阅读说明：本技术 电导体以及用于制造电导体的方法 (Electrical conductor and method for producing an electrical conductor ) 是由 奥利弗·沙尔科夫斯基 于 2020-01-22 设计创作，主要内容包括：本发明涉及一种电导体,尤其扁导体,其包括至少一个通口和在通口处材料配合地与导体连接的接触部件,其中,接触部件具有轴向延伸的第一区段和径向延伸的第二区段,其特征在于,第二区段形成为凸缘,并且凸缘的面向导体的一侧具有与导体焊接的表面,且该表面具有至少一个凹陷和/或至少一个凸起。(The invention relates to an electrical conductor, in particular a flat conductor, comprising at least one through opening and a contact part which is connected to the conductor at the through opening in a material-fitting manner, wherein the contact part has a first section which extends axially and a second section which extends radially, characterized in that the second section is formed as a flange, and the side of the flange facing the conductor has a surface which is welded to the conductor and which has at least one recess and/or at least one projection.)

1. An electrical conductor, especially a flat conductor, comprising

-at least one through opening, and

a contact part connected to the conductor at the opening in a material-locking manner, wherein the contact part has a first section and a second section in the axial direction,

it is characterized in that the preparation method is characterized in that,

the second section is formed as a flange, and the side of the flange facing the conductor has a surface welded to the conductor, and the surface has at least one recess and/or at least one projection.

2. The electrical conductor of claim 1,

the surface facing the conductor is formed in relief, in particular in regular relief or in hump, in particular in regular hump, wherein the projections are formed in particular as humps.

3. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the at least one recess and/or the at least one projection extend circumferentially, in particular coaxially circumferentially, around a center point of the conductor-facing surface.

4. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the at least one projection is undercut.

5. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the at least one projection has a partially circular surface section, in particular the at least one projection has a concave and a convex region.

6. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the at least one depression has a partially circular surface section, in particular the at least one elevation has a convex region.

7. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the contact member is metal coated.

8. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the contact part is configured as a welding eye.

9. An electrical conductor according to claim 1, wherein,

it is characterized in that the preparation method is characterized in that,

the first section is formed in a stick or tube shape.

10. An electrical conductor according to claim 1, wherein,

it is characterized in that the preparation method is characterized in that,

the second section has in particular a round or angular base surface.

11. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the first section has a substantially circular outer periphery, an

The first section has a through opening, wherein the through opening is formed in an inner polygon shape.

12. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the first section and the second section are integrally formed.

13. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the first portion is arranged in a material-fit manner, in particular by friction welding, on the inner diameter of the passage opening.

14. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the flange is connected to the conductor by means of a material fit, in particular by friction welding, with its surface facing the conductor.

15. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the outer periphery of the first section tapers from the second section in the axial direction of the through opening.

16. An electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the contact member is formed of a metal material different from the conductor, particularly, the conductor is formed of an aluminum material and the contact member is formed of a copper material, or the conductor is formed of a copper material and the contact member is formed of an aluminum material.

17. Contact element for contacting an electrical conductor, in particular according to one of the preceding claims, having

-an axially extending first section and a radially extending second section,

it is characterized in that the preparation method is characterized in that,

the second section is formed as a flange and the side of the flange facing the first section has a surface with at least one recess and/or at least one projection.

18. Method for manufacturing an electrical conductor according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the contact part is welded to the conductor by means of resistance welding, in particular projection welding, friction welding, in particular spin friction welding or magnetic pulse welding.

19. The method according to claim 12 or 13,

it is characterized in that the preparation method is characterized in that,

the contact part is welded by its second section to the surface of the conductor.

20. The method according to claim 12 or 13,

it is characterized in that the preparation method is characterized in that,

during welding, the contact surface in the region of the projection is first brought into contact with the conductor, the conductor material in the region of the contact surface is plasticized by the energy introduced, and at least part of the plasticized conductor material flows into the recess and hardens in the recess after welding.

Technical Field

The invention relates to an electrical conductor, in particular a battery conductor, in particular in the form of a flat conductor, in particular for automotive use, and to a method for producing an electrical conductor.

Background

In the automotive industry, flat wires (also called ribbon wires) have recently become more and more frequently used instead of round wires. Especially for battery lines, preferably B + lines, on which high currents are conducted, flat ribbon lines have proven to be advantageous. The flat ribbon wires make it possible to achieve a large wire cross section in a small installation space, in particular in narrow inaccessible areas, on the basis of the form factor, which improves the current carrying capacity of the battery wires. For electric vehicles that obtain multiple 100V voltages via the battery wires, flat ribbon wires are also increasingly used. The energy lines must also meet high demands with regard to current carrying capacity and power.

However, for the contacts of the electrical consumers, circular conductors continue to be used. This is mainly due to the fact that electrical consumers mostly have to be contacted via flexible wires. When installing the connecting lines between the rigid battery lines and the electrical consumer, it is often necessary to incorporate the lines into a narrow installation space, for which it is easier to use round conductors than rigid flat strip conductors. Therefore, when using a flat ribbon conductor as the main wire (Hauptstrang) of the battery wire, contact between the flat ribbon conductor and the round conductor is necessary. Such contact can be achieved, for example, via a connecting bolt. The round wire can then be electrically contacted to the connecting bolt, for example by means of friction welding. The outputs to the electrical consumers may be arranged at different locations along the ribbon conductors. The electrical cable so formed may be installed in Kfz and the consumer connected to the battery line via a round conductor.

However, it has been found that mounting the connecting bolts to the ribbon conductors is problematic in many cases. This connection must be electrically stable and protected against environmental influences. Furthermore, when aluminum is used as the conductor material of the flat strip conductor, it must be ensured that this conductor material does not deform during the connection of the connecting bolt. In particular, when the connecting screw is tightened, it can lead to the screw being pressed into the aluminum. Since aluminum has a relatively high viscosity compared to other metals, there is a problem in that the tightening torque of the screw connection for connecting the bolts may not be maintained. Furthermore, it can happen that the tightening is loosened under mechanical stress, since the aluminum of the flat strip conductor can be deformed in the case of tightening. Furthermore, the transition between aluminum and more noble metals (e.g., copper) is susceptible to contact corrosion. The direct connection point must be protected against environmental influences.

DE 0758107 a discloses a method for producing a cable lug made of aluminum or an aluminum compound, the connecting eye of which is provided with a protective layer, characterized in that the eye of the cable lug is first coated with a layer made of a well-conducting material by means of electroplating, and in this case, in order to protect the sensitive thin electroplated layer, a ring made of the same material is optionally fitted as a further, stronger protective coating, which ring covers the hole of the eye, the flange of which ring covers the contact area of the eye in whole or in part.

Furthermore, a method and a device for connecting an electrical conductor to a metal rod, for example a rail, by means of a screw connection are known from WO 2006/057592 a 1. This document also relates to a tool for fixing the sleeve inside the metal bar. The sleeve forms part of a screw connection.

DE 102006050708 a1 discloses a friction welding sleeve which is welded into an opening of a flat conductor.

The problem of the contact between the connection eye and the flat conductor is the metal coating of the connection eye and/or the flat conductor. The coating material usually has different mechanical and chemical properties than the material of the connecting eye or the conductor. The coating material, particularly nickel, may have a higher melting point and/or a higher hardness. This is disadvantageous during welding, since the welding process is impeded by the different melting points of the joining partners.

Disclosure of Invention

The invention is therefore based on the object of simplifying the connection between the conductor and the contact element by means of soldering.

This object is achieved by a conductor according to claim 1, a contact part according to claim 17 and a method according to claim 18.

The invention relates to a conductor, in particular a flat conductor (ribbon conductor) with a through opening. The through openings are preferably holes. The holes may be cylindrical or frustoconical. The hole is preferably adapted to the contact part inserted into the passage opening, which is likewise provided according to the invention, in particular adapted to the cross section of the contact part in its first section.

Especially when the conductor according to the invention is applied in automotive applications, for example as an electrical energy conductor, for example as a battery conductor, for example as a B + conductor or a B-conductor or as a conductor in an at least double-layer cable, there is always a challenge to provide an electrical output at the conductor. It is in automotive applications that electrical conductors are subject to problematic operating and environmental conditions. The environmental conditions can be very different, so that the connection locations at the electrical conductors are subjected to strongly fluctuating temperatures, humidity, electrolytes, etc. These environmental conditions, which in particular also lead to thermal expansion or accelerated contact corrosion, require that the screw be fixed as reliably as possible to the electrical conductor. On the other hand, electrical conductors are dynamically loaded, especially in automotive applications. The electrical outputs formed by the bolts must also withstand these dynamic loads and be arranged at the electrical conductors in a reliable and electrically conductive manner at all times.

In order to achieve a connection between the electrical conductor and the output, for example a screw, in particular a screw or the like, it is proposed to provide a contact part which is welded to or in the passage in a material-fitting manner. The material-fit connection of the contact element to the conductor ensures a reliable contact at the conductor. The contact member may be formed as a sleeve having a through hole.

However, the mounting of the contact elements at the openings is process-technically demanding.

In particular when the contact parts are coated with metal, it can occur that the soldered connection is technically problematic. Problems may arise in welding if the coating material has a different melting temperature and/or surface hardness than the conductor. In particular in friction welding processes, magnetic pulse welding processes and resistance welding processes, the desired interaction between the joining partners may not occur due to the different melting temperatures. It is necessary for welding that the two mating parts are melted. If one of the mating parts has a surface made of a material with a very high melting temperature, it is possible that no melting occurs. Higher melting temperatures require higher energy input in order to cause melting.

The contact part may be formed by at least two sections. The two sections extend in the axial direction of the contact part. The first section has a first circumference and the second section has a second outer circumference greater than the first circumference. The second section may thus project radially outwards with respect to the first section. When the contact element is fixed to the passage of the conductor, the contact element is preferably inserted with the first section into the passage of the conductor. The second section results in the insertion depth of the contact element in the passage of the conductor being limited, since the second section forms a stop.

After the contact member has been inserted into the through opening of the conductor, the friction welding process may be started. In the friction welding process, the contact part is preferably welded by friction welding in the region of the contact surface between the flat conductor and the second section. The second section is pressed against the surface of the conductor by a pressing force on the contact element. It has been recognized that the greatest welding energy occurs precisely in this region and that this region is welded, in particular, by means of friction welding first.

The second section is preferably designed as a flange and serves on the one hand as an abutment surface for the flat conductor and on the other hand as an enlarged bearing surface for a connecting bolt or a connecting part of the electrical consumer. The contact surface is the surface facing the conductor. The bearing surface is the surface opposite thereto. The bearing surface, in contrast to the contact surface, is preferably flat. The head of the connecting bolt or a nut or washer screwed onto the connecting bolt can be placed on the surface of the flange facing away from the flat conductor. The connection of the consumer can also be arranged on the bearing surface. The bearing surface may be circular, rectangular, square, polygonal, etc. The contact surface can have a radially more outwardly projecting region and a radially less outwardly projecting region along the circumference. The bearing surface may have a uniaxial, biaxial, triaxial or multiaxial geometry. The bearing surface may have a roughness greater than the surface roughness of the flat conductor. Thereby, it may be advantageous for the contact piece to be contacted at the bearing surface, for example by means of friction welding.

It has been found to be particularly advantageous if the first section and the second section are integrally formed. In particular, the contact part can be formed as a stamping or as a lathe. The integrity prevents the contact parts from being damaged during the welding process, in particular the connection between the first section and the second section from being released. On the other hand, it is achieved that the contact element is permanently subjected to dynamic environmental conditions.

Now, according to the invention, it is proposed that by forming the contact location in the region of the flange of the contact part and the flange having a depression and/or a projection in the region of the surface facing the conductor (contact surface), the pressing force at the contact location between the contact part and the flat conductor is increased and thus the input energy is increased. During welding, therefore, the contact surface of the contact element, i.e. the surface of the flange facing the conductor, is supported on the conductor only with a small contact surface. The total welding energy is introduced into this small bearing surface, so that a significantly higher temperature is achieved at the same contact pressure. This results in that not only the contact parts, in particular the coating of the contact parts, melt, but also the conductor. A significantly higher surface pressure occurs during the welding process relative to the beginning of the welding process. The material of the conductor as well as the material of the contact member and/or its coating melts. The molten material, in particular of the conductor, can thus flow into the recess of the contact surface and harden there after welding, so that a form fit can additionally be established in addition to the material fit.

According to one embodiment, it is provided that the surface facing the conductor is embossed, in particular regularly embossed. The projections of the structured surface preferably lie in the same plane at their apex and bear on the conductor during the soldering process. The local maxima of the projections are of small area, so that only a small contact surface is produced, and therefore, with the same contact pressure, the contact pressure is significantly higher than when the flange is supported over the entire surface area on the conductor. This increased pressing force results in an improved melting of the two mating parts.

The protrusions may be referred to as peaks and the depressions may be referred to as valleys.

It is also proposed that the surface facing the conductor is formed in a hump shape, in particular a regular hump shape. The hump may have a peak and a valley. A plurality of the peaks of the hump, in particular all peaks, can lie in one plane in the region of their apex. A plurality of the valleys, in particular all valleys, may also lie in one plane in the region of their vertices.

In particular in the case of rotary friction welding, the contact part is preferably rotated about its center point. In order to obtain good welding results, it is proposed that the at least one recess and/or the at least one projection is circumferential. The depressions and/or projections extend in a circumferential manner to a center point, in particular to a center point of the surface facing the conductor. It is also possible for the depressions or projections to extend only over certain corner sections. Between two adjacent depressions or projections, a region can be formed in which the surface facing the conductor is not altered. The circumferential projection can thus be formed by a plurality of angular segments spaced apart from one another, in each of which a projection is formed, in particular a projection in a circular arc segment around a central point.

According to one embodiment, it is provided that the at least one projection is undercut. By means of the welding energy introduced, the material of the conductor and/or the contact part melts, which can also be referred to as plasticization. When the material of the conductor and/or the contact part plasticizes, the plasticized material can flow into the undercut. After the material has hardened, a material fit is thus formed not only in the region of the intermetallic connection, but also in the region of the hardened material in the undercut. The projections form in particular drops or omega-shapes in the surface.

According to one exemplary embodiment, it is provided that the projection has an arcuate, in particular partially circular, surface section. The projection may have an arcuate, in particular partially circular, section in a cross section parallel to the longitudinal axis of the contact part. In this case, a convex upper apex can be formed in the region of the concave surface section. Undercuts may be formed in the convex regions.

According to one embodiment, it is provided that the at least one recess has an arcuate, in particular partially circular, surface section. In particular, in a section parallel to the longitudinal axis of the contact part, an arc-shaped, in particular partially circular, section can be formed in the region of the depression. In particular, the depression is formed by a convex region.

According to one embodiment, it is provided that the contact element is metallically coated. The metal coating may in particular be tin or nickel plating. In particular, the coating can also be multilayered, in particular tin-plated in the case of an underlying nickel layer.

According to one exemplary embodiment, it is provided that the contact element is designed as a welding eye. Such a welding eye is particularly suitable for subsequent screwing with a bolt, at which a round conductor can be arranged.

According to one embodiment, it is provided that the first section is configured in the shape of a stick or a tube.

The second section, in particular the flange, can have a round or angular base surface.

The through-hole can pass through not only the first section but also the second section. The through-hole may be located in the area of the center points of the first section and the second section in a cross-section perpendicular to the longitudinal axis of the contact part. The through-holes can be round or angular, with regions that project radially more outward and regions that project radially less outward, in particular formed as polygons or as a multi-circle (Mehrrundform).

In spin friction welding, the contact part must not only be pressed against the conductor with a sufficiently large pressing force, but also be set in rotation. Here, the friction welding tool must rotate the contact part during its rotation, while also pressing the contact part against the conductor.

It has proven to be sufficiently good for the electrical contacting of the electrical outputs at the contact elements to take place even if the screw required for this purpose does not abut directly against the inner circumference of the contact elements formed as sleeves. It is sufficient for the bolt head to bear against the contact part at the end face. Then, a sufficiently good electrical contact is possible. On the other hand, this results in that neither a form fit nor a complementary cross section between the inner circumference of the through opening in the contact part or the through opening in the contact part and the outer circumference of the bolt is required. It is conversely to be noted that it is advantageous for the production process to provide a through opening in the contact part, which through opening is formed as an inner polygon. Preferably, an inner circumference of the through-port is preferably formed in a polygonal shape. On the other hand, the outer circumference of the contact member is preferably substantially circular or angular.

In this context, it should be mentioned that the concept of an inner polygon is also understood to mean a multi-circle shape. In particular, the passage opening is formed as a driving contour having a section with a smaller radius and a section with a larger radius, wherein the sections are alternately successive one after the other. A particularly good fit of the contact part at the passage opening is achieved in that the outer circumference of the first section tapers from the second section in the axial direction of the passage opening. The first section is preferably frustoconical here.

The inner circumference of the through opening of the conductor substantially coincides with the outer circumference of the rod-shaped or tubular second section of the contact member. And the inner periphery of the through hole in the contact member is formed polygonal and does not coincide with the outer periphery thereof nor with the bolt inserted into the through hole of the contact member.

The extent of the first section in the axial direction preferably corresponds to the material thickness of the electrical conductor in the direction of the passage opening. It is then ensured that the first section rests preferably flush against the opening of the electrical conductor.

As previously mentioned, it is preferable for the case where the flat wire is formed of aluminum to cause a problem of contact between the flat wire and the round wire. The use of an aluminum material as the material of the flat wire has great advantages in terms of material cost and weight, so that it is preferable that the flat wire is formed of an aluminum material or an aluminum alloy.

The contact member may be formed of a transition metal material or an alloy thereof. Preferably, a stainless steel sleeve, a copper sleeve or a brass sleeve is used. By using a contact member made of a material different from aluminum, two advantages are obtained. On the one hand, the electrical contact between the connection bolt and the wire is prevented from being deteriorated by the alumina. On the other hand, when a material harder than aluminum is used, the mechanical strength of the connection between the flat wire and the connection bolt can be improved. When stainless steel, copper or brass is used, it is ensured that the mechanical stress through the contact parts does not cause significant deformation of the contact parts when the connecting screw is tightened. In the case of a continuous mechanical load, it is also ensured that the end faces of the contact parts are not deformed significantly, so that a permanently fixed connection between the connecting bolt and the sleeve is ensured. The contact part can also be coated with metal, wherein the coating can be formed, in particular, from nickel, tin or alloys thereof. The coating of the contact elements can be matched to the material of the connecting bolts, screws, connections of electrical appliances, etc.

Another aspect is a contact member for contacting an electrical conductor in the manner and method described above. The flange (collar) of the contact part in the region of the second section is formed with at least one depression and/or projection on the side which is in contact with the conductor.

According to another aspect, a method for manufacturing an electrical conductor is presented. The electrical conductor is connected to the contact part in such a way that the contact part is welded to the conductor by means of resistance welding, in particular projection welding, friction welding, in particular spin friction welding or magnetic pulse welding. The relief-like surface makes it possible for the contact element to bear on the conductor with only a small bearing surface in the region of the collar. The welding energy introduced during welding is thus distributed over a very small contact surface, so that even the coating of the material with the high melting point of the contact parts melts. This establishes a reliable material-fit connection between the contact element and the conductor.

First, the contact member is brought into contact with the conductor using the projection. The apexes of some or all of the lobes preferably lie in a single plane. Contact with the conductor occurs in this plane. Energy is then introduced into the contact surface thus formed by means of any of the welding methods described above. By this introduced energy, not only the surface of the contact member but also the surface of the conductor is plasticized. The plasticized material can flow into the recess and harden there after welding. A form-fitting connection is thereby also established in addition to the material-fitting connection.

Drawings

The subject matter is further elucidated below with the aid of the drawing showing an embodiment. In the drawings:

fig. 1 shows a conductor with a contact member;

2a-d illustrate different contact members according to various embodiments;

3a-c illustrate different contact members having conductors according to various embodiments;

fig. 4a-c show the connection of a contact part with a conductor by means of soldering according to an embodiment;

fig. 5 shows a top view of a conductor with a contact member.

Detailed Description

Fig. 1 shows an electrical conductor 2 with a contact member 4. The electrical conductor 2 has a through opening 6. The electrical conductor 2 is formed in particular as a flat conductor. The electrical conductor 2 has in particular a flat surface facing the contact member. In particular, the through opening 6 is formed in the region of the end-side end of the conductor 2. The conductor 2 is preferably surrounded by an insulating part 8 at a distance from the end face. The conductor 2 is preferably composed of an aluminum material or a copper material.

The contact part 4 has a first section 4a and a second section 4 b. The first section 4a extends in the direction of the longitudinal axis 4c of the contact part 4 in a tubular or rod-like manner. The second section 4b extends radially outwards in the form of a flange. The second section 4b has a contact surface 4 b' facing the conductor 2 in the connected state. The contact surface 4 b' is shaped according to the manner of the invention, as will be described below.

Fig. 2a-c show a cross section parallel to the longitudinal axis 4c and a bottom view on the contact surface 4 b' perpendicular to the longitudinal axis 4c, respectively, on the left side.

Fig. 2a shows a contact part 4, wherein the contact surface 4 b' has a projection 10. The projections 10 are applied partly circularly in the form of elevations on the contact surface 4 b'. A through hole 4d extends through the first section 4a and the second section 4b in the direction of the longitudinal axis 4 c.

The protrusion 10 extends in the corner section around the through hole 4 d. Fig. 2a shows that the projections 10 are arranged opposite one another at a distance in the corner section. In particular, two or more projections 10 can be arranged radially from the inside to the outside. The angular segments occupied by the projections 10 may be intermittent, as shown in fig. 2a, or may overlap one another.

Fig. 2b shows a contact part 4 with a protrusion 10 and a depression 12. It can be seen that the apex of the protrusion 10 (kulminatonsuckt) lies in a first plane 14 and the apex of the depression 12 lies in a second plane 16.

In fig. 2b, it can be seen that, in the view of the contact surface 4 b', the elevations 10 and depressions 12 are formed completely circumferentially and circularly around the passage opening 4 d.

Fig. 2c shows a projection 10 with an undercut. The projection 10 has a convex region 10a and a concave region 10 b. The concave area 10b is formed as an undercut. The projection 10 according to fig. 2c is configured in an omega shape. On the surface 4 b', the protrusions 10 may be irregularly or regularly distributed. The distribution of the rules is shown in fig. 2 c.

FIG. 2d shows a projection 10, which is thorn-shaped () Is formed and circumferentially arranged on the contact surface 4 b'.

Fig. 2e shows a part-circular protrusion 10 and an angular depression 12. Here, the elevations 10 and depressions 12 can also be arranged circumferentially at the contact surface 4 b'. It will be appreciated that the arrangement of the protrusions 10 and depressions 12 on the surface 4 b' may be varied freely to be fully circumferential, partially circumferential, angular segmental, intermittent or overlapping, regular or irregular.

Fig. 3a shows the contact element 4 according to fig. 2a on the conductor 2. It can be seen that the projection 10 penetrates into the material of the conductor 2 during soldering. The plasticized material hardens in the region of the spaces between the projections 10. The contact surface 4 b' is located entirely on the conductor 2.

Fig. 3b shows the connection of the contact element 4 according to fig. 2b to the conductor 2. Here, too, the projection 10 penetrates into the material of the conductor 2.

Fig. 3c shows the contact element 4 according to fig. 2c at the conductor 2. During welding, the material of the conductor 2 is plasticized and thus flows into the undercut 10b of the projection 10.

Fig. 4a shows the welding of the contact part 4 with the conductor 2 by means of electromagnetic pulse welding. The coil 16 is energized, whereby the contact element 4 is accelerated in the direction 18 onto the conductor 2. The conductor 2 is supported on the counter support 20. The contact element 4 is accelerated in the direction 18 through the through opening 6. The protrusion 10 collides with the surface of the conductor 2. In this case, both a deformation and a plasticization of the material take place, so that a material-fit and/or form-fit connection is formed.

Fig. 4b shows resistance welding. At this time, the projection 10 is in contact with the conductor 2. The contact member 4 is energized by an electrode, and the conductor 2 is also energized by an electrode. Due to the small contact surface between the contact element 4 and the conductor 2 in the region of the projection 10, an excessively high transition resistance results, so that the material of the contact element 4 and the material of the conductor 2 melts. Due to the small bearing surface, not only the material of the conductor 2 but also the coating material of the possibly contacting part 4 melts.

Fig. 4c shows spin friction welding, wherein a spin plunger 22 is inserted into the through opening 4 d. The rotary piston can rest as a polygon in the inner polygon of the opening 4 d. The rotary plunger 22 rotates in the direction 22', wherein the contact element 4 bears with the projection 10 on the conductor 2 and plasticizes the material.

Fig. 5 shows a top view of the contact part 4. It can be seen that the contact part 4 has a quadrangular bottom surface.

By means of the contact part shown, a reliable welding can be ensured even if the contact part is coated with metal, in particular with a material having a high melting point (in particular a melting point above the melting point of the conductor and/or the contact part 4).