EP0255714B1 - Multiple-roll rolling mill stand with shiftable intermediary rolls having tapered ends - Google Patents

Description

The invention relates to a multi-roll mill stand, the two work rolls of which are each supported directly or indirectly by a pair of axially adjustable intermediate rolls on support rolls or support rollers arranged in series, the intermediate rolls assigned to a work roll on one side of the roll stand and those of the other work roll assigned intermediate rolls on the other side of the roll stand each have a tapered roll bale end and the intermediate rolls assigned to the same work roll are independently adjustable such that the adjacent tapered roll bale ends of the intermediate rolls of the same work roll are axially offset from one another.

It is known that when strips are rolled in a multi-roll stand, the strip edges are exposed to a higher pressure than the central strip areas, unless countermeasures are taken.

A known countermeasure in multi-roll stands, in which the direct bending of the work or intermediate rolls known from other stands is not possible for structural reasons, is that Work rolls are not to be supported over their entire length via intermediate rolls, but only over a partial length, the partial length being adjustable.

In a known roll stand of the type mentioned (DE-PS 28 35 514), each work roll is supported on a pair of intermediate rolls. The intermediate rolls are in the same way tapered at one end, parabolic or otherwise, the tapered roll barrel ends of the intermediate rolls assigned to the different work rolls lying on opposite sides of the roll stand, while the tapered roll roll ends of the intermediate rolls assigned to the same work roll lie on the same side of the roll stand . In such a roll stand, the support length can be adjusted as a function of the width of the strip to be rolled by axially displacing one pair of intermediate rolls and / or both pairs of intermediate rolls such that each edge of the rolled strip overlaps the tapered ends to a greater or lesser extent.

In addition to the adjustment of the intermediate rolls to the edges of the rolled strip, it is also known in such multi-roll stands to influence the roll gap profile in the central region of the rolled strip. This is done by presetting the supports for supports (saddles) between the support rollers on two support rollers, via which the rolling forces are diverted into the one- or two-part housing.

Such a multi-roll mill stand has proven itself in practice for many years; Nevertheless, the setting options for influencing the roll gap profile on such multi-roll rolling stands are sufficient, namely the pairwise axial displacement of the intermediate rolls with tapered roll barrel ends and the presetting of the bending line on two support rolls to achieve this Today's demands on the flatness of the band are often not sufficient. In particular, it is not possible with such multi-roll mill stands to adequately adapt the roll gap profile in the region of the strip edges in the case of the forms of tapering of the roll bale ends of the intermediate rolls, if the roll strip thickness profile changes significantly from strip to strip. The same applies to a sudden change in the resistance to deformation of the rolling stock.

The prior art also includes duo, quarto or six-high roll stands (EP 0 049 798 A2), the axially displaceable intermediate or work rolls of which have oppositely arranged, curved contours over the entire length of the bale and which are seamless in a certain axial position of the intermediate rolls complete. Roll stands, the intermediate or work rolls of which have contoured roll bales, are intended to enable a uniform, continuous change in the roll gap profile over the entire length of the roll gap, the rolling strip in the edge region being influenced by the known method of roll bending possible here.

The invention has for its object to provide a multi-roll mill stand of the type mentioned, in which the support of the work rolls, in particular in the edge regions of the rolled strip, is adjustable to a greater extent than previously.

This object is achieved in the generic multi-roll mill stand according to the invention in that the two tapered roll barrel ends have a different taper contour on each side of the roll stand.

In the invention, it is possible to influence the support curve at the edges of the rolled strip by a more or less strong offset of the roll bale ends lying on the same side of the roll stand, taking into account their shape. Under the influence of the rolling force, the work rolls nestle against this curve. A change in the setting position of one or both work rolls, the tapered roll barrel ends of which are assigned to the same edge of the rolled strip, has an effect on the respective edge region of the rolled strip as a change in the roll gap profile. This also provides a sensitive setting option to influence the flatness of the strip. Since the support curve for the work rolls not only includes the axial offset of the tapered roll bale ends, but also their contour, the roll bale ends assigned to the same strip edge have different tapering contours.

However, not only in the edge areas of the rolled strip can the support curve for the work rolls be influenced with independently axially adjustable intermediate rolls, but also in the area between the edge areas if, according to a further embodiment of the invention, an intermediate roll of each intermediate roll pair has a contour deviating from the cylindrical shape between the roller bale ends. Since the shape of the roll gap resulting from the rolling force results from the addition of the local diameter of the contoured intermediate rolls touching the work rolls at the same point, it is easily possible for the skilled worker in practice to choose the suitable dimensioning of the contour for the respective purpose.

According to an alternative embodiment to this embodiment, it is provided that each lockable intermediate roller is supported on the support rollers or the support rollers by at least one additional intermediate roller with contoured roller balls. With this configuration, comparable effects can be achieved as with contoured roll bales for the intermediate rolls which directly support the work rolls. Within this configuration there are two preferred configurations. One is that the middle intermediate roller supporting an intermediate roller pair has the contoured roller bale, while the other is that the outer intermediate roller supporting each of the intermediate rollers of each intermediate roller pair has the contoured roller bale.

In a preferred embodiment, the contour of each intermediate roller is arranged asymmetrically with respect to the center of the roller bale. In particular, the two intermediate rolls with their asymmetrically contoured roll bales should be arranged in opposite directions. With such an arrangement, a relative axial displacement of the two intermediate rolls increases or decreases the curvature of the roll gap profile in the central region.

The asymmetrical contouring of the intermediate rolls is particularly suitable for multi-roll stands in which the support line cannot be preset on the support rolls, for example when the support rolls are solid. Intermediate rolls with contoured roll bales can also be used with multi-roll stands, which offer the conventional setting option for back-up rolls. In such multi-roll stands, the roll gap affects Effect of the axially displaceable intermediate rollers with the contoured roller bales then to bear when a rolling program is run in which the rolling forces are so low that the intermediate rollers and the axes of the support rollers are not deformed so much that the support saddles of the support rollers are fully adjusted to the preset Can support supports.

Since, when using intermediate rolls directly supporting the work rolls with contoured roll bales, only the work rolls have to adapt to this shape, and therefore this adaptation takes place even with very low rolling forces, this embodiment of the invention is suitable for the stepless adjustment of the roll gap profile when dressing or re-rolling strips to a certain strength.

If intermediate rolls with contoured roll bales are used for the intermediate rolls directly supporting the work rolls, the setting of these intermediate rolls also presets the strip edges. The fine adjustment is then carried out by the other intermediate rolls, in which only the roll barrel ends are tapered.

Fig. 1

die Walzen eines Vielwalzen-Walzgerüstes in schematischer Darstellung in Seitenansicht,

Fig. 2

Endabschnitte der derselben Arbeitswalze zugeordneten Zwischenwalzen des Walzgerüstes gemäß Figur 1 in Aufsicht mit unterschiedlichen Ausführungen der Walzenballenenden,

Fig. 3

das Walzgerüst gemäß Figur 1 in Seitenansicht,

Fig. 4

die Zwischenwalzen und Arbeitswalzen des Gerüstes gemäß Figur 3 in aufgeklappter Darstellung nach der strichpunktierten Linie der Figur 3.

The invention is explained in more detail below with reference to a drawing. In detail show:

Fig. 1

the rolls of a multi-roll mill stand in a schematic representation in side view,

Fig. 2

End sections of the intermediate rolls of the roll stand according to FIG. 1 assigned to the same work roll, in supervision with different designs of the roll bale ends,

Fig. 3

the roll stand according to Figure 1 in side view,

Fig. 4

the intermediate rolls and work rolls of the stand according to FIG. 3 in an expanded view according to the dash-dotted line in FIG. 3.

In the multi-roll mill stand shown in FIG. 1, each work roll 1, 2 is supported on four support rolls 13 to 20 via a pair of intermediate rolls 3 to 6 and three further intermediate rolls 7 to 12. The roll bales of each pair of intermediate rolls 3 to 6 are each tapered conically or parabolically at only one end of the bale. However, other taper contours are also possible.

In the embodiment of Figure 2, the roll barrel ends 23, 24 have a different contour. The same applies to the roll bale ends of the intermediate rolls 5, 6 assigned to the other work roll 2. In this exemplary embodiment, the intermediate rolls 3 to 6, the conical roll bale ends of which lie on the same side of the roll stand, should be diagonally opposite one another with respect to the rolling stock plane.

The intermediate rolls 3 to 6, which lie with their conical roll bale ends on the same roll stand side and therefore act on the same belt edge, are axially adjustable independently of one another, so that an axial offset can be set.

In the exemplary embodiment in FIGS. 3 and 4, the intermediate rolls 33, 34, 35, 36 assigned to each work roll 31, 32 are designed differently. While the intermediate rollers 34, 35 have a cylindrical roller bale 37, 38 with a conical roller bale end 39, 40, the roller bales 41, 42 of the two remaining intermediate rollers 33, 36 are contoured over their entire length. The contour of the roller bales 41, 42 is slightly parabolic, the largest diameter being outside the axial center. This asymmetry is in opposite directions in both roller bales 41, 42. This contour of the roller bales 41, 42 naturally includes at least one tapered roller bale end 43, 44.

Depending on the relative axial adjustment of the two intermediate rolls 33, 36 with the contoured roll bales 41, 42, the roll profile in the strip center area can be curved to a greater or lesser extent. After the desired rolling profile has been set, the axial adjustment of the intermediate rollers 34 and 35 can be used to fine-tune the support curve at the strip edges.

As an alternative to the exemplary embodiment in FIGS. 3, 4 with at least one intermediate roller 33, 36 directly supporting the work rolls 31, 32 with contoured roll bales 41, 42, in the exemplary embodiment in FIGS. 1 and 2 the further intermediate rolls 7-12 contoured roll bales can correspond to the roll bales 41, 42 the intermediate rollers 33, 36 of the embodiment of Figures 3 and 4. In preferred embodiments, either the intermediate rolls 8 and 11 or the intermediate rolls 7, 9 and 10, 12 have a contoured roll barrel. In any case, it is achieved that the work rolls directly support Intermediate rollers 3, 4 and 5, 6 are supported on an intermediate roller 7-12 with a contoured roller bale.

Claims (7)

1. Multi-roll rolling stand whose two work rolls (1,2) are each supported directly or indirectly via a pair of axially adjustable intermediate rolls (3-6,33-36) on back-up rolls (13-20) or on supporting rolls arranged in series, wherein the intermediate rolls (3,4) associated with the first working roll (1) a tapered roll barrel end on the first side of the rolling stand and intermediate rolls (5,6) associated with the second working rolls has a tapered roll barrel end on the second side of the rolling stand and wherein the intermediate rolls (3,4 and 5,6 respectively) associated with the same work roll (1 and 2 respectively) can be adjusted independently of each other and in such a way that the adjacent tapered roll barrel ends of the same working roll (1,2) are axially offset with respect to one another, characterized in that the two tapered roll barrel ends lying on the same side of the rolling stand have different taper contours.
2. Multi-roll stand according to Claim 1, characterized in that the barrel (41 or 42 respectively) of one of the intermediate rolls (33,34 or 35,36 respecitvely) associated with each work roll (31 or 32 respectively) has a tapered roll barrel end (39 or 40) and the other has a contoured shape and in that the contours of the lower and of the upper intermediate rolls (33 and 36 respectively) are designed such that when these rolls (33 and 36) are offset axially in opposite directions, they produce a greater or lesser curvature of the roll nip profile.
3. Multi-roll rolling stand according to Claim 1, characterized in that each adjustable intermediate roll (3-6) is supported on the back-up rolls (13-20) or the support rolls via at least one further intermediate roll (7-12) having a contoured roll barrel.
4. Multi-roll rolling stand according to Claim 3, characerized in that the central intermediate rolls (8 and 11 respectively) which each support a pair of intermediate rolls (3,4 or 5,6 respectively) have the contoured roll barrel.
5. Multi-roll rolling stand according to Claim 3 or 4, characterized in that the outer intermediate rolls (7,9 and 10,12), which each support one of the intermediate rolls (3-6) of each pair of intermediate rolls (3,4 and 5,6 respectively), have the contoured roll barrel.
6. Multi-roll stand according to one of Claims 2 to 5, characterized in that the contour of the contoured roll barrels (41 and 42) is arranged unsymmetrically with respect to the centre of the roll barrel.
7. Multi-roll stand according to Claim 6, characterized in that the unsymmetrically contoured roll barrels (41 and 42) are arranged in opposite directions with respect to their contour.

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