JPH0831660A - Induction apparatus - Google Patents

Abstract

PURPOSE:To reduce loss and cost and improve operational limits by alternately placing electromagnetic steel plates coated with an insulating film and those uncoated therewith one behind another to form a core. CONSTITUTION:A transformer T1 includes a core (E-shaped core) 2 obtained by placing electromagnetic steel plates 2a, 2b one behind another (in the direction of the arrow marked with 'A'); a coil 4 wound around the core 2 that forms an electromagnetic circuit; and another core (I-shaped core) 5 connected with the core 2 at the bottom. Both the sides of the electromagnetic steel plates 2a are coated with an insulating film 6, and the electromagnetic steel plates 2b placed between them 2a are uncoated. An E-shaped electromagnetic steel plate for heat radiation whose front area is larger than that of the E-shaped electromagnetic steel plate 2a, is placed in front of and behind each of them 2a at a specified interval.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction electromagnetic device such as a transformer, and more particularly to cost reduction and improvement of cooling efficiency.

[0002]

2. Description of the Related Art Generally, an induction electromagnetic device such as a transformer is
It is provided with a core in which electromagnetic steel sheets are laminated, and a coil wound around the core to form a magnetic circuit. In this case, in order to reduce the eddy current loss when each electromagnetic steel sheet is excited by the alternating magnetic field, an insulating coating is applied to the front and back surfaces of the steel sheets to increase the electric resistance between the steel sheets.

[0003]

However, in general, a steel sheet provided with an insulating coating is more expensive than a steel sheet having no insulating coating, and it is difficult to reduce the loss while reducing the loss of the transformer. There was a problem.

On the other hand, when the transformer is excited, electric power is consumed as iron loss and copper loss and becomes heat, which is accumulated in the transformer and the internal temperature rises. Copper loss is a resistance loss mainly generated in a copper wire forming a coil, and iron loss is a hysteresis loss and an eddy current loss mainly generated in a core. The part that is easily damaged by this temperature rise is an insulating material such as an insulating material on the surface of the coil or an insulating material between the coil and the core. Since these electric insulating materials are heat insulating materials at the same time, they have a structure in which heat generated in the coil or core is difficult to be released to the outside. For this reason, the heat generated inside cannot be efficiently dissipated to the outside and the cooling efficiency is poor, so that there is a problem that the use limit of the induction magnet must be set low.

An object of the present invention is to solve the above-mentioned problems, to reduce the cost while reducing the loss, and to provide an induction electromagnetic device which can set the usage limit to a high value.

[0006]

In order to achieve the above object, an induction electromagnetic device according to a first aspect of the present invention is an induction electromagnetic device having a coil and a core arranged in a magnetic circuit formed by energizing the coil. In the container, the core is formed by stacking an electromagnetic steel sheet having an insulating coating and an electromagnetic steel sheet having no insulating coating on top of each other. Further, in the induction ceramics of claim 2, a heat dissipation steel plate having a front shape larger than that of the main electromagnetic steel plate forming the core is inserted between the main electromagnetic steel plates. According to a third aspect of the present invention, there is provided the induction electromagnetic device according to the second aspect, wherein the heat radiation steel plate has a higher thermal conductivity than the main magnetic steel plate. Further, the induction porcelain according to a fourth aspect is the induction porcelain according to the second or third aspect, wherein the heat dissipation steel plate has a cross-sectional area substantially the same as the cross-sectional area of the main electromagnetic steel plate. Furthermore, the induction electromagnetic device of claim 5 is the same as that of claim 2 or 3.
Alternatively, in the induction porcelain of No. 4, a cutout is provided in the heat-dissipating steel plate at a position where the magnetic properties are hardly affected, and the stacked cores are processed into a shape that can be blocked by welding.

[0007]

According to the induction electromagnetic device of the present invention, since the electromagnetic steel sheet having the insulating coating is sandwiched between the front and rear of the electromagnetic steel sheet having no insulating coating, the electromagnetic steel sheet having no insulating coating also has the insulating coating. The same as being applied. According to the induction electromagnetic device of the second aspect, the inserted heat dissipation steel plate having a large front shape functions as a magnetic path, and the protruding portion functions as a heat dissipation fin. According to the third aspect of the induction electromagnetic device, the inserted heat-dissipating steel plate having high heat conductivity further facilitates the diffusion of heat to the outside. Further, according to the induction ceramic of the fourth aspect, since the heat radiating steel plate and the main magnetic steel plate have the same cross-sectional area, the characteristics are not affected and the material cost is substantially the same. Further, according to the induction porcelain of the fifth aspect, since the notch is provided in the block welding portion of the heat dissipation steel plate, the stacked cores can be made into blocks by welding.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic perspective view of a first embodiment of an induction magnet (transformer) according to the present invention. This transformer T
1 is the electromagnetic steel plates 2a and 2b in the front-back direction (direction A)
A core (E-shaped core) 2 superposed on the core 2, a coil 4 wound around the core 2 to form a magnetic circuit, and a core (I-shaped core) 5 connected to the core 2 at a lower portion. In FIG. 2, B of FIG.
The enlarged view of the core 2 seen from the direction is shown. This transformer T1
In the above, the magnetic steel sheet 2a is provided with the insulating coating 6 on both the front surface and the back surface as in the conventional case, but the electromagnetic steel sheets 2b sandwiched between the electromagnetic steel sheets 2a are those having no insulating coating. Has been. Even with this configuration,
Since the insulating coating 6 of the electromagnetic steel sheet 2a is present on the front surface and the back surface of the electromagnetic steel sheet 2b, the electric resistance between the steel sheets is sufficiently large, and the eddy current loss when excited by the alternating magnetic field can be reduced. it can.

Further, since the electromagnetic steel plates 2a coated with an insulating film and the electromagnetic steel plates 2b having no insulating film are used by half each, the cost is the same as the number of the electromagnetic steel plates 2b without an insulating film. Only then, the cost can be reduced compared to the conventional one.

Further, as compared with the conventional transformer having a core in which only electromagnetic steel sheets coated with an insulating coating are stacked, this transformer has a magnetic steel sheet 2 without an insulating coating.
Since the number of b can be set to the maximum and the same as the number of the magnetic steel sheets 2a coated with the insulating coating, the portion of the core 2 occupied by the insulating coating can be saved up to 1/2. Therefore, even if the core 2 has the same thickness as the conventional one, the amount of iron used can be increased and a transformer with a small magnetic resistance can be produced.

FIG. 3 shows a schematic perspective view of the induction electromagnetic device (transformer) of the second embodiment. The transformer T2 is provided at a predetermined interval before and after each E-shaped electromagnetic steel sheet 12a.
2a, an E-shaped core 12 into which an E-shaped heat-dissipating steel plate 12b made of an electromagnetic steel plate having a larger front shape is inserted, a coil 4 wound around the E-shaped core 12 to form a magnetic circuit, an E-shaped core 12 and a lower portion. It has an I-shaped core 15 connected by. I
The E-shaped core 15 is similar to the E-shaped core 12 in the I-shaped electromagnetic steel plate 1
I-shaped heat-dissipating steel plate 15b made of an electromagnetic steel plate having a larger front shape than the I-shaped electromagnetic steel plate 15a at predetermined intervals before and after 5a.
Has been inserted. In this case, the predetermined interval means an interval at which air convection may occur between the inserted heat radiation steel plates.

FIG. 4 shows an E-shaped core 12 and an I-shaped core 15.
The front shape of is shown. The E-shaped electrical steel sheet 12a shown by the solid line is
It is composed of a main body portion 12a-1, a middle leg portion 12a-2, and both leg portions 12a-3. E-shaped heat dissipation steel plate 12b indicated by a two-dot chain line
Is a main body portion 12b-1, a middle leg portion 12b-2, both leg portions 12b-3.
It consists of. Compared to the E-shaped electromagnetic steel sheet 12a, the E-shaped heat-dissipating steel sheet 12b has a middle leg (12a-2, 1) with a width β.
2b-2) in common, the main body portion 12b-1 is larger than the main body portion 12a-1 by the height α, and the both leg portions 12b-3 are larger than the both leg portions 12a-3 by the width γ. The I-shaped heat radiation steel plate 15b of the I-shaped core 15 is also larger than the I-shaped electromagnetic steel plate 15a by a height α and a width γ.

The large E-shaped heat-dissipating steel plate 12b and the I-shaped heat-dissipating steel plate 15b, which have a large frontal shape, function as magnetic paths and the body portion 12b of the E-shaped heat-dissipating steel plate 12b.
-1, the protruding portions of the two leg portions 12b-3 and the protruding portions of the I-shaped heat radiating steel plate 15b increase the contact area with the external air and function as heat radiating fins. As a result, the temperature inside the E-shaped core 12 and the I-shaped core 15 of the transformer T2 can be lowered and the usage limit can be set high.

The E-shaped heat radiation steel plates 12b and I
The E-shaped electromagnetic steel plates 12a and I
By using a steel sheet having higher thermal conductivity than the shape electromagnetic steel sheet 15a, heat can be easily diffused to the outside, and the temperature inside the E-shaped core 12 and the I-shaped core 15 can be further lowered.

In this example, an electromagnetic steel plate is used as the heat-dissipating steel plate, but if the thickness of the steel plate can be made sufficiently smaller than the skin depth of the alternating current, a non-magnetic material such as an aluminum plate, a copper plate, or a brass plate is used. May be.

Further, a notch k1 shown in FIG. 4 is provided at a substantially central position of the main body 12b-1 of the E-shaped heat-dissipating steel plate, and the I-shaped core 1 is provided.
A cutout portion k2 is provided in the lower portion of 5b at approximately the center thereof. As a result, in the cutout portion k1, the E-shaped electromagnetic steel plate 12
a and the upper surface of the E-shaped heat-dissipating steel plate 12b at the same level, the I-shaped electromagnetic steel plate 15a and the I-shaped heat-dissipating steel plate 1 at the notch k2.
The lower surface of 5b is at the same level. Therefore, when assembling the E-shaped core 12 and the I-shaped core 15 in which steel sheets are stacked, by performing welding y along the cutouts k1 and k2, E
Blocking is possible for each of the shape and the I shape.
Since the effect of the cutouts k1 and k2 as a magnetic path is extremely small, there is almost no effect on the magnetic characteristics of the core.

FIG. 5 shows a front view of the E-shaped core 22 and the I-shaped core 15 of the induction magnet (transformer) of the third embodiment. In this transformer T3, the E-shaped heat-dissipating steel plate 22b to be inserted has the same cross-sectional area of each part as each E-shaped electromagnetic steel plate 22a, and has a shape in which the outer peripheral portion is projected outward as a whole. The other part of the transformer T3 has the same structure as that of the second embodiment, and the description thereof will be omitted.

The E-shaped electromagnetic steel plate 22a shown by the solid line is composed of a main body portion 22a-1, a middle leg portion 22a-2, and both leg portions 22a-3. The E-shaped heat radiation steel plate 22b indicated by the two-dot chain line is composed of a main body portion 22b-1, a middle leg portion 22b-2, and both leg portions 22b-3. E type heat dissipation steel plate 22b and E type electromagnetic steel plate 22a
And have the following differences in shape.

At the outer peripheral portion of the E-shaped heat-dissipating steel plate 22b, its main body portion 22b-1 is larger than the main body portion 22a-1 of the E-shaped electromagnetic steel sheet 22a by a height α, and both leg portions 22b-3 are respectively both leg portions 22a. It is larger than both legs 22a-3 by a width γ than -3. On the other hand, in the inner peripheral portion of the E-shaped heat-dissipating steel plate 22b, the middle leg (22
a-2, 22b-2) are common, but the main body portion 22b-1 of the E-shaped heat-dissipating steel sheet 22b is higher than the main body portion 22a-1 of the E-shaped electromagnetic steel sheet 22a according to the height α. It is reduced by μ, and both leg portions 22b-3 are smaller than both leg portions 22a-3 by width λ according to width γ, respectively. As described above, the transformer T3 has a shape in which the outer peripheral portion of the inserted E-shaped heat-dissipating steel plate 22b is projected outward as a whole. Since the cross-sectional area of each part is the same, the magnetic properties are not affected and the material cost is almost the same, which is not a significant increase.

The body portion 22b of the E-shaped heat radiation steel plate 22b
-1, the protruding portions of both leg portions 22b-3 and the protruding portions of the I-shaped heat radiating steel plate 15b increase the contact area with the external air and act as a heat radiating fin. As a result, the temperature inside the E-shaped core 22 and the I-shaped core 15 of the transformer T3 can be lowered and the usage limit can be set high.

In this embodiment, a transformer is used as the induction magnet, but a choke or a reactor may be used.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an induction electromagnetic device (transformer) according to a first embodiment of the present invention.

FIG. 2 is an enlarged view showing the induction electromagnetic device (transformer).

FIG. 3 is a schematic perspective view showing an induction magnet (transformer) of a second embodiment.

FIG. 4 is a diagram showing a front shape of a core of the induction electromagnetic device (transformer).

FIG. 5 is a view showing a front shape of a core of an induction magnet (transformer) according to a third embodiment.

[Explanation of symbols]

2, 2a, 2b ... Core (E-shaped core), 4 ... Coil, 5 ...
Core (I-shaped core), 6 ... Insulating film, T1, T2, T3 ...
Induction porcelain (transformer).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Nozato 1-12-22 Minoshima, Nishiyodogawa-ku, Osaka-shi, Tabuchi Electric Co., Ltd. Fuchi Electric Co., Ltd.

Claims (5)

[Claims] 1. An induction porcelain having a coil and a core arranged in a magnetic circuit formed by energizing the coil, wherein the core is an electromagnetic steel sheet coated with an insulating coating, and an electromagnetic steel sheet having no insulating coating. Induction porcelain consisting of steel sheets stacked on top of each other. 2. An induction porcelain having a coil and a core arranged in a magnetic circuit formed by energizing the coil, wherein a heat radiating steel plate having a front shape larger than a main magnetic steel plate forming the core is Induction porcelain inserted between the main magnetic steel sheets. 3. The induction porcelain according to claim 2, wherein the radiating steel plate has a higher thermal conductivity than the main electromagnetic steel plate. 4. The induction porcelain according to claim 2 or 3, wherein the heat radiation steel plate has a shape having a cross-sectional area substantially the same as the cross-sectional area of the main magnetic steel plate. 5. The induction porcelain according to claim 2, 3 or 4, wherein the heat dissipation magnetic steel sheet is provided with a notch at a position that has little influence on magnetic characteristics, and the stacked cores are processed into a shape that can be blocked by welding. Induction porcelain.