JPS6035222Y2 - power transformer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power transformer that uses an insulating tape of suitable shape and material and has good characteristics.

Generally, in the case of a power transformer in which a primary coil and a secondary coil are arranged superimposed on an iron core, as shown in FIG. A thin flat insulating tape 3 such as paper or plastic was wound several times on top to maintain a predetermined thickness, and a secondary coil S was further wound a predetermined number of times on the tape. .

CR indicates iron core.

The reason why a particularly thin tape is used as the insulating tape is to ensure the insulation between the primary coil P and the secondary coil S and to reduce the winding thickness of the entire coil.

However, in reality, it is easy to create a gap between the bobbin and the flange 2, so careful work is required.In addition, the number of turns of the tape is required to maintain the thickness up to the specified withstand voltage and to increase the creepage distance. I had no choice but to make more.

Therefore, not only the electrical performance but also the workability was extremely poor.

The purpose of the present invention is to improve the above-mentioned drawbacks, and to create a power transformer with good characteristics by using an insulating tape with a specified thickness and having tape flanges at both transverse ends, and by bringing the waist tape flanges into close contact with the bobbin flanges. It is about providing.

Embodiments of the present invention shown in the drawings will be described below.

FIG. 2 is a longitudinal sectional view showing a power transformer in which a secondary coil S is wound around a primary coil P using a flanged bobbin 1, and the same reference numerals as in FIG. 1 indicate the same parts.

4 is an insulating tape having the characteristics of the present invention.

Fig. 3 is a perspective view showing the insulating tape before winding. L is equal to the spacing between the flanges 2 of the flanged bobbin 1.

Furthermore, tape flanges 4a are continuously formed integrally with the tape at both ends in the transverse direction.

As shown in the longitudinal sectional view of FIG. 4, the tape collar 4a is
Rather than simply being bent perpendicularly to the tape surface 4b as shown by the dotted line, the inner surface of the tape flange 4a is expanded outwardly in the short direction of the tape 4 as shown by the solid line. It is assumed that the inclined surface 4e has a shape.

That is, the tape 4 has a bent portion 4cy4d, and has a shape that rises from the tape surface at a predetermined angle α.

FIG. 5 shows a sectional view taken along the line ■-■ with the iron core shown in FIG. 2 removed.

Since the circumferential surface of the bobbin 1 or the primary coil P has a curved part or a corner part, when the insulating tape 4 is wound around the circumferential surface, a certain tension is applied to the insulating tape. Tape collar 4a is tape surface 4
Since the tape flange 4a has the inclined surface 4e, it can be avoided that the tape flange 4a bends toward the b side and interferes with the compact winding of the next-stage secondary coil S.

This insulating tape is wound only once on the primary coil P, and as shown in FIG. 5, the overlapping portion 4f may be extremely small.

If it is necessary to increase the dielectric strength, the tape itself can be made thicker, and even in this case, it can be manufactured in large quantities at low cost by pressure extrusion molding using a mold.

In this way, according to the present invention, since the power transformer uses a flexible tape that can be manufactured at a relatively low cost, it is possible to easily increase the dielectric strength between the primary coil and the secondary coil.

In other words, since the insulating tape is flexible, when the secondary coil is wound on the insulating tape, the tape flanges at both ends of the tape are in close contact with the inner wall of the flanged bobbin, so there is no tension between the primary coil and the secondary coil. The insulation is significantly improved, and this effect becomes even more pronounced if the insulating tape has elasticity.

In addition, since the insulating tape has tape flanges at both ends in the transverse direction, this is equivalent to increasing the distance between the primary coil and the secondary coil at the flanges of the bobbin, ensuring an insulating distance between both coils. Since this is easy and the creepage distance is sufficiently long, there will be no short-circuit accident or creepage discharge between the two coils.

Furthermore, since the number of turns of the insulating tape is small, the workability of manufacturing the power transformer is improved, and the transformer can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of a conventional power transformer, Fig. 2 is a configuration of an embodiment of the present invention, Fig. 3 is a perspective view of an insulating tape,
FIG. 4 is a longitudinal sectional view of the insulating tape, and FIG. 5 is a sectional view taken along line 2--V in FIG. P...Primary coil, S...Secondary coil, CR...Iron core, 1...Flanged bobbin,
2... Tsuba, 3... Flat insulating tape,
4... Insulating tape of the present invention, 4a... Tape collar, 4b... Tape surface, 4c, 4d...
...Bent part, 4e...Slanted surface, 4f...
...The part where the winding type fits together.

Claims (1)

[Scope of utility model registration request] In a power transformer, the primary coil, insulating tape, and secondary coil are superimposed and wound around a flanged bobbin attached to the iron core.
The insulating tape has tape flanges formed integrally and continuously with the tape at both ends of the insulating tape in the transverse direction, and at least the tip of the tape flanges has an inclined shape that expands outward in both the transverse directions of the insulating tape. The insulating tape is made of a flexible material such as elastomer or plastic, and has an overlapping portion between the secondary coil and the secondary coil, and is wound only once. A power transformer characterized in that the tape flange is closely attached to the inner wall of the flange of the flanged bobbin.