EP1343597B1 - Roll stand for hot-rolling or cold-rolling metallic strips - Google Patents

Abstract

The invention relates to a roll stand for hot-rolling or cold-rolling metallic strips. The roll stand comprises back-up rolls and work rolls ( 2, 3; 4, 5 ) which are respectively positioned in chocks ( 6; 7 ) in a rotating manner. Each chock ( 6; 7 ) can be displaced on two sides in guiding devices ( 8 ) of the column frame ( 9 ) for adjusting the roll gap ( 10 ) and can be additionally displaced on at least one side for adjusting the play, by means of horizontal piston cylinder units ( 11 ) arranged in the column frame ( 9 ). The aim of the invention is to completely eliminate the play in the vertical guiding device ( 8 ) of the work roll chocks ( 6; 7 ) during the rolling. To this end, the chocks which are guided on at least one side of the column ( 9 a) by means of the piston cylinder unit ( 11 ) arranged in the column frame ( 9 ) and by means of one respective support element ( 14 ) which is arranged on the front side of the piston ( 11 a), can be pressed against the other side of the column ( 9 b) and the guiding device ( 8 ) thereof without play when the vertical roll positioning drive is stopped. and can be released when the vertical roll positioning device is switched on.

Description

The invention relates to a roll stand for hot or cold rolling of metallic Tape material e.g. of different steel grades, with support and work rolls, which are each rotatably supported in chocks, the chocks on both sides in guides of the stand frame for adjustment of the roll gap and additionally arranged in the stand frame horizontal piston-cylinder units at least on one side to adjust the play are adjustable. A corresponding roll stand is according to the preamble of claim 1 e.g. known from DE-A 199 11638.

Because of wear, the work rolls of belt mills are replaced every 4 - Replaced with new work rolls for 6 hours. The procedure of changing the work roll is currently in an automatic cycle using a changing device. For a free play of the chocks in the vertical Adjustment for roll gap control is between the stand and chock A gap of a few millimeters is provided. This gap is disadvantageous when rolling.

When hot rolling individual slabs in a hot strip mill, step during large impacts with enormous accelerations. The chocks are thrown against the stand guide and this is heavily burdened. The impact load wears out the guideway very much fast, the leadership game gets bigger and the acceleration forces become higher and higher. You have already tried, with hardened guide rails and one compliant, soft steel to alleviate these problems.

Cold rolling strives to stabilize the work rolls by a few Millimeters (approx. 4 to 10 mm) in front of the center of the roll stand, in the rolling direction seen to position. A design in which the Center offset in size would be adjustable to support the profile control. The setting via wedge bars at the start of the rolling process is however also disadvantageous, even if the setting is repeated at intervals is because of the need for work roll adjustability the game cannot be completely eliminated. Such a game is on the other hand, necessary because the chuck heats up during hot rolling and expands, but the roller stand remains cold. This will decrease the game though. This reduction in the game after heating can then again cause the vertical adjustment to jam.

In all cases there is an imprecisely defined position of the work roll chocks in the stand both during cold rolling and hot rolling disadvantageous. There is also a requirement that vertical mobility the chocks in the stand guide must be given. It must be taken into account that the modern rolling mills with the so-called AGC regulation (Automatic Gage Control) work. Because of this AGC regulation will be short after tapping, measured whether the roll gap has the desired size. In the event of deviations, the hydraulic adjustment in the stand under rolling force readjusted. In general, the AGC regulation ensures that independent of temperature fluctuations and changes in deformation force Metal strip (steel strip) is always rolled with the exact same thickness. For a rolling with a constant profile of the metal strip is a guide gap between chock and scaffold stand very unfavorable because of the random Position of the work rolls in the stand an unwanted setting of the work rolls can occur among themselves, which falsifies the desired profile.

It is a device for correcting the position of the stand windows of rolling stands guided bearing chocks of the rollers known (DE 44 34 797 A1), which consists of hydraulically actuated cylinder pressure tappets, which in Cylinder recesses are guided, which are guided in the bearing chocks are. The cylinder pressure tappets can be against one or both of the guide surfaces the stand window of the roll stand can be moved. This can the guiding game of the chocks the respective course of the rolling process adjusted, but it cannot be completely eliminated. Moreover is the disconnection and reconnection of the hydraulic connection at Roll change time-consuming and associated with considerable costs, whereby Approx. 80 rollers per finishing train are included in the change program.

It is also a device for controllably influencing the frictional forces between the guide surfaces and contact surfaces of in the stand windows Bearing chocks of the rollers guided by roll stands are known (DE 199 11 638 A1), with plane, load-bearing surfaces on the back that can be pressurized as guide surfaces Carrier plates are arranged in this perpendicular to the guide surfaces or contact surfaces are slidably guided. This will however, very large guide surfaces are created and a residual game can also not be eliminated.

The invention has for its object the game of the work roll chocks to be completely eliminated in their vertical guidance during rolling and to do without a hydraulic connection to the chocks.

The object is achieved according to the invention in that the work roll chocks at least one stand side by means of that in the stand frame arranged piston-cylinder unit and by means of one at each Piston face arranged support element guided against the other side of the stator and their guidance without movement play when the vertical roller actuator is shut down can be pressed on and with the vertical roller adjustment drive switched on is solvable. This will make the game while rolling the chocks in the guides of the stand windows are completely eliminated, which favors the result of the regulation by the AGC process and the rolled profile is adhered to more precisely.

In an embodiment of the invention it is provided that the support element in each case from a round plate made of metal with guide bands embedded in the circumference made of plastic and that the circular blank is guided in the stand frame. The In this design, Ronde absorbs transverse forces that act on the stand frame act and ensures a rigid structure of the game elimination during rolling. The round blank can be retracted when changing the work carriage.

Another embodiment provides that the round plate on the piston rod of the Piston-cylinder unit is attached. As a result, the circular blank guides all movements the piston rod with.

A sensitive movement of the piston can also be achieved by acting on both sides of the piston of the piston-cylinder unit is.

The supply of pressure medium is designed in such a way that the piston-cylinder unit can be supplied by means of pressure medium through channels in the stand frame is. No hose lines need to be loosened when changing the roller and be reconnected.

It is also advantageous for the pressure medium supply that the channels for the pressure medium around the cylinder of the piston-cylinder unit Grooves open.

A design which is advantageous for the movements of the round blank also consists in that the round blank is made of gunmetal and that the recessed on the circumference Guide bands are made of Teflon.

The process of eliminating the game and approving a movement game when setting the Rollspakt, i.e. when vertically adjusting the chocks, can advantageously be influenced in that the hydraulic pressure in the Piston-cylinder unit at different pressures for adjusting the play or Elimination of play for the chock in the guide of the respective stand side is adjustable and that for a vertical adjustment of the chocks Control can be converted to signals from an automatic gage control system (AGC) is. This enables the circular blank to be axially pressed at full hydraulic pressure pressed against the chock and thereby eliminating any play. When working with the AGC control, the hydraulic pressure is slightly reduced, so that allows vertical adjustment of the chocks with the work rolls becomes. It is therefore advantageous to have a control which in turn controls the signals from of the AGC regulation. The controller for the round blank recognizes which one When the AGC control requires a vertical adjustment of the chock and can adjust the hydraulic pressure in the horizontal in a short time Reduce the piston-cylinder unit.

According to further features, a standard link for profile control can also be used can be used completely unhindered via the work roll bend. For this it is proposed that in connection with a several bending cylinders perpendicular to the roll axis individual piston-cylinder units that run at a distance from the bending cylinder are arranged to attack a piston head that is connected to the round blank is provided. Here, e.g. a May-West bending block can be used. CVC control can also be performed by axially shifting profiled sections Rollers are used.

When using such bending devices, it may be advantageous to be symmetrical the piston-cylinder units to the axis of the bending cylinder in polygon corners are arranged for the round blank. This arrangement uses the existing one Space and the existing base areas around the bending cylinder out.

Furthermore, it may be advantageous for reasons of space or space if the Ronde with its central longitudinal axis arranged eccentrically to the work roll axis is.

Another variant of the arrangement of several smaller piston-cylinder units consists in the fact that the Rounds two or more rounds, each with a smaller circular area are. Such measures can be constructively advantageous in individual cases.

In the event that significant frictional resistances, e.g. Stiction at Switching from presses to loosening the blank can occur, the invention also be designed in such a way that the support element consists of a sliding shoe exists, which is shaped like a sled runner with a corresponding runner width and engages in the guide of the chocks.

In the drawing, embodiments of the invention are shown are explained in more detail below.

Fig. 1

einen senkrechten Schnitt durch ein Quarto-Walzgerüst in Vorderansicht,

Fig. 2

eine zugehörige Seiten-Ansicht mit Teilschnitt durch das Quarto-Walzgerüst,

Fig. 3

einen vergrößerten Schnitt durch die Ronde mit horizontaler Kolben-Zylinder-Einheit,

Fig. 4

eine Seiten-Ansicht auf die Ronde,

Fig. 5

eine Ausführungsform mit einem Biegeblock auf einem Walzenzapfen
und mehreren Kolben-Zylinder-Einheiten für die Spielbeseitigung,

Fig. 6

einen horizontalen Schnitt durch eine Ausführungsform mit Biegezylinder und mehreren kleineren Kolben-Zylinder-Einheiten für die Spielbeseitigung der Einbaustücke,

Fig. 7

eine zu Fig. 6 gehörende Seitenansicht auf die Ronde und

Fig. 8A

eine Ausführungsform mit zwei Kolben-Zylinder-Einheiten und vier Führungsstangen, die an der Ronde angreifen, in Seitenansicht und

Fig. 8B

einen Querschnitt durch die Anordnung gemäß Fig. 8A.

Show it:

Fig. 1

a vertical section through a four-high mill stand in front view,

Fig. 2

an associated side view with partial section through the four-high mill stand,

Fig. 3

an enlarged section through the round blank with a horizontal piston-cylinder unit,

Fig. 4

a side view of the round blank,

Fig. 5

an embodiment with a bending block on a roll neck
and several piston-cylinder units for clearance elimination,

Fig. 6

a horizontal section through an embodiment with a bending cylinder and several smaller piston-cylinder units for eliminating play of the chocks,

Fig. 7

a side view belonging to Fig. 6 on the blank and

Figure 8A

an embodiment with two piston-cylinder units and four guide rods that engage the blank, in side view and

Figure 8B

a cross section through the arrangement of FIG. 8A.

The roll stand according to FIG. 1, a four-high roll stand, is used for hot or Cold rolling of metallic strip material 1, e.g. of different steel grades, and has backup rolls 2, 3 and work rolls 4, 5, each in chocks 6, 7 are pivoted. The chocks 6, 7 for the support rollers 2, 3 or for the work rolls 4, 5 are on both sides in guides 8 of a stand frame 9 slidably guided to adjust the nip 10. In addition are at least in the stand frame 9 horizontal piston-cylinder units 11 one-sided (see FIG. 2) for adjusting the play of the chocks 6, 7 for the work rolls 4, 5 provided.

The upper support roller 2 is by means of hydraulic actuating cylinders 12, which accordingly an AGC control, equipped. The lower chocks 7 rest in the stand frame 9 on load cells 13. The work roll chocks 6, 7 for at least one stator side 9a are by means of the in the Stand frame 9 arranged, horizontal piston-cylinder units 11 and by means of a support element arranged on the piston face side 11 a 14, guided on all sides, against the other side of the stand 9b and its Guide 8 without movement with the vertical roller actuator set, from the hydraulic vertical actuators 12 exists, pressed and when the vertical roller actuator is switched on easily solved, so that a sliding adjustment of the chocks 6, 7 take place can.

The support element 14 consists of a cylindrical body, short as Circular blank 14a (FIG. 3), the circular blank 14a being made of metal, e.g. made of gunmetal and on the circumference 14b guide bands 15 made of plastic, e.g. made of Teflon.

The blank 14a is on a piston rod 16 of the horizontal piston-cylinder unit 11 attached by means of a screw 17. The piston 18 of the horizontal As can be seen, the piston-cylinder unit 11 is double-sided with pressure medium acted upon. The pressure medium for the piston-cylinder unit 11 is fed through channels 19 and 20 to the two piston sides. Channels 19 and 20 run within the stand frame 9. The channels 19 and 20 open in grooves 22 running around the cylinder 21 or around the piston rod 16 23. The circular outer shape of the round blank 14a is visible in FIG.

According to an alternative embodiment, the control of the hydraulic pressure in the piston-cylinder unit 11 to the different pressures Adjustment of play when actuating the vertical roller adjustment drive or Eliminate play for chock 6 or 7 by operating the horizontal Piston-cylinder unit 11 in the guide 8 and the respective stator side 9a or 9b adjusted and controllable accordingly, for what with a vertical adjustment the chocks 6 or 7 with the support rollers 2 or 3 the control is switched to signals of an automatic gage control system.

Another embodiment (Fig. 5) provides a connection to one at a Roll pin 4a or 5a, perpendicular to the roll axis 24 Bending cylinder 25 before. In this embodiment, the blank 14a is the support member 14 in the piston-cylinder unit 11 from several smaller piston-cylinder units 27 consisting of a distance 26 (see FIG. 6) to Bending cylinders 25 run, formed. The piston head 11b is with the round blank 14a Mistake. The relatively large piston head 11b and the relatively small piston-cylinder units 27 can expediently by means of Allen screws 33 be connected so that the respective piston head can also be withdrawn.

Polygonal corners 28 are symmetrical to the axis 25a of the bending cylinder 25 the smaller piston-cylinder units 27 are arranged for the round blank 14a (FIG. 7).

Here, the round blank 14a with its central longitudinal axis 29 is eccentric to the work roll axis 30 arranged.

8A and 8B, a further variant of the design is shown with the spaced from the bending cylinder 25 two symmetrically arranged horizontal Piston-cylinder units 11, each on the piston 18 via tabs 31 axially and parallel arranged, paired guide rods 32 are stored, which together hold the blank 14a.

LIST OF REFERENCE NUMBERS

1

band material

2

supporting roll

3

supporting roll

4

Stripper

4a

roll neck

5

Stripper

5a

roll neck

6

chock

7

chock

8th

guide

9

Uprights

9a

stand side

9b

stand side

10

nip

11

horizontal piston-cylinder unit

11a

Piston end face

11b

piston head

12

hydraulic, vertical actuating cylinder (vertical roller actuator)

13

Load cell

14

support element

14a

Ronde

14b

Circumference of the round blank

15

guide belts

16

piston rod

17

screw

18

piston

19

Pressure medium channel

20

Pressure medium channel

21

cylinder

22

groove

23

groove

24

roll axis

25

bending cylinders

25a

Axis of the bending cylinder

26

distance

27

several smaller piston-cylinder units

28

Polygonalecken

29

Central longitudinal axis of the round blank

30

Work roll axis

31

flap

32

in pairs of guide rods

33

Allen screws

Claims (13)

1. Roll stand for hot-rolling or cold-rolling of metallic strip material (1), for example of different steel qualities, with backing rolls and working rolls (2, 3, 4, 5), which are rotatably mounted in respective chocks (6, 7), wherein the chocks are adjustable at both ends in guides (8) of the housing frame (9) for setting of the rolling gap and additionally at at least one end by means of horizontal piston-cylinder units (11), which are arranged in the housing frame, for setting of play, characterised in that the working roll chocks (6; 7) of at least one housing side (9a) are guided relative to the other housing side (9b) by means of the piston-cylinder unit (11) arranged in the housing frame (9) and each by means of a respective support element (14) arranged at the piston end face (11a) and the guides (8) thereof are loadable with pressure without movement play when the vertical roll adjusting drive is stationary and are releasable when the vertical roll adjusting drive is switched on.
2. Roll stand according to claim 1, characterised in that each support element (14) consists of a round plate (14a) of metal with guide strips (15) of synthetic material let in at the circumference (14b) and that the round plate (14a) is guided in the housing frame (9).
3. Roll stand according to one of claims 1 or 2, characterised in that the round plate (14a) is fastened to the piston rod (16) of the piston cylinder unit (11).
4. Roll stand according to one of claims 1 to 3, characterised in that the piston (18) of the piston-cylinder unit (11) can be loaded at both sides.
5. Roll stand according to one of claims 1 to 4, characterised in that the piston-cylinder unit (11) can be supplied by means of pressure medium via channels (19; 20) in the housing frame (9).
6. Roll stand according to claim 5, characterised in that channels (19; 20) for the pressure medium open into grooves (22; 23) running around the cylinder (21) of the piston-cylinder unit (11).
7. Roll stand according to one of claims 1 to 6, characterised in that the round plate (14a) is made of gun metal and that the guide strips (15) let in at the circumference (14b) consist of 'Teflon'.
8. Roll stand according to one of claims 1 to 7, characterised in that the hydraulic pressure in the piston-cylinder unit (11) can be regulated to different pressures for setting play or for eliminating play for the chocks (6; 7) in the guide (8) of the respective housing side (9a; 9b) and that for vertical adjustment of the chocks (6; 7) the regulation can be converted to signals of an Automatic Gauge Control Regulation (AGC).
9. Roll stand according to one of claims 1 to 8, characterised in that in conjunction with a bending cylinder (25), which engages at a roll pin (4a; 5a) and extends vertically relative to the roll axis (24), several individual piston-cylinder units (27) arranged to extend at a spacing (26) relative to the bending cylinder (25) engage at a piston head (11b) which is provided with the round plate.
10. Roll stand according to claim 9, characterised in that the piston-cylinder units (27) for the round plate (14a) are arranged symmetrically to the axis (25a) of the bending cylinder (25) in polygonal comers (28).
11. Roll stand according to one of claims 1 to 10, characterised in that the round plate (14a) is arranged with its centre longitudinal axis (29) eccentric with respect to the working roll axis (30).
12. Roll stand according to one of claims 1 to 11, characterised in that arranged on the theoretically provided circular area of the round plate (14a) are two or more round plates with respectively smaller circular area.
13. Roll stand according to claim 1, characterised in that the support element (14) consists of a slide shoe which is formed similarly to a slide skid with corresponding skid width and engages in the guide (8) of the chocks (6; 7).

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