EP3453079B1 - Method of manufacturing a cable strain relief - Google Patents

Description

The present invention relates to a method for producing a cable strain relief, as well as an overmolded connector assembled with a cable and having such a cable strain relief.

It is known in the prior art that plug connectors are arranged at the end of a cable or a cable set. For this purpose, it is necessary that the connectors, consisting of the plug and mating connector, are provided with a strain relief in order to absorb the tensile or compressive forces on the cable acting on the connector and thus to relieve the contacts within the connector from these forces acting, in particular To avoid or prevent errors and impairments.

From the publications US 6,257,920 B1 , WO 2013/105660 A1 , WO 98/15044 A1 and WO 2013/022899 A1 Concepts and solutions for cable strain relief are already known.

This is how it shows US 6,257,920 B1 a connector with a clip crimped to a front portion of a cable jacket to securely lock to the cable jacket and prevent pullout of the cable while providing strain relief when the cable is jerked up or down, the clip itself can be securely locked to the connector frame.

The previously mentioned WO 2013/105660 A1 discloses a cable with an electrical connector comprising a metal ring as a fastening member at a connection portion between an electrical connector and a multi-core cable.

It is known from electrical installation that a connector housing has a crossbar that can be screwed to the connector housing, which is arranged over an end region of the cable and which, after being screwed, exerts a compressive force on the cable jacket.

Another common solution in the prior art is the use of screw-on cable strain relief elements. A cable gland usually works in such a way that an increasing pressure force acts on the cable as a result of the screwing and, for example, B. a clamping cage holds the cable.

In the case of molded connectors, it is common to produce the connector housing or part of it in an injection/casting process, with the immediate opening area of the cable being inserted into the injection/casting tool at the same time as the injection/casting process and also with the same Material, how the material of the connector housing is overmolded.

The disadvantage here is that the finished connector housing often does not form a sufficient connection with the material of the cable jacket, since the requirements for the material of the connector housing are completely different requirements than the requirements placed on the material of the cable jacket. Consequently, the cable can be undesirably pulled out of the overmolded material.

The invention is therefore based on the object of overcoming the aforementioned disadvantages and of proposing a solution for producing a simple, cost-effective and universally usable cable strain relief for a plug connector.

This task is solved with an arrangement according to the features of claim 1.

A basic idea of the present invention is to provide a specifically designed overmolding adapter sleeve that can be screwed to the connector housing and which at the same time has contours with which a stable overmolding around the overmolding adapter sleeve can be achieved.

A basic idea of the present invention is to provide a connector with a cable strain relief or a method for this, in which the cable strain relief is formed by a metallic ring element which has a certain diameter and thus also a matching inner circumference U2.

However, the ring element is deformed and reshaped from its original cross section to an effectively smaller cross section, so that the "unwound" inner circumference is smaller than the original inner circumference, which results in a tight fit on the cable jacket of the cable. The material that has to be displaced for this purpose is formed as part of a forming and bending process in such a way that there is a doubling of material and element sections of the ring element that protrude radially outwards.

These sections, also referred to below as ring element sections, serve for anchoring in an overmolding of the plug connector, as described later.

1. a) Bereitstellen eines metallischen Ringelementes aus einer ringförmigen Wand mit einem im Wesentlichen kreisförmigen Querschnitt, wobei das Ringelement einen Innenumfang U2 aufweist, der größer ist als der Außenumfang U1 des Kabelmantels;
2. b) Aufbringen des Ringelementes auf den Kabelmantel des Kabels an einer definierten Position;
3. c) Verformen des Ringelementes derart, dass der durch die Verformung erzeugte reduzierte Innenumfang U3 kleiner oder gleich dem Außenumfang U2 des Kabelmantels ist, so dass es am Kabelmantel fixiert ist und die Wand des Ringelementes ferner in wenigstens einem Bereich zur Reduzierung des ursprünglichen Innenumfangs U2 so umgeformt wurde, dass wenigstens ein aus der Wand gebildeter und umgeformter Ringelementabschnitt radial nach Außen gegenüber dem Kabelmantel hervorsteht.

According to the invention, a method for producing a cable strain relief for a cable to be attached to a plug connector with a round cross-section with a cable jacket with an outer circumference U1 is therefore proposed with the following steps:

1. a) providing a metallic ring element made of an annular wall with a substantially circular cross section, the ring element having an inner circumference U2 which is larger than the outer circumference U1 of the cable sheath;
2. b) applying the ring element to the cable jacket of the cable at a defined position;
3. c) deforming the ring element in such a way that the reduced inner circumference U3 generated by the deformation is less than or equal to the outer circumference U2 of the cable sheath, so that it is fixed to the cable sheath and the wall of the ring element further in at least one area to reduce the original inner circumference U2 was formed so that at least one ring element section formed and formed from the wall protrudes radially outwards relative to the cable jacket.

According to the invention, it is further provided in step d) that the cable is encapsulated or cast in a plastic in the area of the ring element, after which the previously described shaping of the ring element has taken place.

In a further advantageous embodiment of the invention it is provided that the ring element was further reshaped by the deformation in several areas to reduce the original inner circumference U2 in such a way that the respective deformed ring element sections protrude radially outwards relative to the cable jacket.

In this way, a kind of star-shaped shape of the ring element can be achieved with several outwardly protruding, i.e. H. Ring element sections projecting radially outwards.

In a further advantageous embodiment of the invention it is provided that in the deformed ring element sections there is a material doubling from wall sections of the wall of the ring element or that the ring element sections are formed from a material doubling.

In a further advantageous embodiment of the invention it is provided that in the area of the material doubling of the wall sections, a first wall section rests flatly with its inside on the inside of the second wall section.

In other words, this means that reshaping outwards and reshaping the wall section leads to the aforementioned material doubling.

It is also advantageous if the inner circumference U2 is approximately 15% to 40%, preferably approximately 25% to 35%, larger than the outer circumference U1 of the cable jacket.

It is also advantageous if the ring element is cut from a cylindrical pipe material in the desired width B.

This is a particularly advantageous embodiment, since using a cheap, simple pipe material, such as. B. a steel pipe, ring element sections or ring elements of width B can be cut off from the pipe and then, as described above, can be deformed from their annular shape so that they sit tightly on the cable jacket and the ring element sections, also previously described, radially outwards stand away from the cable jacket.

Furthermore, it is provided according to the invention that the formed ring element is deformed from a round cross section into a polygonal cross section, preferably a hexagonal cross section.

As a result, particularly suitable crimping tools can be used, which ensure, so to speak, in certain sections that the ring element achieves a substantially polygonal cross-section, while the aforementioned material doubling and material deformations are brought about radially outward in recesses in the crimping tool.

In this respect, it is a further aspect of the present invention to propose a connector connected to a cable with a cable strain relief, which is manufactured according to the method steps mentioned.

Fig. 1

eine perspektivische Ansicht einer Steckverbindung mit einer Kabelzugentlastung;

Fig. 1a

ein Detail aus Fig. 1;

Fig. 2

eine Schnittansicht durch einen Steckverbinder, ähnlich der Ansicht aus Fig. 1, bei dem die Kabelzugentlastung in einem Umspritz-Werkzeug mit einem Kunststoff umspritz wurde.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

Fig. 1

a perspective view of a plug connection with a cable strain relief;

Fig. 1a

a detail Fig. 1 ;

Fig. 2

a sectional view through a connector, similar to the view Fig. 1 , in which the cable strain relief was overmolded with a plastic in an overmolding tool.

The invention is described below with reference to Figures 1 and 2 explained in more detail, with the same reference numbers indicating the same functional and / or structural features.

In the Fig. 1 an embodiment of a cable strain relief 1 on a connector 2 is shown. The plug connector 2 is connected to a cable sheath 31 with a cable 30 with a substantially round cross section. The cable jacket 31 has an outer circumference U1. As can also be seen, a metallic ring element 10 sits on the cable jacket 31 of the cable 30, formed from an annular wall 11 with a substantially polygonal, here hexagonal cross-section, which was brought from its original ring shape into the shape shown with a polygonal cross-section.

The ring element 10 was therefore reshaped in its inner circumference U2 to a reduced inner circumference U3. Furthermore, it can be seen that as a result of the deformation, a deformed ring element section 13 formed from the wall 11 protrudes radially outwards relative to the cable jacket 31.

A second such ring element section 13, diametrically on the opposite side, which is not visible in the perspective view, is not explicitly shown.

The ring element 10 is characterized by the deformation areas 12, which represent the areas for reducing the original inner circumference U2 and have therefore been reshaped so that the respective deformed ring element sections 13 protrude radially outwards relative to the cable jacket 31.

In the detailed view next to the Fig. 1 It can be seen purely schematically with what result the diameter and thus the original inner circumference of the ring element 10 was reduced.

The design of the material doubling is as shown in a detailed section in the Fig. 1a designed so that the wall sections 11a, 11b each lie flat on one another with their inside 12a, 12b and are connected to one another via a bending section 12c.

In the Fig. 2 It can be seen how the cable strain relief 1 is encapsulated around the cable strain relief 1 and at the same time around the cable jacket 31, with parts of the encapsulation encompassing the plug connector 2.

Due to the specific design of the ring element 10, its ring element sections 13 are held in the plastic encapsulation 14.

Reference symbol list

1

Cable strain relief

2

Connectors

10

Ring element

11

Wall

11a, 11b

Wall sections

12

Area

12a, 12b

Inside pages

12c

bending section

13

Ring element section

14

Plastic injection molding

30

Cable

31

Cable jacket

b

Width

Claims (6)

1. Method for producing a cable strain-relief means (1) of a cable (30) which is to be attached to a plug (2) and has a round cross section and has a cable sheath (31) with an outer circumference U1, said method having the following steps:

   a) providing a metal ring (10) from a ring-shaped wall (11) with a substantially circular cross section, wherein the ring (10) has an inner circumference U2 which is greater than the outer circumference U1 of the cable sheath (31);

   b) applying the ring (10) onto the cable sheath (31) of the cable (30) at a defined position;

   c) deforming the ring (10) in such a way that the reduced inner circumference U3, which is generated as a result of the deformation, is smaller than or equal to the outer circumference U1 of the cable sheath (31), such that it is fixed on the cable sheath (31) and the wall (11) of the ring (10) is also reshaped in at least one region (12) to reduce the original inner circumference U2, and at least one ring element portion (13), which has been formed from the wall (11) and reshaped, radially outward in relation to the cable sheath (31);

   d) overmoulding or potting the cable (30) with a plastic (14) in the region of the ring (10), characterized in that the reshaped ring is deformed from a round cross section into a polygonal cross section.
2. Method according to Claim 1, characterized in that the ring (10) has also been reshaped as a result of the deformation in multiple regions (12) to reduce the original inner circumference U2 such that the respectively deformed ring element portions (13) protrude radially outward in relation to the cable sheath (31).
3. Method according to Claim 1 or 2, characterized in that there is material doubling from wall portions (11a, 11b) of the wall (11) of the ring (10) in the deformed ring element portions (13).
4. Method according to Claim 3, characterized in that a first wall portion (11a) bears flatly with its inner side (12a) on the inner side (12b) of the second wall portion (11b) in the region of the material doubling of the wall portions (11a, 11b).
5. Method according to one of the preceding claims, characterized in that the inner circumference U2 is greater by approximately 15 % to 40 %, preferably approximately 25 % to 35 %, than the outer circumference U1 of the cable sheath (31).
6. Method according to one of the preceding claims, characterized in that the ring (10) is cut off in the desired width B from a cylindrical tube material.

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