JPH0587917U - Trance - Google Patents

Abstract

(57) [Abstract] [Purpose] As the size of switching power supplies used in various electronic devices is becoming smaller, the size of transformers used for them is increasing.
There is a strong demand for higher efficiency, and in order to meet these demands, it is an object of the present invention to provide a smaller and more efficient transformer. In a transformer including a bobbin 11, a coil 12, and a magnetic core 13, in a coil insertion portion surrounded by a central magnetic leg 15 and an outer leg magnetic leg 16 of the magnetic core 13, a magnetic leg on a surface facing the coil 12 is magnetized. The uneven portion 17 and the corrugated groove 18 are formed at positions crossing the path perpendicularly. By this, the distribution of the magnetic flux passing through the magnetic core 13 becomes uniform, and the magnetic core can be effectively used, so that the saturation characteristic is extended and the transformer is The efficiency can be improved and the size can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a transformer used in various electronic devices.

[0002]

[Prior Art]

 In recent years, as the miniaturization of switching power supplies has progressed, the switching transformers used for them are also required to be highly efficient and miniaturized. Regarding the shape of the ferrite core used in this transformer, the EE type and the EI type are mainly used, but the shape is smaller and it is desired to have an efficient size and shape.

A conventional transformer will be described below with reference to FIGS. 8 to 10. 8 to 10, the coil 2 is wound around the coil bobbin 1, and the magnetic core 3 shown in FIGS. 9 and 10 is inserted in the magnetic path of the coil 2. The structure of the magnetic core 3 is configured such that half of the cross-sectional area of the central magnetic leg 5 is the cross-sectional area of the outer leg magnetic leg 6.

[0004]

[Problems to be solved by the device]

 However, in the above configuration, first, the magnetic flux 4 passing through the magnetic core 3 is concentrated around the surface of the central magnetic leg 5 and does not flow so much in the central portion, and the magnetic resistance of the outer leg magnetic leg 6 is small. The magnetic flux concentrates inside. Therefore, the entire cross-sectional area of the magnetic core 3 cannot be used efficiently, which causes a problem that magnetic saturation easily occurs.

As described above, the structure of the conventional magnetic core of the transformer has a problem that the shape becomes large because the utilization efficiency of the magnetic core is poor.

The present invention solves the above problems, and an object of the present invention is to provide a smaller transformer that improves the utilization efficiency of the magnetic core.

[0007]

Means for Solving the Problems In order to achieve the above-mentioned object, a transformer of the present invention has a coil insertion window portion surrounded by a central magnetic leg and an outer leg magnetic leg, in which a magnetic leg facing a coil is provided. Concavities and convexities or wavy grooves are provided at positions perpendicular to the magnetic path.

[0008]

[Action]

 In the above structure, since the gaps are formed in the shortest magnetic path of the magnetic leg by the uneven portion and the wavy groove, the magnetic flux is uniformly distributed without being concentrated in a part of the magnetic leg, and an efficient magnetic path can be formed.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view of a transformer according to an embodiment of the present invention. A magnetic core 13 of the present invention is inserted in a coil 12 wound around a bobbin 11.

2 (a), (b) to FIGS. 4 (a), (b) are detailed examples of the magnetic core of the present invention. The E-shaped core or the U-shaped core forming the magnetic core 13 has an outer peripheral surface and both side surfaces of the central magnetic leg 15 and an outer foot magnetic leg 16 on which uneven portions 17 and wavy grooves 18 are formed. The magnetic flux 14 of the coil 12 passing through 13 passes through the central portion of the magnetic leg and has a uniform distribution.

FIGS. 5 and 6 show the flow of the magnetic flux 14. The uneven portion 17 and the wavy groove 18 allow the magnetic flux 14 to flow through the entire magnetic core 13, and the saturation characteristic shown in FIG. Compared with the conventional product 9, it extends like the product 10 of the present invention.

[0013]

[Effect of the device]

 As described above, in the transformer of the present invention, the utilization efficiency of the magnetic core is improved, the magnetic core can be downsized, and the effects of downsizing and cost reduction of the transformer can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a transformer according to an embodiment of the present invention.

2A and 2B are perspective and plan views of a magnetic core showing an embodiment of the present invention.

3A and 3B are a perspective view and a plan view of a magnetic core of another embodiment.

4A and 4B are a perspective view and a plan view of a magnetic core according to another embodiment.

FIG. 5 is a schematic view showing magnetic flux in a magnetic core showing an embodiment of the present invention.

FIG. 6 is a plan view of the same.

FIG. 7 is a saturation characteristic diagram of the present invention and a conventional magnetic core.

FIG. 8 is a perspective view of a conventional transformer.

FIG. 9 is a perspective view showing the flow of magnetic flux in the magnetic core.

FIG. 10 is a plan view of a magnetic core showing the flow of magnetic flux of a conventional transformer.

[Explanation of symbols]

 11 bobbin 12 coil 13 magnetic core 14 magnetic flux 15 central magnetic leg 16 outer leg magnetic leg 17 uneven portion 18 wavy groove

Claims (1)

[Scope of utility model registration request] 1. EE. EI. UU. A transformer in which a ferrite core having a closed magnetic path shape such as a toroidal is used, and an uneven portion or a wavy groove is provided on a magnetic leg surface of the magnetic core facing the coil of a coil insertion window so as to be orthogonal to the magnetic path.