JP2868064B2 - High frequency transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency transformer for surface mounting used in various electronic devices, and more particularly to a high-frequency transformer capable of preventing destruction due to a thermal shock or a difference in the coefficient of thermal expansion of each part. About.

[0002]

2. Description of the Related Art A high-frequency transformer of this type has conventionally been constructed such that a winding is wound around a drum core made of ferrite or the like having flanges formed at both ends, and this drum core is made of synthetic resin and terminal pins are implanted. The terminal of the winding is wire-connected to a terminal pin projecting from a side surface of the terminal plate, and the outer periphery of the drum core is covered with a cylindrical ring core. Further, the ring core is concentrically positioned with a predetermined gap between the ring core and the outer periphery of the drum core, and the lower end surface of the ring core is bonded and fixed to the upper surface of the terminal plate.

[0003]

However, according to the conventional high-frequency transformer constructed as described above, when the drum core and the ring core are concentrically positioned and fixed on the terminal plate, the positional accuracy is stably fixed. However, there is a problem that the electrical characteristics vary. Drum cores and ring cores made of ferrite etc. are bonded and fixed on a terminal board usually made of thermosetting resin, so there is a risk that cracks etc. may occur in each part due to differences in thermal shock and thermal expansion coefficient. was there.

The present invention has been made in view of such a situation, and it is possible to stabilize the positional accuracy of a drum core and a ring core with respect to a terminal plate, and to prevent breakage due to a thermal shock or a difference in a thermal expansion coefficient of each part. It is an object of the present invention to provide a high-frequency transformer capable of performing the following.

[0005]

A high frequency transformer according to the present invention comprises a drum core having a flat plate-like flange provided at both ends of a core, a winding wound around a core between the flanges, and a drum core comprising the drum core. One end of a terminal connected to the winding is embedded, and the other end of the terminal is provided so as to surround a side portion of the drum core between a flat terminal plate protruding from a side portion and a flange portion at both ends. A hollow cylindrical ring core, a holder having a through-hole having a diameter to hold the ring core therein, and a holder having an engaging piece for holding the terminal plate, a surface portion of the terminal plate, and the drum core On the outer surface of one of the collars,
A concave and convex portion for positioning is formed when the terminal plate and the drum core are coupled, and a concave portion for holding by the locking piece of the holder is formed on a side of the terminal plate where the terminal does not project. The terminal plate and the drum core are positioned and coupled by the positioning unevenness, the holder and the terminal plate are fitted by the locking pieces and the concave portions, and the ring core is provided by the holder. Along the inner wall of the through-hole, the drum core is provided so as to surround the side portions of the flange portions of the drum core with a gap therebetween. It is characterized by being bonded in between.

In the high frequency transformer according to the present invention, the outer shape of the ring core is equal to the inner diameter of the through hole of the holder, and the ring core is fitted and held in the through hole of the holder. It is characterized by.

[0007]

According to the high-frequency transformer having the above-described structure, the terminal plate and the drum core are positioned and connected by the positioning unevenness, and the positional relationship therebetween is proper. The holder and the terminal plate are connected by the locking piece and the concave portion. Are fitted, these are fitted in an appropriate positional relationship, and in such a state, the ring core is
It is inserted along the inner wall of the through hole of the holder, and is provided so as to surround the side portions of both the flange portions of the drum core via a gap, so that positioning such that the gap between the ring core and the drum core is appropriate is performed. Done. The ring core is bonded between the two flange portions of the drum core and the flange portion farther from the terminal plate, and the ring core is held by the holder, so that one end of the ring core is attached to the drum core and the other end is attached to the drum core. Cracks due to thermal expansion and the like can be prevented as compared with the conventional structure bonded to the terminal plate.

Further, the outer shape of the ring core is equal to the inner diameter of the through hole of the holder, and the ring core is fitted and held in the through hole of the holder. Positioning is performed so that the gap between them is more appropriate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high-frequency transformer according to the present invention will be described below with reference to the drawings.

FIGS. 1 to 10 show the configuration of an embodiment of the present invention. As shown in FIGS. 6 and 7, the terminal plate 1 is formed of a thermosetting resin in a substantially rectangular plate shape, and the base end of the terminal 2 is embedded in each of two opposing sides. At the center of the terminal plate 1, a circular concave portion 3 for mounting a drum core 5 described later is formed at a predetermined depth, and the circular concave portion 3 is formed on the other two sides adjacent to and opposite to the two sides where the terminal 2 is embedded. Is formed with a concave portion 4 having a predetermined length to which an inner periphery of a lower end of a holder 9 described later is fitted.

As shown in FIG. 5, the drum core 5 is formed of a cylindrical body having disc-shaped flanges 6 integrally formed concentrically on both upper and lower end surfaces, and a winding 7 is provided between the flanges 6. It is wound. The winding 7 is divided into a plurality of coils, and both ends of each winding are connected to the terminal 2.
At the center of the lower surface of the drum core 5, a columnar convex portion 8 is formed integrally with the concave portion 3 formed at the center of the terminal plate 1, and the convex portion 8 is fitted and adhered to the concave portion 3. Thereby, the drum core 5 and the terminal plate 1 are integrally fixed with high positional accuracy.

As shown in FIGS. 8 to 10, a holder 9 formed of a synthetic resin into a rectangular case
The lower end inner periphery is fitted, and on opposite two sides of the lower end inner periphery of the holder 9, a locking piece 10 that fits into the recess 4 formed in the terminal plate 1 is provided so as to protrude. And recess 4
The terminal strip 1 is integrally joined to the holder 9 together with the drum core 5 with high positional accuracy by fitting the locking pieces 10 to the holder 9.

At the center of the holder 9, a through hole 11, which is a round hole, is formed concentrically with the drum core 5.
5 between the inner circumference of the drum core 5 and the outer circumference of the flange 6 of the drum core 5.
As shown in the figure, a predetermined annular gap is formed concentrically. A cylindrical ring core 12 made of ferrite or the like is inserted into this gap.
Is equal to the inner diameter of the through hole 11 formed in the holder 9. A predetermined annular gap 13 is provided between the inner circumference of the ring core 12 and the outer circumference of the flange 6 of the drum core 5.
Are formed concentrically. The outer periphery of the upper flange 6 and the inner periphery of the upper end surface of the ring core 12 are bonded and fixed with an adhesive 14. A locking piece 10 on the lower surface of the holder 9
Terminal outlets 15 are provided on two sides in a direction perpendicular to the two sides provided with. 1 to 5
FIG. 2 is an assembly diagram of the high-frequency transformer according to the embodiment.

Next, the procedure for assembling the high-frequency transformer according to this embodiment will be described. First, the convex portion 8 formed on the lower surface of the drum core 5 is fitted and bonded to the concave portion 3 formed on the upper surface of the terminal plate 1, and the drum core 5 and the terminal plate 1 are integrally positioned and fixed. Next, the terminal plate 1 in which the drum core 5 is integrated is inserted into the through hole 11 of the holder 9 from below, and the locking piece 10 formed on the holder 9 is fitted into the concave portion 4 formed on the terminal plate 1. To fix the position. At this time, by providing a flange (not shown) on the inner periphery at the lower part of the through hole 11 and providing elastically deformable tongues on both sides of the concave portion 4 of the terminal plate 1, positioning in the axial direction is also possible.

Next, the ring core 12 is inserted between the inner periphery of the through hole 11 and the outer periphery of the flange portion 6, and the inner periphery of the upper end surface of the ring core 12 and the outer periphery of the flange portion 6 of the drum core 5 are bonded. The adhesive 14 is used for fixing.

According to the present embodiment, the terminal plate 1 and the drum core 5 are fitted and locked via the concave portions 3 and the convex portions 8 formed respectively, and are integrally positioned and adhered and fixed.
And the holder 9 are positioned and fixed via the recesses 4 and the locking pieces 10 formed respectively, and
Is inserted into the through hole 11 of the holder 9 and is fixedly adhered by the adhesive 14, so that each part can be firmly fixed with high positional accuracy. Therefore, the electrical characteristics of the high-frequency transformer can be stabilized.

On the other hand, the ring cores 12 made of different materials and the terminal plate 1 are not bonded, and the ring cores 1 made of the same material are not bonded.
Since the drum core 2 and the drum core 5 are adhered to each other, there is no possibility that breaks such as cracks occur in each part due to a difference in thermal shock or thermal expansion coefficient. Further, since the ring core 12 is covered with the holder 9, the ring core 12 is not damaged by a grip portion (claw) of a mounting machine when the ring core is mounted on a circuit board or the like.

[0018]

As described above, according to the high-frequency transformer according to the present invention, the terminal plate and the drum core are positioned and connected by the concave and convex for positioning, and the positional relationship therebetween becomes appropriate. Further, the holder and the terminal plate are fitted by the locking pieces and the concave portions, and these are fitted in an appropriate positional relationship. In a state where the terminal plate, the drum core, and the holder are in an appropriate positional relationship, the ring core is inserted along the inner wall of the through hole of the holder, and a gap is formed between the side portions of the flange portions of the drum core. Since it is provided so as to surround it, positioning is performed so that the gap between the ring core and the drum core is appropriate. Accordingly, the positional relationship among the terminal plate, the drum core, the holder, and the ring core is constant, and the electrical characteristics can be stabilized. In addition, the ring core is bonded between the two flange portions of the drum core and the flange portion farther from the terminal plate, and the ring core is held by the holder, so that one end of the ring core is attached to the drum core and the other end is attached to the drum core. Cracks due to thermal expansion and the like can be prevented as compared with the conventional structure bonded to the terminal plate. Further, since the ring core is provided inside the holder, there is no fear of being damaged from the outside.

[Brief description of the drawings]

FIG. 1 is a top view showing a configuration of an embodiment of a high-frequency transformer according to the present invention.

FIG. 2 is a view taken in the direction of arrow A in FIG. 1;

FIG. 3 is a view taken in the direction of arrow B in FIG. 1;

FIG. 4 is a bottom view of FIG. 1;

FIG. 5 is a sectional view taken along line CC of FIG. 1;

FIG. 6 is a top view illustrating a configuration of a terminal plate.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a top view showing a configuration of a holder.

FIG. 9 is a bottom view of FIG. 8;

FIG. 10 is a sectional view taken along line DD of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Terminal board 4 Concave part 5 Drum core 6 Flange part 7 Winding 9 Holder 10 Locking piece 11 Through hole (round hole) 12 Ring core 14 Adhesive

Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) H01F 17/04 H01F 27/06 H01F 27/26

Claims (2)

(57) [Claims] 1. A drum core in which a flat plate-shaped flange is provided at both ends of a core, and a winding is wound around a core between the flanges, and one end of a terminal connected to the winding of the drum core is embedded. And a hollow cylindrical ring core provided so as to surround the side portion of the drum core between the flat terminal plate having the other end of the terminal protruding from the side portion and the flange portions at both ends, and holding the ring core inside. Having a through-hole having a diameter to be provided, and having a holder provided with a locking piece for holding the terminal plate, wherein a surface portion of the terminal plate and an outer surface portion of one flange portion of the drum core have A concave and convex for positioning is formed when coupling the terminal plate and the drum core, and a concave portion for holding by the locking piece of the holder is formed on a side of the terminal plate where the terminal does not protrude. The terminal plate and the drum core The holder and the terminal plate are fitted by the locking pieces and the recesses, and the ring core is inserted along the inner wall of the through hole of the holder; The drum core is provided so as to surround the side portions of the flange portions with a gap therebetween, and is bonded between the flange portions on the side far from the terminal plate in the flange portions. And high frequency transformer. 2. The ring core according to claim 1, wherein the outer shape of the ring core is equal to the inner diameter of the through hole of the holder, and the ring core is fitted and held in the through hole of the holder. High frequency transformer.