WO2023110505A1

WO2023110505A1 - Electrical contact assembly, prefabricated unit, and method for producing an electrical contact assembly

Info

Publication number: WO2023110505A1
Application number: PCT/EP2022/084475
Authority: WO
Inventors: Volker Albert; Martin Burger; Alexander KETT
Original assignee: Leoni Bordnetz-Systeme Gmbh
Priority date: 2021-12-15
Filing date: 2022-12-05
Publication date: 2023-06-22
Also published as: EP4441849A1; DE102021214367A1

Abstract

The invention relates to an electrical contact assembly (2), comprising: a first conductor rail (4), which has a first through-hole (22) having a peripheral first inner wall (26), a contact element (6), which is electrically connected to the first conductor rail (4) and which in particular has a second through-hole (24) having a second peripheral inner wall (28), a bolt, which in particular is in the form of a threaded bolt (8B), and a fastening element for fastening the conductor rail (4) to the contact element (6), the fastening element in particular being in the form of a nut (10). For a reliable electrical contact connection, a contact sleeve (12) having a peripheral side (17) is provided, the contact sleeve (12) being inserted through the first through-hole (22) and in particular the two through-holes (22, 24), and the peripheral side (17) of the contact sleeve (12) being electrically conductively seated against the first, in particular both peripheral inner walls (26, 28).

Description

Electrical contact arrangement and prefabricated assembly and method for producing an electrical contact arrangement

The invention relates to an electrical contact arrangement, especially for the automotive sector, and a prefabricated assembly for such an electrical contact arrangement. The invention also relates to a method for producing an electrical contact arrangement.

The contact arrangement is designed in particular as a screw contact and has a conductor rail which has a first through-hole with a peripheral inner wall. Furthermore, the contact arrangement includes a contact element, which usually rests flat on the conductor rail and is electrically conductively connected to it. The contact element has a second through hole with a further circumferential inner wall. A screw is inserted through the two through-holes onto which a nut is screwed, the conductor rail and the contact element being arranged between the screw and the nut.

Such a contact arrangement can be found, for example, in DE 10 2016 117 835 A1.

Such contact arrangements are used specifically in the automotive sector for connecting a conductor rail to a contact element, such as a cable lug with a line attached thereto, or to another conductor rail. Such contact arrangements are used, for example, to connect to ground tion or for other power supply of power consumers. For reasons of weight, the conductor rail often consists of an aluminum material. This is understood to mean aluminum or an aluminum alloy. If aluminum is mentioned here, this means pure aluminum, for example with the designation AL 99.5 or AL 99.7. Such pure aluminum has good electrical conductivity. The contact element consists optionally also of an aluminum material or of another metal, in particular with a higher strength, such as copper or a copper alloy. If an alloy (Cu, Al) is mentioned here, this means in particular an alloy in which the Cu or Al content is greater than 50% by weight.

With regard to the electrical contact arrangement, the problem with an aluminum material, especially with the pure and comparatively soft aluminum that is preferably used because of its good conductivity, is that aluminum tends to flow. Especially with screw connections, the material begins to flow as a result of the screw force and the contact force decreases over time, which can lead to an increase in contact resistance. There is also the problem that an oxide layer forms on the surfaces, which leads to a significant increase in the contact resistance. Finally, there is the problem that in connection with more noble materials, in particular copper, there is a risk of so-called contact corrosion.

In DE 10 2016 117 835 A1, an AL busbar is electrically connected to a CU cable lug using a screw. In this case, a contacting element is additionally provided, which is connected to the conductor rail in the area of the through-hole in a cohesive manner and on which the cable lug lies flat.

Proceeding from this, the object of the present invention is to ensure a reliable contact arrangement, in particular screw contacting, especially when using an aluminum conductor rail. The object is achieved according to the invention by an electrical contact arrangement with the features of claim 1. This has a conductor rail with a first through-hole with a peripheral inner wall and a contact element which lies flat on the conductor rail and is electrically conductively connected to it. In the present case, the conductor rail is also referred to as the first conductor rail.

The contact element preferably has a second through hole with a second peripheral inner wall. The two through holes are aligned with each other. They are preferably designed as circular through-holes with the same inner diameter. The inner walls are in particular cylindrical inner walls.

Furthermore, a (fastening) bolt, in particular a screw bolt, is provided together with a fastening element, in particular a nut, with the aid of which the conductor rail is fastened to the contact element, in particular the conductor rail is pressed against the contact element. In embodiment variants in which the bolt has a bolt head, the conductor rail and the contact element are arranged and in particular clamped between this and the fastening element (nut). In the variant with the second through-hole in the contact element, the bolt is passed through the two through-holes.

In order to ensure a good and permanently reliable electrical contact connection, a contact sleeve is also provided, which is inserted at least through the first and preferably through the two through-holes. The bolt is in turn passed through the contact sleeve. A peripheral side of the contact sleeve is in electrically conductive contact with the first inner wall and in particular with the two peripheral inner walls. Furthermore, at least one of the components selected from a bolt head (screw head) and fastening element (nut) is usually in electrically conductive contact with a front end of the contact sleeve. Due to the electrically conductive contact of the peripheral side of the contact sleeve with the first inner wall, a reliable electrical connection is established between the conductor rail and the contact sleeve and, via this, with the contact element. The contact sleeve is therefore electrically conductively connected to the contact element.

In the preferred variant with the second through hole also in the contact element, a reliable electrical connection between radial (circumferential) surfaces of the through holes on the one hand and the contact sleeve on the other is achieved via the contact sleeve and the two inner walls. The result of this is that a large part of the current flow of this electrical connection leads via the radial sides of the inner walls and via the contact sleeve. This electrical connection is therefore independent or largely independent of the contact force applied via the bolt and the fastening element. Any flow of the material of the conductor rail that may occur as a result of the contact force and an associated reduction in the contact force leaves the electrical connection via the radial surfaces unaffected or at least largely unaffected.

The contact sleeve preferably consists of a material that is different from the conductor rail, in particular copper. In general, the material of the contact sleeve is preferably harder than that of the conductor rail.

The contact sleeve is an independent component. The contact sleeve is in particular rotationally symmetrical and preferably has a cylindrical sleeve part.

In a preferred embodiment, the surface of the contact sleeve is provided with a coating of a coating material (which is harder than the base material of the contact sleeve), such as nickel. This achieves a better break-up of oxide layers in the through-holes and reduces a possible tendency to corrosion. The conductor rail is in particular a conductor rail made from an aluminum material, in particular from (pure) aluminum.

A conductor rail is generally understood to be a flat, solid conductor with a rectangular cross-sectional area, optionally with rounded corner areas. The conductor rail usually has a thickness in the range of several millimeters.

According to a preferred embodiment, the contact sleeve is oversized in relation to the at least one and preferably in relation to both through-holes, so that the peripheral side is pressed against the at least first inner wall. At least in the initial state, ie before the contact sleeve is pressed into and through the two through-holes, an outer dimension of the contact sleeve is larger than an inner dimension of the first through-hole and preferably of the two through-holes by the oversize. The excess in the initial state is between 1/10 and 2/10 mm, for example.

The first through-hole and in particular both through-holes and the contact sleeve preferably have the same or at least essentially the same cross-sectional geometry and in particular a circular cross-sectional geometry. The contact sleeve is therefore in particular cylindrical in the area of its peripheral side.

In a preferred embodiment, the contact sleeve has a structured surface on its peripheral side, which has in particular elements that protrude radially outwards. In particular, ribs are formed on the peripheral side. In the case of the formed contact arrangement, the structured surface is pressed into the inner walls of the two through-holes. In the embodiment with the ribs, these preferably run parallel to a longitudinal direction, which is defined by a longitudinal axis of the screw or a longitudinal axis of the contact sleeve. A large number of such ribs (for example more than 20) are preferred, in particular uniformly around the peripheral side in the manner of a formed with a knurl. In the area of the peripheral side, the contact sleeve is therefore still of essentially cylindrical design. This means that the ribs or knurling are formed on a cylindrical sleeve part and the ribs themselves in turn span a cylinder jacket surface.

As an alternative to the cylindrical design of the contact sleeve, it can also have a different cross-sectional contour than the through-holes, for example in the manner of a polygonal cross-sectional contour compared to a circular cross-sectional contour of the through-holes. The individual corners of the polygonal cross-sectional contour would then form the ribs.

In general, an outer wall of the contact sleeve, that is to say the peripheral side of the contact sleeve, extends parallel to a central axis of the through-hole of the conductor rail and thus also of the bolt. Specifically, the contact sleeve, at least the partial area defined as the sleeve part, which lies in the through-holes in the installed position, is of cylindrical design. The configuration with the ribs is in particular longitudinal ribs, which therefore extend in the longitudinal direction parallel to the central axis.

The particular advantage of this configuration with the ribs, especially in connection with the oversize described above, is that when the contact sleeve is pressed in, the surface of the respective inner wall is broken up, so that any existing oxide layer is reliably broken through. The contact sleeve is therefore, overall, very intimately interlocked with the respective inner wall by means of the surface structure, specifically the knurling, so that overall a very low contact resistance is permanently ensured.

According to a preferred embodiment, the fastening element, ie in particular the nut, has an underside facing the contact sleeve, in which a recess—in the case of the design as a nut in addition to the mandatory threaded hole of the nut—is formed. Specifically, the recess is formed in the area of the through hole, so that a free space is created following the through hole. Therefore runs around the threaded hole in addition, an annular free space which is delimited at the edge in the radial direction by an annular edge web. This free space serves in particular as a depot for any chips that are scraped off the inner walls as a result of the ribs when the contact sleeve is pressed in.

In a preferred development, the contact sleeve extends into the recess in the mounted position, i.e. a section of the contact sleeve, in particular a bevel at the end, lies in the recess. This ensures the largest possible surface contact between the contact sleeve and the conductor rail and the contact element. The length of the sleeve part adjoining the collar is therefore suitably matched to the thickness of the conductor rail and the contact element.

During assembly, the procedure is preferably such that the contact sleeve during the fastening process, i.e. when the fastening element is connected to the bolt, i.e. for example when tightening the nut or screw, at least a little way through at least the first through hole and in particular through both through holes in particular is pressed completely through, so that the chips mentioned arise during the fastening process and preferably also exit into the recess.

In a preferred embodiment, the contact sleeve has a collar with which it rests on one of the two components selected from the conductor rail and the contact element. The particularly cylindrical sleeve part is connected to this collar. One of the two components selected from the bolt and fastening element (bolt and nut) rests on this collar. In contrast, the other of these two components (nut, screw bolt) rests directly on the other component selected from the conductor rail and contact element. Overall, this ensures that the conductor rail and the contact element are reliably clamped against one another and in particular against the collar of the contact sleeve. Specifically, the bolt with a bolt head (screw head) rests on the collar of the contact sleeve. In a preferred embodiment, the contact arrangement is gas-tight to the extent that no ambient air can reach the area between the contact sleeve and the first inner wall and in particular the entire contact area between the contact sleeve and conductor rail and contact element. This gas-tight configuration is ensured by the pressing of the conductor rail and the contact element between the bolt and the fastening element, specifically with the collar of the contact sleeve being interposed. As previously mentioned, it is provided for assembly that the contact sleeve is only fully guided into an end position during the fastening process, especially when screwing the two screw partners together, ie during the fastening process, the structured surface of the contact sleeve causes the surface of the respective inner wall to break open. At the same time, gas-tight sealing takes place immediately during the assembly process, so that there is no risk of an oxide layer forming on the freshly broken surfaces.

In a preferred embodiment, the conductor rail consists of an aluminum material and in particular of pure aluminum. At the same time, the contact sleeve consists in particular of copper. The contact element optionally also consists of an aluminum material and in particular of pure aluminum or another metal, in particular copper. In a first embodiment variant, the contact element is, for example, a cable lug to which a conventional (sheathed) cable is attached. In a preferred embodiment, however, the contact element is a second conductor rail, which in particular also consists of an aluminum material and in particular of pure aluminum.

As mentioned, the contact element preferably has a (second) through hole. As an alternative to this, only the conductor rail has a through hole. In this case, the bolt is preferably a one-piece part of the contact element and is connected to it, for example, with a material fit, for example by welding, or also with a frictional and/or positive fit, for example by being pressed in. According to one embodiment variant, the bolt is a connection bolt, eg a battery pole of a battery.

As an alternative to the preferred configuration of the bolt as a screw bolt and a screw fastening, a rivet fastening is also provided, for example. This means that the fastening element can be a rivet or a rivet head.

According to the invention, the object is further achieved by an electrical contact arrangement having the features of claim 12 . In this case, the contact sleeve described above is not mandatory. For a reliable electrical contact connection, the conductor rail has a main part with a terminal attached thereto in a materially bonded manner, the terminal having the first through hole and being made of a different material than the main part, at least in the region of the first through hole. The terminal is therefore a part of the conductor rail, which therefore also has a typically rectangular cross section over the entire conductor rail and has a thickness of several millimeters. The terminal is therefore a continuation of the main part, which preferably has the same cross-section as the main part, is aligned with it and is just made of a different material.

Due to this measure, a better and more reliable contact connection is achieved in comparison to (pure) aluminum due to the different material of the terminal. For example, the terminal has a higher strength compared to pure aluminum and/or is more noble compared to pure aluminum and/or is made of a material other than aluminum or an aluminum alloy. Specifically, the terminal is made of copper—whole or at least in the area of the through hole and in the area where the contact element rests.

In a preferred embodiment, the main part and the terminal are in particular connected to one another with a material fit only at their respective end faces and especially welded. In particular, a laser welding process or an ultrasonic welding process is used as the welding process. The main part is therefore butt-welded to the terminal. In the longitudinal direction of the conductor rail, there are preferably no mutually overlapping partial areas between the main part and the terminal; rather, these two parts are directly aligned with one another, in particular without a step or a thickening being formed in the connecting area.

According to a preferred embodiment, the terminal and the main part consist of different aluminum materials, with the terminal having a higher strength than the main part. Specifically, it is provided that the main part is made of pure aluminum and the terminal is made of an aluminum alloy that is higher in strength than the main part. Specifically, the terminal consists of a so-called PAL alloy, e.g. TAL (AlZr) (Al alloy according to EN AW 6101). The particular advantage of this design can be seen in the fact that due to the material similarity (pure aluminum and aluminum alloy) there is no risk of contact corrosion. At the same time, due to the higher strength of the terminal, flow is at least reduced.

To improve the electrical conductivity, the terminal is provided with a coating in a preferred embodiment, so that a reliable electrical contact connection is formed with the contact element. The coating is in particular a coating which optionally has one of the metals SN, AG or Ni either in pure form or in the form of an alloy. The coating is generally preferably made of a more noble material than the material of the terminal.

According to a preferred development, the terminal itself has two parts, namely a first part and a second part, and consists in particular of these two parts, with the two parts in turn being made of different materials. The second part consists of an aluminum material, in particular pure aluminum, and the first part consists of a different metal, in particular copper. Alternatively, the first part consists of the aluminum material described above with higher strength than the second part. The first part has the first through hole. Specifically, this terminal is a prefabricated element in which the two parts themselves are in turn connected to one another with a material fit, for example by means of a suitable welding process. In the variant with this terminal consisting of two material parts, a total of two connection points are therefore formed, namely a first connection point between the two parts of the terminal and a second connection point between the terminal and the main part of the conductor rail. These two connection points are in each case materially bonded connections, specifically welded connections. The two-part terminal is in particular a so-called cupal element, in which the two parts are made of aluminum and copper and are connected to one another. The production of such an element is expensive due to the different material properties between copper and aluminum. The use of a prefabricated element of this type has the particular advantage that when the conductor rail is assembled, the terminal can be formed in a simple manner by means of an aluminum-aluminum welded connection.

In order to enable the simplest possible assembly, a preassembled assembly for the contact arrangement described above with the contact sleeve is also provided according to the invention. This preassembled assembly has a conductor rail with the first through hole, with the contact sleeve preferably only being partially pressed into this hole. This prepared conductor rail therefore only needs to be connected to the contact element by means of the bolt during assembly.

In the preassembled position, the collar is therefore preferably kept at a distance from an upper side of the conductor rail. In this position, the contact sleeve is fixed in particular by friction.

Especially in the case of the configuration with the ribs, these are already pressed into the inner wall of the first through-hole of the conductor rail. In a preferred embodiment, the contact sleeve protrudes beyond an underside of the component, so that this protruding area serves as a positioning aid, specifically for positioning in relation to the second through-hole of the contact element. The protruding area is preferably only a bevel at the end, ie a beveled area, in particular without the ribs protruding. As a result, the conductor rail can be placed over the entire surface of the contact element during assembly and the chamfer can simultaneously penetrate into the second through-hole of the contact element for positioning.

The bolt, in particular the screw with the nut, is also preferably part of the preassembled assembly. In this case, for example, the nut is screwed loosely onto the screw bolt, so that the screw and nut are held captive, e.g. for transport.

To assemble and form the contact arrangement, the procedure according to the invention is such that the contact sleeve is pressed at least a little way through the two through-holes using the screw during the screwing process, for example from the pre-assembly position of the contact sleeve just described. Specifically, during the screwing process, the contact sleeve is pressed to the desired end position, at which point the contact sleeve comes to rest with its collar. In the preferred embodiment with the ribs, the aluminum surface is thus broken open during the screwing process. At the same time, a gas-tight connection area is formed by pressing against each other. This ensures that no oxide layer forms on the torn contact areas. The contact sleeve, in particular its end region on the face side and typically provided with a chamfer, is pressed completely through both through-holes, so that this end region extends into the recess described above and chips removed are taken with them into the recess and caught there. An embodiment of the invention is explained in more detail below with reference to the figures. These show in partially simplified representations:

1 shows a perspective view of a contact arrangement between two conductor rails in an exploded view,

2 shows a perspective view of the contact arrangement in a fully assembled state,

3 shows a sectional view through the contact arrangement,

4.5 shows two perspective views of a preassembled assembly consisting of a conductor rail and a contact sleeve partially pressed into it,

6 shows a perspective view of a second embodiment of a contact arrangement with a terminal made of a different material than the conductor rail in an exploded view and

7 shows a perspective view of a third embodiment variant with a terminal consisting of two parts and a conductor rail consisting of two parts in an exploded view.

The exemplary embodiments of the invention shown in the figures show the preferred variant of a screw connection without restricting the generality.

The first embodiment variant of a contact arrangement 2 shown in FIGS. 1-3 comprises a first conductor rail 4 and a contact element electrically connected thereto, which is formed by a second conductor rail 6 in the exemplary embodiments. The two conductor rails 4.6 are preferably made of (pure) aluminum. Furthermore, the contact arrangement 2 comprises a screw 8, a nut 10 and a contact sleeve 12. The screw 8 has a screw head 8A and a screw bolt 8B. The bolt 8B generally forms a bolt, the screw head 8B a bolt head, and the nut 10 a fastener adapted to be fastened to the bolt. As can be seen in particular from the cross-sectional illustration in FIG. 3, the contact sleeve 12 has a cylindrical sleeve part 14 and a collar 16 at its upper end. The cylindrical sleeve part 14 has a peripheral side 17 on which knurling is formed, which is formed from a multiplicity of ribs 20 extending in a longitudinal direction 18 .

The two conductor rails 4.6 have a first through hole 22 and a second through hole 24 which are aligned with one another. The two conductor rails 4.6 rest on one another with their flat sides, their through-holes 22.24 are aligned with one another. The two through holes 22, 24 and also the screw 8 extend in a longitudinal direction along a central axis shown in dashed lines in FIG. In the final assembled position, as shown in FIG. 3, the contact sleeve 12 is pressed through the two through-holes 22,24. The contact sleeve 12, specifically the cylindrical sleeve part 14, has a slight oversize compared to a respective diameter of the two circular through-holes 22,24. In the exemplary embodiment, the excess is formed by the individual ribs 20 of the knurling. The ribs 20 are generally longitudinal ribs that extend parallel to the central axis. Overall, the peripheral side 17 also runs parallel to the central axis due to the rotationally symmetrical configuration of the contact sleeve 12, specifically due to the cylindrical configuration of the sleeve part 14.

The two through holes 22 , 24 each have a first peripheral inner wall 26 and a second peripheral inner wall 28 . In the finished state, the individual ribs 20 are pressed into these inner walls 26,28.

The collar 16 of the contact sleeve 12 rests on the upper side of the first conductor rail 4 . In the exemplary embodiment, the cylindrical sleeve part 14 has a length which—apart from a possibly slight overhang—corresponds to the total thickness of the two conductor rails 4.6. The contact sleeve 12 has no radial expansion at its end opposite the collar 16 and does not reach behind, for example, the underside of the lower, second conductor rail 4. Preferably, the contact sleeve 12 has a cone at its end opposite the collar 16, which facilitates insertion into the through-holes 22,24.

As can also be seen from the illustration in FIG. 3, the nut 10 has an underside 30 which is oriented towards the contact sleeve 12 and with which it rests on the lower, second conductor rail 6 in the final assembled state. At this end, the nut 10 has a collar-like widening in the exemplary embodiment. A recess 32 is formed on the underside, which is preferably circular in cross section and which, following the second through-hole 24 , forms a free space which is in particular concentric with the through-hole 24 . The outer dimension of the recess 32, i.e. specifically its diameter, is greater than or equal to the outer dimension and thus greater than or equal to the outer diameter of the contact sleeve 12. The nut 10 therefore has an annular web on its underside 30, which surrounds the recess 32 and with which the Nut 10 outside of the second through hole 24 and circumferentially around it on the second conductor rail 6 is supported.

In the exemplary embodiment, the contact sleeve 12 dips into this recess 32 with its front end, which is preferably designed as a conical end. This recess 32 also forms a depot or receiving space for chips that are scraped off the inner walls 26,28 during the assembly process. In the mounted end position, in which the screw 8 is passed through the recess 32, an annular space therefore remains as a receiving space. This is closed, in particular hermetically sealed to the environment.

In the exemplary embodiment, the screw head 8A has a collar-like widening. The screw head 8A rests on the contact sleeve 12 in the final assembled position. The screwing force exerted by the screw 8 and nut 10 therefore presses the collar 16 of the contact sleeve 12 against the top of the upper, first conductor rail 4. From below, the screwing force is transmitted from the nut 10, specifically from the annular web surrounding the recess 32, to the lower, second conductor rail 6.

Overall, this forms a gas-tight screw connection, so that no ambient air can get into the interior of this contact arrangement 2, ie into the region of the inner walls 26,28.

4 and 5 show views of a preassembled assembly consisting of the first conductor rail 4 and the contact sleeve 12 partially pressed into it. As can be seen specifically from FIG. 4, the contact sleeve 12 is initially only partially pressed in, so that its collar 16 is not yet on top of the first conductor rail 4 rests. Contact sleeve 12 is preferably pressed through first through-hole 22 to such an extent that it has a projection 34 on the underside of first conductor rail 4 , which is preferably formed only by the conically tapered front end, also referred to as a chamfer, of contact sleeve 12 . The distance of the collar 16 from the top of the conductor rail 4 therefore corresponds in particular to the thickness of the second conductor rail 6.

During assembly, in a preferred embodiment, a subassembly prepared in this way is positioned on the second conductor rail 6, with the overhang 34 serving as a positioning aid for mutual alignment, so that the two through-holes 22, 24 are aligned with one another. The screw 8 is then passed through and screwed to the nut 10 . With this screw connection, the contact sleeve 12 is successively pressed through the two through-holes 22,24, with the ribs 20 tearing open the surface on the inner walls 26, 28 in the process. Shavings scraped off in the process can accumulate in the recess 32 . Since the gas-tight connection is also established during this assembly process, there is no risk of the freshly torn surfaces oxidizing again.

Overall, this results in a good electrical contact connection between the radial sides of the inner walls 26, 28 and the peripheral side 17. It should be emphasized that during operation the current flow, at least a main current flow and thus the majority of the current between the two conductor rails 4, 6, follows a main current path 36 via the radial surfaces of the inner walls 26, 28 and via the contact sleeve 12, as shown in FIG 3 is drawn. In previous contact arrangements, the current typically flows mainly via the flat sides of the two contact partners (the two conductor rails 4 , 6 ) or is routed via the screw 8 .

Since in the present case the main current path 36 takes place via the contact sleeve 12, which preferably consists of a material with good conductivity and good strength and in particular copper or a copper alloy, the screw 8 can be selected from a suitable material. It preferably consists of a material that is even more strong than copper and is designed in particular as a steel screw.

The two embodiment variants shown in FIGS. 6 and 7 differ from the first variant described with reference to FIGS. 1-5 in that the contact sleeve 12 can be dispensed with. In principle, however, there is the possibility and it is also provided that the contact sleeve 12 is also used in the variants shown in FIGS. 6 and 7.

In the exemplary embodiments of FIGS. 6 and 7, a terminal 40 is attached at each end to the two conductor rails 4.6. This is in each case a continuation of a main part 42 of the respective conductor rail 4.6. The terminals 40 are aligned with the respective main part 42 and form with it a kind of conductor rail 4.6 with a constant cross-sectional contour.

The two terminals 40 each have the first through-hole 22 and the second through-hole 24, ie in this respect they form special contact parts.

While the main parts 42 are made of pure aluminum, the terminals 40 are made at least partially in the area of the through holes 22, 24 from a some other material. The terminals 40 are each butt-welded to the respective main part 42 by means of a welding process, specifically by means of laser welding. This means that--particularly exclusively--an integral connection is formed between the end faces of the terminals 40 and the main parts 42.

In the assembled end position, the two terminals 40 lie flat on one another and thus ensure good power transmission between the flat sides of the terminals 40 of the two conductor rails 4.6.

In a preferred development, the terminals 40, in particular in the embodiment variant in FIG. 6, have an additional coating, not shown here, made of a contact material with improved conductivity and/or increased strength compared to the material of the terminal 40. Coatings made of tin, nickel or silver are specifically applied, for example.

In the embodiment variant according to FIG. 6, the terminal 40 is designed in one piece and consists entirely of only one material. The terminal 40 is preferably made of an aluminum alloy that is higher in strength than the main part 42 .

In contrast, in the embodiment according to FIG. 7, the terminal 40 is designed in two parts with a first part 44 and a second part 46. The two parts 44, 46 in turn consist of different materials, with the respective first part 44 in the area of the through-holes 22, 24 again consisting of a material that is higher strength than aluminum, specifically copper.

In contrast, the second part 46, which forms a sort of central part between the main part 42 and the first part 44 of the terminal 40, is preferably made of an aluminum material, in particular the same aluminum material as the respective conductor rail 4, 6 and thus typically made of pure aluminum, for example. The terminal 40 is in particular a prefabricated terminal 40 in which the two parts 44, 46 are already integrally bonded are connected to each other at their end faces. In particular, they are materially welded to one another or produced by cold rolling. A special welding process or a cold rolling process is required for this in order to reliably produce the preferred connection between the pure aluminum of the second part 46 and the copper of the first part 44 . In contrast, the subsequent attachment of the terminal 40 to the main part 42 can be carried out reliably using a comparatively simple welding process due to the identical materials. The invention is not limited to the embodiment described above. On the contrary, other variants of the invention can also be derived from this by a person skilled in the art without departing from the subject matter of the invention. In particular, all of the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the subject matter of the invention.

Reference List

2 contact arrangement

4 first ladder rail

6 second ladder rail

8 screw

8A screw head

8B bolts

10 mother

12 contact sleeve

14 sleeve part

16 collars

17 peripheral page

18 longitudinal

20 ribs

22 first through hole

24 second through hole

26 first inner wall

28 second inner wall

30 bottom

32 recess

34 overhang

36 main current path

40 terminals

42 main part

44 first part

46 second part

Claims

Claims Electrical contact arrangement (2) with

- a conductor rail (4) which has a first through hole (22) with a peripheral first inner wall (26),

- a contact element (6) which is electrically conductively connected to the conductor rail (4),

- a bolt, in particular a screw bolt, and a fastening element connected to the bolt, in particular a nut (10), for fastening the conductor rail (4) to the contact element (6), characterized in that a contact sleeve (12) with a peripheral side (17 ) is provided, and that the contact sleeve (12) is inserted through the first through-hole (22), the peripheral side (17) of the contact sleeve (12) resting on the first inner wall (26) in an electrically conductive manner. Contact arrangement (2) according to Claim 1, characterized in that the contact element (6) has a second through hole (24) with a second peripheral inner wall (28) and in that the contact sleeve (12) is passed through both through holes (22, 24) and on both inner walls (26, 28). Contact arrangement (2) according to Claim 1 or 2, characterized in that the contact sleeve (12) is oversized relative to the first through hole (22), so that the peripheral side (17) is pressed against the first inner wall (26). Contact arrangement (2) according to one of the preceding claims, characterized in that the peripheral side (17) is designed as a structured surface and in particular has ribs (20) which are pressed into the inner wall (26, 28).

5. Contact arrangement (2) according to any one of the preceding claims, characterized in that the peripheral side (17) extends parallel to a central axis of the bolt.

6. Contact arrangement (2) according to one of the preceding claims, characterized in that the fastener connected to the bolt has a contact sleeve (12) facing underside (30) in which a recess (32) is formed.

7. Contact arrangement (2) according to the preceding claim, characterized in that the contact sleeve (12) in the assembled state extends into the recess (32).

8. Contact arrangement (2) according to any one of the preceding claims, characterized in that the contact sleeve (12) has a collar (16) with which you selected from the conductor rail (4) and contact element (6) rests on one of the two components and on which in turn rest one of the two components selected from a bolt head of the bolt and nut (10).

9. Contact arrangement (2) according to one of the preceding claims, characterized in that at least the area between the contact sleeve (12) and the first inner wall (26) is gas-tight, so that no ambient air can reach this area.

10. Contact arrangement (2) according to one of the preceding claims, characterized in that the conductor rail (4) consists of an aluminum material.

11 . Contact arrangement (2) according to one of the preceding claims, characterized in that the contact element is a second conductor rail (6), in particular made of an aluminum material.

12. Electrical contact arrangement (2), in particular according to one of the preceding claims, with - a conductor rail (4) which has a first through hole (22) with a peripheral first inner wall (26),

- a contact element (6) which is electrically conductively connected to the conductor rail (6),

- a bolt, in particular a screw bolt, and a fastening element connected to the bolt, in particular a nut (10), for fastening the conductor rail (6) to the contact element (6), the bolt being guided through the first through-hole (22), thereby characterized in that the conductor rail (4) has a main part (42) with a terminal (40) firmly attached thereto, the terminal (40) having the first through hole (22) and at least in the region of the first through hole (22) made of another Material exists compared to the main part (42).

13. Contact arrangement (2) according to claim 12, characterized in that the main part (42) and the terminal (40) are integrally welded to one another at their respective end faces.

14. Contact arrangement (2) according to claim 12 or 13, characterized in that the terminal (40) and the main part (42) consist of different aluminum materials, the terminal (40) having a higher strength than the main part (42).

15. Contact arrangement (2) according to any one of claims 12 to 14, characterized in that the terminal (40) has a coating.

16. Contact arrangement (2) according to one of claims 12 to 15, characterized in that the terminal (40) itself has two parts (44, 46) and the two parts (44, 46) consist of different materials, the one second part (46) consists of an aluminum material and the other, first part (44) consists of a different metal, in particular copper, and wherein the first part (44) has the first through hole (22).

17. Contact arrangement (2) according to one of Claims 12 to 16, characterized in that the contact element (6) is also designed as a second conductor rail (6) which also has a main part (42) with a terminal (40) fastened thereto in a materially bonded manner. wherein the terminal (40) has a second through hole (24) and consists of a different material than the main part (42) at least in the region of the second through hole (24).

18. Preassembled assembly for a contact arrangement (2) according to any one of claims 1 to 12, which has a conductor rail (4) with a first through hole (22), wherein in the first through hole (22) a contact sleeve (12) is pressed.

19. The preassembled assembly according to claim 18, in which the contact sleeve (12) is only partially pressed into the first through-hole (22), the contact sleeve (12) having in particular a collar (16) and a sleeve part (14) adjoining it, the collar (16) being arranged at a distance from the conductor rail 4 as a result of the only partial pressing in.

20. Preassembled assembly according to one of claims 18 to 19, characterized in that the contact sleeve (12) protrudes beyond an underside of the first conductor rail (4) and this protruding area serves as a positioning aid.

21 . Method for producing a contact arrangement (2) according to one of the preceding claims, in which the conductor rail (4) and the contact element (6) are fastened with the aid of the bolt, in particular a screw (8) and a fastening element, in particular a nut (10). be pressed against each other.

22. The method according to the preceding claim, wherein the contact sleeve

(12) using the bolt and fastener during a Fastening process at least a portion is pressed through through holes (22, 24) of the conductor rail (4) and the contact element (6). Method according to the preceding claim, in which the contact sleeve (12) has a collar (16) with an adjoining sleeve part (14) and the fastening element has a recess (32) on its underside facing the contact sleeve (12), the contact sleeve (12 ) extends into the recess (32) and when the contact sleeve (12) is pressed through, material scraped off the inner walls (26, 28) of the through-holes (22, 24) is received in the recess (32).