DE102009056799A1 - Thin electrical conductor i.e. aluminum cable, for motor vehicle, has three crimp connections enclosing conductor partial areas, where conductor and contact part are connected with each other by weld joint in areas by areas - Google Patents

Abstract

The conductor (1) has a connection part (2) including three crimp connections (2.1-2.3) enclosing partial areas of the conductor. The conductor and a contact part (3) e.g. bushing, are connected with each other by a weld joint in areas by areas, where the weld joint is produced by laser welding. One of the crimp connections relieves stress of the conductor assembled with the contact part. The crimp connections are arranged at a distance from each other at an insulation free end piece of the conductor. The connection part and the contact part are integrally designed. Independent claims are also included for the following: (1) a method for manufacturing a thin electrical conductor (2) a device for manufacturing a thin electrical conductor.

Description

State of the art

The invention relates to a conductor with contact part according to the preamble of claim 1. Furthermore, the invention relates to a method for the production of a conductor with contact part, and a device for the production.

In the face of ever increasing raw material costs, aluminum is becoming more and more important as a substitute for copper for use on electrical conductors and cables. For the application in motor vehicles, the weight saving of about 40%, which can be achieved with aluminum conductors, is of great interest in comparison with copper lines, since fuel can be saved with lighter vehicles. The production of a reliable, durable and electrically good conductive connection of a cable made of aluminum with a contact piece, such as a cable lug or a pole piece is a great challenge, since forms a comparatively hard, electrically insulating oxide layer on metallic bare aluminum in no time ,

Out US 2006/0102375 A1 is a contact piece for connection with an aluminum cable known. The region of the contact piece facing the cable comprises a blind hole, which is graduated several times in diameter and into which the cable is inserted and then pressed with the contact piece. The multi-layer cable must also be prepared stepwise before assembly with the contact piece, so that it can be inserted into the contact piece. For this purpose, the individual layers of the cable are cut in the contact area at different distances from the end face of the cable.

Out US 4,908,943 A1 is a method for contacting an insulated aluminum cable with a contact piece known. For this purpose, a unilaterally closed sleeve is first pushed onto a stripped end piece of the cable and pressed with the stripped end piece of the cable. The pre-assembled in this way end of the cable is then placed in a mold. In the mold, a contact piece is cast on the prefabricated cable.

Out US 2,806,215 A1 is a method for contacting an insulated aluminum cable with a contact piece known. For this purpose, a unilaterally closed sleeve with graduated inner diameter is first pushed onto the cable to be contacted on a stripped end piece of the cable such that the area of the sleeve with the smaller inner diameter the stripped portion of the cable and the portion of the sleeve with the larger inner diameter the subsequent insulation of the cable encloses. Subsequently, the sleeve pushed onto the cable is pressed with the cable. The end of the sleeve is connected by soldering with a contact piece.

Out DE 102 23 397 B4 a method is known in which in a liquid tin bath, the front side of an existing multi-strand aluminum cable is sonicated by a sonotrode, whereby the alumina layer of the individual conductors is broken, with the result that pure tin is deposited on the aluminum conductors. By this frontal impingement with tin is formed at the cable end a lid-like tinning, which also propagates between the individual conductors inside within the cable. About the stripped end of the cable a tinned sleeve was pushed in advance, which is intimately connected by the ultrasonic tinning process with the individual conductors of the cable and the tin cover at the cable end. Over the whole, a contact terminal made of copper is pushed, which is pressed over the sleeve and part of the insulation of the cable with the cable.

Out DE 103 46 160 B3 are known a method and a connection for contacting an aluminum cable, in which an open-topped contact terminal is pushed over the stripped individual conductors of the aluminum cable and ultrasonically tinned by the remote from the cable end hole opening by means of a sonotrode.

Out DE 10 2005 030 248 B3 For example, a method and a device for contacting an insulated cable made of individual conductors made of aluminum with a metallic, tinned on the inner sides, made of copper or a copper alloy contact terminal are known. It is generated by a plurality of sonotrodes an all-round ultrasonic tinning of the individual conductors in a tin or tin alloy bath at the stripped end of the cable, then pushed a contact terminal on the tinned individual conductors and finally carried out a heating of the contact terminal.

Out WO 2005/091439 A1 is a method for connecting a copper or a copper alloy connecting element for a cable, in particular a cable lug, with an electrical cable comprising a ladder made of aluminum known. In this case, the connection element, which is provided on its the head of aluminum facing surfaces with a coating of nickel, welded to the conductor made of aluminum by means of zinc.

Out US 5,408,743 A1 is a method for connecting a insulated light metal core having a cable having a contact piece is known, which has a step-like stepped, tapered blind hole. After introduction of the piecewise stripped cable in the contact piece of this is pressed and surrounds the stripped end of the cable and an adjoining region of the insulation.

Out US 2002/0162683 A1 For example, an electrical distribution device is known which comprises an insulated aluminum or aluminum alloy cable and a cable lug attached thereto. The cable lug is connected by a crimp connection to a stripped end piece of the cable. The connection is made under the influence of ultrasonic vibrations.

Out EP 0 966 061 A2 is a method for the electrical and mechanical connection of electrically conductive connections, such as in particular an existing aluminum cable with a cable lug or a battery terminal known. The components to be joined are glued by means of an electrically conductive adhesive and preferably positively connected to each other.

Out DE 2007 047 752 A1 a conductor is known with a contact part, in which the contact part is connected via a connection part with the conductor. The connection part comprises at least two crimp connections, which enclose metallic regions of the conductor.

Out US 2006/0292922 A1 For example, a method of connecting a copper or copper alloy connector to an aluminum conductor is known. The connector is covered with a nickel coating. The nickel coated connector and the aluminum conductor are welded to zinc using a plasma welding process.

From the magazine Automobile Production, November 2008, p. 40 , a connection between an aluminum cable and an aluminum bus bar in a vehicle is known. The connection is made by an ultrasonic welding process, with a specially designed sonotrode power of 10,000 watts is introduced into the contact point.

Furthermore, a so-called MP-WELD ^™ technology has become known, in which an electromagnetically induced force is used to produce a weld between a cable and a contact. Suitable materials for the cable are Al and Cu, for contact Al, Cu and brass.

The company M-O-SYS has described a so-called multi orbital friction welding for the connection of components consisting of metal, in particular aluminum. In the process, the components to be welded are rubbed flat against one another in the entire welding plane, as a result of which the welding plane heats up uniformly and quickly. When the joining temperature is reached, the components are connected to each other. With this welding process, the connection of an aluminum cable to a die-cast cable lug should be successful.

Technical task

The invention has for its object to provide a safe, durable and electrically good conductive connection of an existing aluminum cable with a contact piece, such as a pin, a socket, a cable lug or a pole piece, which is particularly inexpensive to produce and it In particular, it also makes it possible to securely connect comparatively thin aluminum cables or aluminum conductors to a contact piece.

This object is achieved by the invention specified in claim 1.

Advantages of the invention

The invention is based on the recognition that a durable, electrically good conductive and therefore particularly reliable connection of a thin aluminum conductor made of aluminum is made possible with a contact part by a arranged between the contact part and the conductor connection part, which comprises at least one crimp, and an additional weld between the electrical conductor and the contact part. The welding connection is advantageously produced by laser radiation, which allows a particularly good metered energy input into the welding station, whereby even thin electrical conductors can be securely connected to a contact part.

Advantageously, the at least one crimp connection serves during the manufacturing process for a secure fixation of the conductor in the contact part in order to obtain a good welded connection. Furthermore, the at least one crimp connection allows a strain relief of the conductor equipped with the contact part. Optional further crimp connections can further improve the electrical contacting of the conductor. In this case, advantageously at least one of the further crimp connections can be pressed even more strongly than the first-mentioned crimp connection, whereby oxide layers formed on the conductor or its components can be penetrated and thus improve the contact.

In an embodiment variant of the invention, the crimp connections enclosing the metallic regions of the conductor are arranged at a distance from one another. This facilitates the approach of different crimping tools to achieve the different compression.

In a further embodiment, the two crimp connections are immediately adjacent and therefore particularly space-saving. The different compression can advantageously be produced simultaneously with a stepped crimping tool.

In order to prevent shearing off of components of the conductor by the crimping process, in particular the strongly pressed crimp connection can be produced at an angle deviating from 90 °. In the case of a conductor sheathed with an insulating sheath, a further crimp connection is advantageously provided which also comprises the conductor in its isolated area.

Particularly advantageous contact part and connecting part are integrally formed, whereby the connection process is simplified with the head.

In a particularly advantageous and inexpensive embodiment, the contact part and the connecting part are integrally formed and preferably consist of a stamped piece.

Further advantages emerge from the subclaims, the description and the drawing.

drawing

Embodiments of the invention are explained below with reference to the drawing.

Show it:

1 a plan view of a conductor with contact part;

2 a conductor with contact part in side view;

3 a plan view of the end face of the contact part;

4 a longitudinal section through the in 3 illustrated contact part;

5 a further embodiment of a conductor with contact part in side view;

6 a device for welding;

7 a flowchart.

Description of the embodiments

1 shows a first embodiment of a conductor 1 with a contact part 3 in supervision. At the ladder 1 it is one consisting of many individual strands of an insulating shell 1.1 Surrounded cable made of aluminum. From the cited in the introduction to the prior art, the problems are known, resulting in the contacting of such conductors. Particularly critical is a rapidly forming hard oxide layer, which is a good contact in the way. Nevertheless, in the automotive sector made of aluminum, existing cables are to be used more intensively, since the cost of the material copper has risen sharply and can be achieved by the lower specific weight of aluminum in comparison to copper also a weight saving. A lower weight in turn allows the saving of fuel. According to the invention is now a reliable and inexpensive to produce connection between a conductor 1 and a contact part 3 through a welded connection between the conductor 1 and the contact part 3 and a connector 2 achieved, the at least one crimp connection 2.1 includes. The at least one crimp connection 2.1 encloses the insulating shell 1.1 of the wrapped conductor 1 , This at least one crimp connection 2.1 is mainly used to fix the insulating sheath 1.1 of the leader 1 in the connection area. At the same time but is at least one crimped by this 2.1 a secure fixation of the conductor 1 in the contact part 3 achieved, so that both components can be connected in an additional welding process, which will be discussed below. However, several crimp connections are particularly advantageous 2.1 . 2.2 . 2.3 intended. So can a second crimp connection 2.2 the leader 1 in a previously from the insulating sheath 1.1 enclose liberated portion of its tail. This second crimp connection 22 is mainly used for transmission from the ladder 1 acting tensile forces. A third crimp connection 2.3 encloses the leader 1 also in a previously from the insulating shell 1.1 freed part of his tail. This third crimp connection 2.3 is much more deformed than the crimped connection 2.2 , Due to the severe deformation, the oxide layers are around the individual strands of the conductor 1 broken and so it is already a good electrical contact between the conductor 1 , the connection part 2 and the contact part 3 allows.

As in 1 shown, in one embodiment of the invention, the crimped connection 2.3 at a distance from the crimped connection 2.2 be arranged. As in 2 shown, in a further advantageous embodiment variant, the third crimp connection can be arranged virtually without spacing immediately adjacent to the second crimp connection. Finally, in a third embodiment, as shown in the side view in FIG 3 can be seen, the third crimping 2.3 also angled with respect to the longitudinal axis, that is deviating from a 90 ° angle, be embossed, so as to shearing off individual strands of the conductor 1 in making the crimped connection 2.3 to avoid.

In the only schematically indicated in the drawing contact piece 3 it may be, for example, a pin or a socket or the like. The contact part 3 is preferably in one piece with the connection part 2 connected. The connection between the contact part 3 and the connector 2 can be done advantageously by welding or soldering. The connection part 2 and the contact part 3 are advantageously made of copper, aluminum or a copper-containing alloy. Particularly advantageous are the connection part 2 and the contact part 3 formed in one piece and manufactured for example as a stamped part. A particularly durable connection between the conductor 1 and the contact part 3 with very good mechanical and electrical properties can be prepared by adding, in addition to the at least one crimp connection 2.1 . 2.2 . 2.3 a welded joint between the conductor 1 and the contact part 3 is provided. This will be explained below with reference to 3 and 4 explained. It shows 3 a section BB (cross section) through the in 4 illustrated connection area between the conductor 12 and the contact part 3 , 4 is a longitudinal section through the connection area along the section line AA of 3 , In the welding area 32 are the individual veins 30 of the leader 1 with the wall 31 of the contact part 3 welded. Through this weld 32 is a mechanically highly stressable and electrically good conductive connection between the conductor 1 and the contact part 3 produced.

The following will, with reference to 6 exemplified the preparation of the welded joint. The welding connection 32 between the conductor 1 or between individual wires 30 of the leader 1 and the contact part 3 , or the wall 31 of the contact part 3 is made by inserting the wires 30 in the contact part 3 that of the contact part 3 and the veins 30 of the leader 1 formed end face is energized. The energy is passed through a welding device 60 provided. The welding device is a strong laser whose laser beam 61 can be focused on the welding area. With a thin conductor 1 or a leader 1 with only a few wires 30 It may be sufficient that a laser beam 61 is used, which is aligned to a single position. For a larger area to be welded, the laser beam is 61 Advantageously designed deflectable so that it is linearly or planar deflected over a greater distance to cover the entire welding area. This distraction is by the double arrow 62 indicated. For a particularly good weld 32 To achieve it, it may be appropriate to perform the welding process in a vacuum or under a protective gas atmosphere. For this purpose, the components to be welded into an evacuable or fillable with inert gas processing chamber 63 introduced and welded there. The processing chamber 63 includes a window 63.1 through the laser beam 61 on the welding area 32 can be directed.

With reference to the in 7 Flowchart shown will now be explained below by way of example the production of a conductor with contact part according to the invention. The leader 1 is done as follows with the connector 2 and the contact part 3 connected. It is initially assumed that it is a leader 1 with an insulating shell 1.1 is. In a first step 70 becomes the leader 1 cut straight to length without grading. In a second step 71 becomes the leader 1 in the designated connection area of the insulating sheath 1.1 freed. The thus prepared leader 1 is then from the top into the open Crimplaschen the connection part 2 inserted and for producing at least one crimp connection 2.1 . 2.2 . 2.3 crimped (step 72 ). An additional surface treatment of the conductor 1 is not necessary because of the strong pressing pressure of the crimp connection 2.3 on the ladder 1 or its constituents are penetrated by existing oxide layers. The at least one crimp connection is the conductor 1 , or are the individual wires 30 of the leader 1 already in the contact part 3 fixed that the end face of the contact part 3 and the end face of the conductor 1 , or the end faces of the individual wires 30 of the leader 1 are aligned essentially in one plane. The thus prepared tail of the conductor 1 will now be in the processing chamber 63 introduced and through the window 63.1 through with the laser beam 61 charged (step 73 ). In the welding area 32 becomes an intimate connection between the leader 1 or its veins 30 and the contact part 3 produced. In the interest of a particularly durable and good electrical connection between the conductor 1 and the contact part 3 or the connection part 2 can also in the context of the invention, the crimp connections 2.2 . 2.3 be welded, the stripped areas of the conductor 1 enclose. This is made possible in a simple way by the fact that the laser beam 61 deflected accordingly and directed to the areas to be welded. With a programmable deflection device for the laser beam 61 are even at multiple welds on the tail of a conductor 1 Very short cycle times can be realized, so that in the production of conductors with contact part according to the invention, a high throughput can be achieved. This has a favorable effect on the production costs.

At a ladder 1 without insulating sheath 1.1 eliminates the stripping of the shell 1.1 in the intended connection area and thus the step 71 , Furthermore, eliminates the crimp connection 2.1 , and it will only at least one of the crimp connections 2.2 . 2.3 made before the conductor 1 with the contact part 3 is welded.

In a particularly advantageous further embodiment, the conductor 1 with contact part in the region of the connection part 2 additionally with a moisture-proof cover 4 be surrounded. As a result, the fatigue strength is improved. The case 4 can for example consist of a plastic and by molding the connection part 2 be prepared.

The essence of the invention relates to the safe electrical and mechanical connection of a thin aluminum conductor with a contact part. Of course, the inventive teaching is also applicable to the secure connection of an aluminum alloy or other metallic materials with a corresponding contact part. With a correspondingly high laser power, it is also possible to weld thicker conductors to a contact part.

LIST OF REFERENCE NUMBERS

1

ladder

1.1

insulating shell

2

connector

2.1

crimp

2.2

crimp

2.3

crimp

3

contact part

4

shell

30

Vein

31

wall

32

welded joint

60

welder

61

laser beam

62

double arrow

63

processing chamber

63.1

window

70

step

71

step

72

step

73

step

A-A

cut

B-B

cut

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2006/0102375 A1 [0003]
• US 4908943 A1 [0004]
• US Pat. No. 2,862,115 A1 [0005]
• DE 10223397 B4 [0006]
• DE 10346160 B3 [0007]
• DE 102005030248 B3 [0008]
• WO 2005/091439 A1 [0009]
• US 5408743 A1 [0010]
• US 2002/0162683 A1 [0011]
• EP 0966061 A2 [0012]
• DE 2007047752 A1 [0013]
• US 2006/0292922 A1 [0014]

Cited non-patent literature

• Automobile Production, November 2008, p. 40 [0015]

Claims (22)

Ladder ( 1 ) with a contact part ( 3 ), characterized in that the contact part ( 3 ) via a connection part ( 2 ) with the ladder ( 1 ), the connection part ( 2 ) at least one crimp connection ( 2.1 . 2.2 . 2.3 ) comprising at least a portion of the conductor ( 1 ) and the conductor ( 1 ) and the contact part ( 3 ) at least partially by a welded joint ( 32 ), wherein the welded connection ( 32 ) is produced by laser welding. Ladder according to claim 1, characterized in that the welded connection ( 32 ) substantially the end faces of the conductor ( 1 ) or its cores ( 30 ) and the contact part ( 3 ). Ladder according to one of the preceding claims, characterized in that at least one of the crimp connections ( 2.1 . 2.2 . 2.3 ) mainly the strain relief of the contact ( 3 ) equipped conductor ( 1 ) serves. Ladder according to one of the preceding claims, characterized in that at least one second crimp connection ( 2.3 ) of the crimp connections ( 2.1 . 2.2 . 2.3 ) predominantly the electrical contacting of the conductor ( 1 ) serves. Ladder according to one of the preceding claims, characterized in that a crimp connection ( 2.3 ) of the crimp connections ( 2.1 . 2.2 . 2.3 ) is more compressed than the first crimp connection ( 2.2 ). Ladder according to one of the preceding claims, characterized in that a crimp connection ( 2.3 ) of the crimp connections ( 2.1 . 2.2 . 2.3 ) is compressed so strongly that possibly on components of the conductor ( 1 ) existing oxide layers are penetrated. Ladder according to one of the preceding claims, characterized in that at least two of the crimp connections ( 2.1 . 2.2 . 2.3 ) at a distance from one another at an insulation-free end piece of the conductor ( 1 ) are arranged. Ladder according to one of the preceding claims, characterized in that the crimp connections ( 2.1 . 2.2 . 2.3 ) immediately adjoin one another. Ladder according to one of the preceding claims, characterized in that at least one crimp connection ( 2.3 ) of the crimp connections ( 2.1 . 2.2 . 2.3 ) is pressed obliquely to shearing off components of the conductor ( 1 ) to prevent. Ladder according to one of the preceding claims, characterized in that at least one of the crimp connections ( 2.1 . 2.2 . 2.3 ) the insulating sheath ( 1.1 ) of the leader ( 1 ) in the region of the connection part ( 2 ) encloses. Ladder according to one of the preceding claims, characterized in that the connecting part ( 2 ) and the contact part ( 3 ) are integrally formed. Ladder according to one of the preceding claims, characterized in that the connecting part ( 2 ) and the contact part ( 3 ) are connected by soldering or welding. Ladder according to one of the preceding claims, characterized in that the connecting part ( 2 ) and the contact part ( 3 ) are integrally formed. Ladder according to one of the preceding claims, characterized in that the connecting part ( 2 ) and the contact part ( 3 ) are formed as a stamped part. Ladder according to one of the preceding claims, characterized in that the contact part ( 3 ) is designed as a socket or pin. Ladder according to one of the preceding claims, characterized in that the contact part ( 3 ) is designed as a cable lug or pole piece. Ladder according to one of the preceding claims, characterized in that the conductor ( 1 ) from individual wires ( 30 ) consists. Ladder according to one of the preceding claims, characterized in that the connecting part ( 2 ) of a moisture-proof envelope ( 4 ) is surrounded. Method for producing a conductor ( 1 ) with contact part ( 3 ) according to one of the preceding claims, characterized in that the conductor ( 1 ) in the region of an end piece by at least one crimp connection ( 2.1 . 2.2 . 2.3 ) with a connection part ( 2 ) or contact part ( 3 ) and that the conductors fixed to one another by the crimp connection ( 1 ) and contact part ( 3 ) by an additional welding connection ( 32 ), wherein the welded connection ( 32 ) is produced by laser welding. Method according to one of the preceding claims, characterized in that the welded connection ( 32 ) is produced in vacuo or in a protective gas atmosphere. Device for the production of a conductor with a contact part according to one of the preceding claims, characterized in that the device is a welding device ( 60 ) with a laser light source. Device according to one of the preceding claims, characterized in that the welding device comprises deflection means and focusing means for moving the laser beam of the laser light source to desired welding regions of the conductor ( 1 ) and the contact part ( 3 ) to distract and focus.

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