JPS60171707A - Miniature transformer - Google Patents

Abstract

PURPOSE:To increase a winding region and to equip with a more coil or winding, by causing transformer cores to form cut portions respectively and by fitting therein terminal pin holders of a bobbin. CONSTITUTION:Cutting portions 1h, 2h are being formed at the core sides corresponding to faces 1f, 2f of transformer cores 1, 2. A bobbin 3 provides with brim portions 3b at both sides of a hollow portion 3a in which inner legs 1g, 2g can be inserted and terminal pin holders 3c each having an increased thickness below the brim portion 3b. First, a plural of coil 4 are wound on the bobbin 3 and each coil end is secured to respective terminal pins 6. Thereafter, the inner legs 1g, 2g of the transformer core 1, 2 are inserted from both the sides of the bobbin 3 respectively and the contacting faces of the cores 1, 2 are bonded together by an adhesive. In this way, the terminal pin holders 3c of the bobbin 3 can be fitted in the cut portions 1h, 2h of the transformer core 1, 2 so the terminal pin holders 3c and transformer cores 1, 2 may be bonded together by the adhesive respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small transformer, and particularly proposes a small transformer suitable for a power transformer.

As is well known, power transformers receive electromagnetic interference from load circuits and the like, and conversely, because electromagnetic influences are exerted on load circuits, most power transformers are equipped with a shielding device.

A first object of the present invention is to reduce the above-mentioned electromagnetic interference as much as possible.

Moreover, since small power transformers and the like are installed in a limited space together with other electrical components, they are susceptible to electrical damage due to contact with other electrical components.

A second object of the present invention is to provide an external structure with high electrical resistance and excellent nonflammability in order to prevent such electrical disturbances.

Furthermore, the third object of the present invention is to facilitate the incorporation of
The aim is to limit the height of the transformer as much as possible and make it flat.

A fourth object of the present invention is to propose a highly efficient compact transformer that is compact and has as many coils or windings as possible.

Therefore, the small transformer according to the present invention includes a coil wound around a bobbin, and a box-shaped core having internal legs inserted into the cylindrical part of the bobbin so as to surround the coil and the bobbin, In addition, a notch is formed in the side portion of the box-shaped core in the direction of the internal leg, and a thick portion of the bobbin for implanting the pin terminal is fitted into the notch.

Examples of the present invention will be described below to further clarify the content of the invention.

Fig. 1 is a perspective view of a small transformer according to the present invention, Fig. 2 is a partially cutaway bottom view of the transformer, Fig. 3 is a longitudinal side view of the transformer, and Fig. 4 FI! J is a sectional view of the transformer taken along line A-A in FIG. 3.

In these drawings, 1.2 is a transformer core of the same shape made of ferrite material, and these cores 1.2 are 1.
It is composed of a hollow hexahedron having faces a to l f and 2 a to '2 f, and integrally formed internal legs 1 g and 2 g having a substantially rectangular cross section protrude from the internal space. internal leg 1
g and 2g are polygonal cross sections obtained by cutting out each corner of a quadrilateral cross section.

FIG. 5 is an exploded perspective view showing the transformer core 12 in detail. As can be seen from this figure, notches 1h and 2h are formed on the sides of the core corresponding to the surfaces 1f and 2f. The notches 1h and 2h have a width up to the inner surface of the side portion corresponding to the opposing surfaces la, le, 2a and 2e, and a height up to the lower surface of the base of the internal legs 1g and 2g. Further, in FIGS. 1 to 4, reference numeral 3 denotes a bobbin around which at least two or more coils 4 are wound, and this bobbin 3 has the form shown in FIG. 6.

That is, the cylindrical part 3 into which the internal legs 1g and 2g are inserted
A has flanges 3b at both ends, and a predetermined number of coils 4 are wound between the flanges. The cylindrical portion 3a is the internal leg 1.
It is a polygonal cylinder with a cross-sectional shape of 2g and 2g.

Further, a thick terminal pin receiver 3c is formed at the lower part of the flange 3b, and a downwardly erected flange 3d is formed on the terminal bottle receiver 3C.

In addition, the width of the terminal pin receiver 3C and the height of this pin receiver 3C including the flange 3d are the notch 1h of the box-shaped soldering iron 1.2,
This is Satoshi Oshima, who fits into 2h.

In addition, reference numeral 5 in the drawings is an insulating tape wrapped around the coil 4, 6 is a terminal pin, and 3e is a guide groove at the end of the coil.

The small transformer having the above structure is first equipped with a plurality of coils 4 by winding them around the bobbin 3, and fixing the ends of each coil to the terminal pins 6. Then, the transformer cores 1 and 2 are connected from both sides of the bobbin 3. The inner legs 1g and 2g are inserted, and the joint surfaces of these cores 1.2 are fixed with adhesive. By assembling in this way, the terminal bin receiver 3c of the bobbin 3 fits into the notches 1h and 2h of the transformer cores l and 2, so the terminal bin receiver 3c and the transformer core 1.2 are fixed with adhesive. You may.

As can be seen from FIGS. 1 to 4, the above-mentioned small transformer has the following effects.

(Since the entire outer periphery except the bottom surface of 11 is covered by the transformer core, this outer periphery core forms a magnetic path as a transformer and at the same time functions as a magnetic shield.

(2) Since the lower end of the bobbin collar 3b is located inside the lower edge of the transformer core 1.2, the semi-crystalline part that secures the coil end to the base of the terminal pin 6 does not protrude from the bottom of the transformer. , electrically and mechanically stable when a transformer is installed.

(3) The internal legs 1g and 2g have a horizontally long polygonal cross section obtained by cutting off the corners of a rectangular cross section, and due to this polygonal cross section, the transformer coil 1.2 has beveled surfaces 1b and Id.

zb, 2d can be formed, which makes it possible to flatten the transformer shape.

(41 Connect the terminal pin receiver 3c of the bobbin 3 to the transformer core 1.
Since it fits into the notches 1h and 2h formed in 2, the space between the left and right terminal bin receivers 3c can be widened, and these terminal bin receivers have a larger space between them, that is, between the bobbin flanges, compared to conventional ones. A large number of coils or windings can be provided,
Transformer efficiency is advantageous.

Next, FIGS. 7 and 8 show an embodiment in which a ferrite plate 7 is fixed to the bottom of the above-mentioned small transformer, and a small hole 7a provided in the ferrite plate 7 is filled with an insulating material, such as an epoxy material, inside the transformer. It is for filling.

According to this embodiment, although almost the entire periphery of the transformer is covered with the ferrite core, the magnetic shielding effect is greatly enhanced.

Note that the ferrite plate 7 can be replaced with another magnetic plate such as a metal plate.

9 and 10 show an embodiment in which stepped flanges 3f are provided on both sides of the terminal pin receiver 3c so as to partially overlap the transformer core 1.2.

According to the embodiment, the terminal bin 6 and the transformer cores l, 2
This ensures electrical insulation between the lower edge of the

Note that the above-described ferrite plate 7 can also be provided in this embodiment.

Figures 11, 12 and 13 are transformer core 1.2
Notches 1h and 2h and terminal pin receivers 3 to be fitted into the notches 1h and 2h.
This is an embodiment in which C is formed into a trapezoid, and the other configurations are the same as the embodiments described above.

According to this embodiment, the projecting parts 1i, 2i are formed on both sides of the notch 111.2h, which is effective in preventing damage to the transformer core 1.2.

Further, when carrying out the present invention, as shown in FIG. 14, the transformer core 1.2 has a triangular cross section,
g, 2g may have a rectangular cross section.Furthermore, the transformer core 1.2 may have a triangular cross section, the internal legs 1g, 2g may have a polygonal cross section, or the transformer core 12 may have oblique surfaces 1b, ld.
, 2b, 2d, and the internal legs 1g, 2g have a rectangular cross section, which may be arbitrarily changed in terms of design and production.

Next, FIG. 15 shows an embodiment in which the horizontal side portion of the bobbin cylindrical portion 3a is made thinner, and the height of the transformer can be reduced by making the horizontal side portion thinner. Bobbin cylindrical part 3 formed into a polygonal cylinder
Since a has an oblique side, sufficient strength can be maintained even if the horizontal side is made thin.

Further, the horizontal side portion of the bobbin cylindrical portion 3a may be cut out to form a through hole. In this case, an insulating tape is wrapped around the bobbin winding portion and the wire is wound thereon.

As described above, since the small transformer according to the present invention is covered with a ferrite core except for one side or a part of the box-shaped core, magnetic interference with the external circuit or magnetic influence from the external circuit can be effectively prevented. In addition, the high electrical resistance outside the transformer prevents it from causing electrical damage even if it comes into contact with other electrical parts, and it is also highly nonflammable.

In particular, in the present invention, a notch is formed in the transformer core, and the terminal pin receiver of the bobbin is fitted into this notch, so the winding area is expanded and the number of windings is increased compared to the conventional one. The number of coils or windings can be equipped, which is very advantageous.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show embodiments of the present invention; FIG. 1 is a perspective view of a small transformer according to the present invention, FIG. 2 is a partially cutaway bottom view of the transformer, and FIG. FIG. 4 is a cross-sectional view of the transformer taken along line A-A in FIG. 3, FIG. 5 is a perspective view of the transformer core, FIG. 6 is a perspective view of the bobbin, and FIG. Figure 7 is a bottom view of a small transformer showing an example in which a ferrite plate is provided on the bottom, and Figure 8 is B on Figure 7.
-B sectional view; FIG. 9 is a partially cutaway bottom view of a small transformer showing an embodiment in which a stepped flange is provided at the lower part of the bobbin;
Figure 1θ is a sectional view taken along line C-C in Figure 9, Figure 11, Figure 1
2 and 13 show an embodiment in which an overhang is provided in the notch of the transformer core, FIG. 11 is a perspective view of the transformer core, FIG. 12 is a perspective view of the bobbin, and FIG. 13 is the same as FIG. 4. FIG. 14 is a sectional view similar to FIG. 4, showing an embodiment in which the shape of the transformer core is modified, and FIG. 15 is a sectional view similar to FIG. 4, showing an embodiment in which the bobbin cylindrical portion is modified. l...trans core, Ig...internal leg, 1h...
Notch, 2...Trans core, 2g...Internal leg, 2
h...notch part, 3...bobbin, 3a...cylindrical part,
3b... Flange, 3C... Terminal pin holder, 4... Coil, 5... Insulating tape, 6... Terminal bin, 7...
・Ferrite plate. Patent applicant: Kijima Musen Co., Ltd. J Figure 9 Figure 10 Figure 11 No. 1 12F! ! U b Section 13 Figure 14 Figure 15

Claims (1)

[Claims] A box-shaped core comprising a coil wound around a bobbin and an internal leg inserted into a cylindrical part of the bobbin to surround the coil and bobbin, and a side portion of the box-shaped core in the direction of the internal leg. A small transformer comprising: a notch formed in the bobbin, and a thick portion of the bobbin for implanting a pin terminal fitted into the notch.