EP2741870B1 - Rolling system and rolling method - Google Patents

Description

Technical area

The present invention relates to a rolling mill, in particular a cold rolling mill for cold rolling a metal strip, with at least one cold rolling mill, with the cold rolling stand upstream uncoiler, wherein between the uncoiler and the cold rolling stand, a unit is interposed. The present invention also relates to a method of rolling.

State of the art

In systems for rolling a metal strip, it may be necessary to pretreat the metal strip before the actual rolling process. For example, prior to a cold rolling process, it may be necessary to recrystallize the metal strip to restore the microstructure to its original unconsolidated state, so that the material is again tough and further deformable. This "recrystallization annealing" is nowadays often carried out in so-called crucible annealing furnaces under a protective gas atmosphere, for example hydrogen. The process of annealing and cooling is about 48 hours on average. In order to prevent glowing from adhering to each other, the coil is loosely wound before it enters the annealing furnace. After treatment in the annealing furnace, the metal strip is fed to the cold rolling stand. For this it must be handled by the federal government. But since the metal band was wound with a low strip tension, it now has to be unwound even with a small strip tension become. The strip tension can fall off sharply. It can come to jerky Bandzugschwankungen.

On the other hand, a certain minimum amount of strip tension is desired when entering the cold rolling stand, as this can reduce the required rolling forces during cold rolling.

To decouple the unwinding of the actual rolling process, for example, in the EP 1 784 266 B1 an S-roll unit proposed. The preamble of claim 1 is based on this document. The disadvantage here is that especially in hard and / or thick metal bands, even with large wrap of the two S-rollers, the desired minimum amount of strip tension in the inlet to a cold rolling mill can be difficult to achieve. On the other hand, the threading of the metal strip into the S-roll unit is complicated due to the rigidity of the metal strip. This is particularly disadvantageous, especially in the case of discontinuous cold rolling mills, since in these systems the complex threading process must be carried out again at each collar.

The FR 7534844 shows a cold rolling plant wherein between the uncoiler and the cold rolling stand a unit is interposed, wherein the unit is formed from at least three rotationally driven about a rotation axis rollers, and wherein two of these roles individually or jointly in a direction transverse to the axis of rotation by means of a drive and adjusting device is adjustable.

It may be the case that a metal strip has to be split in the longitudinal direction in order to be able to process it on a rolling mill with a smaller rolling width. The cross-section of such a longitudinally divided rolled strip is then often not symmetrical. The band is thicker on one side than the other. Such asymmetric rolling belts run out of the center of the rolling mill during operation. In order to ensure that even with an asymmetric cross-sectional profile the rolled strip runs centrally into the cold rolling stand, a correction of the strip run (strip deflection) is required. Only if an exact inlet position of the rolled strip can be maintained in the cold rolling stand, the specified in a cold rolling process tight tolerances can be met.

So far, the desired Zugentkopplung, - low unwinding, the highest possible train in the inlet region of Walzaeüstes -, as well as maintaining a precise Entry position in the first cold rolling stand not satisfactorily solved.

Presentation of the invention

It is an object of the present invention to provide a rolling mill, in particular a cold rolling mill or a method for cold rolling so that even for hard and / or thick metal strips a sufficiently large and fluctuation-free tensile stress can be adjusted in the inlet region of a cold rolling mill, and that a correction the tape running and threading the rolled strip is as simple as possible.

This object is achieved by a rolling mill according to the features of claim 1 and by a method according to the features of claim 11.

In the rolling mill according to the invention, a unit is used between the uncoiler and the first rolling stand, which is formed from at least three driven rollers, wherein the spatial position of these rollers is variable by means of a drive and adjusting device. On the one hand, each of these rollers of the 3-roller system is adjustable in the direction of its roller axis. This adjustment can be done individually or together. By this axial displacement of the rollers ensures that the means of the metal strip also enters the center of the mill stand. Since the work rolls of a roll stand usually have a convex contour or result in a plant symmetrical nip, the inlet of the rolled strip must be as symmetrical as possible. This is the only way to guarantee the accuracy of the strip thickness required for cold rolling. A wedge-shaped band profile in particular tends to run out of the center of the rolling mill. A band deflection is advantageous here.

On the other hand, each of these rollers is adjustable in a direction transverse to the axis of rotation by means of the drive and adjusting device. As a result, on the one hand, a substantial simplification in the threading of the metal strip is achieved: By bringing the middle of the three rollers relative to the other two rollers in a pivoted out position, the beginning of the band can be very easily threaded into the 3-roller system. The threading can also be supported by a transfer table. A pinch roller, with which the tape head is pressed in the direction of the supporting two roles, can thereby provide further assistance in threading, especially for very stiff and thick tapes. In the further course of the tape head then enters the gap of the work rolls. The threading process is then completed. During rolling, the work rolls create a strip tension on the metal strip. By setting the central roller of the 3-roll system, the specification of a desired strip tension in the inlet to the first (cold) stand is very easy. For this purpose, the middle role of the 3-roller system immersed in the located between the two supporting roles section of the metal strip. The spatial position of the three roles specifies the wrap. The deeper the immersion, the larger the wrap. Between the mill stand and the 3-roller arrangement, a desired return tension can be set by appropriate control of the drives, without this strip tension acting on the upstream, between uncoiler and the 3-roller arrangement comparatively lesser Bandzug the metal strip during unwinding. Conversely, fluctuations in the strip tension during unwinding of a loosely wound coil on the inlet into the cold rolling mills do not propagate. The 3-roller system acts as a tensile decoupling during the rolling process.

In order to ensure an exact inlet into the cold rolling stand, in particular in the case of a strongly asymmetrical rolled strip profile, it can be provided in a preferred embodiment that, simultaneously with the axial adjustment of the rolls of the three-roll system, equally the axial position of the uncoiler is adjustable or adjusted.

It may also be advantageous if the axis of rotation of the reel lying to the reel and the axis of rotation of the roller lying to the cold rolling stand lie in a plane and that the roller between them is spatially adjustable with respect to this plane. The deeper the middle roll dips below this level, the greater the wrap and consequently the adhesion between the tape and the roll. As a result, the advantageously high strip tension can be set in the inlet to the first cold rolling stand.

To make the change between threading and rolling as simple as possible, an embodiment may be advantageous in which the middle roller by means of a hydraulic actuator between the pivoted position in which this roller is separated from the rolled strip, and the pivoted position in which the peripheral surface this role is partially wrapped by the rolled strip, is adjustable.

In order to set a high retraction tension in the inlet to the roll stand, it is advantageous if the middle roller immersed sufficiently deep, that is, when the wrap of the middle roller is disposed below the plane spanned by the axis of rotation of the other two rollers plane, and if the wrap the two supporting roles is above this level.

A particularly high strip tension in the inlet region can then be adjusted if the adjustment of the middle roller takes place in such a way that the middle roller has a loop of greater than 180 °.

In a particularly preferred embodiment of the invention can be provided that the distance of lying in the plane of two supporting roles by means of the drive and Adjustment can be changed continuously. This change can be brought about by moving both rollers toward or away from each other, whereby the looping and, as a result, the braking effect in the inlet can be given very differentiated. However, it may also be advantageous to maintain the local position of one of the two in-plane rollers and to change relative thereto only the position of the other roller. As a result, upstream and downstream occurring pull fluctuations in the metal strip can be regulated differentiated.

It may be advantageous if the adjustment movement of the middle roller is a linear movement, which includes a predeterminable angle with respect to the plane. Thus, the wrap of the three roles can be better adapted according to the desired influence on the tape. In addition, the regulation of the drives of the rollers is technically easier.

Depending on the size of the system, it may be advantageous for the influence on the tape (tape guide), when the uncoiler together or separately with the rollers of the 3-roller system in the direction of the axes of rotation of the rollers by means of a common or a separate drive and adjustment is adjustable. For large systems may be a separate version, for small plant a common drive and adjustment advantageous.

It is expedient to detect the lateral position of the strip in the inlet to the first rolling stand by measurement. This can be done for example by means of a sensor which detects the position of a web edge or both web edges and the measurement signal of the drive and adjusting device is supplied. The drive and adjustment determined from the measured signal of the tape layer, a control signal for adjusting the axial position of the 3-roller system, possibly also of the uncoiler.

Brief description of the drawings

To further explain the invention, reference is made in the following part of the description to the drawings, from which further advantageous embodiments, details and further developments of the invention can be found by way of non-limiting embodiment.

Figur 1

eine schematische Seitenansicht der erfindungsgemäßen Walzanlage in einem Zustand des Einfädelns, wobei die mittlere Rolle außer Eingriff gebracht ist;

Figur 2

die Kaltwalzanlage gemäß der Figur 1 im Zustand des Walzens, wobei die mittlere Rolle in Eingriff mit dem Metallband ist;

Figur 3

die Kaltwalzanlage gemäß der Figur 1, wobei die mittlere Rolle unterhalb der Passlinie eingetaucht ist und Zugschwankungen durch eine Verstellbewegung in Bandlaufrichtung der eingangsseitigen und/oder ausgangsseitigen Rolle ausgeregelt werden;

Figur 4

das 3-Rollensystem in einer Detaildarstellung.

Show it:

FIG. 1

a schematic side view of the rolling mill according to the invention in a state of threading, wherein the middle roller is disengaged;

FIG. 2

the cold rolling mill according to FIG. 1 in the state of rolling, wherein the middle roller is in engagement with the metal band;

FIG. 3

the cold rolling mill according to FIG. 1 , wherein the middle roller is immersed below the pass line and Zugschwankungen be adjusted by an adjustment in the direction of tape travel of the input side and / or output side roller;

FIG. 4

the 3-roller system in a detailed view.

Embodiment of the invention

The FIG. 1 schematically shows a side view of the rolling mill according to the invention in a position in which the beginning of the tape is threaded into the rolling stand 1. A rolled to a coil steel strip 2 is unwound from a reel 3 clockwise and passes from left to right in the direction of the unit 10. This unit 10 is in Essentially of three rollers 6, 7, 8, of which the middle roller 7 is pivoted away in this operating position from the tape run and is not in engagement with the metal strip 2 (threading position). The metal strip 2 is first transported on a part of a transfer table 13 and is subsequently supported by the roller 6, a second part of the transfer table 13 and the roller 8. In the case of very stiff metal strips, this threading operation can optionally be assisted by a pressure roller 19. The transfer table 13 can be pivoted in and out by drawing drives, not shown in the tape.

Like in the FIG. 1 indicated by the arrows 12, the spatial position of the rollers 6, 7, 8, possibly also that of the uncoiler 3, by means of a drive and adjusting device 11 is variable. In other words, each of the rollers 6, 7, 8 is rotationally driven by the driving and adjusting device 11 not only about the associated rotation axis 6A, 7A, 8A and (jointly or separately) in the axial direction adjustable, but also the local position of each roller 6, 7, 8 is adjustable in a direction transverse to its axis of rotation 6A, 7A, 8A by means of the drive and adjusting device 11.

Particularly in the case of a wedge-shaped cross section of the rolled strip, it is favorable if, at the same time as the axial displacement of the 3-roll system, the uncoiler 3 is adjusted in the direction of its axis of rotation 3A. As a result, the metal strip 2 can be directed into the middle of the cold rolling stand 1.

It should be noted here that drive and adjusting devices 11, with which a rotational movement and at the same time the spatial position of a roll (or possibly also a reel) can be set or adjusted in a rolling mill, can be actuated hydraulically or electromechanically. Such devices are assumed to be known in the following and therefore need not be explained in detail here.

The FIG. 2 shows the condition during cold rolling. After the rolled strip 2 is threaded into the gap of the work rolls of the roll stand 1 and is detected by these, a strip tension is exerted on the metal strip 2. As already indicated, the strip tension and the strip run in the region of the inlet to the roll stand 1 should be able to be predetermined as independently of the strip tension in the area of the uncoiler 3. Variations in the tension during unwinding of the coil should preferably not reach the region of the inlet to the roll stand 1. As in FIG. 2 shown, the unit 10 is provided for this Zugentkopplung. The middle roller 7 of the unit 10 is pivoted in this illustration. The metal strip 2 wraps around a portion of the lateral surface of the three rollers 6, 7, 8. Each roller 6, 7, 8 is, as I said, rotationally driven by a drive, not shown. The drive torque of the rollers 6, 7, 8 is determined by the drive and adjusting device 11 so that on the one hand a braking effect is exerted on the metal strip 2. By this braking effect, it is possible to maintain a desired minimum amount of tension in the inlet to the cold rolling mill 1. This retraction tension is largely independent and unaffected by pull variations that can occur when unwinding a loosely wound coil. Furthermore, the drive and adjusting device 11 also influences the spatial position of the axes of rotation of the rollers 6, 7, 8 (possibly also that of the uncoiler 3 in the direction of its axis of rotation 3 A). By a shift in the axial direction of the rollers can be influenced in addition to the tape tension on tape. This influence (both on rotary motion and on the axial position of the rotary axes) is in FIG. 2 symbolically indicated by dashed lines (active and signal-conducting connection 4) and indicated by the arrows 12. For the sake of clarity, drives and actuators are for these adjusting operations in the drawings are not shown in detail.

For detecting the band position serves a tape position detection 9, which is arranged between the unit 10 and the cold rolling stand 1. The monitoring of the tape run, for example, be done by the edge (s) of the metal strip is detected metrologically. This band position detection 9 is signal-conducting connected to the drive and adjusting device 11. By the supplied measurement signal can be counteracted well with a conventional control a bleeding of the metal strip 2. This is advantageous in particular in the case of a cross-sectional profile of the metal strip which has the shape of a wedge.

The FIG. 3 also shows the condition during the rolling process. In contrast to the representation of the FIG. 2 the middle roller 7 is deeply immersed below the two rollers 6, 8. This results in a large angle of the wrap of the roller 7, to which also a comparatively larger wrap angle of the rollers 6, 8. This angle of wrap is adjustable by the position of the roller 6 and the position of the roller 8 respectively given in accordance with the arrow 14 becomes. In this case, the axis of rotation of one of the rollers 6, 8 are displaced, or both. If the distance 18 between the axes of rotation 6A, 8A changes, the looping also changes.

Like the detail of the FIG. 4 illustrates the 3-roller system, the middle roller 7, for example, by a hydraulic actuator not shown between a pivoted position 16 and a pivoted position 17 adjustable. This adjustment movement 21 can take place with respect to the plane 15 perpendicular or at an angle 20. A change in the angle 20 of the adjusting movement 21 influences the wrapping of the rollers 6, 7, 8.

The axes of rotation 6A, 7A, 8A of the rollers 6, 7, 8 are parallel to each other and with respect to the plane 15. In the in FIG. 4 6, 8A of the roller in Fig. 6, 8 spanned the plane 15. The axis of rotation 6A and 8A of the outer rollers 6 and 8 is in the plane 15 (approximately in the strip running direction 5) in Direction of the double arrow 14 slidable. With sufficiently large immersion depth of the roller 7, the distance 18 of the two rollers 6, 8 are chosen to be very narrow, so that a high tensile structure can be realized by the 3-roller system. This is particularly advantageous when cold rolling thin and hard metal strips. By the angle 20 of the adjusting movement is predetermined with respect to the plane 15, the wrap of the rollers 6, 7, 8 can also be designed differently.

In principle, it is also possible that in a tightly wound collar, the engageable middle roller 7 remains placed even during rolling away.

The above-described 3-roller system can be achieved in a simple manner at the same time a Zugentkopplung, a desired Zugaufbau in the inlet region and a good band deflection of metal bands. By the immersion depth of the middle roller 7 in conjunction with the horizontal adjustability of the two outer rollers 6, 8 of the 3-roll system can be set during cold rolling train construction in an advantageous manner and thus a high retraction tension in the following rolling stand 1 can be ensured. In conjunction with the transfer table 13 shown above and optionally with the aid of a pinch roller 19, the threading process is relatively simple even for rigid metal strips 2.

Due to the possibility of simultaneous axial displacement of the uncoiler 3 and the fixedly connected to it or separately displaceable 3-roller unit, there is the possibility of a very good tape running control. The advantage An effective tape running control is particularly important in metal bands in the foreground, the cross-sectional profile is uneven.

Although the invention has been illustrated and described in detail above with reference to a preferred embodiment of a cold rolling mill, the invention is not limited by this disclosed example. The invention can just as well be used in other rolling mills, for example during hot rolling. In addition, other variations can be deduced therefrom by those skilled in the art without departing from the scope of the invention.

Compilation of the reference numbers used

1

Roll stand, cold rolling stand

2

tape

3

uncoiler

4

Connection (active and signal-conducting)

5

Tape direction

6

role

7

role

8th

role

9

Tape position detection

10

Unit, 3-roller system

11

Drive and adjusting device

12

Arrow (shifting direction rollers 6,7,8 vertical)

13

transfer table

14

Arrow (displacement direction 6,8 horizontal)

15

level

16

swung-out position of the roller 7

17

pivoted position of the roller 7

18

distance

19

pinch

20

angle

21

Arrow, adjustment direction of the roller 7th

3A

Rotary axis of the uncoiler 3

6A

Rotary axis of the roller 6

7A

Rotary axis of the roller 7

8A

Rotary axis of the roller 8

Claims (22)

1. Rolling mill, in particular a cold-rolling mill for the cold-rolling of a metal strip (2), having at least one cold-rolling stand (1), with a decoiler (3) before the cold-rolling stand (1), where there is a unit (10) in-line between the decoiler (3) and the cold-rolling stand (1), characterised in that the unit (10) is formed by at least three rollers (6, 7, 8) each of which is rotationally driven about an axis of rotation (6A, 7A, 8A), where each of these rollers (6, 7, 8) can be positioned, individually or jointly, in the direction of the axis of rotation concerned (6A, 7A, 8A) and in a direction transverse to the axis of rotation (6A, 7A, 8A), by means of a drive and positioning facility (11).
2. Rolling mill according to claim 1, characterised in that the decoiler (3) can, by means of the drive and positioning facility (11), be positioned in the direction of its axis of rotation (3A).
3. Rolling mill according to claim 2, characterised in that the axis of rotation (6A) of the roller (6) which is located beside the decoiler (3) and the axis of rotation (8A) of the roller (8) which is located beside the cold-rolling stand (1) lie in one plane (15) and that the central roller (7), which is arranged between the two rollers (6, 8), can be spatially positioned relative to this plane (15) by means of the drive and positioning facility (11).
4. Rolling mill according to claim 3, characterised in that the central roller (7) can be repositioned between an out-of-line position (16), in which the roller (7) is not engaged with the rolling strip (2), and an in-line position (17), in which the circumferential surface of the roller (7) is partially wrapped around by the rolling strip (2).
5. Rolling mill according to claim 4, characterised in that, in the in-line position (17) of the roller (7), the wrap-around on the roller (7) is arranged beneath the plane (15), and the wrap-around on the two rollers (6, 8) is arranged above the plane (15).
6. Rolling mill according to claim 5, characterised in that, in the in-line position (17) of the roller (7), the wrap-around on the roller (7) is greater than 180°.
7. Rolling mill according to claim 6, characterised in that the distance (18) between the axes of rotation (6A, 8A) of the two rollers (6, 8) in the plane (15) can be adjusted by means of the drive and positioning facility (11).
8. Rolling mill according to one of the claims 1 to 7, characterised in that the direction of movement (21) when the roller (7) is being positioned is at an angle (20) to the plane (15).
9. Rolling mill according to claim 1, characterised in that the decoiler (3) can be positioned, together with or separately from the rollers (6, 7, 8), in the direction of the axes of rotation (6A, 7A, 8A) of the rollers (6, 7, 8) by means of the drive and positioning facility (11).
10. Rolling mill according to claim 1, characterised in that a measurement device (9) for detecting the position of the strip is arranged between the unit (10) and the cold-rolling stand (1) and this measurement device (9) has a signalling link with the drive and positioning facility (11).
11. Method of rolling, in particular cold-rolling of a metal strip (2) with a rolling mill incorporating:

    at least one cold-rolling stand (1), a decoiler (3) before the cold-rolling stand (1), where a unit (10) which influences the strip path is in-line between the decoiler (3) and the cold-rolling stand (1), which unit is made up of three rollers (6, 7, 8) each driven about an axis of rotation, where each roller (6, 7, 8) is positioned during the rolling operation, by means of a drive and positioning facility (11), in the direction of its axis of rotation (6A, 7A, 8A) and in a direction transverse to the axis of rotation (6A, 7A, 8A).
12. Method according to claim 11, characterised in that the decoiler (3) is positioned by means of the drive and positioning facility (11) in the direction of its axis of rotation (3A), jointly with the axial positioning of the rollers (6, 7, 8).
13. Method according to claim 12, characterised in that the axis of rotation (6A) of the roller (6) located beside the decoiler (3) and the axis of rotation (8A) of the roller (8) located beside the cold-rolling stand (1) are arranged to lie in a plane and the central roller (7) which, looking in the direction of the strip path (5), is arranged between the two rollers (6, 8), is positioned relative to this plane (15) by means of the drive and positioning facility (11).
14. Method according to one of the claims 11, 12 or 13 characterized in that the central roller (7) is positioned between an out-of-line position (16), in which the roller (7) is not engaged with the rolling strip (2), and an in-line position (17), in which the rolling strip (2) partially wraps around the circumferential surface of the roller (7).
15. Method according to claim 14, characterised in that the positioning of the roller (7) in-line is effected in such a way that in the in-line position (17) of the roller (7) the wrap-around on the roller (7) is arranged beneath the plane (15), and the wrap-around on the two rollers (6, 8) lies above the plane (15).
16. Method according to claim 15, characterised in that in the in-line position (17) the rolling strip (2) wraps around the roller (7) over an angle of greater than 180°.
17. Method according to claim 16, characterised in that the distance (18) between the axes of rotation (6A, 8A) of the two rollers (6, 8) in the plane (15) is adjusted by means of the drive and positioning facility (11).
18. Method according to claim 17, characterised in that the direction of movement (21) when the roller (7) is being engaged is effected at an angle (20) to the plane (15).
19. Method according to claim 18, characterised in that the decoiler (3) is positioned, together with or separately from the rollers (6, 7, 8), in the direction of the axes of rotation (6A, 7A, 8A) of the rollers (6, 7, 8) by means of the drive and positioning facility (11).
20. Method according to claim 19, characterised in that a measurement device (9) for detecting the position of the strip is arranged between the unit (10) and the cold-rolling stand (1), and the measurement signal thus obtained for the position of the metal strip (2) is transmitted over a signalling link (4) to the drive and positioning facility (11).
21. Method according to one of the claims 11 to 20, characterised in that when the metal strip (2) is initially being fed in use is made of a two-part transfer table (13), the first part of which is arranged upstream from the roller (6) located beside the decoiler and the second part of which is between the roller (6) and the roller (8).
22. Method according to claim 21, characterised in that during the initial feeding in a pinch roller (19) is moved in towards the transfer table (13) which has been put in-line.

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