TITLE OF THE INVENTION
Sliding nozzle device
TECHNICAL FIELD
[0001]
The present invention relates to a sliding nozzle device for controlling a discharge amount
of molten metal from a molten metal vessel, and more particularly to a sliding nozzle device
comprising surface-pressure applying means adapted to apply a surface pressure between a fixed
plate and a slidable plate.
BACKGROUND ART
[0002]
A sliding nozzle device comprises: a fixed plate; a slidable plate; first and second holding
means holding respective ones of the fixed and slidable plates; sliding drive means adapted to
slidingly drive the slidable plate; and surface-pressure applying means adapted to apply a surface
pressure between the fixed plate and the slidable plate.
[0003]
Typically, the surface-pressure applying means consists of a mechanism designed to press
the slidable plate against the fixed plate by means of a spring force of a compression spring.
For example, in a conventional sliding nozzle device illustrated in FIG. 9, the surface pressure is
applied by clamping a spring casing 52 housing a compression spring 51, and a guide casing 53
coupled to an openable/closeable metal frame (illustration is omitted), by using a loading bar 50.
The loading bar 50 is formed in a J shape in side view, which includes first and second
rod-shaped portions 50a, 50b each having a cutout formed in a lower edge of a distal end thereof
to partially define an inclined surface. When the loading bar 50 is pushed in (moved forwardly)
with the use of a roller 54, the spring casing 52 is pushed downwardly, and the openable/closable
metal frame is pushed upwardly by a spring force of the compression spring 51 housed in the
spring casing 52. Based on this mechanism, a surface pressure is applied between a fixed plate
(illustration is omitted) and a slidable plate (illustration is omitted).
[0004]
The surface-pressure applying means is provided with a stopper 55 to prevent the surface
pressure from being erroneously released during a casting operation. The stopper 55 is adapted
to be swingable about a pivot extending in a forward-backward direction of the loading bar 50.
After completion of the push-in (forward movement) of the loading bar 50, the stopper 55 is
swingingly moved and set to a position just behind a rear end 50c of the loading bar 50 so as to
prevent pull-out (backward movement) of the loading bar 50.
[0005]
The following Patent Document 1 discloses a mechanism designed to allow application and
release of a surface pressure to interlock with a movement of a slidable metal frame. In the
Patent Document 1, a sliding nozzle device comprises cross-sectionally generally angular-C
shaped surface-pressure applying members each adapted to enfold a flange protruding from a
respective one of opposite lateral portions of a base frame (fixed metal frame) fixed to a bottom
of a molten metal vessel, and a lower surface of a respective one of opposite lateral portions of a
slidable casing (slidable metal frame), wherein a compression spring is installed between an
upper arm of each of the surface-pressure applying members and an upper surface of the flange
of the base frame, and a roller pivotally attached to each of the lateral portions of the slidable
casing is supported by a rail laid on an upper surface of a lower arm of each of the
surface-pressure applying members. A proximal end of the rail is formed as an inclined surface
in such a manner to allow a surface pressure to be released when the roller is moved to the
inclined surface. In order to prevent the slidable casing from being erroneously moved to the
inclined surface, a stopper is provided between the base frame and a rod connection portion of
the slidable casing.
PRIOR ART DOCUMENTS
[PATENT DOCUMENTS]
[0006]
[Patent Document] JP 2006-136912A
DISCLOSURE OF THE INVENTION
[PROBLEM TO BE SOLVED BY THE INVENTION]
[0007]
However, in the conventional sliding nozzle device, there sporadically occur troubles, such
as a situation where the surface pressure is erroneously released due to forgetting to set up the
stopper, and a situation where the stopper is damaged by a loading bar pulled under a condition
that the stopper is in a setup position, due to forgetting to release the stopper.
[0008]
In the sliding nozzle device disclosed in the Patent Document 1, when the surface pressure
is applied, the inclined surface of the rail is not used. Thus, there is a disadvantage of being
incapable of fully utilizing a stroke of the rail during control of molten steel flow rate.
Moreover, the slidable plate is slidingly moved under a condition that four rollers are rotated
while receiving the surface pressure. Thus, there is a problem that a large load is imposed on
the rollers. Furthermore, the sliding nozzle device disclosed in the Patent Document 1 cannot
eliminate a possibility of occurrence of forgetting to set up and release the stopper, as with the
conventional sliding nozzle device.
[0009]
In view of the above circumstances, it is an object of the present invention to provide a
sliding nozzle device which is free of the occurrence of forgetting to set up and release a stopper
for preventing release of a surface pressure.
[MEANS FOR SOLVING THE PROBLEM]
[0010]
In order to achieve the above object, the present invention provides a sliding nozzle device
which includes: a fixed metal frame installed at a bottom of a molten metal vessel and holding a
fixed plate; a slidable metal frame adapted to be slidingly moved while holding a slidable plate: a
spring casing housing a compression spring and coupled to the fixed metal frame: and a
transmitting member for transmitting a spring force of the compression spring to the slidable
metal frame, wherein the transmitting member is adapted to be moved to thereby cause

application and release of a surface pressure between the fixed plate and the slidable plate. The
sliding nozzle device is characterized in that it comprises a heat insulating cover swingably
mounted to the fixed metal frame, wherein the heat insulating cover has a stopping portion which
is adapted, when the heat insulating cover is in a closed position, to come into engagement with
the transmitting member to constrain the movement of the transmitting member in a direction
causing the release of the surface pressure. As used herein, the term "direction causing the
release of the surface pressure" means a direction along which the transmitting member is moved
to release the surface pressure. Further, the after-mentioned term "direction causing the
application of the surface pressure" means a direction along which the transmitting member is
moved to apply the surface pressure.
[0011]
The heat insulating cover swingably mounted to the fixed metal frame occupies a large area
in the sliding nozzle device, so that there is no possibility of forgetting to close the heat
insulating cover. Therefore, in the present invention, the heat insulating cover has a stopping
portion (stopper) which is adapted, when the heat insulating cover is in a closed position, to
come into engagement with the transmitting member to constrain the movement of the
transmitting member in a direction causing the release of the surface pressure. Thus, through
an operation of closing the heat insulating cover after moving the transmitting member in a
direction causing the application of the surface pressure, so that it becomes possible to prevent
forgetting to set up the stopper. Further, the transmitting member can be moved in the direction
causing the release of the surface pressure only after the heat insulating cover is opened, so that
it becomes possible to prevent the occurrence of damage of the stopper due to forgetting to
release the stopper.
[0012]
Preferably, the sliding nozzle device of the present invention is designed to allow the heat
insulating cover to become closable only after the transmitting member is moved in the direction
causing the application of the surface pressure. This makes it possible to eliminate a possibility
of forgetting to perform the surface-pressure applying operation.
[0013]

Preferably, in the sliding nozzle device of the present invention, the heat insulating cover
has a pivot shaft disposed to extend in a direction perpendicular to the movement direction of
transmitting member. In cases where the pivot shaft of the heat insulating cover is disposed to
extend in a direction perpendicular to the movement direction of transmitting member, when the
heat insulating cover is in the closed position, a force from the transmitting member is exerted on
the heat insulating cover as in-plane compressive force. Thus, no torsional moment is exerted
on the heat insulating cover, so that it becomes possible to prevent a large load from being
imposed on the pivot shaft
[EFFECT OF THE INVENTION]
[0014]
In the sliding nozzle apparatus of the present invention, the heat insulating cover has the
stopping portion which is adapted, when the heat insulating cover is in the closed position, to
come into engagement with the transmitting member to constrain the movement of the
transmitting member in the direction causing the release of the surface pressure. This makes it
possible to prevent forgetting to set up the stopper. Further, the transmitting member can be
moved in the direction causing the release of the surface pressure only after the heat insulating
cover is opened, so that it becomes possible to prevent the occurrence of forgetting to release the
stopper.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
FIG. 1 is a bottom view illustrating a sliding nozzle device according to one embodiment of
the present invention, wherein a surface pressure is released.
FIG. 2 is a side view illustrating the sliding nozzle device, wherein the surface pressure is
released.
FIG. 3 is a bottom view illustrating the sliding nozzle device, wherein a transmitting
member is in a push-in position.
FIG. 4 is a side view illustrating the sliding nozzle device, wherein the transmitting member
is in the push-in position.
FIG. 5 is a sectional view taken along the arrowed line A-A in FIG. 3.
FIG. 6 is a bottom view illustrating the sliding nozzle device, wherein a heat insulating
cover is in a closed position.
FIG. 7 is a sectional view taken along the arrowed line B-B in FIG. 6.
FIG. 8 is a bottom view illustrating the sliding nozzle device, wherein the heat insulating
cover is in the closed position.
FIG. 9 is a schematic diagram illustrating a surface-pressure applying mechanism of a
conventional sliding nozzle device.
DESCRIPTION OF EMBODIMENTS
[0016]
With reference to the accompanying drawings, the present invention will now be described
based on a specific embodiment thereof, by way of example for facilitating understanding
thereof. In the following description, one side of a sliding nozzle device where a nozzle hole is
provided, and the other side where a heat insulating cover is mounted, will be referred to
respectively as a "front" side and a "rear" side of the sliding nozzle device, for the sake of
convenience.
[0017]
FIGS. 1 and 2 illustrate a sliding nozzle device 10, wherein a surface pressure between
after-mentioned slidable and fixed plates 24, 25 (see FIG. 7) is released, and an after-mentioned
transmitting member 13 is located on a rearmost side. FIGS. 3 to 8 illustrate the sliding nozzle
device 10, wherein the transmitting member 13 is pushed frontwardly to apply the surface
pressure between the slidable and fixed plates 24, 25. FIG. 7 is a sectional view taken along the
arrowed line B-B in FIG. 6, i.e., along a cutting plane extending in a direction perpendicular to
an after-mentioned sliding direction to pass through respective centers of after-mentioned nozzle
holes 24a, 25a. As illustrated in FIGS. 1 to 8, the sliding nozzle device 10 comprises: a fixed
plate 25; a slidable plate 24; first and second holding means holding respective ones of the fixed
and slidable plates 24, 25; sliding drive means adapted to slidingly drive the slidable plate 24:
surface-pressure applying means adapted to apply the surface pressure between the fixed plate 25
and the slidable plate 24; and a heat insulating cover 14.
[0018]
The fixed plate 25 and the slidable plate 24 are formed with a nozzle hole 25a and a nozzle
hole 24a, respectively. The fixed plate 25 is fixed to a bottom of a molten metal vessel 27
through a fixed metal frame 18 (first holding means), in such a manner that an upper nozzle 26 is
connected to the nozzle hole 25a. On the other hand, the slidable plate 24 is fixed onto a
slidable metal frame 17 (second holding means) disposed inside an openable/closable metal
frame 16 provided in an openable/closable manner with respect to the fixed metal frame 18, and
adapted to be slidingly moved along a lower surface of the fixed plate 25. A lower nozzle 23 is
connected to the nozzle hole 24a of the slidable plate 24.
[0019]
The fixed metal frame 18 extends in a sliding direction of the slidable metal frame 17. and
an oil hydraulic cylinder 28 (sliding drive means) is provided at a rear end of the fixed metal
frame 18 in the extension direction (see FIG. 2). The oil hydraulic cylinder 28 has a rod 29
whose distal end is connected to a rear end of the slidable metal frame 17 through a sliding block
43 (see FIG. 3).
[0020]
The openable/closable metal frame 16 has opposite lateral portions in which a pair of
after-mentioned guide casings 22 are formed, respectively. Further, the openable/closable
metal frame 16 has a rear end formed with a pair of arms 21 each extending rearwardly. Each
of the arms 21 has a distal end coupled to a respective one of opposite lateral portions of the
fixed metal frame 18 through a pivot shaft 20. In this manner, the openable/closable metal
frame 16 can be opened and closed about the pivot shaft 20 disposed to extend in a direction
perpendicular to the sliding direction of the slidable metal frame 17.
[0021]
The surface-pressure applying means comprises: a pair of spring casings 30 mounted to
respective ones of the opposite lateral portions of the fixed metal frame 18; a pair of guide
casings 22 mounted to the openable/closable metal frame 16 and located beneath respective ones
of the spring casings 30; and a transmitting member 13 for transmitting a spring force of
after-mentioned compression springs 31 housed in each of the spring casings 30. to the slidable
metal frame 17 (see FIGS. 2 and 7).
[0022]
As illustrated in FIGS. 1 and 2, the transmitting member 13 comprises a pair of loading bars
12 each extending in the sliding direction of the slidable metal frame 17, and a cross beam 11
disposed between respective rear ends 12c of the loading bars 12. Each of the loading bars 12
is formed in a J shape in side view, which includes a first rod-shaped portion 12a formed to have
a length greater than that of a respective one of the guide casings 22 and inserted into the guide
casing 22, and a second rod-shaped portion 12b formed to have a length less than that of the first
rod-shaped portion 12a and located above the first rod-shaped portion 12a. Each of the first
rod-shaped portion 12a and the second rod-shaped portion 12b of the loading bar 12 has an
inclined surface formed in a lower edge of a distal end thereof to extend obliquely upwardly
toward a terminal edge of the distal end.
[0023]
The cross beam 11 has an intermediate portion provided with a coupling jig 40 for coupling
the rod 29 of the oil hydraulic cylinder 28 and the transmitting member 13. More specifically.
in an operation of moving the cross beam 11 rearwardly, the coupling jig 40 and a
convex-shaped fitting 41 provided at the distal end of the rod 29 are coupled together by a
detachable surface-pressure releasing jig 42 (see FIG. 1). The surface-pressure releasing jig 42
has one end provided with a pair of opposed pawls 42a, and the other end provided with a hole
42b for allowing the convex-shaped fitting 41 to be fitted thereinto. Correspondingly, the
coupling jig 40 has opposite lateral portions each formed with a depression 40a for allowing a
respective one of the pawls 42a of the surface-pressure releasing jig 42 to be fitted thereinto (see
FIG. 3). As illustrated in FIG. 5. a lower surface 43a of the sliding block 43 which couples the
rear end of the slidable metal frame 17 and the distal end of the rod 29 of the oil hydraulic
cylinder 28 is located on the side of the fixed metal frame 18 with respect to the coupling jig 40.
Thus, during an operation of slidingly moving the slidable metal frame 17, the convex-shaped
fitting 41 is brought into contact with the coupling jig 40 without contact between the sliding
block 43 and the coupling jig 40, so that the cross beam 11 is pushed frontwardly to apply the
surface pressure.
[0024]
Each of the spring casings 30 is disposed just above a respective one of a pair of jutting
portions 18a jutting laterally from the fixed metal frame 18, and coupled to the jutting portion
18a through a coupling pin 32. The spring casing 30 houses a plurality of compression springs
31 which are arranged along the sliding direction of the slidable metal frame 17 in such a manner
as to press the spring casing 30 upwardly with respect to the jutting portion 18a. The spring
casing 30 has a front end and a rear end which are provided, respectively, with a long
engagement portion 30a and a short engagement portion 30b each extending downwardly.
Each of the long engagement portion 30a and the short engagement portion 30b is comprised of
a rectangular-shaped frame which has a roller 34 mounted to a lower end thereof. The long
engagement portion 30a provided at the front end of each of the spring casings 30 is adapted to
allow a distal end of a respective one of the first rod-shaped portions 12a to be inserted thereinto
from the side of a rear surface thereof, and the short engagement portion 30b provided at the rear
end of each of the spring casings 30 is adapted to allow a distal end of a respective one of the
second rod-shaped portions 12b to be inserted thereinto from the side of a rear surface thereof.
[0025]
Each of the guide casings 22 has a hollow portion 22a formed to extend in the sliding
direction of the slidable metal frame 17, and the first rod-shaped portion 12a of each of the
loading bars 12 is inserted into a respective one of the hollow portions 22a from the side of a rear
end thereof. A pair of rollers 33 are mounted to respective ones of opposite ends of each of the
hollow portions 22a, in such a manner that, when the loading bar 12 is slidingly moved
frontwardly, the rollers 33 are brought into contact with the jutting portion 18a.
[0026]
In the sliding nozzle device 10 having the above structure, under a condition that the
transmitting member 13 is pulled rearwardly as illustrated in FIGS. 1 and 2 and thereby the
surface pressure is released, the distal ends of the first rod-shaped portion 12a and the second
rod-shaped portion 12b of each of the loading bars 12 are not in contact with respective ones of

the long engagement portion 30a and the short engagement portion 30b of a corresponding one
of the spring casings 30, and therefore the spring case 30 and the guide casing 22 are in an
uncoupled state.
[0027]
Then, when the loading bars 12 are slidingly moved frontwardly, the first rod-shaped
portion 12a and the second rod-shaped portions 12b of each of the loading bars 12 are moved
through and over the respective rollers 34 mounted to the long engagement portion 30a and the
short engagement portion 30b each extending from a corresponding one of the spring casings 30
provided in the fixed metal frame 18. During this sliding movement, the rollers 33 are brought
into contact with jutting portions 18a to set a position of each of the guide casings 22 and thus a
position of the openable/closable metal frame 16. As each of the rollers 34 is moved
downwardly while being guided by the inclined surface of a respective one of the loading bars
12, a corresponding one of the spring casings 30 is also moved downwardly and thereby the
compression springs 31 are compressed (see FIGS. 3 and 4). In the above manner, the spring
casings 30 are moved downwardly, and the openable/closable metal frame 16 is pushed
upwardly by a spring force generated in the compression springs 31 housed in the spring casings
30. Therefore, the surface pressure is applied between the fixed plate 25 and the slidable plate
24. In this embodiment, a movement direction of the transmitting member 13 is identical to the
sliding direction of the slidable metal frame 17.
[0028]
In the sliding nozzle device 10, the heat insulating cover 14 is provided just below the rod
29 of the oil hydraulic cylinder 28 to protect the rod 29 from splashed molten metal. In this
embodiment, the heat insulating cover 14 has a rectangular plate shape, and one side thereof is
coupled to the fixed metal frame 18 through a pivot shaft 19 disposed to extend in a direction
perpendicular to the movement direction of the transmitting member 13 (movement direction of
the slidable metal frame 17) (see FIG. 1). Thus, the heat insulating cover 14 can be swingingly
moved in a vertical plane including the movement direction of the transmitting member 13.
The heat insulating cover 14 has a block-shaped stopping portion 15 provided at a swingable free
end thereof. The stopping portion 15 is adapted, when the heat insulating cover 14 is in a
closed position, to prevent the transmitting member 13 from being moved rearwardly, i.e.. to
prevent the transmitting member 13 from being moved in a direction causing release of the
surface pressure. As illustrated in FIG. 8, when the heat insulating cover 14 is closed under a
condition that the transmitting member 13 is pushed frontwardly, i.e., the surface pressure is
applied, the stopping portion 15 of the heat insulating cover 14 is placed just behind the cross
beam 11.
[0029]
In this connection, the fixed metal frame 18 has a pair of pin holding portions 35 provided
respective ones of opposite lateral ends thereof to hold a lock pin 36 for locking the heat
insulating cover 14 in the closed position so as to prevent the closed heat insulating cover 14
from being opened by its own weight (see FIG. 6).
[0030]
Respective processes for application and release of the surface pressure in the above sliding
nozzle device 10 will be described below.
The process of applying the surface pressure will be firstly described.
(1) The state after the surface pressure is released as illustrated in FIGS. 1 and 2 is defined
as an initial state, wherein the surface-pressure releasing jig 42 is not attached.
(2) The rod 29 of the oil hydraulic cylinder 28 is extended (moved forwardly) to allow the
convex-shaped fitting 41 to be brought into contact with a rear surface of the coupling jig 40.
Then, the rod 29 is further extended to push the transmitting member 13 frontwardly through the
coupling jig 40 so as to apply the surface pressure (see FIGS. 3 to 5).
(3) The heat insulating cover 14 is closed, and then the lock pin 36 is inserted into the pin
holding portions 35 (see FIGS. 6 to 8).
(4) The lower nozzle 23 is attached to the slidable metal frame 17 (see FIGS. 6 to 8).
[0031]
The process of releasing the surface pressure will be secondly described.
(1) The lower nozzle 23 is detached from the slidable metal frame 17.
(2) The lock pin 36 is pulled out from the pin holding portions 35, and then the heat
insulating cover 14 is opened.

(3) The surface-pressure releasing jig 42 is attached to couple the coupling jig 40 and the
convex-shaped fitting 41 (see FIG. 1). Then, the rod 29 of the oil hydraulic cylinder 28 is
etracted (moved backwardly) to pull the transmitting member 13 rearwardly so as to release the
surface pressure.
[0032]
Although the present invention has been described in relation to one embodiment thereof,
the description of the embodiment is not meant to be construed in a limiting sense, but various
changes and modifications will be apparent to those skilled in the art. Therefore, unless
otherwise such changes and modifications depart from the scope of the present invention as set
forth in the appended claims, they should be construed as being included therein. For example,
the sliding nozzle device according to the above embodiment is designed such that the slidable
metal frame is held by the openable/closable metal frame, and pressed through the
openable/closable metal frame provided with the guide casings. Alternatively, the guide
casings may be provided in the slidable metal frame while omitting the openable/closable metal
frame.
EXPLANATION OF CODES
[0033]
10: sliding nozzle device
11: cross beam
12: loading bar
12a: first rod-shaped portion
12b: second rod-shaped portion
12c: rear end
13: transmitting member
14: heat insulating cover
15: stopping portion
16: openable/closable metal frame
17: slidable metal frame
18: fixed metal frame
18a: jutting portion
19, 20: pivot shaft
21: arm.
22: guide casing
22a: hollow portion
23: lower nozzle
24: slidable plate
24a: nozzle hole
25: fixed plate
25a: nozzle hole
26: upper nozzle
27: molten metal vessel
28: oil hydraulic cylinder
29: rod
30: spring casing
30a: long engagement portion
30b: short engagement portion
31: compression spring
32: coupling pin
33, 34: roller
35: pin holding portion
36:lock pin
40: coupling jig
40a: depression
41: convex-shaped fitting
42: surface-pressure releasing jig
42a: pawl
42b: hole
43: sliding block
43a: lower surface
50: loading bar
50a, 50b: rod-shaped portion
50c: rear end
51: compression spring
52: spring casing
53: guide casing
54: roller
55: stopper

WE CLAIM
A sliding nozzle device including: a fixed metal frame installed at a bottom of a molten
metal vessel and holding a fixed plate; a slidable metal frame adapted to be slidingly moved
while holding a slidable plate; a spring casing housing a compression spring and coupled to the
fixed metal frame; and a transmitting member for transmitting a spring force of the compression
spring to the slidable metal frame, the transmitting member being adapted to be moved to
thereby cause application and release of a surface pressure between the fixed plale and the
slidable plate, the sliding nozzle device being characterized in that it comprises a heat insulating
cover swingably mounted to the fixed metal frame, the heat insulating cover having a stopping
portion which is adapted, when the heat insulating cover is in a closed position, to come into
engagement with the transmitting member to constrain the movement of the transmitting
member in a direction causing the release of the surface pressure.
2. The sliding nozzle device as defined in claim 1. which is designed to allow the heal
insulating cover to become closable only after the transmitting member is moved in a direction
causing the application of the surface pressure.
3. The sliding nozzle device as defined in claim 1 or 2. wherein the heat insulating cover has
a pivot shaft disposed to extend in a direction perpendicular to the movement direction of
transmitting member.

Provided is a sliding nozzle device which is free of the occurrence of forgetting to set up
and release a stopper for preventing release of a surface pressure. Surface-pressure applying
means comprises a pair of spring casings 30 mounted to respective ones of opposite lateral
portions of a fixed metal frame 18, a pair of guide casings 22 mounted to openable/closable
metal frame 16 and located beneath respective ones of the spring casings 30, and a transmitting
member 13 for transmitting a spring force of a plurality of compression springs 31 housed in
each of the spring casings 30, to the slidable metal frame 17. The transmitting member 13
comprises a pair of loading bars 12 each adapted to clamp corresponding ones of the spring
casings 30 and the guide casings 22, and a cross beam 11 disposed between respective rear ends
12c of the loading bars 12. A heat insulating cover 14 is adapted to be swingingly moved in a
vertical plane including a movement direction of the transmitting member 13. The heat
insulating cover 14 has a block-shaped stopping portion 15 provided at a swingable free end
thereof. The stopping portion 15 is adapted, when the heat insulating cover 14 is in a closed
position, to prevent the transmitting member 13 from being moved rearwardly, i.e.. to prevent
the transmitting member 13 from being moved in a direction causing release of the surface
pressure.