Patent Grant
11654464
This application is the U.S. national phase of International Application No. PCT/FR2019/050483 filed Mar. 4, 2019 which designated the U.S. and claims priority to French Patent Application No. 18 51885 filed Mar. 5, 2018, the entire contents of each of which are hereby incorporated by reference.
The invention relates to a rolling method adapted to a mill for rolling a strip, as well as to a rolling mill as such.
The field of the invention is that of the cold rolling of a metal strip, and more particularly that of rolling mills with a laterally supported sexto cage, and in particular rolling mills known by the term “Z High”.
These rolling mills find their application, in a line, for example in annealing and pickling lines or, off-line, as reversible rolling mills, for metal strips.
A quarto-cage rolling mill comprises a holding cage in which four rolls with parallel axes are provided, namely respectively two working rolls, top and bottom, defining the gap through which the strip to be rolled passes, and two support rollers, top and bottom, bearing respectively on the working rolls on the side opposite to that of the passage gap in order to transmit the rolling force.
A sexto rolling mill comprises two additional rolls compared with a quarto, namely two intermediate rolls interposed respectively between each working roll and the corresponding bearing roller, on either side of the metal strip: the clamping force of each bearing roller is transmitted to the working roll, only through the intermediate roll, the latter having a generatrix in contact with a generatrix of the bearing roller and a diametrically opposed generatrix in contact with a generatrix of the working roll.
In such rolling mills, each bearing roller and each intermediate roll is mounted rotatably at the ends thereof on chocks, by means of bearings, for example rolling bearings or hydrostatic bearings. These chocks are supports that can be moved in a vertical direction parallel to the clamping plane, along and between the two uprights of the cage.
Conventionally, balancing jacks allow movement of the chocks of the intermediate rolls. These balancing jacks make it possible to change the relative position of the chocks and of the roll thereof, making it possible among other things to open the cage in order to facilitate engagement of the product to be rolled, or to move these elements in order to facilitate removal of the rolls. These balancing jacks can also make it possible to camber the intermediate rolls.
One advantage of a sexto-cage rolling mill is the possibility of using, compared with a quarto cage, working rolls with a smaller diameter, which makes it possible to obtain a greater reduction in thickness of the product to be rolled, for the same rolling force.
A sexto rolling mill moreover offers the possibility of axially offsetting the two intermediate rolls, for the purpose of applying the rolling force only over the width of the strip to be rolled rather than over the entire length of the working rolls.
In a sexto rolling mill referred to as “laterally supported”, very often the working rolls are not mounted on chocks, but on the other hand provided floating. It is then necessary to maintain the axial position thereof by means of axial stops, but also to maintain the lateral position thereof by means of lateral support members, such as lateral support wheels or rollers disposed on either side of the clamping plane.
There is known, for example, from the document EP 0 121 811, in particular from the embodiment in FIG. 2, such a sexto rolling mill that comprises two working rolls, two support rollers and two intermediate rolls, interposed respectively between one of the working rolls and the corresponding bearing roller. In this document, the working rolls, the intermediate rolls and the support rollers are all mounted on chocks.
Each working roll is supported laterally, on either side of the working roll, by two pairs of rollers. The rollers of the same pair are provided at the two ends of each working roll, at the ends of the roll that are not in contact with the strip to be rolled. The rollers are mounted in a pivot on forks able to move in translation with respect to the upright of the cage, under the action of hydraulic jacks.
In
Another design of rolling mill, of the laterally supported sexto type, is also known from the document U.S. Pat. No. 4,531,394. Such a rolling mill still comprises two working rolls, two support rollers and two intermediate rolls, interposed respectively between one of the working rolls and the corresponding bearing roller. In this document, the support rollers and the intermediate rolls are mounted at the ends thereof on chocks, while the working rolls are provided floating. Each working roll is supported laterally, on each side of the working roll, by a side support roller, itself bearing on two rows of rollers disposed over the length of the roll.
In this design of rolling mill, for each working roll, the two corresponding side support rollers are secured to the two chocks of said intermediate roll. Each side support roller, as well as the support rollers thereof, are mounted on a support arm that extends between the two chocks of the intermediate roll, each support arm being mounted so as to pivot about a shaft, the ends of which are secured to the chocks.
The assembly consisting of intermediate roll, intermediate-roll chocks, support arms (right and left), rollers and side support rollers, right and left, form a self-supporting assembly, normally referred to as a “cassette” or “insert”, which can be introduced into the cage, or removed from the cage, during maintenance, by sliding the assembly in the direction of the rolls, in the open position of the cage.
Four force-distribution beams extend rigidly between the two uprights of the cage, respectively, facing each support arm. Each force-distribution beam supports a so-called preloading beam, able to move in translation with respect to the corresponding force-distribution beam, movable towards the inside of the cage in a substantially horizontal direction. Preloading jacks make it possible to force the movable beam in contact with the pivoting support arm in order to preload the side support roller on the working roll.
In such a rolling mill, the cooling and lubrication of the working roll and of the intermediate roll are effected by means of nozzles, marked respectively 73 and 72 in FIG. 2 of the document U.S. Pat. No. 4,531,394, physically at a distance from the working roll, situated outside the “insert” or the “cassette”. In FIG. 2, these nozzles are secured to the force-distribution beam, or to the movable preloading beam. So that the jet can reach the intermediate roll, the nozzles referenced 72 are opposite bores passing through the support arms. In practice, and to the knowledge of the inventors, this solution of spraying the support arms by means of bores does not appear to be adopted in rolling mills used industrially.
According to the observations of the inventors, the spray nozzles referenced 73 are incapable of correctly cooling the working roll since they are situated too far away therefrom, the jets thereof coming to interfere too quickly with the lateral support arms and lateral support wheels and rollers and are therefore incapable of following the travel of the strip. Moreover, according to the observations of the inventors, the nozzles referenced 72 are incapable of correctly lubricating the contact between the working roll and the intermediate roll since they are situated too far away therefrom. In use, such rolling mills with insert have a limited service life for the working roll, because of the poor cooling thereof.
Another design of a laterally supported sexto rolling mill, with “insert” or “cassette”, is also known from the document U.S. Pat. No. 6,041,636. As in the previous document, the assembly consisting of intermediate roll, intermediate-roll chocks, support arms (right and left), and lateral rollers and support rollers, right and left, forms a self-supporting assembly that can be introduced into the cage or removed from the cage during maintenance, by sliding of the assembly in the direction of the rolls.
In this document U.S. Pat. No. 6,041,636, the chocks of the intermediate rolls are mounted on Maes blocks. The jacks of the Maes blocks make it possible, in operation, to bring together the intermediate rolls, in a working position illustrated in FIG. 5 of this document, or to separate the intermediate rolls to a position, illustrated in FIG. 4, allowing removal of the inserts by sliding. These jacks can also make it possible, in operation, to camber the intermediate roll.
In this document, supplying lubricant to the bearings of the rollers of the arms supporting the insert, from a source of lubricant, is known. Connection/disconnection devices make it possible, in the working position of the rolls, to connect the source of lubricant to lubrication bores provided in the chocks, and to automatically disconnect the bores when the intermediate rolls and the chocks thereof are moved away vertically by the Maes blocks. This automatic connection/disconnection is advantageous. No additional operation for connecting/disconnecting the source of lubricant is necessary during maintenance, in particular when the inserts must be removed or introduced into the cage. For this purpose, each connection device comprises an element, referenced 57, called a “plunger”, which is hollow, intended to conduct lubricant, and which makes it possible, in the working position of the intermediate rolls, as illustrated in FIG. 9, to join the bore of the chock in a relatively fluid-tight manner by means of a seal. This element is movable, vertically in translation, constrained towards its sealing position by means of a spring, referenced 58. In the connection position, the lubricant flows from the source of lubricant through the movable element as far as the bore of the insert. The lubricant next flows from the bore of the chock, as far as the bearings, by means of the hollow of the shaft, referenced 17, on which the support arm is pivotably mounted.
When the intermediate rolls are moved away by the Maes blocks as far as the retracted position thereof, the travel of the movable element is limited, less than the movement travel of the Maes blocks, thus guaranteeing an interspace between the movable elements and the chock, as illustrated in FIG. 8 of the document U.S. Pat. No. 6,041,636. It is then possible to remove the insert, without friction between the chocks and the movable element.
Such a connection/disconnection device allows lubrication of the bearings of the support arms. However, this document does not deal with the problem of cooling of the working rolls. To the knowledge of the inventors, and according to this design, the cooling of the intermediate and working rolls and the lubrication of the contact between intermediate roll and working roll is still effected by providing nozzles physically at a distance from the rolls.
However, from the document EP 1 721 685, a rolling mill of the laterally sexto type is known, improving the cooling of a working roll. This document proposes to improve the rolling mills of the prior art with “cassettes”, for which there would be no space for placing the cooling nozzles as close as possible to the rolls.
The rolling mill is now a unidirectional (non-reversible) rolling mill that comprises, upstream, in the direction of travel of the strip, a side support roller, as previously described, supported by a support arm. Downstream, the support arm has no bearing roller or roller. This bearing roller is replaced by a pad called a “support pad”, which may be made from bronze or a self-lubricating graphite material, intended to slide on the surface of the working roll, without exerting any substantial force thereon.
This support arm with pad incorporates a plurality of nozzles for a cooling liquid that make it possible to directly cool the working roll, on the downstream side. Downstream, the lubricant liquid is supplied to the nozzles by means of the hollow shaft of the corresponding support arm. Upstream, the hollow shaft of the support arm is used to convey the lubricant to the bearings of the rollers supporting the side support roller. This document thus teaches how to improve the cooling of the working rolls. However, this improvement is done to the detriment of the supporting of the working roll on one of the sides thereof, by eliminating a side support roller and replacing it with a pad, the rolling mill then no longer being a reversible rolling mill.
A method and device for cooling a rolling mill is also known from the document EP 2 391 459. This document is concerned more particularly with the cooling of the working rolls each supported laterally by a pair of rolls, and comprising at least one pair of support rollers for transmitting a rolling force. This document sets out in particular to be an improvement to the document EP 1 721 685 previously described, a solution that would remain prohibited for reversible rolling mills.
According to this document, a direct spraying of at least part of the working rolls is provided, on either side of said plane perpendicular to the direction of travel of the strip. According to this document, the nozzles are positioned on the supports of the side support rollers, in order to directly cool the working roll on both sides, laterally on either side of the clamping plane.
However, the document described in this document EP 2 391 459 is not a “cassette” technology as taught by the documents U.S. Pat. Nos. 4,531,394, 6,041,636, EP 1,721,685, for which the assembly consisting of intermediate roll, chocks of the intermediate roll, support arm (right and left) and lateral rollers and support rollers, right and left, form a self-supporting assembly, referred to as an “insert” that can be introduced into the cage or removed from the cage during maintenance, by sliding of the assembly in the direction of the rolls.
The real difficulty in improving the cooling of the working rolls in a cassette-type rolling mill is not placing the cooling nozzles in the cassette, but knowing how to supply them with lubrication/cooling fluid, and without increasing the maintenance time during operations of removal or insertion of the cassette in the cage of the rolling mill For example, it is not possible to use hoses between the cassette and the cage of the rolling mill to supply the nozzles since these would require being removed and replaced during operations of removing or introducing the cassette, which would considerably extend the time necessary for these maintenance operations.
As previously described, the document U.S. Pat. No. 6,041,636 discloses automatic connection devices making it possible, in the working position of the rolls, to connect the source of lubricant to lubrication bores provided in the chocks, and to automatically disconnect the bores when the intermediate rolls are moved away vertically by the Maes blocks. However, such a device can be used only for supplying lubricant, either solely to the bearings of the rollers of the side support roller of a support arm, or solely for supplying fluid to the nozzles of a support arm. This is the reason why the support arm of the nozzles has no side support roller in the document EP 1 721 685, this being replaced by a pad that does not require a bearing to be lubricated. Moreover, the connection device of this prior art is connected to the chocks, which makes it necessary to convey the fluid on a complex path by means of the hollow shaft and as far as the bottom end of the support arm. This complex path of the fluid, from the chock to the support arm, by means of the hollow shaft, gives rise to significant pressure drops, limiting the flows.
In summary, and according to the aforementioned prior art, in the aforementioned reversible rolling mills of the laterally supported sexto type, with cassettes, the cooling of the working rolls and intermediate rolls is carried out by means of nozzles placed outside the cassette, physically at a distance from the working rolls and the intermediate rolls, and the jets of which cannot directly reach the working rolls. In this type of rolling mill used industrially, it is conventional to place a spray manifold on each side of the clamping plane installed on the force-distribution beam of the cage and the jets of which are directed at the contact between the bearing roller and the intermediate roll.
According to this arrangement, the lubrication of the working roll is therefore obtained, indirectly, by the fact that the intermediate roll has been wetted and this roll transports this lubrication when it rotates by a half turn, to the working roll. According to the observations of the inventors, this lubrication is insufficient, in particular for the rolls placed under the strip.
Furthermore, and when the speed of the rolling mill becomes high, the centrifugal force at the circumference of the intermediate roll tends to dry the roll so that little cooling fluid reaches the working roll.
However, from the document WO 2015/011373 of the present applicant, a rolling mill of the supported sexto type is known, with cassette technology, which provides appreciable progress for the cooling of the working rolls, and compared with the aforementioned prior art, in particular of a rolling-mill cage with cassette.
It is a laterally supported sexto rolling mill that includes:
Each support arm of a side support roller is mounted pivotally on said shaft, consisting of a shaft secured to the chocks of one of the intermediate rolls, each intermediate roll, chocks of the intermediate roll, side support rollers and corresponding support arms forming a self-supporting assembly, referred to as an insert (or “cassette”), which can be removed or introduced by sliding through the access window during maintenance, in the open position of the cage.
The hollow of the shaft may optionally serve, as in the prior art (see U.S. Pat. No. 6,041,636) to channel a fluid intended to lubricate the bearings of the rollers (referenced 52 in FIG. 1) laterally supporting the side support roller. According to the document WO 2015/011373, at least one of the nozzles is installed on one of the support arms, in particular to allow lubrication/cooling of the working rolls and/or of the intermediate rolls.
Advantageously, the circuit supplying fluid to said at least one nozzle comprises a connection/disconnection device referenced 13, having:
According to the document WO 2015/011373, this hollow part is configured to make a sealed connection with the supply opening on the bearing surface in a first connection position, or on the contrary to retract into a second disconnection position, at a distance from the bearing surface.
In the first connection position, as illustrated in FIG. 2 of the document WO 2015/011373, the cooling fluid can be channelled from the source as far as said at least one nozzle referenced 12 (illustrated) or as far as said at least one nozzle referenced 12′ (not illustrated), by means of said connection/disconnection device.
In the second disconnection position, the means for applying a preloading force are withdrawn, in a retracted position, said hollow part being at a distance from the support arm.
This position makes it possible, in particular when the design of the rolling mill is of the type with insert (or with a cassette), to be able to withdraw or introduce the insert, without requiring any additional maintenance time for connecting/disconnecting the fluid source.
Another advantage of such a connection/disconnection device is that it is directly connected to the support arm, rather than to the chocks of the intermediate roll as taught in the prior art known from the document U.S. Pat. No. 6,041,636. To arrive as far as the nozzle or in a rolling mill of the type with insert WO 2015/011373, the fluid does not need to pass through the hollow shaft on which the support arm is pivotally mounted. It is then possible to substantially limit the pressure drops, and thus to obtain fluid flows much superior to those obtained in this prior art, and thus to substantially improve the cooling of the working rolls by placing the cooling nozzles as close as possible to the side support roller.
A rolling-mill cage of the laterally supported sexto type, with working rolls and intermediate rolls, is also known from the document WO 2011/107165. The rolling-mill cage comprises, according to the example in FIG. 5 of the side support rollers, and more particularly for each working roll, a first side support roller and a second side support roller, situated on either side of the clamping plane. Each side support roller is held by two rows of support rollers, the support rollers and the side support roller being carried by an arm mounted so as to pivot about a guide member referenced 72 in FIG. 5.
Remarkably, and in this document WO 2011/107165, the support rollers and their support arms are mounted so as to pivot on the Maes block, able to support a chock of the intermediate roll, a Maes block that is able to move vertically with respect to the upright of the cage. During maintenance, it becomes possible to extract the intermediate roll axially, by sliding its chocks with respect to the Maes blocks, and then for the side support roller to remain fixed in the cage, still connected to the Maes block by means of the support arms.
The invention relates more particularly, at least according to one embodiment, to the problem of cooling the working rolls, when each working roll is held laterally, by two rolls of a pair of side support rollers, disposed on either side of the clamping plane, by a direct spraying of the working roll, and as taught by the document EP 291 459 A1.
Remarkably, however, the invention relates to the solving of this problem in the case where the two rows of support rollers holding each side support roller are mounted pivotably by means of a support arm, whether this support arm be articulated on a pivot axis on the chocks of the intermediate roll as taught by the document WO 2015/011373, or on the Maes block able to support the chock of the intermediate roll, installed on the Maes block, as taught by the document WO 2011/107165.
Each side support roller SSR is itself held by two rows of support rollers G belonging to a bearing support, fixed to one of the ends of an arm Bs, the other end being articulated about a shaft fixed at the ends thereof to the two chocks of the intermediate roll.
At the time of design, the position of the articulation axis between the support arm and the two chocks of the intermediate roll is chosen so that, when the diameter of the working roll WR and the diameter of the intermediate roll IR are at a maximum, there is not any mechanical interference between the side support roller SSR and the intermediate roll IR (see
It will also be noted from
During operation, the surface state of the working roll and the surface state of the intermediate roll deteriorate. Periodically, and as is known, planing of the working roll is carried out, and less frequently planing of the intermediate roll, in order to restore their surface state. These operations involve a reduction in diameter of the planed rolls.
The reduction in diameter of the working roll being thus more rapid than that of the intermediate roll, the inventors observed that the mechanism for supporting and positioning the side support rollers (with a pivot position fixed with respect to the rotation axis of the intermediate roll, and a fixed arm length) has drawbacks for some configurations of diameters of the intermediate roll and of the working roll: thus there are observed risks of interferences between the intermediate roll and the side support roller (or the bearing support thereof), or a risk of obstruction of the passage opening for the jets spraying and lubricating the contact between intermediate roll and working roll, or the jets for lubricating the rolling area.
Thus, and in
Likewise, in
The aim of the present invention is to overcome the aforementioned drawbacks by proposing a rolling method adapted to a mill for rolling a strip making it possible to avoid the aforementioned mechanical interferences between the metal strip and the assembly consisting of side support roller and bearing support, or the mechanical interferences between the assembly consisting of side support roller and bearing support and the intermediate roll, when said bearing support is mounted pivotably on an articulation axis, parallel to the support roll, whether the bearing support be articulated on a pivot axis at the chocks of the intermediate roll as taught for example by the document WO 2015/011373, or on the Maes block able to support the chock of the intermediate roll as taught by the document WO 2011/107165.
More particularly the aim of the present invention is to propose such a method for avoiding the aforementioned interferences throughout the operation of the rolling mill, and whatever the possible configurations of the diameters of the working roll and of the intermediate roll that are caused respectively to reduce the diameter, from a maximum diameter to a minimum diameter.
Another aim of the invention is to propose, at least according to one embodiment, such a method that provides optimum cooling of the contact between intermediate roll and working roll and/or of the rolling area between the working roll and the strip, throughout the operation of the rolling mill, and whatever the possible configurations of the diameters of the working roll and of the intermediate roll.
Another aim of the present invention is to propose a rolling mill as such, suitable for implementing the method.
Other aims and advantages will emerge during the aforementioned description, which is given only by way of indication and which does not aim to limit it.
Thus the invention relates first of all to a rolling method adapted to a mill for rolling a strip, comprising:
and in which method the dimensions of a first interspace defined between the side support roller and the support roll and a second interspace defined between the strip and the assembly consisting of side support roller and bearing support vary during rolling because of the reductions in diameters of the support roll and working roll caused by wear and planing of the rolls.
According to the invention, said method comprises a readjustment step for which the dimension of said first interspace and of the second interspace is adjusted by carrying out an adjustment of the dimension separating the axis of said support roll and the axis of said side support roller defining, with the support roll, said first interspace.
According to optional features of the invention, taken alone or in combination:
The invention also relates to a mill for rolling a strip including at least one cage, comprising:
wherein the mill comprises, during the rolling of the metal strip, a first interspace defined between the side support roller and the support roll and a second interspace defined between the strip and the assembly consisting of side support roller and bearing support liable to vary during rolling because of the reductions in diameters of the support roll and of the working roll caused by wear or planing of the rolls.
According to the invention, said mill comprises an adjustment device configured to adjust the dimension of said first interspace and the dimension of the second interspace using an adjustment of the dimension separating the axis of said support roll and the axis of said side support roller defining, with the support roll, said first interspace.
According to optional features of the invention taken alone or in combination:
The invention will be understood better from a reading of the description accompanied by the appended figures, depicting the invention, among which:
Thus the invention relates to a rolling method adapted to a strip rolling mill comprising the following steps:
The rolling mill may be a rolling cage comprising the two working rolls, the two support rollers and the two support rolls, each support roll being intermediate between said bearing roller and said working roll, namely a rolling-mill cage of the laterally supported sexto type.
According to a possibility illustrated in accordance with
According to another possibility illustrated in
When the rolling method is implemented, the dimensions of a first interspace It1 defined between the side support roller SSR and the support roll SR and of a second interspace It2 defined between the strip ST and the assembly consisting of side support roller SSR and bearing support BS vary during rolling because of the reductions in diameters of the support roll and of the working roll.
The reductions in diameter are caused by wear and planing of the rolls. Periodically, and in a known manner, the working rolls and the support rolls are removed from the cage: planing of the working roll is carried out, and less frequently planing of the intermediate roll, in order to restore the surface state thereof.
The inventors observe that the mechanism supporting and positioning the side support rollers with a pivot position fixed with respect to the axis of rotation of the intermediate roll, and a fixed arm length (as in particular taught by the document WO 2011/107165 or WO 2015/011373) have drawbacks for some configurations of diameters of the intermediate roll and of the working roll: thus risks of interferences between the intermediate roll and the side support roller are observed, or a risk of obstruction of the passage opening for the jets spraying and lubricating the contact between intermediate roll and working roll, or obstruction of the jets for lubricating the rolling area.
Thus, and in
Likewise in
The invention advantageously makes it possible to avoid such mechanical interferences by using a readjustment step for which the dimension of said first interspace It1 and of the second interspace It2 is adjusted by implementing an adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR defining, with the support roll, said first interspace It1.
This readjustment step can advantageously be implemented when there is an interruption of the rolling, for example simultaneously with an interruption of rolling for planing of the working roll and/or of the support roll.
This readjustment step consists in adjusting the dimension separating the axis of said support roll SR and the axis of said side support roller SSR so that the dimension of the first interspace It1 is at least equal to a lower limit Δmin1 and the dimension of the second space It2 is at least equal to a lower limit Δmin2, whatever the configurations, namely as long as:
This lower limit Δmin1 and this lower limit Δmin2, which may be equal or distinct, may be greater than or equal to 5 mm.
These
On either side of the clamping plane, each side support roller SSR is held by two rows of rollers G of a bearing support BS mounted pivotally via an arm AR on the articulation axis A1 on an axis support formed by the chocks of the support roll SR. The support roll SR with its chocks, the arms AR, the bearing supports BS and the pair of side support rollers form a self-supporting assembly that can be removed when the cage is opened, in a way known per se from the prior art.
According to this embodiment, said bearing support BS is fixedly mounted removably on an arm AR, with an adjustable position on the arm, said arm AR itself being articulated on said articulation axis A1, parallel to said support roll, providing the pivoting of said bearing support about said articulation axis A1.
Remarkably, and according to this embodiment, said adjustment of the dimension separating the axis of said support roll SR and the axis of said side support roller SSR implemented during the readjustment step is performed by a step of modification of the position of said bearing support BS on the arm AR.
More particularly, provision can be made for a removable fixing means between said bearing support BS and said arm AR comprising a groove/key positive-location system 1, said key and a groove carried respectively by said bearing support BS and said arm AR, or vice versa.
As can be seen in
The adjustment of the dimension separating the axis of said support roll and the axis of said side support roller implemented during the readjustment step is carried out by a step of turning over said bearing support BS on the arm.
This readjustment step carried out by turning over said bearing support BS on the arm AR is illustrated by way of example in
The two configurations illustrated respectively in
The passage from the first position P1 of the bearing support to the second position P2 of the bearing support is obtained by simple turning of said bearing support BS through 180° on the arm, when rolling is interrupted.
This turning over effects a modification of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR defining, with the support roll, said first interspace It1, and in this case a reduction in the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR (from
A readjustment (a modification) of the dimension of said first interspace It1 and of the second interspace It2 is then observed:
It will be noted that, at this nominal diameter of the support roll SR (here in this case equal to 342.5 mm) and whereas the working roll is at minimum diameter (here in this case 120 mm), the most critical case in terms of risks of mechanical interference, it is possible to proceed with the readjustment step, keeping, before (
It will be noted that this change to be made by turning over the bearing support when the support roll is at its nominal diameter (342.5 mm) but the working roll is at its maximum diameter (140 mm) does not pose any difficulty in that the first interspace It1 and the second interspace It2 have values that are even more comfortable in terms of risks of mechanical interference, and as can be seen in
As can be understood from
The problems of mechanical interferences and obstruction of jets identified in
Thus and in general terms and according to an advantageous embodiment, the diameter of the support roll SR being between a maximum diameter and a minimum diameter, a method in which a nominal diameter is defined, less than the maximum diameter and greater than the minimum diameter and wherein:
It will be noted that the invention also makes it possible to considerably reduce the risks of mechanical interference between the strip and the assembly consisting of bearing support and side support roller on the one hand, or between the assembly consisting of bearing support and side support roller and the support roll on the other hand.
As can be seen in
Advantageously, the rolling mill may thus have at least spray nozzles SN1, SN2 allowing cooling by spraying of at least one jet of fluid on at least part of the strip ST and at least part of said rolls and in which method a cooling step is implemented, comprising at least one direct spraying of at least part of the working rolls WR, on either side of said plane perpendicular to the travel direction of the strip, said nozzles SN1, SN2 being configured to:
For each working roll, a direct spraying can thus be implemented on either side of the clamping plane. The nozzles SN1 and SN2 may be carried by the arm A.R. and/or the bearing support B.S.
Other technical solutions can be envisaged without departing from the scope of the invention, and still with the objective of modifying (adjusting) the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR.
According to another embodiment, said bearing support BS being fixedly mounted on an arm AR itself articulated on said articulation axis A1 parallel to said support roll providing the pivoting of said bearing support about said articulation axis A1, and in said adjustment of the dimension separating the axis of said support roll and the axis of said side support roller implemented during the step of readjustment is performed by a step of adjusting the position of said articulation axis A1 on the support arm AR.
For example, an eccentric Ex1 may be provided between the articulation axis A1 and said arm AR, and wherein the adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR implemented during the readjustment step is performed by a step of rotation of said eccentric Ex1.
Such an embodiment is illustrated in
According to another embodiment, said articulation axis A1 around which the bearing support BS is mounted is supported and mounted on said axis support AS and in which method said adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR implemented during the readjustment step is performed by a step of modifying the position of said articulation axis A1 on said axis support AS.
For example, said step of modifying the position of said articulation axis on said axis support AS is obtained by adding or removing shims between the axis support and said articulation axis (example not illustrated), or said step of modifying the position of said articulation axis on said axis support is obtained by rotating an eccentric Ex2 provided between said articulation axis A1 and said axis support AS.
This latter embodiment with eccentric Ex2 is illustrated in
Again, and according to a fourth possible embodiment, said support roll SR is supported at the ends thereof by chocks Ep, and in which method said adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR implemented during the readjustment step is performed by a step of modifying the position of the axis ASR of said support roll with respect to the Maes blocks MB intended for cambering the support roll.
For example, and according to the embodiment illustrated in
It should also be noted that the chocks Ep are asymmetric, in that they make it possible to obtain two positions of mounting the support roll, with offset of the axis ASR of the support roll depending on whether the chock is mounted in a first mounting direction in the Maes block, or in the second mounting direction, obtained by turning over the chock Ep.
According to this embodiment, the adjustment during the readjustment step is obtained by turning over the block through 180°.
The invention also relates to a mill for rolling a strip ST suitable for implementing the method. Said rolling mill includes at least one cage comprising:
Such a mill comprises, during the rolling of the metal strip, a first interspace It1 defined between the side support roller SSR and the support roll S and a second interspace It2 defined between the strip ST and the assembly consisting of side support roller SSR and bearing support BS liable to vary during rolling because of reductions in diameters of the support roll and of the working roll caused by wear or planing of the cylinders.
According to the invention, said mill comprises an adjustment device configured to adjust the dimension of said first interspace It1 and of the dimension of the second interspace It2 by implementing an adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR defining, with the support roll, said first interspace It1.
The mill may comprise a device configured for cooling by spraying at least one jet of fluid on at least one part of the strip and at least one part of said rollers, comprising at least one nozzle system with nozzles SN1, SN2 configured to:
According to one embodiment, the adjustment device comprises said bearing support BS that is fixedly mounted removably on an arm AR, with an adjustable position on the arm, said arm itself being articulated on said articulation axis parallel to the support roll SR providing the pivoting of said bearing support BS about said articulation axis. The adjustment device is configured so that the adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR is performed by modifying the position of said bearing support BS on the arm AR.
For example, and according to the example in
According to another embodiment illustrated by way of indication in
Said adjustment device may comprise an eccentric Ex1 provided between the articulation axis A1 and said arm AR, said adjustment device being configured so that said adjustment of the dimension separating the axis ASR of said support roll SR and the axis ASSR of said side support roller SSR is performed by a step of rotating said eccentric Ex1.
According to another embodiment illustrated by way of indication in
The adjustment device may then comprise shims, said adjustment device being configured so that the modification of the position of said articulation axis on said axis support is obtained by adding or removing shims between the axis support and said articulation axis.
Alternatively, said adjustment device comprises the eccentric Ex2 provided between said articulation axis and said axis support AS: said adjustment device is configured so that modification of the position of said articulation axis A1 on said axis support AS is obtained by rotating the eccentric Ex2.
| Number | Date | Country | Kind |
|---|---|---|---|
| 18 51885 | Mar 2018 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2019/050483 | 3/4/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/170994 | 9/12/2019 | WO | A |
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| 20120324973 | Charre | Dec 2012 | A1 |
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| Entry |
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| International Search Report for PCT/FR2019/050483 dated Jun. 11, 2019, 5 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20200406323 A1 | Dec 2020 | US |
