Calendering process and machine with dynamic control of the working gap

Abstract

The invention provides calendering machines and methods in which two working rollers (10, 20) define a calendering space (30) that has a working gap (e30) between the working surfaces (11, 21) of the two rollers, comprising: - an initial setting of the working gap, by means of a mechanical stop, to an initial setting value (e30i) strictly greater than a target value (e30c) and between 1.05 and 2 times the target value; - the acquisition, during production, of successive values ​​over time (d60(t)) of at least one quantity representative of the working gap; - the application of a total force (F(t)) adjusted successively over time according to the acquired values ​​of at least one quantity representative of the working gap (e30). Abstract figure: FIG. 7

Description

Title of the invention: Calendering method and machine with dynamic control of the working gap. 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 and also comprising a work surface. The two work rollers are counter-rotating and define, between Their two respective work surfaces, a calendering space in which the strip passes, in a plane of travel, along a direction of travel from upstream to downstream. The distance between the axes of the two work 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 passes between the two work 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 work 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] In the prior art, certain calendering machines are designed to be operated by controlling the calendering force during the calendering operation (“force (in English, "mode"). To achieve this, one or more actuators of the moving support(s) are controlled by the computer control unit to apply a controlled force to the strip as it moves through the rolling chamber. For example, if the actuator has 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 do this, the computer control unit receives information representing the thickness of the strip as it exits the machine, i.e., downstream of the rolling chamber. Based on this information, the computer control unit adjusts its output setpoint, which controls the force applied by the actuator.This method is theoretically the most accurate because it is based on a direct measurement of the strip thickness as it exits the machine, which is precisely the quantity one wants to control. This process is generally efficient in a stable environment, but it has proven less efficient during periods of process variation, particularly variations in the feed speed. Thus, with each machine start and stop, lengths of strip are calendered that do not have the desired thickness. Furthermore, this process appears very sensitive to any dimensional variation of the strip as it enters the machine.

[0012] Alternatively, it is also known in the prior art to operate a calendering machine by placing a mechanical stop between the first and second supports. The thickness of this stop determines the working gap at a specific value (the "gap mode"). The stop can be adjustable. In such a machine, the stop is selected or adjusted so that, ultimately, the thickness of the strip exiting the machine, i.e., downstream of the calendering space, reaches the desired value. It should be noted that for a given stop thickness, in a given machine, the working gap between the rollers during the calendering operation will depend, in particular, on the intrinsic mechanical characteristics of the strip, but also on its feed speed. Indeed, depending on the calendering forces involved, internal deformations of the machine appear and affect the working gap.Thus, all other things being equal, the actual working gap between the rollers during the calendering operation can differ from the actual working gap observed when the machine is empty, before the strip is introduced. Furthermore, it is known that to obtain a constant strip thickness at the machine's output, it is necessary to have working rollers with a near-perfect geometry, for example, almost perfectly cylindrical around the axis of rotation, which is therefore very expensive.

[0013] The invention therefore aims to propose a new design of a calendering process and a calendering machine which allows for optimal control of the thickness of the strip at the machine outlet, in order to obtain optimal quality of the calendering operation. Description of the invention

[0014] A calendering machine for calendering a strip to be calendered is hereby disclosed, 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 passes 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,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, and of the type including a mechanical stop that determines a setting for the working gap.

[0015] According to one aspect of the disclosure, the mechanical stop determines an initial setting of the working gap to an initial setting value, when a setting force is applied to the first support in the direction of the second support.

[0016] According to one aspect of the disclosure, 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.

[0017] According to one aspect of the disclosure, 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.

[0018] According to one aspect of the disclosure, 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 the acquired values ​​of the quantity representing the working gap and the target value of the working gap.

[0019] In some 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 at least one surface of revolution of one of the two work rollers and the auxiliary reference surface belonging to the other of the two work rollers.

[0020] In some embodiments, at least one sensor is a contactless sensor, in particular a capacitive sensor.

[0021] 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 passes through the calendering space, according to the acquired values ​​of the representative quantity 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 to deliver on the first support a total force corresponding to the force setpoint.

[0022] 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.

[0023] In certain embodiments, the first working roller and the second working roller each have at least one auxiliary reference surface, cylindrical of revolution, coaxial, 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.

[0024] In certain embodiments, the calendering machine includes, at each axial end of the calendering space, 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 two quantities representative of 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;Each of the two quantities representing 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 by one; corresponding axial end of the calendering space, and of strictly smaller diameter compared to the working surface of the corresponding working roller.

[0025] In certain embodiments, 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 on the one hand as a function of an instantaneous angular position of the two working rollers around their respective axes, and as a function of values ​​acquired, in a learning phase, of at least one quantity representative, for the instantaneous angular position, of a geometry deviation of the two working rollers, and on the other hand as a function of the acquired values ​​of the quantity representative of the working gap acquired at the corresponding end of the calendering space, and of the target value of the working gap.

[0026] 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 two working rollers.

[0027] 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 control each group of load actuators so that it delivers, 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 working rollers around their respective axes, and as a function of the values ​​acquired at the corresponding end of the calendering space, during the learning phase, of at least one representative quantity, for the instantaneous angular position, of a geometry deviation of the two working rollers, and on the other hand as a function of 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.

[0028] In some embodiments, at least one sensor is a contactless sensor, in particular a capacitive sensor.

[0029] 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.

[0030] Furthermore, calendering methods for a strip to be calendered are also 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 (11) of a first working roller (10), which is mounted to rotate around a first axis (Y 10) on a first support (14), - and a working surface (21) 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), the two working rollers (10, 20) being counter-rotating.

[0031] In these methods, 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 these methods include 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.

[0032] According to one aspect, these processes include: - 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 according to the acquired values ​​of at least one quantity representative of the working gap.

[0033] In certain embodiments, the application, on at least the first support, of at least one total force includes an elastic deformation of at least one among the first support, the second support, the shim and a frame which carries the second support.

[0034] In some embodiments, the method includes calculating a force setpoint adjusted successively in time with negative feedback loop, as a function of the target value and the values ​​acquired successively in time of at least one quantity representative of the working gap, and the at least total force corresponds to the force setpoint.

[0035] In some embodiments, the process comprises: - the acquisition, during a production phase in which the strip passes through the calendering space, of successive values ​​over 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 magnitude 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 to the acquired values ​​of that of the two quantities representing the working gap acquired at the corresponding axial end of the calendering space.

[0036] In certain embodiments, the method includes calculating a separate setpoint for each total force, adjusted successively in time with negative feedback loop, as a function of the target value and the values ​​acquired successively in time of that of the two quantities representing the working gap which is acquired at the corresponding axial end of the calendering space.

[0037] In some embodiments, the process comprises: - the acquisition, during a learning phase prior to a production phase, for each of a series of angular acquisition positions of the two working rollers around their respective axes, the angular acquisition positions being distributed over one revolution, of values ​​of at least one quantity representative of a difference in geometry 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, 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 representative, for the instantaneous angular position, of a geometry deviation of the two working rollers, and on the other hand as a function of the acquired values ​​of at least one quantity representative of the working gap.

[0038] In certain embodiments, the acquisition of the values ​​of at least one quantity representative of a geometry deviation 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 acquisition position of the series, a value representative of the no-load working gap for the angular acquisition position, and the method includes the application, on at least the first support, of at least one total force adjusted according to the instantaneous angular position of the two working rollers around their respective axes, and according to the working gap profile.

[0039] In certain embodiments, the working gap profile comprises, for each working surface, a radial gap profile comprising, for each position angular acquisition of the series, a value of radial position variation of the considered working surface relative to a reference radial position for the considered working roller.

[0040] 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 separated 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, and according to the working gap profile acquired in the corresponding axially aligned acquisition plane.

[0041] 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 correction values ​​indexed angularly according to the angular position of the rollers.

[0042] 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.

[0043] 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.

[0044] In some embodiments, the relative distance is measured with at least one non-contact sensor, in particular a capacitive sensor.

[0045] 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 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.

[0046] In some embodiments, the first working roller is mobile, perpendicular to the plane of scrolling.

[0047] In some embodiments, the second axis is fixed.

[0048] 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 total force, are each operated at a frequency greater than 10 hertz, preferably greater than 100 hertz.

[0049] 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.

[0050] 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

[0051] [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.

[0052] [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].

[0053] [Fig.3] : The [Fig.3] is a schematic perspective view of a side face of the calendering machine of the [Fig.1].

[0054] [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.

[0055] [Fig.5]: The [Fig.5] is a schematic perspective view illustrating one embodiment of an adjustable wedge.

[0056] [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.

[0057] [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.

[0058] [Fig.8]: The [Fig.8] is a flowchart illustrating an example of a calendering process.

[0059] [Fig.9] : The [Fig.9] illustrates in a very schematic way an example of a set of two work rollers exhibiting geometric deviations.

[0060] [Fig. 10]: The [Fig. 10] illustrates in a very schematic way an 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.

[0061] [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.

[0062] [Fig. 12]: The [Fig. 12] illustrates an optional step of angular alignment of the two working rollers exhibiting geometry deviations.

[0063] [Fig. 13]: The [Fig. 13] is a schematic illustration of another way in which a calendering machine and process can be implemented, in a simplified and schematic version.

[0064] [Fig. 14]: The [Fig. 14] is a flowchart illustrating another example of a calendering process. Detailed description

[0065] 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.

[0066] 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.

[0067] 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 certain applications, such a layer of electrode material can therefore be, in the machine In calendering, the electrode material layer can be calendered alone, possibly with added heat, to impart cohesion to the electrode material layer, and / or to give it desired structural, rheological, and dimensional properties. In other applications, such an electrode material layer can therefore be calendered in the calendering machine onto a support layer, for example, onto a metal foil intended to form a current collector for an electrochemical cell, to bond the layers together, and to impart cohesion to the electrode material layer, and / or to give the resulting multilayer foil the desired structural, rheological, and / or dimensional properties.

[0068] 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.

[0069] 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 some variants, 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. the axis of the corresponding roller. The crown is generally designed to compensate for deflection of the corresponding roller during calendering operations; the combination of the crown and the deflection under calendering forces results in a straight line of contact at the calendering space. However, it should be noted that the crown remains very slight in all cases, such that, from the perspective of the invention, the working surface can be considered a cylindrical surface of revolution, which can have a straight generatrix to form a straight cylinder, or a curved generatrix to form a curved cylinder.

[0070] 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 X, from upstream to downstream along this direction. The PXY plane 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, the direction 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 Z direction perpendicular to the PXY plane 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.

[0071] 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.

[0072] The strip 4 may consist of a single sheet, or of a superposition of at least two sheets joined face to face. The strip 4 may be a discrete strip, having a defined length in the direction of travel X, this The length is in the order of magnitude of its width along a transverse direction parallel to the Y10 and Y20 axes of the working rollers 10 and 20; for example, a length between 0.1 and 10 times the width. Alternatively, the strip 4 can have an "infinite" length, meaning a length greater than 10 times its width. For example, the strip can be wound in the form of a roll upstream and / or downstream of the calendering machine 1.

[0073] 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. .

[0074] 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 may be vertical, while the transverse Y direction of the axes Y10 and Y20 of the two work rollers 10 and 20 is also horizontal.

[0075] 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 including for example a chain, a belt, and / or a cascade of gears.

[0076] In the illustrated example, the calendering machine 1 does not include a support roller. However, it is known that a calendering machine may include, associated with at least one of the work rollers, a support group comprising at least 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 in question and bears against that work roller in a bearing area arranged on a side of the work roller opposite the calendering area with respect to the axis of that work roller. The optional support group serves 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.

[0077] 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.

[0078] 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.

[0079] 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 for the position of the second support 24 in the frame 2 to be adjustable, for example during a machine setup phase 1. 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 in relation to frame 2, could be made up of a portion of frame 2, therefore integrated into it.

[0080] 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 and a right lateral upright 5B can thus be arbitrarily distinguished, with reference to the direction of travel X. As can be seen more particularly in [Fig. 2], each lateral upright 5A, 5B has, for example, the shape of a frame with each having an upstream pillar 5A1, 5B1 and a downstream pillar 5A2, 5B2, again with reference to the direction of travel X, which extend in a direction perpendicular to the plane of travel 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 side post 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 scroll direction X. In the example, the side posts 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 side posts 5A, 5B. The cross members 6, 7 extend essentially in a direction perpendicular to the sagittal plane PXZ. The frame includes, for example, two lower cross members 6 connecting the lower ends of the side posts 5A, 5B, and two upper cross members 7 connecting the upper ends of the side posts 5A, 5B.

[0081] 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.

[0082] 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 Bearings 14A and 14B of the first support 14 are independent of each other. Each bearing body 14A and 14B receives, via rotation through the bearing body, the corresponding lateral section, namely a left lateral section 13A and a right lateral section 13B respectively, of the first working roller 10, preferably with an interposed bearing (not shown). In the example, each bearing body 14A and 14B of the first support 14 is slidably mounted in the Z direction perpendicular to the plane of travel, within the corresponding lateral upright. Thus, the left bearing body 14A is slidably mounted, in the Z direction perpendicular to the plane of travel PXY, 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 mounted to slide, along the Z direction perpendicular to the PXY scroll plane, in the central opening of the right lateral upright 5B, between the upstream pillar 5B1 and the downstream pillar 5B2.

[0083] 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.

[0084] 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.

[0085] 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 an upstream left-hand load actuator 32A1 and a downstream left-hand load actuator 32A2, which control the movement, along the translation direction Z perpendicular to the scroll plane PXY, of the left bearing body 14A. Symmetrically, the calendering machine 1 includes a group 32B of two right load actuators, namely a right upstream load actuator 32B1 and a right downstream load actuator 32B2 which control the displacement, along the translation direction Z perpendicular to the scroll plane PXY, of the right 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 scroll direction X, 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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 work roll 10 relative to the second work roll 20 in order to obtain a target value e30c of the working gap e30 between the two work rolls. As mentioned above, the target value e30c of the working gap e30 is distinct from the target thickness of the strip at the machine exit, particularly due to the elasticity of the strip, 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 determines the thickness of the strip 4 at the machine exit.

[0090] 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.

[0091] It follows from what has been described above that the first support 14 is mobile relative to the second support 24 along the direction of translation Z perpendicular to the scroll plane PXY.

[0092] 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 straight pre-charge 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 specifically, the two bearing bodies 24A, 24B of the second support 24 are pressed against the corresponding upper longitudinal member 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 PYZ calendering plane, and the other on the downstream side of the preload bearings relative to the PYZ calendering plane. Symmetrically, the preload actuation system includes, 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 PYZ calendering plane, and the other on the downstream side of the preload bearings relative to the PYZ calendering plane.By actuating the pre-charge actuators 40A, 40B in the direction of a separation, the two working rollers 10, 20 are separated from each other perpendicularly to the PXY flow plane, even before the introduction of the strip four into the calendering space 30.

[0093] As can be seen more particularly in Figures 1 and 4, the calendering machine includes a mechanical stop which, in the example, is interposed between the first support 14 and the second support 24 and which determines a setting of the working gap e30 to an initial setting value e30i. This setting is a setting in the direction perpendicular to the PXY travel plane. The mechanical stop could alternatively be interposed between the movable support, here the first support 14, and the frame 2. In the example, the mechanical stop includes a left stop 50A, here for example interposed between the left bearing bodies 14A, 24A of the first and second supports 14, 24, and a right stop 50B, here for example interposed between the right bearing bodies 14B, 24B of the first and second supports 14, 24.The mechanical stop, which in the example comprises 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 on the first support 14 in the direction of the second support 24, for example by means of the load actuator(s) 32.

[0094] 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.

[0095] In operation, an initial setting of the working gap is first ensured at an initial setting value, determined by the pressure on the mechanical stop 50A, 50B, here for example interposed between the first support and the second support, by applying 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 setting 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 clamping force Fl can be a predetermined constant value. This predetermined constant value may be a function of the parameters of an upcoming production phase (for example, the thickness of the strip entering the machine, and / or the target thickness of the strip exiting the machine, and / or the mechanical characteristics of the strip (particularly its compression perpendicular to the plane of travel), etc.) or it may be independent of the parameters of an upcoming production phase. Typically, the clamping force Fl can be chosen to ensure that, at no point during a phase... During production, the resisting force imposed by the metal strip on the work rollers 1 must not cause the work rollers 10, 20 to recoil, which would cause one of the supports 14, 24 to lose contact with the mechanical stop, here, for example, 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 which aims 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.

[0096] 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.

[0097] 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.

[0098] The initial setup is performed, for example, by adjusting the adjustable mechanical stop. For example, the initial setup can be performed 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 until the working gap e30 reaches a predetermined initial setup value. The direct detection of the working surfaces 11, 21 of the two rollers 10, 20 can correspond to a measurement of the distance between the working surfaces 11, 21 of the two rollers 10, 20, by any conventional measuring means. Direct detection of the working surfaces 11, 21 of the two rollers 10, 20 can correspond to detection by calibrated thickness shim.Thus, the initial shimming can be carried out by detecting the working gap by inserting a calibrated thickness shim, 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 calibrated thickness shim is received without play. and without blocking in the working space between the working surfaces 11,21 of the two rollers 10, 20.

[0099] Preferably, the initial positioning is carried out by applying the positioning force Fl discussed above to the moving support.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] In the illustrated example, the calendering machine includes two sensors, in particular 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 representing 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.

[0105] Typically, the calendering machine can be configured to implement a known relationship between, on the one hand, the values ​​of the quantity(ies) representative(s) 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 computer control unit 110 or accessed by computer by the computer control unit 110.

[0106] Also, the calendering machine 1 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.

[0107] 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.

[0108] 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, and therefore also having as its axis of revolution the axis Y10, Y20 of this work roller. For a given work roller, the auxiliary reference surface 17A, 17B, 27A, 27B is axially offset, with respect to the work surface 11, 21 of this given work roller, along the direction of the axis Y10, Y20 of this work roller 10, 20, and it has a diameter strictly smaller than the diameter of the work surface 11, 21 of this 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 this work roller, on either side of the work 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 work surface 11, 21 of the corresponding work roller.

[0109] 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 In the variant not shown, it can be assumed that at least one representative value of the working gap, acquired by 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.

[0110] 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, for 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, presents an error which is preferably less than 5 microns, or even preferably in a range between 0.5 and 2 microns.

[0111] 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 actual values ​​of the working gap e30. This known relationship is, for each working roller, directly a reflection of the difference between, on the one hand, the diameter of the reference auxiliary surface(s) 17A, 17B, 27A, 27B of a given working roller 10, 20, and, on the other part the diameter of the working surface 11.21 of the work roller considered. This known relationship is preferably stored in a computer memory belonging to the computer control unit 110 or accessible by computer by the computer control unit 110, for example in the form of a conversion function or in the form of a table of corresponding values.

[0112] 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.

[0113] In all cases, since the acquisition uses at least one auxiliary reference surface with a diameter smaller than the diameter of the working surface of this 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 being of a smaller diameter compared to the diameter of the working surface of the corresponding roller to which it belongs, the available distance between these two auxiliary reference surfaces greatly facilitates the arrangement of a sensor to measure the distance between the two auxiliary reference surfaces.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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 work roller to 10, 20 corresponding, freeing 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 that extends substantially in the PXY travel 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 opposing reference auxiliary surfaces 17A, 27A. Preferably, the tangential arm 66 extends in the PYZ calendering plane. containing the axes Y10, Y20 of the two working rollers 10, 20, and therefore has a transverse orientation parallel to the axes of the working 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.

[0118] 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.

[0119] 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 the prior art in which strip thickness measurements are taken at the machine outlet, the measurement instant being in such a case delayed in time relative to the instant at which the measured thickness was created in the calendering space 30.This time delay, inherent in the prior art technique, corresponds to the duration of the journey of a given point of the strip 4, along the direction of travel X, between the calendering space 30 and the measurement point determined by the position of the strip thickness measurement sensor.

[0120] 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 within 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 as it passes through the calendering space 30, a high-frequency acquisition makes it possible to have successive measurements of the working gap e30 at time intervals that correspond to very short distances of the strip 4 passing through.

[0121] With the following operating parameters: V = strip feed speed (m / s) f = acquisition frequency of the quantity representing the working gap (1 / s) Therefore, the linear distance dX, on the strip, in the X direction of travel, between two acquisitions is equal to dX = V / f

[0122] 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.

[0123] In the 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 according to the acquired values ​​of the quantity representing the working gap and the target value of the working gap.

[0124] 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.

[0125] The two working rollers 10, 20, counter-rotating 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 on the first support 14 a total force F(t) adjusted successively over time according to the acquired values ​​d60(t) of the quantity d60 representing the working gap e30 and the target value e30c of the working gap.

[0126] In [Fig.7], it has been illustrated 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.

[0127] 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).

[0128] In the example in [Fig. 7], the clamping force Fl is determined from a minimum value Fmin of a calendering force, which is, for example, supplied as input by an operator, for example via a human / machine interface, of a value F40 representing the weight of the moving assembly formed by the first support 14 and the first working roller 10, and of a value Fg representing the preload forces which are applied by the preload system 40 on the two working rollers 10-20. For example, the stalling force Fl is a sum of these three values.

[0129] The total force F(t), in particular its component which is the complementary force F2(t), is therefore 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.

[0130] 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), and in particular its complementary force component F2(t), is thus determined, for example, based on a series of 3, 5, 10, 20, or 50 values ​​acquired over time for the quantity representing the working gap e30. These values ​​are preferably the most recent available for processing. When considering a time window, 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, in all cases, including when 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 ​​which were acquired less than 1 second before the given instant, preferably less than 100 milliseconds before the given instant, more preferably less than 10 milliseconds before the given instant.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] In [Fig. 7], it has been illustrated that the computer control unit 110 can include a second converter 113 capable of delivering, based on the regulation setpoint cReg30(t) of the working gap value, the additional force setpoint cF2(t) usable by the hydraulic power circuit 120. This second converter 113 could be integrated into another element of the system 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 system computer 110. This algorithm can use values ​​learned directly from the machine, for example during a machine calibration step.

[0136] 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.

[0137] 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.

[0138] For example, the computer control unit 110 is configured to command each group of load actuators to deliver a total force FA(t) and FB(t) respectively to the first support 14, depending on the successively acquired values ​​d60A(t) and d60B(t) of the representative working gap measurement acquired at the corresponding end of the calendering space 30, and the target value e30c of the working gap. In the example, the group 32A of left-hand actuators 32A1, 32A2, is thus capable of applying a total left-hand force FA(t) to the left-hand bearing body 14A of the first support 14, while the The group 32B of right-hand actuators 32B1, 32B2, is thus capable of applying a total right-hand force FB(t) on the right-hand bearing body 14B of the first support 14. The two total left-hand forces FA(t) and right-hand forces FB(t), applied respectively to the left-hand bearing body 14A and the right-hand 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 efforts 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.

[0139] 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.

[0140] These processes are implemented for example with a calendering machine 1 as described above.

[0141] 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 about 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 about a second axis Y20, parallel to the first axis Y10, on a second support 24

[0142] As seen above, the two working rollers 10, 20 are counter-rotating, rotating in opposite directions around their respective axes of rotation Y10, Y20.

[0143] It is defined that the calendering space 30 has, at its minimum spacing point along a Z direction perpendicular to the PXY scroll plane, a working spacing e30, between the working surfaces 11,21 of the two working rollers 10, 20.

[0144] 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.

[0145] 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 contact with the mechanical stop 50, for example interposed between the first support 14 and the second support 24, this contact resulting from an application 1040 of a clamping 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 rollers. The initial clamping operation 1050 can be carried out 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 between the two rollers 10, 20 through the calendering space 30.

[0146] 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.

[0147] 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.

[0148] For example, in such a method, the first work roller 10 is movable, perpendicular to the PXY plane of travel, with the consequence that the working gap e30 between the two work rollers can be adjusted. As seen above, the second work roller can be fixed in translation, in the sense of having a fixed distance from the plane of travel.

[0149] During said production phase, the process includes the application 1300, on at least the first support 14, of at least one total force F(t), 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 gap. working size, 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, 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 will 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 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 operation 1250 of calculating the process setpoint can advantageously include the calculation of a separate setpoint cFA(t), cFB(t) for each total force left FA(t) and right 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, 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.

[0153] 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 work rollers is a cylindrical surface of revolution that is coaxial, axially offset, and of strictly smaller diameter with respect to the working surface 11, 21 of the corresponding work 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 work rollers 10, 20, each auxiliary reference surface being a coaxial cylindrical surface of revolution, axially offset, and of a diameter strictly smaller than that of the work surface 11, 21 of the corresponding work 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 travel plane.

[0154] 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.

[0155] 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.

[0156] Machines and processes are also proposed which, for even greater control of the working gap e30, allow for taking into account any possible geometric defect of the working rollers 10, 20. The concept of geometric defect of the working rollers 10, 20 includes, in particular: - any possible geometric defects of the working surface 11,21 of at least one of the working rollers, which cause the working surface in question to have local deviations from a perfect surface of revolution; and / or - any possible defects in the concordance and / or alignment and / or parallelism of the geometric axis of the working surface 11,21 in question, with respect to the axis of rotation Y10, Y20 of the corresponding working roller in the machine 1; and / or - any defects in concordance and / or alignment and / or parallelism of the two rotation axes Y10, Y20 respectively of the two working rollers in machine 1.

[0157] When the working 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 working surface, in place in the machine, and a perfect cylindrical surface of revolution around a perfect theoretical axis of revolution.

[0158] 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.

[0159] Figure 9 schematically illustrates an example of a set of two work 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 work 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 work roller 10, 20 under consideration, the working surface 11, 21 is by An example is represented by a quasi-circular profile defined by a radius RI 1(0), R21(0) evolving with respect to the Y10, Y20 axis of the roller, with the length of this radius RI 1(0), R21(0) varying according to the angular position considered 0. We can also define, for an angular position considered 0, in the acquisition plane, a local geometry deviation as being for example dR1(0) = RI 1(0) - R10, respectively dR21(0) = R21(0) - R20, with R10 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 working surface considered 11,21.

[0160] 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.

[0161] [Fig. 13] is a schematic illustration of how such machines and calendering processes can be implemented, in a simplified and schematic version. It is identical to [Fig. 7], with the addition of a correction setpoint cor3O(0) 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 ​​of at least one representative quantity, for the instantaneous angular position 0(t), of a geometric deviation of the two work rollers.

[0162] Fig. 14 is a flowchart illustrating an example of such a process. Fig. 14 is identical to Fig. 8, with the addition of initial steps 1010 and 1020.

[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 for the absence, during the learning phase, of a strip 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 empty gap value, without the presence of a strip moving in the calendering space 30. Due to the defects of Due to the geometry, the open 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 to an initial setting value e30i as described above, with application of the setting force Fl. In such a case, the open gap of the working space 30 can therefore be considered to correspond to the initial gap e30i, which can therefore vary and can thus take on different values ​​e30i(0) over one rotation of the working rollers 10, 20 around their respective axes Y10, Y20, due to the 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 then 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, on the one hand, successively adjusted over time according to the acquired values ​​d60A(t), d60B(t)) of at least one quantity d60A, d60B representing the working gap, as described above, and on the other hand adjusted according to the instantaneous angular position 0(t) of the two working rollers 10, 20 around their respective axes, and according to the values ​​(for example d60i(0) and / or dRl 1(0), dR21(0)) acquired from at least one representative quantity, for the instantaneous angular position (0(t)),of a difference in geometry of the two working rollers 10, 20, in particular of the working surfaces 11, 21 of the two working rollers 10, 20.

[0167] 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.Therefore, when we analyze the work of the feedback loop described above, which aims to adjust the total force FA(t), FB(t) as a function of the acquired values ​​d60A(t), d60B(t)) of at least one quantity d60A, d60B representative of the working gap, we understand that this feedback loop does not have to. to compensate for the working gap that would be caused by a geometry deviation of the working rollers 10, 20. The performance of the feedback loop is necessarily improved, particularly in terms of convergence speed and minimization of the error relative to the target value e30c of the working gap.

[0168] Various options are possible with regard to acquiring 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.

[0169] In some examples, the acquisition 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 10, 20, includes the acquisition, in an acquisition plane perpendicular to the axes Y10, Y20 of two working 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 e3Oi(0i) for the angular acquisition position (0i) considered.

[0170] 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 angular acquisition positions, a representative value of the no-load working spacing e30i(0) for the angular acquisition position 0i. It should be noted that the, which can therefore also be called the no-load working spacing profile e30i(0), preferably contains the same number of representative values ​​of the no-load working spacing e30i(0) as the number of angular acquisition positions 0i for which an acquisition has been made.However, in some embodiments, the working spacing profile contains more values ​​than the number of acquisition angular positions for which an acquisition was performed, for example by calculating, for intermediate angular positions between two successive acquisition angular positions, a virtual value representing the open working spacing 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 acquisition angular positions for which an acquisition was performed, for example following filtering, or following a reduction in the storage size of the spacing profile.

[0171] 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, knowing that this acquisition is carried out at during a learning phase during which no strapping is present in the workspace 30.

[0172] 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.

[0173] 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.

[0174] 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 radial reference position RIO, R20 for the working roller (10, 20) considered.

[0175] Fig. 10 illustrates in a very schematic way a first 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 deviation of the two working rollers 10, 20, in particular of the working surfaces 11, 21 of the two working rollers.

[0176] 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. Note that, from the two... radial gap profiles, we can determine a working gap profile with, for each angular acquisition position of the two rollers, a working gap value at no load e3Oi(0) function of the local radial gaps dRl 1(0), dR21(0) recorded for this angular position.

[0177] Figure 11 schematically illustrates a second 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 geometric difference between the two working rollers 10, 20. In this second example, these values ​​are, for each angular acquisition position 0i, the relative distance d60i(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. As seen above, the auxiliary reference surfaces 17A, 17B, 27A, 27B are constructed in such a way that a working gap profile can be considered to be acquired directly.Thus, a working spacing profile is acquired very directly in this way.

[0178] 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.

[0179] 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 located at the angular position corresponding to the calendering space 30, it is opposite the point of minimum radius of the other working surface, this makes it possible to avoid, over the whole of a revolution of the working rollers around their respective axis, an excessive variation of the working gap e30. Of course, after such angular alignment of the two working rollers 10, 20, it is necessary to re-align the two acquired radial gap profiles for each working roller 10, 12, by simple circular permutation of the values.

[0180] 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.

[0181] In the preliminary learning phase 1010, the working gap profile or radial gap profiles of the two rollers, or representative values ​​of these profiles, are preferably stored electronically. For example, a table of correction values ​​cor3O(0) indexed angularly as a function of the angular position 0(t) of the working rollers 10, 30 can be stored. For this purpose, the control computer 110 preferably includes a computer memory capable of electronically storing the working gap profile(s).

[0182] 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 integrated directly into the instantaneous setpoint cF(t) which is used to control the load actuator 32 which controls the movement of the first support 14 relative to the frame 2, for example in the form of a correction 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. 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, that is, increasing or decreasing the total load. This correction therefore causes an increase or decrease in deformations within the machine, corresponding to a decrease or increase in the distance between the axes Y10 and 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 deviations.

[0183] 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.

[0184] Thus, in an example, such as can be seen in the [Fig.

[13] , 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, on the one hand, is adjusted successively in time according to the acquired values ​​d60(t) of the quantity d60 representing the working gap, and of the target value e30c of the working gap, and which is on the other hand also adjusted according to an instantaneous angular position 0(t) of the two working rollers around their respective axes, and according to acquired values ​​(d60i(0) or dRl 1(0), dR21(0)), in a learning phase, of at least one quantity (d6Oi(0) or dRl 1(0), dR21(0)) representing, for the instantaneous angular position 0(t), a geometric deviation of the two working rollers 10, 20, including work surfaces 11, 21 of the two work rollers.

[0185] 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).

[0186] 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.

[0187] In [Fig. 13], 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, the 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 with reference to [Fig. 7]. In an alternative configuration not shown, the controller 114 could, for example, output a force correction command cF3(t) usable by the hydraulic power circuit 120, for example by adding it to the force correction command cF2(t) issued by the second converter 113.

[0188] The controller 114 can take the form of an algorithm executed by the computer control unit 110.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] Advantageously, in such a process, the angular acquisition positions Oi of the values ​​of at least one quantity representing the geometry deviation, and the corresponding correction of at least one total force F(t), FA(t), FB(t), are performed at angles with a difference between them corresponding 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 that is calendered in such a process.

[0194] 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, and of the type comprising a mechanical stop (50) which determines a setting of the working gap, characterized in that the mechanical stop determines an initial setting (e30i) of the working gap at an initial setting value, when a setting force (Fl) is applied on the first support (14) in the direction of the second support (24), in that the calendering machine (1) includes at least one acquisition sensor (60A, 60B), during a production phase during which the strip (4) passes through the calendering space (30), successive values ​​(d60A(t), d60B(t)) in time of at least one quantity (d60A, d60B) representative of the working gap (e30), 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 cylindrical surface of revolution, axially offset, and of a diameter strictly smaller than that of the working surface (11, 21) of the corresponding working roller (10, 20), in that the computer control unit (110) is configured to control at least one load actuator (32A1, 32A2, 32B1, 32B2) to deliver onto the first support (14) a total force adjusted successively in time according to the acquired values ​​of the quantity (d60A,d60B) representative of the working gap (e30) and the target value (e30c) of the working gap.

2. Machine according to claim 1, characterized in that at least one sensor (60A, 60B) is a sensor positioned in a 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) 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).

3. Machine according to any one of claims 1 or 2, characterized in that at least one sensor (60A, 60B) is a non-contact sensor, in particular a capacitive sensor.

4. Machine according to any one of the preceding claims, characterized in that the computer control unit (110) is configured to calculate a force setpoint (cF(t)), cFA(t), cFB(t)), adjusted successively in time during a production phase during which the strip (4) passes through the calendering space (30), as a function of the acquired values ​​of the quantity (d60A, d60B) representing the working gap (e30) and the target value (e30c) of the working gap, 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 (F(t), FA(t), FB(t)) corresponding to the force setpoint (cF(t)), cFA(t), cFB(t)).

5. Machine according to any one of the preceding claims, 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.

6. Machine according to any one of the preceding claims, characterized in that the first working roller (10) and the second working roller (20) each have at least one auxiliary reference surface (17A, 17B, 27A, 27B), cylindrical of revolution, coaxial, axially offset, and of strictly smaller diameter compared to the working surface (11, 21) of the corresponding working roller, the two auxiliary reference surfaces (17A, 17B, 27A, 27B) being opposite each other on either side of the scroll plane (PXY).

7. A machine according to any one of the preceding claims, characterized in that the calendering machine (1) comprises, at each axial end of the calendering space (30), at least one acquisition sensor (30A, 30B), during a production phase in which the strip (4) passes through the calendering space (30), successive time values ​​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), in that each of the two quantities (d60A, d60B) representing 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 (17A, 17B, 27A,27B) belonging to the other of the two work rollers, said auxiliary reference surface of the other of the two work rollers being a coaxial cylindrical surface of revolution, axially offset at a corresponding axial end of the calendering space (30), and of diameter, strictly inferior in relation to the working surface (11, 21) of the corresponding working roller.

8. A machine according to any one of the preceding claims, characterized 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, firstly 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 ​​(dR11(0), dR21(0)), during a 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 two working rollers, and secondly as a function of the acquired values ​​(d60A(t), d60B(t)) of the quantity (d60A, d60B) representative of the working gap acquired at the corresponding end of the calendering space (30), and the target value (e30c) of the working gap.

9. Machine according to claim 8, 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 gap of the two working rollers.

10. Machine according to any one of claims 8 or 9, 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 so that it delivers, on the first support (14), a total force (FA(t), FB(t)) 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)) at the corresponding end of the calendering space (30), in the learning phase, of at least one quantity (d60i(0), dRll(0), dR21(0)) representative, for the instantaneous angular position (0(t)),

11. of a geometry difference of the two working rollers, and on the other hand according to the acquired values ​​of the quantity (d60A, d60B) representing the working gap (e30), acquired at the corresponding end of the calendering space (30), and the target value of the working gap. A calendering process 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 mounted rotatably about a first axis (Y 10) on a first support (14), - and a working surface (21) of a second work roll (20), which is mounted rotatably about a second axis (Y20), parallel to the first axis (Y 10), 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 spacing (e30), between the working surfaces (11, 21) of the two working rollers (10, 20), and of the type in which the process includes the application,on at least one of the supports (14, 24), of a force perpendicular to the plane of movement (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 method comprises:, - an initial setting (1050) of the working gap to an initial setting value (e30i), determined by the support 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 the 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 one total force (F(t), FA(t), FB(t)) 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 (e30).

12. Method according to claim 11, characterized in that the application (1300), on at least the first support, of at least one total force (F(t), FA(t), FB(t) comprises an elastic deformation of at least one among first support (14), second support (24), shim stop (50) and a frame (2) which carries the second support (24).

13. A method according to any one of claims 11 or 12, characterized in that it comprises the calculation (1250) of a force setpoint (cF(t)), cFA(t), cFB(t)) adjusted successively in time with negative feedback loop, as a function of the target value (e30c) and the values ​​acquired successively in time (d60A(t), d60B(t)) of at least one quantity (d60A, d60B) representative of the working gap (e30), and in that the at least total force (F(t), FA(t), FB(t)) corresponds to the force setpoint.

14. A method according to any one of claims 11 to 13, 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)), 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 to the acquired values ​​of that (d60A, d60B) of the two quantities representing the working gap acquired at the corresponding axial end of the calendering space (30).;

15. A method according to claim 14, characterized in that it comprises calculating a separate setpoint (cFA(t), cFB(t)) for each total force (FA(t), FB(t)), adjusted successively over time with negative feedback loop, depending on the target value (e30c) and the values ​​acquired successively in time (d60A(t), d60B(t)) of that of the two quantities (d60A, d60B) representative of the working gap which is acquired at the corresponding axial end of the calendering space (30).

16. A method according to any one of claims 11 to 15, characterized in that it comprises: - 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 distributed over one revolution, of values ​​(d60i(0), dRll(0), dR21(0)) of at least one quantity (d60, dRll, dR21) representative of a geometry deviation 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 a total force (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 around their respective axes, and as a function of the acquired values ​​(d60i(0), dRll(0), dR21(0)) of at least one quantity (d60(0), dRll(0), dR21(0)) representative, for the instantaneous angular position (0(t)), of a geometry deviation 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.;

17. A method according to claim 16, characterized in that the acquisition of the values ​​(dR11(0), dR21(0)) of at least one quantity (dR11, dR21) representing a geometric deviation 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 value representing the no-load working gap e3Oi(0) 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 according to the instantaneous angular position of the two rollers of work around their respective axes, and according to the working spacing profile.

18. Method according to claim 17, characterized in that the working gap profile comprises, for each working surface, a 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.

19. A method according to claim 17 or 18, characterized in that at least two working gap profiles are acquired in separate acquisition planes, perpendicular to the axes of two work rollers and axially separated 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, and according to the working gap profile acquired in the corresponding axially aligned acquisition plane.

20. A method according to claim 19, 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 correction values ​​indexed angularly as a function of the angular position of the rollers.

21. A method according to any one of claims 11 to 20, characterized in that at least one quantity representing 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 a diameter strictly smaller by ratio to the working surface (11, 21) of the corresponding working roller (10, 20).

22. A method according to any one of claims 11 to 21, 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.

23. A method according to any one of claims 21 or 22, characterized in that the relative distance (d60A, d60B) is measured with at least one non-contact sensor (60A, 60B), in particular a capacitive sensor.

24. Method according to claim 23, 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 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).

25. A method according to any one of claims 11 to 24, characterized in that the first working roller (10) is movable, perpendicular to the plane of travel (PXY).

26. A method according to any one of claims 11 to 25, characterized in that the second axis (Y20) is fixed.

27. ​​A method according to any one of claims 11 to 26, characterized in that the acquisition (1200) of successive values ​​in time (d60A(t), d60B(t)) 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 carried out at a frequency greater than 10 hertz, preferably greater than 100 hertz.

28. A calendering method according to any one of claims 11 to 27, 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.

29. A calendering process according to claim 28, 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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