JPH04231104A - Nonsolidification rolling device - Google Patents

Abstract

PURPOSE:To solve problems due to excessive rolling-down reaction force to the rolls of nonsolidification rolling method that a cast billet is rolled down into taper-shape with rolls which are mounted on an upper frame of a segment which is supported movably in the vertical direction with hydraulic cylinders which are provided on columns. CONSTITUTION:In a device for rolling the continuously cast billet, this device is characterized by supporting rollers elastically on at least the upper frame of the segment with springs of coned disc spring or the like and also providing the hydraulic cylinders of which position control with which the same frame can be pressed down to a prescribed opening degree is executed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unsolidified rolling device for rolling down a thin slab cast by a continuous thin slab casting machine such as a twin belt caster before the inside of the slab is completely solidified.

0002

[Prior Art] A method for rolling down unsolidified slabs using segments of a continuous casting machine involves supporting the upper frame of the segment so that it can move vertically by a hydraulic cylinder installed on a column. A method is known in which a slab is rolled down into a tapered shape by setting an arbitrary tapered roll opening degree.

At this time, the means for setting the roll interval to a predetermined tapered shape include a method using a hydraulic clamp cylinder and a worm jack of a column guide as disclosed in Japanese Utility Model Publication No. 1-49350, or a method as disclosed in Japanese Utility Model Application Publication No. 1-15.
There is known a device disclosed in Japanese Patent No. 647 that uses only a hydraulic cylinder whose position can be controlled. For example, the operating principle of the above-mentioned example is as shown in FIG. A method is known in which the roller is used as a stopper in the vertical direction of the upper frame 10 by setting the roller to a predetermined roll opening position.

On the other hand, in the operation of a continuous thin plate caster for high-speed casting, the casting speed is extremely high at 4 to 10 m/min, which may cause bulging cracks or breaks in the unsolidified thin shell thick slab. In order to prevent casting failures such as casting out, it is necessary to use small diameter guide rolls and to reduce the roll pitch.

Under such conditions, when a means of setting the roll spacing to a predetermined tapered shape using hydraulic means as shown in FIG. 2 is applied to the unsolidified reduction of the slab obtained by high-speed casting, The following problems arise.

That is, as shown in FIG. 3, a slab 8 is rolled by being passed between rolls 4 and 5 located between upper and lower frames 14 and 15 forming segments. At that time, when tapering the upper frame 14, the rolling reaction force of each roll A, B, C after the solidification completion point shown by diagonal lines of the slab 8 exceeds the pressing force by the hydraulic cylinder shown in Fig. 2, making rolling impossible. Or, even if it could barely be rolled, it is a small diameter roll that is disadvantageous in terms of strength, and if the shell thickness of the slab 8 is larger than expected for a predetermined rolling amount,
There are problems such as abnormal reaction force occurring in rolls A, B, and C, which may cause rolling failure or breakage of the rolls.

[0007]

[Problems to be Solved by the Invention] The problem to be solved by the present invention is to support the upper frame of the segment so as to be movable in the vertical direction by a hydraulic cylinder installed on a column, and to support the upper frame of the segment by a hydraulic cylinder installed on a column so as to be movable in the vertical direction. The object of the present invention is to solve the problem caused by excessive rolling reaction force against the rolls in an unsolidified rolling method in which slabs are rolled into a tapered shape.

[0008]

[Means for Solving the Problems] The apparatus for rolling unsolidified slabs of the present invention elastically supports rollers on at least the upper frame of the segment via a spring such as a disc spring, and the upper frame is opened in a predetermined manner. It is characterized by the provision of a hydraulic cylinder whose position can be controlled to perform pressure reduction up to a certain degree.

[0009]

[Operation] When the rolling reaction force of the upper roll increases corresponding to the position of the slab after complete solidification, the roll is protected from overload by the elasticity of the spring. In addition, the spring conforms to the shape of the slab and smoothly returns to its original position, allowing expansion and contraction to always match the shape of the slab.

A hydraulic cylinder whose position can be controlled to roll down the upper roll to a predetermined opening degree rolls down to a predetermined tapered shape in response to a command to start rolling after passing the dummy bar and the bottom piece. Alternatively, when the rolling is performed over a plurality of segments, the rolling is performed so that the rolling taper of each segment is continuous.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the apparatus of the present invention.

In the same figure, in the upper and lower frames 1 and 2 forming segments of the rolling mill, the upper frame 1 is supported by a position-controllable electro-hydraulic stepping cylinder 3 installed on a column 7. The unsolidified portion of the slab 8 is rolled by adjusting the opening between the upper and lower rolls 4 and 5 by rolling down the slab by an arbitrary taper amount h by the stepping cylinder 3 during casting. Upper roll 4
are each attached to the upper frame 1 via disc springs 6.

Further, the lower roll 5 is attached to the lower frame 2. As shown in the figure, when the late-solidified slab 8 is rolled down, the rolling reaction force of the upper roll 4 located between the completely solidified slab position y increases, and at this time, the disc spring 6 is The contraction protects the upper and lower rolls 4 and 5 from overload. In addition, as the slab 8 moves to the right from the state shown in the figure, the roll disc spring 6 smoothly returns to its original position along the surface shape of the slab 8, so it is always suitable for the slab shape. A roll path line can be maintained.

Furthermore, if the shell thickness is unexpectedly large relative to the amount of rolling reduction, the disc spring 6 will contract and the rolls 4,
Abnormal reaction force applied to 5 can be absorbed.

The spring constant of the disc spring 6 at this time is Fo:
Unsolidified rolling reaction force Fc: Roll allowable load n: Set quantity of disc springs per row of rolls k: Spring constant of disc spring Xo: Compression amount of disc spring when presetting h: Upper frame taper amount, lower You can set it like this.

Unsolidified rolling reaction force (Fo)≦Disc spring setting force (nkXo) Disc spring setting force (nkXo)+disc spring compression force (nkh
)≦Roll allowable load (Fc), i.e.

[0017]

[Math 1]

[0018]

[Effects of the Invention] The following effects can be achieved by the present invention.

■ Since the rolls are reliably protected from overloading, small diameter rolls can be used without problems for unsolidified rolling of thin slabs.

■ A roll pass line suitable for the slab shape can be maintained at all times.

■ Even if the shell thickness is larger than expected, the abnormal reaction force applied to the roll can be absorbed.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example device of the present invention.

FIG. 2 is a partially sectional front view showing a structural example of a conventional rolling device used in a continuous casting machine.

FIG. 3 is a diagram for explaining problems with the conventional device.

[Explanation of symbols]

1 Upper frame 2 Lower frame 3 Stepping cylinder 4 Top roll 5 Lower roll 6 Disc spring 7 Column 8 Slab A　Roll after solidification completion point B. Roll after solidification completion point C. Roll after solidification completion point

Claims (1)

[Claims] Claim 1: In an unsolidified rolling device that rolls down a thin slab cast by a continuous thin slab casting machine before the inside of the slab is completely solidified, an upper roll is attached to at least an upper frame of a segment via a spring. An apparatus for rolling unsolidified slabs, which is equipped with a hydraulic cylinder that elastically supports the above frame and is positionally controllable for rolling down the frame to a predetermined opening degree.