Electrical contact arrangement, contact assembly and method for producing such a contact assembly

Abstract

The invention relates to an electrical contact arrangement (2) comprising: - a contact component (4) made of a first material, in particular a conductor rail, with a first through-hole (16); - a contact element (6) electrically connected to the contact component (4); - an intermediate element (8) made of a material different from the first material, which has a further, third through-hole (20) and which is materially bonded to the contact component (4), wherein - the intermediate element (8) has a connecting collar (32) on a lower side (30) surrounding the third through-hole (20), via which the intermediate element (8) is materially bonded to the contact component (4) on its upper side (40); and wherein - the connecting collar (32) is spaced radially from a hole edge (38) of the first through-hole (16) of the contact component (4) by a distance (a).so that a storage space (42) is formed for receiving material of the contact component (4).

Description

[0001] The invention relates to an electrical contact arrangement, in particular designed as a screw connection, comprising a contact component made of a first material, in particular a conductor rail, with a first through-hole, with a contact element that is electrically conductively connected to the contact component, and with an intermediate element made of a material different from the first material, which has a further through-hole and which is materially bonded to the contact component.

[0002] The invention further relates to a contact assembly for such a contact arrangement, namely the contact component and the intermediate element connected to it. Finally, the invention further relates to a method for manufacturing such a contact assembly.

[0003] Such a contact arrangement is described in DE 10 2021 213 562 A1. It serves, in particular, for the electrical contacting of an aluminum conductor rail, which forms the contact component, with the contact element, which is, for example, another conductor rail or a contact terminal such as a cable lug, and which is typically made of copper. The intermediate element, which is also made of copper, is welded to a top side of the contact component. The contact element is connected to the intermediate element via a screw connection, whereby a screw head is inserted into the first through-hole in the contact component and is supported exclusively by the intermediate element. This prevents the screw connection from loosening unintentionally due to the soft aluminum flexing.

[0004] Certain requirements exist for the reliable attachment of the intermediate element to the contact component, especially by welding.

[0005] Based on this, the invention aims to provide such a contact arrangement, a contact assembly consisting of the contact component and the intermediate element attached to it, and a method for manufacturing such a contact assembly in which the intermediate element is reliably attached to the contact component.

[0006] The problem is solved according to the invention by an electrical contact arrangement, which is in particular designed as a screw connection, with a contact component made of a first material, which is generally a metal and specifically aluminum, and which is in particular designed as a solid conductor rail. The contact component has a first through-hole through which a connecting bolt, in particular a screw bolt, is inserted in the assembled end position. The contact arrangement further comprises an electrical contact element made of metal, which is electrically conductively connected to the contact component via an intermediate element, and which has a second through-hole.The intermediate element is typically made of a different material than the first contact component, in particular a harder metal, especially copper, and has a further, third through-hole and is metallurgically bonded to the contact component. In the assembled final position, it is positioned between the contact component and the contact element.

[0007] For a reliable, material-bonded connection, the intermediate element has a connecting collar around the third through-hole, via which the intermediate element is materially and electrically connected to the contact component. The connecting collar is radially spaced from the edge of the first through-hole of the contact component, thus creating a reservoir for material from the contact component.

[0008] In a suitably designed manner, the storage compartment also contains material from the contact component that was introduced into the compartment during the joining process, particularly during the welding process. The storage compartment is preferably only partially filled with this material.

[0009] The task is further solved by a contact assembly for such a contact arrangement, which includes the contact component as well as the intermediate element that is materially bonded to it.

[0010] The advantages and preferred design mentioned with regard to the contact arrangement can at least be transferred analogously to the contact assembly, insofar as the components of the contact assembly are concerned.

[0011] Finally, the problem is further solved by a method for manufacturing such a contact assembly, in which the intermediate element is connected to the contact component by a material-bonded joining process, in particular by welding, wherein the storage space provides a free space or receiving space for receiving material of the contact component.

[0012] During the joining process, material from the contact component tends to accumulate in the storage area.

[0013] The inventive solution concept, with the special design of the intermediate element featuring the connecting collar, which is bonded to the contact component, particularly by means of a welding process, is based on the understanding that, during the joining process, especially due to the softer material of the contact component, there is a risk that this material will be displaced radially inwards towards the first through-hole in an undesirable manner. This can potentially lead to an impairment and disruption of the contact arrangement.

[0014] For the joining process, a welding process is used in particular, for example friction welding, rotary welding and especially ultrasonic welding.

[0015] Specifically during a welding process, the material of the contact component softens and partially liquefies, allowing this material to flow towards the first through-hole and accumulate there.

[0016] The intermediate element is preferably designed as a perforated disc which rests on the contact component. It does not extend – for example, with a cylindrical section – into the first through-hole. The perforated disc is preferably flat on its lower side facing the contact component, except for the protruding connecting collar. The perforated disc is preferably positioned between the contact component and the contact element and preferably rests directly against these elements, in particular without extending into any of the through-holes of these elements.

[0017] The intermediate element preferably has only exactly one connecting collar. This collar is formed, in particular, on the outermost circumference of the intermediate element.

[0018] The two through holes of the contact component and the intermediate element are preferably arranged concentrically to each other.

[0019] In a preferred embodiment, the third through-hole of the intermediate element has a smaller opening than the first through-hole. The intermediate element projects radially inward beyond the edge of the first through-hole. This projecting portion forms a support surface for the head of a locking bolt. The support surface is therefore accessible, in particular, from below via the first through-hole. To form the finished contact arrangement, one of the locking bolts, in particular a screw bolt, is inserted into the first through-hole with its head bearing against the support surface, which is in particular annular, on the underside of the intermediate element. A bolt shank, in particular a threaded shank, is guided through the third through-hole and projects beyond the intermediate element. The contact element rests against an upper surface of the intermediate element.The bolt shaft is passed through the second through-hole of the contact element. The contact element is then pressed and clamped against the top of the intermediate element, in particular by screwing it in place, preferably with a nut. This creates a reliable contact connection between the contact component made of the soft material, especially aluminum, and the contact element.

[0020] The support surface is further adjoined in a radial direction to the outside by a particularly ring-shaped section of the intermediate element, before the axially projecting connecting collar is formed.

[0021] Insofar as a storage space is referred to here, this means the space which extends from the connecting collar to the edge of the hole and which is bounded in the axial direction by a bottom side of the intermediate element and a top side of the contact component (excluding any material that may be displaced into the storage space by the joining process).

[0022] This storage space prevents material from penetrating the interior of the through-holes and, in particular, also prevents material from entering the area of ​​the support surface where the bolt head rests against the intermediate element.

[0023] The storage space is primarily designed as a circumferential ring. Alternatively, it is also possible that the storage space is formed by several sub-spaces, for example, by storage pockets arranged segment-like around the circumference.

[0024] The connecting collar is generally a raised, particularly ridge-shaped, feature on the underside of the intermediate element, oriented towards the contact component, in the otherwise preferably flat and level underside. The connecting collar is particularly well-designed as a continuous ring collar encircling the third through-hole. Alternatively, it may be interrupted and, for example, formed by several segments. The connecting collar forms the material bond to the contact component, meaning that the intermediate element is preferably materially bonded to the contact component solely by means of the connecting collar, specifically by welding. This connecting collar can therefore also be referred to as a weld collar or weld ring.

[0025] To ensure proper insertion, the underside of the intermediate element is positioned at a distance from the top side of the contact component within the reservoir area, i.e., radially inward to the connecting collar. This top side is the original, pre-connection state, meaning it is free of any material deposits in the reservoir resulting from the joining process. The joining process is therefore deliberately controlled so that, even after the bond is fully formed, the connecting collar acts as a spacer, maintaining a distance between the underside of the intermediate element and the top side of the contact component.

[0026] During the formation of the material-bonded connection, especially through welding, the material of the contact component softens or liquefies, causing the connecting collar to penetrate at least partially into the top surface of the contact component. The manufacturing process is therefore generally controlled so that the connecting collar only partially penetrates the contact component. In the finished connection, a portion of the connecting collar is thus embedded in the material of the contact component, while a portion protrudes above the top surface of the contact component.

[0027] To ensure a reliable, material-bonded connection, the connecting collar tapers towards the contact component and, in particular, comes to a point. The connecting collar therefore has a circumferential ring edge. The connecting collar preferably has a non-tapering base section and a tapered end section adjoining it.

[0028] In the (half-)cross-sectional profile, the connecting collar – at least in the end section associated with the contact component – ​​is preferably designed in the form of a triangle, the apex of which is oriented towards the contact component. The triangle has two triangular flanks oriented towards the contact component, which have a centering effect and can therefore also be referred to as centering flanks. Preferably, the triangle has flanks of different lengths, with the radially outer flank preferably being longer than the radially inner flank. This particular tapered and especially pointed design achieves a particularly defined energy input and thus a stable welding process and a reliable weld joint.At the same time, the ring-shaped connecting collar, which tapers to a point at the end, ensures good positioning and centering during the welding process, which is particularly advantageous in conjunction with a smooth surface of the contact component.

[0029] The radial distance between the connecting collar, i.e. a radially inner inner surface of the connecting collar, and the edge of the first through hole is preferably in the range between 0.6 mm and 2 mm and particularly in the range between 0.8 mm and 1.5 mm.

[0030] In a preferred embodiment, there is a free height in the storage space between the underside of the intermediate element and the top side of the contact component (excluding any material of the contact component that may be displaced into the storage space during the joining process) in the range between 0.1 mm and 1 mm and in particular in the range between 0.3 mm and 0.5 mm.

[0031] In contrast, the connecting collar itself preferably has a slightly greater height, since it extends somewhat into the contact component during the resulting material-bonded connection. This penetration depth, also known as weld depth, is, for example, in the range of 0.3 mm to 0.7 mm and typically in the range of 0.5 mm to 0.6 mm. The height of the connecting collar is therefore typically 0.3 mm to 0.7 mm above the free height.

[0032] The free height is also referred to as the deposit height. The deposit height is preferably greater than a minimum weld depth.

[0033] The height of the connecting collar is preferably in the range between 0.4 mm and 1.5 mm, and particularly in the range between 0.6 mm and 1 mm, and specifically, for example, at 0.75 mm.

[0034] This contact arrangement is used particularly in the automotive sector and serves primarily for the electrical contacting of a conductor rail designed as a busbar, which forms the contact component. Such a busbar is, for example, an elongated main supply line, especially a so-called backbone, which connects the front and rear sections of the vehicle for electrical power supply. The busbar preferably has a length of at least 0.5 m, at least 0.75 m, or at least 1 m. Generally, certain tolerance requirements apply to the positioning of such a conductor rail, particularly in relation to the contact element to be connected.

[0035] According to a further aspect of the invention, the first through-hole of the contact component and the third through-hole of the intermediate element are designed as elongated holes. This measure provides for tolerance compensation during the fastening of the contact element.

[0036] This embodiment with the elongated hole is considered an independent invention. The filing of a divisional application is reserved. Therefore, an independent inventive concept is understood to be a contact arrangement or a contact assembly which has the features of claim 1 or claim 10, but instead of the features of the characterizing part (special arrangement and design of the connecting collar with the storage space) has the features of claim 8 (through holes as elongated holes).

[0037] In a suitable embodiment, the top surface of the contact component, at least in the area of ​​the intermediate element and in its initial state (i.e., without considering any material of the contact component that may be displaced during the joining process), is flat and without any depression or raised area. In the method for forming the material-fit connection between the contact component and the intermediate element, the intermediate element is therefore placed on the flat top surface of the contact component. Due to the flat surface, the connecting collar rests on the contact component without any form-fit guidance before the joining process is carried out.

[0038] To ensure reliable alignment and, in particular, centering of the intermediate element relative to the contact component, a centering pin is used in the contact assembly manufacturing process. The contact component and the intermediate element, with their respective through-holes, are placed on this pin. Specifically, the two through-holes are aligned concentrically to each other using the centering pin.

[0039] Preferably, the centering bolt is stepped and has a wide bolt base and a comparatively thinner, upwardly projecting centering pin. The bolt base at least partially engages the first through-hole of the contact component, and the centering pin at least engages the third through-hole of the intermediate element, preferably penetrating and extending beyond it. Advantageously, the bolt base is adapted to the dimensions of the first through-hole and the centering pin to the dimensions of the third through-hole, thus achieving precise alignment. The bolt base preferably fits precisely in the first through-hole with the required tolerance clearance, similar to a clearance fit, and the corresponding centering pin fits similarly precisely in the third through-hole, similar to a clearance fit.

[0040] The contact component is preferably the aforementioned circuit board, but is not limited to this. Alternatively, it could be, for example, a terminal such as a cable lug to which a cable to be connected is attached. In the following, the term "circuit board" will be used without limitation to the general definition of a contact component.

[0041] The contact element is, in particular, a contact lug with an attached electrical conductor, which is, for example, a sheathed cable. Its conductor is typically a stranded wire or a solid conductor. The conductor is electrically and mechanically connected to the cable lug by a crimp or screw connection, or by a material bond, for example, by soldering or welding.

[0042] Alternatively, the contact element can be another conductor rail or a fixed attachment point on a structure, such as a vehicle chassis.

[0043] Such contact arrangements are used specifically in the automotive sector to connect a conductor rail to a contact element, such as a cable lug with a cable attached to it, or to another conductor rail or to a chassis.

[0044] Such contact arrangements are preferably used for grounding or for supplying power to devices. The contact arrangement is, in particular, part of a DC power supply. For weight reasons, the conductor rail is often made of an aluminum alloy. This refers to aluminum or an aluminum alloy. When aluminum is mentioned here, it refers to pure aluminum, for example, designated AL 99.5 or AL 99.7. Such pure aluminum exhibits good electrical conductivity. The contact element, and preferably also the intermediate element, is generally made of another metal, particularly one with higher strength, such as copper (e.g., CU ETP) or a copper alloy. In particular, the component is additionally provided with a surface coating.This refers in particular to a corrosion protection layer and / or a layer for improved weldability. Specifically, a nickel or nickel-silver layer is applied, for example with a layer thickness in the range of 3 µm to 6 µm for nickel and 2 µm to 4 µm for silver. Where reference is made to an alloy (Cu, Al), this refers in particular to an alloy in which the Cu or Al content is greater than 50 wt.%.

[0045] An embodiment of the invention is explained in more detail below with reference to the figures. These show, in a partially simplified manner: FIG. 1 a perspective view of a contact assembly, FIG. 2 another perspective view of the contact assembly with a cast element, FIG. 3 a sectional view through the contact assembly, FIG. 4 a simplified sectional view through a contact assembly consisting of a contact component and an intermediate element, FIG. 5A a bottom view of the intermediate element with a circular third through-hole, FIG. 5 leg to the intermediate element according to Figure 5A corresponding contact component with circular first through-hole for forming a contact arrangement with the intermediate element according to FIG 5A FIG 6A a view from below of the intermediate element of an alternative embodiment with a third through hole designed as an elongated hole, FIG 6 leg to the intermediate element according to FIG 6Acorresponding contact component with a first through-hole designed as an elongated hole for forming a contact arrangement with the intermediate element according to FIG 6A , and FIG 7 a schematic representation of a welding device to illustrate the welding process.

[0046] In the Figures 1 to 3An electrical contact arrangement 2 designed as a screw connection is shown. This arrangement comprises a contact component designed as a conductor rail 4, a contact element 6, an intermediate element 8, a connecting bolt designed as a threaded bolt (hereinafter referred to as screw 10), and a nut 12. The screw 10 extends along an axial direction. In the exemplary embodiment, the contact arrangement 2 additionally includes an optional cast element 14 made of plastic. A resilient element is arranged between the plastic part designed as the cast element 14 and the conductor rail 4, if required. This resilient element is designed, for example, as an elastic perforated disc, a resilient perforated disc, or a disc spring. The contact arrangement 2 preferably does not have any further elements.

[0047] The conductor rail 4 has a first through hole 16, the contact element 6 a second through hole 18 and the intermediate element 8 a further, third through hole 20.

[0048] In this context, conductor rail 4 is generally understood to be an electrical conductor made of solid material with a rectangular cross-sectional area. The conductor rail 4 typically has a material thickness of a few millimeters, for example, between 3 and 10 mm. Its width is typically a few centimeters, for example, between 2 cm and 6 cm.

[0049] The screw 10 has a bolt head, hereinafter referred to as screw head 22, and a threaded shank onto which the nut 12 is screwed. Alternatively, a thread can be directly provided in the second through-hole 18, into which the screw 10 is screwed.

[0050] The conductor rail 4 is an AL conductor rail, preferably made of pure aluminum or alternatively of an aluminum alloy. The intermediate element 8 and the contact element 6 preferably consist of a copper alloy, preferably of the same copper alloy or also of pure copper. The screw 10 and the nut 12 are preferably components made of a steel material, alternatively of brass or also of copper.

[0051] The intermediate element 8 is designed as a perforated disc similar to a washer and is attached to a top surface of the conductor rail 4 that faces the contact element 6. The intermediate element 8 is metallurgically bonded to the conductor rail 4, preferably by welding.

[0052] The first through-hole 16 of the conductor rail 4 has a larger internal dimension, in particular a larger diameter, than the third through-hole 20 of the contact element 6. The through-holes 16, 18, 20 are preferably aligned centrally to each other and, in particular, are oriented concentrically to each other. The intermediate element 8 has a support surface 26 that projects radially beyond the edge of the first through-hole 16.

[0053] The inner dimension, in particular a diameter of the first through-hole 16, is larger than an outer dimension, in particular the outer diameter of the screw head 22, and at least larger than the outer dimension of a portion of the screw head 22 adjoining the screw shank, which is located in the first through-hole 16. The screw head 22 therefore extends into the first through-hole 16 and its underside rests against the support surface 26. Preferably, the screw head 22 is seated with clearance in the first through-hole 16 and is, for example, spaced apart from the inner wall of the first through-hole 16.

[0054] The conductor rail 4, together with the attached intermediate element 8, preferably forms a prefabricated contact assembly. To form the contact arrangement 2, the contact element 6 is screwed to this prefabricated contact assembly using the screw 10 and, in particular, the nut 12. The contact element 6 is clamped flat against a top surface of the intermediate element 8 facing away from the contact element 4, exerting a high contact force through the screw connection. The contact force of the screw connection is thereby transmitted indirectly via the intermediate element 8. It is important to emphasize that the conductor rail 4 does not participate in the screw contact in that no screw force acts upon it. This reliably prevents the relatively soft aluminum from flowing into undesirable areas, especially into the screw connection area, and ensures that the contact force is maintained permanently.

[0055] The electrical current flow between the conductor rail 4 and the contact element 6 occurs on the one hand via the material-fit connection between conductor rail 4 and intermediate element 8 and on the other hand via the force-fit connection between intermediate element 8 and contact element 6. In the operating state, at least the largest part of the electrical current flows via the intermediate element 8, specifically via its upper and lower contact surfaces to the contact element 6 on the one hand and to the conductor rail 4 on the other.

[0056] The construction of the intermediate element 8 and its connection to that of the conductor rail 4 is shown using the FIG 4 In more detail: The intermediate element 8 is generally designed in the manner of a perforated or ring-shaped disk and has a downwardly axially projecting connecting collar 32 on its particularly flat underside 30. In the exemplary embodiment, this connecting collar 32 is formed at the outermost circumferential edge.

[0057] The intermediate element 8 is arranged between the contact element 6 and the conductor rail 4 and, in particular, rests directly against them. The intermediate element 8 is designed as a flat and, if necessary, stepped disc. It has, in particular, no shaft section that extends into the first through-hole 16 and preferably also none that extends into the second through-hole 18.

[0058] The underside 30 is, except for the projecting connecting collar 32, particularly flat and planar. As previously described, the third through-hole 20 of the intermediate element 8 has a smaller opening width than the first through-hole 16, so that a radially inner section of the underside projects beyond the edge of the first through-hole 16 and forms the support surface 26. Radially outward from this support surface 26, a further, particularly annular, section of the underside 30 of the intermediate element 8 extends, spaced apart from the top surface of the conductor rail 4 and reaching to the connecting collar 32.

[0059] The connecting collar 32 has, starting from the underside 30 in the axial direction, a base section, to which a tapered end section is attached in the axial direction. The heights of the base section and the end section are preferably approximately equal (e.g., in the range of 40% to 60% of the total height of the connecting collar). The end section has a triangular cross-section. Preferably, an outer, edge-side triangular flank is larger than the inner triangular flank located radially on the inside. The two triangular flanks are preferably oriented at an obtuse angle to each other.

[0060] One upper surface of the intermediate element 8 is stepped and has a radially internal ring collar 34 adjoining the third through-hole 20, on which, during the Figures 1 to 3The contact arrangement 2 shown supports the contact element 6. The axially offset outer ring area 36 serves in particular as a contact or bearing surface for a welding head during the welding process, i.e., when the intermediate element 8 is materially bonded to the contact component 4.

[0061] The connecting collar 32, in particular its radially inner inner surface of the base section, is spaced a distance a from a hole edge 38 of the first through-hole 16. The distance a is preferably in the range between 0.6 mm and 2 mm, and particularly in the range between 0.8 mm and 1.5 mm. Accordingly, the inner radius of the connecting collar 32 is also larger than the radius of the first through-hole 16 by the distance a.

[0062] In the Figure 4The solid lines represent the initial situation before the welding process, in which the intermediate element 8 rests on the top surface 40 with the connecting collar 32. This top surface 40 is flat and without contouring, at least in the area of ​​the intermediate element 8.

[0063] The dashed line schematically indicates the situation after the welding process, in which the connecting collar 32 is partially immersed in the top surface 40 of the contact component 4. As can be clearly seen, even after the weld joint has formed between the top surface 38 of the contact component 4 and the bottom surface 30 of the intermediate element 8, a gap and thus a free height h1 is formed, which is preferably in the range between 0.1 mm and 1 mm and particularly in the range between 0.3 mm and 0.5 mm.

[0064] The connecting collar 32 has a total height h2, which is preferably in the range between 0.4 mm and 1.5 mm and in particular in the range between 0.6 mm and 1 mm and especially at 0.75 mm.

[0065] The radial width of the connecting collar 32 is, for example, 1.5 mm to 4 mm, and particularly in the range between 2 and 3 mm, and for example 2.5 mm. The distribution between the two unequal triangular faces is, in particular, 1 / 3 to 2 / 3.

[0066] Depending on the design, the maximum diameter of the intermediate element 8 is preferably between 15 mm and 40 mm, and in particular between 20 mm and 30 mm, in the case of the round hole variant (see FIG 5AS below). 5B ) In the case of the slotted hole variant (see below) FIG 6A, 6B ) the maximum diameter is typically 5 mm to 10 mm higher.

[0067] Overall, this creates a storage space 42. The storage space 42 is the area that extends from the connecting collar 32 to the edge of the hole 38 and which is bounded in the axial direction by the underside 30 of the intermediate element 8 (namely, in particular, the section extending radially outwards to the support surface 26) and the (original, flat) top surface 40 of the contact component 8.

[0068] In the exemplary embodiment of the FIG 4For illustrative purposes, a material accumulation 44 is shown within this storage space 42. During the welding process, particularly ultrasonic welding or friction welding, the material of the contact component 4 softens on its upper surface 40 and, for example, at least partially liquefies. The softened or liquefied material of the contact component 4 migrates at least partially radially inwards. This material can accumulate in the storage space 42 and form the sketched material accumulation 44. The storage space 42 and the process parameters are preferably selected such that the storage space 42 is not completely filled with the material accumulation 44.

[0069] In the exemplary embodiment, the storage space 42 is designed as a continuous annular space without subdivisions. Alternatively, the storage space 42 can also be subdivided circumferentially into individual, separate storage pockets, which are separated from each other, for example, by partition walls.

[0070] Based on the Figures 5A, 5B In addition, 6A and 6B, two variants for component pairs are shown, namely the intermediate element 8 and the (partially shown) conductor rail 4. Figures 5A, 6A Each shows a view of the underside 30 of the intermediate element 8 and the Figures 5B, 6B Each a view of the top side 40 of the contact component 4. In the Figures 5B, 6B The contour of the third through-hole 20 in the assembled state is shown as a dashed line.

[0071] The Figures 5A, 5B show a variant design with circular through holes 16, 20 and the Figures 6A, 6BOne variant in which these are designed as elongated slots. The ratio of length to width of these elongated slots is, for example, at least 1.2, preferably at least 1.5, or even at least 2.

[0072] It is readily apparent that the third through-hole 20 has a smaller dimension than the first through-hole 16 and is oriented centrally relative to it, thus forming the circumferential support surface 26 against which the screw head of the screw 10 can be supported. In the circular configuration, the two through-holes 16, 20 are preferably oriented concentrically to each other, and in the configuration with the elongated holes, the two large semi-axes and the two small semi-axes of the two through-holes 16, 20 preferably lie on top of each other.

[0073] The previously defined distance a between the edge of the hole 38 of the first through hole 16 and the inside of the connecting collar 32 is defined - especially in the version with the elongated hole - by the smallest distance a.

[0074] The design with the elongated hole allows for length compensation in the formation of the contact arrangement 2, i.e., the relative position of the conductor rail 4 in relation to the contact element 6 can be varied within a tolerance window.

[0075] In the preferred application here, within a motor vehicle, manufacturing tolerances frequently occur, meaning that, for example, the position of the conductor rail 4 and / or the contact element 6 can vary within a tolerance range. For instance, in one application, the conductor rail 4, specifically the prefabricated contact assembly with the welded-on intermediate element, is screwed onto a stationary contact element 6. This contact element may be part of a vehicle chassis or connected to it. The chassis, or a corresponding mounting point, therefore defines the contact element 6. In this case, it is, for example, a ground connection where the conductor rail 6 serves as a return conductor for a DC power supply line and is connected to the vehicle chassis as a ground contact.

[0076] In general, manufacturing tolerances in the present solid and rigid conductor rails 4 are difficult to compensate for. Length compensation is achieved, for example, by attaching length compensation elements, which are, however, complex.

[0077] In contrast, the design with elongated holes allows for compensation of such manufacturing tolerances with minimal design effort. The elongated hole design preferably permits length compensation of several millimeters, for example, up to 10 mm or up to 15 mm, and at least 5 mm.

[0078] The third through-hole 16 is dimensioned such that the screw 10, with its shank, can be inserted as precisely as possible, i.e., it has only a slight oversize relative to the diameter of the screw shank. Typically, M6 or M8 screws are used (also in the version with the circular through-holes 16, 20). The width of the elongated hole is also adapted to the dimensions of the screw shank.

[0079] Overall, the contact arrangement 2 described here provides a reliable contacting solution for connecting the contact component, specifically conductor rail 4, to another contact element 6 via a screw connection. Due to the screw head 22 being recessed into the conductor rail 4, the contact arrangement 2 is space-saving in terms of height. Thanks to its special design with the connecting collar 32 and the storage space 42, it can be manufactured reliably without material accumulation, particularly in contact areas where the screw 10 comes into contact with the intermediate element 8. This means that, in particular, it prevents displaced aluminum material from getting between the screw 10 and the intermediate element 8. Finally, the slotted design variant provides length compensation.

[0080] The joining process, specifically the welding process for forming the contact assembly consisting of contact component 4 and intermediate element 8, is described below in connection with FIG 7 The welding process is explained as follows: Welding is carried out using a welding device 45, which, for example, has a support part 46, referred to as an anvil, onto which the contact component 4 and the intermediate element 8 are successively placed. The alignment and, in particular, the centering of these two components relative to each other is achieved using a centering bolt 48, which has a wider bolt base 48A and a centering pin 48B extending axially from it, which has a smaller radial extension compared to the bolt base 48A.

[0081] The bolt base 48A preferably fits precisely into the first through-hole 16 of the contact component 4 with a clearance fit. The centering pin 48B penetrates the third through-hole 20, i.e., the intermediate element 8 is threaded onto the centering pin 48B. The centering pin 48B also preferably fits precisely into the third through-hole 20 with a clearance fit.

[0082] The intermediate element 8 initially rests with its connecting collar 32 on the flat, level top surface 40 of the contact component 4 and is therefore not guided by the contact component in a form-fitting manner.

[0083] For welding, a welding head 50 designed as a sonotrode is placed from above onto the intermediate element 8, specifically onto the outer circumferential ring area 36. Subsequently, the (ultrasonic) welding is carried out, specifically by ultrasound generated by the sonotrode.

[0084] Alternatively, a rotary friction welding process is performed, for example, in which the intermediate element 8 is rotated. For this purpose, it is gripped by the welding head 50 and set into rotation. After the weld joint has been completed, the finished contact assembly is removed from the welding device 45.

[0085] In a preferred embodiment, the support part 46 has a central part 52 which is axially movable within the support part 18 and is, for example, spring-mounted. This allows the centering pin 58 to move out of the way and be pressed downwards when the welding head 50 is placed on it, so that it does not interfere with the welding process. For example, it is pressed back far enough that it still penetrates the intermediate element 8 and the third through-hole 20, but no longer protrudes. Reference symbol list

[0086] 2 Contact arrangement 4 Conductor rail 6 Contact element 8 Intermediate element 10 Screw 12 Nut 14 Cast element 16 First through hole 18 Second through hole 20 Further (third) through hole 22 Screw head 26 Support surface 30 Underside of intermediate element 32 Connecting collar 34 Ring collar 36 Ring area 38 Hole edge 40 Top side 42 Storage space 44 Material accumulation 45 Welding device 46 Support part 48 Centering bolt 48A Bolt base 48B Centering pin 50 Welding head 52 Center part aDistance h1free height h2Height of the connecting collar

Claims

1. Electrical contact arrangement (2) comprising: - a contact component (4) made of a first material, in particular a conductor rail, with a first through-hole (16), - a contact element (6) which is electrically conductively connected to the contact component (4), - an intermediate element (8) made of a material different from the first material, which has a further through-hole (20) and which is metallurgically connected to the contact component (4), characterized by the fact that- the intermediate element (8) has a connecting collar (32) on a bottom side (30) surrounding the further through-hole (20), via which the intermediate element (8) is materially connected to the contact component (4) on its top side (40) by a joining process, and that - the connecting collar (32) is spaced radially from a hole edge (38) of the first through-hole (16) of the contact component (4) by a distance (a), so that a storage space (42) for receiving material of the contact component (4) is formed.

2. Contact arrangement (2) according to claim 1, characterized by the fact that the intermediate element (8) is welded to the contact component (4), and that material of the contact component (4) displaced during the joining process is arranged in the storage space (42).

3. Contact arrangement (2) according to one of the preceding claims, characterized by the fact thatthe intermediate element (8) is designed as a perforated disc that does not extend into the first through hole (16).

4. Contact arrangement (2) according to one of the preceding claims, characterized by the fact that the further through-hole (20) of the intermediate element (8) has a smaller opening than the first through-hole (16), so that the intermediate element (8) projects radially inwards beyond a hole edge of the first through-hole (16) and forms a support surface (26) on its underside (30) for a bolt head (22) of a locking bolt (10).

5. Contact arrangement (2) according to one of the preceding claims, characterized by the fact that the underside (30) of the intermediate element (8) is spaced apart from the top side (40) of the contact component (4) and / or that the connecting collar (32) only partially immerses in the contact component (4).

6. Contact arrangement (2) according to one of the preceding claims, characterized by the fact thatthe connecting collar (32) tapers towards the contact component (4) and in particular comes to a point.

7. Contact arrangement (2) according to one of the preceding claims, characterized by the fact that - the distance (a) between the connecting collar (32) and the hole edge (38) is in the range between 0.6 mm to 2 mm and in particular in the range between 0.8 mm to 1.5 mm, and / or that - a free height (h1) between the underside (30) of the intermediate element (8) and the top side (40) of the contact component (4) is in the range between 0.1 mm to 1 mm and in particular in the range between 0.3 mm to 0.5 mm.

8. Contact arrangement (2) according to one of the preceding claims, characterized by the fact that the first through hole (16) of the contact component (4) and the further through hole (20) of the intermediate element (8) are designed as elongated holes.

9. Contact arrangement (2) according to one of the preceding claims, characterized by the fact thatthe top surface (40) of the contact component (4) in the area of ​​the intermediate element (8) is flat in the initial state.

10. Contact assembly for a contact arrangement (2) according to one of the preceding claims comprising - a contact component (4) made of a first material, in particular a conductor rail, with a first through-hole (16), - an intermediate element (8) made of a material different from the first material, which has a further through-hole (20) and which is metallurgically connected to the contact component (4), characterized by the fact that- the intermediate element (8) has a connecting collar (32) around the further through-hole (20), via which the intermediate element (8) is materially connected to the contact component (4) by a joining process, and that - the connecting collar (32) is spaced radially from a hole edge (38) of the first through-hole (16) of the contact component (4), so that a storage space (42) for receiving material of the contact component (4) is formed.

11. Method for manufacturing a contact assembly according to the preceding claim, wherein the intermediate element (8) is connected to the contact component (4) by a material-bonding joining process, in particular welding, and a receiving space for receiving material of the contact component (4) is formed by the storage space (42).

12. Method according to the preceding claim, wherein during the joining process material of the contact component (4) is displaced by the connecting collar (32) and accumulates in the storage space (42).

13. Method according to one of the two preceding claims, wherein a top surface (40) of the contact component (4), on which the intermediate element (8) comes to rest at the beginning of the joining process, is designed to be flat, so that the connecting collar (32) rests on the contact component (4) without positive guidance by the contact component (4).

14. Method according to one of claims 11 to 13, wherein a centering bolt (48) is used for the joining process, onto which the contact component (4) and the intermediate element (8) with their through holes (16, 20) are placed.

15. Method according to the preceding claim, wherein the centering bolt (48) is stepped and has a wide bolt base (48A) and a centering pin (48B) that is thinner and protrudes compared to the wide bolt base (48A), wherein the bolt base (48A) at least partially enters the first through-hole of the contact component (4) and the centering pin (48B) at least penetrates the third through-hole (20) of the intermediate element (8), preferably with a precise fit.

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