JPH043653B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a winding component in which various winding members such as coils and transformers are housed in a metal case and molded with resin. This invention relates to a wire-wound component in which a container-shaped electrical insulator disposed along the inner surface of the metal case is made into a porous member so that the molded resin can reach the inner surface of the metal case. Therefore, the present invention is applicable to, but not limited to, a coil member together with a resin filler, for example, in a noise filter or a power transformer that is used under harsh environmental conditions and requires high reliability. This structure is effective when it is desired to seal the structure by enclosing it in a metal case.

[Conventional technology]

Due to the increasing frequency of electronic devices and regulations regarding radiated noise interference, each electronic device is equipped with a noise filter to prevent the intrusion and generation of noise. This noise filter is basically a type of low-pass filter, and uses an inductor with a magnetic core wound around it. In the case of a noise filter, a metal case is used to perform electromagnetic shielding and heat dissipation functions, and a coil member is generally housed inside the case and sealed with a resin filler.

However, in recent years, with the strong demand for smaller parts, the distance between the coil member and the metal case has become extremely narrow, resulting in dimensional variations due to positional misalignment when inserting the coil member and enclosing it in resin. However, it has become difficult to comply with various safety standards by simply incorporating a coil member into a metal case. Therefore, in the conventional technology, a container-shaped electrical insulator is fitted along the inner surface of a metal case, a coil member is installed inside it, and the gap around it is molded with a resin with good thermal conductivity. It has been adopted.

Furthermore, for power transformers and the like that are used under harsh environmental conditions and require particularly high reliability, the transformer body is often enclosed in a metal case together with a filler to form a sealed structure.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional resin mold structure, the heat generated as a loss in the wire itself due to energization of the coil member (so-called heat generation due to copper loss) and the heat generated from the magnetic core (so-called heat generation due to iron loss) are transferred from the coil member to the mold. resin, container-shaped electrical insulators, metal cases,
Heat is transferred to the outside air and radiated. However, many of the electrical insulators used here usually have poor thermal conductivity, making it difficult to dissipate heat. Furthermore, during resin molding, an air layer tends to form between the metal case and the container-shaped electrical insulator fitted therein, and this air layer acts as a heat insulator, resulting in poor heat dissipation.

In this way, according to the prior art, if the metal case is to be made as small as possible with respect to the coil member inserted inside, an electrical insulator must be used to ensure the minimum necessary spacing between the two. As a result, there was a big problem in that heat dissipation deteriorated and the reliability of the coil components was significantly reduced.On the other hand, if you wanted to improve heat dissipation, you would have to make the metal case larger. First, this is undesirable because it goes against the trend of smaller parts.

The purpose of the present invention is to eliminate such drawbacks of the prior art, to make the metal case as small as possible compared to the coil member housed inside, to improve heat dissipation, and to provide a compact and reliable design. Our goal is to provide high quality winding components.

[Means for solving problems]

The present invention, which can solve these problems, involves fitting a container-shaped electrical insulator along the inner surface of a metal case, installing a coil member inside the electrical insulator, and filling the gap around the electrical insulator. This is a wire-wound component that is molded with a resin with good thermal conductivity, and the structure of the container-shaped electrical insulator and the state of the resin molding have been particularly devised. That is, in the present invention, the electrical insulator has a structure in which a large number of through holes are formed in its wall surface, and the molding resin reaches the inner surface of the metal case through the through holes. This type of structure is exactly what makes it unique.

In addition, in the present invention, a coil member is "a member around which a wire is wound to form an electrical path."
It should be interpreted in a broad sense. Therefore, in addition to a narrowly defined coil that acts as a self-inductance without interlinking with other magnetic fluxes in an electric circuit, it is also possible to combine multiple coils with a common magnetic circuit and use the electromagnetic induction phenomenon to function as a transformer. This also includes the case of transformers that perform

[Effect]

With this structure, the molded resin enters into the numerous through holes formed in the electrical insulator as described above, and completely fills the inner surface of the metal case through them. become. As a result, the electrical insulator has the function of supporting the coil member within itself, maintaining the distance between the coil member and the metal case, and ensuring sufficient electrical insulation, while the molding resin has the function of supporting the coil member, maintaining the distance between the coil member and the metal case, and ensuring sufficient electrical insulation. It functions to directly transmit the information to the metal case. As a result, it has sufficient electrical insulation properties to meet safety standards as a whole, and can significantly improve heat dissipation.

The present invention will be explained in more detail below.

Example 1 FIG. 1 is a cross-sectional view showing an example of a winding component according to the present invention, and FIG. 2 is an explanatory diagram of an electrical insulator used therein. The winding component according to the present invention basically has substantially the same configuration as the conventional one, and includes a container-shaped metal case 1 having a mounting flange 1a.
A similarly container-shaped electrical insulator is fitted along the inner surface of the electrical insulator 2, a coil member 3 is installed inside the electrical insulator 2, and the gap around the coil member 3 is molded with a resin 4 having good thermal conductivity. This is the structure. The coil member has a structure in which, for example, a toroidal ferrite core 5 is covered with a core cover 6, and a wire 7 is wound around the core cover 6.

Here, the present invention is significantly different from the prior art in the structure of the container-shaped electrical insulator 2 that is fitted tightly into the inner surface of the metal case 1. That is, as is clear from FIG. 2, this electrical insulator 2
It has a structure in which a large number of through holes 8 are formed in the wall surface. In this case, the shape of each through hole 8 is preferably as shown in FIG. 2. That is, on all four side surfaces of the electrical insulator 2, the through holes 8 are formed not perpendicularly to the wall surface but inclined in the vertical direction. When actually molding the resin, the electrical insulator 2 of the metal case 1 is set in a container shape with the open side facing upward, in the opposite direction to that shown in FIG. Injected. Therefore, if the through holes 8 formed in the side surface of the electrical insulator 2 are oriented downward as shown in FIG. 2, the resin to be molded will flow well and will fill every corner of each through hole 8. This prevents the formation of an air layer inside and completely fills the metal case 1 so that it reaches the inner surface.

According to the present invention, as is clear from FIG. 1, a large number of through holes 8 are formed in the electrical insulator 2,
Moreover, since the inside thereof is filled with mold resin 4 and the resin 4 is in contact with the inner wall of the metal case 1, most of the heat generated from the coil member 3 is transferred from the coil member 3 to the resin 4, The heat is transmitted to the outside air through the metal case 1, and as a result, the heat dissipation effect is significantly improved.

Embodiment 2 FIG. 3 is a sectional view showing another embodiment of the winding component according to the present invention, and FIG. 4 is an explanatory diagram showing an example of an electrical insulator used therein. This embodiment is also basically similar to the one described above, but the structure of the electrical insulator 12 is modified in a different way. As is clear from FIG. 4, a container-shaped electrical insulator 1
2 is provided with protrusions 12a at its four corners, and has a slightly smaller shape so that it can be inserted into the inner surface of the metal case 1 with an appropriate gap. The point that through holes 18 are formed in each wall surface is exactly the same as in the previous embodiment.
In this case, the through hole 18 in the side wall may be perpendicular to the wall surface. The electrical insulator 12 having such a structure is inserted into the metal case 1, and the coil member 3 is housed therein. As is clear from FIG. 3, an appropriate gap is formed between the metal case 1 and the electrical insulator 12. After achieving this condition, resin 4 with good thermal conductivity is
It is molded. molded resin 4
passes through a large number of through holes 18 formed in the electrical insulator 12 and wraps around between the electrical insulator 12 and the metal case 1, and is completely filled without creating an air layer. Become.

The mechanism of heat dissipation from the coil member 3 in the winding component having such a structure is exactly the same as that described in connection with the previous embodiment. In this embodiment, a gap is actively provided between the electrical insulator 12 and the metal case 1 so that the resin can easily wrap around.

〔Effect of the invention〕

Since the present invention is a winding component configured as described above, an electrical insulator is inserted inside, so that
Not only can the dimensions of the metal case be reduced to the minimum size necessary to accommodate the coil components, but the components can also be significantly miniaturized. A large number of through holes are formed in the electrical insulator, and a resin with good thermal conductivity is injected into the inside and through the holes so as to be in close contact with the metal case, so the heat generated in the coil member is transferred to the resin and through the holes. Heat is dissipated to the outside air through the metal case, and there is no air layer between the insulator and the metal case, which together greatly reduces thermal resistance and increases heat dissipation efficiency. In addition to significantly improving the reliability of the coil, it can also increase the current carrying capacity of the coil, which can be extremely effective in making parts smaller, improving performance, and achieving high reliability. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the winding component according to the present invention, FIG. 2 is an explanatory diagram of an electrical insulator used therein, and FIG. 3 is a cross-sectional view showing another embodiment of the winding component according to the present invention. The sectional view shown in FIG. 4 is an explanatory diagram of the electrical insulator used therein. 1... Metal case, 2, 12... Electrical insulator,
3...Coil member, 4...Mold resin, 8,1
8...Through hole.

Claims (1)

[Claims] 1 A coil made by fitting a container-shaped electrical insulator along the inner surface of a metal case, installing a coil member inside the electrical insulator, and molding the gap around it with a resin with good thermal conductivity. In the wire component, the electrical insulator has a structure in which a large number of through holes are formed in the wall surface thereof, and the resin is molded so as to reach the inner surface of the metal case through the through holes. winding parts.