JPH03208314A - Converter transformer - Google Patents

Abstract

PURPOSE:To provide a small-sized converter transformer with reduced loss and satisfactory conversion efficiency by providing a magnetic gap in a magnetic leg on which a winding of a closed magnetic path magnetic core is mounted and forming an insulation part on which a winding of a wound part corresponding to the magnetic gap is not wound. CONSTITUTION:An insulation part 14 is formed integrally with a coil bobbin 12 so as not to lay a winding on a magnetic gap part 15. Hereby, the wiring does not intersect a leakage magnetic field from the magnetic core gap 15, and no proximity effect and no eddy current are produced on a copper wire to reduce heating for improving a coupling among the wirings. Thus, a title converter transformer can be constructed with a single wire without use of a stranded wire, and the converter transformer can be miniaturized by making thin the single wire.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a converter transformer used in various electronic devices.

BACKGROUND ART As shown in FIG. 10, a conventional converter transformer has a structure in which a magnetic core 1 having a magnetic gap 5 is inserted into a coil portion 3 wound around a molded bobbin 2. A coil portion 3 was wound at a location interlinked with the leakage magnetic flux 6 coming out from the magnetic gap 5.

Problems to be Solved by the Invention In such a conventional configuration, in the coil portion 3 to which the leakage magnetic flux 6 emitted from the magnetic core gap 5 interlinks, proximity effect and eddy current loss occur in the coil portion 3, and high frequency resistance increases. Make it bigger. As a result, copper loss increases, leading to deterioration in conversion efficiency such as increased heat generation and decreased coupling in the converter transformer.

Currently, the countermeasure is to use stranded wires that are expensive and have low productivity to reduce the proximity effect and eddy current loss, but this results in higher product costs and larger shapes.

The present invention solves the conventional problems as described above.
The purpose of this invention is to provide a small converter transformer with less loss and high conversion efficiency.

Means for Solving the Problems In order to solve this problem, the present invention provides an integrally formed coil bobbin or an insulating part formed with a spacer separate from the coil bobbin so that no winding is performed on the magnetic core gap part. The configuration is such that the

Effect: With this configuration, the windings are not interlinked with leakage magnetic flux coming out of the magnetic core gap, no proximity effect or eddy current occurs in the copper wires, heat generation due to copper loss is reduced, and coupling between the windings is improved. do. Therefore, it can be configured with a single wire without using twisted wires, and can be made even thinner, allowing the converter transformer to be made smaller. Further, since the insulating portion that is not wound is formed integrally with the bobbin or by using another molded spacer, the winding can be automated.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the structure of an E-type magnetic core 11, a bobbin 12 having flanges at both ends, a coil portion 13, and a gap portion 15 of the magnetic core 11.
It constitutes the insulating section 14 which is a feature of the present invention. This part is made of a plastic molded article such as polyester film in the shape of FIGS. 2 and 3. 17a to 17c are polyester base materials, and 17b and 17c constitute the insulating part 14. 17a serves as an insulating part between the coils. 18 is a space in which the winding wire is wound. When the wire diameter of the winding wire is larger than the thickness t of the spacer, 17c is formed by molding or fusing the same material to form a convex portion. The length 11 of the part of the molded product that will become the insulating part 14 has the number of turns needed to obtain the required height, and the length 12 has the number of turns needed to insulate between the coils.

FIG. 4 shows the magnetic gap 15 of the magnetic leg 11, its leakage magnetic flux 16, the insulating part 14, the coil part 13, and the bobbin 1 of the present invention.
2, and indicates that the leakage magnetic flux 16 does not interlink with the winding.

FIG. 5 shows an embodiment in which the magnetic legs have a plurality of magnetic gaps 15.
Wrap the molded product spacer shown in the figure. 17a is the insulation between the coils, 17b is above the magnetic core gap 15, and 18 is the space in which the coil is wound. FIG. 7 shows an embodiment in which a space is required between the bobbin 12 and the coil part 13 due to restrictions in safety standards, etc. By winding the molded spacer shown in FIG. Ensure a spatial distance between 18
The winding is performed on the part.

FIG. 9 shows an embodiment in which the insulating portion 14 is formed integrally with the bobbin 12. The bobbin 12 is made of a plastic material such as polybutylene terephthalate or phenol.

Effects of the Invention As described above, with the present invention, the winding is no longer affected by magnetic flux leakage from the gap in the magnetic core, eliminating the heat generation caused by the conventional proximity effect and eddy current loss, and making it possible to use copper wire with a smaller diameter. This also eliminates the need for expensive twisted wires. Furthermore, in the formation of the insulating portion, winding can be automated using a molded spacer, so that the converter transformer can be made smaller and lower in cost.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the converter transformer of the present invention, Figs. 2 and 3 are perspective views of a molded product spacer forming an insulating part, Fig. 4 is an enlarged view of the vicinity of the gap, and Fig. 5 6 is a cross-sectional view of an embodiment in which there are multiple gaps, FIG. 6 is a perspective view of a spacer constituting the same insulating section, FIG. 7 is a sectional view of an embodiment in which a distance from the end face of the bobbin is required, and FIG. Figure 8 is a perspective view of the molded spacer, Figure 9 is in line with the bobbin, 14...Insulation section, 15...Magnetic core gap, 16...Leakage magnetic flux, 17...
Molded spacer.

Claims (3)

[Claims] (1) A converter transformer in which a magnetic gap is provided in the magnetic leg to which the winding of a closed magnetic circuit core is attached, and an insulating part where no winding is applied is formed at least in the winding part that corresponds to the magnetic gap and is wound on the inside. . (2) Claim 1 in which the insulating part is integrally formed with the coil bobbin.
Converter transformer as described. (3) The converter transformer according to claim 1, wherein the insulating portion is formed by a spacer formed separately from the coil bobbin.