EP2697866B1 - Manufacture of an electric cable and connection method - Google Patents

Description

The subject matter relates to the connection of an electrical cable formed from a plurality of wires or strands with a connection part, in particular for the electrical system of a motor vehicle, with a support sleeve. The support sleeve for receiving an end portion of the cable is formed and surrounds it. As a result, the wires or strands are held in the support sleeve, wherein the front side of the cable formed from the individual wires or strands is welded to the connecting part by means of an at least frontal weld.

The connection of electrical cables with connector parts is commonplace in the automotive industry in particular. However, the cost pressure is enormous, so that the supplier industry is always looking for process-reliable, durable, but cost-effective connection technologies.

From the European patent application EP 2 131 448 A1 is a connection between a cable and a tubular connector known. For this purpose, the cable is welded to a contact element via a support sleeve 4. Subsequently, the contact element is inserted into the tubular connection element in order to be crimped in the manner of a plug in the tube of the connection element.

From the European patent EP 1 032 077 B1 is for example a connection of an aluminum cable with a connecting part, which may be formed of copper known. Here it is described that the end of the aluminum cable, in particular the stripped end of the aluminum cable is pressed by means of a sleeve, so that the strands of the cable are miteihander pressed. The thus-pressed end of the cable is connected to a connection part by a friction welding process.

The technology described there was a breakthrough in the connection of aluminum cables with connection parts, since for the first time the possibility was created to connect aluminum process-reliable and permanently with other joining partners, in particular copper or brass. The sleeve ensures that the strands of the aluminum cable do not splice during the welding process. This ensures that a good intermetallic connection is created between the end faces of the strands and the connection part. This is an important prerequisite for a permanent, electrically good conductive connection.

A disadvantage of the method described in said EP-letter and the said compound, however, is that the connecting part is formed of a solid material. On the one hand, this is difficult and therefore no longer up to date in the context of the necessary weight reduction in vehicle construction. On the other hand, such a connection part is expensive, since the use of material is considerable. Finally, the connection part is also complex to produce, since it must be made available as a forged part usually, which is expensive to manufacture.

For this reason, the object was the object to provide a connection of a cable with a connector available, which is on the one hand process reliable, on the other hand, however, material and weight savings.

This object is achieved by a compound according to claim 1. In particular, it is suggested that the Connecting part on the opposite side of the weld is hollow.

The connection part is preferably formed from a sheet metal or strip, which has a bearing surface / connection surface facing the support sleeve and the end region of the cable. The fact that the connection part is hollow on the side opposite the weld results in weight and material savings. The connector may provide at one end a crimping shoe, a bore, a bolt, a threaded connection or the like, via which the connection with a copper cable is made possible. On the side facing the cable, the connecting part has a preferably circular connection surface, which is preferably flat. The cable together with the support sleeve can be attached to this connection surface and welded to it. Both pad and cable preferably have circular cross sections, but other cross sections are also possible and within the scope of what is claimed objectually.

Hollow in the sense of the article is to be understood in that on the opposite side of the weld, a space defined by walls of the connection part is formed. This room can be open on one side, but also completely closed. Preferably hollow means that an at least partially circumferential wall is provided along the circumference of the weld.

An end region of the cable is in particular the region of the cable which is stripped. The end face of the cable is preferably formed by the ends of the wires or strands. Preferably, the cable has been cut or cut so that a flat as possible end side of the cable is formed. The strands thus end preferably in a plane, in which case a tolerance range of +/- 1 to 2 mm is possible.

The connection part is tubular. The connection part has a bottom, which forms the connection surface for the weld seam. The floor is welded to the cable along the weld. It is also possible that the weld extends beyond the cable to the support sleeve. In this case, the pad is welded to the support sleeve as well as the end face of the wires or strands.

The floor is formed integrally from the walls of the connection part. In this case it can be provided that initially a tubular connecting part is formed. Subsequently, the ends of the tube are bent toward the center of the tubular connection part so that the bottom forms. It is also possible that the bottom is formed from a lid arranged at the end of the tube of the connecting part. Thus, it is possible either that the bottom and the connecting part are integrally formed, as well as that the bottom and the connecting part are formed in two pieces.

The lid is preferably inserted in the tube or placed on the tube. Preferably, the lid is crimped in the tube. It is possible that the lid has a step-shaped cross section, such that a first Diameter corresponds to the inner diameter of the connecting part and a second diameter at least equal to the outer diameter of the connecting part, but at least greater than the inner diameter. Then, the first diameter of the lid can be inserted into the tube of the connecting part, wherein the second diameter rests against the end face of the tube. Subsequently, the lid can be pressed in the tube. It is also possible that the lid is welded to the tube. Finally, it is possible that the lid is soldered or glued to the pipe. Other connection technologies are also possible as long as there is an electrical connection between the cover and the connection part. The pipe surface facing away from the lid then forms the connection surface.

According to an advantageous embodiment, it is proposed that the wall of the connecting part is deformed forming the bottom at its end. As already mentioned, the wall of the connection part can be bent inwards, in particular in the region of the front end. The wall is preferably bent to the center of the tubular connection part.

According to an advantageous embodiment, it is also proposed that the connection part in the region of the bottom is a drawn, in particular deep-drawn, cup. The connection part may for example be a flat part, which is formed in a drawing process so that it forms a tubular, U-shaped, unilaterally open connection part at least at the end. The outwardly facing surface of the cup serves as a connection surface for the weld. By the method described, it is particularly cost possible to form a connection part.

As already mentioned, the connection part can be formed from a flat part. Then, for example, in a first processing step of a sheet or a strip, the flat part are punched, which has the necessary developments. Subsequently, the flat part can be deformed, in particular bent at the ends tubular, in which case the soil can be formed. Finally, the objective connection part is then formed from the flat part.

According to an advantageous embodiment, it is proposed that in the deformed state of the flat part, the mutually facing end faces are positively connected to each other, in particular schwalbenschwänzig engage behind each other. In a development, a region of the flat part may, for example, be rectangular. The respectively opposite end faces of the flat part can have corresponding projections and recesses, in particular dovetailed projections and recesses. If the flat part is then bent into a tube, then the end faces which are initially opposite one another are turned toward one another. In order to ensure that the tube which has been shaped is retained in its shape, it is proposed that the then facing end faces engage behind one another and are preferably interlocked with one another. It has been found that the dovetail enables a particularly advantageous positive connection. However, the faces can also be soldered or welded.

According to an advantageous embodiment, it is proposed that on the flat part at one end a circular extension is formed, which forms the bottom in the deformed state.

As explained above, the flat part may be rectangular in a development in a first region. This area can be deformed tubular. In order to form the bottom, a circular extension can be arranged on the rectangle, on a long end face. Thus, the flat part can be formed, for example by stamping so that both the rectangle, and the extension is punched directly from a sheet. The extension, after the tube has been formed, be bent so that it rests or rests on the end face of the tube. Then it can be welded, soldered or glued to the front of the pipe.

The connection part can be formed particularly cost-effectively if it is a tubular cable lug. A tubular cable lug is available as a mass-produced particularly favorable. To form the objective connection part, it is only necessary to deform the front ends of the open region of the tubular cable lug into a base or to place a cover thereon.

The connection between the support sleeve, the cable and the connection part is advantageously realized via the weld. This is advantageously a friction weld, a Rotationsreibschweißnaht, a resistance weld, a laser weld or a Ultrasonic weld. These welding methods are all suitable for connecting a cable to a connection part. In particular, these methods are suitable for connecting a cable to a connection part. In particular, these methods are suitable for connecting a cable formed from aluminum or an aluminum alloy with a connecting part formed from a non-ferrous metal, in particular copper, in particular a copper alloy. However, it is also possible that the connecting part is also made of aluminum. The connecting part is advantageously made of a formable material which is conductive, eg brass.

A particularly good weld can be realized in that the end face of the cable is flush with one end of the support sleeve. In this case, not only the end face of the cable or the end faces of the wires or strands can be connected to the connection part during welding, but at the same time also the end face of the support sleeve.

As already explained, the cable can be made of aluminum or an aluminum alloy. In addition, the connection part may be formed from a conductive, preferably formable material. In particular, non-ferrous metals such as copper or copper alloys such as brass or bronze are suitable here.

It is also proposed that the cable is stripped in the region of the support sleeve. In this case, the stripped portion of the cable or the stripped end of the cable can be inserted into the support sleeve and can then be pressed with the support sleeve. For this purpose, the Slotted support sleeve so that the slot is closed during compression and the diameter of the support sleeve is reduced. As a result, a pressing of the strands is facilitated.

The article will be explained in more detail with reference to drawings showing an exemplary embodiments.

Fig. 1

eine Schnittansicht eines Kabels mit einer Stützhülse;

Fig. 2

eine weitere Schnittansicht eines Kabels mit einer Stützhülse;

Fig. 3a

eine Schnittansicht eines Anschlussteils gemäß eines Ausführungsbeispiels;

Fig. 3b

eine Schnittansicht eines Anschlussteils verbunden mit einem Kabel;

Fig. 3c

eine weitere Schnittansicht eines Anschlussteils verbunden mit einem Kabel;

Fig. 4a

eine Schnittansicht eines weiteren Ausführungsbeispiels eines Anschlussteils;

Fig. 4b

eine Seitenansicht eines Anschlussteils gemäß einem Ausführungsbeispiels;

Fig. 4c

eine Schnittansicht eines Anschlussteils verbunden mit einem Kabel;

Fig. 4d

eine weitere Schnittansicht eines Anschlussteils verbunden mit einem Kabel;

Fig. 5

eine Abwicklung eines Anschlussteils;

Fig. 6

eine weitere Ansicht eines Ausführungsbeispiels eines Anschlussteils.

In the figures shows:

Fig. 1

a sectional view of a cable with a support sleeve;

Fig. 2

a further sectional view of a cable with a support sleeve;

Fig. 3a

a sectional view of a connection part according to an embodiment;

Fig. 3b

a sectional view of a connector connected to a cable;

Fig. 3c

another sectional view of a connector connected to a cable;

Fig. 4a

a sectional view of another embodiment of a connection part;

Fig. 4b

a side view of a connection part according to an embodiment;

Fig. 4c

a sectional view of a connector connected to a cable;

Fig. 4d

another sectional view of a connector connected to a cable;

Fig. 5

a settlement of a connection part;

Fig. 6

a further view of an embodiment of a connection part.

FIG. 1 shows a support sleeve 2 in a sectional view. The support sleeve 2 is preferably round and made of aluminum, copper or alloys thereof. Furthermore, in the FIG. 1 an electrical cable 4, in particular a battery cable of a motor vehicle, in particular for connecting a battery with a starter or a generator and also another electrical line of a motor vehicle shown. As can be seen, the cable 4 is covered with an insulation 4a. The cable 4 is freed from the insulation 4a in an end region 4c, so that the strands 4b of the cable 4 are exposed.

The exposed strands 4b of the cable 4 are inserted into the support sleeve 2. It can be seen that the end face 2 a of the support sleeve 2 is flush with the front end 4 d of the cable 4.

The support sleeve 2 is preferably pressed, so that the strands 4b within the support sleeve 2 are close together. FIG. 2 shows a further embodiment of a compound of a support sleeve 2 with a cable 4. In the FIG. 2 It can be seen that the end region 4c does not completely fill the support sleeve 2. The front end 4 d of the strands 4 b is here in the interior of the sleeve 2, so that they are not flush with the end face 2 a of the support sleeve 2. Both the arrangement after FIG. 1 as well as the arrangement FIG. 2 is suitable for connection to a connector as claimed.

FIG. 3a shows a connection part 6. The in FIG. 3a The connecting part shown is a tubular cable lug, which is open at one end 6a and at the other end 6b, for example, is pressed. At the end 6b, for example, a bore is provided for connecting a cable. The connecting part 6 is preferably formed from copper or a copper alloy.

Furthermore, in the FIG. 3a to recognize that the connection part 6 has a cavity 8. The cavity 8 is formed through the tubular end of the fitting 6 and closed by a lid 10. As can be seen, the lid 10 has two diameters. A first smaller diameter is inserted into the cavity 8 and a second diameter, which is larger than the first diameter, abuts against the end 6 a of the connecting part 6.

In the in FIG. 3a As shown, the cover 10 is inserted into the cavity 8 of the connecting part 6 and welded at the front end 6a with the connecting part 6. However, it is also possible that the cover 10 only on the front end 6a of the connecting part. 6 is placed without being inserted into the cavity 8.

In any case, the cover 10 is a preferably flat pad 12 for electrical connection to the front end 4d of the strands available.

FIG. 3b shows a connection between a connector 6 and a cable 4. It can be seen that a weld 16 connects the pad 12 with the end face 2a of the support sleeve 2 and the end faces 4d of the strands 4b. The weld 16 has been made by a friction welding process. However, it is also possible for the weld 16 to be produced by means of a laser welding method, an ultrasonic method, a resistance welding method or another welding method.

Furthermore, in the FIG. 3b to recognize that on the side opposite the weld 16 side of the lid 10, the cavity 8 is located, so that the connecting part 6 relative to the weld 16 is hollow. This leads to weight advantages, since the connection part 6 does not have to be formed from a solid material. As the material usage is lower, lower material costs are also incurred.

Figure 3c shows a further embodiment in which the cable 4 and the support sleeve 2, as in FIG. 2 shown connected to each other. For an electrical connection, the cover 10 is inserted together with the end region of the connection part 6 into the support sleeve 2, and the weld seam 16 is formed at least between the connection surface 12 and the end sides 4d of the strands 4b. At a Resistance welding would also produce the weld 16 along the outer surface of the connecting part 6 and the inner circumferential surface of the sleeve 2.

FIG. 4a shows a further embodiment in which the connection surface 12 is formed from the walls of the connection part 6. The walls of the connecting part 6 are bent inwardly in their end region in such a way that they point in the direction of the central axis 14. The ends 6a are preferably facing each other and optionally welded together. The curved walls of the connection part 6 form a bottom 13 with the connection surface 12.

A side view is in the FIG. 4b shown. Evident is the pad 12 with a circular cross-section. Other cross sections are also possible. Furthermore, the central axis 14 can be seen, to which the ends 6a of the connecting part 6 point.

Figure 4c shows a possibility of connecting the connecting part 6 with the cable 4. Here, the weld 16 along the end face 2a and the end faces 4d of the strands 4b is formed with the pad 12. Again, the weld 16 is the cavity 8 opposite.

FIG. 4d shows a further Aüsführüngs example in which the connecting part 6 is inserted with its end in the support sleeve 2a. Again, a weld 16 may be formed at least between the pad 12 and the end faces 4d of the strands 4b.

FIG. 5 shows a development of a further embodiment of a connection part 6. First, it should be noted that the connection part 6 may be formed from a sheet or strip. Preferably, the sheet thickness is between 1 and 10 mm. From a sheet, the connection part 6, as in FIG. 5 represented, are punched. It can be seen that a first connection tab is provided in the region of the end 6b. At this Anschl tab is followed by a substantially rectangular area. In the finished state, the side turned away from the connection tab forms the end 6a of the connection part 6. The ends 6c along the short edges have dovetail-shaped recesses or protrusions 18a, 18b. The rectangular portion is followed by a substantially circular extension, which forms the bottom 13 in the installed state. The extension is connected via a web 20 with the rectangular part. For producing a connection part 6, the rectangular part is substantially circularly deformed in a first processing step. The recess 18b engages in the projection 18a, whereby the ends 6c are positively connected to each other. Subsequently, the web 20 is bent so that the bottom 13 closes the end 6a and a cavity 8 is formed.

FIG. 6 shows a further embodiment in which a flat part is bent so that a cup is formed having a cavity 8 with a bottom 13, as shown. Also, such a shape is advantageous because it is easy to produce.

Claims (11)

1. Connection of an electrical cable (4) formed from a plurality of wires or strands to a terminal (6), in particular for the electrical system of a motor vehicle, having

   - a support sleeve (2) which encloses an end area of the cable (4) and serves to accommodate an end face of the cable (4), so that the wires or strands are held in the support sleeve (2), wherein

   - the face side of the cable (4) formed from the individual wires or strands is welded to the terminal (6) by means of an at least face side weld seam (16), wherein

   - the terminal (6) is hollow on the side opposite the weld seam (16),
   characterised in that

   - the terminal (6) is tubular with a bottom (13), and in that the bottom (13) is formed as one piece from the walls of the terminal (16) and welded to the cable (4) along the weld seam (16).
2. Connection according to Claim 1, characterised in that the wall of the terminal (6) is deformed at its end forming the bottom (13), wherein in particular the wall is bent towards the centre of the tubular terminal (6).
3. Connection according to any one of the preceding claims, characterised in that the terminal (6) is a drawn, in particular a deep-drawn, cup in the bottom (13) area.
4. Connection according to any one of the preceding claims, characterised in that the terminal (6) is formed from a flat part.
5. Connection according to Claim 4, characterised in that in the deformed state of the flat part the end faces turned towards one another are connected to one another in a form-fit fashion and in particular engage with one another from behind in a dovetail fashion.
6. Connection according to any one of the preceding claims, characterised in that a circular extension is formed on one end of the flat part, this circular extension forming the bottom (13) in the deformed state.
7. Connection according to any one of the preceding claims, characterised in that the terminal (6) is a tube cable lug.
8. Connection according to any one of the preceding claims, characterised in that the weld seam (16) is a friction weld seam, a rotational friction weld seam, a resistance weld seam, a laser weld seam or an ultrasonic weld seam.
9. Connection according to any one of the preceding claims, characterised in that the face side of the cable (4) is flush with one end of the support sleeve (2).
10. Connection according to any one of the preceding claims, characterised in that the cable (4) is formed from aluminium or an aluminium alloy, and in that the terminal (6) is formed from a conductive material, in particular a non-iron metal, in particular copper or a copper alloy.
11. Connection according to any one of the preceding claims, characterised in that an insulation is stripped off the cable (4) in the area of the support sleeve (2).

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