DE3219161C1 - Method and device for decoupling the dummy bar from the cast strand in the continuous casting of metal, especially steel - Google Patents

Abstract

In a method for decoupling the dummy bar (1) from the cast strand (5) in the continuous casting of metal, especially steel, coupling to the cast strand (5) in the continuous casting mould (3) is effected by pouring steel around a claw (2b) with a bevelled recess (2a) in the head (2) of an articulated dummy bar (1). To ensure that the decoupling process is reliable and can be performed within a very restricted space, completely eliminating additional decoupling cylinders, formerly arranged under the cast strand (5) and without losing any length in the continuous casting apparatus, it is proposed that, with the bevelled mating recess (7) of the cast strand (5) facing downwards, the dummy bar head (2) be pressed essentially downwards in the decoupling section (9) by means of a pressing device (12a) arranged downstream of the conveying and straightening machine (8) or the last segment (18) of a conveying and straightening machine (17) of segmental construction and that a lower roller (14) which is present be moved simultaneously or earlier away from the dummy bar head (2). <IMAGE>

Description

55

The invention relates to a method and a device for uncoupling the starting line from Cast strand in the continuous casting of metal, in particular steel, in which in the continuous casting mold through Casting around a claw with a sloping recess within the starting head of a link starting line the coupling is formed with the cast strand.

In such a method, the mold walls and the hook-shaped in their basic shape are formed by the mold walls Design of the approach head a shape complement made of cast metal, which is inside and outside the Continuous casting mold cools down and, with increasing solidification of the cast material, it can withstand stress increases

For the uncoupling of the connection formed, which must always be detachable, the recess of the Approach head in the sense of a draft angle for cast parts "beveled", including all forms of Recesses fall on the one hand, the transmission of a tensile force through the transport straightening machine cause the starting strand, its starting head and thus on the cast strand and, on the other hand, a disengagement or enable notching within the uncoupling section generally provided in the horizontal.

It is known (DE-AS 19 54 107; DE-AS 19 21 312; DE-AS 11 69 088) and generally used in practice, in the beginning horizontal or the horizontal uncoupling section de: i approach head from bottom to to press up and accordingly the inclined recess by suitable arrangement within the Provide continuous casting mold open at the top. This method of uncoupling requires an arrangement of lifting devices below the strand support (DE-OS 27 48 690) and a space above the Continuous web and a distance between the last roller of the driving straightening machine, so that the continuous caster ultimately has to be built up to a few meters longer.

The present invention has for its object to propose a safe uncoupling that can be carried out in a very small space, with the additional, previously arranged under the strand Decoupling cylinders can be completely omitted and in which there is therefore a loss of length of the continuous casting device does not occur.

The object is achieved according to the invention in that in a position with a downwardly open inclined recess of the cast strand, the approach head printed down and a lower roller is moved away from the approach head at the same time or earlier. Advantageously, the inventive Method only lowering a simple pushing device, e.g. B. of rollers and counter rollers, of which for adjusting the strand thickness a role is at least adjustable to the effective, the tensile force transferring part of the thickness of the approach head. The pair of rollers is advantageously only required separately be controlled hydraulically. The starting head, however, tends due to its articulated attachment to the Link starting line to fall down if there is no support, which is also used here. Uncoupling piston-cylinder drives that were previously arranged under the strand are no longer necessary, with the Space for the often very complex facilities (DE-OS 27 48 690) and thus the length of the continuous casting device is saved.

The further invention is directed to the device for carrying out this method with a transport machine in which the lower rollers are stored on plungers and the upper rollers are at a fixed distance Lower rollers are adjustable. In an embodiment of the invention it is provided that at least the last, on the area of the driving straightening machine following lower roll can be lowered by a little more than the amount that the Claw height corresponds to the coupling formed and that the pressing element of the pressing device at least can be lowered by the same amount.

The inventive method can also with

a drive straightening machine designed in segmental construction. In this case it is provided that a separate pair of driving rollers is provided behind the last roller of the driving straightening machine, the lower roller Can be lowered by 60 mm or more and its upper roller is hydraulically height-adjustable when the lower roller is lowered is.

The basic idea of the method according to the invention can also be used without the rollers of the transport straightening machine realize. In this case it is provided that the starting head has a recess on its upper side has, in which a pivotably mounted lever engages, the length of which is greater in intermediate positions than the distance from the center of the pivot bearing to the run-up slope of the recess.

It is advantageous here that the lever is designed as a two-armed lever, the second lever arm is weight-loaded.

Further advantages result from the fact that the second lever arm is equipped with a retraction device for retraction of the lever is connected to its starting position outside of the pulley.

Embodiments of the invention are shown in the drawing and will be found in more detail below described. It shows

Fig. 1 is a vertical section through a continuous casting mold with encapsulated approach head,

F i g. 2 shows a vertical section through the area of the uncoupling section according to the invention as a first embodiment,

F i g. 3 shows a vertical section through the uncoupling section according to the invention as a second Embodiment,

F i g. 4 shows a vertical section through the uncoupling section according to the invention as a third Embodiment.

The inventive uncoupling of the starting line 1 or, more precisely, that of the starting line hinged starting head 2 sets a certain arrangement of the starting head in the Stranggießkokil-Ie 3 ahead. Before the liquid casting metal 4 is poured off, the approach head 2 is inclined with its Recess 2a to be sealed into the preheated continuous casting mold 3 in such a way that the Recess 2a is open at the top in inclined or horizontal positions (F i g. 2 to 4).

The position of the approach head 2 shown in FIG. 1 therefore starts a movement of the cast strand 5 Direction of movement 6 ahead. In this position, the open counter recess 7 of the cast strand 5 shows below.

After the start-up process (FIG. 1), the claw 2b is cast around with casting metal 4, which solidifies through and through after exiting the continuous casting mold 3.

In the phase according to FIG. 2, the starting line 1 with the starting head 2 is already in the direction of movement 6 behind the transport straightening machine 8 and has therefore reached the uncoupling section 9. The transport straightening machine 8 consists in the exemplary embodiment! according to FIG. 2 each made up of top rollers 8a and bottom rollers Sb. The top rollers 8a are each fastened to hydraulic piston-cylinder drives 10, and the bottom rollers Sb are braced on hydraulic plungers 11. Top rollers 8a and bottom rollers 86 are and remain set to normal height or strand thickness during the uncoupling process of starting strand 1 from cast strand 5 the top roller 8a is arranged on the hydraulic piston-cylinder drive 13. Opposite the separate roller 12 is the counter roller 14, which is attached to the hydraulic plunger 15. The additional roller 16 is already part of the subsequent roller table. The separate roller 12 is lowered by the amount “b” , and the counter roller 14 is lowered by at least the amount “b” or by the greater amount “a”. Then the starting strand 1 can be pulled off between the rollers 12 and 16. Bending or other damage to the cast strand 5 is excluded during this uncoupling process.

The embodiment according to FIG. Differs from the principle described. 3 only through the Structure of the transport straightening machine. The transport straightening machine 17 is created in a segmented design. It is one segment 18 for each of the upper rollers 19 and the lower rollers 20 is present, the segment frame 18a and 186 are adjustable in parallel by means of hydraulic piston-cylinder drives 21 and 22.

The embodiments of FIG. 2 and 3 is the lowering of the hydraulically separately controlled roller 12 or the counter roller 14 by the claw height 23 together.

According to FIG. 4 either the transport straightening machine 8 or 17 is provided. The approach head 2 has a recess 2d on its upper side 2c. The recess 2d is provided with a run-up bevel 2e, in the sense that the lever 24, the pivot bearing 25 of which is fixedly arranged here as a pressing element of the pressing device 12a, is carried along in the direction of movement 6 with an unchangeable lever length, ie is pivoted, this being the Starting head 2 pivoted downward about the joint 26 of the next starting strand link la. During the pivoting movement, the starting head 2 is again moved downward by the claw height 23, and the starting strand can be pulled off via the rollers 16 and 27. The lever 24 has a second lever arm 24a which is weight-loaded. In the exemplary embodiment shown, after the starting line 1 has been withdrawn, the weight force is generated by applying a hydraulic piston-cylinder drive 28. This piston-cylinder drive 28 forms, together with an elongated piston rod 28a and a curved guide 29, which is attached to the second lever arm 24a, a return device 30 for the lever 24. The return device does not affect the uncoupling process because the sliding pin attached to the piston rod 28a 286 can slide freely in the groove 29a of the cam guide 29 during uncoupling. The retraction of the piston rod 28a into the cylinder of the piston-cylinder drive 28 moves the lever 24 out of the path of the cast strand 5.

For this purpose 2 sheets of drawings

Claims (6)

Patent claims: 1. Procedure for uncoupling the starting strand from the cast strand during continuous casting of metal, in particular of steel, in which in the continuous casting mold by casting around a claw with a inclined recess within the starting head of a link starting line the coupling is formed with the cast strand, characterized in that in a position with after open at the bottom, inclined counter recess (7) of the cast strand (5) the approach head (2) downwards printed and a lower roller (14) is moved away from the approach head (2) at the same time or earlier. 2. Device for carrying out the method according to claim 1, with a transport machine in which the bottom rollers are mounted on plungers and the top rollers are adjustable at a fixed distance from the bottom rollers, characterized in that at least the last on the area of a driving straightening machine (8) The following lower roller (14) can be lowered by a little more than the amount (b) , which corresponds to the claw height (23) of the coupling formed and that the pressing element of the pressing device (12a, ) can be lowered by at least the same amount (b). 2s 3. Device for performing the method according to claim 1 with the segment design designed driving straightening machine, characterized in that behind the last roller (19) of the Driving straightening machine (17) a separate pair of driving rollers (12, 14) is provided, the lower roller (14) of which 60 mm or more can be lowered and its upper roller (12) is hydraulic when the lower roller (14) is lowered is height adjustable. 4. Device for carrying out the method according to claim 1 with a transport straightening machine, characterized in that the starting head (2) on its upper side {2c) has a recess (2d) into which a pivotably mounted lever (24) engages, the length of which is in Intermediate positions is greater than the distance from the center of the pivot bearing (25) to the run-up slope (2e) of the recess {2d) 5. Device according to claim 4, characterized in that the lever (24) as a two-armed lever is executed, wherein the second lever arm (24a,) is weight-loaded. 6. Device according to claims 4 and 5, characterized in that the second lever arm (24a,} with a return device (30) for returning the lever (24) to its starting position is connected outside of the strand path.