JP3043096U - Coil device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] It has been difficult to easily achieve heat dissipation of a resin-molded transformer. SOLUTION: A strip-shaped copper plate is wound around a core 1 to form a coil 2.
Is configured. The terminals of the coil 2 are projected from the insulating resin body 3 as terminals / radiating plates 4 to 7 having dimensions equal to or larger than the required current capacity. A heat radiating plate 8 is coupled to the middle of the coil 2 and the heat radiating plate 8 is projected from the insulating resin body 3.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to a coil device such as a transformer, a reactor or a current transformer for use in a power supply device such as a high frequency power inverter.

[0002]

[Prior art]

 A power transformer having a structure in which a coil is formed by winding a strip-shaped copper plate having a thickness of 2 mm and a width of 20 mm, which is generally called a bus bar, around a magnetic core, and the wound portion of the coil is molded with a heat-resistant insulating resin. Is known.

[0003]

[Problems to be solved by the device]

 By the way, since the wound portion of the coil is covered with the insulating resin, heat due to copper loss is accumulated inside, and sufficient heat dissipation cannot be obtained.

Therefore, an object of the present invention is to provide a coil device such as a transformer or a reactor that can easily improve heat dissipation.

[0005]

[Means for Solving the Problems]

 The present invention for solving the above problems and achieving the above object provides a magnetic core, at least one coil wound around the core, and an insulating material covering at least a part of the coil and the core. A coil device comprising a resin body, wherein a heat radiating plate is provided so as to project from a winding portion of the coil, and the heat radiating plate is thermally coupled to the coil. Is. It is preferable that the coil is formed by winding a strip-shaped metal plate as described in claim 2, and the heat radiation plate is a metal radiation plate wider than the width of the strip-shaped metal plate. Further, as described in claim 3, a terminal / radiating plate can be fixed to at least one end of the coil. Further, as described in claim 4, it is desirable to fix a terminal / radiating plate to at least one end of the coil and thermally couple the radiating plate between one end and the other end of the coil.

[0006]

[Actions and effects of the invention]

 According to the invention of each claim, since the heat radiation plate is coupled to the coil and protrudes from the winding portion of the coil, the heat generated in the coil conductor is guided to the heat radiation plate and is radiated well. Therefore, it is possible to provide a coil device having a good heat dissipation property despite the simple structure. According to the invention of claim 2, since the coil is the strip-shaped metal plate, not only the heat dissipation of the coil itself is good, but also the coupling with the heat dissipation plate is easy and the heat dissipation through the heat dissipation plate is achieved well. It becomes possible to do. Further, according to the invention of claim 3, since the heat dissipation plate is formed integrally with the terminal, the structure of the coil device can be simplified. Further, according to the invention of claim 4, in addition to the terminal and heat radiating plate, the heat radiating plate is also provided in the middle of the coil, so that the heat radiating property can be further improved.

[0007]

[First Embodiment] Next, an air-cooled high-frequency mold single-winding transformer according to a first embodiment of the present invention will be described with reference to FIGS. This transformer comprises a magnetic core (core) 1, a coil 2, a heat-resistant resin body 3, primary side terminals and heat sinks 4 and 5, secondary side terminals and heat sinks 6 and 7, and a plurality (six pieces). And the heat dissipation plate 8 and are formed so as to form the electric circuit shown in FIG.

The core 1 is composed of a combination of two E-shaped cores 1 a and 1 b, and has three legs. The coil 2 is formed by winding a bare strip copper plate having a thickness of about 2 mm and a width of about 20 mm, which is called a bus bar. The technique of winding the strip-shaped copper plate is a well-known technique. An insulating film (not shown) is inserted between the adjacent coils in the coil 2, that is, between the adjacent copper plates to achieve interlayer insulation.

The primary side terminal / radiating plates 4 and 5 are fixed to one end and the other end of the coil 2 by welding. The secondary side terminals and heat sinks 6 and 7 are fixed to the intermediate position of the coil 2 by welding. The heat dissipation plate 8 is fixed by welding to an intermediate position between one end and the other end of the coil 2. The terminals / heat sinks 4, 5, 6, 7 and the heat sink 8 are strip-shaped copper plates (metal plates) similar to the coil 2 and are wider than the width W1 of the copper plate of the coil 2 as is clear from FIGS. 2 and 4. It has a width W2 and a height W3. Further, the terminals / heat radiation plates 4, 5, 6, 7 and the heat radiation plate 8 are arranged so as to project outward from the outermost periphery of the winding portion of the coil 2 and the insulating resin body 3, and these main components The coil 9 is thermally and electrically connected to the coil 2 by a welded portion 9 which is arranged so that its surface substantially coincides with the main surface of the copper plate of the coil 2 and has a relatively long distance L in the lateral width direction as shown in FIGS. 2 and 4. And mechanically coupled. The primary side terminals and heat sinks 4 and 5 project to one side, and the secondary side terminals and heat sinks 6 and 7 project in the direction opposite to the primary side terminals and heat sinks 4 and 5 to form six heat sinks. 4 out of 8 are projected in the same direction so as to overlap with the primary side terminals and heat sinks 4 and 5 when seen in a plan view, and the remaining 2 are projected against the secondary side terminals and heat sinks 6 and 7. And project in the same direction so that they overlap when viewed in a plane. The primary and secondary side terminals and heat sinks 4 to 7 are provided with holes 10 for connecting to external circuits.

The insulating resin body 3 is formed by molding and covers the coil 2 and also a part of the core 1 to achieve integration of the coil 2 and integration of the coil 2 and the core 1. In addition, a part of the terminal / radiating plates 4 to 7 and the radiating plate 8 are covered to mechanically support them.

Although not shown in FIGS. 1 to 5, the exposed surface of the heat dissipation plate 8 and the exposed surface other than the portions used for connecting the terminals / heat dissipation plates 4, 5, 6, 7 are not shown in FIGS. As shown in, an extremely thin insulating film 11 for preventing electric shock is provided. Since this insulating film 11 is extremely thin, it does not significantly reduce the heat dissipation.

As is clear from the above, the transformer of this embodiment has the following effects. (1) Since the heat radiation plate 8 is thermally coupled between one end and the other end of the coil 2 made of a strip-shaped copper plate, and the heat radiation plate 8 is projected from the outer peripheral surface of the insulating resin body 3, The heat generated by the current flowing can be released to the outside. That is, without using complicated cooling means such as water cooling, the heat can be satisfactorily discharged by natural or forced air cooling, and the transformer can be miniaturized and reduced in cost. (2) Since the terminals and heat sinks 4 to 7 having a size larger than the size determined by the required current capacity required for the terminals are provided, the terminals and heat sinks 4 to 7 have the same effect as the heat sink 8. It also contributes to the improvement of heat dissipation. (3) Since the terminals and heat sinks 4 to 7 and the heat sink 8 are arranged so as to overlap each other in plan view, miniaturization is not impeded. Further, since they protrude from the insulating resin body 3 like comb teeth, they do not interfere with the flow of air for air cooling. (4) The coil 2 is formed of a strip-shaped copper plate, and the terminals / radiators 4 to 7 and the radiator plate 8 are welded to the strip-shaped copper plate at a relatively long distance L. Can be released.

[0013]

[Second Embodiment] Next, a transformer of a second embodiment will be described with reference to FIGS. However, in FIGS. 9 to 11, substantially the same parts as those in FIGS. 1 to 8 are designated by the same reference numerals, and the description thereof will be omitted. The transformer of the second embodiment has substantially the same configuration as that of the first embodiment except that the coil 2 of the first embodiment is divided into a primary coil 2a and a secondary coil 2b. In order to distinguish between the primary coil 2a and the secondary coil 2b in FIGS. 9 and 10, the primary coil 2a is not shaded and the secondary coil 2b is shaded. Further, an insulating film is arranged between the primary coil 2a and the secondary coil 2b which are alternately arranged, but this illustration is omitted in FIGS. 9 and 10. The transformer of the second embodiment is an air-cooled high-frequency mold transformer having a capacity of 20 kVA, a frequency of 30 kHz, a primary voltage of 250 V, and a secondary voltage of 150 to 200 V, and is configured to have the electric circuit of FIG. .

Since the configurations of the terminals and heat sinks 4 to 7 and the heat sink 8 of the transformer of the second embodiment are the same as those of the first embodiment, the second embodiment is the same as the first embodiment. Has the effect of.

[0015]

[Modification]

 The present invention is not limited to the above-mentioned embodiments, and the following modifications are possible, for example. (1) The terminals and heat sinks 4 to 7 may have a normal size terminal structure, and only the heat sink 8 may be provided to improve heat dissipation. Further, if the heat radiation function of the terminals / heat radiation plates 4 to 7 is sufficiently large, the heat radiation plate 8 can be omitted. (2) The lateral width W2 of the terminals / heat sinks 4 to 7 and the heat sink 8 is preferably three times or more, more preferably five times or more, the width W1 of the copper plate of the coil 2. In addition, it is desirable to set W2 in the range of 3 to 10 times W1 in order to prevent the W2 from becoming larger than necessary. (3) The insulating film 11 can be omitted if there is no risk of electric shock. (4) The present invention can be applied to a reactor, a current transformer, and the like.

[Brief description of the drawings]

FIG. 1 is a front view of a transformer according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an AA line of FIG. 1 with an insulating resin body omitted.

FIG. 3 is a cross-sectional view taken along the line BB in FIG. 1 schematically showing the transformer by omitting the insulating resin body and the insulating film.

FIG. 4 is a cross-sectional view showing a CC line in FIG. 1 with an insulating resin body omitted.

5 is a cross-sectional view schematically showing a line D-D of FIG. 1 with an insulating film omitted.

FIG. 6 is a plan view of a terminal and heat sink.

FIG. 7 is an enlarged cross-sectional view of a heat dissipation plate.

FIG. 8 is a circuit diagram showing electrical connection of the transformer of FIG.

FIG. 9 is a sectional view showing the transformer of the second embodiment in a state similar to that of FIG.

FIG. 10 is a sectional view showing the transformer of the second embodiment in a state similar to that of FIG.

FIG. 11 is a circuit diagram showing the electrical connection of the transformer of the second embodiment.

[Explanation of symbols]

 1 core 2 coil 3 insulating resin body 4 to 7 terminal and heat sink 8 heat sink

Claims (4)

[Utility model registration claims] 1. A coil device comprising a magnetic core, at least one coil wound around the core, and an insulating resin body covering at least a part of the coil and the core, wherein the coil is wound. A coil device, wherein a heat dissipation plate is provided so as to project from the portion, and the heat dissipation plate is thermally coupled to the coil. 2. The coil is formed by winding a strip metal plate, the radiator plate is a metal radiator plate fixed to the strip metal plate, and the metal radiator plate is wider than the width of the strip metal plate. The coil device according to claim 1, wherein the coil device has a wide width. 3. A magnetic core, at least one coil wound around the core, and an insulating resin body covering at least a part of the coil and the core, wherein the coil winds a strip-shaped metal plate. In a coil device formed by turning, a metal terminal-radiating plate is fixed to at least one end of the coil, the terminal-radiating plate is arranged so as to project from a winding portion of the coil, and the strip shape is provided. A coil device having a width wider than that of the metal plate. 4. A heat radiation plate thermally coupled between one end and the other end of the coil, wherein the heat radiation plate is arranged so as to project from a wound portion of the coil. The coil device according to claim 3, wherein: