JPH11207444A - Apparatus for casting metallic strip and method for cleaning casting peripheral surface of casting roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the development of an oxide pattern on the surface of a roll and then, to prevent the development of surface defect of a strip without developing the weakening line in the longitudinal direction of the strip surface by uniformly distributing cleaning element over the whole width of the roll so as to hold the brushing effect, at the time of cleaning the peripheral surface of the casting roll. SOLUTION: Related to a metallic strip casting apparatus, a roll cleaning device 21 for cleaning the peripheral surface 10 of the casting roll is constituted of a cleaning element fitting structure 22 adjacently arranged to the casting roll 12, cleaning element 20 fitted so as to provide a slender cleaning head 25 extended over the width direction of the roll and deviated to the peripheral surface 10 of the roll and driving means 42, 50 for linearly driving the cleaning element 20 over the width direction of the roll. Then, the cleaning element 20 is formed as endless or continuous cleaning head 25 to the roll 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal strip casting apparatus and a method for cleaning a peripheral surface of a casting roll.

[0002]

2. Description of the Related Art As a casting apparatus, there is a single roll casting apparatus or a twin roll casting apparatus. For twin roll casting equipment,
By directing the hot metal between a pair of horizontal casting rolls that are cooled and rotated in opposite directions, the metal shells are solidified on the surface of the moving casting roll, and the metal shells are joined at the roll gap to form a roll gap. Remove from the outlet as a solidified metal strip product. In the present specification, "roll gap"
The term shall generally refer to the area where the rolls are closest to each other. Molten metal is poured from a ladle into one or more small containers, and then flows to a metal supply nozzle located above the roll gap, where it is directed to the roll gap and supported on the roll casting surface just above the roll gap. A molten metal casting pool can be formed.

[0003] In order to prevent contaminants such as metal oxides and slag from accumulating on the surface of the casting roll, a roll such as a brush or a cleaning belt is used before the casting roll rotates to reach the roll gap and comes into contact with the molten metal. The cleaning device can be applied to the outer surface in the longitudinal direction of the roll to continuously clean the casting roll surface. An apparatus of this type is disclosed in JP-A-3-230849 of Nippon Steel Corporation and Mitsubishi Heavy Industries, Ltd. In this apparatus, two sets of divided roll brushes are alternately applied to the peripheral surface of each cooling casting roll. Provides brushing action over the entire width of the roll. Also, Japanese Patent Application Laid-Open No. 1-83341 (1992) of Nippon Steel Corporation and Mitsubishi Heavy Industries, Ltd.
Published on March 29, 1997) and JP-A-2-99243 (19)
(Published on April 11, 1990), JP-A-3-118944 (published on May 21, 1991), JP-A-3-11894
No. 6 (published May 21, 1991) discloses a twin roll casting apparatus in which the casting roll is cleaned by a roll brush which extends over the entire width of the casting roll and rotates around each longitudinal axis in a direction opposite to the rotation of each roll. doing.

No. 4,793,400 to Battelle Development Corporation and US Pat. No. 4,727 to Allied Corporation.
08,194 discloses a brush device of the above type applied to a single roll casting device.

Also, Japanese Patent Application Laid-Open Nos. 1-133649 (published on Aug. 2, 1989) and Japanese Patent Application Laid-Open No. 1-192450 (May 2, 1989) by Nippon Steel Corporation and Mitsubishi Heavy Industries, Ltd.
(Published on the 5th) each proposes to use an endless belt instead of a cylindrical roller brush of the type described above, which is driven in a direction opposite to the rotation direction of each roll of the twin roll casting apparatus.

Japanese Patent Application Laid-Open No. 63-1766 by Kawasaki Steel Corporation
No. 50 (published Aug. 3, 1987) describes single and twin roll casting machines having both endless belts and cylindrical roller brushes that are also driven or rotated in the opposite direction of rotation of each casting roll. Both are disclosed.

[0007]

However, cleaning devices of the type described above have an uneven pattern of oxides on the roll surface due to uneven contact along the entire width of the roll, which leads to surface defects in the strip, especially Longitudinal cracking can result in strip longitudinal slits as the strip exits the casting roll in extreme cases. The uneven wear of the brush across the width of the casting roll causes local formation or local reduction of oxides at specific locations across the width of the casting roll, which is caused by relative movement between the roll surface and the brush tip, resulting in a strip. This can result in a longitudinal line of weakening of the surface. The points of contact between the unevenly worn brush tip and the roll surface create an oxide pattern, thereby having a different thickness and, therefore, different heat transfer characteristics than the surrounding roll surface. This results in longitudinally spaced surface defects in the strip being produced, which leads to the aforementioned weakening lines.

Japanese Patent Application Laid-Open No. 3-66451 (published on March 22, 1991) of Nippon Steel Corporation and Mitsubishi Heavy Industries, Ltd. discloses a twin roll casting apparatus having a pair of cleaning devices. The cleaning device is an elongated brush that extends across the entire width of each roll and oscillates along the longitudinal axis to provide a different brushing action than the prior art. However, vibrating brushes can create a pattern of oxide on the roll surface due to vibratory motion and can be a surface defect. In particular, oxide formation can generally occur at the end of each oscillating stroke, ie, each time the brush stroke stops and changes direction. This resting action creates a band on the roll surface with a different surface oxide pattern than the surrounding surface,
A longitudinal line of weakness may be provided in the strip.

The casting roll may be deformed due to thermal expansion and contraction in the casting process, which may cause a problem that sufficient contact between the cleaning roll brush or belt and the cooling casting roll cannot be maintained. In other words, since the casting roll, which was initially cylindrical, has a concave surface, convex surface, or middle-high shape, and is no longer cylindrical, the roll cleaning device can be applied with uniform pressure along the entire length of the casting roll. In an extreme case, it may not even come into contact with a part of the surface of the casting roll, and the cleaning action may be impaired. Applicants' US Patent No. 5,307,861
No. 5,575,327 discloses a roll cleaning brush system which addresses these problems by spring-pressing each of a plurality of brush head portions individually onto the roll surface to be cleaned. However, even with this type of brush system, it has not been found that the entire roll surface can be brushed completely evenly and uneven brushing still causes surface defects. In particular, the rotating pattern of the rotating brush creates an oxide pattern on the roll surface, which can be a surface defect. Maintaining a uniform reaching and brushing effect over the entire width of the roll has proven very important.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in consideration of the above circumstances. In cleaning the peripheral surface of a casting roll, the cleaning element can be uniformly reached over the entire width of the roll and the brushing effect can be maintained. The purpose is to prevent the formation of oxide patterns on the surface, thereby preventing the occurrence of surface defects of the strip and the introduction of longitudinal weakening lines on the strip surface.

[0011]

According to the present invention, there are provided a casting roll, metal supply means for supplying molten metal to the peripheral surface of the casting roll, and a roll cleaning device for cleaning the peripheral surface of the casting roll. A roll cleaning device mounted to provide a cleaning element mounting structure disposed adjacent to the casting roll and an elongated cleaning head extending across the roll width and biased toward the roll periphery. A metal strip casting apparatus, comprising: a cleaning element provided with a cleaning element; and a driving means for driving the cleaning element linearly across the width of the roll, wherein the cleaning element exhibits an endless or continuous cleaning head with respect to the roll. You.

[0012] Preferably, the cleaning element comprises a continuous cleaning brush.

More preferably, the cleaning element comprises a series of brush heads mounted to form an elongated brush row.

Preferably, the deviation of each brush head at a position where the brush head engages the roll peripheral surface is substantially perpendicular to the roll peripheral surface.

[0015] Preferably, the brush heads are each elongated. Each brush head has an elongated brush head base,
Brush bristles extending longitudinally from the base.

The brush head can be fixed to the base element in the form of a web creating a cleaning element.

[0017] The apparatus may further comprise a second roll cleaning device, the second roll cleaning device extending along a roll width direction with a second cleaning element mounting structure disposed adjacent to the casting roll; Consisting of a second cleaning element mounted to provide an elongated cleaning head biased to the roll circumference, and second drive means for driving the second cleaning element linearly across the roll width. The second cleaning element then presents an endless or continuous cleaning head to the roll.

Preferably, the two cleaning elements are pulled in opposite directions.

The present invention also provides a pair of parallel casting rolls each having a roll peripheral surface and forming a roll gap therebetween, supplying molten metal to the roll gap between the casting rolls, and supplying molten metal to the roll gap. A metal supply means for forming a casting pool, and a pair of roll cleaning devices for cleaning the roll peripheral surface arranged to engage with the casting roll at a position spaced apart from the roll gap in the roll peripheral direction, each roll comprising: A cleaning element disposed adjacent to the roll circumference and comprising a cleaning element mounting structure that extends across the width of each roll and mounts the cleaning element at a location that provides an elongated cleaning head that engages with the roll circumference.
The drive means is operable to drive the cleaning element linearly across the roll width, said cleaning element presenting an endless or continuous cleaning head for each roll.

The present invention also drives the casting roll about a longitudinal axis, provides a cleaning element mounting structure adjacent the casting roll, and is mounted to provide an elongated cleaning head extending across the width of the casting roll. A roll cleaning device composed of a cleaning element is applied to the roll peripheral surface, the roll cleaning device is biased toward the roll peripheral surface, and an endless continuous cleaning head is provided across the roll width direction so as to present the cleaning head to the roll. The present invention extends to a method for cleaning a casting peripheral surface of a casting roll, which is constituted by various steps of linearly driving a cleaning element.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

The twin-roll casting apparatus shown in FIGS. 1 to 4 comprises a main frame 11 supporting a pair of parallel casting rolls 12. In the casting operation, molten metal flows from the tundish 13 to the refractory ladle exit shroud 14.
To the distributor 15 and further via the metal feed nozzle 16 to the roll gap 17 between the casting rolls 12. The hot metal thus supplied to the roll gap 17 forms a casting reservoir 30 that contacts the roll peripheral surface 10 above the roll gap 17. The casting pool 30 is divided by the ends of the casting rolls 12 into a pair of side closing plates 1.
The side closing plate 18 is held in contact with the stepped end of the casting roll 12 by the operation of a fluid pressure cylinder unit (not shown). The upper surface of the casting reservoir 30, commonly called the meniscus level, may be above the lower end of the metal supply nozzle 16, in which case the lower end of the metal supply nozzle 16 is immersed in the casting reservoir 30.

Since the casting roll 12 is water-cooled, the metal shell is solidified on the surface of the rotating casting roll 12, joined together at the roll gap 17 and taken out from the roll outlet as a solidified strip product 19. This product 19
Can be fed to a reference coiler (not shown) for winding.

The twin roll casting apparatus described above is disclosed in the applicant's Australian Patent No. 6331728 (19).
Australian Patent Application Publication No. 728971/91 published October 10, 1991) and US Patent No. 5,184,668 issued by the present applicant (issued February 9, 1993).
Reference may be made to these patents for appropriate structural details which do not form part of the present invention.

In the present invention, a pair of roll cleaning devices 21 are provided in the illustrated twin roll casting device,
Are arranged so as to engage with the outer surfaces on the side opposite to the roll gap 17 on the opposite side.

Each of the roll cleaning devices 21 includes a casting roll 12
And a cleaning element 20 mounted on the cleaning element mounting structure 22 to move linearly across the width of the casting roll 12 so as to present a continuous or endless cleaning head with respect to the casting roll 12. It consists of. The cleaning element mounting structure 22 includes the main frame 11.
Since it is connected to the fluid pressure actuator 41 mounted on the casting roll 12, it is possible to approach / retreat from the casting roll 12 and to maintain contact with the casting roll 12. The cleaning element 20 is in the form of a metal web 28 having front and rear surfaces and has a plurality of cleaning heads 25 mounted in a straight line on the front surface.
The yoke 40 of each cleaning element mounting structure 22 is
The elongated cleaning element track 24 that receives and guides it is held.

Each cleaning head 25 can be in the form of a plurality of elongated brush heads. Each brush head comprises an elongated brush head base 26 and a set of brush bristles 27 extending from the brush head base 26 along its length. The brush bristles 27 can be hard wire bristles and can be made of, for example, steel wire. The brush head base 26 may be a rectangular block made of a suitable material such as wood, ceramic, or metal. A rectangular block is a rectangle with each side of 30 mm.
The metal web 28 can be arranged from end to end. The brush head base 26 can be fastened to the metal web 28 by a suitable fastening means such as a fastening screw or a rivet. The length of the track 24 can typically be about 840 mm.

The brush bristles 27 can be grouped in bushes or tufts into spaced parallel rows 32, each of which can be staggered with respect to adjacent bushes or tufts.
The brush bristles 27 of successive longitudinal tufts 32 can be alternately coarse and dense. For example, every other column 32
Is made of a steel wire having a diameter of 0.15 mm, the inter-row 32 is made of a steel wire having a diameter of 0.25 mm, and the bushes or tufts of all the rows 32 have a base diameter of about 3.0 mm, and are about 3. 0
To 3.5 mm. Brush bristles 27
Can protrude from the brush head base 26 by about 30 mm, and can be set to be embedded in the brush head base 26 by about 15 mm.

The track 24 of each cleaning device is comprised of a metal strip having a generally C-shaped cross section, forming a longitudinally extending open groove. The open groove has an inwardly bent end flange 29,
They capture and hold the brush head base 26 in the opening groove and as a stop against the brush head base 26 being displaced by the roller element 31 extending along the opening groove base between the brush head base 26 and the holder. Working to facilitate movement of the cleaning element 20 along the opening groove.

Since the cleaning element 20 is supported by the track 24 of the cleaning element mounting structure 22 and the rollers 42 and 43, each cleaning element 20 is supported by an endless loop having three sides, and one of the three sides is provided by each track 24. Extend. Rollers 42, 4
3 can be mounted so as to move with the cleaning element mounting structure 22 under the influence of the hydraulic actuator 41 or can be pivotable in a mounting fixed to the main frame 11. Roller 42 is provided with sprocket teeth 50 which engage with longitudinally spaced openings 51 (see FIG. 4) of metal web 28 to provide sprocket drive so that cleaning element 20 can be connected to each endless loop or transition path. Can be driven around. The roller 42 can be driven by appropriate driving means such as a fluid pressure motor. The cleaning head 25 has a brush tip engaged with the casting roll 12 and is all biased or loaded against each casting roll 12 at a substantially constant load pressure determined by the pressure of the fluid pressure actuator. Are supported by the cleaning element mounting structure 22 in a position that can accommodate roll profile variations that can occur due to thermal expansion and contraction during metal casting operations while maintaining a substantially constant load on all brush elements.

The longitudinal movement of the brush enhances the cleaning action and ensures that the bristles 27 contact the casting rolls 12 over their full width. Mixing the coarse and dense bristles 27 also enhances the cleaning action. Coarse bristles can exert a strong removal force on exposed contaminants, while dense bristles can enter small depressions and holes on the roll surface where fine contaminants are deposited.

The rollers 42, 43 can also sharply change the direction of movement of the cleaning element 20 along the transition path, which helps to remove contaminants between the bristles 27.

The cleaning head 25 is mounted by the mounting structure 22 so that the bristles 27 of each cleaning head 25 move in a direction substantially perpendicular to the roll surface.

In the illustrated brush system, one cleaning device 21 is provided for each casting roll 12. As these two cleaning devices 21, 21 are drawn together and in opposite directions, the two brush rows 32 are drawn out of phase with each other to provide a complete dynamic balance of the movement of the cleaning elements 20 of the system. To achieve. In another embodiment, two cleaning devices can be mounted on each casting roll to provide two successive rows of brushes carried on separate fixtures, wherein the cleaning elements are independent of each other and in opposite directions. Be moved.

The relative movement of the casting roll 12 about its longitudinal axis and the linear movement of the cleaning element 20 along a horizontal transition path extending substantially parallel to the axis combine to provide a cleaning head 25 and a roll surface. Can be established along a line oblique to the roll axis extending from one end of the casting roll 12 to the other. A brush that oscillates in the longitudinal direction creates a zigzag contact line around the casting roll 12 in a substantially circumferential band, and a cylindrical roller brush that rotates around the longitudinal axis in a direction opposite to the roll rotation direction.
Creating a line of contact along the same trajectory as each rotation of the roll 12 surrounding the roll 2 causes small cracks in the strip and, in extreme cases, may even initiate severe longitudinal mechanical cracking of the strip. It has been found that the present invention promotes a uniform distribution of the oxide on the roll surface.

The present invention provides a strip casting roll 1 which is much more effective than previously possible with known cleaning devices.
2. An apparatus that enables cleaning. The continuous action of the cleaning head 25 over the roll surface not only improves the roll cleaning but also contributes to the self-cleaning of the cleaning head 25 driven in a closed loop. Self-cleaning requires that the cleaning head 25 bend about a transverse axis that is shifted rearward of the cleaning head 25 when following a closed loop transition. The combination of bending and linear movement of the cleaning head 25 allows the oxide flakes to be thrown out of the cleaning head 25 without being caught by the casting roll 12 or clogged by the brush bristles 27.

This particular embodiment has been described by way of example and may be variously modified. For example, the cleaning device
A plurality of cleaning heads may be attached to link means arranged in an endless connected steel belt row or a caterpillar belt row supported on a caterpillar link track.

Thus, the present invention is in no way limited to a particular application and to the structural details of the illustrated configuration, and many modifications and variations will be apparent to those skilled in the art.

In addition to the foregoing summary of the invention, the term "comprising" is used to mean "including" unless the context requires otherwise. That is, the specified features can be combined with further features in various embodiments of the present invention.

[0040]

As described above, according to the metal strip casting apparatus and the method of cleaning the casting peripheral surface of the casting roll of the present invention, when cleaning the peripheral surface of the casting roll, the cleaning element is uniformly distributed over the entire width of the roll. Since the reaching and brushing effects can be maintained, the occurrence of oxide patterns on the roll surface can be prevented, whereby the occurrence of surface defects of the strip can be prevented and the longitudinal weakening lines can be formed on the strip surface. Can be prevented from being brought about.

[Brief description of the drawings]

FIG. 1 shows a twin roll casting apparatus incorporating the components of a pair of cleaning devices according to the present invention.

FIG. 2 is a view of one of the cleaning devices, as viewed generally in II-II of FIG. 1;

FIG. 3 is a partially enlarged perspective view of a brush head and a mounting structure incorporated in the cleaning device shown in FIGS. 1 and 2;

FIG. 4 is a perspective view showing a part of a cleaning element incorporated in the apparatus.

[Explanation of symbols]

 Reference Signs List 10 roll peripheral surface 12 casting roll 15 distributor (metal supply means) 16 metal supply nozzle (metal supply means) 20 cleaning element 21 roll cleaning device 22 cleaning element mounting structure 25 cleaning head 26 brush head base 27 brush bristles 28 metal web 42 Roller (drive means) 50 Sprocket teeth (drive means) 51 Opening (drive means)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Heiji Kato 2-36-2 Nobi, Yokosuka City, Kanagawa Prefecture (72) Inventor Hisahiko Fukase Australia New South Wales Wollongong Smith Street 39 Belmore Apartments (72) Inventor Nicolco S. Nikolavsky Australia 2525 New South Wales Figry Edmund Avenue 2

Claims (11)

[Claims] A casting roll (12) and a casting roll (1).
Metal strip casting comprising metal supply means (15) (16) for supplying molten metal to the peripheral surface (10) of (2), and a roll cleaning device (21) for cleaning the peripheral surface (10) of the casting roll. In the apparatus, the roll cleaning device (21) includes:
A cleaning element mounting structure (22) disposed adjacent to the casting roll (12) and mounted to provide an elongated cleaning head (25) extending across the roll width and biased to the roll circumference (10). Cleaning element (20), and driving means (42) (50) (51) for driving the cleaning element (20) linearly in the roll width direction. A) metal strip casting apparatus characterized by exhibiting an endless or continuous cleaning head (25). 2. The apparatus according to claim 1, wherein the cleaning element comprises a continuous cleaning brush. 3. The metal strip casting apparatus according to claim 1, wherein the cleaning element comprises a series of brush heads mounted to form an elongated row of brushes. 4. When the brush head is engaged with the roll peripheral surface (10), the deviation of each brush head is controlled by the roll peripheral surface (1).
4. The metal strip casting apparatus according to claim 3, which is substantially perpendicular to 0). 5. The metal strip casting apparatus according to claim 3, wherein the brush heads are each elongated. 6. An apparatus according to claim 5, wherein each brush head comprises an elongated brush head base (26) and brush bristles (27) extending longitudinally from the base (26). 7. The metal strip casting apparatus according to claim 3, wherein the brush head is fixed to the base element in the form of a web producing a cleaning element. 8. A roll cleaning device (21) comprising: a second cleaning element mounting structure (22) disposed adjacent to a casting roll (12); A second cleaning element (20) mounted to provide an elongated cleaning head (25) biased toward the second cleaning element (20).
And second driving means for driving the second cleaning element (20) linearly in the roll width direction, wherein the second cleaning element (20) is endless or continuous with respect to the roll (12). The metal strip casting apparatus according to any of the preceding claims, which presents a typical cleaning head (25). 9. The metal strip casting apparatus according to claim 8, wherein the two cleaning elements are pulled in opposite directions. 10. A pair of parallel casting rolls (1) each having a roll peripheral surface (10) and forming a roll gap therebetween.
2) and metal supply means (15) and (16) for supplying molten metal to the gap between the casting rolls (12) to form a casting pool (30) for molten metal in the gap between the rolls. In the apparatus, the roll peripheral surface (1)
A pair of roll cleaning devices (21) for cleaning the casting roll (12) is disposed at a position separated from the roll gap in the direction of the roll peripheral surface (10), and the roll cleaning devices (21) are cleaned. A cleaning element mounting structure (22) disposed adjacent the roll periphery (10) and an elongated cleaning head (25) extending across the roll width and biased toward the roll periphery (10). Cleaning element (2
0) and the cleaning element (2) linearly across the roll width direction.
0) driving means (42), (50) and (51), wherein the cleaning element (20) presents an endless or continuous cleaning head (25) for each roll. Metal strip casting equipment. 11. A casting roll (1) about a longitudinal axis.
2) to drive the cleaning element mounting structure (2) adjacent to the casting roll (12).
2) and a roll cleaning device (21) comprising a cleaning element (20) mounted to provide an elongated cleaning head (25) extending across the width of the casting roll (12). ), And the roll cleaning device (21) is placed on the roll peripheral surface (10).
And the endless continuous cleaning head (25) is rolled (1).
2) A method of cleaning a casting peripheral surface of a casting roll, wherein the cleaning element (20) is driven linearly across the roll width direction so as to exhibit the above.