JP3339265B2 - Coil parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component used for various electronic devices.

[0002]

2. Description of the Related Art In recent years, in coil components such as transformers used in various consumer electronic devices, it has been possible to reduce the howling vibration,
Miniaturization such as lightness and shortness, improvement of electrical characteristics such as low loss, low heat generation and high efficiency, improvement of strength by dropping set, and support for tapping screw of transformer mounting shape to electronic equipment,
Reliability such as high dimensional accuracy and long life is required. In this case, a material having a structure with good productivity, a safe working environment, and a high yield is desired.

Hereinafter, a conventional coil component will be described using a transformer as an example with reference to FIGS. 4 and 5, the bobbin 2 made of molding resin has a flange 5 having several grooves 3 and terminals 4 on both sides, and a coil 6 wound between the flanges 5 on both sides. . The lead 4 of the coil 6 is connected to the terminal 4. And the center hole 8 of the bobbin 2
Then, the central foot 9a of the E-shaped laminated iron core 9 is inserted, and the I-shaped laminated iron core 10 which comes into contact with the end face of the foot 9b is welded. further,
As shown in FIGS. 6 and 7, a resin case 12 having a mounting portion to a device or a metal frame 14 and a metal plate 13 having a mounting portion in the same manner as described above are incorporated in the transformer body 1 to form a transformer 15 shown in FIG. 8. Was.

[0004]

In the above configuration, first,
A mounting portion is provided on the resin case 12, and the transformer body 1 is mounted on the device. For this reason, guarantees against drop strength of equipment and vibration of equipment were not sufficient, and mounting on equipment could not be performed if there was a request for tapping screws, and reliability was inferior. . Further, since the resin case 12 is used, heat dissipation is not good.

[0005] Further, since the growl vibration of the metal frame 14 becomes large, it is necessary to impregnate the metal frame 14 with varnish. Furthermore, since the metal frame 14 and the metal plate 13 are caulked and assembled into the transformer main body 1, the dimensional accuracy is poor, and this has been a bottleneck for automatic mounting on equipment. Also, the metal frame 14 has a custom shape, and a complicated shape has a problem that the yield of the material is poor.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a coil component having a low temperature rise, miniaturization, high reliability, and improved productivity.

[0007]

In order to achieve the above object, a coil component according to the present invention comprises a coil wound around a bobbin, an iron core inserted into a center hole of the bobbin, and a low melting point metal provided on the surface of the iron core. Is injection molded.

[0008]

With the above construction, the heat radiation of the transformer body can be improved, the temperature rise characteristics are excellent, the equipment drop strength and vibration are improved, and the low melting point metal mold is used. By using it, it is possible to recycle it, and it is possible to use the injection molding material efficiently, and it is excellent in cost, production, reliability and quality.

The low-melting point metal injection molding method is easy to handle because the material is recycled at room temperature during the injection molding and at a normal temperature, so that the operation is performed in a clean environment that does not require a melting furnace. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, a coil 6 is wound around a bobbin 2 having a flange 5 having terminals 4 implanted at least at both ends, and the bobbin 2 is provided with EI type laminated iron cores 9 and 10.
And the butted portion is welded to form a transformer main body 1. The transformer main body 1 is held in a mold 16 and molded with a low melting point metal 18 poured from a gate 17, as shown in FIGS. A completed transformer, that is, the coil component 19 or 19a. The portion to be molded with the low melting point metal 18 is a portion excluding a portion from which the terminal 4 and the lead wire 7 of the coil 6 are led out.

At this time, the molding die 16 is thin and has a uniform thickness on the outside of the transformer body 1 and has a low melting point metal 18.
In the mold 16, the E-shaped laminated iron core 9 or the I-shaped laminated iron core 1 of the transformer main body 1 is formed so that the injection molding can be performed.
0, and a convex portion 20 for holding the same is provided,
The mounting holes 21 shown in FIG. 2 and the cooling fins 22 shown in FIG. 3 are set when the coil parts 19 or 19a are formed.

The low-melting point metal 18 is a metal such as a zinc alloy, a tin alloy, and a lead alloy that melts at a temperature of 500 ° C. or less. In particular, a lead alloy has a melt viscosity of 0.026 poise (at 350 ° C.), which is much lower than that of plastic. Since it is a viscous material and has a very high thermal conductivity of 0.08 cal / cm / s / ° C., it can be said that it is an appropriate material as a molding material.

As an injection molding apparatus for realizing these, a high shot system of JSW Corporation or the like can be considered.

In the injection molding method of these systems, since the material is recycled at room temperature during the injection molding, the handling is easy, the safety is high, and the operation is performed in a clean environment that does not require a melting furnace.

[0015]

As described above, since the coil component of the present invention is formed from a low melting point metal, the drop strength of the device and the assurance against the vibration of the device are sufficient, and the tapping of the device to the device is also performed. It becomes possible by using a screw, and it is also excellent in heat radiation and an effect on temperature rise characteristics can be obtained. Since dimensional accuracy and appearance surface accuracy can be increased, automatic mounting and attachment to equipment can also be performed.
In addition, it is not necessary to respond to growl vibration with varnish impregnation, the work environment can be made clean, and low-melting point metal can be recycled at room temperature and materials can be used efficiently,
The effect of being able to provide coil parts of extremely high industrial value, such as being excellent in cost, quality, and production, is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a mold for a coil component according to an embodiment of the present invention.

FIG. 2 is a perspective view of the coil component.

FIG. 3 is a perspective view of a coil component of another embodiment.

FIG. 4 is a perspective view of a conventional coil component body.

FIG. 5 is an exploded perspective view of a conventional coil component body.

FIG. 6 is an exploded perspective view of a conventional coil component.

FIG. 7 is an exploded perspective view of another conventional example.

FIG. 8 is a perspective view of the conventional coil component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transformer main body 2 Bobbin 6 Coil 16 Mold 16 Mold part 18 Low melting metal 19 Coil component 20 Convex part 21 Mounting hole 22 Cooling fin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01F 27/24 H01F 27/02 H01F 27/08 H01F 27/32

Claims (3)

(57) [Claims] 1. A coil component in which an iron core is inserted into a center hole of a bobbin around which a coil is wound, and a low melting point metal is injection-molded and molded on the surface of the iron core. 2. A cooling part having a mounting hole or a cooling fin formed by a low melting point metal to be molded.
The described coil component. 3. The coil component according to claim 1, wherein a lead alloy is used as the low melting point metal.