JPH11154591A - Induction heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating device which can optimally heat both side end parts of a heating object plate to a sufficient temperature without interfering with a center apron even in the case of a narrow material. SOLUTION: In an induction heating device where an upper inductor 3a and a lower inductor 3b are formed by winding a heating coil round iron core leg parts opposed above and below by sandwiching an opening part of C-shaped iron cores 1, and a side end part of a heating object plate 6 is passed through the opening part between these, and C-shaped inductors 4a and 4b to locally and inductively heat the side end part are oppositely arranged between carrier rollers 5, and an apron 9 to prevent a descent of the heating object plate 6 is arranged between these, the C-shaped inductors 4a and 4b are oppositely arranged on both sides of a center line 7 running in the carrying direction of the heating object plate 6 by dislocating a position in the carrying direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating apparatus for inductively heating a continuously heated narrow plate to be heated.

[0002]

2. Description of the Related Art In general, in a hot rolling line, a plate to be heated is heated to a predetermined temperature in advance, continuously conveyed, passed through a plurality of rolling mills, and sequentially rolled to form a thin plate. In the process of transporting the heated plate, the heated plate 6 has a problem that heat is easily radiated at both side ends thereof, and the temperature of this portion gradually decreases as compared with the central portion. In this way, if the end part temperature drops and the whole temperature is rolled while the temperature is not uniform, the quality of the rolled steel sheet is not constant, the hardness of the side end part becomes high and the heated plate is broken, Problems such as flat wear occur. For this reason, an induction heating device is provided upstream of the rolling mill in the hot rolling line, in which both ends of the plate to be heated are locally heated by an inductor to bring the whole to a substantially constant temperature before rolling.

As this conventional induction heating apparatus, for example, as shown in FIG. 7, an iron core 1 is formed in a C shape, and an upper iron leg and a lower iron core vertically opposed to each other with an opening 2 of the C iron core 1 interposed therebetween. Two C-shaped inductors 4a and 4b, each of which is formed by winding a heating coil to form an upper inductor 3a and a lower inductor 3b, are arranged on the legs so as to face each other. Also C
As shown in FIG. 8, the shape inductors 4a and 4b are arranged between the front and rear transport rollers 5, 5 and have a bent end of the heated plate 6 transported on the transport rollers 5, 5. The lower inductors 3b and 3 oppose each other in order to prevent the
A center apron 8 is provided on the center line 7 between the points b.

When locally heating both side ends of the plate 6 to be heated by the induction heating device, the C-shaped inductors 4a, 4b
The high-frequency current is supplied from the power supply to the heating coil by passing the end of the plate to be heated 6 through the opening 2 of the opening 2 to generate a magnetic flux in the vertical direction. The magnetic flux is vertically linked to the heated plate 6 to induce an eddy current, and the eddy current generates Joule heat to locally heat both end portions of the heated plate 6. I have.

In this induction heating apparatus, the width of the heated plate 6 to be heated varies depending on the product, and therefore, as shown in FIG.
It is necessary to change the positions of the openings 2 and 2 between the upper inductor 3a and the lower inductor 3b through which both end portions pass by adjusting the distance between a and b. However, when the plate width of the plate 6 to be heated is reduced, the facing C
The distance between the shape inductors 4a and 4b is also reduced, but in the case of a narrow material, it cannot interfere with the center apron 8 as shown by the imaginary line and cannot be narrowed. There was a problem that heating to temperature was not possible.

Further, when power is supplied to each of the C-shaped inductors 4a and 4b disposed opposite to each other between the transport rollers 5 and 5, the magnetic flux generated from one of the C-shaped inductors 4a generates an eddy current in the plate 6 to be heated. generate. There is also a problem that the opposing C-type inductor 4b is affected by the eddy current and cannot operate stably.

[0007]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned disadvantages, and does not interfere with the center apron even in the case of narrow materials.
It is an object of the present invention to provide an induction heating apparatus that can optimally heat both end portions of a heated plate to a sufficient temperature and that can stably operate without being affected by an eddy current generated in the heated plate.

[0008]

According to a first aspect of the present invention, there is provided an induction heating apparatus, wherein a heating coil is wound around each of upper and lower opposed core legs across an opening of a C-shaped iron core to form an upper inductor. A C-shaped inductor for forming a lower inductor, passing the side end of the plate to be heated through the opening therebetween, and locally inductively heating the side end, is disposed opposite to and between the transport rollers. In the induction heating device provided with an apron for preventing the plate to be heated from lowering during this period,
The inductors are arranged on both sides of a center line along the transport direction of the plate to be heated so as to face each other while being displaced along the transport direction.

Further, the induction heating device according to claim 2 is arranged on a side opposite to the C-shaped inductor with respect to the center line,
An apron is provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described in detail with reference to FIG. As shown in FIGS. 3 and 4, this induction heating apparatus forms a core 1 in a C-shape, and heats the upper and lower iron legs, which are vertically opposed to each other, with an opening 2 of the C-shaped core therebetween. By winding the coil and providing the upper inductor 3a and the lower inductor 3b, C
Shaped inductors 4a and 4b are configured.

As shown in FIGS. 1 and 2, the C-shaped inductors 4a and 4b are displaced along the transport direction on both sides of the center line 7 along the transport direction of the plate 6 to be heated. Are arranged facing each other. In addition, the C-shaped inductor 4
On the side opposite to a and 4b, aprons 9 and 9 are provided for preventing the bent front end of the heated plate 6 to be conveyed from falling down between the conveying rollers 5 and sneaking in. The aprons 9, 9 protrude in a triangular shape on both sides and overlap the rollers 5, 5, and are arranged on both sides of the center line 7 along the transport direction of the heated plate 6, displaced in the transport direction. Have been.

When locally heating both side ends of the narrow heated plate 6 with this induction heating device, the C-shaped inductors 4a and 4b are moved to the center line 7 side as shown in FIGS. Then, the positions of the openings 2 and 2 between the upper inductor 3a and the lower inductor 3b are adjusted according to the end of the plate 6 to be heated. In this case, apron 9, 9
Are C-shaped inductors 4a, 4
b, the C-type inductor 4
a, 4b lower inductors 3b, 3b are apron 9,
9 does not interfere.

In this state, when the plate 6 is passed through the plate 6, the one side end of the plate 6 is locally induction-heated by the C-shaped inductor 4a.
In b, the opposite side end of the heated plate 6 is locally induction-heated, and when passing therethrough, the heated plate 6 is supplied to a rolling mill in a state in which the entire temperature is substantially constant, and is sequentially supplied to the rolling mill. It is being rolled. Therefore, even when the width of the heating plate 6 is narrow, the entire plate can be uniformly heated under the optimal heating condition.

Also, C-shaped inductors 4a arranged opposite to each other,
4b is shifted along the transport direction,
Since the arrangement positions are separated, stable operation can be performed without being affected by eddy current generated in the plate 6 to be heated.

FIG. 5 shows another embodiment of the present invention, in which two C-shaped inductors 4a ₁ and 4a ₂ are mounted in a plane U-shape at intervals with a common power supply for the support mechanism 10a. I have. A common power source is also used for the support mechanism 10b.
The C-shaped inductors 4b ₁ and 4b ₂ are mounted in a plane U-shape at intervals. C-type inductors 4a ₁ and 4a ₂ attached to the support mechanism 10a and a support mechanism 10b
The C-type inductors 4b ₁ and 4b ₂ attached to each of them are arranged between the transport rollers 5.
Are arranged facing each other with their positions shifted along the transport direction.

_On the opposite side of each of the C-shaped inductors 4a ₁ , 4a ₂ , 4b ₁ , 4b _{2 with} the center line 7 interposed therebetween, there are provided aprons 9. ing. The induction heating device of this structure
The side edges of the plate 6 to be heated are sequentially heated so that the whole can be made substantially uniform.

FIG. 6 shows another embodiment of the present invention, in which two C-shaped inductors 4a ₁ and 4a ₂ are mounted in a plane U-shape at intervals with a common power supply for the support mechanism 10a. Have been. Also, two C-shaped inductors 4b ₁ and 4b ₂ are mounted on the support mechanism 10b in a plane U-shape at intervals with a common power supply. This support mechanism
C-type inductors 4a ₁ and 4a ₂ attached to 10a and C-type inductors 4b ₁ and 4b ₂ attached to support mechanism 10b
Means that the C-shaped inductor 4b ₁ is a C-shaped inductor 4a
So as to be located between the _1, 4a _2, on either side of the center line 7, are arranged to face between the transport roller 5 ... by shifting the position along the conveying direction.

On the opposite side of each of the C-shaped inductors 4a ₁ , 4a ₂ , 4b ₁ , 4b ₂ with the center line 7 interposed therebetween, there are provided aprons 9... ing. The induction heating device of this structure
The side edges of the plate 6 to be heated are alternately heated so that the whole can be made substantially uniform.

[0019]

As described above, according to the induction heating apparatus of the present invention, the C-shaped inductor for locally inductively heating the side end is provided on both sides of the center line along the transport direction of the plate to be heated. Because it is arranged facing each other with its position shifted along the transport direction, it does not interfere with the center apron even when heating narrow materials, and optimally heats both side edges of the plate to be heated to a sufficient temperature. be able to. In addition, stable operation can be achieved without being affected by eddy current generated in the plate to be heated.

[Brief description of the drawings]

FIG. 1 is a plan view of an induction heating device according to an embodiment of the present invention.

FIG. 2 is a side view of the induction heating device shown in FIG.

FIG. 3 is a sectional view taken along line AA of the induction heating device shown in FIG.

FIG. 4 is a sectional view of the induction heating device shown in FIG. 1 taken along line BB.

FIG. 5 is a plan view of an induction heating device according to another embodiment of the present invention.

FIG. 6 is a plan view of an induction heating apparatus according to another embodiment of the present invention.

FIG. 7 is a front view showing a conventional induction heating device.

FIG. 8 is a central vertical sectional side view showing the conventional induction heating device shown in FIG. 7;

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 C-shaped iron core 2 Opening 3a Upper inductor 3b Lower inductor 4a C-shaped inductor 4b C-shaped inductor 5 Conveyance roller 6 Plate to be heated 7 Center line 8 Center apron 9 Apron 10 Support mechanism

Claims (2)

[Claims] An upper inductor and a lower inductor are formed by winding a heating coil around iron legs vertically opposed to each other across an opening of a C-shaped iron core. Induction heating, in which a C-shaped inductor that passes the end and locally heats the side end by induction is disposed between the conveying rollers and an apron is provided between the rollers to prevent the plate to be heated from lowering. An induction heating apparatus, wherein the C-shaped inductor is disposed on both sides of a center line along the transport direction of the plate to be heated, facing each other while being displaced along the transport direction. 2. The induction heating apparatus according to claim 1, wherein an apron is provided on the opposite side of the center line from the C-shaped inductor.