DE2303399B2 - Movable storage for an approach head - Google Patents

Description

30th

The invention relates to a movable mounting for a starting head on the lowering table of a semi-continuous continuous caster, which has a horizontal, load-bearing surface to accommodate the foot having at least one self-centering approach head, the foot of the approach head by a leading to a recess in the lowering table, covered by this in every position of the approach head opening through with a limiting the horizontal and vertical freedom of movement of the approach head, is connected in the recess arranged holding part.

Various forms of self-centering approach heads have been tried, but usually the friction between the approach head and the table has been too great to achieve completely satisfactory performance. So is z. B. US Pat. No. 33 84 152 describes a movable mounting of the type mentioned with a spring-loaded starting head which effectively seals against the bottom of the mold, but has a beveled section to enter the mold so that a certain self-centering is achieved will. However, because the fastening for the lower end of the compression spring is not correctly aligned with the axis of the mold, such an arrangement cannot lead to a completely satisfactory seal between the starting head and the mold, since lateral force components occur between the starting head and the mold. There is always the risk that molten metal will run past at the start of casting and / or that cooling water will penetrate into the space above the start-up head. Also, the possibly existing lateral Krafikomponent when the approach head emerges from the mold is such that the strand foot is shifted laterally and seizure occurs at the lower end of the mold. The invention is therefore based on the object of designing a movable mounting of the type mentioned at the outset in such a way that a starting head freely attached to the lowering table can be actuated in a satisfactory, self-aligning manner.

According to the invention, this object is achieved in that the lowering table has devices for feeding pressurized fluid are provided for the recess or the opening.

This solution is based on the knowledge that the desired self-alignment can be achieved, when the friction can be reduced especially during the time when the start-up head enters the mold is introduced. During the remainder of the casting time, it is preferred instead that the approach head remains firmly supported by the lowering table.

Thus, the lowering table of a continuous caster of the present type has at least one approach head provided that a limited degree of freedom for lateral sliding movement with respect to the lowering table having. The lowering table is provided with means for supplying a pressurized fluid to the bottom of the approach head to provide a cushion of fluid between the lowering table and to create the start-up head, why Approach head can be moved relative to the lowering table with a very small lateral force. The top The end of the approach head is preferably slightly rounded so that the approach head when the lowering table is raised can enter the mold. Provided that pressurized fluid is supplied the desired lateral movement of the approach head is very easily brought about automatically, when the approach head enters the mold.

An expedient development of the movable mounting according to the invention with a guide for the starting head is characterized in that the starting head with laterally projecting elements for Engagement is provided with a conical surface of a ring which is below and concentric to the continuous casting mold is arranged.

This measure makes the approach head even easier and easier when the lowering table is raised better to introduce into the lower end of the mold.

The lowering table is preferably formed so that its entire upper surface is flat. However, it is only It is essential that there is a flat area of sufficient extent for each approach head to accommodate the to allow substantial lateral freedom of movement. The approach head or heads can solid or hollow inside. It is necessary for the bottom of the approach head to have an essentially has flat surface, which the opening for the supply of the fluid in the upper surface of the Lowering table surrounds so that a substantially uniform flow of .Strömungsmittel laterally below the starting head when the fluid supply is on, so that the starting head or the approach heads are not in direct contact with it during the upward movement of the lowering table stand to the starting head or the starting heads in a sealing position in the mold or the Bring ingot molds. It is easy to see that after aligning an approach head with the appropriate one Mold a random sideways movement of the approach head onto the table during lowering of the table in the course of the casting process would be extremely undesirable. For these: become reasons Appropriate measures taken, e.g. E). the base of the approach code is roughened

to prevent movement of the approach head on the table when the fluid supply is turned off is. While the fluid is a liquid, e.g. B. water, it is most common. Use compressed air.

In contrast to the construction according to the USA patent specification 33 84 152 can be the self-initiating floating start-up head according to the present invention enter the mold to seal with the peripheral wall instead of sealing against to form the bottom of the mold.

In a preferred embodiment, the lowering table is a continuous caster with several approach heads provided in positions which correspond to the positions of several molds, in which at the same time Metal 'is poured by pouring it from a holding furnace into a common gutter system is, from which the individual molds metal via dip tubes in a manner known to those skilled in the art is fed. The lowering table itself preferably consists of a layered construction in which Passages are formed leading from a fluid inlet lead to the approach head section.

In the following the invention is explained in more detail with reference to the drawing. It shows

F i g. 1 shows a partial section through one with the movable bearing for a starting head according to the present invention Invention equipped lowering table and

F i g. 2 is a schematic plan view of the lowering table.

In Fig. 1 is provided with a holding part 2 Approach head shown. The holding part is within an opening 3 for a supporting fluid Lowering table 4 included, so that the approach head 1 has limited freedom of movement both vertically and also laterally with respect to the lowering table 4 and with respect to the lowering table on a cushion or a film of air or water, which are supplied through the opening 3 under pressure, can float.

The starting head 1 has a rounded edge 5 in order to facilitate the entry of the starting head into the mold 6. However, an additional centering effect can be created by pin 7, which a touch the conical surface 8 at the bottom of the mold, as shown in FIG. I is shown. Though for the sake of simplicity the illustration four pins 7 are shown, three pins are preferably at the same angular intervals on Scope of the approach head used. With this arrangement there is no contact at all between Start-up head and mold occur, so that all possibilities of damage to the mold by the start-up head are avoided. The conical surface 8 and the pin 7 are not absolutely necessary, but allow when using them, that the radius of the rounded edge is reduced to a very small value will.

In operation, it has been found necessary to switch on a supply of compressed air for only 10 to 15 seconds when the approach head penetrates the mold. This is enough to lift the start-up head a few fiftieth of a millimeter on a cushion of air. It was found that a pressure of 2.8 to 4.2 kg / cm ^{2 is} sufficient to support starting heads of conventional weight. At the end of this short period of time, the approach head was allowed to fall back onto the lowering table 4. The lower end of the approach head is preferably roughened or knurled in order to increase the friction between it and the lowering table when they are actually in contact with one another.

The supply of air through the openings 3 can be carried out in the manner shown in FIG. 2 achieved schematically shown manner will. Air can through a flexible hose 10 and through a shut-off valve 11 to a manifold 12 are passed, from the branch pipes 14 to the openings 3 lead.

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: 1.Movable mounting for an approach head on the lowering table of a semi-continuous continuous caster, which has a horizontal, supporting surface for receiving the foot at least one having self-centering approach head, wherein the foot of the approach head through a to a recess In the lowering table leading, in every position of the approach head covered by this opening through with a limiting the horizontal and vertical freedom of movement of the approach head, holding part arranged in the recess is connected, characterized in that that in the lowering table (4) devices (10 to 14) for supplying pressurized fluid to the recess or to the opening (3) are provided are. 2. Movable mounting according to claim 1 with a guide for the approach head, characterized in that that the approach head (1) with its own projecting elements (7) for engagement with one conical surface (8) of a ring is provided below and concentrically to the continuous casting mold is arranged.