Processing method and equipment for welding metal strips

Abstract

The processing equipment for metal strips (1) includes a welding machine, a strip storage unit arranged downstream of the welding machine, and a processing device arranged downstream of the strip storage unit. Using the welding machine, the metal strips (1) are welded to form an endless strip. The endless strip is stored in the strip storage unit and delivered from the strip storage unit to the processing device. The metal strips (1) are connected through an obliquely extending weld seam. The angle that the weld seam forms with the conveying direction (x) is at least partially different from 90°. To connect the weld seam, the leading strip end (2) and the trailing strip end (3) of the participating metal strips (1) are first slightly rotated, and both strips (1) are connected to each other by forming the weld seam. During welding, the weld seam extends exclusively transverse to the conveying direction (x). Finally, the leading strip end (2) and the trailing strip end (3) of the participating metal strips (1) are rotated back. This results in the weld seam extending obliquely to the conveying direction (x).

Description

[Technical field]

[0001] The invention is based on a method for processing metal strips, - the metal strips are fed one after the other in a strip storage unit of a processing facility for the metal strips in a discontinuous and continuous manner, in each case in a uniform transport direction relative to the metal strips, each metal strip having a leading strip edge, a trailing strip edge, and a fillet portion between the leading strip edge and the trailing strip edge; - each metal strip flows into the strip reservoir first at the leading edge of each strip, then at the fillet portion of each strip, and finally at the trailing edge of each strip; - each leading strip edge has a respective leading edge and each trailing strip edge has a respective trailing edge; - each leading edge is welded to the trailing edge of the respective preceding partially fed metal strip in the strip store by means of a welding machine of the processing facility immediately before each metal strip is fed to the strip store, so that a respective weld seam is formed between the leading edge of each metal strip and the trailing edge of the respective preceding partially fed metal strip; each weld seam, when viewed transversely to the conveying direction, extends from a side edge, extending in the conveying direction, of one of the two metal strips involved to the other side edge of the same metal strip or to a side edge of the other metal strip, the metal strip stored in the strip store, including the welded seams connecting the metal strips, is fed from the strip store continuously or intermittently to a processing device of the processing installation; The processing devices are each fed first with the leading strip end of each metal strip, then with the fillet portion and only thereafter with the trailing strip end. [Background technology]

[0002] The invention is further based on a metal strip processing installation, the processing facility has a strip store, into which the metal strips are fed one after the other in a discontinuous and continuous manner, each in a uniform transport direction relative to the metal strip, each metal strip having a leading strip edge, a trailing strip edge, and a fillet portion between the leading strip edge and the trailing strip edge; - each metal strip flows into the strip reservoir first at the leading edge of each strip, then at the fillet portion of each strip, and finally at the trailing edge of each strip; - each leading strip edge has a respective leading edge and each trailing strip edge has a respective trailing edge; the processing facility has a welding machine arranged upstream of the strip store, by means of which a leading edge of each metal strip is welded to a trailing edge of the respective preceding partially fed metal strip into the strip store just before the respective metal strip is fed into the strip store, so that a welded seam is formed between the leading edge of each metal strip and the trailing edge of the respective preceding partially fed metal strip, each weld seam, when viewed transversely to the conveying direction, extends from a side edge extending in the conveying direction of one of the two metal strips involved to a side edge of the other of the same metal strip or to a side edge of the other metal strip, the metal strip stored in the strip store, including the welded seams connecting the metal strips, is fed from the strip store continuously or intermittently to a processing device of the processing installation; The processing devices are each fed first with the leading strip end of each metal strip, then with the fillet portion and only thereafter with the trailing strip end.

[0003] Such a method for processing metal strips and the associated processing installations are known, for example, from DE 10 200 03 133 A1.

[0004] The metal strip may in particular consist of steel or aluminium, but also other metals and alloys are possible. The processing equipment may comprise a pickling device, a stretch leveller or a rolling mill, in particular a cold rolling mill. A plurality of these components may also be present, in particular all components. If a plurality of components is present, the metal strip passes through them successively, one after the other.

[0005] It is possible for each metal strip to be fed from the unwinder to a strip store, in which it is inserted as a coil and subsequently unwound. If necessary, a further strip store may be arranged between the unwinder and the welding machine. However, neither the unwinder nor the further strip store is necessarily required.

[0006] In many cases, the processing devices for metal strips operate continuously. Continuous operation means in this context that each processing device is supplied with an endless strip, so that each component of the processing device continuously processes a portion of the endless strip. Such an operating mode is known, for example, for pickling devices, stretch levellers and rolling mills (especially cold rolling mills). To produce an endless strip, individual, separate metal strips are joined to one another many times, i.e. the leading strip end of a metal strip is joined to the trailing strip end of a preceding metal strip. The metal strips may consist of the same material (e.g. steel with a uniform chemical composition for the metal strip) or of different materials (e.g. steel with different chemical compositions). The dimensions, i.e. width and thickness of the strips, may also be the same or different from one another.

[0007] The connection of the metal strips is effected through the respective weld seams which are produced by means of a welding machine. During the welding process, the corresponding leading and trailing strip ends are not transported. For this reason, a strip store is arranged between the welding machine and the processing device. In the strip store, variable lengths of the endless strip can be stored and buffered. In particular, the speed at which the endless strip leaves the strip store can be adjusted independently of the speed at which the endless strip enters the strip store. If these speeds differ, the filling of the store will obviously change. Considered over a longer period of time, the entering and leaving speeds must therefore be the same on average, since otherwise the strip store would run empty or overflow. Short-term speed differences can, however, be eliminated by the strip store.

[0008] The corresponding aspects of the processing equipment, welding machines and strip storage units and their modes of operation are generally known to those skilled in the art.

[0009] When the endless strip passes through the processing device, the weld seam also passes through the processing device. The weld seam is often a weak point of the endless strip. In a stretch leveller, for example, there is a risk that the endless strip will break when the weld seam passes through the stretch leveller. In a rolling mill stand, there is a risk to a greater extent that the endless strip will tear while the weld seam passes through the roll gap of the corresponding rolling mill stand. It is possible to reduce this risk by producing a high-quality weld seam. However, a high degree of processing know-how and a high-quality maintenance of the welding machine are required. In particular at the end of a production cycle (e.g. before a maintenance stop), this quality cannot always be fully maintained. Furthermore, it is often necessary to weld materials that are difficult to weld together. In the case of such materials, the risk of the strip breaking is particularly high.

[0010] In order to minimize the risk of strip rupture in the region of the weld seams, especially in rolling mills, the transitions from one metal strip to the other, i.e. the respective weld seam and the regions shortly before and after it, are rolled in a special way, for example with a lower rolling force and less pass reduction. However, due to the different rolling methods, the transitions have different properties than the remaining regions of the metal strip. This can apply both to the geometrical properties (e.g. strip thickness) and also to the mechanical properties (e.g. tensile strength, yield strength and yield point). The corresponding transitions are therefore often unusable and are scrapped.

[0011] From DE 10 200 03 133 A1 it is known to connect two metal strips with a weld seam running obliquely. An angle of 15° to 45° to the longitudinal direction of the metal strip is mentioned. The processing device is a tubular device.

[0012] From DE 10 200 03 13 A1 it is known to connect two metal strips with an obliquely extending weld seam, the angle at which the weld seam extends being selected such that its longitudinal extension is greater than the rolling length during the subsequent rolling process.

[0013] From DE 10 200 03 133 A1 it is known to connect two metal strips with a weld seam. The weld seam can run obliquely or in a zigzag manner. The angle which the weld seam forms with the conveying direction is at least 30°. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] DE 19843282 A1 [Patent Document 2] European Patent Application Publication No. 1260301 [Patent Document 3] US Patent Application Publication No. 2010 / 0051590 [Patent Document 4] Japanese Patent Application Publication No. 07-178417 Summary of the Invention [Problem to be solved by the invention]

[0015] The object of the present invention is to create the possibility of minimizing the risk of strip breakage, while at the same time minimizing the amount of scrap produced, particularly in the rolling process. Furthermore, there should be the possibility of improving conventional welding machines, in which only one weld seam can be produced perpendicular to the conveying direction, so that they are also able to produce an obliquely running weld seam 14. [Means for solving the problem]

[0016] The problem is solved by a method for processing metal strips with the features of claim 1. Advantageous embodiments of the method are the subject of dependent claims 2 to 4.

[0017] According to the invention, a processing method of the type mentioned at the outset is provided, in which a welding machine: - before welding the leading edge of each metal strip to the trailing edge of the metal strip partially fed into the strip reservoir, the leading edge of each metal strip and the trailing edge of the metal strip partially fed into the strip reservoir are lightly rotated; - both strips are then connected to one another by forming a weld seam, which during welding runs exclusively transversely to the transport direction, Finally, the leading strip end of each metal strip and the trailing strip end of the metal strips that have been partially fed into the strip store are rotated back, whereby the welded seam is improved by operating such that it extends obliquely to the conveying direction after rotation of the metal strips welded to one another.

[0018] As a result, each weld seam no longer first enters the processing device at the same time and over its entire width and is not processed at the same time in the processing device, but various parts of each weld seam enter the processing device one after the other in time and are processed in the processing device one after the other. Therefore, only a part of each weld seam is subjected to stresses due to the processing process at any one time. In the case of a rolling process, for example, only the corresponding part of each weld seam is deformed at any one time. The part of each weld seam that is processed at a certain time is surrounded on at least one side, but generally on both sides, by the material of one or the other metal strip. The loads can therefore be absorbed by the one and / or the other metal strip. Only a small part of the load acts directly on each weld seam. The linear stress on each weld seam can therefore be significantly reduced. Furthermore, the magnitude of short-term damage caused by the processing of each weld seam can be significantly reduced by the time extension during the processing of each weld seam. This can increase the stability of the processing process. Finally, the method by which the diagonal weld seam is produced is also applicable to existing standard welding machines.

[0019] Each leading edge is prepared for welding with the end of the preceding metal strip. This can be done in particular by preparing the profile of each leading edge, so that it matches the profile of the trailing edge of each preceding metal strip, which matches the subsequent profile of the respective weld seam. This preparation can be, for example, a cropping with scissors. The strip trailing edge can also be prepared in a similar manner. In many cases, the preparation is done with a laser, which cuts off a small piece of each metal strip at the strip leading edge, so that the leading edge formed by this process is the leading edge of the respective metal strip. The trailing edge of the directly preceding metal strip is also prepared in a similar manner. Generally, immediately before welding, both participating metal strips are moved towards each other, so that they are completely adjacent or at least almost adjacent. During the welding process, the strip leading edge of one metal strip and the strip trailing edge of the other metal strip remain fixed in the welding machine, for example by clamps.

[0020] The welding machine may, for example, be operable to rotate the leading strip end of each metal strip and the trailing strip end of the metal strip that has been partially fed into the strip reservoir such that loops are formed within corresponding regions of the leading strip end of each metal strip and the trailing strip end of the metal strip that has been partially fed into the strip reservoir.

[0021] The processing device is often configured as a rolling mill with at least one rolling mill stand, where the metal strip is rolled to each rolling length in the rolling mill stands of the processing device.

[0022] The concept of "rolling length" is generally known to the person skilled in the art. It describes the area, viewed in the transport direction, that the respective metal strip is rolled during the respective rolling process from its thickness at the inlet side of the respective rolling mill stand to its thickness at the outlet side of the respective rolling mill stand. The longitudinal extension, viewed in the transport direction, that the respective weld seam has before rolling in the respective rolling mill stand is preferably greater than the respective rolling length. In particular, this has the effect that during the rolling of the respective weld seam, the entire weld seam is not subjected to a respective rolling process at any one time.

[0023] Preferably, the angle that each weld seam forms with the transport direction varies from 90° by approximately between 5° and 10°, in particular between 6° and 8°.

[0024] In general, the rolling length in the first rolling process is greater or at least not less than the rolling length in the further rolling processes. The rolling of the metal strip causes the longitudinal extension of the respective weld seam to increase in each rolling process. This therefore necessarily also applies to the further rolling processes insofar as the longitudinal extension of the respective weld seam, seen in the conveying direction, is greater before rolling in the first rolling mill stand than the respective rolling length during rolling in the first rolling mill stand. However, even if this is not the case, i.e. exceptionally, for example, the rolling length during the third rolling process is greater than the rolling length during the first rolling process, this is usually not important. This is explained below using an example in which it is assumed that the processing device is configured as a rolling train with, for example, four rolling mill stands. In such a case, even if the longitudinal extent of each weld seam immediately after its formation is smaller than the length to which the metal strip is rolled, for example, in the second rolling mill stand, it is only necessary to ensure that the elongation of the metal strip by rolling in the first rolling mill stand results in a corresponding increase in the longitudinal extent of each weld seam. The same situation applies with respect to rolling in the third and fourth or further rolling mill stands.

[0025] The problem according to the invention is further solved by an installation for processing metal strips with the features of claim 5. Advantageous embodiments of the installation are the subject of the dependent claims 6 to 8.

[0026] According to the invention, a processing plant of the type mentioned at the outset is provided, in which the welding machine: - before welding the leading edge of each metal strip to the trailing edge of the metal strip partially fed into the strip reservoir, the leading strip edge of each metal strip and the trailing strip edge of the metal strip partially fed into the strip reservoir are lightly rotated, - both strips are then connected to one another by forming a weld seam, which during welding runs exclusively transversely to the transport direction, Finally, an improvement is achieved in that the leading strip end of each metal strip and the trailing end of the metal strip that has been partially fed into the strip store are rotated back, whereby the weld seam is configured to extend obliquely to the conveying direction after rotation of the metal strips welded to one another.

[0027] The term "welding machine configuration" in the present invention is to be understood in a comprehensive manner. The advantages obtained by the inventive configuration of the welding machine correspond to the advantages of the processing method.

[0028] Preferably, the welding machine is configured to rotate the leading strip end of each metal strip and the trailing strip end of the metal strip partially fed into the strip reservoir, such that loops are formed in the corresponding areas of the leading strip end of each metal strip and the trailing strip end of the metal strip partially fed into the strip reservoir. The above statements regarding the processing method are equally valid.

[0029] Preferably, the processing device is configured as a rolling mill having at least one rolling stand.

[0030] Preferably, the angle that each weld seam forms with the transport direction varies from 90° by approximately between 5° and 10°, in particular between 6° and 8°.

[0031] The above-mentioned characteristics, features and advantages of the present invention, as well as the manner in which they are obtained, will become more apparent and more clearly understood in connection with the following detailed description of an embodiment, with reference to the drawings, in which: [Brief description of the drawings]

[0032] [Figure 1] FIG. 2 shows a metal strip. [Diagram 2] 1 shows a metal strip processing installation in different operating states successively in time; [Diagram 3]1 shows a metal strip processing installation in different operating states successively in time; [Figure 4] 1 shows a metal strip processing installation in different operating states successively in time; [Diagram 5] 1 shows a metal strip processing installation in different operating states successively in time; [Figure 6] FIG. [Figure 7] FIG. 2 is a top view showing two metal strips before welding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] According to FIG. 1, the metal strips 1 are elongated, flat, rolled material. The metal strips 1 are transported in a transport direction x - see also the other figures. The front area of ​​each metal strip 1 forms the so-called strip leading edge 2, the rear area forms the so-called strip trailing edge 3. Between these there is a central area of ​​each metal strip 1, the so-called fillet section 4. The exact boundaries between the strip leading edge 2 and the fillet section 4, and between the fillet section 4 and the strip trailing edge 3, shown in FIG. 1 by dashed lines, are of secondary importance. Each strip leading edge 2 ends in a respective leading edge 5, and each strip trailing edge 3 ends in a respective trailing edge 6. Between each leading edge 5 and each trailing edge 6 extend respective side edges 7 of the metal strip 1. The side edges 7 extend parallel to the transport direction x.

[0034] The metal strip 1 is supplemented in the other figures by lower case letters a, b etc., in order to distinguish them from one another where necessary in the description of the invention. The same applies to the different parts and sections of the metal strip 1, such as the strip leading edge 2 and the strip trailing edge 3.

[0035] According to Fig. 2, the processing installation for metal strip 1 comprises a strip store 8. According to the representation in Fig. 2, the strip store 8 comprises, for example, a number of upper rolls 9 and a lower roll 10, the metal strip 1 in the strip store 8 being guided to pass alternately between the upper rolls 9 and the lower rolls 10. The upper rolls 9 can, for example, be arranged stationary and the lower rolls 10 can be lowered relative to the upper rolls 9. Depending on the extent to which the lower rolls 10 are processed, the amount of metal strip 1 stored in the strip store 8 varies.

[0036] The processing installation further comprises a processing device 11. The processing device 11 may be configured as a rolling train with several stands, for example according to the representation in FIG. 1. In this case, cold rolling generally takes place in the rolling train. However, other embodiments of the processing device 11 are also possible, either additionally or alternatively to the rolling train. For example, the processing device 11 may be a pickling device or may comprise a pickling device in addition to the rolling train. In the latter case, the pickling device is arranged upstream of the rolling train. However, regardless of its specific configuration, the processing device 11 is arranged downstream of the strip store 8.

[0037] Finally, the processing installation comprises a welding machine 12. The welding machine 12 is arranged upstream of the strip store 8.

[0038] The processing facility operates as follows.

[0039] At a certain point in time, a certain amount of metal strip 1 is stored in the strip storage 8. For example, in the state shown in FIG. 2, metal strip 1c, strip rear end 3b, and most of fillet portion 4b of metal strip 1b are stored, except for strip rear end 3c. Strip front end 2b of metal strip 1b and metal strip 1a have already left the strip storage 8. Specifically, strip front end 2b of metal strip 1b is still on the way to the processing device 11, and metal strip 1a is already in the processing device 11 or may even have already left the processing device 11.

[0040] The strip rear end 3c of the metal strip 1c is still located in the welding machine 12. The metal strip 1d is to be joined at its strip front end 2d to the strip rear end 3b of the metal strip 1c. For this purpose, the strip front end 2b of the metal strip 1d is fed to the welding machine 12. For this purpose, the metal strip 1d is generally unwound from the reel 13 in an appropriate amount. In particular, the unwounding is performed within a range in which the strip front end 2d of the metal strip 1d moves in the welding machine 12 to a position immediately adjacent to the strip rear end 2c of the metal strip 1c. Thus, according to the representation in FIG. 3, the front edge 5d of the metal strip 1d abuts the rear edge 6c of the metal strip 1c at a very small distance (maximum a few millimeters).

[0041] In this state, the leading edge 5d of the metal strip 1d is welded to the trailing edge 6c of the metal strip 1c by means of the welding machine 12. A weld seam 14 is thus formed between these two edges 5d, 6c. By means of the welding, the metal strip 1d becomes a constituent part of an endless strip which previously only contained the metal strips 1a, 1b and 1c. Figure 4 shows this state. After welding, the strip trailing end 3c of the metal strip 1c and the strip leading end 2d and the fillet portion 4d of the metal strip 1d are fed in the conveying direction x to a strip store 8. The feeding of the metal strip 1d takes place in such a way that the strip trailing end 3d still remains at the welding machine 12. Figure 5 shows the corresponding state.

[0042] As far as the supply of the metal strip 1 to the strip store 8 is concerned, the above-described procedure completes one cycle. This cycle is repeated again and again, i.e. again and again, a new metal strip 1 is welded to the preceding metal strip 1 and supplied to the strip store 8. As a result, the strip store 8 is supplied with metal strips 1 intermittently and continuously, one after the other. Furthermore, as a natural consequence, the conveying direction x is uniform for the metal strips 1, and each metal strip 1 enters the strip store 8 first with its strip leading edge 2, then with its fillet portion 4 and finally with its strip trailing edge 3.

[0043] The supply of the metal strip 1 (or corresponding parts of an endless strip) stored in the strip store 8 to the processing device 11 can take place as required. Intermittent supply is possible in individual cases. Generally, however, it takes place continuously. This is evident from figures 2 to 5.

[0044] In particular, the weld seam 14 is located in a specific position between the metal strips 1a and 1b and between the metal strips 1b and 1c in the state shown in FIG. 2, and the lower roll 10 is also located at a specific height, which also corresponds to the filling level of the strip store 8. As shown in FIG. 3, a time has elapsed before the leading strip end 2d of the metal strip 1d approaches the trailing strip end 3c of the metal strip 1c. During this time, the endless strip is generally still being fed out of the strip store 8 and, in connection with this, the endless strip is being fed into the processing device 11. However, the position of the trailing strip end 3c has not changed with respect to the state shown in FIG. 2. The feeding out of the endless strip from the strip store 8 has therefore reduced the filling level of the strip store 8. Correspondingly, the lower roll 10 has been raised with respect to the state shown in FIG. 2. Furthermore, the position of the weld seam 14 is changed between the metal strips 1a and 1b and between the metal strips 1b and 1c.

[0045] Likewise, time is required for the formation of the weld seam 14 between the metal strips 1c and 1d, as shown in FIG. 4. During this time, the endless strip is still being fed out of the strip store 8 and, in connection with this, the endless strip is being fed into the processing device 11. The position of the strip rear end 3c remains unchanged relative to the state shown in FIG. 3. However, the feeding of the endless strip from the strip store 8 has further reduced the filling level of the strip store 8. Correspondingly, the lower roll 10 has been raised further relative to the state of FIG. 2. Furthermore, the position at which the weld seam 14 is present between the metal strips 1a and 1b and between the metal strips 1b and 1c has changed again relative to the state of FIG. 3.

[0046] A certain time is also required to feed the strip tail 3c of the metal strip 1c and the strip head 2d and the fillet 4d of the metal strip 1d to the strip store 8. The position of the weld seam 14 between the metal strips 1a and 1b and between the metal strips 1b and 1c is therefore again changed. However, the feeding of the strip tail 3c of the metal strip 1c and the strip head 2d and the fillet 4d of the metal strip 1d to the strip store 8 is carried out at a higher speed than the feeding of the endless strip from the strip store 8. The feeding of the strip tail 3c of the metal strip 1c and the strip head 2d and the fillet 4d of the metal strip 1d to the strip store 8 therefore increases the filling degree of the strip store 8, despite the simultaneous feeding of the endless strip from the strip store 8. Correspondingly, the lower roll 10 is lowered with respect to the situation in FIG. 4, generally to a level equal to or at least similar to the level in FIG. 2.

[0047] Similar to the feeding of the metal strip 1 to the strip store 8, it naturally follows that each metal strip 1 is fed into the processing device 11 first by its strip leading edge 2, then by its fillet portion 4 and finally by its strip trailing edge 3.

[0048] In the following, reference will be made to the configuration of the weld seam 14 between the metal strips 1c and 1d in relation to figure 6. However, the corresponding configuration is also applicable 1:1 to the weld seam 14 between the other metal strips 1.

[0049] In general, the metal strips 1c, 1d are arranged centered relative to one another according to FIG. 6. In this case, the weld seam 14 extends from the side edge 7c, 7d of one of the two metal strips 1c, 1d to the side edge 7c, 7d of the other of the same metal strips 1c, 1d, regardless of whether the metal strips 1c, 1d have the same strip width bc, bd or different strip widths bc, bd. This case can also occur in the case of an eccentric connection of the metal strips 1c, 1d. However, in the case of an eccentric connection of the metal strips 1c, 1d, it is possible for the weld seam 14 to extend from the side edge 7c, 7d of one of the two metal strips 1c, 1d to the side edge 7d, 7c of the other metal strip 1d, 1c. However, regardless of whether one or the other case is realized, the angle α which the weld seam 14 forms with the conveying direction x differs at least partially from 90°. The welder 12 is configured and operative to form a weld seam 14 .

[0050] How much the angle α differs from 90° may be determined according to need, for example the deviation from 90° may be between about 5° and 10°, in particular between 6° and 8°.

[0051] As regards the welding process itself and the preparation of the leading edge 5 of the one metal strip 1 and the trailing edge 6 of the other metal strip 1, it is not necessary to go into detail.

[0052] Specifically with regard to the oblique extension of the weld seam 14, it is further possible that the metal strip 1 extends obliquely at an angle α in the welding machine 12 by clamping the corresponding areas of the strip leading edge 2 of one metal strip 1 and the strip trailing edge 3 of the other metal strip 1 and by forming a loop. FIG. 7 shows the metal strip 1 in this state, in which the leading edge 5 of one metal strip 1 and the trailing edge 6 of the other metal strip 1 can be pre-processed in a completely conventional manner. As shown by the dashed lines in FIG. 7, the cut can also be performed orthogonally to the conveying direction x in a similarly conventional manner. The welding can also be performed orthogonally to the conveying direction x in a similarly completely conventional manner. Due to the fact that the strip leading edge 2 of one metal strip 1 and the strip trailing edge 3 of the other metal strip 1 extend obliquely forming the angle α during the welding process, but are again oriented in the conveying direction x after welding (see FIG. 6), after welding the weld seam 14 extends at an angle α.

[0053] The invention has many advantages. In particular, due to the profile of the weld seam 14, the processing device 11 does not act on the weld seam 14 over its entire width at a certain time, but only over a partial area, respectively. As a result, only a partial area of ​​the respective weld seam 14 is processed at any one time. In particular in the stretch leveller and the rolling mill, a change in the processing process for the weld seam 14 is no longer necessary. Out-of-standard lengths that have to be sorted out as scrap can be reduced as a result. The production volume can therefore be increased. The risk of cracks in the strip can be reduced to almost zero. A further positive effect is that the maintenance intervals of the welding machine 12 can be increased, which also makes the maintenance of the welding machine 12 easier. This makes it possible to reduce the downtime of the processing installation, which likewise increases the productivity. Furthermore, it is also possible to improve a conventional welding machine 12 in such a way that the welding machine can extend the weld seam 14 obliquely.

[0054] Although the present invention has been illustrated and described in detail through preferred embodiments, the present invention is not limited to the disclosed examples, and other variations may be derived by those skilled in the art without departing from the scope of protection of the present invention. [Explanation of symbols]

[0055] 1 metal strip 2 Strip tip 3 Strip rear end 4 Fillet section 5 Leading Edge 6 Trailing edge 7 Side edges 8 Strip storage 9 Upper Roll 10 Lower Roll 11 Processing equipment 12 Welding machine 13 Rewinder 14 Welded seams b Strip width x Transport direction α angle

Claims

1. A method for processing a metal strip (1), comprising the steps of: - the metal strips (1) are fed one after the other into a strip store (8) of a processing facility for the metal strips (1) in a uniform conveying direction (x) relative to the metal strips (1), - each of said metal strips (1) has a respective strip leading edge (2), a respective strip trailing edge (3) and a respective fillet portion (4) between said respective strip leading edge (2) and said respective strip trailing edge (3); - each of the metal strips (1) flows into the strip reservoir (8) first at each of the strip leading ends (2), then at each of the fillet portions (4) and finally at each of the strip trailing ends (3); - each of said strip tips (2) has a respective leading edge (5) and each of said strip tips (3) has a respective trailing edge (6); - immediately before each of the metal strips (1) is fed to the strip store (8), each of the leading edges (5) is welded to the trailing edge (6) of the metal strip (1) that has been partially fed to the strip store (8) by means of a welding machine (12) of the processing facility, so that a respective weld seam (14) is formed between the leading edge (5) of each of the metal strips (1) and the trailing edge (6) of the metal strip (1) that has been partially fed to the strip store (8), - each of the weld seams (14), when viewed transversely to the conveying direction (x), extends from a side edge (7) of one of the two metal strips (1) involved, which side edge (7) extends in the conveying direction (x), to the other side edge (7) of the same metal strip (1) or to a side edge (7) of the other metal strip (1), the metal strip (1) stored in the strip store (8), including the welded seams (14) connecting the metal strips (1), is fed from the strip store (8) to a processing device (11) of the processing facility, - in which the processing device (11) is respectively supplied first with the strip leading end (2) of each of the metal strips (1), then with the fillet portion (4) and only thereafter with the strip trailing end (3), The welding machine (12) - before welding the leading edge (5) of each of the metal strips (1) to the trailing edge (6) of the metal strip (1) partially fed to the strip storehouse (8), the leading strip edge (2) of each of the metal strips (1) and the trailing strip edge (3) of the metal strip (1) partially fed to the strip storehouse (8) are rotated through an angle of between 5° and 10°, - then both strips (1) are connected to one another by forming said weld seam (14), which during welding extends exclusively transversely to said transport direction (x); - finally, the leading strip end (2) of each of the metal strips (1) and the trailing strip end (3) of the metal strips (1) partially fed into the strip store (8) are rotated back so that the weld seam (14) extends obliquely to the conveying direction (x) after rotation of the metal strips (1) welded together, the welding machine (12) is operated to rotate the strip leading end (2) of each of the metal strips (1) and the strip trailing end (3) of the metal strips (1) partially fed to the strip storage section (8) so that loops are formed in corresponding areas of the strip leading end (2) of each of the metal strips (1) and the strip trailing end (3) of the metal strips (1) partially fed to the strip storage section (8).

2. 2. The method according to claim 1, characterized in that the processing device (11) is configured as a rolling mill with at least one rolling mill stand, the metal strip (1) is rolled in the rolling mill stands of the processing device (11) to a respective rolling length, and the longitudinal extension of each of the weld seams (14), as viewed in the conveying direction (x), before rolling in each of the rolling mill stands is greater than the respective rolling length.

3. 3. Method according to claim 1 or 2, characterized in that the angle (α) that each of the weld seams (14) forms with the conveying direction (x) is between 80° and 85°.

4. An installation for processing metal strips (1), comprising: the processing installation comprises a strip store (8) into which the metal strips (1) are respectively fed one after the other in a uniform conveying direction (x) relative to the metal strips (1), - each of said metal strips (1) has a respective strip leading edge (2), a respective strip trailing edge (3) and a respective fillet portion (4) between said respective strip leading edge (2) and said respective strip trailing edge (3); - each of said metal strips (1) enters into said strip reservoir (8) first with each of said strip leading ends (2), then with each of said fillet portions (4) and finally with each of said strip trailing ends (3); - each of said strip tips (2) has a respective leading edge (5) and each of said strip tips (3) has a respective trailing edge (6); the processing facility comprises a welding machine (12) arranged upstream of the strip store (8), by means of which the leading edge (5) of each of the metal strips (1) is welded to the trailing edge (6) of the respective previously partially fed metal strip (1) respectively to the strip store (8) immediately before the respective metal strips (1) are fed to the strip store (8), so that a respective weld seam (14) is formed between the leading edge (5) of each of the metal strips (1) and the trailing edge (6) of the respective previously partially fed metal strip (1); - each of the weld seams (14), when viewed transversely to the conveying direction (x), extends from a side edge (7) of one of the two metal strips (1) involved, which side edge (7) extends in the conveying direction (x), to the other side edge (7) of the same metal strip (1) or to a side edge (7) of the other metal strip (1), the metal strip (1) stored in the strip store (8), including the welded seams (14) connecting the metal strips (1), is fed from the strip store (8) to a processing device (11) of the processing facility, in a processing installation in which the processing device (11) is respectively supplied first with the strip leading end (2) of each of the metal strips (1), then with the fillet portion (4) and only thereafter with the strip trailing end (3), The welding machine (12) - before welding the leading edge (5) of each of the metal strips (1) to the trailing edge (6) of the metal strip (1) partially fed to the strip store (8), the leading strip edge (2) of each of the metal strips (1) and the trailing strip edge (3) of the metal strip (1) partially fed to the strip store (8) are rotated through an angle of between 5° and 10°, - then both strips (1) are connected to one another by forming said weld seam (14), which during welding extends exclusively transversely to said transport direction (x), - finally, the leading strip end (2) of each of the metal strips (1) and the trailing strip end (3) of the metal strips (1) partially fed into the strip store (8) are rotated back so that the weld seam (14) extends obliquely to the conveying direction (x) after rotation of the metal strips (1) welded together, the welding machine (12) is configured to rotate the strip leading end (2) of each of the metal strips (1) and the strip trailing end (3) of the metal strip (1) partially fed to the strip storage section (8) so that loops are formed in corresponding areas of the strip leading end (2) of each of the metal strips (1) and the strip trailing end (3) of the metal strip (1) partially fed to the strip storage section (8).

5. 5. The processing installation according to claim 4, characterized in that the processing device (11) is designed as a rolling mill with at least one rolling stand.

6. 6. Processing installation according to claim 4 or 5, characterized in that the angle (α) that each of the weld seams (14) forms with the conveying direction (x) is between 80° and 85°.

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