JP2009248110A - Connection method for electromagnetic coil device usable for both electromagnetic stirring and electromagnetic braking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of power source cables connected to power sources without employing an automatic joint system. <P>SOLUTION: To selectively act electromagnetic stirring or electromagnetic braking on molten steel in a mold 2, the following is carried out. Connection terminals of each exciting coil in both-usable electromagnetic coil devices 1 and power sources 11, 12 are connected through power source cables 15. The electromagnetic coil has the total of three exciting coils, two of which are made by putting windings 1b around the outsides of tooth parts 1a, and one of which is made by putting a winding 1c further on the windings 1b of these two exciting coils to integrate them. On the outer peripheries of long sides 2a of the mold, n pieces (n is a natural number of ≥2) of the electromagnetic coils are disposed so as to be rotationally 180° symmetric with respect to the mold 2 put between them. Concerning the electromagnetic coils disposed symmetrically, the start side of one connection terminal is connected to the end side of the other connection terminal, and the start side of the other connection terminal and the end side of one connection terminal are connected to a repeating board 14. Thus, the number of power source cables connected to a repeating board is reduced to half or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of connecting a dual-purpose electromagnetic coil device having both functions of an electromagnetic brake and electromagnetic stirring and a power source by a power cable.

  For example, when continuously casting ultra-low carbon steel used for automobile steel plates, so-called electromagnetic stirring is adopted, in which the molten steel injected into the mold is actively stirred horizontally for the purpose of improving surface quality. ing.

  On the other hand, when continuously casting medium carbon steel containing about 0.07 to 0.16% by mass of carbon, which is used for thick steel plates, etc., it is possible to improve center segregation and suppress operational troubles such as breakout. For the purpose, so-called electromagnetic brakes that brake molten steel flow are employed.

Thus, the components of the steel to be cast differ depending on the use, and the required quality level and operational problems differ. Therefore, when steels of various components are cast by one continuous casting machine, it is necessary to mount an electromagnetic stirring device and an electromagnetic brake device on a continuous casting mold (for example, Patent Document 1).
JP 05-177317 A

  However, in the facility that is individually equipped with the electromagnetic stirring device and the electromagnetic brake device as disclosed in Patent Document 1, there is a problem that a large installation space is required and the facility cost is increased.

In order to solve this problem, the inventors have used one in-mold electromagnetic force control device for continuous casting (hereinafter referred to as a combined electromagnetic coil device) having both functions of an electromagnetic stirring device and an electromagnetic brake device. Proposed (for example, Patent Document 2).
JP 2005-349454 A

  In the case of the dual-purpose electromagnetic coil device proposed in Patent Document 2, the required equipment space can be reduced as compared with the one in which the electromagnetic stirring device and the electromagnetic brake device of Patent Document 1 are individually mounted.

  However, a DC power source is required for the electromagnetic brake and an AC power source is required for the electromagnetic stirring, and a current switching device (hereinafter referred to as a switching panel) for selectively applying a DC current and an AC current is required.

  In addition, according to the general design concept of those skilled in the art, the number of power cables is increased because the number of power cables for connecting the dual-purpose electromagnetic coil device and the power source is the same as the number of terminals of the exciting coil. If the number of power cables increases, for example, the work time for disconnection connection at the relay panel during equipment replacement becomes longer, and the probability that troubles such as incorrect connection methods will occur increases.

In order to solve these problems, Patent Document 3 discloses a method of mechanically connecting a plurality of power cable connection portions together (hereinafter referred to as an auto joint method).
JP 2002-307146 A

  However, the auto joint system of Patent Document 3 requires regular maintenance in order to reliably transmit large power for the electromagnet. In addition, it is desired to reduce the number of installed units from the viewpoint of labor saving of maintenance work and improvement of the operating rate of the continuous casting machine. Furthermore, the auto-joint system is very expensive in equipment itself, resulting in cost disadvantages.

  The problem to be solved by the present invention is that, when a dual-purpose electromagnetic coil device is used, regular maintenance is essential, and the power supply for connecting to the power supply is not used unless the equipment itself employs a very expensive auto-joint system. The increase in the number of cables is a problem in terms of work efficiency.

The connection method of the electromagnetic coil device for electromagnetic brake and electromagnetic stirring of the present invention is as follows:
In order to reduce the number of power cables connected to the power source without using the auto joint method when using a combined electromagnetic coil device,
When continuously casting steel,
In order to selectively apply an electromagnetic brake or electromagnetic stirring to the molten steel in the mold by applying a direct current or a three-phase alternating current,
N pieces (n is a natural number of 2 or more) are arranged on the outer periphery of the long side of the mold.
A total of three excitation coils, two excitation coils with windings on the outside of the teeth portion, and one excitation coil that has been wound further outside the windings of these two excitation coils. An electromagnetic coil having an excitation coil
Arranged 180 degrees rotationally symmetrical across the mold,
A method of connecting a power source cable and a connection terminal of each exciting coil of the electromagnetic coil device for both electromagnetic brake and electromagnetic stirring,
In the electromagnetic coils arranged symmetrically, the connection terminal start side of one electromagnetic coil and the connection terminal end side of the other electromagnetic coil are connected, and the connection terminal start side of the other electromagnetic coil is connected to the one electromagnetic coil. The most important feature is that the terminal end side is connected to the relay panel.

  In the present invention, one connection terminal start side and the other connection terminal end side of electromagnetic coils arranged 180 degrees rotationally symmetrical across the mold are connected, so the number of power cables connected to the relay panel is fully excited. The number of connection terminals of the coil can be reduced to half or less.

  By the way, during operation, the mold moves up and down. Therefore, in the present invention, when the power cable connected to the relay panel interferes with the equipment, the power cable is worn. In order to prevent wear of the power cable, it is desirable to attach the power cable to the mold so as to avoid interference with the equipment.

  In the present invention, the number of power cables connected to the relay panel is conventionally reduced to less than half the number of power cables connected to the relay panel without adopting the auto joint method. It is possible to improve workability and maintainability. Also, the equipment cost is low.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. 1 to 6 together with the process from the idea of the present invention to the solution of the problem.

FIG. 1A shows the structure of a dual-purpose electromagnetic coil device that is a subject of the present invention.
The dual-purpose electromagnetic coil device 1 has a configuration in which, for example, two electromagnetic coils disclosed by the applicant in Japanese Patent Laid-Open No. 60-44157 are coupled to the outer periphery of each long side 2a of the mold 2 in parallel. In FIG. 1A, 2a is the short side of the mold 2, 3 is an immersion nozzle, and 4 is a backup plate.

  The electromagnetic coil disclosed by the applicant in Japanese Patent Application Laid-Open No. 60-44157 is provided with a winding 1b on each of the two teeth 1a, and further on the outside of the two teeth 1a having these windings 1b. It is the structure which gave winding 1c and was put together. This electromagnetic coil is called a pai-type electromagnetic coil (hereinafter referred to as a pai-type coil) because the two tooth portions 1a and the yoke portion 1d are similar to the Greek letter π (pai).

  FIG. 1B shows how to wind the windings 1b and 1c constituting the dual-purpose electromagnetic coil device 1 according to the present invention. Hereinafter, each of the tooth portions 1a provided with the winding 1b is referred to as an inner excitation coil. Further, the outer side of these two inner excitation coils is referred to as an outer excitation coil.

  As shown in FIG. 1B, the inner and outer exciting coils wind the windings 1 b and 1 c in the counterclockwise direction when viewed from the outside of the mold 2. The inner excitation coils are referred to as coil a and coil c from the right side of FIG. 1B, and the outer excitation coil is referred to as coil b. Further, the pai type coil on the right side of FIG. 1A is called coil A, and the pai type coil on the left side of FIG. The pai coils facing each other in the mold 2 are of the same type, and are placed 180 degrees rotationally symmetrical with the mold 2 in between.

  Here, AaS in FIG. 1B means a current connection terminal on the start side of the winding 1b of the coil a in the coil A, and AaE means a connection terminal on the end side of the winding 1b. AbS means the current connection terminal on the start side of the winding 1c of the coil b in the coil A, and AbE means the connection terminal on the end side of the winding 1c. The connection terminals of the coil c in the coil A and the coils a, b, and c in the coil B are similarly attached.

  In the case of the dual-purpose electromagnetic coil device 1 according to the present invention shown in FIG. 1 (a), since each exciting coil has two connection terminals, the pai-type coil having six connection terminals is composed of four. , 24 connection terminals.

  FIG. 2 shows the phase of the alternating current applied during electromagnetic stirring. Here, U, V, and W are three-phase alternating currents having a phase difference of 120 degrees.

  In the case of this alternating current, the coils B, c, a of the coil B, the coils b, c, a of the coil A, the coils b, c, a of the coil A, and the coils b, c, a of the coil B in this order, For example, it is applied like -W, + V, + U, + W, -V, -U, -W, + U, + V, + W, -U, -V (see FIG. 2).

Further, during the electromagnetic brake, a direct current is applied in the direction shown in FIG.
FIG. 4 shows a conventional method for connecting the 24 connection terminals in the dual-purpose electromagnetic coil device 1 for selectively using the three-phase alternating current and direct current as described above during electromagnetic stirring and electromagnetic braking.

  In FIG. 4, two DC power sources 11, a DC power source 11 a for the inner exciting coil (coils a and c), a DC power source 11 b for the outer exciting coil (coil b), an AC power source 12 a for the coil A, The thing using the two alternating current power supplies 12 of the alternating current power supply 12b for coils B is shown.

  In the example shown in FIG. 4, the reason why a plurality of power supplies are used is that the power required for the dual-purpose electromagnetic coil device 1 cannot be supplied with a single power supply capacity. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-24559, it is not intended to control the electromagnetic stirring force of each coil, and the current value for each coil is not controlled. The current value applied to each coil of the dual-purpose electromagnetic coil device 1 is the same.

  In the case of the conventional method shown in FIG. 4, the changeover switch of the changeover panel 13 switches between application of alternating current for electromagnetic stirring and direct current for electromagnetic brake. The number of power cables connected to 14 is 24, which is the same as the connection terminals described above. When connecting the same number of power cables as such connection terminals, it takes a long time to connect the power cables when the equipment is changed.

  Therefore, the inventors have established the present invention described below because the current application method of the dual-purpose electromagnetic coil device 1 is 180-degree rotationally symmetric with respect to the mold 2 during electromagnetic stirring and electromagnetic braking.

  That is, as shown in FIG. 5, the present invention connects the start side and the end side of the connection terminals between the upper and lower coils A and the coils B around the mold 2, and Side and end side are connected to the relay panel 14.

  According to the present invention, it is possible to reduce the number of power cables conventionally connecting all the connection terminals and the relay panel 14 to half.

  Incidentally, in the case of the present invention shown in FIG. 5, the work time required for connecting the power cable at the time of equipment change can be shortened from 45 minutes of the conventional method shown in FIG. 4 to 15 minutes. Furthermore, in the present invention, the number of power cables connected to the relay panel is halved, so the number of troubles caused by connection mistakes has been drastically reduced.

  In continuous casting using the combined electromagnetic coil device 1 to which the method of the present invention is applied, the mold 2 moves up and down during operation. Therefore, in the present invention, when the power cable connected to the relay panel 14 interferes with the equipment, the power cable is worn.

  In order to prevent wear of the power cable, it is desirable to attach the power cable to the mold so as to avoid interference with equipment. FIG. 6 is a view showing an example of a mode in which the power cable 15 is attached to the mold 2 so as to avoid interference with the equipment.

  FIG. 6 shows that a rib for passing the power cable 15 is provided in the rib portion 2c at a predetermined position of the rib portion 2c provided in the mold 2, and the width of the mold 2 is changed by passing the power cable 15 through the hole. In some cases, the power cable 15 is prevented from interfering with the equipment operating unit.

  However, as long as it avoids interference with the equipment of the power cable 15, the present invention is not limited to one in which a hole is formed in the rib portion 2 c of the mold 2. For example, a hook for supporting the power cable may be installed at an appropriate position of the mold 2.

  It goes without saying that the present invention is not limited to the above-described examples, and the embodiments may be appropriately changed within the scope of the technical idea described in each claim.

  For example, the dual-purpose electromagnetic coil device 1 that is the subject of the present invention is not limited to one in which two pai-type coils are arranged on each long side 2a of the mold 2 described with reference to FIGS.

  The above technical idea of the present invention can be applied to any connection as long as the current value applied to the equipment connected from the power source is the same.

(A) is a figure which shows the structure of the combined electromagnetic coil apparatus made into object in this invention, (b) is a figure which shows how to wind the winding which similarly comprises a combined electromagnetic coil apparatus. It is a figure which shows the phase of the alternating current applied to the combined electromagnetic coil apparatus made into object in this invention at the time of electromagnetic stirring. It is a figure which shows the direction of the direct current applied to the dual purpose electromagnetic coil apparatus made into object in this invention at the time of an electromagnetic brake. It is a figure which shows the conventional method which connects 24 connection terminals in a combined use electromagnetic coil apparatus which uses a three-phase alternating current and a direct current separately at the time of electromagnetic stirring and electromagnetic braking. It is a figure similar to FIG. 4 which shows this invention method. It is the figure which showed an example of the aspect which attaches a power cable to a casting_mold | template so that interference with an installation may be avoided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combined electromagnetic coil apparatus 1a Teeth part 1b Winding 1c Winding 1d Yoke part 2 Mold 2a Long side 2c Rib part 11 DC power supply 12 AC power supply 13 Switching panel 14 Relay panel 15 Power cable

Claims (2)

When continuously casting steel,
In order to selectively apply an electromagnetic brake or electromagnetic stirring to the molten steel in the mold by applying a direct current or a three-phase alternating current,
N pieces (n is a natural number of 2 or more) are arranged on the outer periphery of the long side of the mold.
A total of three excitation coils: two excitation coils with windings on the outside of the teeth portion, and one excitation coil that is wound together outside the windings of the two excitation coils. An electromagnetic coil having an excitation coil
Arranged 180 degrees rotationally symmetrical across the mold,
A method of connecting a power supply cable and a connection terminal of each excitation coil of the electromagnetic coil device for both electromagnetic brake and electromagnetic stirring,
In the electromagnetic coils arranged symmetrically, the connection terminal start side of one electromagnetic coil and the connection terminal end side of the other electromagnetic coil are connected, and the connection terminal start side of the other electromagnetic coil is connected to the one electromagnetic coil. A method for connecting an electromagnetic brake and electromagnetic stirring electromagnetic coil device, wherein the terminal end side is connected to a relay panel.   The method for connecting an electromagnetic brake and electromagnetic stirring electromagnetic coil device according to claim 1, wherein the power cable connected to the relay panel is attached to a mold so as to avoid interference with equipment.

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