Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B35/00—Drives for metal-rolling mills, e.g. hydraulic drives
  • B21B35/02—Drives for metal-rolling mills, e.g. hydraulic drives for continuously-operating mills
  • B21B35/04—Drives for metal-rolling mills, e.g. hydraulic drives for continuously-operating mills each stand having its own motor or motors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
  • B21B1/18—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section in a continuous process
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B13/00—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories
  • B21B13/005—Cantilevered roll stands

Definitions

• the invention relates to a rolling stand as part of a rolling stand group in a high-speed wire rod mill, comprising at least one pair of rolls or rolling rings and a drive shaft connected to a motor.
• Rolling stands of the type in question are typically arranged in blocks one behind the other and cause cross-sectional changes that the rolled material undergoes successively in the rolling stand groups under the influence of at least two rolls or rolling rings in each stand.
• the wire rod is conveyed to final rolling speeds of more than 60 m/sec, preferably up to 130 m/sec, as it passes through the finishing blocks of the wire rod mills and especially as it exits the last rolling stand.
• High-speed wire rod mills generally consist of a multitude of individual rolling stands arranged in series, which together or separately form a roughing mill, an intermediate mill, and a finishing mill, optionally employing a prefinisher between the intermediate and finishing mills.
• the finishing mill typically comprises a roughing mill and a finishing mill, optionally with a downstream sizing unit.
• the present invention relates to the aforementioned finishing mill in a high-speed wire rod mill, thus including the roughing mill, the finishing mill, and optionally the downstream sizing unit.
• the roughing and finishing blocks used in such wire rod mills typically consist of a series of individual rolling stands arranged one behind the other, the associated adjustment devices for the roll gap, and rolling assemblies for guiding the rolled material.
• the individual rolling stands are preferably arranged on a common base frame, and the rolls of these stands, preferably in the form of rolling rings, are usually mounted cantilevered on pairs of support shafts. These support shaft pairs, in turn, are driven via gearboxes consisting of spur and bevel gear combinations, arranged together on the base frame, through longitudinal shafts located on both sides of the row of stands.
• Such rolling mill stand arrangements are exemplified in the DE 199 19 778 A1 , the DE 198 00 201A1 , the DE 196 25 811A1 , the DE 102 61 632B4 and the DE 3 109 633A1 described.
• the stands of each block are usually arranged in a V-shape (the rolling stands are arranged in a V-shape to each other and all rolling stands are at a predetermined angle to the foundry floor) or in an H-V-shape (the rolling stands are arranged in a V-shape to each other, with one half horizontally parallel to the foundry floor and the other half vertically perpendicular to the foundry floor) alternating with each other with a predetermined angular offset, such that the rolling stands with odd numbering extend to a first side of the rolling block and the rolling stands with even numbering extend to a second side of the rolling block, or vice versa.
• the longitudinal shafts arranged on both sides of such a rolling block are in turn driven by a common distribution gearbox with one or more motors connected in series.
• the drive of the individual rolling stands is effected via a drive of the support shaft pairs and finally of the rolls or rolling rings via gearboxes consisting of spur and bevel gear combinations, which are jointly arranged on the base frame and assigned to the support shafts.
• Figure 1 A schematic view of such drives used in the prior art is shown in Figure 1 This illustrates that the bending in the drive-gearbox unit occurs spatially via two angles, typically 90° and 45°.
• Common rolling mills of this type consist of 2, 4, 6, 8, or 10 stands. Depending on the material grade to be produced, combinations of rolling mills, such as 6+4 or 8+4 stands, are also used in a wire exit. Each of these mills, however, has separate distribution gearboxes for connection to the longitudinal shafts.
• the mechanical drive system in turn, possesses several natural resonant frequencies due to the large number of masses capable of torsional vibration, which a single drive motor with its high moment of inertia could only partially control. This can lead to a situation where a wire mill cannot reliably operate within certain speed ranges.
• the invention is based on the objective of providing a rolling stand in a roughing or finishing block of a high-speed wire rod mill, in which the overall deformation can be varied with high flexibility and in which an adjustment of the cross-sectional reduction per pass is possible while simultaneously allowing free selection of the rolling ring diameters, the number of rolling stands and the distances between the rolling stands.
• the invention relates to equipment in high-speed wire rolling mills.
• Such rolling mills are operated at wire exit velocities from the last rolling step of approximately 60 to 130 m/s, with the final cross-sections of the wire typically being approximately 4 to 20 mm, preferably 5 to 16 mm.
• plain bearings are used instead of the otherwise conventional rolling bearings.
• such high-speed wire rolling mills have a rolling stand spacing of 800 - 1000 mm.
• each rolling mill stand is assigned its own drive unit with a respective motor and drive shaft, wherein the motor, the drive shaft, and the at least one pair of rolls or rolling rings are arranged linearly relative to each other.
• the linear arrangement is essentially straight and without bends, thus eliminating the need for the otherwise necessary special gear arrangement, such as bevel gear arrangements. This allows the drive unit to be implemented with particularly simple means, offering very high reliability and flexibility with regard to control, while minimizing its installation size.
• This gearbox is located between the auxiliary shafts of these rolls or rolling rings and the drive shaft for the respective rolling stand, possibly with an additional reduction gearbox.
• the bevel gear stage otherwise required for power flow redirection can be omitted, which also leads to a reduction in rotating mass and increased torsional stiffness in the rolling stand.
• the individual mechanical and electrical drive components can be vibrationally tuned to one another. This allows for individual adjustment of the natural frequencies, which influences the overall vibration behavior.
• any control system can be vibrationally calibrated for each individual rolling mill stand.
• adjustable notch filters can preferably be used to counteract any residual resonance in each drive train. It is also possible to use individual notch filters for each rolling mill stand.
• the invention enables the optimization of the tension ratios between the stands, which can lead to reduced friction in the roll gap and thus to improved quality and a significant increase in roll service life.
• the ability to select freely variable speed ratios for the drives of the individual stands allows for targeted gradation of cross-sectional reductions, for example, in the finished billet of a high-speed wire rod mill. This enables a flexible reduction distribution, for example, to reduce the overall heating in the core of the wire rod through a degressive reduction gradation.
• the ability to freely select the reductions and the resulting longitudinal tension between the stands also allows for material-adapted and cross-section-oriented forming processes and forming efficiencies, which can reduce the power requirement for each individual rolling stand and the rolling mill as a whole. Furthermore, cross-sectional influence can be achieved by individually modifying the longitudinal tension between the rolling stands, thereby reducing length-dependent cross-sectional errors, particularly in thickened wire ends.
• the free choice of rolling ring diameter allows for better utilization of the rolling rings, as new and old rings can be combined.
• the oval or round calibers can be inserted at any desired position in the finished billet. Since there are no longer any rigid caliber rows, preferably only wear-adjustment of the respective rolls or rolling rings is required, thus increasing the service life of each individual roll or rolling ring.
• a roughing and finishing ingot system preferably only the rolling stands involved in the rolling process can be driven at high speed.
• the stands not involved can rotate at an arbitrarily slow idle speed, thus avoiding high speeds that are difficult to control from a bearing perspective.
• the free choice of the layout of the individual stands within the roughing or finishing block allows for a targeted adjustment of the distances between the individual stands, whereby these distances can in turn be used specifically as cooling or equalization sections.
• the previously established fixed relationship between the inlet cross-section and the outlet cross-section of a rolling stand group comprising several stands, so-called modules, is therefore preferably not present in the invention, since desired changes to the outlet cross-section no longer necessarily require a change to the inlet cross-section and the associated replacement of all rolls or rolling rings and calibers.
• a significantly improved response time of the drive train can be achieved, thereby improving the dynamic behavior of the rolling stand group or block overall, and particularly during the tapping process.
• This high dynamics and the preferred vibration-related coordination of the individual mechanical and electrical drive components reduces the risk of dangerous resonances, resulting in safe operation across the entire speed range of high-speed wire rod mills.
• the individual rolling stands are largely mechanically decoupled from one another, so that the penetrating shock in one rolling stand cannot excite any natural resonance vibrations in other rolling stands, which can ultimately result in a more stable operating mode in the overall speed range of the rolling stand group and, if applicable, the entire rolling mill.
• the rolling stand according to the invention is part of a rolling stand group of a roughing or finishing module of high-speed wire rod mills, comprising at least two such rolling stands.
• a roughing or finishing module of high-speed wire rod mills comprising at least two such rolling stands.
• the spacing between the respective rolling stands and their number are predetermined.
• This block-like arrangement also allows connection to a control unit, which may be pre-calibrated, and furthermore enables the replacement of entire rolling stand groups without the need to replace individual rolling stands or subgroups of rolling stands.
• the block-like grouping of several rolling stands is particularly advantageous when between two and twelve rolling stands with coordinated roll gap diameters are grouped together. It is also particularly preferred when the rolling stands of the respective rolling module are arranged alternately with a predetermined angular offset to one another. Such an alternating arrangement is always realized when the angular offset between a first and its subsequent rolling stand is fixed. Furthermore, an arrangement according to the invention is always realized when the rolling stands with odd numbers, counted from the entry side to the exit side of the group, are arranged substantially parallel to each other, and the rolling stands with even numbers are also arranged parallel to each other between these rolling stands with odd numbers, or vice versa. The angular offset is thus realized between all rolling stands with odd numbers and all stands with even numbers.
• the rolling stands of the rolling module are arranged in a V-shape relative to each other, with the angular offset defined above preferably being approximately 90°.
• a V-shape in the sense of the invention can also be achieved with a deviation from a right angle, for example with an angular offset of 60 to 120°.
• the rolling stands can preferably all be arranged at a predetermined angle of, for example, 45° to the furnace floor, so that accessibility to each rolling stand in the group is the same and can be automated if necessary. However, essentially the same effects can also be achieved with a deviation of approximately +/- 15°.
• the rolling stands are arranged in a so-called H-V arrangement relative to each other, with the angular offset also being approximately 90°.
• half of the rolling stands are arranged horizontally (H), thus parallel to the furnace floor, and half are arranged vertically (V), thus perpendicular to the furnace floor.
• the successive rolling stands are arranged in a spiral or star shape with a constant angular offset of about 120° (star arrangement) or about 60° (spiral offset), whereby the starting position is reached again after 3 or 6 offset steps respectively, and rolling of the wire is possible without the need to twist the wire between individual or all rolling stands.
• the angular offset between the adjacent rolling stands is 180°, thereby enabling a completely flat arrangement of the roughings or finished billets, which can also be provided at any desired inclination to the mill floor.
• a flat arrangement typically requires the use of suitable twisting elements for the wire, at least between some of the rolling stands, to enable the wire to be rolled into a round shape.
• All of the above-mentioned alternatives provide, in particular, a simplified and standardized structure with easy access to all rolling stands, and especially to all rolling stands of a module, whereby, especially in the 45° arrangement of all rolling stands compared to the furnace floor, an alternating arrangement of 90° of the respective rolling stands to each other with a corresponding symmetrical arrangement of the rolling block as a whole is realized.
• the forming of the wire rod takes place under the influence of at least two rolls or rolling rings.
• the invention is not limited to forming the wire with such pairs of rolls or rolling rings. It is equally preferred if at least one rolling stand of a rolling stand group is assigned three or four rolls or rolling rings and the forming of the material is effected in the roll gap formed by the three or four rolls or rolling rings. This increases the flexibility and versatility of the rolling stand according to the invention with particularly simple means.
• each rolling mill stand is assigned its own motor, which drives the rolls or rolling rings. It is particularly preferred if the motor is an electric or hydraulic motor, which in a highly preferred embodiment of the invention is also designed to be controllable. Such electric or hydraulic motors are particularly space-saving and also facilitate the linear arrangement of the drive train, which consists at least of a motor and drive shaft, and optionally a coupling.
• the drive shaft is furthermore associated with a transmission gearbox, which is preferably integrated into the drive train.
• This transmission gearbox allows the provision of particularly high rotational speeds, such as those occurring in high-speed wire rolling mills, without the need to modulate or even replace the motor itself, since in such high-speed wire rolling mills rotational speeds of the individual rolls of up to 17,000 rpm occur, whereby the rotational speed does not have to be provided solely by the motor by using a transmission gearbox.
• the drive in a rolling mill according to the invention can also include an adjustment unit, which allows the individual rolls or roll rings to be adjusted relative to one another. This provides a rolling mill in which the roll gap can preferably be controlled and adjusted without having to exchange the rolls or roll ring pairs to achieve a specific degree of deformation during the pass.
• the drive of the individual rolling stands grouped together is carried out via respective control devices, in particular via a common control device to which the respective motors are connected.
• a control device can not only serve to advantageously adjust the longitudinal tension and compression between two adjacent rolling stands within each rolling stand group, but can also prevent the occurrence of resonance vibrations within a rolling mill stand or the entire system, or at least dampen them in a stand-specific manner.
• a control device is particularly preferred which processes speed setpoints of the respective drive trains of the individual rolling stands based on technological specifications, such as the rolled material, the maximum forming values of this material, the rolling stand constants, the inlet and outlet cross-sections, the inlet temperature, the available roll sets, the lot sizes and/or the identification number and, if applicable, the turning dimensions of the rolls.
• a control device connected to measuring sensors is particularly preferred, as it determines actual values, at least for the rotational speed of the respective drive trains. Based on this determination of actual values, a comparison can then be made with the previously determined target and actual rotational speeds. This is preferably carried out using adjustable drive power supplies for electric or hydraulic motors in the respective rolling mill stands.
• the at least one control device can then dynamically synchronize the rotational speed of preferably each rolling stand with the rotational speed of at least one adjacent rolling stand, preferably with the rotational speeds of all rolling stands grouped together in modules.
• Figure 1 Figure a shows a schematic section view of a drive train of a (not shown) wire rod mill according to the prior art, as well as an illustration of the angles ⁇ , ⁇ between the planes A, B, C within the drive.
• Half of the rolling stands of a roll block, arranged in a V-shape at an angle of 45° to the mill floor, are driven via a common drive shaft 20.
• the rolling stand drive shaft 22 is driven via a bevel gear stage 21, consisting of two bevel gears 21a, 21b arranged at an angle of 90° to each other.
• This rolling stand drive shaft 22 in turn, extends (not shown) to a (not shown) transmission for driving the (not shown) rolls or roll rings of the rolling stand.
• Figure 1b These planes A, B, C and their angular offset to each other are shown again separately for better understanding, without showing the representation of the gear arrangement.
• Figure 1 a These planes A, B, C and their angular offset to each other are shown again separately for better understanding, without showing the representation of the gear arrangement.
• Figure 2 shows a rolling stand group 2, which comprises rolling stands 1a-1f arranged on a roll frame 3.
• the rolling stands 1a-1f are arranged at an angle of 45° to the furnace floor 4 such that the left rolling stands 1a,b,c alternate with the right rolling stands 1d,e,f at an angle of 90° to each other.
• the arrangement of the rolling stands 1a-1f on the roll frame 3 is such that the roll gaps of the respective pairs of rolls 5a-5f are substantially aligned with each other, so that a wire (not shown) can pass through all the rolling stands 1a-1f of the rolling stand group 2 without bending or kinking.
• the individual rolling stands 1a-1f essentially consist of a motor 6, a drive shaft 7, a gearbox 8, and finally the respective pair of rolls 5.
• these components 5, 6, 7, 8 of the respective rolling stand 1 are arranged linearly relative to each other without spur and bevel gear combinations and without the need for longitudinal shafts running along the roll frame 3.
• the longitudinal axes of these components 5, 6, 7, 8 are therefore essentially on the same line, with a parallel displacement occurring, particularly in the area of the rolls themselves, to the extent specified by the gearbox assembly 8. can, without thereby deviating from the principle of the linear arrangement in the respective rolling stand 1a-1f.
• Figure 3 shows an enlarged top view of the gear unit 8 of the rolling mill 1f.
• Figure 1 which serves as a transmission and drive unit.
• the transmission unit 8 is arranged between the motor 6 and the drive shaft 7 on the one hand, and the roller pair 5f on the other.
• a gear (schematically indicated) 9 is mounted on the end of the drive shaft 7 facing the roller pair 5f, which meshes with an intermediate shaft 10 for the rollers of the roller pair 5f.
• the different number of teeth on the gears of the drive shaft 7 and the intermediate shaft 10 results in a predetermined transmission ratio between the rotational speed of the drive shaft 7 and the rotational speed of the intermediate shaft 10.
• a gear 11 shrunk onto the intermediate shaft 10 is in meshing engagement with a roller drive shaft 12a for one roller of the roller pair 5f and with the auxiliary shaft 13, which in turn is in meshing engagement with the second roller drive shaft 12b for one roller of the roller pair 5f, whereby a predetermined transmission ratio also exists between the intermediate shaft 10 or the auxiliary shaft 13 and the roller drive shafts 12a, 12b, but the two roller drive shafts 12a, 12b are driven with the same rotational speed but in different directions of rotation.
• rollers 5f are replaced individually or in pairs, while the drive shafts 12a,12b are preferably replaced modularly, wherein the roller pairs 5f together with their roller drive shafts 12a,12b, the retaining plate 15 and the (not shown) adjustment unit for the roll gap are pulled out of the transmission gear 8 and replaced by inserting a replacement module.
• FIG. 4 a schematic circuit diagram of the electrical control unit 15 is shown for the rolling stands 1d, 1b, and 1e, which are depicted only as examples.
• the control unit 15 essentially consists of a control unit 17 and a drive supply 19 for each rolling stand.
• the speed and torque of each drive supply 19 can be individually adjusted for vibration in each rolling stand.
• adjustable notch filters 19a counteract the remaining resonances for each drive train.
• the control unit 17 is connected to all rolling stands 1d, 1b, and 1e of the rolling module 2 and receives actual values from all measuring sensors.
• the rotational speed of the motors 6 and their load are measured for each.
• the control unit 17 determines the operating speed of the individual rolling stands using technological and machine-related parameters.
• the motors 6 of the individual rolling stands are interconnected both via the control unit 17 and a drive data bus 16. This enables multi-layered, dynamic synchronization of the individual rolling stands.
• dimensional measuring devices 14a and 14b can be connected at the entry and exit sides to detect the dimensional changes of the wire rod (height, width, ovality).
• an initial speed setpoint is derived from the nominated speed difference to the adjacent drive for each rolling stand 1d, 1b, 1e.
• the control unit 17 is equipped with an observer that determines a dynamic, real-time setpoint correction for each stand based on a mathematical model.
• the speed correction for each stand is transmitted to the drive power supplies.
• a nominated actual speed comparison with the other rolling stands is performed via the drive data bus 16.
• the coupling of the speed controls is controllable and is switched on and off stepwise depending on the material tracking of the wire head. Material tracking is controlled by sensors 18a, 18b upstream and downstream of the rolling stands 1d, 1b, 1e via the motor currents and is computationally corrected depending on material speed and lead.
• the calculation unit 17 is equipped with a second variable setpoint for each rolling stand, which is intended to limit the individual speed drop during the tapping process for each stand 1d, 1b, 1e.
• This second setpoint is switched on and off stepwise depending on the material tracking within the calculation unit. The effects of the second setpoint are monitored metrologically, evaluated in an adaptation algorithm, and varied for the next tapping.
• a third setpoint for the speed of each rolling stand 1d, 1b, 1e is used to modify the speed ratios between the rolling stands.
• the third additional setpoint can be derived from a manual correction, from a first calculated value of the calculation unit 17, which represents the tensile-compressive relationships during rolling using a mathematical simulation model, or from a second calculated value, which originates, for example, from dimensional measuring devices 14a, 14b arranged before or after the rolling stands 1d, 1b, 1e, and the calculated form and diameter deviation.
• the third additional setpoint can be switched on and off stepwise depending on the material tracking.
• the material tracking within the calculation unit 17 controls a state-dependent setpoint specification that defines different speed setpoints for threading, rolling, and unthreading.
• a memory circuit 17b records the currently determined correction values and ensures an adaptive improvement of the synchronization for the next wire rod.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Rolling (AREA)
• Control Of Metal Rolling (AREA)
• Unwinding Of Filamentary Materials (AREA)
• Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)

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• 2009
  • 2009-10-26 DE DE102009050710.8A patent/DE102009050710B4/de active Active
• 2010
  • 2010-10-26 EP EP10776565.3A patent/EP2493634B2/de active Active
  • 2010-10-26 ES ES10776565T patent/ES2532474T5/es active Active
  • 2010-10-26 SI SI201030921T patent/SI2493634T2/sl unknown
  • 2010-10-26 KR KR1020127010225A patent/KR101502087B1/ko active Active
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  • 2010-10-26 WO PCT/EP2010/006514 patent/WO2011054461A2/de not_active Ceased
  • 2010-10-26 RU RU2012121818/02A patent/RU2528931C2/ru active
  • 2010-10-26 CN CN201080049638.4A patent/CN102686324B/zh active Active
  • 2010-10-26 US US13/498,654 patent/US9808843B2/en active Active
  • 2010-10-26 JP JP2012535670A patent/JP5678074B2/ja active Active

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