section of the contact element, which contact does not oxidize and is therefore constant

Resistance ratios guaranteed.

The individual wires made of aluminum or an aluminum alloy are advantageously pressed with a contact section or a contact element (e.g. crimp cable lug, crimp sleeve) made of copper or a copper alloy, e.g. bronze, brass.

The unit according to the invention can be used for high-voltage connector systems. BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail on the basis of exemplary embodiments. The drawings are exemplary and are intended to explain the idea of the invention, but by no means

narrow or even reproduce finally.

It shows:

Fig. La-d a first embodiment of a device for pressing and laser welding (Fig. La-c), for a contact element (Fig. Id) with contact sections of different lengths in the transverse direction

Cable lug claws,

Fig. 2 is a perspective view of the device from FIG

Fig. La-c,

Fig. 3a-b shows the device from Fig. La-c in a sectional view during laser welding,

Fig. 4 is an enlargement from Fig. 3b,

Fig. 5 is a plan view of the contact element after

Laser welding,

Fig. 6 the contact element after laser welding in one

Device according to Figs. La-c,

7a-e show a second variant of a device for pressing and laser welding, the

Pressing tool has a stepped support surface,

Fig. 8 shows a contact element in the initial state, for a

A device for pressing and laser welding in a third variant,

9 shows the contact element from FIG. 8, bent to accommodate the electrical conductor, 10 shows the contact element from FIG. 9 with electrical

Ladder,

11 shows the contact element from FIG. 10 inserted into a

A device for pressing and laser welding in a third variant, seen obliquely from below,

FIG. 12 shows the contact element and the device from FIG. 11, seen obliquely from above,

13 shows the device from FIG. 11 closed

Status,

14 the crimped around the electrical conductor

Contact element from Fig. 10,

15 shows the crimped contact element from FIG

Laser irradiation,

16 shows a possible arrangement of irradiated areas.

WAYS OF CARRYING OUT THE INVENTION

Fig. La-d show a first variant embodiment

Device for pressing and laser welding, this device for contact elements with contact sections with cable lug claws of different lengths in the transverse direction

is trained.

In Fig. La is a longitudinal section through the open

Device shown. In a lower part 1 of the

A contact element 2 (cable lug) is inserted into the pressing tool. By lowering the upper part 3 of the

Pressing tool is the contact section 4 of the

Contact element 2, which contact section 4 encompasses the electrical conductor 5, pressed downward, the ends of the cable lug claws 6, 7 being pressed inward into the conductor 5. In this way, the press or crimp connection is produced in the form of a B crimp. In Fig. Id the contact element 2 is in the state before

Pressing is shown. The contact element 2 has here, seen in its longitudinal direction, a connection section 8 with a round tab for further electrical connection and a contact section 4 for pressing with the electrical conductor 5. The contact section 4 is divided into two longitudinal areas with cable lug claws 6, 7 of different lengths in the transverse direction. The shorter cable lug claw 6 then surrounds an area of the conductor 5 which is closer to the connecting section 8 and which is additionally welded with the laser.

A higher degree of compression therefore results within the cable lug claw 6, e.g. higher than 70%, in particular higher than 80% or higher than 90%. So here should be an open

Cable structure of the individual wires 9 of the conductor 5 can be ensured. This can be seen in Fig. Lb, which shows a cross section along line B-B in Fig. La. Below are the

Individual wires 9 of the conductor 5 shown at this point, which still have a circular cross section.

The longer cable lug claw 7 surrounds an area of the

Conductor 5, which is further away from the connection section 8 and which is not welded with the laser. A lower one therefore results within the cable lug claw 7

Degree of compression, e.g. less than 80%. There are fewer gaps between the individual wires 9 here. This can be seen in Fig. Lc, which shows a cross section along line C-C in Fig. La. At the bottom it can be seen that the individual wires 9 are pressed together so strongly that they already have a rather hexagonal cross section.

The support surface 10 (see Fig. La) of the lower part 1 is straight here and therefore designed to be the same for both cable lug claws 6.7. A laser part 11 can be lowered into the upper part 3.

FIG. 2 shows a perspective view of the device from FIGS. 1 a-c, with a pressed but not yet welded conductor 5. Fig. 3a-b show the device from Fig. La-c in

Sectional view during laser welding, according to the

Representations in Fig. La and lb. The laser part 11 contains or is connected to a laser as a source of radiation. The laser part can, by means of optics containing lenses, mirrors, etc., emit a laser beam in the irradiation direction, here the vertical, and emit this laser beam along a grid

Shift horizontally while maintaining the vertical orientation of the laser beam. In this way, the laser beam can be applied to different, approximately

point-shaped, irradiated areas are directed. The

Laser beams 12 are shown here as thin lines.

Alternatively, the laser beam can be divided into several laser beams 12 by means of an optical system, which simultaneously impinge on the irradiated areas.

In Fig. 3a two laser beams 12 are shown, each impinging in an irradiated area and there each down into the conductor 5 and up to the cable lug 6 on the opposite side an elongated one

Form weld joint 14. In Fig. 3b, six laser beams 12 are shown, which each impinge in an irradiated area and form an elongated weld connection 14 down into the conductor 5 and up to the cable lug claw 6 on the opposite side. The elongated welded connections 14 run essentially in the direction of irradiation, that is to say here vertically. They do not overlap or touch each other.

FIG. 4 shows an enlargement from FIG. 3b, where the elongated welded connections 14 are shown schematically and can be better recognized.

FIG. 5 shows a top view of the contact element 2 after laser welding, where the entry points of the laser beam 12 can each be seen as an irradiated area 13. The

irradiated areas 13 are regular from each other

spaced and here form a grid with in the transverse direction of the contact element 2, that is normal to the longitudinal direction of the

Single wires 9 of the electrical conductor 5, running rows of alternately six and five irradiated areas 13. In the longitudinal direction of the individual wires 9 or in the longitudinal direction of the contact element 2, successive rows are offset from one another in the transverse direction, namely by half

Grid constant.

6 shows the contact element 2 after the laser welding in the lower part 1 of the pressing tool, the irradiated areas 13 on the surface of the contact element 2 being visible here.

7a-e show a second variant embodiment of a

Device for pressing and laser welding, whereby the

Compression tool has a stepped support surface. Fig. 7a largely corresponds to Fig. La except for the fact that the bearing surface 10 of the lower part 1 for the contact section 4 corresponds to the two longitudinal regions of the

Contact section 4 has a different height, thus forming two steps 15, 16. The cable lug claws 6, 7 can, but need not, be of the same length.

7d and 7e show the contact element 2 in the pressed state.

FIG. 7b corresponds to FIG. 1b and has the same

Degree of compression, FIG. 7c corresponds to FIG. 1c and has the same degree of compression.

The cable lug claw 6 surrounds an area of the conductor 5 which is closer to the connecting section 8 and which is additionally welded with the laser. Within the cable lug claw 6 there is a higher degree of compression due to the lower step 15, e.g. higher than 70%, in particular higher than 80% or higher than 90%. Here again an open cable structure of the individual wires 9 of the conductor 5 is ensured, the individual wires 9 have another one, as in FIG

circular cross-section.

The cable lug claw 7 again surrounds a region of the conductor 5 which is further away from the connecting section 8 and which is not welded with the laser. Within the

Cable lug claw 7 therefore results in a lower one Degree of compression, eg less than 80%. Here there are fewer gaps between the individual wires 9, the same as in FIG. 1c below, where the individual wires 9 are so strong

are pressed together so that they already have a more hexagonal cross-section.

Following the pressing, laser welding takes place in the device according to FIGS. 7a-c as in FIGS. 3a-b and 4, with the same result as in FIGS. 5 and 6.

8-15 show a third variant embodiment of the

Invention, the pressing tool here not having a stepped bearing surface. The two cable lug claws 6,7 of the contact element 2 are of the same length here.

The contact element 2 in Fig. 8 again has a

Contact section 4 and a connecting section 8. The contact section 4 comprises two cable lug claws 6, 7 of the same length here on both sides, which are separated from one another by a slot which, when the contact element is pressed, forms an opening 17 through which the surface of the pressed electrical conductor 5 remains accessible. A corrugation between the two cable lug claws 7, which are further away from the end of the electrical conductor 5 than the cable lug claws 6, serves to secure the electrical conductor 5 from being pulled out of the contact element 2 in the longitudinal direction of the electrical conductor 5

Cable lug claws 6,7 could also according to the

Design variants in FIGS. 1 to 7 may be of different lengths.

In FIG. 9, the cable lug claws 6, 7 are already bent towards one another, so that an electrical conductor 5 can be inserted between them, as shown in FIG. 10. The insulation of the electrical conductor 5 has been removed in the area of the cable lug claws 6.7. In contrast to the embodiment variants of FIGS. 1-7, the cable lug claws are here 6,7 relative to the

Connecting section 8 bent upwards. The ends of the Cable lug claws 6, 7 are then pressed into the electrical conductor 5 from above during pressing, see Fig. 11-13. In the design variants 1-7, the cable lug claws 6, 7 are pressed into the electrical conductor 5 from below.

In Figs. 11 and 12, electrical conductors 5 and

Contact element 2 is inserted into the lower part 1 of a pressing tool. By lowering the upper part 3 of the

13, the contact section 4 of the contact element 2, more precisely its cable shoe claws 6, 7, is pressed inwards and then downwards, the ends of the cable lug claws 6, 7 being pressed inwards into the conductor 5. In this way, the press or crimp connection is produced in the form of a B crimp.

The upper part 3 has a transverse to the longitudinal direction of the

Electrical conductor 5 running recess 18, which is aligned with the slot, which later forms the opening 17 of the contact section 4, so that laser beams 12 can be sent from above through this recess 18 and the opening 17 onto the surface of the electrical conductor 5. In this

Embodiment variant of the invention, the laser beams 12 hit the contact element 2 from the side with the ends of the cable lug claws 6, 7, while in the embodiment variants according to FIGS. 1-7 the laser beams 12 hit the opposite side of the contact element 2.

In Fig. 13, the pressed electrical conductor 5 is im

closed pressing tool, comprising the upper part 3 and the lower part 1, shown.

14 shows the pressed electrical conductor 5 with pressed-on contact element 2 without a pressing tool. The opening 17 lies with respect to the contact section 4, in

Seen longitudinal direction of the individual wires 9, closer to

Connecting section 8 than at the end of the contact section 4 which faces away from the connecting section 8. The opening 17 extends in the transverse direction of the contact element 4, that is normal to the longitudinal direction of the individual wires 9, over the entire width of the pressed electrical conductor 5. This ensures that each individual wire 9 is gripped by an elongated welded connection 14.

In FIG. 15, the process of laser irradiation on the pressed electrical conductor 5 from FIG. 14 is shown. This process takes place in the pressing tool 1.3, following the

Compression of the electrical conductor 5, the position of which does not change. The laser beams 12 are arranged in the form of a grid and impinge normally on the surface of the individual wires 9 exposed in the opening 17. The grid-like arrangement of the laser beams 12 here comprises three parallel rows which run normal to the longitudinal direction of the individual wires 9, the middle row being offset by half a grid constant relative to the two outer rows. The outer rows here include, for example, eight laser beams, the middle row seven laser beams.

Correspondingly, three rows of eight or seven irradiated areas 13 are formed in the opening 17 on the surface of the individual wires 9.

Fig. 16 shows a possible arrangement of irradiated

Areas 13 in a larger schematic representation. The irradiated areas 13 are arranged here in two rows of nine irradiated areas 13 each, which rows together cover a length L which corresponds to the width of the pressed electrical conductor 5. The rows run normal to the longitudinal direction of the individual wires 9. Within a row, the irradiated areas 13 are spaced apart from one another which corresponds to the raster constant R. Between

adjacent rows are half a distance apart

Raster constant R. Due to the diameter D of a

irradiated area 13, which is above half the grid constant R, there is an overlap of the irradiated

Areas 13 of adjacent rows, that is to say an overlap in the longitudinal direction of the individual wires 9. It is essential, however, that the projection of all elongated welded connections 14, which in FIG. 16 differ from the

irradiated areas 13 extend downward into the plane of the drawing, on one plane, they extend normal to the plane of the drawing and parallel to the rows of irradiated areas 13

extends, the entire cross section of the grouted

electrical conductor 5 covers. This ensures that all individual wires 9 are covered by an elongated welded connection 14.

The irradiated areas 13 here have a diameter D of 0.6 mm, the grid constant R is 1 mm.

REFERENCE LIST

1 lower part of the pressing tool

2 contact element (cable lug)

3 Upper part of the pressing tool

4 contact section

5 electrical conductors

6 cable lug claw

7 cable lug claw

8 connecting section

9 single wire

10 support pool

11 Laser part (source of laser irradiation, device for laser irradiation)

12 laser beam

13 irradiated area

14 elongated welded joint

15 stage

16 step

17 Opening in the contact element 2

18 recess in the upper part 3

D diameter

L length

R grid constant

Claims

PATENT CLAIMS

1. A method for producing an electrical connection between an electrical conductor (5) comprising a plurality of individual wires (9) and a contact element (2), the electrical conductor (5) in one

Contact section (4) of the contact element (2) is arranged and subsequently the contact section (4) and the electrical conductor (5) are pressed together so that the contact section (4) engages around the electrical conductor (5),

characterized in that by means of a

Laser irradiation of the contact section (4), or by means of laser irradiation of the electrical conductor (5) through an opening (17) in the contact section (4), several elongated welded connections (14) spaced apart from one another between the contact section (4) and the

electrical conductors (5) are produced, the elongated welded connections (14) in one

Direction of irradiation from one irradiated

Area (13) of the contact section (4), or of an irradiated area (13) of the electrical conductor (5), through an entire cross-section of the pressed

electrical conductor (5) up to an area of the

Contact section (4), which lies opposite the irradiated area (13), so that the electrical conductor (5) is connected to this area of the contact section (4), the irradiated areas (13) being arranged in a grid shape.

2. The method according to claim 1, characterized in that the elongated welded connections (14) via a

Most of their length normal to the direction of irradiation are spaced apart.

3. The method according to any one of claims 1 to 2, characterized in that several elongated

Welded connections (14) are produced at the same time, in particular by the same source (11) of the laser irradiation.

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

characterized in that at least one irradiated area (13) is offset from another irradiated area (13) normal to the longitudinal direction of the individual wires (9), so that the projection of all elongated

Welded connections (14) on a cross-sectional area of the electrical conductor (5) which lies in the region of the elongated welded connections (14), a continuous

result in welded surface in the transverse direction of the electrical conductor (5).

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

characterized in that the degree of compression of the individual wires (9) in a longitudinal region of the

Contact element (2) in which no irradiated

Areas are less than in a longitudinal area of the contact element (2) where irradiated areas (13) are located.

6. The method according to claim 5, characterized in that the different degree of compression by a

Pressing tool (1) with a stepped support surface (10,15,16) is produced.

7. The method according to claim 5 or 6, characterized in that the different degree of compression is produced by a contact section (4) with cable lug claws (6,7) of different lengths in the transverse direction.

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

characterized in that the degree of compression of the Single wires (9) in a longitudinal area of the

Contact element (2), where there are irradiated areas (13), is greater than 70%.

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

characterized in that the laser irradiation takes place in that tool (1,3) in which the pressing takes place.

10. The method according to claim 9, characterized in that the position of the pressed electrical conductor (5) is not changed between pressing and laser irradiation.

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

characterized in that the production of an elongated welded connection (14) takes less than 100 ms, in particular less than 80 ms, e.g. around 60 ms.

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

characterized in that the diameter (D) of an irradiated area (13) is between 0.4 and 0.8 mm, in particular between 0.5 and 0.7 mm, preferably 0.6 mm.

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

characterized in that the grid constant (R) of the irradiated areas (13) is between 0.8 and 1.2 mm, in particular between 0.9 and 1.1 mm, preferably 1 mm.

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

characterized in that the largest diameter of an elongated welded connection (14) 0.7 to 0.9 mm,

in particular by 0.8 mm.

15. A device for establishing an electrical connection between an electrical conductor (5) comprising a plurality of individual wires (9) and a contact element (2) which Device comprising a pressing tool (1,3) with which the in a contact section (4) of the

Contact element (2) arranged electrical conductor (5) can be pressed with the contact element (2) so that the contact section (4) engages around the electrical conductor (5),

characterized in that a device (11) for laser irradiation is provided which is designed as a plurality of elongate spaced apart

Establish welded connections (14) between the contact section (4) and the electrical conductor (5), the elongate welded connections (14) each being irradiated by one in an irradiation direction

Area (13) of the contact section (4), or from an irradiated area (13) of the electrical conductor (5) in an opening (17) in the contact section (4), to an area of the contact section (4), which is the irradiated area (13) is opposite, so that the electrical conductor (5) with this area of the

Contact section (4) is connected, the

irradiated areas (13) are arranged in a grid.

16. Unit of an electrical conductor (5) comprising a plurality of individual wires (9) and a contact element (2), the electrical conductor (5) in one

Contact section (4) of the contact element (2) is arranged and the contact section (4) and the electrical conductor (5) are pressed together so that the

Contact section (4) surrounds the electrical conductor (5) and there is an electrical connection between the electrical conductor (5) and the contact element (2), characterized in that several elongated welded connections (14) spaced apart from one another between the

Contact section (4) and the electrical conductor (5) are present, the elongated welded connections (14) each extending in an irradiation direction from an irradiated area (13) of the contact section (4) or from an irradiated area (13) of the electrical

Conductor (5) in an opening (17) in the contact section (4) up to an area of the contact section (4) which is opposite the irradiated area (13), so that the electrical conductor (5) with this area of the contact section (4) connected, where the

irradiated areas (13) are arranged in a grid.

17. Unit according to claim 16, characterized in that the elongate welded connections (14) via a

Most of their length normal to the direction of irradiation are spaced apart.

18. Unit according to claim 16 or 17, characterized in that

that at least one irradiated area (13) is offset from another irradiated area (13) normal to the longitudinal direction of the individual wires (9), so that the projection of all elongated welded connections (14) onto one

Cross-sectional area of the electrical conductor (5), which lies in the area of the elongated welded connections (14), results in a continuous welded surface in the transverse direction of the electrical conductor (5).

19. Unit according to one of claims 16-18, characterized

characterized in that the diameter (D) is one

irradiated area (13) is between 0.4 and 0.8 mm, in particular between 0.5 and 0.7 mm, preferably 0.6 mm.

20. Unit according to one of claims 16-19, characterized

characterized in that the grid constant (R) is the

irradiated areas (13) is between 0.8 and 1.2 mm, in particular between 0.9 and 1.1 mm, preferably 1 mm.

21. Unit according to one of claims 16-20, characterized in that the largest diameter of an elongated welded connection (14) is 0.7 to 0.9 mm, in particular around 0.8 mm.