JP2001210530A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer that is satisfactory in a heat radiation characteristic and can be made compact. SOLUTION: Three kinds of radiators of a first radiator 3, a second radiator 4, and a third radiator 5 formed by, for example plates of high thermal- conductivity metals such as copper and aluminium are used. The first radiator 3 and the second radiator 4 among them make contact with the inner and outer circumferential surface of a winding coil 2 wound around a core 1, such as an E-type iron core respectively, and absorb and radiate the heat generated from the winding coil 2 from each contact point. The third radiator 5 makes contact with the core 1 and absorbs heating and of the core 1 and radiates heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a transformer,
In particular, the present invention relates to a small transformer used in an electric circuit.

[0002]

2. Description of the Related Art Small transformers such as those used in electric circuits generate heat in winding coils and cores during their operation. Part of the heat generated by the wound coil is radiated to the outside by radiation, and part of the heat is transmitted to the core by convection and radiation, and is radiated to the outside by convection and radiation from the core surrounding surface together with the heat generated by the core itself. You.

However, the above-described natural heat dissipation of the winding coil and the core does not sufficiently dissipate heat, so that heat accumulates inside the transformer, causing a rise in the core temperature and deteriorating the performance of the transformer. There is. Further, under recent demands for further downsizing of the transformer, it is necessary to reduce the wire diameter and the core size of the windings forming the winding coils. However, when the winding diameter is small, the electric resistance increases and heat is easily generated. On the other hand, when the size of the core is reduced, the heat generation density increases and heat is easily generated.

Further, when a transformer is used for a high voltage, the transformer is used in a vacuum because it is necessary to ensure good electrical insulation. Therefore, heat generated in the winding coil is generated by a gap between the winding coil and the core. Is transmitted by radiation. In this case, heat radiation due to radiation is insufficient to cool the transformer, so that there is a problem that heat is more easily accumulated inside the transformer and the temperature of the core increases.

Conventionally, various heat dissipating mechanisms have been proposed for transformers. However, since these proposals are still insufficient to solve the above-described heat storage problem, recent demands for further downsizing of transformers have been met. The fact is that we cannot respond.

For example, FIG. 3 is a perspective view of a high-frequency conversion transformer used in an electronic device disclosed in Japanese Patent Application Laid-Open No. 3-124007. In the transformer, the outer periphery of a winding coil 12 and a core 11 is shown. Is covered with a heat-dissipating strip 3 made of a good heat-conductive metal such as copper or aluminum, and the heat pipe 2 is inserted into the cover of the strip 3 so as to be in contact with the outer wall of the core 11. This transformer absorbs the heat of the winding coil 12 and the core 11 only from outside thereof and radiates the heat to the outside. However, the heat inside the winding coil 12 and the core 11 transfers the heat from the inside of the transformer to the outside. The heat transfer resistance of the belt 3 and the heat pipe 2 from the outside is not yet sufficient because the heat transfer resistance of the heat sink is considerably large.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transformer which has a very good heat radiation and can be miniaturized in order to meet the above-mentioned circumstances in the prior art and recent demands. Things.

[0008]

According to the present invention, there is provided a transformer comprising: (1) a first radiator which contacts an inner peripheral surface of a winding coil wound around a core; and a first radiator which contacts an outer peripheral surface of the winding coil. A second heat dissipator and a third heat dissipator in contact with the core. (2) In the above (1), the second heat radiator is in contact with at least half the area of the entire outer peripheral surface of the coil. (3) In the above (1), the first radiator and / or the second radiator is in contact with the core. (4) In the above (1), the first radiator, the second radiator,
At least some of the at least two radiators of the third and third radiators are in contact with each other. (5) In any one of the above (1) to (4), the contact of the heat radiator is a contact via a heat conductive electrically insulating adhesive. The transformer according to claim 1. (6) In the above (1), the second radiator and / or the third radiator constitute a mounting member for mounting the transformer to another object.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a perspective view of a transformer according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line XX of FIG. 1 and 2, 1 is an iron core, 2 is a winding coil, 3 is a first radiator, 4 is a second radiator, 5 is a third radiator, 6 is a pedestal, 7 is an adhesive layer, Reference numeral 8 denotes an outlet terminal, and 9 denotes a screw hole.

The core 1 includes a core portion 11, a core portion 12,
And an E-shape comprising a core portion 13 and the upper winding coil 2 of the core portion 12 is provided. Pedestal 6
Consists of two pedestal portions 61,62. Pedestal part 61,
62 have a height h substantially equal to the winding height h ′ of the coil 2, and the side surfaces of the pedestal portions 61, 62 form the core portion 11 and the core portion in a state in which It is located below part 13.

The third radiator 5 has two upright portions 51 (FIG. 1).
) And one horizontal portion 52 (see FIG. 2), and the two upright portions 51 directly contact both sides of the core 1 and both sides of the pedestal portions 61 and 62, respectively. The horizontal portion 52 is in direct contact with both bottom surfaces of the pedestal portions 61 and 62, and is in contact with a part of the second heat radiator 4 described later directly or via the adhesive layer 7 as described later. ing.

The first radiator 3 comprises two members 31, 32, which are in direct contact between the wound coil 2 and the core portion 12 as shown in FIG. It is installed in a state. Also, the tip portions of these two members 31 and 32 are bent as shown in FIG. 1 and are in contact with the outer surface of the upright portion 51 of the third radiator 5 via the adhesive layer 7.

The second heat radiator 4 comprises a central narrow portion 41 and a wide portion 42 on both sides thereof, and the narrow portion 41 is substantially equal to or slightly smaller than the length of the coil 2. The wide portion 42 has a width equal to the lateral width of the sides of the core portion 11 and the core portion 13, respectively. The narrow portion 41 of the second heat radiator 4 is formed on the entire surface except the upper surface of the wound coil 2 and the adhesive layer 7.
And the wide portion 42 covers the outer surfaces of the core portion 11 and the core portion 13, the outer surfaces of the pedestal portions 61 and 62, and the lower surface of the horizontal portion 52 of the third radiator 5. In contact. The wide portion 42 is directly connected to the surfaces of the core portion 11 and the core portion 13, while the pedestal portions 61, 6 are provided.
2 and the back surface of the horizontal portion 52 of the third heat radiator 5 are in contact with each other via the adhesive layer 7. The narrow portion 41
Is in direct contact with the upper surface of the horizontal portion 52 of the third radiator 5.

In the present invention, the second heat radiator 4 covers as much of the entire outer peripheral surface of the winding coil 2 as possible, particularly in contact with at least half of the entire outer peripheral surface. It is preferable from the viewpoint of effective endothermic.

The pedestal 6 has a screw hole 9, and a screw through hole is formed in the third radiator 5 and the second radiator 4 located directly below the screw hole 9. By utilizing these screw through holes and screw holes 9, the transformer of the first embodiment can be attached to other electric devices or the like. In this case, since the heat absorbed by the third radiator 5 and the second radiator 4 is radiated to the other electric devices, the third radiator 5 and the second radiator 4, particularly, directly to the other electric devices. Second heat radiator 4 that comes into contact
Can efficiently dissipate heat by a heat conduction mechanism between solids.

The first radiator 3, the second radiator 4, the third radiator 5, and the pedestal 6 are all metals having good thermal conductivity and a certain degree of mechanical strength, such as copper and copper-based alloys. It is composed of aluminum, aluminum-based alloys and the like. The pedestal 6 is a lump, and the first radiator 3, the second radiator 4, and the third radiator 5 are plate-like objects having a thickness of about several hundred μm to several mm.

The first radiator 3 is in direct contact with the inner peripheral surface of the winding coil 2 and the outer surface of the core portion 12, so that the heat of the winding coil 2 is absorbed from the inner peripheral surface,
The heat of the core 1 is mainly absorbed from the core portion 12, a part of the absorbed heat is directly radiated to the atmosphere, and the remainder is radiated to the third radiator 5.

The second radiator 4 is in direct contact with the outer peripheral surface of the winding coil 2 via the adhesive layer 7 and directly with the outer surfaces of the core portions 11 and 13, respectively.
Of the core 1 is absorbed from the core portions 11 and 13, a part of the absorbed heat is directly radiated to the atmosphere, and the remaining is absorbed by the third radiator 5 or other electric power. It has the function of dissipating heat to equipment.

The third radiator 5 absorbs the heat generated by the core 1 and the above-mentioned heat absorbed by the first radiator 3 and the second radiator 4, and radiates a part of the heat absorbed directly to the atmosphere, and the remainder to the other. Function to dissipate heat to electrical equipment.

Further, the first radiator 3, the second radiator 4, and the third radiator 5 absorb heat generated from the winding coil 2 and the core 1 at their respective installation positions, and reduce the heat absorption at low temperatures. In this case, the heat dissipation and heat dissipation functions are performed in cooperation with each other, for example, by dissipating heat to any of the heat radiators 3 to 5. Thus, Embodiment 1 has extremely excellent heat dissipation performance due to the effective heat absorption and heat dissipation described above.

Between the first radiator 3 and the third radiator 5, between the second radiator 4 and the third radiator 5, between the winding coil 2 and the second radiator 4, and between the second radiator 4 and the third radiator 4. The radiator 4 or the third radiator 5 and the pedestal 6 are in contact via the adhesive layer 7. When the adhesive layer 7 is not provided, a short circuit current flows due to electromagnetic induction because the metal member goes around the core. This current causes heat generation and significantly reduces the transformer output due to energy loss due to the heat generation. The adhesive cuts off the current flow path and prevents the above-mentioned adverse effects. In addition, it functions to increase the efficiency of heat conduction between the heat dissipators 3 to 5 by bonding.

Preferably, the adhesive constituting the adhesive layer 7 is excellent in both heat conductivity and electrical insulation. For example, polyolefins such as polyethylene, polypropylene, polybutene and poly-4-methylpentene-1 are preferable. Olefins such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-maleic acid copolymer, propylene-maleic acid copolymer Examples thereof include copolymers, polystyrene, ionomers, thermoplastic polyesters, polyamides, low-polarity hot-melt adhesives such as polyvinylidene chloride and the like mixed with various electric insulating heat conduction enhancers. Examples of such an electrically insulating heat conduction improving material include inorganic oxides such as lead oxide, iron oxide and alumina, and inorganic acid salts such as lead sulfate, zinc sulfate and barium sulfate, and other inorganic powders. .

The first radiator 3 and the pedestal 6 may be bonded to the core 1 with an adhesive when their constituent materials are the same as those of the iron core 1. However, the constituent materials are usually different from each other, and if a temperature difference occurs between the core 1 and the first radiator 3 or the pedestal 6, the core 1 may be damaged due to a difference in expansion coefficient. .

The present invention can be variously modified in addition to the first embodiment. The contact between the core 1, the winding coil 2, the first radiator 3, the second radiator 4, the third radiator 5, and the pedestal 6 may generally be direct contact, and the heat generated by the induced current may be reduced. If the problem is large, the contact is preferably made via the above-mentioned heat conductive electrically insulating adhesive.

In the first embodiment, a part of the second heat radiator 4 is located at the lowermost part of the transformer. 52 may be replaced with a structure in which the horizontal portion 52 is located at the lowermost position. The tip of the first radiator 3 contacts not only the third radiator 5 but also the second radiator 4 or the second radiator 4 in place of the third radiator 5 via the adhesive layer 7. You may make it.

When mounting the transformer of the present invention to other electric equipment, etc., in Embodiment 1, the massive pedestal 6 having the screw hole 9 is employed as a support for screwing. When the fourth and third heat radiators 5 have the strength to withstand screwing, the use of the pedestal 6 may be omitted and the strength of the heat radiators may be used to attach the radiator to other objects such as electric equipment. Further, in the present invention, the second radiator 4 and / or
Alternatively, the third radiator 5 may function as an attachment member for attaching the transformer to another object.

[0027]

According to the present invention, the transformer according to the first aspect of the present invention comprises a first heat radiator that contacts an inner peripheral surface of a winding coil provided on a core, and a first radiator that contacts an outer peripheral surface of the winding coil. Since two heat radiators and a third heat radiator in contact with the core are provided, heat generated from the winding coil is generated by the first radiator and the second radiator on both the inner and outer peripheral surfaces thereof. As a result, the heat absorbing and radiating performance is remarkably improved as compared with the heat absorbing and radiating only from the outer peripheral surface of the winding coil as in the conventional transformer. Further, in addition to the above, the heat generated from the core of the winding coil is also absorbed by the third radiator and radiated, so that the heat of the entire transformer can be radiated very efficiently, which is not seen conventionally. Therefore, the downsizing of the transformer, which has been difficult in the past, can be easily realized by the present invention.

Further, when the second radiator is in contact with at least half the area of the entire outer peripheral surface of the winding coil, the performance of heat absorption and heat radiation by the second radiator with respect to heat generation from the winding coil is provided. Is further improved.

Further, when the first heat radiator and / or the second heat radiator are in contact with the core, the heat radiation performance of the whole transformer is further improved, and the miniaturization of the transformer becomes easier.

Further, when at least a part of at least two of the first radiator, the second radiator and the third radiator are in contact with each other, the respective radiators are wound coil coils at respective installation positions. Since the heat generated from the heat sink and the core is absorbed and radiated to one of the other radiators, the radiators cooperate with each other to improve the function of absorbing and dissipating heat.

Further, when the adhesive layer 7 is not provided, a short circuit current flows by electromagnetic induction because the metal member goes around the core. This current not only causes heat generation but also significantly reduces the transformer output due to energy loss due to the heat generation.However, since each of the above-mentioned contacts is a contact through a heat conductive electrically insulating adhesive, even if an electromagnetic induction phenomenon occurs. Even if an induced current is generated in a part of the heat radiator, it does not flow to another heat radiator or the like, so that the other heat radiator does not generate heat. In addition, there is also an effect that the efficiency of heat conduction between the heat dissipating members is increased by the bonding with the adhesive.

Further, since the second heat radiator and / or the third heat radiator also functions as a mounting member for mounting the transformer to another object, the transformer of the present invention is screwed, bonded, welded, or other method. Thus, it can be attached to another object such as another electric device. In this case, there is an effect that the heat absorbed by the second heat radiator and the third heat radiator can be efficiently radiated to the above-mentioned other object by the heat conduction mechanism between the solids.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a perspective view of a conventional transformer.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 core, 2 winding coil, 3 radiator, 4 radiator, 5 radiator, 6 pedestal, 7 adhesive layer, 8
Output terminal, 9 screw holes.

Claims (6)

[Claims] 1. A first radiator that contacts an inner peripheral surface of a coil wound around a core, a second radiator that contacts an outer peripheral surface of the coil, and a third radiator that contacts the core. A transformer characterized by having a body. 2. The transformer according to claim 1, wherein the second heat radiator contacts at least one half of the entire outer peripheral surface of the winding coil. 3. The transformer according to claim 1, wherein the first radiator and / or the second radiator contacts the core. 4. The transformer according to claim 1, wherein at least a part of at least two of the first radiator, the second radiator, and the third radiator are in contact with each other. 5. The heat radiator according to claim 1, wherein the heat radiator is contacted via a heat conductive electrically insulating adhesive.
The transformer according to claim 4. 6. The transformer according to claim 1, wherein the second heat radiator and / or the third heat radiator constitute an attachment member for attaching the transformer to another object.