EP2458685B1 - Cable connector - Google Patents

Description

The present invention relates to an electrical cable connector having a longitudinal axis for connecting a plurality of electrical cables, with only one wire crimping area having at least one pair of wire crimping elements for receiving and fixing the wires of all electrical cables.

In such a cable connector, as he, for example, in US Pat. No. 3,897,992 . DE 200 08 544 U1 or WO 2009/125113 A2 is described, both the electrical and the mechanical attachment of the wires of the electrical cable mainly via the also referred to as claws or wings Adercrimpelemente. For attachment stripped end portions of the cable are inserted into the Adercrimpbereich of the cable connector and connected thereto by folding the Adercrimpelemente, so that the Adercrimpelemente surround the cable core consisting of the wires. The term "cores" is here synonymous with individual wires or individual strands of a stranded wire.

There are two main requirements for such a connection. On the one hand, a loss-free transmission of the electrical currents should be ensured, in which the contact resistance between the cables or between the cable and the cable connector should be as small as possible. On the other hand, the connection must withstand the absorption of mechanical forces, in particular a tensile force between the cables. The conductivity of the connection increases with increasing degree of crimping of the wire crimping elements with the cable core, which corresponds to the force exerted on the wire crimping elements during the fastening operation. During the compression, there is a plastic deformation of the approximately round wires or individual strands to an irregular polygonal, approximately honeycomb-shaped cross section and thus to a compression of the cable core, whereby the contact surface of the wires to each other and to the cable lug is increased. If the pressing force is further increased, the cross-section of the individual wires is reduced, so that under certain circumstances a shearing of the wires takes place.

In any case, in a fastening with too high degree of compression, the mechanical strength of the connection is impaired, in particular the load capacity for tensile forces is reduced.

In order to avoid deterioration of the mechanical strength of the connection or shearing of wires, therefore, the cable connector is pressed with a moderate force with the wires. However, this solution represents only a compromise, since at a medium degree of compression, the electrical connection does not yet have their lowest possible contact resistance, which can be detected by appropriate resistance measurements.

Particularly in the field of automotive electrics, there is a trend towards ever smaller cable cross-sections, which is further promoted by the necessity of reducing the vehicle mass and by introducing bus systems in the automotive electrical system. There is often the requirement to connect cables with different cross-sections with each other. It is known, for example, to use cable connectors with only one pair of wire crimping elements for this purpose, have a continuous crimping and in which the cable cores of the cables to be connected are inserted in opposite directions and then connected by bending or crimping the Adercrimpelemente together. Since the cross-sections of the individual wires or individual strands may differ from each other in cables with different cross-sections, the problem arises with the use of such a cable connector that at a certain pressing force the cores with a large cross-section are pressed so hard that a good electrical Contact is achieved while the wires are already over-compressed with a small cross-section and there is a risk of shearing the wires. Therefore, for cable connectors of this type, the ratio of the diameters of the cores of the cores to be connected should generally be not more than 1.4.

It is the object of the present invention to provide a cable connector which allows a connection of a plurality of electrical cables with high mechanical strength and good electrical conductivity, in particular even if the cables to be connected have different cross-sections.

The object is achieved by a cable connector having the features of claim 1 and in particular by a cable connector, characterized in that the wire crimping elements have at least a first and at least one second fastening crimping section and at least one contacting crimping section provided longitudinally between the fastening crimping sections, wherein the first and second fastening crimp portions are respectively disposed endwise with respect to the longitudinal axis (L) of the cable connector, the settlement of the crimping crimp portion being in an extension direction perpendicular to the longitudinal axis of the cable connector greater than the development of the fastening crimping sections in this direction, and wherein the fastening and contacting crimping sections are formed symmetrically to the longitudinal axis of the cable connector.

In the cable connector, a stripped end portion of a cable is inserted from each side so that there is one end portion between each of the first attachment crimping portions and the contacting portions and the other end portion between the second attachment crimping portions and the contacting portions. Subsequently, the wire crimping elements are folded over, with different degrees of crimping being achieved in the region of the fastening crimp sections and contacting crimp sections due to their different developments. It is also possible to insert not only one, but two or more stripped cable end sections from each side and to press with the cable connector. In this case, cables with in each case the same cross section are preferably inserted on each side.

The fastening crimp sections ensure, when attached to the electrical cable, a mechanically strong connection which can reliably absorb tensile forces. In the area of the fastening crimp sections, only an irregular plastic deformation of the individual wires occurs, but essentially no cross-sectional reduction. The longer contacting crimping sections may extend into the respective cable core, in particular between the wires, thereby increasing the contact area with the wires. Furthermore, they can cause additional compression of the wires, so that a further improvement of the conductivity is achieved by the resulting contacting of the cable core.

Since a separate fastening crimping section is provided on each side of the cable connector, it is possible to achieve a degree of crimping adapted to the respective cable cross-section, for example by exerting a specific pressing force. Thus, the ratio of the cross sections of the wires of the cable connector according to the invention to be connected cables have a ratio of 2.5 and greater.

Another advantage of the cable connector according to the invention consists in particular in the connection of very thin cables, which are conventionally also designed as welded joints. However, welding is mechanically very difficult with thin cables, for example with a cross section of 0.13 mm ² . In addition, it has been found that for cables shorter than 300 mm and welded at the first end, for example by ultrasonic welding at a welding node or connected to a two-part, welded connection terminal, by welding the second end destroys the weld at the first end can be. This danger is avoided by the use of the cable connector according to the invention at the second end.

In comparative experiments, it has been found that in a cable with 0.35 mm ² cross-section, the peel force or tearing force, ie the tensile force at which the cable separates from the cable connector and for the above-mentioned conventional cable connector with simple wire crimp 60 N is increased to 90 N for a cable connector according to the invention.

Finally, it has been found in load tests that cable connections produced with a cable connector according to the invention have a very high long-term stability, which is given in particular even at a bending stress of the connection point. This is due to the fact that the wires are mechanically less stressed when entering the cable connector due to the relatively low degree of compression and therefore lateral forces, such as occur in a bending load, less likely to lead to shearing of the wires in the entry area in the cable connector.

According to a preferred embodiment, the development of the first and second attachment crimp sections are different in size. This allows a particularly good adaptation to the cross sections or the number of cables to be connected together.

The fastening crimp sections are preferably of different lengths in the longitudinal direction. As a result, a good adaptation to the cross sections or number of the respective cables is also achieved.

According to a further advantageous embodiment, the wire crimping elements have only one contacting crimping section for receiving the wires of all cables. If the cables are inserted so that their end portions overlap in the longitudinal direction, a direct contacting of the cables with each other and thus a particularly high conductivity is achieved.

Alternatively, the wire crimping elements may include first and second contacting crimping portions adjacent to each other. In this case, the cable end sections are preferably inserted so that each cable extends into the area of only one of the contacting crimp sections and the end faces of the cables abut one another. As a result, the oppositely inserted cables can be pressed individually in the contacting area.

According to a further advantageous embodiment of the invention, the unwinding of the fastening and contacting crimping sections are chosen such that, in the case of a connection of electrical cables by means of the cable connector, the fastening crimping sections embrace a cable core of the respective cable that surrounds the wires substantially only along its circumference, and an end section of the contacting crimping section extends into the cable core, in particular between the wires.

According to a further preferred embodiment, a transition from the contacting crimping section to the first and / or the second fastening crimping section is formed as a step. This causes a clear separation of the two crimping sections from each other, so that in a cable connection all crimping areas each have clearly defined mechanical and / or electrical properties.

A recess can be provided between the contacting crimping section and the first and / or the second fastening crimping section. This results in an even clearer separation of the different crimping areas.

Optionally, a transition from the contacting portion to the first and / or the second fastening crimping portion may be formed as a transition portion whose end edge is inclined to the longitudinal axis. In such a cable connector, the compression and hence the conductivity within the transition portion of the attachment or crimping portions to the contacting crimping portion continuously increase.

It is preferred if the contacting crimping section and / or at least one of the fastening crimping sections on the inside at least one notch extending transversely to the longitudinal direction of the cable connector having. This further improves the conductivity in the region of the contacting crimping section.

Advantageously, the unwinding of the first and / or the second contacting crimping section in the direction of extent is 2% to 20%, preferably 5% to 15% and in particular 5% to 10% greater than the unwinding of the fastening crimping section.

Furthermore preferably, the end-side edges of the fastening crimp sections and / or the end-side edges of the contacting crimp section are arranged parallel to the longitudinal axis.

According to a further advantageous embodiment, the cable connector has at least one jacket crimping area spaced apart from the wire crimping area in the longitudinal direction, with a pair of jacket crimping elements for receiving and fastening a cable sheath. This Mantelcrimpbereich causes additional strain relief, since it receives directly transmitted via the cable sheath forces and thereby relieves the Adercrimpbereich.

Further advantageous embodiments of the invention are specified in the dependent claims, the description and the drawings.

Fig. 1A bis 1C

perspektivische Ansichten einer Ausführungsform eines erfindungsgemäßen Kabelverbinders;

Fig. 1D

die Abwicklung des Kabelverbinders von Fig. 1A bis 1C;

Fig. 1 E und 1 F

Abwicklungen weiterer Ausführungsformen eines erfindungsgemäßen Kabelverbinders;

Fig. 2A bis 2D

perspektivische Ansichten des Kabelverbinders von Fig. 1A bis 1D mit auf verschiedene Arten eingelegten Kabeln;

Fig. 3A

eine Querschnittsansicht eines an einem Kabel befestigten erfindungsgemäßen Kabelverbinders im Bereich eines Kontaktierungscrimpabschnitts; und

Fig. 3B

eine Querschnittsansicht eines an einem Kabel befestigten erfindungsgemäßen Kabelverbinders im Bereich eines Befestigungscrimpabschnitts.

The invention will now be described by way of example with reference to the drawings, in which:

Fig. 1A to 1C

perspective views of an embodiment of a cable connector according to the invention;

Fig. 1D

the handling of the cable connector of Fig. 1A to 1C ;

Fig. 1 E and 1 F

Developments of further embodiments of a cable connector according to the invention;

Fig. 2A to 2D

perspective views of the cable connector of Fig. 1A to 1D with cables inserted in different ways;

Fig. 3A

a cross-sectional view of a cable attached to a cable connector according to the invention in the region of a Kontaktierungscrimpabschnitts; and

Fig. 3B

a cross-sectional view of a cable attached to a cable connector according to the invention in the region of a Befestigungscrimpabschnitts.

Fig. 1A to 1C show a cable connector 10 according to the invention, which has an elongated, transverse to the longitudinal axis L curved base portion 12. On each longitudinal side of the base portion 12, a wire crimping member 14 is formed, which extends obliquely upward, so that the base portion 12 and the wire crimping elements 14 form a trough-shaped receptacle for cable to be connected together.

The wire crimping elements 14 are mirror-symmetrical to one another with respect to the longitudinal axis L of the cable connector 10 and each comprise three crimping sections which are spaced apart from one another in the longitudinal direction. namely, two end attachment crimping portions 18A, 18B and a crimping crimping portion 16 provided therebetween.

The development of the contacting crimping section 16 in an extension direction A perpendicular to the longitudinal axis L of the cable connector 10 is greater than the unwinding of the two fastening crimping sections 18A, 18B, as in FIG Fig. 1D is good to recognize. In the exemplary embodiment, the development of the two fastening crimping sections 18A, 18B is the same size. Alternatively, it is also possible to provide Befestigungscrimpabschnitte with different size settlement. For example, the settlement of the attachment crimping portion 18B may be smaller than the settlement of the attachment crimping portion 18A, as shown in FIG Fig. 1A and 1D indicated by dashed lines. The edges of the contacting crimping portions 16 and the fastening crimping portions 18A and 18B are parallel to the longitudinal axis L.

The transition between the contacting crimping section 16 and the fastening crimping section 18A or 18B takes place in steps, wherein a respective recess 20 is provided between the contacting crimping section 16 and the fastening crimping sections 18A and 18B. The depth of the recess 20 may be about half of the development of a fastening crimping section 18A, 18B. It should be noted that the recesses 20 may also extend to the base portion 12 so that, instead of the subdivision of a pair of crimping crimping elements 14 into mounting and contacting crimping portions 18A, 18B and 16, respectively, the attachment and contacting crimping portions define a respective separate wire crimping member Pair.

Alternative configurations of the junctions between the contacting crimping portion 16 and the fastening crimping portions 18A and 18B are shown in FIG Fig. 1E and 1F shown. In the embodiment according to Fig. 1E Each transition is formed as a step, so without a separating recess. In the embodiment according to Fig. 1F between the contacting crimping portion 16 and the fixing crimping portions 18A and 18B, there are provided transition portions 17A and 17B, respectively, whose edges are inclined to the longitudinal axis L. Of course, the embodiments of the transitions described here can be combined with each other as desired.

As in particular in Fig. 1C and 1D 1, the cable connector 10 has on its inside in the region of the contacting crimping sections 16 two indentations or grooves 22 for improving the conductivity which extend transversely to the longitudinal axis L from one contacting crimping section 16 via the base section 12 to the other contacting crimping section 16 wherein there is a gap between the edges of the contacting crimping portions 16 and the end portions of the indentations 22.

In the Fig. 2A to 2D For example, various ways of connecting two or more cables to each other are illustrated, with the cable connector 10 being shown in the uncrimped state, respectively. The connection with the cables takes place in a known manner by bending the crimp sections 16, 18A, 18B inwards.

According to Fig. 2A two cables 24A, 24B are inserted in opposite directions in the cable connector 10, so that stripped end portions 26A, 26B of the cables 24A and 24B respectively approximately completely between their respective facing Befestigungsimpimpabschnitten 18A and 18B and extend the Kontaktierungscrimpabschnitten 16. While only one of the end sections 26A and 26B is received between the fastening crimp sections 18A, 18B, in the region of the contacting crimp sections there is an overlap of the end sections 26A, 26B in the longitudinal direction L. After the crimping sections 16 have been bent or pressed there is thus a direct electrical contact between the end portions 26A, 26B.

While in the embodiment according to Fig. 2A the cross-sections of the cables 24A, 24B are the same size, it is also possible to connect individual cables with different cross-sections in the manner shown. It is readily possible to connect a cable with a cross section of 16 mm ² with a cable with a cross section of 0.13 mm ² with the cable connector 10 according to the invention. As above with reference to Fig. 1A For this purpose, the fastening crimp sections, which are provided for receiving the cable with the smaller cross-section, preferably have a smaller development than the attachment crimp sections provided for receiving the cable with a larger cross-section (dashed lines in FIG Fig. 1A ).

The fastening variant according to Fig. 2B largely corresponds to the mounting variant according to Fig. 2A in which, instead of the cable 24B, two cables 24C, 24D are provided, the stripped end portions 26C, 26D of which are inserted into the cable connector 10 corresponding to the end portion 26B. Basically, depending on the application on each side of the cable connector 10, one, two or more cables are inserted in the same direction in the cable connector 10.

When crimping several corotating cables shown here, another advantage of the invention. In a conventional cable connector Due to poor alignment there is a risk that with individual cables an insulated cable section protrudes between the stripped end sections of the remaining cables and thus into the crimp area. At the usual high compression forces, this can lead to a shearing of the wires.

However, in the case of the cable connector 10 according to the invention, this case is at least less critical if the insulation only protrudes into the region of the fastening crimp sections 18A, 18B. Since they are pressed with a relatively small force with the end portions 26A to 26D of the cables 24A to 24D, the risk of shearing the wires is reduced.

Furthermore, due to the reduced requirement for the positioning accuracy, it is possible to reduce the length of the end portions 26A to 26D to be stripped away without sacrificing safety margin.

Fig. 2C shows another way to insert two cables 24A, 24B in the cable connector 10. At this time, the end portions 26A, 26B are butted into the cable connector 10 so that the end portions 26A, 26B extend only to about the middle of the contacting crimping portions 16, respectively.

In connection with this insert variant, a further embodiment of the cable connector 10 is explained, in which - as in Fig. 2C shown by dashed lines - the fastening crimping section 16 is divided by a further recess 20 or by an incision into two contacting crimping sections 16A, 16B. In this variant, the contacting crimping portion 16A only cooperates with the end portion 26A of the cable 24A and the contacting crimping portion 16B only the end portion 26B of the cable 24B together. Thereby, it is possible to press the end portions 26A, 26B of the butted in wires 24A, 24B not only in the attachment portion but also in the contacting portion with individual pressing forces with the cable connector 10.

Yet another attachment variant shows Fig. 2D , In the cable connector 10 a total of four cables 24A to 24D are inserted, wherein the cables 24A, 24B are opposite to the cables 24C, 24D. In contrast to the attachment variants after Fig. 2A to 2C extend the slightly stripped end portions 26A to 26D over the entire length of the cable connector 10 and this - as in Fig. 2D shown - even slightly surmounted on both sides. Each end portion 26A to 26D is thus encompassed by all the contacting and fastening crimping portions 16, 18A, 18B. In this variant, since the total diameter of all the cores to be pressed is the same regardless of the cross sections of the individual end portions 26A to 26D over the entire length of the cable connector 10, the subsequent crimping operation is simplified because both the fastening crimping portions 18A, 18B must be bent by the same amount. Further, the use of cable connectors 10 with mounting crimping portions 18A, 18B of different sized unwinding is unnecessary for the connection of cables having large cross-sectional differences.

Since it is necessary in the above-mentioned conventional cable connectors with only one crimp that the ends protrude a little way from the single crimp, there is always the risk in a subsequent insulation, for example by means of shrink tubing that individual cores pierce the insulating material, which in turn the risk of short circuits. Since in the inventive Cable connector 10, the ends of the individual cable cores are still within the cable connector 10, the risk of puncturing the insulation significantly reduced.

FIGS. 3A and 3B 12 show cross-sectional views of a cable connector 10 attached to a cable. The cable has a cable core 34 comprising a number of individual strands or wires 36. The bent crimp portions 16, 18A, compress the cable core 34 so that the original round cross-section of the wires 36 assumes an irregular polygonal, approximately honeycomb shape. This increases the contact surface of the wires 36 to each other and to the cable connector.

According to Fig. 3B The fastening crimping sections 18 surround the cores 36 essentially only along the circumference of the cable core 34, wherein the degree of crimping is selected so that only a deformation of the cores 34 takes place largely without reducing the cross-section.

According to Fig. 3A End portions 38 of the Kontaktierungscrimpabschnitte 16, which are provided at its free end with chamfers to assist the curling movement during the crimping process, extend into the cable core 34, so that the end portions 38 extend partially between individual wires 36.

As a result, on the one hand the contact surface with the cores 36 is increased, on the other hand cause the end portions 38 due to their additional volume in comparison with the Befestigungscrimpabschnitten a displacement of the cores 36 and thus an additional compression of the sheath core 34 in the contacting crimping, whereby a relation to the in Fig. 3B shown fastening crimp 18A increased degree of compression and thus the desired improvement of Conductivity is achieved. In this case, a slight reduction of the core cross section occur, but which can be accepted, since it takes place only at the only slightly loaded by tensile forces end of the cable.

LIST OF REFERENCE NUMBERS

10

cable connectors

12

base portion

14

Adercrimpelement

16, 16A, 16B

Kontaktierungscrimpabschnitt

17A, 17B

Transition section

18A, 18B

Befestigungscrimpabschnitt

20

recesses

22

notch

24A-24D

electric wire

26A-26D

end

34

cable core

36

Vein

38

end

L

longitudinal axis

A

Extension direction perpendicular to L

Claims (15)

1. Electrical cable connector (10) having a longitudinal axis (L) for connection of a plurality of electrical cables,
   with only one wire crimping region with at least one pair of wire crimping elements (14) for receiving and fastening the wires (36) of all electrical cables,
   wherein the wire crimping elements (14) comprise at least a first and at least a second fastening crimping portion (18A, 18B),
   characterized in that
   the wire crimping elements (14) comprise at least one contact crimping portion (16, 16A, 16B) provided in longitudinal direction between the fastening crimping portions (18A, 18B),
   wherein the length of the contact crimping portion (16, 16A, 16B) in a direction of extension (A) perpendicular to the longitudinal axis (L) of the cable connector (10) is greater than the length of the fastening crimping portions (18A, 18B) in that direction, and
   wherein the fastening and contact crimping portions (16, 16A, 16B, 18A, 18B) are symmetrical with respect to the longitudinal axis (L) of the cable connector (10).
2. The cable connector according to claim 1,
   characterized in that
   the lengths of the first and second fastening crimping portions (18A, 18B) are of different sizes.
3. The cable connector according to claim 1 or 2,
   characterized in that
   the fastening crimping portions (18A, 18B) are of different lengths along the longitudinal axis (L).
4. The cable connector according to one of the claims 1 to 3,
   characterized in that
   the wire crimping elements (14) comprise only one contact crimping portion (16) for receiving the wires (36) of all cables.
5. The cable connector according to one of the claims 1 to 3,
   characterized in that
   the wire crimping elements (14) comprise a first and a second contact crimping portion (16A, 16B) which are adjacent to each other.
6. The cable connector according to one of the preceding claims,
   characterized in that
   the lengths of the fastening and contact crimping portions (16, 16A, 16B, 18A, 18B) are selected such that for a connection of electrical cables using the cable connector (10) the fastening crimping portions (18A, 18B) encompass a cable core (34), comprising the wires (36), of the respective cable substantially only along its periphery and an end portion (38) of the contact crimping portion (16, 16A, 16B) extends into the cable core (34).
7. The cable connector according to one of the preceding claims,
   characterized in that
   a transition from the contact crimping portion (16, 16A, 16B) to the first and/or second fastening crimping portion (18A, 18B) is formed as a step.
8. The cable connector according to one of the claims 1 to 6,
   characterized in that
   a recess (20) is provided between the contact crimping portion (16, 16A, 16B) and the first and/or second fastening crimping portion (18A, 18B).
9. The cable connector according to one of the claims 1 to 6,
   characterized in that
   a transition from the contact crimping portion (16, 16A, 16B) to the first and/or second fastening crimping portion (18A, 18B) is provided as a transition portion (17A, 17B), whose edge on the side of the end is inclined to the longitudinal axis (L).
10. The cable connector according to one of the preceding claims,
    characterized in that
    the contact crimping portion (16, 16A, 16B) and/or at least one of the fastening crimping portions (18A, 18B) on the inside comprise at least one notch (22) extending transversely to the longitudinal direction (L) of the cable connector (10).
11. Cable connection having at least two electrical cables (24A-24D), which are fastened by means of the wire crimping elements (14) to a cable connector (10) according to one of the claims 1 to 10.
12. The cable connection according to claim 11,
    characterized in that
    the fastening crimping portions (18A, 18B) encompass a cable core (34), comprising the wires (36), substantially only along its periphery, and
    an end portion (38) of the contact crimping portion (16, 16A, 16B) extends into the cable core (34).
13. The cable connection according to claim 12,
    characterized in that
    the cable core (34) in the region of contact crimping portion (16, 16A, 16B) is crimped with a higher degree of crimping than in the region of the fastening crimping portions (18A, 18B).
14. The cable connection according to one of the claims 11 to 13,
    characterized in that
    in longitudinal direction of the cable connector (10), stripped end portions (38) of a plurality of cables (24A-24D) are attached to at least one side of the cable connector (10).
15. The cable connection according to one of the claims 11 to 14,
    characterized in that
    the wire crimping elements comprise only one contact crimping portion (16, 16A, 16B) for receiving the wires (36) of all cables (24A-24D), wherein stripped end portions (38) of all cables (24A-24D) overlap in the longitudinal direction.

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