RU2792915C1 - Cold rolling mill having alternative steel strip feeding in two different paths - Google Patents

Abstract

FIELD: steel strip rolling.

SUBSTANCE: first steel strip and the second steel strip are rolled in one rolling stand of the cold rolling mill. Between the rolling of the first steel strip and the rolling of the second steel strip, there is a pause. The first steel strip is fed to the rolling stand exiting the first decoiler along the first path and is not heated during feeding to the rolling stand. The second steel strip is fed to the rolling stand exiting the first decoiler or from a second decoiler different from the first decoiler along the second path and is heated during the supply to the rolling stand. The second path is longer than the first path.

EFFECT: possibility of rolling brittle and easily breaking steel strips in a batch cold rolling mill without the danger of cracking the strip.

10 cl, 9 dwg

Description

Technical field

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

wherein at least one rolling stand of the cold rolling mill rolls a first steel strip and a second steel strip;

wherein between the rolling of the first steel strip and the rolling of the second steel strip there is a pause between rollings during which no steel strip is rolled;

- at the same time, the first steel strip is fed to the rolling stand, leaving the first decoiler, along the first path and does not heat up during feeding to the rolling stand;

- in this case, the second steel strip is fed to the rolling stand, leaving the first decoiler, along the second path.

The present invention also 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 the first steel strip is unwound from the first unwinder, and the second steel strip is rolled immediately after the second steel strip is unwound from the first unwinder;

wherein the cold rolling mill has a first path through which the first steel strip, leaving the first decoiler, can be fed to the rolling stand;

no heating device is located on the first path, by means of which the first steel strip can be heated, so that the first steel strip is fed to the rolling stand, having the same temperature that the first steel strip has when unwinding from the first decoiler;

wherein the cold rolling mill has a second path, along which the second steel strip, leaving the first decoiler, can be fed to the rolling stand.

State of the art

The electrical steel sheet is a relatively thin steel sheet, which, in particular to improve the magnetic properties, may contain a relatively high proportion of silicon. In the production of such sheets during cold rolling, there is a risk of cracks in the strip. These cracks in the strip are in turn the result of edge cracks that can occur during cold rolling. Edge cracks are caused by the brittleness and brittleness of the unrolled cold rolled steel strip combined with the stresses that the steel strip is subjected to during cold rolling.

The brittleness and brittleness of a steel sheet having a high proportion of silicon (or a high proportion of aluminum) strongly depends on the temperature of the steel strip during cold rolling. In particular, it is known that a higher temperature leads to a marked reduction in brittleness and thus to a reduction in the risk of cracks in the strip.

During cold rolling, the temperature of the steel strip rises due to the deformation work done on the steel strip. However, during the first cold rolling pass, the temperature of the steel strip often only corresponds to the ambient temperature, i.e. usually approx. 20°C.

With continuous tandem lines (e.g. PLTCM=Pickling Line Tandem Cold Mill or CTCM=Continuous Tandem Cold Mill) it is known that in In the area in front of the first rolling stand of the continuous tandem line, a strip heating device in the form of induction heating is located. By means of this strip heating device, the temperature of the steel strip is raised, for example, in the range of approx. 80°C to approx. 160°C. As a result, the brittleness of the steel strip is noticeably reduced, so that there is a significantly lower risk of cracks in the strip. In addition, because of this, rolling can be carried out at a higher rolling speed, so that the productivity of the continuous tandem line is increased.

Induction heating needs a significant structural space. However, based on the equipment layout of the continuous tandem line, it is generally possible to arrange a suitable induction heater upstream of the first rolling stand of the continuous tandem line without difficulty.

A tandem batch cold rolling line or a reversing cold rolling stand, in contrast, often does not have such structural space. In particular, these plants are most often built very compactly in order to reduce the run-out length as much as possible (that is, the length of the strip that lies in the head zone and in the back zone of the cold-rolled steel strip outside the desired tolerances and therefore must be scrapped).

However, it is also possible to provide such induction heating in the inlet region of the tandem batch cold rolling line or the reversible cold rolling stand. However, this would require positioning the decoiler from which the steel strip is unwound prior to the first rolling pass at a suitable distance away from the rolling stand which is making the first rolling pass. In addition to reconstruction costs, this would also lead to the fact that the random length of all cold-rolled steel strips, i.e. also those steel strips that can be cold-rolled without difficulty without preheating, would correspondingly increase, and therefore the yield would be reduced, and the would be the resulting amount of scrap.

Brief summary of the invention

The object of the present invention is to provide opportunities whereby brittle and brittle steel strip can be rolled in a batch cold rolling mill without danger, or at least with a markedly reduced risk of cracks in the strip, and yet a small amount of roughness can be maintained. length at least for steel strips, which also without preheating are not prone to cracks in the strip.

The problem is solved using a method of operating a cold rolling mill with the features of claim 1 of the claims. Preferred embodiments of the method of operation are the subject of dependent claims 2-4 of the claims.

According to the invention, the second steel strip is heated during the feed to the rolling stand, whereby also the second path is longer than the first path. The decoiler from which the second steel strip is unwound may be the first decoiler. Alternatively, it may be a second unwinder different from the first unwinder.

Preferably, the second steel strip is heated by inductive heating. Such heating is simple, efficient, economical, reliable and mechanically strong.

Preferably provided,

- that the second steel strip, leaving the first or second decoiler, is first fed to the rolling stand, but this supply to the rolling stand ends before the head of the second steel strip reaches the rolling stand;

- that then a heating device is attached to the second steel strip, so that the heating device, when viewed in the direction of transport of the second steel strip, is located near the section of the second steel strip already unwound at this point in time, and

- that only then does the feeding of the second steel strip towards the rolling stand continue, so that the head of the strip reaches the rolling stand and is gripped by the rolling stand.

This makes it possible to thread the second steel strip in a simple manner without the risk of damage to the heating device by the second steel strip.

Preferably, between the attachment of the heating device to the second steel strip and the subsequent continuation of the feeding of the second steel strip to the rolling stand, the second steel strip is somewhat retracted from the rolling stand so that the head of the second steel strip stops at the outlet of the heating device. This makes it possible to preheat the entire second steel strip, so that the start region of the second steel strip already directly adjacent to the head of the strip is rolled in a preheated state.

The problem is also solved with the help of a cold rolling mill with the features of claim 5 of the claims. Preferred embodiments of the cold rolling mill are the subject of dependent claims 6 to 10 of the claims.

According to the invention, a cold rolling mill of the above-named kind is designed in such a way that

- that a heating device is located on the second path, by means of which the second steel strip can be heated, so that the second steel strip is fed to the rolling stand, having a temperature increased compared to the temperature that the second steel strip has when unwinding from the first or second unwinder, and

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

Similar to the operation method for a cold rolling mill, the decoiler from which the second steel strip is uncoiled may alternatively be a first decoiler or a second decoiler different from the first decoiler.

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

- that the second steel strip is unwound from the first unwinder;

- that the first decoiler is located on a movable platform, which can be placed at least in the first position and the second position, while the first decoiler in the first position of the platform is located closer to the rolling stand than in the second position of the platform, so that the first path extends from the first decoiler to the rolling stand while the platform is in the first position and the second path extends from the first decoiler to the rolling stand while the platform is in the second position, and

- that the heating device, at least when the movable platform is in the second position, can be attached to the second steel strip parallel to the second steel strip, but transverse to the direction of transport of the second steel strip from the first decoiler to the rolling stand, or can be attached to the second steel strip orthogonally second steel strip.

Alternatively, it is possible

- so that the second steel strip is unwound from the first unwinder;

- so that between the first decoiler and the rolling stand there is a loop holder through which, in the first position of the loop holder, the first steel strip passes without deviation, and in the second position of the loop holder, the second steel strip passes with the formation of a loop, so that the first path extends from the first decoiler to the rolling stand without forming a loop, and the second path extends from the first decoiler to the rolling stand to form a loop;

- that the heating device, at least when the loop holder is in the second position, can be applied to the second steel strip in the loop area parallel to the second steel strip, but transverse to the transport direction of the second steel strip in the loop area.

On the other hand, it is alternatively possible

- that the second steel strip is unwound from the second unwinder;

- so that a pulling device is located in front of the rolling stand, so that the first path extends from the first decoiler through the pulling device to the rolling stand, and the second path extends from the second decoiler through the pulling device to the rolling stand, and

- that the heating device is located between the second uncoiler and the hauling device.

In the case of the last mentioned embodiment, the heating device can preferably be attached to the second steel strip parallel to the second steel strip, but transverse to the direction of transport of the second steel strip from the second decoiler to the hauling device, or can be attached to the second steel strip orthogonally to the second steel strip.

Regardless of the rest of the embodiment of the cold rolling mill, the heating device is preferably in the form of induction heating. This embodiment of the heating device is simple, efficient, economical, reliable and mechanically strong.

Brief description of the drawings

The above described features, features and advantages of this invention, as well as how they are achieved, become clearer and more clearly understood in the context of the following description of exemplary embodiments, which are explained in more detail with reference to the drawings. In this case, the schematic image shows:

figure 1: cold rolling mill during rolling of the first steel strip;

figure 2: the cold rolling mill of figure 1 during the pause between rolling, between the rolling of the first steel strip and the rolling of the second steel strip;

figure 3: the cold rolling mill of figure 1 during the rolling of the second steel strip;

4: another cold rolling mill during the rolling of the first steel strip;

Fig. 5: The cold rolling mill of Fig. 4 during the pause between rollings, between the rolling of the first steel strip and the rolling of the second steel strip;

Fig. 6: cold rolling mill of Fig. 4 during rolling of the second steel strip;

7: another cold rolling mill during the rolling of the first steel strip;

Fig. 8: the cold rolling mill of Fig. 7 during the pause between rolling, between the rolling of the first steel strip and the rolling of the second steel strip, and

Fig. 9: The cold rolling mill of Fig. 7 during the rolling of the second steel strip.

Description of Embodiments

Below, with reference to FIGS. 1-3, the first embodiment of the present invention will be explained first.

In accordance with Fig.1, the cold rolling mill has a rolling stand 1 and a first decoiler 2. By means of the first decoiler 2, the first steel strip 3 is unwound. The first steel strip 3 is fed to the rolling stand 1, leaving the first decoiler 2, along the first stand 1 is subjected to cold rolling immediately after unwinding. The term "immediately after unwinding" should mean that between the unwinding of the first steel strip 3 and the rolling pass performed by the rolling stand 1, no other rolling pass is carried out. That is, the rolling pass performed by the rolling stand 1 is the first cold rolling pass. However, it is possible that there are other devices through which the first steel strip 3 passes between unwinding from the first decoiler 2 and reaching the rolling stand 1. Examples of such devices, according to the image in figure 1, are a pair of guide rollers 4 and a straightening device 5.

It is possible that the rolling stand 1 is the only rolling stand of the cold rolling mill. In this case, as a rule, reverse rolling of the steel strip 3 takes place in the rolling stand 1. Alternatively, after the rolling stand 1, other rolling stands not shown in FIG. 1 can be arranged. The implementation of one or the other variant of implementation in the framework of the present invention is of secondary importance. Indeed, in the framework of the present invention, the first cold rolling pass is important.

On the way from the first decoiler 2 to the rolling stand 1, i.e. during the feed to the rolling stand 1, the first steel strip 3 is not heated. For this reason, figure 1 also does not show the heating device 6, which is introduced later (see figures 2 and 3). In particular, in this phase of operation of the cold rolling mill, it is also not located on the first path. Thus, the first steel strip 3 is fed to the rolling stand 1 at the temperature that the first steel strip 3 has when unwinding from the first decoiler 2.

After the first steel strip 3 has been rolled, there is first, most often a relatively short, pause between the rolls. During the pause between rolling, as depicted in FIG. 2, no steel strip is rolled in the rolling stand 1, ie neither the first steel strip 3 nor the second steel strip 7 (see FIG. 3). However, after a pause between rolling, the second steel strip 7 is rolled. The corresponding state of the cold rolling mill is shown in FIG.

For cold rolling of the second steel strip 7, the second steel strip 7 is also unwound from the first decoiler 2 and then fed to the rolling stand 1. The feed takes place out of the first decoiler 2, however, via a second route. The second steel strip 7 is also subjected to cold rolling in the rolling stand 1 immediately after unwinding. The term "immediately after unwinding" should mean, as before, that between the unwinding of the second steel strip 7 and the rolling pass performed by the rolling stand 1, no other rolling pass is carried out. That is, the rolling pass performed by the rolling stand 1 is the first cold rolling pass. However, it is possible that there are other devices through which the second steel strip 7 passes between unwinding from the first decoiler 2 and reaching the rolling stand 1. Examples of such devices are, as before, a pair of guide rollers 4 and a straightening-pulling device 5.

However, unlike the first steel strip 3, the second steel strip 7 on the way from the first decoiler 2 to the rolling stand 1, that is, during the feed to the rolling stand 1, is heated. For this reason, a heating device 6 is located on the second path. Thus, the second steel strip 7 is fed to the rolling stand 1, having a temperature elevated compared to the temperature that the second steel strip 7 has when unwinding from the first decoiler 2.

In order to create the necessary space for the heating device 6, within the framework of the embodiment of FIGS. 1-3, the first unwinder 2 is located on a movable platform 8. For example, this movable platform 8 may be located on rails (not shown). The movable platform 8 can be placed in at least a first position (Fig. 1, Fig. 2: shown on the right with a dashed line) and a second position (Fig. 2: shown on the left with a solid line and Fig. 3). Thus, in the first position of the platform 8, the first decoiler 2 is located closer to the rolling stand 1 than in the second position of the platform 8. At the same time, on the one hand, the second path, like the first path, extends from the first decoiler 2 to the rolling stand. stand 1. However, the second path is longer than the first path, since the first decoiler 2 in the second position of the platform 8 is removed from the rolling stand 1 at a greater distance than in the first position of the platform 8.

Within the framework of the embodiment according to FIGS. 1-3, the heating device 6 can be attached from the retracted position to the second steel strip 7. The attachment is preferably carried out in a direction that runs parallel to the second steel strip 7 but transverse to the transport direction. The transport direction is the direction in which the second steel strip 7 travels from the first decoiler 2 towards the rolling stand 1. Alternatively, a heating device 6 could be attached to the second steel strip 7 from above and/or below.

The heating device 6 can be configured according to need. Preferably it is in the form of induction heating.

In individual cases it may be possible that the heating device 6 can be attached to the second steel strip 7 regardless of whether the movable platform 8 is in the first or second position. But at least a corresponding attachment possibility exists when the movable platform 8 is in the second position.

For rolling the second steel strip 7, according to the image in figure 3, the second steel strip 7, first leaving the first decoiler 2, is fed to the rolling stand 1. However, this supply to the rolling stand 1 ends before the head part 9 of the second steel strip 7 reaches the rolling stand 1. For example, the feed can be ended when the head part 9 of the strip reaches the place indicated by the letter A in FIG. the attachment, when viewed in the direction of transport of the second steel strip 7, is located near the section of the second steel strip 7, which at this point in time is already unwound. For example, a heating device 6, in a suitable embodiment, may surround this area. Only after attaching the heating device 6 to the second steel strip 7 does the second steel strip 7 continue to be fed to the rolling stand 1. This continues until the head part 9 of the strip reaches the rolling stand 1 and is captured by the rolling stand 1. stripes 7.

Preferably, after the heating device 6 has been attached to the second steel strip 7, further feeding to the rolling stand 1 is not carried out immediately. Moreover, the second steel strip 7 is preferably retracted somewhat from the rolling stand 1 first. letter B.

In addition, according to the representation in FIG. 2, it is possible for the shears 10 to be positioned between the two positions marked A and B. In this case, the head portion 9 of the strip can be cut off before the withdrawal. In addition, it is possible for a pressure roller 11 to be positioned between the two places marked A and B, in case there are scissors 10, between the scissors and the place marked A. This pressure roller 11 can generally be attached to the second steel lane 7, for example, by tilting. By means of the pressure roller 11, in particular, precise positioning of the second steel strip 7 can be achieved when the heating device 6 is attached. part 9 of the strip). This significantly reduces the risk of damage to the heating device 6. The same applies when the second steel strip 7 has large non-flatness.

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

In accordance with figure 4, the cold rolling mill, as before, has a rolling stand 1 and a first decoiler 2. By means of the first decoiler 2, the first steel strip 3 is unwound. This first steel strip 3 is fed to the rolling stand 1, leaving the first decoiler 2, along the first path and immediately after unwinding, it is cold rolled in the rolling stand 1. The term "immediately after unwinding", as before, should mean that no other rolling pass is carried out between the unwinding of the first steel strip 3 and the rolling pass 1 performed.

As before, it is possible that the rolling stand 1 is the only rolling stand of the cold rolling mill. Alternatively, after the rolling stand 1, other rolling stands not shown in FIG. 4 can be arranged.

On the way from the first decoiler 2 to the rolling stand 1, i.e. during the feed to the rolling stand 1, the first steel strip 3, as before, is not heated. For this reason, the heating device 6 (see FIGS. 5 and 6) is also not shown in FIG. 4. In particular, in this phase of operation of the cold rolling mill, it is also not located on the first track. Thus, the first steel strip 3 is fed to the rolling stand 1, as before, at the temperature that the first steel strip 3 has when unwinding from the first decoiler 2.

After the rolling of the first steel strip 3, there is first, as before, a pause between rollings, most often relatively short. During the pause between rolling according to FIG. 5, no steel strip is rolled in the rolling stand 1, ie neither the first steel strip 3 nor the second steel strip 7 (see FIG. 6). However, after a pause between rolling, the second steel strip 7 is rolled. The corresponding state of the cold rolling mill is shown in FIG.

For cold rolling of the second steel strip 7, the second steel strip 7, as before, is also unwound from the first decoiler 2 and then fed to the rolling stand 1. The feed is carried out with the exit from the first decoiler 2, along the second path. The second steel strip 7 is also subjected to cold rolling in the rolling stand 1 immediately after unwinding. The term "immediately after unwinding" should mean, as before, that between the unwinding of the second steel strip 7 and the rolling pass performed by the rolling stand 1, no other rolling pass is carried out. That is, the rolling pass performed by the rolling stand 1 is the first cold rolling pass.

However, unlike the first steel strip 3, the second steel strip 7, as before, on the way from the first decoiler 2 to the rolling stand 1, that is, during the feed to the rolling stand 1, is heated. For this reason, a heating device 6 is located on the second path. Thus, the second steel strip 7 is fed to the rolling stand 1, having a temperature elevated compared to the temperature that the second steel strip 7 has when unwinding from the first decoiler 2.

To create the necessary space for the heating device 6 in the framework of the embodiment of Fig.4-6 between the first decoiler 2 and the rolling stand 1 is a loop holder 12. This loop holder 12 can be placed at least in the first position (Fig. 4, Fig. 5) and second position (Fig.6). In the first position, the first steel strip 3 passes through the loop holder 12 without deflection and thus also without forming a loop. In the second arrangement, a second steel strip 7 passes through the loop holder 12 to form a loop. Therefore, the second path is longer than the first path.

Within the framework of the embodiment according to FIGS. 4-6, the heating device 6 can be attached to the second steel strip 7 from the retracted position. strip 7. The direction of transport is the direction in which the second steel strip 7 (locally) moves from the first decoiler 2 to the rolling stand 1. In particular, the second steel strip 1 in the loop area, according to the image in Fig.6, can move along substantially vertically, and the heating device 6 can be applied to the second steel strip 7 in the loop area substantially horizontally and parallel to the width direction of the second steel strip 7.

The heating device 6 can be configured according to need. Preferably it is in the form of induction heating.

Within the framework of the embodiment of the cold rolling mill according to FIGS. 4-6, the heating device 6 can be attached to the second steel strip 7 at least when the loop holder 12 is in the second position. Most often, even exclusively then, there is such a possibility of attachment.

For rolling the second steel strip 7, according to the image in Fig.6, the second steel strip 7, leaving the first decoiler 2, is fed to the rolling stand 1. However, this supply to the rolling stand 1 ends before the head part 9 of the second steel strip 7 reaches the rolling stand 1. For example, the supply may end when the head often 9 strip reaches the place indicated in figure 5 by the letter A. A short distance in front of this place is, as a rule, a pulling device 13, which pulls the second steel strip 7 (and also the first steel strip 3). When the head portion 9 of the second steel strip 7 reaches the pulling device 13, the stitch holder 12 is still generally in the first position. After the pulling device 13 has captured the head part 9 of the strip, the loop holder 12 is moved from the first to the second position. In this case, the second steel strip 7 is unwound to the extent required to form a loop. When the loop holder 12 has reached the second position, then the heating device 6 is attached to the second steel strip 7. In this case, the heating device 6, after being attached, when viewed in the direction of transport of the second steel strip 7, is located near the section of the second steel strip 7, which at this point in time is already unwound. Only after attaching the heating device 6 to the second steel strip 7 does the second steel strip 7 continue to be fed to the rolling stand 1. This continues until the head part 9 of the strip reaches the rolling stand 1 and is captured by the rolling stand 1. stripes 7.

According to the representation in FIG. 5, it is also possible for shears 14 to be arranged between the pulling device 13 and the rolling stand 1. In this case, the head portion 9 of the strip can be cut before being fed to the rolling stand 1.

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

In accordance with Fig.7 cold rolling mill, as before, has a rolling stand 1 and the first decoiler 2. By means of the first decoiler 2 unwinds the first steel strip 3. This first steel strip 3 is fed to the rolling stand 1, leaving the first decoiler 2, along the first path and immediately after unwinding, it is cold rolled in the rolling stand 1. The term "immediately after unwinding", as before, should mean that no other rolling pass is carried out between the unwinding of the first steel strip 3 and the rolling pass 1 performed. However, according to the depiction in figures 7-9, it is possible that there are other devices through which the first steel strip 3 passes between unwinding from the first decoiler 2 and reaching the rolling stand 1. Examples of such devices, similar to the embodiment in accordance with figure 1 -3, are a pair of 4 guide rollers and a correct-pulling device 5.

Again, as before, it is possible that the rolling stand 1 is the only rolling stand of the cold rolling mill. Alternatively, after the rolling stand 1, other rolling stands not shown in FIG. 7 can be arranged.

On the way from the first decoiler 2 to the rolling stand 1, i.e. during the feed to the rolling stand 1, the first steel strip 3, as before, is not heated. Thus, the first steel strip 3 is fed to the rolling stand 1, as before, at the temperature that the first steel strip 3 has when unwinding from the first decoiler 2.

After the rolling of the first steel strip 3, there is first, as before, a pause between rollings, most often relatively short. The corresponding state is shown in Fig.8. During the pause between rollings, no steel strip is rolled in the rolling stand 1, ie neither the first steel strip 3 nor the second steel strip 7 (see FIG. 9). However, after a pause between the rollings, according to the image in Fig.9, the second steel strip 7 is rolled.

For cold rolling of the second steel strip 7, the second steel strip 7 is uncoiled from the second decoiler 15 and then fed to the rolling stand 1. The second decoiler 15 is a different decoiler from the first decoiler 2. The feed is carried out from the second decoiler 15, along the second path. The second steel strip 7 is also subjected to cold rolling in the rolling stand 1 immediately after unwinding. The term "immediately after unwinding" should mean, as before, that between the unwinding of the second steel strip 7 and the rolling pass performed by the rolling stand 1, no other rolling pass is carried out. That is, the rolling pass performed by the rolling stand 1 is the first cold rolling pass. However, according to the depiction in Figs. 7-9, it is possible that there are other devices through which the second steel strip 7 passes between unwinding from the second decoiler 15 and reaching the rolling stand 1. Examples of such devices are, according to the depiction in Figs. 7-9, a pair of 4 guide rollers and a straightening-pulling device 5.

In contrast to the first steel strip 3, the second steel strip 7, as before, on the way from the second decoiler 15 to the rolling stand 1, that is, during the feed to the rolling stand 1, is heated. For this reason, a heating device 6 is located on the second path. Thus, the second steel strip 7 is fed to the rolling stand 1 at a temperature higher than that which the second steel strip 7 has when unwinding from the second decoiler 15.

In order to be able to supply to the rolling stand 1 both the first steel strip 3 coming out of the first decoiler 2 and the second steel strip 7 coming out of the second decoiler 15, a pulling device 18 is located in front of the rolling stand 1. Thus, both paths extend from the respective decoiler 2 , 15 through the pulling device 18 to the rolling stand 1.

In order to also make it possible to shorten the distance from the first decoiler 2 to the rolling stand 1 as far as possible, within the framework of the embodiment of FIGS. of the decoiler 15 to the pulling device 18 is greater than the distance from the first decoiler 2 to the pulling device 18. Therefore, also the second path (that is, the path from the second decoiler 15 to the rolling stand 1) is greater than the first path (that is, the path from the first decoiler 2 to the rolling crates 1).

Within the framework of the embodiment according to FIGS. 7-9, it is possible for the heating device 6 to be permanently located. Preferably, however, in this embodiment, too, the heating device can be attached to the second steel strip 7 from the retracted position. is the direction in which the second steel strip 7 in the region of the heating device 6 moves locally from the second decoiler 15 to the pulling device 18.

The heating device 6 can be configured according to need. Preferably it is in the form of induction heating.

For rolling the second steel strip 7, according to the image in Fig.9, the second steel strip 7, leaving the second decoiler 15, is first fed to the rolling stand 1. However, this supply to the rolling stand 1 ends before the head part 9 of the second steel strip 7 reaches the rolling stand 1. For example, the feed may end when the head part 9 of the strip reaches the place indicated in Fig.8 with the letter A. A short distance in front of this place is, as a rule, a pair of 19 guide rollers, which pulls the second steel strip 7 ( but usually not the first steel strip 3). That is to say, this pair of guide rollers 19 is located in front of the pulling device 18. After the pair of guide rollers 19 has gripped the head part 9 of the strip, if necessary, a short distance in front of or a short distance behind the pair of guide rollers 19 by means of scissors (not shown) can be carried out trimming the head of the 9th strip. In this state, with or without, and under certain conditions before or after cutting the head part 9 of the strip, the heating device 6 is attached to the second steel strip 7. In this case, the heating device 6 after attachment, when viewed in the direction of transport of the second steel strip 7, is located near the section of the second steel strip 7, which at this point in time is already unwound. Only after attaching the heating device 6 to the second steel strip 7 does the second steel strip 7 continue to be fed to the rolling stand 1. This continues until the head part 9 of the strip reaches the rolling stand 1 and is captured by the rolling stand 1. stripes 7.

Various embodiments of the principles explained above are also possible. Thus, in the context of the last-described embodiment, for example, it is possible to remove the top roller of the guide roller pair 19 from the second steel strip 7 as soon as the hauling device 18 grips the second steel strip 7. In addition, the top roller of the guide roller pair 19 can simultaneously perform also pinch roller function. In addition, the sequence in which the first and second steel strip 3, 7 are rolled is of secondary importance in all embodiments of the present invention. That is, the second steel strip 7 can be rolled first, and only after that, after a pause between rolling, the first steel strip 3 can be rolled.

The present invention has many advantages. Thus, in particular, steel strips which are relatively ductile in the cold state can be classified as first steel strips 3 and, as in the prior art, be rolled to a very short random length. Steel strips which are brittle and brittle in the cold state, in particular electrical steel sheet, can, in contrast, be classified as second steel strips 7, so that these steel strips are heated before being rolled in the rolling stand 1. Therefore, these steel strips, although they have a large random length, can be rolled reliably and without the risk of cracks in the strip. In addition, due to the attachment of the heating device 6 only after passing the corresponding second steel strip 7 through the area in which the heating device 6 is attached to the corresponding second steel strip 7, the heating device 6 is also securely protected even when the corresponding second steel strip 7 is strongly bent or has a ski. In addition, in the case of the embodiment according to FIGS. 7-9, in the event of failure of one of the two decoilers 2, 15, further operation of the cold rolling mill is possible. In addition, the invention also allows the retrofitting of already existing batch cold rolling mills. The costs required for the reconstruction of the respective cold rolling mill are relatively low.

Although the invention has been illustrated and described in detail in the preferred embodiment, the invention is not limited to the disclosed examples, and other variations can be derived from the skilled person without departing from the scope of the protection of the invention.

LIST OF REFERENCES

1 rolling stand

2, 15 Uncoiler

3, 7 steel strips

4, 16, 19 Pairs of guide rollers

5, 17 Straightening-pulling device

6 Heating device

8 Mobile platform

9 Strip head

10, 14 Scissors

11 Pressure roller

12 Stitch holder

13, 18 Pulling devices

A, B Locations.

Claims (42)

1. A method for rolling steel strips, including rolling the first steel strip (3) and the second steel strip (7) in at least one rolling stand (1) of the cold rolling mill; while between the rolling of the first steel strip (3) and the rolling of the second steel strip (7) provide a pause between rolling, during which no steel strip is rolled; wherein the first steel strip (3) is fed to the rolling stand (1) leaving the first decoiler (2) along the first path and is not heated during the supply to the rolling stand (1); wherein the second steel strip (7) is fed to the rolling stand (1) leaving the first decoiler (2) or from the second decoiler (15) different from the first decoiler (2) along the second path and during the feed to the rolling stand ( 1) heat up; and the second path is longer than the first path. 2. The method according to claim 1, characterized in that the second steel strip (7) is heated by induction heating (6). 3. The method according to claim 1 or 2, characterized in that the second steel strip (7) exiting the first or second decoiler (2, 15) is first fed to the rolling stand (1), this supply to the rolling stand (1) ending before the head part (9) of the second steel strip (7) reaches the rolling stand (1); then a heating device (6) is attached to the second steel strip (7), so that the heating device (6), when viewed in the direction of transport of the second steel strip (7), is located near the section of the second steel strip (7) already unwound at this point in time , And only then is the feeding of the second steel strip (7) towards the rolling stand (1) continued so that the head part (9) of the strip reaches the rolling stand (1) and is gripped by the rolling stand (1). 4. The method according to claim 3, characterized in that between the attachment of the heating device (6) to the second steel strip (7) and the subsequent continuation of the supply of the second steel strip (7) to the rolling stand (1), the second steel strip (7) is partially withdrawn from the rolling stand (1), so that the head part ( 9) the second steel strip (7) stopped at the outlet of the heating device (6). 5. Cold rolling mill containing a rolling stand (1) made for rolling the first steel strip (3) immediately after unwinding the first steel strip (3) from the first unwinder (2), and rolling the second steel strip (7) immediately after unwinding the second steel strip (7) from the first unwinder (2) or from a second unwinder (15) different from the first unwinder (2); a first path along which the first steel strip (3) exiting the first decoiler (2) is fed to the rolling stand (1); and the first path is made without a heating device for heating the first steel strip (3), so that the first steel strip (3) is fed to the rolling stand (1), having the same temperature that the first steel strip (3) has when unwinding from the first decoiler (2 ); a second path through which the second steel strip (7) exiting the first or second decoiler (2, 15) is fed to the rolling stand (1); and the second path contains a heating device (6) for heating the second steel strip (7), ensuring the supply of the second steel strip (7) to the rolling stand (1) with a temperature increased compared to the temperature that the second steel strip (7) has at unwinding from the first or second unwinder (2, 15), and and the second path is longer than the first path. 6. Cold rolling mill according to claim 5, characterized in that the first decoiler (2) for uncoiling the second steel strip (7) is located on a movable platform (8) configured to be placed at least in the first position and the second position, while the first decoiler (2) is located in the first position of the platform (8) closer to the rolling stand (1) than in the second position of the platform (8), so that the first path runs from the first decoiler (2) to the rolling stand (1), while the platform (8) is in the first position and the second the path runs from the first decoiler (2) to the rolling stand (1), while the platform (8) is in the second position, and the heating device (6) is adapted to be attached to the second steel strip (7) at least when the movable platform (8) is in the second position, parallel to the second steel strip (7), but transverse to the transport direction of the second steel strip (7) from the first decoiler (2) to the rolling stand (1), or attachment to the second steel strip (7) orthogonally to the second steel strip (7). 7. Cold rolling mill according to claim 5, characterized in that between the first unwinder (2) for unwinding the second strip (7) and the rolling stand (1) there is a loop holder (12) having two positions, and in the first position of the loop holder (12) the first steel strip (3) passes through it without deflection, and in the second location of the loop holder (12), the second steel strip (7) passes in a loop, so that the first path runs from the first decoiler (2) to the rolling stand (1) without forming a loop, and the second path runs from the first decoiler (2) to rolling stand (1) with the formation of a loop; moreover, the heating device (6) is adapted to be attached to the second steel strip (7), at least when the loop holder (12) is in the second position, in the loop area parallel to the second steel strip (7), but transverse to the transport direction of the second steel strip strips (7) in the loop area. 8. Cold rolling mill according to claim 5, characterized in that the second decoiler (15) unwinds the second steel strip (7); moreover, a pulling device (18) is located in front of the rolling stand (1), so that the first path passes from the first decoiler (2) through the pulling device (18) to the rolling stand (1), and the second path passes from the second decoiler (15) through the pulling device (18) to the rolling stand (1), and the heating device (6) is located between the second decoiler (15) and the pulling device (18). 9. Cold rolling mill according to claim 8, characterized in that the heating device (6) is configured to be attached to 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 second decoiler (15) to the pulling device (18), or attached to to the second steel strip (7) orthogonally to the second steel strip (7). 10. Cold rolling mill according to any one of claims 5 to 9, characterized in that the heating device (6) is made in the form of an induction heating device.

Images