Method for determining improved setup values for a roll stand for cold rolling a strip

Abstract

Before a rolling pass (i), characterized by a parameter set (Λi), of a strip (100) in a roll stand (10), a minimum and maximum temperature (Tmin, Tmax) and a minimum and maximum coefficient of friction (µmin, µmax) are predefined and, from a setup model (200), limit values (Emin, Emax) for an emulsion actuator (21,..., 23') and setup values for the emulsion actuator (21,..., 23'), for a cooling actuator (41,..., 42') and for a lubricating actuator (31,..., 32') are predefined. During the rolling pass (i), the actuators are set to the setup values. An actual strip temperature (T') is identified by a temperature measuring device (51, 52), and an actual coefficient of friction (µ') is identified from measured manipulated-variable actual values (M'). These are taken as a basis to identify improved setup values either only for the cooling actuator (41,..., 42') and / or the lubricating actuator (31,..., 32'), or, if a change in the applied coolant rate or lubricant rate behaves synergistically with respect to the emulsion rate, additionally also for the emulsion actuator (21,..., 23'). The improved setup values are transferred from the setup model (200) to the parameter set (Λi).

Description

[0001] Description

[0002] Method for determining improved setup values ​​for a rolling mill stand for cold rolling a strip

[0003] The invention relates to a method for determining improved setup values ​​for a rolling mill stand comprising at least one emulsion actuator and at least one lubrication actuator, and to which at least one cooling actuator is assigned.

[0004] In a cold rolling mill, when producing flat metallic rolled products, referred to simply as "strips," several parameters play a crucial role in ensuring consistent quality. These parameters, in addition to the so-called pass schedule (which defines the successive thickness reduction of a strip as it passes through the individual rolling stands), are essential. Since a cold rolling mill can be pushed to its limits when producing strips from modern steel grades, it is imperative to consider critical parameters such as varying friction coefficients and the temperature of the strips in each pass. Appropriate measures for stable process control must be implemented, as these parameters change dynamically during the rolling process and significantly impact the power and energy requirements of the cold rolling mill, as well as the feasibility of the intended pass schedule.

[0005] For example, the friction conditions between a roll and a strip within a pass plan can vary so significantly that the coefficient of friction p rises above a critical value, leading to increased rolling force requirements in individual passes and negatively impacting the rollability of the strip. In other cases, the friction between work rolls and the strip may be too low, resulting in the strip slipping in the roll gap and making controlled process management impossible. In this context, EP 3 448 592 B1 discloses a method for rolling a workpiece, wherein a cooling lubricant in the form of an emulsion is introduced into a contact zone between the workpiece and a work roll.At a predetermined application distance in front of the roll gap, an additional lubricant is applied to the rolled material if the amount of cooling lubricant currently introduced into the contact zone does not cover the lubrication requirements, while at the same time the amount of cooling lubricant introduced into the contact zone is reduced.

[0006] Furthermore, the temperature of a strip may be too low at the beginning of a cold rolling cycle, which leads to difficult forming, while at the end of the cold rolling cycle the temperature may be too high, causing problems with product quality or the further processing of the strip.

[0007] In this regard, WO 2021 / 048038 Al specifies a method for defining a temperature window for the rolled material during cold rolling in a rolling mill with multiple stands and ensuring, through various control measures, that the rolled material temperature remains within this temperature window during rolling. These measures include heating the rolled material before a rolling pass, cooling and lubricating the work rolls or the rolled material itself using appropriate cooling and lubrication bars, creating a suitable pass schedule to account for the heat of deformation generated during rolling, and controlling the rolling speed to account for the frictional power losses in a rolling stand. The effect of these control measures on the rolled material temperature can be determined either based on empirical data in the form of an empirical model or by means of a physical model.Before the actual rolling process, simulations are performed and the setup values ​​for the respective components of the cold rolling mill are adjusted accordingly. Furthermore, the temperature of the rolled material can be measured during rolling, and control measures can be adjusted online. Stable process control with regard to the aforementioned dynamically changing process parameters can also be achieved by selecting a suitable operating mode for the components installed in the cold rolling mill, for example, in the form of appropriate cooling, lubrication, and rolling strategies. The temperature of a strip can be influenced by an operator, for instance, by specifying suitable rolling speeds and selecting an appropriate pass schedule. Lubrication can be adapted by using appropriately ground rolls and by adjusting the operating parameters of the lubrication system (e.g., oil concentration).However, all these operational optimizations are time-consuming and require extensive prior and subsequent analyses, since changing one parameter of a single system usually affects other systems as well. For example, changes in the lubrication system may have a positive impact on process control, but simultaneously have negative consequences for quality (e.g., strip cleanliness).

[0008] It is therefore an object of the invention to keep process variables that vary between the individual passes of a strip in a rolling stand mentioned above, in particular the friction conditions in the roll gap and the temperature of the strips, under control to such an extent that a planned pass plan is feasible and the product quality is within specified tolerance limits.

[0009] Another object of the invention is to make the best possible use of the operating mode of the components present in a rolling mill mentioned above, within their limits, in order to achieve the broadest possible product range.

[0010] These problems are solved according to the invention by a method according to claim 1, in which the emulsion, cooling, and lubrication actuators of the rolling mill stand are considered simultaneously. Preferred embodiments of the method according to the invention are the subject of the dependent process references.

[0011] The inventive method for determining improved setup values ​​relates to the cold rolling of a strip in a rolling stand in one or more passes. The rolling stand can be part of a multi-stand cold rolling mill in which the strip is fed through the multiple stands in a specific strip direction (so-called tandem mill). Alternatively, the rolling stand can also be part of a single- or multi-stand reversing rolling mill in which the strip is fed through the one or more stands in alternating strip directions during cold rolling.

[0012] Each passage of the strip through the rolling stand under consideration is referred to as a rolling pass i, whereby the thickness of the strip is usually reduced and the strip is guided through a roll gap formed by two work rolls that the rolling stand has.

[0013] The rolling stand has an emulsion actuator for dispensing emulsion onto the work rolls and / or into the roll gap. Furthermore, the rolling stand has a lubrication actuator configured to dispense lubricant onto the strip and / or the work rolls. The rate of lubricant dispensed by the lubrication actuator is within a range between a minimum lubricant rate L min and a maximum lubricant rate L max The rolling mill stand can also include further emulsion actuators and / or lubrication actuators, the respective setup values ​​of which, however, are not changed within the scope of the present invention and are therefore not considered separately in the following.

[0014] Furthermore, a cooling actuator is assigned to the rolling stand, which is designed to discharge coolant onto the strip. The rate of coolant discharged by the cooling actuator is within a range between a minimum coolant rate C minand a maximum coolant rate C max Controllable or adjustable. In this context, the expression 'assigned to the rolling stand' does not necessarily mean that the cooling actuator – unlike the respective emulsion or lubrication actuator of the rolling stand – is functionally connected to only that one rolling stand; rather, an 'assigned' cooling actuator can simultaneously be a functional component of several rolling stands. For example, a single cooling actuator can be simultaneously assigned to and arranged between the two rolling stands of a double reversing rolling mill, so that during each rolling pass on such a mill, the cooling actuator simultaneously acts as both an exit-side and an entry-side cooling actuator for each of the rolling stands. Furthermore, additional cooling actuators can be assigned to the rolling stand, but their respective setup values ​​are not changed within the scope of the present invention.

[0015] The emulsion, lubrication, and cooling actuators can, in the usual manner, be, for example, spray bars extending essentially transversely to the belt direction for dispensing a liquid medium, which are equipped, for example, with single- or two-component nozzles and whose dispensing rates of liquid medium are each adjustable by means of corresponding valves. Furthermore, within the scope of the invention, each emulsion, lubrication, or cooling actuator can comprise several active elements (e.g., one or more upper and / or lower spray bars) which are, however, controlled together, so that the dispensed fluid rate is equal to the sum of the rates of the individual spray bars. Likewise, the respective minimum and maximum rates refer to the sum of all individual elements of an actuator.

[0016] The emulsion according to the invention is a mixture of two main components: water (as the primary cooling medium) and pure oil (as the lubricating medium). The oil content in the water is between 0% and 30%, and the oil is optionally chemically stabilized in the water by means of an emulsifier. Due to its application point and its two main components, the emulsion released by the emulsion actuators during a rolling pass has a cooling effect and also adjusts the friction conditions in the roll gap accordingly. Consequently, increasing or decreasing the amount of emulsion applied during a rolling pass reduces or increases the temperature of the strip or the work rolls and also decreases or increases the coefficient of friction ρ' between the strip surface and the work rolls.

[0017] Preferably, the lubricant is applied by the lubrication actuator (considered within the scope of the invention) to the strip at a specific initial application distance di in front of the roll gap, or directly to the work rolls of the respective rolling stand at the entry side. It is essential that the lubricant is not applied to the same location on the strip or work rolls simultaneously with the emulsion or coolant, in order to prevent immediate washing off of the lubricant from the respective surface. Similar to emulsion actuators, the lubrication actuators can be designed as beams with single- or two-component nozzles and, due to the composition of the lubricant and the significantly lower application rate compared to emulsion and cooling actuators, essentially produce a pure lubrication effect with a negligible cooling effect.

[0018] Preferably, the coolant is applied directly to the strip by the cooling actuator (considered within the scope of the invention) either before or after the respective rolling stand; it is essential that the coolant is applied to the strip spatially separated from the emulsion or lubricant. On the entry side, the coolant is applied at a specific second application distance d2, which is preferably greater than the first application distance di for the lubricant, in front of the roll gap, so that up to the point where a lubricant or emulsion is optionally applied to the strip, the majority of the coolant flows off the strip laterally and the effect of the applied emulsion or lubricant is not affected. In the roll gap itself, the strip generally experiences heating due to the forming process, which, however, has no influence on the metallurgical structure of the strip during cold rolling.Therefore, alternatively, the coolant can be applied from the cooling actuator (considered within the scope of the invention) on the outlet side at a specific third application distance behind the roll gap, in order not to influence any outlet-side cooling of the work rolls by the emulsion actuators, whereby a short-term exceedance of the maximum strip temperature T. max The cooling actuator (due to its spatial application and the significantly lower oil content compared to lubricant) essentially provides a cooling effect on the strip in front of or behind the rolling gap.

[0019] Each rolling pass i of the strip in the rolling stand is defined by a specific set of parameters Λ. i characterized. The parameter set Λ i For example, the rolling mill i includes a thickness range D i of the band, a stitch removal area R i , a belt speed range V iand at least one material quality range Q i . In the thickness range D i and the belt speed range V i These can be entry or exit zones for the respective size when entering or exiting the rolling stand. Regarding the pass removal area R i (e.g., 60 to 65 percent) can refer to a specific percentage range by which the strip's thickness is reduced during the rolling process i. Regarding the material quality range Q i This could be a range for a specific material property of the strip (for example, for tensile strength), for the percentage by weight of a specific foreign element (e.g., carbon) in the strip, or for the relative proportion of a specific metallurgical phase.

[0020] Each parameter from the parameter set Λ iBy definition, it lies in exactly one predefined area, so that using the parameter set Λ i The rolling milling process i (within the respective predefined parameter ranges) can be uniquely described. Furthermore, a rolling milling process i can therefore be represented particularly easily – for example, in the form of a table for the individual parameter ranges.

[0021] In the inventive method, in a first step S1 a minimum temperature T is set for the strip before each rolling pass i. min and a maximum temperature T max as well as a minimum coefficient of friction p min and a maximum coefficient of friction p max Furthermore, in the first step S1, an emulsion setup value SE and a lower emulsion limit value E are specified by a setup model for the emulsion actuator. min and an upper emulsion limit E max , for the lubrication actuator a lubricant setup value S L and a coolant setup value S for the cooling actuatorc specified. Again, the setup values ​​S refer to E , S L or S c this refers to the total rate of all elements of the respective actor.

[0022] In contrast to the minimum / maximum coolant rate C min / C max or minimum / maximum lubricant rate L min / L max , which characterize the technically possible adjustment range of the respective actuator itself, the lower / upper emulsion limit value E min / E max to define the adjustment range limits specified by the setup model, within which a desired rolling result can be expected. As a prerequisite, the lower and upper emulsion limit values ​​E are defined. min or E max within the technically possible adjustment limits of the emulsion actuator, which are known to the setup model as prerequisites. Accordingly, the emulsion setup value S represents Eand the lower and upper emulsion limit values ​​E min and E max , the lubricant setup value S L , the minimum and maximum lubricant rate L min and L max , as well as the coolant setup value S c and the minimum and maximum coolant rate C min and C max Each volume flow rate is measured per unit length (considered in the bandwidth direction) and is therefore expressed in volume per unit length and time, e.g. in liters per second and meter or milliliters per second and meter.

[0023] The aforementioned setup models are known from the prior art; these can further include target values ​​for the drives of a rolling mill with regard to thickness reduction or an entry-side or exit rolling speed in a single pass i. Such a setup model is subject to the technological limits of the respective cold rolling mill or the rolling mill in question, such as maximum possible rolling forces, strip speeds, and the minimum and maximum lubricant rate L. min and L max the lubrication actuators as well as the minimum and maximum coolant rate C min and C max The temperature of the cooling actuators, etc., is known. However, such setup models do not determine the temperature or temperature change of the strip, for example, due to its cooling and forming during the rolling process.

[0024] In a second step S2 of the inventive method, the strip is guided through the roll gap during each rolling pass i. Furthermore, in the second step S2, the emulsion actuator is set to the emulsion setup value S. E , the lubrication actuator to the lubricant setup value S L and the cooling actuator to the coolant setup value S c This is set, for example by transmitting appropriate control or regulation signals from a plant control system to the individual actuators.

[0025] Furthermore, in the second step S2, the actual strip temperature T' of the strip is determined using a temperature sensing device. In the context of the invention, an 'actual value' is understood to be a measured quantity recorded during the execution of a rolling pass i or a measured quantity derived from recorded values. In contrast, setup values ​​represent control variables that are defined before the execution of a rolling pass i.

[0026] The temperature sensing device can, for example, be designed as a pyrometer arranged at the entry or exit end of the rolling stand, which advantageously enables non-contact measurement of the strip's surface temperature distribution. From this, an actual strip temperature T' can be determined – for example, by statistical averaging over a specific surface area of ​​the strip. Such statistical averaging over a surface area of ​​the strip, for example, over a region perpendicular to the strip's direction of travel, advantageously allows for a particularly accurate determination of the actual strip temperature at its surface, because erroneous values ​​that distort the result – for example, emulsion or coolant residues on the strip surface – can be largely eliminated when determining the actual strip temperature T' using statistical methods. Such a method, or rather,However, such statistical averaging itself is not the subject of the invention.

[0027] A metrological determination of the actual strip temperature T' provides – compared to a model-based determination – a particularly reliable value for the strip surface temperature because, during cold rolling, only very small residues of applied coolant or lubricant remain on the strip, which generally do not significantly distort the measurement result. In this context, the minimum temperature T in the considered rolling pass i is defined. min together with the maximum temperature T max a temperature window within which a satisfactory rolling result for the strip is expected.

[0028] The minimum temperature T min and the maximum temperature T maxcan be chosen, for example, based on empirical values ​​depending on the material composition of the belt, whereby the minimum temperature T min preferably in a range of 50 °C - 70 °C and the maximum temperature T max preferably in a range of 120 °C to 160 °C.

[0029] Furthermore, in the second step S2, one or more actual values ​​M' of the rolling stand's control variables, preferably including at least one actual rolling force F', are recorded. The control variables for the rolling stand are specified for each relevant rolling pass i by a control system for the individual components, whereby actual values ​​– such as the applied actual rolling force F' – can be read out by a basic automation system of the rolling mill during the rolling pass i using respective sensors. From the recorded actual values ​​M' of the control variables, an actual friction coefficient μ', which characterizes the friction conditions during the rolling pass i in the roll gap, is determined, for example, using a roll gap model. Such roll gap models are known from the prior art, for example from DR Bland, H. Ford, et al., The Calculation of Roll Force and Torque in Cold Strip Rolling with Tensions, Proceedings of the Institute of Mechanical Engineers, Vol. 159, 1948.or from E. Orowan, The calculation of Roll Pressure in Hot and Cold Flat Rolling, Proceedings of the Institute of mechanical engineers, Vol. 150, pp. 140-167, 1948.

[0030] In a preferred embodiment of the method according to the invention, the measured actual values ​​M' of the control variables include, in addition to the actual rolling force F', an actual lead δ' and / or an actual drive torque Γ' of the work rolls. The actual lead δ' is defined as the ratio of the speed difference between the exit-side strip speed and the roll speed with respect to the roll speed itself. By additionally considering the actual lead δ' and / or the actual drive torque Γ' of the work rolls alongside the actual rolling force F', the actual coefficient of friction μ' can be determined advantageously with particularly high accuracy.

[0031] In a third step S3 of the inventive method, in a scenario A, in which

[0032] - either the actual strip temperature T' is greater than the maximum temperature T max and the actual coefficient of friction μ' is smaller than the minimum coefficient of friction μ min is,

[0033] - or in which the actual band temperature T' is less than the minimum temperature T min and the actual coefficient of friction μ' is greater than the maximum coefficient of friction μ max is,

[0034] an improved coolant setup value S c 'based on an initial sensitivity σ1 and an improved lubricant setup value S L ' determined using a second sensitivity σ2. Subsequently, the improved coolant setup value S determined in this way is c 'and improved lubricant setup value S L ' for the parameter set Λ i adopted from the aforementioned setup model.

[0035] Knowing the first and second sensitivities σ1 and σ2 respectively, the improved coolant setup value S can be determined. c 'or the improved lubricant setup value SL ' In scenario A, the lubrication actuator and the cooling actuator can be advantageously set independently of each other to a desired target value because they are arranged in relation to the rolling stand in such a way that they do not influence each other in their respective effects.

[0036] Scenario A describes a situation in which a change in the emulsion rate delivered by the emulsion actuator of the rolling stand would have an opposing effect on the actual strip temperature T' and the actual coefficient of friction μ': an increase in the emulsion rate would advantageously lower the strip temperature, but would also further decrease the coefficient of friction in the roll gap. Conversely, a decrease in the emulsion rate would advantageously increase the coefficient of friction, but would also adversely increase the strip temperature even further. Therefore, according to the invention, no new emulsion setup value S is generated in scenario A. E'determined,' but rather only the actual strip temperature T' within the control range of the cooling actuator and the actual coefficient of friction μ' within the control range of the lubrication actuator are influenced. Within the scope of the invention, the control range of an actuator is defined as the range between a minimum and a maximum possible delivery rate of fluid by the respective actuator. In particular, the minimum delivery rate of an actuator can be zero.

[0037] In scenario A described above, the improved coolant setup value S determined according to the invention also leads to the following results. c ' and the improved lubricant setup value S L ' to an advantageous influence on the actual strip temperature T' or the actual coefficient of friction μ' in a subsequent rolling pass, which is carried out with the same parameters Λ ihow the considered rolling process i is carried out, because the lubrication and cooling actuators are arranged relative to the rolling stand in such a way that they do not influence each other in their respective mode of operation.

[0038] In scenario B, in which

[0039] - either the actual strip temperature T' is greater than the maximum temperature T max is and the actual coefficient of friction μ' is greater than or equal to the minimum coefficient of friction μ min is, - or in which the actual band temperature T' is less than the minimum temperature T min is and the actual coefficient of friction μ' is less than or equal to the maximum coefficient of friction μ max is,

[0040] - or in which the actual band temperature T' is greater than or equal to the minimum temperature T min and less than or equal to the maximum temperature T max is and in which (additionally) the actual coefficient of friction μ' is smaller than the minimum coefficient of friction μ min or greater than the maximum coefficient of friction μ max is,

[0041] In the third step, S3, the improved coolant setup value S c ', the improved lubricant setup value S L 'and an improved emulsion setup value S E ' based on the first and second sensitivities σ1 and σ2, as well as on a third and fourth sensitivity σ3 and

[0042]

[0043] determined and by the aforementioned setup model for the parameter set Λ i The improved emulsion setup value S is adopted. E ' determined as a value greater than or equal to the lower emulsion limit E min and less than or equal to the upper emulsion limit E max is.

[0044] Scenario B, in contrast to Scenario A, describes a situation in which a change in the emulsion delivered by the emulsion actuator has a synergistic effect on the measured actual strip temperature T' or the actual coefficient of friction μ': if the actual strip temperature T' or the actual coefficient of friction μ' is too high, increasing the amount of emulsion advantageously lowers both the strip temperature and the excessively high coefficient of friction in the roll gap. Conversely, reducing the amount of emulsion in the case of an excessively low strip temperature or coefficient of friction advantageously increases both the strip temperature and the coefficient of friction. Therefore, according to the invention, in Scenario B – in addition to the improved coolant setup value Sc' and / or the improved lubricant setup value S – L ' - possibly also an improved emulsion setup value S E ' determined.

[0045] In the described scenario B, in addition to the adjustment ranges of the cooling actuator(s) and the lubrication actuator(s), the adjustment range of the emulsion actuator is also used to improve the strip temperature and the coefficient of friction in the roll gap, which represents an advantageous utilization of the components available on a rolling mill compared to the prior art, because such constellations, in which lubrication and cooling actuators work synergistically with an emulsion actuator, are not captured by conventional setup models.

[0046] The first sensitivity σ1 describes the functional relationship between a change in the actual band temperature ΔT', which is due to a change in the setup value ΔS C for the cooling actuator, starting from the already set setup value S c .

[0047] Similarly, the second sensitivity σ2 describes the functional relationship between a change in the actual coefficient of friction Δμ' in the rolling gap as a function of a change in the setup value ΔS. L for the lubrication actuator, again starting from the set setup value S L .

[0048] In analogous to the first sensitivity σ1, the third sensitivity σ3 describes the functional relationship between a change in the actual band temperature ΔT' and a change in the setup value ΔS. E for the emulsion actuator, again starting from the setup value S already set by the setup model E .

[0049] Again analogous to the second sensitivity σ2, the fourth sensitivity represents

[0050]

[0051] the functional relationship between a change in the actual coefficient of friction Δμ' and a change in the setup value for the emulsion actuator ΔS Erelative to the already set setup value S E .

[0052] In summary, the first, second, third and fourth

[0053]

[0054] Physically speaking, the first and third sensitivities σ1 and σ3, respectively, depend on the set specific application rate Φ. C or Φ E coolant or emulsion onto the belt (specifically: the coolant or emulsion released per belt surface).

[0055] emulsion quantity, e.g. in liters per square meter) and in both cases also indirectly from the strip thickness d of the strip in the considered rolling pass (where the latter is in the coolant or emulsion setup value S). c or S E (already taken into account).

[0056] Similarly, the second and fourth sensitivities σ2 and σ4 respectively also depend physically on the set specific application rate Φ. L or Φ Eon lubricant or emulsion (specifically: the amount of lubricant or emulsion delivered per strip surface, e.g. in milliliters per square meter) in the considered rolling pass.

[0057] The specific application rates of coolant / lubricant or emulsion can be easily derived from the set setup value S. c or S L or S E for the cooling, lubrication, or emulsion actuator according to Φ C = S c / v B or Φ L = S L / v B or Φ E = S E / v B to be determined, whereby v B The belt speed refers to the speed at which the belt passes the corresponding actuator. The belt speed v B This, in turn, can be accessed, for example, from the data of the setup model or from a corresponding basic automation of the rolling mill.

[0058] According to the invention, the sensitivities σ1, σ2, σ3 and σ4 are defined as known functional relationships with known inverse functions σ1 -1 , σ2 -1 , σ3 -1 or σ4 -1 Provided, for example, that the values ​​are empirically determined beforehand as a function between an observed change in the actual strip temperature ΔT' or the actual coefficient of friction Δμ' as a function of a change in the set flow rate ΔS C or ΔS L or ΔS E at the cooling, lubrication, or emulsion actuator, each starting from the already set setup values ​​S c or S L or S E , can be determined.

[0059] The described procedure is based on the premise that the setup model according to the invention has already determined largely optimal process parameters for the rolling process. Therefore, changes to setup values ​​(especially concerning the emulsion actuator) that are close to the already determined setup values ​​and within the permissible limits of the respective actuator do not significantly alter the rolling result with regard to the microstructure. This advantageously eliminates the need for a complete new simulation of the rolling process from scratch with modified setup values, which would also be considerably more complex.

[0060] On the other hand, recording changes in the actual strip temperature AT' or the actual coefficient of friction Ap' when setup values ​​for the cooling, lubrication or emulsion actuator are changed is common practice when optimizing a rolling mill, for example when it is put into operation or when a new rolled product (for which corresponding setup values ​​have already been determined by the setup module) is rolled on the mill for the first time.

[0061] In summary, the inventive method utilizes, when determining improved setup values ​​for the cooling, lubrication and emulsion actuators, those tolerances provided by the adjustment ranges of the cooling and lubrication actuators or by the lower and upper emulsion limit E. min or E max are specified, without changing the throughput of rolled strips at the rolling stand or the cold rolling mill itself, because rolling speeds or batch schedules are not changed.

[0062] The improved setup values ​​determined according to the invention can be used as new setup values ​​for subsequent rolling passes using the same parameter set Λ i are characterized like the rolling pass from which the improved setup values ​​were derived. In these subsequent rolling passes, it is advantageous to encounter fewer instances of both under- and over-exceeding the minimum or maximum temperature T. min or T max as well as the minimum and maximum coefficient of friction μ min or μ max to be calculated.

[0063] Because in the inventive method only the setup values ​​for the cooling, lubrication and, if applicable, the emulsion actuator (within the specified limit values ​​E) min and E maxSince the process parameters lubrication, cooling, and temperature can be modified and adopted from an existing setup model, but not the other setup or default values ​​for the remaining components of the cold rolling mill, the process parameters of lubrication, cooling, and temperature can be decoupled from the conventional core parameters, such as rolling strategy and the effect of the rolling emulsion. This allows the inventive method to be advantageously implemented retroactively on an existing cold rolling mill with minimal effort, without requiring any changes to the roll planning or the roll gap model itself. In particular, the operation of an existing setup model, which already knows the technological limits of the plant, does not need to be changed.

[0064] Knowledge of the first to fourth sensitivities (Ji to C4) or their inverse functions op 1 up to A4 -1This advantageously allows for operation at an actual strip temperature T' or an actual coefficient of friction μ' outside the specified limit values ​​T. mln and T max or p mln and p max to adjust the improved setup values ​​for the individual actuators not only qualitatively (e.g., based on an operator's estimate), but especially quantitatively, in such a way that the undesirable deviations of the actual strip temperature T' or the actual coefficient of friction μ' during a subsequent rolling pass i with the same parameter set Λ i eliminated or - within the range of the individual actuators - at least reduced.

[0065] In a preferred embodiment of the method according to the invention, the improved coolant setup value S c' in the scenario A described above, based on a target temperature T″ (referring back to the preceding equation (1) with ΔT' = T″ - T') and the first sensitivity σ1 or its inverse function σ1 -1 , starting from the set setup value S c , according to

[0066] S c ' = C min if S c + σ1 -1 (T' - T″)| S < C min or

[0067] S c ' = C max if S c + σ1 -1 (T' - T″)| S > C max or

[0068] S c ' = S c + σ1 -1 (T' - T″)| S otherwise (5)

[0069] determined, whereby the improved coolant setup value S c ' between the minimum and maximum coolant rate C min and C max of the cooling actuator – and thus within its operating range. The target temperature T" preferably lies between the minimum temperature T minand the maximum temperature T max and can, for example, be calculated as the average of these values.

[0070] Furthermore, according to the preferred embodiment, the improved lubricant setup value S L ' in scenario A based on a target friction coefficient μ″ (referring back to the preceding equation (2) with Δμ' = μ″ - μ') and the inverse function σ2 -1 the second sensitivity σ2, starting from the set setup value S L , as a value according to

[0071] ^CT' - T")| SL < L min or

[0072] ^CT' - T")| SL > L max or

[0073]

[0074] otherwise ( 6 ) determined, where the improved lubricant setup value S L ' consequently between the minimum and the maximum lubricant rate L min and L max of the lubrication actuator - and thus within its adjustment range.

[0075] The target coefficient of friction μ″ preferably lies between the minimum and maximum coefficient of friction μ min and μ max and can, for example, be calculated as an average.

[0076] In a further preferred embodiment of the method according to the invention, in the scenario B described above, a first correction value A and a second correction value A2j are each initially set to zero. If the actual strip temperature T' is greater than the maximum temperature T max or smaller than the minimum temperature T min If so, the improved coolant setup value S will then be used. c ' and the first correction value Δ1 based on a target temperature (T″), the aforementioned first and third sensitivities σ1 and σ3 (or their inverse functions), each starting from the set setup value S c or S E , as well as based on auxiliary variables h1 and h3 according to

[0077] h1= S c + σ1 -1 (T' - T″)| Sand h3= σ3 -1 (T' - T″)| S

[0078] S c ' = C min and Δ1= h3if h1< C min or

[0079] S c ' = C max and Δ1= h3if h1> C max or

[0080] S c ' = h1 and Δ1 = 0 otherwise, (7)

[0081] determined.

[0082] According to formula (7), the improved coolant setup value S c 'if necessary, to the value of the minimum or maximum coolant rate C min or C max set to comply with the technological limits of the coolant actuator in question, and in these cases the first correction value Δ1 of the auxiliary quantity h3 is additionally set equal.

[0083] Furthermore, according to the further preferred embodiment in scenario B, in the case where the actual coefficient of friction p' is greater than the maximum coefficient of friction p max or smaller than the minimum coefficient of friction μ minis the improved lubricant setup value S L ' and the second correction value Δ2 based on the aforementioned second and fourth sensitivities σ2 and σ4 (or their inverse functions), each starting from the set setup value S L or S E , as well as using auxiliary variables h2 and h4 according to

[0084]

[0085] , ( 8 )

[0086] determined. Again, this is done analogously to the determination of the improved coolant setup value S. c ', the improved lubricant setup value S L ' to the minimum or maximum lubricant rate L min or L max limited to comply with the technological limits of the lubricant actuator(s). Additionally, in these cases, the second correction value Δ2 is again set equal to the auxiliary variable h4.

[0087] Subsequently, in the further preferred embodiment of scenario B, the improved emulsion setup value S is used. E' according to

[0088] S E ' = E min if S E + Δ1+ Δ2< E min , or

[0089] S E ' = E max if S E + Δ1+ Δ2> E max , or

[0090] S E ' = S E + Δ1+ Δ2otherwise (9)

[0091] determined. If both the first and second correction values ​​Δ1 and Δ2 are zero, this means that the cooling and lubrication actuators do not need to be adjusted (in the above sense) in subsequent rolling passes.

[0092] In addition, the improved emulsion setup value S E 'if applicable, the lower or upper emulsion limit value E min or E max equated, in order not to fall below or exceed the adjustment range for the emulsion rate to be applied as provided by the setup model.

[0093] In simplified terms, scenario B, according to the further preferred embodiment, first determines improved setup values ​​for the cooling actuator and / or the lubrication actuator. If it turns out that the respective actuator is 'balanced' (i.e., set to the minimum or maximum technically possible flow rate), additional correction values ​​A1 and A2 are subsequently determined for the emulsion actuator, since this (as described above) influences both the actual strip temperature T' and the actual coefficient of friction p'.

[0094] The correction values ​​A1 and A2 can also take on negative values ​​(which corresponds to a corresponding reduction in the amount of emulsion dispensed) and are converted to the specified emulsion setup value S. E The result is added. If necessary, the result is adjusted to the range between the lower and upper emulsion limit values ​​E. min and E max limited and forms the improved emulsion setup value SE '.

[0095] Since scenario B – as described above – represents the synergistic case between the cooling and lubrication actuator (or the actual strip temperature T') on the one hand and the emulsion actuator (or the actual coefficient of friction p') on the other, in the case of 'regulating' the cooling and / or lubrication actuator, the emulsion actuator is also additionally regulated within its predefined control limits E. min and E max All available components of the rolling mill in question are used optimally within their respective limits to advantageously influence the actual strip temperature T' or the actual coefficient of friction p' (or both simultaneously).

[0096] Scenarios A and B, as well as the possible actions for determining improved setup values ​​in the respective constellations of the actual band temperature T' and the actual coefficient of friction p', can be summarized in the following Table 1 for clarity:

[0097]

[0098]

[0099] Table 1

[0100] In the last column of Table 1, the symbols mean

[0101]

[0102] '0' and that the respective improved setup value for subsequent rolling passes (relative to the existing setup value in the considered rolling pass i) is increased, left unchanged, or decreased. In the constellations #1, #2, #4, #6, #8, and #9, which constitute scenario B, there are two actions each for determining the improved emulsion setup value S. E'possible: which action is specifically carried out in each case depends - as explained in more detail in FIG 4A and FIG 4B - on whether the improved coolant setup value S c 'or the improved lubricant setup value S L ' has already been determined as a value equal to the upper or lower limit C min / C max or L min / L max is.

[0103] In other words, scenario B is characterized by the fact that if the cooling or lubrication actuator is adjusted according to the respective improved setup value S c ' or S L ' is already fully regulated, and if necessary the setup value for the emulsion actuator is also changed, because - as explained above - it behaves synergistically with regard to the actual strip temperature T ' and the actual coefficient of friction p '.

[0104] For example, according to Table 1, in constellation #2, where the actual band temperature T' is less than the minimum temperature T min and the actual coefficient of friction p' is greater than or equal to the minimum coefficient of friction p min and less than or equal to the maximum coefficient of friction p max is the improved setup value S c ' for the cooling actuator, a value is determined that is reduced relative to the existing coolant setup value Sc. Additionally, in configuration #2, the improved lubricant setup value S is used. L ' on the existing value of S L Leave it as is. Finally, the improved emulsion setup value S will be used. E ' for the emulsion actuator either on the existing value S E leave as is or reduce it relative to that.

[0105] The constellations #3 and #7 constitute scenario A, in which the setup value for the eemulsion actuator is not changed because it behaves inversely with respect to the actual strip temperature T ' and the actual coefficient of friction p '.

[0106] Finally, constellation #5 represents the trivial case in which both the actual strip temperature T' and the actual coefficient of friction p' are within their specified limits and consequently no action is required to improve the setup values ​​for the cooling or lubrication actuator.

[0107] Preferably, the lubricant dispensed by the lubrication actuator onto the strip and / or the work rolls during a rolling pass i contains at least 80% pure oil. Similarly, the coolant dispensed by the cooling actuator onto the strip preferably contains at least 80% water; for example, it could be an emulsion of water and oil. Furthermore, preferably the same emulsion used for the emulsion actuator can be used, thus advantageously eliminating the need for a separate media circuit for the coolant.

[0108] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of an exemplary embodiment, which is explained in more detail in conjunction with the figures. These figures show:

[0109] Figure 1 ( FIG 1 ) shows an embodiment of a rolling mill stand with emulsion, lubrication and cooling actuators to which the method according to the invention is applicable;

[0110] Figure 2 ( FIG 2 ) shows a basic flow diagram of the inventive procedure;

[0111] Figure 3A ( FIG 3A) shows an embodiment for determining improved setup values ​​according to scenario A of the inventive method;

[0112] Figure 3B ( FIG 3B) shows an alternative embodiment for determining improved setup values ​​according to scenario A of the inventive procedure;

[0113] Figure 4A ( FIG 4A) shows an embodiment for determining improved setup values ​​according to scenario B of the inventive method; and

[0114] Figure 4B ( FIG 4B) shows an alternative embodiment for determining improved setup values ​​according to scenario B of the inventive method.

[0115] Corresponding parts in the figures are provided with the same reference numerals. FIG. 1 shows a rolling stand 10 with an upper work roll 11 and a lower work roll 11', which form the roll gap 12. In the depicted rolling pass i, a strip 100 is guided through the roll gap 12 from right to left in the strip travel direction 14. The direction of rotation of the lower work roll 11' in the depicted rolling pass i is indicated by an arrow pointing counterclockwise. Furthermore, FIG. 1 shows an upper intermediate or backup roll 13 above the upper work roll 11 and a lower intermediate or backup roll 13' below the lower work roll 11'.

[0116] In FIG. 1, solid lines show the emulsion spray bars of the rolling stand 10 that are activated in the depicted rolling pass i: these include, on the entry side, the emulsion spray bars 21 and 21', which apply an emulsion 20 (solid lines) directly onto the upper and lower work rolls 11 and 11', respectively. Also shown on the entry side are the emulsion spray bars 23 and 23', which apply the emulsion 20 from above and below the strip 100 into the roll gap 12, respectively. Additionally, on the exit side, the emulsion spray bars 22 and 22' are shown, which apply the emulsion 20 directly onto the upper and lower work rolls 11 and 11', respectively. Any further emulsion spray bars that are inactive in the depicted rolling pass i, which are... B. the way in which the emulsion 20 would be applied from the left into the roll gap 12 when the strip direction changes in FIG 1, is not shown in FIG 1 for clarity.

[0117] The inlet soapy emulsion spray bars 21, 21', 23, 23' and the outlet soapy emulsion spray bars 22, 22' form, for the illustrated embodiment, the emulsion actuator of the rolling stand 10 in the sense described above, i.e., they are controlled together and an improved emulsion setup value S is used for this group of emulsion spray bars. E ' determined. The group of emulsion spray bars forming the emulsion actuator can alternatively comprise more or fewer than the six emulsion spray bars 21, 21', 22, 22, 23, 23' shown, which are controlled together, as an alternative to the embodiment shown in FIG. 1.

[0118] Furthermore, in FIG. 1, the lubricant spray bars of the rolling stand 10, activated during the rolling process, are shown with dotted lines. Any other inactive lubrication actuators that are not activated during the rolling process are not shown. Pure lubricant 30 (dotted lines) is atomized as a fine aerosol, for example, using compressed air and two-component nozzles, or dispensed using so-called single-component nozzles. On the inlet side, an upper and a lower lubricant spray bar 31 and 31' respectively apply the lubricant 30 directly to the upper and lower working rolls 11 and 11', respectively. Furthermore, an upper and a lower lubricant spray bar 32 and 32' apply lubricant 30 at a first application distance di to the roll gap 12 onto the upper and lower surfaces of the strip 100, respectively.

[0119] In the embodiment shown in FIG. 1, the lubricant spray bars 32 and 32' directed towards the strip 10 form the lubricating actuator of the rolling stand 10 within the scope of the invention. The lubricant spray bars 32 and 32' are accordingly controlled together, and an improved lubricant setup value S is provided for them. L' determined. In contrast, during the rolling process i, the lubricant spray bars 31 and 31' are active, but no improved setup value is determined for them (i.e., their delivery rate is determined elsewhere, e.g., by a setup model 200). Alternatively, the lubricant spray bars 31 and 31' directed at the work rolls 11, 11' can also form the lubrication actuator of the rolling stand s in the sense of the invention, while in this case no improved setup values ​​are determined for the lubricant spray bars 32 and 32'. The group of lubricant spray bars forming the lubrication actuator can, as an alternative to the embodiment shown in FIG. 1, also comprise more or fewer than two lubricant spray bars 31, 31' or 32, 32', which are controlled together. Furthermore, a temperature sensing device 51 and a temperature sensor 51 are located above the strip 100 on the inlet and outlet sides of the rolling stand 10, respectively.52 pyrometers are arranged and allow for the measurement of the instantaneous distribution of the strip surface temperature in a direction transverse to the strip direction 14. An arrangement above the strip 100 offers the advantage—in contrast to an arrangement below it—that no contamination occurs from residual emulsion 20 or coolant 40 dripping from the strip 100. Any residual emulsion 20 or coolant 40 remaining on the upper surface of the strip 100 can therefore be detected particularly easily due to the significantly reduced surface temperature of the strip 100 at these points, thus enabling a reliable determination of the actual strip temperature T'.

[0120] Finally, FIG. 1 shows the coolant spray bars associated with the rolling stand 10, indicated by dashed lines: on the entry side, coolant 40 (dashed lines) is applied directly to the top and bottom surfaces of the strip 100 by an upper and a lower cooling actuator 41 and 41', respectively. The coolant spray bars 41 and 41' are arranged at a second application distance d2, which is greater than the first application distance di, from the roll gap 12. On the exit side, the coolant 40 can be discharged directly onto the top and bottom surfaces of the strip 100 by an upper and a lower coolant spray bar 42 and 42', respectively, arranged at a third application distance da from the roll gap 12.

[0121] In the embodiment shown in FIG. 1, the outflowing, soapy coolant spray bars 42 and 42' for the rolling mill i form the cooling actuator of the rolling stand 10 within the scope of the invention; accordingly, the coolant spray bars 42 and 42' are controlled together and an improved coolant setup value S is achieved. c ' determined on the basis of the actual strip temperature T ' of strip 100, whereby the actual strip temperature T ' is determined on the basis of measured values ​​from the outward-side pyrometer 52. In contrast, the discharge rates for the inward soapy coolant spray bars 41, 41 ' in rolling section i are specified differently or set to zero and no improved setup values ​​are determined (in rolling section i) for the coolant spray bars 41, 41 '.

[0122] Alternatively, in the rolling section i, the inlet soapy coolant spray bars 41 and 41' can also form the cooling actuator assigned to the rolling stand 10, in which case an improved coolant setup value Sc' is determined for these, and the actual strip temperature T' is determined based on measured values ​​from the inlet-side pyrometer 51. The discharge rates of the outlet soapy coolant spray bars 42, 42' in the rolling section i are then determined differently in this case. Again, the group of coolant spray bars forming the cooling actuator can, as an alternative to the embodiment shown in FIG. 1, also comprise more or fewer than two coolant spray bars 41, 41' or 42, 42', respectively, which are controlled together.

[0123] In FIG 2, steps SI, S2 and S3 of the inventive method are schematically indicated on the right and separated from each other by means of horizontal, dashed lines, wherein the method relates to a specific rolling pass i of a specific strip 100 on a specific rolling stand 10 of a cold rolling mill.

[0124] On the right side of FIG. 2, the index i indicates that the rolling pass i is performed in the second process step S2. In the illustrated embodiment, steps S1 to S3 are executed on a separate computing unit 70, which is connected to a basic automation system 60 of the respective cold rolling mill. This allows the actual data relevant to the rolling stand 10 – such as the actual strip temperature T' and the emulsion, lubricant, or coolant setup value S – to be exchanged between the basic automation system 60 and the computing unit 70. E , S L , or S c - exchanged.

[0125] On the other hand, by connecting to a higher-level control system and / or to an operator interface (not shown in FIG 2), corresponding target data - such as the minimum or maximum temperature T - are provided. min or T max , the minimum or maximum coefficient of friction p min or p max as well as the parameter set Λ i - transmitted to computing unit 70.

[0126] The parameter set Λ i , which uniquely characterizes the rolling mill stitch i for the strip 100, includes, for example, a thickness range Di of the strip, a strip speed range Vi, a stitch reduction range R i, and at least one material quality range Qi. These ranges are known in advance to a setup model 200 because it also specifies the concrete target values ​​for the rolling pass i - such as a target rolling force, a target pass removal, an entry or exit speed or entry or exit thickness into or out of the rolling stand 10.

[0127] In the first step Sl, which is executed before the actual execution of the considered rolling pass i, the setup model 200 provides the emulsion setup value S for the rolling pass i. E for the emulsion actuator 21,..., 23 ' and the lubricant setup value S L for the lubrication actuator 31,..., 32 ' of the rolling stand 10 and the coolant setup value S c for the cooling actuator 41,..., 42 assigned to the rolling stand 10.

[0128] Furthermore, the setup model 200 specifies a lower and an upper emulsion limit value E min and E maxThese values ​​do not necessarily represent technological limits of the emulsion actuator 21,..., 23', but rather the tolerance range within which the emulsion 20 output rate can be varied without affecting the desired rolling result. Furthermore, the technological limits of the lubricant spray bars 31,..., 32' and the coolant spray bars 41,..., 42' are also defined in the setup model 200 in the form of a minimum and maximum lubricant rate L. min , L max for the lubrication actuator or a minimum and maximum coolant rate C min and C max known for the cooling actuator.

[0129] Finally, in the first process step Sl, a minimum temperature T is set for strip 100. min , a maximum temperature T max as well as, if applicable, a target temperature T" (not shown in FIG 2), and furthermore a minimum and a maximum coefficient of friction p min and p maxThese values ​​also represent tolerance ranges within which a desired rolling result is achieved. The specifications can be provided either by the setup model 200 or by another independent entity, such as another processing unit or an operator. The specification or knowledge of all the aforementioned parameters is symbolized by corresponding arrows in the first step S1 in FIG. 2.

[0130] In the second step S2, the rolling operation i is carried out in the rolling stand 10: the emulsion actuator (corresponding to the emulsion spray bars 21..... 23 ' constituting the emulsion actuator) is set to the specified emulsion setup value S E , the lubricating actuator (or the corresponding lubricant spray bars 31,..., 32 ' ) to the lubricant setup value S L and the cooling actuator (or the corresponding coolant spray bars 41...., 42 ' ) to the coolant setup value S cThis can be done, for example, by transmitting the respective setup values ​​to the basic automation unit 60 of the cold rolling mill and is shown in FIG 2 by means of arrows extending to the right into the rectangle symbol of the basic automation unit 60.

[0131] Furthermore, during the rolling process i, the actual strip temperature T' of the strip 100 is determined by means of one or more temperature sensing devices 51, 52. The temperature sensing devices 51, 52 are arranged on the entry and / or exit side of the rolling stand 10 (or on both sides of the rolling stand 10 if it is operated as a reversing rolling stand). In particular, if the temperature sensing devices 51, 52 are designed as pyrometers, the arrangement is such that the strip surface being measured is largely free of residues of emulsion 20 or coolant 40 applied to the strip 10.

[0132] Furthermore, one or more actual values ​​M' of the control variables of the rolling stand 10 are acquired by reading them from the basic automation 60 of the cold rolling mill, and an actual coefficient of friction p' is determined from these values. FIG. 2 indicates that the acquired actual values ​​M' of the control variables include at least an actual rolling force F'; additionally, during the rolling pass i, an actual pre-roll ö' of the strip in the rolling stand 10, as well as an actual drive torque T' and / or other operating parameters of the rolling stand 10, can also be acquired.

[0133] The aforementioned recording of the actual strip temperature T' and the actual coefficient of friction p' can be carried out cyclically during the rolling process i in short time intervals with a respective duration of, for example, 10 to 1000 ms; the determination of the actual temperature T' or the actual coefficient of friction p' is preferably carried out using a statistical method (e.g., median calculation over all recorded values) in order to minimize the influence of incorrect individual values ​​('outliers').

[0134] In the third step S3 of the inventive method, which is carried out during or after the rolling process i, it is checked whether the actual temperature T ' and the actual coefficient of friction p ' are each within the specified limits, whereby three cases are distinguished according to the preceding Table 1 (the constellations #1 to #9 shown in Table 1 are indicated in the third step S3 of FIG 2):

[0135] The so-called scenario A is characterized by the fact that either the actual band temperature T' is greater than the maximum temperature T max and at the same time the actual coefficient of friction p' is smaller than the minimum coefficient of friction p m in is (constellation #7 ), - or that the actual band temperature T ' is smaller than the minimum temperature T min and at the same time the actual coefficient of friction p' is greater than the maximum coefficient of friction p max is (constellation #3).

[0136] Scenario A, as explained above, describes a contrary constellation with respect to a change in the emulsion 20 discharged in the respective rolling pass i. Therefore, if scenario A applies (which is symbolized in FIG. 2 by '1' at the first branch), the setup values ​​S specified by the setup model 200 are E The respective emulsion actuators 21,..., 23 are not changed; instead, only the actual strip temperature T' within the adjustment range of the cooling actuator(s) 41,..., 42' and the actual coefficient of friction p' within the adjustment range of the lubrication actuator(s) 31,..., 32' are influenced by an improved coolant setup value S. c 'and an improved lubricant setup value S L ' can be determined. This determination can be made using appropriate sensitivities (in the node marked 'A' in FIG 2), as explained in more detail in FIG 3A and FIG 3B.

[0137] The improved coolant setup value S c ' and the improved lubricant setup value S L ' are then used by setup model 200 for parameter set A E adopted (during the emulsion setup value S) E for the same parameter set A E (remains unchanged), which is indicated in FIG. 2 by corresponding arrows leading back to setup model 200. Subsequently, in a following rolling pass using the same parameter set A, E is characterized by the modified, improved setup values ​​S from setup model 200. c ' and S L ' specified, while the emulsion setup value S E will remain unchanged.

[0138] If scenario A does not apply (symbolized by '0' at the first branch in FIG. 2), it is checked whether scenario B applies, which is characterized by the fact that

[0139] - either the actual band temperature T' is greater than the maximum temperature T max is and the actual coefficient of friction p' is greater than or equal to the minimum coefficient of friction p m in is, (constellation #8 or #9)

[0140] - or that the actual band temperature T' is less than the minimum temperature T min is and the actual coefficient of friction p' is less than or equal to the maximum coefficient of friction p max is (constellation #1 or #2), or

[0141] - in which the actual band temperature T' is greater than or equal to the minimum temperature T m in and less than or equal to the maximum temperature T max is and additionally the actual coefficient of friction p ' is either smaller than the minimum coefficient of friction p m in or greater than the maximum coefficient of friction p maxis (constellation #4 or #6). Scenario B describes, as explained above, a parallel constellation with regard to a change in the emulsion 20 dispensed in the respective roller pass i. Therefore, in this case, the setup values ​​S may also be changed. E for the emulsion actuator 21,..., 23 ' is changed if the actual strip temperature T ' within the control range of the cooling actuator 41,..., 42 ' and / or the actual coefficient of friction p ' within the control range of the lubrication actuator 31,..., 32 ' cannot be sufficiently influenced (namely when the cooling and / or lubrication actuator 41,..., 42 ' or 31,..., 32 ' reaches its respective control limits).

[0142] In contrast to scenario A, in scenario B the specified minimum or maximum value for the actual strip temperature T' or for the actual coefficient of friction p' (in addition to a simultaneous exceedance or fall below the value) can also be exceeded or fallen below individually: in this case, only an improved setup value Sc' or S is used. E 'and, if necessary, an improved emulsion Setrup value S E ' determined. This determination can in turn be carried out using corresponding sensitivities (in FIG 2 in the node marked ' B '), as is also explained in more detail in FIG 4A and FIG 4B.

[0143] In summary, in the case of scenario B, an improved coolant setup value S is used. c ' and / or an improved lubricant setup value S L 'and, if applicable, an improved emulsion setup value S E ' determined, where the improved emulsion setup value S E' is determined in such a way that it remains within the limits specified by the setup model 200 and is therefore greater than or equal to the lower emulsion limit E min and less than or equal to the upper emulsion limit E max is. The improved setup values ​​S are then applied. c ', S L ', S E ' - provided they were determined for the considered rolling mill i - again from the setup model 200 for the parameter set A E taken over.

[0144] If, in addition to scenario A, scenario B also does not apply (symbolized in FIG. 2 by '0' at the second branch), the trivial case arises in which both the actual strip temperature T' and the actual coefficient of friction p' are within the specified limits (constellation #5) and consequently no improved setup values ​​are determined and adopted by setup model 200 (symbolized in FIG. 2 by the lowest, empty node). A subsequent rolling pass, which is defined by the same parameters A i The value is characterized like the considered rolling mill i, and is therefore also used with the same, unchanged setup values ​​S. c , S L , S E executed.

[0145] According to the embodiments shown in FIG 3A and FIG 3B for scenario A (each marked 'A' in FIG 3A and 3B; additionally, the relevant constellations #3 and #7 are indicated), both an improved coolant setup value Sc 'based on an initial sensitivity value as well as an improved lubricant setup value S L ' determined using a second sensitivity a2.

[0146] The improved setup values ​​are determined using the first and second sensitivities ÖJ and a2 according to the preceding description of equations (5) and (6) such that either the improved coolant setup value S c ' between the minimum and maximum coolant rate C min and C max as well as the improved lubricant setup value SL' between the minimum and maximum lubricant rate L min and L max The values ​​are limited to these values ​​in the event that they are exceeded or fallen below (as a result of the determination based on the first or second sensitivity a2 or a2) in order to reflect the technological limits of the cooling or lubrication actuators accordingly.

[0147] Because – as described above – scenario A represents a contrary constellation with respect to a change in the dispensed emulsion quantity, this is not changed in scenario A according to the invention; instead, only the actual strip temperature T' and the actual coefficient of friction p' are influenced independently of each other within the control range of the cooling actuator and the lubrication actuator, respectively. The alternative embodiment of FIG. 3B differs from that in FIG. 3A only in the order of determining the improved coolant setup value S. c ' and the improved lubricant setup value S L ', however, ran the same result.

[0148] In contrast to scenario A, the embodiment shown in FIG 4A for scenario B (symbolized by 'B' in FIGS 4A and 4B) represents constellations #1, #2, #4, #6, #8 and #9 from Table 1: all these constellations are - unlike scenario A - synergistic with respect to the emulsion actuator, so that for a future rolling pass (with the same parameters A3) in addition to a change in the setup values ​​for the cooling actuator or the lubrication actuator, a change in the amount of emulsion delivered by the emulsion actuator also has an advantageous effect on the correction of the deviation of the actual strip temperature T' or the actual coefficient of friction p' currently considered in the rolling pass i.

[0149] According to the invention, the described synergistic constellations can be dealt with together in accordance with the flow diagram shown in FIG 4A (or FIG 4B):

[0150] Initially, a first and a second correction value A1 and A2j are set as auxiliary variables, each with the value zero.

[0151] Next, the actual strip temperature T' is checked: if this is greater than the maximum temperature T max or smaller than the minimum temperature T min Additional auxiliary variables h1 and h3, as well as the improved coolant setup value S, are used. c ' determined according to the formula ( 7) described above using a first and third sensitivity a1 and a3. Otherwise, the verification of the actual coefficient of friction p ' proceeds directly.

[0152] If, during the check of the actual strip temperature T', the additional auxiliary variable h1 is a value less than the minimum or greater than the maximum coolant rate C min or C max The improved coolant setup value S is determined. c ' - analogous to scenario A - also with the value of the minimum or maximum coolant rate Cm in or C max limited, and the first correction value A c is set equal to the additional auxiliary quantity h3. Otherwise, the improved coolant setup value S is used. c ' the additional auxiliary quantity h1 equated and the first correction value A c set to the value 0.

[0153] The first correction value A c represents in turn (with simultaneous minimum or maximum control of the cooling actuator according to C) min or C max ) a necessary change in the emulsion rate (delivered by the emulsion actuator onto the strip 100) in order to reduce the excessively low or high actual strip temperature T' in a subsequent, similar rolling pass to the range between the minimum and maximum temperature T min and T max to bring. Following the verification of the actual strip temperature T' and the determination of the first correction value A cThe verification of the actual coefficient of friction p' continues.

[0154] If, during the check of the actual coefficient of friction p', it is found that it is greater than the maximum coefficient of friction p max or smaller than the minimum coefficient of friction p min Additional auxiliary variables h2 and h4, as well as the improved lubricant setup value S, are used. L ' determined using a second and fourth sensitivity a2 and a4. Otherwise, the improved emulsion setup value S is determined. E ' continued.

[0155] If, when checking the actual coefficient of friction p', it is greater than the maximum coefficient of friction p max or smaller than the minimum coefficient of friction p m In is, additional auxiliary variables h2 and h4 as well as the improved lubricant setup value S are used. L' determined according to the formula ( 8) described above using a second and fourth sensitivity a2 and a4. Otherwise, the improved emulsion setup value S is determined directly. E ' continued.

[0156] If, during the verification of the actual coefficient of friction p', the additional auxiliary quantity h2 is a value smaller than the minimum or larger than the maximum lubricant rate L min or L max The improved lubricant setup value SL ' is determined analogously to scenario A - also with the value of the minimum or maximum lubricant rate L. min or L max limited, and the second correction value A2 is set equal to the additional auxiliary quantity h4. Otherwise, the improved lubricant setup value S L ' the additional auxiliary quantity h2 is set equal to and the second correction value A2 is set to the value 0.

[0157] The second correction value A2 again represents (with a simultaneous minimum or maximum control of the lubrication actuator(s) according to L) min or L max ) a necessary change in the emulsion rate (delivered by the emulsion actuator onto the belt) in order to reduce the excessively low or high actual coefficient of friction p' to the range between the minimum and maximum coefficient of friction p in a subsequent, similar rolling pass min and p max to bring. Following the verification of the actual coefficient of friction p ' and the determination of the second correction value A2, the process continues with the determination of the improved emulsion setup value SE '.

[0158] The sum Σ = S E + A1+ A2 from the (already set) emulsion setup value S E The first and second correction values ​​A1 and A2 are then used. Again, depending on the technological limitations of the emulsion actuator, the improved emulsion setup value S is calculated. E'either the lower emulsion limit E min (if the sum Σ is less than the lower emulsion limit E min is) or the upper emulsion limit E max (if the sum Σ is greater than the upper emulsion limit E max is) equated. Otherwise - i.e., if the sum Σ between the lower and upper emulsion limit E min and E max The sum Σ is then considered as the improved emulsion setup value S. E ' taken over.

[0159] The alternative embodiment shown in FIG. 4B for determining improved setup values ​​according to scenario B differs from that in FIG. 4A only in the order in which the actual temperature T' and the actual coefficient of friction p' are checked, but otherwise yields identical results for the improved setup values ​​S. L ', S c ', S EIn summary, scenario B covers several cases in which the actual strip temperature T' and / or the actual coefficient of friction p' can be synergistically corrected: accordingly, at least one improved coolant setup value S is achieved. c ' and / or an improved lubricant setup value S L ' and / or an improved emulsion setup value S E ' determined, which is then used by the setup model 200 for parameter set A i be adopted so that a future rolling mill, which uses the same parameters A E The currently considered rolling pass i is performed using the corresponding improved setup values. How many or which of these improved setup values ​​are specifically determined in scenario B depends on the respective configuration, which is shown in FIGS. 4A and 4B by the improved setup values ​​S enclosed in curly brackets. c ', S L ' and S E' symbolized by the arrow from node 'B'. Reference sign list

[0160] 10 Rolling mill

[0161] 11, 11 ' working roller

[0162] 12 Roll gap

[0163] 13, 13 ' Support, intermediate roller

[0164] 14 Belt direction

[0165] 20 Emulsion

[0166] 21...., 23 ' Emulsion actuator, emulsion spray bar 30 lubricant

[0167] 31...., 32 ' Lubrication actuator, lubricant spray bar 40 Coolant

[0168] 41...., 42 ' Cooling actuator, coolant spray bar

[0169] 51, 52 Temperature sensing device

[0170] 60 Basic Automation

[0171] 70 computing units

[0172] 100 volumes

[0173] 200 Setup model

[0174] scenario

[0175] minimum, maximum coolant rate

[0176]

[0177] Band thickness

[0178] di, d2, d3 Bringing distance

[0179] The thickness range

[0180]

[0181] lower, upper emulsion limit F' actual rolling force

[0182] i Rolling stitch

[0183] L min , L max minimum, maximum lubricant rate M' Actual values ​​of control variables

[0184]

[0185] Material quality range

[0186] Ri Stichnahmebereich

[0187] SI, S2, S3 procedure step

[0188] Sc coolant setup value

[0189] AS change coolant setup value S c 'Improved coolant setup value S' E Emulsion setup value

[0190] AS E Change emulsion setup value

[0191] S E ' improved emulsion setup value S L Lubricant setup value

[0192] AS L Change in lubricant setup value S L'Improved lubricant setup value T' Actual strip temperature

[0193] AT ' Change in actual band temperature T min , T max Minimum and maximum temperatures

[0194] Vi band speed range

[0195] ö ' Actual lead

[0196] Ai, A2 correction value

[0197] Φ c Coolant application rate

[0198] Φ L Lubricant application rate

[0199] F' Actual drive torque

[0200] Parameter set

[0201] Actual coefficient of friction

[0202] Change in actual coefficient of friction

[0203]

[0204] minimum, maximum coefficient of friction

[0205] σ1,...,σ4 Sensitivity

[0206] Σ Sum

Claims

Patent claims 1. Method for determining improved setup values ​​for cold rolling a strip s ( 100 ) in one or more rolling passes ( i ) in a rolling stand ( 10 ), wherein - the rolling stand (10) has two work rolls (11, 11') for forming a roll gap (12), an emulsion actuator (21,..., 23') comprising one or more emulsion spray bars (21,..., 23') for supplying emulsion (20) to the work rolls (11, 11') and / or into the roll gap (12), and a lubrication actuator (31,..., 32') configured to supply lubricant (30) in a range between a minimum and a maximum lubricant rate (L) min , L max ) to admit, - wherein the lubricator ( 31,..., 32 ' ) comprises one or more lubricant spray bars ( 31,..., 32 ' ) for dispensing the lubricant ( 30 ) onto the belt ( 100 ) and / or the work rollers ( 11, 11 ' ), - a cooling actuator (41,..., 42') is assigned to the rolling stand (10) which is configured to supply coolant (40) in a range between a minimum and a maximum coolant rate (C) min , C max ) to admit, - wherein the cooling actuator ( 41,..., 42 ' ) comprises one or more coolant spray bars ( 41,..., 42 ' ) for dispensing the coolant ( 40 ) onto the belt ( 100 ), - and where each rolling stitch ( i ) is characterized by a parameter set (Ai ), - wherein in a first step ( S l ) before each rolling pass ( i ) -- a minimum and a maximum temperature (T ) for the strip ( 100 ) min , T max ) and a minimum and a maximum coefficient of friction (μ) min , μ max ) are specified, and -- from a setup model ( 200 ) for the emulsion actuator ( 21,..., 23 ' ) an emulsion setup value ( S ) E ) as well as a lower and an upper emulsion limit ( E min , Emax ), for the lubricant actuator ( 31,..., 32 ' ) a lubricant setup value ( S L ) and for the cooling actuator ( 41,..., 42 ' ) a coolant setup value ( S c ) are specified, -- where the emulsion setup value (S E ), the lower and upper emulsion limit values ​​( E min , E max ), the lubricant- Setup value (S L ), the minimum and maximum lubricant rate (L min , L max ) as well as the coolant setup value (S c ) and the minimum and maximum coolant rate (C min , C max ) each represent volume flows per unit length, - wherein in a second step (S2) during each rolling pass (i) in which the strip (100) is guided through the roll gap (12), -- the emulsion actuator ( 21,..., 23 ' ) to the emulsion setup value ( S E), the lubrication actuator ( 31,..., 32 ' ) to the lubricant setup value ( S L ) and the cooling actuator ( 41,..., 42 ' ) to the coolant setup value ( S c ) will be set up, -- with the aid of a temperature sensing device ( 51, 52 ) an actual strip temperature (T ' ) of the strip ( 100 ) is determined, -- and one or more control variable I st values ​​(M ' ) of the rolling stand ( 10 ) are recorded and an I st friction coefficient ( p ' ) is determined from them, - wherein in a third step (S3) -- in a scenario (A) in which - either the I st band temperature (T ' ) is greater than the maximum temperature (T ) max ) and the I st coefficient of friction ( p ' ) is smaller than the minimum coefficient of friction ( p min ) is, - or in which the I st band temperature (T ' ) is less than the minimum temperature (T ) min ) and the I st coefficient of friction (p ' ) is greater than the maximum coefficient of friction (p max ) is, an improved coolant setup value (S C ' ) based on an initial sensitivity (σ1) and an improved lubricant setup value ( S L ' ) determined using a second sensitivity (σ2) and by the setup model ( 200 ) for the parameter set (Λ i ) be taken over, -- or in a scenario (B) in which - either the I st band temperature (T ' ) is greater than the maximum temperature (T ) max ) and the I st coefficient of friction ( p ' ) is greater than or equal to the minimum coefficient of friction ( p min ) i st, - or in which the I st band temperature (T ' ) is less than the minimum temperature (T ) min ) and the I is- Coefficient of friction (p') less than or equal to the maximum coefficient of friction (p max ) is, - or in which the I st band temperature (T ' ) is greater than or equal to the minimum temperature (T ) min ) and less than or equal to the maximum temperature (T max) is and in which the I st coefficient of friction ( p ' ) is either smaller than s the minimum coefficient of friction ( μ ). min ) or greater than the maximum coefficient of friction (p max ) is, the improved coolant setup value (Sc'), the improved lubricant setup value (S) L ' ) and an improved emulsion setup value ( S E ' ), which is greater than or equal to the lower emulsion limit ( E min ) and less than or equal to the upper emulsion limit (E max ) is determined based on the first and second sensitivities (σ1, σ2) as well as on a third and fourth sensitivity (σ3, σ4) and by the setup model (200) for the parameter set (Λ i ) be taken over, - where the first and third sensitivities (σ1, σ3) and their inverse functions (σ1 -1 , σ3 -1 ) as functional relationships between a change in the actual band temperature (ΔT') and a change in the setup value (ΔS) C) of the cooling actuator (41,...,42') or a change in the setup value (ΔS E ) of the emulsion actuator (21,...,23') are known, - and where the second and fourth sensitivities (σ2, σ4) and their inverse functions (σ2 -1 , σ4 -1 ) as functional relationships between a change (Δμ') of the actual friction coefficient (μ') and a change in the setup value (ΔS) L ) of the lubrication actuator (31,...,32') or the change in the setup value (ΔS) E ) of the emulsion actuator (21,...,23') are known.

2. Method according to claim 1, wherein in scenario (A) - the improved coolant setup value (S c ' ) based on a target temperature (T" ) according to < C mln or > C max or -- S C ' = S C + σ1 -1 (T' - T″)| S otherwise - and the improved lubricant setup value (S L ' ) according to — S L ' = Lmin if or -- S L ' = L max if S L + σ2 -1 (T' - T″)| S > L max or — S L ' otherwise is determined.

3. Method according to claim 1 or 2, wherein in scenario (B) - first a first and a second correction value (Δ1, Δ2) are set to zero, and wherein subsequently - in the case where the I st band temperature (T ' ) is greater than the maximum temperature (T ) max ) or smaller than the minimum temperature (T min ) is the improved coolant setup value (S c ' ) and the first correction value (Ai ) are determined based on a target temperature (T'' ), the first and third sensitivities (σ1, σ3) and on auxiliary variables (h1, h3) according to or — S c ' = C max and A3 = h3 if h3 > Cmax or -- Sc ' = hi and Ai = 0 otherwise, - and in the case where the I st coefficient of friction (p ' ) is greater than the maximum coefficient of friction (p max ) or smaller than the minimum coefficient of friction (μ) min ) is the improved lubricant setup value (S L ' ) and the second correction value (A2) are determined based on the second and fourth sensitivities (σ2, σ4) as well as on auxiliary variables (h2, h4) according to -- h2= S L + σ2 -1 (T' - T″)| S and h4= σ4 -1 (T' - T″)| S — S L ' = L min and A2= h4if h2< L min or -- S L ' = L max and A2 = h4 if h2 > L max or -- S L ' = h2 and A2 = 0 otherwise, - and finally, the improved emulsion setup value (S E ' ) is determined according to -- S E ' = E min if S E + Ai + A2< E min, or -- S E ' = E max if S E + Δ1+ Δ2> E max , or -- S E ' = S E + Δ1+ Δ2other.

4. Method according to one of the preceding claims, wherein the lubricant (30) is applied on the lead-in side at a certain first application distance (di) in front of the roll gap (12) onto the strip (100) or on the lead-in side directly onto the work rolls (11, 11').

5. Method according to one of the preceding claims, wherein the coolant (40) is applied directly to the roller at a second application distance (d2) in front of the roller gap (12) or at a third application distance (d3) behind the roller gap (12). Band ( 100 ) is applied.

6. Method according to one of the preceding claims, wherein the control variable I st values ​​(M ' ) at least st comprise an I st rolling force ( F ' ).

7. Method according to one of the preceding claims, wherein the actual values ​​of the control variables (M') further comprise an actual lead (δ') and / or an actual drive torque (Γ') of the work rolls (11, 11').

8. Method according to any of the preceding claims, wherein the parameter set (Λ i ) for the rolling cut (i) a thickness range (D i ), a sampling area (R i ), a belt speed range (V i ) and at least one material quality range (Q i ) includes.

9. Method according to one of the preceding claims, wherein the temperature detection device ( 51, 52 ) is designed in the form of a pyrometer arranged on the inlet side or outlet side of the rolling stand ( 10 ).

10. Method according to any of the preceding claims, wherein the lubricant ( 30 ) has a proportion of at least 80% pure oil.

11. Method according to any of the preceding claims, wherein the minimum temperature (T min ) in a range of 50°C - 70°C and the maximum temperature (T max ) in a range of 120°C to 160°C.

12. Method according to any of the preceding claims, wherein the coolant ( 40 ) comprises a proportion of at least 80% water.

13. Method according to claim 12, wherein the emulsion ( 20 ) is used as the coolant ( 40 ).

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