JP2002316244A - Method for drawing out dummy bar in continuous casting facility for billet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an operating efficiency of a facility by shortening a preparing time for casting, in a continuous casting facility for billet. SOLUTION: In a method for drawing out a dummy bar in the continuous casting facility for billet, provided with the dummy bar set in a mold for pouring molten metal, pinch rolls for drawing out the dummy bar and guide rolls for holding the dummy bar, during casting till cutting off the cast billet from the dummy bar, a gap between the cast billet and the pinch roll, is secured by releasing the pinch rolls. Simultaneously, the dummy bar drawing-out function is changed over into the pinch rolls for holding the dummy bar to draw out the dummy bar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for pulling out a billet using a dummy bar in a continuous billet casting facility.

[0002]

2. Description of the Related Art In continuous casting equipment for billets,
Before the molten steel is poured into the mold, a dummy bar head at the tip of the dummy bar is inserted into the bottom of the mold and plugged in order to hold the molten steel cast in the mold at the start of casting.
Thereafter, the molten steel held in the mold is cooled and solidified, and is bonded to the dummy bar head.

A dummy bar head is disclosed in Japanese Unexamined Patent Publication No.
There is a technique disclosed in Japanese Patent No. 285851. This technology is to connect the dummy bar head to the dummy bar at the start of casting, insert the dummy bar head at the bottom of the mold, solidify and bond the molten metal to the dummy bar head, pull out the dummy bar, and manufacture slabs The structure of the dummy bar head.

[0004] A dummy bar pull-out and storage device is disclosed in Japanese Patent Application Laid-Open No. 9-108792. This technique is an apparatus for moving a dummy bar accommodating apparatus out of the way when extracting a slab that has been broken out during continuous casting, and discloses that a dummy bar is pulled out by a pinch roll. The dummy bar has the same curvature as the standard slab arc trajectory of the continuous casting equipment,
It is housed in a dummy bar housing device arranged behind the pinch roll stand along the reference slab track.

[0005] The cast piece connected to the dummy bar head is guided to a pinch roll by pulling out the dummy bar connected to the dummy bar head with a pinch roll, and then the dummy bar head is separated by a dummy bar separating device, so that the cast piece is transferred to the next process line. The dummy bar is transported, and is stored in the dummy bar storage device.

[0006] When there are a plurality of slab sizes, as the cross-sectional size of the mold changes, the dummy bar head to be inserted into the bottom of the mold is exchanged according to the cross-sectional size of the mold to perform casting. FIG. 9 shows a conventional casting flow accompanying a change in the cross-sectional size of a mold.

[0007]

SUMMARY OF THE INVENTION A dummy bar head is
Each time the mold is changed, a dummy bar head for the size of the mold needs to be installed on the dummy bar. This is to prevent the molten metal injected into the mold from leaking, and at the same time, by making the cross section of the dummy bar head and the cross section of the slab bonded thereto the same size, the step between the slab and the dummy bar head is reduced. Is eliminated, and slipping by the pinch roll for pulling out is prevented.

[0008] The replacement of the dummy bar head is performed in a state where the dummy bar is accommodated by utilizing the casting preparation time when the slab size is changed. It was a constraint on improvement.

[0009]

Means for Solving the Problems In order to solve the above problems, the present invention has the following features. That is, in a method of pulling out a slab and a dummy bar in a billet continuous casting facility having a dummy bar set in a molten metal injection mold, a pinch roll for pulling out the dummy bar, and a pinch roll accommodating the dummy bar. During casting until separating, the drawer pinch roll is opened to secure a gap between the cast piece and the pinch roll, and at the same time, the dummy bar withdrawing function is switched to the dummy bar accommodating pinch roll, and the dummy bar is pulled out. This is a method of pulling out a dummy bar of a continuous casting facility for billets.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall schematic view of a continuous casting facility, FIG. 2 is a view showing a sequence of a pinch roll in the present invention, FIG. 3 is a partial side view of a drawing pinch roll portion, and FIG. It is an image side view at the time. FIG. 5 is a side view of the image when the pinch roll for pulling down the billet, FIG. 6 is a schematic side view of the tip of the dummy bar, FIG. 7 is a front view of FIG. 6, and FIG. It is an image side view.

In FIG. 1, the dummy bar 4 is inserted from the bottom of the mold 2. In the present invention, a dummy bar head having a smaller sectional size than the mold size is used. At this time, the gap between the mold and the dummy bar head is sealed by installing one flat plate corresponding to the sectional size of the mold. When the insertion and sealing of the dummy bar head are completed, the molten metal in the tundish 1 is injected into the mold 2.

The injected molten metal is pulled out by the dummy bar while solidifying. The slab 6 drawn by the dummy bar passes through a drawing pinch roll device 7 composed of a pinch roll 8 and a measuring roll 9 and a separating device 16 composed of a separating roll 14 and a guide roll 15. The slab 6 is stored in the storage device 17 and transported to the next step.

FIG. 2 is a diagram showing a sequence of the pinch roll 7. The dummy bar 4 is pulled out by the pinch roll device 7 and sent to the dummy bar storage device 17. The pinch roll device 7 is roughly composed of a pressing roll 8, a cylinder 10 for pressing down the roll, and a measuring roll 9 for measuring a traveling distance of the dummy bar 4. The travel distance of the dummy bar 4 measured by the measurement roll 9 is input to the control device 11 and compared with a preset travel distance.
And the cylinder 10 is operated to release the pressing roll 8. As the travel distance setting value, the travel distance immediately before the connection between the dummy bar 4 and the slab 6 enters the screw down device 7 is input to the control device 11.

Simultaneously with the release of the pressing roll 8, this signal is sent to the driving device 18 of the dummy bar storage device 17, and the operation of pulling out the dummy bar in the pinch roll device 7 is switched to the driving device 18 of the dummy bar storage device 17, and the driving is performed. The dummy bar 4 is pulled out by the device 18. Then, the distance that the connecting portion between the tip of the dummy bar 4 and the slab 6 passes through the pinch roll device 7 is input to the control device 11 in advance, and is compared with the distance measured by the measurement roll 9 to reach the input distance. Then, the signal is sent to the cylinder 10 and the pressing roll 8
Is closed (moved in the direction of the slab) to reduce the slab.

FIG. 3 is a schematic diagram showing the relationship between the dummy bar 4 and the slab 6 of the pinch roll device 7. The pressing roll 8 of the pinch roll device 7 sandwiches the dummy bar 4, and Shows a state in which is pulled out. In other words, the connection between the tip of the dummy bar 4 and the slab 6 is approaching the entrance of the pinch roll device 7.

FIG. 4 is a view showing a state in which the pressing roll 8 is released. At the same time as the release, the driving device 18 of the dummy bar housing device 17 causes the dummy bar 4 to be pulled out. Then, as shown in FIG. 5, when the connecting portion between the tip of the dummy bar 4 and the slab 6 passes through the pinch roll device 7, the squeezing roll 8 is reduced to clamp the slab.

FIGS. 6 and 7 show the shape of the tip of the dummy bar 4. The tip of the dummy bar 4 is formed with an inverted U-shaped groove 19 whose lower part is opened. This groove 19 has a T-shaped bar 13
Is inserted. The bar 13 is fitted so as to protrude from the tip of the dummy bar 4. On the tip side of the dummy bar 4,
A hole 20 for fixing the bar 13 is provided to penetrate a side portion of the dummy bar 4. A wooden plug 21 for fixing the bar 13 is fitted into the hole 20.

FIG. 8 shows the process of separating the dummy bar 4 and the cast slab 6 from each other by pressing down with a roll 14.
Of the bar 13 by separating the upper surface of the
Is broken, and the slab 6 and the dummy bar 4 are separated.

[0019]

As described above, according to the present invention, the operation of pulling out the dummy bar by the pinch roll device is switched to the driving device of the dummy bar accommodating device at the same time as the pressing down roll of the pulling pinch roll device is released. Even if a step occurs in the slab joint, the slab can be pulled out. According to this method, there is no need to replace the dummy bar head, the casting preparation time can be greatly reduced, and the operation rate of the continuous casting facility can be greatly improved.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a continuous casting facility.

FIG. 2 is a diagram showing a sequence of a pinch roll in the present invention.

FIG. 3 is a partial side view of a pinch roll unit.

FIG. 4 is a side view of an image when a pressing roll is released.

FIG. 5 is a side view of an image when a rolling roll presses down a billet.

FIG. 6 is a schematic side view of a tip portion of a dummy bar.

FIG. 7 is a front view of FIG. 6;

FIG. 8 is an image side view when a slab is separated from a dummy bar.

FIG. 9 is a view showing a conventional casting flow when changing a mold size.

[Explanation of symbols]

 1: Tundish 2: Mold 3: Foot roll 4: Dummy bar 5: Support roll 6: Cast piece 7: Pinch roll device 8: Pinch roll 9: Measurement roll 10: Hydraulic cylinder 11: Control device 12: Control signal 13: Bar 14 : Separation roll 15: guide roll 16: separation device 17: dummy bar storage device 18: drive device 19: insertion hole 20: hole 21: wood stopper

Claims (1)

[Claims] 1. A dummy bar set in a mold for injecting molten metal, a pinch roll for pulling out the dummy bar,
In the method of drawing a dummy bar in a continuous casting facility for billets having a pinch roll accommodating the dummy bar, during casting until the slab is separated from the dummy bar, the drawer pinch roll is opened to release the slab and the pinch roll. A method of pulling out a dummy bar of a billet continuous casting facility, wherein a dummy bar withdrawing function is switched to the dummy bar accommodating pinch roll and a dummy bar is pulled out at the same time as securing a gap.