EP1601474B1 - Method for changing the configuration of a rolling mill and advanced rolling mill for carrying out said method - Google Patents

Abstract

A method is claimed for changing the configuration of a rolling mill incorporating at least two work rolls and two support rolls, some means for applying a tightening effort and two assemblies of hydraulic jacks for cambering, at least the two work rolls. One realizes at least two types of work rolls (C1, C2) having, respectively a greater or smaller diameter and one passes the rolling mill from a quarto configuration to a sexto configuration and inversely, the rolls of greater diameter (C1, C'1) being utilized as work rolls in the quarto configuration and, in the sexto configuration, as intermediary rolls between each support roll and a roll of smaller diameter (C2, C'2) being used as the work roll. An independent claim is also included for a rolling mill equipped in such a way that this method of changing the working configuration can be realized.

Description

The invention relates to a method of changing the configuration of a rolling mill and an improved rolling mill for carrying out the method.

It is known that a rolling mill comprises, in a general manner, a holding cage having two spaced apart columns between which are arranged a set of superimposed cylinders with substantially parallel axes and comprising, at least, two working cylinders, respectively upper and lower which define a gap for passage of the product to be rolled and are supported, on the side opposite the product, respectively on two support cylinders. Each cylinder is rotatably mounted, at its ends, on bearings carried by support pieces called chocks, which are slidably mounted in windows formed in the two columns of the cage, parallel to a substantially vertical clamping plane in which are placed substantially the axes of the cylinders. For this purpose, each chock is provided, on either side of the clamping plane, sliding faces cooperating with corresponding guide faces formed on both sides of the corresponding window of the cage.

Because the work rolls have a smaller diameter than the support rolls, their chocks are narrower and their guide faces must therefore be narrower. In the former rolling stands, these guide faces are often arranged on legs integral with the chocks of the support rollers and extending towards the rolling plane.

More recently, it has been proposed to provide the guiding faces of the working chocks on the ends of guiding parts integral with the cage and projecting in each window, on either side of the clamping plane.

Hydraulic cylinders known as balancing, allow to adjust the relative positions of the cylinders for the engagement of the product or for the disassembly of the cylinders.

During rolling, the working rolls tend to move away from each other and the air gap between the generatrices opposite must be maintained by applying a clamping force between the chocks of the support rolls. The rolling force to be exerted on the product to obtain a certain thickness reduction ratio depends, in particular, on the diameter of the working rolls which determines the length of the reduction zone in which the metal flows and characteristics mechanical and metallurgical thereof such as its yield strength and composition, eg low carbon low carbon steel, stainless steel, alloy steel, etc.

Rolling cages used in the metallurgical industry may have several types of configuration depending on the nature of the product to be treated.

The most common rolling mills, especially for large productions, are of the "quarto" type having two work rolls associated, each with a larger diameter support roll, or of "sexto" type in which intermediate rolls are interposed between each working roll and the corresponding support roll. This arrangement makes it possible, in particular, to offset axially, with respect to one another, the two intermediate rolls in order to apply the rolling force, not on the entire roll table, but only over the width of the roll. product. This reduces the deformations of the cylinders and gives a product of better flatness.

Furthermore, the use of intermediate rolls makes it possible to use working rolls of smaller diameter and thus to reduce the rolling force required for the same reduction in thickness.

On the other hand, because the clamping forces are normally applied between the two ends of the two support cylinders and the rolled product, of variable width, does not generally fully cover the length of the work rolls, each roll can flex under the action of applied efforts. This results in a variation in thickness of the passage space of the strip between the working rolls which generates defects in profile and flatness.

In addition, the forces applied during rolling being extremely important, there necessarily occurs a slight flattening of the outer face of each cylinder, due to the so-called Hertz pressure.

Thus, during rolling, flatness defects that can be measured downstream of the mill, in order to correct them.

For this purpose, in recent years, there have been developed sophisticated systems for modulating the distribution of stresses applied to the product during rolling.

In a commonly used system, controlled bending forces are applied to both ends of the shaft of each working roll in order to achieve cambering effects to correct the stress distribution. For this purpose, the balancing cylinders can be used to adjust the spacing of the working rolls.

These cylinders can be interposed between the chocks of the work rolls. Such an arrangement, however, makes it more difficult to supply the cylinders with hydraulic fluid and it is generally preferred to mount the cylinders in the guide pieces of the chocks which, in recent installations, are often provided with protruding parts. massive fixed, on each side of the window, on the two uprights of each column of the cage. It is easier, in fact, to mount the hydraulic circuits on these parts which are called, for this reason "hydraulic blocks".

In this case, the cylinders cooperate with bearing members often called "ears" formed on each lateral side of the chock, on either side of the clamping plane.

Usually, a so-called positive bending is carried out, by spacing the chocks of the two working rolls to compensate for an extra thickness of the central part of the product, but it is also often interesting to have the possibility of producing a so-called negative bending, by tightening chocks. two working cylinders, to compensate for an extra thickness of the edges of the product.

To achieve a bending in both directions, it is possible to use single-acting cylinders each acting in a cambering direction, but such an arrangement complicates the construction of the hydraulic blocks since, on each side of the clamping plane, the chock must be associated. two cylinders each acting in one direction. However, at the level of the work rolls and near the band, the available space is quite limited and makes it difficult to install such a number of cylinders.

To reduce the number of cylinders, so often use double-acting cylinders whose rod is fixed on the chock, to act in both directions.

In the so-called "sexto" rolling mills, the bending forces can also be applied to the intermediate rolls which are interposed between each working roll and the associated support roll and can, in addition, be moved axially in opposite directions so as to to apply the rolling force, only over the width of the product, which makes it possible to obtain a product of better flatness.

Because flatness defects are easier to correct on a small roll mill, this type of mill is often used for rolling relatively small thicknesses.

However, the thickness of the rolling mill product may have to vary over a large range, in particular for the rolling of non-ferrous metals.

However, the use of small diameter cylinders makes it more difficult to engage the product between the cylinders and may lead to a refusal of commitment.

To solve this problem, it was proposed in the document JP-A-63 013 603 , to use working cylinders of large diameter, in quarto arrangement, for the large thicknesses and to replace each work roll by a set comprising an intermediate cylinder and a work roll of smaller diameter, to thus pass into a sexto configuration better adapted to low thicknesses.

To use the same bending cylinders, the chocks of the quarto working rolls and the intermediate sexting rolls are adapted so that their bearing lugs are substantially at the same level in each of the configurations.

On the other hand, the camber cylinders of the sexting work rolls are not used in the quarto assembly.

Such an arrangement therefore makes it easy to adapt to a considerable variation in the thickness of the product to be rolled, for example for the rolling of a copper or aluminum slab in a reversible cage.

However, it has appeared, even in the case where the mill is not provided for a significant variation in the thickness of the product, it would be interesting to have the opportunity to quickly change the configuration of the cage to adapt , not to a variation in thickness, but to a modification of the characteristics of the product to be rolled, for example its hardness.

It has been discovered that such a change of configuration would make it easy to adapt to the needs of users who constantly evolve in the direction of a diversification of the qualities required.

Thus, in the automotive industry, we are moving towards the use of steels with very specific shades to obtain high performance.

In addition, it is sought to reduce, as much as possible, the weight of the products manufactured without decreasing the strength and therefore, for the same performance, sheets with thinner and smaller thicknesses that require reduction rates are required. high, while maintaining the same requirements of regularity of thickness, flatness and surface quality.

For example, for the body sheet, we have seen successively appear the shades called, in the trade, CQ, DQ, DDQ, EDDQ whose elastic limit extends from 180Mpa to 250 MPa and very hard steels having a high elastic limit (HSLA) of up to 600 MPa. In contrast, very low carbon soft steels (IF) with an elastic limit of about 160 MPa are also required.

On the other hand, even the rolling process must be able to adapt to the quality of the treated steels, for example to take account of the fact that, in a tandem rolling mill, the rolling determines, by hardening, a progressive increase in the hardness of the produced and, consequently, the rolling force to be applied for the same reduction in thickness, from one cage to the next.

Therefore, the application means of the clamping force may be saturated in effort if the hardness of the starting material is too high.

In the case, for example, of a tandem mill, it is possible to adapt the configuration of successive cages to increase the hardness of the product by first using one or more quarto cages followed by sexto cages or cages said Z.High which allow, as we know, to further reduce the diameter of the working rolls.

However, the cage itself must be adapted to the configuration, because the height of the window in which the superimposed chocks must be threaded depends on the number of cylinders and their diameters.

In addition, the height of the hydraulic blocks also depends on the configuration since it is necessary to provide, in a sexto cage, support and guide parts for the intermediate cylinders.

Furthermore, as indicated above, it is necessary to have different means to improve the flatness and surface quality of the rolled product. For example, in addition to the cambering devices described above, it is advantageous to have the possibility of modulating the rolling force along the generatrix of contact with the working roll or the intermediate roll, by transmitting the rolling force. by means of a cylinder comprising a casing rotatably mounted around a fixed shaft and resting on it by means of a series of jacks making it possible to vary the distribution of the stresses along the bearing generatrix .

All these devices, as well as other improvements, developed for several years, have made it possible in the cold rolling technique, in particular in tandem mills, to constantly improve the quality of the final product. However, these devices are expensive and are therefore profitable only from a certain volume of production, especially since this profitability must be maintained for several years to justify the amount of investment.

To solve such a problem, the invention will make it possible to extend the production range of a rolling plant, by giving the possibility of adapting the configuration of the rolling mill to the structural and dimensional characteristics of the product to be treated in order to pass through example, a quarto configuration sexto configuration or even a configuration called "Z.High".

However, this configuration change must be done very quickly because there is a tendency, in modern installations, to work in a continuous line by welding end-to-end metal strips of different qualities and it is therefore necessary that the time of change of configuration is compatible with other online transactions.

However, in the layout of the document JP-A-63 013 603 , it is necessary to use double-acting cylinders to make a bending in both directions, respectively positive and negative.

As a result, the rods of the cylinders must be removably attached to the chocks and these disassembly and reassembly of the cylinders lengthen the time required for the change of configuration. Such a disadvantage can be accepted when one simply has to adapt to a change in thickness of the product. On the other hand, if the configuration of the rolling mill is modified, according to the invention, so as to adapt to a change of the product to be rolled, it is necessary to minimize the time of replacement of the rolls.

To avoid having to disassemble the bending cylinders, it is therefore preferable to use only single-acting cylinders which bear in one direction on the chocks without being connected to them. However, as indicated above, this doubles the number of cylinders and it is then difficult to find the necessary space in the working rolls and close to the tape whose scrolling should normally be continued.

However, it is necessary as much as possible, the bending cylinders remain fixed on the cage.

Furthermore, the rolls and in particular the working rolls wear out in service and must be periodically removed for cleaning and grinding of their surface. Their diameter therefore varies over a certain range.

To allow immediate replacement, there is therefore, for each category, a set of cylinders having substantially the same diameter, to the near wear range.

These cylinders are, however, very expensive and it is necessary, as much as possible, to limit the number.

In addition, each cylinder is carried by two chocks which are also complex and expensive organs. Their disassembly is quite long and it is therefore preferable, for a replacement, to remove the block with its chocks to replace it with a new cylinder provided in advance with its chocks. This requires, however, to have a large number of chocks.

The invention aims to solve all of these problems through a method and an installation for changing easily and quickly the configuration of a rolling mill to better adapt to the nature of the product to be rolled. The invention also makes it possible to use the same cylinders with their chocks in several configurations and thus to limit the number of cylinders and chocks the installation must be equipped with.

According to the invention, three types of working rollers having three diameters, one large, one medium and one smallest diameter, are produced with a range of wear, the rolls of each type being equipped with one another. advance of their chocks, and keeping the same cage, the same means of applying the tightening and cambering forces and the same type of support rolls, and by changing the arrangement of the rollers interposed between the support rolls, one gives the mill one or other of at least three configurations, respectively, at least one quarto configuration in which the cylinders of large or medium diameter are used as work rolls, a sexto configuration in which the cylinders of medium diameter are used as working rolls and large diameter rolls are used as intermediate rolls, between each working roll of medium diameter and a cylinder and a Z.High type sexto configuration, in which the small diameter rolls are used as work rolls and the larger diameter or medium diameter rolls are used as intermediate rolls between each small work roll. diameter and a support cylinder.

According to another preferred feature of the method, it is used, as positive or negative bending cylinders, single-acting cylinders that bear in one direction on the chocks.

On the other hand, each cylinder remains equipped with its chocks, they can simply be returned depending on the position of the cylinder in the cage.

Thanks to the invention, all means for applying and adjusting the distribution of clamping forces remain in place in the cage during a configuration change. However, insofar as the cylinders of the same type have, after grinding, diameters varying over a certain range, it may be advantageous, for a quarto configuration, to set up larger support rolls in the cage. diameter only for a sexto configuration.

In addition, it should be noted that, for maintenance and spares, the invention makes it possible to superimpose the wear areas of the working and intermediate rolls and, thus, to have a greater total wear range of the cylinders even if a reprocessing on the surface is to be redone. Likewise, for the support cylinders, the invention makes it possible to associate the wear ranges in order to increase the total range.

The invention also covers an improved rolling mill for the implementation of the method, comprising, in a general manner, a holding cage, a set of superposed cylinders rotatably mounted, each on two chocks, means for applying a clamping force and means for applying vertical bending forces, at least on the chocks of the work rolls, respectively in a positive direction of separation of said chocks with respect to the rolling plane and in a negative direction of approximation and comprising, on each side of the clamping plane, two sets of upper and lower cambering cylinders, which cooperate with bearing members provided on the sides of each chock, on either side of the clamping plane. .

According to the invention, the rolling mill is equipped with at least three pairs of cylinders respectively having a large, a mean and a small diameter and usable as working rolls within the same stand in at least three configurations of the rolling mill, respectively at least one quarto configuration in which the rolls of large or of medium diameter are used as working rolls, a sexto configuration in which the rolls of medium diameter are used as working rolls and the rolls of large diameter as intermediate rolls and a sexto configuration of Z.High type in which the rolls of small diameter are used as working cylinders associated with lateral support means and the cylinders of medium diameter as intermediate cylinders.

According to another particularly advantageous characteristic of the invention, for the change of configuration, the rolls remain equipped with their chocks and the chocks support members, at least larger diameter cylinders, are offset in height relative to the the axis of rotation of the cylinder, so that, after displacement in height of the larger diameter cylinder and 180 ° turning of its chocks around the axis, the support members of said cylinder are substantially at the same level with respect to at the rolling plane, respectively in the quarto configuration and in the sexto configuration, and that the same bending jacks act in the positive direction on the same chocks, respectively in the working position in the quarto configuration and, after flipping, in an intermediate position in the sexto configuration.

In a preferred embodiment, the support members of the chocks of the two working rolls which, in a conventional manner, extend in projection relative to the corresponding sliding faces, are placed in each configuration substantially at the level of the plane. of rolling and each support member of a first working chock placed on a first side of the rolling plane is provided with a passage recess of the rod of a bending jack placed on said first side and crossing the plane rolling member for bearing, in the positive direction, on a corresponding bearing member of the second working chock placed on the second side of the rolling plane and provided with a recess for the passage of the stem of a bending cylinder placed on said second side and passing through the rolling plane to bear, in the positive direction, on the support member of the first work chock.

According to another preferred feature of the invention, the sets of camber cylinders, respectively upper and lower, are centered substantially in two planes parallel to the clamping plane and spaced symmetrically on either side thereof.

As indicated above, each column of the cage is provided with two hydraulic blocks fixed, on either side of the clamping plane, on the sides of the corresponding window and comprising guide pieces in which are housed bending cylinders, respectively upper and lower, and extending projecting towards the inside of the cage, to a guiding face parallel to the clamping plane and cooperating, in the quarto and sexto configurations, with a corresponding sliding face of a working chock.

According to another characteristic of the invention, in the sexto configuration, the sliding faces of the larger diameter chocks acting as intermediate chocks co-operate with guide faces formed on support pieces removably mounted inside. corresponding window of the cage, respectively, above and below the two projecting parts of the hydraulic block, these support pieces may be legs removably attached to the chocks of the two support cylinders.

According to another preferred feature of the invention, each protruding part of a hydraulic block carries two groups of jacks respectively acting towards the rolling plane and the side opposite to it, by bearing on said projecting piece, and the support members of the chocks are placed substantially on three levels which remain the same in all configurations, respectively a central level of support of the working chocks, substantially corresponding to the rolling plane, and two levels, respectively upper and lower, support of the intermediate cylinders, placed respectively above and below the projecting parts of the hydraulic blocks.

Preferably, each protruding part of a hydraulic block carries, in a central zone, at least one pair of opposed cylinders acting respectively in the direction of approaching and away from the rolling plane and, on either side of the this central zone, two lateral cylinders acting in the direction of removal from the rolling plane.

According to another particularly advantageous feature of the invention, each chock of a cylinder of large or medium diameter, consists of three contiguous parts, respectively a central support portion of a centering bearing of the corresponding cylinder and two end portions of support, each, two support members extending on either side of the clamping plane, fixed on two lateral sides, perpendicular to the axis, of the central part, in a removable manner allowing, d ' one hand, to secure the central portion with the two end parts for the transmission of clamping forces and, secondly, to rotate the end portions relative to the central portion, after separating the three parts.

Moreover, the central portion of each chock is provided on each side of the clamping plane with a support member for at least one central cambering cylinder placed on a first side of the rolling plane, said support member comprising at least one recess for the passage of the rod of at least one central bending cylinder placed on the other side of the rolling plane.

In this case, each hydraulic block of bending placed on one side of the clamping plane, advantageously comprises a central group of cylinders comprising at least two pairs of opposed cylinders acting respectively on the support members of the central portions of the two working chocks placed on either side of the rolling plane, each pair comprising two cylinders respectively acting in the positive direction and in the negative direction on a bearing member of one of the chocks, and each positive cambering cylinder of a first chock placed on a first side of the rolling plane bears on the other side on the hydraulic block and passes through said rolling plane through a recess in the corresponding support member of a second chock placed on the other side of said rolling plane.

In a preferred embodiment, the central portion of a first working chock placed on a first side of the rolling plane comprises, on a first side of the clamping plane, a support member having a cooperating single support portion. with a pair of opposing camber cylinders and framed by two recesses, and on the second side of the rolling plane, a support member having two support portions spaced apart on either side of a single and cooperating recess respectively with two pairs of opposite cylinders controlled in synchronism, the arrangement of the support members and cylinders being reversed for the second working chock placed on the other side of the rolling plane.

In addition, the arrangements according to the invention are applicable to a rolling mill comprising means for axial displacement, with respect to each other, of the intermediate rolls in order to adapt to the width of the product the length of the rolls on which 'exerts the rolling effort.

For this purpose, in a preferred embodiment, each protruding piece, respectively upper or lower of a hydraulic block comprises a central portion fixed relative to the cage and two movable lateral parts placed on either side of the part. central and sliding axially on the hydraulic block, and each set of bending cylinders, respectively upper or lower, comprises at least one central cylinder bearing on the fixed central portion of the projecting piece and acting towards the rolling plane, and at least two lateral cylinders bearing respectively on the two movable lateral parts of the projecting piece and acting on the opposite side to the rolling plane, each chock comprising a central portion provided, on each side, a support member for at least one central cylinder, and two end portions contiguous on either side of the central portion and each provided, on each side of the clamping plane, a body of support for a lateral cylinder mounted on a corresponding movable part of the projecting piece.

• La figure 1 montre, en coupe transversale, un laminoir permettant, selon l'invention, le montage des cylindres en trois configurations, respectivement quarto (a), sexto (b) et Z.High (c).
• La figure 2 montre, à échelle agrandie, la disposition des cylindres et de leurs moyens de cambrage, en position de laminage, dans une configuration quarto (a).
• La figure 3 montre la disposition des cylindres dans une configuration sexto (b).
• La figure 4 montre la disposition des cylindres dans une configuration Z.High (c).
• La figure 5 montre, à échelle agrandie, la disposition des cylindres et de leurs moyens de cambrage, en position de démontage dans la configuration sexto (b).
• La figure 6 montre, en perspective, un type d'empoise adapté à un cylindre de grand diamètre.
• La figure 7 montre, en perspective, un type d'empoise adapté à un cylindre de moyen diamètre.
• La figure 8 montre, en perspective, un type d'empoise utilisable pour un cylindre de petit diamètre, dans une configuration Z.High.
• La figure 9 et la figure 10 sont des vues partielles en perspective, respectivement, du cambrage positif et du cambrage négatif des cylindres de travail dans une configuration quarto.
• La figure 11 et la figure 12 sont des vues partielles, en perspective, des moyens de cambrage, respectivement positif et négatif des cylindres dans une configuration sexto, avec décalage axial des cylindres intermédiaires.
• La figure 13 et la figure 14 sont des vues partielles, en perspective, des moyens de cambrage, respectivement positif et négatif des cylindres dans une configuration Z.High, avec décalage axial des cylindres intermédiaires.
• La figure 15 montre, en perspective, un bloc hydraulique avec décalage axial dans un sens ou dans l'autre, d'une partie des vérins de cambrage.

Other particularly advantageous features, which come within the scope of protection of the invention, will become apparent from the following description of a particular embodiment, given as a simple example and shown in the accompanying drawings.

• Figure 1 shows, in cross section, a rolling mill according to the invention, the mounting of the cylinders in three configurations, respectively quarto (a), sexto (b) and Z.High (c).
• Figure 2 shows, on an enlarged scale, the arrangement of the cylinders and their cambering means, in the rolling position, in a quarto configuration (a).
• Figure 3 shows the disposition of the cylinders in a sexto configuration (b).
• Figure 4 shows the arrangement of the cylinders in a Z.High (c) configuration.
• FIG. 5 shows, on an enlarged scale, the arrangement of the rolls and their cambering means, in disassembly position in the sexto configuration (b).
• Figure 6 shows, in perspective, a type of chock adapted to a large diameter cylinder.
• Figure 7 shows, in perspective, a type of chock adapted to a cylinder of medium diameter.
• Figure 8 shows, in perspective, a type of chock usable for a cylinder of small diameter, in a Z.High configuration.
• Fig. 9 and Fig. 10 are partial perspective views, respectively, of the positive bending and the negative bending of the working rolls in a quarto configuration.
• FIG. 11 and FIG. 12 are partial views, in perspective, of cambering means, positive and negative respectively of the rolls in a sexto configuration, with axial displacement of the intermediate rolls.
• FIG. 13 and FIG. 14 are partial views, in perspective, of bending means, respectively positive and negative of the rolls in a Z.High configuration, with axial displacement of the intermediate rolls.
• Figure 15 shows, in perspective, a hydraulic block with axial offset in one direction or the other, a portion of the bending cylinders.

In Figure 1, there is shown in cross section, the three configurations (a), (b), (c) that can be given to a rolling mill according to the invention.

This rolling mill comprises, as usual, a support cage A having two columns connected by a cross member and resting on a foundation. Each column has two amounts A1, A2 limiting a window A3 in which are threaded the chocks of the cylinders.

In the quarto configuration shown in FIG. 1a, the rolling mill comprises two working rolls C1, C'1 placed on either side of a rolling plane P1 that is substantially horizontal and bearing, on the opposite side, two rolls. support S, S 'carried at their ends by unrepresented bearings which are housed in chocks S1, S'1 slidably mounted in the windows A3 of each column A, parallel to a generally vertical clamping plane P2, in which the axes of the cylinders are placed substantially. It is the same, in the embodiment shown in the drawings, for the working cylinders C1, C'1 which are also carried by chocks E1, E'1 sliding vertically.

Thus, it is possible, on the one hand, to adjust the spacing, or air gap, between the working rolls C1, C'1 as a function of the gross thickness of the product to be rolled, to allow the engagement of the latter. and on the other hand, to exert a clamping force between the rolls for rolling the product.

As usual, in the example shown in the drawings, using clamping means D such as screws or jacks bearing, on one side on the cage, the upper part of each window A3 and the other, on the chocks S1 of the upper support cylinders S, then that the chocks S'1 of the lower support cylinders S are supported on the lower part of each window A3, by means of wedging means not shown, the height of which can vary in order to adjust the level of the rolling plane P1 .

To allow the height adjustments of the rolls, each chock S1, S'1 of a support roll S, S 'is provided with lateral sliding faces S2, S'2 which slide along parallel conjugate guide faces A4. at the clamping plane P2, formed on the internal faces of the two uprights A1, A2 of the column A.

The chocks E, E 'of the working rolls C1, C'1 must also slide vertically but they have a smaller width because of the reduced diameter of the working rolls C1, C'1. Therefore, each window A3 of the cage is provided at the level of the rolling plane P1, bearing and guiding parts B1, B2 generally called "hydraulic blocks" for the reasons indicated above. Each chock E is therefore slidably mounted along guide faces formed on the ends of parts F, F 'of the two hydraulic blocks which project from both sides of the window A3, towards the inside of the -this. These projections F, F 'bear, on the other hand, sets of jacks V, V' exerting bending forces on the chocks E, E 'of the two working rolls C1, C'1.

In general, these provisions are well known and do not require a detailed description.

It should be noted, however, that, as shown by each drawing in two half-sections, on either side of the vertical axis, the diameter of each type of cylinder may vary over a certain range because, as indicated above, High, it is necessary to rectify periodically, by machining, the outer face of cylinders whose surface quality may deteriorate in the long run. This is the case, in particular, of the working rolls which are in contact with the rolled product. But the other cylinders, intermediate or support, must also be replaced after some time of use, by new cylinders ground.

A rolling plant must therefore be equipped with several examples of cylinders of each type having, in the new state, a determined diameter which can then decrease over a certain wear range, as and as successive rectifications. Each cage must therefore be equipped with means for clamping and guiding the cylinders extending over a range of adjustment which depends not only on the variation in thickness of the product but also on the number of cylinders and their diameters.

As shown by the three views, a, b, c, of FIG. 1, the invention makes it possible to give the same rolling mill one or the other of three configurations respectively quarto (a), sexto (b) or Z .High (c), keeping the same cage A, the same support rolls S, S ', the same means D of application of the clamping force, the same hydraulic blocks B1, B2 and the same bending means V, V '.

Figures 2, 3 and 4 show respectively in cross section and for each configuration (a), (b), (c), the central portion of the cage, between the support cylinders.

In the rolling position shown in these figures, the rolls are supported on each other along a common generatrix, the two working rolls C1, C'1 being spaced apart, simply, from an air gap corresponding to the thickness to give the product to be rolled.

In general, the overall height of the set of cylinders depends on the configuration of the rolling mill. The height H of the window A3 must therefore be sufficient to allow the threading of all the chocks in the most bulky configuration, that is to say the sexto configuration shown in FIG. 3, and for the maximum diameter of the cylinders. of each type.

Usually, the height of the hydraulic blocks B1, B2 which carry the parts F, F 'for guiding the working chocks and the sets V, V' of bending cylinders, depends on the number of cylinders placed between the support cylinders and their diameters. However, because these hydraulic blocks B1, B2 are fixed on the uprights A1, A2, on each side of the window B, their height is limited to the space between the chocks S1, S'1 of the support rolls S , S 'and must therefore be reduced in the quarto configuration for which only two working rolls C1, C'1 are interposed between the support rolls S, S'.

Until now, therefore, a rolling mill stand was provided for a given configuration.

The invention allows, on the other hand, to give the same rolling mill one of the three configurations (a), (b), (c) shown in Figure 1 while maintaining the same cage A and the same hydraulic blocks B1, B2 . In addition, thanks to the provisions that will be described later, the invention makes it possible to give the hydraulic blocks B1, B2 a minimum height (h), valid for all configurations and which, in practice, can be of the same order as the sum of the diameters of the working cylinders C1, C'1 in the quarto configuration, as shown in FIG.

This reduction in the height of the hydraulic blocks B1, B2 results in particular from the fact that each of said hydraulic blocks comprises only two projecting parts F, F 'which carry bending cylinders V, V' acting in the positive direction and in the direction negative, these cylinders being further centered in two vertical planes Q1, Q2 parallel to the clamping plane and spaced symmetrically on either side thereof.

For this purpose, particular chocks adapted to the three configurations and of the type shown in perspective are used in FIGS. 4, 5 and 6, the mounting of said chocks between the hydraulic blocks being shown in FIGS. 7 to 12.

As indicated above, the diameters of the rolls can vary over a certain wear range and the various rolling mill members, in particular the cage, the hydraulic blocks and the bending jacks, are normally adapted to a certain type of roll. . In addition, as the cylinders must be dismantled for maintenance and rectification after use and it is necessary to reduce the downtime of the rolling mill, it is normally equipped with several sets of cylinders for the rapid replacement of cylinders in service by new rectified cylinders.

The working cylinders placed on either side of the rolling plane must be replaced more often and, to the extent that they wear out in the same way, the two work rolls are usually dismounted and replaced simultaneously.

On the other hand, the support cylinders and the intermediate cylinders, in sexto configuration, can be replaced individually.

A roll stand is therefore associated with means for rapid replacement of the rolls which will be used for the configuration change according to the invention.

In addition each cylinder is disassembled with its chocks and new cylinders must be equipped in advance, in the workshop, their two chocks with bearings.

According to the invention, in order to allow the choice of a configuration adapted to the nature of the product to be treated, the roll stand shown in FIG. 1 will be equipped on the one hand with a certain type of support rolls S, S 'which remains the same in all configurations and, secondly, of at least two and, preferably, three types of working rolls having different diameters, respectively cylinders of large diameter C1, cylinders means C2 diameter and C3 small diameter cylinders.

In the quarto configuration shown in FIGS. 1 (a) and 2, two cylinders of large diameter C1, C'1 are used as working rolls. In the sexto configuration shown in FIGS. 1 (b) and 3, two cylinders of medium diameter C2, C'2 and, as intermediate cylinders, two cylinders of large diameter C1, C'1 between each cylinder are used as working cylinders. working C2, C'2 and the corresponding support cylinder S, S '.

In the Z.High configuration shown in FIGS. 1 (c) and 4, cylinders of small diameter C3, C'3 and two cylinders of medium diameter C2, C'2 are used as work rolls as intermediate rolls. each working cylinder C3, C'3 and the corresponding support cylinder S, S '.

It should be noted that, in the quarto configuration, two cylinders of medium diameter C2, C'2 could also be used as work rolls.

To avoid complicating the drawings, the lateral support means associated, as we know, with the working rolls C3, C'3 in the Z.High configuration, have not been shown in FIGS. 1, 4, 8 , 13, 14.

According to one of the features of the invention, the configuration change can be made very quickly, for example using a known type of replacement system in which the cylinders are disassembled and replaced by displacement parallel to their axis, each chunk being provided with rollers rolling on rails formed on the cage, at a disassembly level for which the rollers are spaced from each other so that their surface is not deteriorated .

Thus, to move from the quarto configuration of FIG. 1 (a) to the sexto configuration of FIG. 1 (b), the support cylinders S, S'4 which can, moreover, remain in the cage, are all first, upwards and downwards, substantially to the levels it must occupy in sexto configuration, and the working cylinders C1, C'1 are placed at their disassembly level. It is advantageous to use a replacement device comprising two boxes, respectively an empty box in which are transferred the two working rolls C1, C'1 previously in service, and a box in which were placed on the one hand two cylinders of medium diameter C2, C'2 at the working rolls and, secondly, at the levels of the intermediate rolls, two cylinders of large diameter C1, C'1, of the same type as those which have just been removed . All these cylinders were equipped in advance with their chocks. After placing the new cylinders in alignment with the rails, they are introduced into the cage in the service position and the support cylinders can be tightened. In known manner, to facilitate disassembly and replacement, the cylinders and their chocks can be placed in cassettes comprising either two working rolls C1, C'1, or a set of two working rolls and two intermediate rolls, for the sexto configuration.

Since the change of configuration is justified by a change in production range, several sets of cylinders can be placed in stock and cylinders having, for example, a surface quality better adapted to the new product to be introduced into the cage. rolled.

On the other hand, as indicated above, for the same type of cylinder, the diameters can vary over a certain range.

In order for the configuration change to be particularly rapid, it is preferable that the support rolls remain in place in the cage. However, in some cases, it may be advantageous to choose, in the set of support cylinders that are available, cylinders large enough diameter for the quarto configuration and cylinders of the same type but slightly smaller diameter in sexto configuration to reduce the overall size of the cylinders.

According to another particularly advantageous feature of the invention, which will be described in more detail below, the two cylinders of the same type, respectively large diameter, medium diameter or small diameter, can be equipped with the same chocks which are arranged in such a way that, by simple turning, they can equip either an upper cylinder or a lower cylinder. It thus benefits from a modular arrangement making it possible to have in stock, simply, three types of chocks, respectively for large diameters, for average diameters and for small diameters and to equip on demand the new cylinders by orienting the chocks according to the arrangement they must occupy, either above or below the rolling plane.

Figures 6, 7 and 8 show respectively the three types of chocks usable for a large diameter cylinder (Figure 6) of medium diameter (Figure 7) or small diameter (Figure 8).

In this preferred embodiment, shown in the drawings, each chock consists of three contiguous portions, respectively a central portion and two end portions.

Thus, Figure 6 shows a chock E1 for a large diameter cylinder, having a central portion 1 on the sides of which are fixed two end portions, respectively 2a, 2b. Figure 6 shows a chock for a lower cylinder but an upper chock would be constituted in the same way, turning it 180 ° in block to mount it on an upper cylinder.

As is known, each cylinder is provided at each end with a journal which rotates in a centering bearing housed in a casing constituting the chock on which are formed the support members of the camber cylinders and the sliding faces. side. In the invention, the bearing (not shown) is housed in the central portion 1 of the chock and each end portion 2a, 2b consists of a flange provided with a circular hole 25 for the passage of the trunnion. The central portion 1 of the chock is provided, as usually support members 11, 12 for the bending cylinders. In the example shown, these support members form ears extending projecting from the sides 15 of the chock on which are provided the sliding faces thereof, which are parallel to the clamping plane P2 (Figure 2).

However, the arrangement of the support members is particular. Indeed, on one side of the chock, for example the right side in Figure 6, the support member 12 has a central recess 14 between two spaced bearing portions 12a, 12b. On the other hand, on the other side of the clamping plane, the support member 11 comprises a single support portion between two recesses 13a, 13b. In addition, the two support members 11, 12 are offset in height relative to the x'x axis of the pin threaded into the chock so that, in the working position shown in Figure 2, these organs of support are located substantially at the rolling plane P1.

Similarly, the two flanges constituting the end portions 2a, 2b fixed on either side of the central portion 1 of the chock carry, each two support members, respectively 21a, 22a, on the front flange 2a and 21 b, 22b on the rear flange 2b, which are offset in height relative to the x'x axis of the chock. In addition, each flange 2a, 2b is provided with a protruding portion forming a stud 23 extending horizontally and capable of engaging in a conjugate groove of the same section, formed on the side of the central portion 1 of the chock and forming a mortise. Thus, it is possible, by turning the flanges 2a, 2b relative to the central portion 1, to place the support members, or on two planes spaced in height, as shown in Figure 6, or in the same plane, these support planes being offset in height on one side or the other of the x'x axis of the chock.

Thanks to these provisions, a chock of the type shown in Figure 6, can be arranged in various ways, by turning, or all of the chock, or only the end parts.

Firstly, by turning 180 ° about the x'x axis of the entire chock, it can be mounted either on an upper working cylinder C1 or a working cylinder lower C'1, in a quarto configuration.

In addition, by turning the only end portions 2a, 2b relative to the central portion 1, the same chock can be adapted to the configuration sexto maintaining substantially the same spacing of the support members relative to the rolling plane P1.

Figures 9 and 10 show the arrangement and use of two chocks of the type of Figure 6, respectively for the positive bending and for the negative bending of the working rolls, in the quarto configuration.

As shown in FIG. 2, the respective positive and negative cambering of the rolls is performed by two sets of cylinders, respectively upper V and lower V ', which are centered in two planes Q1, Q2 parallel to the clamping plane P2. As usual, these bending cylinders are supported on projecting parts F, F 'of the two hydraulic blocks B1, B2 fixed on both sides of the window A3.

However, for the implementation of the invention, it is particularly advantageous to use the particular arrangement of the chocks and hydraulic blocks shown in the drawings, wherein, firstly, each hydraulic block has only two projecting parts. spaced apart on both sides of the rolling plane, and, secondly, the support members of the chocks can be placed, by simply turning them, or between the two projecting parts, substantially at the level of rolling plane, above and below it. Such an arrangement makes it possible, in fact, to reduce the height requirement of the hydraulic blocks, by defining only three support levels of the chocks which remain the same in all the configurations, respectively a central level of support of the corresponding work chocks. substantially to the rolling plane and two levels, respectively upper and lower, support of the intermediate cylinders placed respectively above and below the projecting parts of the hydraulic blocks.

FIGS. 9 and 10 are partial views, in perspective, showing, in a quarto configuration, the arrangement of the working chocks as well as the bending cylinders, respectively in the positive direction in FIG. 9 and in the negative direction in FIG. 10.

In this quarto configuration, large diameter cylinders associated with chocks of the type shown in FIG. 6 are used and it is seen that, in a particularly advantageous manner, the same chocks can, by simple reversal, serve as upper chock E1, or lower chock E'1, each chock being symmetrical with respect to a median plane perpendicular to the x'x axis of the trunnion.

Each hydraulic block B1, B2 comprises a solid piece 5 fixed on the inner face of the corresponding amount A1, A2 of the column A and carrying two parts 6, 6 'placed symmetrically with respect to the rolling plane P1 and which project. inwardly of the window to an end 61, 61 'carrying a vertical guiding face of the corresponding chock E1, E'1.

On each projecting piece 6, 6 ', the jacks are arranged in two groups, respectively a central group of jacks acting towards the rolling plane P1 and a group of lateral jacks placed on either side of the central group and acting from opposite side to the rolling plane P1. These two groups of cylinders are placed, respectively, in a central portion 62 and two lateral parts 63, 64 of the projecting parts 6 and are centered on the same plane Q1, Q2 parallel to the clamping plane P2, on both sides. other of it.

For the reasons given below, in the preferred embodiment shown in the figures, the central portion 62 is integral with the solid part 5 fixed on the corresponding amount of the cage while the two lateral parts 63, 64 can slide axially in grooves 51, 51 'formed on this part 5.

In the preferred embodiment shown in the figures, the central portion 62 of each projecting piece 6, 6 'carries three jacks all acting towards the rolling plane but controlled separately, one for positive bending and the other for bending negative. On the other hand, the cylinders placed in the lateral parts 63, 64 act on the opposite side to the rolling plane, only for positive cambering.

Figure 9 is a partial view, in perspective, showing only positive bending cylinders. As indicated above, the upper chock E1 placed above the rolling plane comprises a central portion 1 provided with two support members 11, 12 projecting from either side of the sides 15 of the chock, respectively to the right (11) and to the left (12) in the figure, these support members being placed at a level substantially corresponding to that of the rolling plan. On the other hand, as shown in Figure 6, the two support members extending on either side of the central portion 1 of the chock have inverted slots profiles, one having a recess central framed by two support parts while the other has a central support portion framed by two recesses.

It should be noted that the arrangement of Figure 6 corresponds to a lower chock E'1, the upper chock E1 being returned in block of 180 °.

Thus, in the assembly of FIG. 9, the central portion 1 of the upper chock E1 placed above the rolling plane comprises, on the right, a central support portion 11 flanked by two recesses 13a, 13b while the 12 support ear placed on the left side and not visible in the figure, has a central recess flanked by two support parts.

In contrast, the lower chock E'1 comprises, on the right side, two bearing portions 11'a, 11'b flanking a central recess 13 ', the disposition being reversed on the left side. Thus, the support members vis-à-vis have overlapping tooth profiles.

In this way, the positive bending of the upper chock E1 can be controlled by a central jack V'1 mounted in the central part of the corresponding projecting piece 6 'and passing through the rolling plane P1 to exert a positive bending force on the central support part 11 of the upper chock 1.

Conversely, the positive cambering of the bottom chord E'1 is effected on the right side of the figure by two jacks V1a, V1b mounted in the central part of the upper projecting piece 6 and acting in the positive direction on the bearing portions 11'a, 11'b of the lower chock 11'a between which passes the jack V'1 positive camber of the upper chuck E1.

In this arrangement, a positive bending force can also be exerted by lateral cylinders, respectively V3a, V3b on the right side and V4a, V4b on the left side, mounted in the lateral parts 63, 64 of the projecting piece 6 and acting in the positive direction, that is to say on the opposite side to the rolling plane, on the bearing members of the two end portions 2a, 2b of the chock, respectively 21a, 21b on the right side and 22a, 22b on the left side.

Of course, the arrangement is reversed for the lower chord E'1.

Thus, the positive bending forces can be applied by all cylinders and two levels on each working chock in the quarto configuration, which allows to have a higher bending effort.

For the negative bending, the jacks acting on the rolling plane and mounted in the central portion 62 of each projecting piece 6, 6 'are used in the manner indicated in FIG.

In a general manner, the central group of jacks cooperating with the central parts 1, 1 'of the two chocks E1, E'1, consists of at least two pairs of opposed jacks acting respectively in the positive direction and in the negative direction on both sides of the corresponding support member of the chock. As we have seen, in the preferred embodiment shown in Figures 9 and 10, the central portion 1 of the upper chock E1 is provided with a central support member 11 on which bears, in the direction negative, a central cylinder V1 mounted in the central portion 62 of the upper projecting piece 6 of the hydraulic block and, therefore, opposite to the positive camber cylinder V'1 of the same chock, which is placed on the other side of the rolling plane and passes through it.

Conversely, the negative curve of the bottom chord E'1 is made, on the right side of the figure, by two cylinders V'1 a and V'1b mounted in the lower projecting piece 6 ', which exert bending forces directed towards the rolling plane on the bearing parts 11'a, 11'b passing on both sides of the jack V'1 positive bending of the upper chuck E1, and are opposed to the cylinders V1 a, V1 b positive bending of the same lower chock E'1, mounted in the upper projecting piece 6.

Of course, the arrangement is reversed on the hydraulic block B2 placed to the left of the clamping plane and the upper projecting part 6 carries in its central part two negative bending cylinders of the upper chock E1 and a central cylinder bending positive of the lower chock E'1, the arrangement being reversed on the central portion 62 'of the lower projecting piece 6' of the hydraulic block B2.

To move from the quarto configuration to the sexto configuration shown in FIG. 3 and partly in perspective in FIGS. 11 and 12, intermediate cylinders of the same type as the working cylinders C1, C are used according to the invention. 1 of the quarto configuration, which are therefore spaced apart from each other in order to set up medium-diameter work rolls C2, C'2.

The ends 61 of the two protruding parts 6, 6 'then serve to guide the working chocks E2, E'2. Since, according to one of the features of the invention, the height of the hydraulic blocks B1, B2 must be limited to that which is necessary for the quarto configuration, the guidance of the intermediate chocks E1, E'1, in the configuration sexto, is provided by two support pieces B3 bearing laterally on the uprights A1, A2 which limit the sides of the window A3 and on which are formed vertical guide faces (f) parallel to the clamping plane P2.

In this configuration, the hydraulic blocks B1, B2 still define three support levels of the bending cylinders, respectively a central level H1 corresponding substantially to that of the rolling plane P1 and two levels, respectively upper H2 and lower H'2 placed at above and below the protruding parts 6, 6 '. The two sets of cylinders V, V 'placed in these protruding parts 6, 6' remain the same but their functions are different. As in the quarto configuration described above, the central cylinders V1, V2, V'1, V'2 which act at the central level H1, in the direction of the rolling plane P1 will be used for the positive and negative bending of the working cylinders C2 , C'2 whereas the lateral cylinders V3, V4, V'3, V'4 which act at the H2 and H'2 levels, towards the opposite side of the rolling plane, serve for positive cambering of the intermediate cylinders C1, C ' 1.

It is necessary, however, that the side faces 15 of the intermediate chocks E1, E'1 slide between the guide faces (f) formed on the support pieces B3, B'3. For this, the end portions 2a, 2b of each chock E1, E'1 are turned 180 ° relative to the central portion 1. This reversal can be done easily because, as indicated, the end portions 2a , 2b of the empoise are equipped with horizontal tenons 23 which engage in corresponding grooves in the central part 1.

With respect to the arrangement shown in FIG. 6, after the end portions 2a, 2b have been turned upside down, the support members 21, 22 change from one side to another and are substantially aligned with the support members 11, 12 of the central part 1. After raising the cylinder C1, the support members 21, 22 of the end portions substantially return to the same level H2 as in the quarto configuration. As shown in Figure 11, the cylinders V3a, V3b placed on the right side, therefore exert positive bending forces on the bearing members 22a, 22b of the two end portions 2a, 2b of the upper intermediate chock E1. Similarly, the two support members 21 placed to the left after reversal cooperate with the lateral cylinders V4 for the positive camber of the intermediate cylinder C1.

The arrangement is the same, in the opposite direction, for the chock E'1 of the lower intermediate cylinder C'1.

As shown in FIG. 7, the chocks of the cylinders of medium diameter which, in the sexto configuration, constitute the working rolls C2, C'2, are similar to the chocks E1, E'1 of the large-diameter rolls and therefore comprise a central portion 10 on which are joined two end portions 20a, 20b. Of course, the bearings, not shown in the figures, are adapted to the diameter of the trunnions of cylinders C2, C'2 of medium diameter, but the spacing between the lateral faces 150 of the work chocks E2, E'2 is the same that the spacing between the side faces 15 of the chocks E1 large diameter. The sliding faces 150 of the chocks E2, E'2 can therefore slide along the same guide faces 61 formed at the ends of the protruding parts 6, 6 'of the two hydraulic blocks B1, B2.

However, to allow mounting in Z.High configuration as will be described later, the sliding faces 150 of a chock E2 medium diameter, extend only over a portion of the height of the chock, this being provided, on the remaining part, with two sliding lateral faces 16 whose spacing is reduced.

On the other hand, as for the chocks of the intermediate rolls E1, E'1, the end portions 20a, 20b are fixed on the central portion 10 so that their support members 210, 220 are at the same level as the support members 110, 120 of the central portion 10.

Figures 11 and 12 show, in perspective, the arrangement of the bending cylinders to the right of the clamping plane, respectively in the positive direction in Figure 11 and in the negative direction in Figure 12.

As can be seen in FIGS. 3 and 11, the upper working chock E2 is turned upside down relative to FIG. 7, so that its support members 210, 220 are substantially at the level of the rolling plane P2. the sliding faces 150 extending upwardly to slide between the ends 61 of the upper projecting pieces 6. As in the quarto configuration, the positive cambering of the working roll C2 is effected, to the right of the figure, by the central cylinder V'1 which is mounted on the other side of the rolling plane and passes therethrough to be applied to the support member 110 of the central portion 10.

Conversely, the positive cambering of the bottom chord E'2 is made, on the right, by the two jacks V1a, V1b which pass through the recesses formed on either side of the central support member. 110 to apply on the bearing portions 110'a, 110'b of the lower chock E'2, extending on either side of the central cylinder V'1. Of course, the arrangement is symmetrical for the left side.

In this sexto configuration, the support members 210a, 210b of the end portions 20a, 20b of the working chock E2 are thus not used for cambering but simply carry rollers G which, in a conventional manner, roll on rails R put in place for disassembly, these rollers G being, thus, sufficiently spaced to ensure, in good conditions, the sliding retention of the chock.

According to the invention, cylinders of medium diameter C2, C'2 provided with their chocks E2, E'2 can be used as intermediate cylinders in a Z.High type sexto configuration, as shown in the view (c) of Figure 1, as well as in Figures 4, 13 and 14.

In this case, working cylinders C3, C'3 of small diameter are used which are associated with chocks E3, E'3 of the type shown in FIG.

Such a chock preferably comprises, preferably, three contiguous portions, respectively a central portion 3 and two end portions 4a, 4b. The central portion 3 carries the centering bearings of the cylinder and can have a fairly reduced height, the journals of a working cylinder having a small diameter in the case of a Z.High mounting.

As previously, this central portion 3 is provided, on either side of the x'x axis of the bearing, with two sliding faces 35 whose spacing corresponds to that of the facing ends 61 of the protruding parts 6 two hydraulic blocks B1, B2 and two support members 31, 32 which protrude from the plane of the sliding faces 35.

In FIG. 8, the chock is shown in its position E3 corresponding to an upper work roll and therefore comprises a central bearing portion 31 which extends only over part of the length of the chock and is surrounded by two recesses 33a, 33b. On the other hand, on the left side, the support member 32 comprises two parts spaced apart on either side of a central recess 34.

Thus, as shown in FIGS. 13 and 14, the chock E3 of the upper work roll C3 is provided on the right of the figure with a bearing portion 31 which extends substantially at the level of the rolling plane P2. and passes between the rods of the two cylinders V1, V'1 respectively housed in the projecting parts 6, 6 ', the lower cylinder V'1 acting in the positive direction (FIG. 13) and the upper cylinder V1 in the negative direction (FIG. Figure 14). Conversely, the chock E'3 of the lower cylinder C'3 is provided on the right of the figure with two bearing parts 31'a, 31'b on which two pairs of opposed cylinders act, respectively, the upper cylinders. V1 a, V1 b in the positive direction (Figure 13) and the lower cylinders V'1a, V'1b in the negative direction (Figure 14).

As before, the arrangement of the cylinders and support members on the left of the figure is deduced from the right one by a central symmetry.

As shown in FIG. 4, in this Z.High configuration, cylinders of medium diameter C2, C'2 are used as intermediate cylinders, which are therefore spaced apart from one another to set up cylinders of small diameter C3. , C'3 and whose chocks E2, E'2 are returned in block with respect to the sexto arrangement of FIG. 220, 210 of the end portions 20a, 20b of the upper chock E2 are above the upper level of the projecting parts 6 and therefore cooperate with the lateral cylinders V3, V4 hydraulic blocks B1, B2 respectively to the right and left of the figure, the arrangement being symmetrical for the lower intermediate chock E'2.

In this arrangement Z.High as in the sexto arrangement described above, the invention allows to exert positive bending forces on the intermediate cylinders.

These sliding faces 35 which extend above or below the support members 31, 32, are formed on two vertical legs 36 of the central portion 3 of the chock E3 whose inner sides 37 form faces guide for the intermediate chock E2, as will be seen later.

As indicated, the sliding faces 150 of a medium-diameter chock E2 extend only over part of the height thereof and are extended by narrower sliding faces 16 which, in the assembly Z.High slide along the inner faces 37 of the legs 36 of the central portion 3 of the chock E3 of the small diameter cylinder C3.

Thus, as shown in FIG. 4, the guide faces 61 formed at the ends of the protruding parts 6, 6 'serve, over part of their height, to guide the work chocks E3, E'3 and, on the part remaining, guiding intermediary chocks E2, E'2 which are also guided, by their sliding faces 16, on the legs 36 of the working chocks E3, E'3.

The arrangements just described also allow an axial shift of the intermediate cylinders, in sexto or Z.High configurations.

Indeed, as shown in Figure 15, the two side portions 63, 64 of a projecting piece 6 are mounted to slide axially in a groove 51 of the solid portion 5 of the hydraulic block B, the central portion 62 remaining fixed. In this way, the central cylinders V2, V'2 which act towards the rolling plane B2 remain fixed axially but the lateral cylinders, respectively upper V3, V4 and lower V'34, V'4 mounted on both sides of the clamping plane, on the moving parts 63, 64 of the parts projection 6, 6 'can move axially with the chocks of the corresponding cylinder.

This displacement can be done in both directions, as shown by the three perspective views (a) (b) (c) of Figure 15.

Fig. 11, for example, corresponds to view (c) of Fig. 15 with a backward shift for the upper intermediate roll C1 and forwards for the lower intermediate roll C'1. FIG. 12, on the other hand, corresponds to the view (a) of FIG. 15 with a shift towards the front of the upper intermediate cylinder C1 and towards the rear of the lower intermediate cylinder C'1. In view (b) of FIG. 15, which corresponds to the quarto configuration shown in FIGS. 9 and 10, there is no axial shift of the rolls, the moving parts 63, 64 being spaced symmetrically with respect to the central piece 62, as shown in view (b) of FIG.

Thus, in the sexto or Z.High configurations, the intermediate cylinders C1, C'1 or C2, C'2 can be moved axially with their chocks and the positive bending cylinders V3, V4, V'3, V'4. On the other hand, in the three configurations, the chocks of the work rolls remain centered in the median plane of the hydraulic blocks B1, B2, as well as the central cylinders V1, V2, V'1, V'2.

As usual, in each configuration, the cylinders can be disassembled and replaced by moving parallel to their axis, rolling on removable or retractable rails.

These rails may consist, for example, of sections 7 slidably mounted on grooves 52 parallel to the axes of the cylinders and formed on each side of the clamping plane, on the solid portions 5 of the two hydraulic blocks B1, B2.

As shown in Figure 15, these grooves may be provided on four levels, on either side of each projecting piece 6, 6 ', to allow the assembly of four pairs of rails, respectively upper 71, 72 and lower 71 ', 72'.

As already indicated, the support members of the end portions 2, 20, 30, of each type of chock E1, E2, E3 carry rollers G spaced axially.

By way of example, FIG. 5 shows the cylinders in disassembly position, for the sexto configuration. The two upper cylinders, C2 and C1 working respectively can be raised by their positive bending cylinders, a little above the rail levels to allow the introduction of the latter inside the cage, by axial sliding on the grooves 52. The rolls can then be lowered so that their rollers G rest on the rails 71, 72.

As shown in FIG. 3, in the rolling position, the rollers mounted at the ends of the support members of the chocks E'2, E'1 of the two lower cylinders, respectively C'2 working and C'1 intermediate, are located in any case, above the level of the lower rails 72 '71' which can therefore be set up, by axial sliding, for disassembling the rolls. If the lower support cylinder S 'is lowered by means of not shown timing means, the two cylinders C'1, C'2 descend with it and their rollers come to rest on the respective rails 72', 71 'to allow the disassembly and reassembly of the cylinders by axial displacement.

The profiles 7 constituting the rails could also be provided with retractable support parts to allow adjustments of the levels of the chocks, during rolling.

The arrangements that have just been described thus make it possible to easily and quickly change the configuration of a rolling mill to change, depending on the nature of the product to be rolled, from a quarto configuration to a sexto or Z.High configuration and vice versa, using only three types of cylinders having, respectively, a large, a medium and a small diameter and keeping all the essential organs of the rolling mill, that is to say the cage A, the clamping means D, and the hydraulic blocks B1 , B2 carrying cylinders for adjusting cylinder levels. As indicated, because the same hydraulic blocks are used in the three configurations, the height of the latter can be limited, the guidance being provided by simple mounted legs B3 which can be removably fixed on the chocks of the support rolls S, S '.

The height H of the window A3 must, however, correspond to the total height of the chocks in the sexto configuration and that is why it is advantageous in the quarto and Z.High configurations represented. respectively on the views (a) and (c) of Figure 1, to have, at the ends of each window A3, two massive pieces M, M 'forming interposed shims, on the one hand between the clamping means D and the chocks S1 of the upper support cylinder and secondly between the lower part of each window A3 and unrepresented wedging means on which support the lower support chocks S'1. This avoids increasing the stroke of the clamping cylinders D.

But the invention is not limited to the details of the embodiment which has just been described as a preferred example and covers on the contrary variants or equivalent means providing the same functions and remaining within the scope of the claimed protection .

For example, in the embodiment which has just been described, the positive and negative cambering of the rolls is ensured by pairs of opposing single-acting cylinders acting, respectively, towards the rolling plane and on the side opposite to it. . Indeed, such cylinders are simply applied to the support members of the chocks and release them when they are retracted. It would, however, be possible to use double-acting cylinders having a rod removably attached to the support member of the chock and thus, to ensure the negative and positive bending of the corresponding cylinder.

On the other hand, in the arrangements described above, the support members of the chocks, sometimes called "ears" project protruding from the sliding faces on each side of the chock. The invention could, however, adapt to other known arrangements. For example, the cambering forces could be applied, on each side of the chock, on an intermediate piece engaging in a groove formed in the corresponding sliding face, this groove being offset with respect to the axis of the empoise so as to allow two positions thereof, by simple reversal.

Moreover, the invention does not necessarily apply to a new installation but has, on the contrary, great advantages for the modernization of an existing installation.

In the case of a new installation, as described above, three types of cylinders having a large, medium and small diameter and to treat a very wide range of products, the dimensions of the cage being determined according to the sexto configuration which has the maximum size.

However, the invention also makes it possible, in the context of modernization, to extend the range of products that can be processed in an existing mill while keeping the same cage, which is simply adapted, for example to place it there. hydraulic blocks of bending. For example, an existing quarto cage having a window height too low for a conventional sexto configuration, could be modernized, thanks to the invention, allowing to go from a quarto configuration to a Z.High configuration or vice versa, the range of laminatable products being thus extended.

Moreover, it is usually preferred to use cages that are symmetrical with respect to the rolling plane, but in certain cases the arrangements just described would make it possible to produce asymmetrical assemblies.

Indeed, because we can keep the same hydraulic blocks in all configurations, it would be possible, for example, to perform a quarto assembly with a working cylinder of large diameter on one side of the rolling plane and a Z.High fixture with a working cylinder of smaller diameter, on the other side of the rolling plane.

The invention therefore provides many possibilities to respond very flexibly to a change in the characteristics of the products to be rolled.

On the other hand, the modular construction that has been described has the advantage of using only three types of chocks for all configurations, because each chock is provided, on either side of the clamping plane, support members having inverted profiles and can be used on either side of the rolling plane.

It would be possible, however, to make chocks having the same support members on either side of the clamping plane, but with inverted slot profiles above and below the rolling plane. For example, a superior chock could have, on each side, a single support part placed between two recesses, the chock lower part having, conversely, support members comprising, on each side, two bearing parts flanking a single recess. Such an arrangement would still make it possible to produce hydraulic blocks of reduced height having a C-shaped profile with two parts projecting from support of bending cylinders acting on support members placed substantially at the level of the rolling plane while traversing it in the direction of positive bending.

The reference signs inserted after the technical features mentioned in the claims, are intended only to facilitate the understanding of the latter and in no way limit the scope.

Claims (32)

1. A method for changing the configuration of a rolling mill including:

   - a holding stand (A) having two spaced apart standards each fitted with a window (A3) having two opposite sides (A1, A2),

   - a set of superimposed cylinders with substantially parallel axes, containing at least two working rolls, respectively upper (C1) and lower (C'1), placed on both sides of a rolling plane (P1) substantially horizontal of a product to be rolled and two back-up rolls (S), respectively upper and lower,

   - each roll (C1, C'1) having two ends set up rotary, each, on a bearing carried by a chock (E) set up slidingly, parallel to a clamping plane (P2), along sliding faces cooperating with corresponding guiding faces arranged on both sides of the corresponding window (A3) of the stand,

   - means (D) for applying a clamping load between the chocks (S1, S'1) of the back-up rolls (S, S'),

   - means for applying vertical cambering loads including, on both sides of the clamping plane (P2), two sets (B, V) of hydraulic cambering cylinders at least of both working rolls respectively upper (C1) and lower (C'1),

   - said cambering cylinders (V, V') cooperating with resting members arranged on the sides of the chocks (E) of said rolls, on both sides of the clamping plane (P2), method in which the rolling mill is changed from a quarto configuration to a sexto configuration and conversely by replacing each working roll (C1, C'1) of the quarto configuration by a smaller diameter working toll (C2, C'2) and an intermediate roll while having the same stand (A), the same means (D, B,V) for applying the clamping and cambering loads and the same type of back-up rolls (S,S')

   characterised in that three types of working rolls (C1, C'1) (C2, C'2) (C3, C'3) are made having at near a wearing range, three different diameters, respectively a great, an average and a small diameter, the rolls of each kind being provided previously with the chocks thereof and that, while keeping the same stand (A), the same means (D, B, V) for applying the clamping and cambering loads and the same type of back-up rolls (S, S'), and by changing the disposition of the rolls interposed between the back-up rolls, the rolling mill is given one or other of at least three configurations, respectively, at least one quarto configuration wherein the rolls with great (C1) or average (C2) diameter are used as working rolls, a sexto configuration wherein the rolls with average diameter (C2) are used as working rolls and the rolls with great diameter (C1) are used as intermediate rolls, between each working roll with average diameter (C2) and a back-up roll (5), and a Z.High-type sexto configuration, wherein the rolls with small diameter (C3) are used as working rolls and the rolls with great diameter (C1) or with average diameter (C2) are used as intermediate rolls between each working roll with small diameter (C3) and a back-up roll (S).
2. A method according to claim 1, characterised in that the cambering of the working rolls is performed, in the positive spacing-apart direction of the chocks and in the negative bringing-closer direction, by using, on both sides of the rolling plane (P1) and on both sides of the clamping plane (P2), at least two pairs of single-effect cylinders (V1, V'1) (V'1a, V'1b) acting on the working rolls with great diameter (C1,C'1) in the quarto configuration, on the working rolls with average diameter (C2, C'2) in the sexto configuration and on the working rolls with small diameter (C3, C'3) in the Z. High configuration.
3. A method according to one of the claims 1 and 2, characterised in that, on both sides of the rolling plane (P1) and on both sides of the clamping plane (P2), at least one pair of single-effect cylinders (V3, V'3) is used acting in the positive direction on the working rolls with great diameter (C1, C'1) in the quarto configuration, on the same rolls with great diameter (C1, C'1) serving as intermediate rolls in the sexto configuration and on the rolls with average diameter (C2, C'2) in the Z.High configuration.
4. A method according to one of claims 1 to 3, wherein, for each type of rolls, several pairs of rolls, respectively back-up or working rolls, are available, having slightly different diameters, characterised in that, for a quarto configuration, a pair of back-up rolls (S, S') is placed in the stand, having a diameter slightly greater than that of the back-up rolls used for a sexto or Z-High configuration.
5. A rolling mill including:

   - a holding stand (A) having two spaced apart standards each fitted with a window (A3) having two opposite sides (A1, A2),

   - a set of superimposed cylinders with substantially parallel axes, containing at least two working rolls, respectively upper and lower, placed on both sides of a rolling plane (P1) substantially horizontal of a product to be rolled and two back-up rolls, respectively upper (S) and lower (S'),

   - each roll having two ends set up rotary, each, on a bearing carried by a chock (E) set up slidingly, parallel to a clamping plane (P2), along sliding faces cooperating with corresponding guiding faces arranged on both sides of the corresponding window (A3) of the stand,

   - means (D) for applying a clamping load between the chocks (S1, S'1) of the back-up rolls (S, S'),

   - means (B, V) for applying vertical cambering loads including, on both sides of the clamping plane (P2), two sets (V, V') of hydraulic cambering cylinders, at least of both working rolls, respectively upper and lower,

   - said cambering cylinders (V, V') cooperating with resting members arranged on the sides of each chock, on both sides of the clamping plane (P2),

   characterised in that it is fitted with at least three pairs of interchangeable rolls having at least three different diameters, respectively a great, an average and a small diameter and usable as working rolls inside the same stand, in at least three configurations of the rolling mill, respectively at least one quarto configuration wherein the rolls with great diameter (C1, C'1) or average diameter (C2, C'2) are used as a working roll, a sexto configuration wherein the rolls with average diameter are used as working rolls and the rolls with great diameter (C1, C'1) are used as intermediate rolls, between each working roll with average diameter (C2, C'2) and a back-up roll (S, S'), and a Z.High-type sexto configuration, wherein the rolls with small diameter (C3, C'3) are used as working rolls associated with lateral resting means and the rolls with great diameter (C1, C'1) or with average diameter (C2, C'2) are used as intermediate rolls between each working roll with small diameter (C3, C'3) and a back-up roll (S, S').
6. A rolling mill according to claim 5, characterised in that, for changing the configuration, the rolls remain fitted with their chocks (E) and that the resting members (11, 12) of the chocks (E1, E'1), at least of the rolls with great diameter (C1, C'1), are offset vertically with respect to the rotational axis (x'x) of the roll, so that, after vertical displacement of a roll with great diameter (C1) and inversing its chocks (E1) by 180° around the axis thereof, the resting members (11, 12) thereof are situated substantially at the same level with respect to the rolling plane (P1), respectively in the quarto configuration and in the sexto configuration, and that the same cambering cylinders (V1, V2) act, at least in the positive direction on said chocks (E1) placed, respectively, in working position in the quarto configuration and, after rotation, in intermediate position in the sexto configuration.
7. A rolling mill according to one of claims 5 and 6, characterised in that, on both sides of the clamping plane (P2), the cambering cylinders, respectively upper (V) and lower (V'), are housed on both sides of the rolling plane (P1), in two protruding parts, respectively upper (6) and lower (6') parts, arranged on a hydraulic block (B1, B2) attached to each side of the corresponding window (A3) of the stand.
8. A rolling mill according to claim 7, characterised in that each protruding part (6, 6') of a hydraulic block (B1, B2), extends, towards the inside of the window (A3), up to a guiding face (61) parallel to the clamping plane and cooperating, in the quarto and sexto configuration, with a sliding face (15) of the corresponding chock (E1, E2) of a working roll (C1, C2).
9. A rolling mill according to claim 8, characterised in that, in the sexto configuration, the sliding faces (15) of the chocks with great diameter (E1, E'1) serving as intermediate chocks, co-operate with guiding faces (f) arranged on supporting parts (B3) set up removably inside the corresponding window (A3) of the stand (A), respectively, above and below both protruding parts (6, 6') of the hydraulic block (B1, B2).
10. A rolling mill according to claim 9, characterised in that the supporting parts (B3, B'3) of the guiding faces (f) of the intermediate chocks (E1, E'1), in the sexto configuration, are legs fixed removably to the chocks (S1, S'1) of both back-up rolls (S, S').
11. A rolling mill according to claim 7, characterised in that, on both sides of the clamping plane (P2), both protruding parts, respectively upper (6) and lower (6') parts, arranged, on both sides of the rolling plane (P1) on the corresponding hydraulic block (B1, B2), extend each, towards the inside of the window (A3), up to a guiding face (61, 61') parallel to the clamping plane and co-operate, in the Z High configuration, with two superimposed sliding faces, respectively (35) of a working chock (E3, E'3) and (150) of an intermediate chock (E2, E'2).
12. A rolling mill according to one of claims 7 to 11, characterised in that the resting members (11,12), (110, 120) of the chocks of the working rolls, respectively upper (C1), (C2) and lower (C'1), (C'2), are placed substantially in the vicinity of the rolling plane P1, between the protruding parts, respectively upper (6) and lower (6') parts of both hydraulic blocks (B1, B2).
13. A rolling mill according to one of claims 7 to 11, wherein each chock (E1) is fitted, on both sides of the clamping plane (P2), with at least one resting member (11, 12) protruding with respect to the corresponding sliding face (15) of the chock (E1), in order to co-operate with the cambering cylinders (V1, V2), characterised in that, in each configuration, the resting members (11, 12), (11', 12') of the chocks (E1, E'1) of both working rolls (C1, C'1) are placed substantially in the vicinity (H1) of the rolling plane (P1), between the protruding parts (6, 6') of each hydraulic block (B1, B2), and that each resting member (11) of a first working chock (E1) placed on a first side of the rolling plane (P1) is fitted with at least one recess (13a) for letting through the rod of at least one cambering cylinder (V1a) placed on said first side and running through the rolling plane (P1) for resting, in the positive direction, on a corresponding resting member (11') of the second working chock (E'1) placed on the second side of the rolling plane (P1), which is fitted with at least one recess (13') for letting through the rod of at least one cambering cylinder (V'1) placed on said second side and running through the rolling plane (P1) for resting, in the positive direction, on the resting member (11) of the first working chock (E1).
14. A rolling mill according to claim 13, characterised in that, on both sides of the clamping plane (P2), each protruding part (6, 6') of a hydraulic block (B1), (B2) carries two groups of single-effect cylinders, respectively (V1, V'1), (V2, V'2) acting towards the rolling plane (P1) and (V3, V'3), (V4, V'4) acting on the opposite side thereto, while resting on said protruding part (6, 6'), and that the corresponding resting members of the chocks (E1, E'1) are placed on three levels which remain substantially the same in all the configurations, respectively a central resting level (H1) of the working chocks, corresponding substantially to the rolling plane, and two resting levels, respectively upper (H2) and lower (H'2), of the intermediate chocks, placed respectively above and below the protruding parts (6, 6') of the hydraulic blocks (B1, B2).
15. A rolling mill according to one of claims 5 to 14, characterised in that the sets of cambering cylinders, respectively upper (V) and lower (V') are centred substantially in two planes (Q1, Q2) parallel to the clamping plane (P2) and spaced apart symmetrically on both sides thereof.
16. A rolling mill according to one of claims 14 and 15, characterised in that, on both sides of the clamping plane (P2) and on both sides of the rolling plane (P1), each protruding part (6) of a hydraulic block (B1) carries at least one central cylinder (V1) acting in the direction of the rolling plane (P1) and two lateral cylinders (V3a, V3b) acting in the direction opposite to the rolling plane (P1).
17. A rolling mill according to claim 16, characterised in that, in the quarto configuration, the lateral cylinders (V3a, V3b) (V'3a, V'3b) act, in the positive direction, on the chocks (E1) (E'1) of the working rolls, respectively upper (C1) and lower C'1).
18. A rolling mill according to one of claims 5 to 17, characterised in that each chock (E1), (E2) of a roll with greater diameter (C1) or average diameter (C2), is formed of three abutting portions, respectively a central portion (1) for supporting a centring bearing of the corresponding roll (C1), (C2) and two end portions (2a, 2b) carrying, each, two resting members (11a, 12a), (11b, 12b) extending on both sides of the clamping plane (P2) and attached to both lateral sides, perpendicular to the axis, of the central portion (1), removably enabling, on the one hand, to interconnect the central portion (1) with both end portions (2a, 2b) for transmitting the cambering loads and, on the other hand, for turning over the end portions (2a, 2b) with respect to the central portion (1), after disconnection of the three portions.
19. A rolling mill according to claim 18, characterised in that the central portion (1) of each chock (E1) is fitted, on both sides of the clamping plane (P2), with a resting member (11) (12) for at least one first central cambering cylinder (V1) placed on a first side of the rolling plane (P1), said resting member (11) (12) containing at least one recess (13) for letting through the rod of at least one second central cambering cylinder (V'1) placed on the other side of the rolling plane (P1).
20. A rolling mill according to claim 19, characterised in that each hydraulic cambering block (B1) placed on one side of the clamping plane (P2) includes a central group of cylinders containing at least two pairs of opposite cylinders acting respectively on the resting members (11, 11') of the central portions (1, 1') of both working chocks (E1, E'1) placed on both sides of the rolling plane (P1), each pair including two opposite cylinders acting respectively in the positive direction (V'1, V1a) and in the negative direction (V1, V'1a) on a resting member (11, 11') of one of the chocks (E1, E'1), each positive cambering cylinder (V'1) of a first chock (E1) placed on a first side of the rolling plane (P1) bearing on a protruding part (6') of the hydraulic block placed on the second side of the rolling plane (P1) and running therethrough while going through a recess (13') provided in the corresponding resting member (11') of a second chock (E'1) placed on the second side of said rolling plane (P1).
21. A rolling mill according to claim 20, characterised in that the central portion (1) of a first working chock (E1) placed on a first side of the rolling plane (P1) includes, on a first side of the clamping plane (P2), a resting member (11) containing a single resting portion cooperating with a pair of opposite cambering cylinders (V1, V'1) and sandwiched by two recesses (13a, 13b) and, on the second side of the clamping plane (P2), a resting member containing two resting portions (12a, 12b) spaced apart on both sides of a single recess (14) and cooperating each with a pair of opposite cylinders, the disposition of the resting members and of the cylinders being reversed for the second working chock (E'1) placed on the other side of the rolling plane (P1).
22. A rolling mill according to one of claims 18 to 21, characterised in that the lateral cylinders (V3a, V3b), bearing on each protruding part (6) of a hydraulic block (B1), (B2) act in the positive direction on resting members (21a, 21b), (22a, 22b) arranged respectively on the end portions (2a, 2b) of a chock (E1) with great diameter forming at least one intermediate chock in the sexto configuration or in the Z.High configuration.
23. A rolling mill according to claim 22, characterised in that the lateral cylinders (V3a, V3b) act in the positive direction on resting members (21a, 21b) arranged respectively on the end portions (2a, 2b) of a chock with great diameter (E1) forming a working chock in a quarto configuration.
24. A rolling mill according to one of claims 18 to 23, characterised in that the resting members (21a, 21b), (22a, 22b) arranged on the end portions (2a, 2b), respectively, of a chock (E1) of a roll (C1) with great diameter (E2) or of a roll (C2) with average diameter, are fitted with rollers (G) running on rails (R, 7) parallel to the rolling plane (P1) and to the clamping plane (P2) for disassembly and reassembly of the corresponding roll by a displacement parallel to the axis thereof.
25. A rolling mill according to one of claims 18 to 24, characterised in that each chock (E3) of a roll with small diameter (C3) used as a working roll in the Z.High configuration, is formed of three abutting portions, respectively a central portion (3) for supporting a centring bearing of the corresponding roll (C3), fitted, on both sides of the clamping plane (P2), with a resting member (31, 32) for at least two opposite cambering cylinders, respectively positive (V'1) and negative (V1), and two end portions (4a, 4b) interconnected with the central portion (3) and fitted each, on both sides of the clamping plane (P2), with a resting member (41 a, 41b), (42a, 42b) carrying at least one roller (G) running on a rail (R) parallel to the rolling plane (P1) and to the clamping plane (P2), for disassembly of the corresponding roll (C3) by a displacement parallel to the axis thereof.
26. A rolling mill according to one of claims 24 and 25, characterised in that the stand (A) is fitted with disassembly rails (R) placed on three levels, respectively a central level (H1) corresponding substantially to that of the rolling plane (P1), containing two superimposed running rails (72, 72') of the chocks of the working rolls, respectively upper and lower, and two levels, respectively upper (H2) and lower (H'2), containing each a running rail (71, 71') of the chocks of the intermediate rolls, respectively upper (C1) and lower (C'1).
27. A rolling mill according to one of claims 7 to 26, characterised in that at least one portion (63, 64) of each protruding part, respectively upper (6) and lower (6') parts, carrying a set of cambering cylinders, is set up slidingly, parallel to the rolling plane (P1) and to the clamping plane (P2), on the corresponding hydraulic block (B1, B2) and that the rolling mill includes means for controlling the simultaneous axial sliding motion, with the cambering cylinders and a corresponding roll, of the mobile portions (63, 64) of the protruding parts (6) placed respectively on both sides of the clamping plane (P2) and on a same side of the rolling plane.
28. A rolling mill according to claim 27, characterised in that it includes means for controlling the sliding motion of each pair of protruding parts (6) placed respectively on both sides of the clamping plane (P2) and on the same side of the rolling plane (P1), with an intermediate roll with great diameter (C1) in the sexto configuration and with an intermediate roll with average diameter (C2) in the Z.High configuration.
29. A rolling mill according to one of claims 27 and 28, characterised in that, on both sides of the clamping plane (P2), each protruding part, respectively upper (6) or lower (6'), of a hydraulic block (B1, B2) includes a fixed central portion (62) with respect to the stand (A) and two mobile lateral portions (63, 64) placed on both sides of the central portion (62) and set up slidingly axially on the hydraulic block (B1, B2), that each set of cambering cylinders, respectively upper (V) or lower (V'), includes at least one central cylinder (V1) bearing on the fixed central portion (62) of the protruding part and acting towards the rolling plane, and at least two lateral cylinders (V3a, V3b) bearing respectively on both lateral mobile portions (63, 64) of the protruding part (6) and acting of the side opposite to the rolling plane (P1), and that each chock comprises a central portion (1) fitted, on each side, with a resting member (11) for at least one central cylinder (V1), and two end portions (2a, 2b) abutting on both sides of the central portion (1) and fitted each, on both sides of the clamping plane, with a resting member (21a, 22a), (21b, 22b) for a lateral cylinder (V3a, V3b) set up on a corresponding mobile portion (63, 64) of the protruding part (6).
30. A rolling mill according to claim 29, characterised in that the resting members (21a, 21b) arranged on each end portion (2a) of a chock are offset vertically with respect to the axis (x'x) of the roll in order to determine, by rotation of the end portion (2a) around said axis, two levels of the resting members with respect to the axis, respectively a level (H1) offset towards the rolling plane (P1) for a chock of a working roll in quarto configuration and a level (H2) offset of the side opposite to the rolling plane (P1) for a chock of an intermediate roll in sexto configuration.
31. A rolling mill according to one of claims 5 to 30, characterised in that, in a sexto configuration, working rolls and intermediate rolls are used having, respectively, an average (C2) and a great (C3) diameter suited to the height (h) of the windows (A3) of both columns of the stand (A) and that shims (M, M') are interposed between each end of the window (A3) and the corresponding chock (S1, S'1) of a back-up roll (S, S'), in order to reduce the height of the windows (A3) for the quarto and Z.High configurations.
32. A rolling mill according to one of claims 5 to 31, characterised in that the means (V, V') for applying the cambering loads are arranged in hydraulic blocks (B1, B2) which, in all the configurations, have a height not exceeding substantially the sum of the diameters of both rolls with great diameter (C1, C'1) used as working rolls in the quarto configuration.

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