EP1454681A2 - Device and method for rolling metal strips - Google Patents

Abstract

Device for rolling steel strips (S) comprises a mill stand (4), a winding unit (2, 6) and strip compensation units (3, 5) arranged between the mill stand and the winding unit. The strip compensation units each have a roller (9, 10) which can be adjusted in the horizontal direction. An independent claim is also included for a process for rolling steel strips.

Description

The invention relates to a device for rolling Metal strips, in particular steel strips, with a Roll stand, with a winding device and with at least one between the roll stand and the winding device arranged strip tension compensation device.

The invention also relates to a method for rolling Metal strips, especially for cold rolling Steel strips in which the strip to be rolled is coiled uncoiled, rolled in a roll stand and then is coiled, the one resting on the metal belt Belt tension regulated by means of a belt tension compensation device becomes.

When using devices of this type and when Such procedures can be carried out as a result of Differences between the retraction speed of the Roll stand and the unwinding speed of the strip on Unwinder fluctuations in strip tension occur. The Speed deviations are caused by this, for example caused it due to the Diameter change at the winding origin of the reel too one occurring at regular intervals, in Substantial abrupt change in speed comes with which the respective tape runs off the reel. Also fluctuations in the thickness of the tape can be so great that a noticeable deviation from the current one Unwind speed and current Feed speed occurs on the roll stand.

Corresponding changes in the strip tension arise due to deviations between the speed with which exits the rolled strip from the roll stand, and the Winding speed with which the tape from the rewinder is wrapped. In this case, polluters can also Thickness fluctuations in the band can lead to one Difference from current rewind and Discharge speed can lead.

Regardless of where they arise, affect the speed changes and the associated load fluctuations Rolling conditions in the roll gap of the roll stand with the Consequence that unwanted on the finished rolled strip Non-uniformities in the belt geometry arise. there the speed fluctuations occur highly dynamically and go so far that it's hard to move the band between the roll stand and the reel device safely and to control reliably.

The ones described above are particularly critical Problems of belt unevenness in the sun called "flexible rollers", with the metal strips rolled a gradually changing thickness profile become. The one that is gradually taking place to a considerable extent Increasing or decreasing the strip thickness causes it to do the same step by step to a sudden change in Belt speed comes at the exit of the roll stand. The change in thickness also influences the speed of the belt run at the inlet of the roll stand. The concerned Fluctuations are so big and occur in so short Time intervals on that the speed control of the Reel device them due to the large of the Winding devices can no longer follow moving masses.

It has been tried to solve the problem by itself changing band geometries or external influences occurring As a result, speed and belt tension fluctuations solve that between the mill stand and each of the Winding devices each have at least one so-called Dancer role is arranged. These dancer roles work each with two pulleys together, between which they adjustable in a vertical direction in a stand are. That in the conveying direction on the so formed Belt tension compensating metal belt is on the first pulley from the horizontal to the Deflected vertical, then wraps around Dancer roll by about 180 ° and is then on the second Deflection pulley directed back into the horizontal. To this A band loop is formed in which the Dancer role lies. A correspondingly constructed device is known from EP 1 121 990 A2.

By adjusting the dancer roll in the vertical direction can that of the metal strip between the respective Winding device and the path covered by the roll stand continuously at the respectively occurring speed and Belt tension change can be adjusted. Because of the on rolling mills required high tape tensile forces is the use of However, dancer roles are very complex. So are high Actuators and powerful drives required to suddenly in a sufficiently short reaction time occurring speed change due to a change to be able to compensate for the position of the dancer role. It is difficult to operate and control the known Dancer roles also in that the additional Deflections of the belt on the pulleys in particular thick tapes lead to additional losses through the additional band bend and the accompanying additional material stress can be caused. Also need for the use of the dancer roles required equipment a significant amount of space, the the production costs additionally increased. The one with the installation an extension of the Funding path also causes a less favorable yield when Rollers.

The object of the invention was based on the a device and to create a process with which to deal with their geometry high quality metal strips with reduced Manufacturing control and device engineering effort to let.

This object is according to the invention on the one hand been solved that with a device of the beginning specified type of the band tension compensation device the one each rolled strip comprises a deflecting roller in operation, whose distance from the measured in the horizontal direction Roll stand is adjustable.

Regarding the method of rolling metal strips, especially for cold rolling steel strips, in which the strip to be rolled unwound from a coil, in one Rolling mill is rolled and then coiled solved the above-stated object in that the belt tension on the metal belt by means of a Belt tension compensation device is regulated, the horizontal distance from the roll stand depending on the the respectively recorded belt tension is adjusted.

By adjusting the pulley of the Belt tension compensation device can Belt run geometry to which each between winder and Adjust the roll length of the roll stand and thus the maintain the desired tape tension.

In contrast to the state of the art that works with dancer roles Technology, the invention is based on the knowledge that is also effective through a horizontal direction Adjustment of a deflection roller from the one rolled Belt between roll stand and winding device traveled distance can be adjusted so that the Speed fluctuations are minimized and, provided they do occur within short response times can be compensated. The number of Redirections that the tape on its way between Must pass through the winding device and roll stand, also reduced to a minimum. So are at inventive procedure and configuration between the roll stand and the respective winding device in the Usually, a maximum of two redirections are sufficient to achieve the Make speed compensation according to the invention and ensure the smooth running of the rolled strip to be able to.

This is beneficial compared to conventional devices improved control behavior of an inventive Device in that significantly lower masses shorter distances need to be moved to each required adjustment of the between mill stand and Unwinder to accomplish each existing strip length.

Can be implemented particularly easily and in a practical manner the adjustability of the pulley Belt tension compensation device in that the position of the Roller is linearly adjustable in the horizontal direction. To for this purpose, the role can, for example, from one a rail movable carriage carried be based on a suitable actuator easy to move. Such a car will by means of the respective drive from a position in which a first distance between the roll and the roll stand exists, moved into at least a second position in which another distance between the roll and the roll stand consists. In addition to the simple control and adjustability there is the main advantage of this embodiment of the Invention in that the strip between the roll stand and the pulley of the belt tension compensation device in one single horizontal plane can be performed. To this In this way, optimal conditions can also be found in the roll gap then ensure if a "flexible rolling" with strong fluctuating loads on the strip and the roll stand is carried out.

The at an adjustment of the deflection of the Belt balancer moving masses can continue be reduced by following an alternative Embodiment of the invention, the role of a swing arm is worn. In addition to the minimized weight, the essential advantage of this configuration in the particular small space required for the arrangement and adjustment of the Deflection roller is required.

To hold and adjust when using a swing arm the pulley despite the adjustment required pivotal movement to allow that Belt between the roll stand and the deflection roller essentially the swing arm can be guided horizontally for example, be coupled to an actuating device, over which their length can be changed during operation.

The deviations by which the strip run between the nip and deflection roller from the horizontal plane of the roll gap deviations can also be minimized by the fact that the Swing arm in a middle position of her in the company executed pivoting movements substantially perpendicular is aligned. On the other hand, the actuating forces should be minimized the middle position of the rocker can also be chosen in this way that in this middle position they are one against the Horizontal inclined position.

To ensure that the metal strip runs smoothly when unwinding or winding, it may be appropriate between the respective winding device and the associated strip tension compensation device a deflection roller provided.

This enables the controlled construction of the belt tension accomplish that one or more of that Steel strip on its way from the unwinder to the Drum passed rollers or be slowed down. To this end, the roles of Belt tension compensation device and / or the additional arranged deflection roller with a drive or Brake device be coupled. In addition to building a Belt tension can be controlled by a targeted braking or Accelerate the desired unwanted relative movements between the rollers and the steel belt ("belt slide") safely avoid.

The invention can be particularly effective Use the device if with it metal strips changing strip thicknesses generated by flexible rolling should be. For this purpose, at device according to the invention the rolling stand in itself known manner equipped with an actuator be the height of the roll gap during operation changed so that the rolled strip in one position a small strip thickness and in another position receives larger strip thickness.

Fig. 1

eine Vorrichtung zum Kaltwalzen von Stahlbändern in seitlicher Ansicht;

Fig. 2

eine Ausgestaltung der in Fig. 1 dargestellten Vorrichtung in seitlicher Ansicht;

Fig. 3

eine weitere Vorrichtung zum Kaltwalzen von Stahlbändern in seitlicher Ansicht.

The invention is explained in more detail below on the basis of a drawing illustrating an exemplary embodiment. They show schematically:

Fig. 1

a device for cold rolling steel strips in a side view;

Fig. 2

an embodiment of the device shown in Figure 1 in a side view.

Fig. 3

another device for cold rolling steel strips in a side view.

The one shown in FIG. 1 that can be operated in reverse operation Device 1 for cold rolling a steel strip S is with an unwinder 2, a first Strip tension compensation device 3, a roll stand 4, one second band tension compensation device 5 and one Rewinder 6 equipped. The Unwinder 2, the first Belt tension compensation device 3, the roll stand 4, the second band tension compensation device 5 and Rewinder 6 are placed in line and are from the cold-rolled steel strip S in the conveying direction F happened in succession.

The band tension compensation devices 3.5 each comprise a car 7.8. Each of the carriages 7,8 can be set up independently rails 7a, 8a arranged in a horizontal plane by means of each of a suitable drive linear between the Roll stand 4 and the unwinder 2 and the Roll stand 4 and the winding device 6 move become. The carriages 7,8 each carry a role 9,10, the Axis of rotation essentially parallel to the axis of rotation the work rolls of the roll stand 4 is aligned.

That of the unwinding device 2 from a first in Diameter large coil CA steel strip S running from below lies on the roll 9 of the strip tension compensation device 3 from which it enters the roll gap 4a of the roll stand 4 enters. The position of the axis of rotation of the roller 3 is oriented taking into account their diameter, that the steel strip S between the roll 3 and the roll gap 4a of the roll stand 4 in a constant through which Rolling gap 4a running horizontal plane H runs.

That which runs out of the roll gap 4a in the conveying direction F. Steel strip S is on the roll 10 of the second Belt tension compensation device 5 deflected lying thereon, that it is from below into the take-up device 6 wound coil CB runs in. The position of the Axis of rotation of the roller 10 of the second Belt tension compensation device 5 is aligned so that the steel strip S between the roll stand 4 and the Roll 10 runs in the horizontal plane H.

Both role 9 and role 10 are from Steel belt S wrapped around less than 90 ° of its circumference.

Fluctuations in the strip tension are caused by the rolling operation Belt tension measuring devices, not shown, are detected. Become in the conveying direction F in front of or behind the roll stand 4 lying area 4b, 4c over a tolerance range Deviations of the strip tension from a target value going beyond this is determined, so the respective Belt tension compensation device 3 or 5 as long as in the Compensate for this deviation moving in the correct direction until the setpoint is reached again.

For example, if it is found that the belt tension in the Infeed area 4b of the roll stand 4 is too high, so the band tension compensation device 3 in the direction of Roll stand 4 moves. With this approach the Strip tension compensation device 3 goes to the roll stand 4 a shortening of the distance between the Coil CA and the roll stand free running tape length. The position in question the band tension compensation device 3 is in FIG. 1 shown in dashed lines.

In contrast, for example, in the outlet area 4c of the Roll stand 4 detects too little strip tension, so the Strip tension compensation device 5 moved away from the roll stand 4, the distance between the roller 10 and the roll stand and along with that between the Coil CB and the Roll stand free-running strip length to enlarge. The relevant position of the band tension compensation device 3 shown in dashed lines in Fig. 1.

By the described shift of Belt tension compensation devices 3 and 5 can also be used strong fluctuations in the speed of the tape run, like them typically when rolling in the course of changing the Enter the strip thickness, master it easily and safely.

The device 20 shown in FIG. 2 corresponds in terms of their functional units and the way they work the band tension compensation devices 3.5 of the previous Device 1 explained. In contrast to device 1 is however in the device 20 between the Unwinding device 2 and the associated Belt tension compensation device 3 a deflection roller 11 arranged. The deflection roller 11 is so on the one hand positions that the steel strip S at maximum diameter of the coil CA essentially runs horizontally from below to the pulley 11 and then is deflected upwards at her so that it is on the Coil CA side facing the roll 9 of the Bandzugausgleichseinrichtung 3, where it then hits again in the horizontal plane H in the direction of Roll gap 4a of the roll stand 4 is deflected. Through the Deflection roller 11 is thus ensured that the steel strip S even with large diameters of the coil CA in enters the conveyor path of the device 20.

In a corresponding manner, the device 20 is between the band tension compensation device 5 and the Winding device 6 a deflection roller 12 is provided. Also this deflection roller 12 is positioned so that the Steel strip wound on the Coil CB with maximum circumference of the coil CB is guided essentially horizontally. The emerging from the roll gap 4a of the roll stand 4 In this case, steel strip S is first on roll 10 the band tension compensation device 5 deflected such that it on the side assigned to the roll stand 4 on the Deflection roller 12 hits. The steel strip S is then attached to it again directed towards the coil CB.

Operation of device 20 with respect to FIG Regulation of the belt tension by the Belt tension compensation devices 3.5 corresponds to that of Device 1.

The device 30 shown in FIG. 3 also corresponds in its basic concept that shown in Fig. 1 Device 1. It is accordingly also with a Winding device 2, a first Belt tension compensation device 33, a roll stand 4, one second band tension compensation device 35 and one Rewinder 6 equipped in the conveying direction F in line from the cold to be rolled Steel belt S are run through.

In contrast to the devices 1 or 20 are in the Device 30 the strip tension compensation devices 33,35 each formed by a rocker 36 and 37, respectively one end each parallel to the axis Rotation axes of the roll stand aligned pivot axis 38.39 are pivotally mounted. The swivel actuation takes place thereby by hydraulic cylinder 40.41. Of course other drive types can also be used for this purpose use that have a comparably fast response time and ensure a sufficiently high generation of force.

At its free end each rocker 36, 37 carries one Roll 9.10. The length of the wings 36.37 is below Taking into account the diameter of each of them worn roll 9.10 dimensioned so that with vertical Alignment of the wings 36,37 the steel strip S between the rollers 9, 10 and the roll gap 4a of the roll stand 4 in the horizontal plane H running through the roll gap 4a is led. The vertical position corresponds the respective middle position around which the wings 36, 37 be pivoted during the rolling operation.

There are fluctuations in the strip tension during rolling operation one that is beyond a tolerance range of one Deviate from the setpoint, the wings become 36.37 in the right direction to compensate for this deviation pivoted until through with the pivoting accompanying change in the length of the steel strip S the setpoint is reached again.

For example, if it is found that the belt tension in the Infeed area 4b of the roll stand 4 is too small, so the rocker moves in the direction of the winding device 2. In this way, the distance from the rocker 36 worn roll 9 to the roll stand 4 and accordingly the of the steel strip S as a whole between the roll stand and the coil CA. run length increased with the consequence that the Belt tension again assumes the required value.

In a corresponding manner, the rocker 37 is in the direction the winding device 6 moves when in the outlet area 4c of the roll stand 4 there is too little strip tension. Through this pivoting movement, the distance between the roller 10 carried by the rocker 37 and the roll stand and in turn the associated between the Coil CB and the mill stand 4 increased free running length of strip, so that after a sufficiently wide swiveling also in Infeed area 4c of the roll stand 4 the required Belt tension is restored.

The relevant positions of the Belt tension compensation device 33, 35 are shown in FIG. 3 shown in dashed lines.

If the strip tension in the lead-in area 4b or is too high Outfeed area 4c of the roll stand 4 become the wings 36.37 of the band tension compensation devices 33.35 each in Direction of the mill stand 4 pivoted through Shortening the free running length of the steel strip S to compensate for the undesirable increase in tape tension.

REFERENCE NUMBERS

1,20,30

Device for cold rolling a steel strip

2

unwinding

3

first belt tension compensation device

4

rolling mill

4a

Roll gap of the roll stand 4

4b

Infeed area of the roll stand 4

4c

Outfeed area of the roll stand 4

5

second belt tension compensation device

6

takeup

7.8

dare

7a, 8a

rail

9.10

role

11.12

idler pulley

33

first belt tension compensation device

35

second belt tension compensation device

36.37

wing

38.39

swivel axis

40.41

hydraulic cylinders

S

steel strip

F

conveying direction

CA

coil

CB

coil

H

WL

Claims (12)

Device for rolling metal strips, in particular steel strips (S), with a roll stand (4), with a winding device (2,6) and with at least one strip tension compensation device (3) arranged between the roll stand (4) and the winding device (2,6) , 5), characterized in that the strip tension compensation device (3, 5) comprises a roller (9, 10) deflecting the respectively rolled strip (S) during operation, the distance from the roll stand (4) measured in the horizontal direction being adjustable. Device according to claim 1, characterized in that the position of the roller (9, 10) is linearly adjustable in the horizontal direction. Device according to one of the preceding claims, characterized in that the roller (9,10) is carried by a carriage (7,8) which is driven by a drive from a position in which a first distance between the roller (9,10) and the roll stand (4) can be moved into at least a second position in which there is a different distance between the roller (9, 10) and the roll stand (4). Device according to one of the preceding claims, characterized in that the roller (9, 10) is carried by a rocker (36, 37). Apparatus according to claim 4, characterized in that the pivot axis (38,39) of the rocker (36,37) is arranged axially parallel to the axes of rotation of the work roll of the roll stand (4). Device according to one of claims 4 or 5, characterized in that the length of the rocker (36,37) can be changed during operation. Device according to one of claims 4 to 6, characterized in that the rocker (36,37) is oriented substantially vertically in a central position of the pivoting movements performed by it in operation. Device according to one of the preceding claims, characterized in that at least one strip tension compensation device (9, 10) is arranged in the conveying direction (F) of the metal strip (S) in front of and behind the roll stand (4). Device according to one of the preceding claims, characterized in that in the conveying path of the steel belt (S) between the belt tension compensation device (3,5,33,35) and the unwinding or winding device (2,6) at least one deflection roller (11,12) is arranged. Device according to one of the preceding claims, characterized in that the roller (9, 10) of the strip tension compensation device (3, 5, 33, 35) and / or the additionally arranged deflection rollers (11, 12) are coupled to a drive or a braking device , Device according to one of the preceding claims, characterized in that the roll stand (4) is equipped with an adjusting device which changes the height of the roll gap (4a) during operation in such a way that the rolled metal strip (S) in one position has a small strip thickness and receives a larger strip thickness in another position. Process for rolling metal strips, in particular for cold rolling steel strips (S), in which the rolling metal strip uncoiled from a coil (CA), rolled in a roll stand (4) and then is coiled, the on the metal band (S) heavy belt tension by means of a Belt tension compensation device (3,5,33,35) regulated whose horizontal distance from the roll stand (4) in Adjusted depending on the tape tension recorded becomes.

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