阅读说明：本技术 通过两种不同的路径来备选地输送钢带的冷轧机 (Cold rolling mill for alternatively conveying steel strip by two different paths ) 是由 R·凯勒梅耶 K·克里姆派尔斯泰特尔 A·斯塔德尔鲍尔 于 2020-04-15 设计创作，主要内容包括：在冷轧机的至少一个轧制机架(1)中,先后对第一钢带和第二钢带(7)进行轧制。在对所述第一与第二钢带(7)进行的轧制的之间存在轧制停顿,在所述轧制停顿内不对钢带进行轧制。所述第一钢带以第一开卷机(2)为出发点通过第一路径输送给所述轧制机架(1),所述第二钢带(7)以所述第一开卷机(2)或者不同于所述第一开卷机(2)的第二开卷机为出发点通过第二路径输送给所述轧制机架(1)。在输送到所述轧制机架(1)的期间,不对所述第一钢带进行加热,但是对所述第二钢带(7)进行加热。所述第二路径比所述第一路径长。(In at least one rolling stand (1) of a cold rolling mill, a first steel strip and a second steel strip (7) are rolled one after the other. Between the rolling of the first and second steel strip (7) there is a rolling pause in which no steel strip is rolled. The first steel strip is fed to the rolling stand (1) via a first path starting from a first uncoiler (2), and the second steel strip (7) is fed to the rolling stand (1) via a second path starting from the first uncoiler (2) or a second uncoiler different from the first uncoiler (2). During the transfer to the rolling stand (1), the first steel strip is not heated, but the second steel strip (7) is heated. The second path is longer than the first path.)

1. A method for operating a cold-rolling mill,

-wherein a first steel strip (3) and a second steel strip (7) are rolled in at least one rolling stand (1) of the cold rolling mill,

-wherein there is a rolling pause between the rolling of the first steel strip (3) and the rolling of the second steel strip (7) during which no rolling of the steel strip takes place,

-wherein the first steel strip (3) is transported to the rolling stand (1) through a first path starting from a first uncoiler (2) and is not heated during the transport to the rolling stand (1),

-wherein the second steel strip (7) is transported to the rolling stand (1) through a second path starting from the first uncoiler (3) or a second uncoiler (15) different from the first uncoiler (3) and is heated during the transport to the rolling stand (1),

-wherein the second path is longer than the first path.

2. The method of operation of claim 1,

it is characterized in that the preparation method is characterized in that,

the second steel strip (7) is heated by means of an induction heating device (6).

3. The operating method according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

-moving the second steel strip (7) first towards the rolling stand (1) starting from the first or second uncoiler (2, 15), whereas the movement towards the rolling stand (1) is ended before the strip head (9) of the second steel strip (7) reaches the rolling stand (1),

-then adjusting the heating means (6) onto the second steel strip (7) such that the heating means (6) is at a section of the second steel strip (7) that has been uncoiled at this point in time, as seen in the direction of conveyance of the second steel strip (7), and

-only thereafter, the second strip (7) is moved further towards the rolling stand (1) so that the strip head (9) reaches the rolling stand (1) and is gripped by the rolling stand (1).

4. The method of operation of claim 3,

it is characterized in that the preparation method is characterized in that,

between the setting of the heating means (6) on the second steel strip (7) and the subsequent further transfer of the second steel strip (7) to the rolling stand (1), the second steel strip (7) is transferred off the rolling stand (1) by a length such that the strip head (9) of the second steel strip (7) stops at the outlet of the heating means (6).

5. A cold-rolling mill,

-wherein the cold rolling mill has a rolling stand (1) by means of which the first steel strip (3) is rolled immediately after unwinding the first steel strip (3) from a first unwinder (2) and the second steel strip (7) is rolled immediately after unwinding the second steel strip (7) from the first unwinder (3) or a second unwinder (15) different from the first unwinder (3),

-wherein the cold-rolling mill has a first path by means of which the first steel strip (3) can be fed to the rolling stand (1) starting from the first uncoiler (2),

-wherein no heating means are arranged in the first path that can be used to heat the first steel strip (3) in order to transport the first steel strip (3) to the rolling stand (1) at the temperature the first steel strip (3) has when uncoiled from a first uncoiler (2),

-wherein the cold-rolling mill has a second path by means of which the second steel strip (7) can be fed to the rolling stand (1) starting from the first or second uncoiler (2, 15),

-wherein in the second path a heating mechanism (6) is arranged by means of which the second steel strip (7) can be heated in order to feed the second steel strip (7) to the rolling stand (1) at a temperature that is increased with respect to the temperature that the second steel strip (7) has when uncoiled from the first or second uncoiler (2, 15), and

-wherein the second path is longer than the first path.

6. The cold-rolling mill according to claim 5,

it is characterized in that the preparation method is characterized in that,

-unwinding said second steel strip (7) from said first unwinder (2),

-said first unwinder (2) is arranged on a movable platform (8) that can be positioned at least at a first position and at a second position, wherein said first unwinder (2) is arranged closer to said rolling stand (1) in the first position of said platform (8) than in the second position of said platform (8), such that said first path extends from said first unwinder (2) to said rolling stand (1) when said platform (8) is in said first position and said second path extends from said first unwinder (2) to said rolling stand (1) when said platform (8) is in said second position, and

-the heating means (6) can be adjusted onto the second steel strip (7) parallel to the second steel strip (7), but transverse to the direction of transport of the second steel strip (7) from the first uncoiler (2) to the rolling stand (1), or can be adjusted onto the second steel strip (7) orthogonal to the second steel strip (7), at least if the movable platform (8) is in the second position.

7. The cold-rolling mill according to claim 5,

it is characterized in that the preparation method is characterized in that,

-unwinding said second steel strip (7) from said first unwinder (2),

-a loop pick (12) is arranged between the first uncoiler (2) and the rolling stand (1), which loop pick is passed without offset by the first steel strip (3) in a first position of the loop pick (12) and is passed by the second steel strip (7) with loop formation in a second position of the loop pick (12) such that the first path extends from the first uncoiler (2) to the rolling stand (1) without loop formation and the second path extends from the first uncoiler (2) to the rolling stand (1) with loop formation,

-the heating means (6) can be adjusted onto the second steel strip (7) in the region of the loop parallel to the second steel strip (7) but transverse to the transport direction of the second steel strip (7) in the region of the loop, at least if the loop tongue (12) is in the second position.

8. The cold-rolling mill according to claim 5,

it is characterized in that the preparation method is characterized in that,

-unwinding said second steel strip (7) from said second unwinder (15),

-a transmission mechanism (18) is arranged in front of the rolling stand (1) such that the first path extends from the first uncoiler (2) to the rolling stand (1) via the transmission mechanism (18) and the second path extends from the second uncoiler (15) to the rolling stand (1) via the transmission mechanism (18), and

-said heating means (6) are arranged between said second unwinder (15) and said transmission means (18).

9. The cold-rolling mill according to claim 8,

it is characterized in that the preparation method is characterized in that,

the heating device (6) can be adjusted parallel to the second steel strip (7) but transversely to the direction of transport of the second steel strip (7) from a second uncoiler (15) to a drive (18) onto the second steel strip (7) or can be adjusted orthogonally to the second steel strip (7) onto the second steel strip (7).

10. The cold rolling mill according to any one of claims 5 to 9,

it is characterized in that the preparation method is characterized in that,

the heating device (6) is designed as an induction heating device.

Technical Field

The invention relates to a method for operating a cold-rolling mill,

-wherein a first steel strip and a second steel strip are rolled in at least one rolling stand of the cold rolling mill,

-wherein there is a rolling pause between the rolling of the first steel strip and the rolling of the second steel strip, during which no rolling of the steel strip takes place,

-wherein the first steel strip is transported to the rolling stand through a first path starting from a first uncoiler and is not heated during the transport to the rolling stand,

-wherein the second steel strip is transported to the rolling stand through a second path starting from the first uncoiler.

Furthermore, the invention relates to a cold-rolling mill,

-wherein the cold rolling mill has a rolling stand by means of which the first steel strip is rolled immediately after being uncoiled from a first uncoiler and the second steel strip is rolled immediately after being uncoiled from the first uncoiler,

-wherein the cold-rolling mill has a first path via which the first steel strip can be fed to the rolling stand starting from the first uncoiler,

-wherein no heating means are arranged in the first path that can be used to heat the first steel strip in order to deliver the first steel strip to the rolling stand at the temperature the first steel strip has when uncoiled from a first uncoiler,

-wherein the cold-rolling mill has a second path by means of which the second steel strip can be fed to the rolling stand starting from the first uncoiler.

Background

Electrical steel sheets are relatively thin steel sheets which, in particular for improving the magnetic properties, can contain a relatively high proportion of silicon. In the production of such sheets, there is a risk of strip breakage during cold rolling. The strip breakage is a consequence of possible edge cracking during cold rolling. The brittleness and fragility of the not yet rolled steel strip in cold rolling, together with the load to which the steel strip is subjected during cold rolling, are responsible for the edge cracking.

The brittleness and the fragility of steel sheets with a high proportion of silicon (or also of aluminum) depend strongly on the temperature of the steel strip during cold rolling. It is known in particular that higher temperatures lead to a significant reduction in brittleness and thus to a reduction in the risk of a belt breakage.

During cold rolling, the temperature of the strip increases due to the forming work added to the strip. However, in the first rolling pass of the cold rolling, the temperature of the steel strip usually corresponds only to ambient temperature, i.e. typically to about 20 ℃.

In Continuous Tandem rolling Mill trains (for example, in the form of PLTCM or CTCM Continuous Tandem Cold rolling), it is known to arrange a strip heating device in the form of an induction heating device in the region upstream of the first rolling Mill of the Continuous Tandem rolling Mill train. The temperature of the steel strip is increased by means of the strip heating means, for example to a temperature in the range of about 80 ℃ to about 160 ℃. This significantly reduces the brittleness of the steel strip, so that the risk of a strip break is significantly less. In addition, rolling can be performed at a higher rolling speed, thereby improving the productivity of the continuous tandem mill train.

The induction heating means require a considerable amount of installation space. However, due to the plant layout of the continuous tandem rolling train, it is generally possible without any problem to arrange the respective induction heating means before the first roll stand of the continuous tandem rolling train.

In contrast, such installation space is often not available for discontinuous tandem cold rolling trains or cold rolling reversing stands. In particular, these systems are usually very compact in order to keep the offset length (that is to say the length of the strip which lies outside the desired tolerances in the head and tail regions of the cold-rolled strip and which therefore has to be converted into scrap) as small as possible.

Although it is conceivable to provide such an induction heating in the feed region also in a discontinuous tandem cold rolling train or in a cold-rolling reversing stand. However, this would require that an uncoiler from which the steel strip is uncoiled prior to the first rolling pass of the cold rolling be arranged correspondingly remote from the rolling stand performing the first rolling pass of the cold rolling. In addition to the retrofitting effort, this can therefore result in a corresponding enlargement of the offset length of all cold-rolled strips, i.e. strips which can be cold-rolled without prior heating, and thus in a reduction of the yield and an increase in the amount of scrap produced.

Disclosure of Invention

The object of the present invention is to provide a possibility by means of which brittle and fragile steel strips can be rolled in a discontinuous cold rolling mill without the risk of strip breakage or at least with a significantly reduced risk of strip breakage, and the offset length can still be kept small, at least for steel strips which are less prone to strip breakage without prior heating.

This object is achieved by an operating method for a cold-rolling mill having the features of claim 1. Advantageous embodiments of the operating method are the subject matter of the dependent claims 2 to 4.

According to the invention, the second steel strip is heated during the transport to the rolling stand, wherein the second path is longer than the first path. The second steel strip is uncoiled from the uncoiler, which can be the first uncoiler. Alternatively, the unwinder can be a second unwinder different from the first unwinder.

Preferably, the second steel strip is heated by means of an induction heating device. Such heating is simple, efficient, low cost, reliable and durable.

Provision is preferably made for:

-moving the second steel strip first towards a rolling stand starting from the first or second uncoiler, but ending the movement towards the rolling stand before the head of the second steel strip reaches the rolling stand,

the heating device is then adjusted to the second steel strip such that, as seen in the direction of conveyance of the second steel strip, it is located in a section of the second steel strip that has been uncoiled at this point in time, and

only then does the second strip continue to be transferred to the rolling stand so that the strip head reaches the rolling stand and is gripped by the rolling stand.

The threading of the second steel strip can thus be achieved in a simple manner without the heating means being damaged by the second steel strip.

The second steel strip is preferably transferred away from the rolling stand by a length between the setting of the heating means onto the second steel strip and the subsequent continuation of the transfer of the second steel strip towards the rolling stand, so that the strip head of the second steel strip stops at the outlet of the heating means. The entire second steel strip can thereby be preheated, so that the starting region of the second steel strip immediately adjacent to the strip head is already rolled in the preheated state.

Furthermore, the object is achieved by a cold-rolling mill having the features of claim 5. Advantageous embodiments of the cold rolling mill are the subject matter of the dependent claims 6 to 10.

According to the invention, a cold-rolling mill of the type mentioned at the outset is designed in such a way that:

in the second path, a heating device is arranged, by means of which the second steel strip can be heated in order to be fed to the rolling stands at a temperature which is increased relative to the temperature which the second steel strip has when uncoiled from the first or second uncoiler stand, and

-the second path is longer than the first path.

Similarly to the operating method for the cold-rolling mill, as an alternative, the second steel strip is unwound from an unwinder, which can be the first unwinder or a second unwinder different from the first unwinder.

In a first possible embodiment of the cold-rolling mill it is provided that,

-unwinding the second steel strip from the first unwinder,

-the first unwinder is arranged on a movable platform, which platform can be positioned at least at a first position and at a second position, wherein the first unwinder is arranged closer to the rolling stand in the first position of the platform than in the second position of the platform, such that the first path extends from the first unwinder to the rolling stand when the platform is in the first position and the second path extends from the first unwinder to the rolling stand when the platform is in the second position, and

-the heating mechanism is adjustable parallel to the second steel strip, but transverse to its direction of transport from the first unwinder to the rolling stand, or orthogonal to the second steel strip, onto the second steel strip, at least if the movable platform is in the second position.

As an alternative, it is possible that,

-unwinding the second steel strip from the first unwinder,

-a loop pick is arranged between the first unwinder and the rolling stand, which loop pick in its first position is passed through by the first steel strip without offset and in its second position is passed through by the second steel strip with loop formation, so that the first path extends from the first unwinder to the rolling stand without loop formation and the second path extends from the first unwinder to the rolling stand with loop formation,

at least if the loop take-up is in the second position, the heating means can be adjusted to the second steel strip in the region of the loop parallel to the second steel strip, but transversely to the transport direction of the second steel strip in the region of the loop.

As an alternative, it is possible that,

-unwinding the second steel strip from the second unwinder,

-a transmission is arranged in front of the rolling stand such that the first path extends from the first unwinder to the rolling stand via the transmission and the second path extends from the second unwinder to the rolling stand via the transmission, and

-the heating mechanism is arranged between the second unwinder and the transmission mechanism.

In the case of the last-mentioned embodiment, the heating device can preferably be adjusted parallel to the second steel strip, but transversely to the direction of transport of the second steel strip from the second uncoiler to the drive, or can be adjusted orthogonally to the second steel strip.

The heating device is preferably designed as an induction heating device, without being dependent on the remaining design of the cold-rolling mill. This design of the heating mechanism is simple, effective, low cost, reliable and durable.

Drawings

The above features, characteristics and advantages of the present invention and the manner and method of how to achieve them will become more apparent in conjunction with the following description of embodiments that are further set forth in conjunction with the accompanying drawings. Here, in the schematic view:

figure 1 shows the situation of a cold rolling mill during rolling of a first steel strip,

figure 2 shows the situation of the cold-rolling mill of figure 1 during a rolling pause between the rolling of the first steel strip and the rolling of the second steel strip,

figure 3 shows the situation of the cold-rolling mill of figure 1 during rolling of the second steel strip,

figure 4 shows the situation during rolling of the first strip in another cold rolling mill,

figure 5 shows the situation of the cold-rolling mill of figure 4 during a rolling pause between the rolling of the first strip and the rolling of the second strip,

figure 6 shows the situation of the cold-rolling mill of figure 4 during rolling of the second steel strip,

figure 7 shows the situation during rolling of the first strip in another cold rolling mill,

FIG. 8 shows the cold rolling mill of FIG. 7 during a rolling pause between the rolling of the first steel strip and the rolling of the second steel strip, and

fig. 9 shows the cold rolling mill of fig. 7 during rolling of the second steel strip.

Detailed Description

A first embodiment of the present invention will be explained first with reference to fig. 1 to 3.

According to fig. 1, a cold-rolling mill has a rolling stand 1 and a first uncoiler 2. The first steel strip 3 is uncoiled by means of said first uncoiler 2. The first steel strip 3 is fed to the rolling stand 1 via a first path starting from a first uncoiler 2 and is cold-rolled in the rolling stand 1 immediately after uncoiling. The term "immediately after uncoiling" is intended to mean that no further rolling passes take place between the uncoiling of the first steel strip 3 and the rolling pass performed by the rolling stand 1. The rolling pass performed by the rolling stand 1 is thus the first rolling pass of the cold rolling. However, other mechanisms can also be present, which pass through the first steel strip 3 between unwinding from the first unwinder 2 and reaching the rolling stand 1. An example of such a mechanism is according to the illustration in fig. 1 a turning roll pair 4 and a straightening drive 5.

It is possible that the rolling stand 1 is the only rolling stand of the cold rolling mill. In this case, the steel strip 3 is usually rolled in a reversible manner in the rolling stand 1. As an alternative, further rolling stands not shown in fig. 1 can be arranged after the rolling stand 1. Whether one embodiment or another is implemented is of secondary significance within the scope of the invention. Since within the scope of the invention it is important that the first rolling pass of the cold rolling is the first pass.

On the way from the first unwinder 2 to the rolling stand 1, i.e. during the transfer to the rolling stand 1, said first strip 3 is not heated. For this reason, the heating means 6 (see fig. 2 and 3) which is still to be introduced later is also not shown in fig. 1. In particular, the heating means is not arranged in the first path in this operating phase of the cold-rolling mill. Therefore, the first steel strip 3 is fed to the rolling stand 1 at the temperature at which the first steel strip 3 has when being unwound from the first unwinder 2.

After rolling the first steel strip 3, a mostly relatively short rolling pause first occurs. During the rolling stand pause, according to the illustration in fig. 2, no strip is rolled in the rolling stand 1, i.e. neither the first strip 3 nor the second strip 7 is rolled (see fig. 3). However, the second steel strip 7 is rolled after the rolling stops. The corresponding state of the cold-rolling mill is shown in fig. 3.

For cold rolling the second steel strip 7, the second steel strip 7 is likewise unwound from the first unwinder 2 and is then fed to the rolling stand 1. However, the transport takes place through a second path starting from the first unwinder 2. The second steel strip 7 is also cold rolled in the rolling stand 1 immediately after uncoiling. The concept "immediately after uncoiling" shall mean, as already mentioned, that no further rolling passes are performed between the uncoiling of the second steel strip 7 and the rolling passes performed by the rolling stand 1. The rolling pass performed by the rolling stand 1 is therefore the first rolling pass of the cold rolling. However, it is also possible that other mechanisms are present, which pass through by the second steel strip 7 between unwinding from the first unwinder 2 and reaching the rolling stand 1. Examples of such mechanisms are as before the turning roll pair 4 and the straightening drive 5.

Unlike the first steel strip 3, however, the second steel strip 7 is heated on its way from the first uncoiler 2 to the rolling stand 1, i.e. during the transport to the rolling stand 1. For this reason, the heating mechanism 6 is arranged in the second path. Therefore, the second steel strip 7 is fed to the rolling stand 1 at a temperature that is increased with respect to the temperature that the second steel strip 7 has when being unwound from the first unwinder 2.

In order to provide the necessary space for the heating means 6, the first unwinder 2 is arranged on a movable platform 8 within the scope of the design of fig. 1 to 3. For example, the movable platform 8 can be on a track (not shown). The movable platform 8 can be positioned in a first position (shown in dashed lines on the right in fig. 1, 2) and in a second position (shown in solid lines on the left in fig. 2 and in fig. 3). Thus, in the first position of said platform 8, said first unwinder 2 is arranged closer to the rolling stand 1 than in the second position of the platform 8. Thus, although the second path extends from the first unwinder 2 to the rolling stand 1 just as the first path. However, since said first unwinder 2 is more distant from the rolling stand 1 in the second position of the platform 8 than in the first position of the platform 8, said second path is longer than said first path.

In the scope of the embodiment according to fig. 1 to 3, the heating device 6 can be adjusted from the parked position onto the second steel strip 7. The adjustment is preferably carried out in a direction which runs parallel to the second steel strip 7 but is oriented transversely to the conveying direction. The direction of transport is the direction along which the second steel strip 7 is transported from the first uncoiler 2 to the rolling stand 1. Alternatively, it is possible to adjust the heating device 6 from above and/or below onto the second steel strip 7.

The heating mechanism 6 can be configured as needed. Preferably it is configured as an induction heating mechanism.

In individual cases it is possible that the heating device 6 can be adjusted to the second steel strip 7 independently of whether the movable platform 8 is in the first position or in the second position. However, at least a corresponding adjustability occurs when the movable platform 8 is in the second position.

For rolling the second steel strip 7, the second steel strip 7 is first transferred to the rolling stand 1 starting from the first uncoiler 2, as shown in fig. 3. However, the transfer to the rolling stand 1 is ended before the strip head 9 of the second steel strip 7 reaches the rolling stand 1. For example, when the tape head 9 reaches a position indicated by a in fig. 2, the transfer can be terminated. After stopping the second steel strip 7, the heating device 6 is then adjusted to the second steel strip 7. The heating means 6 are therefore located after the adjustment, viewed in the direction of transport of the second steel strip 7, at the section of the second steel strip 7 which has been unwound at this point in time. For example, in a corresponding embodiment, the heating means 6 can surround the section. The transfer of the second steel strip 7 to the rolling stand 1 is continued only after the heating means 6 has been adjusted to the second steel strip 7. This transfer continues until the strip head 9 reaches the rolling stand 1 and is gripped by the rolling stand 1. After this, the rolling of the second steel strip 7 is started.

Preferably, no further transfer to the rolling stand 1 takes place immediately after the adjustment of the heating means 6 to the second steel strip 7. Instead, the second steel strip 7 is preferably first removed from the rolling stand 1 by a length. The transfer is preferably carried out in such a way that the strip head 9 of the second steel strip 7 stops at the outlet of the heating device 6, i.e. approximately at the point marked B in fig. 2.

Furthermore, it is possible, according to the illustration in fig. 2, to arrange a shear 10 between two points a and B. In this case, the tape head 9 can be cut before being transferred away. Furthermore, between the two regions denoted a and B, if the shear 10 is present, a pressure roller 11 is arranged between the shear and the region denoted a. The pressure rollers 11 can be adjusted to the second steel strip 7, for example, by deflection. By means of the pressure rollers 11, it is possible in particular to position the second steel strip 7 precisely when the heating device 6 is adjusted. In this way, a particularly possible slipping (that is to say an upwardly bent strip head 9) can be suppressed during the adjustment of the heating means 6 onto the second steel strip 7. The risk of damage to the heating means 6 is thereby significantly reduced. The same applies to the case where the second steel strip 7 should have large unevenness.

Now, a second embodiment of the present invention will be explained with reference to fig. 4 to 6.

According to fig. 4, the cold-rolling mill has a rolling stand 1 and a first uncoiler 2 as before. The first steel strip 3 is uncoiled by means of said first uncoiler 2. The first steel strip 3 is fed to the rolling stand 1 via a first path starting from a first uncoiler 2 and is cold-rolled in the rolling stand 1 immediately after the uncoiling. The term "immediately after the uncoiling" is to be understood as meaning, as before, that no further rolling passes are carried out between the uncoiling of the first steel strip 3 and the rolling passes carried out by the rolling stand 1.

As before, it is possible that the rolling stand 1 is the only rolling stand of a cold rolling mill. As an alternative, further rolling stands not shown in fig. 4 can be arranged after the rolling stand 1.

In the path from the first uncoiler 2 to the rolling stand 1, i.e. during the transport to the rolling stand 1, the first steel strip 3 is not heated as before. For this reason, the heating mechanism 6 (refer to fig. 5 and 6) is not shown in fig. 4. In particular, the heating means is not arranged in the first path in this operating phase of the cold-rolling mill. As described above, the first steel strip 3 is thereby fed to the rolling stand 1 at the temperature at which the first steel strip 3 is uncoiled from the first uncoiler 2.

After the rolling of the first steel strip 3, as before, a mostly relatively short rolling pause first occurs. During the rolling stand pause, according to fig. 5, no strip is rolled in the rolling stand 1, i.e. neither the first strip 3 nor the second strip 7 is rolled (see fig. 6). However, the second steel strip 7 is rolled after the rolling stops. The corresponding state of the cold-rolling mill is shown in fig. 6.

For cold rolling the second steel strip 7, the second steel strip 7 is likewise unwound from the first unwinder 2 as before and is then fed to the rolling stand 1. The transport takes place through a second path starting from the first unwinder 2. The second steel strip 7 is also cold rolled in the rolling stand 1 immediately after the uncoiling. The term "immediately after the uncoiling" is to be understood as meaning, as before, that no further rolling passes are carried out between the uncoiling of the second steel strip 7 and the rolling passes performed by the rolling stand 1. The rolling pass performed by the rolling stand 1 is therefore the first rolling pass of the cold rolling.

Unlike the first steel strip 3, however, the second steel strip 7 is heated as before on the way from the first uncoiler 2 to the rolling stand 1, i.e. during the transport to the rolling stand 1. For this reason, the heating mechanism 6 is arranged in the second path. The second steel strip 7 is therefore fed to the rolling stand 1 at a temperature that is raised with respect to the temperature that the second steel strip 7 has when being unwound from the first unwinder 2.

In order to provide the necessary spatial position for the heating device 6, a loop take-off 12 is arranged between the first uncoiler 2 and the rolling stand 1 within the scope of the design of fig. 4 to 6. The loop bar 12 is positionable in at least a first position (fig. 4, 5) and a second position (fig. 6). In the first position, the loop tongue 12 is passed through by the first steel strip 3 without deflection and thus also without forming a loop. In the second position, the loop tongue 12 is penetrated by the second steel strip 7 forming a loop. Thus, the second path is longer than the first path.

Within the scope of the embodiments according to fig. 4 to 6, the heating device 6 can be adjusted from the parked position onto the second steel strip 7. The adjustment is preferably carried out in a direction which runs parallel to the second steel strip 7 but is oriented transversely to the (local) transport direction of the second steel strip 7. The direction of transport is the direction along which the second steel strip 7 is (locally) delivered from the first uncoiler 2 to the rolling stand 1. In particular, the second steel strip 7 can be transported substantially vertically in the region of the loop, as shown in fig. 6, and the heating means 6 can be adjusted substantially horizontally and parallel to the width direction of the second steel strip 7 onto the second steel strip 7 in the region of the loop.

The heating mechanism 6 can be configured as needed. Preferably it is configured as an induction heating mechanism.

In the context of the design of the cold-rolling mill according to fig. 4 to 6, the heating means 6 can be adjusted at least to the second steel strip 7 if the loop bar 12 is in the second position. Usually, even then only such adjustability is produced.

For rolling the second steel strip 7, the second steel strip 7 is first transferred to the rolling stand 1 starting from the first uncoiler 2, as shown in fig. 6. However, the transfer to the rolling stand 1 is ended before the strip head 9 of the second steel strip 7 reaches the rolling stand 1. For example, when the tape head 9 reaches a position indicated by a in fig. 5, the transfer can be terminated. Shortly before this point, there is usually a drive 13 which drives the second steel strip 7 (and also the first steel strip 3). When the leader 9 of the second steel strip 7 reaches the drive 13, the loop bar 12 is normally still in the first position. After the drive mechanism 13 has gripped the belt head 9, the loop tab 12 is transferred from the first position into the second position. In this case, the second steel strip 7 is uncoiled to the extent necessary for forming the loop. When the looper 12 reaches the second position, the heating device 6 is then adjusted to the second steel strip 7. The heating means 6 are thus situated, after the adjustment, at the section of the second steel strip 7 that has been uncoiled at this point in time, viewed in the direction of transport of the second steel strip 7. Only after the heating means 6 have been adjusted to the second steel strip 7 does the second steel strip 7 continue to be moved towards the rolling stand 1. This transfer continues until the strip head 9 reaches the rolling stand 1 and is gripped by the rolling stand 1. After this, the rolling of the second steel strip 7 is started.

Furthermore, according to the illustration in fig. 5, it is possible to arrange a shear 14 between the transmission 13 and the rolling stand 1. In this case, the strip head 9 can be truncated before being fed to the rolling stand 1.

Now, a third embodiment of the present invention will be explained with reference to fig. 7 to 9.

According to fig. 7, the cold-rolling mill has a rolling stand 1 and a first uncoiler 2 as before. The first steel strip 3 is uncoiled by means of said first uncoiler 2. The first steel strip 3 is fed to the rolling stand 1 via a first path starting from a first uncoiler 2 and is cold-rolled in the rolling stand 1 immediately after the uncoiling. The term "immediately after the uncoiling" is to be understood as meaning, as before, that no further rolling passes are carried out between the uncoiling of the first steel strip 3 and the rolling passes performed by the rolling stand 1. However, according to the illustrations in fig. 7 to 9, it is possible that there are other mechanisms which are crossed by the first steel strip 3 between unwinding from the first unwinder 2 and reaching the rolling stand 1. Examples of such mechanisms are, in analogy to the embodiments according to fig. 1 to 3, a deflecting roller pair 4 and a straightening drive 5.

As also before, it is possible that the rolling stand 1 is the only rolling stand of a cold rolling mill. Alternatively, a further rolling stand not shown in fig. 7 can be arranged after the rolling stand 1.

In the path from the first uncoiler 2 to the rolling stand 1, i.e. during the transport to the rolling stand 1, the first steel strip 3 is not heated as before. As described above, the first steel strip 3 is thereby fed to the rolling stand 1 at the temperature at which the first steel strip 3 is uncoiled from the first uncoiler 2.

After the rolling of the first steel strip 3, as before, a mostly relatively short rolling pause first occurs. The corresponding state is shown in fig. 8. During the rolling stand 1, no rolling strip, i.e. neither the first strip 3 nor the second strip 7, is being rolled (see fig. 9). After the rolling pause, however, the second steel strip 7 is rolled according to the representation in fig. 9.

For cold rolling the second steel strip 7, the second steel strip 7 is unwound from a second unwinder 15 and is then fed to the rolling stand 1. The second unwinder 15 is an unwinder different from the first unwinder 2. The transport takes place through a second path starting from a second unwinder 15. The second steel strip 7 is also cold rolled in the rolling stand 1 immediately after the uncoiling. The term "immediately after the uncoiling" is to be understood as meaning, as before, that no further rolling passes are carried out between the uncoiling of the second steel strip 7 and the rolling passes performed by the rolling stand 1. The rolling pass performed by the rolling stand 1 is thus the first rolling pass of the cold rolling. However, according to the illustrations in fig. 7 to 9, it is possible that there are other mechanisms which pass by the second steel strip 7 between unwinding from the second unwinder 15 and reaching the rolling stand 1. An example of such a mechanism is a turning roll pair 16 and a straightening drive 17 according to the illustrations in fig. 7 to 9.

In contrast to the first steel strip 3, the second steel strip 7 is heated as before on the way from the second uncoiler 15 to the rolling stand 1, i.e. during the transport to the rolling stand 1. For this reason, the heating mechanism 6 is arranged in the second path. The second steel strip 7 is thus fed to the rolling stand 1 at a temperature that is increased with respect to the temperature that the second steel strip 7 has when being unwound from the second unwinder 15.

In order to be able to feed the first steel strip 3 to the rolling stand 1 both from the first uncoiler 2 and from the second uncoiler 15, a gear mechanism 18 is arranged upstream of the rolling stand 1. Thereby, two paths extend from the respective unwinders 2, 15 to the rolling stand 1 via the transmission 18.

In order to be able to keep the distance between the first uncoiler 2 and the rolling stand 1 as small as possible, the heating device 6 is also arranged between the second uncoiler 15 and the gear 18 within the scope of the embodiments of fig. 7 to 9. In addition, due to the presence of the heating means 6, the distance between the second unwinder 15 and the transmission means 18 is greater than the distance between the first unwinder 2 and the transmission means 18. Therefore, said second path (that is to say the path from the second unwinder 15 to the rolling stand 1) is also greater than said first path (that is to say the path from the first unwinder 2 to the rolling stand 1).

In the scope of the embodiments according to fig. 7 to 9, it is possible for the heating means 6 to be arranged stationary. However, it is preferred in this embodiment that the heating device 6 can also be adjusted from the parking position onto the second steel strip 7. The adjustment is preferably carried out in a direction which runs parallel to the second steel strip 7 but is oriented transversely to the (local) transport direction of the second steel strip 7. The direction of transport is the direction in which the second steel strip 7 is transported locally in the region of the heating device 6 from the second uncoiler 15 to the drive 18.

The heating mechanism 6 may be configured as necessary. Preferably it is configured as an induction heating mechanism.

For rolling the second steel strip 7, the second steel strip 7 is first transferred to the rolling stand 1 starting from the second uncoiler 15, as shown in fig. 9. However, the transfer to the rolling stand 1 is ended before the strip head 9 of the second strip 7 reaches the rolling stand 1. For example, when the tape head 9 reaches a position indicated by a in fig. 8, the transfer can be terminated. Shortly before this point there is usually a pair of deflection rollers 19 which drive the second steel strip 7 (but usually not the first steel strip 3). The deflection roller pair 19 is therefore located before the gear mechanism 18. After the band head 9 has been gripped by the deflecting roller pair 19, the band head 9 can be trimmed, if necessary, by means of a shear (not shown) shortly before or shortly after the deflecting roller pair 19. In this state, the heating means 6 is adjusted to the second steel strip 7 with or without the cutting of the strip head 9 and if necessary before or after the cutting of the strip head 9. As a result, the heating means 6, after the adjustment, are located, as viewed in the direction of transport of the second steel strip 7, at the section of the second steel strip 7 that has been unwound at this point in time. Only after the heating means 6 have been adjusted to the second steel strip 7 does the second steel strip 7 continue to be moved towards the rolling stand 1. This transfer continues until the strip head 9 reaches the rolling stand 1 and is gripped by the rolling stand 1. After this, the rolling of the second steel strip 7 is started.

Furthermore, different designs of the above explained principles are possible. In the context of the last-explained embodiment, it is thus possible, for example, to lift the upper roller of the deflecting roller pair 19 from the second steel strip 7 as soon as the second steel strip 7 is gripped by the gear mechanism 18. The upper rollers of the deflecting roller pair 19 can also simultaneously assume the function of pinch rollers. In all embodiments of the invention, the sequence in which the first steel strip 3 and the second steel strip 7 are rolled is furthermore less critical. It is therefore also possible to roll the second steel strip 7 first and then to roll the first steel strip 3 only after the rolling has stopped.

The present invention has many advantages. The steel strip which can be extended in particular in the cold state can therefore be classified as the first steel strip 3 and also rolled with a very small offset length as in the prior art. In contrast, steel strips which are brittle and brittle in the cold state, in particular electrical steel strips, can be classified as second steel strips 7, so that these are heated before rolling in the rolling stand 1. Thus, these strips, although having a greater offset length, can be rolled reliably and without the risk of strip breakage. Since the heating means 6 are adjusted only after the respective second steel strip 7 has been passed through the region in which the heating means 6 are adjusted to the respective second steel strip 7, the heating means 6 are also reliably protected against damage when the respective second steel strip 7 is strongly bent or has a slip. In the case of the embodiments according to fig. 7 to 9, furthermore, a further operation of the cold-rolling mill is possible in the event of failure of one of the two unwinders 2, 15. Furthermore, the invention can also be added to already existing discontinuous cold rolling mills. The costs required for retrofitting a corresponding cold rolling mill are relatively low.

Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variants can be derived therefrom by the person skilled in the art without departing from the scope of protection of the invention.

List of reference numerals:

1 Rolling Mill Stand

2. 15 uncoiler

3. 7 steel belt

4. 16, 19 turning roll pair

5. 17 straightening transmission device

6 heating mechanism

8 Movable platform

9 tape head

10. 14 shearing machine

11 pressure roller

12 loop is chosen

13. 18 drive mechanism

A. And (B) part.