JPH0820823A - Induction heating apparatus - Google Patents

Abstract

PURPOSE:To uniformly heat a strip through the center of hollow part of an induction heating coil even if the deflection rate of the strip varies. CONSTITUTION:An inclination angle of the whole frame base 101 to the horizontal surface is adjusted with a jack 102 for tilting the the frame base, and an inclination angle of each induction heating coil 104 to the whole frame base 101 is adjusted with a jack 103 for inclining the coil. By this constitution, the bent strip 1 carried with pinch rollers 13a, 13b is uniformly heated through the center of the hollow part of each induction heating coil 104. Further, the circulating current is conducted to a coil case 107 and a diffusion plate 108 and scarcely conducted to the whole frame base 101. Therefore, the whole frame base 101 can be made of an iron having high strength and can be made to be a large scale apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating device, which is effective for heating a strip-shaped member such as flat steel plate.

[0002]

2. Description of the Related Art Induction heating is a method of heating an electric conductor (object to be heated) itself by generating heat by an eddy current resulting from an electromagnetic induction effect. In recent years, there have been many examples of applying the induction heating method to heating a metal material. This is because the advantages of being able to suppress pollution such as air pollution and noise, in addition to the possibility of mass production by rapid heating, ease of control, ease of starting and stopping, were noted.

In the field of steel, induction heating devices are used to heat flat steel (hereinafter referred to as "strip") and the like. FIG. 4 shows a conventional induction heating device for heating strips. The strip 1 is conveyed by a pinch roller (not shown) in the direction perpendicular to the paper surface and passes through the annular induction coil 2. Induction heating coil 2 is insulator 3
Is mounted on the pedestal 4 via the insulator, and is covered with the metallic coil case 5 via the insulator 3a.
It is connected to the.

When a high frequency current is passed through the induction heating coil 2, the strip 1 is heated by the electromagnetic induction effect. As described above, since the heating by the induction heating coil 2 can directly heat the strip 1 by the eddy current, the heating efficiency is several times higher than the combustion heating, and the temperature control can be performed accurately and quickly. During this induction heating, the coil case 5 magnetically shields the leakage magnetic flux generated from the induction heating coil 2, and the leakage magnetic flux causes an eddy current to the surrounding conductive machine device (outside the coil case). It prevents unnecessary induction heating. In addition, coil case 5
This prevents the occurrence of electric shock accidents.

In the induction heating device shown in FIG. 4, when the coil case 5 is installed near the induction heating coil 2,
The eddy current thus induced heats the coil case 5 to a high temperature, which is dangerous. Further, as shown in FIG. 5, a circulating current I, which is a collection of eddy currents, flows through the gantry 4 and the coil case 5 in the form of a short-circuit ring as a circulation path, and a bolt connecting the gantry 4 and the coil case 5 The nuts and other parts are heated.

Therefore, in order to reduce the eddy current and the circulating current I, the coil case 5 is enlarged so that the coil case 5 is separated from the induction heating coil 2. When the coil case 5 is enlarged in this way, the entire device becomes large, a large installation space is required, and maintenance is inconvenient.

Therefore, in the past, various measures have been taken in order to reduce the size of the coil case 5.

The first device for reducing the size of the coil case is
The coil case 5 and the pedestal 4 are made small, and the material thereof is a copper plate or an aluminum plate having a low electric resistance to reduce the eddy current loss. A second device for reducing the size of the coil case is to reduce the size of the coil case 5 and use an insulating material (bakelite, vinyl chloride, etc.) to prevent eddy currents. A third device for reducing the size of the coil case is to reduce the size of the coil case 5, and use a water-cooled copper plate as the material for preventing overheating due to eddy current loss and circulating current by water cooling. A fourth device for reducing the size of the coil case is to reduce the size of the coil case 5 and to dispose the insulator 7 between the coil case 5 and the frame 4 or in the middle of the coil case 5, as shown in FIG. The circulating current I to prevent
To prevent heat generation.

FIG. 7 shows a coil case 5 having a fourth device.
Is disassembled and shown. As shown in the figure, in this coil case 5, a plate material 9 of copper or aluminum is attached to a frame 8 with an insulator 7 interposed therebetween, and a ground wire 10 is connected to the plate material 9 for preventing electric shock. Further, as shown in FIG. 8, the insulating bush 11 and the bolt 12 are used to mechanically fasten the plate member 9 and the frame 8 to secure electrical insulation. In this example, when maintaining, inspecting, or replacing the induction heating coil, the bolt 12 can be loosened and the single plate material 9 can be removed to perform the work.

[0010]

By the way, in the above-mentioned device for miniaturizing the coil case, the pedestal 4 to which a heavy load is applied is applied.
In addition, since it is not possible to use a strong iron plate, it is difficult to manufacture a large induction heating device.

In the above-mentioned device for reducing the size of the coil case,
The coil case 5 can prevent the occurrence of electric shock, but since electromagnetic shielding cannot be performed, the nearby conductive machine or the like overheats due to the leakage magnetic flux.

In the above-mentioned device for reducing the size of the coil case,
Since water is used, the complicated work of brazing and connecting the cooling pipe to the coil case is required, and the structure for preventing water leakage and the cooler are required, resulting in an increase in cost.

In the above-mentioned device for miniaturizing the coil case,
Insulator 7, Insulation bush 11, Bolt 12, Ground wire 1
Since 0 or the like is required, the number of parts is large and the configuration is complicated, resulting in an increase in cost.

Further, as shown in FIG. 9, the strip 1 is conveyed by the pinch rollers 13a and 13b and passes through the inside of the coil case 5, but the pinch rollers 13a and 13b.
In the meantime, the strip 1 bends like a catenary curve. This amount of bending changes depending on the tension applied to the strip 1. In order to satisfactorily uniformly heat the strip 1, it is possible to change the inclination angle (angle with respect to the horizontal plane) of the induction heating coil in accordance with the amount of bending of the strip 1 so that the strip 1 passes through the center of the induction heating coil. Although preferable, each of the above prior arts did not make such a device at all.
Further, in the conventional technique, when the amount of flexure of the strip 1 becomes extremely large, the strip 1 may come into contact with the induction heating coil and cause a dielectric breakdown accident.

In view of the above-mentioned conventional technique, the present invention can favorably and uniformly heat a strip-shaped object to be heated (strip or the like) which is conveyed in the longitudinal direction in a state of being stretched between separated rollers, and at the same time, a coil case can be provided. It is an object of the present invention to provide an induction heating device that can be downsized.

[0016]

The structure of the present invention which solves the above-mentioned problems is such that a belt-shaped object to be heated is conveyed in the longitudinal direction in a state of being bridged between separated rollers, and an annular member arranged between the rollers. Is an induction heating device that conveys the object to be heated while penetrating the hollow part of the induction heating coil, and an inclination angle of the induction heating coil with respect to the entire mount and the entire mount installed on the entire mount. An induction heating coil tilting support portion that supports the induction heating coil while making it possible to adjust
It is characterized in that the induction heating coil is surrounded by a conductive electromagnetic shield portion provided on the entire pedestal while surrounding the induction heating coil.

Further, in the structure of the present invention, the belt-shaped object to be heated is conveyed in the longitudinal direction in a state of being bridged between the separated rollers, and penetrates through the hollow portion of the annular induction heating coil arranged between the rollers. An induction heating device for carrying out induction heating while transporting the object to be heated, comprising: a whole mount, a whole mount tilting support part for supporting the whole mount while adjusting a tilt angle of the whole mount with respect to a horizontal plane, and a whole mount on the whole mount. Installed on the whole of the gantry, the induction heating coil tilting support part supporting the induction heating coil while adjusting the tilt angle of the induction heating coil, and the conductive electromagnetic shield provided on the whole gantry while surrounding the induction heating coil. It is characterized in that it is configured with a section.

Further, according to the structure of the present invention, the electromagnetic shield part is a coil case attached to the overall mount so as to cover the induction heating coil from above, and above the overall mount and below the induction heating coil. And a diffuser plate provided at a position and joined to the coil case.

Further, in the configuration of the present invention, the electromagnetic shield portion further includes a flexible conductor for electrically connecting the coil frame located at the top of the induction heating coil tilting support portion and the diffusion plate. It is characterized by

Further, the structure of the present invention is characterized in that the electromagnetic shield portion has an electric resistance smaller than that of the whole mount, and the whole mount has a higher strength than the electromagnetic shield part.

[0021]

According to the present invention, the object to be heated by induction heating is adjusted by adjusting the tilt angle of the entire gantry by the tilt support part of the whole gantry and individually adjusting the tilt angle of the induction heating coil by the tilt support part of the induction heating coil. It passes through the center of the hollow part of the coil.
The circulating current flows through the electromagnetic shield, coil frame, flexible conductor and diffuser plate, and hardly flows through the entire frame. Also, the coil tilting jack made of iron is magnetically shielded so that overheating due to induction heating does not occur.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and FIG.
II-II section of is shown. In this embodiment, the pinch roller 13
The strip 1 that is bridged between a and 13b and curved in a catenary curve and conveyed in the direction of arrow A is heated by two induction heating devices 100 arranged in series.

In this induction heating apparatus 100, the whole frame 1
01 is made of iron, and the bottom portion of the entire pedestal 100 is supported by the gantry tilting jacks 102 on the front side (upstream side in the transport direction of the strip 1) and the rear side (downstream side in the transport direction). . Therefore, the tilt angle of the entire gantry 101 with respect to the horizontal plane can be adjusted by making the elevation lengths of the front and rear gantry tilting jacks 102 different from each other.

Three induction heating coils 10 are mounted on one whole frame 101 via a coil tilting jack 103.
4 are provided. More specifically, the coil tilting jack 103 includes a jack bolt 103a and a coil tilting piece 103b, and a coil frame 105 made of aluminum is provided on the coil tilting piece 103b. On the coil frame 105, three induction heating coils 104 are provided via an insulator 106. Therefore, by making the lifting length of the coil tilting jacks 103 provided on the front side and the rear side of the coil frame 105 different,
The tilt angle of the induction heating coil 104 with respect to the surface of the entire gantry 101 can be adjusted individually or independently. Further, the induction heating coil 104 has an annular shape, and the induction heating coil 1
The strip 1 is conveyed so as to penetrate through the hollow portion 04 (see FIG. 2).

The coil case 107 is bolted to the entire mount 101 so as to cover the three induction heating coils 104 from above. The coil case 107 is formed by bolting an aluminum plate to an aluminum frame. Further, a diffusion plate 108 made of aluminum is provided above the entire gantry 101 and below the induction heating coil 104 and the coil frame 105.
The diffusion plate 108 is joined to the coil case 107 at its four sides. Therefore, the induction heating coil 104 has a coil case 107 and a diffusion plate 108, which are made of aluminum around the periphery.
Surrounded by and magnetically shielded. Further, since the coil frame 105 is electrically connected to the diffusion plate 108 by the flexible conductor 109, the strong magnetic field from the induction heating coil 104 is shielded, and the iron coil tilting jack 103 and the like are not overheated. Absent.

The induction heating coil 104 is supplied with a high-frequency current from the high-frequency power source 6, and is heated by the induction heating coil 104.
Causes the strip 1 to be induction-heated.

Next, the operation of this embodiment having the above configuration will be described. In this embodiment, when the tension of the strip 1 is determined, the bending of the strip 1 along the catenary curve is uniquely determined. Therefore, the jack for tilting the gantry is adjusted so that the inclination angle of the entire pedestal 10 is adjusted according to the bending of the strip 1. Adjust the ascending / descending length of 102. Furthermore, so as to match the angle between each induction heating coil 104 and the strip 2,
The ascending / descending length of each coil tilting jack 103 supporting each induction heating coil 104 is individually adjusted. By making such adjustments, the strip 1 can be made into each induction heating coil 10
It penetrates through the central position of the hollow part of 4. Therefore, the strip 1 can be uniformly heated well, and it is possible to prevent the strip 1 from coming into contact with the induction heating coil 104 and causing a dielectric breakdown accident.

The leakage magnetic flux generated from the induction heating coil 104 is linked to the coil case 107 and the diffusion plate 108 to generate an eddy current, but since the coil case 107 and the diffusion plate 108 are made of aluminum, the electric resistance is small and the eddy current loss. Is small. Therefore, the coil case 107 and the diffusion plate 108
The amount of heat generated in the induction heating coil 104 is small, and even if the coil case 107 and the diffusion plate 108 are made small to approach the induction heating coil 104, the temperature does not increase so much. Since the coil case 107 and the diffuser plate 108 can be downsized in this way, the entire induction heating device 100 can be downsized. Of course, the coil case 107 and the diffusion plate 10
8, the induction heating coil 104 can be magnetically shielded.

Further, the circulating current I is, as shown in FIG. 3, a coil case 107 and a diffusion plate 1 made of aluminum.
08 as a route, and hardly flows to the entire iron mount 101. This is because iron has a larger electric resistance than aluminum. Similarly, the induced current induced in the coil frame 105 is transmitted through the flexible conductor 109, flows into the diffusion plate 108, and becomes a part of the circulating current I. Since the induced current I hardly flows through the entire gantry 101 in this manner, the entire gantry 101 can be made of iron to increase the strength. That is, iron is known to have a higher strength than aluminum but generate a large amount of heat when an electric current flows, but in the present invention, the entire pedestal 101 is formed of high-strength iron, and further a diffusion plate 108 is provided. As a result, the whole pedestal 101 is devised so that no circulating current flows. Also,
Circulating current does not flow to the whole stand 101, so the whole stand 1
01 does not overheat the bolt that fastens the coil case 107. By the way, in the present embodiment, the temperature of the bolt is 30 to 50 ° C., whereas in the past, the bolt temperature was 120 to 180 ° C.

As described above, since the whole mount 101 is made of iron to increase the strength, one whole mount 101
It is also possible to build a large-scale induction heating device 100 with a large number of induction heating coils 104 on top.

In the above embodiment, the coil case 107 is used.
And the diffusion plate 108 is made of aluminum, and the whole mount 1
Although 01 is made of iron, the material of the coil case 107 and the diffusion plate 108 has a lower electric resistance than the material of the entire mount 101, and the material of the entire mount 101 has a high strength. If it exists, various materials other than the above-mentioned material can be used.

[0033]

According to the present invention, the tilt angle of the entire gantry can be adjusted by the tilt support of the gantry, and the tilt angle of each induction heating coil can be adjusted by the tilt support of the induction heating coil. It is possible to satisfactorily uniformly heat the object to be heated through the center of the hollow portion of the induction heating coil and prevent the object to be heated from contacting the induction heating coil and causing a dielectric breakdown accident.

The circulating current flows through the electromagnetic shield (coil case and diffuser plate), and hardly flows through the entire mount. Therefore, it is possible to suppress heat generation and reduce the size of the coil case by using the electromagnetic shield part as a member having a small electric resistance. In addition, a large-scale induction heating device can be realized by using the entire gantry as a high-strength member.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a II-II section of FIG.

FIG. 3 is an explanatory diagram showing a path of a circulating current.

FIG. 4 is a sectional view showing a conventional induction heating device.

FIG. 5 is an explanatory view showing a route of a circulating current in the conventional technique.

FIG. 6 is a sectional view showing a conventional induction heating device.

FIG. 7 is a perspective view showing an example of a conventional coil case.

FIG. 8 is a cross-sectional view showing a tightened portion of a coil case.

FIG. 9 is a configuration diagram showing an outline of an induction heating device for heating a strip.

[Explanation of symbols]

 1 Strip 2 Induction Heating Coil 3, 3a Insulator 4 Frame 5 Coil Case 6 High Frequency Power Supply 7 Insulator 8 Frame 9 Plate Material 10 Ground Wire 11 Insulation Bushing 12 Bolt 13a, 13b Pinch Roller 100 Induction Heating Device 101 Overall Mount 102 Tilt Jack 103 Coil Tilting Jack 103a Jack Bolt 103b Coil Tilting Piece 104 Induction Heating Coil 105 Coil Frame 106 Insulator 107 Coil Case 108 Diffusing Plate 109 Flexible Conductor

Claims (5)

[Claims] 1. A belt-shaped object to be heated is conveyed in a longitudinal direction in a state of being bridged between separated rollers, and is heated in a state of penetrating a hollow portion of an annular induction heating coil arranged between the rollers. An induction heating device for carrying out induction heating while transporting an object, the induction heating coil tilting supporting an induction heating coil while enabling adjustment of an inclination angle of the induction heating coil with respect to the overall mounting base and the entire mounting base. An induction heating device comprising: a support part; and an electrically conductive electromagnetic shield part provided on the entire frame while surrounding the induction heating coil. 2. A belt-shaped object to be heated is conveyed in a longitudinal direction in a state of being bridged between separated rollers, and is heated in a state of penetrating a hollow portion of an annular induction heating coil arranged between the rollers. An induction heating device for carrying out induction heating while transporting an object, comprising:
An induction heating coil tilting support part which is installed on the whole mount and which supports the induction heating coil while adjusting the tilt angle of the induction heating coil with respect to the whole mount, and a conductive property provided on the whole mount while surrounding the induction heating coil. And an electromagnetic shield part of the induction heating device. 3. The electromagnetic shield part is provided in a coil case attached to the overall pedestal so as to cover the induction heating coil from above, and at a position above the overall pedestal and below the induction heating coil. The induction heating device according to claim 1 or 2, comprising a diffusion plate joined to the coil case. 4. The electromagnetic shield portion is further provided with a flexible conductor that electrically connects a coil frame located at the top of the induction heating coil tilting support portion and the diffusion plate. The induction heating device according to claim 3. 5. The electromagnetic shield part has an electric resistance smaller than that of the entire mount, and the entire mount has a higher strength than the electromagnetic shield part. The induction heating device according to claim 4.