EP0091540B1 - Roll stand with axially movable rolls - Google Patents

Abstract

1. Four-high roll stand with working rolls (54 and 55), which bear on backing rolls (52 and 53), where in the working rolls (54 and 55) are axially displaceable one relative to the other and the working rolls (54 and 55) as well as also the backing rolls (52 and 53) are provided with a curved outline, which extends over the entire barrel length and is composed of a convex and a concave region and has a structure, in which the barrel outlines of mutually bearing (52, 54, 53, 55) or co-operating (52 and 53, 54 and 55) rolls complementarily augment each other exclusively in a certain relative axial setting of these rolls, characterised thereby, that also the backing rolls (52 and 53) are axially displaceable one relative to the other and that the displacement of the backing rolls (52 and 53) takes place either independently of or together with the working rolls (54 and 55).

Description

The invention relates to a four-high rolling mill with work rolls which are supported on support rolls, the work rolls being axially displaceable relative to one another and both the work rolls and the support rolls being provided with a curved contour which extends over the entire length of the bale and consists of a convex and a concave region composed and which has a shape in which the bale contours of mutually supporting or cooperating rollers complement each other only in a certain relative axial position of these rollers.

Such a four-high mill stand is known from "Patent Abstracts of Japan Volume 5, No. 83, May 30, 1981 page 5M71 & JP-A-56-30014". With this stand, the work rolls are axially displaceable against each other, while the backup rolls are immovable, i.e. the support rollers are fixed in the axial direction. The particular advantage of this type of stand is that the shape of the roll gap and thus the cross-sectional shape of the rolling stock can already be influenced by the small displacement paths of the contoured rolls.

The roll gap is changed by the axial relative displacement of the two contoured work rolls. This change in roll gap is superimposed by a bending of the work rolls, which is caused by the fact that an axial displacement of a work roll also means a relative displacement with respect to the fixed contoured support roll supporting it. Since after the work roll shift the contours of the two supporting rolls no longer complement each other, the pressure distribution changes over the length of the contact section of both roll bales; the work rolls are bent. The bending of the work gap, which results from the axial relative displacement of the work rolls relative to one another, increases the effect of the roll gap.

A disadvantage of this type of scaffolding is that the pressure distribution between each work roll and the supporting roll supporting it changes with the axial displacement of the work rolls. This leads to the creation of marking zones on the bale surface of the work roll, which are also transferred to the surface of the rolling stock. This is particularly undesirable when dressing tapes.

The invention is concerned with the development of the known four-high mill stand. It is based on the task of improving the possibility of influencing the roll gap profile, but also of ensuring, if necessary, an optimal equalization of the pressure distribution.

To solve this problem, it is proposed for a four-high rolling stand of the type mentioned at the outset that the support rolls are also axially displaceable relative to one another and that the support rolls are displaced either independently of or together with the work rolls.

If the back-up rolls are moved together with the work rolls in contact with them in the same direction and by the same path, the complementary addition of the contours of these rolls is retained. There is no significant change in the even distribution of pressure between each work roll and the backup roll supporting it. Markings on the bale surface of the work rolls and thus also on the surface of the rolling stock are avoided.

If the quality of the surface of the rolling stock is not paramount, the work rolls and backup rolls can be moved independently of one another. As a result, the roll gap profile can be influenced much more sensitively than in the known four-high roll stand with supporting rolls fixed in the axial direction.

With claim 2, the invention also includes a six-high rolling stand, the rolling stand coming closest to EP-A2-49798 [Art. 54 (3) EPC], which has work rolls which are supported on backup roll-supported intermediate rolls. The work rolls and / or intermediate rolls and / or backup rolls are axially displaceable. Each roller of one of these roller pairs is provided with a curved contour running in the direction towards the end of the bale. This contour extends over the entire length of the bale of both rollers on opposite sides and has a shape in which the two bale contours complement each other exclusively in a certain relative axial position.

The object is to not only improve the uniformity of the pressure distribution over the contact length of two adjacent rolls, but also to increase the continuous mechanical influence on the shape of the roll gap.

To solve this problem, a six-high roll stand with work rolls is proposed, which are supported on support roll-supported intermediate rolls, the work rolls and / or support rolls and / or intermediate rolls being axially displaceable relative to one another and providing the rolls of at least two pairs of rolls with a curved contour extending over the entire length of the bale are, which is composed of a convex and a concave area, the bale contours of mutually supporting or interacting rollers complement each other exclusively in a certain relative axial position of these rollers.

According to claim 3, a configuration option for a six-high roll stand is that only the back-up rolls have cylindrical or conventionally crowned roll balls, while according to claim 4 only the work rolls are provided with cylindrical or conventionally crowned roll balls.

• Fig. 1 ein Quarto-Walzgerüst,
• Fig. 2 ein Sexto-Walzgerüst,
• Fig. 3 eine andere Bauart eines Sexto-Walzgerüstes und
• Fig. 4 eine weitere Ausbildungsmöglichkeit für ein Sexto-Walzgerüst.

Various exemplary embodiments of roll stands according to the invention are explained below with reference to the drawing. Here, each seen in the rolling direction

• 1 is a four-high mill stand,
• 2 a six-high mill stand,
• Fig. 3 shows another type of six-high rolling mill and
• Fig. 4 shows another training option for a six-high rolling mill.

For the sake of simplicity, only the roller sets of the four-high mill stand according to FIG. 1 and the six-high mill stands according to FIGS. 2 to 4 are shown in the drawing.

The four-high mill stand 51 according to FIG. 1 has a set of rolls consisting of the pair of backup rolls 52, 53 and the pair of work rolls 54, 55.

The pair of work rolls 54, 55 delimits the roll gap 56 for the rolled strip 57. The height of the roll gap 56 is determined in a conventional manner by adjusting devices (not shown) which act on the chocks of the support roll pair 52 and 53.

The roll balls 52 'and 53' of the support rolls 52 and 53 have a curved contour over their entire length, in such a way that in the case of the upper support roll 52 this contour is convex over the left half of the roll roll 52 'and over the right one Half of the same is concave, while in the lower support roller 53 'it is concave over the left half of the roller barrel 53' and convex over the right half of the same. Both sections of the roller bales 52 'and 53' are determined by the same curvature curves, and it can also be seen from FIG. 1 that both support rollers 52 and 53 have an identical - here bottle-like shape of the roller bale 52 'and 53' as well as in the roller stands of the roll stand 51 are accommodated relative to one another in the installation position turned through 180 °.

The two work rolls 54 and 55 of the work roll pair also have roll bales 54 'and 55' with a contour that is curved over their entire length, this being designed to be complementary to the contour of the roll bale 52 'and 53' of the adjacent support roll 52 and 53, respectively. Accordingly, the roll bale 54 'of the upper work roll 54 has a concave course over its left half and a convex course over its right half, while conversely the roll bale 55' of the lower work roll 55 has a convex curve over the left half and a concave curve over the right half. 1, the two work rolls 54 and 55 have an identical — in this case bottle-like — shape of their roll bales 54 ′ and 55 ′ and are also accommodated in the roll stand relative to one another in an installed position turned through 180 °.

At least the rollers of one of the two pairs of rollers 52, 53 and 54, 55 of the four-high mill stand 51 according to FIG. 1, but preferably the rollers of both pairs of rollers 52, 53 and 54, 55 are axially displaceable in the (not shown) chocks of the Roll stand supported, the devices for axial adjustment each attack one of the roll neck.

With medium axial adjustment of both the support rollers 52 and 53 of the support roller pair 52, 53 and the side rollers 54, 55 of the work roller pair 54, 55, as shown in FIG. 1, the roller gap 56 has a constant cross-sectional height over the entire bale length, although it runs slightly S-shaped welded. The rolled strip 57 is therefore rolled out over its entire width with a uniform thickness.

mit a = Abstand der Arbeitswalzenachsen und r; (z) = Walzenradien.The height of the roll gap 56 between the two curved contoured bales 54 ', 55' of the work rolls 54 and 55 results from the formula

with a = distance between the work roll axes and r; (z) = roll radii.

If one or both of the work rolls 54 and 55 are moved together with the support rolls 52 and 53 in contact with it in the axial direction by certain amounts v _i and _V2 , then the shape of the roll gap 56 changes according to the formula

As a result, a continuous mechanical influence on the shape of the roll gap 56 is possible, specifically in such a way that, depending on the setting made, either the rolling pressure on the longitudinal edges of the rolled strip 57 is increased or reduced.

A further influence on the shape of the roll gap 56 is possible, however, in that the work rolls 54 and / or 55 are also displaced axially relative to the support rolls 52 and / or 53. As a result, the pressure distribution between the roll bales 52 'and 54' and 53 'of the backup roll set 52, 53 and the work roll set 54, 55, which are in contact with one another, can be influenced very sensitively and the shape of the roll gap 56 can thus be further optimized.

The basic structure of the six-high mill stand 61 according to FIG. 2 is the same as that of the four-high mill stand 51 according to FIG. 1. However, the set of rolls here does not only consist of the support roll pair 62, 63 comprising the two support rolls 62 and 63, and that of the two Work rolls 64 and 65 comprising work roll pair 64, 65, but an additional pair of intermediate rolls 68, 69 consisting of the two intermediate rolls 68 and 69 is additionally provided. The roll gap for the rolled strip 67 is limited between the two work rolls 64 and 65 of the work roll pair 64, 65.

All rolls of the six-high roll stand 61 according to Fig. 2d.h. So not only the support rollers 62 and 63 of the support roller pair 62, 63 and the work rollers 64, 65 of the work roller pair 64, 65, but also the intermediate rollers 68 and 69 of the intermediate roller pair 68, 69, have roller balls 62 ', 63'; 64 ', 65'; 68 ', 69' with contours curved over their entire length. The contours, which are each convex over one bale half and concave over the other bale half, are on the roller bales 62 ', 68', 64 'and 63', 69 ', 65' of the support rollers 62, 63, the intermediate rollers 68, 69 which are in contact with one another and the work rolls 64, 65 are coordinated with one another in such a way that they complement one another in the central axial position of all the roll pairs of the six-high mill stand 61 according to FIG. 2. The roll gap 66 for the rolled strip 67 therefore, despite its slightly S-shaped cross-sectional shape, has the same height over its entire length.

The contour of the nip 66 can then be delicately influenced by relative axial displacement of the rollers of any one roller pair 62, 63 or 64, 65 or 68, 69 to one another and / or to the rollers of the other roller sets, specifically by the additional presence of the intermediate roller pair 68, 69 even more sensitive than in the case of the four-high mill stand 51 according to FIG. 1.

Also in the case of the six-high roll stand 61 according to FIG. 2, the support rollers 62 and 63 of the support roller pair 62, 63 as well as the work rollers 64 and 65 of the work roller pair 64, 65 and finally the intermediate rollers 68 and 69 of the intermediate roller pair 68 and 69 have an identical one , bottle-like shape of the roller barrel. They are accommodated in the roll stands of the rolling stand relative to each other in each case by 180 ⁰ turned-over installation position.

As FIGS. 3 and 4 make clear, six-high roll stands 71 and 81 can also be varied with respect to the design of their roll set compared to the design according to FIG. 2.

While the back-up rolls 72 and 73 of the pair of back-up rolls use roll balls 72 'and 73' of cylindrical or conventionally spherical shape over their entire length in the design according to FIG. 3, the work rolls 74 and 75 of the work roll pair 74, 75 and the intermediate rolls 78 and 79 of the intermediate roller pair 78, 79 equipped with roller balls 74 ', 75' and 78 ', 79', which have a curved contour over their entire length. In this case, only the work rolls 74 and 75 of the work roll pair 74, 75 and / or the intermediate rolls 78 and 79 of the pair of intermediate rolls 78, 79 are axially displaceably provided in the roll stand 71, while the support rolls 72 and 73 of the support roll pair 72, 73 are axially immovable therein to store.

In the six-high roll stand 81 according to FIG. 4, the work rolls 84 and 85 of the work roll pair 84, 85 roll bales 84 'and 85' have a cylindrical or conventionally spherical shape over their entire length. On the other hand, however, the roll balls 82 ', 83' of the support rolls 82 and 83 and the roll balls 88 'and 89' of the intermediate rolls 88 and 89 are provided with a contour that is curved over their entire length.

The influencing of the roll gap 86 for the rolled strip 87 takes place here through the axially displaceable arrangement of the support rolls 82 and 83 and / or the intermediate rolls 88 and 89, while the work rolls 84 and 85 are axially immovable in their chocks.

Claims (4)

1. Four-high roll stand with working rolls (54 and 55), which bear on backing rolls (52 and 53), wherein the working rolls (54 and 55) are axially displaceable one relative to the other and the working rolls (54 and 55) as well as also the backing rolls (52 and 53) are provided with a curved outline, which extends over the entire barrel length and is composed of a convex and a concave region and has a structure, in which the barrel outlines of mutually bearing (52, 54, 53, 55) or co-operating (52 and 53, 54 and 55) rolls complementarily augment each other exclusively in a certain relative axial setting of these rolls, characterised thereby, that also the backing rolls (52 and 53) are axially displaceable one relative to the other and that the displacement of the backing rolls (52 and 53) takes place either independently of or together with the working rolls (54 and 55).

2.Six-high roll stand with working rolls (64 and 65), which bear on intermediate rolls (68 and 69), which are backed by backing rolls, wherein the working rolls (64 and 65) and/or backing rolls (62 and 63) and/or intermediate rolls (68 and 69) are axially displaceable one relative to the other and the rolls of at least two roll pairs (62, 63; 64, 65; 68, 69) are provided with a curved outline, which extends over the entire barrel length and is composed of a convex and a concave region, wherein the barrel outlines of mutually bearing (62 and 68, 64 and 68, 63 and 69, 65 and 69) or co-operating (62 and 63, 64 and 65, 68 and 69) rolls complementarily augment each other exclusively in a certain relative axial setting of these rolls.

3. Roll stand according to claim 2, characterised thereby, that the backing rolls (72 and 73) of the backing roll pair (72 and 73) exclusively display cylindrical or conventionally cambered roll barrels (72', 73').

4. Roll stand according to claim 2, characterised thereby, that the working rolls (84 and 85) of the working roll pair (84, 85) exclusively display cylindrical or conventionally cambered roll barrels (84', 85').

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