EP1784266B1 - Rolling mill for rolling a metallic strip - Google Patents

Abstract

In a rolling mill for rolling metal strip ( 1 ), especially steel strip, which has at least one rolling stand ( 2 ), an upstream coiler ( 3 ), and a downstream coiler ( 4 ), wherein an "S" roll unit ( 5, 6 ), which has two rolls ( 7, 8; 9, 10 ) that guide the strip ( 1 ) in the form of an "S", is arranged between the upstream coiler ( 3 ) and the rolling stand ( 2 ) and/or between the rolling stand ( 2 ) and the downstream coiler ( 4 ), the invention provides that a first roll ( 7, 9 ) of the "S" roll unit ( 5, 6 ) is arranged in a fixed manner, and a second roll ( 8, 10 ) of the "S" roll unit ( 5, 6 ) is arranged in such a way that it can move relative to the first roll ( 7, 9 ).

Description

The invention relates to a rolling mill for rolling metallic strip, in particular steel strip, which has at least one rolling mill, an upstream reeling device and a downstream reeling device, wherein an S-reel unit is arranged between upstream reeling device and rolling stand and / or between rolling stand and subordinate reeling device. the two having the band S-shaped leading rollers, wherein a first roller of the S-roller unit is arranged stationary and a second roller of the S-roller unit is arranged to be movable relative to the first roller and wherein the second roller arranged movably relative to the first roller on a Swivel arm is rotatably mounted, which is mounted on one side in a fixed space axis.

The increasing pressure to save weight, especially in the automotive industry, led to the development and use of load-adapted components, so-called tailored blanks. The essential feature of these components, which is of particular interest in this context, is that they have a variable thickness. First of all, tailored blanks were mainly made by welding. However, for the production of flexible cold rolling has proven to be particularly advantageous, can be produced with the tailored blanks.

In flexible cold rolling, the thickness of the rolled stock is changed during rolling. The change of the roll gap can be done periodically. The change in thickness leads to mass flow disturbances and to tensile fluctuations, in particular on the inlet side, but also on the outlet side of the roll stand. In the case of the rolling speeds necessary for profitable production, the dynamics of the reel motors are no longer sufficient for their compensation, so that in such systems so-called dancer rollers are used between the rolling stand and the reels.

In the WO 03/008122 A1 such a solution is described. It is known therefrom a cold rolling mill for cold rolling of metallic strip and has a single stand with means for adjusting the roll gap and a reeling the upstream of the cold roll stand reeling device for unwinding the tape and a reel downstream reel means for reeling the tape. In order to enable flexible rolling, a strip store for mass flow regulation or strip tension control of the rolling process is provided between the upstream reeling device and the rolling stand. This tape storage consists of at least three rollers, wherein the middle roller is designed as a dancer roll and can be moved perpendicular to the conveying direction of the tape.

Generic rolling mills are also in the DE 30 24 682 A1 and in the JP 04 182019 A described. The swivel arm for adjusting the one roller of the S-roller unit relative to the other is mounted here above the upper roller. A moving element engages below the lower roller. Thus, very large adjustment paths are required to accomplish the role adjustment.

One to WO 03/008122 A1 similar solution - but using a larger number of roles - goes out of the EP 1 121 990 A2 out. The same applies to a design that is made from the JP 10034204 A is known.

The dancer rollers described in said documents are connected to a linear actuator, with which they can be controlled or moved in a direction perpendicular to the conveying direction of the tape direction. This can fulfill the tape storage function which is indispensable for flexible cold rolling.

From the DE 198 18 207 C2 and from the JP 60231516 So-called Looper are known, ie rollers that are applied to the run or guided to the rolling mill band, for example, to make a tensile force determination in the band can.

When rolling, the rolling force can be reduced by tensile forces on each side of the nip, it must not be too high only in the last trick, otherwise experience shows that problems may occur in the subsequent process steps, especially during annealing. To build a train difference between roll stand and reel, S-roll units (S-rolls) can be used.

If both a band storage function - usually with dancers - are met and a desired Zugdifferenz between rolling mill and reel - usually by S-roller units - are generated, a considerable expenditure on equipment is required in the known solutions.

The invention is therefore based on the object, a rolling mill for rolling metallic strip of the type mentioned in such a way that can be achieved with simple means and thus in an economical manner that both a band storage function, especially in flexible rolling, is given as well as a Defined controllable Zugdifferenz between roll stand and reels can be kept defined.

This object is achieved in that the spatially fixed axis of the axis of rotation of the first roller corresponds, wherein the pivot arm in a remote from the fixed axis fulcrum a linear actuator is articulated and wherein the fulcrum is located on a connecting line between the axes of rotation of the two rollers.

Apart from possibly still provided guide rollers for the band, only the S-reel unit between reel and stand is to be provided, however, both the tape storage function and the required train can be exercised on the tape by the proposed design of the S-reel unit.

Both axes of the rollers of the S-roller unit are arranged parallel to each other.

As a linear actuator advantageously a hydraulic piston-cylinder system is used.

In order to optimally influence the tensile structure in the band, means for driving at least one of the rollers of the S-roller unit can be provided.

The invention proposal is advantageously used in a cold rolling mill. Furthermore, the rolling stand is preferably provided as a single frame. The proposed system is particularly suitable for flexible rolling, which is why the rolling stand can have means for flexibly adjusting the roll gap.

The belt transport or its handling is finally improved by the fact that at least one of the reel devices is equipped with means for speed control.

With the proposed system, it is possible in a very simple and thus cost-effective manner to provide a rolling mill for flexible rolling, which provides a tape storage, which is essential in this type of process. Furthermore, the band is held under the required train, so that the rolling itself can be carried out in procedurally advantageous manner.

Fig. 1

schematisch die Seitenansicht eines Walzwerks zum flexiblen Walzen eines Metallbandes und

Fig. 2

eine S-Rolleneinheit der Auslaufseite des Walzwerks in vergrößerter Darstellung.

In the drawing, an embodiment of the invention is shown.
Show it:

Fig. 1

schematically the side view of a rolling mill for flexible rolling of a metal strip and

Fig. 2

an S-roll unit of the outlet side of the rolling mill in an enlarged view.

In Fig. 1 schematically shows a rolling mill, in which a coiled steel strip 1 is unwound from an upstream coiler 3 and a single cold rolling mill 2 is supplied. In the conveying direction R of the metal strand 1 behind the rolling stand 2, a downstream reeling device 4 is provided, which rewinds the rolled metal strip 1. The reels 3, 4 are provided with drives, not shown, so that the tape 1 in a controlled or regulated manner and can be wound up.

In the rolling stand 2, a flexible cold rolling of the strip 1 takes place. The tape 1 has - viewed in its longitudinal direction - a non-constant thickness. That is, during the rolling process, the roll gap is changed according to a predetermined profile to produce a strip whose thickness changes periodically.

For this process to be carried out under favorable process conditions, it is necessary to compensate for the mass flow change in the strip, which results from the variable strip thickness. Furthermore, a defined train must be built up or held in band 1 in order to keep the rolling force low.

In order to achieve this, an S-roll unit 5 or 6 is arranged both between the upstream reeling device 3 and the rolling stand 2 and between the rolling stand 2 and the downstream reeling device 4. Each S-roller unit 5, 6 has two rollers 7 and 8 or 9 and 10, which are arranged in a conventional manner to each other so that the band 1 is guided S-shaped. Due to the consequent wrapping of the rollers 7, 8, 9, 10, it is possible, with appropriate drive of the rollers to transmit a force to the belt 1 and so the desired tensile force in the belt 1 between the S-roller unit 5, 6 and the rolling stand 2 to hold.

In order to be able to exert the tape storage function in addition to the application of the train in the band 1, the S-roll units 5 and 6 are as in Fig. 2 clearly structured. One roller 9 (or 7), which feeds the belt 1 to the rolling stand 2 or removes it from it, is mounted in a stationary manner. The other roller 10 (or 8), however, is pivotally mounted relative to the first roller 9, 7, for which purpose it is arranged at the end of a pivot arm 11. The other end of the pivot arm 11 is mounted on a fixed axis 12, which corresponds to the axis of rotation of the first roller 9, 7.

Somewhat remote from the axis of rotation of the second roller 8, 10, namely at a pivot point 13, the one end of a linear actuator 14 is articulated, this being designed as a hydraulic piston-cylinder system. The supply of the actuator 14 with hydraulic oil is in Fig. 2 indicated.

By controlled or controlled admission of the piston-cylinder system 14 with hydraulic oil, the pivot point 13 can be raised or lowered, so that the second roller 8, 10 can be pivoted about its pivot axis 12. This results in a longer or shorter distance for the strip 1 between roll stand 2 and reel devices 3 and 4, whereby it is the S-roll units 5, 6 possible to exercise a tape storage function.

The described construction of the rolling plant and in particular of the two S-roll units 5, 6 makes it possible to compensate for the mass flow change occurring during flexible cold rolling and at the same time to build up that draw difference between rolling stand 2 and reel devices 3, 4 with a very simple rolling process is possible. With a correspondingly fast control of the linear actuator 14, it is possible to compensate for the mass flow disturbances without significant pull fluctuations.

So far, a larger number of roles was foreseen and needed to achieve this goal, which made the corresponding equipment expensive.

By balancing the mass flow disturbances and the concomitant reduction of pull variations, the strip thickness control can be improved. It becomes possible to make the settings of the tensile stresses favorable for the rolling process without regard to the tensile stresses present at the reeling devices.

The compensation of the mass flow disturbances and the band storage function are now realized in one device, namely in the described S-roll unit, for which separate devices were hitherto necessary.

LIST OF REFERENCE NUMBERS

1

metallic band (steel band)

2

rolling mill

3

upstream reel device

4

downstream reel device

5

S-roller conveyor

6

S-roller conveyor

7

role

8th

role

9

role

10

role

11

swivel arm

12

fixed space axis

13

pivot point

14

linear actuator

R

Conveying direction of the band

Claims (7)

1. Rolling mill for rolling metallic strip (1), particularly of steel strip, which comprises at least one roll stand (2), an upstream coiler (3) and a downstream coiler (4), wherein arranged between upstream coiler (3) and roll stand (2) and/or between roll stand (2) and downstream coiler (4) is an S roller unit (5, 6) comprising two rollers (7, 8; 9,10) guiding the strip (1) in S shape, wherein a first roller (7, 9) of the S roller unit (5, 6) is arranged to be stationary and a second roller (8, 10) of the S roller unit (5, 6) is arranged to be movable relative to the first roller (7, 9) and wherein the second roller (8, 10) arranged to be movable relative to the first roller (7, 9) is rotatably arranged at a pivot arm (11) mounted at one end at a three-dimensionally fixed axis (12), characterised in that the three-dimensionally fixed axis (12) corresponds with the axis of rotation of the first roller (7, 9), wherein a linear actuator (14) is pivotably arranged at the pivot arm 11 at a fulcrum (13) remote from the three-dimensionally fixed axis (12) and wherein the fulcrum (13) lies on a connecting line between the axes of rotation of the two rollers (7, 9; 8,10).
2. Rolling mill according to claim 2, characterised in that the linear actuator (14) is a hydraulic piston-cylinder system.
3. Rolling mill according to claim 1 or 2, characterised by means for driving at least one of the rollers (7, 8, 9, 10) of the S roller unit (5, 6).
4. Rolling mill according to any one of claims 1 to 3, characterised in that it is constructed as a cold rolling mill.
5. Rolling mill according to any one of claims 1 to 4, characterised in that the roll stand (2) is provided as a single stand.
6. Rolling mill according to any one of claims 1 to 5, characterised in that the roll stand (2) is equipped with means for flexible setting of the rolling gap.
7. Rolling mill according to any one of claims 1 to 6, characterised in that at least one of the coilers (3, 4) is provided with means for rotational speed regulation.

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