EP3662543B1 - Electrical plug contact for high-current applications and electrical connector system for high-current applications - Google Patents

Description

Field of invention

The invention relates to an electrical plug contact for high-current applications. The invention further relates to a connector system for high-current applications.

State of the art

Motor vehicles with a high degree of electrification (electric or hybrid vehicles) require connectors in which very high currents (up to approx. 300 A) have to be transmitted. With these currents, even small increases in the contact resistance become noticeable due to high power loss, which leads to high thermal stress on the plug. Therefore, increased demands are placed on contact stability even under the high shaking stresses that occur in the vehicle.

A damping element contained in the socket contact can weaken the vibrations introduced into the plug connector by the cable and thus protect the contact points, which are subject to life-limiting frictional wear.

From the DE 101 38 755 a contact is known in which the damping element consists of a meandering section of the stamped and bent part, which forms the current-conducting element of the socket contact.

From the EP 0 926 766 a contact is known in which the damping element consists of a flexible braid.

From the DE 10 2011 076 988 A1 Contacts are known that are not designed as a socket, but have a contact lamella that protrudes to one side and that contacts directly with a conductive counter body. Such contacts are known as direct contact.

From the DE 10 2009 012 726 A1 a contact plug with a plug housing is known which has a length compensation space in which a cable of the contact plug runs curved.

From the GB 2 353 415 A a coaxial cable arrangement is known.

From the EP 0 926 766 A1 an electrical contact element is known to which a flexible electrically conductive cable is connected, which is curved in sections.

From the DE 101 07 234 C1 A connector with a strain relief in the form of a curvature is known. An electrical conductor of the plug connector is fixed in position within a housing of the plug connector, the electrical conductor being curved between the position fixation and a contacting element of the plug connector. From the EP 0 276 895 B1 is known a power connector for connecting a cable with a plurality of conductors and a printed circuit board.

Disclosure of the invention

The invention is based on the knowledge that with the cable cross-sections of several square millimeters (mm ² ) used for transmitting the high currents, considerable vibration loads are introduced into the contact, which could only be absorbed by a single damping element if it was very delicate and flexible is. At the same time, it should transmit high currents (I >> 10A) with low electrical resistance, which means it has a large conductor cross-section and have short length. This represents a conflict of objectives with the delicate mechanical design.

There may therefore be a need to provide a plug contact and a plug connector system in which the plug contact is designed to reliably dampen the vibration loads that occur and thus increase the service life without losing current carrying capacity. At the same time, the plug contact should be simple and inexpensive to produce.

Advantages of the invention

This need can be met by the subject matter of the present invention according to the independent claim. Advantageous embodiments of the present invention are described in the dependent claims.

In the context of the application, the terms “comprising” and “having” are used synonymously unless otherwise expressly stated.

According to the invention, an electrical plug contact for high-current applications is proposed according to claim 1. The plug contact comprises a housing which extends along a longitudinal axis and has an interior space for receiving a mating contact element. The plug contact further comprises at least two contacting elements and a cable which is formed from a plurality of strands, the cable being guided from an external space of the housing into the interior of the housing and being fastened to the housing. The cable has an end in the interior, with the cable having a damping section adjacent to the end, in which the cable is split into a plurality of separate line strands, with a contacting element being fixed to at least two line strands. The contacting elements are suitable for electrical and mechanical contacting of the mating contact element. According to the invention, one contacting element is fixed to each of the at least two cable strands.

In other words: it is intended to divide the electrical conduction path, which is formed by the cable with its strands, into a larger number of individual paths within the connector, each of which can be dampened in terms of vibration independently of one another. This happens because the cable, which can have a large cross-section due to its high current-carrying capacity, is divided into several Cable strands are braided, and the damping element is thus formed from the separated cable strands. The free ends of the cable strands are then connected to individual contacting elements, which independently contact the mating contact. In particular, several contacting elements are provided, preferably one contacting element per cable strand.

By dividing the electrical conduction path into many smaller ones connected in parallel, the conflict of objectives between flexible mechanical design and high current-carrying capacity can be advantageously alleviated. Furthermore, an optimal mechanical decoupling of the individual contacting elements from one another is guaranteed.

Overall, the proposed plug contact advantageously ensures significantly better vibration damping while at the same time having a high current-carrying capacity. In addition, no additional elements are required for vibration damping per se, but the components of the cable as such are sufficient. This makes the vibration damping of the plug contact particularly simple and cost-effective.

For the purposes of this application, a “plurality of elements” means at least two elements.

Contacting elements are preferably connected to most of the cable strands. Contacting elements are particularly preferably connected to all cable strands. The contacting elements can initially be separate elements from the cable or line strands. They can be fixed, for example, by a crimp connection on the wiring harnesses or by a material connection, such as a welded connection or a soldered connection.

The contacting elements can be made, for example, as stamped and bent parts from a sheet metal. They can, for example, have a resilient element and/or a type of contact lamella, which points in the direction of the contact surface of the mating contact element to be inserted, for example in a radial direction, i.e. in a direction transverse to the longitudinal axis.

The contacting element can also have a latching element, for example in the form of a latching lance which projects obliquely outwards and can be resiliently reversibly sprung inwards. Such a locking element can be located, for example, in the housing of the plug contact Lock the undercut and thus secure the contacting element against being pulled out of the housing in the opposite direction of insertion.

Alternatively, such a locking lance can also be made of plastic, for example, as part of the connector housing and engage in a locking geometry on the contact.

The current-carrying cable can preferably be firmly connected to the housing or to a wall of the housing. It can be advantageous to create a connection that is as strong as possible. As a result, the vibrations introduced by the connection can advantageously be dissipated particularly well via the housing.

The cable can advantageously have insulation or an insulating jacket at least outside the housing of the plug contact, i.e. in the outside, which is made of a plastic, for example, and does not conduct electrical current well. The insulation or the insulating jacket can also be routed into the interior of the housing.

The current-carrying parts of the cable, in particular the large number of strands, can be made of a material that conducts electricity very well and includes, for example, copper, aluminum or alloys of these materials.

The mating contact element to be inserted into the plug contact usually has a radially outwardly facing surface, its contact surface, which comprises a material from the group of silver, gold, tin, nickel or alloys of the materials mentioned.

It goes without saying that the strands can also be coated, for example tinned.

The fact that an extension length of the line strands 5 in the damping section 4 is at least 20% greater than a length L of the damping section 4 along the longitudinal axis A advantageously results in particularly good vibration damping.

The damping section can extend between the end of the contacting element facing the wiring harness and the stripping of the cable. If the stripped cable has not yet been separated into individual cable strands over a longer distance, the damping section extends between the cable strand facing end of the contacting element and the point of the cable at which the individual cable strands are routed separately.

The fact that the cable has an electrically conductive cross section of at least 10mm ² advantageously ensures that the cable has a high current carrying capacity of at least 10A, preferably at least 50A and most preferably at least 150A. The cable advantageously has an electrically conductive cross section of at least 50mm ² . The cross section can be determined, for example, perpendicular to the longitudinal axis.

Because, according to the invention, each wiring harness is formed from several strands, a particularly high current-carrying capacity of the wiring harnesses and a high mechanical stability of the individual wiring harness are achieved.

The fact that each line strand has a cross section of at least 0.2mm ² and at most 6mm ² advantageously results in a particularly good flexibility of the individual line strands, which results in particularly good vibration damping. At the same time, each wiring harness is sufficiently mechanically stable and capable of carrying current and a contacting element can be easily connected to it. The cross section of each line strand is particularly preferably in a range of 0.5mm ² and 2mm ² .

The fact that the damping section is arranged completely in the interior of the housing advantageously ensures that the plug contact is compact and the risk of an unwanted short circuit between two plug contacts or of getting caught between two plug contacts remains low. In other words: the housing encloses the damping section and houses it.

The fact that the cable strands in the damping section extend along a shape that is selected from the group: an arch, an omega-shaped loop, a looping advantageously results in particularly good damping of vibrations. Thanks to the proposed shapes, particularly good damping can be achieved in a small space or a short extension length of the damping section along the longitudinal axis. As a result, the plug contact can advantageously be made particularly compact and small. This is a great advantage, for example, when space is limited in automobiles or other technical facilities.

The fact that the contacting elements are arranged along a circle around an axis, with the axis extending parallel to the longitudinal axis (A), advantageously ensures particularly secure electrical and mechanical contacting of the contact surfaces of the mating contact element. A mating contact element inserted into a contact element designed in this way is automatically centered by the contacting elements in the radial direction, i.e. transversely to the longitudinal axis. If the counter-contact element is displaced in a radial direction by a vibration, the contact pressure on one of the contacting elements could be reduced, but at the same time the contact pressure on the opposite contacting element increases. This ensures reliable electrical contact between the contact element and the mating contact element.

According to a second aspect of the invention, a connector system, in particular for high-current applications, is proposed.

The connector system includes an electrical plug contact as described above. The connector system further includes a mating contact element. The counter-contact element is mechanically and electrically contacted with the contacting elements.

This advantageously creates a connector system which at the same time has particularly good vibration damping and a high current carrying capacity of more than 10A, preferably more than 50A, and can be produced easily and inexpensively with just a few elements.

The counter-contact element can, for example, have at least one material on its radially outward-facing outer side, which is selected from the group of silver, gold, tin, nickel or alloys of the materials mentioned. This enables a particularly high current carrying capacity and, when using precious metals, particularly good corrosion resistance. This can also result in a particularly low contact resistance.

Because the counter-contact element has a round cross-section, the counter-contact element is particularly easy to produce and can be inserted particularly easily into the plug contact or its housing, since there is no preferred direction in the circumferential direction around the longitudinal axis. This also makes contact particularly easy. It can therefore be designed as a so-called round pin.

The counter contact element can be inserted into the housing of the plug contact along an insertion direction, for example.

The interior of the housing can correspondingly have a circular cross section. This advantageously makes it possible to produce the plug contact in a particularly simple manner. In this way, the counter-contact element can be inserted particularly easily,

Because the counter-contact element is designed as a flat knife and the plug-in contact is designed to be pushed onto the flat knife, the contacting element can electrically and mechanically contact contact surfaces of the flat knife and is also particularly reliable for contacting and/or for direct contacting contacts of male connectors designed as flat knives and cost-effective vibration decoupling can be provided.

Such contacting can be provided by a single contacting element per flat knife. In this case, the flat knife is only electrically contacted on one side. If there are several flat knives on a knife strip, the electrical plug contact can have several contacting elements next to each other, each of which contacts a flat knife.

However, the electrical plug-in contact for contacting each flat knife can, for example, also have two opposing contacting elements, between which the flat knife can then be inserted for contacting. In other words, in such an embodiment, a gap or a slot or a type of shaft can be formed between the opposing contacting elements, into which the flat blade of a male connector is inserted for electrical contacting. For contacting a plurality of flat blades of a male connector, the plug contact can have a series of contacting elements lying opposite one another in pairs.

drawings

Further features and advantages of the present invention will become apparent to those skilled in the art from the following description of exemplary embodiments, which, however, are not considered The invention should be construed in a restrictive manner with reference to the accompanying drawings.

Fig. 1:

eine perspektivische Ansicht eines Kabels eines Steckkontakts;

Fig. 2a:

einen schematischen Querschnitt eines Steckkontakts;

Fig. 2b:

eine Frontansicht des Steckkontakts aus Fig. 2a

Fig. 2c:

eine schematische Detailansicht des Kabels aus dem Steckkontakt aus Fig. 2a

Figs. 3a-3c:

verschiedene Ausführungsformen des Verlaufs des Kabels im Dämpfungsabschnitt;

Fig. 4:

eine schematische Detailansicht des Kabels in einer weiteren Ausführungsform des Steckkontakts.

Show it

Fig. 1:

a perspective view of a cable of a plug contact;

Fig. 2a:

a schematic cross section of a plug contact;

Fig. 2b:

a front view of the plug contact Fig. 2a

Fig. 2c:

a schematic detailed view of the cable from the plug contact Fig. 2a

Figs. 3a-3c:

different embodiments of the route of the cable in the damping section;

Fig. 4:

a schematic detailed view of the cable in a further embodiment of the plug contact.

Figure 1 shows a cable 1 for an electrical plug contact for high-current applications, the cable extending along a longitudinal axis A. The cable 1 is formed from a large number of strands 5a. Several strands 5a are bundled together to form a wiring harness 5. The cable is thus formed from a plurality of cable strands 5. However, the line strands 5 are all in electrical and mechanical contact with an adjacent line strand 5 and are not guided separately from one another or spaced apart from one another. This structure makes the cable 1 quite rigid compared to separately routed cable strands 5 or even individual strands 5a. On the other hand, it is more flexible than a cable made of solid material. The cable 1 is very compact in a radial direction R, which extends transversely to the longitudinal axis A and can therefore easily be covered with insulation 2, which is designed as an insulating jacket. The cable 1 also has a high current carrying capacity due to the large number of strands.

The strands 5a of the cable 1 can comprise, for example, copper, aluminum, tin, silver or alloys of the materials as a material. The strands can also be coated, for example tinned. The insulation 2 can have an electrical conductivity of at least is two orders of magnitude lower than that of the strands. It can be made of a poorly electrically conductive plastic.

The cable 1 is designed to conduct high currents, for example at least 10A, preferably at least 50A and most preferably at least 150A. For this purpose, it can have a cross section of, for example, at least 5mm ² , preferably at least 10mm 2 and very particularly preferably at least 25mm ² . For example, the cable 1 can have a cross section of 25mm ² or 50mm ² or 100mm ² .

The figure also shows the circumferential direction U, which revolves around the longitudinal axis A.

Figure 2a shows a schematic cross section through a connector system 100 for high-current applications. The connector system 100 has an electrical plug contact 10 for high-current applications and a mating contact element 8. The plug contact 10 comprises a housing 20, which extends along a longitudinal axis A and has an interior 21 for receiving the mating contact element 8. Outside the plug contact 1 there is an external space 22 of the plug contact 1. The interior 21 can be delimited by a wall 23. The plug contact 10 further comprises a cable 1, which at least partially corresponds to the cable 1 Figure 1 can correspond. Cable 1 is like the one in Figure 1 formed from a large number of strands 5a. The cable 1 is guided from the outer space 22 of the housing 20 into the interior 21 of the housing 20 and attached to the housing 20. The attachment can be carried out using conventional fastening means 9, for example with clamps, union nuts, clamps, etc.

The cable 1 has an end 1a in the interior 21. The cable 1 has a damping section 4 adjacent to the end 1a. The cable 1 is split into a plurality of separate cable strands 5 in the damping section 4. In contrast to the in Figure 1 Wiring harnesses 5 shown are the wiring harnesses 5 of Figure 2a in the damping section 4 therefore do not lie closely together and are not in mechanical and / or electrical contact with at least one adjacent line strand 5 along their extension. Rather, they are separate from one another and therefore mechanically decoupled from one another at least in the radial direction R. A contacting element 6 is fixed to at least two line strands 5. These contacting elements 6 are suitable for mechanically and mechanically contacting the mating contact element 8 when inserted into the housing 20 to contact electrically. The contacting elements 6 are arranged facing each other in the housing 20 and delimit a contacting space 7 into which the counter-contact element 8 can be inserted. The contacting elements 6 have contact lamellae 6a on their surfaces facing the contacting space 7, which can be designed as resilient contact tongues and can come into mechanical and electrical contact with a contacting surface of the mating contact element 8 as soon as the mating contact element is inserted into the contacting space 7. The contacting elements can be fixed in their position in the housing 20 with a narrow tolerance along the longitudinal axis A, for example by an in Fig. 4 Locking lance 6c shown, which locks in the interior 21 of the housing 20.

The vibration decoupling of the cable 1 is made possible by the damping section 4, which in the exemplary embodiment shown is arranged completely in the interior 21 and is enclosed by the housing 20. The damping section 4 has a length L along the longitudinal axis A, which extends between the end of the contacting elements 6 facing the damping section 4 and the splitting of the line strands 5 into separate line strands 5. The line strands, on the other hand, have a length L1 in the damping section 4 along their respective extension direction, which is at least 10% greater than the length L of the fastening section 4. Preferably, the length L1 of the line strands 5 is at least 50% greater than the length of the fastening section 4. As a result Particularly good vibration damping is achieved even at large amplitudes.

By separating the cable strands 5, greater flexibility of the cable 1 in the damping section 4 is achieved, as a result of which vibrations are not transmitted directly from the contacting element 6 into the cable 1 or from the cable 1 to the contacting elements 6.

In the Figure 2a the counter contact element 8 has not yet been inserted into the housing 20 along an insertion direction E, which here runs parallel to the longitudinal axis A.

Figure 2b shows a top view of an insertion opening 25 for the mating contact element 8 in the housing 20. Six contacting elements 6 are shown as an example with their contact lamellae 6a facing the contacting space 7. The contacting elements 6 are arranged on a circle that revolves around an axis that runs parallel to the longitudinal axis A.

Figure 2c shows a top view of the cable 1 in the plug contact 10 Figure 2a . It is shown from right to left how the cable strands 5 initially run intertwined within the insulation 2. The cable strands 5 then continue to run intertwined with one another as in Figure 1 in a stripped section. Finally comes the damping section, in which the cable strands 5 are unbraided, i.e. run separately from one another - they are mechanically decoupled from one another here. The contacting elements 6 adjoin the damping section 4 and are each fastened to a free end of a separate wiring harness 5 in a connecting section 6b of the contacting element 6. In this connection section 6b, for example, the wiring harness 5 can be crimped (see Figure 2c ), but it can also be soldered, welded or glued on with a conductive adhesive, for example.

The contacting elements can be made, for example, from a thin or thicker metal sheet with a material thickness of 0.1mm to 5mm, preferably 1mm to 3mm. They can be designed as stamped and bent parts.

The counter contact element 8 can be designed, for example, as a round element or contact knife. It can have aluminum or copper or silver as a material or alloys of these substances. On its outer radial surface it can be coated, for example, with a material which contains gold, silver, copper, platinum, tin or alloys of these materials.

In the Figures 3a-3c Various forms are shown in which the separated cable strands 5 of the cable 1 can run in the damping section. Fig. 3a shows the shape of an arch. Figure 3b shows the shape of an omega-shaped loop and Figure 3 shows the shape of a loop or a loop-shaped loop. Through these configurations, the longest possible decoupling path or length L1 of the respective separated line strand 5 can be achieved over a short distance along the longitudinal axis A. Accordingly, the vibration damping effect can be improved.

Figure 4 shows a connector system 100, in which the mating contact element 8 is formed by a flat knife 30 with a contact surface 31. For reasons of clarity, only a single contacting element 6 is shown here on a single, separate wiring harness 5. The housing 20 was also omitted, which ensures that the contacting element 6 is pressed against the contacting surface 31 (similar to an insertion slot for an SD card in an SD card reader). At the left end of the The figure shows the damping section 4, at the end (further to the right) of which the contacting element 6 is crimped, for example, in the connecting section 6b. The contacting element 6 contacts the contact surface 31 of the flat knife with its contact lamella 6a. On the side of the contacting element 6 facing away from the contact lamella 6a, an elastically reversible locking lance 6c, which can be resiliently reversibly sprung inwards, is arranged, for example, and can lock in an undercut of the housing 20 of the plug contact 1, not shown here.

It is understood that in an embodiment not shown here, the flat knife 30 can also have a further contact surface on its side facing away from the contact surface 31, which points downward in the figure. The contact can then be made through an electrical plug contact 10, which is like the one in Fig. 4 is formed, but has a further contacting element, which lies opposite the contacting element 6 and electrically and mechanically contacts the further contact surface. A gap or slot or shaft can be formed between the contacting element 6 and the further contacting element, into which the flat knife 30 can be inserted, so that its contact surface 31 and further contact surface are electrically contacted by the contacting element 6 or the further contacting element. The contacting element 6 and the further contacting element can be mechanically connected to one another in such a way that they clamp the flat knife 30 between them and thus always apply a sufficiently high contact force acting on the flat knife on both sides.

Such an electrical plug contact 10 can also contact several flat blades of a male connector at the same time. In this case, several pairs of opposing contacting elements 6 and further contacting elements are arranged next to each other in a row.

In this way, vibration-damped direct contacting of flat knives, e.g. flat knives of a knife strip, can be made easily and cost-effectively.

Claims (9)

1. Electrical plug contact for high-current applications, comprising

   -- a housing (20) which extends along a longitudinal axis (A) and has an interior (21) for receiving a mating contact element (8),

   -- a cable (1) which is formed from a plurality of braids (5a),

   wherein the cable (1) is routed from an exterior (22) of the housing (20) into the interior (21) of the housing (20) and is fastened to the housing (20),

   wherein the cable (1) has one end (1a) in the interior (21),

   -- at least two contacting elements (6) which are suitable for electrically and mechanically contacting the mating contact element (8);

   wherein the cable (1), adjacent to the end (1a), has a damping portion (4) in which the cable (1) is split into a plurality of separate line sections (5),

   wherein established on at least two line sections (5) is in each case at least one contacting element (6),

   wherein each line section (5) is formed from a plurality of braids (5a).
2. Electrical plug contact according to Claim 1,
   wherein a length of extent (L1) of the line sections (5) in the damping portion (4) is at least by 20% longer than a length (L) of the damping portion (4) along the longitudinal axis (A).
3. Electrical plug contact according to one of the preceding claims,
   wherein the cable (1) has an electrically conductive cross section of at least 10mm².
4. Electrical plug contact according to one of the preceding claims,
   wherein each line section (5) has a cross section of at least 0.2mm² and at most 6mm².
5. Electrical plug contact according to one of the preceding claims,
   wherein the damping portion (4) is disposed completely in the interior (21) of the housing (20).
6. Electrical plug contact according to one of the preceding claims,
   wherein the line sections (5) in the damping portion (4) extend along a shape which is selected from the group of: an arc, an omega-shaped loop, a loop formation.
7. Electrical plug contact according to one of the preceding claims,
   the contacting elements (6) are disposed along a circle about an axis, wherein the axis extends parallel to the longitudinal axis (A).
8. Plug connector system, comprising:

   -- an electrical plug contact (10) according to one of the preceding claims,

   -- a mating contact element (8) which is mechanically and electrically contacted with the contacting elements (6) .
9. Plug connector system according to the preceding claim,

   wherein the mating contact element (8) has a round cross section,
   and/or

   wherein the mating contact element (8) is configured as a flat blade (30), and the plug contact (10) is configured to slide onto the flat blade (30), wherein the contacting element (6) electrically and mechanically contacts contact faces (31) of the flat blade (30).

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