ELECTRICAL CONTACT ELEMENT FOR A CONNECTOR AND CONNECTOR ASSEMBLY WITH AN ELECTRICAL CONTACT ELEMENT

Description

[0001] The invention relates to a connector arrangement with a connector having an electrical contact element, with a metal flat contact plug, in which a plastic body is arranged at least on its plug-side end face, wherein the cross-sectional area of ​​the section of the plastic body extending from the plug-side end face of the flat contact plug has two wave-shaped edge contours extending symmetrically or asymmetrically to the central axis of the cross-sectional area, the distance of which varies continuously along the plug-in direction and has at least one local maximum (Max) outside the end areas. Every electrical circuit with higher electrical voltages must be protected against contact to avert dangers to life and limb.

[0002] In the automotive industry, connectors, especially in the engine compartment, have therefore been designed with touch protection for many decades. Various concepts for touch protection have been known to connector manufacturers and designers for many years and are applied in their products.

[0003] So-called passively touch-protected connectors have suitable geometries to prevent accidental contact.

[0004] A generic connector arrangement with an electrical contact element which has a plastic touch guard is known from German patent application DE 10 2018 211 043 A1.

[0005] A similar and generic embodiment of an electrical contact element for high-voltage applications, which enables the separation of a current-carrying connection without arc formation, is also known from DE 11 2017 003 854 T5, which discloses the preamble of claim 1.

[0006] Other solutions with integrated touch protection are described, for example, in publication US 2020 161 795 A1.

[0007] The connector arrangement shown there aims to provide a connector that incorporates both a finger touch protection element and a pre-locking structure, without increasing the overall size of the connector arrangement.

[0008] JP 2014 179 290 A also presents a proposal to demonstrate a corresponding solution for a connector arrangement in which a finger contact protection element is also formed at the front end of the connector in the form of an insulating element.

[0009] In addition to protection against contact, another essential aspect of a connector arrangement is its mechanical durability and the associated plugging process.

[0010] The section of the plastic body that rests against the mating end face of the flat connector particularly influences the properties of the contact element during the insertion process. Depending on the geometry of this section, relatively high insertion forces or an unfavorable distribution of insertion forces can occur. The amount of plastic abrasion generated during insertion also depends on the geometry of this section. Furthermore, the shape of the plastic body should, in a given environment, make it as difficult as possible for a finger to approach the flat connector.

[0011] The task was to create an electrical connector arrangement that is particularly advantageous with regard to these requirements.

[0012] This problem is solved according to the invention by providing a counter-contact element which has several lamellae which contact the flat contact plug, by having each of the lamellae a lamella spring and by having a lamella cap connected to each lamella spring.

[0013] The distance between the edge contours, measured perpendicular to the central axis of the cross-sectional area, is subsequently also referred to as the cross-sectional width.

[0014] This design has proven particularly advantageous because it keeps the insertion forces and the resulting plastic abrasion on the plastic body relatively low when a spring-loaded mating contact is attached. Low insertion forces simplify the handling of connectors with such contact elements. Minimal plastic abrasion is desirable because plastic abrasion also impairs the electrical properties of the contact element.

[0015] A double-wave-shaped contour of the plastic body's edge shape has proven to be particularly advantageous.

[0016] Advantageous embodiments and further developments of the invention will become apparent from the dependent claims and the following description of the invention with reference to the drawings. These show Figure 1 shows an electrical contact element in two views and a detailed enlargement; Figure 2 shows a connector arrangement with a contact element and a mating contact element; Figure 3 shows a connector tip in section; Figure 4 shows a connector tip with marked contact surfaces; Figure 5 shows two connector tips according to the prior art in section; Figure 6 shows a pair of lamellae on an electrical contact element, as well as on two contact elements according to the prior art.

[0017] The Figure 1Figure 1 shows an electrical contact element 10 according to the invention in a top view of a contact surface 19 and in a sectional view A - A. Furthermore, an enlarged detail view B of the sectional view is shown.

[0018] The contact element 10 consists of a metal flat contact plug 11 with an injection-molded plastic body 12.

[0019] The one-piece plastic body 12 can surround the flat contact connector 11 from several sides, in which case side parts 14 of the plastic body 12 abut the two narrow longitudinal sides of the flat contact connector 11, while a connector tip 13 connecting the side parts 14 is arranged on the plug-side end face of the flat contact connector 11.

[0020] The electrically non-conductive plug tip 13 serves to prevent direct contact between the end face of the flat contact plug 11 and a part of the human body. The two side parts 14 achieve the same effect for the two narrow longitudinal sides of the flat contact plug 11. The plastic body 12 thus forms a contact guard for the flat contact plug 11.

[0021] The access options to the front and rear contact surfaces 19 of the flat contact connector 11, which are for contacting by a mating contact element 20 ( Figure 2 ) must be kept clear, are restricted in a generally known manner by housing parts of a connector housing (not shown here) that surround the contact element 10.

[0022] The plug tip 13 of the electrical contact element 10, formed by the plastic body 12, is characterized in that its two edge surfaces each form at least one simple wave contour in cross-section. In the examples shown here, a double wave contour is even depicted in each case.

[0023] The electrical contact element 10 is designed to connect to a device located in the Figure 2The schematically depicted mating contact element 20 forms an electrical connector arrangement. The mating contact element 20 has several lamellae 26a, 26b, 26c, 26d, which can be arranged on a U-shaped support component 21 as opposing lamellae 26a and 26c, as well as 26b and 26d, or as successive lamellae 26a and 26b, as well as 26c and 26d in the insertion direction. Additionally, further lamellae parallel to the depicted lamellae 26a, 26b, 26c, 26d can also be provided in a plane parallel to the plane of the drawing, but these are not located in the Figure 2 are not explicitly shown.

[0024] Each of the lamellae 26a, 26b, 26c, 26d has a resilient section, which is simplified here as a cylindrical spring and is referred to below as a lamellar spring 27a, 27b. A lamellar tip 28a, 28b is connected to each lamellar spring 27a, 27b, and rests against one of the contact surfaces 19 of a counter-contact element 20 that is fully connected to a contact element 10.

[0025] When the mating connector 20 is joined with the contact element 10, the lamellar tips 28a, 28b touch the edge surfaces of the plug tip 13 and the contact surfaces 19 of the flat contact plug 11. Due to the spring forces of the lamellar springs 27a, 27b, insertion forces arise when a contact element 10 is attached, the magnitude and course of which are determined by the design of the lamellar springs 27a, 27b and by the cross-sectional shape of the contact element 10.

[0026] While a flat contact connector 11 is generally simply designed with plane-parallel contact surfaces 19, the shape of the connector tip 13, which consists of an insulating material, can in principle be varied. However, simple cross-sectional shapes are mostly chosen for an insulating connector tip 13, since its purpose, apart from the touch protection function, is generally only seen as opening the lamellae of the mating connector sufficiently so that they can slide over the connector tip onto the contact surfaces of the flat contact connector.

[0027] In the Figure 5Two exemplary embodiments of an insulating plug tip 13', 13" according to the prior art are shown. In view a), the front section of the plug tip 13' forms a kind of dome, the cross-section of which reaches the cross-sectional width of the flat contact plug 11 after only a short distance in the insertion direction. With this plug tip 13', a very high force is required, especially at the beginning of the insertion process, to expand the contact lamellae. View b) shows a further embodiment, a wedge-shaped plug tip 13", in which the insertion force increases continuously until the flat contact plug 11 is reached.

[0028] In the contact element 10 according to the invention, a new shape for the plug tip 13 was found, which optimizes the insertion force profile when joining a contact element 10 with a mating contact element 20. Figure 3Figure 1 shows a vertical cross-section through the electrical contact element 10 in the area of ​​the plug tip 13. The edge contours 17a, 17b of the cross-sectional area 18 of the plug tip 13 are subdivided into several zones I, II, III and IV by encircling for the following explanation.

[0029] The two edge contours 17a, 17b of the cross-section of the illustrated plug tip 13, which run symmetrically to each other with respect to the central axis 22 of the cross-sectional area 18 of the plug tip 13, each have a wave-like shape and in particular a double wave shape, which is characterized by the fact that the cross-sectional widths of the edge contours 17a, 17b vary continuously in the insertion direction and have two cross-sectional maxima Max in their course (zones II), which are not located at the front or rear end section of the edge contours 17a, 17b.

[0030] Specifically, the depicted shape of the plug tip 13 has two elevation zones II, each of which has a local maximum Max of the cross-sectional width, as well as an intermediate valley zone III, in which the cross-sectional width becomes locally minimal in a minimum Min.

[0031] The beginning and end of the edge contours 17a, 17b also form a local minimum Min in the cross-sectional width in the plastic connector chamfer zone I and in the recess zone IV, respectively. In the plastic connector chamfer zone I, the edge contour begins with a molded chamfer 16.

[0032] The plastic surface of the connector tip 13 and the metal surface of the flat contact connector 11 meet in the recess zone IV in a concave material transition area at an angle of 90° to 179°, which is hereinafter referred to as recess 15. The metal area in this material transition is designed to ensure an angular transition 29. This can be created by forming a chamfer, a radius, an edge, or a polynomial shape. The recess 15 ensures that there is no contact between the contact element 10 and the lamellar tips 28a, 28b and 27a, 27b in the material transition area.

[0033] Through the in the Figure 3 The waveform of the plug tip 13 shown results in several qualitatively different contact zones a, b, c with regard to a plugging operation due to different slopes in the curve, which are shown in the cross-sectional view of the Figure 4are applied along an edge contour 17a of the plastic body 12.

[0034] Here, the designation a denotes contact zones in which, when a mating contact element 12 is attached, the Figure 2 The illustrated lamellae 26a, 26b, 26c, 26d can slide without widening. In the contact zones b, the lamellae 26a, 26b, 26c, 26d each widen, while in the contact zones c the lamella springs 27a, 27b of the lamellae 26a, 26b, 26c, 26d are relieved.

[0035] The lamellar tips 28a, 28b contact the contact element successively in all three contact zones a, b, c along the entire contour of the plastic body 12. Force is exerted due to the expansion of the contact lamellae 26a, 26b, 26c, 26d only when one of the contact tips 28a, 28b passes over one of the contact zones b. The lamellae 26a, 26b, 26c, 26d can slide over the contact zones a without any expansion, while when passing over the contact zones c, the lamellar springs 27a, 27b of the respective lamellae 26a, 26b, 26c, 26d are even relieved of stress.

[0036] In contrast, there are those in the Figure 5 The illustrated plug tips 13', 13" do not have contact zones c according to the state of the art, which relieve the lamellar springs in between.

[0037] Using multiple contact surfaces protects the lamella and, when joining the contact element 10 with the mating contact element 20, can distribute the force to be applied over the entire connection path. In this way, loading and unloading areas of the lamellae 26a, 26b, 26c, 26d can be sequentially controlled.

[0038] If, as in the Figures 3 and 4 As shown, the plug tip 13 has a multiple wave contour, the spacing of the waves is designed such that the successively arranged lamellar domes 28a, 28b of the mating contact element 20 come into contact at the same time with areas of the plug tip 13 that have significantly different cross-sectional widths.

[0039] This will be in the Figure 6, View c) is shown schematically. It can be seen that the lamellar tips 28a, 28b, which abut a wave-shaped edge contour 17a, and the associated lamellar springs 27a, 27b, deflect to different degrees when the lagging contact point is under maximum load. This occurs multiple times at the connector tip 13 with a wave contour such that the edge contour 17a follows this shape.

[0040] The alternating loading and unloading zones of the lamellar springs 27a, 27b ensure that the insertion forces in the area of ​​Max Zones II ( Figure 3 ) are limited, which can prevent the occurrence of extreme force peaks.

[0041] In comparison, views a) and b) of the Figure 6 schematically depicts the edge contours of plug tips 13' and 13" according to the prior art, as shown in views a) and b) of the Figure 5are shown. In the state of maximum deflection of the lagging lamella 26b, the leading lamella 26a can only be at the same level, which leads to force peaks.

[0042] The insertion forces occurring during a mating process consist of contributions for the insertion work of the lamellar springs 27a, 27b, frictional forces due to the surface properties of the contact element 10 and lamellar caps 28a, 28b, the shaping of the edge contours 17a, 17b, and the expansion work on the lamellar springs 27a, 27b. The individual contributions vary along the length of the mating area.

[0043] The settling work refers to the mechanical work that must be applied for a permanent plastic deformation of lamellar springs 27a, 27b. The settling work therefore only needs to be applied once, during the initial use of a counter-contact element 12. This single mechanical settling work is complete when the maximum deflection of the lamellar springs 27a, 27b is reached and is therefore determined by the maximum cross-section of the contact element 10.

[0044] A plug tip 13 with a wave-shaped edge contour distributes the setting work across several areas in the force-displacement curve. The double-wave plug allows the lamellar springs 27a and 27b to be deflected successively.

[0045] The shape of the wavy edge contours 17a, 17b of the plastic body 12 makes it possible, especially with a lamellar geometry with offset lamellar tip heights 28a, 28b, to avoid simultaneous full deflection of all lamellar tip heights 28a, 28b. This reduces the maximum force during expansion and especially during the setting of the lamellar springs 27a, 27b.

[0046] The recess 15 between the plastic area and the metal area is not touched by the lamellar tips 28a, 28b ( Figures 2 and 3 , Zone IV). This results, firstly, in less abrasion, as no material transition edge is crossed here. Secondly, the recess prevents an additional force peak from occurring in the force-displacement curve at the transition from the plastic body 12 to the flat contact connector 11. Thirdly, loose particles can detach in the area of ​​the recess 15 and remain in an area unaffected by the lamellar tips 28a, 28b. Reference sign

[0047] 10 Contact element 11 Flat contact connector 12 Plastic body 13, 13', 13" Connector tip 14 Side parts 15 Recess 16 Chamfer 17a, 17b Edge contours 18 Cross-sectional area 19 Contact surface(s) 20 Mating contact element 21 Carrier component 22 Center axis 26a, 26b, 26c, 26d Laminates 27a, 27b Laminate springs 28a, 28b Laminate caps 29 Angled transition a, b, c Contact zones (contact surfaces) a Contact zone (sliding without expansion work) b Contact zone (expansion of the lamellar springs during the insertion process) c Contact zone (relieving the lamella during the insertion process) Zones I, II, III, IV I Plastic connector chamfer zone II Elevation zones III Valley zone IV Depression zone

Claims

1. Connector assembly comprising a connector having an electrical contact element (10) with a metallic flat contact plug (11) having plane-parallel contact surfaces (19), wherein a plastic body (12) is arranged on the flat contact plug (11) at least on its plug-side end face, wherein the cross-sectional area (18) of the portion of the plastic body (12) extending from the plug-side end face of the flat contact plug (11) has two edge contours (17a, 17b) extending in a wave-shaped manner symmetrically or asymmetrically with respect to the central axis (22) of the cross-sectional area (18), the spacing of which varies continuously along the plugging direction and in the course thereof has at least one local maximum (Max) outside the end regions, characterized in that a mating contact element (20) is provided, which has a plurality of lamellae (26a, 26b, 26c, 26d) which contact the flat contact plug (11), that each of the lamellae (26a, 26b, 26c, 26d) has a lamella spring (27a, 27b), and that connected to each lamella spring (27a, 27b) is a lamella crest (28a, 28b) which, when the mating contact element (20) is fully connected to the contact element (10), bears against one of the contact surfaces (19) of the contact element (10).

2. Connector assembly according to claim 1, characterized in that the transitions of the edge contours (17a, 17b) of the plastic body (12) to the contact surfaces (19) of the metallic flat contact plug (11) form a concave recess (15).

3. Connector assembly according to claim 1, characterized in that the transition from the flat contact plug (11) to the plastic body (12) is formed as an angular transition (29) in the form of a chamfer, a radius, an edge, or a polynomial shape.

4. Connector assembly according to claim 1, characterized in that the mating contact element (20) has at least two lamellae (26a, 26b; 26c, 26d) arranged successively in the plugging direction.