WO2014117769A1

WO2014117769A1 - Method for producing a current strip

Info

Publication number: WO2014117769A1
Application number: PCT/DE2014/100014
Authority: WO
Inventors: Martin Janssen
Original assignee: Connex Gmbh
Priority date: 2013-02-04
Filing date: 2014-01-21
Publication date: 2014-08-07
Also published as: DE102013101080B9; DE102013101080B3

Abstract

The present invention relates to a method for producing a current strip (1), wherein the current strip (1) has at least one solid end piece (6) to which a flexible stack (2) of laminations is coupled, wherein the method is characterized by the following method steps: - providing two end pieces (6) and one stack (2) of laminations, wherein the stack (2) of laminations has at least two films (3) which are situated one above the other, - placing an end face (4) of the stack (2) of laminations at an end face (9) of an end piece (6), wherein there is a distance of less than 1 mm, preferably less than 0.5 mm, between the end faces (4, 9), and fixing said end faces in relation to one another, - electron-beam welding the stack (2) of laminations to the end piece (6), so that each film (3) is cohesively coupled, by way of its film end face, to the end piece (6) substantially over the whole area.

Description

Method for producing a current band

The present invention relates to a method for producing a current band according to the features in the preamble of claim 1.

To conduct electricity, it is necessary that a corresponding component, a consumer or even a cable line is coupled to a supply line coming from the power source. For this purpose, so-called current bands are known in particular in the field of high-current technology. In this case, two spaced-apart contact points are brought into electrical contact with each other via the current band. However, in order to conduct currents with an amperage of more than 50 A here, the current strips in question sometimes have a cross-sectional area of 100 × 20 mm. Common applications are switchgear, industrial furnaces, transformers, generator stations, electrolysis applications, electric locomotives or even vacuum systems. In order for a properly electrical contact is ensured at the respective coupling point and the current band itself is electrically conductive, it is usually made of precious metals, especially copper.

To compensate now, for example, between two different components different linear expansions, switching paths, production tolerances or even vibrations, flexible current bands are still known from the prior art. Such a current band is usually designed as an elongated component. At its ends, it then has in each case a fixed end piece, which is usually made solid, in order to couple the current band at the respective coupling point. In particular, this coupling is done by mounting with a bolt. Between the two massive end pieces then extends a disk set, consisting of several layered or packaged foil strips. Each foil and thus the lamellar composite allows compared to the solid and therefore solid tail a flexible design and thus, for example, a bending or compressing, without causing mechanical damage or a loss in the eclectic conductivity of the current band.

Such flexible current bands are made in the prior art in two different ways. On the one hand, films are stacked on top of each other, which in their longitudinal extension have a longitudinal extent that is similar to that of the later current band. The thus packaged films are then cohesively coupled together at their ends in a welding device by a resistance welding process, so that in the end regions due to the resistance welding melting of the individual films takes place and these are coupled to form a solid solid end cohesively. The disadvantage here is that inclusions of air and / or lubricants may be present in the end regions, which are present between the individual films. In addition, in order to now fasten the end region with a screw connection to an object, the end region must then be reworked, for example with a drilling method, in order to introduce mounting holes in the end region produced by the resistance welding. Here sometimes suffers the precision of the holes introduced, wherein in particular, a current band produced in this way is difficult to arrange in a drilling apparatus due to the flexible blades. Such a manufacturing method is known for example from DE 197 34 968 A1. The ends of the expansion band described there are superimposed and joined by pressure welding to form a compact package.

A second production method is known from the prior art, in which the individual films are stacked to form a lamella packet and then welded at their end faces by means of a thermal joining process. The weld produced in this case is then mechanically machined, for example, by a grinding or milling process, and then the thus produced, welded at its ends disc pack is placed on each end side of an end piece and the end face of the tail and the previously produced Weld seam of the disk pack are welded together on both sides with a respective fillet weld. A disadvantage of this method, on the one hand performing at least two welding operations, which leads to increased production costs, as well as the fact that when welding the individual films to the disk set a change in length takes place, which leads to high production tolerances in the production of current bands with this method ,

It is therefore an object of the present invention, starting from the state of the art, to show a method with which flexible current bands can be produced cost-effectively and at the same time with higher geometrical precision with at least constant electrical conductivity compared with methods known from the prior art.

The aforementioned object is achieved with a method for producing a current band according to the features in the preamble of claim 1.

Advantageous embodiments of the method according to the invention are the subject of the dependent claims. The method for producing a current band, wherein the current band has at least one solid end piece to which a flexible plate pack is coupled, is characterized according to the invention by the following method steps:

Providing at least one end piece and a plate pack, wherein the plate pack has at least two superimposed films,

- Creating an end face of the disk set to an end face of an end piece, wherein between the end faces a distance of less than 1 mm, preferably less than 0.5 mm is present, and fixing the position to each other,

- Electron beam welding of the disk set with the tail, so that each film with its film front side is substantially full-surface coupled to the tail cohesively.

The advantage essential to the invention can be seen in the fact that, on the one hand, a simple and geometrically highly precise pretreatment of a respective end piece is possible. As a result, holes, recesses or other processing on the end pieces can be made freely and independently of the disk pack. By means of the electron beam welding according to the invention, it is furthermore possible, in only one welding operation, to fully couple each individual foil of the disk pack with its end face to the end piece. Due to the penetration depth of up to 200 mm of the electron beams, it is thus possible not only to produce tapes with a thickness of approximately 5 mm, but also tapes having a thickness of 50 or even 100 mm in a welding process with constant precision. The electron beam welding can be carried out under vacuum, but also under a corresponding electron welding atmosphere.

At the same time, however, offers the possibility of the frontal application of tail and disk set with a distance of less than 1 mm and in particular less than 0.5 mm, most preferably almost a gap-free concerns of disk pack and tail, the possibility of a geometrically high-precision Produce power band and minimize the occurring geometric production tolerances. In the preferred gap-free abutment of the end faces, if necessary, unevenness due to the individual production of the films and / or of the end piece can be neglected.

In the context of the invention, the current band preferably has two massive end pieces each at its end sides, the lamella packet then being arranged between the end pieces and being coupled to the end pieces in each case.

In the context of the invention, current strips with an elongated configuration are preferably formed. However, it is also possible to form current bands with other geometric configurations, for example in U-shape, L-shape or any hybrid forms. With the current band according to the invention, it is possible to conduct ampere-strengths of 50 to 20,000 A, with current loads of 0.2 A / mm ² to 3 A / mm ^{2 being} realized.

In particular, the end piece itself is provided as a cuboid component, wherein the end piece is preferably formed from a copper alloy. The tail is formed as a cuboid flat component and has a thickness of in particular 2 to 200 mm, preferably 5 to 150 mm. The construction height or thickness of the cuboid component is largely determined by on the one hand the electrically conductive current, on the other hand, the expected mechanical stresses. In particular, the cuboid component can be provided with mounting holes in order to be able to subsequently mount the current band produced by the method according to the invention accordingly. In the context of the invention, it is also possible that the tail itself is made of an aluminum alloy, a silver alloy or even an iron alloy, in particular steel. In the context of the invention, it is also possible that the tail itself is coated, and thus, for example, has a copper core and a silver surface layer.

Further particularly preferably, the films themselves have a thickness of 0.01 to 3 mm, in particular of 0.02 to 2 mm, wherein the films are in particular formed from a copper alloy. Again, it is within the scope of the invention possible that the films themselves are made of an aluminum alloy, of a silver alloy or else of an iron alloy, in particular of steel. The individual foils are then stacked or packaged one above the other to form a lamella packet, so that a lamella packet is produced which essentially has the same construction height or thickness as that of the previously described end piece. When the end faces are arranged one inside the other, the thickness of the disk pack and the thickness of the end piece are essentially the same, whereby a corresponding weld seam can be produced by the electron beam welding.

Another essential feature of the invention is that the material selection of tail and films can be combined with each other as desired. Thus, for example, a tail made of a copper alloy with silver foils or aluminum foils are welded or vice versa. Due to the electron beam welding, it is furthermore particularly preferred to record only a small heat-affected zone on the films themselves, and consequently only a small structural change resulting from the welding process, so that the flexibility of the films is also substantially maintained in the connection region after welding.

Thus, the two components can be aligned and positioned to each other, therefore, the end face of the disk pack can be applied to the front side of the tail and then the welding process is feasible, the method of the invention provides different positioning options that can be combined with each other.

Thus, on the one hand, it is provided that the end piece with the disk pack is positioned relative to each other via an auxiliary device and subsequently fixed in position in the welding position. Under an auxiliary device, for example, a collet or even a functional principle in the manner of a screw clamp to understand.

Another possibility provides that the disk set and the end piece are fixed to the respective end faces positively and / or non-positively to each other. This is to be understood in the context of the invention that the tail more preferably has a lip, wherein the lip opposite the end face of the tail protrudes and the plate pack is placed on the lip itself. Here it is now possible to form-fit the disk pack itself with the lip, for example by a rivet, and fix it in such a way that the welding process can then be carried out on the end faces.

Alternatively or additionally, it is possible that the tail itself has two lips, both lips projecting from the end face of the tail and forming a pocket, the disc pack is placed in the pocket and is particularly preferably pressed between the lips, so that a positive connection arises. Following this, the electron beam welding process is applied to the components positioned in this way through one of the lips and the end faces are welded together.

In the context of the invention, in particular the lower lip is arranged to possibly receive a refractory material during welding and thus serves as a bath casserole. There is thus no weld material from the produced weld seam at the bottom, wherein the upper side of the weld seam has a visually appealing surface due to the electron beam welding itself due to electron beam welding. If the embodiment variant provide that the tail has no lip, it is also possible within the scope of the invention that a plate is arranged below the weld to be produced, which absorbs any emerging weld metal and thus produces a visually appealing weld, which in particular has high mechanical strength because there are no pores or spouts.

Further features, advantages, features and aspects of the present invention are part of the following description. Preferred embodiments are shown in the schematic figures. These are for easy understanding of the invention. Show it:

1 a and b a known from the prior art manufacturing method of a current band,

FIG. 2 shows a current band produced by the production method according to the invention, FIG. 3 shows a current band with a lip lying on the end piece produced according to the method according to the invention;

FIG. 4 shows a process produced by the process according to the invention

Stromband with lower and upper lip

FIG. 5 shows a current band according to FIG. 4, which is additionally riveted,

Figure 6a and b a produced according to the invention current band according to Figure 4, which is additionally pressed for the joining process.

In the figures, the same reference numerals are used for the same or similar components, even if a repeated description is omitted for reasons of simplicity.

Figure 1 a and b show a manufacturing method for a current band 1, as it is known from the prior art. For this purpose, a lamella packet 2, consisting of individually stacked foils 3, is first welded to an end face 4. In particular, this is a TIG welding process. The weld 5 thus produced is subsequently mechanically reworked, in particular ground, and subsequently the end face 4 is applied to an end piece 6. The tail 6 is shown here as a cuboid body with tapered tip 7, wherein in the connection an upper and a lower fillet weld 8 is set to couple the disk set 2 with the end piece 6 cohesively.

In contrast, the welding method according to the invention according to FIG 2 provides that the disk set 2, consisting of the individual sheets 3, is initially packaged externally and then the end face 4 of the disk set 2 with an end face 9 of the end piece 6 are positioned against each other. Then, an electron beam welding is carried out, which generates an electron beam weld seam 10 and essentially couples both end faces 4, 9 with one another in a materially cohesive manner. Consequently, each individual film 3 is also substantially cohesively coupled over its entire width with the end face 9 of the end piece 6. Figure 3 shows an alternative embodiment variant, wherein the end piece 6 here has a respect to its underside 1 1 protruding lip 12 on which the plate pack 2 is placed and then an electron beam welding is performed according to the invention. The resulting electron weld seam 10 can optionally, as shown in Figure 3, not only at the end faces, but also circumferentially formed on the lower lip 12 with.

In addition, Figure 4 shows an alternative embodiment in which the end piece 6 has a lower lip 12 and an upper lip 13, wherein the upper and lower lip 12, 13 are formed in each case opposite the end face 9 of the end piece 6 and thus a Form a receptacle for the disk pack 2. When carrying out the electron beam welding, the electron beam is then passed through the upper lip 13 all the way to the lowermost film 14, so that firstly the end face 4 of the disk pack 2 is welded to the end face 9 of the end piece 6, and secondly the lip 12 first the electron beam is separated and then connected by the welding process with the tail 6 again.

Figure 5 shows an alternative possibility, wherein the plate pack 2 is additionally coupled to the end piece 6 by rivets 15 form-fitting with the plate pack 2. In this case, it is particularly avoided that the disk set 2 is moved away from the end piece 6 in the direction R shown. In the context of the invention, it is particularly provided that the rivet is formed, for example, only in the form of a round rod, which remains plugged in for the time of the joining process and is removed after the joining, so that the full flexibility of the current band is given.

Figure 6a and b show an alternative embodiment to the possibility described in Figure 4, wherein here also an upper lip 13 and a lower lip 12 are formed, wherein between the upper lip 13 and the lower lip 12, the plate pack 2 with its individual films 3 is arranged. In addition, as can be clearly seen in FIG. 6b, a front end 16 of the upper lip 13 has been pressed against the lower lip 12 in such a way that the foils 3 of the disk pack 2 located therebetween are frictionally locked in a receiving position. area 17 are held. Thus, the electrode welding beam process can be performed and the electron beam weld 10 from a surface 18 of the end piece 6 through to the lowest film 14 are introduced. The lower lip prevents, here shown well, a leakage of melting weld metal on the bottom 19 of the tail. 6

Reference numerals:

1 - power band

2 - disc pack

3- slides

4- face to 2

5- weld to 4

6- tail

7 - top

8- fillet weld

9- face to 6

10- electron beam weld

11 - bottom to 6

12 - lip

13- upper lip

14- lowest film

15 rivet

16- front end

17 - Recording area

18- Surface to 6

19- bottom to 6

R direction

Claims

claims

Method for producing a current band (1), wherein the current band (1) has at least one solid end piece (6) to which a flexible plate pack (2) is coupled, characterized by the following method steps:

- Providing an end piece (6) and a disk set (2), wherein the disk pack (2) has at least two superimposed films (3),

- Creating an end face (4) of the disk set (2) on an end face (9) of an end piece (6), wherein between the end faces (4, 9) is a distance of less than 1mm, preferably less than 0.5 mm, and fixing able to each other,

- Electron beam welding of the disk set (2) with the end piece (6), so that each film (3) with its film front side substantially over the entire surface with the end piece (6) is materially coupled.

A method according to claim 1, characterized in that the end piece (6) is provided as a cuboid component, wherein the end piece (6) is in particular formed of a copper alloy.

A method according to claim 1 or 2, characterized in that films (3) are used with a thickness between 0.01 to 3mm, preferably from 0.02 to 2mm, wherein the films (3) are in particular made of a copper alloy.

Method according to one of the preceding claims, characterized in that in the electron beam welding a plate below the resulting electron beam weld (10) is arranged.

Method according to one of the preceding claims, characterized in that the position of disc pack (2) and tail (6) is fixed to each other with an auxiliary device.

6. The method according to any one of the preceding claims, characterized in that the disk set (2) and the end piece (6) are positively fixed and / or non-positively fixed to each other.

7. The method according to any one of the preceding claims, characterized in that the end piece (6) has a lip (12), wherein the lip (12) opposite the end face (9) of the end piece (6) protrudes and the plate pack (2) the lip (12) is placed.

8. The method according to claim 7, characterized in that the lip (12) with the disk pack (2) is positively coupled, in particular via a riveted joint.

9. The method according to any one of the preceding claims, characterized in that the end piece has two lips (12, 13), wherein both lips (12, 13) opposite the end face (9) of the end piece (6) protrude and form a pocket, said the disc pack (2) is placed in the bag.

10. The method according to the preceding claim, characterized in that the disk set (2) between the lips (12, 13) is pressed.

11. The method according to any one of the preceding claims, characterized in that the current band (1) is produced with a thickness between 1mm and 200mm, preferably between 5mm and 100mm and in particular between 10 and 150mm.