Patent Application
20130256439
The invention relates to a method and to a device for handling a metal strip. The device comprises in particular a coiling device for winding the metal strip to form a coil and a coil stripper car for receiving the coil from the coiling device.
Numerous documents are known in the prior art that deal in general with the topic of handling wound metal strips.
Thus, the unexamined German Patent Application DE 10 2007 051 976 A1 discloses a coiling device and a method for securing the coils in the coiling device. In concrete terms, the unexamined patent application discloses a coiling device for winding the hot rolled strip after the rolling to form a coil. Moreover, a device is disclosed for producing a welded connection, in order to weld the end of the metal strip on the outer circumference of the coil to a winding that is located farther inward. In this manner, the coil is secured and prevented from violently uncoiling.
In the patent application DE 10 2009 060 257.7, which has not been prepublished, a support for a metal coil on a coiling device is proposed, wherein the coil, referred to also as a coil in the English language, is deposited on three support points. A hold-down device for pressing the coil onto the support points is not disclosed; this has the disadvantage that high-strength metal strips that have a strong tendency to uncoil violently cannot be stored absolutely securely on three support points.
The unexamined German Patent Application DE 10 2007 017 383 A1 discloses a device for binding a coil, which is located on a mandrel set in rotation by a driving unit. In order to be able to achieve a secure and reliable hold, even in the case of a coil that has been coiled from thick strips and has a strong tendency to uncoil violently, the document discloses that at least one pressing roller is provided, by means of which the previously bent flat steel strip is guided around the coil, in order to secure the coil against violent uncoiling.
More remote from the subject matter of the invention are the following additional documents, for example: JP 6047438 A, DE 29 01 454, DE 102004029067 A1, EP 1 647 508 A1, DE 19714551 A1, DE 1940426 A, U.S. Pat. No. 5,044,862 A, DE 3 609 086 A1, DE 43 34 582 A1 and DE 2 806 245 A1.
The European Patent EP 1 888 284 B1 discloses a device and a method for removing a sample from a metal strip that has been wound to form a coil. The device according to the invention provides two floor rollers for storing a coil. At least one of the floor rollers is designed so it can be driven by a driving unit. The strip end has to be fixed, particularly in the case of higher strength strips but also in the case of thicker strips, permanently by one of the rollers, in order to prevent undesired violent uncoiling of the coil. Besides the two floor rollers, at least one pressing roller is provided, which contacts the coil at its outside surface, and fixes it with regard to its position. One of the two floor rollers is designed so that it can be lowered, and, after the fixation of the coil, it can be swiveled by the remaining bottom roller and the at least one pressing roller away from the coil. Due to the swiveling away of one of the floor rollers, an enlarged free strip length remains between the remaining floor roller and the pressing roller, as a result of which the local deformation of the strip end is reduced, without any associated risk of violent uncoiling of the coil.
The invention is based on the following closest prior art:
In the production of hot-rolled strips, that is hot rolled metal strips, on hot strip coiling devices, the finished coils are transported at the end of the winding process by means of a coil stripper car out of the coiling device. For this purpose, the coil stripper cars move under the coil when the latter has been completely wound in the coiling device on the coiling mandrel. The typically two supports of the coil stripper car are then raised, and placed from below against the coil on the coiling mandrel in such a manner that the coil then is applied against the two supports, after the coiling mandrel has been contracted and/or pulled out of the eye of the coil. The coil stripper car is used here first for securing the end of the metal strip, by twisting the coil in such a manner on the two supports that the strip end is pressed due to the gravity force of the coil against the support. After such a deposition of the coil on the coil stripper car, the coil is moved to a coil binding device by means of the coil stripper car.
In conventional hot strips, the production of metal strips tends to involve particularly high strengths and strip thicknesses. Said metal strips are used for producing pipe steels, as well as for extremely strong surfaces. If these materials are wound, then a residual tension remains in the coil, which will open the end of the metal strip again. This tendency increases with greater strength and greater strip thickness, and it occurs particularly in the case of small coils of low gravity force and small diameter. Typical coil diameters are 1000-2300 mm.
In such special coils with high internal residual tension, the coil gravity force often is insufficient to secure the end of the metal strip or the coil on the two supports of the coil stripper car. Rather, there is a risk that the coil can no longer be pulled reliably off the coiling mandrel and moved to the binding station. The coil can remain suspended on the coiling mandrel, and lift itself from the coil stripper car or violently uncoil.
Based on this prior art, the problem of the invention is to further develop a device and a method for handling a metal strip so that the handling of the metal strip, particularly of a metal strip with high residual tension is additionally secured, at the time of the transfer from the coiling mandrel to the coil stripper car, as well as during a transport with the coil stripper car.
The problem is solved by the object of claim 1. It is characterized by a first hold-down arm for exerting a first hold-down force onto the outer circumference of the coil, for pressing the coil against the supports of the coil stripper car.
As a result of the claimed provision of the hold-down arm, a force having at least one component in the direction of the gravity force is applied to the outer circumference of the coil, as a result of which the coil is advantageously prevented from violently uncoiling.
In principle, the invention can be used for coils without inner residual tension, with slight residual tension, or with high residual tension. In the case of coils without residual tension or with only slight residual tension, the first hold-down arm can in fact be dispensed with; however, it is not detrimental if said hold-down arm according to the invention is nonetheless provided even in these cases. The hold-down arm can be designed to exert an active pressing force onto the outer circumference of the coil. Alternatively, the hold-down arm can also be applied without force but at a fixed height against the outer circumference of the coil. In the case of a placement without force, the active pressing force, which is the same as the hold-down force, is exceptionally equal to zero. A (counter) force can be produced in this case, when the coil attempts to uncoil violently, but the first hold-down arm positioned such that its height is fixed prevents the violent uncoiling.
Definitions:
Coil refers to a coil or a wound coil made of a flat metal strip, particularly a hot-rolled metal strip, or of a nonflat material, for example, wire. The coil is typically made of metal, for example, of steel.
The term “handling a metal strip” in the sense of the present invention denotes in particular the transfer of a coil from a coiling mandrel to a coil stripper car and to the transport of the coil on the coil stripper car.
The supports of the coil stripper car can be designed in such a manner that a point-shaped, line-shaped or flat contact with the deposited coil is produced.
According to a first embodiment example, the device for handling a metal strip comprises an overhang beam which is arranged over a path for the coil stripper car, a trolley for holding the hold-down arm and for moving the hold-down arm on the overhang beam, and a synchronization device for synchronizing the movement of the trolley with the hold-down arm and of the coil stripper car in such a manner that the first hold-down arm is applied advantageously during the movement of the coil stripper car continuously against the outer circumference of the coil. In this manner, advantageously, a continuous securing of the coil during the transport on the coil stripper car is ensured.
The synchronization device can be designed in the form of an electric control or in the form of a mechanical coupling of the coil-side end of the hold-down arm on the coil. The overhang beam is anchored, for example, at at least one end in a fixed position on or in the area of the coiling device.
Alternatively to moving the first hold-down arm with a trolley along the overhang beam, the first hold-down arm can also be coupled mechanically at its end away from the coil circumference to the coil stripper car.
In addition to the first hold-down arm, the device advantageously comprises a second hold-down arm for exerting a second pressing force F2, which is the same as a second hold-down force, with its coil-side end in the eye of the coil so that the coil is pressed onto the coil stripper car.
The second hold-down arm can be attached to the coil stripper car or an additional coil car. The additional coil car is then designed preferably so that it can be shifted synchronously with the coil stripper car which carries the coil.
The first and/or second hold-down arm is/are preferably designed with adjustable height. The first and/or second hold-down arm can be designed so that it can be moved in or out telescopically.
The first hold-down arm is preferably designed so as to be placed on the circumference of the coil in such a manner that the first hold-down force Fl applied to the coil has at least one component in the direction of the gravity force. The second hold-down arm is preferably designed so that it is placed in the eye of the coil in such a manner that the second hold-down force F2 exerted by same has at least one component in the direction of the gravity force.
The above-mentioned problem is solved moreover by a method for handling the metal strip. The advantages of this method correspond in principle to the advantages mentioned above in reference to the claimed device.
In a particularly advantageous embodiment, the method according to the invention provides that, during the removal of the coil from the coiling device, the first hold-down arm acts on the outer circumference of the coil, wherein the first hold-down arm is moved synchronously with the coil and the coil stripper car.
However, the range of the first hold-down arm is limited if it is moved by means of a trolley along an overhang beam arranged on the coiling device. In order to ensure, even during the further transport of the coil, a secure stowing of the coil on the coil stripper car, beyond the range of the first hold-down arm, the method according to the invention provides that, using the second hold-down arm, a second hold-down force is applied in the eye of the coil, in order to press the coil against the support of the coil stripper car. Then the second hold-down arm can, however, protrude into the eye of the coils, after the coil has been moved at least some distance out of the coiling device and pulled off the coiling mandrel by means of the coil stripper car.
After the second hold-down arm engages in the eye of the coil, the first hold-down arm can be removed from the outer circumference of the coil, because its function of pressing the coil against the support is then taken over by the second hold-down arm.
Since the second hold-down arm takes over the function of the first hold-down arm and thus secures the coil on the coil stripper car, the coil on the coil stripper car can also be transported beyond the range of the first hold-down arm, for example, toward a coil binding machine.
When the second hold-down arm by means of its end away from the coil is anchored or attached on an additional coil car, it is necessary to ensure that the additional coil car moves synchronously with the coil stripper car, in order to maintain the second hold-down force F2 continuously in the eye of the coil during a further transport of the coil.
After securing the coil by welding its strip end or by binding in a coil binding machine, the second hold-down arm can also be removed from the eye of the coil.
As already indicated above, the device according to the invention and the method according to the invention are preferably suitable for handling coils with high residual tension, which tend to uncoil violently. However, the invention is not limited to such coils, but can in principle also be used with coils without risk of violent uncoiling. With a view to a preferred use, the method according to the invention provides that, before the use of the method, a verification is first carried out to determine whether there is a risk of violent uncoiling of the coil to be handled owing to a higher internal residual tension. It is preferable that the method according to the invention for handling the coil be provided only if the risk of violent uncoiling of the coil established beforehand exceeds a predetermined threshold value. The risk of violent uncoiling can be evaluated physically depending on the strength of the material strip, the strip thickness, and the gravity force or the diameter of the coil to be handled. In concrete terms, the mentioned physical parameters can each be compared with a predetermined threshold value, and the risk of violent uncoiling of the coil can then be defined as existing if at least some thresholds are exceeded.
In concrete terms, the risk of violent uncoiling can be established if the threshold values for the thickness and strength of the metal strip have been exceeded, and at the same time the threshold value for the diameter of the coil has not been reached.
Additional advantageous embodiments of the device according to the invention and of the method according to the invention constitute the subject matter of the dependent claims.
Eight figures are included with the invention, wherein
The invention is described in detail below in reference to the mentioned figures in the form of embodiment examples. The same technical elements are marked with the same reference numeral in all the figures.
Moreover, the device 100 according to the invention comprises a coil stripper car 120, which, as an example in
In order to prevent a violent uncoiling of the coil in the coiling device, particularly in the case of coils having a high residual tension, a first hold-down arm 130 is provided according to the invention, in order to exert a first hold-down force Fl onto the outer circumference of the coil 200. The hold-down arm is used for pressing the coil against the support of the coil stripper car. According to the first embodiment example shown in
A synchronization device 140 according to the invention, which is preferably designed in the form of an electronic control, is designed to synchronize the movement of the trolley with the first hold-down arm 130 with the movement of the coil car 120 with the coil 200 in such a manner that the first hold-down arm 130, while the coil 200 is being removed from the coiling device 110, is continuously applied against the outer circumference of the coil 200. For this purpose, the trolley 135 with the first hold-down arm 130 has to be moved synchronously with the coil stripper car 120 and the coil 200. If the distance, for example, the height H, between the overhang beam 133 and the track configuration 122 along the course of the overhang beam varies, then the synchronization device 140 has to be designed additionally so as to compensate for these varying distances, for example, by variably adapting the first hold-down arm 130 in terms of its height position with respect to the trolley 135, or by adjusting its height.
Alternatively to a design of the synchronization device in the form of an electronic control, the synchronization device can also be designed in a simplified manner in the form of a mechanical coupling of the coil-side end of the first hold-down arm 130 to the outer circumference of the coil 200. The coil-side end of the first hold-down arm is then guided by the coil itself. The mechanical coupling of the end away from the coil 132 of the first hold-down arm on the trolley then has to be designed in such a manner that the exertion of the first hold-down force Fl onto the coil is still ensured.
It is important that the first hold-down arm 130 always still acts on the outer circumference of the coil 200, in order to secure the coil on the coil stripper car, while the second hold-down arm is introduced into the eye 210.
In
Below, the method according to the invention is described in reference to the mentioned figures. It comprises the following steps:
a) Removing the coil 200 from the coiling device 110 on a coil stripper car 120, wherein the coil is applied against two supports 124 of the coil stripper car 120, and at the same time it is pressed by a first hold-down force Fl applied from above onto the outer circumference of the coil 200 against the supports, and is thus secured against violent uncoiling; see
b) Stopping the coil stripper car 120 before the coil stripper car is beyond the range of the hold-down arm, see
c) Moving a second coil car 160, with a second hold-down arm 150 arranged thereon, closer to the coil stripper car 120;
d) Moving the second hold-down arm into the coil eye 210 of the transported coil 200, and applying a second hold-down force F2 in the coil eye for pressing the coil onto the support 124 and for securing the coil 200 against violent uncoiling; see
e) Subsequently removing the first hold-down device 130;
f) Further transport of the coil by means of the coil stripper car 120 to one or more binding position(s) of a coil binding machine for binding the coil with at least one binding to produce a dimensionally stable coil 200, wherein the coil car is preferably shifted synchronously with respect to the coil stripper car 12, in order to maintain the second hold-down force F2 by the second hold-down arm in the coil eye 210 during the further transport; and
g) After binding the coil in the coil binding machine: removing the second hold-down device from the coil eye of the transported coil 200.
The step a) comprises moreover:
100 Device for handling a metal strip
110 Coiling device
112 Coiling mandrel
120 Coil stripper car
122 Fixed track configuration
124 Support
130 First hold-down arm
131 Coil-side end of the first hold-down arm
132 End away from the coil of the first hold-down arm
133 Overhang beam
135 Trolley
140 Synchronization device in the form of an electronic control
150 Second hold-down arm
160 Additional coil car
200 Coil
210 Eye of the coil
F1 First hold-down force
F2 Second hold-down force
H Height
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 062 865.4 | Dec 2010 | DE | national |
| 10 2011 080 410.2 | Aug 2011 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP11/69612 | 11/8/2011 | WO | 00 | 6/7/2013 |
