MOLDING DEVICE FOR CONTINUOUS CASTING EQUIPPED WITH
AGITATOR
Technical Field
The present invention relates to a molding device for
continuous casting, which is equipped with an agitator, of
continuous casting ent that produces a billet, a slab or the
like made of non-ferrous metal of a conductor (conductive body),
such as Al, Cu, Zn, or an alloy of at least two of them,
or an Mg
alloy, or other metal.
Background Art
In the past, a melt agitating method to be described below
has been ed in a casting mold for continuous casting. That
is, for the improvement of the quality of a slab, a billet, or the like,
in a s for solidifying the melt, that is, when the melt passes
h the casting mold, a moving magnetic field, which is
generated from the e of the casting mold by an
electromagnetic coil, is applied to the melt present in the g
mold so that agitation occurs in the melt not yet fied. A main
object of this agitation is to degas the melt and to uniformize the
structure. However, since the electromagnetic coil is disposed at
the position close to high-temperature melt, the cooling of the
electromagnetic coil and troublesome maintenance are needed and
large power consumption is obviously needed. In addition, the
generation of heat from the electromagnetic coil itself caused by
the power consumption cannot be avoided, and this heat should be
removed. For this reason, there are various problems in that the
device itself cannot but become expensive, and the like.
Citation List
Patent Literature
[0003]
Patent Literature 1: JP 9-99344 A
Summary of Invention
Technical Problem
The invention has been made to attempt to solve the
above-mentioned problems, and an object of the invention is to
provide a molding device for continuous casting equipped with an
agitator that reduces the amount of generated heat, is easy to
carry out maintenance, is inexpensive, and is easy to use in
practice.
Alternatively, it is an object of the invention to at least
provide the public with a useful choice.
A molding device for uous casting equipped with an
agitator ing to an embodiment of the present invention is a
device which receives liquid-phase melt of a conductive material
and from which a solid-phase cast product is taken out through the
cooling of the melt. The molding device includes a casting mold
including a casting space that includes an inlet and an outlet at a
central portion of a substantially cylindrical side wall and a
magnetic field generation device receiving chamber that is formed
in the side wall and is positioned outside the casting space, the
g mold receiving the -phase melt from the inlet into the
casting space and discharging the solid-phase cast product from
the outlet through the cooling in the g space, and an agitator
provided so as to correspond to the casting mold, the agitator
including an ode unit that includes first and second electrodes
supplying t to at least the liquid-phase melt present in the
casting space, and a magnetic field generation device having a
permanent magnet that s a magnetic field to the liquid-phase
melt. The magnetic field generation device is received in the
magnetic field generation device ing chamber of the casting
mold, generates magnetic lines of force toward a center in a lateral
ion, makes the magnetic lines of force pass through a part of
the side wall of the casting mold and reach the casting space, and
applies lateral
[followed by page 2a]
magnetic lines of force, which cross the current, to the melt,
wherein the magnetic field generation device ing chamber
functions as a cooling water.
Unless the context clearly requires otherwise, throughout the
description and claims the terms “comprise”, “comprising” and the
like are to be construed in an inclusive sense, as opposed to an
ive or exhaustive sense. That is, in the sense of “including,
but not limited to”.
Brief Description of Drawings
[followed by page 3]
Fig. 1(a) is a view illustrating the entire structure of an
embodiment of the invention, and Figs. 1(b) and 1(c) are
explanatory views illustrating the operation thereof.
Fig. 2(a) is an explanatory plan view taken along line II(a) -
II(a) of Fig. 1 and Fig. 2(b) is an explanatory view illustrating the
bottom of an outer casting mold.
Fig. 3(a) is an explanatory plan view of a magnetic field
generation device 31 of an agitator 3, and Fig. 3(b) is an
explanatory plan view of a modified example thereof.
Fig. 4(a) is a plan view of another modified example of the
ic field generation device 31 of the agitator 3, and
Fig. 4(b)
is an explanatory plan view of a modified
example thereof.
Fig. 5 is a view illustrating the entire structure of r
embodiment of the ion.
Fig. 6 is a view illustrating the entire structure of another
embodiment of the invention.
Fig. 7 is a view illustrating the entire structure of still
another embodiment of the invention.
Fig. 8(a) is a view illustrating the entire structure of yet
another embodiment of the ion, Fig. 8(b) is a cross—sectional
view taken along line ) - VIII(b) of Fig. 8(a), Fig. 8(c) is a
cross-sectional view taken along line VIII(c) — VIII(c) of Fig. 8(a),
Fig. 8(d) is an explanatory plan view of a magnetic field
generation
device, and Fig. 8€ is an explanatory plan view of a lid.
Fig. 9(a) is a view rating the entire structure of still
another embodiment of the invention, Fig. 9(b) is a cross—sectional
view taken along line IX(b) — IX(b) of Fig. 9(a), and Fig. 9(c) is an
explanatory plan view of a magnetic field generation device.
3O Fig. 10 is a view illustrating the entire structure of yet
another embodiment of the invention.
Description of Embodiments
For deeper understanding of an embodiment of the
ion, an electromagnetic agitator, which uses electricity as
power, of continuous casting equipment in the related art will be
described briefly.
In the related art, a fixed amount of melt M of non-ferrous
metal is discharged from a melt receiving box that is called a
h and is poured into a casting mold that is provided on the
lower side. g water for cooling the casting mold is circulated
in the casting mold. Accordingly, high-temperature melt starts to
solidify from the outer ery thereof (a portion thereof close to
the casting mold) from the moment that the high—temperature
melt
comes into contact with the casting mold.
Since the melt, which is positioned at the central portion of
the casting mold, is distant from the wall of the casting mold that
being cooled, the solidification of the melt oned at the central
portion of the casting mold is obviously later than that of the melt
positioned at the peripheral portion of the casting mold. For this
reason, two kinds of melt, that is, liquid (liquid—phase) melt and a
solid (solid-phase) cast product are simultaneously present in the
casting mold while being adjacent to each other with an interface
interposed therebetween. Further, generally, if melt is solidified
too y, gas remains in the cast t (product) having been
changed into a solid and causes the quality of the product to
deteriorate. For this reason, ing is facilitated by the
agitating of the melt that is not yet solidified. The electromagnetic
agitator, which uses electricity as power, has been used for the
agitating in the related art.
However, when such an electromagnetic agitator is used,
there are various difficulties as described above.
3O [0010]
Accordingly, the invention is to e a molding device for
continuous g equipped with an agitator that does not
use the
electromagnetic agitator using electricity as power and uses
permanent magnets.
[0011]
An embodiment of the invention will be described in more
detail below.
The entire structure of an embodiment of the invention is
illustrated in Fig. 1(a). Fig. 2(a) is an explanatory plan view taken
along line II(a) - II(a) of Fig. 1(a), and mainly illustrates a part of
an agitator 3 and a casting mold 2, and Fig. 3(a) is an explanatory
plan view of the magnetic field generation device 31 of the agitator
[0013]
As understood from Fig. 1(a), a device according to an
embodiment of the invention broadly includes a melt supply unit 1
that supplies melt M of non—ferrous metal of a conductor
(conductive body), such as Al, Cu, Zn, or an alloy of at least two of
them, or an Mg alloy, or other metal; a casting mold 2 that
receives the melt from the melt supply unit 1; and an agitator 3
that agitates the melt M present in the casting mold 2. A central
portion of the g mold 2 forms a so-called g space 2A(1)
that includes an inlet 2A(1)1 and an outlet 2A(1)2.
[0014]
The melt supply unit 1 includes a tundish (melt receiving
box) 1A that es melt M from a ladle (not illustrated) or the
like. The melt M is stored in the tundish (melt ing box) 1A,
inclusion is removed from the melt, and the melt M is supplied to
the casting mold 2 from a lower opening 18 of the tundish at a
constant supply rate. Only the tundish (melt receiving box) 1A is
illustrated in Fig. 1.
The casting mold 2 is adapted in this embodiment so that a
columnar product P (billet) is taken out from the casting mold. For
this purpose, the casting mold 2 is formed so as to have a
substantially cylindrical double structure (of which the cross—section
has a ring . That is, the casting mold 2 includes an inner
casting mold 21 and an outer casting mold 22 that are fitted to
each other. The inner casting mold 21 is provided on the inside
and made of a non-conductive al (non-conductive refractory
material) such as graphite (carbon). The outer casting mold 22 is
provided on the outside and made of a conductive material
(conductive refractory material), such as aluminum or copper.
As described in detail below, the magnetic field generation
device 31 is assembled so as to be received within the side wall of
the outer casting mold 22. Meanwhile, since the technical idea is
the same as described above even when a prismatic product (slab)
is taken out, the technical idea of an embodiment to be bed
below can be applied as it is. Briefly, the shapes of components
corresponding to a gular slab, which is a product, are merely
changed.
The casting mold 2 further includes a water jacket 23
outside the outer casting mold 22.
The water jacket 23 is to cool the melt M that flows into the
inner casting mold 21. That is, cooling water flows into the water
jacket 23 from an inlet (not illustrated) and is circulated in the
water jacket 23, the outer portion of the outer casting mold 22 is
cooled by the cooling water, and the cooling water is discharged
from an outlet (not illustrated). The melt M is rapidly cooled by
the water jacket 23. Since water jackets having various known
structures may be employed as the water jacket 23, the detailed
description thereof will not be provided here.
In on, a plurality of ode insertion holes 2a, 2a,
into which electrodes 32A to be described below are inserted are
formed at a predetermined interval on the ference of the
casting mold 2 having the mentioned structure. The
electrode insertion holes 2a are formed so as to be inclined
downward toward the center of the casting mold 2. For this
reason, if the surface of the melt M is lower than the upper
gs of the electrode insertion holes 2a even though the melt
M is contained in the casting mold 2, there is no concern that the
melt M will leak to the outside.
[0018]
As described above, y, the agitator 3 is provided so as
to be built in the side wall of the casting mold 2. The agitator 3
includes a permanent magnet type magnetic field generation
device 31, and a pair of upper and lower electrodes (positive and
negative electrodes) 32A and 328.
In particular, as understood from Fig. 3(a), the ic
field generation device 31 is formed in the shape of a ring (in a
frame shape). The entire inner peripheral portion of the magnetic
field generation device may be magnetized to an N pole, and the
entire outer peripheral portion of the magnetic field generation
device may be magnetized to an S pole. Further, four ns of
the inner and outer peripheral portions may be partially
magnetized to an N pole and an S pole as illustrated in, for
example, Fig. 3(a), respectively.
[0020] ,
As understood from the following description, the ic
field tion device 31 does not necessarily need to be formed
in the shape of a ring, and may be divided. That is, for e,
as illustrated in Fig. 8(d), the cross—section of the magnetic field
generation device may be formed of a plurality of arc—shaped
permanent magnet pieces (Fig. 4). As briefly described above,
particularly, as understood from Fig. 1(a), the magnetic field
generation device 31 is assembled in the outer casting mold 22.
In more detail, as understood from Fig. 1(a), the outer
casting mold 22 includes a magnetic field tion device
receiving chamber 22a which is formed in the side wall thereof and
has a haped cross—section and of which a lower portion forms
a release port. The magnetic field generation device receiving
3O chamber 22a is also understood from Fig. 2(b). Fig. 2(b) is a view
of the outer casting mold 22 when the outer g mold 22 is
seen from below. In particular, as understood from Fig. 1(a), the
magnetic field generation device 31 also having a ring-shaped
cross—section is received in the magnetic field generation device
receiving chamber 22a, which has a ring—shaped cross-section and
of which the lower n is opened, from below so that the
position of the magnetic field generation device in the vertical
direction can be ed by movement. That is, the magnetic
field generation device 31 is provided so that the height of the
magnetic field generation device can be adjusted in the magnetic
field generation device receiving chamber 22a by desired
units (not
illustrated). Accordingly, it is possible to more efficiently agitate
the melt M as described below by adjusting the height of the
magnetic field generation device so as to correspond to
liquid—phase melt M as understood from Fig. 1(a). The lower
opening of the magnetic field generation device receiving r
22a is closed by a ring-shaped lid 228. The lid 228 may be
formed so as to include discharge channels ZZB (1) for discharging
cooling water to the outside such as a lid 228 of Fig. 8(a) to be
described below.
[0022]
As described above, the four portions of the
magnetic field
generation device 31 are magnetized and form pairs of magnetic
poles 31a, 31a, as illustrated in Fig. 3(a). That is, a portion of
each of the magnetic poles 31a, 31a facing the inside of the
ring-shaped magnetic field generation device is ized to an N
pole, and a n thereof facing the e of the ring-shaped
magnetic field generation device is magnetized to an S pole.
Accordingly, magnetic lines of force ML generated from the N pole
horizontally pass through the melt M that is t in the casting
mold 2.
The ization may be contrary to this. That is, the
inner portions of all magnetic poles
may be magnetized to a certain
pole and the outer portions thereof may be magnetized to an
opposite pole. One of additional characteristics of the invention is
3O that a plurality of magnetic poles are disposed at a ity of
positions‘surrounding the melt M, which is not yet solidified, as
understood from Fig. 3(a). Accordingly, it is possible to improve
the quality of the t P by agitating all the melt M with an
electromagnetic force that is generated ing to Fleming's rule
by magnetic lines of force and current as described below.
Therefore, the number of the magnetic poles is four in Fig. 3(a),
but is not limited to four and may be arbitrary. Further, as
described above, the magnetic field generation device 31 does
need to be formed of a ring—shaped single body, and may be
divided into a plurality of magnet bodies (magnet pieces), of which
the number is arbitrary, as illustrated in Fig. 8(d).
In Fig. 1(a), t flows between the pair of electrodes
32A and 328 through the melt M and a cast product (product) P.
One electrode 32A may be used, but a plurality of electrodes 32A
' may be used. In this embodiment, two electrodes 32A are used.
The electrodes 32A are formed in the shape of a probe.
The respective electrodes 32A are inserted into the
above-mentioned electrode insertion holes 2a. That is, the
electrodes 32A penetrate into the casting mold 2 (the inner
casting
mold 21 and the outer casting mold 22) from the water
jacket 23.
Inner ends of the electrodes 32A are exposed to the inside of the
inner casting mold 21, come into t with the melt M, and
conduct electricity to the melt M. Outer ends of the electrodes
32A are exposed to the outside of the water jacket 23.
The outer
ends are connected to a power supply 34 that
can supply variable
direct current. The power supply 34 may have the function of
AC power supply as described below, and
may have a function of
changing frequency. The odes 32A may be supported above
the upper opening of the casting mold 2 without penetrating the
side wall of the casting mold 2 so that the inner ends of the
electrodes 32A are inserted into the melt M from the e of
melt M flowing into the casting mold 2. The electrodes 32A may
be electrically connected to the inner casting mold 21 made of
te or the like.
3O [0024]
The number of electrodes used as the odes 32A
be ary, and an arbitrary number of the electrodes
32A may be
inserted into arbitrary electrode ion holes of the electrode
insertion holes 2a, 2a,
[0025]
In Fig. 1(a), the lower electrode 328 is provided so that the
position of the lower electrode 32B is fixed. The electrode 32B is
formed of a roller type electrode. That is, the lower electrode 32B
includes a rotatable roller 32Ba at the end thereof. The roller
.3ZBa comes into press contact with the outer surface
of a columnar
product P as a cast product (a billet or a slab) that is extruded in a
solid phase state. Accordingly, as the product P extends
downward, the roller 328a is rotated. That is, when the t P
is extruded downward, the product P extends downward
in Fig. 1
while coming into t with the roller 32Ba and rotating the
roller 328a.
Accordingly, when a voltage is applied between the pair of
electrodes 32A and 328 from the
power supply 34, current flows
between the pair of electrodes 32A and 328 through the
melt M
and the product P. As described above, the power supply 34 is
adapted so as to be capable of controlling the amount of t
flowing between the pair of electrodes 32A and 328.
Therefore, it
is possible to select current where the liquid-phase
melt M can be
agitated most efficiently in a relationship with the magnetic lines
of force ML.
Next, the operation of the device having the
above-mentioned structure will be described.
In Fig. 1(a), a fixed amount of the melt M, which is
discharged from the h (melt receiving box) 1A, is input to the
upper portion of the g mold 2. The casting mold 2 is cooled
through the circulation of water in the water jacket 23, so that the
melt M present in the casting mold 2 is rapidly cooled and solidified.
3O However, the melt M t in the casting mold 2 has a two-phase
structure where the upper n of the melt is liquid (liquid
phase), the lower portion thereof is solid (solid phase), and the
upper and lower portions of the melt are adjacent to each other at
an interface ITO. When passing through the casting mold 2, the
melt M is formed in the shape (a columnar shape in this
embodiment) corresponding to the shape of the casting mold.
Accordingly, a product P as a slab or billet is continuously formed.
r, since the permanent magnet type magnetic field
generation device 31 is received in the side wall of the casting mold
2 as tood from Fig. 1(a) and the like, the magnetic field
(magnetic lines of force ML) of the magnetic field generation device
reaches the melt M, which is present in the casting mold 2, in the
l direction. In this state, when direct t is supplied to
the lower electrode 328 from the upper odes 32A by the
power supply 34, the current flows to the lower electrode 328 from
the upper electrodes 32A through the melt (liquid phase) M of
aluminum or the like and the product (solid phase) P. At this time,
the current crosses the ic lines of force ML, which are
generated from the permanent magnet type magnetic field
generation device 31, substantially at right angles to the magnetic
lines of force. Accordingly, rotation occurs in the —phase melt
M in accordance with Fleming's left-hand rule. The melt M is
agitated in this way, so that impurities, gas, and the like contained
in the melt M float and so-called degassing is actively performed.
Accordingly, the quality of the product (a slab or a billet) P is
improved.
Now, cooling capacity is increased or reduced by the water
jacket 23 or the like, the solidification rate of the melt M is changed
and the interface ITO between the melt d-phase) M and a
product (solid-phase) P moves up and down according to this.
That is, when cooling capacity is increased, the interface ITO moves
up like an interface IT1 as illustrated in Fig. 1(b). When cooling
capacity is reduced, the interface 1T0 moves down like an interface
IT2 as illustrated in Fig. 1(c). r, it is preferable that the
magnetic field tion device 31 be moved up and down
according to the positions of the interfaces ITO, IT1, and IT2 in
order to efficiently agitate the melt M. Accordingly, it is possible to
obtain a product P as a high—quality product by reliably and
efficiently agitating the melt M. For this purpose, the magnetic
field generation device is adapted so that the height of the
magnetic field generation device 31 can be ed in the vertical
direction according to the heights of these interfaces IT1 and IT2
as illustrated in Figs. 1(b) and 1(c) and the position of the
magnetic field generation device 31 can be kept. Accordingly, it is
le to efficiently agitate the melt M as described above.
On the ry, the double structure of the casting mold 2
may be formed so that the inner n of the casting mold is
made of a tive material and the outer portion thereof is
made of a non-conductive material. In this case, at least the
electrodes 32A may come into electronically contact with the
conductive material that forms the inner portion of the casting
mold. Even in this case, a ic field generation device
receiving chamber 22a may be formed in an outer member.
[0032]
Further, the casting mold 2 may have not a double ure
but a single structure. In this case, the g mold 2 may be
made of only a conductive material, and the electrodes 32A may
conduct electricity to the casting mold 2. The structure of the
other electrode 32B may be the same as described above.
On the contrary, the casting mold 2 may be made of only
non-conductive material. In this case, it is necessary to make the
electrodes 32A conduct electricity to the melt M present in the
casting mold 2 by making the electrodes 32A penetrate into the
casting mold 2 as illustrated in Fig. 1(a).
In these cases, obviously, a magnetic field generation device
receiving chamber 22a may be formed in a member having a single
3O structure.
A magnetic field generation device 31A of Fig. 3(b) may be
used instead of magnetic field generation device 31 of Fig. 3(a).
The magnetization direction of the magnetic field generation device
31A of Fig. 3(a) is opposite to that of the magnetic field generation
device 31 of Fig. 3(b). Both the magnetic field generation devices
have the same function.
Further, magnetic field generation s 31-2 and 31A-2
of Figs. 4(a) and 4(b) may be used instead of the magnetic field
generation devices 31 and 31A of Figs. 3(a) and 3(b). The
magnetic field generation devices 31-2 and 31A-2 of Figs. 4(a) and
4(b) are adapted so that a ity of ke permanent magnets
PM are fixed to the inside of a ring-shaped support (yoke) SP.
These have the same function.
[0037]
Furthermore, an electrode, which includes the roller 328a at
the end thereof, has been described as the lower electrode 328
the above-mentioned embodiment. However, the lower electrode
does not need to necessarily include the roller 328a. Even though
a product P is continuously extruded, the ode 328 only has to
t electricity to the product P and may employ various
structures. For example, an elastic member having a
predetermined length is used as the electrode 328 and is bent, for
example, so as to be convex upward or downward in Fig. 1, and
the end of the elastic member comes into press contact with the
cast product P by the force of restitution. In this state, the cast
product P may be allowed to extend downward.
According to the above-mentioned embodiment of the
invention, it is possible to obtain the ing effects.
In the embodiment of the invention, melt M that is not yet
solidified is agitated to give movement, vibration, and the like to
the melt M, so that a degassing effect and the uniformization and
3O refinement of the structure are achieved.
In more detail, since the magnetic field generation device 31
is adapted so as to be capable of being adjusted in the vertical
ion in the ment of the invention, it is possible to obtain
a high-quality product P by reliably ing the melt M. This is
one of the characteristics of the invention as described above, and
an idea, in which a ic field generation device 31 provided
outside the casting mold is moved up and down in a device that is
apt to be high temperature and large in size and hardly has an
empty space as in the embodiment of the invention, itself is an
idea that is not accustomed to those skilled in the art. Accordingly,
a technique of the invention, in which a magnetic field generation
device is received in a casting mold and can be adjusted in the
vertical direction, is a technical idea that is peculiar to the inventor.
Further, since the magnetic field generation device 31 is
formed in the embodiment of the invention so that a plurality of
magnetic poles are disposed at the positions nding the melt
M or a ring-shaped magnet surrounding the melt M is disposed, it
is possible to efficiently agitate all the melt M with an
electromagnetic force that is generated according to g's rule
by magnetic lines of force and current. Accordingly, it is possible
to obtain a product P as a high-quality product. That is, in the
embodiment of the invention, it is possible to efficiently agitate the
melt M by making the best use of an electromagnetic force that is
generated according to Fleming's rule. In on, the axis of the
rotation of the melt M, which is caused by this. agitating of the melt,
is an axis parallel to the center axis of the product P in Fig. 1(a).
Accordingly, it is possible to obtain a high-quality product as a
product P by making the rotational drive of the melt M reliable.
[0042]
Moreover, in the embodiment of the invention, melt M is
agitated with an omagnetic force that is generated according
to Fleming's rule and is agitated by the cooperation between small
current flowing in the melt M and a magnetic field generated from
3O the magnetic field generation device 31. ingly, it is possible
to obtain a device that stably and continuously expects reliable
agitation unlike melting and ion performed using the
ittent flow of large t according to the principle of arc
welding or the like and has low noise and high durability.
[0043]
It is obvious that the above—mentioned effects are obtained
from all embodiments to be described below.
Meanwhile, direct current has been ed between the
electrodes 32A and 32B in the above description, but alternate
current having a low frequency of about 1 to 5 Hz may be supplied
from the power supply 34. In this case, the melt M does not
rotate but repeatedly vibrates according to the cycle thereof in the
relationship with a magnetic field that is generated from the
magnetic field generation device 31. Impurities are removed from
the melt M even by the vibration. This modified example may be
applied to all embodiments to be described below. In this case, it
is s that a power supply having a function of changing
frequency is employed as the power supply 34.
Further, the realization of mass production facilities is
currently required in the ry. It is essential to e a
casting mold that is as small as le when mass production is
considered.
Here, the electromagnetic agitating device in the related art
can cope with a case where several slabs or billets are produced at
one time. However, at present, there is a demand for the
production of billets of which the number exceeds 100. The
electromagnetic agitator in the related art cannot cope with this
demand.
However, permanent magnets are used as the magnetic
field generation device in the device of the invention. For this
, it is possible to make the device very compact in
comparison with the electromagnetic agitator that is supplied with
large current. ingly, it is possible to sufficiently realize a
molding device for a mass production facility. r, since the
magnetic field generation device is permanent magnet type, it is
possible to obtain a device having effects, such as no heat
generation, power saving, energy , and less maintenance, as
a magnetic field generation device.
Fig. 5 illustrates another embodiment of the invention.
More current is supplied to this liquid-phase melt M to
te a larger electromagnetic force so that the melt M is
rotationally driven.
This embodiment is different from the ment of Fig.
1(a) in the structure of a casting mold 2A. Other structures are
substantially the same as Fig. 1(a). Accordingly, the detailed
description thereof will not be repeated here.
That is, the casting mold 2A of this embodiment includes a
substantially cylindrical casting mold body 2A1. The casting mold
body 2A1 includes a circumferential groove 2A1(a) that is formed
on the inner peripheral surface thereof. An insulating film 2A2 is
formed on the inner surface (the peripheral surface and the
bottoms) of this groove, and an embedded layer 2A3 is formed by
embedding the same conductive material as the casting mold body
2A1 on the insulating film 2A2. An insulating layer portion is
formed of the ting film 2A2 and the ed layer 2A3.
The insulating layer portion is formed on a part of the inner surface
of the casting mold, and functions as a portion that does not allow
the flow of current from the casting mold.
[0052]
This insulating layer portion is formed on a slightly lower
portion of the inner surface of the g mold body 2A1.
Accordingly, t is hardly allowed to flow to the cast
product P from the insulating layer portion of the g mold
3O body 2A1, that is, a n adjacent to the cast product P.
In addition, a terminal 2A4 is provided on the outer
periphery of the casting mold body 2A1. Power can be supplied to
the casting mold 2A from the power supply 34 through this
terminal 2A4.
When a voltage is applied between the terminal 2A4 and the
electrode 328 by the power supply 34 in the device having this
ure, current flows in the casting mold body 2A1, the melt M,
and the cast product P. Since current does not flow in the
insulating film 2A2 and the embedded layer 2A3 at this time, larger
current flows in the melt M. Accordingly, a larger electromagnetic
force, which allows the melt M to be agitated, is obtained.
Fig. 6 rates still another embodiment.
[0056]
This embodiment is a modification of the embodiment of Fig.
1(a).
This embodiment is different from the embodiment of Fig.
1(a) in the ition of the upper electrodes 32A of Fig. 1(a).
That is, in this embodiment, one ode 32A0 is disposed or a
plurality of electrodes 32A0 are disposed annularly, these
electrodes 32A0 are supported by arbitrary units other than the
casting mold 2A and the like (the casting mold 2A and the water
jacket 23), and a lower end portion of each of the odes 32A0
is inserted into the melt M. Accordingly, it is possible to adjust the
length of the lower end portion, which is inserted into the melt M,
of the electrode 32A0 with large degree of freedom regardless of
the casting mold 2A and the like. Moreover, obviously, a normal
mold may be used as the casting mold 2A or the like, and electrode
insertion holes 2a for electrodes 32A1 do not need to be formed in
the casting mold 2A or the like. Therefore, it is also possible to
t the increase in the manufacturing costs of these.
3O Other structures are the same as the embodiment of Fig.
1(a).
Fig. 7 illustrates yet another embodiment.
This embodiment may be regarded as a modified e of
the embodiment of Fig. 6.
The embodiment of Fig. 7 is assumed as a device that can
be operated when melt M is poured into a casting mold 2A, which is
provided on the lower side, from a h (melt receiving box) 1A,
which is provided on the upper side, as continuous melt with no
interruption. That is, it is assumed that the melt M present in the
tundish (melt receiving box) 1A and the melt M present in the
g mold 2A are integrally connected to each other.
In Fig. 6, the electrodes 32A0 are inserted into the melt M
present in the casting mold 2. However, in Fig. 7, an electrode
32A1 is supported by ary units so as to be inserted into the
melt M present in the tundish (melt receiving box) 1A on the
premise of the above—mentioned case. Accordingly, it is le
to obtain the same advantage as the above-mentioned
embodiment of Fig. 6. In addition, it is possible to set and adjust
a distance between the tundish (melt receiving box) 1A and the
casting mold 2A or the like regardless of the electrode 32A1.
Other structures are substantially the same as Fig. 6.
Figs. 8(a) to 8(d), Figs. 9(a) to 9(c), and Fig. 10 illustrate
other embodiments of the invention, respectively.
The same members of these ments as the members
of the above-mentioned embodiment are d by the same
reference numerals and the description thereof will not be
repeated.
3O In these embodiments, a water jacket for cooling does not
need to be separately provided, a water flow chamber ,
which functions as both a cooling chamber and a magnetic field
generation device receiving chamber, is formed in the side wall of a
g mold 2, that is, the side wall of the outer casting mold 22,
and a magnetic field generation device 31 as a permanent magnet
is received in the water flow chamber 22a(2) so that the position of
the magnetic field tion device can be adjusted in the vertical
direction.
Meanwhile, a magnetic field generation device receiving
space (magnetic field generation device receiving chamber) 22a(2)
illustrated in Fig. 8(c) may be divided so as to receive a plurality of
permanent magnet pieces 31A, which are rated in Fig. 8(d)
and disposed at a ermined interval, respectively. For
example, the magnetic field generation device receiving space may
be formed of a plurality of partial magnetic field generation device
receiving chambers having an arc-shaped cross~section.
First, a device of manufacturing a billet of the embodiment
rated in Figs. 8(a) to 8(e) will be described.
[0069]
That is, as understood from Fig. 8(a), the outer casting
mold 22 includes a water flow chamber 22a(2) that is opened
downward and has a ring-shaped cross-section, and the water flow
chamber 22a(2) is hermetically-sealed by a lid 22B(1). Fig. 8(b) is
a view illustrating the inner casting mold 21 and the outer casting
mold 22 taken along line VIII(b) - ) from below when the lid
228(1) is removed. This lid 228(1) forms a part of the casting
mold 2.
As understood from Fig. 8(a), a magnetic field tion
device 31, which is formed of a plurality of permanent magnet
pieces 31A (Fig. 8(c)) having an arc-shaped cross-section, is
received in the ring—shaped water flow chamber 22a(2) serving
a magnetic field tion device receiving space (receiving
3O chamber) so as to be capable of being adjusted in the vertical
direction. That is, the water flow chamber (cooling chamber)
22a(2) functions as both a cooling water flow chamber and a
magnetic field generation device receiving r. A plan view
of these permanent magnet pieces 31A is illustrated in Fig. 8(d).
The inner portion of each of the permanent magnet pieces 31A is
magnetized to an N pole and the outer n thereof is
magnetized to an S pole. The magnetization may be contrary to
this. That is, the magnetic field generation device 31 is provided
so that the height of the magnetic field generation device can be
adjusted in the water flow chamber 22a(2) by arbitrary units (not
illustrated). Accordingly, it is possible to more efficiently agitate
the melt M by adjusting the height of the magnetic field generation
device so as to correspond to -phase melt M as described
above.
The lower opening of the water flow chamber 22a(2) is
closed by the above-mentioned ring-shaped lid 228. A plan view
of the lid 228 is illustrated in Fig. 8(e). As tood from Figs.
8(e) and 8(a), a plurality of discharge channels 228(1) for cooling
water are formed in the lid . As understood from Figs. 8(a)
and 8(e), the plurality of discharge channels 228(1) include a
plurality of inlets 228(1)a1 that are opened to the upper surface of
the lid 228, and include outlets 228(1)a2 on the peripheral surface
of the lid 228. Accordingly, cooling water present in the water flow
chamber 22a(2) enters from the plurality of inlets 228(1)a1, flows
out of the s 228(1)a2, and is jetted to the outer periphery of
the product P to cool the product P. That is, cooling water enters
the water flow chamber 22a(2) from inlets (not illustrated), is
circulated in the water flow chamber while cooling the product, and
is discharged while being jetted to the outside from the discharge
channels .
Since the operation of the above-mentioned device of Figs.
8(a) to 8(e) is the same as that of the above—mentioned
embodiment, the description thereof will not be ed.
3O [0073]
Meanwhile, the magnetic field generation device 31 has
been formed of the plurality of ent magnet pieces 31A in
the above-mentioned embodiment of Figs. 8(a) to 8(e). However,
it is obvious that the magnetic field generation device may be
integrally formed as in Fig. 3(a). r, the water flow chamber
22a(2) serving as the magnetic field generation device receiving
space is formed in a circumferential shape as tood from Fig.
8(b). However, the water flow chamber is not d to this shape,
and may be formed of a plurality of cell chambers that are divided
in the circumferential direction and have an arc-shaped
cross—section. It is preferable that cooling water can flow in each
cell chamber and the permanent magnet piece 31A be received
each cell chamber so as to be capable of moving
up and down.
In the device of Figs. 8(a) to 8(e), the ic field
generation device 31 is not provided outside the g mold 2,
and a cavity (water flow chamber 22a(2)) is formed in the casting
mold 2 (outer casting mold 22) and the magnetic field generation
device 31 is received in the cavity. Accordingly, it is possible to
obtain the following characteristics.
[0075]
- A permanent magnet, which is small and has a small
capacity, may be used as the ic field generation device 31.
That is, if the magnetic field generation device 31 is
provided outside the casting mold, it is inevitable that’a distance
between the magnetic field generation device 31 and the melt M is
slightly increased. However, since the magnetic field tion
device is built in the casting mold 2 in this embodiment, the
distance between the magnetic field generation device 31 and the
melt M is reduced. Accordingly, a permanent magnet, which is
small and has a small capacity, may be used to obtain the same
agitating performance.
- It is possible to significantly improve a working property.
That is, when this device is operated, a plurality of
inspectors should be positioned around the device to perform
various kinds of measurement, nondestructive inspection, and the
like and should perform such the measurement and the like for the
check of a product P. However, in the case of the magnetic field
generation device that is provided outside, the increase in size and
volume cannot be d and it cannot be denied that it is difficult
to perform such the measurement since a strong magnetic field is
generated. However, since the magnetic field generation device 31
is provided in the casting mold 2 in this embodiment, a volume is
not increased and the intensity of a magnetic field emitted to the
outside is d. For this , it is easy to perform various
kinds of measurement and the like.
— It is possible to icantly improve productivity.
That is, it is possible to reduce time required for the
above-mentioned measurement and the like. As a result, it is
possible to increase the manufacturing rate of a product P per unit
time.
- It is possible to reduce size.
That is, since the magnetic field generation device 31 is a
built-in type, it is possible to provide a device that is small as a
whole as much as that.
— It is possible to save a space of an installation location.
That is, since the magnetic field generation device 31 is a
'20 built-in type when the device is regarded as a device
manufacturing the same product P although being the same as
bed above, the size of the device is d as a whole.
Accordingly, it is possible to install the device even at a narrow
place. As a result, flexibility is obtained in the usefulness of the
device.
The mentioned effects will be described below from a
different standpoint.
When a product P is manufactured by this device, for
example, five or six workers gather around the device and should
perform high-density works (works for monitoring and preventing
the leakage of melt, works for ring and preventing the jet of
melt, and the like) in a short time. When these works are
med by a plurality of workers, a working property is good in
the built—in type device of this embodiment as compared to a case
where the magnetic field generation device 31 is provided outside
so as to protrude. That is, since the external appearance of the
device has the same dimensions as the dimensions of a device that
does not include the magnetic field generation device 31 that is a
device in the related art, the device of this embodiment is very
easy to use at the work site.
Further, it is preferable that the magnetic field generation
device 31 be close to the melt M as much as possible in order to
reliably apply a ic field to the melt M, and this is realized in
a built—in type.
When the ic field generation device 31 is provided
outside, the influence of a magnetic field on various measuring
ments such as ature sensors should be considered.
However, since the nce thereof is reduced in a built-in type, a
built-in type is more advantageous in measurement. That is,
when a product P, such as a slab or a billet, is manufactured, the
measurement, management, and the like of temperature in several
positions are very important to maintain the quality of a product.
This embodiment is very advantageous in the measurement of
temperature and the like. '
If a built-in type magnetic field generation device as in this
embodiment is used instead of the magnetic field generation device
ed e, the size, weight, and volume of a device may be
reduced when the same ic field is applied to the melt M.
Accordingly, the device is easy to use. That is, since the
respective components of this device are consumables, the
3O respective components of this device need to be replaced er
a predetermined operation time has passed. However, since the
magnetic field generation device 31 is small and light, a work for
replacing the magnetic field generation device and the like are very
easily performed.
[0085]
Since a work at the device of this embodiment is a work
that is performed at a so—called high temperature of about 700°C,
the work is very dangerous for a worker. r, a magnetic
field generation device, which is small and of which the intensity of
a magnetic field is low, may be used as the magnetic field
generation device 31. Further, a tool, which is used for the
ment, maintenance, and the like of the device, is generally a
ferromagnetic body made of iron and safety shoes and the like are
also made of iron. However, if a magnetic field of the magnetic
field generation device 31, which is emitted by the e, is
reduced a little, the safety of a security officer, a worker, a
measuring person, and the like is ensured.
It is obvious that the effects described above with reference
to Figs. 8(a) to 8(e) are ned in not only the device of Fig. 1
and the like but also devices for manufacturing a slab that are to
be described below and illustrated in Figs. 9(a) to 9(c) and 10.
Figs. 9(a) to 9(c) illustrate a device for cturing a slab.
However, the basic technical idea of the device is the same as
bed above except that a billet has a circular shape and a slab
has a rectangular shape. Accordingly, the same members are
denoted by the same reference numerals and the description
thereof will not be repeated.
A difference will be described below.
The weight of a slab as a product P is very heavy. For this
reason, a billet can be pulled in the horizontal direction, but a slab
as a product P is not obtained unless taken out in the vertical
3O direction. For this reason, a pedestal 51 is ed, and a
product P is taken out while riding the pedestal 51 and being
gradually pulled downward. A lower electrode 32B is embedded in
the pedestal 51. A magnetic field tion device 31 is
illustrated in Figs. 9(b) and 9(c). Fig. 9(b) is a cross-sectional
view taken along line IX(b) - IX(b) of Fig. 9(a), and Fig. 9(c) is a
plan view of the magnetic field generation device 31. Here, the
magnetic field tion device 31 uses four permanent magnet
pieces 31A and forms two pairs facing each other, but may use any
one pair.
Fig. 10 illustrates a modified example of Fig. 9(a).
In Fig. 10, a pair of odes 32A and 328 is used while
being inserted into melt M. The inventor confirmed by an
experiment that the melt M is agitated even though the electrodes
32A and 328 are used in this way. That is, even though the pair of
electrodes 32A and 323 is employed as illustrated in Fig. 10, the
magnetic lines of force generated from a magnetic field generation
device 31 and current flowing between the pair of electrodes 32A
and 328 flow in various paths in the melt M and generate an
electromagnetic force according to Fleming's rule.