JP2871399B2 - Induction heating method for sheet material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of inductively heating both edges of a hot-rolled sheet material, a joint at the front and rear ends, and the like using an inductor.

[0002]

2. Description of the Related Art Conventionally, an induction heating method in which an eddy current is induced by a magnetic flux penetrating a sheet material in a sheet thickness direction to heat the sheet material has been widely applied to an edge heater, a heat bonding apparatus, and the like of a hot-rolled sheet material.

FIG. 3 shows an example in which such an induction heating method is used for an edge heater. A substantially C-shaped opening of a pair of inductors 4 arranged at both edges of a plate material 1 is formed as follows. In order to avoid collision with the plate 1, it is formed so as to form a minimum gap g ₁ with the lower surface and the upper surface of the plate 1 having the maximum allowable plate thickness t ₁ .

A magnetic flux penetrates through the plate material 1 in the thickness direction of the plate material 1 while passing the plate material 1 through the substantially C-shaped opening of the inductor 4 to induce an eddy current to perform induction heating, thereby forming both edges of the plate material 1. Prevents cooling.

[0005]

The distance t ₁ + 2g ₁ between the upper part and the lower part of the substantially C-shaped opening of the inductor 4 in the conventional induction heating method for both edges of the plate material as described above is constant.

[0006] However, the inductor 4 should correspond to the plate material of various thickness, for example, when the sheet material 2 having a thickness t _2, as shown by a two-dot chain line induction heating, the sheet material 2 thickness t ₂ It decreases as the gap g ₂ increases.

If the gap g ₂ is large (the space is long), the magnetic flux spreads and heats an unnecessarily wide area of the plate member 2 to lower the heating efficiency. Is increased.

The present invention has been proposed in order to solve such disadvantages of the prior art, and an induction for reducing the spread of magnetic flux and reducing the magnetic resistance even when the gap between the plate material and the inductor becomes large. It is intended to provide a heating method.

[0009]

In order to achieve the above object, according to the present invention, there is provided a method for induction heating a plate, wherein the plate is passed through or stopped at an opening of a substantially C-shaped inductor. In the method of performing induction heating by applying a magnetic flux penetrating in the thickness direction of the plate between the openings and generating an eddy current in the plate, when a gap between the plate and the opening is larger than a minimum gap, In the gap between the plate and the opening, the magnetic resistance is smaller than that of the plate and iron
Inserting a gap plate made of an iron core material with a small loss , forming a minimum gap between the gap plate and the plate material to reduce the spread of magnetic flux and the air magnetic resistance of this gap. I have.

[0010]

In the method of induction heating a plate according to the present invention, the thickness of the plate passing through the opening of the substantially C-shaped inductor is less than the maximum allowable value. A gap plate having a thickness corresponding to the increased value is inserted into a portion of the opening facing the plate material, and adjustment is made so that the gap plate and the plate material form a minimum gap.

When a high-frequency current is applied to the inductor and energized so that both edges of the plate pass through the substantially C-shaped opening of the inductor and eddy current penetrates in the thickness direction of both edges of the plate, the magnetic flux becomes The magnetic resistance is smaller than the plate material and
The core material passes through the area where the gap plate made of iron material with little iron loss exists intensively, the spread is reduced and only the intended portion of the plate material is effectively induction-heated to reduce the air magnetic resistance of the magnetic flux passage. Make it smaller.

As a result, the power used for induction heating of the plate can be greatly reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of the present invention in which an induction heating device is used for an edge heater, and FIG.
FIG. 2 is a sectional view taken along line II-II of FIG.

In FIGS. 1 and 2, reference numeral 4 denotes an inductor, which is disposed on both edges of the advancing plate 2 and has a top surface on both sides in the line direction above the respective substantially C-shaped openings. A support plate 5 having an inclined portion is fixedly provided.

The plate thickness t ₂ of the plate ₂ is shown in FIG.
Corresponds to the small plate thickness indicated by the two-dot chain line.

Reference numeral 6 denotes an iron core material having a smaller magnetic resistance and less iron loss than the plate material 2 to be induction-heated , for example, a gap plate having a thickness t ₆ of laminated silicon steel plates. Hooks 7 which are inserted into gaps between the substantially C-shaped openings of the inductors 4 disposed on both edges and are provided on both sides with inclined portions for engaging with the inclined portions of the support plate 5 are fixed. Have been.

Next, the operation of the present apparatus will be described. As shown in FIGS. 1 and 2, while each hook 7 is engaged with both support plates 5 from the center in the width direction of the plate material, each gap plate 6 is connected to a substantially C-shaped opening of both inductors 4. respectively mounted on the upper, forms a minimum gap g ₁ between the upper surface of the sheet material 2 having a thickness t _2.

Then, a high-frequency current is applied to the inductor 4 to pass it, so that both edges of the plate 2 pass through the substantially C-shaped opening of the inductor 4, and an eddy current penetrates in the thickness direction of both edges of the plate 2. is allowed, the magnetic flux path by the magnetic flux was only effective inductive heating portion of interest of the plate 2 to reduce its spread by intensively passes through the gap filling plate 6 to form a minimum gap g ₁ To reduce the air magnetic resistance and the loss of electric power used.

It should be noted that the present invention is not limited to the above-described embodiment, and that the joint portion of the hot-rolled plate is stopped at the substantially C-shaped opening of the inductor 4 and the contact portion of the preceding plate material and the succeeding plate material is stopped. Can also be applied to a method of bonding by induction heating and pressurization, all of which fall within the technical scope of the present invention.

[0020]

According to the induction heating method of the sheet material of the present invention as described above, according to the present invention, the gap between the plate member and the opening when the gap between the plate member and the inductor opening is larger than the minimum gap, the Lower magnetic resistance and less iron loss than sheet material
By inserting a gap plate made of an iron core material and forming a gap between the gap plate and the plate material to a minimum, magnetic flux can be intensively passed through the region where the gap plate exists, so that Spreading can be prevented and only the intended portion of the plate can be effectively induction-heated, and the space through which the magnetic flux passes becomes shorter, so that the aeromagnetic resistance of the magnetic flux passage can be reduced. Therefore, electric power used for induction heating of the plate can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing an example in which an induction heating device according to an embodiment of the present invention is used for an edge heater.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a front view showing a conventional plate material heating method.

[Explanation of symbols]

1,2 thickness of the plate 4 inductor 6 Hamasukizai g ₁ minimum gap g ₂ plate 2 thickness t ₆ Hamasukizai 6 clearance t ₁ allowable maximum thickness t ₂ plate 2 by

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kanji Hayashi 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima Sanritsu Heavy Industries, Ltd. Hiroshima Works (72) Inventor Kiyoshi Izumi 4-2-2 Kanon Shinmachi, Nishi-ku, Hiroshima City No. 3 Hiroshi Heavy Industries, Ltd.Hiroshima Laboratory (72) Inventor Kazuya Tsuruzaki 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Research Laboratories (72) Inventor Hideyuki Nikaido Kawasaki, Chuo-ku, Chiba, Chiba No. 1 Kawasaki Steel Corporation Chiba Works (72) Inventor Takeshi Hirabayashi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Kawasaki Steel Corporation Chiba Works (72) Inventor Hiroyoshi Yamada Kawasaki-cho, Chuo-ku, Chiba Chiba No. 1 Kawasaki Steel Corporation Chiba Works (72) Inventor Toshiaki Amagasa 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corp. Company Chiba steelworks (58) investigated the field (Int.Cl. ^6, DB name) B21B 45/00 H05B 6/10

Claims (1)

(57) [Claims] 1. A plate material is passed through or stopped at an opening of a substantially C-shaped inductor, and a magnetic flux penetrating between the openings in a thickness direction of the plate material is applied to generate an eddy current in the plate material. a method of induction heating by, than the plate in a gap between the plate and the opening when the gap between the plate and the opening is larger than the minimum gap
A gap plate made of an iron core material having a small magnetic resistance and a small iron loss is inserted , a minimum gap is formed between the gap plate and the plate material, and the spread of magnetic flux and the air magnetic resistance of this gap are reduced. An induction heating method for a sheet material, characterized by reducing the size.