JPH0576147B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an induction heating device, for example, an induction heating device for heating the entire slab or the like.

[Conventional technology]

FIG. 4 is a perspective view of a furnace frame structure showing a conventional induction heating device disclosed in, for example, Japanese Utility Model Publication No. 52-31449.

In the figure, numeral 1 is a horizontal member, 2 is a vertical member that supports the horizontal member 1, and 3 is an insulating support that supports the induction heating coil 4. The horizontal member 1 is wound in the same direction as the induction heating coil 4. It is configured.

Further, FIG. 5 shows another example of the conventional induction heating device disclosed in, for example, Japanese Utility Model Publication No. 52-43012, and is a perspective view thereof.

In the figure, reference numeral 5 indicates an iron core attached to the outer frame 1, which is a horizontal member. Note that 4 is an induction heating coil.

The conventional induction heating device is configured as described above. For example, when heating a slab, the slab is inserted into the induction heating coil 4 and a current is passed through the induction heating coil 4. The magnetic flux generated by the heating coil 4 causes an induced current to flow through the slab to heat it.

The magnetic flux generated from the induction heating coil 4 goes out from inside the induction heating coil 4 and returns to the induction heating coil 4 via an outside structure, so an induced current also flows through the structure and reduces stray loss. Occur.

In order to reduce this external stray loss, an iron core 5 formed by laminating a large amount of silicon steel plates is disposed around the outer periphery of the induction heating coil 4 to guide magnetic flux to the iron core 5.

In addition, the magnetic flux generated from the induction heating coil 4 is
Since it is almost interlinked with the horizontal member 1, a back electromotive force is induced in the horizontal member 1 and a large current flows. Normally, the horizontal member 1 is a structurally strong member and is therefore made of highly rigid steel. Due to the large specific resistance of this steel material and the induced large current, the iron loss and Joule loss generated in the horizontal member 1 become extremely large, causing the horizontal member 1 to overheat. Further, since the magnetic flux enters the vertical member 2, heating due to the magnetic flux occurs, and the vertical member 2 also becomes overheated.

[Problem that the invention seeks to solve]

In conventional induction heating as described above, a large amount of iron cores are used as described above. If the magnetic flux density of this iron core is increased, iron loss will increase, so the effect will be lost. Therefore, in order to reduce the magnetic flux density, it is necessary to increase the size of the iron core or increase the number of iron cores to widen the cross-sectional area.

For this reason, the amount of iron core used increases, and therefore,
There were problems such as an increase in the weight of the entire device and an increase in the number of parts due to an increase in the number of iron cores, which impeded maintainability.

Furthermore, the noise caused by electromagnetic vibrations emitted from the core itself increased, causing pain to the workers and people nearby.

This invention was made to solve the above problems, and it is possible to prevent magnetic flux from entering the horizontal and vertical members, suppress overheating of the horizontal and vertical members, and reduce loss. To obtain an induction heating device capable of reducing the cross-sectional area of an iron core, thereby reducing the weight of the whole, improving maintainability, and reducing noise caused by electromagnetic vibration of the iron core. With the goal.

[Means for solving problems]

The induction heating device according to the present invention includes a plurality of annular horizontal members, a plurality of vertical members supporting the horizontal members, and a plurality of insulating columns supported on the inner walls of the vertical members. and one or more induction heating coils attached to this insulating column, and the inner peripheral side of the horizontal member and the horizontal member so that the induction heating coil is wound in the same winding direction as the induction heating coil. A plurality of short-circuiting conductors are arranged on the inner circumferential side between the two, and an iron core made of a silicon steel plate is provided near the vertical member and on the side of the induction heating coil.

[Effect]

In the present invention configured as described above, the magnetic flux generated from the induction heating coil is pushed toward the heating coil side of the short-circuited conductor by the induced current flowing through the short-circuited conductor, thereby preventing stray structures. Reduce losses.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of the present invention. Note that numerals 1 to 4 are exactly the same as or equivalent to those having the same numerals shown in the above-mentioned conventional device.

Reference numeral 6 denotes short-circuiting coils 7 provided at the upper and lower ends of the induction heating coil 4 to form a short-circuit circuit.
is the material to be heated, 8 is the induction heating coil 4 of the horizontal member 1
A first short-circuiting conductor 9 is arranged on the side and has a structure similar to that of the first short-circuiting conductor 8, which is wound around the outer periphery of the induction heating coil 4 along the horizontal member and short-circuited. However, the above induction heating coil 4
A second short-circuiting conductor 10 disposed at a portion corresponding to the central portion of 10 has the same configuration as the first short-circuiting conductor 8, and is connected to the induction heating coil 4 with respect to the first shorting conductor 10. a third shorting conductor located at a position corresponding to the end opposite to 8;
An iron core is installed between the first to third short-circuiting conductors 8 to 10 and the horizontal member 1 and vertical member 2 constituting the furnace frame, and is made of a silicon steel plate.

Next, the operation of the above embodiment will be explained with reference to FIG.

FIG. 3 is a schematic diagram showing the flow of magnetic flux in this invention. It should be noted that the reference numerals shown in the drawings are the same or equivalent to the reference numerals shown in FIG. 1 above.

In the figure, the symbol φ represents lines of magnetic flux generated from the induction heating coil 4.

In the figure, the magnetic flux φ generated from the induction heating coil 4 is repelled toward the induction heating coil 4 by the first, second, and third shorting conductors 8, 9, and 10, and no longer interlinks with the horizontal member 1. Since the amount of magnetic flux generated by the induction heating coil 4 is determined by the amount of heating of the material to be heated 7, it has almost no effect on external conditions. That is, the magnetic flux is approximately constant at the above magnetic flux. For this reason, the current flowing through the first, second and third shorting conductors 8, 9, 10 is the same as the current flowing through the horizontal member 1 when the first to third shorting conductors 8, 9, 10 are not present. Almost identical. Therefore, the first, second and third shorting conductors 8, 9, 10, for example,
By constructing it with a copper bus bar or the like, the Joule loss that occurs here can be extremely reduced. For this reason,
The amount of overheating of the first to third shorting conductors 8, 9, and 10 is also significantly reduced.

In addition, the first to third shorting conductors 8, 9, 10
Even if only the vertical member 2 is disposed, leakage magnetic flux enters the vertical member 2, so the vertical member 2 is heated. For this reason,
By disposing an iron core having a small cross-sectional area that absorbs leakage magnetic flux only in the vertical member 2, overheating of the vertical member 2 can be prevented and losses can also be reduced.

〔Effect of the invention〕

As explained above, this invention has a plurality of short circuit conductors arranged on the inner circumferential side of the horizontal member and the inner circumferential side between the horizontal members, and an iron core provided on the induction heating coil side near the vertical member. , magnetic flux is prevented from entering the horizontal members and vertical members, overheating of the horizontal members and vertical members can be suppressed, and loss in the horizontal members and vertical members can be reduced. Because it only needs to be installed at the core, the cross-sectional area of the core can be reduced, which reduces the overall weight and improves maintainability, as well as reducing noise caused by electromagnetic vibration of the core. This has the effect of providing a highly efficient induction heating device.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention;
Fig. 2 is a plan view of Fig. 1, Fig. 3 is a schematic diagram showing the flow of magnetic flux in Fig. 1 in the right half, and Fig. 4
This figure is a perspective view of an example of a furnace frame structure showing a conventional induction heating device, and FIG. 5 is a perspective view of another example of a conventional induction heating device. In the figure, 1...Horizontal member, 2...Vertical member, 3...Insulating support column, 4...Induction heating coil, 6...
...Short circuit coil, 8 to 10...Short circuit conductor (first to
3rd short-circuit conductor), 11...iron core. In addition, in each figure,
The same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1 a plurality of annular horizontal members;
a plurality of vertical members supporting the horizontal member; a plurality of insulating columns supported on the inner wall of the vertical member; one or more induction heating coils attached to the insulating columns; a plurality of short-circuit conductors disposed on the inner circumferential side of the horizontal member and on the inner circumferential side between the horizontal members so as to wind the induction heating coil concentrically with the coil; and a plurality of short-circuit conductors arranged near the vertical member An induction heating device comprising: an iron core made of a silicon steel plate provided on the side of the induction heating coil.