Device for determining a force in a rolling body forming a gap with a counterbody and method for determining a force in a rolling body forming a gap with a counterbody

Abstract

Device for determining a force in a rolling body (1) forming a gap with a counterbody, wherein the device comprises at least one sensor (5), characterized in that the deformation of the gap can be determined and the sensor (5) is designed and arranged for determining a shear of the rolling body (1).

Description

[0001] The invention relates to a device for determining a force in a rolled body forming a gap with a counterbody and a method for determining a force in a rolled body forming a gap with a counterbody.

[0002] The geometry that a material assumes between a counter body and a rolled body, for example in a roll gap, cannot be directly measured, since the gap geometry between the counter body and the rolled body is also unknown. The gap geometry is usually estimated indirectly using models that incorporate forces, temperatures, roll shape, and other factors. It is also possible to estimate a roll gap geometry from measuring the incoming and outgoing thickness profile.

[0003] Non-contact methods for measuring or determining the dimensions and shape deviations of rolled material, such as radiometric, X-ray diffraction, and optical methods, are subject to the difficulty that their use is limited due to the harsh environmental conditions at typical rolling mills. Furthermore, dead times necessitate additional effort for dead-time compensation in control engineering applications. All these methods share the characteristic that they detect not the cause, but rather the result of the gap geometry.

[0004] DE 16 98 113 A discloses an electrical force measuring device in which the force to be measured and the counterforce are introduced into a measuring body in opposite directions along essentially parallel lines of action that are laterally offset from each other, and the shear stresses thereby caused in the measuring body are converted into corresponding measurement signals by electrical strain gauges arranged on the measuring body.

[0005] From EP 0 315 043 A2, a method for measuring rolling force on rolling mill rolls is known. At least two sensors, arranged at different angles, are used for the measurement. The result is the rolling force F. N , the horizontal force F H , the vertical force F S and the angle Gamma between rolling force F N and the vertical. Determining the geometry of the rolling gap is not possible with this method.

[0006] The object of the invention is to create a device for determining a force in a rolling body forming a gap with a counterbody, in which the geometry of the gap can be determined.

[0007] This problem is solved by the subject matter of the subordinate claims.

[0008] Advantageous embodiments are the subject of the corresponding independent patent claims and the description below.

[0009] The invention is based on the fundamental idea that a deformation in the form of shearing of the rolling body can be detected by a sensor, which allows conclusions to be drawn about the deformation of the gap between the counter body and the rolling body and thus about the geometry of the gap. The roll gap geometry has a direct influence on the local rolling force across the strip width and strip length, the cross-sectional thickness profile, the vibration behavior and consequently on the microwaviness, which are x-order form deviations, and / or tribological conditions in the gap (friction, etc.).

[0010] The device according to the invention enables the acquisition of the gap geometry using a robust real-time method. Process parameters such as forces and moments in the gap or rolling gap can be derived from the gap geometry, temperatures, and material data. Precise online acquisition of the friction coefficients in the gap or rolling gap is also possible. Corresponding analyses, modeling, and simulation of (rolling) processes can be refined, and process control can be optimized.

[0011] The device can be installed in an existing base body and / or an existing rolling body that form a gap between them, for example, a rolling mill stand. One or more rolls can be equipped with one or more sensors. For the transmission of measurement data for further model-based processing, the measurement data or the sensor signals present at the sensor(s) can be transmitted via a data connection.

[0012] In a preferred embodiment, the sensor, for example a suitable sensor arrangement, or a further sensor, enables the determination of the roll body's torsion, thus providing an improved representation of the gap geometry. The gap geometry can be calculated with particularly high accuracy if the shear and torsion, and especially the bending of the counter body or roll body in the lateral direction (roll axis direction), are known. This allows for an increase in process knowledge, particularly regarding the friction conditions of a rolling process. The stress states in the rolls, in the rolled material, and between the rolled material and the roll are no longer estimated, but rather measured or derived using a model.

[0013] Depending on the application, the sensors / measuring points can be configured as follows: A measuring point corresponds to a location where the deformation of the roll (shear, torsion, and / or bending) is determined using a measuring method. A sensor corresponds to a technical unit used to measure the local strain. Measuring points can be spaced a defined distance apart or arranged along a direction that is not necessarily straight (e.g., a spiral or spline). The measuring points can be located on a bore wall or on a rod clamped into the bore. The more measuring points there are per bore or rod, the higher the resolution in the roll axis direction (transverse direction of the rolled material). A sensor pair can, in particular, comprise two individual sensors arranged rotated by 180° around the central axis of the rolls. A sensor pair can, most preferably, consist of two of the aforementioned arranged individual sensors.At least one pair of sensors can be used per roll. The more sensor pairs are installed at angular offset, the more accurate the resolution can be in the circumferential direction of the roll (longitudinal direction of the rolled material). Circumferential arrangements of the individual sensors can be: approximately 180°, approximately 90°, approximately 60°, approximately 45°, approximately 30°, approximately 15°. The sensor pairs preferably have the same distance from the central axis of the roll. Preferably, two sensors are present that have approximately the same distance from the central axis of the roll. The device can be used in hot or cold rolling of strip or film up to heavy plates made of steel, light metal, and / or non-ferrous metal.

[0014] In a preferred embodiment, the sensor(s) are designed to detect shear, torsion, and / or bending in the subnanometer range. For this purpose, the sensor(s) are preferably designed as a piezocapacitive sensor or as a sensor using fiber optic technology. One or more sensors can have one or more fiber optic cables. The multiple fiber optic cables can be arranged in a structured or random pattern. When using multiple fiber optic cables, a mesh-like or nonwoven-like arrangement of the fiber optic cables can be provided. The mesh-like or nonwoven-like structure of the multiple fiber optic cables can be arranged around the neutral axis. This allows for the formation of a plurality of sensor pairs. A mesh-like structure of the multiple fiber optic cables is preferred, in which the fiber optic cables are arranged in a grid-like pattern in lines. This allows the sensor to be positioned as close as possible to the roller axis.The sensor may also be a strain gauge sensor, in particular a semiconductor strain gauge. The sensor can determine the quantity to be measured using an inductive and / or a magnetic method.

[0015] In a preferred embodiment, sensors are arranged in pairs in the rolling body and / or a backup roll of the rolling body around the neutral fiber in the rolling body or the backup roll with an angular offset of at least 120°. This allows for the formation of several sensor pairs; for example, three sensors, each with an angular offset of 120°, can be used. It is also possible to use one or more sensor pair(s) that have an angular offset of approximately 180° to each other. The sensors can be arranged in the rolling body and / or a backup roll around the neutral fiber with an angular offset of approximately 180°, preferably with a tolerance range of ±20°, more preferably ±10°, and most preferably 45°.

[0016] In a preferred embodiment, a connecting line of a sensor pair intersects the neutral fiber of the roller body and / or the backup roller.

[0017] To determine the spatially resolved gap geometry, sensors are arranged in a preferred embodiment distributed along the longitudinal axis of the rolling body and / or the backup roll, particularly along the longitudinal axis at equal distances from the center point of the rolling body or the backup roll. Increasing the number of sensors along the longitudinal axis of the rolling body and / or the backup roll can contribute to an improvement in the resolution (in the transverse direction to the rolled material) of the gap geometry to be determined.

[0018] The sensor(s) can be one or more force or displacement sensors. In addition to force or displacement sensors, one or more temperature sensors are also possible. The sensors, or their measuring points, can each be arranged in an axial bore. The position of a measuring point is preferably outside the axis of rotation and below the highly stressed outer fiber. Several sensors can be arranged along an axial bore parallel to the central axis or axis of rotation.

[0019] In a preferred embodiment, a sensor can be integrated into a measuring rod that is arranged in an axial bore of the rolling body and / or the backup roll, thus simplifying the implementation of sensors in the rolling body and / or the backup roll. Alternatively, the sensor can be integrated directly into an axial bore of the rolling body or the backup roll. The sensor can be joined to the wall of the bore or to the rod. This joining can be achieved by gluing, plugging, screwing, and / or soldering.

[0020] The sensors can be wireless sensors that transmit a signal correlated with the measured quantity wirelessly to a receiver unit. In a particularly preferred embodiment, the sensor can be powered by a rechargeable battery or accumulator. It is also possible for energy to be transferred via electromagnetic transmission or energy harvesting. The use of a rotary transmitter is also possible.

[0021] The sensors can advantageously utilize the fact that the roller body or a support roller rotates, so that even with a curved roller a pulsating, especially sinusoidal, signal for the stress or strain value can be expected, thus preventing, for example, drift in the measured values. A measurement signal that steadily increases due to rising temperature can be separated from the periodic measurement signal of the force or displacement sensor.

[0022] Force or displacement sensors can be based on strain gauge technology, where changes in resistance resulting from changes in length and thickness of electrical conductors are converted into strains. NiCr and constantan strain gauges are possible, with NiCr strain gauges being more advantageous for large temperature ranges, especially for temperature differences of 150°C and above between minimum and maximum temperatures. These strain gauges exhibit a very low temperature coefficient of approximately 1% per 100 K. Complete compensation can be achieved by using a full-bridge strain gauge or by alternative methods in which the thermal strain is additionally measured with a strain gauge on an unloaded component of the same material, particularly using a temperature-compensated strain gauge.Passive temperature compensation strain gauges are generally connected as a half-bridge with active strain gauges, which largely eliminates temperature-dependent strain.

[0023] Force and displacement sensors can also be designed as (piezo)capacitive position sensors, where the capacitance between the sensor and target (single-plate sensors) or between two sensors (dual-plate sensors) is measured. Calibration enables very high measurement resolution. A technical limit to accuracy is imposed by the noise of the evaluation electronics in the picometer range. The maximum operating temperature is 100°C. A temperature change of 10 K results in a measurement error of approximately 0.2% of the measuring range. Measurement errors can be minimized by temperature measurement and external compensation.

[0024] Force or displacement sensors can also be designed as fiber optic sensors, where a change in temperature and / or strain leads to a change in the wavelength of the light reflected from the fiber's Bragg gratings, and this wavelength change can be converted. The advantage lies in its applicability in explosion-proof areas and areas with strong electromagnetic fields. Multiple measuring points / sensors can be integrated into a single fiber, resulting not only in high measurement density but also in reduced cabling requirements. Fiber optic strain measurement technology enables drift-free, long-term stable measurements. Optical fiber materials are not susceptible to vibration-induced mechanical damage. The measurements are highly temperature-stable (<600 °C).

[0025] The device according to the invention can be used in rolling, distributing, grinding, or drying processes where a rotationally symmetrical rolling body is employed. Application in profile rolling (forming with rolls having a rotationally symmetrical cross-section and a non-constant radius around the roll axis) is not excluded.

[0026] The invention also provides a method for determining a force in a rolled body forming a gap with a base body, wherein a sensor is used. The deformation of the gap is determined and the sensor detects a shear force.

[0027] If numerical data are used in the description and the claims, these data include - unless otherwise indicated in the context - a range in which deviations of + / - 20%, preferably + / - 15%, most preferably + / - 10%, and most preferably + / - 5% are possible.

[0028] The invention will now be explained in more detail with reference to an embodiment shown in the drawings.

[0029] The drawings show: Fig. 1a a rolling body designed as a work roll with sensors arranged in a central axial bore in a partially cutaway view transverse to the machining direction of a workpiece; Fig. 1b a cross-section of the Fig. 1a; Fig. 2a a rolling body designed as a work roll with sensors arranged in off-center axial bores in a partially cutaway view transverse to the machining direction of a workpiece; Fig. 2b a cross-section of the Fig. 2a; Fig. 3a a support roller with a central axial bore and sensors arranged therein in a partially cutaway representation transverse to the processing direction of a workpiece; Fig. 3b a cross-section of the Fig. 3a; Fig. 4a a support roller with sensors arranged in off-center axial bores in a partially cutaway view transverse to the machining direction of a workpiece and Fig. 4b a cross-section of the Fig. 4a.

[0030] In Fig. 1a is a rolling body designed as a work roll 1 transverse to the machining direction of a material to be machined 3 ( Fig. 1b) shown in a partially cutaway view. Sensors 5 are attached to the wall of a central axial bore 4.

[0031] In Fig. 2a Two bores 4 with an angular offset of 180° are axially and eccentrically provided in the rolling body 1, which is designed as a work roll. Sensors 5 are attached to the wall of the bores 4 along the longitudinal axis.

[0032] Fig. Figure 3a shows a support roller 2 that supports the roller body 1. Sensors 5 are attached to the wall of the bore 4 along the longitudinal axis of the support roller 2 in a central axial bore 4 of the support roller 2.

[0033] Fig. Figure 4a shows a support roller 2 that supports the roller body 1. Sensors 5 are attached to the wall of the support roller 4 in axially off-center bores 4 along the longitudinal axis.

[0034] In embodiments not shown, the sensors 5 can also be attached to a rod-shaped material; the rod with the sensors 5 attached to it can be inserted into a corresponding axial bore.

Claims

[1] Device for determining a force in a rolling body (1) forming a gap with a counter-body, the device comprising at least one sensor (5), characterized by that the deformation of the gap can be determined and the sensor (5) is designed and arranged to determine a shear of the rolling body (1). [2] Device according to claim 1, characterized by that the or a further sensor (5) is designed and arranged to detect a bend. [3] Device according to claim 1 or 2, characterized by that the or a further sensor (5) is designed and arranged to determine a torsion. [4] Device according to one of claims 1 to 3, wherein the sensor (5) is designed to determine shear and / or bending and / or torsion in the subnanometer range. [5] Device according to one of claims 1 to 4, wherein sensors (5) are arranged in pairs in the roller body (1) and / or a support roller around the neutral fiber with an angular offset of at least 120°. [6] Device according to one of claims 1 to 5, characterized by that a connecting line of a pair of sensors (5) in the roller body (1) and / or in a support roller intersects the neutral fiber. [7] Device according to one of claims 1 to 6, characterized by that sensors (5) are arranged distributed along the longitudinal axis of the rolling body (1) and / or the support roller. [8] Device according to one of claims 1 to 7, characterized by that sensors (5) are arranged on a rod which is arranged in a bore (4) of the rolling body (1) and / or the support roller. [9] Device according to one of claims 1 to 6, characterized bythat a sensor (5) has one or more optical fibers which are arranged in an orderly or random manner. [10] Method for determining a force in a rolling body (1) forming a gap with a counter body, wherein a sensor (5) is used, characterized by that the deformation of the gap is determined and the sensor (5) detects a shear of the rolling body (1).

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