EP0059417A1 - Roll stand - Google Patents

Abstract

A roll stand with two work rolls 2, 3, two intermediate rolls 4, 5 and two support rolls 6, 7 (six-high roll stand) is provided with axially displaceable intermediate rolls for rolling out strips of a wide range of widths. It should be improved in such a way that not only can be worked for all rollable bandwidths with constant operating conditions with the smallest possible Hertzian pressure between the work rolls 2, 3 and the intermediate rolls 4, 5, but it should also have an enlarged correction range, one Allow improvement of the strip profile quality as well as optimization of the joint pressures from work rolls to the intermediate rolls and from the intermediate rolls to the backup rolls. Furthermore, an optimal choice of diameter for the work rolls 2, 3 and the intermediate rolls 4, 5 - based on the rolling task and on mastering the peripheral forces - and a problem-free change of these roll sets are to be achieved. The purpose of the axially displaceable intermediate rolls 4 and 5 is to prevent the thickness of the rolling out of the rolled strips in the region of their longitudinal edges and the particularly high stress on the sections of the work rolls 2, 3 which act on the edges of the rolling stock. Such a six-high mill stand has fixed blocks 12, which are provided on the one hand with vertical guide surfaces for the chocks 13, 14 of the work rolls 2, 3 and for the chocks 15, 16 of the intermediate rolls 4, 5, which on the other hand have adjusting means for balancing and bending the Have rollers. Certain adjusting means are brought into effect with the direction of action against the upper support roller 6 on the chocks 15 of the upper intermediate roller 4. The chocks 15 and 16 of both intermediate rollers 4 and 5 are assigned adjusting means 22, 38 provided in the blocks 12 as a bending device for the intermediate rollers 4, 5 and on each block 12 there is a lower and an upper one, each with guide surfaces for the chocks 15, 16 of the intermediate rollers 4, 5 provided guide piece 19, 20 vertically displaceably, the adjusting means 22, 38 forming the bending device for the intermediate rolls 4, 5 are relative to the guide pieces 19, 20 and / or to the chock 15, 16 in the horizontal direction parallel to the roller axes provided relocatable. The chocks 13, 14 of both work rolls 2, 3 are also assigned adjustment means 55, 60 in the blocks 12 as bending devices which engage guide pieces 117, 118, which in turn on the one hand have vertical guides 53, 54; 58, 59 are held in the blocks 12 and on the other hand have horizontal guides for the chocks 13, 14 of the work rolls 2, 3.

Description

The invention relates to a roll stand with two work rolls, two intermediate rolls and two support rolls, i.e. a so-called six-high roll stand, in which at least the support rolls and the intermediate rolls lie essentially one above the other in the same vertical plane, in which the intermediate rolls between the support rolls and the work rolls are also axially displaceable are arranged and in which stand-fixed blocks are provided on the one hand with vertical guide surfaces for the chocks of the work rolls and the intermediate rolls and on the other hand have adjusting means for balancing and bending the rolls, certain adjusting means with direction of action against the upper support roller being able to bring the chocks of the upper intermediate roll into effect are.

From DE-PS 955 131 multi-roll stands have long been known in which two work rolls each work with intermediate rolls via intermediate rolls and in which the intermediate rolls are arranged axially displaceably between the support rolls and the work rolls. The purpose of the axially displaceable intermediate rolls, it is to prevent the stronger, thinning of the roll bands in the region of their longitudinal edges and particularly high stress on the _W alz- gutkanten acting portions of the work rolls. Therefore, the upper and the lower intermediate roller are each so by opposite axial displacement set that the rolling pressure can only be mutually transferred up to the edge of the rolling stock on the work rolls. The parts of the work rolls that protrude beyond the edges of the rolling stock are thus relieved of the rolling pressure and are therefore subject to reduced deformation. Thus, the axially movable intermediate rolls allow a very fine adjustment of the effective gap _W alz- to the different rolling stock widths and thus an optimal cross-sectional constancy of rolled products.

So that the end regions of the work rolls, which are not supported by the intermediate rolls and which are inevitably subject to increased deflection in the direction of the roll gap, in the multi-roll roll stand according to DE-PS 955 131, do not bring about any disadvantageous upsetting of the rolling stock edges, they are ground to a slightly spherical shape, that their increased deflection, which inevitably occurs in the free end regions, is compensated for.

Instead of slightly crowned work rolls, cylindrical work rolls can also be used if they are assigned, for example in accordance with DE-AS 12 81 981, roll bending devices which act on the chocks of the work rolls and are so effective that they touch the ends of the Spread the work rolls opposite the roll gap in the opposite direction to the deflection that normally occurs.

A generic six-high roll stand is part of the prior art through BR patent application 678285. Here, the work rolls and the intermediate rolls with their chocks are each guided between stationary blocks, which on the one hand have adjustment means for balancing and bending the rolls, but on the other hand are also provided with vertical guide surfaces for the chocks of the work rolls and the intermediate rolls.

In this known six-high roll stand, cylindrical ground work rolls are also used, the adjusting means assigned to their chocks in the blocks being designed as roll bending devices which counteract the deflection of the free end sections of the work rolls projecting beyond the rolling stock.

Furthermore, in this known roll stand, adjustment means for the upper intermediate roll are also assigned in the blocks, which act on their chocks, on the one hand to bring about a balance thereof and on the other hand to be able to lift this intermediate roll from the work rolls when they are replaced have to.

Finally, DE-OS 27 52 750 also includes a six-high roll stand, which works with axially immovable work rolls, intermediate rolls and backup rolls, and in which the longitudinal extent of the effective bale surface of each backup roll is less than that of the intermediate rolls and in which the effective bale surface of the intermediate rolls is in turn less than that of each work roll.

In this known six-high roll stand, at least the chocks of the intermediate rolls, but preferably also the chocks of the work rolls and / or the backup rolls, are assigned to roll bending devices. By acting on these roll bending devices, it is to be achieved that the bale surfaces of the upper and lower work rolls in contact with the rolling stock run essentially in a straight line.

In contrast to the multi-roll mill stands with axially displaceable intermediate rolls, the six-high mill stand according to DE-OS 27 52 750 is only suitable for strip widths that move within relatively narrow limits because of the effective bale top area of the work rolls in relation to the intermediate rolls on the one hand and the intermediate rolls in relation to the backup rolls on the other hand and thus the deflection of the work rolls can only be effectively influenced over those end regions which are not supported by the bale surface of the intermediate rolls and the backup rolls. The minimum width of the rollable strip material is therefore dependent on the effective bale length of the back-up rolls, while its maximum width is determined by the effective bale length of the intermediate rolls.

The invention has for its object to provide a six-high roll stand of the generic type, that is, a six-high roll stand with axially displaceable intermediate rolls, which is suitable for rolling out strips of a wide range, which for all rollable strip widths with constant operating conditions and as small as possible Hertzian pressure between the work rolls and the intermediate rolls works as well as an optimal choice of diameter for the work and intermediate rolls - based on the rolling task and the control of the peripheral forces - and finally also allows the problem-free changing of the work and intermediate rolls.

This object is achieved according to the invention primarily in that the chocks provided in the blocks are assigned adjusting means as bending devices, that on each block a lower and an upper guide piece provided with the guide surfaces for the chocks of the intermediate rolls can be moved vertically is guided, and that the adjusting means forming the bending devices for the intermediate rolls are provided such that they can be displaced relative to the guide pieces and / or the chock in the horizontal direction parallel to the roll axes.

This structure of a six-high mill stand according to the invention has the essential advantage that there is little wear on the work rolls because the work rolls are not to be corrected around the edge of the intermediate rolls. On the other hand, it also proves advantageous that the bending lever arm of the axially displaceable intermediate rolls remains constant for all strip widths to be rolled. Finally, the shifting conditions for the intermediate rolls are also significantly improved. It has also been shown that due to the achievable favorable Hertzian pressure and the high temperature gradients (large material tensions) on the work rolls, a higher security against shell breakouts can be achieved. Finally, the measures according to the invention also prevent a mutual impairment of the available design spaces, so that with an optimal choice of diameter of work rolls and intermediate rolls there is no restriction with regard to the design of the effective force transmission systems for the bending correction forces, so there are no dimensioning difficulties.

An essential development feature according to the invention is that each guide piece consists of a stator-side part and a part assigned to the chock of the intermediate roller, the adjusting means forming the bending device being arranged between these two parts.

According to the invention, an advantageous type of roll stand is characterized in that the two parts of the guide pieces can only be displaced vertically relative to one another, that between them two adjusting means, which are located one behind the other in the axial direction of the intermediate rolls, act as bending devices and that the chocks of the intermediate rolls are relative are arranged exclusively horizontally displaceable to the parts of the guide pieces assigned to them. In this embodiment, it has proven particularly useful if the adjusting means forming the bending device are installed in the stator-side part of the guide pieces and act on the chock-side part thereof.

_D a, the two behind the other in spaced-adjusting means in dependence on the respective axial shift position of the intermediate roll chocks their restoring forces are in terms variable, can be a simple way of bending lever arm of the axially displaceable intermediate rolls for rolling conditions constant.

Another advantageous training possibility for a rolling stand according to the invention is that the two parts of the guide pieces are horizontally and vertically displaceable relative to one another, that between them an adjusting means built into the chock-side part of the guide pieces is provided in each case on the central plane of the intermediate roll chocks , and that the chock-side part of the guide pieces is connected to the associated chock horizontally displaceable relative to the stator-side part.

In both types of roll stand according to the invention, the adjusting means serving as a bending device consist of hydraulically actuatable piston-cylinder units which are installed in one part of the guide piece, while the piston rod acts on the other part.

For both positive and negative bending influence of the intermediate rolls, it is important that the piston-cylinder units are double-acting and are anchored to both parts of the guide pieces in a tensile and compressive manner.

The structure according to the invention is not only suitable for six-high roll stands in which all the rolls - work rolls, intermediate and back-up rolls - lie on a common vertical plane, it can also be used in six-high roll stands of the type in which the work rolls are made of vertical axis plane of the intermediate rollers and the support rollers are displaced and are supported in the direction of displacement by intermediate rollers and / or support rollers mounted on support bridges on their bales, as is known per se from DE-AS 25 22 213.

An important feature of a roll stand according to the invention is that the guide pieces which are guided vertically displaceably in the blocks and which contain the adjusting means forming the bending devices are positively connected to the chocks of the intermediate rolls by horizontal guides in the vertical direction, which are parallel to the roll change between the stands the rollers are continued. This results in a very compact structure for the guide pieces containing the bending devices, which hardly exceeds the dimensions of the intermediate roller chocks and thus favors the optimal choice of diameter for the working and intermediate rollers. The smallest diameter of the intermediate rolls is only limited by the height of their chocks or the guide pieces provided between them and the stand.

The roll stand according to the invention can be developed with simple means so that there is an effective expansion of the bending correction range, which enables an improvement in the strip profile quality and also an optimization of the joint pressures on the one hand at the contact points of the work rolls with the intermediate rolls and on the other hand at the contact points of the intermediate rolls with the support rollers. This can be achieved by the fact that also the chocks of both work rolls lök- in the _B ken provided adjusting means are assigned as bending devices which engage at guide pieces, which are in turn supported on the one hand on vertical guides in the blocks and have on the other hand horizontal guides for the chocks of the invention .

The particular advantage of such a measure is that by simultaneously engaging the bending device separately assigned to the intermediate rolls and the work rolls the strip profile quality can be increased so that the separate controllability of the joint pressures at the contact points of work rolls and intermediate rolls, as well as intermediate rolls and back-up rolls, enables roll wear to be reduced and the roll load and the roll bearing load to be reduced.

Finally, it is also essential that on the one hand the backing roll profile correction can be brought about by the bending of the intermediate rolls, while on the other hand the bending of the work rolls can be used for process interventions.

So that each work roll can be bent independently of the other and also independently of the intermediate rolls, an important further development feature of the invention is that each guide piece consists of a stand-side part and a part assigned to the chock of the work roll, the adjusting means forming the bending device between them both parts are arranged and the stator-side parts of the guide pieces of both work rolls are connected to one another via piston-cylinder units.

Another important embodiment is also seen according to the invention in that the two parts of the guide pieces can only be displaced vertically relative to one another and the chocks of the work rolls are in turn only provided horizontally displaceable relative to the parts of the guide pieces assigned to them.

The adjusting means forming the bending device can - like the piston-cylinder units - be installed in the part of the guide pieces on the stator side and act on the part of the same on the mounting piece side. However, it is also possible for the adjusting means forming the bending device in the chock part of the guide pieces on the side and engage the part on the stator side.

Finally, however, it is also important that the adjusting means consist of hydraulically actuated piston-cylinder units and are designed to be double-acting and engage between the guide pieces in a manner that is resistant to tension and compression. In this way, there is also a very compact structure for the guide pieces containing the bending devices of the work rolls, which practically hardly exceed the work roll chocks and thus favors the optimal choice of diameter for the work and intermediate rolls.

• Figur 1 in schematisch vereinfachtem, parallel zur Walzrichtung liegendem Vertikalschnitt eine erste Ausführungsform eines erfindungsgemäßen Walzgerüstes,
• Figur 2 in größerem Maßstab den in Fig. 1 mit II gekennzeichneten, erfindungswesentlichen Teilbereich,
• Figur 3 eine teilweise geschnittene Draufsicht auf die Anordnung nach Fig. 2,
• Figur 4 ein Kräfteschema zum Walzgerüst nach Fig. 1 im Bereich einer axial verschiebbaren Zwischenwalze,
• Figur 5 eine der Fig. 1 entsprechende Darstellung einer anderen Ausführungsform eines erfindungsgemäßen Walzgerüstes,
• Figur 6 in größerem Maßstab den in Fig. 5 mit VI gekennzeichneten, erfindungswesentlichen Teilbereich,
• Figur 7 in einer den Fig. 1 und 5 entsprechenden Darstellung eine weitere Bauart eines Walzgerüstes, welche mit Zwischenwalzen-Biegevorrichtungen nach den Fig. 2, 3 und 6 ausgerüstet werden kann,
• Figur 8 in schematisch vereinfacht dargestelltem, parallel zur Walzrichtung liegendem Vertikalschnitt eine weitere Ausführungsform eines erfindungsgemäßen Walzgerüstes,
• Figur 9 in größerem Maßstab den in Fig. 8 mit II gekennzeichneten, erfindungswesentlichen Teilbereich,
• Figur 10 eine der Fig. 8 entsprechende Darstellung einer anderen Ausführungsform eines erfindungsgemäßen Walzgerüstes,
• Figur 11 in größerem Maßstab den in Fig. 9 mit IV gekennzeichneten, erfindungswesentlichen Teilbereich.

Further features and advantages of the invention are explained below using exemplary embodiments shown in the drawing. Show it

• 1 shows a schematically simplified vertical section lying parallel to the rolling direction, a first embodiment of a roll stand according to the invention,
• FIG. 2 on a larger scale the part of the invention marked II in FIG. 1,
• FIG. 3 shows a partially sectioned top view of the arrangement according to FIG. 2,
• FIG. 4 shows a force diagram for the roll stand according to FIG. 1 in the region of an axially displaceable intermediate roll,
• 5 shows a representation corresponding to FIG. 1 of another embodiment of a roll stand according to the invention,
• FIG. 6 on a larger scale the part of the invention marked VI in FIG. 5,
• 7 in a representation corresponding to FIGS. 1 and 5, a further type of roll stand, which can be equipped with intermediate roll bending devices according to FIGS. 2, 3 and 6,
• 8 shows, in a schematically simplified, vertical section lying parallel to the rolling direction, a further embodiment of a rolling stand according to the invention,
• 9 shows, on a larger scale, the part of the invention marked II in FIG. 8,
• FIG. 10 shows a representation corresponding to FIG. 8 of another embodiment of a roll stand according to the invention,
• FIG. 11 on a larger scale the part of the invention marked IV in FIG. 9.

The roll stand shown in FIG. 1 has in the usual way two roll stands 1 arranged next to one another at a distance. only one of which is shown in FIG. 1. In these roll stands 1, two work rolls 2 and 3, two intermediate rolls 4 and 5 and two support rolls 6 and 7 are accommodated, so that a so-called six-high roll stand is formed. The upper support roller 6 and the lower support roller 7 are held and guided directly via their chocks 8 and 9 in the stand windows 10 of the two roll stands 1, the adjusting devices 11 of the roll stand attacking the chocks 8 of the upper support roller 6.

In the installation area of the work rolls 2 and 3 and the intermediate rolls 4 and 5 are in the stand windows 10 of the two roll stands 1 fixed blocks 12, between which on the one hand the chocks 13 and 14 for the two work rolls 2 and 3 and on the other hand the chocks 15 and 16 for the two intermediate rollers 4 and 5 are added.

The chocks 13 of the upper work roll 2 are positively connected in the vertical direction, but are horizontally displaceably connected to guide pieces 17 for the changing process, which in turn are guided vertically displaceably in the blocks 12 fixed to the stand. Likewise, the chocks 14 of the lower work roll are connected to guide pieces 18, which are also guided vertically displaceably in the blocks 12 fixed to the stand.

The chocks 15 of the upper intermediate roll 4 _F 19 are assigned üh- approximately pieces, but where here too the chocks 15 are in the vertical direction form-fitting horizontally slidable with the guide pieces 19 in engagement. Guide pieces 20 of the same type and mode of operation are also assigned to the chocks 16 for the lower intermediate roller 5. The horizontal guides 21 between the chocks 15 and 16 for the intermediate rolls 4 and 5 and the associated guide pieces 19 and 20 are designed so that they not only allow the change of the intermediate rolls 4 and 5 together with the work rolls 2 and 3, but that they also ensure an axial displacement of the intermediate rolls 4 and 5 relative to the work rolls 2 and 3 and to the support rolls 6 and 7 for the rolling operation. The axial displacement of the intermediate rolls 4 and 5 is important for the rolling operation because this allows the rolling stand to be adjusted to the different widths of the strips to be rolled out. This setting prevents the rolling out of the rolled strips in the region of their longitudinal edges and the particularly high stress on the sections of the work rolls which act on the rolled material edges.

For a rolling stand that is to be used for rolling out strips of a wide range of widths, it is essential that all rollable strip widths with constant operating conditions can be worked with the smallest possible Hertzian pressure between the work rolls of the intermediate rolls and optimal diameters for the Work and intermediate rolls - based on the rolling task and the control of the peripheral forces - can be selected. Therefore, special precautions have been taken on the roll stand in the installation area of the intermediate rolls 4 and 5: the mounting pieces 15 of the upper intermediate roll 4 and the corresponding mounting pieces 16 of the lower intermediate roll 5 are each adjusting means 22 in the form of the blocks 12 fixed to the stand in the form of hydraulically actuatable piston-cylinder Associated units, their arrangement and training clearly 2 and 3 results. These adjustment means or bending devices 22 for the intermediate rolls 4 and 5 are each installed in the guide pieces 19 and 20 assigned to the blocks 12.

2 and 3, the right guide piece 19 for the chocks 15 of the upper intermediate roller is shown. All guide pieces 19 for the upper intermediate roll 4 and also all guide pieces 20 for the lower intermediate roll 5 have the same design; however, they are installed relative to each other in a mirror image position in the roll stand 1, i. H. the left-hand guide pieces 19 and 20 are each mirror images of the right-hand guide pieces 19 and 20, while the upper guide pieces 19 in turn assume a mirror-image position to the lower guide pieces 20 in the roll stands 1.

From Fig. 2 it can be seen from a guide piece 19 that each of the guide pieces 19 and 20 consists of a stator-side part 23 and a part 24 assigned to the chock 15 or 16 of the intermediate roller 4 or 5. In the stator-side part 23, the adjustment means 22 forming the bending device for the intermediate roller 4 or 5 are installed, which in turn engage via their piston rod 25 on the chock-side part 24. The operative connection between the piston rods 25 of the adjusting means 22 and the chock-side part 24 of each guide piece 19 or 20 is of such a type that with the help of the chocks 15 or 16 bending forces on the intermediate roller 4 or 5 at least in the direction against the Back-up roller 6 and 7 can be exercised. However, it is particularly advantageous to design the connection between the piston rods 25 of the adjusting means 22 and the chock-side part 24 of the guide piece 19 in such a way that bending forces on the intermediate roller 4 and 5 both in the direction against the associated support roller 6 and 7 as well let exercise in the direction away from it. This is on the one hand, it is necessary to make the adjusting means 22 double-acting and, on the other hand, to connect their piston rods 25 with tensile and pressure resistance to the chock-side part 24 of the guide piece 19 or 20. The two parts 23 and 24 of the guide piece 19 are composed exclusively vertically displaceable relative to one another, that is to say secured against any horizontal displacement relative to one another.

From Fig. 3 it can be seen that in each guide piece 19 or 20 two in the axial direction of the intermediate roller 4 or 5 spaced adjusting means 22 are installed, which together form the bending device for the intermediate roller 4 or 5. The axial displaceability of the intermediate rolls 4 and 5, which is necessary for the rolling operation, is ensured by the fact that their chocks 15 and 16 are vertically positively engaged with the chock-side part 24 of each guide piece 19 and 20 via the horizontal guides 21.

The two adjusting means 22 installed in each guide piece 19 and serving as a bending device for the intermediate roller 4 or 5 have the purpose of keeping the bending lever arm of the intermediate roller 4 or 5 constant in any possible axial displacement position thereof. Therefore, the two adjusting means 22 are designed such that they each depend on the momentary axial sliding position of the two intermediate roller chocks 15 and 16 relative to the guide piece 19 with regard to the actuating forces exerted by them. can be varied. In the axial sliding position of the intermediate roller chock 15 shown in FIG. 3, the higher adjusting force is applied by the adjusting means 22 'and the lower adjusting force by the adjusting means 22 ". The reverse is true if the intermediate roller chock 15 has the opposite axial extreme position Varying the actuating forces also ensures that all four individual forces acting on an intermediate roller act symmetrically with respect to their transfer to the backup roller to the center of the stand.

Concordant restoring forces exerted by both adjusting means 22 'and 22 "when the intermediate roll chock 15 is in its central axial shift position. The respectively applied by the adjusting means 22 actuating forces therefore vary in proportion to the extent of axial displacement of the _Z wi- rule roll chock 15 relative to the guide piece 19 in such a way that the bending lever arm for the intermediate roller 4 always engages in the central plane of the intermediate roller chocks 15 and 16 lying transversely to the roller axis and that the total effect of the actuating forces at both ends of the intermediate rollers is symmetrical to the center of the stand The operation of the intermediate roller bending device is shown schematically in Fig. 4. The force arrows 26, 27, 28 and 29 indicate the position and effect of the four adjusting means 22 acting as an intermediate roller bending device, the two double arrows 30 and 31 represent the Middle plane of the intermediate roll Installation pieces and the two arrows 32 and 33 indicate the forces opposing the bending of the intermediate rolls, which emanate from the associated backup roll. The relative position of the double arrows 30 and 31 on the one hand to the force arrows 26 and 27 or 28 and 29 and on the other hand to the arrows 32 and 33 corresponds to the respective axial displacement position of the intermediate roller chocks and thus also the intermediate roller relative to the associated work roller and the associated backup roller.

The basic structure of the six-high rolling mill shown in FIG. 5 corresponds completely to that of the rolling mill according to FIG. 1. However, the structure and mode of operation of the guide pieces 19 and 20 for the two intermediate rolls 4 and 5 are different here.

6, the right guide piece for the chocks 15 of the upper intermediate roller 4 is shown on a larger scale. All guide pieces 19 for the upper intermediate roll 4 and also all guide pieces 20 for the lower intermediate roll 5 have the same design here. They differ only in terms of their installation position in the roll stands 1.

Ig from _F. 6 is shown based on the upper right guide piece 1 ₉ that the guide pieces 19 and 20 in turn have a stator-side part 34 and a chock-side part 35, but that an intermediate part 36 is also present. The stand-side part 34 is installed as a component of the block 12 in the roll stand 1. It acts via extending parallel to the roll axis _H orizon- talführungen 37 with the intermediate part 36 together, and specifically such that the intermediate portion 36 is in the axial direction of the intermediate roll 4 and 5, slidable in the stator-side member 34 but is supported in the vertical direction formschlüss.ig therein becomes. In the intermediate part 36, the chock-side part 35 of the guide piece 19 or 20 engages only vertically displaceably, so that the intermediate part 36 and the chock-side part 35 can carry out the horizontal displacement relative to the stator-side part 34 together. The form-fitting horizontal guidance in the vertical direction between the chock 15 or 16 of the intermediate roller 4 or 5 and the chock-side part 35 of the guide piece 19 is only useful here for changing the intermediate roller 4 or 5; the chock 15 and 16 and the chock-side part 35 of the guide piece 19 and 20 are thus locked together during the rolling operation against horizontal displacement.

When the guide piece 19 and 20 of Fig. 6 this is the _B device iege- for the intermediate roll 4 and 5 forming adjusting means 38 in the form of a hydraulically loadable piston-cylinder unit in the installation piece side part 35 of the guide piece installed 19 and 20 and its piston rod 39 acts with the intermediate part 36 together. Here, too, the adjusting means 38 can be double-acting and act on the intermediate part 36 with its piston rod 39 in a tensile and compressive manner.

In the guide piece 19 or 20 according to FIG. 6 there is only a single adjusting means 38, namely that it is installed in such a way that it is effective on the central plane of the chock 15 or 16 running transversely to the longitudinal axis of the intermediate roller 4 or ₅ .

With each axial displacement of the intermediate roller 4 or 5, the chock-side part 35, together with the intermediate part 36, carries out a corresponding horizontal displacement relative to the stator-side part 34 without the effective plane of the adjusting means 38 changing relative to the intermediate roller chock 15 or 16. As a result, its bending lever arm remains unchanged in every axial sliding position of the intermediate roller 4 or 5.

Compared to the exemplary embodiment of an intermediate roll bending device according to FIG. 2, the one according to FIG. 6 has a simplified structure in that it only requires one adjustment device 38 serving as a bending device. A control for the bending device according to FIG. 6 can thus be made simpler because only the effect of the actuating forces of both intermediate roller ends has to be symmetrical to the center of the stand. Instead, the intermediate part 36 is required as an additional element in the exemplary embodiment according to FIG. 6, which, however, can be implemented inexpensively as a mechanically simple component.

Both in the exemplary embodiment of an intermediate roller bending device according to FIG. 2 and according to that according to FIG. 6, it is essential that only one installation space is required to accommodate it in the roll stand, which space is anyway required for accommodating the intermediate roller chocks 15 or 16 is required. Due to this fact, there is no obstacle to the optimal choice of diameter for the work and intermediate rolls. The problem-free changing of the work and intermediate rolls is guaranteed without further ado, and there is also no mutual impairment of the available design space and therefore no restriction on the design of the effective power transmission systems for the bending correction forces of the intermediate rolls.

The roll bending that takes place on the axially displaceable intermediate rolls 4 and 5 improves the rolling result that can be achieved because there is a reduction in the Hertzian pressure between the work rolls and the intermediate rolls and the resulting temperature gradients on the work rolls offer greater security against shell breakouts. Work roll wear is also significantly reduced because the work rolls are not corrected around the edge of the intermediate rolls.

7 shows a six-high mill stand, which differs in its basic structure from the mill stands according to FIGS. 1 and 5. 1 and 5, the work rolls 2, 3, the intermediate rolls 4, 5 and the backup rolls 6, 7 lie on a common vertical axis plane, in the roll stand according to FIG. 7, this essentially common axis plane is of a certain size shifted from the vertical. In the direction of the displacement, the work rolls 2 and 3 are supported on their bale circumference by intermediate rolls 42 and 43 and / or support rolls 44, 45 mounted on support bridges 40 and 41. In this case too, the chocks 15, 16 of the intermediate rolls 4 and 5 intermediate roll bending devices of the embodiment shown in FIGS. 2 and 6 can be assigned and consequently the advantages of the intermediate roll bending can be optimally used.

8 and 9, in addition to the intermediate roll bending device, a work roll bending device can be seen in which the guide pieces 117 and 118 for the chocks 13 and 14 of the work rolls 2 and 3 basically have the same structure as the guide pieces 19 and 20 for the two intermediate rolls 4 and 5. Also their relative position to each other in the roll stand basically corresponds to that of the guide pieces 19 and 20 for the intermediate rolls 4 and 5.

From Fig. 8 it can be seen from a guide piece 117 that each of the guide pieces 117 and 118 consists of a stator-side part 53 and a part 54 assigned to the chock 13 and 14 respectively. In the stator-side part 53, the adjusting means 55, which form the bending device for the work rolls 2 and 3, are installed, which are designed as piston-cylinder units and engage via their piston rod 56 on the chock-side part 54. The operative connection between the piston rods 56 of the adjusting means 55 and the chock-side part 54 of each guide piece 117 and 118 is of such a type that with the help of the chocks 117 and 118 bending forces on the work roll 2 and 3 both in the direction against the associated intermediate roller 4 or 5 as well as exercise in the direction away from it. For this purpose, it is necessary on the one hand to make the adjusting means 55 double-acting, while on the other hand their piston rods 56 must be connected to the part 54 of the guide piece 117 and 118, which is resistant to tension and compression. The two parts 53 and 54 of the guide piece 117 and 118 are exclusively vertically displaceable relative to one another, that is to say secured against any horizontal displacement relative to one another.

The stand-side parts 52 of the guide pieces 117 and 118 are expediently supported via abutments against the blocks 12 and / or against one another, in such a way that their chock-side parts 54 and thus also the chocks 13 and 14 for the work rolls 2 and 3 are formed by the bending device Adjustment means 55 can be shifted independently of the respective support position of the stand-side parts 53 for work roll bending.

8, piston-cylinder units 57 are provided as abutments, for example, which hold the stator-side parts 53 of the guide pieces 117 and 118 in connection with one another in such a way that they enable a basic setting of the roll gap between the work rolls 2 and 3, but a common, Allow vertical relative displacement of the guide pieces 117 and 118 relative to the blocks 12 to an unlimited extent. Regardless of this possible relative displacement of the work roll set 2, 3 in the vertical direction to the blocks 12, the two work rolls 2 and 3 can be bent individually in each of the two possible directions in the vertical plane by the adjusting means 55 in order to achieve the respectively desirable interventions in the rolling process enable.

The combination of work roll bending and intermediate roll bending with the use of displaceable intermediate rolls not only results in an extension of the correction range, but also an improvement in the strip profile quality can be achieved by the simultaneous intervention of the two correction means, work roll bending and intermediate roll bending. Furthermore, optimization of the joint pressures on the one hand of the work rolls to the intermediate rolls and on the other hand of the intermediate rolls to the backup rolls is possible, so that not only is less roll wear achieved, but also reduced roll loads and roll bearing loads result. Finally, a backup roll profile correction can be brought about by the intermediate roll bending, while at the same time the work roll bending offers the possibility of interventions in the rolling process.

The basic structure of the six-high mill stand shown in FIG. 10 corresponds entirely to that of the roll stand according to FIG. 8. However, the construction and mode of operation of the guide pieces 19 and 20 for the intermediate roll chocks 15 and 16 on the one hand and the structure on the other hand are different of the guide pieces 117 and 118 for the work roll chocks 13 and 14.

11 shows, in addition to the intermediate roll bend already described in connection with FIG. 6, the right guide piece 117 for the chocks 13 of the upper work roll 2 shown in FIG. 10. It should also be pointed out here that all guide pieces 117 for the upper work roll 2 as well all the guide pieces 118 for the lower work roll 3 have the same design with respect to one another and that they differ from one another only with regard to their installation position in the roll stands 1.

10 and 11, using the example of the upper right guide piece 117 for the chocks 13 of the upper work roll 2, it can be seen that the guide pieces 117 and 118 also have a stator-side part 58 and a chock-side part 59.

Notwithstanding the formation of the guide pieces 117 and 118 of FIGS. 8 and 9 is in the guide pieces 117 and 118 of the embodiment of FIGS. 10 and 11, the _B IE feed mechanism for the work roll 2 or 3 forming adjusting means 60 in the form a hydraulically actuated piston-cylinder unit with the chock-side parts 59 of the guide pieces 117 and 118, respectively, and its piston rod 61 interacts with the stator-side part 58. Here too, the adjusting means 60 is double-acting and is fastened to the stator-side part 58 with its piston rod 39.

As has already been mentioned in connection with the rolling stand according to FIGS. 8 and 9, it is useful to assign the guide pieces 117 and 118 for the chocks 13 and 14 of the work rolls 2 and 3 in the stator-side blocks 12 so that on the one hand the relative position between the stator-side parts 58 of the respective superimposed guide pieces 117 and 118 to one another, but on the other hand also their relative position to the blocks 12 can be determined without a change in the relative position between the stator-side parts 58 and the chock-side parts 59 is necessary via the actuating means 60. As shown in FIG. 10 with the aid of the left guide pieces 117 and 118 for the chocks 13 and 14 of the work rolls 2 and 3, piston-cylinder units 62 and 63 can be formed in the upright part 58 of the guide pieces 117 and 118 in order to form these abutments to be built in. The piston rods 64 and 65 of the two piston-cylinder units 62 and 63 are supported on the one hand against one another or can be coupled to one another, while on the other hand they come to rest against horizontally extending support surfaces of the blocks 12. By acting on the double-acting piston-cylinder units 62 and 63, it is then possible to change the relative position of the stator-side parts 58 of the guide pieces 117 and 118 on the one hand and on the other hand to the blocks 12 without this as a bending device for the work rolls 2 and 3 serving adjustment means 60 in the guide pieces 117 and 118 must be influenced.

Both in the embodiment of a roll stand according to FIGS. 8 and 9 and in that according to FIGS. 10 and 11, it is essential that both the accommodation of the intermediate roll bending device and the work roll bending device in the roll stand practically only one installation space is needed, which anyway for the accommodation of the intermediate roller chocks 15. 16 and the work roll chocks 13 and 14 is required. Due to this fact, there is no obstacle to the optimal choice of diameter for the work and intermediate rolls and the problem-free changing of the work and intermediate rolls is also easily guaranteed. Furthermore, there is no mutual interference with the available design space for the intermediate roll and work roll bending devices with the result that there is also no restriction with regard to the design of the effective force transmission systems for the bending correction forces of the intermediate and work rolls.

Due to the possible roll bending not only on the axially displaceable intermediate rolls 4 and 5 but also on the work rolls 2 and 3, the rolling result that can be achieved is considerably improved because the joint pressures on the one hand of the work rolls to the intermediate rolls and on the other hand of the intermediate rolls to the backup rolls can be optimized Strip profile quality can be improved by simultaneous intervention of both correction means and a support roller profile correction is possible through the intermediate roll bending, while the work roll bending serves to intervene in the rolling process.

Claims (18)

1. Roll stand with two work rolls, two intermediate rolls and two support rolls (six-high roll stand), in which at least the support rolls and the intermediate rolls lie essentially one above the other in the same vertical plane, in which the intermediate rolls between the support rolls and the work rolls are arranged axially displaceably and at which stationary blocks are provided, on the one hand, with vertical guide surfaces for the chocks of the work rolls and the intermediate rolls and, on the other hand, have adjustment means for balancing and bending the rolls, certain adjustment means with direction of action against the upper back-up roll being able to act on the chocks of the upper intermediate roll,
characterized,
that the chocks (15, 16) of the two intermediate rolls (4, 5) in the blocks (12) are assigned adjusting means (22, 38) as bending devices that a lower (20) and an upper (19) with each block the guide surfaces for the chocks (16 and 15) of the intermediate rollers (5 and 4) provided guide piece (20,19) is guided vertically displaceably, and that the adjusting means (22,38.) forming the bending devices for the intermediate rollers (4,5) ) relative to the chocks (15, 16) and / or the guide pieces (19, 20) can be displaced in the horizontal direction parallel to the roller axes. 2. Roll stand according to claim 1,
characterized ,
that each guide piece (19, 20) consists of a stator-side part (23, 34) and a part (24, 35) assigned to the chock (15, 16) of the intermediate roller (4, 5), the adjusting means (22 , 38) are arranged between these two parts (23, 24 and 34, 35). 3. Roll stand according to claim 1 or 2,
characterized ,
that the two parts (23 and 24) of the guide pieces (19, 20) can only be displaced vertically relative to one another, that between them two adjusting means (22; 22 ', 22 ") which are located one behind the other in the axial direction of the intermediate rolls (4, 5) attack and that the chocks (15, 16) of the intermediate roller (4, 5) relative to the associated parts (24) of the guide pieces (19, 20) are arranged exclusively horizontally displaceable (21; Fig. 1 to 3). 4. Roll stand according to at least one of claims 1 to 3,
characterized ,
that the adjusting means forming the bending device (22) are installed in the stator-side part (23) of the guide pieces (19, 20) and act on the chock-side part (24) (25). 5. Roll stand according to at least one of claims 1 to 4,
characterized ,
that the two adjusting means (22; 22 ', 22 ") located one behind the other can be varied with regard to their actuating forces depending on the respective axial sliding position of the intermediate roller chocks (15, 16). 6. Roll stand according to claim 1 or 2,
characterized ,
that the two parts (34, 35) of the guide pieces (19, 20) are horizontally and vertically displaceable relative to each other (36), that between them in the chock-side part (35) of the guide pieces (19, 20) installed adjusting means (38) each is provided on the central plane of the intermediate roller chocks (15, 16), and that the chock-side part (35) of the guide piece (19, 20) with the associated chock (15, 16) can be displaced horizontally (21) relative to the stator-side part (34) ) connected is. 7. Roll stand according to claim 6,
characterized ,
that the stator-side part (34) with the chock-side part (35) of the guide pieces (19, 20) is connected via an intermediate part (36), which on the one hand horizontal sliding guides (37) to the stator-side part (34) and on the other hand vertical sliding guides to the chock-side Part (35). 8. Roll stand according to at least one of claims 1 to 7,
characterized ,
that the adjusting means (22, 38) consist of hydraulically actuated piston-cylinder units which are installed in one part (23 or 35) of the guide piece (19, 20) and whose piston rod (25 or 39) on the other part (24 or 36, 34). 9. Roll stand according to at least one of claims 1 to 8,

characterized ,
that the adjusting means are double-acting and engage between the guide pieces (19, 20) in a tensile and compressive manner. 10. Roll stand according to at least one of claims 1 to 9,
characterized ,
that the chocks (13, 14) of both work rolls (2, 3) in the blocks (12) provided adjustment means (55; 60) are assigned as bending devices which engage guide pieces (17 and 18), which in turn on the one hand via vertical guides (53, 54 and 58, 59) are held in the blocks (12) and on the other hand have horizontal guides (54 and 59) for the chocks (13, 14). 11. Roll stand according to claim 10,
characterized ,
that each guide piece (17 or 18) consists of a stator-side part (53 or 58) and a part (54 or 59) associated with the chock (13 or 14) of the work roll (2 or 3), the die Adjusting means (55 and 60) forming the bending device are arranged between these two parts (53, 54 and 58, 59). 12. Roll stand according to claim 10 or 11,
characterized ,
that the two parts (53, 54 and 58, 59) of the guide pieces (17, 18) can only be displaced vertically relative to one another, and the chocks (13, 14) of the work rolls (2, 3) relative to the parts assigned to them ( 54, 59) of the guide pieces (17, 18) are only arranged horizontally displaceable. 13. Roll stand according to one of claims 10 to 12,
characterized ,
that the adjusting means forming the bending device (55) are installed in the stator-side part (53) of the guide pieces (17, 18) and act on the chock-side part (54) (56). 14. Roll stand according to one of claims 10 to 12,
characterized ,
that the adjusting means forming the bending device (60) are installed in the chock-side part (59) of the guide pieces (17, 18) and engage on the stator-side part (58) (61). 15. Roll stand according to one of claims 10 to 14,
characterized ,
that the adjusting means (55 or 60) consist of hydraulically actuated piston-cylinder units which are installed in one part (53 or 59) of the guide piece (17 or 18) and their piston rod (56 or 61) on the other part (54 or 58) attacks. 16. Roll stand according to one of claims 1 to 15,
characterized ,
that the adjusting means are designed to be double-acting and engage in a tensile and compressive manner between the guide pieces (17, 18). 17. Roll stand according to one of claims 1 to 16,
characterized ,
that the stand-side parts (53 or 58) of the guide pieces (17, 18) within the blocks (12) of the roller stand (1) are assigned abutments (57 or 62, 63) via which the relative position of the stand-side parts (53 or 58) of the guide pieces (17 and 18) to one another and / or to the blocks (12) can be determined. 18. Roll stand according to claim 17,
characterized ,
that the adjustable abutments (57 and 62, 63) consist of piston-cylinder units built into the stator-side parts (53 and 58) of the guide pieces (17, 18).

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