JP2005211955A - Method and apparatus for preventing bending of cast slab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for preventing the bending of a cast slab with which the bending of the cast slab at the outlet side of the finish-correcting rolls at a correcting machine last step in a slab continuous caster. <P>SOLUTION: This method comprises a process of measuring the inclination of these rolls and a process of adjusting the pushing press of the roll independently in the width direction of the cast slab so that the inclination of the roll becomes the horizontal direction based on the measured inclination, to an upper roll and a lower roll in the finish-correcting rolls, and the bending is prevented by eliminating the thickness difference in the width direction of the cast slab. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for preventing bending of a slab generated on the slab outlet side in a slab continuous casting machine.

  First, a slab continuous casting machine will be briefly described with reference to FIG.

  First, molten steel is poured into the tundish 1 from an upstream process (not shown). Next, the molten steel 2 is cast from the tundish 1 into the casting machine 3, and the cast molten steel is pulled out by the pinch roll 4 as a continuous slab 8 in the casting machine 3. Then, after making the horizontal direction with the bending roll 5, the bend is corrected with the straightening machine 6, cut with the torch car 15, and carried out to the next process as one slab.

  In addition, although the straightening machine 6 illustrated in FIG. 2 is configured with five straightening rolls H to L, it is not limited to this.

  Several factors can be cited regarding the bending that occurs on the slab exit side (correction machine exit side) in the slab continuous casting machine.

  Typical factors include the deviation of the casting machine 3, the deviation of the parallelism of the pinch roll 4 that pulls out the cast piece, the deviation of the parallelism of the roll of the straightening machine 6, and the like. Any of these results in a difference in thickness in the width direction of the slab, resulting in bending of the transport of the slab, resulting in meandering. It is known that the direction and amount of this bending change variously under various conditions such as casting conditions at that time.

  Conventionally, the occurrence of this bending has been dealt with by the operator visually confirming and manually adjusting the pressure reduction of the straightening machine.

  By the way, in Patent Document 1, as a related technique, the amount of bending of the slab to be conveyed is measured by an image sensor on the slab conveyance line after cutting the slab, and the position is controlled by a centering device provided on the conveyance line. It is disclosed.

Patent Document 2 discloses a straightening roll control method for straightening a slab bent by a continuous casting machine with a straightening roll.
JP 61-222626 JP 62-130759 A

  The present invention makes it possible to automatically correct the bending of such a slab without intervention by an operator.

The present invention has solved the above problems by a method and an apparatus for preventing bending of a cast slab described below.
(1) A method for preventing bending of a slab to prevent bending of a slab on the outlet side of a final straightening roll in a final stage of a straightening machine in a slab continuous casting machine, comprising: On the other hand, with respect to the step of measuring the vertical inclination of the roll and the pressing means for independently pressing the roll, the roll in the slab width direction so that the inclination is horizontal based on the measured inclination. And preventing the bending by keeping the upper roll and the lower roll horizontal when the slab is straightened before the slab passes through the final straightening roll. A method for preventing bending of a slab characterized by the above.
(2) A method for preventing bending of a slab to prevent bending of a slab on the outlet side of a final straightening roll in a final stage of a straightening machine in a slab continuous casting machine, comprising: On the other hand, with respect to the step of measuring the vertical inclination of the roll and the pressing means for independently pressing the roll, the roll in the slab width direction so that the inclination is horizontal based on the measured inclination. And the step of preventing the bending by leveling the upper roll and the lower roll that straighten the slab while the slab passes through the final straightening roll. A method for preventing slab bending.
(3) A slab bend prevention device for preventing bending of the slab at the final straightening roll outlet side of the final stage of the straightening machine in the slab continuous casting machine, in the upper roll and lower roll of the final straightening roll,
An inclinometer that measures the inclination of the roll, a pressing means that independently reduces the pressing pressure of the roll in the slab width direction, and the pressing means, the inclination of the roll based on the inclination measured by the inclinometer A slab bend prevention device characterized by comprising a bend control device that is adjusted so as to be horizontal, and preventing the bend by eliminating the thickness difference in the width direction of the slab.

  According to the present invention, the bending of the slab can be eliminated without imposing any load on the operator, the operator's man-hours can be reduced, and the load on the operator can be greatly reduced.

  A preferred configuration example of the slab bend prevention device of the present invention will be described with reference to FIG.

  The slab bend prevention method and apparatus of the present invention are applied to the final straightening roll in the final stage of the straightening machine in the slab continuous casting machine. That is, the slab continuous casting machine illustrated in FIG. 1 is applied to the K roll 6a and the L roll 6b, which are the straightening rolls in the final stage of the straightening machine 6.

  First, in the first method of preventing bending of a slab according to the present invention, the vertical inclination of each of the upper roll (K roll 6a) and the lower roll (L roll 6b) of the final straightening roll is measured. In addition, based on the measured inclination against the pressing means 9 that presses these rolls independently, the offset is adjusted independently in the slab width direction so that the inclination is horizontal, Before the slab passes through the final straightening roll, the upper roll and the lower roll at the time of straightening the slab are previously leveled to prevent bending.

  By applying this first slab bend prevention method, it was possible to completely eliminate the bend caused by the straightening machine factor.

  However, when a thickness difference in the width direction of the slab occurs due to other factors upstream from the straightening machine, the straightening machine that only applies light reduction for straightening cannot completely remove the thickness difference. Bending will occur on the exit side of the straightening machine.

  Therefore, in the second method of preventing bending of the slab according to the present invention, the step of measuring the inclination of the roll with the inclinometer 7 with respect to the upper roll (K roll 6a) and the lower roll (L roll 6b) of the final straightening roll. And a step of independently adjusting the pressing pressure of the roll in the width direction of the slab so that the inclination is horizontal based on the measured inclination, and the slab passes through the final straightening roll. The bending is prevented by eliminating the thickness difference in the width direction of the slab.

  Here, this second slab bending prevention method is always applied in real time during casting of the slab. In this way, it is possible to respond quickly and effectively to bends that do not know when they occur.

  And in the slab bend prevention apparatus to which this second slab bend prevention method is applied, as shown in FIG. 1, the upper roll (K roll 6a) of the final straightening roll formed by sandwiching the slab 8 is used. An inclinometer 7 for measuring the inclination of the lower roll (L roll 6b) is provided. From the inclinometer 7, the inclinations of the rolls 6 a and 6 b are output to the bending control device 10. In FIG. 1, the bending control device 10 is described as an independent device that controls the inclination of each of the K roll 6a and the L roll 6b, but the upper and lower K rolls 6a and L rolls 6b are controlled by one control device. Needless to say, it may be controlled.

  The bending control device 10 outputs control signals for the pressing means 9 installed at both ends of the upper and lower K rolls 6a and L rolls 6b, and controls the rolls 6a and 6b to be horizontal. Here, in the present invention, the horizontal direction is defined as a direction orthogonal to the direction of gravity of the earth.

  In FIG. 1, a pressure cylinder is illustrated as the pressing means 9 that presses the correction roll. However, the pressing means may be reduced by, for example, an electric motor, and the pressing means is not particularly limited. Further, in order to simplify the explanation of the present invention, in FIG. 1, the description of the original reduction control performed for correcting the slab is omitted.

  Conventionally, an operator monitors the bending of the slab on the exit side of the straightening machine and adjusts the reduction of the final straightening roll of the straightening machine.

  Therefore, conventionally, if the operator does not make corrections, a bend occurs on the final straightening roll exit side of the straightening machine, so a bend of about 70 mm may occur in the vicinity of the torch car 15 meters downstream. Implementation was necessary. Further, for this care, the operator has to constantly monitor the slab bending that occurs suddenly on the correction machine delivery side.

  Therefore, the slab bend prevention device of the present invention was installed in a slab continuous caster, and the control of the present invention was performed to automatically correct the slab bend.

  As a result, there was no bending of the slab, and the operator's monitor could be dispensed with.

It is a schematic diagram which shows the structural example of the bending prevention apparatus of the slab of this invention. 1 is an overall schematic view of a slab continuous casting machine to which the present invention is applied.

Explanation of symbols

1 Tundish 2 Molten Steel 3 Casting Machine 4 Pinch Roll 5 Bending Roll 6 Straightening Machine
6a, 6b Straightening roll 7 Inclinometer 8 Slab 9 Pressing means (pressure cylinder)
10 Bending control device
15 Torch Car

Claims (3)

A method for preventing bending of a slab that prevents bending of the slab at the final straightening roll exit side of the final stage of a straightening machine in a slab continuous casting machine,
For each of the upper roll and lower roll of the final straightening roll,
Measuring the vertical tilt of the roll;
A step of independently adjusting the roll in the width direction of the slab so that the inclination is horizontal based on the measured inclination with respect to the pressing means for independently pressing the roll. Before passing through the final straightening roll,
A method for preventing bending of a slab, wherein the upper roll and the lower roll when the slab is straightened are previously leveled to prevent bending. A method for preventing bending of a slab that prevents bending of the slab at the final straightening roll exit side of the final stage of a straightening machine in a slab continuous casting machine,
For each of the upper roll and lower roll of the final straightening roll,
Measuring the vertical tilt of the roll;
A step of independently adjusting the roll in the width direction of the slab so that the inclination is horizontal based on the measured inclination with respect to the pressing means for independently pressing the roll. While passing through the final straightening roll,
A method for preventing bending of a slab, wherein the upper roll and the lower roll for correcting the slab are made horizontal to prevent bending. A slab bending prevention device for preventing bending of a slab at the final straightening roll exit side of the final stage of a straightening machine in a slab continuous casting machine,
In the upper roll and lower roll of the final straightening roll,
An inclinometer to measure the tilt of the roll;
Pressing means for independently reducing the pressing pressure of the roll in the slab width direction;
The pressing means comprises a bending control device that is adjusted based on the inclination measured by the inclinometer so that the inclination of the roll is horizontal,
An apparatus for preventing bending of a slab, wherein bending is prevented by eliminating a thickness difference in the width direction of the slab.

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