JPH05299168A - Induction heating coil - Google Patents

Abstract

PURPOSE:To reduce the loss of a water-cooled copper plate and extend the life of the water-cooled copper plate of an iron core. CONSTITUTION:An induction heating coil is provided with an iron core 2 laminated with silicon steel plates 1 having protruded leg sections, water-cooled copper plates 3B, 3C pinching the iron core 2 from both side faces, multiple water- cooled copper plates 3B, 3C pinched in the lamination direction of the silicon steel plates 1 of the iron core 2, insulating bolts 4 fastening them in the lamination direction, and a winding 5 wound around the iron core 2 and the protruded leg sections of the cooling copper plates 3A-3D fastened by the insulating bolts 4 and applied with an alternating current, and it induction-heats an object to be heated 6. The interval (g+h) between the water-cooled copper plate 3A and the heated object 6 faced to it is set larger than the interval (g) between the silicon steel plates 1 and the heated object 6 faced to them, and a step (h) is provided between the water-cooled copper plate 3A and the silicon steel plates 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating coil for plane heating with an iron core.

[0002]

2. Description of the Related Art As a conventional induction heating coil of this type, for example, the one described in Japanese Patent Publication No. 62-29875 is known. The induction heating coil and the water-cooled copper plate described in this publication will be described with reference to FIGS.
In each figure, 1 is a silicon steel plate having convex leg portions, 2 is an iron core having convex leg portions formed by stacking silicon steel plates 1, 3A,
3D is two water-cooled copper plates sandwiching the iron core 2 from both sides, 3B,
3C is sandwiched in the stacking direction of the silicon steel plates 1 of the iron core 2
One water-cooled copper plate, 4 is a silicon steel plate 1 and water-cooled copper plates 3A to 3D
Insulation bolts 5 fastened in the stacking direction are windings wound around the iron core 1 and the convex legs of the water-cooled copper plates 3A to 3D to apply an alternating current, and 6 is a heated object.

Next, the operation will be described. When an alternating current is passed through the winding 5 wound around the convex leg portion of the iron core 2, an alternating magnetic flux is generated in the iron core 2, and this alternating magnetic flux flows into the metal body to be heated, that is, the object to be heated 6, The heating object 6 is induction-heated. At this time, since the iron core 2 is formed by stacking the convex silicon steel plates 1, the leakage of the magnetic flux to the outside is minimized, and the iron core 2 has a hysteresis loss due to the magnetic flux in the A direction and the magnetic flux in the B direction. Self-heating due to eddy current loss. When the amount of generated heat is small, it is not necessary to cool the iron core 2, but the object to be heated 6
In the case of an induction heating coil that requires a high magnetic flux density (10000 to 20000 Gauss) in order to increase the heat generation density of the core 2, the amount of heat generated in the core 2 increases and the core 2 is cooled. I have to do it. In performing the cooling, conventionally, for example, four water-cooled copper plates 3
A to 3D are used by making the spacing g between the silicon steel plate 1 and the object to be heated 6 the same and fastening them with the insulating bolt 4. As shown in FIG. 4, these water-cooled copper plates 3 </ b> A to 3 </ b> D were brazed so as to surround the copper plate 7 with a copper pipe 9 having an outlet pipe 8.

[0004]

However, since the conventional induction heating coil has the above-mentioned configuration, the magnetic flux B is particularly likely to cause the water-cooled copper plates 3A and 3D at both ends of the iron core 2 to be induction-heated, which causes a large heat loss. And other water-cooled copper plate 3
As compared with B and 3C, the life of the copper pipe 9 of the water-cooled copper plates 3A and 3D is short, and there is a problem that a crack may occur in the copper pipe 9 and a water leakage accident may occur.

The present invention has been made to solve the above problems, and provides an induction heating coil capable of reducing the loss of the water-cooled copper plate and extending the life of the water-cooled copper plate of the iron core. It is an object.

[0006]

An induction heating coil according to the present invention includes an iron core formed by laminating silicon steel plates having convex legs, a water-cooled copper plate sandwiching the iron core from both sides, and a silicon steel plate sandwiched in the laminating direction. A plurality of water-cooled copper plates, insulating bolts that fasten them in the stacking direction, and windings that are wound around the convex legs of the iron core and the cooling copper plate that are fastened with the insulating bolts and that apply an alternating current. In an induction heating coil that induction-heats a heated object, the gap between the water-cooled copper plate and the object to be heated facing the water-cooled copper plate is set to be larger than the gap between the silicon steel plate and the object to be heated that faces the water-cooled copper plate. A copper plate and a silicon steel plate are provided with a step.

[0007]

According to the present invention, the gap between the water-cooled copper plate and the object to be heated is set to be larger than the gap between the silicon steel plate and the water-cooled copper plate and the silicon steel plate are attached with a step, so that the water-cooled copper plate can generate magnetic flux. It is less affected and self-heating is reduced to reduce the loss of the water-cooled copper plate, and the life of the water-cooled copper plates at both ends of the iron core can be extended.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, based on the embodiment shown in FIG. 1, the same or corresponding parts as those in the prior art will be designated by the same reference numerals, and the characteristics of the present invention will be mainly described. 1 is a side view showing an embodiment of the induction heating coil of the present invention.

As shown in FIG. 1, the induction heating coil of this embodiment has an iron core 2 formed by laminating silicon steel plates 1 having convex legs, and two water-cooled copper plates 3 sandwiching the iron core 2 from both sides.
A, 3D and two water-cooled copper plates 3B and 3C sandwiched in the laminating direction of silicon steel plates, an insulating bolt 4 for fastening these in the laminating direction, and an iron core 2 and water-cooled copper plates 3A to 3D fastened with the insulating bolts 4. The winding 5 is wound around the convex leg to apply an alternating current, and is configured to induction-heat the object 6 to be heated.

Thus, in the induction heating coil of this embodiment, the gap (g +) between the water-cooled copper plate 3A and the object 6 to be heated which faces it.
h) is set to be larger than the gap g between the silicon steel plate 1 and the object 6 to be heated facing the silicon steel plate 1 by a distance h, and a step is formed between the water-cooled copper plate 3A and the silicon steel plate 1. In addition, each of the water-cooled copper plates 3A to 3D is configured by brazing so as to surround the periphery of the copper plate 7 with a copper pipe 9 having an outlet pipe 8 as in the conventional case.

Next, the operation will be described. The alternating magnetic flux generated by applying an alternating current to the winding 5 wound around the convex leg of the iron core 2 is concentrated on the edge 6A side rather than the center side 6C of the object 6 to be heated in the plate width direction due to the edge effect. .. In particular, the water-cooled copper plate 3A is located farther from the object 6 to be heated than the silicon steel plate 1 by the distance h, and the longer the distance, the less likely it is to be affected by the magnetic flux.
The self-heating amount is reduced and the loss is reduced. In total,
The stress of the water-cooled copper plate 3A is also reduced and the life thereof is extended.

The water-cooled copper plate 3A is less affected by the magnetic flux as the step h with the silicon steel plate 1 is increased, but conversely,
Since the temperature of the surface of the silicon steel plate 1, particularly the surface of the silicon steel plate 1 located between the water-cooled copper plate 3A and the water-cooled copper plate 3B, which faces the object to be heated 6 rises and the temperature exceeds the allowable temperature of the silicon steel plate 1, The step h is naturally limited. Therefore, water-cooled copper plate 3A
When the relationship between the loss of the height h and the temperature of the silicon steel plate 1 and the step h was obtained by experiment and numerical calculation, the optimum dimension of the step h was 2
It was found to be -10 mm.

In the above embodiment, the step h between the water-cooled copper plate 3 and the silicon steel plate 1 is provided on the edge 6A side of the object to be heated 6, that is, on the water-cooled copper plate 3A on the left side surface of the iron core 2 in FIG. Although only explained, other water-cooled copper plate 3B ~
By providing a similar step in 3D, the same effect as in the above embodiment can be expected. In short, the induction heating coil of the present invention sets the distance between the water-cooled copper plate and the object to be heated facing the water-cooled copper plate to be larger than the distance between the silicon steel plate and the object to be heated facing the water-cooled copper plate and the silicon steel plate. Anything with a step may be used.

[0014]

As described above, according to the present invention, it is possible to provide an induction heating coil capable of reducing the loss of the water-cooled copper plate and extending the life of the water-cooled copper plate of the iron core.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an induction heating coil of the present invention.

FIG. 2 is a front view showing an example of a conventional induction heating coil of the present invention.

3 is a side view showing the induction heating coil shown in FIG. 2. FIG.

4 is a front view showing a water-cooled copper plate of the induction heating coil shown in FIGS. 1 and 2. FIG.

[Explanation of symbols]

 1 Silicon Steel Plate 2 Iron Core 3A Water Cooled Copper Plate 4 Insulation Bolt 5 Winding 6 Heated Object

Claims (1)

[Claims] 1. An iron core formed by stacking silicon steel plates having convex legs, a water-cooled copper plate sandwiching the iron core from both sides, and a plurality of water-cooled copper plates sandwiched in the stacking direction of the silicon steel plates of the iron core.
Insulation bolts that fasten these in the stacking direction, and windings that are wound around the convex legs of the iron core and cooling copper plate that are fastened with the insulation bolts and that apply an alternating current are provided. In the heating coil, the interval between the water-cooled copper plate and the object to be heated facing it is set to be larger than the interval between the silicon steel plate and the object to be heated facing it,
An induction heating coil characterized in that a step is formed between the water-cooled copper plate and the silicon steel plate.