Four-roller or six-roller cold rolling mill

Abstract

The utility model relates to a four-roll or six-roll cold rolling mill (1) configured to roll a metal strip,-a roll stand (2) comprising a first pair of uprights on the front side and a second pair of uprights on the rear side,-an upper working roll (WRS) comprising a roll table configured to be in contact with the upper surface of the metal strip and two guide ends,-a lower working roll (WRI) comprising a first pair of uprights on the front side and a second pair of uprights on the rear side, the utility model relates to a metal strip roller comprising a roller table configured to be in contact with a lower surface of a metal strip and two guide ends. A first left and right pushing mechanism (31g, 31d) and a second left and right pushing mechanism comprising all or part of the rotating screw pushing means to ensure lateral displacement between the working rolls and the roll bearings on the working rolls.

Description

[0001] The present disclosure relates to a 4- or 6-high rolling mill comprising a side shift adjustment system configured to implement a side shift between, on the one hand, the axis of the lower work roll (or the upper work roll) and, on the other hand, the axis of the roll chock of the work roll, as seen in the rolling direction. TECHNICAL FIELD

[0002] The present disclosure relates to the field of cold rolling, in particular to a six-high (6-high) or four-high (4-high) rolling mill in which the work rolls are driven by electric motors, in particular to such a reversing mill, i.e. a mill configured to roll a strip while alternating the running direction of the strip in the mill. BACKGROUND

[0003] A 4-high rolling mill comprises, as shown in figure (a) of Figure 10

[0004] - two work rolls, distributed below and above the metal strip, the upper work roll being supported according to the width of the strip according to the upper contact line of the strip, and the lower work roll being supported according to the width of the strip according to the lower contact line of the strip,

[0005] - two support rolls, comprising an upper support roll which rests against the upper work roll on the side opposite the strip via a contact line, and a lower support roll which rests against the lower work roll on the side opposite the strip via a contact line.

[0006] A 6-high rolling mill comprises, as shown in figure (b) of Figure 10

[0007] - two work rolls, distributed below and above the metal strip, the upper work roll being supported according to the width of the strip according to the upper contact line of the strip, and the lower work roll being supported according to the width of the strip according to the lower contact line of the strip,

[0008] - two support rolls, comprising an upper support roll and a lower support roll;

[0009] - two intermediate rolls, comprising an upper intermediate roll which is in contact with the upper support roll via a first contact line and with the upper work roll via a second contact line, and a lower intermediate roll which is in contact with the lower support roll via a first contact line and with the lower work roll via a second contact line.

[0010] In both cases, whether the mill is a 4-high rolling mill or a 6-high rolling mill, a hydraulic clamping unit exerts a clamping force between the upper support roll and the lower support roll, tending to approach the axis of rotation of the two support rolls, in order to transmit the clamping force to the work rolls, either directly between each support roll and each work roll in the case of a 4-high rolling mill, or via the intermediate rolls in the case of a 6-high rolling mill.

[0011] ​​The so-called 6-high rolling mill, i.e. the so-called laterally supported rolling mill, as shown in figure (c), i.e. the rolling mill comprises two backup rolls, two intermediate rolls, two work rolls and, for each work roll, two laterally supporting rolls on the right and on the left side of each work roll, which support the two sides of the rolling mill via contact lines. In this six-high rolling mill with six laterally supporting rolls, the work rolls are usually floating and not directly driven, the motor drives directly drive the intermediate rolls.

[0012] It is also known a 20-high rolling mill, as shown in figure (d) of the prior art, comprising an upper group and a lower group of one on each side of the strip. Figure 10

[0013] The upper group and the lower group each comprise:

[0014] - a work roll, which comes into contact with the strip to be rolled;

[0015] - two first intermediate rolls, which come into contact with the work roll via two support lines;

[0016] - three second intermediate rolls, which come into contact with the two first intermediate rolls via four support lines;

[0017] - four groups of backup rolls, which come into contact with the second intermediate rolls via six support lines.

[0018] In this 20-high rolling mill, the work rolls are not directly driven to rotate, but only via the second intermediate rolls.

[0019] The present disclosure only covers a 4-high rolling mill according to figure (a) or a 6-high rolling mill according to figure (b), i.e. a rolling mill without lateral support of the work rolls.

[0020] In this 4-high or 6-high rolling mill, each work roll is pivotably mounted in a pad at its guide end, each work roll being a body made of machined metal, comprising a roll work table, usually cylindrical, but also comprising two extended guide ends, which have a smaller diameter than the diameter of the roll work table. The guide ends comprise a first guide end, which is configured to be pivotably mounted in a first bearing seat, usually via a bearing, such as a roller bearing, and a second guide end, which is configured to be pivotably mounted in a second bearing seat, usually via a bearing, such as a roller bearing.

[0021] Such a rolling mill comprises a stand, which comprises an entry window, defined between two front uprights of the stand, and on the opposite side of the stand, defined between two rear uprights of the stand.

[0022] During a maintenance operation, such as the replacement of a roll, for example a work roll, the roll can be extracted axially through the entry window. The motor drives for driving the work rolls are implemented on the other side, i.e. on the side of the two rear uprights of the stand.

[0023] ​In such a rolling mill:

[0024] - the first chock, located at one end of the (lower or upper) work roll, can be guided vertically between the two front uprights of the stand, but the position of the chock along the strip direction is blocked by a support on the two front uprights,

[0025] - the second chock, located at the other end of the (lower or upper) work roll, can be guided vertically between the two rear uprights of the stand, but the position of the chock along the strip direction is blocked by a support on the two rear uprights.

[0026] In such a 4-high or 6-high rolling mill, the work rolls are driven by motors and preferably directly by the motors with counter-rotating torques to the two lower work rolls and to the upper work rolls, respectively, to assist the rolling action. For a 6-high rolling mill, it is preferable to drive the work rolls directly by motors, instead of driving the intermediate rolls by motors.

[0027] An indirect motor drive can cause slippage between the rolls, which is the source of the deterioration of the surface condition of the roll table, which can be avoided by driving the work rolls directly by motors.

[0028] In such a 4-high or 6-high rolling mill, during the rolling process, vertical forces are exerted on the work rolls to ensure the reduction of the thickness of the strip by the work rolls, which are also subjected to horizontal forces.

[0029] As shown in Figure 9 , four main horizontal forces are mainly exerted on the work rolls:

[0030] - the horizontal component of the clamping force,

[0031] - the tension difference of the strip,

[0032] - the rolling force due to the torque transmitted to the work rolls, which should be considered only when the work rolls are driven directly by motor drives,

[0033] - the horizontal component of the force exerted by the chocks on the guiding ends of the work rolls.

[0034] The vertical and horizontal forces unbalance the work rolls and cause the work rolls to bend. Under the action of the vertical component of the force on each work roll, the work roll bends according to the vertical component, and under the action of the horizontal component of the force, the work roll bends according to the horizontal component.

[0035] The rolling mill can generally comprise an opening / closing mechanism comprising a left side cylinder system located at the front and rear of the stand, which is interposed between the left side upright in the front (or rear) upright and the two chocks of the lower work roll and the upper work roll, at the left side, the mechanism comprises a right side cylinder system interposed between the other right side upright and the two chocks of the right side.

[0036] Each (right or left) cylinder system can be removably connected to the two chocks of the lower and upper rolls. Typically, cylinders deployed according to the vertical direction allow spacing the chocks of the upper and lower rolls in order to open the mill. These cylinders can also be actuated to vertically constrain the guide ends of the work rolls in order to vertically balance the work rolls and thus reduce the vertical component of the bending.

[0037] For 4-high or 6-high mills without lateral support, the motor torque resulting from the direct drive of the work rolls generally causes the work rolls to bend in a horizontal plane when the ends of the work rolls are blocked by the chocks, with the deflection between the two ends of the work rolls being maximized. The direction of the deflection is opposite to the running direction of the strip, i.e. the horizontal component of the bending extends upstream of the strip in the running direction.

[0038] In 4-high or 6-high mills, it is known to reduce the horizontal component of the bending by offsetting the axis of the work rolls according to the running direction of the strip (hereinafter referred to as the rolling direction), so as to balance the horizontal component exerted on the work rolls. As shown in Figure 9 the axis of the work rolls is offset in the same direction as the running direction of the strip with respect to the roll chocks on the work rolls.

[0039] For reversible mills, it is also known to reverse the direction of the offset change during rolling in the event of reversal of the running direction of the strip.

[0040] A first type of system for laterally offsetting the chocks of the work rolls is known from the prior art, which comprises horizontal hydraulic cylinders which press the chocks of the work rolls against a reference surface, i.e. the offset induced by the actuation of the hydraulic cylinders is generally all or nothing.

[0041] For example, documents JP 2790741 or WO 2323 / 073998 disclose such prior art. This offset system allows to properly balance the work rolls when the work rolls are not too small to avoid excessive horizontal deflection.

[0042] A second type of displacement system is also known in the prior art, which is based on the use of linear tilting wedges comprising a first tilting wedge inserted between the left side of the chock and the left side upright, and a second tilting wedge inserted between the right side of the chock and the right side upright, on both sides of the stand.

[0043] Each wedge extends in length parallel to the longitudinal axis of the work rolls and is configured to slide along a first surface over a wear plate of the upright and along a support pad which is supported on the second inclined surface of the wedge on the one hand and on a vertical guide plate on the other hand for vertical guiding of the vertical cylinder system for opening the stand.

[0044] Such a regulation system allows to regulate the lateral displacement of the bearing block by synchronizing the movement of the first wedge and of the second wedge, i.e. when the first wedge is longitudinally moved in a direction tending to space the bearing block from the left upright, the second wedge is longitudinally moved in the opposite direction to allow the bearing block to approach the right upright.

[0045] Such prior art, for example disclosed by document US 4.736.609, has the advantage of allowing a large regulation progression. When the ratio between the work roll diameter and the strip width becomes small, typically less than 0.23, the regulation system with inclined wedges is precise enough to properly balance the forces acting on the work roll and avoid excessive horizontal deflection, which is not allowed by prior art based on horizontal cylinders.

[0046] According to the inventor's observation, this inclined wedge system comprises a considerable volume for each linear wedge, which extends longitudinally not only according to the length of the inclined wedge, but also according to the length of the actuation cylinder, which cantilevers outside the stand in the transverse direction of the rolling mill, on both sides of the stand, in the front and in the rear of the stand.

[0047] This regulation system with inclined wedges considerably increases the volume of the rolling mill, beyond the limits of the stand, particularly on the sides of the mill where the maintenance window is, disadvantageously for the maintenance operations.

[0048] Another drawback of this inclined wedge system found by the inventor is that, during operation, its inclined guide surfaces get dirty with rolling impurities, in particular rolling oil, and rolling metal particles, thus requiring regular maintenance.

[0049] The present disclosure improves this situation. Utility model content

[0050] The present disclosure aims to improve this situation completely or partially.

[0051] A 4-high or 6-high cold rolling mill is provided, configured to roll a metal strip:

[0052] - a mill stand comprising a first pair of uprights on the front side and a second pair of uprights on the rear side,

[0053] - an upper work roll comprising a roll table configured to be in contact with the upper surface of the metal strip and two guide ends,

[0054] - a lower work roll comprising a roll table configured to be in contact with the lower surface of the metal strip and two guide ends,

[0055] - an upper backup roll configured to transmit the clamping force directly to the upper work roll according to a contact line between the upper work roll and the upper backup roll, or indirectly to the upper work roll via the upper intermediate roll through a first bearing line between the upper backup roll and the upper intermediate roll and a second bearing line between the upper intermediate roll and the upper work roll,

[0056] - a lower backup roll configured to transmit the clamping force directly to the lower work roll according to a contact line between the lower work roll and the lower backup roll, or indirectly to the lower work roll via the lower intermediate roll through a first bearing line between the lower backup roll and the lower intermediate roll and a second bearing line between the lower intermediate roll and the lower work roll,

[0057] - two upper chocks arranged at the two guide ends of the upper work roll, comprising: a first upper chock between the two columns of the first pair of columns, and a second upper chock between the two columns of the second pair of columns,

[0058] - two lower chocks arranged at the two guide ends of the lower work roll, comprising: a first lower chock between the two columns of the first pair of columns, and a second lower chock between the two columns of the second pair of columns,

[0059] - a system for adjusting the side shift configured to implement a side shift between, according to the rolling direction, on the one hand the axis of the lower work roll or the upper work roll, and on the other hand the axis of the roll bearing on the work roll, the work roll consisting of the lower intermediate roll or the upper intermediate roll when the rolling mill is a 6-high rolling mill, the work roll consisting of the lower backup roll or the upper backup roll when the rolling mill is a 4-high rolling mill,

[0060] and wherein the adjusting system comprises:

[0061] - a first left side push mechanism, on the one hand between the left column of the first pair of columns and the first upper chock and first lower chock assembly, and on the other hand configured to exert a pushing force on the first upper chock and first lower chock assembly to move said first upper chock and first lower chock assembly in a first way according to the rolling direction,

[0062] - a first right side push mechanism, on the one hand between the other right column of the first pair of columns and the first upper chock and first lower chock assembly, and on the other hand configured to exert a pushing force on the first upper chock and first lower chock assembly to move said first upper chock and first lower chock assembly in a second way according to the rolling direction,

[0063] - a second left pushing mechanism, which is located between the left column of the second pair of columns and the second upper bearing block and second lower bearing block assembly on the one hand, and which is configured to exert a pushing force on the second upper bearing block and second lower bearing block assembly to move said second upper bearing block and second lower bearing block assembly in a first manner according to the rolling direction, on the other hand,

[0064] - a second right pushing mechanism, which is located between the other right column of the second pair of columns and the second upper bearing block and second lower bearing block assembly on the one hand, and which is configured to exert a pushing force on the second upper bearing block and second lower bearing block assembly to move said second upper bearing block and second lower bearing block assembly in a second manner according to said rolling direction, on the other hand.

[0065] According to the present disclosure, the first left and right pushing mechanisms and the second left and right pushing mechanisms comprise a complete or partial rotary screw pushing device, each rotary screw device comprising a first part supported on one column of the first pair of columns or on one column of the second pair of columns, and a second part configured to laterally push the first lower bearing block and first upper bearing block (E1I, E1S) or respectively the second lower bearing block and second upper bearing block, and wherein the first part and the second part of each rotary screw pushing device are configured to pivot relative to each other about a rotation axis under the action of an actuator, the first part and the second part comprising screw guide surfaces arranged about said rotation axis, which support each other, configured to cause, upon relative rotation between the first part and the second part, a spacing of the second part relative to the first part in the direction of the rotation axis.

[0066] The features outlined in the following paragraphs can optionally be implemented independently of each other or in combination with each other:

[0067] According to one embodiment, the screw guide surfaces can comprise:

[0068] - cam surfaces of the first part and the second part, which consist of a first cam and a second cam, or,

[0069] - an internal thread and an external thread which engage together between the first part and the second part respectively.

[0070] According to one embodiment:

[0071] - the first part is a first cam comprising a first screw guide surface extending about said rotation axis on a first angular portion of the first cam and a second guide surface extending on a second angular portion of the first cam,

[0072] - the second part is a second cam comprising a third helical guide surface extending over a first angular portion of the second cam and a fourth helical guide surface extending over a second angular portion of the second cam,

[0073] and wherein the first helical guide surface and the second helical guide surface of the first cam are configured to simultaneously cooperate with the third helical guide surface and the fourth helical guide surface of the second cam for guiding.

[0074] According to one embodiment, the first part and the second part are enclosed in a casing protecting the helical guide surfaces from the outside environment, in particular the casing comprising a cylindrical wall whose axis is coaxial with the rotation axis of the rotating helical pushing device.

[0075] According to one embodiment, the actuators of the rotating helical pushing devices consist of pneumatic cylinders extending longitudinally according to the height of the column.

[0076] According to one embodiment, all or part of the pneumatic cylinders are articulated to said second part via a first end of the cylinder and to one of the columns via a second end via a pivoting axis, in particular parallel to the rotation axis of said rotating helical pushing device.

[0077] According to one embodiment, the helical guide surfaces of each rotating helical pushing device are arranged to overlap in a transverse direction the width of one of the columns supported by the rotating helical device, the diameter D of the helical guide surface being contained in the transverse direction along the width of the column.

[0078] According to one embodiment, the second part has an extension or a lever arm extending radially outwards to said second part around the rotation axis beyond the diameter of the helical guide surface, said extension or lever arm protruding in the transverse direction from the column, the pneumatic cylinders being articulated on said extension or on the lever arm via a first end of the hydraulic cylinder.

[0079] According to one embodiment:

[0080] - the first left pushing mechanism and the first right pushing mechanism each comprise a pair of first and second parts extending in height, which overlap the height of the first upper bearing block and the first lower bearing block assembly,

[0081] - the second left pushing mechanism and the second right pushing mechanism each comprise a pair of first and second parts extending in height, which overlap the height of the second upper bearing block and the second lower bearing block assembly.

[0082] According to one embodiment, the rolling mill comprises:

[0083] - a first left side opening / closing mechanism with a vertical cylinder comprising an upper part laterally connected to a left side first upper bearing block, and a lower part laterally connected to a left side first lower bearing block, and a hydraulic cylinder configured to separate or bring together the first lower bearing block and the first upper bearing block, the first left side pushing mechanism being interposed between the left side upright column and said first left side opening / closing mechanism,

[0084] - a first right side opening / closing mechanism with a vertical cylinder comprising an upper part laterally connected to a right side first upper bearing block, and a lower part laterally connected to a right side first lower bearing block, and a hydraulic cylinder configured to separate or bring together the first lower bearing block and the first upper bearing block, the first right side pushing mechanism being interposed between the right side upright column and said first right side opening / closing mechanism,

[0085] - a second left side opening / closing mechanism with a vertical cylinder comprising an upper part laterally connected to a left side second upper bearing block, and a lower part laterally connected to a left side second lower bearing block, and a hydraulic cylinder configured to separate or bring together the first bearing blocks, the second left side pushing mechanism being interposed between the left side upright column and said second left side opening / closing mechanism,

[0086] - a second right side opening / closing mechanism with a vertical cylinder comprising an upper part laterally connected to a left side second upper bearing block, and a lower part laterally connected to a left side second lower bearing block, and a hydraulic cylinder configured to separate or bring together the first bearing blocks, the second left side pushing mechanism being interposed between the left side upright column and said first right side opening / closing mechanism.

[0087] According to one embodiment, the upper work rolls and the lower work rolls comprise a transmission shaft connected to the motor drive for directly driving the work rolls in rotation.

[0088] According to a second aspect, the disclosure enables a method of rolling a metal strip implemented by a rolling mill according to the disclosure, comprising:

[0089] - / A / rolling a metal strip by running between two upper work rolls and lower work rolls pressed on the strip by the hydraulic clamping action between the two lower support rolls and the upper support rolls, and transmitting the motor torque to the upper work rolls and the lower work rolls,

[0090] - / B / balancing the upper work rolls, the lower work rolls,

[0091] - an upper side shift between the axis of the upper work rolls and the axis of the roll bearings on the work rolls,

[0092] - a lower side shift between the axis of the lower work roll and the axis of the roll bearing on said work roll,

[0093] and wherein the upper side shift and the lower side shift are obtained by real-time progressive control of the angular position of the first part with respect to the second part of each rotary screw pusher to ensure the lateral pushing of the lower work roll and the upper work roll and of the lower first bearing chock and the upper first bearing chock and of the lower second bearing chock and the upper second bearing chock with gap compensation. BRIEF DESCRIPTION OF DRAWINGS

[0094] Other features, details and advantages will appear obvious after reading the detailed description below and analyzing the drawings, in which:

[0095] Figure 1

[0096] [ Figure 1 ] shows a perspective view of a 6-roller rolling mill.

[0097] Figure 2

[0098] [ Figure 2 ] is a cross-sectional view of the rolling mill in Figure 1 along a vertical plane passing through the axis of the support rolls.

[0099] Figure 3

[0100] [ Figure 3 ] is a front view of the rolling mill showing the bearing chocks of the rolls, including the bearing chocks of the upper work rolls and of the lower work rolls, and the system for adjusting the side shift, configured to implement the side shift between, on the one hand, the axis of the work rolls and the axis of the roll bearings on said work rolls, the work rolls consisting of intermediate rolls, and on the other hand, comprising, on the left side, a first left side pushing mechanism interposed between the left side upright and the first upper bearing chock and the first lower bearing chock, and, on the right side, a first right side pushing mechanism interposed between the right side upright and the first upper bearing chock and the first lower bearing chock, the first pushing mechanism and the second pushing mechanism comprising a screw pusher with gap compensation, the screw pusher comprising a first part and a second part, the first part and the second part being rotatably hinged with respect to each other and being actuated in rotation with respect to each other by a pneumatic cylinder actuator, the cylinder being extended according to the height of the left side upright and of the right side upright on the elevation.

[0101] Figure 4

[0102] [ Figure 4is a rear view of the rolling mill, on the motor driver side of the work rolls, showing the system for adjusting the side shift of this side, which comprises a second left pusher mechanism between the left upright and the second upper and lower chocks, and a second right pusher mechanism between the right upright and the second upper and lower chocks, the first and second pusher mechanisms comprising a screw pusher with gap compensation, the pusher comprising a first part and a second part, the first part and the second part being hingedly rotatable by a pneumatic cylinder actuator, the cylinder extending according to the height of the uprights at the rear of the stand.

[0103] Figure 5

[0104] [ Figure 5 ] is a sectional view along a vertical plane through the axis of rotation, the right and left screw pushers being respectively between the first upper and lower chocks of the work rolls and the left and right uprights.

[0105] Figure 6

[0106] [ Figure 6 ] is a sectional view along a horizontal plane through the axis of rotation, the right and left screw pushers being respectively between the first upper and lower chocks of the work rolls and the left and right uprights.

[0107] Figure 7A

[0108] [ Figure 7A ] is a view of a screw pusher (without protective cover) comprising a first part formed by a first cam and a second part formed by a cam, the first and second parts being rotatably hinged to each other, cooperating with each other by means of a helical guide surface.

[0109] Figure 7B

[0110] [ Figure 7B ] is a detailed view of the second cam, comprising a helical guide surface, and a radially extending portion forming a lever arm configured to be connected to an actuator.

[0111] Figure 7C

[0112] [ Figure 7C ] is a detailed view of the first cam.

[0113] Figure 7D

[0114] [ Figure 7D ] is a detailed view of an internal guide member between the first and second cams.

[0115] Figure 7E

[0116] [ Figure 7E ] is a detailed view of the inner guiding member between the first cam and the second cam.

[0117] Figure 8

[0118] [ Figure 8 ] is a detailed view showing the arrangement of the actuator of the screw pusher, which is formed by a substantially vertical cylinder, which extends along the column carried by the cam, one end of which is articulated on the radial extension of the second cam and the other end is articulated on the column.

[0119] Figure 9

[0120] [ Figure 9 ] shows:

[0121] - the forces occurring during the rolling process, which are exerted on the work rolls, receive the motor torque when the work rolls are guided and fixed at their two ends by bearing chocks,

[0122] - a lateral displacement between the (rotational) axis of the work roll and the (rotational) axis of the roll bearing on the work roll occurs from the running direction of the strip, in the same way as the running of the strip, the work roll is balanced by limiting the bending of the work roll in the horizontal plane.

[0123] Figure 10

[0124] [ Figure 10 ] shows schematically different roll configurations, in particular:

[0125] - (a) a 4-high rolling mill configuration, which comprises motor-driven work rolls,

[0126] - (b) a 6-high rolling mill configuration, which comprises motor-driven work rolls,

[0127] - (c) a so-called laterally supported 6-high rolling mill configuration, which comprises work rolls laterally fixed by lateral support rolls and motor-driven intermediate rolls,

[0128] - (d) a 20-high rolling mill configuration. DETAILED DESCRIPTION

[0129] The present disclosure relates to a cold rolling mill 1 for rolling a metal strip, in particular a 4-high rolling mill as shown in figure (a) of Figure 10 or a 6-high rolling mill as shown in figure (b) of Figure 10 .

[0130] More specifically, the present disclosure relates to rolling mills in which the work rolls are driven (directly) by motor drives.

[0131] The rolling mill 1 comprises:

[0132] - a rolling mill stand 2 comprising a first pair of columns M1, M2 at the front side and a second pair of columns M3, M4 at the rear side,

[0133] - an upper work roll WRS comprising a roll working surface configured to be in contact with an upper surface of the metal strip and two guide ends,

[0134] - a lower work roll WRI comprising a roll working surface configured to be in contact with a lower surface of the metal strip and two guide ends,

[0135] - an upper backup roll WAS configured to transmit the clamping force directly to the upper work roll WRS according to a contact line between the upper work roll and the upper backup roll in case the rolling mill is a 4-high rolling mill, or indirectly via an upper intermediate roll WIS by a first bearing line between the upper backup roll WAS and the upper intermediate roll WIS and a second bearing line between the upper intermediate roll WIS and the upper work roll WRS in case the rolling mill is a 6-high rolling mill,

[0136] - a lower backup roll WAI configured to transmit the clamping force directly to the lower work roll WRI according to a contact line between the lower work roll and the lower backup roll, or indirectly via a lower intermediate roll WII by a first bearing line between the lower backup roll WAS and the lower intermediate roll WII and a second bearing line between the lower intermediate roll WII and the lower work roll WRI,

[0137] - two upper chocks arranged at the two guide ends of the upper work roll WRS, comprising a first upper chock E1S interposed between the two columns M1, M2 of the first pair of columns and a second upper chock E2S interposed between the two columns M3, M4 of the second pair of columns,

[0138] - two lower chocks arranged at the two guide ends of the lower work roll, comprising a first lower chock E1I interposed between the two columns M1, M2 of the first pair of columns and a second lower chock E2I interposed between the two columns M3, M4 of the second pair of columns.

[0139] In general:

[0140] - the upper support roll WAS comprises a roll stand which, in the case of a 4-high rolling mill, is supported on the roll stand of the upper work roll WRS or, in the case of a 6-high rolling mill, is supported on the roll stand of the upper intermediate roll WIS. The roll stand of the upper support roll WAS extends with guide ends which are rotatably guided in two upper chocks EAS. The two upper chocks EAS are each received and vertically guided between the two uprights M1, M2 of the first pair of uprights on the front side of the stand and between the two uprights M3, M4 of the second pair of uprights on the rear side of the stand,

[0141] - the lower support roll WAI comprises a roll stand which, in the case of a 4-high rolling mill, is supported on the roll stand of the upper work roll WRI or, in the case of a 6-high rolling mill, is supported on the roll stand of the lower intermediate roll WII. The roll stand of the lower support roll WAI extends with guide ends which are rotatably guided in two lower chocks EAI. The two lower chocks EAS are each received and vertically guided between the two uprights M1, M2 of the first pair of uprights on the front side and between the two uprights M3, M4 of the second pair of uprights.

[0142] Generally, the rolling mill comprises clamping hydraulic devices configured to transmit the rolling force (or clamping force) by approaching the support rolls, in particular hydraulic units configured to press on the chocks of the support rolls. Two hydraulic units PT can be arranged in the upper part of the stand, between the first pair of uprights M1, M2 and the second pair of uprights M3, M4, respectively, to press on the two upper chocks EAS of the upper support roll WAS, as shown in the figures. Alternatively, the hydraulic units can be arranged in the lower part of the stand to act on the lower chocks EAI of the lower support roll WAI, according to another embodiment (not shown).

[0143] Generally, the 4-high (or 6-high) rolling mill can comprise a system for adjusting the rolling line, configured to adjust the height of the rolling line.

[0144] Generally, with reference to Figure 1 , and in the present disclosure, the reference systems X, Y and Z are defined as:

[0145] - the so-called longitudinal direction X, according to the direction of travel DL of the strip B between the work rolls, is generally horizontal,

[0146] - the so-called transverse direction Y, which extends perpendicularly according to the width direction of the metal strip,

[0147] - the direction Z, which is the vertical direction of the stand uprights.

[0148] In the case of the present disclosure, the support rolls, the work rolls and possibly the intermediate rolls are oriented substantially parallel to the transverse direction Y.

[0149] As shown in Figure 1 or Figure 2 and according to one embodiment, such a system for adjusting the rolling line is arranged in the lower part of the stand to cooperate with the lower bearing seat EAI of the lower backup roll WAI when the hydraulic unit engages with the upper bearing seat EAS of the upper backup roll WAS.

[0150] The system for adjusting the rolling line comprises one or more straight tilting wedges configured to act on the two bearing seats EAI of the lower backup roll and to change the vertical position of the bearing seats when the tilting wedges are moved by actuators. In the case where the hydraulic unit is in the bottom position of cooperation with the lower bearing seat of the backup roll, the system for adjusting the rolling line comprising the tilting wedges is arranged in the upper part of the stand to cooperate with the upper bearing seat EAS of the upper backup roll.

[0151] Generally, in the case of a 6-high rolling mill, each of the lower and upper intermediate rolls WII and WIS comprises a work roll of smaller diameter extended by a guide end. The guide end is rotatably mounted in an upper bearing seat EIS for the upper intermediate roll and in a lower bearing seat EII for the lower intermediate roll.

[0152] The bearing seat EII or EIS of each intermediate roll WII or WIS is arranged vertically between the uprights of the stand to transmit the clamping force.

[0153] The rolling mill can be equipped with a first device DAX1 for adjusting the axial position of the upper intermediate roll WIS comprising a first actuator configured to move the upper bearing seat EIS according to the axis of the upper intermediate roll WIS and with a second device for adjusting the axial position of the lower intermediate roll comprising a second actuator configured to move the upper bearing seat EIS according to the axis of the lower intermediate roll WII.

[0154] The first and second devices DAX1, DAX2 are configured to axially move the two intermediate rolls in opposite directions so as to be able to adjust the axial overlapping area between the two lower and upper intermediate rolls and generally to allow the adjustment of the overlapping area to the width dimension of the strip.

[0155] Generally, the rolling mill comprises an opening and closing system which can comprise:

[0156] - a first left side opening / closing mechanism 9, with a vertical cylinder comprising an upper part 90 connected laterally to a left side first upper bearing seat E1S, and a lower part 91 connected laterally to a left side first lower bearing seat E1I, and a hydraulic cylinder VR connecting the upper and lower parts 90, 91, configured to separate or bring together the first lower and upper bearing seats E1I, E1S, said first opening mechanism being interposed between the left side upright column M1 and the first upper and lower bearing seats,

[0157] - a first right side opening / closing mechanism 10, with a vertical cylinder comprising an upper part 100 connected laterally to a right side first upper bearing seat E1S, and a lower part 101 connected laterally to a right side first lower bearing seat E1I, and a hydraulic cylinder connecting the upper and lower parts 100, 101, configured to separate or bring together the first lower and upper bearing seats, said first opening mechanism being interposed between the right side upright column M2 and the first upper and lower bearing seats,

[0158] - a second left side opening / closing mechanism, with a vertical cylinder comprising an upper part connected laterally to a left side second upper bearing seat E2S, and a lower part connected laterally to a left side second lower bearing seat E2I, and a hydraulic cylinder connecting the upper and lower parts, configured to separate or bring together the first bearing seats, said first opening mechanism being interposed between the left side upright column M3 and the second upper and lower bearing seats,

[0159] - a second right side opening / closing mechanism, with a vertical cylinder comprising an upper part connected laterally to a left side second upper bearing seat E2S, and a lower part connected laterally to a left side second lower bearing seat E2I, and a hydraulic cylinder connecting the upper and lower parts, configured to separate or bring together the first bearing seats, said first opening mechanism being interposed between the left side upright column M3 and the second upper and lower bearing seats.

[0160] When opening the stand, the vertical cylinders of the first and second mechanisms can be deployed in order to separate, on the one hand, the first upper and lower bearing seats E1S, E1I, and, on the other hand, the second upper and lower bearing seats E1S, E1I, so as to space apart the upper work rolls WRS and the lower work rolls WRI in the vertical direction Z.

[0161] The vertical cylinders can also be actuated under the pressure of the hydraulic unit PT during the rolling operation, in order to balance the upper and lower work rolls, in particular in terms of vertical force.

[0162] The upper work rolls WRS and the lower work rolls WRI can generally comprise a drive shaft ARB connected to a motor driver for directly driving the lower work rolls and the upper work rolls in opposite directions. The use of a drive shaft connected to a motor driver for directly driving the work rolls ensures an efficient and constant transmission of the motor torque. This improves the accuracy and stability of the rolling, thus reducing the risk of slippage and wear.

[0163] During the rolling process, the work rolls are subjected to the action of the strip, which comprises a clamping vertical force FS.

[0164] As shown in Figure 10 the three main horizontal forces acting on the roll working stands of the work rolls comprise:

[0165] - the horizontal component of the clamping force FC of the roll bearings on the work rolls,

[0166] - half (1 / 2T) of the tension difference T between the entry strip Tf and the exit strip Tb,

[0167] - the rolling roll force CirF generated by the transmission of the motor torque to the work rolls when the work rolls are directly driven by the motor driver.

[0168] The work rolls are also subjected to the horizontal component of the force FE exerted by the chocks E1S, E1I, E2S, E2I on the guide ends of the work rolls.

[0169] When the axes of the rolls lie in the same vertical plane, the rolling roll force is generated due to the transmission of the motor torque to the work rolls, then the guide ends of the rolls are held by the chocks, the work rolls bend, thus generating a maximum amplitude of deflection between the guide ends, the deflection direction being directed with respect to the upstream side of the rolls according to the running direction of the strip.

[0170] According to the direction of the strip, the offsetting of the axes of the work rolls with respect to the axes of the roll bearings on the work rolls makes it possible to obtain a horizontal component of the rolling clamping force FC opposite to the horizontal component of the rolling force, thus making it possible to balance the work rolls and thus to reduce the horizontal component of the deflection due to the motor torque.

[0171] As shown in Figure 9 it is essential to be able to adjust the value of the offset OFS between the axis of the work rolls and the axis of the roll bearings on the work rolls (i.e. intermediate rolls or support rolls) step by step (rather than all or not), in particular during the rolling operation, and to be able to optimally control the horizontal balancing of the work rolls during the rolling operation.

[0172] The present disclosure finds a particular application for small-diameter work rolls, generally where the ratio of the diameter of the work rolls to the maximum width of the strip is less than 0.23, and which are more sensitive to bending than roll pairs with larger diameters.

[0173] To this end, the rolling mill comprises a system 3 for adjusting the side shift, configured to implement a side shift OFS, located between, according to the rolling direction DL, on the one hand the axis Awr of the lower work roll WRI or of the upper work roll WRS and, on the other hand the axis Ap of the roll bearing on the work roll.

[0174] When the rolling mill is a 6-high rolling mill, the roll bearing on the lower work roll or on the upper work roll WRI, WRS is composed of the lower intermediate roll WII or of the upper intermediate roll WIS.

[0175] When the rolling mill is a 4-high rolling mill, the roll bearing on the lower work roll or on the upper work roll WRI, WRS is composed of the lower backup roll WAI or of the upper backup roll WAS.

[0176] This system 3 for adjusting the side shift comprises:

[0177] - a first left side pushing mechanism 31g, located between the left column M1 of the first pair of columns and the first upper bearing chock E1S and first lower bearing chock E1I assembly, configured to exert a pushing force on the first upper bearing chock E1S and first lower bearing chock E1I assembly to move said first upper bearing chock E1S and first lower bearing chock E1I assembly in a first manner according to the rolling direction DL,

[0178] - a first right side pushing mechanism 31d, located between the other right column M2 of the first pair of columns and the first upper bearing chock E1S and first lower bearing chock E1I assembly on the one hand, configured to exert a pushing force on the first upper bearing chock E1S and first lower bearing chock E1I assembly to move said first upper bearing chock E1S and first lower bearing chock E1I assembly in a second manner according to the rolling direction DL,

[0179] - a second left side pushing mechanism 32g, located between the left column M3 of the second pair of columns and the second upper bearing chock E2S and second lower bearing chock E2I assembly on the one hand, configured to exert a pushing force on the second upper bearing chock E2S and second lower bearing chock E2I assembly to move said second upper bearing chock E2S and second lower bearing chock E2I assembly in a first manner according to the rolling direction DL,

[0180] - a second right side pushing mechanism 32d, located between the other right column M4 of the second pair of columns and the second upper bearing chock E2S and second lower bearing chock E2I assembly on the one hand, configured to exert a pushing force on the second upper bearing chock E2S and second lower bearing chock E2I assembly to move said second upper bearing chock E2S and second lower bearing chock E2I assembly in a second manner according to the rolling direction DL.

[0181] The adjustment system can also comprise a monitoring and control unit for synchronizing:

[0182] - the first left side pushing mechanism 31g and the second left side pushing mechanism 32g, which push the first upper bearing chock and the first lower bearing chock simultaneously on one hand and the second upper bearing chock and the second lower bearing chock simultaneously on the other hand, to move the axes of the lower work rolls and the upper work rolls in a first manner according to the rolling direction,

[0183] - the second right side pushing mechanism 31d and the second right side pushing mechanism 32d, which push the first upper bearing chock and the first lower bearing chock simultaneously on one hand and the second upper bearing chock and the second lower bearing chock simultaneously on the other hand, to move the axes of the lower work rolls and the upper work rolls in a second manner according to the rolling direction,

[0184] Generally, the first and second left side pushing mechanisms 31g, 32g are antagonistic mechanisms with the first and second right side pushing mechanisms 31d, 31d, the control units of the right side mechanisms 31g, 32g operating in an opposite manner to the left side mechanisms 31d, 32d, i.e.:

[0185] - when the left side mechanisms 31g, 32g exert a pushing force on the bearing chocks, the right side mechanisms 31d, 32d retract so as not to hinder the movement of the bearing chocks of the work rolls in the first manner,

[0186] - when the right side mechanisms 31d, 32d exert a pushing force on the bearing chocks, the left side mechanisms 31g, 32g retract so as not to hinder the movement of the bearing chocks of the work rolls in the second manner.

[0187] The monitoring and control unit synchronizes the first and second left side pushing mechanisms 31g, 32g and the first and second right side mechanisms 31d, 32d to ensure right and left gap compensation on the upper bearing chocks and the lower bearing chocks E1I, E1S, E2I, E2S.

[0188] Generally:

[0189] - the first left side pushing mechanism 31g can be interposed between the left side upright M1 and said first left side opening / closing mechanism 9,

[0190] - the first right side pushing mechanism 31d can be interposed between the right side upright M2 and said first right side opening / closing mechanism 10,

[0191] - the second left side pushing mechanism 32g can be interposed between the left side upright M3 and said second right side opening / closing mechanism,

[0192] - the second left side pushing mechanism 32d can be interposed between the left side upright M4 and said second right side opening / closing mechanism.

[0193] According to the present disclosure, and as shown in particular in the drawings of the present application, the first left and right pushing mechanisms 31g, 31d and the second left and right pushing mechanisms 32g, 32d comprise all or part of the rotating screw pushing devices 4.

[0194] In particular, the adjustment system comprises:

[0195] - a (first left) rotating screw pushing device for the first left pushing mechanism 31g,

[0196] - a (first right) rotating screw pushing device for the first right pushing mechanism 31d,

[0197] - a (second left) rotating screw pushing device for the second left pushing mechanism 32g,

[0198] - a (second right) rotating screw pushing device for the second right pushing mechanism 32d.

[0199] Each rotating screw pushing device comprises a first portion 5, which is directly or indirectly supported on one of the first pair of uprights M1, M2, or respectively on one of the second pair of uprights M3, M4, and a second portion 6, which is configured to laterally push the first lower and upper bearing seats E1I, E1S when it reaches the first (left or right) pushing mechanism, or respectively the second lower and upper bearing seats E2I, E2S when it reaches the second (left and right) pushing mechanisms.

[0200] The first portion 5 and the second portion 6 of each rotating screw pushing device are pivotably articulated with respect to each other about a rotation axis A4, which is oriented according to the rolling direction DL, i.e. according to the X direction, under the action of an actuator AT.

[0201] The first portion 5 and the second portion 6 comprise screw guide surfaces 7 about said rotation axis A4, which support each other, configured to cause, upon relative rotation between the first portion 5 and the second portion 6, a spacing of the second portion 6 with respect to the first portion 5 in the direction of the rotation axis A4.

[0202] The screw guide surfaces 7 can consist of cam surfaces of the first portion 5 and of the second portion 6, which consist of a first cam and of a second cam, respectively, and are shown according to the embodiment in the figures.

[0203] According to an embodiment not shown, the screw guide surfaces can also consist of an internal thread and an external thread engaged together between the first portion 5 and the second portion 6, the first portion 5 and the second portion 6 being screwed together. The internal thread and the external thread can be simple threads distributed between the first portion and the second portion.

[0204] The spiral guide surface may also consist of multiple threads, including multiple internal threads, which engage with multiple external threads, with the internal and external threads respectively located between the first part 5 and the second part 6.

[0205] Therefore, by controlling the angular position of the second part 6 relative to the second part 5, the distance between the second part 6 and the first part 5 can be adjusted according to the direction of the rotation axis 4, thereby applying a pushing effect by increasing the distance between the two cams 5 and 6, or conversely, decreasing the distance on the other side of the bearing seat to compensate for the gap on the other side of the pushed bearing seat.

[0206] According to this disclosure, this includes preferably progressive control, i.e., the angular position of the second portion 6 relative to the first cam can take the following different intermediate angular positions:

[0207] - The first angular position between the second part 6 and the first part 5 corresponds to the minimum distance between the second cam 6 and the first cam 5.

[0208] - The second angular position between the second part 6 and the first part 5 corresponds to the maximum distance between the second cam 6 and the first cam 5.

[0209] Therefore, the intermediate position allows for different spacings between the two parts 5 and 6, with the spacing increasing from the first angular position to the second angular position. In particular, parts 5 and 6 can achieve continuous adjustment between extreme angular positions between the first and second positions.

[0210] In particular, as shown in the embodiment of the rotating helical drive device, the helical guide surface 7 may extend along one or more helical paths around the rotation axis A4 on the first part 5 and the second part 6.

[0211] In particular, according to Figures 7A to 7C The example shown:

[0212] - The first part 5 forms a first cam, which may include a first helical guide surface 70 extending about a first corner portion of the first cam around the rotation axis A4 and a second helical guide surface 71 extending about a second corner portion of the first cam.

[0213] - The second part 6 forms a second cam, which includes a third helical guide surface 72 extending on a first corner portion of the second cam and a fourth helical guide surface 73 extending on a second corner portion of the second cam.

[0214] Typically, the first and second angular portions (the first portion being particularly of the cam and the second portion being particularly of the cam) can have the same angular range of less than or equal to 180°.

[0215] The first helical guide surface 70 and the second helical guide surface 71 of the first cam are configured to guide in cooperation with the third helical guide surface 72 and the fourth helical guide surface 73 of the second cam.

[0216] The first angular portion and the second angular portion of the first cam are respectively less than or equal to 180°. For example, according to one embodiment, the first helical guide surface 70 extending along a helical path extends over an angular portion of more than 180° around said axis of rotation, the second helical guide surface 71 extending along a helical path extends over a second angular portion of more than 180°.

[0217] The first angular portion and the second angular portion of the second cam 6 are respectively less than or equal to 180°. For example, according to one embodiment, the third helical guide surface 72 extends over an angular portion of more than 180° around said axis of rotation, the fourth helical guide surface 73 extending along a helical path extends over a second angular portion of more than 180°.

[0218] A first advantage of the rotating helical pusher device, compared to the prior art with inclined wedges described in the background, is its small volume.

[0219] In particular, the helical guide surfaces 70 of the portions 5, 6 of each rotating helical pusher device 4 can be arranged according to the transverse direction Y, overlapping the width of one of the columns M1, M2, M3, M4 supported by the rotating helical pusher device 4; the helical guide surfaces 7 of diameter D of each rotating helical pusher device can advantageously be housed according to the transverse direction Y, according to the width direction of the column.

[0220] Thus, for example in Figure 6 the rotating helical pusher device of the left pusher mechanism 31 g has a number of helical guide surfaces 7 of diameter D housed according to the width direction of the left column M1 of the first pair of columns, the rotating helical pusher device of the right pusher mechanism 31 d has a number of helical guide surfaces 7 of diameter D housed according to the width direction of the right column M2 of the first pair of columns.

[0221] Similarly, the rotating helical device of the left pusher mechanism 32g has a number of helical guide surfaces 7 of diameter D housed according to the width direction of the left column M3 of the second pair of columns, the rotating helical pusher device of the right pusher mechanism 32d has a number of helical guide surfaces 7 of diameter D housed according to the width direction of the right column M4 of the second pair of columns.

[0222] In general:

[0223] - the first left pushing mechanism 31g and the first right pushing mechanism 31d each comprise a pair of first and second portions 5, 6, in particular a pair of first and second cams, which extend in height, overlapping the height of the first upper bearing seat E1S and the first lower bearing seat E1I assembly; in particular, as shown in the left side view, the helical guide surface 7 of diameter D of the first (left or right) mechanism can extend in the Z direction, overlapping the first upper bearing seat E1S and the first lower bearing seat E1I. Figure 5

[0224] - the second left pushing mechanism 32g and the second right pushing mechanism 31d each comprise a pair of first and second portions 5, 6, in particular a pair of first and second cams, which extend in height, overlapping the height of the second upper bearing seat E2S and the second lower bearing seat E2I, in particular, as shown in the left side view, the helical guide surface 7 of diameter D of the first (left or right) mechanism can extend in the Z direction, overlapping the second upper bearing seat E2S and the second lower bearing seat E2I.

[0225] By using a pair of portions 5, 6 for each pushing mechanism, the system simplifies the design while ensuring accurate adjustment of the side shift. This improves the adjustment efficiency and reduces the mechanical complexity. This configuration allows to cover the entire height of the bearing seats, thus ensuring a uniform distribution of the applied force. This minimizes the stress on the bearing seats and improves the stability of the work rolls. By reducing the number of components required, the system reduces the maintenance needs and the risk of malfunctions, thus contributing to a more reliable and durable operation of the rolling mill.

[0226] Therefore, the adjustment system can comprise only four rotary helical pushing devices 4, respectively for the first left 31g and first right 31d, 31d pushing mechanisms and for the second left 32g and second right 32d pushing mechanisms.

[0227] According to an advantageous embodiment (shown in the figures), to limit the volume of the rolling mill in the transverse direction Y, the actuators AT of the helical pushing devices can consist of gas cylinders (typically hydraulic or electric gas cylinders) which extend longitudinally according to the height of the columns M1, M2, M3, M4. By integrating the gas cylinders along the columns, the system optimizes the space and reduces the volume, thus facilitating maintenance and improving the installation ergonomics.

[0228] The first left gas cylinder extends substantially longitudinally according to the height of the (first) left column M1, configured to control the angular position of the second portion 6 with respect to the first portion 5 of the first left pushing mechanism 31g.

[0229] The second right gas cylinder extends substantially longitudinally according to the height of the (second) right column M2, configured to control the angular position of the second portion with respect to the first portion of the first right pushing mechanism 31d.

[0230] ​The third left cylinder extends substantially longitudinally according to the height of the (third) left upright M3 and is configured to control the angular position of the second part of the second left pushing mechanism 32g relative to the first part.

[0231] The fourth right cylinder extends substantially longitudinally according to the height of the (fourth) right upright M4 and is configured to control the angular position of the second part of the second right pushing mechanism 31d relative to the first part.

[0232] The second part 6 can have an extension 60 or lever arm that extends outwardly from said second part 6 around the rotation axis 4, radially beyond the diameter D of the helical guide surface 7, for example beyond the diameters of the third and fourth guide surfaces 72, 73.

[0233] Said extension 60, or more generally lever arm, protrudes from an upright, in particular the first upright M1, the second upright M2, the third upright M3 or the fourth upright, generally outwardly from the frame in the transverse direction Y, the cylinder VR, in particular the first cylinder, the second cylinder, the third cylinder or the fourth cylinder, being articulated on said extension 60, or more generally on the lever arm, via the first end of the hydraulic cylinder.

[0234] All or part of the cylinder VR, i.e. the first cylinder, the second cylinder, the third cylinder and the fourth cylinder, is articulated to said second part 6 via the first end of the cylinder and to one of the uprights M1, M2, M3, M4 via the second end via a pivot axis Av, in particular parallel to the rotation axis 4 of said pushing device with the rotary cam 4.

[0235] When the cylinder is deployed or retracted, it causes the second part 6 to rotate relative to the first part 5, while pivoting slightly relative to said pivot axis Av relative to the upright.

[0236] In order to limit the volume in the transverse direction Y, by approaching as closely as possible the substantially vertical cylinder VR and the upright, the depth cut ECH of the upright can extend along the Y direction to the direct face of the cylinder connected to the upright. This makes it possible for the cylinder to pivot around said pivot axis Av while penetrating the cut ECH without interfering with the upright when the cylinder is deployed or retracted.

[0237] According to another embodiment (not shown), the rotational movement between the first part 5 and the second part 6 can be obtained by means of a ring gear mounted rotationally fixed to the second part (or to the first part), coaxial with said rotation axis, the ring gear being engaged via a motor pinion driven by an electric gear motor forming the actuator. The force or the position of the gear motor can be adjusted during control.

[0238] According to an advantageous embodiment, the first part 5 and the second part 6 are preferably enclosed within a cover 8 to protect the helical guide surface 7 from the influence of the external environment. In particular, the cover 8 comprises a cylindrical wall whose axis is coaxial with the rotation axis A4 of the rotating helical drive device 4. Enclosing parts (particularly the cam's indentation) within the cover protects the helical guide surface (particularly the cam's guide surface or internal and external threads) from external contaminants such as oil and metal particles. This reduces the need for frequent maintenance and extends the service life of the components.

[0239] This disclosure also relates to a method for rolling metal strip by the rolling mill 1 of this disclosure, comprising:

[0240] / A / The metal strip B is rolled by running between two upper work rolls and a lower work roll. The upper and lower work rolls are pressed onto the strip by the hydraulic clamping action between two lower support rolls and the upper support rolls WAS and WAI, and the motor torque is transmitted to the upper work roll WRS and the lower work roll WRI.

[0241] / B / The upper and lower work rolls are balanced in the following way.

[0242] - Upper lateral displacement between the axis of the upper work roll WRS and the axis of the roll bearing on the work roll.

[0243] - Lateral displacement between the axis of the lower work roll WRI and the axis of the roll bearing on the work roll.

[0244] Furthermore, the upper and lower lateral shifts OFS are obtained by real-time progressive control of the angular position of the first part 5 of each rotating screw drive device 4 relative to the second part 6, to ensure the lateral drive of the lower first bearing seat and the upper first bearing seat E1I, E1S of the lower and upper working rolls, as well as the lower second bearing seat and the upper second bearing seat E2I, E2S.

[0245] The rolling method using real-time progressive control for the 5 and 6 angle sections allows for precise adjustment of lateral displacement during rolling. This ensures optimal balance of the work rolls, thereby improving the quality of the final product.

[0246] Real-time control allows for rapid adjustment of rolling parameters to adapt to changing conditions, thereby optimizing process efficiency and productivity.

[0247] In summary, this disclosure may have all or some of the following advantages.

[0248] 1) The use of a rotary screw drive in systems for adjusting lateral displacement allows for precise and progressive adjustment of the position of the work roll bearing housing. This improves the balance of horizontal forces and reduces roll deflection, which is crucial for maintaining rolling quality, especially when the work roll diameter is small.

[0249] 2) Compared with the rolling mill equipped with a linear cam thrust device disclosed in US 4.736.609, the use of a rotary screw thrust device can limit the overall volume of the rolling mill in the transverse direction Y.

[0250] 3) Using a rotating helical thrust device can protect the guide surfaces with a cover, thereby preventing these surfaces from being contaminated by oil and the rolled metal particles contained in the oil.

[0251] List of reference numerals

[0252] - 1: Rolling mill,

[0253] - 2. Rack,

[0254] - 3. Lateral shift adjustment system,

[0255] - 31g, 31d. First lateral adjustment mechanism, for the left and right sides respectively.

[0256] - 32g, 32d. Second lateral adjustment mechanism, for the left and right sides respectively.

[0257] - 4. Screw drive device,

[0258] - A4. Rotation axis,

[0259] - 5, 6, are respectively the first part and the second part.

[0260] - 7. Spiral guiding surface,

[0261] - 71, 72, 73, 74. First, second, third, and fourth spiral guide surfaces,

[0262] - B. Strip (metal)

[0263] - M1, M2. Columns (the first pair of columns of the frame, on the left and right sides respectively).

[0264] - M3, M4. Columns (the second pair of columns on the frame, on the left and right sides respectively).

[0265] - PT: Hydraulic clamping unit,

[0266] - PST. Rolling line adjustment system,

[0267] - WRI. Lower work roll,

[0268] - WRS. Upper work roll,

[0269] - WAI upper support roller,

[0270] - WAS. Lower support roller,

[0271] - WII. Lower intermediate roller,

[0272] - WIS. Upper intermediate roller,

[0273] - E1S, E2S. First upper bearing housing and second upper bearing housing (for upper work roll WRS).

[0274] - E1I, E2I. First and second lower bearing housings (for the lower work roll WRI).

[0275] - EII, EIS. Lower and upper bearing housings (for intermediate rollers).

[0276] - EAI, EAS. Lower and upper bearing housings (used to support the rollers).

[0277] - 8. Cover,

[0278] - 9. First opening / closing mechanism, left side,

[0279] - 90 and 91 represent the lower and upper parts, respectively.

[0280] - 10. First opening / closing mechanism, left side.

[0281] - 100, 101. These represent the lower and upper parts, respectively.

Claims

1. 4-roller or 6-roller cold rolling mill (1) configured to roll a metal strip, - a mill stand (2) comprising a first pair of columns on the front side and a second pair of columns on the rear side, - an upper work roll (WRS) comprising a roll working surface configured to be in contact with an upper surface of the metal strip and two guide ends, - a lower work roll (WRI) comprising a roll working surface configured to be in contact with a lower surface of the metal strip and two guide ends, - an upper backup roll (WAS) configured to transmit a clamping force to the upper work roll either directly according to a contact line between the upper work roll and the upper backup roll or indirectly via an upper intermediate roll (WIS) through a first bearing line between the upper backup roll and the upper intermediate roll and a second bearing line between the upper intermediate roll and the upper work roll, - a lower backup roll (WAI) configured to transmit a clamping force to the lower work roll either directly according to a contact line between the lower work roll and the lower backup roll or indirectly via a lower intermediate roll (WAI) through a first bearing line between the lower backup roll and the lower intermediate roll and a second bearing line between the lower intermediate roll and the lower work roll, - two upper chocks arranged at the two guide ends of the upper work roll (WRS) comprising: - a first upper chock (E1S) interposed between two columns (M1, M2) of the first pair of columns and a second upper chock (E2S) interposed between two columns (M3, M4) of the second pair of columns, - two lower chocks arranged at the two guide ends of the lower work roll comprising a first lower chock (E1I) interposed between two columns (M1, M2) of the first pair of columns and a second lower chock (E2I) interposed between two columns (M3, M4) of the second pair of columns, - a system (3) for adjusting the side shift configured to implement a side shift between, seen in the rolling direction (DL), on the one hand, an axis (Awr) of the lower work roll (WRI) or of the upper work roll (WRS) and, on the other hand, an axis (Ap) of a roll bearing on the work roll, the work roll consisting of a lower intermediate roll or an upper intermediate roll (WII; WIS) when the rolling mill is a 6-roller rolling mill, the work roll consisting of a lower backup roll or an upper backup roll (WAI; WAS) when the rolling mill is a 4-roller rolling mill, and wherein the adjusting system comprises: - a first left pushing mechanism (31g) located between, on the one hand, a left column (M1) of the first pair of columns and the first upper chock (E1S) and the first lower chock (E1I) assembly and, on the other hand, the first left pushing mechanism being configured to exert a pushing force on the first upper chock (E1S) and the first lower chock (E1I) assembly to move the first upper chock (E1S) and the first lower chock (E1I) assembly in a first manner according to the rolling direction (DL), - a first right pushing mechanism (31d) located, on the one hand, between the other right upright (M2) of the first pair of uprights and the first upper bearing block (E1S) and the first lower bearing block (E1I), and, on the other hand, configured to exert a pushing force on the first upper bearing block (E1S) and the first lower bearing block (E1I) assembly to move the first upper bearing block (E1S) and the first lower bearing block (E1I) assembly in a second way according to the rolling direction (DL), - a second left pushing mechanism (32g) located, on the one hand, between the left upright (M3) of the second pair of uprights and the second upper bearing block (E2S) and the second lower bearing block (E2I) assembly, and, on the other hand, configured to exert a pushing force on the second upper bearing block (E2S) and the second lower bearing block (E2I) assembly to move the second upper bearing block (E2S) and the second lower bearing block (E2I) assembly in the first way according to the rolling direction (DL), - a second right pushing mechanism (32d) located, on the one hand, between the other right upright (M4) of the second pair of uprights and the second upper bearing block (E2S) and the second lower bearing block (E2I) assembly, and, on the other hand, configured to exert a pushing force on the second upper bearing block (E2S) and the second lower bearing block (E2I) assembly to move the second upper bearing block (E2S) and the second lower bearing block (E2I) assembly in the second way according to the rolling direction (DL), characterized in that the first left and right pushing mechanisms and the second left and right pushing mechanisms comprise all or part of a rotary screw pushing device (4), each rotary screw device comprising a first part (5) supported on one of the uprights of the first pair of uprights (M1, M2) or on one of the uprights of the second pair of uprights (M3, M4) and a second part (6) configured to laterally push the first lower and upper bearing blocks or respectively the second lower and upper bearing blocks, and in that the first part (5) and the second part (6) of each of the rotary screw pushing devices (4) are configured to pivot relative to each other about a rotation axis (A4) under the action of an actuator (AT), the first part (5) and the second part (6) comprising screw guide surfaces (7) arranged about the rotation axis (A4) which support each other and are configured to cause, on relative rotation between the first part (5) and the second part (6), a spacing of the second part (6) relative to the first part (5) in the direction of the rotation axis (A4).

2. The 4-high or 6-high cold rolling mill (1) according to claim 1, characterized in that, The screw guide surfaces (7) are: - cam surfaces of the first part (5) and of the second part (6) consisting of a first cam and a second cam, or - an internal thread and an external thread respectively engaged together between the first part (5) and the second part (6).

3. The 4-high or 6-high cold rolling mill (1) according to claim 2, characterized in that: - said first portion (5) is a first cam comprising a first helical guide surface (70) extending on a first angular portion of said first cam about said rotation axis (A4) and a second helical guide surface (71) extending on a second angular portion of said first cam, - said second portion (6) is a second cam comprising a third helical guide surface (72) extending on a first angular portion of said second cam and a fourth helical guide surface (73) extending on a second angular portion of said second cam, and wherein the first (70) and second (71) helical guide surfaces of said first cam are configured to guide in cooperation with the third (72) and fourth (73) helical guide surfaces of said second cam simultaneously.

4. The 4-high or 6-high cold rolling mill (1) according to claim 1 or 2, characterized in that Said first (5) and second (6) portions are enclosed within a cover (8) protecting said helical guide surfaces (7) from the external environment.

5. The 4-high or 6-high cold rolling mill (1) according to claim 1 or 2, characterized in that, The actuators (AT) of said rotary helical pushing devices (4) consist of air cylinders (VR) extending longitudinally according to the height of said uprights (M1, M2, M3, M4).

6. The 4-high or 6-high cold rolling mill (1) according to claim 5, characterized in that, All or part of said air cylinders (VR) are articulated to said second portion (6) via a first end of said air cylinders and to one of said uprights (M1, M2, M3, M4) via a second end via a pivot axis (Av).

7. The 4-high or 6-high cold rolling mill (1) according to claim 1 or 2, characterized in that The helical guide surface (7) of each rotary helical pushing device (4) is arranged to overlap in a transverse direction (Y) the width of one of the uprights (M1, M2, M3, M4) supported by said rotary helical device, the diameter D of said helical guide surface (7) being contained in said transverse direction (Y) along the width of said upright.

8. The 4-high or 6-high cold rolling mill (1) according to claim 6, characterized in that, The helical guide surface (7) of each rotary helical pushing device (4) is arranged to overlap in a transverse direction (Y) the width of one of the uprights (M1, M2, M3, M4) supported by said rotary helical device, the diameter D of said helical guide surface (7) being contained in said transverse direction (Y) along the width of said upright, and wherein said second portion (6) has an extension (60) or lever arm extending radially outwards to said second portion (6) about said rotation axis (A4) beyond the diameter D of said helical guide surface (7), said extension (60) or lever arm protruding from said upright in said transverse direction (Y), said air cylinder (VR) being articulated on said extension (60) or on said lever arm by a first end of a hydraulic cylinder.

9. The 4-high or 6-high cold rolling mill (1) according to claim 1 or 2, characterized in that: - said first left pushing mechanism (31g) and said first right pushing mechanism (31d) each comprise a pair of first (5) and second (6) portions extending in height, said first (5) and second (6) portions overlapping the height of said first upper (E1S) and first lower (E1I) chock assemblies, - said second left side push mechanism (32g) and said second right side push mechanism (32d) each comprise a pair of first (5) and second (6) portions extending in height, said first (5) and second (6) portions being height-wise overlapping said second upper (E2S) and second lower (E2I) chocks assembly.

10. The 4-high or 6-high cold rolling mill (1) according to claim 1 or 2, characterized in that: - a first left side opening / closing mechanism (9) having a vertical cylinder comprising an upper part (90) laterally connected to a left side first upper chock (E1S) and a lower part (91) laterally connected to a left side first lower chock (E1I) and a hydraulic cylinder (VR) configured to separate or bring together said first lower chock and said first upper chock, said first left side push mechanism (31g) being interposed between a left side upright column (M1) and said first left side opening / closing mechanism (9), - a first right side opening / closing mechanism (10) having a vertical cylinder comprising an upper part (100) laterally connected to a right side first upper chock (E1S) and a lower part (101) laterally connected to a right side first lower chock (E1I) and a hydraulic cylinder configured to separate or bring together said first lower chock and said first upper chock, said first right side push mechanism (31d) being interposed between a right side upright column (M2) and said first right side opening / closing mechanism, - a second left side opening / closing mechanism having a vertical cylinder comprising an upper part laterally connected to a left side second upper chock (E2S) and a lower part laterally connected to a left side second lower chock (E2I) and a hydraulic cylinder configured to separate or bring together said first chocks, said second left side push mechanism (32g) being interposed between a left side upright column (M3) and said second left side opening / closing mechanism, - a second right side opening / closing mechanism having a vertical cylinder comprising an upper part laterally connected to a left side second upper chock (E2S) and a lower part laterally connected to a left side second lower chock (E2I) and a hydraulic cylinder configured to separate or bring together said first chocks, said second right side push mechanism (32d) being interposed between a left side upright column (M3) and said first right side opening / closing mechanism.

11. The 4-high or 6-high cold rolling mill (1) according to claim 1 or 2, characterized in that said upper work rolls (WRS) and said lower work rolls (WRI) comprise a transmission shaft (ARB) connected with a motor driver for directly driving the work rolls rotation.

Images