JPH09122859A - Device for carrying out continuously cast slab and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the adoption even in the case of using a universal applicable AC motor, to reduce flawing of a cut cast slab and to smoothly carry out the cast slab. SOLUTION: A carry-out device 30 is constituted of plural carry-out rollers 32 used as a carry-out table, the universal applicable AC motor 34 for driving each carry-out roller 32 and a controller 36 for controlling the universal applicable AC motor 34. The carry-out rollers 32 are intermittently driven for a prescribed time from the time in a little before the cast slab 14 is perfectly cut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting slab unloading device and a unloading method for unloading a slab that has been cut in the width direction using a cutting torch.

[0002]

2. Description of the Related Art Continuous casting (hereinafter referred to as continuous casting) equipment for continuously casting slabs from molten metal is widely used. This continuous casting facility is generally equipped with a cutting torch that cuts the slab to a predetermined length in the final step of the casting line, and among the slabs cut by the cutting torch, the downstream side of the casting line. A carry-out table including a plurality of carry-out rollers for carrying out the cut slab located at is installed in the vicinity of the cutting torch and on the downstream side of the vicinity in the carry-out direction.

As the electric motor for driving the plurality of carry-out rollers, one of a DC electric motor, an AC variable speed electric motor, and a general-purpose AC electric motor is generally used. The DC motor and the AC variable speed motor are configured so that the control means can control the current to control the rotational speeds of the plurality of carry-out rollers and suppress the overload current. Therefore, when a DC motor or an AC variable speed motor is used, when carrying out the above-mentioned cut slab, even if a plurality of unloading rollers are driven before the cast slab is completely cut, an overload occurs. The current can be suppressed. Therefore, a plurality of unloading rollers are driven before the cast slab is completely cut, and the cut slab is carried out at the same time when the slab is completely cut.

On the other hand, in the case of using a general-purpose AC motor, if the general-purpose AC motor is an ON / OFF control system, the rotation speed of the carry-out roller cannot be controlled and the overload current cannot be suppressed. Therefore, if a plurality of unloading rollers are driven before the cast slab is completely cut and the unloading roller does not rotate due to the frictional force between the unloading roller and the slab, it is used. An overload current acts on the general-purpose AC motor, and the general-purpose AC motor trips.
Also,. Even if the carry-out roller rotates, the cast piece is not carried out, so the cast piece is rubbed by the carry-out roller, which may damage the cast piece.

Therefore, when using a general-purpose AC motor,
Generally, at the same time that the operator receives a "cutting completion signal" indicating that the slab has been completely cut,
You are operating a switch that drives the carry-out roller. However, since the "cutting completion signal" is output with a time margin until the slab is completely cut, it takes a while until the "cutting completion signal" is output after the slab is completely cut. I have time. Due to the presence of this time, the cut slab and the other slab upstream in the carrying-out direction may be welded to each other, which may make it difficult to carry out the cut slab. Further, after the slab has been completely cut, if the cutting slab is stopped without being immediately carried out, the rear end surface of the cutting slab is scooped by the cutting torch, and after rolling the cutting slab, There is a risk that the rear end will become scrap and the yield will decrease.

In order to solve the above-mentioned problem, it is possible to consider a method in which the operator manually pushes the operation start button of the carry-out roller at the same time when the slab is completely cut.
However, according to this method, since the work is busy in the multi-strand continuous casting machine, the operation start button may be forgotten or delayed. Therefore, the above-mentioned problem cannot be completely solved.

Among the above-mentioned problems, as a method for solving the problem that the cut slab and the other slab are welded,
Until the above-mentioned "cutting completion signal" is output, the unloading roller is operated at the same speed as the slab drawing speed, and after the "cutting completion signal" is output, at a unloading speed faster than the slab drawing speed. A method of operating the carry-out roller has been proposed (Japanese Patent Laid-Open No. 58-119447). However, since this method is premised on using a DC motor or an AC variable speed motor, this method cannot be adopted when a general-purpose AC motor is used.

Further, the above-mentioned "cutting completion signal" is promptly output to promptly operate the carry-out roller at the carry-out speed,
As a method of solving the problem that the cutting slab and the other slab are welded, the torque of the drive motor that drives the unloading roller is controlled so that the slab is unloaded in the unloading direction before it is completely cut. A method of urging downstream is proposed (JP-A-3-110050 and JP-A-5-305).
No. 406). However, since this method is also premised on using a DC motor or an AC variable speed motor, this method cannot be adopted when a general-purpose AC motor is used.

[0009]

In view of the above circumstances, the present invention can be adopted even when a general-purpose AC motor is used, the cut slab is less likely to be scratched, and the slab is smoothly carried out. It is an object of the present invention to provide a device and a method for carrying out continuously cast slabs.

[0010]

Means for Solving the Problems A device for carrying out continuously cast slabs according to the present invention for achieving the above object is to draw out the slabs in a predetermined carrying-out direction while continuously casting the slabs from a molten metal, In a continuous casting facility for cutting the drawn slab in the width direction of this slab using a cutting torch, among the slabs that have been cut, a continuous casting cast that carries out the slab that is located on the downstream side in the unloading direction. In the piece unloading device, (1) unloading means for unloading the cutting slab, which is installed in the vicinity of the cutting torch and on the downstream side of the vicinity in the unloading direction (2) driving means for driving the unloading table ( 3) It is characterized in that it is provided with control means for controlling the drive means so that the carry-out means is driven intermittently.

Further, the method for carrying out continuously cast slabs of the present invention for achieving the above object is one of the slabs cut in the width direction while being continuously cast from the molten metal, drawn out in a predetermined unloading direction. , The cutting slab located on the downstream side in the unloading direction, in a method of unloading a continuous casting slab that unloads using a unloading means, the unloading means from a predetermined time before the time when the cutting slab is completely cut It is characterized in that it is operated intermittently, and after the cut slab is completely cut, the carry-out means is continuously operated.

[0012]

According to the unloading device for continuously cast slabs of the present invention, the driving means is controlled by the control means so that the unloading means is driven intermittently, so that the slab is completely cut by the cutting torch. The unloading means can be operated intermittently from a predetermined time before the time. Due to the intermittent operation from before this predetermined time, when the cast piece is completely cut, at the same time as the cut piece, the cut piece on the downstream side in the carry-out direction is separated from the cast piece on the upstream side in the carry-out direction. You can As a result, the cutting slab on the downstream side in the unloading direction and the slab on the upstream side in the unloading direction can be prevented from welding and the slab can be carried out smoothly, and the cutting torch scoops the rear end surface of the cutting slab. Since this can be prevented, the yield is improved. Furthermore, before the slab is completely cut by the cutting torch, the carry-out means is operated intermittently, so that even if a general-purpose AC motor is used as the drive means, this general-purpose AC motor can be used without being brought into an overcurrent state.

Further, according to the method for unloading a continuously cast slab of the present invention, the unloading means is intermittently operated from a predetermined time before the time at which the slab is completely cut by the cutting torch. Almost at the same time, the cut slab on the downstream side in the carry-out direction can be separated from the slab on the upstream side in the carry-out direction. As a result, the cutting slab on the downstream side in the carry-out direction and the casting slab on the upstream side in the carry-out direction can be prevented from being welded again, and the slab can be carried out smoothly, and the rear end surface of the cutting slab is scooped by the cutting torch. It is also possible to prevent such occurrences, so that the yield is improved. Furthermore, since the unloading means is operated intermittently before the slab is completely cut by the cutting torch, even if the unloading means is operated using the general-purpose AC motor, this general-purpose AC motor can be used without overcurrent. it can.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing continuous casting equipment in which a device for carrying out continuously cast slabs is installed. The continuous casting facility 10 is a mold 1.
2 and a plurality of pinch rollers 16 that pull out the cast slab 14 that has been cast. The cast slab 14 that has been pulled by the pinch roller 16 passes over the transport roller 18 and is transported in the direction of arrow A, and the cutting machine 20 To reach the cutting position to be cut by. When the slab 14 reaches a predetermined length, the cutting machine 20
While being clamped to the slab 14 and moving integrally with the slab 14, the slab 1 is cut by the gas torch (an example of the cutting torch according to the invention) 22, 24 (see FIG. 2) of the cutting machine 20.
4 is cut in its width direction. When the slab 14 is completely cut, among the slabs 14 that have been cut, the cutting slab 14 ′ located on the downstream side in the unloading direction has a plurality of unloading rollers (an example of unloading means according to the present invention) 32. It is carried out to the downstream side in the carrying-out direction by the carrying-out device 30 provided. Then, the cutting machine 20
Is unclamped from the slab 14 and self-propelled to a predetermined reference position on the upstream side in the carry-out direction to prepare for the next cutting. Unloading device 3
In addition to the plurality of carry-out rollers 32, 0 is a general-purpose AC electric motor (an example of a driving unit according to the invention) 34 that drives each carry-out roller 32, and a controller that controls the general-purpose AC electric motor 34 (of the control unit according to the invention). One example) 36 is provided.

The cutting of the slab 14 by the cutting machine 20 will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic diagram showing how the slab 14 is cut, and FIG. 3 is an explanatory diagram showing the operation of the gas torch. As shown in FIG. 2, the gas torches 22, 2
4 moves freely in the width direction of the slab 14, and the gas torch 22
Cut the slab 14 from the direction of arrow B, while the gas torch 24 cuts the slab 14 from the direction of arrow C. As shown in FIG. 3, the gas torch 22 begins cutting at position 26,
On the other hand, the gas torch 24 starts cutting from the position 28.
When the gas torch 22 travels the distance L1 and the gas torch 24 travels the distance L2, and the two collide with each other at the position 29 in the widthwise center of the slab 14, the gas torch 22 returns to the position 26. On the other hand, the gas torch 24 further advances the distance L3 to reach the position 29 ', and then returns to the position 28. This position 29 'is called the cutting completion point. The reason for advancing the gas torch 24 to the position 29 'is to cut a sufficiently safe length until there is no uncut portion of the cast piece 14. The moving distances of the gas torches 22 and 24 are calculated by a torch moving distance calculation device (see FIG. 4) 40, and the movement of the gas torches 22 and 24 is controlled by the cutting control device (see FIG. 4) 42 based on the calculation result. To be done. If the slab 14 has a short width, the gas torches 22, 24
A cutting machine equipped with either one of them may be used.

FIG. 4 is a block diagram showing the controller 36, the torch movement distance calculation device 40, and the cutting control device 42 described above, and FIG. 5 is an explanatory diagram showing the operating state of the carry-out roller shown in FIG. [Fig. 2] is a schematic view showing positions of the slab before and after cutting the slab, and the same components as those of Fig. 1 are denoted by the same reference numerals. When the cutting of the slab 14 is started by the gas torches 22 and 24, the moving distance of the gas torches 22 and 24 is calculated by the torch moving distance calculation device 40, and based on the calculation result, the cutting control device 42 causes the gas torch 22,
The movement of 24 is controlled. Torch movement distance calculation device 40
The calculation result of is input to the controller 36 that controls the general-purpose AC motor 34 (see FIG. 1), and the general-purpose AC motor 34 is controlled based on the calculation result.

The time t at which the gas torches 22 and 24 move to the position 29, that is, the time t at which the slab 14 is completely cut.
The carry-out roller 32 is intermittently operated from a predetermined time (here, about 1.5 seconds) before 1 (see FIG. 5). In particular,
When the moving distance of the gas torches 22 and 24 is calculated by the torch moving distance calculation device 40, the carry-out roller 32 is intermittently started to operate. Here every 3 seconds for about 0.5 seconds 3
The carry-out roller 32 is operated about the number of times. FIG. 6 (a) shows the position of the cast slab 14 'during the operation at the time a shown in FIG.
During the operation for the time a, the slab 14 is not completely cut, so that the slab 14 ′ is cut by the transport roller 32.
Even if is driven, it does not move by this driving. As described above, the cutting slab 14 ′ does not move even when the transport roller 32 is operated, but the general-purpose AC motor 34 is controlled by the controller 36 so that the transport roller 32 is operated intermittently. The AC motor 34 can be used without being brought into an overcurrent state. Further, since the operation is intermittent, it is possible to reduce damage to the cast piece 14. FIG. 6B shows time b shown in FIG.
The position of the cutting slab 14 'moved by the operation of is shown. During the operation of time b, the slab 14 has been completely cut, so the cutting slab 14 ′ moves in the carry-out direction and separates from the slab 14 by the operation of the time b. By the operation at time c shown in FIG. 5, the cast slab 14 ′ is carried out to the position shown in FIG. 6 (c), and as a result, the cut slab 14 ′ is separated from the cast slab 14 by the distance L.
4 cm away. Therefore, the slab 14 that is pulled out by the pinch roller 16 (see FIG. 1) and moves downstream in the unloading direction and the cutting slab 14 ′ located downstream in the unloading direction.
It is prevented that and are contacted and welded. Gas torch 2
4 (see FIG. 2) goes to position 29 '(see FIG. 3),
At time t3 when the gas torch 24 reaches the position 29 ′, a “cutting completion signal” indicating that the slab 14 has been completely cut is input to the controller 36 from the torch movement distance calculation device 40, and the carry-out roller 32 sets the time. It is operated continuously from t3,
Thereby, the cutting slab 14 'is carried out in the carrying-out direction.

As described above, the reason for intermittently operating the carry-out roller 32 from a predetermined time (here, about 1.5 seconds) before the time t1 (see FIG. 5) is that the torch movement distance calculation device 40 is used. This is for avoiding the measurement error at time t1 due to the calculation error of. Further, in the above-described example, the number of intermittent operations is set to 3 and the operating time is set to 0.5 seconds, but the number of times and the operating time are determined according to the characteristics of the general-purpose AC motor 34. is there.

[0019]

As described above, according to the apparatus for carrying out continuously cast slabs of the present invention, the unloading table is intermittently operated from a predetermined time before the time when the slabs are completely cut by the cutting torch. Therefore, almost at the same time when the cast piece is completely cut, the cut piece on the downstream side in the carry-out direction can be separated from the cast piece on the upstream side in the carry-out direction. As a result, the cutting slab on the downstream side in the unloading direction and the slab on the upstream side in the unloading direction can be prevented from being welded again to prevent the trouble of unloading in advance, and the rear end surface of the cutting slab can be prevented by the cutting torch. It is possible to prevent scooping and improve the yield. Furthermore, since the unloading table is operated intermittently before the slab is completely cut by the cutting torch, even if a general-purpose AC motor is used as the driving means, this general-purpose AC motor can be used without being brought into an overcurrent state. In addition, since it is not necessary to perform visual observation before completely cutting, the burden on the operator can be reduced.

Further, according to the method for unloading a continuously cast slab of the present invention, almost at the same time when the slab is completely cut, the cut slab on the downstream side in the unloading direction among the cut slabs is upstream in the unloading direction. Since it can be separated from the slab on the side, the cutting slab on the downstream side in the unloading direction and the slab on the upstream side in the unloading direction can be prevented from welding again, and troubles in the unloading can be prevented in advance.
It is also possible to prevent the rear end surface of the cut slab from being scooped by the cutting torch and improve the yield. Furthermore, since the unloading table is operated intermittently before the slab is completely cut by the cutting torch, even if the unloading table is operated using the general-purpose AC motor, this general-purpose AC motor can be used without overcurrent. it can.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a continuous casting facility in which a carry-out device according to an embodiment of the present invention is installed.

FIG. 2 is a schematic view showing a state of cutting a cast piece.

FIG. 3 is an explanatory view showing the operation of the gas torch.

FIG. 4 is a block diagram showing a controller, a torch movement distance calculation device, and a cutting control device.

5 is an explanatory diagram showing an operating state of the carry-out roller shown in FIG. 1. FIG.

FIG. 6 is a schematic diagram showing the positions of the slab before and after cutting.

[Explanation of symbols]

 10 Continuous casting equipment 14 Cast slab 14 'Cutting slab 22,24 Gas torch 30 Unloading device 32 Unloading roller 34 General-purpose AC electric motor 36 Controller t1 Time when the slab is completely cut

Claims (2)

[Claims] 1. A continuous casting facility for continuously casting a slab from a molten metal, pulling out the slab in a predetermined carry-out direction, and cutting the pulled slab in the width direction of the slab using a cutting torch. Of the cut slabs, in a continuous casting slab unloading device that unloads a cutting slab located on the downstream side in the unloading direction, the vicinity of the cutting torch and the downstream of the vicinity in the unloading direction. And a driving means for driving the discharging means, and a control means for controlling the driving means so that the discharging means is driven intermittently. A device for carrying out continuously cast slabs characterized by: 2. A slab, which has been continuously cast from the molten metal and has been pulled out in a predetermined unloading direction and cut in the width direction, has a cutting slab located downstream of the unloading direction using a unloading means. In the carry-out method of the continuous cast slab to be carried out, the cutting slab is intermittently operated from a predetermined time before the time when the cutting slab is completely cut, after the cutting slab is completely cut, the A method for carrying out continuously cast slabs, characterized in that the carrying-out means is continuously operated.