JPH10156503A - Method for receiving cut cast slab of vertical type continuously cast slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakage of a cast slab holder caused by the dropping load of the cast slab at the time of cutting off and to obtain a receiving method for the cut cast slab avoiding the danger caused by the dropping of the cast slab by applying a torque control pushing the cast slab holder to the tip part of the cast slab with lower rising force than the drop-shifting load of the cast slab during cutting off. SOLUTION: The cast slab 1 after casting is cut off while following to the dropping speed. The cast slab holder 4 pushes to the tip part of the cast slab 1 with the lower rising force than the drop-shifting load of the cast slab. Current value of a motor 8 for driving the cast slab holder is introduced from an ammeter 10 to a controller 9 for driving the cast slab holder and the torque control with the current value is applied so that the cast slab holder 4 pushes to the tip part of the cast slab 1 with the lower rising force than the dropping load of the cast slab 1 to push down the cast slab holder 4 with the drop shifting of the cast slab 1, Further, at the same time, it is always grasped whether the cast slab holder is pushed down or not. When the current value is low and the cast slab holder is not pushed with the low rising force, a winch 7 is driven and the cast slab holder 4 is pushed to the tip part of the cast slab 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving a cut slab of a vertical continuous cast slab.

[0002]

2. Description of the Related Art In a vertical continuous casting apparatus, it is possible to lower the slab according to the moving speed of the slab while bringing the tip of the slab into contact with the slab holder, and receive the cut slab in the slab holder. Are known. Also, while the slab holder is in contact with the tip of the slab, the slab holder is moved down to avoid falling collision with the slab holder when cutting the slab, and to prevent damage to the slab holder. Before cutting with a torch, the lower part of the slab is supported and moves in synchronization with the slab.After cutting the slab, the output signal characteristics of the motor driven slab receiving truck that receives the slab and descends at high speed A function generator for setting the output torque of the slab receiving trolley drive motor, which has a constant signal in the winding direction below the casting speed set value and has a reverse droop characteristic signal in the range exceeding the casting speed set value,
By detecting the completion of cutting of the slab based on the signal indicating that the descending speed of the slab receiving truck has exceeded the slab receiving truck speed set in advance in the reverse drooping characteristic region, the slab holder is cut when the slab is cut. Japanese Patent Application Laid-Open No. 6-142864 discloses that a slab is made to follow a slab to prevent the slab from falling into a slab holder.

[0003]

In the method for receiving a cast slab after cutting as described above, it is difficult to move the cast slab holder to follow the falling cast slab while making sure that the slab holder is brought into contact with the slab tip. is there. That is, at the same time as the slab load is applied when cutting the slab holder, the descent of the slab holder is controlled, and the timing may not be accurately taken, so that a slight gap between the slab tip and the slab holder occurs. Even tens of tons
There is a problem that the cast slab holder is damaged by dropping the cast slab. The method of the present invention has been made in order to advantageously solve such a problem, and the slab holder is pressed against the slab tip with a lower ascending force than the slab drop load during cutting, so that the slab is surely cast. The tip is lowered while being brought into contact with the slab holder to prevent the occurrence of a gap between the slab tip and the slab holder and to prevent the slab from dropping to the slab holder during cutting. is there.

[0004]

A feature of the method of the present invention is that a slab holder is pressed against a slab tip with a low ascending force from a slab drop moving load during cutting to perform a downward movement. A method for receiving a cut slab of a vertical continuous cast slab, wherein the slab is received by a slab holder while the slab holder is pushed down by the slab.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, in the method of the present invention, the slab holder is pressed against the slab tip with a low ascending force from the slab drop moving load during cutting, so that the slab drop speed can be ensured. When the slab is cut, no gap exists between the tip of the slab and the slab holder. Therefore, the slab at the time of cutting does not fall to the slab holder, and the breakage of the slab holder can be reliably prevented.

However, when the slab holder is pressed against the slab tip with a higher ascending force than the slab descent moving load, the set descent speed (casting speed) of the slab is delayed, and molten steel overflows from the mold. Therefore, it is necessary to press the slab holder against the slab tip with a low ascending force from the slab drop moving load as described above.

[0007]

Next, examples of the method of the present invention will be described. In FIG. 1, the cast slab 1 after casting is vertically lowered while being held by a pinch roll 2, and the torch 3 is cut by following the descent speed (casting speed) of the slab 1. On the other hand, a slab holder (cart, etc.) 4 is attached to the tip of the cut slab 1 by a pulley 5 and a cable 6.
Then, the slab holder driving motor 8 presses the slab tip against the slab tip with a low ascending force from the slab drop moving load via the winch 7. That is, the current value of the slab holder drive motor 8 is guided from the ammeter 10 to the slab holder drive controller 9, and the current is increased as the slab holder 4 is pressed against the tip of the slab 1 with a lower rising force than the drop load of the slab 1. By performing torque control based on the value, the slab holder 4 is pushed down by the downward movement of the slab 1. At the same time, it is always grasped whether or not it is being pushed down. Thus, when the current value is low and the slab holder 4 is not pressing the tip of the slab 1 with a lower rising force than the slab drop moving load, the slab holder drive controller 9 instructs the slab holder drive motor 8. Then, the winch 7 is driven and the slab holder 4 is pressed against the tip of the slab 1 via the cable 6 as described above.

Thus, when the slab 1 is cut by the torch 3, there is no gap between the tip of the slab 1 and the slab holder 4, and the slab 1 does not drop to the slab holder 4 and the slab 1 The delivery to the holder 4 is completed. Since the load of the cut slab 1 is applied to the slab holder 4, the lowering speed of the slab holder 4 is exceeded and the lowering rotation speed of the slab holder driving motor 8 is increased, but as shown in FIG. The slab holder drive controller 9 instructs a slab holder moving device (not shown) to move to a predetermined position by a speed limiting circuit built in the controller 9 without exceeding a set speed and to a transfer conveyor or the like. After the transfer, the slab 1 is returned to the position where the slab 1 is lowered during casting, pressed again to the tip of the slab 1, and the operation described above is repeated to cut the slab.

When the slab holder 4 is first pressed against the tip of the slab 1, the slab holder 4 is pressed against the tip of the slab 1 by ACR control (torque control) with a low ascending force due to the slab drop moving load as described above. In addition, when the casting is stopped, for example, when it is restarted, a gap may be generated between the tip of the slab 1 and the slab holder 4 due to the extension or contraction of the cable 6 for operating the slab holder 4. Further, at the moment when the slab holder 4 is pressed against the tip of the slab 1, the slab holder 4
In order to press down the slab holder 4 with the slab 1 while reliably pressing, the pressing force of the slab holder 4 against the slab 1 end may be generated. By performing the torque control based on the current value, the slab 1 can be pushed down by the downward movement and the slab holder 4 can be tuned down.

[0010]

According to the method of the present invention, the slab can be cut while the slab and the slab holder are securely adhered to each other.
Excellent effects are obtained, such as preventing damage to the slab holder due to the slab drop load at the time of cutting, and avoiding the danger of slab drop.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of the method of the present invention.

FIG. 2 is a circuit diagram showing a speed limiting circuit of a slab holder.

Claims (1)

[Claims] A slab holder is pressed against the slab tip with a low ascending force from a slab drop moving load during cutting, and the slab holder is pushed down by the descending slab to cut while the slab holder is lowered. A method for receiving a cut slab of a vertical continuous cast slab, wherein the subsequent slab is received by a slab holder.