EP3590616B1 - Method and device for changing millers on a milling frame - Google Patents

Description

The invention relates to a method for changing backup rolls on a roll stand according to the preamble of claim 1, and to a roll stand with a corresponding device according to the preamble of claim 8.

According to the prior art, a so-called roll changing frame can be used to change back-up rolls in a roll stand, which can be seen, for example, from WO 2003/015949 A1 is known. The process here is complex: after the work rolls have been moved out of the roll stand, they have to be removed from the stand area, with a displacement device onto which the work rolls have been extended must also be removed. The lower support roll is then extended from the roll stand transversely to the rolling direction, the roll changing frame then being placed onto the lower support roll from above. Thereafter, the lower back-up roll is moved back into the roll stand in conjunction with the roll changing frame placed on it, the upper back-up roll then being lowered and placed on the roll changing frame accordingly. Then the lower back-up roll and the upper back-up roll, which is lowered or placed thereon with the help of the roll changing frame, are moved out of the roll stand together again. After this extension, the upper support roller can be lifted off with an indoor crane and a new support roller can be placed on the roller changing frame. In this way, the new back-up roll can then be moved back into the stand area in conjunction with the roll frame and the lower back-up roll.

The procedure explained above is subject to the disadvantage that it is first necessary to prepare for an exchange of the upper backup roll, the lower one To move the backup roll out of the stand area in order to place the roll changing chair on it. The extension of the lower support roller and the subsequent retraction of the lower support roller together with the roller changing frame placed on it requires expensive set-up time. Another disadvantage of this approach is that, as explained, an indoor crane is used to lift the upper support roll off the roll changing frame, after the combination of the lower backing roll, roll changing frame and the upper backing roll placed on it has moved out of the stand area Changing the upper backup roll is not available for other processes.

Out CN 105 618 489 A a generic method with the features according to the preamble of claim 1 and a generic roll stand with the features according to the preamble of claim 8 are known.

Accordingly, the invention is based on the object of simplifying the changing of backup rolls in a roll stand, in that it can be carried out in a shorter time and thus at lower costs.

This object is achieved by a method given with the features of claim 1 and by a roll stand defined with the features of claim 8. Advantageous further developments of the invention are defined in the dependent claims.

The method according to the present invention is used to change back-up rolls on a roll stand. Here, after the work rolls have been extended, a roll changing frame is introduced into the roll stand transversely to the rolling direction, the lower part of the roll changing frame being supported on chocks of the lower back-up roll and the upper back-up roll being lowered onto the roll changing frame. The roll changing frame is retracted into the roll stand via the extension rails provided for the work rolls of the roll stand, after which, after the upper support roll has been lowered onto the roll change frame, either only the upper support roll or a unit formed from the lower and upper support roll is extended from the roll stand will become.

A roll stand according to the present invention serves the same purpose and for this purpose comprises a device for changing backup rolls. In such a roll stand, an upper back-up roll is guided in chocks that can be raised or lowered on a stand frame of the roll stand. The device according to the invention comprises a roll changing frame which can be supported on chocks of a lower support roll of the roll stand. The roll changing frame preferably has entry aids with sliding rollers or sliding elements on both sides thereof, which can be brought into interaction with the extension rails provided for the work rolls of the rolling stand transversely to the rolling direction to move the roll changing frame into the roll stand. Furthermore, the roll changing frame has a lowering device, by means of which the lower part of the roll changing frame can be supported on the chocks of the lower support roll of the rolling frame after the roll changing frame has been introduced into the roll stand. The roll changing frame is designed in two parts in the form of an upper part and a lower part, the upper part of the roll changing frame being displaceable relative to its lower part, so that this upper part, after the upper support roll has been lowered and supported thereon, laterally out of the roll stand can be extended or retracted again.

The invention is based on the essential knowledge that the roll changing frame, after the work rolls have previously been extended from the roll stand, is or can be retracted into the roll stand via the extension rails provided for the work rolls. These extension rails, which are primarily intended for extending the work rolls, are only referred to as such in the following. For the purpose of moving into the roll stand, the roll changing frame is preferably equipped on both sides thereof with entry aids, which comprise sliding rollers or sliding elements which can be brought into contact or interaction with the extension rails. As a result, the roll changing frame can be moved into the roll stand without it being necessary - as in the conventional procedure explained at the beginning - to move the lower backup roll out of the roll stand beforehand. As a result, the time for replacing the backup rolls can be reduced considerably.

After the roll changing frame has been moved into the roll stand transversely to the rolling direction via the extension rails, it can be lowered by means of an integrated lowering device within the roll stand so that a lower part of the roll changing frame rests on the chocks of the lower support roll. Following this, the upper support roller can be lowered - in a manner known per se - and supported on an upper part of the roller changing frame.

According to one possible embodiment of the invention it is provided that the roll changing frame forms a unit with its upper and lower part. With such a roll changing frame, which, as explained, is supported with its lower part on the chocks of the lower back-up roll, it is possible to extend the upper back-up roll laterally out of the roll stand together with the lower back-up roll when it is supported on the upper part of the roll changing frame .

Because the roll changing chair is designed in two parts, namely in the form of an upper part and a lower part, these two parts of the roll changing chair can be coupled to one another and - if necessary - decoupled from one another. Between the upper part and the lower part of the roll changing frame sliding elements, sliding surfaces or rails are provided which - if the two Parts are decoupled from each other - allow a relative displacement between the upper part and the lower part of the roll changing frame. As already explained above elsewhere, the lower part of the roll changing frame can be supported on the chocks of the lower support roll by actuating the mentioned lowering device. This two-part embodiment of the roll changing frame is used to ensure that the upper back-up roll, when it is lowered onto the upper part of the roll changing frame and supported on it, is then extended out of the roll stand together with the upper part of the roll changing frame and independently of a lower back-up roll, or vice versa the roll stand can be retracted. In any case, it is of essential importance here that when the upper support roller is extended or retracted from or into the roll stand, the lower support roll then remains stationary within the roll stand and is not moved. This also leads to a reduced set-up time with regard to changing the upper backup roll.

The last-mentioned embodiment of the invention, according to which the roll changing frame is designed in two parts in the form of an upper and a lower part, essentially serves to remove or change the upper support roll of a roll stand. As explained, the lower part of the roll changing frame is supported on the chocks of the lower backup roll. By simultaneously relaxing the lowering device, the weight of the roll changing frame and the upper back-up roll lowered onto its upper part are then diverted into these chocks and in any case does not weigh on the extension rails of the work rolls.

For both of the above-mentioned embodiments of the roll changing frame, it is pointed out separately that if either the unit is formed from the upper and lower support roll or only the upper support roll is extended from the roll stand or into the roll stand are retracted, then the entry aids of the roll changing chair and their sliding rollers or sliding elements are at least load-reduced or essentially load-free with respect to the extension rails.

In the context of the present invention, the feature "load reduced" means that when the roll changing chair is moved, in particular when the upper support roll has been lowered on it, the lowering device is relaxed along the extension rails to the extent that a weight of the roll changing chair which is on the extension rails does not exceed the weight of the work rolls of the roll stand. Conversely, this means that the lowering device is actuated or relaxed to the extent that the main load of the upper part of the roller changing chair, on which the upper support roller is also supported, is absorbed by the sliding elements or sliding surfaces between the upper part and the lower Part of the roll changing frame are provided, and is then diverted via the lower part of the roll changing frame into the chocks of the lower backup roll. This prevents overloading and thus possible damage to the extension rails.

The invention advantageously enables an automated change either of the upper support roller or a unit formed from the lower and upper support roller. This change is preferably largely automated and can also take place fully automatically. The targeted retraction of the roll changing frame into the roll stand on the extension rails and the subsequent support of the roll changing frame on the chocks of the lower back-up roll means that otherwise time-consuming manual adjustment of the roll changing frame on the extended lower back-up roll is no longer necessary. Such an automatic change of at least one support roll, based on the mentioned lateral retraction of the roll changing chair over the extension rails, leads to a considerable saving in set-up time and at the same time to increased safety for the operating personnel.

Fig. 1

eine schematisch vereinfachte Seitenansicht eines Teils eines Walzgerüstes, mit einem darin eingefahrenen Walzenwechselstuhl in einer ersten Betriebsposition,

Fig. 2

eine schematisch vereinfachte Seitenansicht des Walzgerüstes von Fig. 1, mit einem darin eingefahrenen Walzenwechselstuhl in einer zweiten Betriebsposition,

Fig. 3

eine schematisch vereinfachte Seitenansicht des Walzgerüstes von Fig. 2, mit einer auf den Walzenwechselstuhl abgesenkten oberen Stützwalze,

Fig. 4

eine schematisch vereinfachte Seitenansicht des Walzgerüstes von Fig. 2 nach einer alternativen Ausführungsform, mit einer auf den Walzenwechselstuhl abgesenkten oberen Stützwalze,

Fig. 5.1, 5.2

eine jeweils vereinfachte Seitenansicht und Draufsicht eines Walzgerüstes in einer Ausgangsposition,

Fig. 6.1, 6.2

eine jeweils vereinfachte Seitenansicht und Draufsicht eines Walzgerüstes mit herausgefahrenen Arbeitswalzen,

Fig. 7.1, 7.2

eine jeweils vereinfachte Seitenansicht und Draufsicht eines Walzgerüstes mit einem auf einer Verschiebeeinrichtung bereitgestellten Walzenwechselstuhl,

Fig. 8.1, 8.2

eine jeweils vereinfachte Seitenansicht und Draufsicht eines Walzgerüstes, mit eingefahrenem Walzenwechselstuhl in einer ersten Betriebsposition gemäß Fig. 1,

Fig. 9

eine vereinfachte Seitenansicht eines Walzgerüstes, mit eingefahrenem Walzenwechselstuhl in einer zweiten Betriebsposition gemäß Fig. 2,

Fig. 10

eine vereinfachte Seitenansicht eines Walzgerüstes von Fig. 9, wobei eine obere Stützwalze auf den Walzenwechselstuhl - gemäß der Darstellung von Fig. 3 - abgesenkt ist, und

Fig. 11.1,11.2

eine jeweils vereinfachte Seitenansicht und Draufsicht eines Walzgerüstes, wenn der Walzenwechselstuhl zusammen mit der oberen Stützwalze aus dem Walzgerüst ausgefahren ist.

Further advantages and features of the present invention emerge from the following description of advantageous embodiments, which are explained in detail with reference to a schematically simplified drawing. Show it:

Fig. 1

a schematically simplified side view of part of a roll stand, with a roll changing frame retracted therein in a first operating position,

Fig. 2

a schematically simplified side view of the roll stand of Fig. 1 , with a roll changing chair retracted in a second operating position,

Fig. 3

a schematically simplified side view of the roll stand of Fig. 2 , with an upper backup roller lowered onto the roller changing frame,

Fig. 4

a schematically simplified side view of the roll stand of Fig. 2 according to an alternative embodiment, with an upper support roller lowered onto the roller changing frame,

Fig. 5.1, 5.2

a simplified side view and top view of a roll stand in a starting position,

Fig. 6.1, 6.2

each a simplified side view and plan view of a roll stand with extended work rolls,

Fig. 7.1, 7.2

each a simplified side view and top view of a roll stand with a roll changing frame provided on a shifting device,

Fig. 8.1, 8.2

each a simplified side view and plan view of a roll stand, with retracted roll changing frame in a first operating position according to FIG Fig. 1 ,

Fig. 9

a simplified side view of a roll stand, with retracted roll changing frame in a second operating position according to Fig. 2 ,

Fig. 10

a simplified side view of a roll stand from Fig. 9 , with an upper backup roll on the roll changing chair - as shown in FIG Fig. 3 - is lowered, and

Fig. 11.1,11.2

each a simplified side view and plan view of a roll stand when the roll changing frame is extended from the roll stand together with the upper backup roll.

With reference to the Figs. 1 to 11 preferred embodiments of a device 10 according to the invention and a corresponding method for changing backup rolls 12 on a roll stand 11 are explained. The same features in the drawing are each provided with the same reference symbols. At this point, it is pointed out separately that the drawing is only shown in a simplified manner and, in particular, without a scale.

In the Fig. 1-4 parts of a roll stand 11 are each shown in a simplified side view. It can be seen here that the roll stand 11 has an upper support roller 12.1 and a lower support roller 12.2. The upper support roll 12.1 is guided in chocks 18.1 (not shown in full) that can be raised or lowered on a stand frame of the roll stand 11. The lower support roller 12.2 is arranged or guided on chocks 18.2.

The device 10 is used to change back-up rolls 12 on the roll stand 11, and is provided for this purpose, from the side, ie transversely to the rolling direction W (cf. Fig. 1 ) to be moved into the roll stand 11.

The roll stand 11 comprises extension rails 24 via which the work rolls can be moved out of the roll stand 11. In the representations of the Fig. 1-4 the work rolls have already been moved out of the roll stand 13 and are therefore not shown in these figures.

The device 10 comprises a roll changing frame 14 which has entry aids 20 on both sides thereof. These insertion aids 20 are equipped with sliding rollers or sliding elements, which are jointly referred to below as sliding means 21 and ensure a relative movement of the insertion aid on or with respect to the extension rail 24. Furthermore, the roll changing frame 14 comprises a lowering device 22 attached to the entry aids 20, the function of which is explained separately below.

According to a first embodiment of the device 10, which is shown in the Fig. 1-3 is shown, the roll changing frame 14 is designed in two parts, namely in the form of an upper part 15 and a lower part 16. These two parts 15, 16 of the roll changing frame 14 can be coupled to one another, and - if necessary - decoupled from one another. Between the upper part 15 and the lower part 16 sliding surfaces 17 are provided which - if the two parts 15, 16 are decoupled from one another - allow the upper part 15 to be displaced relative to the lower part 16. As an alternative to sliding surfaces, it is also possible to provide sliding elements or rails between the two parts 15, 16 of the roll changing frame 14, which in the same way ensure a relative movement of the upper part 15 to the lower part 16 even under heavy loads (e.g. 60-70 tons).

In an initial state in which the upper part 15 is coupled to the lower part 16, the roll changing frame 14 can be moved from the side, ie transversely to the rolling direction W (cf. Fig. 1 ), are moved into the roll stand 11. In this case, the sliding means 21 of the entry aids 20 come into contact with the extension rails 24, and thus enable the roll changing frame 14 to be moved into the roll stand 11 Fig. 1 shows the roll changing frame 14 in a first operating position after it has been completely retracted into the roll stand 11 via the extension rails 24.

With regard to this position of the roll changing frame 14, it is pointed out separately that the lower part 16 of the roll changing frame 14 is not yet in contact with the chocks 18.2 of the lower support roll 12.2.

In the Fig. 2 the roll changing frame 14 is shown in a second operating position. Here, the roll changing frame 14 is lowered by actuation of the lowering device 22, so that the lower part 16 of the roll changing frame 14 is supported on the chocks 18.2 of the lower support roll 12.2. Thus, a vertical position of the roll changing frame 14 with respect to the lower support roll 12.2 can be set with the aid of the lowering device 22.

A support pan 23 is provided on an upper side of the upper part 15 of the roll changing frame 14. By lowering the chocks 18.1 assigned to the upper support roller 12.1, it is achieved that the chocks 18.1 of the upper support roller 12.1 are placed in the support pan 23. This is simplified in the representation of Fig. 3 shown.

The aforementioned support of the lower part 16 of the roll changing frame 14 on the associated chocks 18.2 means that the entry aids 20 are at least reduced in load or even free of load in relation to the extension rails 24. In the context of the present invention, this means that a weight load of the roll changing chair 14 and in particular the upper support roll 12.1 lowered thereon does not bear on the extension rails 24, but is initially absorbed by the sliding elements 17 between the two parts 15, 16 of the roll changing chair 14 and then via the lower part 16 of the roll changing frame 14 is derived into the chocks 18.2 of the lower support roll 12.2.

The device 10 further comprises a displacement device 26, which is simplified in the side view of FIG Fig. 5.1 or in the top view of Fig. 5.2 is shown. This displacement device 26 can - in accordance with its name - be moved transversely to the roll stand 11, which is, for example, in Fig. 5.2 is indicated by the arrow Q.

The displacement device 26 is suitable for the roller changing chair 14 to be positioned or "parked" on it. The surface of the displacement device 26 is dimensioned sufficiently large that the work rolls 13 of the roll stand 11 can also be accommodated on it. In the representation of Fig. 5.2 the space occupied by the work rolls 13 (when they have been moved out of the roll stand 11) is symbolized by dashed lines.

The side views according to the Fig.> 5.1-8.1 , after the Figures 9 and 10 , and after the Fig. 11.1 illustrate the use of the device 10 according to the invention and a corresponding method according to the invention. In this regard, it should be noted that the Fig. 5.2 - 8.2 , and the Fig. 11.2 , each show top views of the roll stand 11, the side views after Fig. 5.1 - 8.1 , and Fig.11.1 , each correspond.

The Fig. 5.1 and Fig. 5.2 show the roll stand 11 in a state in which the work rolls 13 are still located inside the roll stand 11. The roller changing frame 14 is arranged or "parked" on the displacement device 26. Here, the displacement device 26 is arranged adjacent to one side of the roll stand 11, namely in such a way that the available space, symbolized by the dashed lines, which is provided for the work rolls 13, is aligned with a longitudinal axis L of the roll stand 11 (cf. Fig. 5.2 ) flees.

The Fig. 6.1 and 6.2 show the roll stand 11 in a state after the work rolls 13 have been extended onto the displacement device 26 adjacent thereto. This extension can take place in that the work rolls 13 are coupled to a straight thrust drive, e.g. in the form of a locomotive or an especially hydraulic piston-cylinder drive, with which the work rolls 13 are pulled out of the roll stand 11 via the extension rails 24.

At this point it is pointed out separately that rails are attached to an upper side of the displacement device 26, on which the roller changing frame 14 can be moved. These rails are for example in the 6.2 , 7.2 , 8.2 and 11.2 provided with the reference number "28" which - insofar as they are covered by the roll changing frame 14 or the work rolls 13 - are only shown in dashed lines. These rails 28 are adapted in their "track width" to the extension rails 24 of the work rolls. Correspondingly, it is possible that the roll changing frame 14 is moved into the roll stand 11 via the rails 28 and the sliding means 21, which are provided on the insertion aids 20, then come into contact with the extension rails 24.

Furthermore, rails 29 are provided on the upper side of the displacement device 26, the "track width" of which is smaller than that of the rails 28. The function of these rails 29 will be explained separately below.

The Fig. 7.1 and 7.2 show the displacement device 26 in a position in which it is compared to FIG Fig. 5.2 has been shifted in the direction Q in such a way that the position in which the roll changing frame 14 is arranged on the shifting device 26 is now aligned with the longitudinal axis L of the roll stand. Starting from this position of the displacement device 26 can now, as by the Fig. 8.1 and 8.2 illustrates the roll changing chair 14 via the im Roll stand 11 provided extension rails 24 and the rails 28 arranged on the top of the displacement device 26 are moved into the roll stand 11. For this purpose, the roll changing frame 14 can be coupled to a straight thrust drive, which exerts a sufficient thrust force on the roll changing frame 14 in the direction of the rolling frame 11. The guidance of the roll changing frame 14 on the rails 28 facilitates its movement in the direction of the roll stand 11. The straight thrust drive (e.g. locomotive or in particular hydraulic piston-cylinder drive) to which the roll changing frame 14 is coupled can be the same straight thrust drive which has already been used for pulling out the work rolls 13. The position of the roll changing frame 14, which he within the roll stand 11 according to Fig. 8.1 has reached corresponds to the representation of Fig. 1 .

The roll changing frame 14 can now be lowered inside the roll stand 11 by actuating the lowering device 22. This has the consequence that the lower part 16 of the roller changing frame 14 is supported on the chocks 18.2 of the lower support roller 12.2. This position of the roll changing chair 14 is in the side view of FIG Fig. 9 shown what the representation of Fig. 2 corresponds.

Subsequently, the upper support roller 12.1 is lowered onto the support pan 23 via the associated chocks 18.1. Thus, the weight of the upper support roller 12.1 is now on the upper part 15 of the roller changing frame 14. This position of the upper support roller 12.1 is in the side view of FIG Fig. 10 shown what the representation of Fig. 3 corresponds.

It has already been pointed out that the embodiment of the roll changing chair 14 according to the Fig. 1-3 Is formed in two parts, namely in the form of the upper part 15 and the lower part 16. Starting from the position the support roller 12.1, which in the representations of Fig. 3 and Fig. 10 is shown, the upper part 15 of the roll changing frame 14 is then first decoupled from its lower part 16, and then the upper part 15 together with the upper support roll 12.1 lowered on it laterally out of the roll stand 11, e.g. with the aid of the straight thrust drive already mentioned above, which is coupled to the upper part 15. During this lateral extension, the upper part 15 of the roll changing frame 14 moves on the sliding elements 17 relative to its lower part 16, which remains stationary within the roll stand 11. In the course of the lateral extension, the upper part 15 of the roll changing frame 14 then reaches the rails 29, which - as already explained above - are also attached to the top of the displacement device 26. The Fig. 11.1 and 11.2 show the upper part 15 of the roll changing frame 14 when this has been extended or shifted together with the upper support roll 12.1 out of the roll stand 11 on the displacement device 26.

After the upper part 15 of the roll changing frame 14, when it has been extended onto the displacement device 26 and the rails 29 arranged thereon, has been fitted with a new upper support roll 12.1, the sequence explained above can be carried out in reverse order to add this new support roll 12.1 to be introduced into the roll stand 11.

The displacement device 26 can be provided on its upper side with a platform 30 which is adjustable in height in the vertical direction. This height adjustability is for example in the Fig. 5.1 symbolized by the arrow H, and enables an adjustment to a possibly different height level between the sliding elements 17 and the rails 29 of the displacement device 26.

Another embodiment of the device 10 according to the invention is shown in FIG Fig. 4 shown. In contrast to the embodiment according to the Fig. 1-3 is here the upper part 15 of the roll changing frame 14 either firmly connected to its lower part 16, or the two parts 15 and 16 are integrally formed - and thus as a common component. This embodiment of the device 10 is suitable for that, after the upper support roller 12.1 has been lowered onto the support pan 23 provided on the upper part 15 of the roller changing frame 14, then the roller changing frame 14 together with the upper backup roller 12.1 and the lower backup roller 12.2 - as Unit - can be moved out of the roll stand 11. The upstream retraction of the roll changing frame 14 into the roll stand 11 via the extension rails 24 takes place in the same way as in the two-part embodiment of the roll changing frame 14, so that to avoid repetition, refer to the explanations relating to Fig. 1-3 may be referred.

Finally, it should be pointed out that the two-part embodiment of the roll changing frame 14 - in the same way as the embodiment of FIG Fig. 4 - is suitable for moving the upper support roller 12.1 together with the lower support roller 12.2 - as a unit - out of the roll stand 11. It should be noted here that the coupling between the upper part 15 and the lower part 16 of the roll changing frame 14 is maintained, so that the upper and lower parts 15, 16 together after the upper support roll 12.1 has been lowered onto the support pan 23 be moved together. This means that the sliding elements 17 then remain inoperative.

Regardless of the various possible uses of the roll changing chair 14 explained above, the common advantage is that this enables a considerable reduction in the set-up time for changing at least the upper backup roll 12.1, because the roll changing chair 14 - with the work rolls 13 already removed - then into the Roll stand 11 can be moved into it, during which the lower back-up roll 12.2 is still located in the roll stand 11.

A further reduction in the set-up time is ensured by the fact that the above-mentioned processes - in both directions (i.e. moving the roll changing frame 14 into the roll stand 11 via the extension rails 24, and then extending at least one support roll 12 in connection with at least the upper part 15 of the Roll changing frame 14; or vice versa: moving new or "fresh" backup rolls 12 into the roll stand 11 in connection with the roll changing frame 14 or its upper part 15, and then moving the roll changing frame 14 out of the roll stand 11 via the extension rails 24). in particular are carried out fully automatically, and can thus be controlled from a control station (not shown) of a system to which the roll stand 11 belongs.

List of reference symbols

10

contraption

11

Roll stand

12

Backup roller (s)

12.1

upper back-up roll

12.2

lower backup roll

13

Work rolls

14th

Roll changing chair

15th

upper part (of the roll changing frame 14)

16

lower part (of the roll changing frame 14)

17th

Sliding elements or sliding surfaces (between the upper part 15 and the lower part 16 of the roll changing frame 14)

18.1

Chock (s) of the upper back-up roll 12.1

18.2

Chock (s) of the lower back-up roll 12.2

20th

Entry aid

21st

lubricant

22nd

Lowering device

23

Support pan

24

Extension rails

26th

Sliding device

28

Rails for changing the work rolls (on the top of the shifting device 26)

29

Rails for changing the upper support roller (on the top of the shifting device 26)

30th

Platform (on the sliding device 26)

L.

Longitudinal axis (of roll stand 11)

W.

Rolling direction

Claims (14)

1. Method of changing backing rolls (12) at a roll stand (11), in which after the working rolls (13) have been moved out a roll change chair (14) is introduced into the roll stand (11) transversely to the rolling direction (W), wherein the roll change chair (14) can be supported by a lower part (16) thereof on chocks (18.2) of the lower backing roll (12.2) and the upper backing roll (12.1) is lowerable onto the roll change chair (14), wherein the roll change chair (14) is moved into the roll stand (11) by way of the movement-out rails (24) provided for the working rolls (13) of the roll stand (11), wherein after the upper backing roll (12.1) has been lowered onto the roll change chair (14) then either only the upper backing roll (12.1) or a unit formed from the lower and upper backing rolls (12.1, 12.2) is moved out of the roll stand (11),
   characterised in that the roll change chair (14) is of two-part construction in the form of an upper part (15) and the lower part (16), wherein the upper backing roll (12.1) when it has been lowered onto the upper part (15) of the roll change chair (14) and supported thereon is moved out of or into the roll stand (11) together with the upper part (15) of the roll change chair (14) and independently of a lower backing roll (12.2).
2. Method according to claim 1, characterised in that the roll change chair (14) comprises introducing aids (20) with slide rollers or slide elements, which for movement of the roll change chair (14) into the roll stand (11) are brought transversely to the rolling direction (W) in interaction with the movement-out rails (24) provided for the working rolls of the roll stand (11).
3. Method according to claim 2, characterised in that if either only the upper backing roll (12.1) or the unit formed from the lower and upper backing rolls (12.1, 12.2) is moved out of or into the roll stand (11) then the introducing aids (20) of the roll change chair (14) are set to be reduced in load or free of load with respect to the movement-out rails (24).
4. Method according to any one of claims 1 to 3, characterised in that the upper part (15) and lower part (16) of the roll change chair (14) can be coupled with one another and slide elements or slide surfaces are provided between these two parts and enable relative displacement between the upper part (15) and the lower part (16) of the roll change chair (14), wherein after the lower part (16) of the roll change chair (14) has been supported on the chocks (32) of the lower backing roll (12.2) of the roll stand (11) the upper part (15) of the roll change chair (14) is then decoupled from the lower part thereof and subsequently moved laterally out of the roll stand (11) together with the upper backing roll (12.1).
5. Method according to any one of the preceding claims, characterised in that the roll change chair (14) after it has been moved into the roll stand (11) transversely to the rolling direction (W) is lowered by means of an integrated lowering device (22) and thus the lower part (16) thereof is supported on the chocks (32) of the lower backing roll of the roll stand (11).
6. Method according to any one of the preceding claims, characterised in that a displacing device (26) by way of which or on which the roll change chair (14) is moved into or out of the roll stand (11) is positioned adjacent to the roll stand (11).
7. Method according to any one of the preceding claims, characterised in that the movement of the roll change chair (14) into the roll stand (1) takes place automatically, particularly fully automatically, by way of the movement-out rails (24), the subsequent lowering of the upper backing roll onto the roll change chair (14) and the movement of the roll change chair (14) out of the roll stand (11) with either only the upper backing roll (12.1) or the unit formed from the lower and upper backing rolls (12.1, 12.2).
8. Roll stand (11) comprising
   an upper backing roll (12.1) and a lower backing roll (12.2),
   a housing frame, wherein the upper backing roll (12.1) is guided in raisable or lowerable chocks (18.1) at the housing frame and the lower backing roll (12.2) is arranged or guided at chocks (18.2),
   a device (10) for change of the backing rolls (12.1, 12.2) at the roll stand (11), comprising a roll change chair (14) which can be supported on the chocks (18.2) of the lower backing roll (12.2) of the roll stand (11),
   wherein the roll change chair (14) comprises introducing aids (20) with slide rollers or slide elements (21) which for movement of the roll change chair (14) into the roll stand (11) transversely to the rolling direction (W) can be brought into interaction with the movement-out rails (24) provided for the working rolls of the roll stand (11), and
   wherein the roll change chair (14) comprises a lowering device (22) by means of which the roll change chair (14) can be supported by its lower part (16) on the chocks (18.2) of the lower backing roll of the roll stand (11) after the roll change chair (14) has been introduced into the roll stand (11),
   characterised in that
   the roll change chair (14) is of two-part construction in the form of an upper part (15) and a lower part (16), wherein the upper part (15) of the roll change chair (14) is displaceable relative to the lower part (16) thereof so that this upper part (15) after the upper backing roll (12.1) has been lowered thereonto and supported thereon is laterally movable out of or back into the roll stand (11).
9. Device (10) according to claim 8, characterised in that slide elements, slide surfaces or rails (17) which enable relative displacement between the upper part (15) and the lower part (16) of the roll change chair (14) are provided between the upper part (15) and the lower part (16) of the roll change chair (14).
10. Device (10) according to claim 9, characterised in that the slide elements or slide surfaces (17) are equipped with drive means by which displacement of the upper part of the roll change chair (14) relative to the lower part thereof takes place.
11. Device (10) according to any one of claims 8 to 10, characterised in that the upper part (15) of the roll change chair (14) can be coupled with a linear thrust drive in order to move this upper part (15) out of or into the roll stand (11).
12. Device (10) according to claim 11, characterised in that the linear thrust drive is formed from a hydraulic piston/cylinder drive of variable stroke length or is provided by means of a locomotive.
13. Device (10) according to any one of claims 8 to 12, characterised in that arranged adjacent to the roll stand (11) is a displacing device (26) onto which the roll change chair (14) can be brought, preferably in that rails (28, 29) on which the roll change chair (14) or the upper part (15) thereof is movable are mounted on an upper side of the displacing device (26).
14. Device (10) according to claim 13, characterised in that provided at an upper side of the displacing device (26) is a platform (30) which is adjustable in height in vertical direction (H), preferably in that the rails (28, 29) for movement of the roll change chair (14) are mounted on the platform (30).

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