Contact element and plug device, and manufacturing method and use

Abstract

The invention relates to a contact element (1) for a plug device (2), such as a charging plug or a charging socket, comprising a core (18) made of a first electrically conductive material, a shell (20) made of a second electrically conductive material, which at least partially surrounds the core from the outside, and a coating (64) made of a third electrically conductive material, which is applied to the outside of the shell at least in some regions. The first material has a lower density or a higher tensile strength than the second material, and the third material is different from the first material and the second material. The core-shell structure with a relatively light core in particular allows weight to be saved in the contact element. Furthermore, the invention relates to a manufacturing method for producing such a contact element from a profile, which is produced from at least two materials by extrusion, pressing or rolling, and to the use of a co-extruded rod (78) for producing such a contact element. Furthermore, the invention relates to a plug device having such a contact element.

Description

Technical Field

[0001] This invention relates to a contact element for a plug device, such as a charging plug or charging socket for a charging system of an electric vehicle. Furthermore, this invention relates to a method for manufacturing such a contact element made of a bimetal, the bimetal comprising at least two materials, preferably a co-extruded profile, such as a rod. The invention also relates to the use of such a rod in the manufacture of this contact element. Additionally, this invention relates to a plug device having such a contact element. Background Technology

[0002] Electric vehicles are understood herein to be vehicles driven entirely by electric power or vehicles with an electric drive unit as a partial drive unit, such as hybrid vehicles, especially plug-in hybrid vehicles, regardless of their size, i.e., passenger cars, trucks and commercial vehicles, including those used in agriculture and forestry.

[0003] Plug devices are used in many technical fields to create detachable connections for transmitting current and / or signals. This typically involves the mutual contact between the conductive contact elements of the plug devices to be connected.

[0004] In electric vehicle applications, some plug devices are fixed, such as those in charging stations, while others are part of the electric vehicle and must always be transported with it. This leads to different requirements for plug devices and their contact elements. For example, fixed plug devices should be as inexpensive and robust as possible to provide long-distance, durable charging infrastructure. For efficiency reasons, on-board plug devices should be as lightweight as possible.

[0005] Therefore, the object of the present invention is to provide a possibility for saving cost and weight in plug connectors. Summary of the Invention

[0006] The aforementioned objective is achieved by the aforementioned contact element, wherein the contact element comprises a core made of a first conductive material, a housing made of a second conductive material that at least partially surrounds the core from the outside, and a coating made of a third conductive material that is at least partially applied to the outside of the housing, wherein the first material has a lower density or a higher tensile strength than the second material, and the third material is different from the first and second materials.

[0007] Here, density describes mass density. A third material differs from the first and second materials if it includes at least one component not present in either the first or second materials, or if it lacks a component present in either the first or second materials. In other words, a third material may differ from the first and second materials in its chemical composition.

[0008] The advantages achieved by utilizing this invention are based, in part, on the core-shell structure of the contact element. This allows for weight savings by using a relatively lightweight core. If the core is made of a material with higher strength, this can contribute to a longer service life of the contact element. If, for example, the shell is made of a more conductive material to provide the necessary conductive cross-section and simultaneously encloses the core, i.e., surrounds or coats the core from the outside, this can be achieved with relatively small losses in current carrying capacity or current load capacity. Due to its arrangement on the outer periphery of the core, the shell therefore has a large contact area relative to its conductive cross-section, which in turn reduces contact resistance, thus benefiting current carrying capacity or current load capacity.

[0009] On the other hand, the coating can be used to extend the service life and maintenance intervals of the contact elements, thereby reducing the maintenance and replacement costs of plug devices with contact elements according to the present invention.

[0010] Therefore, the above-mentioned objective is also achieved by a plug device having at least one contact element according to the invention and a housing accommodating at least one contact element. The plug device benefits from the functionality and advantages of the invention, thus saving cost and weight.

[0011] The plug device can be a standardized plug device for charging systems used in electric vehicles. The charging system can be DC powered, AC powered, or three-phase powered.

[0012] The invention can be further improved by the following designs, each of which is advantageous in itself and can be combined with each other as needed.

[0013] According to a first possible embodiment, the third material can have higher abrasion resistance than the first and second materials. In other words, the coating can be more abrasion-resistant than the core, and particularly more abrasion-resistant than the housing. Therefore, the contact element can be used for more charging cycles without repair compared to the case without a coating. Abrasion resistance can be defined, for example, according to ASTM G99.

[0014] Alternatively or additionally, the third material can have a higher electrical conductivity than the first and second materials. In other words, the coating can conduct current better than the core, and especially better than the housing, which is advantageous as it further reduces the contact resistance of the contact elements.

[0015] Conversely, the housing can have a higher conductivity than the core. This means the second material can have a higher conductivity than the first material. High conductivity is generally associated with high material cost. However, due to the core, the contact element according to the invention does not necessarily have to be made entirely of a more conductive material. This can lead to further cost savings.

[0016] Due to the core-shell structure of the contact element, individual materials can be selected as needed. Therefore, the core, shell, and coating can be dedicated to certain sub-functions to achieve maximum cost and weight savings. Based on exemplary material selections, the first material may include aluminum, the second material may include copper, and / or the third material may include silver. In other words, the core may be made of aluminum or an aluminum alloy, the shell may be made of copper or a copper alloy, and the coating may be made of silver or a silver alloy. However, the first material may also contain zinc and / or iron, and the third material may also contain nickel and / or gold.

[0017] According to another possible embodiment, the core and the shell can be cold-welded together in at least some areas. Specifically, the cold welding can occur at the interface between the core and the shell, where there are direct metallic bonds between the first material of the core and the second material of the shell. As explained in more detail below, the cold welding can be achieved, for example, by a cold forming process. This results in sufficient mechanical cohesion between the core and the shell, without the first material contaminating the second material through material migration, as is the case with diffusion processes at high temperatures.

[0018] For use as a contact pin, the contact element can extend in a particularly elongated or pin-shaped manner along the main direction. Here, the elongated contact element has a size or extension that is many times larger than the rest of the contact element, for example, five times, preferably four times, or at least three times larger.

[0019] According to another possible embodiment, in a first cross-section perpendicular to the main direction of the contact element, the area ratio between the core and the housing can be at least three to one. This means that the cross-sectional area of ​​the core is three times the cross-sectional area of ​​the housing. This represents a suitable trade-off between weight reduction in the core and the existing conductor cross-section of the housing. Of course, any other area ratio between the core and the housing, such as 4:1, 2:1, 1:1, or 1:2, can also exist in the first cross-section.

[0020] Optionally, the contact element may be formed entirely of either the second or first material in a second cross-section perpendicular to the main direction. In other words, the contact element may have at least one segment without a core or a housing. In this embodiment, the coreless second cross-section extends through the coreless segment and is spaced apart from the first cross-section along the main direction. Advantageously, the coreless portion may be formed particularly thin, and thus preferably positioned at the end of the contact element when viewed along the main direction.

[0021] For example, the aforementioned coreless portion can be configured to place or carry a touch (or contact) protective cap on the end of the contact element. Therefore, the contact element may include such a touch protective cap configured to be placed on the end of the contact element. In this embodiment, the touch protective cap is made of a non-conductive material for insulation purposes.

[0022] Additionally or alternatively, the contact element may be formed entirely of the first material in a third cross-section perpendicular to the main direction. In other words, the contact element may include at least one segment having a bare or exposed core without a shell and without a coating or a third material. In this embodiment, the third cross-section extends through the exposed segment and is spaced apart from the first and second cross-sections along the main direction.

[0023] Alternatively, the exposed portion mentioned above can be arranged at the base (extension; German: Ansatz) of the contact element, wherein the base is located in the main direction opposite to the end of the contact element. When the contact element is installed, the base points inward toward the plug assembly, while the end of the contact element points outward toward the mating part of the plug assembly.

[0024] Exposed portions can perform purely mechanical functions, which is why a housing and coating made of a more conductive material can be omitted there. Of course, the core wire, especially the exposed section of the contact element, can also be part of the conductor's cross-section, particularly since the primary material of the core wire is also conductive.

[0025] Specifically, the core may have a fastening section for a conductor of the plug assembly. Therefore, the plug assembly may have at least one conductor, thereby electrically connecting the core to at least one conductor. The fastening section may be formed, for example, by an exposed section of a contact element and may include a solder surface and / or threads. Alternatively or additionally, the housing may also have a fastening portion for a current conductor.

[0026] Preferably, at least one conductor is made of the same first material as the core or housing. Due to this material homogeneity, the connection between the core or housing and at least one conductor is particularly advantageous from an electrochemical perspective, as it is less susceptible to electrochemical corrosion. Therefore, contact elements with an aluminum-containing core are particularly well-suited for combination with aluminum busbars, whose use is steadily increasing in the electric vehicle sector. Contact elements comprising a housing made of copper or a copper alloy are particularly suitable for connection to copper cables, and due to material similarity, facilitate the soldering process, for example.

[0027] Alternatively, the core or first material may also include copper. Similarly, the housing or second material may also include aluminum.

[0028] Also advantageous is that the first material of the core has better weldability and / or better machinability than the second material of the shell. This makes it easy to form fastening segments on the core.

[0029] According to another possible embodiment, the contact element may have an external shape that deviates from the straight body in at least some areas. The external shape may be defined by the outer contour or volume of the contact element. This deviation from the straight body results in additional degrees of freedom in the design, which allows for improvements in the functionality of the contact element. For example, the contact element may have an insertion bevel at its end, which facilitates the contact process. Similarly, the contact element may have a shoulder for securing the contact element within the housing of the plug connection.

[0030] To achieve the desired external shape, the contact element may have at least one cross-sectional variation portion, i.e., a portion with a changing cross-section. This at least one cross-sectional variation portion may relate to the total circumference of the contact element measured in the circumferential direction relative to the main direction, and particularly the total diameter of the contact element measured perpendicular to the main direction. The at least one cross-sectional variation portion may be located between the base and the end of the contact element. For simplicity, it may be assumed in this specification that the base is located before the cross-sectional variation portion and the end is located after it. From the base to the end, the at least one cross-sectional variation portion may represent a tapering or expanding cross-section.

[0031] Furthermore, the at least one cross-sectional change portion can be stepped to achieve the aforementioned shoulder. Alternatively, the at least one cross-sectional change portion can be gradual, which may, for example, provide the aforementioned insertion ramp. Optionally, the contact element may also have several such cross-sectional changes.

[0032] According to another possible embodiment, the first thickness of the housing before the cross-sectional change portion can be different from the second thickness of the housing after the cross-sectional change portion. This means that the housing does not have a constant thickness, but rather has different thicknesses on different sides of the cross-sectional change portion or along the longitudinal axis of the component. Here, the housing thickness, specifically the first and second thicknesses, is measured perpendicular to the main direction.

[0033] For example, the housing thickness can decrease as the cross-section decreases, and increase as the cross-section increases. Preferably, the housing thickness can be proportional to the total perimeter or total diameter of the contact element. Similar to cold welding described above, variable housing thickness can also be achieved through a cold forming process by applying locally varying pressing pressures to the contact element.

[0034] Optionally, the contact element may have a flange that projects radially outward relative to the main direction. The flange allows the contact element to be held in the housing of the plug device in a form-fitting manner relative to the main direction. Furthermore, the flange need not be rotationally symmetrical about the main direction, thus additionally serving to secure the contact element within the housing of the plug device against rotation or without rotation.

[0035] A flange is one possibility for implementing at least one section with a changing cross-section. Depending on the requirements, the flange can be formed from a first material of the core and / or a second material of the housing. For example, the flange can be arranged on an exposed section of the contact element and can project radially from the exposed core. Alternatively, the flange can be arranged on and project from the housing.

[0036] The above objective is also achieved by a method for manufacturing a contact element. This method includes the steps of: providing a profile or rod having a core made of a first conductive material and a shell made of a second conductive material that surrounds the core from the outside; forming the profile or rod into a shaped pin; and coating the pin with a third conductive material, wherein the first material has a lower density than the second material, and wherein the third material is different from the first and second materials.

[0037] The provided bars may be co-extruded bars. Alternatively, the bars may also be manufactured by rolling, pressing, and / or welding. The bars may be directly formed into the final shape of the part by cold forming below the recrystallization temperature or by thermoforming above the recrystallization temperature.

[0038] The manufacturing process produces contact elements that provide the advantages and functions already described. Therefore, the manufacturing process contributes to cost and weight savings in plug connectors. By using bimetals, especially in cases where pins are to be manufactured using co-extruded rods, the core-shell structure of the contact elements can be achieved in a simple and cost-effective manner, and the final shape can be produced in a manufacturing process with several integrated steps.

[0039] Therefore, if the co-extruded bar comprises a core made of a first conductive material and a shell made of a second conductive material with a higher density and surrounding the core from the outside, the above-mentioned objective is also achieved by using a bimetallic (in this case, a co-extruded bar for manufacturing a contact element according to one of the above embodiments)

[0040] Co-extruded bars can be produced via an extrusion process in which first and second materials are placed together and pressed through a forming die. Depending on the desired shape of the bimetal, the material can be cut to the correct length before or after forming to produce parts, particularly profiled pins.

[0041] As an alternative to co-extruded bars, solid bars or filaments made of a first material and hollow tubes made of a second material can be pushed into each other to obtain a core-shell structure. A shaped pin geometry is then formed to ensure that the core or solid bar is cold-welded to the shell or hollow tube, thus creating a durable, high-strength connection.

[0042] The aforementioned coreless sections can be created, for example, by ensuring that the hollow tube has a suitable protruding / excess length relative to the solid rod. In other words, the shell of the profile or rod can be longer than the core of the profile or rod. During cold forming, the protruding portion of the hollow tube can then be radially compressed, thereby creating a coreless section for the contact element. Alternatively (or if suitable protrusions are present on both sides), a conductor can be inserted or fitted into the protruding portion of the hollow tube to electrically connect there to, for example, a fastening section of the core.

[0043] Similarly, the aforementioned exposed section can be created when solid strip material protrudes from the hollow tube and is therefore not completely covered by the second material of the hollow tube. Therefore, the core of a profile or rod can also be longer than the shell of the profile or rod.

[0044] Another alternative for producing bimetallic materials may involve using a rolling process to mechanically wrap a profile material made of a first material with a second material under pressure, thereby creating a shell.

[0045] The above objective is also achieved by an electric vehicle, wherein the electric vehicle includes a plug device according to any one of the foregoing embodiments, wherein the plug device is configured as a charging socket for connecting to a charging plug of a charging cable.

[0046] The above objective is also achieved by a charging station for electric vehicles, wherein the charging station includes a plug device and a charging cable according to any of the foregoing embodiments, wherein the plug device is configured as a charging plug on the charging cable for connection to a charging socket of the electric vehicle.

[0047] Charging stations can be, for example, public charging stations. Specifically, charging stations can be fast-charging stations. Charging stations can be configured to charge the energy storage devices of connected electric vehicles via charging cables, charging plugs, and charging sockets during charging operations.

[0048] All references to specifications and standards (e.g., ASTM standards) in this application refer to the version of the relevant specification or standard that was in effect at the time of submission. Attached Figure Description

[0049] The invention will now be explained in more detail with reference to the accompanying drawings and several embodiments, the different features of which can be combined with each other as needed based on the above description.

[0050] In the attached diagram:

[0051] Figure 1 A schematic perspective cross-sectional view of a contact element according to a first exemplary embodiment is shown;

[0052] Figure 2 It shows Figure 1A schematic cross-sectional view of the contact element along section II-II;

[0053] Figure 3 It shows Figure 1 A schematic cross-sectional view of the contact element along section III-III;

[0054] Figure 4 A schematic perspective cross-sectional view of a contact element according to a second exemplary embodiment is shown;

[0055] Figure 5 A schematic perspective view shows steps in the manufacturing process of a contact element according to another exemplary embodiment;

[0056] Figure 6 A schematic perspective view showing another step in the manufacturing process; and

[0057] Figure 7 A schematic perspective view showing another step in the manufacturing process is shown. Detailed Implementation

[0058] First, refer to Figures 1 to 4 A schematic structure illustrating a possible embodiment of contact element 1 is explained below. Next, refer to... Figure 4 A schematic structure illustrating a possible embodiment of the plug device 2 is described. Finally, refer to... Figures 5 to 7 This describes a method for manufacturing contact element 1.

[0059] Contact element 1 can be constructed as contact pin 4, such as Figure 1 As shown. For this purpose, the contact element 1 can extend from the base 8 (extension; German: Ansatz) to the end 10 in a slender or pin-shaped manner along the main direction 6. When the contact element 1 is in the installed state 12, the base 8 points inward toward the inside of the plug device 2, while the end 10 of the contact element 1 points outward (see...). Figure 4 ).

[0060] The size 14 or extension 16 of the elongated contact element 1 is many times, for example, five times, preferably four times, and at least three times, of the remaining size 14' or extension 16' of the contact element 1.

[0061] Alternatively, the contact element 1 can be configured to be rotationally symmetrical with respect to the main direction 6. Depending on the application, a cuboid shape (not shown) or a prism shape (not shown) may also be considered for the contact element 1.

[0062] from Figure 1As can be seen from the partial cross-sectional view, the contact element 1 has a core 18 and a housing 20, the housing 20 at least partially surrounding / enclosing the core 18 from the outside. The core 18 is made of a first conductive material 22', and the housing 20 is made of a second conductive material 22'', wherein the first material 22' has a lower density than the second material 22''.

[0063] This core-house structure of contact element 1 and the relatively lightweight core 18 save weight without excessively sacrificing current-carrying capacity or current-load capacity. This is because the housing 20 provides the necessary conductor cross-section 24 and simultaneously encloses the core 18, i.e., surrounds or wraps it from the outside. Due to its arrangement on the outer periphery of the core 18, the housing 20 therefore has a large contact area 26 relative to its conductor cross-section 24. This reduces contact resistance, which is beneficial for better current-carrying capacity or current-load capacity.

[0064] The housing 20 can have a higher conductivity than the core 18. This means that the second material 22'' can have a higher conductivity than the first material 22'. High conductivity is generally associated with high material cost. However, due to the core 18, the contact element 1 does not have to be made entirely of a more conductive material. This results in cost savings.

[0065] The core 18 and the housing 20 can be cold-welded to each other in at least some areas. In particular, the cold welding can occur at the interface 28 between the core 18 and the housing 20, wherein there is a direct metallic bond between the first material 22' of the core 18 and the second material 22'' of the housing 20. As explained in more detail below, the cold welding can be achieved, for example, by a cold forming process.

[0066] from Figure 1 It can also be seen that the contact element 1 may have an external / external shape 30 that deviates from the straight body in at least some areas. The external shape 30 may be defined by the external contour 32 or volume 34 of the contact element 1. For example, the contact element 1 may have an insertion bevel (or angle) 36 at its end 10. Similarly, the contact element 1 may have a shoulder 38 for securing the contact element 1 to the housing 40 of the plug device 2 (see...). Figure 4 )middle.

[0067] In other words, the contact element 1 may have one or more cross-sectional variation portions 42. Each cross-sectional variation portion 42 may affect the total circumference 46 of the contact element 1 measured in the circumferential direction 44 relative to the main direction 6, and in particular the total diameter 48 of the contact element 1 measured perpendicular to the main direction 6. Where a shoulder 38 is required, the cross-sectional variation portion 42 may be stepped. Other cross-sectional variation portions 42 may be progressive, which provides the aforementioned insertion ramp 36.

[0068] The cross-sectional variation portion 42 can be distributed between the base 8 and the end portion 10 of the contact element 1. Figure 1 In the example shown, the contact element 1 includes a cross-sectional extension 50 and three cross-sectional cones 52, serving as a cross-sectional variation 42 from the base 8 to the end 10. Depending on the internal geometry of the housing 40 of the plug-in device 2, different combinations of the cross-sectional variation 42 may also exist.

[0069] In the first cross-section 54' of the contact element 1 perpendicular to the main direction 6, the area ratio between the core 18 and the housing 20 can be at least three to one. Of course, any other area ratio between the core and the housing can also exist in the first cross-section 54', such as 2:1, 1:1, 1:2 or 1:3.

[0070] Figure 2 and Figure 3 Cross sections 54 before and after the cross-sectional change section 42 are shown respectively. The first thickness 56' of the housing 20 before the cross-sectional change section 42 may be different from the second thickness 56" of the housing 20 after the cross-sectional change section 42. In other words, the housing 20 does not necessarily include a constant thickness 56. More precisely, different thicknesses 56 exist on different sides of the cross-sectional change section 42. Here, the housing thickness 56, especially the first thickness 56' and the second thickness 56", can each be measured radially in the principal direction 6 and can describe the distance between the outermost material layer and the innermost material layer. Therefore, the housing thickness 56 corresponds to the material thickness of the housing 20.

[0071] Figure 2 and Figure 3 It is shown that the housing thickness 56 can decrease with the cross-sectional taper 52, and conversely, the housing thickness 56 increases with the cross-sectional expansion 50. The housing thickness 56 can be proportional to the total perimeter 46 or the total diameter 48 of the contact element 1.

[0072] Figure 4 A contact element 1 is shown mounted in the housing 40 of the plug device 2. In this embodiment, the contact element 1 in the housing 40 is accessible from the outside to the mating plug (not shown). Depending on the requirements and application, the plug device 2 may also have multiple contact elements. If the plug device 2 is a DC charging system, two contact elements may be provided, for example, one as a positive contact (DC+) and the other as a negative contact (DC-). In AC or three-phase charging systems, contact elements are provided for the neutral conductor, the protective conductor, and a corresponding number of phase conductors.

[0073] exist Figure 4As can be seen, the contact element 1 may have a flange 58 that projects radially outward relative to the main direction 6. With the aid of the flange 58, the contact element 1 can be held in the housing 40 of the plug device 2 in a form-fit manner relative to the main direction 6. Furthermore, the flange 58 need not be rotationally symmetrical relative to the main direction 6, allowing the flange 58 to also serve as a rotationally fixed or non-rotationally attached element for the contact element 1 within the housing 40 of the plug device 2.

[0074] exist Figure 4 In the example shown, the flange 58 is formed from the second material 22'' of the housing 20. Specifically, the flange 58 may be arranged on and project from the housing 20. Alternatively, the flange 58 may be formed from the first material 22' of the core 18. For example, the flange 58 may be arranged on an exposed portion (not shown) of the contact element 1 without the housing 20 and may project radially from the exposed core 18. A plastic flange (not shown) molded onto the contact element 1 represents another alternative.

[0075] Optionally, flange 58 may have a retaining pouch 60 for a temperature sensor (not shown). Following flange 58 in the main direction 6, sealing ring 62 may be arranged on contact element 1, for example by overmolding.

[0076] The contact element 1 includes a coating 64 made of a third conductive material 22'', which is applied at least in some areas on the outer side of the housing 20. The coating 64 is preferably located on the end 10 of the contact element 1. Specifically, the coating 64 may be limited to the end 10. If desired, the coating may also be applied to the base 8.

[0077] The third material 22''' differs from the first material 22' and the second material 22'' in that the third material 22''' contains at least one component that is not present in the first material 22' and the second material 22'', or the third material 22''' lacks a component present in the first material 22' or the second material 22''.

[0078] For example, the third material 22''' can have a higher conductivity than the first material 22' and the second material 22''. In other words, the coating 64 can conduct electricity better than the core 18, and especially better than the housing 20, thereby advantageously reducing the contact resistance of the contact element 1.

[0079] Alternatively or additionally, the third material 22''' may have higher abrasion resistance than the first material 22'' and the second material 22''. In other words, the coating 64 may be more abrasion resistant than the core 18, and especially more abrasion resistant than the shell 20. Therefore, the contact element 1 can be used for more charging cycles without repair compared to the case without a coating. Abrasion resistance may be defined, for example, according to ASTM G99.

[0080] Depending on the exemplary selection of materials, the first material 22' may include aluminum, the second material 22'' may include copper, and / or the third material 22''' may include silver. In other words, the core 18 may be made of aluminum or an aluminum alloy, the housing 20 may be made of copper or a copper alloy, and the coating 64 may be made of silver or a silver alloy.

[0081] from Figure 4 It can also be seen that the contact element 1 can be formed entirely of the second material 22'' in the second cross section 54" perpendicular to the main direction 6. In other words, the contact element 1 can have at least one coreless portion 66 without the core body 18. In this embodiment, the second cross section 54" extends through the coreless portion 66 and is spaced apart from the first cross section 54' along the main direction 6. As shown, the coreless portion 66 can be formed to be particularly thin and is therefore preferably arranged at the end 10 of the contact element 1.

[0082] Specifically, the coreless portion 66 can be configured to place or support a touch protection cap 68 on the end 10 of the contact element 1. Therefore, the contact element 1 can have such a touch protection cap 68 placed on the end 10 of the contact element 1. For insulating purposes, the touch protection cap 68 is made of a non-conductive material.

[0083] As already noted, contact element 1 may have a section with an exposed or bare core without a housing. This exposed section may result in contact element 1 being entirely formed of the first material 22' in a third cross-section (not shown) perpendicular to the main direction 6. The third cross-section extends through the exposed portion and is spaced apart from the first cross-section 54' and the second cross-section 54" along the main direction 6.

[0084] Figure 4 The plug device 2 is further shown to have a conductor 70, which may preferably be made of the same first material 22' as the core 18 to avoid galvanic corrosion. The core 18 may be electrically connected to at least one conductor 70. For this purpose, the core 18 may have a retaining section 72 for the conductor 70. The retaining section 72 may, for example, be provided with a welding surface 74. Alternatively or additionally, the retaining section 72 may have threads (not shown). Therefore, it is advantageous that the first material 22' of the core 18 has better weldability and / or better machinability than the second material 22'' of the housing 20, so that the retaining section 72 can be easily implemented.

[0085] If the plug device 2 conforms to a standard or specification, the shape 76 of the contact element 1, particularly the end 10, may at least partially correspond to the geometry defined in that standard or specification. Furthermore, the coating 64 may be applied to the contact area 26 as specified in this standard or specification.

[0086] The following describes a method for manufacturing contact element 1. For example... Figure 5 As shown, the manufacturing process first includes the step of providing a co-extruded bar 78, wherein the core 18 is made of a first material 22' and the shell 20 is made of a second material 22″.

[0087] As an alternative to the co-extruded bar 78, a solid bar (not shown) made of a first material 22' and a hollow tube (not shown) made of a second material 22'' can be inserted into each other to obtain a core-shell structure. Another alternative to the co-extruded bar 78 is to cover the solid bar made of the first material 22' with the second material 22'', thereby forming a shell 20 thereon.

[0088] After that is Figure 6 The step shown is the cold forming of the bar 78 into the shaped pin 80. Cold forming ensures that the housing 20 is cold-welded to the core 18 and thus held together. The area where the total circumference 46 or total diameter 48 of the pin 80 is to be significantly reduced is subjected to higher pressure than the rest of the pin 80. In the finished contact element 1, this results in the housing thickness 56 being proportional to the total circumference 46 or total diameter 48 of the contact element 1.

[0089] Figure 7 The subsequent steps of coating pin 80 with a third material 22″′ are shown. However, the indicated coating layer is to be understood as an example only. Other coating methods, such as electroplating, vacuum coating (PVD / CVD), dip coating, powder coating, and flame spraying, are also possible and anticipated.

[0090] Figure Labels

[0091] 1. Contact element

[0092] 2. Plug assembly

[0093] 4 Contact pins

[0094] 6 main directions

[0095] 8. Base

[0096] 10 End

[0097] 12 Installation Status

[0098] 14, 14' size

[0099] 16, 16' extension

[0100] 18 cores

[0101] 20. Housing

[0102] 22' First Material

[0103] 22'' Second Material

[0104] 22''' Third Material

[0105] 24. Conductor cross-section

[0106] 26 Contact area

[0107] 28 Interfaces

[0108] 30 external shape

[0109] 32 External contour

[0110] 34 volume ratio

[0111] 36 Insert inclined plane

[0112] 38 Shoulders

[0113] 40. Outer shell

[0114] 42. Sectional Variation Section

[0115] 44 Circumferential direction

[0116] 46 Total perimeter

[0117] 48 Total diameter

[0118] 50 cross-sectional expansion

[0119] 52. Cross-sectional taper

[0120] 54 cross sections

[0121] 54' First cross section

[0122] 54” Second cross section

[0123] 56 Thickness

[0124] 56' First Thickness

[0125] 56” Second Thickness

[0126] 58 Flange

[0127] 60 Retaining recess

[0128] 62 Sealing ring

[0129] 64 Coating

[0130] 66 Coreless Section

[0131] 68. Touch protection cap

[0132] 70 conductor

[0133] 72 Fastening Section

[0134] 74 Welding surface

[0135] 76 Shapes

[0136] 78 bar stock

[0137] 80 irregular pins

Claims

1. A contact element (1) for a plug device (2), said plug device being, for example, a charging plug or a charging socket, wherein, The contact element (1) includes: - Core (18) made of a first conductive material (22'). - A housing (20) made of a second conductive material (22''), the housing (20) at least partially surrounding the core (18) from the outside, and - A coating (64) made of a third conductive material (22'''), said coating (64) being applied at least partially to the outer side of the housing (20), The first material (22') has a lower density or a higher tensile strength than the second material (22''), and the third material (22''') is different from the first material (22') and the second material (22'').

2. The contact element (1) according to claim 1, wherein, The third material (22''') has higher wear resistance and / or higher electrical conductivity than the first material (22') and the second material (22'').

3. The contact element (1) according to claim 1 or 2, wherein: - The first material (22') includes aluminum, copper, zinc and / or iron, - The second material (22'') includes aluminum and / or copper, and / or - The third material (22''') includes silver, nickel and / or gold.

4. The contact element (1) according to any one of claims 1 to 3, wherein, The core (18) and the housing (20) are cold-welded to each other in at least some areas.

5. The contact element (1) according to any one of claims 1 to 4, wherein, The contact element (1) extends along the main direction (6), and in the first cross section (54') of the contact element (1) perpendicular to the main direction (6), the area ratio between the core (18) and the housing (20) is at least four to one.

6. The contact element (1) according to claim 5, wherein, The contact element (1) is formed entirely of the second material (22'') in a second cross section (54") perpendicular to the main direction (6), and / or entirely of the first material (22') in a third cross section perpendicular to the main direction (6).

7. The contact element (1) according to any one of claims 1 to 6, wherein, The core (18) or the housing (20) has a fastening portion (72) for the conductor (70) of the plug device (2).

8. The contact element (1) according to any one of claims 1 to 7, wherein, The contact element (1) has an external shape (30) that deviates from the straight body in at least some areas.

9. The contact element (1) according to any one of claims 1 to 8, wherein, The contact element (1) has at least one cross-sectional variation portion (42).

10. The contact element (1) according to claim 9, wherein, The first thickness (56') of the housing (20) in front of the cross-sectional change portion (42) is different from the second thickness (56") of the housing (20) behind the cross-sectional change portion (42).

11. The contact element (1) according to any one of claims 1 to 10, wherein, The contact element (1) has a flange (58) formed of the first material (22') and / or the second material (22'').

12. A plug device (2) having at least one contact element (1) according to any one of claims 1 to 11 and a housing (40), wherein the at least one contact element (1) is held in the housing (40).

13. The plug device (2) according to claim 12, wherein, The plug device (2) has at least one conductor (70) made of the same first material (22') as the core (18) of the at least one contact element (1), wherein the core (18) of the at least one contact element (1) is electrically connected to the at least one current conductor (70).

14. The plug device (2) according to claim 13, wherein, The housing (20) of the at least one contact element (1) is longer than the core (18) of the at least one contact element (1), and wherein the at least one conductor (70) is inserted into or fitted into the housing (20) of the at least one contact element (1).

15. A method for manufacturing a contact element (1), comprising the following steps: - Provide a profile or rod (78) having a core (18) made of a first conductive material (22') and a shell (20) made of a second conductive material (22''), the shell (20) surrounding the core (18) from the outside. - The profile or bar (78) is formed into a shaped pin (80), and - Coat the pin (80) with a third conductive material (22'''). The first material (22') has a lower density than the second material (22''), and the third material (22''') is different from both the first material (22') and the second material (22'').

16. The manufacturing method according to claim 15, wherein the shell (20) of the profile or rod (78) is longer than the core (18) of the profile or rod (78).

17. Use of a co-extruded bar (78) having a core (18) made of a first conductive material (22') and a shell (20) made of a second conductive material (22''), the shell (20) surrounding the core (18) from the outside (22'') and having a higher density or lower tensile strength, for manufacturing a contact element (1) of a plug device (2).

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