EP0707902A1 - Rolling installation - Google Patents

Abstract

The rolling mill consist of two uprights (11,11') with working (2) and pressure rollers between them, each working roller having a shaft (21) with bearings (22) held in place by chocks (4). Between each of the chocks and the adjoining upright there is an intermediate element (6a,6b) interacting with a corresponding guide face (13a,13b) on the upright. The intermediate elements can slide relative to the guide faces of the uprights, and one intermediate element at each end of a roller has a lateral thrust member (7). The rolling mill also incorporates retaining members of variable thickness to ensure proper alignment of the rollers.

Description

The subject of the invention is an installation for rolling a flat product such as a strip of ferrous or non-ferrous metal and can be applied to hot or cold rolling.

A rolling mill generally comprises a set of superimposed rolls placed inside a fixed support cage having two spaced apart uprights in which are formed openings or "windows" having two vertical parallel sides.

Generally, the product to be laminated is passed, in a longitudinal direction, between two relatively small diameter working rolls which bear, on the side opposite to the product, each on one or more large diameter supporting rolls. The "Quarto" type rolling mills comprise two working rolls each associated with a support roll. In rolling mills of the "Sexto" type, intermediate cylinders are interposed between each working cylinder and the associated support cylinder.

The axes of all the cylinders are normally placed in the same clamping plane substantially perpendicular to the longitudinal axis of travel of the product and which generally coincides with a transverse median plane of the cage.

Each cylinder is carried by a shaft having two ends rotatably mounted, by means of bearings, on two chocks threaded, respectively in the two windows of the amounts of the cage.

The rolling of the product is carried out by exerting a clamping force applied between the chocks of the support rolls and transmitted to the product by the working rolls. Each cylinder must therefore be able to move vertically for tightening so as to adapt to the thickness of the product and to variations in diameter resulting, for example, from wear.

In general, therefore, the chocks of each cylinder are provided with sliding faces cooperating with guide faces provided on the two sides of each window.

As the working rolls have a smaller diameter, the guide faces of their chocks can be closer together and are generally formed on projecting parts formed in the central part of each window.

However, the cylinders must be able to be changed either in the event of wear or deterioration, or to use cylinders of different diameter. To this end, the cylinders can be introduced into or removed from the cage by sliding, parallel to their axes, on rails fixed to the uprights of the cage and on which the chocks rest, for example by means of pebbles. It is also possible to replace the two working cylinders at the same time, the chocks of the upper cylinder resting on the chocks of the lower cylinder which, themselves, move on the fixed rails. The chocks of the cylinders must therefore slide not only vertically, but also horizontally between the guide faces provided on the two sides of the window.

To allow the different sliding movements of the chocks, as well as the placement of the cylinders inside the cage or their removal, it is necessary to leave a minimum clearance between the lateral faces of the chock and the guide faces corresponding.

As a result, the positioning of the axes of the different cylinders and, in particular, their parallelism cannot be guaranteed in a perfectly rigorous manner.

However, during rolling, the working rolls bear, on one side, on the product being scrolling and, on the other side, on a support cylinder or an intermediate cylinder and this results in a misalignment, even very small, of the axis of a working cylinder relative to the direction of travel of the product and the axis of the corresponding support cylinder can result in an axial displacement effect of the cylinder which is pushed towards one of the uprights of the cage, the associated support cylinder being, generally, subjected to an effect axial displacement in the other direction. The cylinders are retained by axial stops, but this results, however, in friction with a hysteresis effect which can disturb the thickness control normally carried out by the clamping system.

Furthermore, as the clamping forces are applied to the ends of the shafts of the support cylinders, these can deform slightly by bending, especially since the product can have a variable width and therefore does not extend , normally, over the entire length of the working rolls. It follows that the ends of these tend to approach and that the compressive force is not evenly distributed over the entire width of the product, the lateral edges being more flattened than the central part.

This effect can be offset by giving the support cylinders a domed profile, possibly variable.

However, it is also possible to exert on the ends of the shafts of the working rolls adjustable cambering forces so as to correct the profile of the working rolls to compensate for the bending of the support rolls.

To this end, groups of jacks are often used bearing on the chocks to separate them from each other by producing a so-called "positive" bending of the working rolls.

Often, cylinders acting in the opposite direction are also used, which bear directly on the cage or on the chocks of the associated support cylinder, in order to bring the two chocks of the working cylinders closer to each other and achieve a so-called "negative" bending.

In some provisions, bending is carried out in both directions by double-acting cylinders.

To compensate for the lateral clearances and guarantee the positioning of the axes of the working rolls, it has been proposed to associate with each chock means of lateral thrust consisting of jacks or deformable faces disposed on the two sides of the chock and bearing horizontally on the cage, each chock being thus secured to the corresponding amount by lateral thrust on the two sides of the window (DE-A-3,807,654).

In a similar arrangement suitable for reversible rolling, it was even planned to increase the clearance between the chocks of the working rolls and their guide faces so as to determine, by means of lateral support cylinders, an offset from the line of axes of the working rolls on one side or the other of the line of the axes of the supporting rolls, depending on the direction of rolling (FR-A-1.314.027).

In all cases, the chocks are secured, in service, with the uprights of the cage, by lateral support on the two sides of the window. Consequently, if it is desired to camber the rolls to compensate for bending, this effect must be adjusted in advance, the spacing of the chocks cannot be modified during rolling.

It has even been proposed, in a particular arrangement disclosed by the document JP-A-61-129208, to increase the lateral tightening of the chocks in the event of separation of the latter during rolling.

To this end, each chock is provided with camber cylinders and lateral jacks whose chambers are connected together so that an increase in pressure in the direction corresponding to the spacing of chocks determines an increase in the force lateral thrust and therefore a blockage of the chock.

However, for several years, it has appeared that it was very advantageous to use the camber cylinders not only to compensate for the bending of the support rolls, but also to vary, during rolling, the profile of the air gap and the stress distribution in the transverse direction so as to correct flatness defects detected downstream.

To solve this kind of problem, the invention relates to a new arrangement making it possible to carry out all the adjustments necessary to carry out rolling under the best conditions, even during rolling, by immediately correcting all the defects detected.

In fact, the invention makes it possible to rigorously control the position and, in particular, the parallelism of the axes of the cylinders, without ceasing to apply corrective bending forces in these directions in one direction or the other.

The arrangements according to the invention also make it possible to make the positioning of the chocks all the corrections necessary to minimize the axial thrusts, compensate for the bending of the support cylinders, and correct the flatness defects.

In addition, thanks to the great flexibility of adjustment provided by the improved means according to the invention, it is also possible to slightly offset the axes of the support cylinders relative to the clamping plane passing through the axes of the working cylinders or else to achieve a determined crossing of the axes of the different cylinders so as to obtain particular effects.

The invention therefore applies, in general, to an installation for rolling a flat product comprising a support cage comprising two spaced apart uprights between which are placed at least two superimposed working rolls rotating respectively around axes placed substantially in a clamping plane perpendicular to the direction of travel of the product, and limiting a gap for the passage of the product, and a means for clamping the cylinders bearing on the fixed cage, each cylinder being carried by a shaft having two ends mounted rotary, by means of bearings, respectively on two chocks threaded in two windows provided respectively in the two uprights of the cage and mounted sliding along fixed guide faces, parallel to the clamping plane P and formed on both sides of each window, games being left on either side of each chock to allow the assembly and disassembly of e each cylinder with its chocks, each chock being associated with lateral thrust means against said guide faces for taking up, in service, said games.

According to the invention, each chock of a working cylinder is associated with two intermediate parts interposed respectively between the two sides of the chock and the corresponding guide faces and on which are mounted means for bending the working cylinders taking support on the chocks at least in a positive direction of spacing of the chocks, the said intermediate parts being kept applied with the possibility of sliding without play, parallel to the clamping plane, respectively along the corresponding guide faces of the window, and lateral thrust means are interposed between at least one of said intermediate parts and the corresponding side of the chock so as to bear on the guide face corresponding to push the chock, on the opposite side, against the other intermediate piece and the other guide face, the latter constituting a permanent lateral holding face for positioning the axis of the cylinder with the possibility of sliding the chock with the two intermediate parts associated parallel to said lateral retaining face, under the action of the cambering means.

In a particularly advantageous manner, retaining means of adjustable thickness are interposed between at least the intermediate piece placed on the side opposite to the lateral thrust means and the side facing the chock, said retaining means defining, on each window, a virtual side for holding the chock, the position of which can be adjusted by varying the thickness of said retaining means.

The invention applies especially to a quarto type rolling mill, comprising two working rolls each associated with at least one support roll. In this case, each window of an upright is provided with two planar guide faces, parallel to the clamping plane and each extending over the entire height of the window, so as to include the chocks of all the cylinders, the latter being each associated with two intermediate parts fitted with means for holding sliding without play along said guide faces and on which are mounted lateral pushing means constituting, on one side, an application means and, on the other, a adjustable means for retaining the corresponding chock.

Preferably, the two intermediate pieces placed on either side of the chock are each associated with adjustable stroke thrust means interposed respectively between said intermediate piece and the side facing the chock , the thrust means placed on the side of the guide face against which is applied the chock being adjustable in position so as to define a virtual face for lateral support of the chock.

Thanks to such provisions, the rolling mill can be provided with means for measuring the axial thrust exerted, in one direction or the other, by one or the other of the ends of a cylinder on the corresponding amount of the cage and the respective positions of the virtual retaining faces of the two chocks are determined by adjusting the retaining means, as a function of the measurement of the axial thrust so as to determine an orientation of the axis of the cylinder capable of canceling said axial thrust measured.

In this way, it is possible to define virtual retaining faces of chocks whose positions can be adjusted to vary the position of the axis of a cylinder relative to the others, for example to remove the measured axial force or well to achieve a crossing of the axes or an offset of the plane passing through the axes of the working rolls relative to the plane passing through the axes of the support rollers.

The invention also covers many particularly advantageous constructive provisions which are the subject of the subclaims.

However, the invention will be better understood from the detailed description of several embodiments given by way of example and shown in the accompanying drawings.

Figure 1 is a schematic view in elevation of a Quarto type rolling mill.

Figure 2 is a schematic top view of the rolling mill, partially broken away.

Figure 3 is a schematic top view of a working cylinder provided with its alignment adjustment means.

Figure 4 is an elevational view of an improved rolling mill according to the invention.

Figure 5 is a detail view showing, in elevation, the chocks of two superimposed working rolls.

Figure 6 is a top view, in partial section, along the line AA, of Figure 5.

Figure 7 is a partial view, in elevation, of another embodiment.

Figures 8 and 9 are, respectively, a side view and a top view of the embodiment of Figure 7.

In Figures 1 and 2, there is shown schematically, in elevation, a rolling stand 1 comprising two spaced vertical uprights 11, 11 ', fixed on a bed base 10 or else, directly, on a foundation, and connected by a cross 10 '.

In the example shown, the rolling mill is of the Quarto type and comprises two working rolls 2, 2 ′, limiting an air gap in which the product to be laminated M passes and bearing, respectively, on the side opposite to the product M, each on a support cylinder 3, 3 '.

Each working cylinder 2 is rotatably mounted on a central shaft having two ends 21 respectively rotating in aligned bearings 22 defining the axis of rotation x'x of the cylinder.

The bearings 22 are mounted respectively in support chocks 4 which are inserted in windows 12 formed respectively in the two uprights 11 of the cage 1.

Similarly, each support cylinder 3 is rotatably mounted around its axis y'y on a shaft whose ends 31 rotate in bearings 32 mounted in chocks 5 threaded in the windows 12, the axes of all the cylinders being placed substantially in the same clamping plane P constituting a median plane of the cage.

The rolling force is exerted by clamping means 14 such as screws or jacks, mounted on the cage 1 and bearing on the chocks 5 of one of the support cylinders 3.

To allow the cylinders to be clamped, the chocks must be slidably mounted along guide faces parallel to said plane P.

As indicated above, the guide faces of the working chocks are usually formed on projecting parts, the cylinders having a smaller diameter.

In the invention, on the other hand, each window 12 of the cage is limited by two flat faces 13a, 13b which extend over the entire height of the window so as to each constitute a single guide face for the chocks of all the cylinders.

In addition, as shown, respectively on the left and on the right of FIG. 2, the chocks 4 of the working rolls and, preferably, the chocks 5 of the support cylinders are each placed between two intermediate parts 6a, 6b, respectively 60a, 60b, which are applied and held against the guide faces 13a, 13b of the window 12 with a possibility of sliding without play.

To allow the mounting and dismounting of the cylinders, a certain clearance is left between the side faces 41, 51, working chocks 4 and support 5, and, respectively, the side faces facing the intermediate pieces. 6, 60.

As shown schematically in Figure 2, this game can be canceled by pushing means 7 interposed between at least one of the intermediate parts 6b and the face opposite the chock 4 so to push it towards the guide face opposite 13a which therefore constitutes a permanent lateral holding face of the corresponding cylinder 2.

The two lateral faces 13a, 13'a placed on the same side of the plane P on the windows 12, 12 'thus define a reference plane P1 for the positioning of the axes x'x and y'y of the working rolls 2, 2 'and support 3, 3'.

On the other hand, according to another essential characteristic of the invention, the sliding mounting of the intermediate parts 6a, 6b for guiding the chocks 4 of the working rolls 2 makes it possible to place on them bending cylinders 81 of the said rolls 2 which are associated with oil supply means, the assembly constituting a hydraulic cambering block which, contrary to the usual arrangements, therefore moves with the chock along the guide faces 13a, 13b.

To allow the sliding without play of the intermediate parts 6 along the guide faces 13, it is possible to use roller or else slide systems, which will be described in more detail below, with reference to FIGS. 5 to 9.

Furthermore, it is particularly advantageous to interpose retaining means of adjustable thickness between each chock 4 and the intermediate piece 6a to which it is applied. To this end, in the embodiment shown schematically in Figure 3, hydraulic cylinders 70a, 70b are used, placed, respectively, on either side of each chock 4 and which can be adjusted in pressure and in position.

The jacks 70b, interposed between each chock 4 and the intermediate piece 6b bear on the latter and the corresponding side 13b of the window to push the chock 4 towards the opposite side 13a and therefore constitute the means of application of each chock 4 on the guide face 13a of the upright 11.

The pressure exerted by the jacks 70b is, however, adjusted so as to be only sufficient to cancel the games, but limited enough to avoid clamping the chock on the amounts of the cage and thus allow the sliding of the intermediate parts 6a, 6b under the action of the cambering means 8.

On the other side of the chock, the jacks 70a bearing on the intermediate piece 6a, can be adjusted in position so as to constitute a retaining means of adjustable thickness which makes it possible to adjust the distance between the lateral side 41 chock 4 and the guide face 13a.

In this way, the ends of the two jacks 70a facing the chock 4 define a virtual holding face of the chock, the position of which can be adjusted by varying the stroke of the jacks 70a.

Thus, while, in the case of FIG. 2, each cylinder could be applied against a reference plane P1 defined by two fixed guide faces 13a, 13'a, it is possible, in the case of FIG. 3, varying one with respect to the other, the positions of the virtual retaining faces A, A ', relative to the guide faces 13a, 13'a, of the two uprights 11, 11', and, consequently, of give the axis x'x of the cylinder 2 a determined direction which, if necessary, can be slightly angularly offset relative to the plane P2 passing through the guide faces 13a, 13'a, of the two uprights 11, 11 '.

Thanks to such arrangements, it is therefore possible, on the one hand, to position the axis of each cylinder relative to a fixed reference plane, or else to vary the orientation of the reference plane as required and , on the other hand, to permanently exert on the cylinders positive or negative bending forces, the two types of adjustment being able to be carried out simultaneously and during rolling.

In Figure 4, there is shown, in elevation, an embodiment of an improved rolling mill according to the invention, in the changing position of the working rolls.

The rolling mill is of the "Quarto" type and therefore comprises two working rolls 2, 2 ', associated with two support rollers 3, 3', whose axes are placed substantially in a vertical clamping plane P which constitutes a median plane transverse of the stand 1 of the rolling mill, this comprising two uprights 11, 11 ′, provided with windows 12, 12 ′, in which the chocks of the various cylinders are threaded.

The tightening of the cylinders is carried out by a screw or jack system 14 bearing, in the example shown, on the chocks 5 of the upper support cylinder 3, while the chocks 5 'of the lower support cylinder bear directly on the bed base 10.

Each chock 4 of a working cylinder 2 is placed between two intermediate parts 6a, 6b, and is provided with two ears 42 on which bear positive or negative cambering means of the cylinder. These cambering means consist, as usual, of small jacks housed, with their supply and evacuation pipes, in the intermediate parts 6a, 6b, which thus each constitute a hydraulic cambering block.

In the embodiment of Figures 4 and 5, each chock 4 is provided with two ears 42 which engage with play in notches 62 formed respectively in the central part of each intermediate piece 6a, 6b.

Each intermediate piece 6 is provided, on its lateral face turned towards the chock, with two pairs of jacks 70 with a horizontal axis, placed respectively above and below the notch 62 and bearing on the corresponding side face 41 of the chock 4.

The jacks 70, placed on either side of the chock, act in opposite directions and can therefore be single acting. The supply lines, which have not been shown in FIGS. 4 and 5, are formed inside the intermediate parts 6 which thus constitute mobile hydraulic blocks.

As indicated above, the horizontal thrusts exerted by the jacks 70 ensure a joining of each chock 4 with the intermediate pieces 6a, 6b, which frame it and therefore move vertically with the chock by sliding without play, along the faces guide 13a, 13b, of the window 12.

For this purpose, each intermediate piece 6 is provided, on each side, with two pairs of rollers 64 which are mounted to rotate about axes parallel to the axis of the cylinder and can roll on the guide faces 13a, 13b, formed on along the two lateral sides of the window 12 and parallel to the clamping plane P. Each intermediate piece 6 can be kept applied against the upright 11, for example by means of hooks sliding in grooves. However, it is also possible to mount on each chock auxiliary rollers 64 ′ associated, respectively, with the rollers 64 so as to frame the protruding parts 16 formed on the two sides of each guide face 13a, 13b.

The clearance (e) which is left between the lateral sides 41 of each chock and the opposite faces 61 of each piece 6 can be relatively large, so as to allow possible adjustments of the orientation of the axis x'x of the cylinder. relative to the guide faces 13.

During the maneuvers of introduction and withdrawal of a cylinder, the chocks remain threaded on the trunnions and move with the cylinder while the intermediate parts 6a, 6b, are kept applied to the guide faces 13 of the cage by the pairs of rollers 64, 64 '.

Since, during bending, the intermediate parts 6a, 6b, move vertically with the chock 4, the notches 62 simply have to be a little wider than the ears 42 of the chocks so as to simply provide the clearance necessary for the engagement of the ears 42 in the notches 62 during the positioning of the cylinder with its chocks inside the cage.

The camber cylinders are housed in bores made on the intermediate parts associated with each working chock (4, 40). The negative cambering cylinders (81, 81 ') which are supported, in a conventional manner, on the chocks 5, 50, of the corresponding support cylinders 3, 3', are thus housed in bores 63, 63 ', formed on the external side of each working chock, respectively upper 4 and lower 40, facing the corresponding bearing chock 5, 50.

The positive bending is carried out, in a known manner, by jacks 82 interposed between the two working chocks 4, 40. In the embodiment shown in Figures 4 and 5 by way of example, the positive bending cylinders 82 are housed in bores 65 formed on the internal side, facing the upper chock 4, of each intermediate piece 6 'associated with the lower working chock 40. The rod of each jack 82 is supported on a pusher 83 which is slidably mounted vertically in a bore 66 passing through the lower part of the intermediate piece 6 of the upper chock 4 and which comes to bear on the corresponding ear 42 to apply the latter against the upper side of the notch 62 under the action of the jack 82, the intermediate piece 6 being held by the negative camber jacks 81 which bear on the chock 5 of the upper support cylinder 3.

In the lower part, between the notch 62 ′ and the external side of each intermediate piece 6 ′ associated with the lower chock 40, there is slidably mounted a pusher 84 in the form of a jack, coaxial and opposite to the negative camber jack 81 ', the chambers of the two cylinders 84, 81', communicating with each other. In this way, the pressure applied to the cylinder 81 'for the negative bending determines the lifting of the pusher 84 for the application of the lug 42' against the upper side of the notch 62 'and the take-up of the play.

The two clearance take-up pushers 83, 84 are thus actuated by the positive 82 and negative bending cylinders 81, 81 '.

In the service position shown in FIG. 5, the positive 82 and negative 81, 81 ′ cambering cylinders are pressurized and push the pushers 83, 84, which apply each lug 42, 42 ′, against the upper face of the corresponding notch 62, 62 '.

In this way, all the games are caught up, each chock 4, 40, being secured to the corresponding hydraulic blocks 6, 6 '.

It should be noted that the positive 82 and negative 81, 81 ′ cambering cylinders, as well as the pushers 83, 84, placed on each side of the chock are aligned, respectively, in two directions parallel to the plane P and at equal distance from this one. In addition, all the cylinders are supplied at the same time and therefore act in opposite directions, balancing each other.

It is thus possible to carry out a positive or negative bending by simply adjusting the relative pressures applied to the positive bending cylinders 82 or negative 81, 81 ′ so as to move the chock up or down by simple adjustment of the pressure difference one way or the other.

Thanks to this arrangement and to the sliding assembly of the hydraulic blocks constituted by the parts intermediate 6, 6 ′, the positive or negative bending forces close on the cage by passing through the support chocks 5, 5 ′, the jacks 14 and the bed base 10.

When the working cylinders are put in place, the camber cylinders 81, 81 ', 82 and, consequently, the pushers 83, 84 are retracted and allow the ears 42 to slide freely in the notches 62, as is the case. shown in Figure 4.

Preferably, sections of rails 43 which extend between the two uprights of the cage and which move with the intermediate parts 6, 6 ′ are placed inside the notches 62.

When the pushers 83, 84 are lowered, the chocks 4, 40 come to rest on said rails 43, 43 'by means of rollers 44, 44' mounted to rotate at the ends of the ears 42, 42 '.

In the position for withdrawing the working cylinders, the rollers 64 ′ associated with each intermediate piece 6a, 6b come to rest on fixed wedges 67 at a level for which the rail sections 43, 43 ′ come in the extension of fixed rails 45 shown schematically in Figure 6.

In this position, it is therefore possible to mount or dismount the working cylinders 2, 2 'whose chocks 4, 4' are carried by the rollers 44, 44 'rolling on the movable rails 43, 43' aligned respectively with fixed rails.

The support cylinders can be disassembled in a similar manner, the corresponding intermediate parts 60a, 60b being supported by the jacks 15, 15 '.

Of course, in the usual case where the bending is carried out, for each chock, by two pairs of jacks, arranged respectively on either side of the chock, pairs of pushers 83 and 84 will also be used, so as to associate a pusher to each cylinder.

The chocks 5, 50, of the support cylinders 3, 3 ', can be mounted in a conventional manner in the windows 12, 12', of the cage. In this case, the invention applies only to the working rolls 2, 2 '. Since the horizontal push cylinders 70 are adjustable in position, it is possible, as we have seen, to adjust the positions of the virtual retaining faces to cancel the axial thrusts resulting from a possible angular offset of each cylinder of work in relation to its support cylinder.

But it is particularly advantageous to also apply the invention to the support cylinders 3, 3 '.

In this case, as indicated in FIG. 4, each chock 5, 50 of a support cylinder 3, 3 'is associated with two intermediate parts 60a, 60b, interposed between the lateral faces 51a, 51b, chock 5 and the guide faces 13a, 13b, of the upright 11 which extend practically over the entire height of the window 12.

The cage 1 is also provided with two pairs of jacks 15, 15 'allowing the height adjustment of the support cylinders 3, 3' while maintaining the two pairs of chocks 5, 50, respectively, against the clamping system 14 and the box spring 10.

In the example shown, the chocks 5, 50, of the two support cylinders 3, 3 ', are each associated with two intermediate pieces 60a, 60b, similar to the intermediate pieces 6a, 6b, working chocks 4 and on which the rods of the holding cylinders 15, 15 'are articulated.

In addition, the two intermediate parts 60a, 60b, surrounding each chock 5, 50, are each provided with two projecting parts 65 limiting a recess in which engages with play an ear 52 of chock 5 to allow adjustment in height of the cylinders by means of the cylinders 15, 15 ′.

On the other hand, horizontal thrust cylinders 72 are housed in said protruding parts 65 and bear on lateral faces 53 of the chock 5, on either side of the ear 52, so as to apply the 'chock 5 on one of the guide faces 13a by resting on the other face 13b, through the parts 60a, 60b.

The jacks 72 are adjustable in position and therefore make it possible to define a virtual holding face serving as a reference for the positioning, with the possibility of sliding, of the axis y'y of the support cylinder 3.

There are thus flexible and precise means for maintaining the alignment of the axis of each cylinder with respect to a reference plane and for possibly adjusting the positioning of the cylinders with respect to each other.

In particular, this positioning can be adjusted as a function of the axial force detected at the end of a cylinder. For example, if an axial force exerted by a working cylinder on one side of the cage is detected, the positioning cylinders of the chock of the cylinder placed on the same side are adjusted to move the axis in the opposite direction to the rolling and acting in the opposite direction on the corresponding support cylinder, so as to cancel the detected axial force, the directions of action being reversed, for each of the two cylinders, on the other side of the cage .

But we can also act differently on chocks, for example to move the clamping plane passing through the axes of the working cylinders relative to the plane passing through the axes of the support cylinders, to adjust the alignment of a cylinder assembly working cylinder support relative to each other or to cross the clamping planes of the two sets.

It can therefore be seen that the invention presents multiple possibilities and is not limited only to the details of the embodiment which has been described by way of simple example and to which variants could be made without departing from the protective framework defined by the claims.

In particular, the bearing supports of the intermediate parts can be replaced by simple smooth bearings with soft sliding, as shown in Figures 7, 8, 9.

As seen in Figures 8 and 9 each intermediate piece 6 comprises a sliding face 68 along the side face 13 of the upright 11, lubrication means not shown to ensure smooth sliding.

Lateral hooks 69 surround projecting parts 16 formed on either side of the guide face 13 to ensure the maintenance against the latter of the intermediate part 6.

As before, in the cylinder withdrawal position, the hooks 69 come to rest on fixed wedges 67a shown diagrammatically in FIG. 8.

Furthermore, other arrangements could be used for the positive or negative cambering of the cylinders and, for example, the bearing lugs provided on either side of each chock can, in known manner, extend above or below the hydraulic block.

In general, in fact, the invention requires only fairly minor modifications to the cage and can therefore be easily adapted to any existing type of rolling mill. In particular, the arrangements described by way of example in the case of a Quarto rolling mill can be used in a Sexto rolling mill comprising intermediate rolls interposed between each working roll and the support roll, or even in the case where each working cylinder is supported on a set of cylinders arranged on either side of the median plane.

The reference signs inserted after the technical characteristics mentioned in the claims have the sole purpose of facilitating the understanding of the latter and in no way limit their scope.

Claims (23)

Rolling mill for rolling a flat product moving in a longitudinal direction, comprising a fixed support cage (1) comprising two spaced apart uprights (11, 11 ') between which are placed at least two superimposed working rolls (2, 2') ) rotating respectively around axes placed substantially in a clamping plane (P) perpendicular to the direction of travel of the product (M), and limiting a gap for the passage of the product (M), and a means (14) for clamping the cylinders bearing on the fixed cage (1), each cylinder (2, 2 ') being carried by a shaft having two ends rotatably mounted, by means of bearings, respectively on two chocks (4, 40) threaded in two windows (12) formed respectively in the two uprights (11, 11 ') of the cage and mounted sliding along fixed guide faces (13a, 13b), parallel to the clamping plane (P) and formed on the two sides of each window (12), games being left s on either side of each chock (4) to allow the mounting and dismounting of each cylinder (2) with its chocks (4, 4 '), each chock being associated with means (7) for lateral thrust against said guide faces (13a, 13b) for taking up, in service, said clearances,
characterized in that each chock (4, 40) of a working cylinder (2, 2 ') is associated with two intermediate parts (6a, 6b) interposed respectively between the two sides of the chock (4) and the corresponding guide faces (13a, 13b) and on which are mounted means (8) for bending the working rolls bearing on the chocks (4, 40) at least in a positive direction of spacing of said chocks (4, 40 ), that said intermediate parts (6a, 6b) are kept applied with the possibility of sliding without play, parallel to the clamping plane (P), respectively along the corresponding guide faces (13a, 13b) of the window (12), and that lateral thrust means (7) are interposed between at least one of said intermediate parts (6b) and the corresponding side of the chock (4) so as to bear on the corresponding guide face (13b) to push the chock (4), on the opposite side, against the other intermediate piece (6a) and the other guide face (13a ), the latter constituting a permanent lateral holding face for positioning the axis (x'x) of the cylinder with the possibility of sliding the chock (4) with the two associated intermediate parts (6a, 6b) parallel to said lateral holding face (13a), under the action of the cambering means (8). Rolling mill according to claim 1, characterized in that retaining means (70a) of adjustable thickness are interposed between at least the intermediate piece (13a) placed on the side opposite the lateral pushing means (7) and the side (41a ) facing the chock (4), said retaining means (70a) defining, on each window (12), a virtual face (AA ') for lateral support of the chock (4), the position can be adjusted by varying the thickness of said retaining means (70a). Rolling mill according to claim 2, characterized in that the retaining means are constituted by thrust means (70) of adjustable stroke, acting in a direction perpendicular to the corresponding guide face (13) and bearing in one direction on the chock (4) and in the opposite direction on the corresponding intermediate piece (6). Rolling mill according to claim 3, characterized in that the two intermediate parts (6a, 6b) placed on either side of the chock (4) are each associated with thrust means (70a, 70b) adjustable stroke interposed respectively between said intermediate piece (6a, 6b) and the side facing (41a, 41b) of the chock (4), the pushing means (70a) placed on the side of the guide face (13a) against which is applied the chock (4) being adjustable in position so as to define a virtual face for lateral support of the chock (4). Rolling mill according to one of claims 2 to 4, characterized in that it comprises means for measuring the axial thrust exerted, in one direction or the other, by one or the other of the ends of a cylinder on the corresponding upright (11) of the cage (1) and that the respective positions of the virtual retaining faces of the two chocks are determined by adjusting the retaining means (70a), according to the measurement of the axial thrust of so as to determine an orientation of the axis (x'x) of the cylinder (2) capable of canceling said measured axial thrust. Rolling mill according to one of the preceding claims, comprising two working rolls (2, 2 ') each associated with at least one support roll (3, 3'), characterized in that each window (12) of a upright (11) is provided with two flat guide faces (13a, 13b), parallel to the clamping plane (P) and each extending over the entire height of the window (12), so as to include the chocks (4 , 40) (5, 50) of all the cylinders (2, 2 ') (3, 3') the latter each being associated with two intermediate parts (6a, 6b) (60a, 60b) equipped with sliding retaining means without clearance (64) along said guide faces (13a, 13b) and on which are mounted lateral thrust means (70) constituting, on one side, an application means (70b) and, on the other, an adjustable means for retaining (70a) the corresponding chock (4, 40) (5, 50). Rolling mill according to claim 6, characterized in that the two guide faces (13a, 13'a) against which the two chocks (4, 4 ') (5, 5') of each cylinder (2, 3) are placed on the same side of the clamping plane (P) and define a fixed reference plane (P1) for positioning the axis (x 'x, y'y) of the cylinder (2, 3). Rolling mill according to one of the preceding claims, characterized in that the slide-free holding means of each intermediate piece (6, 60) comprise at least two rollers (64) bearing on the corresponding guide face (13) , placed on two levels spaced apart in height and rotatably mounted around axes parallel to the axis of the cylinder (2, 3), said support rollers (64) being associated with holding rollers (64 ') rolling on opposite faces of projecting parts (16) formed respectively on the two sides of each guide face (13). Rolling mill according to one of claims 1 to 8, characterized in that the sliding holding means of each intermediate piece (6, 60) consist of a slide (9) comprising at least one face (91) of sliding support formed on the side of the intermediate piece (6, 60) facing the corresponding guide face (13) and associated with means for forming a lubricating film, said intermediate piece (6, 60) being provided with two pieces forming hook (92) surrounding two projecting parts (16) formed respectively on the two sides of each guide face (13) for holding the intermediate piece (6, 60). Rolling mill according to one of the preceding claims, characterized in that each chock (4, 5) of a cylinder (2, 3) is provided, on its two sides, respectively, with two lateral ears (42, 52) s '' engaging with clearance in notches (62, 53) formed, respectively, on the two intermediate parts (6, 60) associated with the chock (4, 5) so as to allow the disassembly of the cylinder (2, 3) with these chocks (4, 5), the guide pieces (6, 60) remaining secured to the cage (1). Rolling mill according to claim 10, characterized in that the two intermediate pieces (6a, 6b) framing each chock (4) of a working cylinder (2) are provided with removable means for securing said intermediate piece with the ear (42) corresponding chock (4) by taking up the clearance of the notch (62). Rolling mill according to claim 11, characterized in that the clearance take-up means are pushers (83, 84) mounted to slide, respectively, in the intermediate pieces (6, 6 ') associated, respectively, with the chocks (4, 40 ) of the two working cylinders (2, 2 ') and actuated, in service, by the cambering means (8) in the direction of application of the corresponding lug (42) of each chock against the opposite side of the corresponding notch (62). Rolling mill according to claim 12, characterized in that the intermediate parts (6, 6 ') associated, respectively with the chocks (4, 40) of the two working rolls (2, 2') carry cylinders (81) of negative camber bearing, in one direction on the intermediate piece (6, 6 ') and in the other on the chocks (5, 50) of the corresponding support cylinder so as to determine the approximation of chocks (4, 40) of two working cylinders (2, 2 '). Rolling mill according to claim 13, characterized in that the positive cambering means consist of jacks (82) housed in the intermediate parts (6 ') associated with the chocks (40) of a first working cylinder (2') and bearing, in the positive direction of spacing of chocks (4, 40), on a pusher (83) slidably mounted in the chock opposite (4) of the second working cylinder (2) and taking pressing itself on the corresponding ear (42), and the intermediate parts (6'a, 6'b) associated with each chock (40) of the first working cylinder (2 ') are provided with pushers (84) actuated by the negative camber cylinders (81') of said chock (40 ) and bearing on the ears (42 ') of the latter for catching the clearance of the notch (62'). Rolling mill according to claim 14, characterized in that the positive (82) and negative (81, 81 ') camber cylinders are actuated simultaneously and that, after taking up the clearances in the notches (62, 53), the effect of positive or negative cambering is determined, in service, by adjusting the supply pressure difference between the positive cambering cylinders (82) and the negative cambering cylinders (81, 81 '), the intermediate parts (6, 6') associated with the chocks (4, 40) of the working rollers (2, 2 ') sliding freely and the intermediate pieces (60, 60') associated with the chocks (5, 50) of the support cylinders (3.3 ') taking support on the cage so that the bending efforts close on it. Rolling mill according to claim 15, characterized in that the positive camber cylinders (82), the two pushers (83, 84) and the negative camber cylinders (81, 81 ') placed on each side of the clamping plane (P ) are aligned, respectively, along two axes symmetrical with respect to said clamping plane (P). Method for rolling a flat product moving in a longitudinal direction, in a rolling mill comprising a fixed support cage (1) comprising two spaced apart uprights (11, 11 ') between which are placed at least two superimposed working rolls (2, 2 ') respectively rotating around axes placed substantially in a clamping plane (P) perpendicular to the direction of travel of the product (M), and limiting a gap for passage of the product (M), and a means (14) for tightening of the cylinders resting on the fixed cage (1), each cylinder (2, 2 ') being carried by a shaft having two ends rotatably mounted, by means of bearings, respectively on two chocks (4, 40) threaded in two windows (12) formed respectively in the two uprights (11 , 1l ') of the cage and mounted sliding along fixed guide faces (13a, 13b), parallel to the clamping plane (P) and provided on both sides of each window (12), clearances being left aside and other of each chock (4) to allow the mounting and dismounting of the corresponding cylinder (2) with its chocks (4, 4 '), each chock being associated with means (7) for lateral thrust against said faces of guide (13a, 13b) for taking up, in service, said games,
characterized in that at least the chocks of each working cylinder (2) are associated with intermediate pieces (6) interposed between the sides of the chock (4) and the guide faces (13a, 13b), that said lateral thrust means (7) bear on at least one of said intermediate pieces (6b) to push the chock towards the other intermediate piece (6a) and the corresponding guide face (13a), and that said pieces intermediate (6a, 6b) are secured vertically with the chock (4) and are held with the possibility of sliding without play along said guide faces (13a, 13b) so as to move vertically with the chock (4) under the effect of a cambering effort from the cylinder (2). Laminating method according to claim 17, characterized in that there is interposed between the side of the chock (4) placed on the side opposite to the lateral thrust force and the corresponding intermediate piece (6a) of the retaining means (70), the thickness of which is adjusted so as to define a virtual lateral support face for positioning the axis of the cylinder (2). Laminating method according to claim 18, characterized in that the axial force exerted by a cylinder is measured on one side of the cage and that the positioning of the axis of the cylinder is acted upon by adjusting the means retainer (70) so as to cancel the detected axial force. Laminating method according to claim 18, in a rolling mill comprising two working rolls (2, 2 ') each bearing on at least one support roll (3, 3'), characterized in that the l 'axial force exerted by each working cylinder on one or the other amount of the stand of the rolling mill and that one acts on the relative positions of the axes of each working cylinder (2) and the support cylinder ( 3) corresponding in a way making it possible to cancel the axial force detected. Method according to claim 18, in a rolling mill comprising two working rolls (2, 2 ') each associated with at least one support roll (3, 3'), characterized in that the retaining means are adjusted (70) chocks of at least one of the cylinders so as to determine a crossing of the axis of a working cylinder (2) relative to the axis of the corresponding support cylinder (3). Method according to claim 18, in a rolling mill comprising two working rolls (2, 2 ') each associated with at least one support roll (3, 3'), characterized in that the retaining means are adjusted (70) chocks of at least one of the cylinders so as to modify the angular position of the assembly formed by a working cylinder (2) and the corresponding support cylinder or cylinders (3), with respect to the assembly formed by the other working cylinder (2 ') and the corresponding support cylinder (s) (3'). Method according to claim 18, in a rolling mill comprising two working rolls (2, 2 ') each associated with at least one support cylinder (3, 3 '), characterized in that the retaining means (70) of the chocks of at least one of the cylinders are adjusted so as to modify the position of the clamping plane passing through the axes of the two working cylinders (2, 2 ') relative to the plane passing through the axes of the support cylinders (3, 3').

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