KR20080062687A - Apparatus for manufacturing a metal strip - Google Patents

Abstract

An apparatus for manufacturing a metal strip is provided to form a solidified shell having a uniform thickness at an edge of a casting roll by adjusting a thickness of an oxide layer. An apparatus for manufacturing a metal strip comprises a thickness measuring unit(20) for measuring a thickness of an oxide layer formed on a surface of casting rolls(11,12), a defect measuring unit(40) for measuring defects formed in the metal strip, a controller(30) for receiving signals from the thickness measuring unit and the defect measuring unit, a brush assembly, and a driving unit. The driving unit is operated under the control of the controller to drive the brush assembly. The thickness measuring unit includes first and second sensors(21,22) and thickness calculation units(23,24).

Description

Sheet casting apparatus {Apparatus for manufacturing a metal strip}

1 is a side view of a thin sheet casting apparatus including an upper casting roll, a lower casting roll, and a nozzle assembly.

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a perspective view of a thin sheet casting apparatus according to the present invention.

Figure 4 is a block diagram for explaining the control system of the thin sheet casting apparatus according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin plate casting apparatus, and more particularly, to a thin plate casting apparatus capable of controlling the thickness of an oxide layer (oxide film) formed on the surface of an edge portion of a casting roll to eliminate defect factors on the surface of the thin plate.

In order to manufacture a non-ferrous metal (for example, magnesium) and a thin plate of the alloy, a thin casting apparatus for cooling and solidifying a non-ferrous metal molten metal (hereinafter referred to as "melt") is passed between two rotating rolls. I use it.

1 shows a schematic configuration of a twin rolls sheet casting apparatus, in which a sheet casting apparatus is placed up and down and rotated in opposite directions to each other, and a bottom casting roll 2. And a nozzle assembly 3 installed at the inlet of the upper casting roll 1 and the lower casting roll 2 to supply the molten metal.

FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1, and the lower casting roll 2 is not shown in dashed lines for convenience. The melt supplied into the nozzle assembly 3 is dispersed in the nozzle assembly 3 and flows between the upper casting roll (1 in FIG. 1) and the lower casting roll 2. At this time, the refractory dams 4 arranged on both sides of the nozzle assembly 3 limit the dispersion width of the molten metal to prevent the molten metal from protruding outward of the respective casting rolls 1 and 2.

The molten metal flowing in this way is cooled by the upper casting roll 1 and the lower casting roll 2 to start solidification, thereby forming a solidifed shell.

That is, in the thin casting process, an oxide layer (oxide film) is formed on the surfaces of the upper casting roll 1 and the lower casting roll 2 in contact with the hot melt. The molten metal is cooled and solidified in a state in which an oxide film having a constant thickness is formed on the surfaces of the upper casting roll 1 and the lower casting roll 2 to form a solidification angle on the oxide film surface.

This solidification angle grows gradually as the casting rolls 1 and 2 rotate, that is, as time passes, and at which point the solidification angles grown in the upper casting roll 1 and the lower casting roll 2 are kissed. The meeting stops growing.

However, the temperature of the solidification angle continues to fall, and the thickness of the solidification angle decreases in order to pass through the roll nip. This kiss point becomes the solidification completion point and the sheet is released through the roll nip.

On the other hand, in each casting roll 1 and 2, the thickness of the solidification angle appears thinner than the center part in the edge part where cooling capacity is small compared with the center part, and solidification of a molten metal is delayed, and therefore the edge of the casting rolls 1 and 2 is therefore shown. Solidification of the molten metal in the part proceeds incompletely. As a result, the edge part of the thin plate corresponding to the edge part of each casting roll 1 and 2 becomes nonuniform in thickness, and a crack occurs in severe cases.

The cracks at the edges of the thin plates reduce the yield of the thin plates and, in severe cases, produce defects in quality that require stopping the casting process. The thin plate having such a defect cannot be coiled, and the thin plate breaks.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems in the thin casting process, and removes (or reduces the thickness) of the oxide film formed on the surface of the upper casting roll and the lower casting roll edge portion, which acts as a heat transfer barrier, and thereby the upper casting roll. And a thin sheet casting apparatus capable of forming a solidification angle having a uniform thickness at the edge of the lower casting roll.

The inventors found that the cooling and solidification angle formation of the molten metal at the edge of each casting roll are greatly influenced by the oxide film formed on the surface of each casting roll, and thus the solidification angle at the edge portion of each casting roll by controlling the thickness of the oxide film. It was found that the thickness can be kept uniform.

That is, by thinning the thickness of the oxide film formed on the surface of each casting roll and acting as a heat transfer barrier, in particular, the thickness of the oxide film formed at the edge portion, the cooling effect of the molten metal by each casting roll can be maximized, thereby solidifying Enable uniform formation of angles.

The casting device invented by this principle includes a first casting roll and a second casting roll disposed adjacent to each other; A nozzle assembly installed at an inlet of the first casting roll and the second casting roll to supply molten metal; A brush assembly comprising a rotating shaft movably installed at a position corresponding to the casting roll and a brush mounted to the rotating shaft; And drive means including a drive for rotating the axis of rotation of the brush assembly and a cylinder for moving the brush assembly to the casting roll surface.

Here, the casting apparatus according to the present invention is an oxide film thickness measuring unit for measuring the thickness of the oxide film formed on the surface of the casting roll; And a controller for receiving a signal from the oxide film thickness measuring unit and selectively driving the driving unit and the cylinder of the driving unit according to the signal.

In particular, the oxide film thickness measuring unit receives signals from sensors and sensors corresponding to the edge surfaces of the first casting roll and the second casting roll, respectively, calculates the thickness of the oxide film formed on each casting roll surface, and then transfers the calculation result to the controller. Oxide film thickness calculation means.

The brush assembly also includes a first brush assembly corresponding to the first casting roll and a second brush assembly corresponding to the second casting roll, and the driving means are connected to and rotated respectively on the rotation axes of the first and second brush assemblies. First and second cylinders for moving and adhering the first and second drives and the first and second brush assemblies to the upper and lower casting roll surfaces.

In addition, the casting apparatus according to the present invention is a thin film defect measuring means which is installed on the transfer path of the thin plate discharged from the first and second casting rolls to measure defects present on the surface of the thin plate and transmit the signal to the controller. It may include.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

3 is a perspective view of a thin sheet casting apparatus according to the present invention, the thin sheet casting apparatus according to the present invention is arranged up and down and rotated in opposite directions to each other, the upper casting roll 11 and the lower casting roll 12 and the upper casting roll ( 11) and a nozzle assembly 13 installed at an inlet of the lower casting roll 12 to supply molten metal.

The melt supplied into the nozzle assembly 13 is dispersed in the nozzle assembly 13 and passes between the upper casting roll 11 and the lower casting roll 12. Thus, the molten metal discharged from the nozzle assembly 13 is cooled and solidified in the course of passing through the upper casting roll 11 and the lower casting roll 12, and then the upper casting roll 11 and Ejected from the lower casting roll 12.

4 is a block diagram illustrating a control system of a thin sheet casting apparatus according to the present invention. In the thin plate casting apparatus according to the present invention, an oxide film thickness measuring unit for measuring a thickness of an oxide film formed on a surface of a casting roll 11 or 12 is illustrated. (20), the thin film defect measuring means 40 for measuring a defect present in the thin plate S, the control unit 30 receiving a signal from the oxide film thickness measuring unit 20 and the thin plate defect measuring means 40, the brush assembly 50 and drive means 60 operating under the control of the controller 30 to operate the brush assembly 50.

The configuration and function of each component are as follows.

Oxide film  thickness Measuring unit 20

The oxide film thickness measuring unit 20 includes a first sensor 21 installed at a position adjacent to the upper casting roll 11, a second sensor 22 provided at a position adjacent to the lower casting roll 12, and first and second sensors. And oxide film thickness calculation means 23 and 24 connected to 21 and 22, respectively.

The first sensor 21 and the second sensor 22 correspond to the edge portions of the upper casting roll 11 and the lower casting roll 12, and thus, on the surface of the edge portions of the upper and lower casting rolls 11 and 12. Generate a signal for the formed oxide film.

The signals generated in the first sensor 21 and the second sensor 22 are transmitted to the oxide film thickness calculating means 23 and 24, respectively, and the respective oxide castings are calculated based on the transmitted signals in the oxide film thickness calculating means 23 and 24, respectively. The thickness of the oxide film formed on the surface of the edge portions of the rolls 11 and 12 is calculated.

Lamination  Fault measuring means (40)

The thin plate defect measuring means 40 is installed on a position corresponding to the thin plate S discharged from the upper casting roll 11 and the lower casting roll 12, that is, on the transfer path of the thin plate S, Measure for possible defects on the surface. The sheet defect measuring means 40 which performs this function is, for example, a visual sensor.

Control unit 30

The controller 30 connected to the oxide film thickness calculating means 23 and 24 and the thin film defect measuring means 40 of the oxide film thickness measuring part 20 is composed of the oxide film thickness calculating means 23 and 24 and the thin film defect measuring means 40. The operation of the brush assembly, which will be described later, is controlled according to the information on the oxide film thickness and the sheet defects.

That is, when an oxide film having a thickness greater than or equal to a predetermined thickness is formed on the upper casting roll 11 and the lower casting roll 12 edge surfaces, the control unit 30 determines this to operate the brush assembly to operate each casting roll 11 and 12. The oxide film on the surface is removed below a predetermined thickness.

If it is determined through this process that the oxide film formed on the surface of the edge portion of the upper casting roll 11 and the lower casting roll 12 is reduced to less than the set thickness, the controller 30 stops the operation of the brush assembly.

At the same time, defects on the surface of the sheet S through the signal transmitted from the sheet defect measuring means 40 (that is, defects of the flake edge portion formed by an oxide film formed excessively on the surface of the edge portions of the respective casting rolls 11 and 12). ), The controller 30 operates the brush assembly to remove the oxide film on the surface of each casting roll 11 and 12 to a predetermined thickness or less.

In addition, the oxide film formed on the surface of the edge of the upper casting roll 11 and the lower casting roll 12 by the brush assembly 50 is reduced to less than the set thickness, thereby the thin surface by the sheet defect measuring means 40. If not measured in the defect of the control unit 30 stops the operation of the brush assembly 50.

Brush assembly 50

The configuration of the brush assembly 50 will be described with reference to FIG. 3.

Brush assembly 50 includes first and second brush assemblies 51 and 52.

The first and second brush assemblies 51 and 52 are installed at positions adjacent to the upper casting roll 11 and the lower casting roll 12, respectively, and move toward the upper casting roll 11 and the lower casting roll 12. It is possibly installed.

Each brush assembly 51 and 52 is driven respectively with respect to the corresponding casting rolls 11 and 12, and for the sake of convenience only the first brush assembly 51 will be described below.

The first brush assembly 51 includes a rotating shaft 51-3 movably installed toward the casting roll 11 and at least brushes 51-1 and 51-2 fixed to the rotating shaft 51-3. In accordance with such rotation of the brush assembly 51, that is, rotation of the brushes 51-1 and 51-2, the surface of the casting roll 11 is polished by the brushes 51-1 and 51-2 (in FIG. 3). Only one brush 52-1 of the brushes constituting the second brush assembly 52 is shown).

Here, the number of brushes is not limited when the brush corresponds to both edge portions of the casting roll for the purpose of the present invention, namely for polishing the edge portion surface of the casting roll.

In the present invention, the drive means 60 for rotating the first and second brush assemblies 51 and 52, i.e., rotating the rotary shaft 51-3, is the axis of rotation of the first and second brush assemblies 51 and 52. The first casting part 61-1 and the second driving part (61-2 in FIG. 4) and the first and second brush assemblies 51 and 52 which are connected to the 51-3 and rotated, respectively, are top cast rolls 11. ) And a first cylinder 62-1 and a second cylinder (62-2 in FIG. 4) which move and adhere toward the lower casting roll 12.

The first and second driving units 61-1 and 61-2 and the first and second cylinders 62-1 and 62-2 are electrically connected to the control unit 30. The driving of the first and second drive units 61-1 and 61-2 and the first and second cylinders 62-1 and 62-2 is controlled.

 The overall operation of the sheet-casting apparatus according to the present invention configured as described above and the specific function of each constituent means will be described with reference to the drawings.

The molten metal discharged from the nozzle assembly 13 flows between the upper casting roll 11 and the lower casting roll 12, and the molten metal is cooled and solidified while passing through the upper casting roll 11 and the lower casting roll 12. It is discharged in the form of a thin plate of a predetermined width.

During this process, the first sensor 21 and the second sensor 22 disposed adjacent to the upper casting roll 11 and the lower casting roll 12 are the upper casting roll 11 and the lower casting roll. Information (signal) on the surface of (12), particularly, the oxide film formed at the edge portion is transmitted to the oxide film thickness means 23 and 24.

The oxide film thickness calculating means 23 and 24 calculate the thickness of the oxide film formed at the edge portions of the respective casting rolls 11 and 12 based on the signals generated from the first sensor 21 and the second sensor 22, The calculated result is transmitted to the control unit 30.

 If the thickness of the oxide film on the edges of the upper casting roll 11 and the lower casting roll 12 transmitted from the oxide film thickness calculating means 23 and 24 is greater than or equal to the set value, the control unit 30 determines this to determine the driving unit, i. First and second drives 61-1 and 61-2 and first and second cylinders 62-1 and 62-2 connected to the rotary shafts 51-3 of the first and second brush assemblies 51 and 52. ).

Thus, the brushes 51-1, 51-2 of the first and second brush assemblies 51, 52 rotate in contact with the upper casting roll 11 and the lower casting 12 roll edge surfaces. As a result, the oxide film formed on the surface of the edge portions of the upper casting roll 11 and the lower casting roll 12 is removed or its height is reduced.

When the height of the oxide film formed on the surface of the edge portion of the upper casting roll 11 and the lower casting roll 12 is reduced to the set value or less by the above process, the controller 30 controls the first and second driving units 61-1. 61-2) and the first and second cylinders 62-1 and 62-2 are deactivated to move the first and second brush assemblies 51 and 52 to the upper casting roll 11 and the lower casting roll ( In addition to spaced apart in 12) to stop the rotation of the brush (51-1, 51-2).

On the other hand, the thin plate defect measuring means 40 provided on the transfer path of the thin plate (S) to be passed through the upper casting roll 11 and the lower casting roll 12 is a defect that may exist on the surface of the thin plate (S), namely The defects of the flake edge portions formed by the oxide films formed excessively on the edge portions of the respective casting rolls 11 and 12 are measured, and the signal is transmitted to the controller 30.

The controller 30 determines whether there is a thin plate defect on the basis of the signal transmitted from the thin plate defect measuring means 40, and if it determines that the defect exists, the control unit 30 determines the first and second driving units 61-. 1, 61-2 and the first and second cylinders 62-1, 62-2 to operate the above-described process, thereby making the oxide film on the surface of the edge portion of each casting roll 11 and 12 less than a predetermined thickness. Remove

Through this polishing process, the heat transfer barrier film that prevents the heat of the molten metal from being transferred to each of the casting rolls 11 and 12, that is, the oxide film formed on the surface of the edge portion of the upper casting roll 11 and the lower casting roll 12. The thickness will be reduced.

Therefore, the heat of the molten metal is effectively transmitted to the respective casting rolls 11 and 12, in particular, each edge portion where the solidification is delayed due to the low cooling ability, so that the solidification angle of the molten metal is uniformly formed at the edge portions of the respective casting rolls 11 and 12. As a result, edge defects of the thin plate do not occur.

The present invention described above has been disclosed for purposes of illustration, and those skilled in the art having various ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. It should be regarded as belonging to the claims.

According to the present invention, the thin sheet casting apparatus performs a polishing process on each casting roll edge portion, which is a solidification-vulnerable region of the molten metal, thereby removing the oxide film acting as a heat transfer barrier or reducing the thickness of the oxide film. In the solidification angle of uniform thickness can be formed. This makes it possible to produce a thin plate with good quality at the edges.

Claims (5)

Adjacently disposed first casting rolls and second casting rolls; A nozzle assembly installed at an inlet of the first casting roll and the second casting roll to supply molten metal; A brush assembly comprising a rotating shaft movably installed at a position corresponding to the casting roll and a brush mounted to the rotating shaft; And And drive means including a drive for rotating the axis of rotation of the brush assembly and a cylinder for moving the brush assembly to the casting roll surface. The method of claim 1, An oxide film thickness measuring unit for measuring a thickness of the oxide film formed on the surface of the casting roll; And And a controller for receiving a signal from the oxide film thickness measuring unit and selectively driving the driving unit and the cylinder of the driving unit according to the signal. The method of claim 2, wherein the oxide film thickness measuring unit receives signals from sensors and sensors corresponding to the surfaces of the edge portions of the first casting roll and the second casting roll, respectively, and calculates a thickness of the oxide film formed on each casting roll surface. Thin film casting apparatus comprising an oxide film thickness calculation means for transmitting to the control unit. The method of claim 1, The brush assembly comprises a first brush assembly corresponding to the first casting roll and a second brush assembly corresponding to the second casting roll, The drive means includes first and second drives connected to the rotary shafts of the first and second brush assemblies, respectively, and the first and second brush assemblies move and adhere to the upper casting roll and the lower casting roll surfaces, and the first and second brush assemblies are rotated. A thin sheet casting apparatus comprising a second cylinder. The method of claim 1, further comprising a sheet defect measuring means installed on the conveying path of the sheet discharged from the first and second casting rolls to measure the defect present on the surface of the sheet and transmit the signal to the controller. Features of lamination casting device.

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