EP1414597B1 - Device and working method for automatically changing the work rolls, the back-up rolls and the intermediate rolls of a single-stand or multiple-stand strip mill - Google Patents

Description

The invention relates to a device and a working method for automatically changing the existing work, support and intermediate rolls sets of a single or multi-stand strip rolling mill.

The standstill of the rolling stand and the associated whole rolling mill naturally leads to production failure. This is particularly unfavorable if the mill other systems are upstream or downstream, z. B. a pickling plant, which could actually continue. The aim of each roll change process is therefore to keep the downtime of the rolling mill as low as possible.

In the German DE-OS DE 198 15 029 a roll change process for a rolling stand of a multi-stand strip rolling mill is described, whose rolling stands have work rolls and back-up rolls. After completing the rolling of a first metal strip, the rolling stand is stopped and the work rolls are removed. If the roll stand has intermediate rolls, the intermediate rolls are preferably removed and installed together with the work rolls.

The backup rolls of this known strip rolling mill are exchanged with the aid of a removal traverse in the form of a slotted back-up roll changing chair, which is retracted into the scaffold after removal of the set of work rolls. The work is carried out to a large extent manually.
Another method and apparatus for changing the working and support rollers of a strip rolling mill is described in DE 39 30 125 C2. Here, the roll change is made to convert the rolling stand, for example, from a six-roll system, ie a rolling mill with working, intermediate and backup rolls, on a four-roll system with working and support rollers. To remove the roller sets roll changing cars are used, which are movable transversely to the rolling stand and with Guides and rails for the extendable sets of rollers are equipped. At least the drawing Figure 4 of this document shows the expansion of the support rollers by means of a removal cross-piece, which rests on the lower support roller and carries the upper support roller.

While the change of work and intermediate rolls is largely automated, by using the roll changing carriage and the corresponding extraction device, the sets of rolls are pulled out of the rolling stand on the roll changing car, where they are moved by transverse displacement in a replacement position, the change of the backup rolls mostly manually. The expansion beam is brought by means of a crane between the support rollers, the upper support roller is placed on the seated on the lower support roller expansion beam and the support roller set is moved out on guide rails under the chocks of the lower support roller. Much manual activities when changing the support rollers and crane work require long downtime of the rolling mill. In addition, the crane work is more dangerous than the automatic change of work and / or intermediate rolls.

Finally, from US-A-3 638 468 a device for automatically changing the sets of rolls is known, with a transverse to the roll stand roll changing carriage, which receives the pull-out on guide rails roller sets and transversely displaces into a set-up position. An expansion truss can take up the upper support roller when removing, wherein it is supported on the lower support roller. The expansion beam is movable on wheels.

The aim of the present invention is to incorporate also the previously manually executed backup roll change at least partially in the automatic roll change process and to provide with a corresponding device a method for automatically changing the existing work, support and intermediate rolls sets of a single or multi-stand strip rolling mill, with which the Watzenwechselzeiten can be reduced and the safety when changing rolls can be increased.

This object is achieved with a device for automatically changing the existing work, support and intermediate rolls sets of a on or multi-stand strip rolling mill, by means of at least one transverse to the rolling mill in an aligned with the belt frame center changing position rolling car, which receives on parallel to the rollers extending guide rails pull-out sets of rolls and transversely in a set-up position, in which the replacement takes place against a new set of rollers, for removal the support roller set is provided with a support rail carrying the upper support roller, which is supported on the lower support roller when the work and intermediate rollers have been removed and can be pulled out of the rolling stand together with the support roller set, wherein the extension beam can be positioned on the roll change carriage provided for the work and support roller change and provided with wheels on which the expansion beam on running parallel to the rollers guide rails from the roll changing carriage in the roll stand and retractable together with the support roller set the strip rolling mill is extendable and wherein the wheels of the expansion beam are mounted on both sides in the upper region and roll in the strip rolling mill on the raised and lowered intermediate roll rails of the upper intermediate roll.

The interaction of the roller change carriage with the expansion beam of the support roller set and the special design of the expansion beam with its own wheels allows the integration of the support roller change in the automatic sequence. On the one hand, the provision of the expansion beam on the roll changing carriage shortens the roll change time and makes crane work unnecessary, on the other hand allow the wheels on the expansion beam, the extension and retraction of the expansion beam from and into the roll changing car or from and into the strip rolling mill.

Characterized that the wheels of the expansion beam are mounted on both sides in the upper region and roll in the strip rolling mill on the raised and lowered intermediate roller rails of the upper intermediate roll, the expansion beam can be moved from the change carriage on equal height guide rails directly on the positioned in the upper position raised and lowered intermediate roller rails from where it can be discontinued by lowering the intermediate roller rails on the lower support roller or its chock. Together with the attached upper support roller then the support roller set can be moved out manually or automatically from the strip rolling mill, the wheels of the expansion beam are free and the extension is done on the guide rails below the chocks of the lower support roller Advantageously, the expansion beam is provided with a roll neck, which can be coupled to the puller of the roll changing car.

If it is provided according to a further feature of the invention that the expansion beam is positioned laterally next to the work and intermediate roll set on the roll change carriage and can be moved by transversely moving the roll change carriage in a position to the roll stand, in which the guide rails of the roll change carriage with the raised intermediate roll rails in Strip rolling mill aligned, so also this proposal serves to shorten the roll change times. The expansion beam no longer needs to be laboriously threaded into the strip rolling mill by means of a crane; it hangs ready in the roll change carriage and only needs to be displaced by transversely displacing the roll change carriage into the position in which the guide rails on which the wheels of the removal cross-piece roll, aligned with the intermediate roller rails.

With the device according to the invention, the working method of the invention can be carried out, which consists of the sequence of the following working steps:

The roll stand is raised hydraulically by opening the roll gap. The roll change carriage is moved to the side of the strip rolling mill parallel to the rolling direction rails running on the center of the frame, so that the working and intermediate rollers can be coupled with the puller and pulled into the roll changing car. Together with the working and intermediate rolls of the roll changing carriage is then moved transversely, at the same time the side of the working and intermediate rolls on the roll changing carriage provided expansion beam is moved by transverse displacement of the roll change carriage in the middle of the frame, so that guide rails and intermediate roll rails are aligned.

The expansion beam is moved out on its wheels from the roll changing car and, guided on the intermediate roller rails, retracted into the strip rolling mill. As soon as the expansion traverse has reached its position in the strip rolling mill, the intermediate roller rails are lowered, whereby the expansion traverse on the lower support roller or its chock is discontinued. Now, by lowering the intermediate roller rails, the upper support roller can be placed on the expansion beam. During these operations, the roll changing carriage is transversely displaced with the working and intermediate rolls, whereby the working and intermediate rolls reach an exchange position, from which they can be exchanged with the crane for new sets of rolls. The now supported on the expansion beam support roller set is extended on guide rails from the strip rolling mill and replaced by crane against a new support roller set, which is retracted into the strip rolling mill.

At the same time as the backup roll change, new working and intermediate rolls were placed in the roll changing car.

The upper backup roll of the roll set and the intermediate roll rails are raised again, the intermediate roll rails engage under the wheels of the expansion beam and lift them from the lower support roller. The roll changing carriage now moves into position and pulls the expansion beam on the intermediate roller rails out onto the guide rails of the roller change vehicle. Subsequent transverse displacement of the roll-changing vehicle, the new work and intermediate roll set is spent in the framework center and inserted into the scaffold. After closing the nip of the working intermediate and backup roller change is completed.

With the invention, the downtime of the rolling mill shorten considerably. The resulting greater availability of the rolling mill increases the output and thus improves the efficiency. The automatic feed of the expansion beam is also much safer for the operator compared to the conventional operation.

With reference to the drawing, an embodiment of the invention will be described below.

Fig. 1

Eine Seitenansicht eines Sechs-Walzen-Bandwalzgerüstes beim Stützwalzenwechsel mit Hilfe des Walzenwechselwagen und der Ausbautraverse,

Fig. 2

die Ausbautraverse,

Fig. 3

einen Schnitt durch das Bandwalzgerüst beim Stützwalzenwechsel mit auf der Ausbautraverse aufgesetzter oberer Stützwalze und

Fig.4

einen Schnitt durch das Bandwalzgerüst beim Stützwalzenwechsel mit angehobener Ausbautraverse.

It shows:

Fig. 1

A side view of a six-roll strip rolling mill during the backup roll change using the roll changing carriage and the expansion beam,

Fig. 2

the expansion beam,

Fig. 3

a section through the strip rolling mill in the backup roll change with attached to the expansion traverse upper backup roll and

Figure 4

a section through the strip rolling mill during the backup roll change with raised expansion beam.

In Figure 1, a centrally-cut known six-roll strip rolling mill 1 is shown in a side view in which the existing of working and support rolls set of rolls has already been expanded. The set of rolls was pulled in a known manner with the aid of the roll changing carriage 2 from the strip rolling mill 1 and on the roll changing carriage 2 transversely, i. perpendicular to the drawing plane, moved.

For supporting roller change according to the invention designated 3 expansion beam is used. As Figure 1 shows, this expansion beam 3 is positioned laterally next to the existing work and intermediate rolls set of rollers on the Walzenwechselwagen 2 and was moved by transverse displacement of the roll changing carriage 2 in a position central to the strip rolling mill 1. The set of work and intermediate rolls set of rollers is not visible in Figure 1, it is covered by the standing in the foreground extension beam 3.

The roll changing carriage 2 with the expansion beam 3 is ready for use in front of the strip rolling mill 1, the provided expansion beam 3 depends on wheels 4 Guide rails 5 of the roll-changing vehicle 2. As shown in the drawing Figure 2 in a single part illustration, the expansion beam 3 is C-shaped, so that it allows the extension and retraction of the expansion beam 3 even when befindlichem in the strip rolling mill 1 band. In each of the four upper corner areas of the removal cross-piece, the wheels 4 are arranged with which the expansion cross-member 3 hangs in the guide rails 5 (FIG. 1) of the roll-changing vehicle 2. On the - in the plane of the drawing - right side of the expansion beam 3, a roll neck 6 is mounted, which, corresponding to the gripping device 7 of the roll changing carriage 2, allows an automated integration of the expansion crosshead 3 in the backup roll change.

In Figure 1, the expansion beam 3 is shown in the strip rolling mill 1 in the left half of the drawing, where it fills the space of the developed, consisting of support and work rolls set of rollers. To get from the roll changing car 2, starting from the preparation in the right half of the drawing shown in the drawing half 3 in the position shown in the left half of the drawing in the strip rolling mill 1, the height equal intermediate roller rails 8 in the strip rolling mill 1 and the guide rails 5 in the roll changing carriage. 2 brought into a mutually aligned position. In this position, the expansion beam 3 of the roll changing device 2 via the guide 5 and the intermediate roller rails 8 are automatically retracted into the strip rolling mill 1. By subsequent lowering of the intermediate roller rails 8, the expansion beam 3 is lowered onto the chocks 9 of the lower support roller 10 and parked there. This process is shown in the figure 3. Pins 11 on the underside of the expansion beam 3 engage in holes 12 on the chock 9 and stabilize the expansion beam 3. The no longer required roll change carriage 2 is driven by lateral displacement so far to the side that the window of the strip rolling mill 1 is free for the backup roll change.

After the expansion crossmember 3 has been discontinued, the upper support roller 13 is hydraulically deposited on top of the expansion crossmember 3 and also secured by engaging in bores 14 of the chocks 16 pin 15. The entire support roller set can now in a known manner on the lower Ausfahrschienen 17 (Fig.1) from the Strip mill 1 extended and manually with the help of a (not shown) crane to be changed.

Simultaneously with the procedure described above, the removed intermediate and work rolls were replaced; a new set of intermediate and work rolls was provided on the roll change carriage 2. A new set of back-up rolls 10/13 is now retracted in the strip mill 1 in the reverse procedure, as described above for the removal of the old support roll set. The back-up rolls 10/13 are brought into position; the upper support roller 13 is lifted hydraulically, so that the chocks 16 are lifted from the removal cross-piece 3. The expansion beam 3 is lifted by means of the raised intermediate roller rails 8 from the lower chocks 9 and now depends freely on the intermediate roller rails 8 in the strip rolling mill 1, as shown in the drawing figure 4.

The roll changing carriage 2, which has meanwhile been displaced transversely in position, grips the roll neck 6 on the removal traverse 3 with its roll changing device 7 and pulls it out onto the intermediate roll rails 8 and over the aligned guide rails 5 from the strip rolling mill 1 into the roll changing carriage 2.

By renewed transverse displacement of the roll changing carriage 2, the new set of rollers from intermediate and work rolls, which is laterally next to the expansion beam 3 in preparation position, brought into a position centered on the strip rolling mill 1, from which the set of rolls can be retracted into the strip rolling mill 1. This process is conventional and therefore need not be further described here. After closing the nip, the strip rolling mill 1 is ready for use.

Claims (4)

1. Device for automatically changing the roller sets, consisting of working, backup and intermediate rollers, of a single-stand or multiple-stand strip rolling mill (1), by means of at least one roller changing carriage (2) which can be moved at right angles to the roller frame into a change position which is in alignment with the centre of the strip stand, which carriage picks up the roller sets (10/13) that can be pulled out on guide rails that are parallel to the rollers, and moves them crosswise into a set-up position, in which position their replacement by a new set of rollers takes place, there being, for the purpose of dismantling the set of backup rollers, a take-off cross rail (3) that carries the top backup roller, which cross rail rests on the bottom backup roller when the working and intermediate rollers are dismantled, and which can be pulled out from the roller frame together with the set of backup rollers,
   wherein the take-off cross rail (3) can be positioned on the roller changing carriage (2) provided for changing the working and backup rollers, and is fitted with wheels (4) on which the take-off cross rail (3) can be moved from the roller changing carriage (2) into the strip rolling stand (1) on guide rails (5) that run parallel to the rollers (10 / 13) and pulled out, together with the backup roller set (10/13), from the roller frame (1), and wherein the wheels (4) of the take-off cross rail (3) are mounted on bearings at both sides in its upper area, and run in the strip rolling stand (1) on the intermediate roller rails (8) - which can be raised and lowered - of the top intermediate roller.
2. Device as in claim 1,
   characterised in that
   the take-off cross rail (3) is fitted with a roller neck (6) which can be coupled to the withdrawing device (7) of the roller changing carriage (2).
3. Device as in one of claims 1 and 2,
   characterised in that
   the take-off cross rail (3) can be positioned laterally close to the working and intermediate roller set on the roller changing carriage (2), and can, by moving the roller changing carriage (2) crosswise, be brought into a position relative to the strip roller stand (1) in which the guide rails (5) of the roller changing carriage (2) are in alignment with the raised intermediate roller rails (8) in the strip rolling stand (1).
4. Method for automatically changing the roller sets which are fitted in the rolling stands of a single- or multiple-stand strip rolling mill and which consist of working, backup and intermediate rollers, by means of a device as in one of claims 1 to 3, characterised by the sequence of the following stages:

   - The rollers of the rolling stand (1) are brought into position.

   - The roller changing carriage (2) is moved to the centre of the stand and coupled up to the working and intermediate rollers.

   - The working and intermediate rollers are pulled out of the rolling stand (1) on the roller changing carriage (2).

   - The roller changing carriage (2), with the working and intermediate rollers, is pushed crosswise.

   - The take-off cross rail (3), which is positioned at the side of the working and intermediate rollers on the roller changing carriage (2), is moved to the centre of the stand by moving the roller changing carriage crosswise.

   - The take-off cross rail is moved into the stand, guided along the intermediate roller rails.

   - The intermediate roller rails are lowered, as a result of which the take-off cross rail is set down on the bottom backup roller (11).

   - The top backup roller (13) is lowered and set down on the take-off cross rail (3).

   - The roller changing carriage (2), with the working and intermediate rollers, is pushed sideways, as a result of which the working and intermediate rollers arrive at a change position.

   - The set of backup rollers is moved out along guide rails and changed by means of a crane.

   - A new set of backup rollers is moved into position.

   - At the same time as the changing of the backup rollers, new working and intermediate rollers are placed into the roller changing carriage.

   - The intermediate roller rails, with the take-off cross rail, are raised up again.

   - The roller changing carriage (2) moves into position and pulls the take-off cross rail (3) from the intermediate roller rails on to the guide rails of the roller changing carriage.

   - By moving the roller changing carriage (2) crosswise, the new working and intermediate roller set is brought into the centre of the stand.

   - The new set of working and intermediate rollers is pushed into the stand.

   - The roller gap is closed.

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