JPS60200505A - Transformer - Google Patents

Abstract

PURPOSE:To prevent the buzzing noise due to magneto-strictive vibration from sounding as well as a crack in cores from happening by a method wherein a sheet of film or paper is inserted between central pole shoes of ferrite cores and a coil bobbin to bond the pole shoes with adhesive. CONSTITUTION:A square sheet of polyester film or paper 8 e.g. around 0.05mm. thick cylindrically rolled is inserted into a bobbin 3 to be engaged with central pole shoes 2 of ferrite cores 1 while the pole shoes 2 of a pair of cores 1 is bonded by coating the gap of pole shoes with adhesive 5 to constitute a transformer further by impregnating the pole shoes 2 with resin 6 as necessary. Through these procedures, a crack in cores 1 may be prevented from happening since the adhesion between the central pole shoes 2 of ferrite cores 1 and the coil bobbin 3 may be reduced to decrease the tension by contraction of bobbin 3.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a transformer using a ferrite core.

Conventional configurations and their problems Generally, in switching power supply circuits and the like, transformers and chokes using ferrite cores are used. Such a transformer usually has two E-type ferrite cores combined, and FIG. 2 is a cross-sectional view of an example of a conventional transformer in which a gear is connected between central magnetic legs. (1) is E
In the type 7 elite core, two cores (1) are combined, a coil (4) wound around a bobbin (3) is fitted to the central magnetic leg (2), and a gap is provided in the central magnetic leg (21). There is.

In such a transformer, in order to prevent humming noise due to foundation strain vibration of the ferrite core, adhesive (5) is applied to the gap of the central magnetic leg (21), or the entire body is impregnated with resin (6). The following methods are being taken.

However, in such a configuration, the adhesive (5) is
, (flowing between 31 and the central magnetic leg (2) of the core,
When the bobbin is glued to the central magnetic leg, or the central magnetic leg (21) of the core and the bobbin (3) are bonded using impregnated resin such as polyester, and the transformer temperature decreases and the bobbin contracts, the upper and lower parts of the ferrite core The central magnetic leg was pulled and a crack (7) appeared in the core, causing it to split.

There are some drawbacks. Such core cracking can be prevented by using a soft material such as silicone rubber as an adhesive or impregnation agent, but in the case of cleaning materials, it is difficult to prevent the Ichitomi strain knitting. It is not possible to sufficiently prevent the humming sound.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a transformer that eliminates the drawbacks of the conventional transformer using a ferrite core as described above, has no fear of cracks occurring in the core, and can prevent humming noise due to magnetostrictive vibration. The purpose is to

Structure of the Invention The misfire 814 is made by inserting a film or paper between the central magnetic legs of a pair of E-type ferrite cores and the coil bobbin fitted thereto, to fill the gap provided in the central magnetic legs of the pair of cores. Adhesive is applied to join the central magnetic legs of both cores.

With this configuration, the adhesive force between the central magnetic leg of the ferrite core and the coil bobbin is weakened, the tension caused by contraction of the bobbin is weakened, and cracks in the core can be prevented.

DESCRIPTION OF EMBODIMENTS FIG. 5 is a sectional view of a transformer according to an embodiment of the present invention, and FIG.
The figure is an exploded perspective view of the main parts. In Fig.
1) is a pair of E-type ferrite cores, (21 is the central magnetic leg thereof, <311-1 is the bobbin on which the coil (4) is wound,
The pair of E-type ferrite cores (1) are combined with a gap provided between their central magnetic legs (21).
This is the same as the conventional example explained with reference to FIGS. (8
) is a polyester film or paper with a thickness of, for example, about 0.05 mm. As shown in Figure 4, roll a rectangular piece into a cylindrical shape and insert it into the bobbin (3), and insert it into the ferrite core. Fit the central magnetic legs (1), apply adhesive (5) to the gap between the central magnetic legs, and then
are joined and further impregnated with mallet fat (6) as required to construct a transformer.

Effects of the Invention As described above, the present invention involves interposing a film or paper between the central magnetic leg of the ferrite core and the bobbin of the coil, and joining the central magnetic leg with an adhesive. Since there is a film or paper between the bobbin and the coil bobbin, even if the bobbin contracts, the force will be weakened by the film or paper surface, and the force applied to the central magnetic leg of the core will be weakened, causing a crack in the core. can be prevented from entering.

The thinner the film (k) is, the easier it is to deform, so the contraction force of the bobbin is prevented from being applied to the central magnetic leg of the core, which is highly effective.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a conventional transformer, FIG. 2 is a sectional view thereof, and FIG. 3 is a sectional view of an embodiment of the transformer of the present invention.
FIG. 4 is an exploded perspective view of the main parts. (1)... E-type ferrite core, (2)... Central magnetic leg, (3)... Bobbin, (4)... Coil, (5)
... Adhesive, (6) ... Impregnated resin, (7) ... Crack, (8) ... Film or paper. Name of agent: Patent attorney Etsuji Yoshizaki Figure 1 M2

Claims (1)

[Claims] Two E-type ferrite cores are combined with a gap between the central magnetic legs, and a paper or film is interposed between the bobbin of the coil fitted to the central magnetic leg and the central magnetic leg, and applied to the gap. A transformer made by joining the central magnetic legs of two ferrite cores with adhesive.