JPH0974022A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise a low temperature zone and reduce the size and increase a reliability and productivity by winding a coil around a bobbin and inserting an iron core into a central hole of the bobbin and injection molding low-melting- point metal on the surface of the iron core. SOLUTION: A coil is wound around a bobbin 2 which has a flange on which terminals 4 are formed erect at least on both sides. EI-type laminate iron cores 9, 10 are assembled into this bobbin 2 and then abutting faces of the iron cores are welded to form a main body of a transformer 1. The main body of a transformer 1 is held in a molding die 16 and then is molded out of low-melting-point metal 18 which is charged from a gate section 17 to obtain a finish product of a transformer. The low-melting-point metal 18 is a metal which can be melted at about 500 deg.C or below such as a zinc alloy, a tin alloy, a lead alloy, etc. By this method, a coil component which is excellent in terms of cost, quality, and productivity and which is a high industrial value can be obtained.

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 in 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, reduction of roaring vibration,
Miniaturization such as light, thin, short and small, improved electrical characteristics such as low loss, low heat generation, high efficiency, improved strength by dropping the set, tapping screw compatible with transformer mounting shape to electronic equipment,
Reliability such as high dimensional accuracy and long life is required. In this case, there is a demand for a recyclable material having a good productivity, a safe working environment, and a high yield.

A conventional coil component will be described below with reference to FIGS. 4 to 8 using a transformer as an example. In FIGS. 4 and 5, the bobbin 2 made of molding resin has a collar 5 having several grooves 3 and terminals 4 on both sides, and a coil 6 wound between the collars 5 on both sides. . The lead wire 7 of the coil 6 is connected to the terminal 4. And the central hole 8 of the bobbin 2
The central foot portion 9a of the E-shaped laminated iron core 9 is inserted into the, and the I-shaped laminated iron core 10 that abuts against the end surface of the foot portion 9b is provided, and the abutting portion 11 that is assembled and matched is welded. further,
As shown in FIGS. 6 and 7, a resin case 12 having a mounting portion to the device as shown in FIG. I was there.

[0004]

In the above structure, first,
The resin case 12 is provided with a mounting portion to mount the transformer body 1 on the device. As a result, the guarantee against equipment drop strength and equipment vibration was not sufficient, and it was not possible to attach it to equipment when there was a request for tapping screws, and it was inferior in terms of reliability. . Furthermore, since it is the resin case 12, the heat dissipation is also not good.

Further, since the growl vibration of the metal frame 14 becomes large, it is necessary to impregnate the varnish, which causes a serious deterioration of the working environment. 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 it becomes a bottleneck for automatic mounting on a device. Further, the metal frame 14 has a custom shape, and if the shape is complicated, there is a problem that the yield of the material becomes poor.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a coil component having a low temperature rise, a small size, high reliability, and improved productivity.

[0007]

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

[0008]

With the above structure, the heat dissipation of the transformer main body can be improved, the temperature rise characteristics are excellent, the drop strength of the equipment and the vibration can be improved, and the low melting point metal mold can be formed as compared with the conventional transformer main body. By using it, it becomes possible to recycle, it is possible to efficiently use the injection molding mold material, and it is excellent in terms of cost, production, reliability, and quality.

The low melting point metal injection molding method is easy to handle at the time of injection molding or because the material is recycled at room temperature, so that the safety is high and the work 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 collar 5 in which terminals 4 are planted at least at both ends, and the bobbin 2 has an EI type laminated iron core 9 or 10.
2 and 3, the butting portion is welded to form a transformer main body 1, and the transformer main body 1 is held in a molding die 16 and molded with a low melting point metal 18 poured from a gate portion 17, as shown in FIGS. A finished 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 the portion where the lead wire 7 of the terminal 4 and the coil 6 is drawn out.

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

The low-melting metal 18 is a metal such as a zinc alloy, a tin alloy, and a lead alloy, which melts at 500 ° C. or lower. Particularly, the 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 to be an appropriate material as a molding material.

A high shot system manufactured by JSW can be considered as an injection molding apparatus for realizing these.

The injection molding method of these systems is easy to handle at the time of injection molding or because the material is recycled at room temperature, so that 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 of a low melting point metal, the drop strength of the device and the vibration of the device are sufficiently guaranteed, and the device is tapped. This can be achieved by using a screw, and the heat dissipation is also excellent and the effect of temperature rise characteristics can be obtained. Since dimensional accuracy and external surface accuracy can be improved, automatic mounting and mounting on equipment is also possible.
In addition, there is no need to respond to growl vibrations impregnated with varnish, the working environment can be made clean, and low melting point metals can be recycled at room temperature, and materials can be used efficiently.
It is possible to provide a coil component having an extremely high industrial value such as being excellent in cost, quality, and production.

[Brief description of drawings]

FIG. 1 is a sectional view of a molding die 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 according to 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]

 1 Transformer Main Body 2 Bobbin 6 Coil 16 Mold Die 17 Gate Part 18 Low Melting Point Metal 19 Coil Component 20 Convex Part 21 Mounting Hole 22 Cooling Fin

Claims (3)

[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 mounting portion having a mounting hole or a cooling fin is formed of a low melting point metal to be molded.
Described coil parts. 3. The coil component according to claim 1, wherein a lead alloy is used as the low melting point metal.