JPH0647508A - Electromagnetic stirring device for continuous caster - Google Patents

Abstract

PURPOSE:To provide an electromagnetic stirring device, in which only a mold can be carried out to out of a machine while remaining an electromagnet on the machine, at the time of exchanging the mold in a continuous caster having rotary magnetic field type electromagnetic stirring device. CONSTITUTION:To plural yokes 2A, 2B of the electromagnets 2, which can attach/separate by an attaching/separating mechanism 6, plural coils are individually arranged. At the time of stirring the molten steel 3, each yoke is shifted to a position approaching to the mold 1 to mutually integrate plural yokes 2A, 2B. At the time of exchanging the mold 1, each yoke is shifted to a position separating from the mold 1 and each coil is separated and held to the position without any trouble to the exchange of the mold 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic stirrer of a continuous casting machine for continuously drawing molten steel poured into a mold to cast a slab, and more specifically, it is arranged around a mold having a relatively small cross section. The present invention relates to a rotating magnetic field type electromagnetic stirrer for stirring molten steel injected into a mold by the electromagnet.

[0002]

2. Description of the Related Art As means for agitating molten steel in a continuous casting machine for continuously drawing molten steel injected into a mold to cast a slab, for example, an electromagnet 2 is provided around a mold 1 as shown in FIG. When arranged, this electromagnet 2 is composed of an iron core (yoke) and a coil, and stirs the molten steel 3 injected into the mold 1 by generating a moving magnetic field between a plurality of magnetic poles.

By the way, in an ordinary electromagnetic stirrer, the electromagnet 2 is integrated with the mold 1. Therefore, when exchanging the mold 1 of this electromagnetic stirrer, the electric wiring (power supply cable) of the electromagnet 2 and the water supply / drainage pipe for cooling water must be disconnected to lift the mold 1 together with the electromagnet 2. There was a problem that the workability was lowered.

Further, in the electromagnetic stirrer in which the electromagnet 2 and the mold 1 are integrated with each other, the mold 1 and the electromagnet 2 vibrate together, so that the vibration load becomes large and the structure of the vibration system becomes large. There was a flaw.

Conventionally, in order to solve such a problem of the electromagnetic stirrer, an electromagnet supporting means is installed mechanically independent of the mold, and the electromagnet supporting means is installed along the electromagnet guide rail of the mold. The electromagnet mounting structure has been proposed in which the electromagnet can be moved toward or away from each other to improve the workability at the time of mold replacement and to reduce the vibration load to reduce the structure of the vibration system (for example, Japanese Patent Publication 1). No. 28864 publication).

[0006]

The electromagnetic stirrer of a continuous casting machine is a rotating magnetic field type stirrer of a horizontal stirrer type as shown in FIG. 6 depending on the direction of action of the magnetic field of the electromagnet 2, and FIG. It is classified into a linear electromagnetic stirrer of a horizontal stirring system as shown and a linear electromagnetic stirrer of a vertical stirring system as shown in FIG.

As the rotating magnetic field type electromagnetic stirring device, as shown in FIG. 9, the electromagnet 2 is installed in the water jacket of the mold frame 5 and the electromagnet 2 is immersed in cooling water. Electromagnetic stirrer and FIGS. 10 to 1
As shown in FIG. 4, the electromagnet 2 is provided outside the mold frame 5.
There is known an external electromagnetic stirrer of the type that is equipped with.

By the way, in the electromagnet mounting structure disclosed in Japanese Patent Publication No. 1-28644, the emphasis is placed on the maintenance aspect (workability at the time of mold replacement) of carrying out only the mold while leaving the electromagnet on the machine. Therefore, there is a problem that the stirring force cannot be applied in parallel to each surface of the slab.

As shown in FIGS. 7 and 8, the electromagnet mounting structure shown in this Japanese Patent Publication No. 1-286464 has a tangential direction on the long side surface layer of a slab such as a slab having a large flatness ratio. There is no problem in terms of quality when applied to a linear electromagnetic stirrer that induces a molten steel flow. However, for a slab having a relatively small cross section or a square or a slab having a rectangular cross section close to a square, a four-sided rotating magnetic field type electromagnetic stirrer capable of inducing a uniform stirring speed on each surface of the slab Is preferred.

However, in such a rotating magnetic field type electromagnetic stirrer, it is difficult to move the electromagnet 2 to and from the mold 1 as in the electromagnet mounting structure disclosed in Japanese Patent Publication No. 1-286464. Becomes

That is, in the rotating magnetic field type electromagnetic stirring device which drives the four surfaces, as shown in FIGS. 7 and 8, unlike the linear type electromagnetic stirring device in which the electromagnets 2 are divided and arranged in advance in plural, As shown in FIG. 6, since the electromagnet 2 is arranged so as to surround the periphery of the mold 1, there were many difficulties in mechanically separating the mold 1 and the electromagnet 2 as they were. In particular, in order to take out the electromagnet 2 from the mold 1 in a submerged electromagnetic stirring device,
It's not as convenient as it can be done on board.

On the other hand, also in the case of the exterior type electromagnetic stirrer, in order to easily take out the electromagnet 2 from the mold 1, it is necessary to drastically change the structure around the mold.
Mold 1 because it is difficult to maintain and manage.
At the time of replacement, there was no choice but to adopt a method in which the electromagnet 2 is attached to the mold 1 and carried out together with the electromagnet 2.

Therefore, in order to replace the mold 1 in a short time in this rotating magnetic field type electromagnetic stirrer, it is necessary to put the replacement mold assembly to which the electromagnet is attached in advance into standby. Two or more spare electromagnets were needed.

Further, in the rotating magnetic field type electromagnetic stirring device, it is necessary to disconnect and connect the electric wiring of the electromagnet 2 and the cooling water pipe each time the mold is replaced.

The present invention has been made in view of the above points, and an object thereof is to leave the electromagnet on the machine at the time of mold replacement of a continuous casting machine having an electromagnetic stirring device of a four-sided driving rotating magnetic field type. And to provide an electromagnetic stirrer configured so that only the mold can be carried out of the machine.

[0016]

In order to solve the above-mentioned problems, the present invention provides a mold into which molten steel is poured, and a rotating magnetic field type electromagnetic stirring means in which an electromagnetic coil is arranged around the mold. In a continuous casting machine for casting a cast piece by continuously extracting molten steel injected into the mold while stirring, an electromagnet and a plurality of parts for supporting the electromagnet are separated and independent from the mold. A coil-equipped yoke, and a yoke support means for supporting each of the above-mentioned yokes so as to move toward and away from the mold,
When the molten steel is stirred, the yokes are moved to a position close to the mold on the yoke supporting means to integrate the divided yokes, and when the mold is replaced, the yoke supporting means are moved to the yoke supporting means. And a yoke contacting / separating means for separating the yokes from each other by moving the yokes to a position away from the mold.

[0017]

According to the present invention, the electromagnet is divided into a plurality of pieces, and the electromagnets are separated and independent of the mold and are individually arranged on the plurality of yokes with the coil. Since the yokes are supported, when the molten steel is stirred, the yoke contacting / separating means moves each yoke to a position close to the mold on the yoke supporting means,
By integrating the yokes, a flow of magnetic flux that is approximately the same as that of a single yoke is ensured and iron loss is maintained at a low level. The respective yokes are moved to positions separated from the mold so that the respective yokes are separated from each other.

[0018]

Embodiments of the present invention will be described in detail below with reference to the drawings. However, with respect to the configuration, operation and the like within the range that can be clearly recalled from the description of the present specification, their illustration and disclosure will be omitted or simplified in order to avoid complication of the description.

As shown in FIGS. 1 and 2, the electromagnetic stirrer of the continuous casting machine according to the present invention includes yokes 2A and 2B with coils for the electromagnet 2, a mold frame 5, an attaching / detaching mechanism 6, a vibrating table 7, and , Support brackets 8A, 8B
Etc. As shown in FIG. 3, the yokes 2A and 2B are divided from each other with the AA cross section as a boundary, and each of the yokes 2A and 2B has two inner peripheral portions so as to surround the periphery of the mold 1. The coil 10 is arranged. In addition, these yokes 2A and 2B are attached by the attaching / detaching mechanism 6 provided on the yoke or the yoke case.
It is configured to be able to abut and separate from each other.

As a result, the yoke 2 is detached by the attaching / detaching mechanism 6.
When A and 2B are brought into contact with each other, it is possible to secure a flow of magnetic flux that is substantially the same as that of the conventional yoke having an integral structure, so that the iron loss can be maintained at a low level. Here, in the attachment / detachment mechanism 6 of the present embodiment, as shown in FIG. 4, a mounting metal fitting for easy attachment / detachment operation is used in order to speed up the contact / separation of the yokes 2A, 2B.

The respective yokes 2A and 2B which are brought into contact with each other and integrated by the attaching / detaching mechanism 6 as described above are mounted via the mounting bracket 9 provided outside the respective yokes 2A and 2B or below the yoke case. And is supported and fixed to the mold frame 5, the mold vibration table 7, or the support brackets 8A and 8B.

In the continuous casting machine configured as described above, when stirring the molten metal in the mold 1, as shown by the solid lines in FIGS.
A and 2B are bonded to each other.

Thus, during this operation, each coil 1
0 is arranged so as to surround the periphery of the mold 1 to form a rotating magnetic field type electromagnetic stirring device.

Therefore, according to this electromagnetic stirrer, by applying an electric current to each coil 10, each coil 1
An eddy current is generated on the inner wall surface of the mold 1 by the magnetic force line from 0, and the molten metal in the mold 1 is agitated by this eddy current.

On the other hand, when replacing the mold 1 with another mold, after removing the attaching / detaching mechanism 6 to separate the yokes 2A and 2B from each other, the mold 1 is moved to a position that does not interfere with the carry-out / carry-in of the mold 1, The yokes 2A and 2B are retracted to the positions (the positions shown by the chain lines in FIGS. 1 and 2) where the yokes 2A and 2B do not interfere with the mold 1 that is carried out and carried in.

At this time, the yokes 2A, 2B retracted to the positions retracted from the mold 1 are respectively supported by the support brackets 8A, 8B until the replacement of the mold 1 is completed.

Here, the support brackets 8A of the present embodiment,
8B shows an example provided on the vibration table 7 as shown in FIGS. 1 and 2, but these support brackets 8A, 8
B may be provided on a pedestal fixed to the foundation of the continuous casting machine, or may be divided and installed on both the pedestal and the vibration table. In the former case, the support brackets 8A and 8B are cantilever beams extending from the gantry to the mold side. If the cantilever beams are integrated with the gantry and extended to a place where the electromagnets can be supported, the electromagnets are molded and vibrated. Supported mechanically independently from.

Further, each yoke 2A, 2 in this embodiment is
The power supply cable and the cooling water supply / drainage hose (not shown) connected to each coil 10 arranged in B are connected to each yoke 2
It is made of a material having a flexibility and a length such that it can be flexed by following the respective yokes 2A and 2B when the A and 2B move toward and away from each other. The ground side of the continuous casting machine (the vibration table 7 of the mold 1). Power supply and water supply / drainage are performed through each connection port.

Therefore, according to this embodiment, each yoke 2
It is not necessary to disconnect the connection between the power supply cable and the water supply / drainage hose and each coil 10 at the time of contact / separation movement of A and 2B, and the opening / closing operation of the attachment / detachment mechanism 6 and the yokes 2A and 2A.
Only by moving the mold B, the mold 1 can be replaced with the electromagnet 2 left on the machine.

[0030]

According to the present invention, a uniform stirring speed can be induced on each surface of the slab. Moreover, by separating and retracting the yoke when replacing the mold with respect to the rotating magnetic field type electromagnetic stirrer, the electromagnet can be left on the machine and only the mold can be carried out and carried out of the machine. Therefore, since it is not necessary to remove the power supply cable and the water supply / drainage hose connected to the coil, it is possible to shorten the mold replacement work time and eliminate the increase in the number of auxiliary electromagnets.

Further, according to the present invention, the electromagnet can be mechanically supported independently from the mold and the vibration table by extending the bracket supporting the yoke in order to move the yoke closer to and away from the mold. Therefore, the mold or the vibration table and the electromagnet do not vibrate together, and the vibration load does not increase or the structure of the vibration system does not increase.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a continuous casting machine according to an embodiment of the present invention.

FIG. 2 is a schematic front view of the continuous casting machine.

FIG. 3 is a schematic plan view of electromagnetic stirring means in the continuous casting machine.

FIG. 4 is a detailed view of a mechanism for attaching and detaching each yoke of the electromagnetic stirring unit.

FIG. 5 is a schematic sectional view of a continuous casting machine.

FIG. 6 is a schematic perspective view showing a stirring system of an electromagnetic stirring device of a continuous casting machine.

FIG. 7 is a schematic perspective view showing a stirring method of an electromagnetic stirring device of a conventional continuous casting machine.

FIG. 8 is a schematic perspective view showing another stirring method of the electromagnetic stirring device of the conventional continuous casting machine.

FIG. 9 is a schematic sectional view of a conventional continuous casting machine.

FIG. 10 is a schematic plan view of an electromagnetic stirring device of a continuous casting machine.

FIG. 11 is a schematic front view of an electromagnetic stirring device of a continuous casting machine.

FIG. 12 is a schematic side view of an electromagnetic stirring device of a continuous casting machine.

FIG. 13 is a partially cutaway plan view of the continuous casting machine.

FIG. 14 is a partially cutaway side view of the continuous casting machine.

[Explanation of symbols]

 1 Mold 2 Electromagnet 2A, 2B Yoke 3 Molten Steel 5 Mold Frame 6 Attachment / Detachment Mechanism 7 Vibration Table 8A, 8B Support Bracket 9 Mounting Bracket 10 Coil

Claims (1)

[Claims] 1. A mold, into which molten steel is poured, and a rotating magnetic field type electromagnetic stirring means having an electromagnetic coil arranged around the mold. Continuously stirring the molten steel poured into the mold. In a continuous casting machine for drawing a cast piece by pulling it out to an electromagnet, a yoke with a coil that is divided into a plurality of parts to support the electromagnet, and is arranged separately from the mold, and with respect to the mold. The yoke supporting means for supporting the respective yokes so as to be movable toward and away from each other and the yokes divided into the plurality by moving the respective yokes to a position close to the mold on the yoke supporting means at the time of stirring the molten steel. A yoke contact that integrates the yokes and moves the yokes to positions separated from the molds on the yoke support means when exchanging the molds to separate the yokes from each other. An electromagnetic stirrer for a continuous casting machine, comprising a separating means.