EP4076778B1 - Method for changing a roll configuration in a roll stand and roll arrangement - Google Patents

Description

The invention relates to a method for changing a roll configuration in a roll stand. The invention also relates to a roller arrangement as a replacement set for carrying out the method.

For the rolling of metal flat products, strip thickness reduction is of particular importance. The forming machines required for this are referred to as horizontal roll stands or roll stands. Roll stands are used for hot rolling slabs into hot strips and for cold rolling cold strips. Various roll stands are used, which differ in terms of dimensioning, the number and arrangement of rolls, as well as in terms of the equipment with technical adjustment systems and in terms of roll cooling and roll lubrication.

Stand types are usually differentiated according to the number and arrangement of the rolls. Probably the most frequently used type of stand is the so-called four-high mill (Quarto, 4-high-mill), which has two work rolls and two back-up rolls. Six-high mills (6-high mill) are often chosen for the cold rolling of high-strength steels with particularly high quality requirements. These include additional intermediate rolls and any associated support devices. Also common are 18-roll stands and 20-roll stands (multi-roll stands, for example 18-high-mill), which have work rolls with relatively small diameters. These come into consideration for the cold rolling of high-strength steels.

A roll stand normally comprises a pair of work rolls with associated work roll chocks, blocks for guiding the work roll chocks with work roll bending and shifting, a pair of back-up rolls with associated back-up roll chocks, a screwdown and adjustment system for setting/adjusting the roll gap, i.e. the gap between upper and lower work roll, force gauges for measuring the rolling force, roll stand, drive systems, work roll cooling and lubrication as well as equipment for guiding the rolling stock.

For the rolling of steels with special alloys and high-strength grades, the use of small work roll diameters is necessary in order to achieve the final gauge required for the metal strip. Multi-roll stands have corresponding work rolls with small diameters, but these are limited with regard to the permissible entry thickness of the rolling stock. Since such flat products usually make up only a relatively small part of the usual production of a rolling train, often only four-roll stands or six-roll stands are used, which are converted as required. The conversion is expensive.

A typical roll stand in the form of a multi-roll stand for rolling a metal strip is, for example, from WO 2004/052568 known.

From the EP 2 451 592 B1 a 4-high/6-high/18-HS roll stand is known, with which different operating modes and roll diameters can be rolled in one roll stand while minimizing changeover times. It is envisaged that the work roll sets of the 4-high/6-high stand will be replaced by intermediate roll sets including lateral support rollers and the work rolls of the 18-HS stand in cassette design. Such a conversion from a 4-high or a 6-high configuration to a multi-roll mill is relatively expensive. Despite the cassette design, which basically minimizes the changeover times, it is necessary to change over the drive trains, the bending and shifting systems and the like. When changing the roll configuration, the intermediate roll sets must first be installed, then the new work rolls with a smaller diameter must be installed.

Further prior art is from the publications US2039959B1 , FR284657A1 , JPS05228504 , US7481089 B2 , and US20060010951 A1 known.

A method and an apparatus according to the preamble of claim 1 are from JPS55027473 A1 known. Further prior art is from U.S. 2,039,959A known.

The object of the invention is to provide a method and a device for changing the roll configuration, which make it possible to convert a roll stand from work rolls with a large diameter to work rolls with a smaller diameter with the least possible changeover effort.

The object is achieved with the features of the method according to claim 1 and with the features of the roller arrangement according to claim 6.

Advantageous configurations of the invention result from the dependent claims.

According to one aspect of the invention, a method for changing a roll configuration in a roll stand is preferably provided in a roll stand, in which at least one work roll of the roll stand is replaced by a roll arrangement as a replacement set, the replacement set comprising at least three replacement rolls stored in a common cassette are whose outer geometry corresponds at least partially to that of the chocks of the work roll to be exchanged. This makes it possible to install the cassette in the roll stand of the roll stand to be converted without further conversion measures.

A cassette within the meaning of the invention is to be understood as a structural unit for the simultaneous storage of a plurality of drums or rolls.

The cassette according to the invention comprises two bearing housings for the rollers of the replacement set and any required support rollers and/or support bearings. The outer geometry of the bearing housing largely or completely corresponds to that of the work roll chocks to be removed, so that the configuration change, such as a work roll change, can take place within a few minutes.

A work roll chock is generally understood to be a bearing housing for a work roll that is compatible with a roll stand.

Preferentially, exactly three rolls of a replacement set and any additional support rolls and/or support bearings that may be required are mounted together in a single cassette.

The configuration change is preferably carried out on a 4-high or on a 6-high roll stand. The replacement of the work roll can be performed with a replacement kit that includes a work roll whose diameter is smaller than the diameter of the particular work roll to be replaced.

Within the scope of the invention, the configuration change described above can also be carried out on a duo stand (2-high), so that this can then be converted into a multi-roll stand.

In the method according to the invention, all work rolls are preferably replaced, although it is also possible within the scope of the invention to replace only one work roll with a corresponding cassette.

In a preferred variant of the method according to the invention, it is provided that the sum of the roll diameters of all replacement rolls in a replacement set corresponds to the maximum or minimum diameter of the work roll to be replaced in each case.

The replacement set expediently comprises at least one first and one second additional roll, the first additional roll preferably having a larger diameter than the working roll of the replacement set and preferably the second additional roll having a diameter corresponding to the working roll of the replacement set.

The roll arrangement according to the invention expediently comprises a working roll and a first and a second additional roll which are arranged in a common cassette. The additional rolls take on the function of vertical backup rolls. A triple configuration within the meaning of the present invention comprises a work roll and two additional rolls, with any support rollers and/or support bearings that may be required for the lateral guidance of the work rolls and/or the additional rolls not being taken into account.

Within the scope of the invention, such a triple configuration also includes lateral support rollers and/or support bearings.

In an expedient embodiment of the invention, it is provided that the cassette comprises two bearing housings for the work roll and the additional rolls, each of which has an external geometry that essentially corresponds to that of the work roll chocks of the roll stand.

The work roll and the first and second additional rolls are arranged vertically one above the other in the installation position of the cassette. The second auxiliary roll and the work roll of the replacement set can have approximately the same diameter. Preferably, the first backup roll has a larger diameter than the work roll of the replacement set. The first additional roll can be, for example, the driven roll of the replacement set.

As mentioned above, the replacement set may include support rolls and/or support bearings that laterally support the work roll and/or the first and second auxiliary rolls.

Conveniently, the driven roller of the replacement kit is provided with a drive pin adapter. The drive trunnion adapter expands the diameter of the auger roll hit to fit into the existing drive spindle hit.

The cassette is preferably embodied symmetrically or rotationally symmetrically about the longitudinal axis of the driven auxiliary roller with respect to a plane that is horizontal in the installed position. This makes it possible to install the cassette rotated 180° around the longitudinal axis, so that the position of the second additional roller of the replacement set and the working roller of the replacement set or the position of the first and second additional roller can be exchanged. This makes it possible to delay wear-related rework.

Due to the symmetrical structure of the cassettes, an upper and a lower cassette can also be exchanged in a frame.

The roll arrangement according to the invention can be used in an advantageous manner both for single stands and for rolling mills with multiple stands, both in one-way and in reversing operation. Both the method and the roll arrangement according to the invention are particularly suitable for retrofitting or upgrading existing rolling mills in addition to equipping new mills.

Figur 1 A

eine schematische Darstellung einer umzurüstenden 4-high oder 6-high Walzenkonfiguration gemäß Stand der Technik,

Figur 1 B

eine schematische Darstellung der in Figur 1 A dargestellten Walzenkonfiguration, bei der die Arbeitswalzen durch jeweils einen Austauschsatz gemäß der Erfindung ersetzt wurde,

Figur 2 A

eine schematische Darstellung entsprechend Figur 1 A, bei der schematisch der Antrieb der Arbeitswalze dargestellt ist,

Figur 2 B

eine der Figur 1 B entsprechende Darstellung, bei der schematisch der Antrieb des Austauschsatzes bzw. der Kassette dargestellt ist,

Figur 3 A

eine schematische Darstellung einer umzurüstenden 4-high oder 6-high Walzenkonfiguration gemäß Stand der Technik, bei der die Stützwalzen bzw. Zwischenwalzen angetrieben sind,

Figur 3 B

eine schematische Darstellung der in Figur 3 A gezeigten Walzenkonfiguration, bei der die Arbeitswalzen der Anordnung gemäß Figur 3 A durch einen Austauschsatz bzw. eine Kassette gemäß der Erfindung ersetzt wurde,

Figur 4

eine schematische Darstellung eines oberen Austauschsatzes bzw. der Kassette gemäß der Erfindung, inklusive optionaler Stützrollen,

Figur 5

eine Schnittansicht entlang der Linie V-V in Figur 4 und

Figur 6

eine Schnittansicht entlang der Linie VI-VI in Figur 4.

The invention is explained below with reference to an embodiment shown in the drawings. Show it:

Figure 1A

a schematic representation of a 4-high or 6-high roll configuration to be converted according to the prior art,

Figure 1B

a schematic representation of the in Figure 1A illustrated roll configuration, in which the work rolls have each been replaced by a replacement set according to the invention,

Figure 2A

a schematic representation accordingly Figure 1A , in which the drive of the work roll is shown schematically,

Figure 2B

one of the Figure 1B corresponding representation, in which the drive of the replacement set or the cassette is shown schematically,

Figure 3A

a schematic representation of a 4-high or 6-high roll configuration to be converted according to the prior art, in which the backup rolls or intermediate rolls are driven,

Figure 3B

a schematic representation of the in Figure 3A shown roll configuration, in which the work rolls according to the arrangement figure 3 A has been replaced with a replacement kit or cassette according to the invention,

figure 4

a schematic representation of an upper replacement set or the cassette according to the invention, including optional support rollers,

figure 5

a sectional view along the line VV in figure 4 and

figure 6

a sectional view along the line VI-VI in figure 4 .

It will first on the Figures 1A and 1B referenced. There, a roll stand 1 is shown in a 4-high or 6-high configuration. The vertical backup rolls 2' of the 6-high configuration are indicated with dashed lines. The following explanations in relation to the invention apply to both possible configurations of the roll stand 1.

In the simplest case, as a 4-high configuration, the roll stand 1 comprises two vertical backup rolls 2 and between them two work rolls 3, which are each mounted in work roll chocks 4.

According to the invention, when the roll stand 1 is converted to a configuration with a smaller work roll diameter, the work rolls 3 are each replaced by a cassette 5 comprising a relatively smaller diameter work roll 3', a first auxiliary roll 6 and a second auxiliary roll 7. The Cassette 5 further comprises a first bearing housing 5A and a second bearing housing 5B which respectively accommodate the ends of the work roll 3' and the auxiliary rolls 6,7. The geometry of the bearing housing essentially corresponds to the geometry of the work roll chocks 4 in each case, so that the work roll 3 in question can be replaced with the associated work roll chocks 4 without further conversion or conversion measures. Both work rolls 3 according to the configuration Figure 1A are each replaced by a cassette 5. For the conversion of mill stand 1 from the configuration in Figure 1A into the configuration according to Figure 1B So the provision of a total of two cassettes 5 is required.

The embodiment according to Figures 2A and 2B corresponds essentially to the embodiment according to Figures 1A and 1B , It being provided here that in the configuration without a replacement set the work rolls 3 are each driven and in the configuration with a replacement set the first additional roll 6 is driven in each case. At this point it should be emphasized that the same components are provided with the same reference symbols in all the exemplary embodiments.

The sum of the diameters of all vertically arranged rolls of the cassette 5 corresponds almost to the diameter of the driven work roll 3 to be exchanged figure 4 referenced. Again figure 4 As can be seen, the cassette 5 comprises a relatively small work roll 3', above which a driven first additional roll 6 arranged vertically in line with the work roll 3' and a second additional roll 7 arranged above in a line, the diameter of which is close to that of the work roll 3' corresponds. The working roll 3' and the second additional roll 7 preferably have the same diameter. In the figure 4 Cassette 5 shown is rotationally symmetrical with respect to the longitudinal center axis of the driven first additional roller 6 . Each of the rollers arranged vertically in a line is supported laterally by support rollers 8, respectively.

The diameter of a work roll 3 in a 6-high configuration can be, for example, about 470 to 430 mm, whereas the diameter of the work roll 3' of the replacement set can have a diameter of 140 to 120 mm, for example. The first additional roll 6 can, for example, have a diameter of 190 to 180 mm, whereas the diameter of the second additional roll 7 preferably corresponds to the diameter of the working roll 3' of the replacement set. The support rollers 8 can have a diameter of about 120 mm, for example. The rolling speed that can be achieved with the roller arrangement according to the invention can be in the range between about 100 to 2500 m/min, preferably between about 1000 to 1500 m/min.

Like this the figures 2 , 4 and 6 can be seen, in the preferred variant of the roller arrangement according to the invention, it is provided that the first additional roller 6 is designed as a driven roller. For this this is how this is the figure 6 can be seen, provided at one end with a drive journal adapter 9, which expands the diameter of the roll hit 10 of the first additional roll 6 so that it fits into the roll-side hit of the drive spindle, not shown. This takes account of the fact that the drive journal of the work roll to be exchanged usually has a diameter which is matched to the drive torques to be transmitted.

At one in the Figures 3A and 3B shown variant of the invention can be provided that the intermediate rollers 2 are each driven. In this case, the work rolls 3 of the roll configuration to be converted are not driven. Consequently, it is not necessary to drive the replacement sets provided in the form of the cassettes 5 in a three-pack configuration.

Reference List

1

mill stand

2

Back-up rolls with 4-high configuration or intermediate rolls with 6-high configuration

2'

Support rollers in 6-high configuration

3

Work rolls of the roll stand to be converted

3`

Replacement set work rolls

4

Work roll chock

5

cassette

5A

first bearing housing

5B

second bearing housing

6

first additional roll

7

second additional roll

8th

support rollers

9

drive pin adapter

10

reel hit

Claims (12)

1. Method of changing a roll configuration in a roll stand, wherein the roll stand comprises at least two work rolls (3), wherein for a change in configuration at least one work roll (3) of the roll stand is exchanged for a roll arrangement as exchange set, wherein the exchange set comprises at least three exchange rolls all mounted in a common cassette (5), the outer contour of which substantially corresponds at least in part with each of those of the work roll chocks (4) of the work roll (3) to be replaced, characterised in that the exchange set comprises a first and a second additional roll (6, 7) as well as a work roll (3') and that the work roll (3') as well as the first and second additional rolls (6, 7) of the exchange set are arranged vertically one above the other in the installed position of the cassette (5).
2. Method according to claim 1, characterised in that the change in configuration is carried out to a four-high or six-high roll stand.
3. Method according to one of claims 1 and 2, characterised in that the exchange of the work roll (3) is carried out with an exchange set comprising a work roll (3'), the diameter of which is smaller than the diameter of the respective work roll (3) to be exchanged.
4. Method according to any one of claims 1 to 3, characterised in that the sum of the roll diameters of all vertically exchange rolls of an exchange set corresponds almost or entirely with the maximum or minimum diameter of the work roll (3) to be exchanged.
5. Method according to any one of claims 1 to 4, characterised in that the first additional roll (6) has a larger diameter than the work roll (3') of the exchange set and preferably the second additional roll (7) has a diameter corresponding with the work roll (3') of the exchange set.
6. Roll arrangement for carrying out the method according to any one of claims 1 to 5, as exchange set for changing a roll configuration in a roll stand comprising at least two work rolls (3), wherein for a change in configuration at least one work roll (3) of the roll stand is exchanged for a roll arrangement as exchange set, the roll arrangement comprising a work roll (3') and first and second additional rolls (6, 7), which are mounted in a common cassette (5), wherein the cassette (5) comprises two bearing housings for the work roll (3') and the additional rolls (6, 7), which each have an outer contour substantially corresponding with that of the work roll chocks (4) of the roll stand, and wherein the work roll (3') as well as the first and second additional rolls (6, 7) are arranged vertically one above the other in the installed position of the cassette (5).
7. Roll arrangement according to claim 6, characterised in that the second additional roll (7) and the work roll (3') of the exchange set have approximately the same diameter (10).
8. Roll arrangement according to one of claims 6 and 7, characterised in that the first additional roll (6) has a larger diameter than the work roll (3') of the exchange set.
9. Roll arrangement according to any one of claims 6 to 8, characterised in that the first additional roll (6) is driven.
10. Roll arrangement according to any one of claims 6 to 9, characterised in that the exchange set comprises backing rollers (8) and/or support bearings, which laterally support the work roll (3') and/or the first and second additional rolls (6, 7).
11. Roll arrangement according to any one of claims 6 to 10, characterised in that the driven roll of the exchange set is provided with a drive journal adapter (9).
12. Roll arrangement according to any one of claims 6 to 11, characterised in that the cassette (5) is constructed to be rotationally symmetrical about a longitudinal centre axis.

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