Patent Application
20120080159
The present invention relates to a mold for the continuous casting of blooms, slabs or billets, with a mold tube surrounded by a jacket and supported by profiles running in the longitudinal direction and distributed over the circumference on the jacket and connected positively to the latter via connectors, cooling passages for the routing of cooling water being distributed over the entire circumference between the jacket and being arranged essentially over the entire mold length.
Continuous casting molds are reusable, downwardly open molds for casting metal or alloys. For this purpose, the liquid metal or liquid alloy is conducted through the mold that consists of cooled copper plates and the metal or alloy solidifies in the desired form.
A particular problem with continuous casting is that uniform and careful cooling of the copper tubular mold is advantageous for this purpose. To this effect, coolant is conducted through prefabricated coolant passages, the coolant employed usually being water. In this case, a uniform temperature of the coolant is desirable, so that the mold is not damaged due to sharp local temperature gradients. Furthermore, with a constant cooling capacity, the casting has a higher surface quality.
Continuous casting molds of the type described above are known, for example, from EP 2 014 393 (US 2001/0155570]and from EP 1 468 760 (U.S. Pat. No. 7,422,049). These describe connection profiles as connectors between the mold tube and the jacket, the connection profiles being arranged in the longitudinal direction along the entire circumferential line. In the embodiment according to EP 2 014 393 A1, the connection profile arranged in one piece on the mold tube has a rounded nose, behind which a further nose of a connection strip, connected to the jacket, is engaged. For this purpose, a plurality of fastening screws are provided that reach through the jacket from outside. By contrast, in the embodiment according to EP 1 468 760 B1, there is provision for the profile strips on the mold tube to be designed as T-profile pieces or as dovetail profile pieces, the profile piece on the jacket being shaped correspondingly in order to provide an appropriate connection.
The molds described have the disadvantage, in the first place, that manufacture or machining is relatively complicated, thus increasing the production costs. Moreover, assembly is comparatively complicated, since the respective strips have to be oriented first parallel to one another and then at the correct height, which has proved to be difficult. A particular problem, however, is that a reduced cooling action takes place in the region of the profile strips, thus leading to the sharp local temperature gradients already referred to. This is also intensified in that, in the known solutions, the cooling passages are covered on one side.
It is therefore an object of the present invention to provide an improved continuous-casting mold.
Another object is the provision of such an improved continuous-casting mold that overcomes the above-given disadvantages, in particular in which as constant and as uniform a cooling capacity as possible is afforded along the entire surface.
A continuous-casting mold has according to the invention an inner mold tube having a plurality of side walls formed with coolant passages, a plurality of profiles extending longitudinally on each of the side walls and each formed with a respective plurality of longitudinally spaced undercut grooves, an outer jacket surrounding the mold tube, respective connectors each having a base generally complementarily fitting in a respective one of the grooves and a tubular and internally threaded body projecting outward from the respective base, and respective screws engaged from outside through the holes in the bodies.
In other words, according to the invention the rib-shaped supporting profiles arranged on the outer surface of the mold are formed with a plurality of spaced-apart undercut grooves into which engage the connectors that also have a cylindrically tubular body with an internal threaded bore that receives a fastening screw for fixing the jacket. This jacket consists of a plurality of plates that are connected indirectly to the mold tube via screws that engage into the cylindrically tubular body, for which purpose the latter has a corresponding threaded portion. The hollow body is mounted positively inside the recesses on the rib-shaped supporting profiles. The jacket plates can thereby be assembled quickly and in a labor-saving way, since the correct positioning is already defined by only two connection points, and the jacket plate is prevented from being axially displaced longitudinally with respect to the mold tube. The other fastening screws can subsequently be fitted without difficulty.
Furthermore, the cylindrically tubular body with the threaded bore affords a comparatively long threaded portion, so that there is a stable connection. This is not so if the threaded bores were to be threaded directly into the supporting profiles that are designed to be as flat as possible and therefore offer only a small amount of space for a threaded portion.
According to a first advantageous embodiment of the present invention, the grooves with undercuts and the parts engaged therein of the connectors are T-profiles or dovetail profiles. Such profile cross sections can be produced simply, quickly and therefore cost-effectively and, moreover, provide an optimal hold of the connectors.
In order to make positioning even easier when the jacket plates are being assembled, the cylindrically tubular bodies of the connectors each have on an outer end a frustoconical outer surface that serves as a centering aid for the jacket plate to be attached. Furthermore, according to a further embodiment of the invention, each jacket plate has perforations that may preferably be bores into which the cylindrically tubular bodies of the connectors project in the assembled state. Hence, during assembly, the jacket plate first merely has to be positioned roughly, so that the tips of the hollow bodies project into the perforations. When the jacket plate is subsequently being “plugged on”, it is correctly positioned automatically. Alternatively or additionally to this, the perforations could also be designed frustoconically inside the jacket plates.
So that the jacket plate can be connected firmly to the mold tube, the perforations of the jacket plate each have restrictions with a diameter designed for passing the screw shank, but not the screw head. Preferably, in the assembled state, the screw head rests in a countersink of the jacket plate.
The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:
According to a first actual embodiment of the present invention, the mold consists of a mold tube 1 and of a jacket 2. The mold tube 1 has supporting profiles 3 distributed over its outer surface and extending in a longitudinal direction 4, so that the mold tube 1 is supported via these in the jacket 2. Furthermore, the side walls of the mold tube 1 are formed with outwardly open cooling grooves or passages 5 that also extend in the longitudinal direction 4 and through which a coolant flows.
As may be gathered from
On account of the thermal expansion that the mold tube 1 experiences during continuous casting and of the different expansion between the mold tube 1 and jacket 2, some play between the cylindrically tubular bodies 9 and the corresponding bores 12 in the jacket plate 11-11″′ must be allowed in calculations.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102010047392.8 | Oct 2010 | DE | national |
