JPH0355964B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wound core of a transformer to which a cylindrical coil bobbin is applied.

[Conventional technology]

Recently, circular cross-section cores, which have the advantages of being ultra-thin, compact, and lightweight, have come to be used as wound cores for transformers to which cylindrical coil bobbins are applied (Reference: Japanese Patent Publication No. 60-28375, 61 -22851). That is, the wound core 1 shown in FIG. 4 is obtained by winding a band-shaped material with excellent magnetic properties, whose width direction has been cut out in advance into a predetermined shape shown in FIGS. 5A and B, according to the shape. The cross section has a circular shape. A cylindrical coil bobbin 2, which has been divided into two in advance, is pressed against the wound core 1 at the pressure contact surface 3, and by rotating the coil bobbin 2 with respect to the wound core 1, the coil bobbin 2 is wound (Fig. (not shown). Therefore,
In this case, the gap 4 between the wound core 1 and the coil bobbin 2 becomes smaller, resulting in excellent magnetic properties.

[Problem that the invention seeks to solve]

However, in the wound core 1 shown in FIG. 4, the winding start and winding end portions of the strip material are likely to shift from the winding center position depending on the winding device or the end processing operation, for example, as shown in FIG. Arrow X,
It may collapse as shown in Y. As a result, when the coil bobbin 2 is pressed and rotated, the inner surface of the coil bobbin 2, especially the pressure-welded part, may become stuck, or the winding operation may become impossible, or in the worst case, the pressure-welding operation of the coil bobbin 2 may become impossible. The problem was that it was possible.

Therefore, an object of the present invention is to provide a wound core that can prevent the inner surface of the coil bobbin 2 from getting caught and the coil bobbin 2 to be unable to be pressed, even if the winding start and end portions of the wound core are deviated from the winding center position. Our goal is to provide the following.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has the following features:
As shown in the figure, the cross-sectional shape of the winding start and winding end portions of the wound core is elliptical, and the cross-sectional shape of the other portions is circular as in the conventional case. Note that only one of the winding start and winding end portions may have an elliptical shape.

[Effect]

According to the above-described means, the inner surface of the coil bobbin is prevented from being caught and the coil bobbin cannot be pressed into contact with each other. In this case, although the gap between the wound core and the coil bobbin increases, the amount thereof is kept to a minimum.

〔Example〕

FIG. 2 is a sectional view showing a wound core equipped with a coil bobbin according to the present invention. In FIG. 2, a winding start portion 11 and a winding end portion 12 of the wound core 1' are shown.
The cross section of is elliptical. Therefore, the winding start portion 11, the winding end portion 12, and the coil bobbin 2
The air gap 4' between the two is larger than in the case of FIG. 4, but its amount is minimal. In the wound core 1' shown in FIG. 2, even if the winding start portion 11 or the winding end portion 12 deviates from the winding center position, the gap 4' between the coil bobbin 2 and the coil bobbin 2 is sufficiently large, so that the inner surface of the coil bobbin 2, In particular, it is rare that the pressure contact portion 3 gets caught or that the coil bobbin 2 becomes impossible to pressure contact.

Further, the thickness t' of the wound core 1' in FIG. 2 is smaller than the thickness t of the wound core 1 in FIG. 4. Therefore, the total length L of the wound core 1' shown in FIG. 3, that is, the total length of the transformer, is also reduced, which contributes to the miniaturization of the transformer.

In the above-mentioned embodiment, both the winding start and winding end portions are elliptical, but even if only one of them is formed into an ellipse, the effect is slightly inferior, but still more effective than the conventional type.

〔Effect of the invention〕

As explained above, according to the present invention, even if both or one of the winding start and winding end portions of the strip material deviates from the winding center position, the inner surface of the coil bobbin is not caught and the coil bobbin cannot be pressed. It can be prevented.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the basic configuration of the present invention, Fig. 2
3 is a perspective view showing the overall configuration of FIG. 2, FIG. 4 is a sectional view showing a wound core equipped with a conventional coil bobbin, and FIG. 5 is a plan view showing an example of the strip material shown in FIG. 4, and FIG. 6 is a sectional view for explaining the problem in FIG. 4. 1, 1': Winding core, 11, 12: Winding start part,
Winding end portion, 2: coil bobbin, 4, 4': void.

Claims (1)

[Scope of Claims] 1. In a wound core to which a cylindrical coil bobbin for winding a winding wire is applied, both or one of the winding start and winding end portions of the winding core have an elliptical cross-sectional shape, and the other A winding characterized in that the cross-sectional shape of the portion is circular, so that when the coil bobbin is applied to the winding core, a space is created between the elliptical shape of the winding core and the coil bobbin. Iron core.