Device for Accommodating a Continuous Casting Mold on an Elevating Table

Abstract

A device for accommodating a continuous casting mold (1) on an elevating table for casting molten metals, in particular molten steel materials, which is set in an oscillatory motion with several hydraulic oscillation drives, is modified from having two separate elevating table sides so that the elevating table (8) is formed as one-piece frame-shaped table with an inner space (8a) for passing through the cast strand (4) and correspondingly dimensioned, and in that the oscillation drives (3) are arranged in corners (8b) inside a frame surface (8c) and are controlled in a fully synchronized manner with a lateral pairwise offset with regard to an arched, or together, for a perpendicular straight, draw-out movement.

Description

The present invention relates to a device for accommodating a continuous casting mold on an elevating table for casting molten metals, in particular molten steel materials, which is set in an oscillatory motion with several hydraulic oscillation drives during drawing out of a partially solidified cast strand, wherein frequency and amplitude are adapted to a respective cross-section, e.g., of slab, thin strand, bloom, beam blank or billet strand cross-section, and to a respective cast material and/or cast parameter (cast speed), and guide members are connected with stationary articulated means for an optimal oscillation curve of the elevating table.

The above-described device is disclosed in EP 1 029 616 A1. This device serves in particular for casting thin strands from steel. It includes an oscillating continuous casting mold positioned on two elevating tables arranged on opposite sides of the cast strand. The oscillation drive is formed by piston-cylinder units in form of servocylinders supported on a base frame. Each elevating table side is hingedly connected with a head of a piston-cylinder unit. The foots of the piston cylinder units are hingedly connected, respectively, with the base frame. Each elevating table side is guided with respect to the base frame with a hingedly connected guide bar. The axes of the hinges and of hinges at the heads of the piston-cylinder units and the axes of the hinges of the guide bars extend parallel to each other.

Periodic oscillation movements of the continuous casting mold cause friction between the continuous casting mold and the cast strand or its strand shell and which can be prevented with lubricating anti-seizure means. At different speeds between the continuous casting mold and the cast speed, an oscillating excitation of the entire cast strand and/or the bath level in the continuous casting mold take place, in particular at sinusoidal oscillations, which is undesirable. Such oscillation can be damped with oscillation curves that deviate from sinusoidal curves. Such deviating curves advantageously influence also oscillation marks, their depth and shape on the strand surface and improve the surface quality.

A prerequisite for generation and transmission of suitable oscillation curves is the construction and the system of the device itself that accommodates the continuous casting mold. The generation of oscillation (e.g., described in EP 0 121 622 B1) is effected with a function generator which produces oscillations with a preselected oscillation amplitude signal at a frequency that is greater than the natural frequency of the device.

An object of the invention is to provide a combination of an elevating table and a continuous casting mold and which would be capable to provide for transmission of functionally correct oscillations with a high precision.

The stated object is achieved according to the invention by forming the elevating table as a one-piece frame-shaped table with an inner space for passing through the cast strand and correspondingly dimensioned, and in that the oscillation drives are arranged in corners inside a frame surface and are controlled in a fully synchronized manner with a lateral pairwise offset with regard to an arched, or together, for a perpendicular straight, draw-out motion. Thereby an increased stiffness of the device is achieved, so that the influence of the device on the oscillation behavior of the continuous casting mold has changed in such a way that critical frequencies are not reached any more, and the predetermined frequencies and amplitudes are reliably and precisely implemented. The practical experience has shown that a complete synchronization of two or more hydraulic drives can be achieved. An overall low height of the device, e.g., contributes thereto. In addition, another advantage is a possibility of subsequent modernization of the existing devices into new ones.

According to one of the embodiments, the continuous casting mold with its cooling units is directly placed on the frame-shaped elevating table. The frame-shaped elevating table provides therefore a satisfactory bearing surface.

According to a further development, the frame-shaped elevating table is provided with cooling channels connected with a cooling medium network. The advantage consists in a narrow inner space of rings about the cast strand cross-section with a small spacing. At a smaller cooling capacity, the spacing from a hot cast strand is increased. In addition, the cooling capacity is increased to a certain extent as a result of the otherwise available, spray cooling.

A further improvement consists in that the stationary articulation means of the guide members consists of leaf springs in form of an assembly hingedly supported on the elevating table and a stationary base frame.

In the drawing, an embodiment, which will be described in detail below, is shown.

The single drawing FIGURE shows a perspective view of a combination continuous casting mold/elevating table which are supported on a base frame.

A device for accommodating a continuous casting mold 1 with a water box 1a and a narrow side 1b includes, according to the state of the art, two separate elevating tables 2 and 2 for casting molten metals, in particular molten steel materials. The elevating tables 2, 2 are set in an oscillatory motion by several oscillation drives 3 upon drawing out of a partially solidified cast strand 4. The frequency and the amplitude are adapted to a strand cross-section 5 of, e.g., slab strand, thin strand, bloom strand, beam blank strand or billet strand, cross-section 5 and in accordance with a respective cast material. In addition, there are provided guide members 6 which connect the elevating tables 2, 2 with a stationary articulation joint 7 for an optimal oscillation curve.

The present invention modifies the known system by formation of one-piece, frame-shaped elevating table 8. Therefore, the elevating table 8 has an inner space 8a which is kept open for passing of the cast strand 4 and is accordingly dimensioned. The oscillation drives 3 are formed as piston-cylinder units 3a, with those formed as servo-cylinder units 3b being arranged in corners 8b inside the frame surface 8c, and are controlled with a pairwise lateral offset with regard to an arched, or together, for a perpendicular, straight, draw-out movement 9. The synchronization of two or more hydraulic drives was proved to be practical with such a construction and is, therefore, possible. The deviation of several hundredth mm between both elevating table sides can be achieved.

The so-formed elevating table 8 lifts the continuous casting mold 1 with all its cooling units 10 and, therefore, can be easily formed as a frame-shaped elevating table 8.

For protection from the radiating heat of the cast strand 4, the frame-shaped elevating table 8 is provided with cooling channels connected with a cooling medium network.

From many possible embodiments of guide means of the elevating table 8, an advantageous construction was selected according to which the articulated join of the guide members 6 is formed of leaf springs 7a in form of spring assemblies 7b hingedly supported on the elevating table 8 and a stationary base frame 11.

LIST OF REFERENCE NUMERALS

• 1. Continuous Casting Mold
• 1a. Water box
• 1b. Narrow side
• (2, 2. Known elevating tables)
• 3. Oscillation drive
• 3a. Piston-cylinder unit
• 3b. Servo-cylinder unit
• 4. (partially solidified) cast strand
• 5. Strand cross-section
• 6. Guide member
• 7. Stationary articulated joint
• 7a. Leaf spring
• 7b. Assembly
• 8. Frame-shaped one-piece elevating table
• 8a. Inner space
• 8b. Corners
• 8c. Frame surface
• 9. Draw-out movement
• 10. Cooling units
• 11. Base frame

Claims

1. A device for accommodating a continuous casting mold (1) on an elevating table (2) for casting molten metals, in particular molten steel materials, which is set in an oscillatory motion with several hydraulic oscillation drives (3) during drawing out of a partially solidified cast strand (4), wherein frequency and amplitude are adapted to a respective cross-section (5), e.g., of slab, thin strand, bloom, beam blank or billet strand cross-section (5), and to a respective cast material and/or cast parameter such as, e.g., cast speed, guide member (6) are connected with stationary articulated means (7) for an optimal oscillation curve of the elevating table,

characterized in that

the elevating table (8) is formed as one-piece frame-shaped table with an inner space (8a) for passing through the cast strand (4) and correspondingly dimensioned, and in that the oscillation drives (3) are arranged in corners (8b) inside a frame surface (8c) and are controlled in a fully synchronized manner with a lateral pairwise offset with regard to an arched, or together, for a perpendicular straight draw-out movement.

2. A device according to claim 1,

characterized in that

the continuous casting mold (1) with its cooling units (1a) is directly placed on the frame-shaped elevating table (8).

3. A device according to claim 1,

characterized in that

the frame-shaped elevating table (8) is provided with cooling channels connected with a cooling medium network.

4. A device according to claim 1,

characterized in that

the stationary articulation means (7) of the guide members (6) consists of leaf springs (7a) in form of an assembly (7b) hingedly supported on the elevating table (8) and a stationary base frame (11).