JPH0677791B2 - Operating method of continuous casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a continuous casting facility for cast slabs, and more particularly to a method for operating a continuous casting facility of a dummy bar upper insertion type for shortening the casting preparation time.

B. Outline of the Invention The present invention is intended to improve the production capacity of the equipment and the operating rate by realizing the shortening of the casting preparation time in the operation method of the continuous casting equipment, and the position detection means provided in the roll band of the equipment is It is possible to perform the pull-out operation of the pre-charge slab, the insertion of the dummy bar, and the casting operation of the next charge slab during the pulling operation by the position signals of the rear end of the pre-charge slab, the tip of the dummy bar and the tip of the next charge slab to be detected. In addition, by carrying out the drawing-casting operation in which the next charge slab is continuously cast, the achievement of the above-mentioned object and the synchronized operation of the pre-process and the post-process become easy, and a high-efficiency production facility can be provided.

C. Conventional technology Conventionally commonly used continuous casting equipment has a dummy bar lower insertion method and a dummy bar upper insertion method. The fifth is the outline of the main mechanism of the dummy bar lower insertion method.
It is a figure. In the continuous casting equipment shown in the figure, a dummy bar is inserted directly below the mold 4 and sealed. First, the pinch roll 6 inserts the dummy bar from the lower part of the mold 4. Next, as shown in the figure, the molten steel whose components have been adjusted in the converter is transferred to a ladle (ladle) 1. The ladle 1 is carried onto the ladle turret 115 by a ladle crane (not shown). The ladle turret 115 swivels to set the ladle 1 containing molten steel at the pouring position.

Molten steel in the ladle 1 is poured into the tundish 3 from the lower part of the ladle 1, and when the amount of molten steel in the tundish 3 reaches a certain level or more, it is fed from a sliding nozzle (not shown) of the tundish 3 into a mold (mold) 4. Molten steel is poured. Prior to the start of casting, the dummy bar 5 is fed by a pinch roll 6 so that the tip of the dummy bar 5 is tightly fitted into the opening at the bottom of the mold 4 and the bottom of the mold 4 is closed.
The pinch roll 6 is driven and rotated by a motor.

The molten steel injected into the mold 4 loses heat due to contact with the mold 4 and solidifies from the outer peripheral side. Therefore, the pinch roll 6 is gradually accelerated according to this solidification speed, and the dummy bar 5 is pulled out in the carry-out direction. Then, cooling the molten steel
The solidified slab is pulled by the dummy bar 5 to be continuously formed. This is a casting operation.

When the dummy bar 5 reaches the separation position A, the cast piece 7 and the dummy bar 5 are separated. The separated dummy bar 5 is wound up by the dummy bar winch 118 and stored in the dummy bar table 119. On the other hand, the separated slab 7 advances through the post-pinch roll table 10 and the torch front table 111, is cut into a length determined by the torch cutter 112, and is carried out by the torch lower table 113 and the torch post table 114. .

As described above, in the continuous casting equipment using the lower part of the dummy bar, the casting preparation time for performing the setup required for casting is defined as follows. That is, it is the time from the end of pre-charge casting to the start of slab extraction-the end of slab extraction-the start of dummy bar insertion-the end of dummy bar insertion to the start of the next charge casting. Also, in the dummy bar upper insertion method, dummy bar 5 is inserted from above mold 4. In this method, the preparatory casting time of this method is the end of pre-charge casting ~ Start of withdrawing of the slab ~ Position where the rear end of the slab can be inserted with the dummy bar ~ Start of inserting the dummy bar
This is the time from the end of inserting the dummy bar to the start of the next charge casting. FIG. 4 shows a state immediately after the start of casting by the method of inserting the dummy bar into the upper part. The dummy bar, which has been inserted from above the mold 4 during the drawing operation of the pre-charged slab, stands by immediately below the mold until the drawing operation of the pre-charged slab is completed, and the next charge casting is started at the end of the drawing operation (Fig. 4). It is a thing. This dummy bar upper insertion method shortens the casting preparation time compared to the dummy bar lower insertion method, but it still required about 40 minutes / cycle of casting preparation time.

D. Problems to be Solved by the Invention The production capacity of the continuous casting equipment that requires the above-mentioned casting preparation time is usually around 200,000 tons / month in many cases, but if the casting preparation time is shortened, the production capacity will be greatly improved. For example, in a continuous casting facility with a production capacity of 210,000 tons / month, 300 tons of 1-charge casting, 700 charges / month with an operating setting of 5 in a row, 140 times / month for this
The number of preparations for casting the moon is required. By shortening this casting preparation time by 10 minutes each time, 280,000 tons /
Monthly production will be possible and the production capacity will be improved by 30% compared to the conventional one.

Also, regarding the operating rate, if the casting preparation time can be shortened, synchronous operation with the pre-process and post-process will be facilitated, and a highly efficient production system will be established. It was an important issue to be solved for operation.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for operating a continuous casting facility that shortens the casting preparation time and that realizes a highly efficient production system of the continuous casting facility.

E. Means for Solving the Problems The present invention makes use of the advantages of the dummy bar upper insertion method,
This is a method of operating a continuous casting facility that continuously performs a draw-casting operation while accurately detecting and maintaining the distance between the precharged slab and the dummy bar. Operation of a continuous casting facility equipped with a dummy bar insertion mechanism for inserting the above from above and a roll band composed of a pinch roll and an idling roll capable of controlling the drive for at least one pair for pulling and conveying the cast pieces in the mold together with the dummy bar. In the method, the operating method of the continuous casting equipment is a plurality of position detection consisting of a dummy bar in the roll band of the continuous casting equipment and a position detection sensor that detects the position of the slab and a counter that counts the detection signals of this position detection sensor. Means is provided, and based on the measurement information of the position detecting means, after the pre-charge casting is completed, the pre-charge casting is completed. Immediately before the rear end of the piece passes through the pinch roll, the pinch roll is opened to stop the rotation, and when the rear end of the front charge cast piece advances to the dummy bar insertable position, the dummy bar is inserted, and the tip of the dummy bar. When the dummy bar is conveyed by pressing the pinch roll close to the pinch roll to rotate and drive it,
While controlling the insertion speed of the dummy bar so as to maintain the distance between the tip of the dummy bar and the rear end of the pre-charged slab to a set value or more, when the rear end of the dummy bar comes to a fixed position in the mold, the dummy bar is temporarily Stop the casting of the next charge and perform the drawing operation and the casting operation at the same time, and keep the distance between the tip of the dummy bar and the rear end of the previous charge slab above the set value after starting the drawing and casting operation. It is characterized by controlling the drawing speed of the pre-charged slab.

F. Action By using the above means, a three-dimensional state of the precharge slab, the dummy bar, and the next charge slab is always created in the pinch roll band, and the interval between the precharge slab and the dummy bar is maintained above the set value. The drawing and casting operation is carried out, and the casting preparation time can be shortened.

G. Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 and FIG. 2 are diagrams showing a configuration of a main part of an operating method of a continuous casting facility according to an embodiment of the present invention. FIG. 1 shows a pre-charged slab and a dummy bar immediately after the start of casting according to the present embodiment. Fig. 2 shows the positional relationship between the next charge slab and the arrangement position of the measuring means. Fig. 2 shows the drawing casting operation progressing, and the front charge slab, the dummy bar, and the next charge slab are well controlled by the pinch roll band. It is shown that.

In FIGS. 1 and 2, the pinch roll band arranged from the lower part of the mold 4 to a considerable length is closely provided with rolls as in FIG. 5, but for the sake of explanation, the rolls are pinched. Only the roll 6 is shown, and the idling roll is omitted. Further, the number of pinch rolls 6 is also shown in a simplified manner as compared with the actual number.

First, the configuration of this embodiment will be described with reference to FIG.
The same parts as those shown in FIGS. 4 and 5 referred to in the description of the conventional technique are designated by the same reference numerals and the description thereof will be omitted.

In the method for operating the casting equipment according to the present embodiment, the dummy bar 5 is inserted into the bottom of the mold 4 by using the dummy bar upper insertion method in which the dummy bar 5 is inserted from the upper portion of the mold 4, and the dummy bar insertion mechanism (not shown) for inserting the dummy bar 5 is shown. No.) is arranged near the mold 4. On the other hand, as shown in the drawing, the measuring rolls 2a, 2b, 2c, ... Sensors 11a, 11b, 11c ... For measuring the number and counters 111a, 111b, 111c ... For counting the positions of the slab and the dummy bar 5 from the mold 4 in response to a signal from the sensor are provided. Sensors 11a, 11b, 11c ... are pulse generators, synchro oscillators,
Any device such as a resolver or a cam switch that can continuously detect the position may be used. In the present embodiment, a pulse oscillator that facilitates signal processing is used. The measuring rolls 2a, 2b, 2c ... start to rotate when they come into contact with the slab or the dummy bar 5, and the sensors 11a, 11b, 11c. The counters 111a, 111b, 111c ... Measure the position of the detected member such as a cast piece from the mold 4. The counters 111a, 111b, 111c ... Are connected to a control unit (not shown), such as a central processing unit and a control unit, and the measured information is used as control information.

On the other hand, the pinch rolls 6 are arranged at predetermined positions from immediately below the mold 4 in pairs with the pinch rolls 1PR, 2PR, 3PR, ...
A motor is directly connected to each pinch roll to drive them individually in pairs, left and right or up and down, and the rotation speed and pressing force for clamping the slab from both sides, and conversely, the opening operation from the slab, etc. It is configured to be individually controlled by the control unit.

The casting operation method of the casting equipment of this embodiment configured as described above will be described in detail.

The present invention is a drawing operation in which a dummy bar is inserted during a drawing operation of a pre-charged slab, and if the distance between the rear end of the pre-charged slab and the tip of the dummy bar that has finished being inserted is equal to or greater than a set value, casting of the next charge is immediately started. This is an operation method characterized by a drawing casting operation in which the above and the casting operation are performed continuously. The contents of the drawing casting operation according to the present embodiment will be described below with reference to the flow chart of FIG.

First, the dummy bar is inserted during the drawing operation of the pre-charged slab. That is, when the front charge slab 7a moves in the pinch roll band at the drawing speed by the drawing operation (Fig. 3), the starting point of zero distance is set when the rear end of the front charge slab 7a is in the predetermined position in the mold 4. As a measurement of the distance between the rear end of the pre-charged slab 7a and a predetermined position in the mold 4 by at least one of each measuring roll 2, each sensor 11, and each counter 111, that is, the rear end of the slab 7a. Is measured (FIG. 3), the pinch rolls 6 are sequentially paired by a command from the control unit based on the measurement result of each counter 111 immediately before the rear end of the front charge slab 7a passes. The pinch rolls are separated from each other by an interval equal to or larger than the thickness width of the precharged slab 7a and stopped (Fig. 3). When the drawing operation progresses and the rear end of the front charge slab 7a passes the measuring roll 2a, the measuring roll
The rotation of 2a is stopped (Fig. 3), and the insertion of the dummy bar 5 is started (Fig. 3) based on the instruction from the counter 111a which receives the signal from the sensor 11a. This is a pull-out insertion operation because the dummy bar 5 is inserted during the pull-out operation.

The tip of the dummy bar 5 inserted from above in the pulling insertion operation passes the position of the measuring roll 2a, and the measuring roll 2a rotates,
The sensor 11a and the counter 111a start measuring the tip position of the dummy bar 5 (FIG. 3). Then, the pinch rolls PR are approached and pressed according to the passage of the dummy bar 5 (Fig. 3), and the tip of the dummy bar 5 and the pre-charged slab are measured by the measurement information from the sensor 11a and the sensor 11b of the measuring roll 2b.
The insertion speed of the dummy bar 5 is controlled so that the distance between the rear ends of the 7a is kept at the set value (Fig. 3). The operation of inserting the dummy bar 5 is completed in a short time, and then the casting of the next charge slab 7b is started (FIG. 3). This is for casting the next charge slab 7b during the drawing operation, and is the drawing casting operation in which the state immediately after the start of operation is shown in FIG.

When starting the casting of the next charge slab 7b, molten steel is injected from the converter into the ladle 1, and the ladle 1 is set at the casting position. On the other hand, the dummy bar 5 is tightly fitted in advance at a predetermined position of the bottom opening of the mold 4 and the mold 4
Is blocking the bottom of. The molten steel in the ladle 1 is poured into the tundish 3 and is poured into the mold 4 when the charge amount is reached. The molten steel poured into the mold 4 is deprived of heat by the mold 4 and gradually solidifies from the outer peripheral side to become a cast slab 7b. As the solidification progresses, the dummy bar 5 at the bottom of the mold 4 is pulled out in the carrying-out direction, so that the slab 7b is pulled by the dummy bar 5 and moves together with the dummy bar 5 in the pinch roll band that is continuously provided from the bottom of the mold 4. To do.
FIG. 2 is a diagram in which the dummy bar 5 connecting the slab 7b for the next charge to the rear end moves a focus roll band with a separation distance (setting value) 1 from the rear end of the slab 7a for the previous charge. is there.

In the drawing-casting operation, the pre-charged slab 7a is operated at the drawing speed, and the dummy bar 5 and the next-charged slab 7b are operated at the casting speed. In FIG. 2, measuring roll 2c and sensor 11c
Is the rear end position of the front charge slab 7a, the measuring roll 2b and the sensor 11b are the front end position of the dummy bar 5, the measuring roll 2a
And the sensor 11a detects the tip position of the next charge slab 7b, and the counters 111c, 111b, which are connected to the respective sensors,
The position signal is sent to the control unit by 111a.

In the drawing-casting operation, as shown in FIG. 1, first, as in the drawing-insertion operation, the sensor 11b of the measuring roll 2b (or the sensor 11c of the measuring roll 2c) and the sensor 11a of the measuring roll 2a are used to charge the precharged slab 7a. The distance between the rear end and the tip of the dummy bar 5 is measured, and when the distance is smaller than the set value l and abnormally approaches, an alarm is issued and at the same time, all the pinch rolls 6 during the drawing operation are changed to the casting speed (Fig. 3). ,). However, when the above-mentioned interval holds the set value l or more, the pinch roll 6 during the drawing operation is just before passing the rear end of the front charge slab 7a, for example, the pinch roll 3PR receives a signal from the sensor 11b. Counter 111b and pinch rolls 4PR, 5PR, 6PR are sensors 11c
In response to a command from the control unit based on the measurement result with the counter 111c that has received the signal of, the slabs are sequentially opened at intervals equal to or greater than the thickness width of the slab. Opened pinch rolls 3PR,… 6PR are canta 111a, 111b
Immediately after passing through the tip of the dummy bar 5, the approach pressure is applied again, and the rotation is driven at the casting speed to shift to the casting operation.

Next, the rear end of the front charge slab 7a is the measuring roll 2 of the sensor 11b.
After passing b, the measuring roll 2b stops rotating and the counter 111c, which receives the measurement signal together with the counter 111b, causes the distance from the mold 4 to the measuring roll 2b which is known from that moment (or the pre-charge by the counter 111b). 7a and the measurement value of the rear end position)
The measurement of the position of the rear end of the front charge slab 7a is started by 11c, and the rear end of the front charge slab 7a and the tip of the dummy bar 5 are measured by the measuring roll 2a of the sensor 11c and the measuring roll 2c of the sensor 11c. And the same control as above is performed. In addition, the counter 11 also controls the opening and closing pressurization of the pinch roll 6.
The command of 1c is added and performed (Fig. 3).

Further, as shown in FIG. 2, the tip of the dummy bar 5 is a sensor.
After passing the measuring roll 2b of the sensor 11b, the measuring roll 2b of the sensor 11b thereafter measures the tip position of the dummy bar 5, and the counter 111b and the sensor 1 receiving the signal of the sensor 11b.
Precharged slab by the counter 111c which received the signal of 1c
The distance 1 between the 7a and the dummy bar 5 is measured and the control is carried out in the same manner as above (FIG. 3,). Further, the pinch rolls 6 that have been approaching and pressurized to the dummy bar 5 are cast from the pressure applied to the dummy bar 5 according to the passage of the tip of the next charge cast piece 7b by the signal of the sensor 11 of each measuring roll 2. The pressure is switched to one pressure. When the precharged slab 7a moves between all the pinch rolls 6 and exits, the drawing and casting operation ends, and the casting operation is not stopped and only the casting operation is performed (Fig. 3,).

As described above, the casting method in the continuous casting facility can be continuously operated by the operating methods of the slab drawing operation-drawing insertion operation-drawing casting operation-casting operation. In the above-mentioned pulling insertion operation to pulling casting operation, the predetermined position in the mold 4 is the starting point of the distance of zero, and the rear end position of the front charge slab 7a is measured from the beginning to the end of the operation of the measuring roll 2c and the sensor 11c. It may be performed by. In this case, the measuring roll for measurement and the sensor 11 are not switched. Further, in this case, the tip position of the front charge slab 7a is measured by the counter 111c, and at the same time, the rear end position of the front charge slab 7a is measured by the counter 111b starting from a predetermined position in the mold in response to the signal from the sensor 11c. May be performed.

In the above embodiment, the measuring roll 2, the sensor 11,
Although the case where three counters 111 are arranged and the counters 111 are arranged respectively, the number of counters 111 is not limited to three, and each two may be four or four or more.

H. Effects of the Invention As described above, the present invention uses the position information obtained by the position detecting means provided in the pinch roll band of the casting equipment to rotate the pinch rolls one by one or a plurality of pairs and pressurize the pinch rolls.
By performing the drive control of opening and closing and maintaining the distance between the pre-charged slab and the dummy bar at a set value or more, it is possible to perform the pulling-casting operation in which the next charge slab is continuously cast. Furthermore, by only adding a control system to the conventional casting equipment, the casting interval was shortened and the operating rate was increased to 95% or more, resulting in an increase in production capacity of 30% or more.

Also, by shortening the pouring preparation time when the casting of slabs is interrupted, it is possible to operate the pre-process and post-process of the casting process synchronously, resulting in a consistent high-efficiency production facility. We were able to obtain ripple effects such as improvement, quality improvement, and energy-saving effects with less heat loss.

[Brief description of drawings]

FIG. 1 and FIG. 2 are diagrams showing a configuration of a main part of a continuous casting equipment operating method in an embodiment of the present invention, FIG. 3 is a flow chart of steps of casting equipment in the embodiment, and FIG. And the fifth
The figure is a diagram showing a configuration of a conventional technique. 2a, 2b, 2c ... Measuring roll (position detecting means), 4 ... Mold, 5 ... Dummy bar, 6 ... Pinch roll, 7a ... Previous charge slab, 7b ... Next charge slab, 11 ... Sensor (position detection means) , 111 ... Counter (position detection means), l ... Set interval length.

Front page continuation (72) Inventor Shigeru Kurata 2-17-1 Osaki, Shinagawa-ku, Tokyo Inside Meidensha Co., Ltd. (72) Inventor Toshihiko Imai 2-17-1 Osaki, Shinagawa-ku, Tokyo Inside Meidensha Co., Ltd. (56 ) Reference JP-A-49-111823 (JP, A) JP-A-62-6749 (JP, A)

Claims (1)

[Claims] 1. A dummy bar insertion mechanism for inserting a dummy bar into a mold from above, and a roll band composed of a pinch roll and an idling roll capable of controlling the drive for at least one pair for pulling and conveying the cast pieces in the mold together with the dummy bar. In a method of operating a continuous casting equipment comprising, a plurality of position detection consisting of a position detection sensor for detecting the position of the dummy bar and the slab in the roll band of the continuous casting equipment and a counter for counting the detection signals of this position detection sensor. After the provision of the means, based on the measurement information of the position detecting means, the pinch roll was opened and the rotation was stopped immediately after the end of the pre-charge casting and immediately before the rear end of the pre-charge cast piece passed through the pinch roll. After that, when the rear end of the front charge slab has advanced to the dummy bar insertable position, the dummy bar is inserted into the mold. Then, when the tip of the dummy bar passes through the pinch roll, the pinch roll is approached and pressed, and the dummy bar is conveyed by rotating the pinch roll, and between the tip of the dummy bar and the rear end of the front charge slab. The interval of is measured based on the measurement information of the position detection means, while controlling the insertion speed of the dummy bar so as to keep the interval above a set value, when the rear end of the dummy bar comes to a fixed position in the mold, The movement of the dummy bar is temporarily stopped, the casting of the next charge is started, and the drawing operation and the casting operation of the slab are performed at the same time, and after the start of the drawing and casting operation, between the tip of the dummy bar and the rear end of the previous charge slab. A method for operating a continuous casting facility, characterized in that the withdrawal speed of the precharged slab is controlled so as to maintain the interval between the set values or more.