Note: Descriptions are shown in the official language in which they were submitted.
CA 02633942 2008-06-11
1
DESCRIPTION
INDUCTION HEATER DEVICE
TECHNICAL FIELD
The present invention relates to an induction heater device
used for heating rolled material as subj ect-to-heating material
in a hot rolling production line.
BACKGROUND ART
In a hot rolling production line, rolled steel heated up
to a temperature at which the rolled steel is capable of being
rolled is roughly rolled by means of a roughing mill, and is
subsequently formed into a so-called rough bar. Subsequently,
the rough bar is temporarily coiled into a coil by means of a
coil box. Thereafter, the rough bar is un-coiled from the coil
box, and rolled by means of a finishing mill, and then a product
of rolled material having a desired thickness and width is
obtained.
In such a hot rolling line, the rough bar un-coiled from
the coil box is in general re-heated by means of a device for
heating in total width, referred to as a bar heater, or a device
for heating only edges, referred to as an edge heater.
For example, in Japanese Patent Application Laid-open
H06-320202, an art to dispose an induction heater device
comprised of a bar heater or an edge heater between a coil box
CA 02633942 2008-06-11
2
and a descaling device so as to prevent temperature decrease
in the descaling device is disclosed.
However, as shown in Fig. 6, as the rolled material P is
coiled in the coiled box B, it will considerably wave after
un-coiling from the coil box B. In a case where the rolled
material P as being wavily warped in such a way is heated by
means of edge heaters 2a, 2b, inconveniences in which the rolled
material P collides with the edge heaters 2a, 2b unless an inductor
gap is widened may arise, when prior induction heater devices
are applied thereto. Further, a widened inductor gap is
inconvenient in that it causes decrease in a heating ability
or power.
DISCLOSURE OF INVENTION
The present invention has been achieved in view of solving
the aforementioned inconveniences and its object is to provide
an induction heater device, which levels the warp of the roughly
rolled material un-coiled from the coil box and is therefore
capable of substantially improving a heating ability.
To achieve the object, a first aspect of the present
invention provides an induction heater device comprised of a
heater portion having a predetermined gap therein configured
to heat a subject-to-heating material in the gap by means of
high-frequency induction, a conveyor portion configured to
convey the subject-to-heating material to pass through the gap,
and a leveler portion configured to level a warp of the
CA 02633942 2008-06-11
3
subject-to-heating material so as not to bring the
subject-to-heating material into contact with the heater
portion.
In accordance with the first aspect, because the lever
portion configured to level a warp of the subject-to-heating
material so as not to bring the subj ect-to-heating material into
contact with the heater portion is provided, a height of the
warp of the rolled material un-coiled from the coil box is limited
to a predetermined height. Therefore, the gap of the heater
portion is enabled to be narrowed. Therefore, the
subject-to-heating material can be effectively heated, and it
leads to substantial improvement of the heating ability of the
heater.
A second aspect of the present invention provides the
induction heater device according to the first aspect in that
the aforementioned leveler portion includes an entrance leveler
portion provided at an entrance of the gap which the
subject-to-heating material enters.
In accordance with the second aspect, the height of the
warp of the rolled material is limited by means of the entrance
leveler portion in advance of entrance into the gap.
A third aspect of the present invention provides the
induction heater device according to the first aspect in that
the leveler portion includes an entrance leveler portion provided
at an entrance of the gap which the subject-to-heating material
enters, and an exit leveler portion provided at an exit of the
CA 02633942 2008-06-11
4
gap which the subject-to-heating material exits.
In accordance with the third aspect, because the height
of the warp of the rolled material can be limited further at
the entrance as the exit leveler portion is provided at the exit
of the gap of the heater portion in addition to the entrance
leveler portion, the height of the warp is limited even in a
case where a leading portion of the rolled material is warped
up as a result of that a trailing portion of the rolled material
is pressed down at the entrance leveler portion.
A fourth aspect of the present invention provides the
induction heater device according to the third aspect in that
the leveler portion further includes an intermediate leveler
portion provided in between the entrance leveler portion and
the exit leveler portion.
In accordance with the fourth aspect, even when the
trailing portion is pressed down and the leading portion is,
in response thereto, warped up, the height of the warp is limited
by means of the intermediate leveler portion as with the exit
leveler portion.
A fifth aspect of the present invention provides the
aforementioned induction heater device in that the entrance
leveler portion is comprised of a guiding portion sloping
downward relative to a direction of conveyance of the
subject-to-heating material, and a leveling face provided in
parallel with a plane of conveyance of the subject-to-heating
material.
CA 02633942 2008-06-11
In accordance with the fifth aspect, because the rolled
material is pressed down by means of the guiding portion even
in a case where the height of the warp of the rolled material
conveyed from the heater portion exceeds a predetermined height,
5 the height of the warp is effectively limited.
A sixth aspect of the present invention provides the
aforementioned induction heater device in that the entrance
leveler portion is further comprised of an adjuster mechanism
which makes a height of a leveling position at which the entrance
leveler portion abuts on the subject-to-heating material
variable. Further, a seventh aspect of the present invention
provides the aforementioned induction heater device in that the
exit leveler portion is further comprised of an adjuster
mechanism which makes a height of a leveling position at which
the exitleveler portion abuts on onthe subject-to-heatimaterial
variable.
In accordance with these aspects, because the height of
the entrance leveler portion and/or the exit leveler portion
can be set variable by means of the height adjuster mechanism,
a leveling amount can be steadily kept optimal depending on a
thickness of the subject-to-heating material and an interval
of the gap of the heater portion.
An eighth aspect of the present invention provides the
induction heater device in accordance with the aforementioned
aspect in that the aforementioned entrance leveler portion is
a rectangular tube, which has an exit having a lower height than
CA 02633942 2010-05-04
6
a height of an entrance which the subject-to-heating material
enters, and a sloping portion provided in between the entrance
and the exit, configured to level the warp of the
subject-to-heating material by means of the sloping portion.
In accordance with the eighth aspect, because the sloping
portion slopes downward relative to a conveyance direction of
the subject-to-heating material, the rolled material is pressed
down by means of the sloping portion after entering through the
entrance and thereby the height of the warp of the rolled material
is limited in a case where the rolled material is warped upward
as higher than a height of the exit.
In another aspect, the invention provides an
induction heater device, comprising:
a heater portion having a predetermined gap and
being configured to heat a subject-to-heating
material in the gap by means of high-frequency
induction;
a conveyor portion configured to convey the
subject-to-heating material to pass through the gap;
and
a leveler portion configured to level a warp of the
subject-to-heating material so as not to bring the
subject-to-heating material into contact with the
heater portion;
wherein the leveler portion includes an entrance
leveler portion provided at an entrance of the gap
which the subject-to-heating material enters, and an
exit leveler portion provided at an exit of the gap
which the subject-to-heating material exits; and
CA 02633942 2010-05-04
6a
wherein the entrance leveler portion comprises a
guiding portion sloping downward relative to a
direction of conveyance of the subject-to-heating
material, and a leveling face provided in parallel
with a plane of conveyance of the subject-to-heating
material.
BRIEF DESCRIPTION OF THE DRAWINGS
(FIG. 1] Fig. 1(a) is a schematic plan view showing an
induction heater device in accordance with a first embodiment
of the present invention, and Fig. 1 (b) is a schematic side view
showing the induction heater device in accordance with the first
embodiment of the present invention.
[FIG. 21 Fig. 2 is a graph showing a heating power of an edge
heater of the induction heater devicd in accordance with the
first embodiment of the present invention.
[FIG. 31 Fig. 3 is a schematic side view showing an induction
heater device in accordance with a second embodiment of the
present invention.
(FIG. 4] Fig. 4(a) is a schematic plan view showing an
essential portion of the induction heater device in accordance
CA 02633942 2008-06-11
7
with the second embodiment of the present invention, and Fig.
4 (b) is a perspective view showing an essential portion of the
induction heater device in accordance with the second embodiment
of the present invention.
[FIG. 5] Fig. 5 is a side view showing an induction heater
device in accordance with another embodiment of the present
invention.
[FIG. 6] Fig. 6 is a drawing of a constitution of a prior
induction heater device.
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be
described hereinafter with reference to the appended drawings.
(1) FIRST EMBODIMENT
(1-1) CONSTITUTION
An induction heater device 1 in accordance with a first
embodiment of the present invention is, as shown in Fig. 1,
disposed downstream relative to a coil box B in a direction of
conveyance of rolled material P un-coiled from the coil box B.
The induction heater device 1 is constituted of a heater portion
2, a plurality of feeder rollers R and a leveler portion 3.
The heater portion 2 includes edge heaters 2a, 2b which
respectively have inductors and, by means of high-frequency
induction, heat a subj ect-to-heating material. More concretely,
a pair of edge heaters 2a are disposed at a position close to
the coil box B in the aforementioned direction of conveyance,
CA 02633942 2008-06-11
8
and are opposed to each other to have a gap therebetween in the
perpendicular direction. Further, another pair of edge heaters
2a are provided so as to have a gap therebetween in a direction
which horizontally crosses the aforementioned direction of
conveyance at right angles. On the other hand, a pair of edge
heaters 2b are disposed downstream relative to the edge heaters
2a in the direction of conveyance, and are opposed to each other
to have a gap therebetween in the perpendicular direction.
Further, another pair of edge heaters 2b are provided so as to
have a gap therebetweenin a direction which horizontally crosses
the aforementioned direction of conveyance at right angles.
Meanwhile, the edge heaters 2a (2b) are disposed so that
edge portions, in its lateral direction, of the rolled material
P, which is conveyed by the feeder rollers R, are inserted into
gaps thereof in the perpendicular direction, and mainly heat
the edge portions.
The plurality of feeder rollers R convey the
subject-to-heating material to pass through the gap of the edge
heaters 2a and the gap of the edge heaters 2b. A plane formed
by uppermost portions of the respective feeder rollers R is
defined as a conveyance plane F, and a height measured from the
conveyance plane F to the edge heaters 2a, 2b is defined as an
inductor height Hi hereinafter (Fig. 1(b)).
The leveler portion 3 is composed of an entrance leveler
portion 4, an exit leveler portion 5 and an intermediate leveler
portion 6 disposed therebetween, and disposed so as to form the
CA 02633942 2008-06-11
9
letter of "H" when viewed from the above position as shown in
Fig. 1 (a) . The leveler portion 3 levels a warp of the
subject-to-heating material so as not to bring the
subject-to-heating material passing through the edge heater 2a
(2b) into contact with the edge heater 2a, 2b.
In detail, the entrance leveler portion 4 is disposed
upstream relative to the edge heaters 2a and at a position at
a predetermined height from the conveyance plane F. Further,
the entrance leveler portion 4 has a greater width than a width
of the rolled material P. A cross section of the entrance leveler
portion 4 is, as shown in Fig. 1 (b) , a reversed trapezoid shape.
More specifically, the entrance leveler portion 4 has a guiding
portion 4a sloping downward relative to the conveyance plane
F so as to press down the warped rolled material P, and a leveling
face 4b for curing an amount of the warp (a height) of the rolled
material P, which is provided in parallel with the conveyance
plane F.
The exit leveler portion 5 is disposed downstream relative
to the edge heaters 2b in the direction of conveyance. Further,
the exit leveler portion 5 has a greater width than a width of
the rolled material P. As with the entrance leveler portion
4, the exit leveler portion 5 has a guiding portion 5a and a
leveling face 5b and is so configured that a cross section thereof
isa reversed trapezoid shape. Further, the exit leveler portion
5 is so disposed that a lower face of the leveling face 5b is
at a predetermined height from the conveyance plane F, or
CA 02633942 2008-06-11
preferably at the same height as the entrance leveler portion
4.
The intermediate leveler portion 6, as shown in Fig. 1 (b) ,
has a substantially rectangular planer shape when viewed from
5 its side face, and is provided in between the entrance leveler
portion 4 and the exit leveler portion 6. The lower face of
the intermediate leveler portion 6 is disposed at the same height
(h) as the leveling face 4b of the entrance leveler portion 4
and the leveling face 5b of the exit leveler portion 5. Further,
10 the intermediate leveler portion 6 is, in the present embodiment,
disposed above the rolled material P and at the center in the
lateral direction of the rolled material P, and further along
the direction of conveyance.
Meanwhile, the entrance leveler portion 4, the
intermediate leveler portion 6 and the exit leveler portion 5
(the leveler portion 3) are constituted so that the
aforementioned height h is lower than the inductor height Hi.
More concretely, upon calculating a position where heating power
of the edge heaters becomes a maximum, the edge heaters 2a, 2b
are preferably set lower than the position. Fig. 2 shows an
inductor height (Hi) dependency of heating power of the edge
heaters. As illustrated in Fig. 2, the heating power comes to
be a maximum in a case where the inductor height Hi is 120mm,
therefore preferably the inductor height Hi should be set 120mm
and the height h of the leveling face should be 120mm or less,
for example 100mm. Further, the height h of the leveling face
CA 02633942 2008-06-11
11
can be determined in light of a thickness of the rolled material
P as the subject-to-heating material, as well as the heating
power of the edge heaters.
The induction heater device 1 in accordance with the
present embodiment as structured as above functions in the
following manner.
The rolled material P is uncoiled from the coil box B and
conveyed to the induction heater device 1 by means of the feeder
rollers R.
In a case where a height of the warp of the rolled material
P, which is measured from the conveyance plane F, is greater
than the height h (100mm, for example) of the leveling face 4b,
the rolled material P is brought into contact with the guiding
portion 4a of the entrance leveler portion 4 and therefore pressed
down by the slope of the guiding portion 4a. Next, the height
of the warp of the rolled material P is limited to be smaller
than the height h of the leveling face 4b or later. Next, the
rolled material P, the height of the warp of which is limited
in such a way, is further conveyed by means of the feeder roller
R and reaches the gap between the edge heaters 2b. In the course
of this, the height of the warp of the rolled material P is limited
to be the height h or lower by means of the intermediate leveler
portion 6. Further, when the rolled material P passes through
the edge heaters 2b, the height of the warp of the rolled material
P is limited to be the height h or lower by means of the exit
leveler portion 6.
CA 02633942 2008-06-11
12
In accordance with the aforementioned constitution,
because the height of the warp of the rolled material P is limited
to be the height h (100mm) or lower by means of the leveler portion
3, the rolled material P is prevented from being in contact with
the edge heaters 2a, 2b, thereby the edge heaters 2a, 2b are
prevented from being damaged or malfunctioning.
Further, supposing that the edge heaters are installed
to have wider gaps than the height of the warp of the rolled
material P for the purpose of prevention of contact, portions
warping upward in the rolled material P can be suf ficiently heated
but portions just above the conveyance plane F (lower portions)
come to be insufficient in being heated. Further, if one would
have the lower portions heated sufficiently, heaters having
greater capacities would be required and therefore increase in
electric power consumption could not be avoided, because electric
power supplied to the edge heaters must be increased. However,
according to the induction heater device 1 in accordance with
the present embodiment, by means of the leveler portion 3, the
inductor height Hi can be reduced, therefore the electric power
consumption is prevented from unnecessary increase and heating
with high efficiency is enabled because the rolled material can
be unitarily heated.
Further, because the entrance leveler portion 4 is, by
having the guiding portion 4a and the leveling face 4b, formed
to be a reversed trapezoid shape, the rolled material P under
conveyance is pressed down by the guiding portion 4a and
CA 02633942 2008-06-11
13
subsequently pressed by the leveling face 4b so that the height
of the warp is limited. In this way, the height of the warp
of the rolled material P is smoothly limited and the rolled
material P is prevented frombeing in contact with the edge heaters
2a.
Even if a warp of a leading portion of the rolled material
P is limited at the entrance leveler portion 4, in a case where
the leading portion passes through the edge heaters 2a, 2b, when
a warp of following portions following the leading portion is
limited by means of the entrance leveler portion 4, the leading
portion is susceptible of warping upward and coming into contact
with the edge heaters 2a, 2b. However, in the present embodiment,
by means of the entrance leveler portion 5 and the intermediate
leveler portion 6 provided between the exit leveler portion 4
and the exit leveler portion 5, even in a case where the leading
portion warps upward in response to a downward press of the
following portions by the entrance leveler portion 4, its height
of the warp is limited. Thereby the rolled material P is
prevented from being in contact with the edge heaters 2a, 2b.
Furthermore, according to the induction heater device 1
in accordance with the present embodiment, the height of the
warp of the rolled material P is totally in its lateral direction
limited at the exits of the edge heaters 2a, 2b, therefore the
rolled material P is limited within a predetermined height as
a whole.
In the aforementioned manner, by means of the entrance
CA 02633942 2008-06-11
14
leveler portion 4, the exit leveler portion5 and the intermediate
leveler portion 6, the rolled material P passing through the
heater portion 2 as a whole is limited within a predetermined
height h or a lower height. As a result, the inductor height
Hi can be lowered and heating ability of the edge heaters 2a,
2b can be effectively utilized, and further, the rolled material
P is prevented from being in contact with the edge heaters 2a,
2b.
(2) SECOND EMBODIMENT
As compared with the induction heater device 1 of the first
embodiment, an induction heater device 10 in accordance with
a second embodiment of the present invention is identical in
points of the constitution and the arrangement of the edge heaters
and the feeder rollers R and, on the other hand, different
therefrom in points of concrete constitutions of the leveler
portion 3. The following description will weigh on differences
therebetween. Further, any structure or member identical or
similar to the structure or member in the first embodiment will
be referred to by an identical reference sign and repeating
descriptions will be omitted.
As shown in Fig. 3, a leveler portion in the second
embodiment has an entrance leveler portion 11, an exit leveler
portion 12 and an intermediate leveler portion 13.
The entrance leveler portion 11 is disposed upstream
relative to the edge heaters 2a and is provided with a height
adjuster mechanism lla and a leveling roll llb provided at a
CA 02633942 2008-06-11
lower portion ofthe height adjuster mechanismlla. The leveling
roll llb has a cylindrical shape and elongatedly exists in
parallel with the conveyance plane F as being longer than the
width of the rolled material P. Further, the leveling roll lib
5 is, at the lowermost end (contact point), capable of getting
into contact with the rolled material P conveyed into the gap
between the edge heaters 2a (2b) by means of the feeder rollers
R. The height adjuster mechanisms lla, lib are, for example,
constituted with using a motor, ball screws and such, and adjust
10 the height of the leveling roll 1lb provided below it. Meanwhile,
the height adjuster mechanism 11a can be constituted by any known
means.
The exit leveler portion 12 is disposed downstream relative
to the edge heaters 2b, which is disposed downstream relative
15 to the edge heaters 2a in regard to the direction of conveyance
of the rolled material P. The exit leveler portion 12 has a
height adjuster mechanism 12a and a leveling roll 12b, which
are respectively constituted and function in similar ways as
the height adjuster mechanism lla and the leveling roll 12a of
the entrance leveler portion 11.
Further, the intermediate leveler portion 13 is
constituted to be a substantially rectangular planer shape and
attached to the height adjuster mechanisms lla, 12a. In more
detail, a height of a leveling face of a bar-like shape as a
lowermost end of the intermediate leveler portion 13 from the
conveyance plane F is the same as the height of the contact points
CA 02633942 2008-06-11
16
of the leveling rolls lib, 12b from the conveyance plane F.
Further, as being attached to the height adjuster mechanisms
1la, 12a, the intermediate leveler portion 13 is capable of moving
upward and downward along with the leveling rolls llb, 12b in
accordance with up-and-down movements of the height adjuster
mechanisms 11a, 12a. Therefore, a contact point (leveling
point) of the intermediate leveler portion 13 and leveling faces
of the leveling rolls llb, 12b are steadily kept in the same
height.
As described above, the heater device 10 in accordance
with the second embodiment provides effects of the first
embodiment and is further capable of determining and regulating
the heights of the leveling points of the leveling rolls lib,
12 and the leveling point of the leveling roll 13 by means of
the height adjuster mechanisms 11a, 12a at will. Therefore,
it is enabled to assure the height of the leveling points or
the leveling plane from the conveyance plane F at optimal values
steadily on the basis of the thickness of the rolled material
and the inductor height.
Therefore, the height of the warp of the rolled material
un-coiled from the coil box and conveyed to the induction heater
device 10 can be limited within an optimally set value or lower.
Consequently, it is enabled to reduce the inductor heights Hi
of the edge heaters 2a, 2b and therefore the edge heaters 2a,
2b are allowed to be efficiently operated. Further, the heating
ability of the edge heaters 2a, 2b can be practically improved.
CA 02633942 2008-06-11
17
(3) THIRD EMBODIMENT
As compared with the induction heater devices 1, 10
according to the first and second embodiments, an induction
heater device 20 in accordance with a third embodiment of the
present invention is identical thereto in points of the
constitution and the arrangement of the edge heaters and the
feeder roller R and, on the other hand, different therefrom in
points of concrete constitutions of the entrance leveler portion
of the leveler portion. The following description will weigh
on differences therefrom. Further, any structure or member
identical or similar to the structure or member in the first
embodiment will be referred to by an identical reference sign
and repeating descriptions will be omitted.
In the induction heater device 20 in accordance with the
third embodiment, an entrance leveler portion 21 is, as shown
in Fig. 4, substantially a hexadron in which two faces thereof
perpendicular to the direction of conveyance of the rolled
material P open and side faces along the direction are trapezoid
shapes. In more detail, the entrance leveler portion 21 has
a broad opening portion 21a opposed to an incoming direction
of the rolledmaterial P, and a narrow opening portion 21b provided
downstream relative to the broad opening portion 21a in respect
to the direction. A bottom face of the entrance leveler portion
21 forms an identical plane to the conveyance plane F. A height
of the broad opening portion 21a is set to be substantially
identical to the inductor heights of the edge heaters 2a, 2b,
CA 02633942 2008-06-11
18
and a height of the narrow opening portion 21b is set to be a
height to which a height of the warp of the rolled material P
isto belimited. By difference between the broad opening portion
21a and the narrow opening portion 21b, an upper inner face 21c
of the entrance leveler portion 21 slopes downward along the
direction of conveyance of the rolled material P.
In accordance with the aforementioned constitution, the
rolled material P un-coiled from the coil box enters the entrance
leveler portion 21 via the broad opening portion 21a before
reaching the edge heaters 2a. Subsequently, the rolled material
P progresses with having the height of the warp thereof limited
along the upper inner face of the entrance leveler portion 21,
and goes out of the narrow opening portion 21b of the entrance
leveler portion 21.
Subsequently, the rolled material P is capable of passing
through the induction heater device 20 with having' the height
of the warp limited by the operations of the intermediate leveler
portion and the exit leveler portion as described in the first
and second embodiments. More specifically, also by the third
embodiment, because the height of the warp of the rolled material
P can be kept to be an optimum set value or lower, the edge heaters
2a, 2b are allowed to be efficiently operated. Further, the
heating ability of the edge heaters 2a, 2b can be practically
improved.
(4) ANOTHER EMBODIMENT
The present invention is not limited to the first to third
CA 02633942 2008-06-11
19
embodiments and modifications or variations may occur. For
example, the thickness of the intermediate leveler portion in
the aforementioned first to third embodiments may be modified
at will as long as the intermediate leveler portion does not
interfere the edge heaters.
In the first to third embodiments, the edge heaters are
provided at two sites along the direction of conveyance of the
rolled material P, however, the edge heaters may be provided
at one site between the entrance leveler portion and the exit
leveler portion or may be provided at three sites.
Further, instead of and/or in addition to the intermediate
leveler portion 6, 13, 23, an additional intermediate leveler
portion 7 may be provided on a plane identical to the conveyance
plane F. The intermediate leveler portion 7 cooperates with
the entrance leveler portion 4, the exit leveler portion 5 and
the intermediate leveler portion 6, 13, 23 (or the entrance
leveler portion 4 and the exit leveler portion 5) to enable
leveling of the warp amount of the rolled material P from above
and beneath. Meanwhile, concrete constitutions such as the
shape and the thickness of the intermediate leveler portion 7
can be properly designed. For example, a lateral width (a length
in a direction perpendicular to the direction of conveyance of
the rolled material P) maybe either identical to the intermediate
leveler portion 6 or substantially identical to a lateral width
of the rolled material P.
INDUSTRIAL APPLICABILITY
CA 02633942 2008-06-11
An induction heater device related to the present invention
is preferably applied to a hot rolling production line. In
accordance with the induction heater device, because a warp of
a rolled material as a subject-to-heating material is leveled,
5 a gap of a heater portion in which the rolled material is heated
can be narrowed so as to provide heating with high efficiency.
Further, the rolled material is prevented from being in contact
with the heater portion, therefore damage and malfunction of
the heater portion is prevented. Accordingly, in a case where
10 the present invention is applied to the production line, the
present invention contributes to operation with high efficiency
and electric power saving.
