Patent Application
20120167653
The invention relates to a guide assembly in a plant for deforming a workpiece, and particularly to a guide assembly forming part of a metal-rolling mill, especially a strip mill. The guide assembly serves to guide strip ov various strip materials, particularly metal of various compositions, temperatures, widths and thicknesses.
Straight edge guides used in guide assemblies of rolling mills in particular to edge guides of milled or split strip, are described for instance in DE 14 27 923 A. This state of the art deals with the wear of straight edge guides when guiding strip in particular.
DE 31 162 78 A1 [GB 2,100,475] discloses a device that will control the strip position when rolling where according to the extent of the positioning of the band that is transported through the rolling train, monitoring elements of sensors trigger signals as to which servomotors will switch on to either deflect the roll axis or adjust the edge guides at the upstream end of the rolling train. This is supposed to remedy the causes of a strip that is moving off the desired position.
In addition, EP 0 721 812 A1 [U.S. Pat. No. 5,687,603] describes the guides at side edges of the band for the same purpose, the edge guides consisting of a number of subdivided segments both near the rolls as well as between them. Moreover, these individual segments or segment pairs can be moved individually and independently of the adjacent segments on the strip toward it or away from it to control the wear of the strip and of the lateral guide.
GB 2,031,771 A in turn describes a guide assembly for a rolling train provided between at least two adjacent roll stands along a roller conveyor. The objective of the assembly as well as of the strips used is to limit wear of the strip guides to a minimum, and at the same time to minimize damage to the guided strip edges.
On roller conveyors of rolling trains, particularly of strip-rolling mils such as for example steel or aluminum rolling mills it necessary in principle to evenly and safely guide strip consisting of various strip materials at various temperatures, widths, and thicknesses. However, the required contact force of devices of this type changes, when guiding strip, dependent on the strip, its temperature but also its width and thickness. The softer, warmer, wider and/or thinner that a strip is that must be guided, the lower the required contact force must be in order to ensure safe guiding of the strip along the rolling train, and one must also ensure that the strip edges are not deformed, that the strip will not arch as a whole or even deform in its entirety so that the strip edges or the straight edge guides are damaged.
In practice, a number of different actuators are known to adjust or press the straight edge guides against the respective strip edges. Mechanical actuators frequently include rack-and-pinion arrangements, nuts running on threaded rods, sprocket wheel chain threaded rods nut actuators or external fluid actuators. The fluid actuators are in turn generally hydraulic.
When using an actuator of this type, in addition to the limited space requirements, the fact that they are frequently exposed to aggressive media such as cooling liquids, rolling oils, chipping roll scales etc., as well as high temperatures is generally disadvantageous to the guides of a guide assembly. This generally results in increased wear of the actuators in addition to mechanical wear of the straight edge guides that themselves are in direct contact with the guided strip. Frequently, in practice, the problem of inadequate accessibility exists for maintenance and exchange purposes for all or individual elements of such guide assemblies, which results in lengthy down times of the rolling train, and thus to considerable production losses. However, the person skilled in the art is aware that changes of the process run due to wear are tolerable only within strict limits as otherwise a loss of quality of the strip, and, in the medium term, strip-travel problems must be seriously considered.
It is therefore the object of the invention to provide a guide assembly in a strip-working plant comprising positionable and preferably parallel guides at both longitudinal edges of the strip, which guides are able to ensure a safe and straight guidance of strip being worked by positioning of the guides, and also to reduce the susceptibility to wear of the actuators as a whole by means of a considerable reduction of possible down times.
This object is attained in an innovative manner by a guide assembly having the characteristics of claim 1. The advantageous embodiments of the invention are defined in the dependent claims.
The invention relates to guide assemblies of the type described above as used for instance in strip-rolling mils at the intake side and/or the output side of roll stands such as for example Steckel rolling mills, reversing roll stands of cold-rolling mills, or at the intake and/or output side of roll stands that are arranged in tandem, and particularly upstream or downstream of coilers.
The invention can be applied to form all conceivable types of strip, particularly to metal rolling mills or plastic deformation trains. It is preferred particularly that the guide assembly according to the invention be at the upstream or downstream side of at least one roll stand of a finishing rolling train or of a so-called finish rolling mill.
Guides that are positionable and preferably parallel to each other are provided in the guide assembly in accordance with the invention that can center or align the strip being worked in the working device and particularly between the forming arrangements, such as for example the roll stands. At least one guide will be acted on by at least one actuator to ensure a wide field of application of the guide assemblies for diverse strip profiles or dimensions. In the event that only one guide's position can be changed or pressurized, the actuator also effects a positioning to the opposing guide via the pressurized guide and via the guided strip itself.
However, in the preferred case where the guides at both longitudinal edges of the strip can be directly adjusted, each guide has its own actuator.
According to the invention, the actuator must be provided in such manner that pistons shiftable in a cylinder are attached to a straight edge guide. The cylinder for the piston in turn is formed in a guide beam and integrated into it. Thus, the guide beam not only assumes the function of the guide itself but also the function of a cylinder for the piston attached to the guide.
Because of the piston's attachment to the guide, any movement of the piston in the cylinder integrated into the guide beam effects a direct and contemporaneous equal movement of the guide along the guide beam. This therefore ensures a safe and undelayed positioning of the guide or guides relative to the longitudinal edges of the strip being worked. Because of the integration of the cylinder in the guide beam of the actuator only has a minimal number of spaces where aggressive media, particulate matter, etc. could get caught or collect. Furthermore, using the actuator arrangement according to the invention, the occurrence of so-called “drawer effects” where foreign matter, which collected in a large hollow space or cavity that could lead to a blockage of the arrangement particularly in the event of a reduced volume of the space or cavity can be reduced. This allows wear of the individual components of the actuator and of the guide assembly to be reduced altogether to a minimum.
In a preferred embodiment of the guide assembly according to the invention, two guides opposite to each other are connected with each other via a common guide beam. For instance this common guide beam can extend between and below the conveyor rolls of a roller conveyor and accordingly below the strip being worked or the strip to be formed. In this case it is preferred that the guide beam be essentially symmetrical and that in both ends of the guide beams, preferably the outer ends, respective cylinders be formed in such a way that a piston that is attached to a respective one of the edge guides can shift. This will advantageously reduce the number of parts used in the guide assembly and also increase the stability of the guide assembly as a whole. In addition, this ensures that two guides that are opposite of each other can be moved in a synchronized manner along the same displacement path toward each other or away from each other. This in particular supports in an advantageous manner centering the material or strip travel within the forming device.
According to the present invention, the shape of the guide beam is not limited any further. However, it is preferred that the guide beam basically be cylindrical and it is especially preferred that the cylindrical form basically have a circular profile extending perpendicular to the guide beam's longitudinal direction. By way of comparison, such a guide beam is easily made and supports modular design of the guide assembly for movement of the guides. Finally, the cylindrical form of a guide rail is less susceptible to particulate matter adhering to it and moreover, it can be cleaned using comparatively simple means. All this supports the resistance to the wear of the guide assembly and an extension of the maintenance and/or exchange intervals of the actuators.
The number of actuators that are connected to each guide is not limited in accordance with the invention. However, it is preferred that two actuators be attached to one guide, preferably that two actuators be connected to the two guides of the guide assembly. This ensures a particularly safe guidance through the guide assembly of the strip being worked or of the material that is to be formed. In addition, it allows the guides to remain essentially undeformed by the strips' longitudinal edges at comparatively high pressures.
Especially when more than one actuator is connected to a guide, the coupling of the respective actuators to each other is preferred in order to prevent any misadjustments of the respective guides due to the positions of the ends of a guide with respect to the longitudinal strip edges. As long as a coupling is provided, it is preferred that it be realized mechanically, particularly by providing at least one rack-and-pinion arrangement that positions the guides preferably in a synchronized manner.
As already mentioned above, maintenance time and down time can be advantageously reduced particularly when the guide assembly, and particularly the respective actuator, is designed as a module. A modular assembly of the actuators is preferred where a guide beam, a guide and at least one piston are assembled that can be installed and/or removed as a unit. In addition, in a preferred embodiment of the invention, such a modular assembly allows the continued use of a control unit or controller that is adjusted to the type of module and/or preadjusted hydraulic systems.
The wear resistance and the influence of aggressive media are essentially caused by a reduction of the spaces or cavities. It is therefore preferred that the actuator of the guide assembly according to the invention has a cover, and preferably a common cover. In particular, such a cover should extend over the entire module mentioned above in order to reduce its total wear to a minimum.
In an additional embodiment of the guide assemblies in accordance to the invention, it is preferred that the guides be positionable independently from each other. This allows a specially safe process at both sides of the strip. Particularly when rolling so called continuous custom blanks having various thicknesses across the width of the strip, exercising a low pressure upon the comparatively thin strip side can avoid strip-edge damage at both sides compared to pressurizing the comparatively thick strip side.
In any case it is preferred, however, that control units or controllers be attached to at least one actuator of the guide assembly according to the invention. In the event that several actuators are provided, it is particularly preferred that they can be controlled or regulated independently of each other. In a particularly preferred manner this provides maximum flexibility of the process in a forming plant having a product variety that is as comprehensive as possible.
As already mentioned in the beginning, the invention is particularly suitable for use in metal-rolling mills, preferably strip-rolling mills. In this case, it is preferred that the guide assembly in accordance of the invention be at the intake side of at least one roll stand of a finishing rolling train. Alternatively it is also preferred that the guide assembly in accordance with the invention be arranged at the output side of at least one roll stand of a Steckel train. In such an especially preferred embodiment of the invention, the invention's advantages are clearly apparent and have an optimal effect on the process.
The invention is explained in more detail below with reference to two schematic views of the invention. The schematic views only serve to illustrate and are not in any way designed to limit the scope of protection defined in the dependent claims. In the figures:
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2009 042 694.9 | Sep 2009 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2010/005815 | 9/23/2010 | WO | 00 | 3/6/2012 |
