EP1005923A1 - Rolling mill provided with means for bending the work rolls - Google Patents

Abstract

A rolling mill comprises respectively positive (5,5') and negative (6,6') cambering rams supported on lugs (7,7') of chocks (4,4') of the two working cylinders. Each lug of a chock (4) has a staged section comprising at least one support part (73) and a clearance (74). The negative cambering rams (6) of a first chock (4) are arranged on the same side of the rolling plane (P1) than the positive cambering rams (5') of the second chock (4') crossing the rolling plane through the clearance (74). The chocks of the two working cylinders are similar and can be mounted on either cylinders (2,2').

Description

Rolling metal products in the form of tape is normally carried out in a train of rolling mills each consisting of a cage comprising two support columns spread apart and connected by sleepers, between which is mounted a set of superimposed cylinders having parallel axes and placed substantially in the same clamping plane substantially perpendicular to the direction of displacement of the product.

We can realize rolling mills of different types. Generally, in a rolling mill, the product to be rolled passes between two cylinders of work which define the rolling plan; these cylinders are generally of relatively large diameter reduced with regard to the efforts to which they are subjected, they are therefore generally supported respectively on at least two support cylinders between which is applied the rolling force.

The so-called "quarto" rolling mills, therefore have four superimposed cylinders, respectively two associated working cylinders, respectively, with two more supporting cylinders large diameter.

In the "sexto" rolling mills, cylinders intermediaries are interposed between each cylinder and the corresponding support cylinder.

Other types of rolling mill, including a plus or fewer cylinders are known and used in industry.

The cylinders are supported one on the others along substantially support lines parallel, and directed along a generator whose the profile, normally straight, depends on the forces applied and resistance of the cylinders. Generally the clamping force is applied by screws or cylinders interposed between the cage and the support cylinder shaft ends upper, the lower support cylinder taking support by these ends directly on the cage. AT apart from the latter, the other cylinders must therefore ability to move relative to the cage and at this effect, are carried by mounted support members sliding vertically in two windows in the two columns of the cage.

Clamping means such as screws or jacks, leaning on the cage, exert a vertical force in the direction of tightening of the cylinders for the rolling of the product passing between the cylinders of job.

Generally, each cylinder is mounted rotatable, around its axis, on bearings carried by two support members called chocks and this one are slidably mounted, parallel to the plane of clamping passing through the axes of the working cylinders, each between two flat guide faces provided respectively on either side of said plane of clamping on both sides of the window corresponding from the cage.

The clamping forces are applied between the two ends of the two support cylinders. Since the rolled product, of variable width does not fully cover the length of the work, each cylinder can flex under the action applied efforts.

This results in a thickness variation of the space of passage of the strip between the cylinders of working, the edges of the strip can thus be more thinner than the central part.

For a long time, we have tried to correct these thickness defects on the cross section of the rolled product and used for this purpose different means.

For example, it has been proposed to compensate for the deformation of the rolls due to the rolling force by a bulging of their surface obtained by machining according to a particular profile. This presents the disadvantage of not being perfectly suited to all widths of the rolled product. In addition, the thickness defect on the cross section of the product laminate is complex because it is the result of all the deformations of all the cylinders, which are different diameters, and the deformation of all the constituent parts of the rolling stand under the effort.

This is why, we also proposed to realize a continuously adjustable correction, by cambering effects of working cylinders, which are usually small diameters, applying controlled bending forces on both ends from their tree.

For this purpose, we usually use hydraulic cylinders placed on either side of each chock and leaning in one direction on a fixed part and in the other on side parts protruding forming support ears of the chock.

We can thus achieve a so-called cambering negative, by tightening the chocks of the two working rolls, to compensate for excess thickness edges of the product or a so-called positive camber, by spacing the same chocks from the two cylinders to compensate for an excess thickness of the central part of the product.

To reduce the number of cylinders, you can consider using double acting cylinders realizing, in a sense the positive cambering and in the other the negative camber. However, then that the rods of the cylinders are connected, in both sense, to the chalkboard. However, the cylinders must be replaced periodically and for this purpose are withdrawn of the cage by displacement parallel to their axis in sliding or rolling on rails. Then remove the camber cylinders at the same time as the chocks, or apply the bending effort to intermediate pieces on which the chocks are supported with the possibility of axial sliding.

Such an assembly is quite complicated and, generally, we prefer to use single cylinders effect acting in opposite directions on chocks, respectively for the positive camber and for the negative camber of the cylinder. For this, the cylinders of positive camber can be simply interposed between the chocks of the two working rolls, respectively upper and lower taking support in opposite directions on them. However, we do not can then have only a symmetrical effect on the two cylinders on either side of the rolling plane.

It is therefore preferable to use cylinders associated with each chock to apply individually specific bending efforts on each of the working cylinders. However, a such a provision obviously increases the number of cylinders and complicates their installation, in particular for positive camber cylinders which are placed between the chocks.

In addition, it must be taken into account that, working cylinders having a fairly large diameter weak, their chocks are smaller than those support cylinders. So it seems natural, for adjust the levels of the work chocks, take support on the support chocks, which can, in addition, be extended by guide legs between which the work chocks are mounted sliding.

However, the level of support chocks may vary and, to ensure precise control of the profile of the working cylinders, it is preferable that the cambering cylinders bear directly on the cage.

For this purpose, it is therefore more advantageous to mount the camber cylinders in two pieces of support fixed respectively on the two sides of each window of the cage at the level of the cylinders of work and in which the circuits are arranged hydraulic, these support parts being, for this reason, sometimes called "hydraulic blocks".

Usually positive camber cylinders and negative are housed in support parts projecting inward from the window and provided with guide faces at their ends lateral of the chock, the ears thereof extending outwardly between said parts in protrusion.

For this reason, each support block usually has three projecting parts, respectively a central part placed at the level of rolling plan, in which the cylinders are housed of positive bending of the two chocks and two parts support placed, respectively, above and in below the rolling plane and in which are housed the negative camber cylinders of both cylinders, respectively upper and lower.

As seen in Figure 1 which shows, at as an example, a provision like this, each support block, therefore has an E shape comprising, on either side of the projecting part central, two notches in which extend, respectively, the ears of the two chocks. These notches must therefore have a sufficient height to allow the relative levels to be varied cylinders.

However, the rolls of a rolling mill and, in particular, the working cylinders, wear out enough quickly and their diameter can therefore vary, as well that, of course, the relative positions of cylinders applied on top of each other. The figure 1 shows, for example, the relative positions of the new and used cylinders, respectively on the right and to the left of the clamping plane. It follows that the heights of the guide faces and the strokes of the cylinders should be increased depending on the range wear to allow height adjustment necessary cylinders.

In addition, disassembly of the cylinders cannot be do that in a determined position that matches at the level of fixed chutes sliding rails and, in this position, the cylinders must be all separated from each other. Now usually the camber cylinders are used to balance the weight working rolls and their chocks and must therefore withstand these throughout the race of adjustment between disassembly position and position the tightest of the chocks.

For all these reasons, the central part support blocks in which the positive camber cylinders, as well as the notches in which extend the ears of chocks, must each have a minimum height for ensure the necessary stroke.

As a result, the total height of the blocks hydraulic must be relatively large and it it is therefore necessary to have an interval sufficient between the chocks of the support cylinders to place the hydraulic blocks there. This complicates the installation of the cambering system in the event of modernization of an existing cage and in the case of a new cage, these requirements increase the cage dimensions and therefore the cost of this one.

In addition, to determine the dimensions and the installation of hydraulic blocks, cylinders and support ears, you must take into account set of parameters related to conditions operating. For example, the rolling plan should normally be placed at a level substantially constant and one is brought, as shown, the figure 1, to be produced, respectively, for the cylinder of upper work and for the work cylinder lower, special chocks having faces of lateral guidance extended downwards to ensure correct guidance over the entire height required, taking into account the wear range.

Such a provision cannot be symmetrical and we must therefore have two types chocks, respectively for the cylinders upper and lower cylinders. During the replacement, new cylinders must be fitted in advance adequate chocks according to their position in the cage, respectively above or in below the rolling plane.

It therefore appears that, in the design of a new rolling stand or for the adaptation of camber systems to an existing cage it takes consider a set of requirements sometimes contradictory while obviously seeking to reduce the overall cost of the cage and allow a setting as precise as possible the profile of cylinders.

The object of the invention is therefore to resolve all of these problems by avoiding disadvantages mentioned above, thanks to a new arrangement of chocks and cylinders bending which allows to use, for the cylinders of work, chocks of a single model, these can be adapted either to an upper cylinder or to a lower cylinder, by simple turning.

Furthermore, in the arrangement according to the invention makes it possible to reduce the height of the blocks support and simplify their implementation.

The invention therefore applies, in a way general, to a known type rolling mill comprising two sets of cylinders placed on either side of the plane clamping and acting respectively on two choke support ears of each cylinder of work, respectively higher or lower, each set of camber cylinders comprising at least two positive camber cylinders supported, respectively, on the inner faces of the ears two chocks and at least two camber cylinders negative bearing respectively on the face outer ears of the two chocks, the cylinders of negative arching of a first chock and the jacks of the camber of the second chock having fixed elements mounted on the same side of the rolling plane and mobile elements supported, respectively, on the external face of the support ear of the first chock and on the inner side of the ear support of the second chock, the mobile elements second camber positive camber cylinders crossing the rolling plane.

In accordance with the invention, the chocks of the two working rolls are identical and can, by simple reversal, be mounted on one or the other of said cylinders, and the camber cylinders positive and negative respectively of the two chocks are centered respectively in two parallel planes at the clamping plane and are arranged symmetrically by relation to a central axis of symmetry placed in the clamping plane, each ear of a first chock having a stepped profile comprising at least one support part which extends in the longitudinal direction of the cylinder axis, on only part of the length of the chock so as to spare at least one free space for the moving element to pass at least a second cambering positive camber cylinder. On the same side of the clamping plane, the profiles storied ears, respectively, of the two chocks are inverted so that a supporting part of a first choise corresponds to a free space of the second chock and, on the same side of the plane of rolling, the layered profiles of the ears of the same chock placed respectively on either side of the clamping plane are reversed so that each support part of an ear of the chock placed on one side of the clamping plane is symmetrical, relative to the central axis, a free space of the ear of the same chock placed on the other side of the clamping plane.

In the usual case of a rolling mill comprising two working cylinders, respectively upper and lower, placed on either side of a plane of substantially horizontal rolling, each block of support includes an upper holding part in which the fixed elements of the working cylinder negative cam cylinders upper and positive camber cylinders of the lower working cylinder and part of lower support in which the fixed elements of the negative camber cylinders of the lower working cylinder and cylinders positive camber of the upper working cylinder.

Thanks to the invention, the two cylinders of work of a rolling stand and, even, of all cages in a tandem rolling mill, can be fitted of one model.

But the invention also makes it possible to facilitate the installation of the cambering system in the cage.

Indeed, according to another characteristic particularly advantageous, the fixed elements of the bending cylinders, positive and negative respectively of the two chocks are mounted respectively in protruding parts of two fixed support blocks respectively on each column of the cage, by hand and on the other side of the clamping plane, each support block being symmetrical with respect to the rolling plane and comprising, between said projecting parts, a unique central notch in which lie the support ears of the chocks of the two cylinders, respectively upper and lower, and each chock is provided, on each side of the clamping plane, of a single lateral support face extending from side opposite to the rolling plane with respect to the supporting ear and sliding along one face of fixed guide formed at the end of a part in corresponding projection of the support block.

Preferably, the support ears of each chocks are shifted to the rolling plane by relation to the axis of the corresponding cylinder of such so that the internal bearing faces of the cylinders positive camber are found almost in contact one on the other in the position of maximum wear of the working cylinder.

In a preferred embodiment, the ear support parts of a first chock and the free spaces of the ears of the second chock are centered in a first diagonal plane passing through the central axis of symmetry and in which are centered, respectively, two camber cylinders positive and two negative camber cylinders of the first chock and ear support parts of the second chock and the free spaces of ears of the first chock are centered on a second diagonal plane passing through the central axis of symmetry and in which two cylinders are centered positive camber and two negative camber cylinders the second chock.

In another embodiment, each a first working cylinder is provided, on a first side of the clamping plane, first ear with a single centered support part on a median plane of the sponge passing through the axis center of symmetry and on which are supported, opposite directions, a positive camber cylinder and a negative camber cylinder of the first cylinder, said cylinder single support part framed by two spaces free passage of the moving parts of two cylinders positive bending of the second working cylinder and, on the second side of the clamping plane, one second ear in which a free space is provided central passage of the movable element of a cylinder positive camber of the second working cylinder, centered on the median plane of the chock, said free space central being framed by two support parts, respectively, of two positive camber cylinders and two negative camber cylinders of the first cylinder of work.

The invention applies to rolling mill stands new but it is particularly advantageous for the modernization of existing cages, for which the dimensional constraints of the columns and chocks from existing support cylinders can complicate or prevent the installation of a arching of classic design.

• la figure 1 est une vue en coupe transversale de la partie centrale d'une cage de laminoir quarto de type connu.
• la figure 2 est un schéma de principe de la disposition, selon l'invention, des empoises et des vérins de cambrage des cylindres de travail.
• La figure 3 est un schéma de principe, en vue de dessus selon la ligne III-III de la figure 2.
• La figure 4 montre schématiquement, en perspective, la disposition des vérins de cambrage.
• La figure 5 est une vue partielle de côté des empoises de travail, dans un mode de réalisation préférentiel.
• La figure 6 est une vue en coupe transversale selon la ligne VI-VI de la figure 5.
• La figure 7 est une vue de dessus schématique d'un autre mode de réalisation.

The invention also covers other characteristics which will emerge during the following description of certain particular embodiments, given by way of example and shown in the appended drawings in which:

• Figure 1 is a cross-sectional view of the central part of a known type quarto rolling stand.
• Figure 2 is a block diagram of the arrangement, according to the invention, chocks and camber cylinders of the working rolls.
• Figure 3 is a block diagram, seen from above along line III-III of Figure 2.
• Figure 4 shows schematically, in perspective, the arrangement of the camber cylinders.
• Figure 5 is a partial side view of the working chocks, in a preferred embodiment.
• Figure 6 is a cross-sectional view along line VI-VI of Figure 5.
• Figure 7 is a schematic top view of another embodiment.

In Figure 1, there is shown in section transverse, the classic layout of a rolling mill quarto type including, inside a cage having two spaced apart columns 1, two cylinders of work, respectively upper 2 and lower 2 ', which are supported, respectively, on two cylinders support, upper 21 and lower 21 'and define an air gap for the passage of an M band to be laminated, moving along a rolling plane P1.

Figure 1 shows the central part of a window of a column 1 of the cage, in section transverse to the axis of the cylinders, the second column being identical.

Each working cylinder 2, 2 'is mounted rotating, at its ends, on revolving journals in bearings housed in chocks 4, 4 '. Of even, the support cylinders 21, 21 'are carried by chocks 41, 41 '.

The axes of the cylinders are parallel and must be kept substantially in a plane of clamping P2 perpendicular to the rolling plane P1. Usually the latter is horizontal, the plane of clamp P2 being substantially vertical.

In the rolling position shown on Figure 1, the cylinders are tight, and their levels may vary depending on their wear. AT As an example, the right half view represents the relative positions of new cylinders and half view left represents the positions of used cylinders of smaller diameter.

It is therefore necessary to be able to adjust the relative cylinder levels and that's why the cylinder chocks are strung in a window 10 from column 1 of the cage and can slide parallel to the clamping plane P2.

The chocks 41, 41 'of the support cylinders 21, 21 'which have a large diameter, are mounted sliding along guide faces 11a, 11b formed directly along the two uprights la, 1b which frame window 10 of column 1.

However, the chocks 4, 4 ′ of the cylinders of work 2, 2 'of smaller diameter are less wide that the chocks 41, 41 ′ of the support cylinders 21, 21 'and their guide faces must therefore be less set aside. This is why, according to a provision conventional, the guide faces 12a, 12b of the chocks are arranged on the faces opposite two machined blocks 3a, 3b which are mounted respectively on the two uprights la, 1b of the column and extend inwardly projecting from window 10.

It is advantageous, in a rolling mill, that the rolling plan P1 is maintained at a level substantially constant, especially when the band to laminate M passes successively in several rolling mills operating in tandem.

In the example shown in Figure 1, to adjust the level of the rolling plan, we act on wedges 16 of adjustable height, by corners or by cylinders, which are placed on the bottom bottom of each column 1 of the cage and on which take support chocks 41 'of the support cylinder lower 21 '; the level of the lower holds 16 is adjusted according to the diameters of the cylinders for that, taking into account the diameter of the working cylinder lower 2 ', the upper generator thereof located substantially at the level of the plane of rolling P1.

Level of upper support cylinder 2 is adjusted by clamping means not shown, such as screws or cylinders, which are mounted at the upper part of the two columns 1 of the cage for build on chocks 41 and which allow, in addition, to apply the necessary rolling force thickness reduction.

Of course, other provisions may be used to adjust the relative levels of cylinders inside the cage.

As indicated, the cylinders, in especially the working cylinders, must be periodically removed from the cage for maintenance or replacement and, for this, their chocks roll or slide on fixed guide rails. These rails (not shown in the figure) are mounted on the cage columns and placed at a constant level for which all the cylinders are spread apart others. To place the cylinders in the position replacement, lower the support cylinder lower 21 'to its lower level by means of lower wedges and the cylinder is raised higher support 21 at its higher level through clamping means and possibly cylinders auxiliaries 15 mounted in the support blocks 3a, 3b and bearing on the chocks 41 of the cylinder of upper support 21. In service, these cylinders 15 also serve to balance the weight of cylinder 21 and its chocks 41.

The support cylinders are thus spaced of a large opening, the relative levels of working cylinders 2, 2 'can be adjusted by cylinders housed in the support blocks 3a, 3b. Of the as indicated above, these jacks also serve, in service, to apply bending efforts, respectively positive or negative, on chocks working cylinders.

Figure 1 shows the most classic in which each chock 4, 4 'is associated with two sets of cylinders placed respectively on either side of the clamping plane P2 and comprising, for each working cylinder, respectively upper 2 or lower 2 ', at least a positive cambering cylinder 5, 5 'and at least one 6,6 'negative camber cylinder.

Usually, these cylinders act on support parts provided on either side of each chocks and which form opposite ears 7, 7 ' each projecting from the side corresponding side 42 of the chock.

Therefore, each support block 3 has a E-shape comprising three holding parts in projection, respectively an upper part 32, a central part 33 and a lower part 32 ', which frame two notches, respectively upper 31 and lower 31 ′, into which the ears 7, 7 'of the working chocks, respectively upper 4 and lower 4 '. Camber cylinders resting on the ears of the chock are housed in these three holding parts whose ends facing each other form the guide faces 12a, 12b the along which the lateral sides 42a slide, 42b, 42'a, 42'b, of the two chocks 4, 4 '.

So the two positive camber cylinders, respectively 5 of the upper working cylinder 2 and 5 'from the lower working cylinder 2', are housed in the central part 33 of the support block 3 and are supported, respectively, on the internal faces 71, 71 ', facing the rolling plane P1, ears 7, 7 ', of the two working chocks 4, 4'. The negative cambering cylinders 6, 6 'are housed, respectively, in the upper projection 32 and in the lower projecting part 32 'of each support block 3 and rest on the external faces 72, 72 'of the ears 7, 7' of the two chocks 4, 4 ', turned on the side opposite the plane of rolling P1.

As seen in Figure 1, to accommodate the positive camber cylinders 5, 5 'in the part control unit 33 with the stroke necessary to adjust the levels of the working cylinders it is necessary to give a relatively large thickness to the central support part 33 of the support block 3 including the end 34 must constitute, over a height sufficient, one guide face for the sides corresponding side chocks 4, 4 '.

In addition, in the tightened position of the working cylinders shown in the half view of left and for which the used cylinders have the smaller diameter, the two chocks 4, 4 'come practically in contact with each other. The dimensioning of the different parts of the blocks support 3 and working chocks must therefore hold account of the wear range, especially when you want to keep the rolling plan at a constant level. For example, in the cage shown in Figure 1, the underside 43 of the chock 4 is located below the rolling plane in the maximum wear position.

These different imperatives complicate the implementation in place cambering means in the cage and most often lead to a disposition asymmetrical with respect to the rolling plane, the chocks being necessarily different for them two working cylinders.

As we will see now, the invention avoids such disadvantages, and simplify the installation of hydraulic blocks.

The principle of the invention is shown schematically in Figures 2 and 3 and more in detail in Figures 5 and 6.

The invention is described, by way of example, in the case of a quarto type rolling mill such as shown in Figure 1 and therefore comprising all the usual arrangements. In Figures 2 and 3, we have only shown schematically the two amounts 1a, 1b of the column between which are arranged the two working rolls 2, 2 'which are carried by chocks 4, 4 'mounted sliding between support blocks 3a, 3b.

As seen in Figure 2, each block support 3a, 3b has a single notch 35a, 35b which extends on either side of the rolling plane P1, the central projecting part 33 of the arrangement known being, therefore, deleted. So each block of support has a section in C and not in E.

As a result, in each support block 3, the camber cylinders must all be housed in two support parts, respectively upper 32 and lower 32 'framing a central notch 35. The arrangement of the 6,6 'negative camber cylinders remains unchanged but, on the other hand, each cylinder of 5, 5 'positive camber must necessarily be accommodated in the projecting holding part of the block support which is on the side opposite the chock on which it must act, in relation to the rolling plan P1.

This is why the positive camber cylinders 5a, 5b bearing on the internal faces 71a, 71b of the two ears 7a, 7b of the upper chock 4 are housed in the lower protruding parts 32'a, 32'b of the support blocks 3a, 3b, with the cylinders 6'a, 6'b of negative bending of the chock lower 4 '.

Therefore, the body 51 of each cylinder of positive camber 5 must be placed next to the body 61 ' of the 6 'negative camber cylinder, in the lower projection 32 ′, and the rod 52 of the jack 5 must cross the ear 7 'of the lower chock 4' to pass to the other side of the rolling plane P1 and lean on the internal face 71 of the ear 7 of the top working chock 4.

In addition, in order not to increase the overhang projecting support parts 32, the jacks camber are placed next to each other and centered, respectively in two planes Pa, Pb parallel to the clamping plane P2 and spaced apart symmetrically on either side of it.

Figure 3 schematically shows a mode of realization of the ears of the chocks allowing to get this result. We see, in fact, that each side of the chock, the camber cylinders, respectively, positive 5 and negative 6 'are placed one next to the other and offset axially, respectively on either side of the median plane P3 of chock 4 'on which the bearings 40' are centered rotary support for the working cylinder 2 '. Each 7 'ear of the chock therefore has a stepped profile comprising a part 73 ′ for supporting the cambering cylinder negative 6 'which covers only part of the length of the chock, in the longitudinal direction of the axis of the cylinder, so as to leave a free space 74 'allowing passage of the cylinder rod 5 of positive camber.

In addition, this provision is reversed, one part between the opposite sides of the same chock 4 ', of on either side of the clamping plane P2 and on the other hand, between the same sides of the two chocks respectively lower 4 'and upper 4, placed on either side of the rolling plane P1.

For example, we see in Figure 3 that the ear 7'a of the lower chock 4 'lying at left of clamping plane P2, has a stepped profile comprising a portion 73'a for supporting the actuator 6'a negative camber which is placed in front of the plane median P3 of the bearings, and extends at most over the half the length (L) of the chock, so that leave a free space 74 'placed behind the same median plane P3, for the passage of the rod of the jack 5a of positive arching of the upper chock 4. In revenge, the ear 7'b of the lower chock 4 ' placed to the right of the clamping plane P2 has a reverse stepped profile including part 73'b of the negative bending cylinder 6'b, which is placed behind the median plane P3 and leaves a free space 74'b placed in front of the same median plane P3 for passage of the cylinder rod 5b for bending positive of the upper chock 4.

In the preferred embodiment shown in Figures 5 and 6, the bodies 51, 61 different cylinders, which are single acting, can be made up of simple bores in opposite angles of the projecting parts corresponding 32, 32 ', support blocks 3. The Figure 6, which is a cross section through a plane passing through the axes of the cylinders, of the support block 3a placed to the left of the clamping plane P1 in FIG. 5, shows that the lower holding part 32 'of said block 3a has two bores placed side by side, respectively 61 'forming the cylinder body negative bending 6 'and 51 forming the cylinder body 5 positive arching of the upper chock 4.

As shown in Figure 3, the cylinders of positive camber 5a, 5b of the working cylinder upper 2 are thus placed in two opposite angles lower holding parts 32'a, 32'b of two support blocks 3a, 3b and are therefore centered on a first diagonal plane Q1 inclined at an angle not straight with respect to the clamping plane P2. So is even free spaces 74'a, 74'b provided in the ears 7'a, 7'b of the lower chock 4 '. From this done, the negative camber cylinders 6'a, 6'b of the lower working cylinder 2 'are placed on the side and on the other side of the plane P2, in the other two angles of the holding parts 32'a, 32'b of the two blocks of support 3a, 3b and centered in a second diagonal plane Q2, as well as the support parts 73'a, 73'b of the two ears 7'a, 7'b.

In Figure 4 which shows schematically, in perspective, the set of two chocks 4, 4 ', we sees that the layout is reversed for the chock upper work 4 and the cylinders placed in the upper holding parts 32a, 32b of the blocks support 3a, 3b; the 5'a positive camber cylinders, 5'b of the lower cylinder 2 'are centered in the second diagonal plane Q2 while the cylinders of negative camber 6a, 6b of the working cylinder upper 2 are centered in the first diagonal plane Q1.

The entire provision therefore includes a central axis of symmetry OO 'placed at the intersection of the clamping plane P2 with the median plane P3 of the chocks and through which the two diagonal planes Q1 and Q2.

Therefore, although the camber cylinders acting on two opposite ears of a chock, are axially offset on either side of the plane median P3, the cambering action exerted on the chock remains well centered with respect to the bearing, in the positive as in the negative.

The arrangement shown in the figures is particularly simple and can be easily adapted to an existing cage. We could, however, imagine other arrangements to make go through the center of the chock the resulting bending forces exerted in the positive direction or negative. In particular, the arching effort could be applied, on each side of the chock, by a greater number of cylinders arranged so as to ensure the centering of the result of the efforts applied.

By way of example, FIG. 7 shows another arrangement in which the bending force is applied on one side of the chock by a single cylinder and on the other by two cylinders supplied in parallel. In this case, each ear of a chock has a stepped profile having two free spaces on either side of a support part or else two support parts on either side of a free space. Thus, the ear 7'a of the lower working chock 4 ', placed to the left of the clamping plane P2, comprises a support part 73'a which is centered on the median plane P3 of the bearings, on which take support the positive 5'a and negative 6'a camber cylinders. This support portion 73'a is framed by two free spaces 74'a ₁ , 74'a ₂ through which pass the rods of two jacks 5a ₁ , 5a ₂ of positive bending of the upper working cylinder which are supplied in parallel. On the right side of the clamping plane P2, the ear 7'b comprises two support parts 73'b ₁ , 73'b ₂ symmetrically spaced apart on either side of the median plane P3, on which two pairs of cylinders operating in parallel, respectively 5'b ₁ , 5'b ₂ of positive bending and 6'b ₁ , 6'b ₂ of negative bending of the lower cylinder 2 '. Between these two support parts 73'b ₁ , 73'b ₂ is placed a central recess 74'b for the passage of the rod of the jack 5b for positive bending of the upper chock 4.

The support ears 7a, 7b of the upper working chock 7 shown in phantom in FIG. 7 are arranged in an inverse manner and therefore comprise, on the left, two parts 73a ₁ , 73a ₂ , for supporting the two jacks positive camber 5a ₁ , 5a ₂ and, on the right, a support part 73b framed by two free spaces 73b ₁ , 73b ₂ for passage of the rods of the jacks 5'b ₁ , 5'b ₂ of positive camber of the lower cylinder 2 '.

Thus, the bending efforts applied to each chock, in the positive direction or in the direction negative have a resultant directed along the axis center of symmetry OO 'which passes through the center of each level.

Since the support ears 7, 7 'of the two chocks 4, 4 ′ penetrate into the same notch central 35 of each support block 3, the faces of lateral support 42, 42 'of each chock 4, 4' extend on one side of the ear 7, 7 'of so as to slide along the guide faces 36, 36 ' formed at the ends of the holding parts in projection 32, 32 '. Therefore, the two chocks can be symmetrical with respect to the rolling plane P1. As a result, chocks can be used identical for the two working cylinders, the chock being simply turned 180 ° according to whether it is placed above or below the plane of rolling P1.

It should be noted that, to allow the disassembly of the cylinders, the cylinder rods must be fully retracted so as to release entirely the central notch 35. As a result, as shown in figures 5 and 6, the height of each holding part, respectively upper 32 or lower 32 ', from a support block 3 is determined according to the stroke of the cylinder positive camber which itself depends on the length that we have to give to the cylinder rod to make it lean on the ear of the chock placed from the other side of the rolling plane P1, the cylinders of negative camber with a lower stroke.

The invention has the advantage of allowing a reduction in the overall height of each block of support compared to usual arrangements since we remove the protruding central part which was previously necessary to house the positive camber cylinders. This results in a decrease in height of the area that should remain available between chocks 41, 41 'of the cylinders support to allow the implantation of the blocks of support. This provision is particularly interesting in the case of the modernization of a existing rolling stand because it allows facilitate the installation of the cambering system positive and negative between the support cylinders without notable modification of the cage columns.

Furthermore, the fact that the faces of support 42 extend on one side of the ears 7, these can be brought closer possible of the rolling plan, which allows minimize the length of the rods 52 positive camber cylinders. The internal faces 71a, 71b of the two ears 7a, 7b are then placed substantially at the level of the internal face 43 of chock 4 facing the rolling plane. This is itself spaced from the cylinder axis by a distance a little less than the smallest radius of the working cylinder 2. In this way, when the cylinders are in their maximum state of wear, the internal faces 71, 71 'of the ears 7, 7' of the two chocks 4, 4 'being almost in contact with one of the other, in the rolling plane P1, taking into account the necessary adjustments for negative bending.

But the invention still presents other benefits.

For example, the number of guide faces fixed and lateral chock holding faces is decreased. Now, we know that the surfaces of slip must be fitted with attachments made of a material with a coefficient of friction suitable for use and which constitute parts of wear. The decrease in their number, through the adoption of all the arrangements according to the invention, reduces the cost of installation as well as production costs by simplifying operations maintenance and by reducing the necessary duration of interventions.

Furthermore, we know that in a rolling mill tandem, it is desirable to maintain the plan of rolling at a substantially constant level.

Thanks to the invention, because the height overall hydraulic blocks and chocks is lower, it is possible to insure without difficulty the necessary adjustment ranges and use for all cages of support blocks of the same height and even identical.

Of course, the invention is not limited to details of the embodiments which have not been described as an example, other provisions equivalents that can be imagined without deviating from the protective framework defined by the claims. In particular, insofar as the camber cylinders positive and negative should be placed in the same support blocks it is advantageous to use, as we have described it, single cylinders simply offset compared to the median plane of the chock, but others layouts are possible using a larger number of cylinders arranged in the support parts of so that the result of the efforts always goes through the center of the chock.

Furthermore, the invention has been described in the case of a quarto rolling mill but could apply to any type of rolling mill, for example quinto or sexto, whenever it is useful to carry out a cambering working cylinders.

The reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding and limiting them in no way the scope.

Claims (6)

Rolling mill comprising, inside a holding cage having two spaced apart columns (1a, 1b), a set of rollers comprising at least two working rolls (2, 2 '), with substantially parallel axes defining a rolling plane ( P1) of a strip product (M), each cylinder having two ends and rotating around its axis, at each end, on a chock threaded into a window (10) of the corresponding column of the cage and mounted sliding along fixed guide faces (12), parallel to a clamping plane (P2) passing substantially through the axes of the working rolls, each chock (4, 4 ′) being provided, on either side of said clamping plane, lateral sides (42) for sliding maintenance, respectively, along said fixed guide faces (12), said rolling mill being equipped with means for applying bending forces to the ends of the two working rollers comprising, for each pair of chocks (4, 4 '), two in jacks of jacks placed on either side of the clamping plane (P2) and acting respectively on two support ears (7a, 7b, 7'a, 7'b) of each chock (4, 4 ') s' extending projecting, respectively, relative to the two lateral faces (42) for holding the chock and each having an internal bearing face (71) facing the rolling plane (P1) and an external bearing face ( 72) turned to the opposite side, each set of cambering jacks comprising at least two jacks (5, 5 ') of positive cambering bearing, respectively, on the internal faces (71, 71') of the ears (7, 7 ') two chocks (4.4 ′) and at least two cylinders (6, 6 ′) of negative camber bearing, respectively, on the external face (72, 72 ′) of the ears (7, 7 ′) of the two chocks (4 , 4 ') the jacks (6) of negative bending of a first chock (4) and the jacks (5') of positive bending of the second chock (4 ') having fixed elements (61, 51') mounted on the same side of the plane of the mining (P1) and mobile elements (62, 52 ') bearing, respectively, on the external face (72) of the bearing lug (7) of the first chock (4) and on the internal face (71 ') of the support lug (7') of the second chock (4 '), the movable elements (52') of the jacks (5 ') of positive camber of the second chock (4') crossing the plane of rolling (P1),
characterized in that the chocks of the two working cylinders (2, 2 ') are identical and can, by simple turning, be mounted on one or the other of said cylinders (2, 2'), that the cylinders of respectively positive (5.5 ') and negative (6.6') bending of the two chocks (4.4 ') are centered respectively in two planes (Pa, Pb) parallel to the clamping plane (P2) and are arranged symmetrically by relative to a central axis of symmetry (OO ') placed in the clamping plane (P2), that each lug (7) of a first chock (4) has a stepped profile comprising at least one support part (73a) extending, in the longitudinal direction of the axis of the cylinder, over only part of the length of the chock (4) so as to provide at least one free space (74a) for the passage of the movable element (52 'a) at least one jack (5'a) for positive bending of the second chock (4'), that, on the same side of the clamping plane (P2), the stepped profiles of the ori they (7a, 7'a), respectively, of the two chocks (4, 4 ') are reversed so that a support part (73a) of a first chock (4) corresponds to a free space (74 'a) of the second chock (4') and that, on the same side of the rolling plane (P1), the stepped profiles of the ears (4a, 4b) of the same chock (4) placed respectively on the side and d 'other of the clamping plane (P2) are reversed so that each support part (73a) of an ear (7a) of the chock (4) placed on one side of the clamping plane (P2) is symmetrical , relative to the central axis (OO '), of a free space (74b) of the ear (7b) of the same chock (4) placed on the other side of the clamping plane (P2). Rolling mill according to claim 1, characterized in that the fixed elements (51, 51 ', 61, 61') of the camber cylinders, respectively positive (5, 5 ') and negative (6, 6') of the two chocks (4, 4 ') are mounted respectively in parts in projection (32, 32 ') of two support blocks (3a, 3b) fixed respectively on each column (la, 1b) of the cage (1), on either side of the clamping plane (P2), and that each support block (3a, 3b) is symmetrical with respect to the rolling plane (P1) and includes, between said protruding parts (32, 32 '), a single central notch (35a, 35b) in which extend the support ears (7a, 7'a) (7b, 7'b) chocks (4, 4 ') of the two cylinders, respectively upper (2) and lower (2 '), each chock (4) being provided, on each side of the plane of clamping (P2), with only one lateral holding face (42) extending on the side opposite to the rolling plane (P1) relative to the supporting ear (7) and sliding along a fixed guide face (12) formed at the end of a corresponding projecting part (32) of the support block (3). Rolling mill according to claim 2, characterized by the fact that the ears (7, 7 ') support of each chock (4, 4 ') are shifted towards the rolling plane (P1) relative to the axis of the matching cylinder so that the faces internal (71, 71 ') for supporting the camber cylinders positive (5, 5 ') are almost in contact with one on the other in the position of maximum wear of the working cylinder (2, 2 '). Rolling mill according to one of the claims previous, characterized in that the parts support (73a, 73b) of the ears (7a, 7b) of a first chock (4) and the free spaces (74'a, 74'b) ears (7'a, 7'b) of the second chock (4 ') are centered in a first diagonal plane (Q1) passing through the central axis of symmetry (OO ') and in which are centered, respectively, two cylinders (5a, 5b) of positive cambering and two cylinders (6a, 6b) of negative arching of the first chock (4) and that the support parts (73'a, 73'b) of the ears (7'a, 7'b) of the second chock (4 ') and the free spaces (74a, 74b) ears (7a, 7b) of the first chock (4) are centered on a second diagonal plane (Q2) passing by the central axis of symmetry (OO ') and in which two cambering cylinders (5'a, 5'b) are centered positive and two cylinders (6'a, 6'b) of negative bending of the second chock (4 '). Rolling mill according to one of claims 1, 2, 3, characterized in that each chock (4) of a first working cylinder (2) is provided, on a first side of the clamping plane (P2), with a first lug (7b) comprising a single support part (73b) centered on a median plane (P3) of the chock (4) passing through the central axis of symmetry (OO ') and on which are supported, opposite directions, a cylinder (5b) for positive bending and a cylinder (6b) for negative bending of the first cylinder (2), said single bearing part (73b) being framed by two free spaces (74b ₁ , 74b ₂ ) passage of the mobile elements of two cylinders (5'b ₁ , 5'b ₂ ) of positive bending of the second working cylinder (2 ') and, on the second side of the clamping plane (P2), of a second ear (7a) in which is provided a central free space (74a) for the passage of the movable element of a jack (5'a) of positive camber of the second working cylinder (2 '), centered on the median plane (P3 ) of chock, said central free space (74a) being framed by two parts (73b ₁ , 73b ₂ ) for supporting, respectively, two positive cambering cylinders (5a ₁ , 5a ₂ ) and two cambering cylinders negative (6a ₁ , 6a ₂ ) of the first working cylinder (2). Rolling mill according to one of the claims above, applicable to a rolling plant comprising at least two cages operating in tandem, characterized in that the chocks (4, 4 ') of the working cylinders (2, 2 ') and support blocks (3) of all cages are identical.

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