JP4109424B2 - Steel plate edge heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heating device for a steel plate edge portion that can uniformly heat the edge portion of a strip steel plate.
[0002]
[Prior art]
Conventionally, in the rolling line, when the strip-shaped steel sheet after rolling is transported to the next finishing step, the temperature drop of the steel plate edge portion is larger than that of other portions, and if the finishing treatment is performed as it is, the steel plate edge portion is not cracked. Since shape defects such as intermediate elongation occur, only the steel plate edge portion is heated. As such a steel plate edge heating apparatus, as shown in FIG. 6, the left and right edge portions of the steel plate W are sandwiched from above and below by an edge heater 31 having a U-shaped cross section to generate a high-frequency magnetic flux, and guided to the steel plate edge portion. An electric current is generated and the steel plate edge portion is heated by Joule heat.
[0003]
On the other hand, for example, when a resin film is laminated on both surfaces of the steel sheet W as a finishing process, the resin film is pressure-bonded using the heat retained by the steel sheet W, so that a very uniform heating state in the width direction of the steel sheet W is obtained. Will be required. However, according to the study of the present inventor, as shown in FIG. 7, when edge heating is performed, the entire edge portion is heated, but the temperature is rapidly increased at the boundary portion with the adjacent portion not heated. It turns out that the change point is generated. As a result, there is a problem that a sufficiently satisfactory resin film-coated steel sheet cannot be obtained.
[0004]
[Problems to be solved by the invention]
The present invention solves the conventional problems as described above, and can uniformly heat the edge portion of the strip-shaped steel sheet, particularly at the boundary portion between the edge-heated portion and the non-edge-heated adjacent portion. The present invention has been completed for the purpose of providing a heating device for a steel plate edge portion that can be heated with a gently inclined heating distribution without generating a temperature change point.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the heating device for steel sheet edge portions according to the present invention includes a steel plate edge portion which is heated by sandwiching the left and right edge portions of the steel plate from above and below with edge heaters having a U-shaped cross section that generates high-frequency magnetic flux. In the heating apparatus, a magnetic flux density control member in which conductive wires are printed on a resin substrate with a constant width is disposed in the vicinity of the opening of the edge heater on the surface facing the steel plate of the upper and lower pieces of the edge heater. To do.
[0006]
The control member of the magnetic flux density, and the invention according to claim 2 formed by laminating gradually progressively as permeation flux density is decreased toward the inlet opening.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
The drawings show a case where the present invention is applied to a process of laminating a resin film F on both surfaces of a steel plate W, wherein FIG. 1 is an explanatory diagram of the whole process, FIG. 2 is a plan view thereof, and FIG. 2 is a cross-sectional view taken along line AA in FIG.
In the figure, 1 is a heating furnace for raising the temperature of the steel sheet W to the optimum temperature in the next finishing step, and 2 is a pair of laminating rolls for laminating a resin film on the front and back surfaces of the steel sheet W by thermocompression bonding. Between the heating furnace 1 and the laminating roll 2, an induction heating type edge heater 3 for preventing a temperature drop at the edge portion of the steel sheet is disposed.
[0008]
The edge heater 3 has a U-shaped cross section and generates a high frequency magnetic flux with the left and right edge portions of the steel plate W sandwiched from above and below, generates an induced current in the steel plate edge portion, and the steel plate edge portion by Joule heat. Is to heat. And in this invention, it has the structure which has arrange | positioned the magnetic flux density control member 5 in the surface facing the steel plate W of the upper piece 3a of the said edge heater 3, and the lower piece 3b.
When heating is performed with a conventional edge heater, the entire edge portion is heated appropriately, but when viewed microscopically, an abrupt temperature change point is generated at the boundary portion between adjacent portions that are not heated. In the present invention, the edge heater 3 provided with the magnetic flux density control member 5 is heated so that the boundary between the heated portion and the unheated adjacent portion has a smooth temperature distribution. Heat treatment is performed.
[0009]
That is, when the edge heater 3 provided with the magnetic flux density control member 5 is heated, as shown in FIG. 4, the temperature rise near the opening of the edge heater 3 is suppressed. It is possible to obtain a smooth temperature distribution between adjacent portions that are heated appropriately and that are not heated. The smooth temperature distribution here means that the temperature distribution in the width direction of the steel sheet W is conventionally 2 to 5 ° C., but is 1 ° C. or less.
[0010]
The magnetic flux density control member 5 is disposed near the opening of the edge heater 3 having a U-shaped cross section. The vicinity of the opening refers to a range of about 200 mm from the inlet opening when the length of the insertion portion of the steel plate W into the edge heater 3 is, for example, 300 mm, and depends on the material of the steel plate W, heating conditions, etc. The condition is that the inlet opening is always covered with the control member 5, and the portion corresponding to the end of the steel plate W, which is the back of the edge heater 3, is not covered with the control member 5.
[0011]
The magnetic flux density control member 5 is formed of a member that controls transmission of high-frequency magnetic flux generated by the edge heater 3 toward the steel plate W. For example, a conductor printed on a resin substrate with a certain width is used. Can be used. Also, a smoother heating temperature distribution can be obtained by changing the transmitted magnetic flux density. For example, as shown in FIG. 5, control is performed so that the transmitted magnetic flux density gradually decreases toward the inlet opening. The members 5 may be stacked in stages. Furthermore, it is also possible to apply the print width and print pattern of the conducting wire so that the transmitted magnetic flux density gradually decreases as going to the entrance opening.
[0012]
As described above, the present invention is such that the magnetic flux density control member 5 is disposed on the surface of the upper piece 3a and the lower piece 3b of the edge heater 3 facing the steel plate W. The temperature rise distribution becomes smooth, and it is possible to reliably prevent a sudden temperature change point from being generated at the boundary portion with the adjacent portion that is not edge-heated as in the prior art. As a result, extremely uniform heating without temperature difference is possible over the entire width direction of the steel sheet W. For example, when the resin film is laminated in the next finishing process, the resin film can be thermocompression bonded satisfactorily.
[0013]
【The invention's effect】
As is clear from the above description, the present invention can uniformly heat the edge portion of the strip-shaped steel sheet, and in particular, a sharp temperature is applied to the boundary portion between the edge-heated portion and the non-edge-heated adjacent portion. Heating can be performed with a gently inclined heating distribution without generating a change point.
Therefore, the present invention contributes greatly to the development of the industry as a heating device for the edge portion of the steel plate that has eliminated the conventional problems.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an entire production process when the present invention is applied to a laminated steel plate production apparatus.
2 is a plan view of FIG. 1. FIG.
FIG. 3 is a cross-sectional view taken along the line AA in FIG.
FIG. 4 is an explanatory diagram showing a temperature distribution of a steel plate portion that has been edge-heated.
FIG. 5 is a cross-sectional view of a main part showing another embodiment.
FIG. 6 is a cross-sectional view showing a conventional example.
FIG. 7 is an explanatory diagram showing a temperature distribution of a steel plate portion edge-heated in a conventional example.
[Explanation of symbols]
1 Heating furnace 2 Laminating roll 3 Edge heater 5 Control member W Steel plate

Claims (2)

In a heating apparatus for a steel sheet edge portion that is heated by sandwiching the left and right edge portions of the steel sheet from above and below with an edge heater having a U-shaped cross section that generates a high-frequency magnetic flux, a resin is provided on the upper and lower pieces of the edge heater facing the steel plate An apparatus for heating a steel sheet edge portion, characterized in that a magnetic flux density control member in which a conducting wire is printed on a substrate on a constant width is disposed in the vicinity of the opening of the edge heater . The steel sheet edge portion heating apparatus according to claim 1, wherein the magnetic flux density control member is laminated step by step so that the transmitted magnetic flux density gradually decreases toward the inlet opening .

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