Patent Application
20250058374
The invention relates to a mold for a continuous casting installation.
In a continuous casting installation, a metallic melt is conveyed into a cooled mold in which solidification of the melt begins. Within the mold, surface regions of the melt solidify into a so-called strand shell, which encloses a metal core which is still liquid. A metal casting strand having the strand shell is discharged from the mold and is then cooled further.
The mold is often set into a vertically oscillating movement during the continuous casting so that the casting strand does not adhere to inner surfaces of the mold and casting powder, which is used for the lubrication, is better drawn in between the casting strand and the inner surfaces of the mold.
However, such vertical movements of the mold create score marks, which are called oscillation marks, on the product produced during the continuous casting. The oscillation marks are a problem for the further processing of the product, and therefore the surface of the product often has to be ground after the continuous casting. This grinding is highly complicated and costly.
The invention is based on the object of reducing oscillation marks during the continuous casting.
The object is achieved according to the invention by a mold having the features of claim 1.
Advantageous refinements of the invention are the subject matter of the dependent claims.
A mold according to the invention for a continuous casting installation comprises
The horizontal width direction refers to a horizontal direction in a plane lying centrally between the two broad-side inserts.
The mold according to the invention permits a horizontal oscillation of the broad sides of the mold in relation to the narrow sides in addition to a vertical oscillation of the mold. This allows oscillation marks on the surface of the product produced during the continuous casting to be reduced or completely avoided, and therefore the quality of the product can be advantageously improved. This is made possible by a movably mounted frame, on which broad-side inserts are arranged and which is movable in an oscillating manner relative to the narrow sides by an oscillation drive. The frame consists of two subframes, on each of which a broad-side insert is arranged and which are held together by a clamping device. The subframes are each guided by two spring band assemblies which absorb weight forces and forces acting from a casting strand produced in the mold.
In one refinement of the invention, the oscillation drive comprises a first oscillation drive, preferably in the form of a hydraulic cylinder, which is arranged on a first longitudinal frame of the mold, on a side of the first subframe facing away from the second subframe, and is coupled to the first subframe, and a second oscillation drive, preferably in the form of a hydraulic cylinder, which is arranged on a second longitudinal frame of the mold, on a side of the second subframe facing away from the first subframe, and is coupled to the second subframe.
The abovementioned refinement of the invention makes it possible, on the one hand, to divide the forces generating the horizontal oscillations of the frame and, on the other hand, to make said forces symmetrical.
In a further refinement of the invention, at least one, preferably each, narrow-side copper plate has a rounding or a chamfer at the edges which are in contact with the broad-side copper plates and are substantially at a right angle to the horizontal width direction, wherein the rounding has a radius of between 0.1 mm and 3 mm, preferably between 0.3 mm and 1 mm, and the chamfer has a dimension of between 0.1 mm and 3 mm, preferably between 0.3 mm and 1 mm. This rounding or chamfering reduces the friction and additionally reduces the wear of the copper plates. It is of course also conceivable for all of the edges that are in contact with the broad-side copper plate to have such radii or chamfers.
In a further refinement of the invention, broad-side foot rollers are arranged on the underside of each longitudinal frame, the roller axles of which in each case run in the width direction and which are designed for guiding a metal casting strand emerging from the mold. This means that forces exerted on the mold by a casting strand discharged from the mold act only on the longitudinal frames and not on the movable frame.
In a further refinement of the invention, each end face of the narrow-side copper plates has grooves in which a lubricant as the lubrication can be supplied to the end face. For this purpose, lubricant is guided via flexible hoses and pipes to the side of the narrow-side copper plates facing away from the strand and from there on to the grooves.
Alternatively, each end face has, for example, as the lubrication, a wear strip, preferably made of sintered metal, with an integrated lubricant, preferably a solid lubricant.
The abovementioned refinement of the invention takes into account that, in the event of horizontal movements of the frame in relation to the narrow sides, the broad-side inserts arranged on the frame rub on the end faces of the narrow-side copper plates, which lie on the broad-side inserts. The lubrication of the end faces advantageously reduces this friction.
In a further refinement of the invention, the first broad-side insert has a support plate arranged on the first subframe and a broad-side copper plate arranged on the support plate, and the second broad-side insert has a support plate arranged on the second subframe and a broad-side copper plate arranged on the support plate.
The abovementioned refinement of the invention takes into account that broad-side copper plates wear relatively quickly due to their contact with casting strands cast in the mold and therefore have to be replaced from time to time. It is therefore expedient to provide support plates for the broad-side copper plates, on which the broad-side copper plates can be arranged.
In a further refinement of the invention, the mold for each subframe has two compensators, through which cooling water can be supplied to the subframe and cooling water can be dissipated from the subframe and the horizontal movements of the subframe are compensated for.
The abovementioned refinement of the invention takes into account that the broad-side inserts and in particular the broad-side copper plates thereof have to be cooled in order to be able to cool a casting strand produced in the mold sufficiently so that the casting strand forms a strand shell. In order to compensate for the horizontal movements of the frame, compensators are therefore provided for supplying the subframes with cooling water, the compensators compensating for the horizontal movements of the subframes. The cooling water conducted through the subframes is used to cool the broad-side inserts and in particular the broad-side copper plates.
In a further refinement of the invention, the clamping device has two clamping units which are arranged on the frame on opposite sides in the width direction and are designed to exert, on the subframes, a respective clamping force acting between the subframes. For example, each clamping unit has a hydraulic cylinder for producing the clamping force.
The abovementioned refinement of the invention permits a two-sided clamping of the subframes. Compared to clamping only on one side, this advantageously permits a symmetrical clamping of the subframes on opposite sides in the width direction. As a result, for example, forces caused by the clamping and acting between the narrow sides and the subframes on opposite sides of the subframes in the width direction can be adjusted to one another. For example, it is thus possible to avoid a higher friction force between the narrow sides and the subframes on one side of the subframes than on the other side.
In a further refinement of the invention, the clamping units arranged on the frame have pivoting units on both sides, allowing movements of the frames in the horizontal width direction at least temporarily in a different direction.
An expedient embodiment makes provision that the clamping force is set by a control and/or regulating device in such a way that a contact pressure between each narrow-side copper plate and the broad-side copper plates in contact therewith is set in such a way that the contact pressure immediately before the start of the oscillation and during the oscillation, by the oscillation drive, has a value of between 0 and 1 N/mm2, preferably 0 and 0.5 N/mm2.
The above-described properties, features and advantages of this invention, and the manner in which these are achieved, will become clearer and more clearly understandable in conjunction with the following description of an exemplary embodiment, which will be explained in more detail in conjunction with the drawings, in which:
Parts that correspond to one another are provided with the same reference signs in the figures.
The figures show an exemplary embodiment of a mold 1 for a continuous casting installation.
The mold 1 comprises, inter alia, a movably mounted frame 2, two broad-side inserts 3, 4, two narrow sides 7, 8, a clamping device 11, an oscillation drive 13, two longitudinal frames 14, 15, spring band assemblies 17 and compensators 18.
The frame 2 comprises a first subframe 2.1 and a second subframe 2.2 which is spaced apart from the first subframe 2.1.
Each broad-side insert 3, 4 comprises a support plate 5 and a broad-side copper plate 6. A first broad-side insert 3 is arranged on a side of the first subframe 2.1 facing the second subframe 2.2. In this case, the support plate 5 of the first broad-side insert 3 is arranged on the first subframe 2.1. The broad-side copper plate 6 of the first broad-side insert 3 is arranged on a side of the support plate 5 of the first broad-side insert 3 facing the second broad-side insert 4. For example, the support plate 5 of the first broad-side insert 3 is bolted to the first subframe 2.1 and the broad-side copper plate 6 of the first broad-side insert 3 is bolted to the support plate 5 of the first broad-side insert 3.
Accordingly, the second broad-side insert 4 is arranged on a side of the second subframe 2.2 facing the first subframe 2.1. In this case, the support plate 5 of the second broad-side insert 4 is arranged on the second subframe 2.2. The broad-side copper plate 6 of the second broad-side insert 4 is arranged on a side of the support plate 5 of the second broad-side insert 4 facing the first broad-side insert 3. For example, the support plate 5 of the second broad-side insert 4 is bolted to the second subframe 2.2 and the broad-side copper plate 6 of the second broad-side insert 4 is bolted to the support plate 5 of the second broad-side insert 4.
Therefore, the broad-side copper plates 6 of the two broad-side inserts 3, 4 face each other and are spaced apart from each other. The narrow sides 7, 8 of the mold 1 are arranged between the two broad-side inserts 3, 4. Each narrow side 7, 8 has a narrow-side copper plate 9 which lies on the broad-side copper plates 6 of the two broad-side inserts 3, 4, with the narrow-side copper plates 9 facing each other. Therefore, the broad-side copper plates 6 and the narrow-side copper plates 9 form the inner walls of the mold 1.
The clamping device 11 has two clamping units 11.1, 11.2 which are arranged on the frame 2 on opposite sides in the horizontal width direction H and are designed to exert, on the subframes 2.1, 2.2 of the frame 2, a respective clamping force acting between the subframes 2.1, 2.2. For this purpose, each clamping unit 11.1, 11.2 has a hydraulic cylinder 12 for producing the clamping force.
The oscillation drive 13 is designed to move the frame 2 in an oscillating manner in the width direction H relative to the narrow sides 7, 8 and the longitudinal frames 14, 15 of the mold 1. For this purpose, the oscillation drive 13 has two hydraulic cylinders 13.1, 13.2. A first hydraulic cylinder 13.1 is arranged on the first longitudinal frame 14, on a side of the first subframe 2.1 facing away from the second subframe 2.2, and is coupled to the first subframe 2.1. The second hydraulic cylinder 13.2 is arranged on the second longitudinal frame 15, on a side of the second subframe 2.2 facing away from the first subframe 2.1, and is coupled to the second subframe 2.2.
By means of the two hydraulic cylinders 13.1, 13.2, the frame 2 is thus movable in the width direction H and counter to the width direction H relative to the longitudinal frames 14, 15 and the narrow sides 7, 8. During these movements of the frame 2, the broad-side copper plates 6 rub against end faces 9.1 of the narrow-side copper plates 9 which lie on them. In order to reduce this friction, the end faces 9.1 of the narrow-side copper plates 9 lying on the broad-side copper plates 6 each have a lubrication 10. For example, each end face 9.1 has grooves in which a lubricant as the lubrication 10 can be supplied to the end face 9.1. The lubricant used is, for example, a grease or oil. Alternatively, each end face 9.1 has, for example, as the lubrication 10, a wear strip with an integrated lubricant. For example, graphite is used as the lubricant.
In order to further reduce the friction between the broad-side copper plates 6 and the narrow-side copper plates 9, the clamping force exerted on the subframes 2.1, 2.2 by the clamping units 11.1, 11.2 during the horizontal oscillation of the frame 2 is reduced, for example, in relation to a start of the continuous casting of a metal casting strand.
The spring band assemblies 17 are used to guide the frame 2 during its horizontal movements or oscillations. A respective spring band assembly 17 is arranged on each subframe 2.1, 2.2 of the frame 2, on opposite sides in the width direction H. The spring bands run vertically and are respectively connected at their ends to a longitudinal frame 14, 15. In order to avoid excessive tensions in the spring bands, the spring bands each extend substantially over the entire vertical extent of the mold 1 in order to realize a greatest possible length of the spring bands.
Broad-side foot rollers 16 are arranged on the underside of each longitudinal frame 14, 15, the roller axles of which in each case run in the width direction H and which are designed for guiding a metal casting strand emerging from the mold 1. This means that forces exerted on the mold 1 by the casting strand act only on the longitudinal frames 14, 15 and not on the frame 2.
In order to cool the subframes 2.1, 2.2 and the broad-side inserts 3, 4 when casting a casting strand, each subframe 2.1, 2.2 is connected to two compensators 18, by which cooling water from a longitudinal frame 14, 15 can be supplied to the subframe 2.1, 2.2 and cooling water from the subframe 2.1, 2.2 can be conducted away into the longitudinal frame 14, 15.
Guide strips, not illustrated in the figures, are arranged on the upper side of the mold 1, said guide strips serving to suspend and guide the narrow sides 7, 8 and each being bolted externally to the longitudinal frames 14, 15, but being spaced apart from the frame 2 in order not to obstruct the horizontal movements of the frame 2.
In addition to the components described, the mold 1 has further components, which are not relevant to the invention, however, and are therefore not described and illustrated here. For example, the mold 1 may have a further oscillation drive, which is designed to move the mold in an oscillating manner in the vertical direction.
The subframes 2.1, 2.2 are each connected to a support plate 5 and the broad-side copper plate 6 is mounted on the support plate. The narrow sides 8, 9 are mounted between the broad-side copper plates 6, the clamping units 11.1, 11.2 are controlled or regulated by a control or regulating device 24 in such a manner that a contact pressure between the broad-side copper plate 6 and the narrow side 7, 8 is kept at a predetermined value. The control or regulating device 24 receives as an input variable, inter alia, pressures which are measured by the pressure measuring devices 22, and transmits corresponding signals to a hydraulic station 23. During the oscillation movement, the contact pressure should be between 0 and 1 N/mm2.
Although the invention has been illustrated and described in more detail by a preferred exemplary embodiment, the invention is not restricted by the disclosed example and other variations may be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| A51037/2021 | Dec 2021 | AT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/087204 | 12/21/2022 | WO |
