Temperature control device and method for heating work rolls
Patent Information
- Application Number
- EP2023812922
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-05-12
- Filing Date
- 2023-11-23
- Publication Date
- 2025-12-24
AI Technical Summary
Existing temperature control devices for inductive heating of work rolls in rolling stands face challenges such as slow heating, poor efficiency, and high costs due to the need for thick, expensive cables to carry high current intensities, as well as the requirement for numerous induction coils to achieve uniform heating, which complicates the structural design and assembly.
A temperature control device with a transformer integrated directly into the housing adjacent to the induction coil, which transforms input voltage into a lower output voltage and current, allowing for thinner cables and reduced costs, along with a guide device for precise positioning of the induction coil, enabling efficient and cost-effective heating of work rolls.
The solution provides precise and cost-effective temperature control of work rolls by reducing cable thickness and cost, enabling efficient heating and precise control of the roll gap, thus improving the efficiency and affordability of the temperature control system.
Smart Images
Figure EP2023082869_22082024_PF_FP
Abstract
Description
[0001] Tempering device and method for heating work rolls
[0002] The invention relates to a tempering device and a method for inductive heating of work rolls for rolling strip or sheet-shaped rolled stock, strips, foils, metal foils, metal foils made of aluminum or the like, wherein the tempering device comprises at least one tempering unit with at least one induction coil which is assigned to a work roll.
[0003] Such temperature control devices and methods are regularly used on rolling stands for the local heating of rolls or work rolls. The radial expansion of the roll associated with the heating of the roll can influence the cross-sectional profile of the roll and thus the rolled stock. It is known to determine the area of a roll in which a roll gap cross-sectional profile should be influenced by means of local heating and the associated radial expansion of the roll by measuring the longitudinal tensile stress distribution in the rolled stock or by measuring a thickness distribution across the width of the rolled stock. In addition to the use of induction coils, it is known to apply heated cooling lubricant or rolling oil to a roll, which consequently expands radially. The disadvantages here are sluggish heating of the roll, poor efficiency, and unclear definition of the effective range.
[0004] DE 2 743 130 A1 discloses a tempering device consisting of a number of induction coils arranged along a roller. Since the induction coils are fixedly positioned, heating of the roller is only possible in the respective arrangement area of the induction coils. Furthermore, depending on the roller width, a correspondingly large number of induction coils is required to heat the roller in the desired arrangement areas.
[0005] EP 1 222 973 overcomes this disadvantage by arranging two induction coils on a guide device that can be moved axially along a roller. This makes it possible to move the respective induction coils to a specific area of the roller that is to be heated. This allows any desired area of the roller to be heated with just a few induction coils.
[0006] Since comparatively high currents are required for the inductive heating of rolls to generate a sufficiently strong magnetic field using an induction coil, cables running between the induction coil and a power source must have a correspondingly large cross-section in order to be able to permanently supply the induction coil with a high current. However, cables with correspondingly large conductor cross-sections are comparatively expensive and can only be laid with large bending radii, which results in a complex design and complex assembly of the temperature control device. In the case of induction coils that can be moved on a roll, the cables must be designed to be movable, which makes the temperature control device significantly more expensive. The present invention is therefore based on the object of proposing a temperature control device and a method for the inductive heating of work rolls, whichwhich enables precise and cost-effective tempering of a work roll.
[0007] This object is achieved by a tempering device having the feature of claim 1, a rolling stand having the features of claim 17 and a method having the features of claim 19.
[0008] The tempering device according to the invention for the inductive heating of work rolls for rolling strip or sheet-shaped rolled stock, strips or foils, metal foils, metal foils made of aluminum or the like, comprises at least one tempering unit with at least one induction coil which is assigned to a work roll, wherein the induction coil is arranged in or on a housing of the tempering unit, wherein the tempering device comprises a transformer, wherein the transformer is designed to transform an input voltage into a lower output voltage of the transformer, to which the induction coil is connected, wherein the transformer is arranged adjacent to the induction coil, wherein the transformer is integrated directly in the housing or arranged directly on the housing.
[0009] By using the transformer, which is connected downstream of a power source of the temperature control device, an output voltage of the power source or the input voltage of the transformer can be transformed into the lower output voltage. Consequently, the transformer is also designed to transform an input current of the transformer into a higher output current, to which the induction coil is connected. Since the transformer is arranged adjacent to the induction coil, i.e., for example, on a rolling stand with the work roll, cables from the power source to the transformer can be thinner, i.e., with a comparatively smaller cross-section, due to the input voltage being comparatively higher than the output voltage.This makes laying the cables to the power source much easier and the thinner cables are much more cost-effective to procure than comparatively thicker cables that would otherwise have to be laid from the power source to the work roll.
[0010] The induction coil is arranged in or on a housing of the temperature control unit. The housing can, for example, be designed with a completely closed or partially open solid shell. The housing can also be formed by a body or physical object. The induction coil is arranged outside the housing or inside the housing. The induction coil can also be encapsulated in the housing, for example in a plastic material or another suitable material. In this case, it is advantageous if the housing is made at least in sections from a dielectric material. Accordingly, the housing can be made of various materials. It is important that in the area of the work roll, a magnetic field of the induction coil is not weakened or significantly influenced by the housing or housing parts.
[0011] Furthermore, the transformer is either directly integrated into the housing or arranged directly on the housing. The transformer is therefore arranged outside the housing, in connection with the housing, or inside the housing. The housing can then essentially completely surround the transformer, protecting the transformer from adverse environmental influences. This also allows the transformer to be arranged a short distance from the work roll. For example, the housing can be made of sheet steel or the like.
[0012] The transformer can be connected to the induction coil with rigid cables and / or to a power source with flexible cables. Due to a lower output voltage or a higher output current, a cable connection between the transformer and the induction coil can be formed using comparatively thicker cables. The cables can therefore advantageously be rigid here. A cable connection between the power source and the transformer is possible using comparatively thinner cables, so that this cable connection can be formed at least partially or entirely with flexible cables. Since the flexible cables can be comparatively thinner, the costs for flexible cables are significantly reduced. Furthermore, the use of flexible cables also enables movement of the tempering device or the induction coil on the work roll.
[0013] The temperature control device can comprise a further transformer, wherein the further transformer can be configured to transform an input voltage into a higher output voltage of the further transformer, to which the transformer can be connected. The further transformer can then be connected between the power source and the transformer, such that an output voltage of the power source can be converted into an even higher output voltage by means of the further transformer. This makes it possible to further reduce the cross-section of cables running between the further transformer and the transformer. The further transformer can be arranged adjacent to the power source, such that the cable connection from the power source to the induction coil can be formed predominantly or over as long a distance of the cable connection as possible with the thin cables.The transformer and the further transformer can be matched to each other with regard to the higher output voltage and the input voltage.
[0014] The temperature control unit can include the transformer. If multiple temperature control units are provided, each temperature control unit can have a transformer. In principle, however, it is also possible for a single transformer to be provided for multiple temperature control units.
[0015] The temperature control unit can comprise several induction coils. The temperature control unit can then be designed so that several induction coils can be arranged, for example, side by side, around the circumference of a work roll. These induction coils can be supplied with power via a single transformer.
[0016] The housing can be formed from a first housing part with the induction coil and a second housing part with the transformer, wherein the first housing part and the second housing part can be connected at a distance from one another via a hollow profile. The first housing part with the induction coil can then be arranged close to the work roll, wherein the second housing part with the transformer can be arranged at a distance from the work roll or the induction coil. The distance can be < 3 m, preferably < 2 m, particularly preferably < 1 m. Furthermore, it can optionally be provided that the first housing part and the second housing part are connected to one another via a hollow profile, wherein the hollow profile bridges the distance between the housing parts. The hollow profile is then likewise part of the housing.Within the hollow profile, which can also be designed as a simple cover, cables, in particular rigid, straight cables with a large cross-section for transmitting large currents from the first housing part with the induction coil to the second housing part with the transformer, can then run in a protected manner.
[0017] A magnetic field of the induction coil can be adapted to a circumference of the work roll. The induction coil can then be designed such that the magnetic field follows the circumference or a radius of the work roll, at least in sections.
[0018] For example, a coil axis of the induction coil can be straight or with a radius adapted to the circumference of the work roll. A coil axis here refers to a winding axis or longitudinal axis of a helically wound induction coil. In principle, it is possible to design the induction coil with a straight coil axis. If the coil axis is adapted to the circumference of the work roll, in particular with a radius that runs coaxially to a radius of the work roll, field lines of a magnetic field of the induction coil can run at a uniform distance from a surface of the work roll, thereby optimizing heating of the work roll.
[0019] The distance between the coil axis and the circumference of the work roll can always be constant. Field lines of the magnetic field can then run at a substantially uniform distance from a surface of the work roll, allowing optimal heating of the relevant area of the work roll.
[0020] The temperature control unit can be adapted to the circumference of the work roll in such a way that a uniform gap is formed between the temperature control unit and the work roll. For example, a housing of the temperature control unit can be designed so that the housing conforms to the circumference of the work roll, and a uniform gap is formed between the housing and the work roll. The induction coil can thus be arranged as close as possible to the work roll. It is possible for a coil axis of the induction coil to run in the axial or radial direction of the work roll. In principle, it is then also possible to arrange several induction coils next to one another.
[0021] The tempering device can comprise at least one guide device for at least one tempering unit or a plurality of tempering units, by means of which the tempering unit can be positioned relative to the work roll in an axial direction. The guide device can be formed, for example, by a linear guide on which the tempering unit or a plurality of tempering units can be displaced independently of one another in the axial direction. This displacement or positioning can be carried out by means of one or more motors, for example by means of an electric motor, spindle gear or the like, of the guide device. It can be provided that the transformer can be positioned together with the induction coil, i.e. can be moved together.Furthermore, the guide device can also be designed such that the temperature control unit or several temperature control units can be positioned together or independently of each other in the radial direction relative to the work roll. Thus, the distance of the induction coil relative to the work roll can be adjusted, or the induction coil can be removed from the work roll for changing the work roll.
[0022] The tempering device can comprise a further guide device for at least one tempering unit or multiple tempering units, by means of which the tempering unit can be positioned relative to the work roll in a radial direction. Furthermore, the tempering unit or multiple tempering units can be pre-positioned in the radial direction relative to the work roll by means of a guide device. The further guide device can be used for fine positioning. Thus, the guide device can be used for fast or rough positioning, and the further guide device for comparatively slower or precise positioning.
[0023] The temperature control device can include a frequency converter. The frequency converter can be used to change the output frequency and / or output amplitude of a power source. The frequency converter can be powered by the power source with single-phase AC voltage, three-phase AC voltage, or DC voltage, so that, in principle, any type of voltage S or power source can be used for the temperature control device.
[0024] The transformer's transformation ratio can be between 1:2 and 1:1000 or more. In particular, the transformer's transformation ratio can be 1:2, 1:10, 1:100, or up to 1:1000 or more. The transformer's output voltage can be changed in this ratio to the input voltage using the transformer.
[0025] The temperature control device may include a cooling device for cooling the temperature control unit. The cooling device can be operated with various cooling media, for example, water, deionized water, cooling lubricant, or oil.
[0026] The temperature control device can comprise a control device for controlling the temperature control device and / or the relative positioning of the temperature control unit and / or for regulating a temperature of the work roll and / or a roll gap. The control device can be formed by a computer or a programmable logic controller. With the control device, the induction coil can be positioned relative to the work roll by means of a drive. Furthermore, an output voltage or an output current of the transformer can be regulated by the control device such that a desired temperature is maintained. The temperature of the work roll can, in turn, be regulated by the control device such that a desired roll gap is maintained as a result of thermal expansion in the work roll.A thickness of the rolled stock can be determined by measuring a strip tension or the like and processed by the control device, which can adjust the thickness if necessary, as described above.
[0027] The rolling stand according to the invention for rolling strip or sheet-shaped rolled stock, strips, foils, metal foils, metal foils made of aluminum or the like comprises at least one tempering device according to the invention.
[0028] One or more tempering units of the tempering device can be arranged on one or more work rolls of the rolling stand. This allows all work rolls of the rolling stand to be heated with tempering units of the tempering device, if necessary. This enables a very precise formation of a roll gap and thus a precise thickness of the rolled stock.
[0029] Further advantageous embodiments of the rolling stand emerge from the descriptions of the features of the subclaims referring back to device claim 1.
[0030] In the method according to the invention for inductively heating work rolls for rolling strip or sheet-shaped rolled stock, strips, foils, metal foils, aluminum metal foils, or the like, a temperature of a work roll and thus a radial expansion of the work roll are influenced by at least one induction coil of at least one temperature control unit of a temperature control device. A transformer of the temperature control device, which is arranged adjacent to the induction coil, transforms an input voltage and a lower output voltage of the transformer to which the induction coil is connected. For the advantageous effects of the method, reference is made to the description of the advantages of the device according to the invention.
[0031] Further advantageous embodiments of the method emerge from the descriptions of the features of the subclaims which refer back to device claim 1.
[0032] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings.
[0033] They show:
[0034] Fig. 1 is a schematic diagram of a first embodiment of a temperature control device; Fig. 2 is a schematic diagram of a second embodiment of a temperature control device;
[0035] Fig. 3 is a schematic representation of a third embodiment of a tempering device;
[0036] Fig. 4 is a partial perspective view of a rolling stand with a fourth embodiment of a tempering device;
[0037] Fig. 5 is a partial perspective view of a fifth embodiment of a tempering device;
[0038] Fig. 6 is a detailed view of Fig. 5.
[0039] Fig. 1 shows a first embodiment of a temperature control device 10 with a temperature control unit 11, a transformer 12, a frequency converter 13 and a power source 14 to which the temperature control device 10 is connected. The temperature control unit 11 has an induction coil 15 by means of which a work roll (not shown here) can be inductively heated. The temperature control device 10 is supplied with voltage via the power source 14, wherein the frequency converter 13 adapts a frequency and / or an amplitude of the voltage, and wherein the downstream transformer 12 converts an input voltage from the frequency converter 13 into a lower output voltage. A correspondingly higher transformed output current can advantageously be used to heat the work roll by means of the induction coil 15.
[0040] Fig. 2 shows a temperature control device 16, which is formed from a temperature control unit 17 with a transformer 18 and an induction coil 19 within a housing 20 of the temperature control unit 17. In particular, the transformer 18 is directly integrated into the housing 20 and connected to a power source 21. Here, too, the transformer 18 is designed to transform an input voltage into a lower output voltage, to which the induction coil 19 is connected. The housing 20 is adapted to a circumference 22 of a work roll 23 such that a uniform gap 24 is formed between the temperature control unit 17 and the work roll 23. Furthermore, a coil axis 25 of the induction coil 19 is formed with a radius r adapted to the circumference 22 of the work roll 23. Thus, a distance of the coil axis 25 relative to the circumference 22 is always the same.This makes it possible to adapt a magnetic field of the induction coil 19 (not shown here) to the circumference 22 and thus to optimize heating of the work roll 23 by means of the induction coil 19.
[0041] Fig. 3 shows a tempering device 26 with a tempering unit 27 and an induction coil 28 in a housing 29 on a work roll 30. In contrast to the tempering device from Fig. 2, here a transformer (not shown) is arranged at a distance from the induction coil 28. The housing 29 thus forms a first housing part 31 with the induction coil 28 and a second housing part (not shown here) with the transformer. The first housing part 31 is rigidly connected to the second housing part via a hollow profile 32. Comparatively thick cables (not shown here) that run from the transformer to the induction coil 28 are passed through the hollow profile 32.
[0042] Fig. 4 shows a rolling stand 33, but here only with work rolls 34 and backup rolls 35, without any representation of the roll stands. Strip-shaped material or rolled stock 36 is guided between the work rolls 34. Tempering units 37 of a tempering device 38 are arranged on each of the work rolls 34. The tempering units 37, shown schematically here, are arranged on guide devices 39 for each work roll 34 and can be positioned relative to the work rolls 34 in an axial direction as required. Each of the tempering units 37 is supplied with power via a common power source 40. In a respective housing 41 of the tempering units 37 there is an induction coil (not shown here) and a transformer, by means of which an input voltage from the power source is transformed into a lower output voltage to which the induction coil is connected.This makes it possible to design cables 42 from the power source 40 to the respective temperature control units 37 to be comparatively thin and also flexible.
[0043] 5 and 6 together shows a temperature control device 43 which is designed for arrangement on a work roll (not shown in detail here) of a rolling stand. The temperature control device 43 comprises two temperature control units 44, each of which has an induction coil (not visible here) and a transformer. The induction coil is arranged in a first housing part 45 and the transformer in a second housing part 46 of a housing 47 of the temperature control unit 44. The first housing part 45 is connected to the second housing part 46 by means of a hollow profile 48. A flexible hose 49 is arranged on the second housing part 46 and leads to a power source (not visible here). Comparatively thin cables running in the flexible hose 49 are flexible and connect the transformer to the power source.Relatively thick and rigid cables running through the hollow profile 48 connect the transformer to the induction coil. The transformer is configured to convert an input voltage from the power source into a lower output voltage from the transformer, to which the induction coil is connected. This makes it possible to design the cables running from the power source to the transformer as thin and flexible.
[0044] The temperature control device 43 further comprises a guide device 50 which is fastened to a holding device 51. In particular, the guide device 50 is designed with a cross member 52 and lateral rails 53 such that the cross member 52 can be moved in the radial direction relative to the work roll. This also makes it possible to adjust the distance between the temperature control units 44 or the respective induction coils and the work roll. Furthermore, the guide device 50 is designed with linear guides 54 on the cross member 52, which enable a movement of a table 55, on which the second housing part 46 is mounted, in the axial direction of the work roll. For the purpose of fine adjustment of the temperature control device 43, the cross member 52 is designed with a further guide device 58 with a linear guide 57 with the table 55 in the manner of a cross table.This serves for the fine positioning of the tempering device 43 in the radial direction relative to the work roll. The guide device 50 can be moved in the desired manner by means of a control device (not shown here) of the tempering device 43, thus pre-positioning the tempering units 44 relative to the work roll. For fine positioning, a distance sensor 56 is arranged on the first housing part 45, with which a distance to the work roll can be determined and / or controlled.
Claims
Patent claims 1. Tempering device (10, 16, 26, 38, 43) for the inductive heating of work rolls for rolling strip or sheet-shaped rolling stock (36), strips, foils, metal foils, metal foils made of aluminum or the like, wherein the tempering device comprises at least one tempering unit (11, 17, 27, 37, 44) with at least one induction coil (15, 19, 28) which is assigned to a work roll (23, 30, 34), characterized in that the induction coil is arranged in or on a housing (20, 29, 41, 47) of the tempering unit, wherein the tempering device comprises a transformer (12, 18), wherein the transformer is designed to transform an input voltage into a lower output voltage of the transformer, to which the induction coil is connected, wherein the transformer is arranged adjacent to the induction coil wherein the transformer is directly integrated into the housing or arranged directly on the housing.
2. Tempering device according to claim 1, characterized in that the transformer (12, 18) is connected to the induction coil (15, 19, 28) with rigid cables and / or to a power source (14, 21, 40) with flexible cables (42).
3. Tempering device according to claim 1 or 2, characterized in that the tempering device (10, 16, 26, 38, 43) comprises a further transformer, wherein the further transformer is designed to transform an input voltage into a higher output voltage of the further transformer to which the transformer (12, 18) is connected.
4. Tempering device according to one of the preceding claims, characterized in that the tempering unit (11, 17, 27, 37, 44) comprises the transformer (12, 18).
5. Tempering device according to one of the preceding claims, characterized in that the tempering unit (11, 17, 27, 37, 44) comprises a plurality of induction coils (15, 19, 28).
6. Tempering device according to one of the preceding claims, characterized in that the housing (20, 29, 41, 47) is formed from a first housing part (31, 45) with the induction coil and a second housing part (46) with the transformer (12, 18), wherein the first housing part and the second housing part are connected at a distance from one another via a hollow profile (32, 48).
7. Tempering device according to one of the preceding claims, characterized in that a magnetic field of the induction coil (15, 19, 28) is adapted to a circumference (22) of the work roll (23, 30, 34).
8. Tempering device according to one of the preceding claims, characterized in that a coil axis (25) of the induction coil (15, 19, 28) is straight or with a radius (r) adapted to a circumference (22) of the work roller (23, 30, 34).
9. Tempering device according to claim 8, characterized in that a distance of the coil axis (25) relative to the circumference (22) is always the same.
10. Tempering device according to one of the preceding claims, characterized in that the tempering unit (11, 17, 27, 37, 44) is adapted to a circumference (22) of the work roll (23, 30, 34) in such a way that a uniform gap (24) is formed between the tempering unit and the work roll.
11. Tempering device according to one of the preceding claims, characterized in that the tempering device (10, 16, 26, 38, 43) comprises at least one guide device (39, 50) for at least one tempering unit (11, 17, 27, 37, 44) or several tempering units, by means of which the tempering unit can be positioned relative to the work roll (23, 30, 34) in an axial direction.
12. Tempering device according to one of the preceding claims, characterized in that the tempering device (10, 16, 26, 38, 43) comprises a further guide device (58) for at least one tempering unit (11, 17, 27, 37, 44) or several tempering units, by means of which the tempering unit can be positioned relative to the work roll (23, 30, 34) in a radial direction.
13. Tempering device according to one of the preceding claims, characterized in that the tempering device (10, 16, 26, 38, 43) comprises a frequency converter (13).
14. Tempering device according to one of the preceding claims, characterized in that a transformation ratio of the transformer (12, 18) is between 1:2 and 1:1000 or more.
15. Tempering device according to one of the preceding claims, characterized in that the tempering device (10, 16, 26, 38, 43) comprises a cooling device for cooling the tempering unit (11, 17, 27, 37, 44).
16. Tempering device according to one of the preceding claims, characterized in that the tempering device (10, 16, 26, 38, 43) comprises a control device for controlling the tempering device and / or relative positioning of the tempering unit (11, 17, 27, 37, 44) and / or for regulating a temperature of the work roll (23, 30, 34) and / or a roll gap.
17. Roll stand (33) for rolling strip-shaped or sheet-shaped rolled stock (36), strips, foils, metal foils, metal foils made of aluminum or the like, with at least one tempering device (10, 16, 26, 38, 43) according to one of the preceding claims.
18. Roll stand according to claim 17, characterized in that one or more tempering units (11, 17, 27, 37, 44) of the tempering device (10, 16, 26, 38, 43) are arranged on one or more work rolls (23, 30, 34) of the roll stand (33).
19. Method for the inductive heating of work rolls (23, 30, 34) for rolling strip or sheet-shaped rolling stock (36), strips, foils, metal foils, metal foils made of aluminum or the like, wherein at least one induction coil (15, 19, 28) of at least one tempering unit (11, 17, 27, 37, 44) of a tempering device (10, 16, 26, 38, 43) influences a temperature of a work roll (23, 30, 34) and thus a radial expansion of the work roll, characterized in that an input voltage is transformed into a lower output voltage of the transformer, to which the induction coil is connected, by means of a transformer (12, 18) of the tempering device, which is arranged adjacent to the induction coil.