Uses and methods of cold rolling apparatuses for controlled cold rolling of aluminum foil

Abstract

To provide uses and methods of cold rolling apparatuses for controlled cold rolling aluminum foil.SOLUTION: The invention relates to a use of a cold rolling apparatus 2 for an aluminum foil 20, in particular, a battery foil. The cold rolling apparatus 2 comprises: a plurality of rolls 6, 8; a control device 16 which is configured to control evenness and / or flatness of the aluminum foil 20; cooling medium spray devices 38, 40 configured to spray a liquid cooling medium on the rolls 6, 8 in a separately controllable manner; and roll heating devices 42, 44 configured to heat the rolls 6, 8. The cooling medium spray devices 38, 40 are configured to spray the liquid cooling medium on zones of the rolls 6, 8, and the control device 16 is configured to perform control partially though zone cooling, and to control the roll heating means 42, 44 so that the rolls 6, 8 are heated over substantially the entire roll width during when the zone cooling is proceeding.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to the use of a cold rolling apparatus for the controlled cold rolling of aluminum foils, in particular battery foils. Further, the present invention relates to a method for the controlled cold rolling of aluminum foils, in particular battery foils.

Background Art

[0002] A common method for the production of thin aluminum strips and foils is cold rolling. In cold rolling, among other criteria, the flatness (i.e., the strip tension distribution under strip tension) or the evenness (i.e., the wave height in the absence of tension or at very low auxiliary tension) of the rolled foil are essential quality criteria for subsequent processing without defective products. In order to set and control a clear flatness or evenness respectively, a cold rolling mill is usually parameterized as a function of a selected operating point (e.g., work roll bevel, backup roll bevel) or as a function of the strip tension distribution measured in-line to a roll gap or roll gap contour, for example, by adjusting roll bending, roll rotation or the contact force gradient in the roll width direction, axial roll displacement, a contour variable backup roll, or by zone cooling, optionally with an actuator that affects each in a closed control loop. Each actuator has its respective effective range (linear, quadratic, quartic, x n ) as well as physical limits.

[0003] To control higher-order flatness errors, zone cooling is preferably used. Zone cooling differs from other actuators in that the temperature difference between the cooling medium and the work roll, which is used as a driving force for roll gap contour changes, is formed from the forming operation itself. The temperature of the work roll is controlled by the amount of heat released during forming.

[0004] Zone cooling reaches its limit when the amount of heat generated from the forming operation is too low to set an effective temperature difference of the work roll with respect to the cooling medium. Lowering the cooling medium temperature to increase the temperature difference also has a lower limit because, for example, the solubility of additives in the cooling medium or condensate formation in plant components sets the limit.

[0005] A rolling mill having zone cooling (or zone heating instead thereof) is known from Patent Document 1. Further, Patent Document 2 discloses a method for thermal control of a work roll by local heating or cooling, but it is not related to aluminum foil.

[0006] In view of this background, the present invention is based on the object of satisfying high flatness requirements even in the case of a rolled product from a rolling pass having a low heat input due to a low forming process amount, that is, in the cold rolling of aluminum foil.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Means for Solving the Problems

[0008] According to a first aspect of the present disclosure, there is provided the use of a cold rolling apparatus for the controlled cold rolling of aluminum foil, particularly battery foil, the cold rolling apparatus comprising a plurality of rolls, the cold rolling apparatus particularly comprising a control device configured to perform control of a cold rolling operation for controlling the evenness and / or flatness of the aluminum foil, the cold rolling apparatus comprising a cooling medium injection device configured to inject a liquid cooling medium into at least one of the plurality of rolls, particularly a work roll or a backup roll, the cold rolling apparatus comprising a roll heating device configured to heat at least one of the plurality of rolls, the cooling medium injection device being configured to inject the liquid cooling medium into a plurality of cooling zones of at least one of the plurality of rolls in an individually controllable manner, and the control device being configured to perform control at least in part by zone cooling by controlling the cooling medium injection device. In the use of such a cold rolling apparatus, this object is achieved according to the invention in that the roll heating device is configured to heat at least one of the plurality of rolls substantially over the entire roll width during the progress of zone cooling. For this purpose, the control device can particularly be configured to control the roll heating device in such a way that at least one of the plurality of rolls is heated substantially over the entire roll width during the progress of zone cooling.

[0009] In particular, the roll heating device may be in the form of a heating medium injection device configured to inject a liquid heating medium into at least one of the plurality of rolls, and the control device may particularly be configured to control the heating medium injection device in such a way that the liquid heating medium is injected substantially over the entire roll width into at least one of the plurality of rolls during the progress of zone cooling, so that at least one of the plurality of rolls is heated substantially over the entire roll width during the progress of zone cooling.

[0010] Alternatively, the roll heating device may be in the form of an induction roll heating device configured to inductively heat at least one of a plurality of rolls, and the control device may be configured to control the induction roll heating device such that at least one of the plurality of rolls is inductively heated substantially across the entire roll width, particularly during zone cooling progression.

[0011] According to a first aspect of the present disclosure, a cold rolling operation is performed on an aluminum foil using a cold rolling apparatus having a plurality of rolls, particularly using the cold rolling apparatus described above, and in particular, control of the cold rolling operation is performed to control the evenness and / or flatness of the aluminum foil. The control is at least partially performed by zone cooling of at least one of the plurality of rolls, particularly to the work roll or the backup roll. In a method for controlled cold rolling of an aluminum foil, particularly a battery foil, the above object is further solved by the present invention in that at least one of the plurality of rolls is heated substantially across the entire roll width during control by zone cooling, particularly by being sprayed with a liquid heating medium or inductively heated.

[0012] In the above use of the cold rolling apparatus or in the above method according to the first aspect of the present disclosure, heating at least one of the plurality of rolls substantially across the entire roll width enables the roll to be brought to a high temperature across the entire area, even with a low heat input due to a small rolling pass reduction during the cold rolling operation itself, so that a sufficient temperature difference between the roll surface and the cooling medium is achieved, and thus effective zone cooling is possible.

[0013] Therefore, during the cold rolling operation, in particular, overall heating of at least one of some of the rolls to a higher temperature level as a whole is combined with local cooling of the rolls for zone cooling.

[0014] For this purpose, at least one of the plurality of rolls is preferably heated substantially uniformly over the entire width of the roll during the cold rolling operation, in particular by being sprayed with a liquid heating medium or by induction heating.

[0015] For example, the roll may be provided for heating independently of the control of the cold rolling operation, in particular for spraying a liquid heating medium or for induction heating it. The heating of the roll, in particular the spraying or induction heating of the roll by the heating medium, cannot be changed by the actual control, but may affect the control of other operating variables in certain situations.

[0016] Furthermore, the roll may be provided for heating independently of the control of the cold rolling operation using the basic heating power, in particular for spraying with a liquid heating medium of a basic flow rate or for induction heating it using the basic heating power. In addition to this basic heating power, in particular this basic flow rate, additional heating power, in particular an additional flow rate of the heating medium, can be included in the control as an operating variable.

[0017] The basic flow rate may in particular be in the range of 30 to 300 l / h. The temperature of the liquid heating medium, in particular oil, is preferably in the range of 65 to 85 °C. The temperature difference between the roll surface and the liquid cooling medium, which is sufficient to achieve zone cooling for these operating parameters, is preferably in the range of 15 to 35 °C.

[0018] According to a second aspect of the present disclosure, there is provided the use of a cold rolling apparatus for the controlled cold rolling of aluminum foil, particularly battery foil, the cold rolling apparatus comprising a plurality of rolls, the cold rolling apparatus particularly comprising a control device configured to perform control of the cold rolling operation for controlling the evenness and / or flatness of the aluminum foil, the cold rolling apparatus having a roll heating device configured to heat at least one of the plurality of rolls, particularly a work roll or a backup roll, and the roll heating device being configured to individually and controllably heat a plurality of heating zones of at least one of the plurality of rolls. In the use of such a cold rolling apparatus, the above object is achieved according to the present invention in that the control device is configured to perform control at least in part by reverse zone cooling by controlling the roll heating device.

[0019] According to a second aspect of the present disclosure, a cold rolling operation is performed on an aluminum foil, particularly a battery foil, using a cold rolling apparatus having a plurality of rolls, particularly using the cold rolling apparatus according to the second aspect of the present disclosure, the cold rolling operation being controlled particularly for controlling the evenness and / or flatness of the aluminum foil. In a method for the controlled cold rolling of aluminum foil, particularly battery foil, the above object is further solved according to the present invention in that the control is performed at least in part by reverse zone cooling in at least one of the plurality of rolls, particularly in a work roll or a backup roll.

[0020] In the above use of the cold rolling apparatus or in the above method according to the second aspect of the present disclosure, reverse zone cooling enables effective zone control even in passes having a low forming amount and thus a low heat input.

[0021] Conventional zone cooling involves variations in the local injection of a cooling medium into the cooling zone of the roll. In contrast, reverse zone cooling instead involves variations in the heating of complementary heating zones of the roll, particularly variations in the injection of a heating medium into the complementary heating zones of the roll or variations in the induction heating of the complementary heating zones of the roll. Thus, reverse zone cooling involves targeted heating of other, particularly adjacent zones of the roll instead of specifically cooling local zones of the roll. In this way, the effects of different zones that effectively correspond to each other can be realized. Thus, reverse zone cooling involves heating but not necessarily cooling.

[0022] Thus, the control device is preferably configured to control the roll heating device in such a way that, for reverse zone cooling, in the case of a setpoint offset of a control variable assigned to a first one of a plurality of heating zones, the heating of one or more second heating zones is increased compared to the first heating zone, particularly to control the heating medium injection device in such a way that the injection of the heating medium into one or more second heating zones is increased compared to the first heating zone. Thus, preferably, in this method, in reverse zone cooling, in the case of a setpoint offset of a control variable associated with a first one of a plurality of heating zones of at least one of a plurality of rolls, the heating of one or more second heating zones is increased compared to the first heating zone, particularly the injection into one or more second heating zones is increased compared to the first heating zone. The one or more second heating zones are heating zones different from the first heating zone, preferably heating zones adjacent to the first heating zone.

[0023] The control variable assigned to a heating zone is particularly a control variable that refers to a position on the roll corresponding to the position of the heating zone or on the aluminum foil being cold-rolled. For example, if the strip tensile stress of the aluminum foil being cold-rolled is detected over the width as a control variable (strip tensile stress distribution), the heating zone can be assigned as a control variable to the strip tensile stress measured at the corresponding position over the width.

[0024] Inverse zone cooling includes complementary heating instead of local cooling (as in conventional zone cooling), so it is possible to control or influence the flatness of aluminum foil during cold rolling operations even in cases of low heat input for rolling passes with low forming heat.

[0025] The use and method by the first side and the second side in each case relate to the controlled cold rolling of aluminum foil, especially battery foil (flatness).

[0026] Aluminum foil is understood to particularly mean a strip-shaped material made of aluminum or an aluminum alloy and having a thickness of 200 μm or less. In contrast, an aluminum strip is understood to particularly mean a corresponding strip-shaped material but having a thickness exceeding 200 μm.

[0027] In particular, the cold rolling apparatus described above can be used to cold roll aluminum foil having a final thickness of 20 μm or less. Thus, the final thickness of the aluminum foil in the described method may particularly be 20 μm or less. At such a final thickness, the heating of the rolls performed per pass is too low to provide sufficient flatness control by conventional zone cooling. In contrast, the methods and cold rolling apparatus described herein can achieve reliable flatness control even at such low final thicknesses.

[0028] The cold rolling operation may particularly be a texturing rolling pass or a skin-pass rolling pass. Such cold rolling operations typically have a low rolling pass reduction rate and thus a low amount of forming work at low foil thicknesses. Furthermore, the aluminum foil may particularly be made of an alloy having low thermal stability and thus must be cold rolled at a reduced speed and / or a low pass reduction rate to achieve a specific strength value.

[0029] A thermally unstable alloy is an alloy having a low recovery and / or recrystallization temperature. This results in early softening of such an alloy even at low temperatures.

[0030] The rolling reduction per rolling pass in this cold rolling operation may particularly be in the range of 1.5 to 55%. At these rolling reductions, the heating of the rolls caused by the forming operation during the rolling of the aluminum foil is typically not sufficient on its own to carry out effective zone cooling, and therefore the use and method according to the first or second aspect of the present disclosure are particularly advantageous.

[0031] Preferably, the aluminum foil intended for the production of battery electrodes, particularly battery positive electrodes, so-called battery foils, is cold rolled. On the other hand, since there are particularly high flatness requirements on the customer side for such foils, the use and method according to the first and second aspects are particularly advantageous for battery foils. On the other hand, battery foils often consist of thermally unstable alloys that recover at relatively low temperatures, and therefore, in particular, a low rolling temperature is required to achieve the required high final strength, which is realized by a low pass reduction and / or a low rolling speed. At the same time, high flatness requirements that cannot be met if there are higher-order flatness defects are imposed on the battery foils. Therefore, the use and method described herein are particularly advantageous for battery foils.

[0032] By the use and method according to the described first and second aspects, particularly when the first and second aspects are combined, in particular, a battery foil having a thickness in the range of 5 to 20 μm and having a flatness deviation of <2 mm wave height at an auxiliary tension of 8 N / mm can be produced over the strip width and strip length. 2

[0033] ​According to the first aspect and the second aspect, the cold rolling apparatus includes a plurality of rolls. In particular, the plurality of rolls includes two work rolls. A work roll is understood to mean a roll that comes into direct contact with the rolling material. A roll gap is arranged between the work rolls, and the roll gap has a roll gap contour in the width direction. In addition to the work rolls, the cold rolling apparatus can have two or more backup rolls. For example, a quarto cold rolling apparatus includes two work rolls and two backup rolls. However, three or more backup rolls, such as intermediate rolls, may also be provided.

[0034] At least one of the plurality of rolls can be a work roll or a backup roll, respectively.

[0035] The control device of the cold rolling apparatus according to the first aspect and the second aspect is configured to perform control of the cold rolling operation, in particular, to control the uniformity and / or flatness of the aluminum foil. Preferably, the control also includes thickness control.

[0036] The control is preferably carried out in one or more, possibly combined, control loops in which one or more control variables are detected, compared with relevant reference variables, and one or more manipulated variables are set according to the comparison results.

[0037] According to a first aspect, the control device is configured to perform control by at least partially zone cooling by controlling a cooling medium injection device. For this purpose, in particular, the cooling medium injection device or the individual nozzles of the cooling medium injection device are controlled as the manipulated variable of a control loop. In particular, during zone cooling, the cooling medium injection device, in particular its individual nozzles, is controlled in such a way that the injection of the cooling medium into at least one individual cooling zone of a plurality of rolls is varied in a targeted manner. By selectively varying the injection of the cooling medium into the cooling zones, in particular by varying the cooling medium flow rate and / or the cooling medium pressure and / or the cooling medium temperature for each respective cooling zone, it is possible to vary the temperature of at least one of the plurality of rolls in each respective cooling zone such that a change in the thermal expansion of the roll occurs in each respective cooling zone. In this way, it is possible to locally influence the roll gap geometry in the region of each respective cooling zone, enabling higher-order roll gap corrections.

[0038] According to a second aspect, the control device is configured to perform control at least in part by reverse zone cooling by controlling a roll heating device, in particular a heating medium injection device. For this purpose, the roll heating device, in particular the heating medium injection device or the individual nozzles of the heating medium injection device, is controlled as a manipulated variable of a control loop. In particular, during reverse zone cooling, the roll heating device, in particular the heating medium injection device, in particular its individual nozzles, is controlled in such a way that the heating of at least one of one or more second heating zones of a plurality of rolls is specifically changed, in particular the injection of the heating medium into at least one of one or more second heating zones of a plurality of rolls is specifically changed. By selectively changing the heating of one or more second heating zones, in particular the injection of the heating medium into one or more second heating zones, in particular by changing the heating medium flow rate and / or the heating medium pressure and / or the heating medium temperature for each respective second heating zone, the temperature of the rolls in each respective second heating zone can be changed such that a change in the thermal expansion of the rolls in each respective second heating zone occurs. In contrast, in one or more first heating zones, the rolls show no change in thermal expansion or at least a smaller change in thermal expansion, so that they can locally affect the roll gap geometry in the region of the relevant first heating zone, enabling higher-order roll gap corrections.

[0039] The first and second aspects of the present disclosure may in particular be combined with each other. Thus, the control device may in particular be a) controlling a cooling medium injection device, and the roll heating device is controlled in such a way that at least one of a plurality of rolls is heated during zone cooling progression, in particular by injecting a liquid heating medium substantially over the entire roll width, so as to perform control using at least in part zone cooling, and b) controlling the roll heating device so as to perform control at least in part by reverse zone cooling, configured.

[0040] Zone cooling control and reverse zone cooling control can be carried out simultaneously or successively, in particular alternately.

[0041] In this method, on the one hand, sufficient energy is applied to the rolling operation by the roll heating device so that the zone cooling effect functions again even with a low forming processing amount. Furthermore, by reversing this effect to targeted zone heating in reverse zone cooling, a direct influence can be exerted on the roll gap contour.

[0042] The input of heat during zone cooling and / or reverse zone cooling is, in particular, optionally controlled in a closed control loop as a function of the strip tension distribution measured in-line, and may be superimposed with other flatness actuators. In this way, good results can be achieved with respect to the flatness and uniformity of the aluminum foil.

[0043] Various embodiments of the use and method according to the first aspect of the present disclosure and the use and method according to the second aspect of the present disclosure are described below, and each embodiment is independently applicable to both the use and method according to the first aspect and the use and method according to the second aspect. Furthermore, the first aspect and the second aspect of the present disclosure may be combined. Furthermore, the individual embodiments may be combined with each other as desired.

[0044] In one embodiment, the roll heating device is a heating medium injection device configured to inject a liquid heating medium onto at least one of a plurality of rolls, and preferably is designed in the form of a heating medium injection device configured to inject the liquid heating medium controllably individually into a plurality of heating zones of at least one of the plurality of rolls. The heating medium injection device may in particular have a plurality of nozzles arranged adjacent to one another in the direction of the roll axis, which may preferably be controlled individually. Preferably, the flow rate, pressure and / or heating medium temperature of the individual nozzles can be adjusted. In this way, it is possible to apply the heating medium to the roll in a position-dependent manner. According to a first aspect of the present disclosure, this heating medium injection device can also be used for the injection of the heating medium onto the roll in a uniform, position-independent manner.

[0045] In a further embodiment, the roll heating device is an inductive roll heating device configured to inductively heat at least one of a plurality of rolls, and in particular is designed in the form of an inductive roll heating device configured to inductively heat a plurality of heating zones of at least one of the plurality of rolls controllably individually. In this way, position-dependent heating of the roll becomes possible. According to a first aspect of the present disclosure, this inductive roll heating device can also be used to provide uniform, position-independent heating of the roll.

[0046] In an embodiment, the cold rolling apparatus is a cooling medium injection device configured to inject a liquid cooling medium into at least one of a plurality of rolls, and preferably has a cooling medium injection device configured to individually and controllably inject the liquid cooling medium into a plurality of cooling zones of at least one of the plurality of rolls. The cooling medium injection device particularly may have a plurality of nozzles arranged adjacent to each other in the direction of the roll axis, and preferably may be individually controlled. Preferably, the flow rate, pressure, and / or cooling medium temperature of each individual nozzle can be adjusted. In this way, injection of the cooling medium onto the roll depending on the position becomes possible. When using this cooling medium injection device, in the use or method according to the second aspect of the present disclosure, the roll may be injected with a cooling medium in addition to reverse zone cooling, particularly to supply sufficient rolling oil as a lubricant for the cold rolling operation.

[0047] In an embodiment, the cold rolling apparatus includes a cooling medium injection device and a heating medium injection device. The cooling medium injection device includes a first nozzle bar, the heating medium injection device includes a second nozzle bar, and the first nozzle bar and the second nozzle bar have respective frames arranged adjacent to each other and having nozzles that can be controlled respectively. In this way, independent, particularly simultaneous injection of the cooling medium and the heating medium onto the roll, and thus more flexible temperature control of the roll, is possible.

[0048] In a further embodiment, the width of at least one cooling zone and / or heating zone of the plurality of rolls is in the range of 10 to 150 mm.

[0049] In a further embodiment, rolling oil is used as the heating medium and / or the cooling medium. In this method, additional injection of the rolling oil is unnecessary. Preferably, during the cold rolling operation, a liquid cooling medium is continuously injected onto at least one of several rolls substantially over the entire roll width. When rolling oil is used as the cooling medium, lubrication of the rolls can be ensured in this method. When the rolling oil is continuously injected onto the rolls, zone cooling can be achieved, for example, by varying the cooling medium flow rate around a predetermined average cooling medium flow rate or by locally varying the cooling medium temperature.

[0050] The cold rolling apparatus may have a detection device configured to measure the strip tensile stress distribution of the cold rolled aluminum foil, and the control device may be configured to perform control as a function of the value measured by the detection device. To measure the strip tensile stress distribution, a segmented roll segmented in a direction transverse to the rolling direction may be provided, and the aluminum foil is wound around the segmented roll to some extent. By measuring the force in each segment of the roll, it is possible to determine the respective strip tensile stress as a function of each position in the direction transverse to the rolling direction in this method, and thus to determine the strip tensile stress distribution. The measured values of such a detection device represent suitable control variables for strip tension distribution control that can improve the flatness or uniformity of the aluminum foil. In particular, strip tension distribution control can be achieved by zone cooling involving simultaneous uniform application of the heating medium to the rolls and / or by reverse zone cooling.

[0051] In a further embodiment, the liquid cooling medium has a cooling medium temperature in the range of 20 to 65 °C, preferably 35 to 45 °C. On the one hand, the minimum temperature of 20 °C, preferably 35 °C, ensures a stable solution state of the additives typically contained in the liquid cooling medium. On the other hand, the maximum temperature of 65 °C, preferably 45 °C, ensures operation at a temperature well below the flash point, which increases operational safety. Furthermore, oxidation of the cooling medium that may occur can be reduced.

[0052] In a further embodiment, the cooling medium flow rate of the cooling medium injection device is in the range of 200 to 5000 l / min, particularly 300 to 3000 l / min. In particular, the cooling medium flow rate of the cooling medium injection device may be in the range of 0.2 l / min to 1.0 l / min per mm of roll width. At a cooling medium flow rate below the minimum flow rate mentioned above, sufficient lubrication for the rolling operation and sufficient cleaning of the rolls by the cooling medium may not be guaranteed. At a cooling medium flow rate above the maximum speed mentioned, excessive cooling of individual zones that can deteriorate the rolling result may occur.

[0053] In another embodiment, the liquid heating medium has a heating medium temperature in the range of 60 to 100 °C, preferably 65 to 90 °C. By maintaining the minimum heating medium temperature, a sufficient temperature difference between the roll and the cooling medium can be ensured in the first aspect of the present disclosure, and a sufficient temperature difference between the roll and the heating medium can be ensured in the reverse zone cooling in the second aspect of the present disclosure. The maximum temperature of 100 °C, preferably 90 °C, ensures operation at a temperature below the flash point, thereby increasing operational safety. Furthermore, oxidation of the cooling medium that may occur can be reduced.

[0054] In a further embodiment, the heating medium flow rate of the heating medium injection device is in the range of 0 to 500 l / min. In particular, the heating medium flow rate of the heating medium injection device may be in the range of 0 l / min to 0.5 l / min per mm of roll width. At a heating medium flow rate above the maximum flow rate mentioned, the operation is no longer economical.

[0055] In a further embodiment, the cooling capacity of the cooling medium injection device and / or the heating capacity of the heating medium injection device are in the range of 50 to 200 kW per roll width m.

[0056] Further advantages and features of the cold rolling apparatus and method will become apparent from the following description of the embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0057]

Figure 1A

Figure 1B

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0058] Figures 1A and 1B show a cold rolling apparatus suitable for exemplary embodiments of the use and method of controlled cold rolling of an aluminum foil according to the first and second aspects of the present disclosure. Figure 1A shows a schematic cross-sectional view corresponding to the cross-section designated as Ia in Figure 1B. Figure 1B shows a schematic view of the supply side of the cold rolling apparatus corresponding to the cross-section designated as Ib in Figure 1A.

[0059] The cold rolling apparatus 2 has a cold rolling stand 4 designed as a quarto cold rolling stand having an upper work roll 6, a lower work roll 8, an upper backup roll 12, and a lower backup roll 14 in this example. The roll gap 10 is disposed between the upper and lower work rolls 6, 8. When rolling the aluminum foil 20, the work rolls 6, 8 contact each other due to the thin thickness of the aluminum foil 20 in the area outside the aluminum foil 20, so the roll gap is typically called a closed gap.

[0060] The cold rolling apparatus 2 further includes a control device 16 configured to perform (flatness) control of the cold rolling operation such that the aluminum foil 20 supplied to the cold rolling mill from the supply side 18 is cold rolled so that the aluminum foil 20 has a reduced thickness at the discharge side 22. The control device 16 may include, for example, a microcontroller control system or control software installed in a computer.

[0061] The cold rolling apparatus 2 may include a detection device 24 for determining the thickness of the aluminum foil 20 after rolling.

[0062] The cold rolling apparatus 2 may further include a detection device 26 for measuring the strip tension distribution of the cold rolled aluminum foil 20. For this purpose, the detection device 26 may have, for example, a plurality of roll segments 27 arranged longitudinally in a direction transverse to the rolling direction and through which the aluminum foil 20 is guided. By measuring the force in each individual roll segment, the strip tensile stress of the associated section of the aluminum foil 20 at the corresponding position in the direction transverse to the rolling direction can be measured, and as a result, the strip tensile stress distribution can be obtained from the measurements in the individual rolls.

[0063] To achieve sufficient winding of the aluminum foil 20 around the roll segment 27, preferably additional rolls 36, 37 around which the aluminum foil 20 is guided are provided. The roll 36 can be made movable (see double-headed arrow) to facilitate the passage of the aluminum foil 20 around the rolls 27, 36, 37.

[0064] The control device 16 controls, as manipulated variables, various components of the cold rolling mill 2, namely, for example, a) the adjusting actuators 30, 30' for adjusting the vertical positions of the work rolls 6, 8 and / or the backup rolls 12, 14, b) the adjusting actuators 32, 32' for adjusting the widthwise gradient of the force with which the work rolls 6, 8 press against each other, c) the adjusting actuators 33, 33' for bending the work rolls 6, 8 and / or the backup rolls 12, 14 and / or d) the adjusting actuators 34, 35 for adjusting the strip tension on the supply side or the discharge side, in particular the adjusting actuators for adjusting the rewinding speed and / or the recoiling speed configured to be controlled.

[0065] Furthermore, the cold rolling mill 2 includes upper and lower cooling medium injection devices 38, 40 configured to inject a liquid cooling medium onto the upper and lower work rolls 6, 8, respectively. Alternatively or additionally, the cooling medium injection devices 38, 40 can also be configured to inject a liquid cooling medium onto the backup rolls.

[0066] Furthermore, the cold rolling mill 2 includes roll heating devices 42, 44 in the form of upper and lower heating medium injection devices configured to inject a liquid heating medium onto the upper and lower work rolls 6, 8, respectively. Alternatively or additionally, the heating medium injection devices 38, 40 can also be configured to inject a liquid heating medium onto the backup rolls.

[0067] The cooling medium injection devices 38, 40 and the heating medium injection devices 42, 44 each include frames 46, 47 having nozzles 48, 49 arranged side by side. The nozzles 48 of the cooling medium injection devices 38, 40 are connected to a cooling medium supply source 52 via a supply line 50, and the nozzles 49 of the heating medium injection devices 42, 44 are connected to a heating medium supply source 56 via a supply line 54. The cooling medium supply source 52 may be configured to supply the nozzles of the cooling medium injection devices 38, 40 with rolling oil having an adjustable temperature in the range of, in particular, 20 to 65°C, particularly 35 to 45°C, as the cooling medium. The heating medium supply source 52 may be configured to supply the nozzles of the heating medium injection devices 42, 44 with rolling oil having an adjustable temperature in the range of, in particular, 60 to 100°C, particularly 65 to 90°C, as the heating medium.

[0068] Alternatively, it is also conceivable to connect the nozzles 48 of the cooling medium injection device and the nozzles 49 of the heating medium injection device to a common supply source, and to provide heating means at the individual nozzles 49 of the heating medium injection devices 42, 44 in order to heat the rolling oil to the desired temperature range.

[0069] The nozzles 48 of the cooling medium injection devices 38 and 40 and the nozzle 49 of the heating medium injection device can be individually controlled by the control device 16, and thus, the amount of rolling oil ejected from each nozzle 48 or nozzle 49 can be selectively controlled. Each nozzle 48 of the cooling medium injection devices 38 and 40 is assigned to a respective cooling zone 58 of the corresponding work rolls 6 and 8, and the cooling medium can be injected into the cooling zone by this nozzle 48. Correspondingly, each nozzle 49 of the heating medium injection devices 42 and 44 is assigned to a respective heating zone 59 of the corresponding work rolls 6 and 8, and the heating medium can be injected into the heating zone by this nozzle 49. The individual cooling zones 58 or heating zones 59 are separated from each other by dashed lines in FIG. 1B (as in FIGS. 2 to 4). The cooling zones 58 and heating zones 59 of the work rolls may be the same (each cooling zone corresponding to a respective heating zone) or different as shown in FIG. 1B, and if different, the cooling zones and heating zones may particularly differ in their respective numbers and / or respective widths.

[0070] In an alternative embodiment, the roll heating devices 42 and 44 may be designed as inductive roll heating devices. Such roll heating devices include at least one respective associated induction coil that can pass a heating current in a manner that is individually controllable for each heating zone 59 of the roll, in particular for inductively heating the roll in the region of the corresponding heating zone 59.

[0071] Next, the control device 16 is configured to control the nozzles 48 of the cooling medium injection devices 38 and 40 and / or the nozzles 49 of the heating medium injection devices 42 and 44 as manipulated variables for the control of the cold rolling operation (flatness). In this way, in particular, the roll geometry of the work rolls 6 and 8 can be locally influenced so that the offset of the manipulated variable from the higher-order setpoint variable can be corrected during control.

[0072] Next, with reference to FIGS. 2 to 4 below, possible controls of the cold rolling operation using the cooling medium injection devices 38, 40 and / or the heating medium injection devices 42, 44 will be described.

[0073] FIGS. 2 to 4 schematically show the upper work roll 6 of the cold rolling mill together with the nozzles 48 of the cooling medium injection device 38 and the nozzles 48 of the heating medium injection device 42. For clarity, in FIGS. 2 to 4, for illustrative purposes, the nozzles 48 of the cooling medium injection device 38 are depicted above the work roll 6, the nozzles 48 of the heating medium injection device 38 are depicted below, and reference numerals 48.1 to 48.11 and 49.1 to 49.11 are provided respectively to identify the individual nozzles. The associated cooling zones and heating zones of the work roll 6 are provided with reference numerals 58.1 to 58.11 and 59.1 to 59.11 respectively, and the cooling zone 58.1 is assigned to the nozzle 48.1, the cooling zone 58.2 is assigned to the nozzle 48.2, etc., the heating zone 59.1 is assigned to the nozzle 49.1, the heating zone 59.2 is assigned to the nozzle 49.2, etc.

[0074] FIG. 2 first illustrates zone cooling known from the prior art. In conventional zone cooling, by selective control of the individual nozzles (e.g., nozzles 48.2 and 48.7 in FIG. 2), a larger flow rate of the cooling medium 60 is locally applied to the associated cooling zones of the work roll 6 (e.g., cooling zones 58.2 and 58.7 in FIG. 2), and as a result, the work roll 6 is locally cooled more strongly in the associated cooling zones, and thus, the diameter of the work roll 6 locally varies in these cooling zones, in particular, decreases.

[0075] During the control of the cold rolling operation, for example, when the characteristics of a section in a direction orthogonal to the rolling direction of the cold rolled aluminum foil 20 deviate from the reference variable, and in particular, when it is determined that the strip tensile stress is too low, by controlling the nozzles 48 of the cooling zone corresponding to this section, in particular, by increasing the flow rate of the cooling medium of this nozzle, a local correction of the work roll diameter, and thus the roll gap, can be achieved. The change in the diameter of the work roll 6 in zone cooling is typically within the range of μm.

[0076] However, when cold rolling the aluminum foil 20 at a small pass reduction rate and / or a slow rolling speed, it has been found that the surfaces of the work rolls 6, 8 do not become hot enough due to the heat introduced during cold rolling to achieve a sufficient temperature difference from the temperature of the cooling medium for effective zone cooling. Furthermore, the temperature of the cooling medium typically cannot be arbitrarily reduced because, for example, the solubility of additives in the cooling medium or condensate formation sets a limit. In the cold rolling of the aluminum foil 20, therefore, the prior art zone cooling illustrated in FIG. 2 can only be used to a limited extent.

[0077] Next, FIG. 3 illustrates an embodiment of the use and method according to a first aspect of the present disclosure using the cold rolling apparatus shown in FIGS. 1A and 1B. In the control illustrated in FIG. 3, the control device 16 is configured to control the heating medium injection device 42 by controlling the nozzles 49.1 to 49.11 of the heating medium injection device 42 during the progress of zone cooling, such that the work roll 6 is substantially sprayed with the liquid heating medium 62 over the entire roll width.

[0078] In this method, the surface temperature of the work roll 6 increases as a whole over the entire roll width, so that even in the case of actual zone cooling with a small pass reduction rate, a sufficient temperature difference from the liquid cooling medium 60, and thus effective zone cooling, is ensured. In other words, by applying the heating medium 62 to the work roll 6, the temperature of the entire work roll 6 increases.

[0079] In this control, since local application of the heating medium to the work roll 6 is not required, the nozzles 49.1 to 49.11 of the heating medium injection device 42 can also be controlled together, and thus it is possible to dispense with individual control of the nozzles. Further, instead of the nozzles 49.1 to 49.11, it is possible to provide only a single longitudinal nozzle that extends over the roll width of the work roll 6 and thus enables the heating medium to be uniformly injected onto the work roll 6.

[0080] In an alternative embodiment, the work roll 6 may be inductively heated substantially over the entire roll width during zone cooling by controlling the provided inductive roll heating device. For this purpose, the inductive roll heating device may include, for example, at least one inductive coil that extends substantially over the entire roll width, thereby enabling uniform inductive heating of the work roll 6.

[0081] In FIG. 3, the actual zone cooling by the cooling medium injection device 38 is carried out by local variations in the cooling medium flow rate of specific nozzles (illustrated by arrows of different sizes in FIG. 3). Preferably, all the nozzles 48.1 to 48.11 of the cooling medium injection device are operated at a predetermined basic flow rate, which is locally increased (for example, at nozzles 48.2 and 48.7 in FIG. 3) for zone cooling. In this way, the nozzles of the cooling medium injection device 38 ensure the supply of rolling oil to the work roll 6 simultaneously over the entire roll width independently of zone cooling, and thus individual rolling oil supply is unnecessary. Alternatively, by operating the nozzles 49.1 to 49.11 at a predetermined basic flow rate, it is also possible to ensure the supply of rolling oil for lubrication and cleaning using the heating medium injection device.

[0082] Next, FIG. 4 illustrates an exemplary embodiment of the use and method according to a second aspect of the present disclosure using the cold rolling apparatus illustrated in FIGS. 1A and 1B. In the control illustrated in FIG. 4, the control device 16 is configured to perform control by at least partially inverse zone cooling by controlling the heating medium injection device 42.

[0083] In inverse zone control, in the case of a setpoint deviation of a control variable assigned to one or more first heating zones (for example, heating zones 59.2 and 59.7 in FIG. 4), the heating medium injection device 42 is configured such that the injection of the heating medium into one or more second heating zones (for example, the remaining heating zones 59.1, 59.3 to 59.6, and 59.8 to 59.11 in FIG. 4) is increased. For this purpose, the heating medium flow rate of the nozzles assigned to these second heating zones (corresponding nozzles 49.1, 49.3 to 49.6, and 49.8 to 49.11 in FIG. 4) is increased (for example, from zero to a specific value in FIG. 4).

[0084] The control variable assigned to the heating zone may be, for example, the strip tension of the aluminum foil at a position corresponding to the heating zone in a direction orthogonal to the rolling direction in the cold-rolled aluminum foil.

[0085] Therefore, (conventional) zone cooling includes cooling of the cooling zone affected by the setpoint deviation (see FIG. 2), while inverse zone cooling includes a heating zone different from the affected zone. In this method, local cooling is replaced by complementary heating of the work roll 6, whereby a similar local geometric adjustment of the work roll 6 and thus the roll gap contour can be achieved.

[0086] The use of a heating medium instead of a cooling medium ensures a sufficient temperature difference with the work roll even at a small rolling pass reduction rate.

[0087] In the exemplary embodiment of FIG. 4, to provide sufficient rolling oil for the cold rolling operation, a cooling medium of a basic flow rate is further sprayed more uniformly onto the work roll 6 by the cooling medium injection device 38.

[0088] FIG. 5 schematically illustrates an exemplary embodiment of the use and method according to the first and second aspects of the present disclosure. FIG. 5 illustrates a control loop 70 that can be used to control the apparatus 2 of FIG. 1 using closed-loop control. For purposes of explanation, the control loop 70 is illustrated in FIG. 5 as a simple single-loop control loop. Alternatively, the control loop can also be designed as a multi-loop, particularly a cascade control loop.

[0089] A control variable 72 is obtained for the control loop, and the control variable 72 is compared with respective reference variables 76 in a comparison unit 74. The comparison result is processed in a controller 78, and the controller 78 uses the comparison result to determine an operating variable 80. The control of the operating variable affects the controlled system 82, and the controlled system 82 itself is dependent on an external influence 84 and thus in turn on the control variable 72, whereby the control loop is closed.

[0090] In particular, one or more of the following control variables can be regarded as control variables. The rated thickness of the cold-rolled aluminum foil 20, the strip tension distribution of the cold-rolled aluminum foil, other measured variables regarding the flatness and / or uniformity of the cold-rolled aluminum foil 20, measured variables calculated from the aforementioned measured variables.

[0091] To detect the control variable, the apparatus 2 has corresponding detection devices, particularly a detection device 26 for the strip tension distribution and, if necessary, further detection devices.

[0092] As reference variable 76, for the above-described control variables, in particular, for the desired rated thickness of the cold-rolled aluminum foil 20, for the desired flatness and / or uniformity, for the desired strip tension distribution, the setting of the corresponding setpoint can be considered.

[0093] For the control in the controller 78, in particular, one or more of the following controls that may be executed simultaneously can be particularly considered. Thickness control, uniformity control, or flatness control.

[0094] One or more of the following manipulated variables can be regarded as the manipulated variable 80. The vertical distance between the work rolls 6, 8 from each other (by the adjustment actuators 30, 30'), the alignment of the work roll and / or backup roll with respect to each other, or the adjustment of the contact force gradient in the roll width (by the adjustment actuators 32, 32'), the bending of the work roll and / or backup roll (by the adjustment actuators 33, 33'), the strip tension (by the adjustment actuators 34, 35), the rolling speed, the injection of the cooling medium or heating medium into the individual cooling zones and / or heating zones of the work rolls 6, 8 (by the cooling medium injection devices 38, 40 or the heating medium injection devices 42, 44).

[0095] In this specification, the controlled system 82 includes a cold rolling operation, and the cold rolling operation is affected on the one hand by the above-mentioned manipulated variables and on the other hand by external influences (such as ambient temperature fluctuations, fluctuations in the thickness or mechanical properties of the supplied aluminum foil 20, etc.).

[0096] In the device 2, the reference variable may be stored, in particular, in the memory of the control device 16. Further, the comparison unit 74 and the controller 78 may be implemented in the control device 16. For example, the control device 16 may have a memory with instructions, and the execution of the instructions in at least one microprocessor of the control device 16 causes the control according to FIG. 5 to be implemented.

[0097] In this specification, the controller 78 is configured to control the coolant injection devices 38, 40 and the heating medium injection devices 42, 44 in such a way that control is carried out by zone cooling using simultaneous injection of the liquid heating medium over the entire roll width of each work roll (see FIG. 3) and / or by reverse zone cooling (see FIG. 4). At the same time, preferably, thickness control is carried out so that the cold-rolled aluminum foil 20 has a desired rated thickness and / or a desired thickness profile.

[0098] The thickness control can be carried out independently of the flatness control or the uniformity control, for example, based on the aluminum foil thickness measured by the detection device 34 and by setting the global strip tension by controlling the unwind speed and / or the rewinding speed using the actuator 34 and / or the actuator 35.

Claims

1. Use of a cold rolling device (2) for the controlled cold rolling of aluminum foils (20), in particular battery foils, comprising: - said cold rolling device (2) comprises a number of rolls (6, 8), - said cold rolling device (2) comprises a control device (16) configured to effect the control of the cold rolling operation, in particular for controlling the uniformity and / or flatness of said aluminium foil (20); - said cold rolling device (2) comprises a cooling medium injection device (38, 40) configured to inject a liquid cooling medium (60) onto at least one of said rolls (6, 8); - said cold rolling device (2) comprises a roll heating device (42, 44) configured to heat said at least one of said rolls (6, 8); - said cooling medium injection devices (38, 40) are configured for individually and controllably injecting liquid cooling medium (60) into said at least one cooling zone (58.1-58.11) of said rolls (6, 8); the control device (16) is configured to implement said control at least in part by zone cooling by controlling the cooling medium injection devices (38, 40); In the use of the cold rolling apparatus (2), - said roll heating device (42, 44) is configured to heat said at least one of said rolls (6, 8) during said zone cooling progression substantially across the entire width of said roll; The use characterized by.

2. Use of a cold rolling device (2), preferably according to claim 1, for the controlled cold rolling of aluminum foils (20), in particular battery foils, comprising: - said cold rolling device (2) comprises a number of rolls (6, 8), - said cold rolling device (2) comprises a control device (16) configured to effect the control of the cold rolling operation, in particular for controlling the uniformity and / or flatness of said aluminium foil (20); - said cold rolling device (2) comprises a roll heating device (42, 44) configured to heat at least one of said rolls (6, 8); and the roll heating devices (42, 44) are configured for individually and controllably heating the heating zones (59.1-59.11) of at least one of the rolls (6, 8); In the use of the cold rolling apparatus (2), - said control device (16) is configured to control said roll heating devices (42, 44) and thereby to effect said control at least in part by reverse zone cooling; The use characterized by.

3. characterised in that the roll heating device is designed in the form of a heating medium injection device (42, 44) configured for injecting a liquid heating medium (62) onto the at least one of the rolls (6, 8), the heating medium injection device (42, 44) being preferably configured for individually controllable injection of the liquid heating medium (62) onto a plurality of heating zones (59.1-59.11) of the at least one of the rolls (6, 8).

3. Use according to claim 1 or 2.

4. characterised in that the roll heating device is designed in the form of an inductive roll heating device configured for inductively heating the at least one of the rolls (6, 8), the roll heating device being preferably configured for individually controllable inductive heating of a plurality of heating zones (59.1-59.11) of the at least one of the rolls (6, 8).

3. Use according to claim 1 or 2.

5. characterised in that, for the reverse zone control, the control device (16) is configured to control the roll heating devices (42, 44) in such a way that, in the event of a setpoint deviation of a control variable assigned to a first one of the plurality of heating zones (59.1-59.11), one or more second heating zones (59.1-59.11) are heated more intensively compared to the first heating zones (59.1-59.11), in particular the injection of a heating medium (62) into one or more second heating zones (59.1-59.11) is increased compared to the first heating zones (59.1-59.11) or the induction heating power for one or more second heating zones (59.1-59.11) is increased compared to the first heating zones (59.1-59.11), Use according to any one of claims 1 to 4.

6. the cold rolling apparatus (2) comprises a cooling medium injection device (38, 40) configured to inject a liquid cooling medium (60) onto the at least one of the rolls (6, 8), the cooling medium injection device (38, 40) being preferably configured to individually and controllably inject the liquid cooling medium (60) onto a plurality of cooling zones (58.1 to 58.11) of the at least one of the rolls (6, 8), Use according to any one of claims 2 to 5.

7. the cooling medium injection device (38, 40) comprises a first nozzle bar and the heating medium injection device (42, 44) comprises a second nozzle bar, the first and second nozzle bars having respective frames (46, 47) with nozzles (48.1-48.11; 49.1-49.11) arranged side by side and each of which is controllable, 7. Use according to any one of claims 3, 5 or 6.

8. A rolling mill oil is used as the heating medium (62) and / or the cooling medium (60). Use according to any one of claims 1 to 7.

9. the cold rolling apparatus (2) comprises a detection device (26) configured to measure a measurement value for a strip tension distribution of the cold rolled aluminum foil (20), and the control device (16) is configured to perform the control as a function of a value measured by the detection device (26). Use according to any one of claims 1 to 8.

10. A method for the controlled cold rolling of aluminum foil (20), in particular battery foil, comprising the steps of: - a cold rolling operation is carried out on the aluminium foil (20) using a cold rolling device (2) having a number of rolls (6, 8), in particular using a cold rolling device according to any one of claims 1 to 9, - a control of the cold rolling operation is carried out, in particular to control the uniformity and / or flatness of the aluminium foil (20), said control being at least partly carried out by zone cooling in at least one of the rolls (6, 8); In the method, - during said zone cooling control, said at least one of said rolls (6, 8) is heated substantially over its entire roll width, in particular by being sprayed with a liquid heating medium (62) or by being inductively heated; The method comprising:

11. characterised in that during the cold rolling operation, said at least one of said rolls (6, 8) is heated substantially uniformly across substantially its entire roll width, in particular by being sprayed with a liquid heating medium (62) substantially uniformly across substantially its entire roll width or by being inductively heated substantially uniformly across substantially its entire roll width. The method of claim 10.

12. 12. A method, in particular according to claim 10 or 11, for the controlled cold rolling of an aluminium foil (20), in particular a battery foil, comprising the steps of: - a cold rolling operation is carried out on the aluminium foil (20) using a cold rolling device (2) having a number of rolls (6, 8), in particular using a cold rolling device according to any one of claims 1 to 9, - control of the cold rolling operation is carried out, in particular to control the uniformity and / or flatness of the aluminium foil (20); In the method, said control is at least partly achieved by reverse zone cooling in at least one of said rolls (6, 8); The method comprising:

13. characterised in that in the reverse zone cooling, in the case of a setpoint deviation of a control variable assigned to a first one of the at least one plurality of heating zones (59.1-59.11) of the plurality of rolls (6, 8), one or more second heating zones (59.1-59.11) are heated more intensively compared to the first heating zone (59.1-59.11), in particular the injection into the one or more second heating zones (59.1-59.11) is increased compared to the first heating zone (59.1-59.11) or the induction heating power for the one or more second heating zones (59.1-59.11) is increased compared to the first heating zone (59.1-59.11), The method of claim 12.

14. During the cold rolling operation, a liquid cooling medium (60) is continuously sprayed onto the at least one of the rolls (6, 8) over substantially the entire roll width. The method according to any one of claims 10 to 13.

15. The control comprises controlling the thickness of the cold rolled aluminum foil (20) and / or controlling the strip tension distribution. The method according to any one of claims 10 to 14.

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