Electrically conductive contact assembly, module connector, connection assembly and method for mechanical fastening

Abstract

To provide a module connection part which is more freely configurable regarding the selection of a geometrical shape and a material and of which the manufacture is further facilitated.SOLUTION: A contact assembly (100, 100') comprises a contact element (106), a busbar (102) and a fastening element (110, 110') for mechanically fastening the contact element (106) to the busbar (102). The contact element (106) is configured to be affixed to the busbar (102) in a frictionally engaged manner at least on a first friction surface (120) in a receiving opening (104), and the fastening element (110, 110') comprises a knurled section (138). The knurled section (138) in the assembled state of the contact assembly (100, 100') exerts a contact force upon the contact element (106), and the contact force presses the first friction surface (120) of the contact element (106) flatly against the inner side of the receiving opening (104) of the busbar (102).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electrically conductive contact assembly for module connection, for example, of battery modules, for applications in the automotive and energy technology fields, for example, but not exclusively. The present invention further relates to a module connector, a connection assembly, and a method for mechanically fastening contact elements to busbars. [Background technology]

[0002] Busbars made of copper, aluminum, or alloys containing copper and / or aluminum are often used in automotive and energy technology to transmit currents of the order of hundreds of amperes between electric modules, such as battery modules, and electric motors or other power consumption units. To enable the electric modules to be connected to each other, each busbar is often provided with contact portions that protrude from the rest of the busbar, provide a defined contact surface, and are pressed together using fixing elements. Here, the protruding contact portions cause discontinuities in the shape of the respective busbar, which often poses problems during manufacturing.

[0003] When busbars are manufactured integrally with their contacts, for example by a forging or extrusion process, the busbar parts excluding the contacts are often subject to design constraints that prevent complete freedom of configuration, since otherwise the entire busbar would not be possible to manufacture, or could only be manufactured with great effort. In other words, busbars manufactured in one piece cannot have complex shapes because their geometry is limited. However, modern battery applications, particularly in the field of electromobility, require busbars with complex shapes, especially since battery modules and electric motors are increasingly being distributed in vehicles to save installation space.

[0004] Alternatively, welding the contacts to the busbar as separate components during manufacture would also present limitations, since the weldability aspect must take priority over other material and design characteristics. In certain circumstances, the lack of weldability precludes the use of particularly lightweight materials or material combinations. Summary of the Invention [Problem to be solved by the invention]

[0005] The invention is therefore based on the object of providing a modular connection which can be configured with more freedom in terms of geometry and material choice and which is therefore easier to manufacture. [Means for solving the problem]

[0006] This object is met by the objects of the independent claims. Advantageous embodiments are the object of the dependent claims.

[0007] According to a first aspect, a conductive contact assembly is provided, the contact assembly comprising a contact element, a busbar, and a fixing element for mechanically fixing the contact element to the busbar. The busbar includes a receiving opening for receiving at least a portion of the contact element, the contact element including a passage opening for inserting the fixing element, and a contact portion extending tubularly along the passage opening and having a cylindrical contact surface facing radially outward, the contact element configured to be attached to the busbar by frictional engagement with at least a first friction surface in the receiving opening. The fixing element includes a knurled section axially longer than or equal to the receiving opening of the busbar, the knurled section configured to exert a contact force on the contact element in an assembled state, the contact force pressing the first friction surface of the contact element flat against an inner surface of the receiving opening of the busbar.

[0008] The present disclosure is particularly based on the inventive concept of designing the fixing element such that the fixing element includes a knurled portion whose axial height is equal to or greater than the thickness of the busbar and which exerts a force on the collar portion of the contact element, ensuring that the first friction surface of the collar portion is pressed flat against the inner surface of the busbar receiving opening. When the contact assembly is fixed, material of the contact portion moves both axially relative to the axis of symmetry of the receiving opening and radially toward the inner surface of the busbar receiving opening. This allows for an increased contact area between the contact element and the busbar, facilitating non-welded contact even with thin busbars having thicknesses in the range of less than 6 mm. In particular, this contact assembly facilitates the non-welded connection of multiple stacked thin metal sheets, also referred to hereinafter as "thin sheet metal," "layered sheet metal (conductor)," "laminated conductor," "laminated sheet metal," or "thin sheet metal conductor." This particularly includes multiple thin metal sheets that may have thicknesses ranging from 0.03 mm to 0.5 mm. In such applications, the non-welded connection is particularly advantageous for reducing energy consumption and achieving cleaner contact and fastening of the multiple thin metal sheets. Additionally, the non-welded connection of the multiple thin metal sheets avoids contamination that may occur during the welding process.

[0009] In summary, this means that the geometric configuration of the contact assembly makes it particularly easy to reliably electrically contact thin busbars or busbars consisting of many individual layers of thin sheet metal by pressing instead of welding.

[0010] According to a second aspect, the contact force exerted by the knurled portion on the contact element has both a radial and an axial component relative to the axis of symmetry of the passage opening. In this way, when the contact assembly is mechanically fastened in the region of the first friction surface, the knurled area prevents the material of the contact ring from being displaced only in the axial direction, thereby reducing the contact area between the contact ring and the busbar. This ensures reliable mechanical and electrical contact between the contact element and the busbar, even when the busbar is thin or made of multiple thin metal sheets.

[0011] According to a third aspect, the fixing element includes a cylindrical fixing portion insertable into the passage opening of the contact element, and at least a portion of the knurled portion surrounds the cylindrical fixing portion in a frustoconical shape. The frustoconical configuration of the knurled portion assists plastic deformation of the contact element, forcing material of the contact element toward the contact surface between the contact element and the busbar, thereby increasing the contact area and contact pressure.

[0012] According to a fourth aspect, the outer surface of the knurled portion is axially tapered to increase the movement of material of the contact element in the direction of the first friction surface.

[0013] According to a fifth aspect, the fixing element has a bearing portion extending radially outward and having a bearing surface for the busbar. For example, the bearing portion can be plate-shaped and protrude circumferentially from the part of the fixing device excluding the bearing portion. The bearing portion can be formed, for example, by an annular enlargement of the fixing device configured as a threaded sleeve. In the assembled state of the contact assembly, the bearing portion of the fixing device and the contact portion of the contact element are located opposite each other with respect to the busbar, so as not to restrict the accessibility of the contact surface of the contact portion.

[0014] According to a sixth aspect, the bearing surface for the busbar forms at least a portion of the knurled portion. By knurling the bearing surface, torque generation between the fixing element and the contact element can be reduced, and thus twisting of the fixing element relative to the contact element can be prevented. In other words, by knurling the bearing surface, the loosening torque of the fixing element relative to the contact element (and therefore relative to the busbar to which the contact element is connected with a positive fit) is increased. This helps the knurled surface to exert forces acting axially and radially relative to the axis of symmetry of the receiving opening when the contact assembly is fixed.

[0015] According to a seventh aspect, the knurled portion comprises a plurality of triangular and / or rectangular tooth elements extending parallel to one another at least in the axial direction. In this way, a knurled surface is obtained that is particularly easy to manufacture and practical in design. The tooth elements can in particular take the form of radially projecting, axially extending ribs distributed circumferentially over the knurled portion. The ribs can, for example, have a plurality of beveled surfaces and / or tooth flanks extending parallel to one another in the axial direction A.

[0016] According to an eighth aspect, the busbar comprises a plurality of thin sheet metal conductors arranged one on top of the other in the axial direction, the thickness of each of the plurality of thin sheet metal conductors being preferably less than 0.5 mm. In this way, the flexibility of the busbar can be increased, and furthermore, the special configuration of the fixing element can ensure that the electrical contact resistance between the contact element and the plurality of thin sheet metal conductors is sufficiently low (especially in the range of a few μΩ). The thin sheet metal conductors of the busbar can be unwelded or welded.

[0017] Alternatively or additionally, the receiving opening of the busbar may have an axial thickness of 6 mm or less. In this way, a particularly space-saving busbar can be provided, and the special configuration of the fixing element can further ensure that the electrical contact resistance between the contact element and the plurality of thin sheet metal conductors is sufficiently low (especially in the range of a few μΩ).

[0018] According to a ninth aspect, at least a portion of the first friction surface of the contact element is knurled. Particularly when the busbar is formed from aluminum or multiple thin aluminum sheet metal conductors, the knurling of the first friction surface can aid in material transfer of the contact element and disrupt oxide layers that form on the inner surfaces of the receiving openings.

[0019] According to a tenth aspect, the fixing element is configured as a threaded sleeve having an internal thread for screwing onto the threaded retaining element, in this way the fixing device can be detachably screwed onto the contact assembly, thus allowing good accessibility of the fixing device in case of maintenance or repair.

[0020] According to an eleventh aspect, the fixing element is configured as a threadless collar sleeve for receiving a threaded retaining element, in this way the fixing device can also be detachably screwed onto the contact assembly, thus allowing good accessibility of the fixing device in case of maintenance or repair.

[0021] According to a twelfth aspect, there is provided a modular connector comprising at least one contact assembly according to one of the above aspects and a touch guard housing, the touch guard housing being configured to receive the at least one contact assembly. The provided modular connector benefits from the above advantages of the contact assembly. Furthermore, the provided modular connector is characterized by high electrical safety, which greatly expands the possible fields of application. The touch guard housing is preferably formed from an electrically insulating material. Optionally, the touch guard housing may include at least one touch guard cap arranged on the fastening device.

[0022] According to a thirteenth aspect, a connection assembly is provided, comprising two or more contact assemblies, each configured to complement the other. The provided connection assembly also benefits from the above-mentioned advantages. In addition, the provided connection assembly can be directly used to establish a modular connection. For this purpose, the contact elements of the two contact assemblies are attached to the respective busbars by frictional engagement, pressed against each other at their contact surfaces, and fixed using a retaining element.

[0023] According to a fourteenth aspect, there is provided a method for mechanically securing a contact element to a busbar, the method including: (i) inserting the contact element into a receiving opening of the busbar, the contact element being frictionally attached to the busbar at at least a first friction surface in the receiving opening, the contact element including a contact portion extending tubularly along the passage opening of the contact element and having a cylindrical contact surface facing radially outward; (ii) inserting a fixing element into the passage opening of the contact element, the fixing element including a knurled portion that is axially longer than or the same length as the receiving opening of the busbar; and (iii) securing the fixing element in the passage opening of the contact element with a threaded retaining element, the knurled portion exerting a contact force on the contact element, the contact force pressing the first friction surface of the contact element flat against an inner surface of the receiving opening of the busbar. The provided method also benefits from the above mentioned advantages, in particular allowing for no welding and thus energy saving and clean contact between the thin busbar and the thin sheet metal conductor.

[0024] According to a fifteenth aspect, the busbar includes a plurality of non-welded thin sheet metal conductors arranged one on top of the other in the axial direction. This has the advantage that the flexibility of the busbar can be increased, and at the same time, the above-mentioned fastening method ensures low ohmic contact resistance between the busbar and the contact ring. Alternatively, the busbar can include a single thin sheet metal having an axial thickness of less than 6 mm.

[0025] The present invention will be described in more detail below based on several exemplary embodiments and with reference to the drawings. Different features of the exemplary embodiments can be combined with each other as needed according to the above findings. In particular, individual features can be added to the described embodiments according to the above explanations if the effects of these features are necessary for a specific application. Conversely, individual features can be omitted from existing embodiments if the technical effects of these features are not important in a specific application. Similar, identical, and functionally identical elements in the drawings are denoted by the same reference numerals as needed. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic perspective view of a busbar including two exemplary contact assemblies. [Figure 2] FIG. 2 is a schematic perspective view of the back side of the bus bar of FIG. 1. [Figure 3] FIG. 3 is a schematic cross-sectional view of an exemplary busbar taken along section line III-III shown in FIGS. 1 and 2. [Figure 4] 1 is a schematic exploded view of a first exemplary contact assembly. [Figure 5] 1 is a schematic exploded view of a second exemplary contact assembly configured complementary to the first exemplary contact assembly. [Figure 6] 10 is a schematic cross-sectional view of a second exemplary contact assembly without a retaining element. [Figure 7] 1 is a schematic side view of a first exemplary fixation element. [Figure 8] FIG. 10 is a schematic side view of a second exemplary fixation element. [Figure 9] FIG. 10 is a schematic side view of a third exemplary fixation element. DETAILED DESCRIPTION OF THE INVENTION

[0027] The invention will now be explained in more detail with reference to the drawings, in particular initially to Figures 1 to 5. It should be noted that the size ratios in all figures, in particular the ratios of layer thicknesses, are not necessarily drawn to scale. Furthermore, parts that are not necessary for or that impede understanding, in particular electrically insulating housing elements and protective covers, are not shown.

[0028] 1 and 2 are schematic perspective views of an exemplary bus bar 102 including two exemplary contact assemblies 100′, 100″ in an assembled state, respectively. FIG. 3 is a schematic cross-sectional view of the exemplary bus bar 102 taken along section line III-III shown in FIGS. 1 and 2. The bus bar 102 may be a bus bar extending between at least two electrical modules (also referred to as an “electrical bus bar”). Alternatively, the bus bar 102 may be a bus bar segment that is part of an electrical module. In the illustrated example, the bus bar 102 includes a first receiving opening 104, e.g., at a first end region, that is part of the first exemplary contact assembly 100′ (see also the schematic exploded view in FIG. 4). Additionally, the bus bar 102 includes a second receiving opening 104, e.g., at a second end region, that is part of the second exemplary contact assembly 100″ (see also the schematic exploded view in FIG. 5). The first exemplary contact assembly 100' is configured to be complementary to the second contact assembly 100", such that the contact assembly 100' and the contact assembly 100" together can provide a connection assembly in which two different bus bars 102 are electrically connected to each other.

[0029] To this end, the complementary contact assemblies 100', 100" each have a contact element 106 (also referred to as a "contact ring"). As will be explained in more detail below, the contact element 106 and the bus bar 102 may each exist as separate components (see FIGS. 4 and 5) and may mate with one another by frictional engagement. This allows the contact element 106 to be completely covered with a coating comprising nickel and / or silver.

[0030] The contact element 106 includes a passage opening 108 for inserting the fixing element 110′ or the fixing element 110″. A contact portion 112 of the contact element 106 extends tubularly along the passage opening 108. A collar portion 114 of the contact element 106 adjoins the contact portion 112 and extends the passage opening 108 in a sleeve-like manner. In each of the two contact assemblies 100′, 100″ of the busbar 102, at least the collar portion 114 of the fixing element 110′, 110″ is received in the respective receiving opening 104 of the busbar 102.

[0031] The receiving opening 104 has a uniform inner diameter 116 throughout its depth, and the outer diameter 118 of the collar 114 is oversized relative to the uniform inner diameter 116 (see FIGS. 4 and 5 ). In particular, the contact element 106 is configured to be frictionally attachable to the busbar 102 at the receiving opening 104 at a first friction surface 120. The first friction surface 120 is disposed on an outer surface of the collar 114. In FIGS. 1-3 , the contact element 106 is shown frictionally attached to the busbar 102 at the first friction surface 120 and thus mated to the busbar 102. In the illustrated example, the contact element 106 is configured as a cylindrical contact ring and is frictionally inserted into the receiving opening 104 of the busbar 102 at the collar 114. On the front side of the contact portion 112 facing away from the collar portion 114, the contact elements 106 include contact surfaces 122 for mating contact. The contact surfaces 122 of the contact elements 106 of the contact assembly 100' are used in particular to make electrical contact with the associated contact surfaces 122 of the contact elements 106 of the complementary contact assembly 100" to form the mating contact (and vice versa). The contact elements 106 of the complementary contact assemblies 100', 100" are in contact with each other at their front sides and are pressed together by the fixing elements 110', 110" (and the holding device).

[0032] In the example shown, the contact element 106 has a circular cross section in the axial direction A relative to the passage opening 108. Alternatively, the contact element 106 may have, at least in part, for example at the collar portion 114, a non-circular cross section (not shown), in particular an oval, elliptical, square, rectangular or polygonal cross section.

[0033] 3, it can be seen that the collar portion 114 is configured shorter in the axial direction A than the receiving opening 104 of the busbar 102. This means that the height h1 of the collar portion 114, measured in the axial direction A relative to the receiving opening 104, is less than the height h2 of the receiving opening 104, measured in the axial direction A, which typically corresponds to the thickness of the busbar 102 in the axial direction. To compensate for thermal expansion processes, an annular gap 124 exists between the collar portion 114 of the contact element 106 and the bearing portion 126 of the fixing element 110 in the assembled state of the contact assembly 100.

[0034] Alternatively, the collar portion 114 can be configured to have the same length in the axial direction A as the receiving opening 104 of the busbar 102. This means that in the assembled state, the collar portion 114 is flush with the busbar 102 and, together with the busbar 102, provides as large a bearing surface as possible for the bearing portion 126 of the fixing element 110.

[0035] The fixing element 110' of the contact assembly 100' and the fixing element 110" of the contact assembly 100" are used to establish reliable mechanical and electrical contact between the contact element 106 and the bus bar 102, respectively. The fixing elements 110', 110" are fitted to the contact element 106 by frictional engagement. For this purpose, the fixing element 110' or the fixing element 110" each includes a cylindrical fixing portion 127 (see Figures 4 and 5) that is inserted into the passage opening 108 of the contact element 106 to secure the contact element 106 to the bus bar 102 and to establish a low ohmic electrical contact resistance (particularly in the range of a few μΩ) between the contact element 106 and the bus bar 102.

[0036] The fixing element 110' of the contact assembly 100' in the illustrated example is configured as a threaded sleeve having an internal thread 128. The internal thread 128 is arranged in the threaded portion of the fixing element 110' and is used to screw onto a mating thread 130 of a threaded retaining element 132 (here also referred to as a "retaining device" in the form of a screw) that is part of the complementary contact assembly 100". The fixing element 110" of the contact assembly 100" is configured as a threadless collar sleeve in the illustrated example. This means in particular that the inner surface that is arranged within the volume of the fixing element 110" is devoid of threads, and therefore the fixing element 110" can accommodate the threaded retaining element 132 without the threads 130 of the threaded retaining element 132 engaging with the fixing element 110". This allows the threaded retaining element 132 to be threaded through the fixing element 110" and into the internal threads 128 of the fixing element 110' when the two complementary contact assemblies 100', 100" are assembled to form a connection assembly for electrically connecting the two associated bus bars 102 without welding.

[0037] In all of the illustrated examples, the fixing element 110 includes a radially outwardly extending bearing portion 126 adjacent to a cylindrical fixing portion 127 of the fixing element 110. The bearing portion 126 protrudes circumferentially in a plate-like shape from the rest of the fixing element 110. In particular, the bearing portion 126 is formed by an annular enlarged portion 134. In the assembled state of the contact assembly 100, the bearing portion 126 is disposed opposite the contact portion 112 of the contact element 106 relative to the busbar 102 (see FIG. 3). Furthermore, when the threaded portion of the fixing element 110' is inserted into the passage opening 108 of the contact element 106 received in the receiving opening 104 of the busbar 102, the bearing portion 126 of the fixing element 110' rests on the busbar 102 on the other side of the threaded portion. The busbar 102 can then be clamped between the contact portion 112 of the contact element 106 and the bearing portion 126 of the fixing element 110 .

[0038] The contact elements 106 of the contact assemblies 100', 100" are each configured to be frictionally attachable to the fixed element 110' (or fixed element 110") at the second friction surface 136 at the passage opening 108, i.e., the inner surface of the contact element 106. Figures 3 and 6 show the contact element 106 with the second friction surface 136 attached to the associated fixed element 110 by frictional engagement, such that the contact element 106 and the associated fixed element 110 are rotationally fixedly attached to one another. In particular, it can be seen that the first friction surface 120 and the second friction surface 136 of the contact element 106 are offset from one another in a radial direction R relative to the axis of symmetry 144 of the passage opening 108.

[0039] The frictional connection between the contact element 106 and the fixing element 110 is enhanced by a knurled portion 138 (also called a "knurled area") provided on the fixing element 110. This knurled portion 138 is oversized with respect to the inner diameter 140 of the passage opening 108 of the contact element 106. In the example shown, the knurled portion 138 includes radially projecting, axially extending, and circumferentially distributed ribs 142 over the knurled portion 138. The ribs 142 can include, for example, a plurality of beveled and / or toothed surfaces extending parallel to one another in the axial direction A. The ribs 142 can be formed, in particular, by triangular and / or rectangular toothed elements. The knurled portion 138 may be formed by knurling a rotationally symmetrical portion of the fixing element 110, but is not limited to circular cross sections; in the case of non-circular cross sections, in particular oval, elliptical, square, rectangular or polygonal cross sections, it may also be formed by other forming processes (e.g. embossing), by machining processes (e.g. milling) and / or by primary forming processes (e.g. casting) in which a surface structure like that obtained by knurling is achieved.

[0040] In particular, the larger size of the knurled portion 138 is selected so that the collar portion 114 of the contact element 106 is plastically deformed by the knurled portion 138 after the fastening element 110 is inserted into the passage opening 108. This deformation also enhances the frictional connection between the contact element 106 and the busbar 102 by affecting the outer surface 120 (first friction surface 120) of the collar portion 114.

[0041] In the case of thin busbars 102, i.e., when the height h2 of the receiving opening 104 of the busbar 102 is in the range of less than 6 mm, or in the case of busbars 102 having multiple, in particular non-welded, thin sheet metal conductors stacked on top of each other (in the axial direction A), as shown diagrammatically, the height h3 of the knurled area 138 measured in the axial direction A is the same as or greater than the height h2 of the passage opening. Due to the small size of the inner surface 146 of the receiving opening 104 or of the passage openings of the individual thin sheet metal conductors that make up the receiving opening 104, in such cases it is important to maximize the contact area between the first friction surface 120 of the contact element 106 and the inner surface 146 of the receiving opening 104 to reduce the contact resistance between the contact element 106 and the busbar 102. For this purpose, after installation of the contact assembly 110′, 110″, the knurled region 138 is configured such that the knurled region 138 exerts a contact force FK on the contact element 106, which presses the first friction surface 120 flat against the inner surface 146 of the receiving opening 104 of the busbar 102. This avoids point-only contact between the first friction surface 120 of the contact element 106 and the busbar 102, thereby increasing the contact resistance.

[0042] In particular, the knurled portion 138 is configured such that the contact force FK that the knurled portion 138 exerts on the first friction surface 120 of the contact element 106 has a force component directed in the axial direction A and a force component directed in the radial direction R. This prevents the knurled portion 138 from pushing the material of the contact element 106 only in the axial direction, i.e., away from the inner surface 146 of the receiving opening 104, when the contact assembly 100′, 100″ is secured. Due to the special configuration of the knurled portion 138, the material of the contact element 106 is instead also displaced in the radial direction R, thereby forcing it against the inner surface 146 of the receiving opening 104.

[0043] To illustrate the above effects, FIG. 6 shows a schematic cross-sectional view of an exemplary contact assembly 100″. The retention device 132 is not shown here. Furthermore, FIGS. 7 and 8 each show an exemplary schematic configuration of the fixation element 110′, and FIG. 9 shows an exemplary schematic configuration of the fixation element 110″. It should be noted here that each of the exemplary configurations of the knurled portion 138 described below can be used for the fixation elements 110′, 110″, even if only one of the fixation elements 110′, 110″ is described.

[0044] As shown in FIGS. 4-9 , the knurled region 138 includes at least a first partial region surrounding the cylindrical fixing portion 127 in a frustoconical shape. In other words, the portion of the knurled region 138 extending along the axial direction A is inclined by an inclination angle α relative to the second friction surface 136 of the contact element, thus taking the form of a frustoconical jacket surface. In particular, the outer surface of the knurled region 138 tapers from the bearing portion 126 along the fixing portion 127 toward the axial direction A at the inclination angle α. This ensures that when the inner surface 146 of the receiving opening 104 is pressed by fastening the contact assembly 100′, 100″, the knurled portion 138 displaces material of the contact element 106 in the radial direction R. Even when the thickness h2 of the receiving opening 104 is small and / or the busbar 102 includes multiple thin sheet metal conductors, a low ohmic contact resistance can be achieved between the contact element 106 and the busbar 102 without the need for an energy-intensive welding process.

[0045] To further enhance this effect, for example, as shown in FIG. 8 , a portion of the knurled area can be provided on the bearing surface 148 of the bearing portion 126. At least a portion of the bearing surface 148 of the bearing portion can be knurled, and the knurling can again take the form of the ribs 142 described above. Alternatively, the knurling on the bearing surface 148 can be scalloped or circular. The knurling on the bearing surface 148 also has the effect that, when the contact assembly 100′, 100″ is installed, the material of the contact element 106 is pressed against the inner surface 146 of the receiving opening 104, thus increasing the bearing surface between the contact element 106 and the inner surface 146 of the receiving opening 104. Additionally, the knurling of the bearing surface 148 has the advantage of reducing torque between the fixing element 110 and the contact element 106, thus preventing twisting of the fixing element 110 relative to the contact element 106. In other words, the knurling of the bearing surface increases the loosening torque of the fixing element relative to the contact element (and therefore relative to the busbar to which the contact element is connected in a positive fit).

[0046] Optionally, a portion of the first friction surface 120 may also be knurled to further improve electrical contact between the contact element 106 and the busbar 102. The knurling may again take the form of the ribs 142 described above, particularly protruding radially from the first friction surface 120, extending parallel to one another in the axial direction A, and being circumferentially distributed across the first friction surface. Knurling of the first friction surface may also help to break up oxide layers that may form on the inner surface 146 of the receiving opening 104, particularly when the busbar 102 is formed from aluminum or multiple aluminum thin sheet metal conductors (and further when the busbar 102 or the thin sheet metal conductors it contains are formed from copper or a copper alloy).

[0047] To facilitate easier insertion into one another, the contact elements 106, bus bars 102, and / or fixing elements 110 may each optionally include an insertion bevel.

[0048] As previously described, at least two complementary contact assemblies 100′, 100″ are attached to form a connection assembly (not shown) for electrically connecting two bus bars 102 by means of the contact elements 106 of the two contact assemblies 100′, 100″, respectively. In particular, a threaded retaining element 132 is threaded through the threadless fastening element 110″ and threaded into the internal threads 128 of the fastening element 110′ to mechanically secure the contact elements 106 to each other and to the respective bus bars 102. The connection assembly may include a touch guard housing for each contact assembly 100′, 100″, respectively, and the fastening elements 110′, 110″ may include a touch guard cap 150′, 150″ as part of the respective touch guard housing (see FIGS. 1-3 ). The touch guard caps 150′, 150″ are not shown in FIGS. 4-6 .

[0049] To mechanically secure the contact element 106 to the bus bar 102, the collar portion 114 of the contact element 106 is first inserted into the receiving opening 104 of the bus bar 102 along an insertion direction extending parallel to the axial direction A until the contact element 106 is attached by frictional engagement to the bus bar 102 at at least the first friction surface 120 in the receiving opening 104. Next, the fastening element 110', 110" is inserted into the passage opening 108 of the contact element 106. The fastening element 110', 110" is then secured to the contact assembly 100', 100" by a threaded retaining device 132, where the threaded retaining device 132 of the complementary mating contact assembly 100" is screwed onto the fastening element 110', or the threaded retaining device 132 is threaded through the fastening device 110" and onto the fastening device 110' of the complementary mating contact assembly 100'. During this fastening step, a contact force FK is generated by the knurled portions 138 of the fastening elements 110′, 110″, displacing material of the contact element 106 in the axial direction A and radial direction R, thereby pressing the first friction surface 120 of the contact element 106 flat against the inner surface 146 of the receiving opening 104 of the busbar 102. In this way, the contact area between the first friction surface 120 and the inner surface 146 of the receiving opening 104 of the busbar 102 can be increased, and the contact resistance between the busbar 102 and the contact element 106 can be reduced.

[0050] This is particularly advantageous when the busbar 102 (or more precisely, the receiving opening 104 of the busbar 102) has a small thickness, in particular less than 6 mm, in particular less than 2.5 mm, and / or when the busbar 102 may have a thickness in the range of less than 0.5 mm, preferably in the range of 0.01 mm to 0.1 mm, in the axial direction A, and comprises a plurality of thin sheet metal layers stacked one on top of the other in the axial direction A. Furthermore, the contacting method of the described contact assemblies 100', 100" is particularly advantageous when the busbar 102 or the plurality of thin sheet metal layers are made of a material that is easily oxidized, such as aluminum, copper, or a copper and / or aluminum alloy.

[0051] The described contacting method is particularly suitable for the non-welded electrical contacting of multiple thin sheet metal conductors (or "laminated sheet metal") having a thickness in the axial direction A in the range of less than 0.5 mm, preferably in the range of 0.01 mm to 0.1 mm. By fastening with the contact assemblies 100', 100", the thin sheet metal conductors can be easily formed into a spring package of elastically deformable busbars 102. [Explanation of symbols]

[0052] 100, 100', 100" Contact Assembly 102 Busbar 104 Receiving opening 106 Contact Elements 108 Passage opening 110, 110', 110" Fixed elements 112 Contact part 114 Color Section 116 inner diameter of receiving opening 104 118 Outer diameter of collar portion 114 120 First friction surface 122 Contact surface 124 Gap 126 Bearing surface 127 Fixed part 128 female thread 130 mating screw 132 Holding Element 134 Enlarged section 136 Second Friction Surface 138 Knurled part 140 Inner diameter of passage opening 108 142 Ribs 144 Axis of symmetry of passage opening 108 146 inner surface of receiving opening 104 148 bearing surface of bearing portion 126 150, 150', 150" Touch Guard Cap A axis direction α Incline angle h1, h2, h3 height R Radial direction

Claims

1. A conductive contact assembly (100, 100', 100"), said contact assembly (100, 100', 100") comprising: a contact element (106); A bus bar (102); a fixing element (110, 110', 110") for mechanically fixing the contact element (106) to the busbar (102); Equipped with The busbar (102) includes a receiving opening (104) for receiving at least a portion of the contact element (106); The contact element (106) includes a passage opening (108) for inserting the fixing element (110, 110', 110"), and a contact portion (112) extending tubularly along the passage opening (108) and having a cylindrical contact surface (122) facing radially outward; the contact element (106) is configured to be attachable to the busbar (102) by frictional engagement with at least a first friction surface (120) in the receiving opening (104); the fixing element (110, 110', 110") includes a knurled portion (138) that is axially (A) longer than or equal to the receiving opening (104) of the busbar (102); the knurled portion (138) is configured such that, in an assembled state of the contact assembly (100, 100', 100"), the knurled portion (138) exerts a contact force (FK) on the contact element (106), and the contact force (FK) presses the first friction surface (120) of the contact element (106) flat against an inner surface of the receiving opening (104) of the bus bar (102).

2. 2. The conductive contact assembly (100, 100', 100") of claim 1, wherein the contact force (FK) exerted by the knurled portion (138) on the contact element (106) has a radial component and an axial component relative to an axis of symmetry (144) of the passage opening (108).

3. 3. The conductive contact assembly (100, 100', 100") according to claim 1 or 2, wherein the fixing element (110, 110', 110") includes a cylindrical fixing portion (127) insertable into the passage opening (108) of the contact element (106), and at least a portion of the knurled portion (138) surrounds the cylindrical fixing portion (127) in a frustoconical shape.

4. The conductive contact assembly (100, 100', 100") of claim 3, wherein an outer surface of said knurled portion (138) is tapered in said axial direction (A).

5. 5. The conductive contact assembly (100, 100', 100") according to claim 1, wherein the fixing element (110, 110', 110") includes a bearing portion (126) extending radially outward and including a bearing surface (148) for the bus bar (102).

6. The conductive contact assembly (100, 100', 100") of claim 5, wherein the bearing surface (148) for the bus bar (102) forms at least a portion of the knurled portion (138).

7. 7. The conductive contact assembly (100, 100', 100") according to claim 1, wherein the knurled portion (138) includes a plurality of triangular and / or rectangular tooth elements (142) extending parallel to one another at least in the axial direction (A).

8. the busbar (102) comprises a plurality of thin sheet metal conductors arranged one on top of the other in the axial direction, each of the plurality of thin sheet metal conductors preferably having a layer thickness of less than 0.5 mm; and / or 8. The conductive contact assembly (100, 100', 100") according to claim 1, wherein the receiving opening (104) of the busbar (102) has a thickness (h2) in the axial direction (A) of 6 mm or less.

9. The conductive contact assembly (100, 100', 100") according to any one of claims 1 to 8, wherein at least a portion of the first friction surface (120) of the contact element (106) is knurled.

10. 10. The conductive contact assembly (100, 100') according to any one of claims 1 to 9, wherein the fixing element (110, 110') is configured as a threaded sleeve having an internal thread (128) for screwing onto a screw-like retaining element (132).

11. The conductive contact assembly (100, 100') according to any one of claims 1 to 9, wherein the fixing element (110, 110') is configured as a threadless collar sleeve for receiving a threaded retaining element (132).

12. A module connector, At least one contact assembly (100, 100', 100") according to any one of claims 1 to 11; Touchguard housing (150, 150', 150") and Equipped with The touch guard housing (150, 150', 150") is configured to receive the at least one contact assembly (100, 100', 100").

13. A connection assembly comprising two contact assemblies (100, 100', 100") according to any one of claims 1 to 11, A connection assembly, wherein each of the two contact assemblies (100, 100', 100") is configured to complement each other.

14. A method for mechanically securing a contact element (106) to a busbar (102), the method comprising: inserting the contact element (106) into the receiving opening (104) of the busbar (102), the contact element (106) being attached to the busbar (102) by frictional engagement at least with a first friction surface (120) at the receiving opening (104), the contact element (106) including a contact portion (112) extending tubularly along the passage opening (108) of the contact element (106) and having a cylindrical contact surface (122) facing radially outward; inserting the fixing element (110, 110', 110") into the passage opening (108) of the contact element (106), the fixing element (110, 110', 110") including a knurled portion (138) that is longer in an axial direction (A) than the receiving opening (104) of the busbar (102) or that is the same length as the receiving opening (104); and fixing the fixing element (110, 110', 110") in the passage opening (108) of the contact element (106) by a screw-like retaining element, wherein the knurled portion (138) exerts a contact force (FK) on the contact element (106), the contact force (FK) pressing the first friction surface (120) of the contact element (106) flat against the inner surface of the receiving opening (104) of the busbar (102). A method comprising:

15. 15. The method of claim 14, wherein the busbar (102) comprises a plurality of unwelded thin sheet metal conductors arranged one on top of the other in the axial direction (A).

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