JP3533047B2 - Flow controller for molten metal - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control device for driving a molten metal in a mold with a linear motor, and particularly, although not intended to be limited to this, a pair of opposed long sides extending in the y direction. On the other hand, the present invention relates to a flow control device suitable for a variable-width mold that can change the position of the short side in the y direction.

[0002]

2. Description of the Related Art In continuous casting, for example, molten steel is poured into a mold from a tundish, and in the mold, the molten steel is drawn from the wall surface of the mold while being gradually cooled. On the upper surface of the molten steel in the mold, a powdery heat insulating material or a slab drawing lubricant (commonly called powder) is put. If the temperatures on the wall surfaces of the mold having the same height are not uniform, surface cracking or shell breakage (breakout) due to seizure of the slab on the inner surface of the mold is likely to occur. Further, if powder remains as lumps in the molten steel or on the surface of the slab, this becomes a foreign substance, that is, a defect in the slab. In order to improve this, conventionally, using a linear motor, the molten steel in the mold is flow-driven in parallel with the upper surface thereof along the wall surface of the mold to make the temperature of the surface in contact with the mold uniform and Prompt the floating of the powder (for example, Japanese Patent Laid-Open No. 1-228645).

Although the flow driving of molten steel presented in Japanese Patent Application Laid-Open No. 1-228645 has some effect, the circulating flow along the wall surface of the mold is disturbed by the flow of molten steel flowing into the tundish through the injection nozzle. . For this type of flow drive, a linear motor type electromagnet in which an electric coil is wound around each of a plurality of magnetic poles arranged along the long side of the mold is used, and the electric coil is for every three phases. Bundled in
It is connected to each phase of a three-phase power supply with a 120 ° phase shift in a bundled unit, and the voltage and / or frequency of the three-phase power supply is adjusted by an inverter or a cycloconverter.
The required driving force and speed are obtained. For example, there is one in which a linear motor is arranged along the long side of the mold and an electromagnetic driving force is applied to the molten steel to generate a circulating flow that circulates along the inner wall of the mold with a uniform flow velocity distribution in the surface layer of the molten steel. When the circulating flow stably flows at the surface layer at a constant speed, the floating of bubbles is promoted,
The powder is not entrained in the molten steel, the inner surface of the mold near the surface layer is wiped clean, and the molten steel does not stay.

[0004]

By the way, in general,
Although the linear motor has the same length as the effective length of the long side of the mold (corresponding to the width of the slab) extending in the y direction, the effective length of the long side of the mold is often different depending on the equipment. The length (y direction) is insufficient or too long. Designing and manufacturing a linear motor of the most suitable length for each equipment increases the equipment cost.

On the other hand, there is also a variable width mold in which the position of the short side in the y direction can be changed with respect to the opposite long side so that it can be adapted to several kinds of slab sizes (in particular, slab width). The size of the mold may be changed depending on the type of product (cast piece) to be cast. In such a case, the short side of the mold is moved in the y direction (the direction in which the long side extends). However, since changing the specifications of the linear motor requires a great deal of time and labor, it is usual that the specifications of the linear motor are not changed even if the size of the mold is changed. However, the size of the mold is, for example, 1.0 m
Applying a large linear motor manufactured to a large mold over a range of ~ 2.4 m to a small mold causes the size of the mold to be smaller than the execution length of the linear motor, so Not an electric coil will generate unnecessary electromagnetic force. On the other hand, if a small linear motor manufactured according to a small mold is applied to a large mold, the size of the mold is large relative to the running length of the linear motor, and the electromagnetic force required for flow driving is large. The force cannot be sufficiently applied to the molten steel in the mold.

The first object of the present invention is to increase the adaptability of the linear motor to the large and small mold widths, and to effectively apply the required electromagnetic thrust to both the large and small mold widths. The second purpose is to add to the molten metal.

[0007]

The flow control device of the present invention has a pair of opposed short sides with respect to long sides extending in the y direction.
mold surrounding the y molten metal capable variable width changes direction position (MM), a first electromagnet core having a plurality of slots distributed in the y direction along the first long side (5F) (10F), A number of a + b, a <b electric coils (AF1-6, BF1-12) inserted in each slot, a number of a-coils
Between the first group (#AF) consisting of (AF1 to 6) and the second group (#BF) consisting of b electric coils, there is a nozzle (30) for injecting molten metal into the mold. First linear motor (LMF) arranged so as to be positioned; a plurality of the first long sides (5F) and a plurality of them distributed in the y direction along the second long side (5L) that faces the molten metal (MM). A second electromagnet core (10L) having a slot and a plurality of electric coils (AL1 to 6, BL1 to 12) of c + d and c <d respectively inserted in the respective slots, and c electric coils (AL1 ~
6), which is the third group (#A) facing the second group (#BF).
L) and d electric coils (BL1 to 12), and the first group (#A
The second linear motor (LML) arranged so that the nozzle (30) is located between the fourth group (#BL) facing the F); the first
Multi-phase for generating a moving magnetic field along the y direction in the first group (#AF) of the linear motor (LMF) and the third group (#AL) of the second linear motor (LML) First energizing means (20A) for energizing alternating current; and second group of the first linear motor (LMF)
Group (#BF) and the fourth group (# of the second linear motor (LML)
BL) is provided with a second energizing means (20B) for energizing a multi-phase alternating current for generating a moving magnetic field along the y direction.

Molten metal entering the mold from the nozzle (30) flows toward the short side of the mold (protruding flow), hits the short side and partly descends and partly rises, and the ascended molten metal is At the surface (meniscus) of the molten metal inside, there is a horizontal flow toward the nozzle. This allows, for example, the level of the molten metal outlet of the nozzle.
When the center of the linear motor in the z direction is located in the (height direction z), the molten metal flows in a direction from the nozzle toward the short side on a horizontal plane where the center is located. This flow is corrected by a thrust force given by a linear motor to a clockwise or counterclockwise horizontal swirling flow along the inner surface of the mold, which is caused by seizure of molten metal on the inner surface of the mold or metal of foreign matter such as powder lumps (slabs). ) It is effective for preventing biting on the surface and for promoting the floating of foreign matter and gas mixed in the molten metal. When such a swirling flow is formed, the flow direction (direction of natural flow) generated by the inflow of the molten metal is opposite to the left and right in the y direction with the nozzle as the center. In the direction, a strong thrust that overcomes the natural flow is applied to the molten metal with a linear motor, and on the left side, a thrust in the same direction or in the opposite direction as the natural flow, which slightly accelerates the natural flow or slightly attenuates it, It may be given to molten metal. In this case, a strong thrust is required on the right side of the nozzle, but a weak thrust is required on the left side.

In the above-mentioned flow control device of the present invention (for example, FIG. 2), for example, the second group (#BF) of the first linear motor (LMF) having a large number of electric coils b is set to the above right side, The above swirling flow can be obtained by associating the first group (#AF) having a small number of electric coils a so as to be on the left side.
The same applies to the second linear motor (LML). That is, the second linear motor (LML) is 180 degrees centered on the nozzle (30).
Since the first linear motor (LMF) is rotated horizontally by a degree, the first and second linear motors (LMF, LML) work together to generate one swirl flow on the same horizontal plane. It will be.

The thrust generated by the second group (#BF) and the fourth group (#BL) having a large number of electric coils b and d of the first and second linear motors (LMF, LML) is The above-described flow control device of the present invention can be applied up to the maximum mold width that can provide thrust to overcome the natural flow of molten metal. In this case, the first group (#AF) and the third group (#A) in which the numbers of electric coils a and c of the first and second linear motors (LMF, LML) are small.
L) exerts a substantial thrust on only a part of the region of half the mold width, that is, the effective length of the linear motor (LMF, LML) is considerably shorter than the mold width, but in that region the natural flow and the The thrust is in the same direction or in the opposite direction in which the natural flow is decelerated, and in either case, the absolute value of the thrust may be small, so that a swirling flow that makes the entire mold width in order can be generated.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

(2) The first energizing means (20A) and the second energizing means (20B) are
It includes level setting means (22A1 to 24A1, 22B1 to 24B1) for setting the current level of the multi-phase alternating current to be applied to the electric coil.

[0012] According to this, as the actual mold width (effective length: slab width) becomes smaller than the maximum mold width described above, the energizing current level of the electric coil is lowered, so that the strength corresponding to the mold width is increased. It can generate a swirling flow, and is highly compatible with various widths below the maximum mold width.

(3) The first energizing means (20A) and the second energizing means (20B) include direction switching means (31A1, 31B2) for switching the moving direction of the moving magnetic field generated by the electric coil.

According to this, when the mold width is small and most of the electric coils of the second group (#BF) and the fourth group (#BL) deviate from the effective width of the mold, the direction switching means. (31A1,31
By switching the direction of the moving magnetic field in B2), the direction of the swirling flow described above is reversed. At the same time, energization of the first group (#AF) and third group (#AL) electric coils in which the numbers of electric coils a and c of the first and second linear motors (LMF, LML) are small. The level, that is, the output current value of the first energizing means (20A) is set such that the thrust generated by those electric coils overcomes the natural flow of the molten metal, and the number of electric coils b and d is large. -Group (#BF) and 4th group (#B)
L) the energization level of the electric coil, that is, the second energizing means (20
By setting the output current value of B) to a small value such that the thrust generated by the natural flow and those electric coils are in the same direction or in the opposite direction to decelerate the natural flow, the entire mold width is A stable small swirl flow is generated. At this time,
The energization levels of the second group (#BF) and the fourth group (#BL), which have a large number of electric coils b and d, are extremely low, and the electric coils (#BF, #BL Since the current value flowing through the () is small, the magnetic field that is wastefully generated is weak, and wasteful power consumption is small. Other objects and features of the present invention include:
It will be apparent from the following description of the embodiments with reference to the drawings.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a linear motor L according to an embodiment of the present invention.
A vertical cross section of the MF, LML and the mold MD between them is shown, and a horizontal cross section is shown in FIG. The mold MD is composed of a pair of long sides 5F, 5L facing each other and extending in the horizontal y direction and a pair of short sides 6R, 6L facing each other extending in the horizontal x direction. The positions of the short sides 6R and 6L can be changed in a direction y toward and away from the pouring nozzle 30, and a distance y between the inner surfaces of the short sides 6R and 6L, that is, the mold M.
The effective width of D can be set within the range of 1.0 m to 2.4 m. FIG. 2 shows a state in which the length is set to 1.6 m. In FIG. 9 described later, the state set to 1.0 m (lower limit value) is shown in FIG.
Shows the state set to 2.4 m (upper limit value). In any case, the pouring nozzle 30 is located at the center of the effective width of the mold. That is, the short sides 6R and 6L are y from the nozzle 30.
The distances are set to be the same.

Molten steel MM is injected into the mold MD by the injection nozzle 30.
Is injected toward the short sides 6R and 6L through the outlet 30a. The meniscus (surface) of the molten steel MM in the mold MD is covered with the powder PW. The mold MD is cooled by a water box (not shown) and cooling water flowing in a water channel in the mold, and the molten steel MM gradually solidifies from the part in contact with the cooled surface of the mold toward the inside, and is continuously extracted as a slab. Be done. However, since the molten steel MM is poured into the mold MD through the injection nozzle 30, the molten steel MM is constantly poured into the mold MD.
Exists.

Along the longitudinal direction of the long side 5F of the mold MD,
In addition, the first linear motor LMF is located at substantially the same height as the outlet 30a of the injection nozzle 30, and the second linear motor LML is arranged along the longitudinal direction of the long side 5L of the mold MD so as to face the linear motor LMF. Are provided and these are nozzles 3
Electromagnetic thrust is applied to the molten steel MM having substantially the same height as the zero outlet 30a.

FIG. 3 shows an enlarged cross section taken along line 3A-3A of FIG. Referring to FIGS. 2 and 3, 5F and 5L are first and second long pieces of the inner wall 50 of the continuous casting mold MD, 6R and 6L are first and second short pieces, and an injection nozzle is provided in a space surrounded by these. Molten steel MM passes through 30 from the front side to the back side in FIG. 2 (from the upper side to the lower side in the vertical direction z)
Injected. Each side is a copper plate 2F, 2L, 4R, 4L backed by a non-magnetic stainless steel plate 1F, 1L, 3R, 3L.

By the way, the first long side 5F is fixed,
The distance between the second long side 5L and the long side 5F can be changed by shifting the position in the x direction parallel to the first long side 5F depending on the specifications (thickness) of the product (cast piece) to be manufactured. Further, the first and second short sides 6R and 6L can be removed and replaced with those having different widths (lengths in the x direction in FIG. 2). Short side 6R,
Several types of 6L having different dimensions are prepared, and these are the inner wall 5 as the first and second short sides 6R and 6L.
When 0 is configured, the lengths of the sides in the thickness direction of the cast slab are different. Before the continuous casting is started, the worker parallels the first long side 5F with the second long side 5 according to the specifications of the product to be manufactured.
Adjust the position of L in the x direction. Then, depending on the x-direction distance (thickness of the mold) between the first long side 5F and the second long side 5L, an appropriate x-direction length (thickness) is selected from among several types of short sides. , And the first and second short sides 6R and 6L are symmetrically installed about the nozzle 30 between the first and second long sides 5F and 5L. Thus, the inner wall 50 of the mold is formed. The positions of the first and second short sides 6R and 6L in the width direction (y direction in FIG. 2) are also adjusted according to the specifications of the product to be manufactured, and are installed symmetrically about the nozzle 30 and parallel to each other. . Thereby, for example, the intermediate width (1.6 m in the y direction) shown in FIG. 2 (and FIG. 5), the minimum width (1.0 m) shown in FIG. 9, and the maximum width (2.4 m) shown in FIG.
For example, the casting size of the mold MD can be set to a size from the minimum width of 1.0 m to the maximum width of 2.4 m.

By the way, as shown in FIG. 2, in this embodiment, the electromagnet core 10F of the first linear motor LMF has 18 slots on the inner side facing the first long side 5F,
Electric coils AF1 to AF6, BF in each of the slots
1 to BF12 are inserted, and these electric coils are "body winding" that circulates around the core portion of the core 10F. An end surface of the convex portion between the slots of the electromagnet core 10F on which each electric coil is mounted faces the molten steel MM at approximately the same height as the outlet 30a of the nozzle 30. Although the electromagnet core 10F and the electric coils AF1 to AF6 and BF1 to BF12 are cooled and covered with a heat-resistant cover, the cooling structure and the cover are not shown. The second linear motor LML has the same structure as the first linear motor LMF,
The mold MD is sandwiched with respect to the first linear motor LMF, and the nozzle 30 is located in point symmetry. That is, the electromagnet core 10L of the second linear motor LML has a comb shape having 18 slots inside which oppose the second long side 5L, and the electric coils AL1 to AL6, B are provided in the respective slots.
L1 to B12 are inserted and attached in a “body winding”.

In FIG. 2, #AF and #BF are respectively the first group of electric coils of the first linear motor LMF.
The first group is composed of a = 6 electric coils AF1 to AF6, and the second group is composed of b = 12 electric coils BF1 to BF12. There is. Third group #AL and fourth group #BL
Are c = 6 electric coils AL1 to AL6 and d = 12 electric coils B of the second linear motor LML, respectively.
It is composed of L1 to BL12.

The first linear motor LMF is arranged so that the boundary between the first group #AF and the second group #BF is aligned with the position (y direction) of the nozzle 30, and similarly. The second linear motor LML has a third group #AF and a fourth group #AF.
It is arranged so that the boundary with the nozzle #BL matches the position of the nozzle 30.

In this embodiment, a = c = 6, b = d = 2
a = 12, and the first linear motor LMF and the second linear motor LML have the same structure and the same size. Conventionally, in order to be applicable to a maximum width of 2.4 m, each linear motor is long in the y direction in which 24 electric coils are mounted with a = b = 12 (the linear motor L shown in FIG. 2).
MF and LML are set to be long to two-dot chain lines 10Fa and 10La), but in this embodiment, each linear mode is used.
The number of electric coils of the computer is 6 + 12 = 18, which is 18/2 of the conventional
4 = 3/4, and therefore linear motors LMF and LML
Is 3/4 of the conventional length (y direction).

In the embodiment shown in FIG. 2 in which the mold is set to the intermediate size, the linear motors LMF, LML cores 10F,
10L is shorter than the effective length of the long sides 5F and 5L of the mold (the length in the y direction where the molten steel MM contacts = the distance between the short sides 6R and 6L: 1.6m), but the center in the width direction (y) of the first linear motor LMF. Is shifted from the center (y) of the mold MD in the width direction (nozzle 30) toward the shorter side 6L, and the center of the second linear motor LML in the width direction (y) is shorter than the center of the mold MD in the width direction (y). It is displaced toward the side 6R, and the displacement amount from the center in the width direction (y) of each mold MD is the same. However, the shift direction is opposite. That is, the first linear motor LMF and the second linear motor LML are offset in the opposite directions to each other in parallel with the width direction (y) along the long sides 5F and 5L.
Are arranged in point symmetry with respect to the center point of the horizontal section (where the nozzle 30 is arranged in this embodiment).
Therefore, in the molten steel MM in the mold MD shown in FIG. 2, the central region sandwiched between the first linear motor LMF and the second linear motor LML, and either the first linear motor LMF or the second linear motor LML. There is a region near the short side where only one of them faces.

Core 10 of linear motors LMF, LML
Electric coil groups #AF, 10L are provided in the slots of the portions of F, 10L that face each other across the molten steel MM in the central region.
# AL all electric coils AF1-AF6, AL1-AL6
Also, half the electric coils BF1 to BF6 and BL1 to BL6 adjacent to the electric coil groups #AF and #AL of the electric coil groups #BF and #BL are mounted.
Then, #B is provided in the slots of the cores 10F and 10L facing the molten steel in the region near the short side closer to the shorter side.
Electric coil B of the other half of F group and #BL group
F7 to AF12 and BL7 to BL12 are attached.

The linear motors LMF, LML have thrusts (directions and magnitudes) Faf, Fbf, shown by dotted arrows in FIG.
FaL and FbL are given to molten steel MM. By the way, nozzle 3
The flow of molten steel injected into the mold from 0 is generally in the direction from the nozzle to the short sides 6L and 6R, as indicated by the two-dot chain line arrow. This is called natural flow. First group #A
Electromagnetic thrust FaF (weak) given to molten steel by electric coil of F
Is in the same direction as the natural flow, so the natural flow is accelerated, but the electromagnetic thrust FbF (strong) applied to the molten steel by the electric coil of the second group #BF is in the opposite direction to the natural flow. Since it is stronger than the flow, the molten steel flows in the opposite direction to the natural flow,
This strength is the difference between the electromagnetic thrust FbF and the natural flow. As a result, the molten steel near the long side 5F flows in the direction from the short side 6L to the short side 6R (to the left) along the long side 5F. For the same reason, the molten steel near the long side 5L flows along the long side 5L in the direction from the short side 6R to 6L (to the right). As a combination of them, molten steel makes a counterclockwise swirl.

FIG. 4 shows the system configuration of this embodiment.
Nozzle 30 of linear motors LMF and LML shown in FIG.
The electric coil groups #AF and #AL, which face each other with respect to the molten steel MM in a point-symmetrical manner, are connected to the same power supply, that is, the first power supply circuit 20A. In addition, the nozzles 30 are adjacent to the electric coil groups #AF and #AL, respectively.
The electric coil groups #BF and #BL that face each other in a point-symmetrical manner with the molten steel MM in between are connected to the same power source, that is, the second power source circuit 20B. The first power supply circuit 20A and the second power supply circuit 20B generate a three-phase AC voltage and apply it to each electric coil group connected thereto. In FIG. 4, three wirings for each phase (U, V, W) of the three-phase AC voltage generated by the first power supply circuit 20A and the second power supply circuit 20B are collectively shown as one line and indicated by a chain double-dashed line. , Connection terminals with each power supply (U11 ~ U22, V11 ~ V22,
Illustration of (W11 to W22) is omitted.

According to FIG. 4, electric coil group #A
F and #AL and electric coil groups #BF and #BL have different supply powers of the supplied three-phase AC voltage, and the frequency or voltage of the supplied three-phase AC voltage is the power supply circuits 20A and 20B. Frequency command value Fdc
By changing A1, FdcB2, and voltage command values VdcA1, VdcB2, it is possible to control independently. Further, a direction signal given to the power supply circuits 20A and 20B (FIGS. 6 and 7)
By switching the energization level (H or L) of
It is possible to switch the phase of the three-phase AC voltage applied to each electric coil group connected to each of the power supply circuits 20A and 20B (switch the U phase and the W phase). As will be described later, by switching the phase of the three-phase AC voltage applied to each electric coil group, the linear motor LMF,
The phase arrangement of LML is switched, and each linear motor LMF,
The direction of the thrust that the LML gives to the molten steel MM is reversed.

The electric coil on the starting point side of the liquid molten steel, that is, the exciting current flowing through the second group #BF and the fourth group #BL is I1, and the electric coil on the end point side of the liquid molten steel, that is, the first group #. Letting I2 be the exciting current flowing through the AF and the third group #AL, the current ratio α is α
= I2 / I1, the velocity of the molten steel at the starting point is Vs,
When the end point velocity is Ve, the molten metal M is flow driven
The horizontal direction velocity along the long sides 5L and 5F of M is Vs ≧
In order to achieve Ve, it is desirable that 0 ≦ α ≦ 0.5. Thrust Fb on the starting side of the molten steel shown in FIGS. 2 and 4.
F, FbL and the thrust forces FaF, FaL on the end point side are α =
It is when it is set to 0.5.

FIG. 5 shows the first linear motor LM shown in FIG.
All electric coils AF1 of F and the second linear motor LML
~ BF12 and AL1-BL12 connection and power supply circuit 2
The connection mode with 0A and 20B is shown. The linear motors LMF and LML shown in FIG. 5 have three poles, and each electric coil is energized with a three-phase alternating current generated by the power supply circuits 20A and 20B. For example, the first linear motor LMF
Electric coil of group #AF (#AF: AF1 to AF
6) are shown as W, W, v, v, U, U in this order in FIG. Also, the electric coil of the second group #BF (#B
F: BF1 to BF12), w, w
Represented as w, V, V, u, u, W, W, v, v, U, U.
The electric coils (#AL: AL1 to AL6) of the third group #AL of the second linear motor LML are shown as W, W, v, v, U, U in this order in FIG. Fourth group #B
The L electric coil (#BL: BL1 to BL12) is shown in FIG.
Then, in this order, w, w, V, V, u, u, W, W, v,
Represented as v, U, U.

"U" represents the positive-phase energization of the three-phase AC (the energization as it is) and "u" represents the U-phase reverse-phase energization (the phase-shift energization of 180 degrees from the U-phase). While the U-phase is applied to the coil "U" at the winding start end,
This means that the U phase is applied to the electric coil "u" at the end of the winding. Similarly, “V” is the positive phase conduction of the V phase of the three-phase AC, “v” is the reverse phase conduction of the V phase, and “W” is the positive phase conduction of the W phase of the three-phase AC, “w”. Represents the reverse-phase energization of the W phase, respectively.

Terminals U11, V11, W11 shown in FIG.
Is a power supply connection terminal of the electric coils AF1 to AF6 of the first group #AF, and terminals U21, V21, W21 are power supply connection terminals of the electric coils BF1 to BF12 of the second group #BF. In addition, terminals U12, V12, W12
Are power supply connection terminals of the electric coils AL1 to AL6 of the third group #AL, and terminals U22, V22, W22 are power supply connection terminals of the electric coils BL1 to BL12 of the fourth group #BL.

FIG. 6 shows the configuration of the first power supply circuit 20A for supplying a three-phase alternating current to the first group #AF and the third group #AL. A thyristor bridge 22A1 for DC rectification is connected to the three-phase AC power supply (three-phase power line) 21, and its output (pulsating flow) is smoothed by the inductor 25A1 and the capacitor 26A1. The smoothed DC voltage is a power-transistor bridge 27A for forming a three-phase AC.
1 is applied. In this embodiment, when the molten steel MM in the mold MD set to the intermediate size is flow-driven (FIGS. 2 and 5), the operator makes an L level (counterclockwise rotation) via a host computer (not shown). A direction signal "instructing driving" is input to the power supply circuit 20A. During counterclockwise turning drive in which the direction signal input to the power supply circuit 20A is L level, the U phase of the three-phase AC output from the power transistor bridge 27A1 is the power supply connection terminal U1 shown in FIG.
1, U12, V phase to power supply connection terminals V11, V12,
Further, the W phase is applied to the power supply connection terminals W11 and W12.
However, during clockwise turning drive in which the direction signal is at the H level, the U phase applied to the power supply connection terminals U11, U12 and the W phase applied to the power supply connection terminals W11, W12 are switched, and the power supply connection terminal U11 is switched. , U12 is applied with the W phase, and the power supply connection terminals W11, W12 are applied with the U phase. As a result, the direction of the thrust applied to the molten steel by the linear motor is opposite to the direction shown by the dotted arrow in FIG.
This clockwise turning drive in which the direction signal is at the H level will be described later with reference to FIG.

The electric coil of the first group #AF and the third coil
A coil voltage command value VdcA at which the electric coil of the group #AL generates thrusts FaF and FbL indicated by dotted arrows in FIG.
1 is given to the phase angle α calculator 24A1, and the phase angle α calculator 24A1 outputs the conduction phase angle α corresponding to the command value VdcA1.
(Thyristor trigger-phase angle) is calculated and a signal representing this is given to the gate driver 23A1. The gate driver 23A1 starts the phase counting of the thyristor of each phase from the zero-cross point of each phase, and the conduction trigger at the phase angle α.
To do. As a result, the direct current voltage indicated by the command value VdcA1 is applied to the transistor bridge 27A1.

On the other hand, the three-phase signal generator 31A1 has a frequency designated by the frequency command value FdcA1 (4 in this embodiment).
Constant voltage three-phase AC signals (U, V, W) of (Hz) are generated. When the "direction signal" is at the L level, the three-phase signal generator 31A1 outputs U of the transistor bridge 27A1.
The U phase of the constant voltage 3-phase AC signal is applied to the phase output transistor pair 27uA to the comparator 29A1, and the V phase of the constant voltage 3-phase AC signal is applied to the V phase output transistor pair 27vA of the transistor bridge 27A1. Given to
The W phase of the constant voltage three-phase AC signal is applied to the comparator 29A1 to the W-phase output transistor pair 27wA of the transistor bridge 27A1.

The comparator 29A1 also includes a triangular wave generator 3
0A1 gives a constant voltage triangular wave of 3 KHz. Comparator 2
9A1 is a high level H (transistor on) when the U-phase signal has a positive level and is higher than the level of the triangular wave provided by the triangular wave generator 30A1, and a low level L (transistor off) when it is less than the level of the triangular wave. To the positive section of the U-phase output transistor pair 27uA (to the U-phase positive voltage output transistor).
When the U-phase signal is at a negative level, it is at a high level H when it is below the level of the triangular wave provided by the triangular wave generator 30A1, and at a low level L when it exceeds the level of the triangular wave. The signal is output to the gate driver 28A1 to the negative section of the pair 27uA (to the U-phase negative voltage output transistor). The same applies to the V-phase signal and the W-phase signal. The gate driver 28A1 corresponds to the signals for the respective phases, positive and negative sections, and outputs the transistor pair 27uA for each phase of the transistor bridge 27A1.
Each of the 27 vA and 27 wA transistors is turned on and off.

As a result, when the direction signal is at the L level (instruction for counterclockwise turning drive), the power supply connection terminal U11,
U-phase voltage of three-phase AC is output to U12, similar V-phase voltage is output to power supply connection terminals V11 and V12, and similar W-phase voltage is output to power supply connection terminals W11 and W12. The level between the upper peak and the lower peak of the voltage is determined by the coil voltage command value VdcA1. The frequency of this three-phase voltage is 4 Hz according to the frequency command value FdcA1 in this embodiment. That is, the three-phase AC voltage of 4 Hz designated by the coil voltage command value VdcA1 corresponds to the electric coil of the first group #AF and the third group #AF shown in FIGS. 2, 4 and 5.
Applied to the AL electric coil.

FIG. 7 shows the electric coils of the second group #BF of the first linear motor LMF and the second linear motor LML.
Three-phase alternating current is passed through the electric coil of the fourth group #BL of
The structure of the 2nd power supply circuit 20B is shown. This power supply circuit 20B
The configuration is the same as that of 20A described above, but the frequency command value FdcB2 and the coil voltage command value VdcB2 are different. The second power supply circuit 20B supplies the power supply connection terminals U21 and U22 with a three-phase AC voltage having a frequency designated by the frequency command value FdcB2 (4 Hz in the present embodiment) at a voltage level designated by the coil voltage command value VdcB2. , V21, V22, W
21 and W22, the first and second linear motors LMF,
It is applied to the electric coils of the second and fourth groups #BF and #BL of the LML. Similar to the power supply circuit 20A described above,
In this embodiment, when the mold MD is set to the intermediate size, the worker inputs a direction signal of L level to the power supply circuit 20B via the host computer. As a result, the gate driver 28B2 becomes a three-phase signal generator 31B.
Corresponding to the U phase generated by 2 and the signals addressed to the positive and negative sections,
The positive and negative section voltage output transistors of the U-phase output transistor pair 27uB of the transistor bridge 27B2 are turned on and off, and the V phase output of the transistor bridge 27B2 corresponding to the signals for the V phase, positive and negative sections. Each positive and negative interval voltage output transistor of the transistor pair 27vB is turned on and off, and each positive of the W phase output transistor pair 27wB of the transistor bridge 27B2 is responded to in response to the signal addressed to the W phase, positive and negative intervals. , Energizes the negative interval voltage output transistor on and off. Thus, the U phase of the three-phase AC voltage is output to the power supply connection terminals U21 and U22, the V phase of the three-phase AC voltage is output to the power supply connection terminals V21 and V22, and the three phases are output to the power supply connection terminals W21 and W22. The W phase of the AC voltage is output.

Frequency command value FdcA1 (FIG. 6), frequency command value FdcB2 (FIG. 7), and coil voltage command value VdcA
1 (FIG. 6), the coil voltage command value VdcB2 (FIG. 7) and the direction signal (FIG. 6, FIG. 7) are given to the respective power supply circuits 20A and 20B by an external high-order computer (not shown). The values of all can be changed or adjusted by the operator through the above mentioned supercomputer. In the present embodiment, frequency command values FdcA1 and FdcB2 designating the frequency 4 Hz of the given three-phase AC voltage are given to the three-phase signal generators 31A1 and 31B2.

Please refer to FIG. 4 again. First power supply circuit 2
0A is the frequency command value FdcA1 and the voltage command value VdcA1
The three-phase AC voltage having the frequency and voltage level designated by is applied to the first and second linear motors LMF and LML.
Energize the groups #AF and #AL. In addition, the second power supply circuit 20B uses the frequency command value FdcB2 and the voltage command value V
A three-phase AC voltage having a frequency and voltage level designated by dcB2 is supplied to the second and fourth groups #BF and #BL of the first and second linear motors LMF and LML. This allows
Driving force (thrust) FaF, FbF, FaL, FbL along the long sides 5F, 5L provided by the linear motors LMF, LML to the molten steel at the level of the outlet 30a of the nozzle 30 (Figs. 2, 4 and 5). Accordingly, the molten steel is flow-driven along each long side of the mold, and the surface of the long side of the mold is constantly wiped, so that the wiping effect is high.

In FIG. 8, α = I2 / I1, I1: current value flowing in the electric coils of the second and fourth groups #BF, #BL, I2: first and third groups #AF, # The following shows the results of implementation when the value of the current flowing in the AL electric coil and the value of were changed. DKM means a linear motor (LMF, LML), and the nozzle 30 jets molten steel at a position of 0.8 m on the horizontal axis indicating the long side direction of the mold. The level of the outlet 30a is about 0.
It is 5m.

FIG. 8 shows the distribution of horizontal velocity components of molten steel in the meniscus portion. Here, the electric current I1 excited by the electric coil groups #BF and BL is always constant,
α = 0.0 means that I2 = 0, that is, the current excited in the electric coil groups #AF and AL is zero. Further, 1 <α indicates that I1 <I2. It should be noted that the molten steel is driven to rotate by the linear motors LMF and LML as follows.
Level of the outlet 30a, that is, about 0.5 m below the meniscus
However, due to the swirling flow there, a similar swirling flow also appears in the meniscus (the upper surface of the molten steel).

For example, when α = 1.0, the first and third
The electric current I2 of the electric coils of the groups #AF and AL and the electric current I1 of the electric coils of the second and fourth groups #BF and BL have the same value (I1 = I2), and the first and third groups #AF , AL give thrust to molten steel MM FaF, FaL
In contrast, the second and fourth groups #BF and BL are molten steel MM
The thrusts FbF and FbL applied to the coil are approximately doubled because the number of coils in the group is doubled. This strong thrust FbF,
FbL overcomes the natural flow (two-dot chain line arrow in FIG. 2) generated when the molten steel is injected into the mold, and drives the molten steel in the direction opposite to the natural flow direction.

Further, α <1.0 is lowered (I2 is lowered → the supply voltage of the power supply circuit 20A is lowered →
By lowering the coil voltage command value VdcA1),
Although the thrust decreases, looking at the graph in FIG. 8, α = 0.5
Even so, the flow rate of the molten steel MM necessary for stirring near the nozzle 30 is secured. Furthermore, even if the application of the voltage of the power supply circuit 20A is stopped (VdcA1 = 0; I2 = 0; α = 0.
0), the minimum thrust for stirring the inside of the mold MD is secured. Therefore, power consumption can be reduced by lowering the level of the voltage applied to the power supply circuit 20A depending on the ease with which foreign matter in the molten steel MM is entrained and the quality requirements of the product. Moreover, α ≦ 1
When compared with the case of 1 <α (I1 <I2: thick solid line in FIG. 8), the reverse flow near the short side is smaller, so the possibility of inclusion of foreign matter in the molten steel MM near the short side Is reduced.

Next, the minimum size (width y
= 1.0 m), the most preferable mode of use will be described with reference to FIG.

FIG. 9 shows a mode in which the mold is set to the minimum size in the embodiment described above with reference to FIGS. 2nd and 4th as mold size decreases
Most of the electric coils of the groups #BF and #BL are located outside the molten metal, and energization of the electric coils outside the molten metal results in unnecessary magnetic field generation and unnecessary power consumption. When the mold size is large, as described above, the second and fourth groups capable of generating a large thrust are used.
It is necessary to apply a strong thrust to overcome the natural flow with the electric coils of #BF and #BL, but if many electric coils are of a small mold size that deviates from the molten metal, the linear motors LMF and LML are The thrust generated is reversed and the first
And the third group #AF and #AL electric coils give a strong thrust to overcome the natural flow, and the second and fourth groups
By accelerating the natural flow with the electric coils of #BF and #BL, or slightly decelerating the natural flow, and giving a weak thrust, the molten steel can be swirled clockwise to stir smoothly. If the second and fourth groups #BF
Since the current value I1 of the electric coils of # and #BL is extremely low, that is, the electric current to the electric coil which is out of the molten metal is low, the generation of useless magnetic field and the useless consumption of power are significantly reduced. To do.

Therefore, for the minimum size mold MD shown in FIG. 9, such a clockwise turning drive is performed. In this case, what is different from the mode when the intermediate size (FIG. 2) is set is the size of the mold, the coil voltage command value VdcB2 given to the power supply circuit 20B, and the direction signal (coil group #
AF, BF, AL, and BL, which are three-phase AC voltages supplied to AF, and other functions and structures are the same, and therefore, description thereof will not be repeated. In this mode, the direction signal is set to the H level (clockwise turning drive is designated).
Thus, when the mold MD has an intermediate size (FIG. 2), the U phase and the W phase output to the U phase connection terminal and the W phase connection terminal are exchanged, and the first linear motor LMF and the second linear motor Fig. 5 shows the thrust that LML gives to molten steel MM.
Thrust force in the direction opposite to the direction indicated by the dotted arrows FaF, FbF, FaL, FbL, that is, the dotted arrows FaF, F in FIG.
The coil voltage command values VdcA1 and VdcB2 are changed according to the size of the mold while being inverted in the directions indicated by bF, FaL, and FbL.

Please refer to FIG. 6 again. The operator sets the direction signal given to the three-phase signal generator 31A1 to the H level via the host computer. 3-phase signal generator 3
1A1 has a frequency designated by the frequency command value FdcA1 when the direction signal becomes H level (4 Hz in this embodiment).
The constant voltage three-phase AC signals (U, V, W) are generated. Then, the three-phase signal generator 31A1 changes the "W" of the constant voltage three-phase AC signal to the U-phase output transistor pair 27uA of the transistor bridge 27A1 according to the H level of the direction signal.
Phase ”to the comparator 29A1 and the transistor bridge 2
The V phase of the constant voltage 3-phase AC signal is applied to the comparator 29A1 for the V-phase output transistor pair 27vA of 7A1, and the W-phase output transistor pair 2 of the transistor bridge 27A1.
Comparator 2 for "U phase" of constant voltage 3-phase AC signal addressed to 7wA
Give to 9A1.

As a result, the power supply connection terminals U11, U12
, A three-phase AC “W-phase” voltage is output, the power-supply connection terminals V11 and V12 output the same V-phase voltage, and the power-supply connection terminals W11 and W12 output the same “U-phase” voltage. It The level between the upper and lower peaks of these voltages is determined by the coil voltage command value VdcA1. That is,
At the level designated by the coil voltage command value VdcA1 and at the frequency designated by the frequency command value FdcA1 (4 Hz in this embodiment) in the molten steel in the intermediate size mold, the U phase and the W phase are stirred. The three-phase AC voltage having the opposite polarity is applied to the electric coil of the first group #AF and the electric coil of the third group #AL shown in FIG.

Still referring to FIG. The H-level direction signal is also given to the second power supply circuit 20B. The gate driver 28B2 responds to the "W-phase" generated by the three-phase signal generator 31B2 to the positive and negative signals to the U-phase output transistor pair 2 of the transistor bridge 27B2.
7uB each positive and negative section voltage output transistor is turned on,
It is turned off and the positive and negative section voltage output transistors of the V phase output transistor pair 27vB of the transistor bridge 27B2 are turned on and off in response to signals addressed to the V phase, positive and negative sections. The positive and negative section voltage output transistors of the W-phase output transistor pair 27wB of the transistor bridge 27B2 are turned on and off in response to signals addressed to the "phase", positive and negative sections. Thus, the power supply connection terminal U
"W phase" of three-phase AC voltage is output to 21, U22,
The V phase of the three-phase AC voltage is output to the power supply connection terminals V21 and V22, and the "U phase" of the three-phase AC voltage is output to the power supply connection terminals W21 and W22. Peak above these voltages /
The level between the lower peaks is determined by the coil voltage command value VdcB2. That is, at the level designated by the coil voltage command value VdcB2, at the frequency designated by the frequency command value FdcB2 (4 Hz in this embodiment), when the molten steel is stirred in the medium-sized mold, the U phase and the W phase are set. A three-phase AC voltage having opposite phases is applied to the electric coil of the second group #BF and the electric coil of the fourth group #BL shown in FIG.

Thus, the phase distribution of the three-phase AC voltage supplied to each coil is reversed, so that the linear motor LM
The electromagnetic force phase arrangements of F and LML are reversed, and the thrust indicated by the dotted arrows FaF, FbF, FaL, and FbL in FIG.
Give to.

In the example shown in FIG. 9, the electric coil on the starting side of the molten steel flow, that is, the first and third groups #AF,
The exciting current flowing through the AL is I1, and the electric coils on the end side of the molten steel flow, that is, the second and fourth groups #BF, BL
The exciting current flowing through the coil is I2, α = I2 / I1 = 0.5
I am trying. That is, the second and fourth groups #BF, BL
The electric current I2 flowing through the electric coils of is equal to half of the electric current I1 flowing through the electric coils of the first and third groups #AF and AL. Here, the power supply circuit 20A is the first and third groups #A.
The voltage levels of the three-phase AC applied to F and AL are the same as those of the first and third groups #A in the mode shown in FIGS. 2, 4 and 5 when the power circuit 20A is stirring the molten steel in the intermediate size mold.
It is the same level as that applied to F and AL.

As described above, the second and fourth groups #B
F, BL electric coils BF1 to BF12, BL1 to BL
The total number of 12 (12 each) is the first and third groups #A.
F, AL electric coils AF1 to AF6, AL1 to AL6
Is twice the total number (6 each). The magnetic fields generated by the electric coils of the first and third groups #AF and AL substantially act on the molten steel. 2nd and 4th groups #BF, BL
Although some of the electric coils BF1 to BF12 and BL1 to BL12 are out of molten steel, the electric current value is small, so that useless magnetic field generation and useless power consumption by the electric coil out of molten steel are extremely small.

Further, α is lowered to 0.0 (I2
Lowering → lowering the supply voltage of the power supply circuit 20B → lowering the coil voltage command value VdcB2), the power consumption by the electric coil that is out of the molten steel is further reduced.

FIG. 10 shows the results of implementation when the value of α was changed in the minimum size mold shown in FIG. Here, α = I2 / I1, I1: current value flowing in the electric coils of the first and third groups #AF, #AL, I2: electric coils of the second and fourth groups #BF, #BL Is the value of the current that flows through. Nozzle 30 is 0.5 on the horizontal axis indicating the long side direction of the mold.
At the m position, molten steel is ejected. The level of the outlet 30a is about 0.5 m below the meniscus. FIG. 10 shows the distribution of horizontal velocity components of molten steel in the meniscus portion.
Here, the energization current value I1 of the first and third groups #AF and #AL is always constant, and α = 0.0 means the second and fourth.
Energization current value I2 of group #BF, BL = 0, that is,
The voltage supply from the power supply circuit 20B is 0. Further, 1 <α means that I1 <I2. Figure 10
Looking at the graph of No. 2, even if the current I2 from the power supply circuit 20B is extremely extreme, even if the current I2 is stopped (α = 0.0), the minimum thrust for stirring the inside of the mold MD is secured.

Next, the mold size is the maximum (width y = 2.4).
A preferred mode of use of the above-described embodiment in the case of m) will be described.

FIG. 11 shows the relative positional relationship between the mold size and the linear motor in this embodiment. This mode is shown in FIGS.
The intermediate-sized mold (width direction y length 1.
6m) is substantially the same as the case where the mold MD is set to an intermediate size, and the difference is the size of the mold and the power supply circuit 2
0A, 20B coil voltage command values VdcA1, Vdc
B2 only, each group #AF, BF, AL, BL
Since the structures and functions including the phase distribution of the three-phase AC voltage supplied to the same are the same, the description of the overlapping parts will be omitted. In this embodiment, the coil voltage command values VdcA1 and VdcB2 are changed according to the size of the mold.

That is, the operator, via the host computer, uses the three-phase signal generator 31 of the power supply circuits 20A, 20B.
The direction signal given to A1 and 31B2 is L level (instruction of counterclockwise turning drive). As a result, the power connection terminals U11, U12, U21, and U22 have three-phase alternating current U
Phase voltage is output and power supply connection terminals V11, V12, V2
Similar V-phase voltages are output to V1 and V22, and similar W-phase voltages are output to power supply connection terminals W11, W12, W21 and W22. In addition, the upper peak / lower peak of these voltages
The inter-curve level is determined by the coil voltage command values VdcA1 and VdcB2. Thus, the linear motors LMF, LML are
The thrust in the directions indicated by the dotted arrows FaF, FbF, FaL, and FbL in 1 is given to the molten steel MM in the mold.

In the example shown in FIG. 11, the electric coils on the starting side of the molten steel flow, that is, the second and fourth groups #B
Let I1 be the current flowing through the electric coils of F and BL, and I2 be the current flowing through the electric coils on the end point side of the molten steel, ie, the electric coils of the first and third groups #AF, AL.
α = I2 / I1 = 1.0. That is, the current I2 of the first and third groups #AF, AL has the same value as the current I1 flowing in the second and fourth groups #BF, BL.

When the molten steel MM in the maximum size mold MD shown in FIG. 11 is flow-driven, the effective lengths of the electromagnet cores 10F and 10L (the lengths facing the molten steel MM) are shorter than the length of the mold inner wall 50 in the y direction. Therefore, there is a region in the molten steel MM that is not reached by either the electromagnet core 10F or the electromagnet core 10L. However, α = I2 / I1 = 1.
By setting it to 0, the first and third groups #AF, #AL
The thrust forces FaF and FaL given by are large, and the combined thrust (counterclockwise thrust) with the thrusts FbF and FbL given by the second and fourth groups #BF and #BL is large. As a result, the molten steel MM in the large-sized mold in which the width direction (y) of the inner wall 50 is 2.4 m is flow-driven along the long sides 5F and 5L.

FIG. 12 shows the results of implementation when the value of α was changed. Nozzle 30 is 1. on the horizontal axis indicating the long side direction of the mold.
At the 2m position, molten steel is ejected. The level of the outlet 30a is about 0.5 m below the meniscus. FIG. 12 shows the distribution of horizontal velocity components of molten steel in the meniscus portion. Here, I1 is always constant, and α = 0.0 means I
2 = 0, that is, the voltage supply from the power supply circuit 20A is 0. Further, 1 <α means that I1 <I2. Looking at the graph of FIG. 12, when the current I2 from the power supply circuit 20A is extreme, even if stopped (α = 0.0),
The minimum thrust for stirring the mold MD is ensured. The power consumption is further reduced by decreasing α to 0.0 (reducing I2 → increasing the supply voltage of the power supply circuit 20A → decreasing the coil voltage command value VdcA1).

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a relative positional relationship between a linear motor and a mold according to an embodiment of the present invention.

FIG. 2 shows cores 10F and 10 taken along line 2A-2A shown in FIG.
FIG. 6 is a horizontal cross-sectional view in which L is horizontally broken, showing the mold set to an intermediate size (the width direction y length of the mold is 1.6 m).

3 is an enlarged sectional view taken along line 3A-3A in FIG.

FIG. 4 is a block diagram showing a schematic configuration of the embodiment shown in FIG.

5 is an electric circuit diagram showing connection of the electric coil shown in FIG.

6 is an electric circuit diagram showing a configuration of a power supply circuit 20A shown in FIGS. 4 and 5. FIG.

7 is an electric circuit diagram showing a configuration of a power supply circuit 20B shown in FIGS. 4 and 5. FIG.

FIG. 8 is a graph showing a flow velocity distribution in the width direction y of the molten steel MM in the mold set to the intermediate size shown in FIG.

9 is an electric circuit diagram corresponding to FIG. 5, showing a state where the embodiment shown in FIGS. 1 and 5 is applied to a mold set to a minimum size (the width direction y length of the mold is 1.0 m). .

FIG. 10 is a graph showing the flow velocity distribution in the width direction y of the molten steel MM in the mold set to the minimum size shown in FIG. 9.

FIG. 11 is an electric circuit diagram corresponding to FIG. 5, showing a state in which the embodiment shown in FIGS. 1 and 5 is applied to a mold set to a maximum size (the width direction y length of the mold is 2.4 m). .

FIG. 12 is a graph showing a flow velocity distribution in the width direction y of the molten steel MM in the mold set to the maximum size shown in FIG. 11.

[Explanation of symbols]

1F, 1L, 3R, 3L: Non-magnetic stainless steel plate 2F, 2L, 4R, 4
L: Copper plate 5F, 5L: Long side 6R, 6
L: Short side 10F, 10L: Core 20A, 2
0B: Power supply circuit 21: Three-phase AC signal generator 30: Injection nozzle 50: Mold inner wall LMF, LML:
Linear motor MM: Molten steel PW: Powder AF1 to AF6: Electric coils BF1 to BF12 of first group #AF: Electric coils AL1 to AL6 of second group #BF: Electricity of third group #AL Coils BL1 to BL12: Electric coils U11, V11, W11 of the fourth group #BL: Power supply connection terminals U12, V12, W12 of the first power supply circuit 20A: Power supply connection terminals U21, V21, W21 of the first power supply circuit 20A : Power supply connection terminals U22, V22, W22 of the second power supply circuit 20B: Power supply connection terminals of the second power supply circuit 20B

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-8-108257 (JP, A) JP-A-7-256412 (JP, A) JP-A-7-246444 (JP, A) JP-A-63- 104763 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B22D 11/115 B22D 11/04 311 B22D 27/02

Claims (3)

(57) [Claims] 1. A pair of opposed long sides extending in the y direction
And a first electromagnet core having a plurality of slots distributed in the y direction along the first long side of a mold surrounding a variable width molten metal whose position in the y direction can be changed, and A first group including a plurality of electric coils a + b and a <b, which are inserted, and a first group of a electric coils and b
A first nozzle arranged so that a nozzle for injecting molten metal into a mold is located between the second group of electric coils.
Linear motor: y along the second long side that faces the first long side with the molten metal in between
A second electromagnet core having a plurality of slots distributed in the direction, and a plurality of c + inserted in the respective slots
A third group including electric coils of d and c <d, consisting of c electric coils facing the second group, and a fourth group consisting of d electric coils facing the first group. A second linear motor arranged so that the nozzle is positioned between the first linear motor and the second linear motor;
First energizing means for energizing a multi-phase alternating current for generating a moving magnetic field along the y direction to a third group of the motor; and a second group and a second linear motor of the first linear motor.
A molten metal flow control device comprising: a second energizing means for energizing a multi-phase alternating current for generating a moving magnetic field along the y direction in a fourth group of the rotor. 2. The molten metal flow control device according to claim 1, wherein the first energizing means and the second energizing means include level setting means for setting a current level of the polyphase alternating current to be applied to the electric coil. 3. The molten metal flow control device according to claim 1, wherein the first energizing means and the second energizing means include direction switching means for switching the moving direction of the moving magnetic field generated by the electric coil.