Calendering process and machine with dynamic compensation for geometry defects of the working rollers

Abstract

The invention provides calendering machines and methods in which two work rollers (10, 20) define a calendering space (30) that has a working gap (e30) between the working surfaces (11, 21) of the two rollers, and in which a support (14) of one of the rollers is movable under the effect of at least one load actuator (32) to obtain a target value (e30c) of the working gap, characterized in that the at least one load actuator (32) delivers, on the first support (14), a total force (F(t)) adjusted successively in time as a function of an instantaneous angular position (θ(t)) of the two work rollers around their respective axes, and as a function of acquired values ​​(d60i(θ)), during a learning phase, of at least one quantity (d60(θ)) representative, for the instantaneous angular position (θ(t)), of a gap geometry of the working surfaces of the two working rollers. Figure from the abstract: FIG. 7

Description

Title of the invention: Calendering method and machine with dynamic compensation for geometry defects of working rollers. Technical field

[0001] The invention relates to the field of calendering processes and calendering machines. A calendering process and / or machine are used for calendering a strip to be calendered. Such a strip may consist of a single sheet or layer, or of a superposition of at least two sheets or layers joined face to face, the different sheets of the same strip being able to be made of different materials. The calendering operation of the strip, which is carried out in a calendering machine, aims in particular to calibrate the thickness of the strip, and / or to compact at least one layer of the strip, and / or to join different layers of the strip together.

[0002] Such a process and / or such a calendering machine may be used in particular for the manufacture of electrochemical cell components, in particular electrode components for electrochemical cells, especially for electrochemical cells of electric accumulator batteries. Technical background

[0003] In the field of manufacturing accumulator batteries, particularly of the lithium-ion type, it is known to manufacture electrode components comprising at least a metallic support in the form of a metallic sheet, and, at least on one face of the metallic support, a layer of electrode material, by imposing on such components a calendering operation carried out in a calendering machine.

[0004] In particular, in certain applications, such a calendering machine may be used to manufacture an electrode component comprising a strip having a metallic foil, which can form a current collector for the electrochemical cell, and which can form a metallic support, and having, at least on one face of the metallic support, a layer of electrode material.

[0005] In certain applications, such a machine may be used to manufacture a layer of self-supporting electrode material, which may then be implemented in the manufacture of an electrochemical cell.

[0006] In a known manner, a calendering machine comprises a first work roller mounted to rotate about a first axis on a first support and comprising a work surface, and comprises a second work roller rotating on a second support about a second axis, parallel to the first axis. The two work rollers The two working rollers are counter-rotating and define, between their respective working surfaces, a calendering space in which the strip travels, in a plane of travel, along a direction of travel from upstream to downstream. The distance between the axes of the two working rollers determines the thickness of the calendering space, also called the working gap, and therefore determines the calendering force imposed on the strip as it travels between the two working rollers through this calendering space. This calendering force consists of a compressive force applied to the strip in a direction that is approximately perpendicular to the plane of travel of the strip between the two working rollers. This calendering force depends, in particular, on the thickness of the calendering space relative to the thickness of the strip at the entrance to the calendering space.

[0007] In a known manner, a calendering machine is intended to process a strip having a transverse dimension, perpendicular to the direction of travel in the travel plane, which, depending on the machines, may be on the order of a few tens of centimeters, for example being within the range from 50 cm to 150 cm.

[0008] Controlling the working gap, i.e., the thickness of the calendering space, is crucial for the quality of the calendering operation. An important aspect of the calendering operation is obtaining a constant and controlled thickness of the strip downstream of the calendering space. Controlling the thickness of the calendering space during the calendering operation is a key parameter for controlling the thickness of the strip downstream of the calendering space.

[0009] In certain applications, particularly calendering operations aimed at calibrating the thickness of the strip, and / or compacting at least one layer of the strip, and / or joining different layers of the strip together, especially for the manufacture of electrochemical cell components, as described above, the aim is to obtain, at the output of the calendering machine, a strip whose thickness is for example between 50 and 250 microns, and the precision sought for this thickness is generally less than + / - 10 microns, sometimes less than + / - 5 microns.

[0010] In the prior art, it is known that there are machines in which at least one of the supports, for example the first support, is movable relative to a machine frame, perpendicular to the plane of travel, by means of at least one load actuator controlled by a computer control unit to obtain a target value for the working gap. The at least one load actuator comprises a single actuator or several actuators.

[0011] It is known that working rollers can have geometric defects, for example in the form of cylindricity defects of the working surface. minus one of the work rollers, defects in the alignment and / or parallelism of the geometric axis of the work surface in question, relative to the axis of rotation of the corresponding work roller in the machine, and / or defects in the alignment and / or parallelism of the two respective axes of rotation of the two work rollers in the machine. Such defects are generally very small, with, for example, errors of only a few microns in the radial position of a point on the work surface relative to the axis of rotation of the work roller in question. However, it is understood that such defects in the geometry of the work rollers and their work surfaces affect the accuracy of the working gap. This leads to very careful manufacturing of the work rollers, which makes them very expensive.To further increase the precision of the work rollers, costs increase exponentially.

[0012] The invention therefore aims to propose a new design of a calendering process and a calendering machine which allows increased control of the thickness of the calendering space during the calendering operation, for a controlled cost. Description of the invention

[0013] A calendering machine for calendering a strip to be calendered is disclosed herein, of the type comprising a first work roller mounted rotatably about a first axis on a first support and comprising a work surface, of the type comprising a second work roller mounted rotatably about a second axis, parallel to the first axis, on a second support, and comprising a work surface, of the type in which the two work rollers are counter-rotating and define, between their two respective work surfaces, a calendering space suitable for receiving the strip as it moves in a plane of travel along a direction of travel from upstream to downstream, of the type in which the calendering space has, at its point of minimum spacing along a direction perpendicular to the plane of travel, a working spacing between the work surfaces of the two work rollers,and of the type in which the first support is movable relative to a machine frame, perpendicular to the plane of travel, under the effect of at least one load actuator controlled by a computer control unit to obtain a target value for the working gap.

[0014] According to one aspect, the computer control unit is configured to command at least one load actuator to deliver, on the first support, a total force adjusted successively in time according to an instantaneous angular position of the two working rollers around their axes respective, and based on acquired values, in a learning phase, of at least one representative quantity, for the instantaneous angular position, of a geometry difference of the working surfaces of the two working rollers.

[0015] In certain embodiments, the computer control unit includes a computer storage memory capable of storing at least one working gap profile comprising, for each of a series of distinct angular positions, a representative value, for the angular position, of the geometry gap of the working surfaces of the two working rollers.

[0016] In certain embodiments, the working gap profile includes, for each of a series of distinct angular positions of the two working rollers around their respective axes, a value representative of the working gap at idle.

[0017] In certain embodiments, the working gap profile includes, for each of a series of distinct angular acquisition positions of the two working rollers around their respective axes, a force correction value corresponding to the angular position of the rollers.

[0018] In certain embodiments, the working gap profile includes, for each working surface, at least one radial gap profile comprising, for each of a series of distinct angular positions of the two working rollers around their respective axes, a value of radial position variation of the working surface considered relative to a reference radial position for the working roller considered.

[0019] In certain embodiments, the machine comprises at least two groups of load actuators, each associated with one of the two axial ends of the calendering space, and the computer control unit is configured to command each group of load actuators to deliver on the first support a total force adjusted successively in time according to the instantaneous angular position of the two work rollers around their respective axes, and according to the values ​​acquired at the corresponding end of the calendering space, for the instantaneous angular position, of at least one quantity representative of a deviation in the geometry of the working surfaces of the two work rollers.

[0020] In some embodiments, the computer storage memory stores at least two working gap profiles corresponding to distinct acquisition planes, perpendicular to the axes of two working rollers and axially separated from each other, one towards an axial end and the other towards the opposite axial end of the calendering space.

[0021] In some embodiments, the machine includes a mechanical stop, which is for example interposed between the first support and the second support which determines a setting of the working gap to an initial setting value; the calendering machine includes at least one acquisition sensor, during a production phase during which the strip passes through the calendering space, successive values ​​in time of at least one quantity representative of the working gap;and the computer control unit is configured to control at least one load actuator so that it delivers on the first support a total force adjusted successively in time, firstly as a function of an instantaneous angular position of the two working rollers around their respective axes, and as a function of the values ​​acquired, in the learning phase, of at least one representative quantity, for the instantaneous angular position, of a deviation in the geometry of the working surfaces of the two working rollers, and secondly as a function of the acquired values ​​of the representative quantity of the working gap and the target value of the working gap. ;

[0022] In certain embodiments, the machine comprises at least two groups of load actuators, each associated with one of the two axial ends of the calendering space, and the computer control unit is configured to command each group of load actuators to deliver on the first support a total force adjusted successively in time, on the one hand as a function of an instantaneous angular position of the two work rollers around their respective axes, and on the other hand as a function of the values ​​acquired at the corresponding end of the calendering space, during the learning phase, of at least one quantity representative, for the instantaneous angular position, of a geometric deviation of the working surfaces of the two work rollers,and on the other hand, depending on the acquired values ​​of the representative quantity of the working gap acquired at the corresponding end of the calendering space and the target value of the working gap.

[0023] In certain embodiments, at least one representative quantity of the working gap is a relative distance between at least one surface of revolution of one of the two working rollers and an auxiliary reference surface belonging to the other of the two working rollers, said auxiliary reference surface of the other of the two working rollers being a coaxial surface of revolution, axially offset, and of strictly smaller diameter compared to the working surface of the corresponding working roller.

[0024] In certain embodiments, at least one sensor is a sensor positioned in a calendering plane containing the two axes of the two work rollers, at an axial end of the calendering space outside of it, opposite the minus a surface of revolution of one of the two working rollers and of the auxiliary reference surface belonging to the other of the two working rollers.

[0025] In some embodiments, at least one sensor is a contactless sensor, in particular a capacitive sensor.

[0026] In certain embodiments, the computer control unit is configured to calculate a force setpoint, adjusted successively in time, during a production phase during which the strip moves through the calendering space, on the one hand as a function of an instantaneous angular position of the two work rollers around their respective axes, and as a function of the values ​​acquired, in the learning phase, of at least one quantity representative, for the instantaneous angular position, of a deviation in geometry of the working surfaces of the two work rollers, and on the other hand as a function of the acquired values ​​of the quantity representative of the working gap and the target value of the working gap; and the computer control unit is configured to command at least one load actuator so that it delivers on the first support a force corresponding to the setpoint.

[0027] In some embodiments, the initial calibration value is strictly greater than the target value and is between 1.05 and 2 times the target value.

[0028] A calendering method for a strip to be calendered is further disclosed, of the type in which the strip is made to move, in a flow plane along a flow direction from upstream to downstream, through a calendering space defined between: - a working surface of a first working roller, which is mounted to rotate around a first axis on a first support, - and a working surface of a second working roller, which is mounted to rotate around a second axis, parallel to the first axis, on a second support, the two working rollers being counter-rotating, of the type in which the calendering space has, at its minimum spacing point in a direction perpendicular to the plane of travel, a working spacing, between the working surfaces of the two working rollers, and of the type in which the process involves the application, on at least one of the supports, of a force perpendicular to the plane of travel, in the direction of a reduction of the working spacing, to obtain a target value of the working spacing.

[0029] According to one aspect, the process comprises: - the acquisition, during a learning phase prior to a production phase, for each of a series of angular positions of the two working rollers around their respective axes, the angular positions acquisitions being distinct and distributed over a turn, of values ​​of at least one quantity representative of a difference in geometry of the working surfaces of the two working rollers; - the application, during a production phase in which the strip passes through the calendering space, on at least the first support, of at least one total force adjusted successively in time according to the instantaneous angular position of the two working rollers around their respective axes, and according to the acquired values ​​of at least one quantity representative, for the instantaneous angular position, of a geometry deviation of the working surfaces of the two working rollers.

[0030] In certain embodiments, the acquisition of the values ​​of at least one quantity representative of a deviation in geometry of the working surfaces of the two working rollers includes the acquisition, in an acquisition plane perpendicular to the axes of two working rollers, of at least one working gap profile comprising, for each angular position of acquisition of the series, a value representative of the deviation in geometry of the working surfaces of the two working rollers, for the angular position of acquisition, and the method includes the application, on at least the first support, of at least one total force adjusted successively in time as a function of the instantaneous angular position of the two working rollers around their respective axes, and as a function of the working gap profile.

[0031] In certain embodiments, the working gap profile includes, for each of a series of distinct angular positions of the two working rollers around their respective axes, a value representative of the working gap at idle.

[0032] In certain embodiments, the working gap profile includes, for each of a series of distinct angular acquisition positions of the two working rollers around their respective axes, a force correction value corresponding to the angular position of the rollers.

[0033] In certain embodiments, the working gap profile includes, for each working surface, at least one radial gap profile comprising, for each angular acquisition position of the series, a value of radial position variation of the working surface considered relative to a reference radial position for the working roller considered.

[0034] In certain embodiments, the radial gap profile is acquired for the two working rollers in the same acquisition plane perpendicular to the axes of two working rollers.

[0035] In certain embodiments, at least two working gap profiles are acquired in separate acquisition planes, perpendicular to the axes of two work rollers and axially offset from each other, one towards one axial end and the other towards the opposite axial end of the calendering space, and the method comprises applying, on at least the first support, at least two forces, parallel to each other and axially offset from each other, one towards one axial end and the other towards the opposite axial end of the calendering space, each adjusted according to the instantaneous angular position of the two work rollers around their respective axes, and according to the work gap profile acquired in the acquisition plane acquired at the corresponding axial end.

[0036] In certain embodiments, for each of the two work rollers, at least two radial gap profiles are acquired in separate acquisition planes, perpendicular to the axes of two work rollers and axially offset from each other, one towards an axial end and the other towards the opposite axial end of the calendering space, and the method comprises applying, on at least the first support, at least two forces, parallel to each other and axially offset from each other, one towards an axial end and the other towards the opposite axial end of the calendering space, each adjusted according to the instantaneous angular position of the two work rollers around their respective axes, according to the radial gap profiles acquired in the corresponding axially aligned acquisition plane.

[0037] In some embodiments, the method includes, in the prior learning phase, the computer storage of at least one working gap profile or representative values ​​of at least one working gap profile, such as force correction values ​​indexed angularly as a function of the angular position of the working rollers.

[0038] In certain embodiments, the process also comprises: - an initial setting of the working gap to an initial setting value, determined by the support on a mechanical stop, by applying a setting force on at least one of the first and second supports in the direction of the other of the first and second working roller, the initial setting value being strictly greater than the target value and being between 1.05 and 2 times the target value; - the acquisition, during a production phase in which the strip passes through the calendering space, of successive values ​​over time of at least one quantity representative of the working gap; - the application, during said production phase, on at least the first support, of at least one total force adjusted successively in time, firstly according to the instantaneous angular position of the two working rollers around their respective axes, and secondly according to the acquired values ​​of at least one quantity representative, for the instantaneous angular position, of a geometric deviation of the working surfaces of the two working rollers, and on the other hand according to the acquired values ​​of at least one quantity representative of the working gap.

[0039] In some embodiments, the process comprises: - the acquisition, during a production phase during which the strip passes through the calendering space, of successive values ​​in time of at least two quantities representing the working gap, a first quantity being acquired at a first axial end of the calendering space, and a second quantity being acquired at a second, opposite axial end of the calendering space; - the application, on at least the first support, of at least two total forces, in parallel with each other and each offset axially on the side of the corresponding axial end of the calendering space, each adjusted successively in time on the one hand as a function of the instantaneous angular position of the two working rollers around their respective axes, and as a function of the acquired values ​​of at least one quantity representing, for the instantaneous angular position, a deviation in geometry of the working surfaces of the two working rollers, and on the other hand as a function of the acquired values ​​of that of the two quantities representing the working gap which is acquired at the corresponding axial end of the calendering space.

[0040] In certain embodiments, at least one representative quantity of the working gap is a relative distance between at least one surface of revolution of one of the two working rollers and an auxiliary reference surface belonging to the other of the two working rollers, said auxiliary reference surface of the other of the two working rollers being a coaxial cylindrical surface of revolution, axially offset, and of strictly smaller diameter compared to the working surface of the corresponding working roller.

[0041] In certain embodiments, at least one quantity representing the working gap is a relative distance between two auxiliary reference surfaces belonging respectively to each of the two working rollers, each auxiliary reference surface being a coaxial cylindrical surface of revolution, axially offset, and of strictly smaller diameter compared to the working surface of the corresponding working roller, the two auxiliary reference surfaces being opposite each other on either side of the scroll plane.

[0042] In some embodiments, the relative distance is measured with at least one non-contact sensor, in particular a capacitive sensor.

[0043] In certain embodiments, at least one sensor is positioned in a calendering plane containing the two axes of the two work rollers, at one axial end of the calendering space but outside of it, opposite the at least a cylindrical surface of revolution of one of the two working rollers and of the auxiliary reference surface, belonging to the other of the two working rollers.

[0044] In some embodiments, the first working roller is mobile, perpendicular to the plane of scrolling.

[0045] In some embodiments, the second axis is fixed.

[0046] In certain embodiments, the acquisition of successive values ​​in the time of at least one quantity representative of the working gap, and the successive adjustment in time of at least one force, are each operated at a frequency greater than 10 hertz, preferably greater than 100 hertz.

[0047] In some embodiments, the calendered foil is an electrode component for electrochemical cells, comprising a layer of electrode material, in particular an electrode component comprising a layer of electrode material supported on a support layer or a self-supported layer of electrode material.

[0048] In certain embodiments, the electrode material layer is, in the calendering process, calendered alone or on a support layer, possibly with the addition of heat, to give cohesion to the electrode material layer, and / or to give it desired structuring properties, and / or to give it desired rheological properties, and / or to give it desired dimensional properties and / or to assemble the electrode material layer on a support layer. Brief description of the drawings

[0049] [Fig-1]: [Fig.1] is a schematic view illustrating an example of a machine calendering, according to a view oriented in the direction of travel, from the upstream of the machine.

[0050] [Fig.2] : The [Fig.2] is a schematic view illustrating the calendering machine of the [Fig.1], in cross-section along the PXZ plane of the [Fig.1].

[0051] [Fig.3] : The [Fig.3] is a schematic perspective view of a side face of the calendering machine of the [Fig.1].

[0052] [Fig.4]: [Fig.4] is a detail of [Fig.1], illustrating more particularly the arrangement of a wedge between the supports of the two working rollers.

[0053] [Fig.5] : The [Fig.5] is a schematic perspective view illustrating one embodiment of an adjustable wedge.

[0054] [Fig.6] : The [Fig.6] is a view analogous to that of the schematic [Fig.4] illustrating an example of the implementation of the implantation of a sensor for acquiring at least one quantity representative of the working gap.

[0055] [Fig.7]: The [Fig.7] is a schematic illustration of a way in which a calendering machine and process can be implemented, in a simplified and schematic version.

[0056] [Fig.8]: The [Fig.8] is a flowchart illustrating an example of a calendering process.

[0057] [Fig.9] : The [Fig.9] illustrates in a very schematic way an example of a set of two work rollers exhibiting geometric deviations.

[0058] [Fig. 10]: The [Fig. 10] illustrates in a very schematic way an example of a method of acquisition, during a learning phase prior to a production phase, for each of a series of angular acquisition positions, of values ​​of at least one quantity representative of a geometry difference of the two working rollers.

[0059] [Fig. 11]: The [Fig. 11] illustrates in a very schematic way another example of an acquisition method, during a learning phase prior to a production phase, for each of a series of angular acquisition positions, of values ​​of at least one quantity representative of a geometry difference of the two working rollers.

[0060] [Fig. 12]: The [Fig. 12] illustrates an optional step of angular alignment of the two working rollers exhibiting geometry deviations. Detailed description

[0061] Figures 1 to 3 illustrate a calendering machine 1 comprising at least one frame 2 and at least one calendering unit 3. The calendering machine 1 is configured to be used for calendering a strip 4 which is to be calendered.

[0062] In the example, the strip 4, illustrated in Figures 1 and 2, is an electrochemical cell component, in particular an electrode component for electrochemical cells, especially for electrochemical cells of electric accumulator batteries, in particular of the lithium-ion type.

[0063] The foil 4 can, for example, be a layer of electrode material that is either supported on a support layer, for example supported on a transfer film or supported directly on a metal foil intended to form a current collector for an electrochemical cell, or self-supported. In some applications, such a layer of electrode material can therefore be, in the calendering machine, calendered alone, possibly with the addition of heat, to give cohesion to the electrode material layer, and / or to impart desired structural properties, and / or to impart desired rheological properties, and / or to impart desired dimensional properties. In other applications, such a layer of electrode material can therefore be, in the calendering machine, calendered on a support layer, for example on a metal sheet intended to form a current collector for an electrochemical cell, to assemble the layers together, and to give cohesion to the electrode material layer, and / or to give the multilayer strip thus formed the desired structural, rheological, and / or dimensional properties.

[0064] The electrode material may, for example, comprise an active electrode material associated with a binder, for example, a fibrillable binder. The active electrode material may, for example, be or comprise a lithium metal oxide (for example, of the NMC, NCA, or LFP type) and / or graphite and / or activated carbon in the case of a cathode, or graphite or silicon in the case of an anode. The fibrillable binder may, for example, be or comprise polytetrafluoroethylene (PTFE), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), polyethylene oxide (PEO), polyethylene (PE), and / or carboxymethylcellulose (CMC), or a combination thereof. Fibriltable binders can be characterized by their soft, flexible, and pliable consistency and, in particular, by their ability to stretch, elongate, and become thinner, taking on a fibrous appearance when subjected to shear stress.

[0065] An example of a calendering unit 3 for a calendering machine 1, as illustrated, comprises a first work roll 10 that rotates about a first axis Y10 and a second work roll 20 that rotates about a second axis Y20, the second axis Y20 being parallel to the first axis Y10 of the first work roll 10, within the limits of standard manufacturing tolerances in the field. The first work roll 10 has a working surface 11, which is an external surface of revolution of the first work roll 10, that is, a surface that is invariant under rotation about a fixed axis. Generally, the working surface 11 is cylindrical in revolution about the first axis Y10, that is, generated by the rotational sweep about the axis Y10 of a straight line parallel to the axis and at a distance from the axis.The second working roller 20 has a working surface 21, which is an external surface of revolution of the second working roller 20. Generally, the working surface 21 is cylindrical in revolution about the second axis Y20. In certain variations, particularly for working rollers with a diameter of less than 300 millimeters, or even less than 150 millimeters, one or both of the working surfaces may be barrel-shaped surfaces of revolution around the axis of the corresponding roller. The crowning is generally intended to compensate for deflection of the corresponding roller during calendering operations, the combination of the crowning and the deflection under calendering forces resulting in a straight line of contact at the calendering gap. However, it should be noted that the crowning remains very small in all cases, such that, from the point of view of the invention, one... can consider that the working surface is a cylindrical surface of revolution, which can have a rectilinear generatrix to form a straight cylinder, or a convex generatrix to form a convex cylinder.

[0066] In the illustrated example, the two work rolls 10, 20 are counter-rotating and define between them a calendering space 30 in which the strip 4 moves along a PXY plane in a direction of travel X, from upstream to downstream along this direction. The PXY plane of travel is parallel to the first axis Y10 of the first work roll 10 and to the second axis Y20 of the second work roll 20. In this PXY plane of travel, the direction of travel X is perpendicular to a transverse direction Y which is parallel to the first axis Y10 of the first work roll 10 and to the second axis Y20 of the second work roll 20. The direction Z, perpendicular to the PXY plane of travel, is generally the direction between the axes Y10 and Y20 of the two work rolls.The calendering force applied by the two work rollers 10, 20 to the strip 4, as it passes between the two work rollers 10, 20 through the calendering space, is essentially a compressive force along a direction that is approximately perpendicular to the PXY plane of the process, across the entire width of the strip parallel to the Y10, Y20 axes of the two work rollers. We can thus define a calendering plane PYZ containing the Y10, Y20 axes of the two work rollers 10, 20 and passing through the calendering space 30, perpendicular to the PXY plane of the process, and perpendicular to the X direction of the process. The calendering plane contains the Z direction perpendicular to the PXY plane of the process.

[0067] In a general case, the diameter of each work roller is, for example, between 100 millimeters and 1200 millimeters, most often between 400 millimeters and 1000 millimeters. Although the two work rollers may have respective working surfaces of different diameters, the case of a machine in which the two work rollers have respective working surfaces of the same diameter will be described in more detail below. In this case, the work rollers 10 and 20 have the same angular speed of rotation about their respective axes Y10 and Y20, in opposite directions.

[0068] The strapping 4 may consist of a single sheet, or of a superposition of at least two sheets joined face to face. The strapping 4 may be a discrete strap, having a defined length in the X-direction of travel, this length being on the order of magnitude of its width in a transverse direction parallel to the axes Y10, Y20 of the working rollers 10, 20, for example, a length between 0.1 and 10 times the width. Alternatively, the strapping 4 may have an "infinite" length in the sense of a length greater than 10 times its width. As For example, the strip can, upstream and / or downstream of the calendering machine 1, be wound in the form of a roll.

[0069] In applications for manufacturing components of electrochemical cells, the strip 4 may have a thickness which, at the entrance of the calendering unit 3, therefore upstream of it according to the direction of the X-flow, is for example within the range of 0.05 mm to 2 mm. Generally, the calendering space 30 has, at its minimum spacing point along the Z direction perpendicular to the PXY flow plane, a spacing between the two working rollers that is of the same order as the thickness of the strip 4 at the inlet of the calendering unit 3, while being less than it, for example by being equal to a value in the range of 95% to 10% of the thickness of the strip 4 at the inlet of the calendering unit 3, preferably in the range of 90% to 60% of the thickness of the strip 4 at the inlet of the calendering unit 3. The spacing between the two working rollers 10, 20, hereinafter referred to as the working spacing e30 (see [Fig.4]), is the distance, along the Z direction perpendicular to the PXY scroll plane, between the working surfaces 11, 21 of the two working rollers 10, 20 at the point of minimum spacing of the rollers 10, 20. .

[0070] The orientation in space, relative to the direction of Earth's gravity, of the various directions may vary depending on the applications and installations. For example, in the illustrated examples, the Y direction of the axes Y10 and Y20 of the two work rollers 10 and 20 can be considered horizontal. In the examples in Figures 1 to 6, the X travel direction can also be considered horizontal. However, a calendering unit can be implemented with a different orientation relative to the direction of Earth's gravity. For example, the X travel direction can be vertical, while the transverse Y direction of the axes Y10 and Y20 of the two work rollers 10 and 20 is also horizontal.

[0071] Preferably, each work roller 10, 20 is driven in rotation about its axis Y10, Y20 by drive means not shown in the figures. These drive means may include a motor, in particular an electric motor. Such a motor may be arranged coaxially along the axis of the work roller in question, for example at an axial end of the work roller in question, in line with it. Alternatively, such a motor may be arranged in a position offset from the axis of the work roller in question, and may be connected to it by a transmission mechanism comprising, for example, a chain, a belt, and / or a series of gears.

[0072] In the illustrated example, the calendering machine 1 does not have a support roller. However, in a known manner, a calendering machine may include, associated with at least one of the working rollers, a support group comprising at minus one support roller bearing on the work roller in question. Generally, a support roller of a support group associated with a given work roller is parallel to the work roller and bears against it in a support area located on the side of the work roller opposite the calendering area relative to the axis of that work roller. The function of the support group, if any, is to limit or compensate for deformations of the work roller during operation in a calendering process, particularly when the work roller in question has a relatively small diameter, for example, less than 300 millimeters.

[0073] At least one of the two work rollers 10, 20 is movable relative to the machine frame 2, and therefore movable relative to the other work roller. In the illustrated embodiment, the second work roller 20 occupies a fixed position relative to the machine frame 2, preferably with the possibility of statically adjusting its relative position, while the first work roller 10 is mounted for rotation about the first axis Y10 on a first support 14 which is movable relative to the frame 2, perpendicular to the PXY travel plane. For example, the first support 14 is connected to the frame 2 by a slide. Thus, in the example, the first support 14 and the first work roller 10 form a movable assembly relative to the machine frame 2.More specifically, in this example where the PXY scroll plane is horizontal, the moving assembly formed by the first support 14 and the first working roller 10 is vertically movable relative to frame 2.

[0074] By way of example, an embodiment is illustrated in which the first work roller 10, which is movable relative to the frame 2 of the machine 1, is arranged vertically below the second work roller 20, which is fixed relative to the frame 2. However, other relative arrangements between the two work rollers are possible.

[0075] In the example, the second working roller 20 is mounted in the frame 2 by means of a second support 24 which, in this example, is fixed relative to the frame 2 during a calendering operation, with the possibility, however, of providing that the position of the second support 24 in the frame 2 is adjustable, for example during a machine 1 setup phase. In the example, the second support 24, which is fixed relative to the frame, is nevertheless separate from the frame 2. However, alternatively, the second support 24, fixed relative to the frame 2, could be made of a portion of the frame 2, and thus integrated into it.

[0076] In the illustrated example, the frame 2 of the machine 1 comprises two lateral uprights 5A, 5B which are arranged on either side of a sagittal plane PXZ of the machine that is perpendicular to the axes Y10, Y20 of the two work rollers 10, 20, spaced apart. A left lateral upright 5A can thus be arbitrarily distinguished. and a right lateral post 5B, with reference to the scroll direction X. As can be seen more particularly in [Fig.2], each lateral post 5A,5B has for example the shape of a frame with each an upstream pillar 5A1, 5B1 and a downstream pillar 5A2, 5B2, again with reference to the scroll direction X, which extend in a direction perpendicular to the scroll plane PXY, therefore in the vertical direction in the example chosen for illustration. The upstream pillars 5A1, 5B1 and downstream pillars 5A2, 5B2 of a given lateral upright 5A, 5B are connected by at least one lower stringer 5A3, 5B3 and at least one upper stringer 5A4, 5B4, the stringers extending substantially along the direction of travel X. In the example, the lateral uprights 5A, 5B are frames and are therefore parallel to the sagittal plane PXZ. The frame 2 also includes cross members 6, 7 that connect the two lateral uprights 5A, 5B.The cross members 6, 7 extend essentially in a direction perpendicular to the sagittal plane PXZ. The frame comprises, for example, two lower cross members 6 connecting the lower ends of the side uprights 5A, 5B, and two upper cross members 7 connecting the upper ends of the side uprights 5A, 5B.

[0077] Each of the two working rollers 10, 20 has a central part 12, 22, which includes in particular the working surface 11, 21 of the roller 10, 20 considered, and has, axially on each side of the central part 12, 22 of the roller 10, 20 considered, lateral sections 13A, 13B, 23A, 23B which extend axially outwards on either side of the central part 12, 22 along the axis of the roller 10, 20 considered. In the example, the central parts 12, 22 of each of the two working rollers 10, 20 extend between the two side posts 5A, 5B of the frame 2, while the side sections 13A, 13B, 23A, 23B of each of the two working rollers 10, 20 extend axially outwards through a central opening in the corresponding side post 5A, 5B, between the upstream pillars 5A1, 5B1 and downstream pillars 5A2, 5B2 and between the lower stringers 5A3, 5B3 and upper stringers 5A4, 5B4 of the corresponding side post 5A, 5B.

[0078] In the illustrated example, the first support 14 for the first work roller 10 comprises two bearing bodies, namely a left bearing body 14A and a right bearing body 14B, which are arranged axially on either side of the central portion 12 of the first work roller 10. In the illustrated example, the two bearing bodies 14A, 14B of the first support 14 are independent of each other. Each bearing body 14A, 14B receives, by rotation through the bearing body, the corresponding lateral section, namely respectively a left lateral section 13A and a right lateral section 13B, of the first work roller 10, preferably with an interposed bearing (not shown). In the example, each bearing body 14A, 14B of the first support 14 is mounted to slide along the Z direction perpendicular to the The left bearing body 14A is slidably mounted, along the Z direction perpendicular to the PXY sliding plane, in the central opening of the left lateral upright 5A, between the upstream pillar 5A1 and the downstream pillar 5A2. Symmetrically, the right bearing body 14B is slidably mounted, along the Z direction perpendicular to the PXY sliding plane, in the central opening of the right lateral upright 5B, between the upstream pillar 5B1 and the downstream pillar 5B2.

[0079] In the illustrated example, the mounting of each bearing body 14A, 14B of the first support 14 in the corresponding lateral upright of the frame 2 allows a translation, along a direction of translation perpendicular to the PXY scroll plane, of this bearing body 14A, 14B relative to the frame 2, therefore consequently allows the same translation of the first support 14, and therefore of the first working roller 10 relative to the frame 2.

[0080] In this example, the connection between the first support 14 and the frame 2 allows the first support 14, and therefore the roller 10, to move purely along the translational direction Z perpendicular to the traversing plane PXY. However, other types of mechanical connections between the first support 14 and the frame 2 can be provided, which ensure not a purely linear movement along the translational direction perpendicular to the traversing plane PXY, but a movement with a component along the translational direction perpendicular to the traversing plane PXY, preferably a major component. Such a mechanical connection could, for example, be a parallelogram linkage, an eccentric linkage, etc.

[0081] The calendering machine 1 also includes at least one load actuator 32 for controlling the movement of the first support 14 relative to the frame 2, in the direction of bringing the two work rollers 10, 20 closer together. In the illustrated example, in which the first support 14 has two independent bearing bodies 14A, 14B, the calendering machine 1 includes at least one load actuator associated with each of the bearing bodies 14A, 14B associated with this first work roller 10. As can be seen more particularly in the figures, the calendering machine 1 illustrated by way of example includes a group 32A of two left-hand load actuators, namely a left-hand upstream load actuator 32A1 and a left-hand downstream load actuator 32A2, which control the movement, along the translational direction Z perpendicular to the travel plane PXY, of the left-hand bearing body 14A.Symmetrically, the calendering machine 1 comprises a group 32B of two straight load actuators, namely an upstream straight load actuator 32B1 and a downstream straight load actuator 32B2 which control the displacement, along the translational direction Z perpendicular to the traversing plane PXY, of the straight bearing body 14B. For each group of load actuators, . The upstream load actuator and the downstream load actuator are offset from each other along the X scroll direction, and, in the example, they are interposed between the bearing body and the adjacent side member of the corresponding side member, in this case the lower side member of the corresponding side member.

[0082] In the illustrated example, each load actuator 32A1, 32A2, 32B1, 32B2 is, for example, a hydraulic actuator, in particular a hydraulic cylinder. However, other types of actuators, in particular electric ones, are also possible. Furthermore, a transmission mechanism may be provided between the load actuator(s) and the movable work roller 10, and where applicable its dedicated movable support 14, for example, a reduction gear and / or right-angle drive mechanism.

[0083] As will be described in more detail, the load actuator(s) allows for a dynamic adjustment of the relative position of the two working rollers 10, 20, including during a production phase, in order to adapt in real time the spacing between the two working rollers 10, 20 at the level of the calendering space 30, in particular to adapt to variations in calendering conditions as the strip 4 passes through the calendering space 30.

[0084] In the illustrated example, the second support 24, for the second working roller 20, also comprises two bearing bodies, namely a left bearing body 24A and a right bearing body 24B, which are arranged axially on either side of the central portion 22 of the second working roller 20. In the illustrated example, the two bearing bodies 24A, 24B of the second support 14 are independent of each other. Each bearing body 24A, 24B receives, by rotation, through the bearing body, the corresponding lateral section, namely respectively a left lateral section 23A and a right lateral section 23B, of the second working roller 20, preferably with an interposed bearing (not shown). In the example, each bearing body 24A, 24B of the first support 14 is mounted in the corresponding side post 5B of the frame 2, possibly with means for adjusting the position of the bearing body in the frame 2.Thus, the left bearing body 24A is mounted in the central opening of the left side post 5A, between the upstream pillar 5A1 and the downstream pillar 5A2. Symmetrically, the right bearing body 24B is mounted by sliding, along the Z direction perpendicular to the PXY scroll plane, in the central opening of the right side post 5B, between the upstream pillar 5B1 and the downstream pillar 5B2.

[0085] The calendering machine also includes a control system 100 which allows the calendering machine 1 to be controlled, in particular to control the load actuator(s) 32 in order to move the first working roller 10 relative to the second working roller 20 in order to obtain a target value e30c of the working gap e30 between the two working rollers. As mentioned above, the target value e30c of the working gap e30 is to be distinguished from The target thickness of the strip at the machine exit is affected, notably by the strip's elasticity, which generally causes it to regain thickness as it exits the calendering space 30 in the direction of travel. However, the target value e30c of the working gap e30 directly influences the thickness of the strip 4 at the machine exit.

[0086] The control system 100 may include, in particular, one or more computer control units 110 and one or more power circuits, such as, for example, a hydraulic power circuit 120 capable of delivering to the load actuator or load actuators 32 the power necessary for the movement of the first working roller 10. The control system 100 may also include one or more sensors, a computer communication network enabling computer communication between different components of the control system 100 and / or with external systems, one or more human-machine interfaces, etc.A computer control system can take the form of a computer, an electronic control unit and / or a programmable logic controller, and may include at least one computer processor, computer memory, input and / or output interfaces, etc.

[0087] It follows from what has been described above that the first support 14 is mobile relative to the second support 24 along the translation direction Z perpendicular to the scroll plane PXY.

[0088] In the illustrated example, but optionally, the calendering machine one includes a pre-loading mechanism for the two working rollers 10, 20, more particularly visible in Figures 2 and 3. In the example, each of the lateral sections 13A, 13B, 23A, 23B of the two working rollers 10, 20 includes an end end 15A, 15B, 25A, 25B which extends outwards beyond the corresponding lateral upright 5A, 5B of the frame 2 and, in the illustrated example, beyond the corresponding bearing body 14A, 14B, 24A, 24B. On each of these end ends 15A, 15B, 25A, 25B, a preload bearing 16A, 16B, 26A, 26B is rotatably mounted on the corresponding end end 15A, 15B, 25A, 25B, around the axis Y10, Y20 of the corresponding work roller 10, 20. Each work roller 10, 20 is therefore equipped with two preload bearings, namely a left preload bearing 16A, 26A and a right preload bearing 16B, 26B.A preload actuation system is provided between the preload bearings of the two work rollers 10, 20 to separate the two work rollers 10, 20 perpendicularly to the PXY travel plane, in order to preload the two work rollers 10, 20, and to take up any possible play between on the one hand the work roller 10, 20 and its support 14, 24, and on the other hand between the support 14, 24 and the frame 2. More precisely, the . Two bearing bodies 24A, 24B of the second support 24 are pressed against the corresponding upper spar 5A4, 5B4 of the frame 2, and the two bearing bodies 14A, 14B of the first support 14 are pressed against the load actuators 32A1, 32A2, 32B1, 32B2. In the example, the preload actuation system includes, between the left preload bearings 16A, 26A, a left preload actuator 40A, for example a spreader cylinder, and a left rigid connecting rod 42A, which connect the left preload bearings 16A, 26A, one on an upstream side of the preload bearings relative to the calendering plane PYZ, and the other on the downstream side of the preload bearings relative to the calendering plane PYZ.Symmetrically, the preload actuation system comprises, between the straight preload bearings 16B, 26B, a straight preload actuator 40B, for example a spreader cylinder, and a rigid straight connecting rod 42B, which connect the straight preload bearings 16B, 26B, one on an upstream side of the straight preload bearings relative to the calendering plane PYZ, and the other on the downstream side of the preload bearings relative to the calendering plane PYZ. By actuating the preload actuators 40A, 40B in the direction of a spread, the two working rollers 10, 20 are spread apart perpendicularly to the feed plane PXY, even before the introduction of the strip four into the calendering space 30.

[0089] In certain embodiments, the invention can be implemented in a calendering machine designed to be operated by controlling the calendering force during the calendering operation ("force mode"). To this end, one or more actuators of the moving support(s) are controlled by a computer control unit to apply a controlled force to the strip being moved through the calendering space. For example, if the actuator includes one or more hydraulic cylinders, the computer control unit monitors the hydraulic pressure delivered to the cylinders, for example, by controlling a supply valve for the cylinder(s). To this end, the computer control unit receives information representing the thickness of the calendering space, for example, by implementing the sensor system described below.Based on this information, the computer control system adjusts its output setpoint, which controls the force applied by the actuator. In theory, this method is accurate. Such a process is generally efficient within a stable process, but it has proven less efficient during periods of process variation.

[0090] Also, in the illustrated example, as can be seen more particularly in Figures 1 and 4, but optionally, the calendering machine includes a mechanical stop, which is interposed, for example, between the first support 14 and the second support 24 and which determines a setting of the working gap e30 at a Initial calibration value e30i. This calibration is a calibration along the direction perpendicular to the PXY scroll plane. Alternatively, the mechanical stop could be interposed between the movable support, here the first support 14, and the frame 2. In the example, the mechanical stop comprises a left stop 50A, interposed between the left bearing bodies 14A, 24A of the first and second supports 14, 24, and a right stop 50B interposed between the right bearing bodies 14B, 24B of the first and second supports 14, 24. The mechanical stop, which in the example includes the left stop 50A and the right stop 50B, determines an initial setting of the working gap e30 to an initial setting value e30i, when a setting force is applied to the first support 14 in the direction of the second support 24, for example by means of the load actuator(s) 32.

[0091] In the illustrated example, the mechanical stop is an adjustable stop, in the sense that the initial positioning can be set, before any production phase, by predetermining the thickness of the stop along the Z direction perpendicular to the PXY flow plane. In the example, each of the left stop 50A and right stop 50B is made in the form of a pair of angled shims, lower 51 and upper 52. Each angled shim 51, 52 has two opposing flat faces 53, 54 which form an angle, or slope "p", a slope "p" which can, for example, be in the range of 1% to 10% along a direction of greatest slope. The two angled wedges 51, 52 of an adjustable stop 50A, 50B are stacked in support against each other by their respective inclined faces 53, 54, head-to-tail, as illustrated in particular on [Fig.5].Each of the left stop 50A and right stop 50B, formed by a pair of stacked angled wedges 51, 52, taken as a whole, thus presents a lower face 55 and an upper face 56 that are parallel to the PXY travel plane and that can bear against an upper face 57 of the first support 14 and against a lower face 58 of the second support 24, respectively. The respective inclined faces 53, 54, by which the angled wedges 51, 52 bear against each other, are oriented head-to-tail with their directions of greatest slope aligned. By varying the relative position of the two angled wedges 52, 54 along their common direction of greatest slope, the thickness of the stop formed by the two angled wedges 51, 52 is varied, that is to say, the distance between the lower face 55 and the upper face 56 of the stop.The adjustment of the relative position of the two angled wedges 51,52, and therefore the adjustment of the thickness of the stop, can be mechanized, or even motorized.

[0092] In operation, initial adjustment of the working gap is first made to an initial adjustment value, determined by the contact on the mechanical stop 50A, 50Bn, which is, for example, interposed between the first support and the second support, by applying an adjustment force Fl on at least one of the first and second supports 14, 24 in the direction of the other of the first and second rollers working 14, 24. The holding force Fl is preferably strictly less than the calendering force F, applied, on at least one of the first and second support 14, 24, during a production phase in which a strip 4 is being calendered by passing through the calendering space 30. The holding force Fl can be a predetermined constant value, this predetermined constant value being a function of the parameters of a future production phase (for example thickness of the strip at the machine inlet, and / or target thickness of the strip at the machine outlet, and / or mechanical characteristics of the strip (in particular in compression perpendicular to the plane of movement), etc...) or being independent of the parameters of a future production phase.Typically, the clamping force Fl can be chosen to ensure that, at no point during a production phase, the resisting force imposed by the strip on the work rollers 1 can cause the work rollers 10, 20 to recoil, which would cause one of the supports 14, 24 to lose contact with the mechanical stop interposed between the first support 14 and the second support 24. In an embodiment where the first work roller 10, which is movable relative to the frame 2 of the machine 1, is arranged vertically below the second work roller 20, which is fixed relative to the frame 2, the weight of the moving assembly formed by the first support 14 and the first work roller 10 can advantageously be taken into account. Thus, the clamping force Fl can include a component Fg intended to compensate for the weight exerted by gravity on this moving assembly.Furthermore, the clamping force Fl may include a component F40 intended to compensate for the preload forces applied by the preload system to the two working rollers 10-20, ensuring that the actual force applied to the strip is the intended force. In some applications, the clamping force Fl may range from 40 to 85 percent of the total force F applied to the support during a production phase.

[0093] The initial offset value e30i is distinct from, and strictly greater than, the target value e30c of the working gap e30. For example, the initial offset value e30i is between 1.05 and 2 times the target value e30c.

[0094] Initial setup is preferably carried out outside of any production phase, i.e. in the absence of strapping in the workspace 30. Initial setup is carried out for example without rotation of the work rollers.

[0095] The initial setup is carried out, for example, by adjusting the adjustable mechanical stop. For example, the initial setup can be carried out by directly detecting the working gap by directly detecting the working surfaces 11, 21 of the two rollers 10, 20, outside of any production phase, i.e., in the absence of strip in the working space 30, and without rotation of the working rollers 10, 20, and by adjusting The adjustable mechanical stop is moved until the working gap e30 reaches a predetermined initial shim value. Direct detection of the working surfaces 11, 21 of the two rollers 10, 20 can be achieved by measuring the distance between the working surfaces 11, 21 of the two rollers 10, 20 using any conventional measuring method. Direct detection of the working surfaces 11, 21 of the two rollers 10, 20 can also be achieved using a calibrated shim. Thus, the initial shimming can be carried out by detecting the working gap by inserting a shim of calibrated thickness, having a thickness equal to the initial shimming value, into the working space between the working surfaces 11,21 of the two rollers 10, 20, and by adjusting the adjustable mechanical stop until the shim of calibrated thickness is received without play and without blocking in the working space between the working surfaces 11,21 of the two rollers 10, 20.

[0096] Preferably, the initial positioning is carried out by applying the positioning force Fl discussed above to the moving support.

[0097] It is noted that the initial calibration can be carried out by exploiting the acquisition sensor(s) 60A 60B of at least one representative quantity d60A, d60B of the working gap e30, as described below, in addition to or instead of a direct detection of the working surfaces 11, 21 of the two rollers 10, 20 as described above.

[0098] Of course, other forms of mechanical stop can be implemented, including fixed stops, subject to the possible provision of different fixed stops having different thicknesses.

[0099] The calendering machine 1 also includes at least one acquisition sensor 60A, 60B, which, during a production phase in which the strip passes through the calendering space, acquires successive time values ​​d60A(t), d60B(t) of at least one representative quantity d60A, d60B of the working gap e30. As mentioned above, the working gap e30 can have a very small value, for example, between 50 and 250 microns. In such a case, the direct measurement of this working gap e30, by directly measuring the gap between the two working surfaces 11, 21 of the two working rollers 10, 20, is very difficult, even more so during a production phase since the moving strip 4 then occupies the calendering space 30 as it passes through it.

[0100] In the present application, a production phase is therefore a phase during which the strip to be calendered passes through the calendering space 30. In such a phase, the first support 14 and the second support 24 are in contact with the mechanical stop which is for example interposed between the two.

[0101] In the illustrated example, the calendering machine includes two sensors, namely a left sensor 60A and a right sensor 60B, which are arranged at each axial end of the calendering space 30, in the direction parallel to the axes Y10, Y20 of the two working rollers 10, 20. Thanks to these two sensors 60A, 60B, the calendering machine 1 can acquire, during a production phase during which the strip 4 passes through the calendering space 30, successive values ​​in time d60A(t), d60B(t) of at least two quantities representative d60A, d60B of the working gap, a first quantity d60A being acquired at a first axial end of the calendering space 30, and a second quantity being acquired at a second, opposite axial end of the calendering space.

[0102] Typically, the calendering machine can be configured to implement a known relationship between, on the one hand, the values ​​of the representative quantity(ies) d60A, d60B of the working gap, and, on the other hand, the corresponding values ​​of the working gap e30. This known relationship can, for example, be stored in computer memory belonging to the control computer 110 or accessed by computer by the control computer 110.

[0103] Also, the calendering machine 1 described herein by way of example is configured so that at least one quantity representative of the working gap, acquired by the sensor 60A, 60B is a relative distance between at least one cylindrical surface of revolution of one of the two work rollers 10, 20 and an auxiliary reference surface 17A, 17B, 27A, 27B belonging to the other of the two work rollers 10, 20, said auxiliary reference surface 17, 20 being distinct from the working surface of the work roller to which it belongs.

[0104] In the illustrated example, the two work rollers 10, 20 are each equipped with auxiliary reference surfaces 17A, 17B, 27A, 27B. More specifically, each work roller 10, 20 is equipped with two auxiliary reference surfaces, distinct from each other and each distinct from the work surface 11, 21 of the work roller 10, 20 to which it belongs.

[0105] In the illustrated examples, for a given work roller 10, 20, an auxiliary reference surface 17A, 17B, 27A, 27B is a cylindrical surface of revolution coaxial with the work surface 11,21 of this given work roller, therefore also having as its axis of symmetry of revolution the axis Y10, Y20 of this work roller. For a given work roller, the auxiliary reference surfaces 17A, 17B, 27A, 27B are axially offset, relative to the work surface 11, 21 of that given work roller, along the direction of the Y10, Y20 axis of that work roller 10, 20, and their diameter is strictly smaller than the diameter of the work surface 11, 21 of that work roller 10, 20. In the illustrated example, the two auxiliary reference surfaces 17A, 17B, 27A, 27B of the same work roller 10, 20 are arranged axially, that is, along the direction of the Y10, Y20 axis of that work roller. on either side of the working surface 11,21 of this work roller. In the illustrated example, each auxiliary reference surface 17A, 17B, 27A, 27B is immediately axially attached to the working surface 11,21 of the corresponding work roller.

[0106] In the illustrated example, the two work rollers 10, 20 are each equipped with at least one auxiliary reference surface 17A, 17B, 27A, 27B which is axially opposite an auxiliary reference surface of the other of the two work rollers 10, 20. In such a case, at least one quantity representative of the working gap, which is acquired by means of a sensor of the machine 1, is preferably a relative distance d60A, d60B between these two auxiliary reference surfaces belonging respectively to each of the two work rollers.However, in an alternative not shown, it can be assumed that at least one representative value of the working gap, acquired by means of a sensor on machine 1, is a relative distance between an auxiliary reference surface 17A, 17B, 27A, 27B of one of the working rollers and a portion, for example an axial end portion, of the working surface 11, 21 of the other of the two working rollers. For example, such a case can be implemented if the auxiliary reference surface of one of the working rollers is arranged axially opposite an axial end of the working surface 11, 21 of the other of the two working rollers 10, 20.

[0107] In all cases, the auxiliary reference surface 17A, 17B, 27A, 27B of a given work roll 10, 20 is manufactured to exhibit a geometric accuracy, particularly in terms of cylindricity and surface finish, comparable to that of the work surface 11, 21 of the same work roll 10, 20. Generally, the final manufacturing steps of the work surface of a work roll typically include grinding and surface treatment operations. Advantageously, the manufacturing of the work roll in question may be arranged so that the manufacturing of the auxiliary reference surface is carried out in exactly the same way as that of the work surface 11, 21 of the same work roll 10, 20, particularly with regard to the final grinding and / or surface treatment steps of these two surfaces.Thus, the radial position of a point on the auxiliary reference surface, having a certain angular coordinate around the roller axis, can be considered representative of the radial position of a point on the working surface occupying the same angular coordinate around the roller axis, taking into account, of course, the difference in diameter between the auxiliary reference surface and the working surface. Preferably, the final grinding and / or surface treatment steps of the auxiliary reference surface and the working surface of the same roller are carried out simultaneously, on the same machines, and under the same conditions for both surfaces. Such precautions make it possible to obtain a radial position correspondence. any pair of points with the same angular coordinate of the two surfaces, which, taking into account the difference in diameter of the two surfaces, has an error which is preferably less than 5 microns, or even preferably in a range between 0.5 and 2 microns.

[0108] In such an example, it will thus be easy to determine a known relationship between, on the one hand, the values ​​of the representative quantity(ies) d60A, d60B of the working gap, and, on the other hand, the corresponding real values ​​of the working gap e30. This known relationship is, for each working roller, directly the reflection of the difference between, on the one hand, the diameter of the reference auxiliary surface(s) 17A, 17B, 27A, 27B of a working roller 10, 20 considered, and, on the other hand, the diameter of the working surface 11,21 of the working roller considered. This known relationship is preferably stored in a computer memory belonging to the control computer 110 or accessible by computer by the control computer 110, for example in the form of a conversion function or in the form of a table of corresponding values.

[0109] In cases where the calendering machine has two sensors, in particular a left sensor 60A and a right sensor 60B arranged at each axial end of the calendering space 30, each of the two representative quantities d60A, d60B of the working gap e30 acquired by these two sensors 60A, 60B is preferably a relative distance between at least one cylindrical surface of revolution of one of the two work rollers and a reference auxiliary surface belonging to the other of the two work rollers. In the illustrated example, each of the two representative quantities d60A, d60B of the working gap e30 is a relative distance between two reference auxiliary surfaces, respectively 17A, 27A and 17B, 27B, one of which belongs to one of the two work rollers 10 and the other to the other of the two work rollers 20.

[0110] In cases where the acquisition uses at least one auxiliary reference surface with a diameter smaller than the diameter of the working surface of that roller, the distance acquired is greater than the working gap. The difference in diameter between the auxiliary reference surface and the working surface of the same roller can be chosen to facilitate the integration of a sensor between the surfaces of the two rollers whose distance is to be acquired. Of course, by using two opposing auxiliary reference surfaces, each belonging to one of the two working rollers, each auxiliary reference surface having a diameter smaller than the diameter of the working surface of the corresponding roller to which it belongs, the available distance between these two auxiliary surfaces is The reference greatly facilitates the placement of a sensor to measure the distance between the two auxiliary reference surfaces.

[0111] Thus, as illustrated in Figures 1, 4, and 6, the at least one sensor 60A, 60B used for data acquisition can be a sensor positioned in the calendering plane PYZ containing the two axes Y10, Y20 of the two work rollers 10, 20. The sensor 60A, 60B can be arranged between at least one cylindrical surface of revolution of one of the two work rollers and the auxiliary reference surface belonging to the other of the two work rollers, opposite it. The sensor 60A, 60B is advantageously arranged at an axial end of the calendering space 30 in a direction parallel to the axes Y10, Y20 of the two work rollers 10, 20, while remaining outside the calendering space 30.

[0112] Preferably, at least one sensor 60A, 60B used to acquire at least one representative quantity d60A, d60B of the working gap e30 is a non-contact sensor, in particular a capacitive sensor. Such sensors are commercially available, for example from MICRO-EPSILON FRANCE SARL, 14-16 rue des Gaudines, 78100 Saint Germain en Laye, France. Such capacitive non-contact sensors, in particular those of the "capaNCDT" series, are sold as having a resolution on the order of nanometers, for measurements requiring sub-micrometer accuracy, including in industrial environments. However, other types of sensors can be used, such as optical sensors (including confocal-chromatic sensors, laser sensors, in particular laser triangulation displacement sensors), magnetic sensors, inductive sensors, eddy current sensors, and / or any combination thereof.

[0113] As illustrated more particularly in [Fig. 6], to acquire the relative distance d60A between at least one cylindrical surface of revolution of one of the two working rollers and an auxiliary reference surface belonging to the other of the two working rollers, at least one of the sensors 60A, 60B may include two measuring cells 61, 62, one of which is used to measure the distance between the sensor and one of the surfaces, and the other is used to measure the distance between the sensor and the other of the surfaces. With these two distances, it is easy to calculate the relative distance d60A by simply calibrating the sensor 60A equipped with its two measuring cells 61, 62.

[0114] Figure 6 illustrates an embodiment of the implementation of such a contactless sensor. In this example, the two work rollers 10, 20 are each equipped with auxiliary reference surfaces 17A, 27A, each of which is immediately axially adjacent to the work surface 11, 21 of the corresponding work roller. The two auxiliary reference surfaces 17A, 27A are axially opposite each other, each near a shoulder 18A, 28A of the work roller 10, 20 to which they respectively belong. Each shoulder 18A, 18B forms a diameter reduction of the corresponding work roller 10, 20, freeing up a free space 63 axially adjacent to the work rollers 10, 20, axially on one side of the central part 12, 22 of the work rollers 10, 20. A sensor support 64 is arranged in the free space 63. The sensor support 64 is, for example, fixed to the frame 2 of the machine 1, for example on the corresponding side post 5A. In the example, the sensor support 64 has a tangential arm 66 which extends substantially in the PXY scroll plane and is inserted tangentially between the two rollers, such that a free end 68 of the tangential arm 66 is located between the two reference auxiliary surfaces 17A, 27A opposite each other.Preferably, the tangential arm 66 extends in the calendering plane PYZ containing the axes Y10, Y20 of the two work rollers 10, 20, and therefore has a transverse orientation parallel to the axes of the work rollers 10, 20. The sensor 60A is arranged at the free end 68 of the tangential arm 66. The sensor support 64 is preferably adjustable in terms of geometry to best position the sensor 60A between the surfaces considered.

[0115] Thus equipped with at least one sensor, preferably two sensors arranged axially on either side of the calendering space 30, the machine 1 is able to determine the instantaneous value of the working gap e30 with very high precision, preferably with an error of less than 10 microns, more preferably less than 5 microns, for example less than 2 microns.

[0116] Advantageously, the arrangement of the sensor or sensors, which measures the representative quantity of the working gap in the calendering plane PYZ, therefore performs a measurement that can be described as a real-time measurement of the working gap, exactly coinciding in time with the moment when this working gap acts on the strip in the calendering space 30. This is particularly advantageous compared to variants in which strip thickness measurements are taken at the machine outlet, the measurement time being in such a case delayed in time relative to the time at which the measured thickness was created in the calendering space 30.This time delay, inherent in the measurement technique at the machine output, corresponds to the duration of the journey of a given point on the strip 4, according to the direction of travel X, between the calendering space 30 and the measurement point determined by the position of the strip thickness measurement sensor.

[0117] Preferably, the acquisitions, by the sensor(s), of the quantity(ies) representing the working gap are repeated successively in time with a high frequency, preferably with an acquisition frequency of at least 10 Hz, preferably at least 100 Hz, for example included in the range from 200 Hz to 10,000 Hz. When the working rollers 10, 20 are rotating, particularly during a production phase in which a strip 4 is being calendered by passing through the calendering space 30, a high-frequency acquisition allows successive measurements of the working gap e30 at time intervals that correspond to very short distances of the strip 4 passing through.

[0118] With the following operating parameters: V = strip conveying speed (m / s) f = acquisition frequency of the quantity representing the working gap (1 / s), then the linear distance dX, on the strip, in the X direction of conveying, between two acquisitions is equal to dX = V / f

[0119] Thus, as an example, with a strip speed of 60 m / min, i.e. 1 m / s, and an acquisition frequency of 1000 Hz, corresponding to an acquisition every millisecond, the representative quantity of the working gap e30 is measured for each millimeter of strip speed 4.

[0120] In machine 1, the computer control unit 110 is configured to control at least one load actuator 32A1, 32A2, 32B1, 32B2 so that it delivers on the first support 14 a total force F(t) adjusted successively in time.

[0121] Optionally, the computer control unit 110 is configured to control at least one load actuator 32A1, 32A2, 32B1, 32B2 so that it delivers on the first support 14 a total force F(t) adjusted successively in time according to the acquired values ​​of the quantity representing the working gap and the target value of the working gap.

[0122] Figure 7 schematically illustrates a first example of how a machine and calendering process as described can be implemented, in a simplified and schematic version.

[0123] The two counter-rotating working rollers 10, 20, about their respective axes Y10, Y20, are schematically illustrated. The first working roller 10 is mounted to rotate about the first axis Y10 on the first support 14, which is movable relative to the machine frame 2. At least one sensor 60 acquires, during a production phase, successive values ​​over time of at least one quantity d60 representing the working gap e30. The computer control unit 110 is configured to control, here via the hydraulic power circuit 120, the load actuator 32 so that it delivers a total force F(t) to the first support 14, adjusted successively over time according to the d60(t) values ​​acquired of the quantity d60 representing the working gap e30 and the target value e30c of the working gap.

[0124] Figure 7 illustrates that the computer control unit 110 can receive, as input, for example via a human / machine interface or via an input computer communication, a target value e30c of the working gap e30.

[0125] In certain implementations, the total force F(t) can be analyzed as the stalling force Fl, which can be fixed over time for a given production phase, or which can vary slowly, for example, according to an evolution of the production conditions, to which is added a complementary force F2(t) adjusted successively over time during the given production phase, with for example the relation F(t) = Fl + F2(t).

[0126] In the example of [Fig.7], the clamping force Fl is determined from a minimum value Fmin of a calendering force, which is supplied as input by an operator, for example via a human / machine interface, a value F40 representing the weight of the moving assembly formed by the first support 14 and the first work roller 10, and a value Fg representing the preload forces which are applied by the preload system 40 on the two work rollers 10-20. For example, the clamping force Fl is a sum of these three values.

[0127] The total force F(t), in particular its component which is the complementary force F2(t), is therefore likely to vary over time

[0128] According to an optional aspect, the complementary force F2(t) is likely to vary over time according to the variations observed for the values ​​acquired successively over time of the quantity d60 representing the working gap e30.

[0129] In such a case, the total force F(t), in particular its component which is the complementary force F2(t), is preferably determined as a function of at least the last value acquired in time of the quantity representing the working gap e30, available for processing, preferably as a function of a series of last values ​​acquired in time of the quantity representing the working gap e30, available for processing, on the principle of taking into account a sliding time window including preferably the last value acquired in time of the quantity representing the working gap e30 available for processing.The total force F(t), in particular its component which is the complementary force F2(t), is thus, for example, determined as a function of a series of 3, 5, 10, 20, or 50 values ​​acquired over time of the quantity representing the working gap e30, these values ​​preferably being the most recent values ​​available for processing. In the case of taking into account a time window, the consideration of . Taking into account a series of values ​​makes it possible to mitigate or even eliminate the impact of one or more erroneous, abnormal, or aberrant values, for example by implementing a filtering and / or smoothing algorithm. Preferably, including in the case of taking into account a time window, the value or all values, acquired successively over time, of the quantity d60 representing the working gap e30, which are taken into account, at each given instant, for the adjustment of the total force F(t) during the production phase, are values ​​that were acquired less than 1 second before the given instant, preferably less than 100 milliseconds before the given instant, and more preferably less than 10 milliseconds before the given instant.

[0130] In other words, the total force F(t), in particular its component which is the complementary force F2(t), is preferably determined in "real time" with respect to the calendering process, with the smallest possible time lag.

[0131] It should be noted that, preferably, the complementary force F2(t) and the initial stalling force Fl are, in the illustrated example, applied by the same actuator that delivers the total force F(t), more precisely by the same load actuators 32A1, 32A2, 32B1, 32B2. However, the complementary force F2(t) and the initial stalling force Fl could be applied by separate actuators, totally or in part.

[0132] For example, the computer 110 can be programmed to minimize the difference between, on the one hand, the actual values ​​of the working gap e30, in this case deduced from the acquired values ​​of the quantity d60 representing the working gap, and on the other hand, the target value e30c for this working gap. The computer 110 can, for example, be programmed to apply a calculation algorithm comprising the calculation of a total force setpoint cF(t), including in particular the calculation of a complementary force setpoint cF2(t), adjusted successively over time during a production phase during which the strip 4 passes through the calendering space 30, as a function of the acquired values ​​d60(t) of the quantity representing the working gap and the target value e30c of the working gap. In the example of [Fig.[7], the computer calculator 110 performs the calculation of a total force setpoint cF(t) as the sum of a complementary force setpoint cF2(t) with a setpoint cFl of initial setting force, the initial setting force setpoint being determined as a function of a setpoint cFmin of minimum calendering force value, a setpoint cFg representing the weight of the moving assembly formed by the first support 14 and the first work roller 10 and a setpoint cF40 representing the preload forces which are applied by the preload system 40 on the two work rollers 10-20. For example, the setpoint cFl of initial setting force is a sum of these three setpoints cFmin, cF40 and cFg.

[0133] For example, as illustrated in [Fig. 7], the computer 110 may include a negative feedback loop controller 112, the negative feedback being based on one or more successive acquired values ​​of the quantity representing the working gap. The computer 110 may, for example, include a proportional (P), proportional-integral (PI), proportional-derivative (PD), and / or proportional-integral-derivative (PID) controller 112, etc., or several of these controllers, for example, in cascade. The controller 112 may thus, for example, deliver at each instant a control setpoint cReg30(t) for the working gap value as a function, on the one hand, of the acquired values ​​d60(t) of the quantity representing the working gap, and on the other hand, of the target value e30c.

[0134] In [Fig. 7], it has been illustrated that the control computer 110 can include a second converter 113 capable of delivering, based on the control setpoint cReg30(t) for the working gap value, the complementary force setpoint cF2(t) usable by the hydraulic power circuit 120. This second converter 113 could be integrated into another element of the control system 100, for example, the hydraulic power circuit 120. This second converter 113 implements a known relationship between, on the one hand, a variation in the force applied by the load actuator on the support 14, and, on the other hand, the corresponding variation in the working gap e30(t). The second converter 113 can take the form of an algorithm executed by the control computer 110.This algorithm can use values ​​learned directly from the machine, for example during a machine calibration step.

[0135] The computer control unit 110 is configured to control at least one load actuator 32A1, 32A2, 32B1, 32B2 so that it delivers on the first support 14 the total force F(t), adjusted successively in time during the production phase, corresponding to the total force setpoint cF(t), corresponding to the complementary force setpoint cF2(t) in the example described.For this purpose, within the control system 100, the computer control unit 110 can be in computer communication with a hydraulic power circuit 120 capable of delivering to the load actuator 32 or to the load actuators 32A, 32B, the power necessary for the movement of the first working roller 10, for example one controlling the supply to hydraulic cylinders of a regulated pressure P(t) of hydraulic fluid, this regulated pressure corresponding to the setpoint cF(t) calculated by the computer control unit 110.

[0136] As in the described and illustrated example, the machine 1 preferably comprises at least two groups 32A, 32B of load actuators, each associated with one of the two axial ends of the calendering space. The left group 32A and the right group 32B of load actuators each comprise one or more actuators. In the example, each right group of load actuators comprises two actuators that are offset respectively upstream and downstream of the calendering plane PYZ along the direction of travel. In the illustrated example, the two groups left 32A and right 32B of load actuators are controlled independently of each other.

[0137] For example, the computer control unit 110 is configured to control each group of load actuators so that it delivers on the first support 14 a total force respectively FA(t) and FB(t), depending on the successively acquired values ​​d60A(t), d60B(t) of the representative quantity of the working gap acquired at the corresponding end of the calendering space 30, and of the target value e30c of the working gap. In the example, the group 32A of left actuators 32A1, 32A2, is thus likely to apply a total left force FA(t) on the left bearing body 14A of the first support 14, while the group 32B of right actuators 32B1, 32B2, is thus likely to apply a total right force FB(t) on the right bearing body 14B of the first support 14.The two total forces left FA(t) and right FB(t), applied respectively to the left bearing body 14A and the right bearing body 14B, can thus be different, for example to compensate for a heterogeneity, along the transverse direction Y, in the structure of the strip at the machine inlet, a heterogeneity which would require differentiated calendering forces on the left and right in order to obtain a more homogeneous strip at the exit of the calendering machine 1. When a group of actuators, assigned to a given axial end of the calendering space 30, comprises several actuators, the actuators of this group can receive the same instruction, or each a distinct instruction.

[0138] Furthermore, calendering methods for a strip 4 to be calendered are proposed herein. [Fig. 8] is a flowchart illustrating an example of such a method.

[0139] These processes are implemented for example with a calendering machine 1 as described above.

[0140] In a known manner, such methods 1000 comprise the operation 1100 of causing the strip 4 to slide, in a slide plane PXY along a slide direction X from upstream to downstream, through a calendering space 30 defined between: - a cylindrical working surface 11 of a first working roller 10, which is mounted to rotate around a first axis Y10 on a first support 14, - and a cylindrical working surface 12 of a second working roller 20, which is mounted to rotate around a second axis Y20, parallel to the first axis Y10, on a second support 24

[0141] As seen above, the two working rollers 10, 20 are counter-rotating, rotating in opposite directions around their respective axes of rotation Y10, Y20.

[0142] It is defined that the calendering space 30 has, at its minimum spacing point along a direction Z perpendicular to the PXY scroll plane, a working spacing e30, between the working surfaces 11,21 of the two working rollers 10, 20.

[0143] To obtain a strip with desired characteristics, the process 1000 involves applying, on at least one of the supports 14, 24 of one or the other of the working rollers, a pressure force perpendicular to the plane of travel (PXY), in the direction of a reduction of the working gap, to obtain a target value of the working gap.

[0144] In one example, the method includes an initial setting 1050 of the working gap e30 to an initial setting value e30i. This initial setting value is determined by the bearing on the mechanical stop 50, which is for example interposed between the first support 14 and the second support 24, this bearing resulting from an application 1040 of a setting force Fl on at least one of the first and second supports 14, 24, in the direction of the other of the first and second working roller. The initial setting operation 1050 can be conducted before or after the start of a production phase during which the strip 4 is introduced between the two rollers 10, 20 through the calendering space 30, i.e. before or after the start of the introduction of the strip 4 is introduced between the two rollers 10, 20 through the calendering space 30.

[0145] Preferably, the initial setting value e30i of the working gap e30 is strictly greater than the target value e30c and is between 1.05 and 2 times the target value e30.

[0146] The process further comprises acquiring, during a production phase in which the strip 4 passes through the calendering space 30, successive values ​​over time of at least one quantity d60A, d60B representative of the working gap. Various methods can be implemented for this operation, including the methods resulting from the description, developed above, of an example machine.

[0147] For example, in such a method, the first working roller 10 is movable, perpendicular to the plane of travel PXY, with the consequence of being able to adjust the working gap e30 between the two working rollers. As seen above at the top, the second working roller can be fixed in translation, in the sense of having a fixed distance from the scrolling plane.

[0148] During said production phase, the process comprises the application 1300, on at least the first support 14, of at least one total force F(t), adjusted successively in time

[0149] In some examples, the total force is adjusted successively in time according to the values ​​acquired in time d60A(t), d60B(t) of at least one quantity d60A, d60B representative of the working gap, to obtain the target value e30c of the working gap e30.

[0150] In certain embodiments, this application 1300, on at least the first support 14, of at least one total force F(t) includes an elastic deformation, caused in particular by the complementary force F2(t), of at least one of the following: the first support 14, the second support 24, the shim 50, and a frame 14 on which the second support 24 is fixed. It is understood here that, in certain embodiments, this deformation concerns parts which, in general, are considered rigid. Indeed, in general, the deformation induced by the complementary force F2(t) will lead to a reduction in the working gap which will be, for example, between 0.05 times and 1 time the target value of e30c of the working gap, which will generally be in the range of 20 to 1500 microns, more particularly in the range of 20 to 250 microns.

[0151] To obtain the application 1300 of such a total force F(t) comprising the complementary force F2(t), which, as seen above, can be applied collectively by several actuators, or even by several groups of actuators, the method may advantageously include the calculation 1250 of a total setpoint cF(t), possibly by means of a calculation of a complementary setpoint cF2(t), adjusted successively over time with a negative feedback loop, for example as a function of the target value e30c and the values ​​acquired successively over time d60A(t), d60B(t) during the acquisition operation 1200 described above, of at least one quantity d60A, d60B representative d60A, d60B of the working gap. This calculation operation 1150 is, for example, carried out in whole or in part by the computer control unit 110.The computer control unit 1110 is configured to control, for example through the control system 100, and in particular for example through the hydraulic power circuit 120, at least one load actuator 32 so that it delivers on the first support 14 a total force corresponding to the setpoint cF(t), possibly by means of a complementary force F2 corresponding to the complementary setpoint cF2(t).

[0152] As described above in the context of machine 1, the acquisition 1200 can include the acquisition, during the production phase in which the strip 4 passes through the calendering space 30, of successive time values ​​d60A(t), d60B(t) of at least two representative quantities d60A, d60B of the working gap e30. Thus, the successive time values ​​of a first quantity d60a can be acquired at a first axial end of the calendering space 30, and the successive time values ​​of a second quantity d60b can be acquired at a second, opposite axial end of the calendering space 30.In such a case, but this is not mandatory, it would be advisable to ensure that the application 1300 of the total force F(t), including the complementary force F2(t), is done in the form of the application, on at least the first support 14, of at least two total forces FA(t), FB(t), respectively left and right, each comprising for example a complementary force F2A(t), F2B(t), in parallel with each other and each offset axially on the side of the corresponding axial end of the calendering space 30, each adjusted successively in time.

[0153] In certain examples, each of the complementary forces F2A(t), F2B(t) is successively adjusted over time according to the acquired values ​​d60A(t), d60B(t) of that of the two quantities d60A and d60B which is representative of the working gap e30 and which is respectively acquired at the corresponding axial end of the calendering space (30). In such a case the total force F(t) is for example related to the two total forces left FA(t) and right FB(t), by the relation F(t) = FA(t) + FB(t).In such a case, the process setpoint calculation operation 1250 may advantageously include the calculation of a separate setpoint cFA(t), cFB(t) for each total left force FA(t) and right force FB(t), possibly by means of a complementary setpoint cF2A(t), cF2B(t)) for each complementary force F2A(t), F2B(t), each separate setpoint being adjusted successively in time, with negative feedback loop, for example as a function of the target value e30c and the values ​​acquired successively in time d60A(t), d60b(t) of that d60A or d60b of the two quantities representing the working gap which is acquired at the corresponding axial end of the calendering space 30.

[0154] As described in the context of the calendering machine 1, at least one quantity d60A, d60B representing the working gap is, for example, a relative distance between at least one cylindrical surface of revolution of one of the two work rollers 10, 20 and an auxiliary reference surface 17A, 17B, 27A, 27B belonging to the other of the two work rollers. As described above, said auxiliary reference surface 17A, 17B, 27A, 27B of the other of the two rollers The working surface is a cylindrical surface of revolution that is coaxial, axially offset, and of strictly smaller diameter than the working surface 11,21 of the corresponding working roller 10,20. However, preferably, and as in the example illustrated in the figures and already described above, at least one quantity d60A, d60B representing the working gap is a relative distance between two auxiliary reference surfaces 17A and 27A, or 17B and 27B, belonging respectively to each of the two working rollers 10,20, each auxiliary reference surface being a coaxial cylindrical surface of revolution, axially offset, and of strictly smaller diameter than the working surface 11,21 of the corresponding working roller 10,20.Advantageously, the two auxiliary reference surfaces 17A and 27A, or 17B and 27B, between which the relative distance representing the working gap is measured, are opposite each other, i.e. facing each other, on either side of the PXY scroll plane.

[0155] As seen above, this relative distance is for example measured with at least one non-contact sensor 60A, 60B, in particular a capacitive sensor. Preferably, for the implementation of such a method, the at least one sensor is positioned in the calendering plane PYZ containing the two axes Y10, Y20 of the two work rollers 10, 20, at an axial end of the calendering space 30 but outside of it, opposite at least one cylindrical surface of revolution of one of the two work rollers and the auxiliary reference surface belonging to the other of the two work rollers.

[0156] Advantageously, in such a process, the acquisition of successive values ​​d60B(t), d60B(t) over time of at least one quantity d60B, d60B representing the working gap e30, and the successive adjustment over time of at least one total force FA(t) FB(t), possibly by means of the successive adjustment over time of the complementary force F2A(t), F2B(t), are each carried out at a frequency greater than 10 hertz, preferably greater than 100 hertz. Such an acquisition frequency makes it possible to regulate the working gap e30 very precisely, and consequently to control, at the machine outlet, the thickness of the strip that is calendered in such a process.

[0157] According to one aspect, machines and processes are proposed which, for a particularly high level of control of the working gap e30, make it possible to take into account any possible geometric defect of the working rollers 10, 20. The concept of a geometric defect of the working rollers 10, 20 includes, in particular: - any potential geometric defects in the working surface 11,21 of at least one of the working rollers, which mean that the working surface in question may locally exhibit deviations from a perfect surface of revolution; and / or - any defects in concordance and / or alignment and / or parallelism of the geometric axis of the work surface 11,21 considered, with respect to the axis of rotation Y10, Y20 of the corresponding work roller in the machine 1; and / or - any defects in concordance and / or alignment and / or parallelism of the two respective axes of rotation Y10, Y20 of the two work rollers in the machine 1.

[0158] When the work surfaces 11,21 are intended to be cylinders of revolution, such geometric defects can be described as cylindricity defects, as any deviation between the actual work surface, in place in the machine, and a perfect cylindrical surface of revolution around a perfect theoretical axis of revolution.

[0159] Such defects are generally very small, with, for example, errors of only a few microns in the radial position of a point on the working surface 11, 21, relative to the axis of rotation Y10, Y20 of the working roller 10, 20 under consideration. However, it is understood that such defects in the geometry of the working rollers 10, 20 and their working surfaces 11, 21 affect the accuracy of the working gap e30.

[0160] Figure 9 schematically illustrates an example of a set of two working rollers 10, 20 exhibiting geometric deviations. The defects are greatly exaggerated for illustrative purposes and are very schematic. In this example, it can be seen that the working surface 11, 21 of a working roller 10, 20 may contain irregularities that can be interpreted as deviations from a cylindrical reference surface. In a given acquisition plane, perpendicular to the Y10, Y20 axis of the working roller 10, 20 under consideration, the working surface 11, 21 is, for example, represented by a quasi-circular profile defined by a radius RI1(0), R21(0) that varies with respect to the Y10, Y20 axis of the roller, with the length of this radius RI1(0), R21(0) varying according to the angular position considered.We can also define, for a considered angular position 0, in the acquisition plane, a local geometry deviation as being for example dR1(0) = RI1(0) - RIO, respectively dR21(0) = R21(0) - R20, with RIO and R20 a reference radius which can be the distance to the Y10, Y20 axis from an arbitrary reference point, or which can be the theoretical radius or the average radius of the considered working surface 11,21.

[0161] Machines and processes are therefore proposed in which defects in the geometry of the working rollers 10, 20 are advantageously at least partially compensated by implementing, for example, the means described below.

[0162] In [Fig.7], we have illustrated the implementation of a correction instruction cor3O(0) as a function of the instantaneous angular position 0(t) of the two working rollers around their respective axes, and as a function of the acquired values ​​of at least one representative quantity, for the instantaneous angular position 0(t), of a geometry deviation of the two working rollers.

[0163] Thus, it is proposed that the process and the machine include the acquisition 1010, during a learning phase prior to a production phase, for each of a series of angular positions 0i of acquisition of the two working rollers 10, 20 around their respective axes Y10, Y20, of values ​​(for example d60i(0) and / or dRl 1(0), dR21(0)) of at least one quantity dRl 1, dR21 representative of a geometry deviation of the two working rollers 10, 20, in particular of the working surfaces 11, 21 of the two working rollers 10, 20.

[0164] For such a learning phase, the angular acquisition positions 0i are preferably distributed, more preferably at regular intervals, over one rotation of the working rollers 10, 20. For example, del80 to 720 angular acquisition positions 0i will be provided distributed at regular intervals over one rotation of the working rollers 10, 20.

[0165] Preferably, the learning phase is carried out under conditions as close as possible to those of a production phase, except that, during the learning phase, a strip is not moving in the calendering space 30. Thus, the learning phase is carried out under conditions in which the working gap e30 has a value that is a so-called free gap value, without the presence of a strip moving in the calendering space 30. Due to geometric defects, the free gap can therefore vary over one rotation of the working rollers 10, 20 around their respective axes Y10, Y20. Preferably, for the machines and processes described above, the learning phase is carried out under the initial setting conditions of the working gap at an initial setting value e30i as described above, with application of the setting force Fl.In such a case, we can therefore consider that the open gap of the working space 30 corresponds to the initial gap e30i, which can therefore vary and can therefore take different values ​​e30i(0) on a rotation of the working rollers 10, 20 around their respective axes Y10, Y20, due to geometric deviations.

[0166] On this basis, once these values ​​(for example d60i(0) and / or dRl 1(0), dR21(0)) representing a geometry deviation have been acquired in a learning phase, it is therefore possible to predict the application 1300, during a production phase in which the strip 4 passes through the calendering space 30, on at least the first support 14, of at least one total force FA(t), FB(t), which is adjusted successively in time as a function of the instantaneous angular position 0(t) of the two work rollers 10, 20 around their respective axes, and as a function of the values ​​(for example d60i(0) and / or dRl 1(0), dR21(0)) acquired of at least one quantity representing, for the instantaneous angular position (0(t)), a geometry deviation of the two work rollers 10, 20, including work surfaces 11,21 of the two work rollers 10, 20.

[0167] Optionally, as in the illustrated example, at least one total force FA(t), FB(t) can also be adjusted successively in time according to the acquired values ​​d60A(t), d60B(t)) of at least one quantity d60A, d60B representative of the working gap, as described above.

[0168] The correction cor3O(0) is determined to generate a variation in the working gap 30 that compensates as closely as possible for any variation in this working gap that would appear, in the absence of this correction, solely due to deviations in the geometry of the working rollers. It is understood here that this compensation is preferably performed at the exact same time as the working gap that would appear, in the absence of this correction cor3O(0), solely due to deviations in the geometry of the working rollers, which simply depends on the instantaneous angular position of the working rollers around their respective axes. This compensation is not performed in reaction to an observed variation in the working gap e30, but simultaneously and in the opposite direction to a variation in this working gap that would appear, in the absence of this correction cor3O(0), by canceling it out.

[0169] Therefore, in an application which includes a feedback loop to regulate the working gap, for example in a "force mode" type operation or in the case of the feedback loop as described above, which aims to adjust the total force FA(t), FB(t) according to the acquired values ​​d60A(t), d60B(t)) of at least one quantity d60A, d60B representative of the working gap, it is understood that the feedback loop does not have to compensate for working gap which would be caused by a deviation in the geometry of working rollers 10, 20. The performance of the feedback loop is necessarily improved, in particular in terms of speed of convergence and minimization of the error with respect to the target value e30c of the working gap.

[0170] Different options are possible with regard to the acquisition of at least one quantity representative of a geometry difference of the two working rollers 10, 20, in particular of the working surfaces 11,21 of the two working rollers.

[0171] In some examples, the acquisition of at least one quantity representative of a geometry deviation of the two work rollers 10, 20, in particular of the work surfaces 11, 21 of the two work rollers 10, 20, includes the acquisition, in an acquisition plane perpendicular to the axes Y10, Y20 of two work rollers, of at least one working gap profile comprising, for each angular acquisition position 0i of a series of angular acquisition positions 0i, a value representative of the no-load working gap e30i(0i) for the angular acquisition position (0i) considered.

[0172] A working spacing profile can therefore take the form of a table of values ​​associating, with each of the angular acquisition positions 0i of a series of positions angular acquisition, a representative value of the no-load working gap e3Oi(0) for the angular acquisition position 0i. Note that the, which can therefore also be called the no-load working gap profile e3Oi(0), preferably contains the same number of representative values ​​of the no-load working gap e3Oi(0) as the number of angular acquisition positions 0i for which an acquisition was performed. However, in some embodiments, the working gap profile contains more values ​​than the number of angular acquisition positions for which an acquisition was performed, for example by calculating, for intermediate angular positions between two successive angular acquisition positions, a virtual value representing the no-load working gap e3Oi(0) for the intermediate angular position 0, for example by interpolation.Conversely, in some embodiments, the working spacing profile contains fewer values ​​than the number of angular acquisition positions for which an acquisition was made, for example following filtering, or following a reduction in the storage size of the spacing profile.

[0173] In certain embodiments, a representative value of the no-load working gap e3Oi(0) for the acquisition angular position 0) can be a measure of the no-load working gap e3Oi(0) for the acquisition angular position 0i. Such a measure of the no-load working gap e3Oi(0) can be acquired by one or more non-contact or contact sensors, provided that this acquisition is carried out during a learning phase in which no strip is present in the workspace 30.

[0174] In certain embodiments, a representative value of the no-load working gap e30i(0) for the angular acquisition position (0i) can be the relative distance d6Oi(0i) between the two auxiliary reference surfaces 17A, 17B, 27A, 27B belonging respectively to each of the two working rollers, as described above, which can advantageously be acquired as described above.

[0175] In some embodiments, the representative values ​​of the no-load working gap e30i(0) for the different angular acquisition positions 0i are preferably acquired by direct detection, with or without contact, of the working surfaces 11, 21 of rollers.

[0176] In certain embodiments, the working gap profile may include, for each working surface 11, 21, a radial gap profile comprising, for each angular acquisition position 0i of the series, a radial position variation value dRl 1(0), dR21(0) of the working surface 11,21 considered relative to a reference radial position RIO, R20 for the working roller (10, 20) considered.

[0177] Figure 10 illustrates in a very schematic way a first example of an acquisition method, during a learning phase prior to a production phase, for each of a series of angular acquisition positions, of values ​​of at least one quantity representative of a geometry deviation of the two working rollers 10, 20, in particular of the working surfaces 11,21 of the two working rollers.

[0178] Figure 10 illustrates the possibility of measuring a local geometry deviation as a local radial deviation dRl 1(0), dR21(0) for a given point on the work surface 11, 21. This point is defined by the acquisition plane, perpendicular to the Y10, Y20 axis of the work roller 10, 20 under consideration, and by an angular position 0 around this axis. The local radial deviation dRl 1(0), dR21(0) is, for example, defined as the local difference between, on the one hand, the radial distance RI 1(0), R21(0) between this point and the Y10, Y20 axis of the work roller 10, 20 under consideration, and on the other hand, a reference radius RIO, R20 of the work surface under consideration. This reference radius is, for example, the distance to the Y10, Y20 axis from an arbitrary reference point on the work surface under consideration. In the example of [Fig.

[10] , a comparator 200 is placed against the working surface 11,21 under consideration, and, for a series of angular acquisition positions of the working roller 10,20 around its axis Y10, Y20, the local radial deviation dR1(0), dR21(0) is recorded. Thus, for each working roller 10,11, and therefore for each working surface 11,21, a radial deviation profile can be acquired, preferably in the same acquisition plane perpendicular to the axes Y10, Y20 of the two rollers. These two radial deviation profiles can thus together constitute a geometry deviation profile. It is noted that, from the two radial gap profiles, a working gap profile can be determined with, for each angular acquisition position of the two rollers, a working gap value at no load e30i(0) as a function of the local radial gaps dRl 1(0), dR21(0) recorded for this angular position.

[0179] Figure 11 illustrates in a very schematic way a second example of a method During a learning phase prior to a production phase, for each of a series of angular acquisition positions, values ​​of at least one quantity representative of a geometric difference between the two working rollers 10 and 20 are acquired. In this second example, these values ​​are, for each angular acquisition position 0i, the relative distance d6Oi(0i) between the two auxiliary reference surfaces 17A, 17B, 27A, and 27B belonging respectively to each of the two working rollers, as described above. This distance can advantageously be acquired as described above. As seen above, the auxiliary reference surfaces 17A, 17B, 27A, and 27B are constructed in such a way that a working gap profile can be considered to be acquired directly. Thus, a working gap profile is acquired very directly in this manner.

[0180] Figure 12 illustrates an optional angular adjustment step 1020 for the two work rollers 10, 20, which have geometric deviations, aimed at reducing the gap between a minimum and a maximum value of the no-load working gap value e30i(0) for the two work rollers 10. This angular adjustment step 1020 is preferably prior to a production phase. This angular adjustment step 1020 can be implemented following the learning phase 1010 described above, to use either the two radial gap profiles acquired for each work roller 10, 12, and therefore for each work surface 11, 21, or an acquired working gap profile as illustrated in Figure 11.

[0181] In the case of using two acquired radial gap profiles as illustrated in [Fig.10], it is possible to note, for at least one of the working surfaces 11, 21 of the two working rollers, an angular position of maximum radius 01 Imax, 021max, for which the radial distance RI 1(01 Imax), R21(021max) is maximum, and, for at least the other of the working surfaces 11,21 of the two working rollers, an angular position of minimum radius 011min, 021min, for which the radial distance RI 1(011min), R21(021min) is minimum. We can then angularly shift one of the working rollers 10, 20 around its axis so that the angular position of maximum radius 01 Imax, 021max of one of the working surfaces 11, 21 of the two working rollers, corresponds to the angular position of minimum radius 011min, 021min of the other of the working surfaces 11, 21 of the two working rollers. Thus, as illustrated in [Fig.

[12] , when the point of maximum radius of one of the working surfaces is at the angular position corresponding to the calendering space 30, it is opposite the point of minimum radius of the other working surface, thus preventing, over the course of a revolution of the working rollers around their respective axes, an excessive variation in the working gap e30. Of course, after such angular calibration of the two working rollers 10, 20, it is necessary to recalibrate the two acquired radial gap profiles for each working roller 10, 12, by simple circular permutation of the values.

[0182] When using a working gap profile acquired as illustrated in [Fig. 1 1], one can search for the angular setting for which the variation in the working gap over one revolution of the working rollers is minimized, for example, to an average value, or, according to another example, for which the variation in the working gap over one revolution of the working rollers exhibits extremes with a minimized difference. Of course, after such an angular setting of the two working rollers 10, 20, it is necessary to recalculate or acquire a new working gap profile over one revolution of the working rollers.

[0183] In the pre-learning phase 1010, it is preferable to store the working gap profile or the radial gap profiles of the two on a computer. rollers or representative values ​​of these profiles. For example, a table of correction values ​​cor3O(0) can be stored, indexed angularly according to the angular position 0(t) of the working rollers 10, 30. For this purpose, the computer control unit 110 preferably includes a computer storage memory capable of storing the working gap profile(s) electronically.

[0184] Based on this knowledge of the geometric defects of the two working rollers 10, 20, in particular of the working surfaces 11, 21, and of their impact, in the absence of any corresponding correction, on the actual instantaneous value of the working gap e30, it is proposed that the method includes the application, on at least the first support 14, of at least one total force F(t) adjusted according to the instantaneous angular position 0(t) of the two working rollers 10, 20 around their respective axes, and according to the working gap profile acquired during the learning phase 1010.This correction can be directly integrated into the instantaneous setpoint cF(t) used to control the load actuator 32, which in turn controls the movement of the first support 14 relative to the frame 2. For example, it could be applied as a correction cor3O(0), a function of the instantaneous angular position 0 of the rollers, to the control setpoint cReg30(t) of the working gap value provided by the controller 112. Alternatively, this correction could be in the form of a force correction setpoint added to the force setpoints cF1 and cF2(t) discussed with reference to [Fig. 7]. In both cases, this correction cor3O(0) can be positive or negative, i.e., increasing or decreasing the total load.This correction therefore causes an increase or decrease in deformations in the machine, which correspond to a decrease or increase in the distance between the axes Y10, Y20 of the two rollers, to the extent necessary to compensate for the variation in working gap e30 that would be induced by these geometric deviation defects.

[0185] It is noted that the geometry deviations of the working rollers 10, 20 play a cyclical role in determining the working gap e30, at each revolution of the working rollers. Consequently, the correction cor3O(0) which is applied based on the working gap profile is also cyclic, at each revolution of the working rollers 10, 20.

[0186] Thus, in an example, such as can be seen in [Fig. 7], the computer control unit 110 is advantageously configured to control at least one load actuator 32 so that it delivers, on the first support 14, a total force F(t) which is adjusted according to an instantaneous angular position 0(t) of the two working rollers around their respective axes, and according to Acquired values ​​(d6Oi(0) or dRll(0), dR21(0)), during a learning phase, of at least one quantity (d6Oi(0) or dRll(0), dR21(0)) representative, for the instantaneous angular position 0(t), of a geometric deviation of the two working rollers 10, 20, in particular of the working surfaces 11, 21 of the two working rollers. In the illustrated example, optionally, the total force F(t) is also successively adjusted over time according to the acquired values ​​d60(t) of the quantity d60 representing the working gap, and the target value e30c of the working gap.

[0187] In certain implementations, the total force F(t) can then be analyzed as the setting force Fl, which can be fixed in time for a given production phase, to which is added a complementary force F2(t) adjusted successively in time during the given production phase, and which is a function of the instantaneous angular position 0(t) of the two working rollers 10, 20 around their respective axes and a function of the working gap profile acquired during the learning phase 1010, with for example the relation F(t) = Fl + F2(t).

[0188] The total force F(t), is therefore likely to vary over time, through its component which is the complementary force F2(t), on the one hand as a function of the working gap profile acquired during the learning phase 1010, and on the other hand, as a function of the variations observed, during the production phase, for the values ​​acquired successively over time of the quantity representing the working gap e30.

[0189] In [Fig. 7], it is illustrated that the computer control unit 110 can include a controller 114 capable of delivering a correction setpoint cor3O(0), a function of the instantaneous angular position 0 of the rollers, applied to the regulation setpoint value cReg30(t) of the working gap value, which is delivered by the controller 112. This value cor3O(0) can take into account a phase shift due to a time phase shift in the processing by the calculation and actuation chain, so that the correction cor3O(0) introduced into the processing is applied by the load actuator 32 precisely at the required time to compensate for the corresponding geometry deviation. This controller 114 implements the acquired working gap profile to determine, as a function of the instantaneous angular position 0 of the rollers, the correction setpoint cor3O(0).In the illustrated example, controller 114 directly outputs a working gap correction command cor3O(0), which is converted into a force correction command by the second converter 113 and is therefore integrated into the force correction command cF2(t) issued by the second converter 113 as described above. In an alternative configuration not shown, controller 114 could, for example, output a force correction command cF3(t) usable by the power circuit. hydraulic 120, for example by being added to the force correction setpoint cF2(t) delivered by the second converter 113.

[0190] The controller 114 can take the form of an algorithm executed by the computer control unit 110.

[0191] In this case too, the total force F(t) is determined in "real time" with respect to the calendering process, with the smallest possible time lag.

[0192] Preferably, at least two working gap profiles are acquired in separate acquisition planes, both of which are perpendicular to the Y10, Y20 axes of two working rollers, and are axially separated from each other, one towards one axial end and the other towards the opposite axial end of the calendering space 30.

[0193] In such a case, particularly in calendering machines in which the first support 14 comprises two bearing bodies 14A, 14B and at least one load actuator 32A, 32B associated with each of the bearing bodies 14A, 14B, the method may advantageously comprise the application, on at least the first support 14, of at least two forces FA(t), FB(t), in parallel with each other and axially offset from each other, one towards an axial end and the other towards the opposite axial end of the calendering space 30, each of these two forces FA(t), FB(t) being adjusted according to the instantaneous angular position of the two work rollers 10, 20 around their respective axis Y10, Y20, according to the working gap profiles acquired in the axially corresponding acquisition plane.

[0194] It is also possible to acquire more than two radial working gap profiles, in separate acquisition planes, perpendicular to the axes Y10, Y20 of two working rollers, and axially separated from each other, preferably at regular intervals, between the two opposite axial ends of the calendering space 30. In this case, the working gap profiles thus acquired can be used to determine an appropriate correction, taking into account, for each instantaneous angular position of the two rollers, average or extreme values ​​of the radial gap values ​​for this angular position among the working gap profiles.

[0195] Advantageously, in such a method, the angular acquisition positions Oi of the values ​​of at least one quantity representative of the geometry deviation, and the corresponding correction of at least one total force F(t), FA(t), FB(t), are performed for angles having a difference between them that corresponds to a frequency greater than 10 hertz, preferably greater than 100 hertz, taking into account the rotational speed of the rollers. For example, the angular difference between two successive angular acquisition positions Oi is less than or equal to 2 degrees, for example, between 0.5 and 2 degrees. Such an acquisition frequency makes it possible to regulate the working gap e30 very precisely. and consequently to control, at the machine output, the thickness of the strip which is calendered in such a process.

[0196] The process may also optionally include different steps and features which derive from the possible features of the calendering machine 1 as described above.

Claims

1. Demands Calendering machine (1) for calendering a strip (4) to be calendered, of the type comprising a first working roller (10) mounted rotatably around a first axis (Y 10) on a first support (14) and comprising a working surface (11), of the type comprising a second work roller (20) mounted rotatably about a second axis (Y20), parallel to the first axis (Y10), on a second support (24), and comprising a work surface (12), of the type in which the two work rollers (10, 20) are counter-rotating and define, between their two respective work surfaces (11, 21), a calendering space (30) suitable for receiving the strip (4) as it flows in a flow plane (PXY) along a flow direction (X) from upstream to downstream, of the type in which the calendering space (30) has, at its point of minimum spacing along a direction (Z) perpendicular to the flow plane (PXY), a working spacing (e30) between the work surfaces (11, 21) of the two work rollers (10, 20), of the type in which the first support (14) is movable relative to a frame (2) of the machine, perpendicularly to the scroll plane (PXY), under the effect of at least one load actuator (32A1, 32A2, 32B1,32B2) controlled by a computer control unit (110) to obtain a target value (e30c) of the working gap, characterized in that, in that the computer control unit (110) is configured to control at least one load actuator (32A1, 32A2, 32B1, 32B2) so that it delivers, on the first support (14), a total force (F(t) FA(t), FB(t)) adjusted successively in time as a function of an instantaneous angular position (0(t)) of the two working rollers around their respective axes, and as a function of acquired values ​​(d60i(0), dRll(0), dR21(0)), in a learning phase, of at least one quantity (d6O(0), dRll(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a geometry deviation of the working surfaces of the two working rollers.

2. Machine according to claim 1, characterized in that the computer control unit (110) comprises a computer storage memory capable of storing in computer format at least one working gap profile comprising, for each of a series of distinct angular positions (0i), a representative value, for the angular position (0i), of the geometry deviation of the working surfaces of the two working rollers.

3. Machine according to claim 2, characterized in that the working gap profile comprises, for each of a series of distinct angular positions (0i) of the two working rollers around their respective axes, a value (d6Oi(0i)) representative of the no-load working gap e3Oi(0i).

4. Machine according to claim 2, characterized in that the working gap profile comprises, for each of a series of distinct angular acquisition positions (0i) of the two working rollers around their respective axes, a force correction value corresponding to the angular position (0i) of the rollers.

5. Machine according to claim 2, characterized in that the working gap profile comprises, for each working surface, at least one radial gap profile comprising, for each of a series of distinct angular positions (0i) of the two working rollers around their respective axes, a value of radial position variation (dR11(0), dR21(0)) of the working surface (11, 21) considered relative to a reference radial position (R10, R20) for the working roller (10, 20) considered.

6. A machine according to any one of the preceding claims, characterized in that the machine comprises at least two groups (32A, 32B) of load actuators, each associated with one of the two axial ends of the calendering space (30), and in that the computer control unit (110) is configured to control each group of load actuators to deliver, on the first support (14), a total force (F(t), FA(t), FB(t)) adjusted successively in time as a function of the instantaneous angular position (0(t)) of the two work rollers (10, 20) around their respective axes (Y10, Y20), and as a function of the acquired values ​​(d60i(0), dR11(0), dR21(0)) at the corresponding end of the calendering space (30), for the instantaneous angular position (0(t)), of at least one quantity (d60, dRll(0), dR21(0)) representative of a geometry difference of the working surfaces (11,21) of the two working rollers (10).

7. Machine according to claim 6 in combination with any one of claims 2 to 5, characterized in that the computer storage memory stores at least two working gap profiles corresponding to separate acquisition planes, perpendicular to the axes of two working rollers and axially separated from each other, one towards one axial end and the other towards the opposite axial end of the calendering space (30).

8. A machine according to any one of the preceding claims, characterized in that the machine comprises a mechanical stop (50) which determines a setting of the working gap at an initial setting value (e30i), in that the calendering machine (1) comprises at least one acquisition sensor (60A, 60B), during a production phase in which the strip (4) passes through the calendering space (30), successive values ​​in time of at least one quantity (d60A, d60B) representative of the working gap (e30), and in that the computer control unit (110) is configured to control at least one load actuator (32A1, 32A2, 32B1, 32B2) so that it delivers, on the first support (14), a total force adjusted successively in time, on the one hand as a function of an instantaneous angular position (0(t)) of the two working rollers around their respective axes,and as a function of the acquired values ​​(d60i(0), dRll(0), dR21(0)), in the learning phase, of at least one quantity (d60, dRll(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a geometry deviation of the working surfaces of the two working rollers, and on the other hand as a function of the acquired values ​​of the quantity (d60A, d60B) representative of the working gap (e30) and the target value (e30c) of the working gap.

9. Machine according to claim 8, characterized in that the machine comprises at least two groups (32A, 32B) of load actuators each associated with one of the two axial ends of the calendering space (30), and in that the computer control unit (110) is configured to control each group of load actuators (32A, 32B) so that it delivers, on the first support (14), a total force (FA(t), FB(t)) adjusted successively in time, firstly as a function of an instantaneous angular position (0(t)) of the two work rollers around their respective axes, and as a function of the acquired values ​​(d60i(0), dRll(0), dR21(0)) at the corresponding end of the calendering space (30), during the learning phase, of at least one quantity (d60(0), dRll(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a geometric deviation of the working surfaces of the two work rollers, and secondly as a function of the acquired values ​​of the quantity (d60A, d60B) representative of the gap of work (e30) acquired at the corresponding end of the calendering space (30) and the target value (e30c) of the working gap.

10. Machine according to any one of claims 8 or 9, characterized in that at least one representative quantity of the working gap (e30) is a relative distance (d60A, d60B) between at least one surface of revolution of one of the two working rollers and an auxiliary reference surface (17A, 17B, 27A, 27B) belonging to the other of the two working rollers (10, 20), said auxiliary reference surface (17A, 17B, 27A, 27B) of the other of the two working rollers being a coaxial surface of revolution, axially offset, and of strictly smaller diameter compared to the working surface (11, 21) of the corresponding working roller (10, 20).

11. Machine according to any one of claims 8 to 10, characterized in that at least one sensor (60A, 60B) is a sensor positioned in a calendering plane (PYZ) containing the two axes (Y 10, Y20) of the two work rollers (10, 20), at an axial end of the calendering space (30) outside thereof, opposite at least one surface of revolution of one of the two work rollers (10, 20) and the auxiliary reference surface (17A, 17B, 27A, 27B) belonging to the other of the two work rollers (10, 20).

12. Machine according to any one of claims 8 to 11, characterized in that at least one sensor (60A, 60B) is a non-contact sensor, in particular a capacitive sensor.

13. A machine according to any one of claims 8 to 12, characterized in that the computer control unit (110) is configured to calculate a force setpoint, adjusted successively over time during a production phase in which the strip (4) passes through the calendering space (30), firstly as a function of an instantaneous angular position (0(t)) of the two work rollers around their respective axes, and as a function of the acquired values ​​(dR11(0), dR21(0)), during the learning phase, of at least one quantity (dR11(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a geometric deviation of the working surfaces of the two work rollers, and secondly as a function of the acquired values ​​of the quantity (d60A, d60B) representative of the working gap (e30) and the target value (e30c) of the working distance,and in that the computer control unit (110) is configured to control at least one load actuator (32A1, 32A2, 32B1, 32B2) so that it delivers on the first support (14) a force (F(t), FA(t), FB(t)) corresponding to the setpoint.

14. Machine according to any one of claims 8 to 13, characterized in that the initial setting value (e30i) is strictly greater than the target value (e30c) and is between 1.05 and 2 times the target value.

15. A calendering method for a strip (4) to be calendered, of the type in which the strip (4) is made to move, in a conveying plane (PXY) along a conveying direction (X) from upstream to downstream, through a calendering space (30) defined between: - a working surface (11) of a first work roll (10), which is rotatably mounted about a first axis (Y10) on a first support (14), - and a working surface (21) of a second work roll (20), which is rotatably mounted about a second axis (Y20), parallel to the first axis (Y10), on a second support (24), the two work rolls (10, 20) being counter-rotating, of the type in which the calendering space (30) has, at its point of minimum spacing along a direction (Z) perpendicular to the conveying plane (PXY), a working distance (e30), between the working surfaces (11,21) of the two working rollers (10, 20), and of the type in which the process involves applying, on at least one of the supports (14, 24), a force perpendicular to the plane of travel (PXY), in the direction of a reduction of the working gap (e30), to obtain a target value (e30c) of the working gap, characterized in that the process includes: - the acquisition, during a learning phase prior to a production phase, for each of a series of angular positions (0i) of acquisition of the two working rollers (10, 20) around their respective axes (Y10, Y20), the angular positions of acquisition being distinct and distributed over a revolution, of values ​​(dRll(0), dR21(0)) of at least one quantity (dRll, dR21) representative of a deviation in geometry of the working surfaces (11,21) of the two working rollers (10, 20);- the application (1300), during a production phase during which the strip (4) passes through the calendering space (30), on at least the first support (14), of at least one total force (FA(t), FB(t)), adjusted successively in time as a function of the instantaneous angular position (0(t)) of the two working rollers around their respective axes, and as a function of the acquired values ​​(d60i(0), dRll(0), dR21(0)) of at least one quantity (d60, dRl 1(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a deviation in geometry of the working surfaces of the two working rollers.;

16. A method according to claim 15, characterized in that the acquisition of the values ​​(dR1(0), dR21(0)) of at least one quantity (dR11, dR21) representative of a geometric deviation of the working surfaces of the two working rollers comprises the acquisition, in an acquisition plane perpendicular to the axes of two working rollers, of at least one working gap profile comprising, for each angular acquisition position (0i) of the series, a representative value (d60i(0)) of the geometric deviation of the working surfaces of the two working rollers, for the angular acquisition position (0i), and in that the method comprises the application, on at least the first support (14), of at least one total force adjusted successively in time as a function of the instantaneous angular position (0(t)) of the two working rollers (10, 20) around their respective axes (Y 10, Y20) and according to the working spacing profile.

17. Method according to claim 16, characterized in that the working gap profile comprises, for each of a series of distinct angular positions (0i) of the two working rollers around their respective axes, a value representative of the no-load working gap e30i(0).

18. Method according to claim 16, characterized in that the working gap profile comprises for each of a series of distinct angular acquisition positions (0i) of the two working rollers around their respective axes, a force correction value corresponding to the angular position (0i) of the rollers.

19. Method according to claim 16, characterized in that the working gap profile comprises, for each working surface, at least one radial gap profile comprising, for each angular acquisition position (0i) of the series, a value of radial position variation (dR11(0), dR21(0)) of the working surface (11, 21) considered relative to a reference radial position (RI1, R21) for the working roller (10, 20) considered.

20. Method according to claim 19, characterized in that the radial gap profile is acquired, for the two working rollers (10, 20), in the same acquisition plane perpendicular to the axes (Y 10, Y20) of two working rollers (10, 20).

21. A method according to any one of claims 16 to 20, characterized in that at least two working gap profiles are acquired in separate acquisition planes, perpendicular to the axes (Y10, Y20) of two work rollers (10, 20) and axially separated from each other, one towards one axial end and the other towards the opposite axial end of the calendering space (30), and in that the method comprises applying, on at least the first support (14), at least two forces (FA(t), FB(t)), parallel to each other and axially offset from each other, one towards one axial end and the other towards the opposite axial end of the calendering space (30), each corrected (F3A, F3B) according to the instantaneous angular position ((0(t)) of the two work rollers (10, 20) around their respective axes (Y 10,Y20) and depending on the working gap profile acquired in the acquisition plane acquired at the corresponding axial end.

22. A method according to claim 21 taken in combination with any one of claims 19 or 20, characterized in that, for each of the two work rollers, at least two radial gap profiles are acquired in separate acquisition planes, perpendicular to the axes of two work rollers and axially offset from each other, one towards an axial end and the other towards the opposite axial end of the calendering space (30), and in that the method comprises applying, on at least the first support (14), at least two forces, parallel to each other and axially offset from each other, one towards an axial end and the other towards the opposite axial end of the calendering space (30), each adjusted according to the instantaneous angular position of the two work rollers around their respective axes, according to the radial gap profiles acquired in the corresponding axially aligned acquisition plane.

23. A method according to any one of claims 15 to 22, characterized in that the method comprises, in the prior learning phase, the computer storage of at least one working gap profile or representative values ​​of at least one working gap profile, such as force correction values ​​indexed angularly as a function of the angular position (0(t)) of the working rollers (10, 20).

24. A method according to any one of claims 15 to 23, characterized in that it further comprises: - an initial setting (1050) of the working gap to an initial setting value (e30i), determined by bearing on a mechanical stop (50A, 50B), by application (1040) of a setting force (Fl) on at least one of the first and second support (14, 24) in the direction of the other of the first and second working roller (14, 24), the initial setting value (e30i) being strictly greater than the target value (e30c) and being between 1.05 and 2 times the target value; - the acquisition (1200), during a production phase during which the strip (4) passes through the calendering space (30), of successive values ​​in time (d60A(t), d60B(t)) of at least one quantity (d60A, d60B) representative of the working gap;- the application (1300), during said production phase, on at least the first support (14), of at least a total force (F(t),; FA(t), FB(t)), adjusted successively in time on the one hand as a function of the instantaneous angular position (0(t)) of the two working rollers (10, 20) around their respective axes, and as a function of the acquired values ​​(dR11(0), dR21(0)) of at least one quantity (dR11(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a geometry deviation of the working surfaces of the two working rollers, and on the other hand as a function of the acquired values ​​(d60A(t), d60B(t)) of at least one quantity (d60A, d60B) representative of the working gap.

25. A method according to claim 24 in combination with any one of claims 21 or 22, characterized in that the method comprises: - the acquisition (1200), during a production phase during which the strip (4) passes through the calendering space (30), of successive values ​​in time (d60A(t), d60B(t)) of at least two quantities (d60A, d60B) representative of the working gap, a first quantity (d60A) being acquired at a first axial end of the calendering space (30), and a second quantity (d60B) being acquired at a second, opposite axial end of the calendering space (30);- the application, on at least the first support, of at least two total forces (FA(t), FB(t)), parallel to each other and each axially offset on the side of the corresponding axial end of the calendering space (30), each adjusted successively in time, firstly, as a function of the instantaneous angular position (0(t)) of the two work rollers around their respective axes, and as a function of the acquired values ​​(d60i(0), dRl1(0), dR21(0)) of at least one quantity (d60, dRl1(0), dR21(0)) representing, for the instantaneous angular position (0(t)), a geometric deviation of the working surfaces of the two work rollers, and secondly, as a function of the acquired values ​​(d60A(t), d60B(t)) of that (d60A, d60B) of the two quantities representing the working gap which is acquired at the corresponding axial end of the calendering space (30).;

26. A method according to any one of claims 24 or 25, characterized in that at least one quantity representative of the working gap is a relative distance (d60A, d60B) between at least one surface of revolution of one of the two working rollers (10, 20) and an auxiliary reference surface (17A, 17B, 27A, 27B) belonging to the other of the two working rollers (10, 20), said auxiliary reference surface (17A, 17B, 27A, 27B) of the other of the two working rollers being a coaxial cylindrical surface of revolution, axially offset, and of strictly smaller diameter compared to the working surface (11, 21) of the corresponding working roller (10, 20).

27. ​​A method according to any one of claims 24 to 26, characterized in that at least one quantity representing the working gap is a relative distance (d60A, d60B) between two auxiliary reference surfaces (17A, 17B, 27A, 27B) belonging respectively to each of the two working rollers (10, 20), each auxiliary reference surface (17A, 17B, 27A, 27B) being a coaxial cylindrical surface of revolution, axially offset, and of strictly smaller diameter compared to the working surface (11, 21) of the corresponding working roller (10, 20), the two auxiliary reference surfaces (17A, 17B, 27A, 27B) being opposite each other on either side of the plane of travel.

28. A method according to any one of claims 26 or 27, characterized in that the relative distance (d60A, d60B) is measured with at least one non-contact sensor (60A, 60B), in particular a capacitive sensor.

29. A method according to claim 28, characterized in that at least one sensor (60A, 60B) is positioned in a calendering plane (PYZ) containing the two axes (Y 10, Y20) of the two work rollers (10, 20), at one axial end of the calendering space (30) but outside of it, opposite at least one cylindrical surface of revolution of one of the two work rollers and the auxiliary reference surface (60A, 60B), belonging to the other of the two work rollers (10, 20).

30. A method according to any one of claims 15 to 29, characterized in that the first working roller (10) is movable, perpendicular to the plane of travel (PXY).

31. A method according to any one of claims 15 to 30, characterized in that the second axis (Y20) is fixed.

32. A method according to any one of claims 15 to 31, characterized in that the acquisition (1200) of successive values ​​over time of at least one quantity (d60A, d60B) representative of the working gap, and the successive adjustment in time of at least one total force (F(t), FA(t), FB(t)), are each operated at a frequency greater than 10 hertz, preferably greater than 100 hertz.

33. A calendering method according to any one of claims 15 to 32, characterized in that the strip (4) to be calendered is an electrode component for electrochemical cells, comprising a layer of electrode material, in particular an electrode component comprising a layer of electrode material supported on a support layer or a self-supporting layer of electrode material.

34. A calendering process according to claim 33, characterized in that the electrode material layer is, in the calendering process, calendered alone or on a support layer, optionally with the addition of heat, to give cohesion to the electrode material layer, and / or to give it desired structural properties, and / or to give it desired rheological properties, and / or to give it desired dimensional properties and / or to assemble the electrode material layer on a support layer.

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