JPH06310347A - Transformer - Google Patents

Abstract

PURPOSE:To reduce the number of component parts and thinly form the title transformer by a method wherein an elastic piece is inserted into the inserting hole of a printed board by changing provided on one of flanges to a coil bobbin, the coil bobbin is the shape of the elastic piece, and the elastic piece is restored after insertion. CONSTITUTION:The title transformer 10 is provided with a coil 12 which is helically formed on the surface of a printed board 11, and a winding coil 14 which is wound on a coil bobbin 13 and having flanges 13d and 13e on both ends to be inserted into the inserting hole 11a provided on the coil region of the printed board 11. Also, cores 15 and 16, which are attached to the printed board 11, are provided in such a manner that they are opposingly positioned from both surfaces of the printed board 11 in the region of a coil 12. An elastic piece 13d is provided at least on one of the flanges of the coil bobbin 13, the elastic piece 13d is deformed, and the coil bobbin 13 is inserted into the inserting hole 11a of the printed board 11. After insertion, the elastic piece 13d is restored, and the coil bobbin 13 is fixed to the printed board 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer arranged on a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, when a transformer is arranged on a printed circuit board, the transformer is constructed as shown in FIG. 6, for example. That is, in FIG. 6, the transformer 1 is
For a coil bobbin 2 formed in a hollow cylindrical shape having a hollow portion 2a and having collar portions 2b, 2c at both ends, winding a winding in a winding groove 2d between the collar portions 2b, 2c. To form the primary coil 3 and the secondary coil 4,
The winding lead terminals of the coils 3 and 4 are connected to the coil bobbin 2
The hollow portion 2 of the coil bobbin 2 is twisted to the pin 5 provided so as to extend downward from the lower collar portion 2c of the coil bobbin 2.
It is configured by inserting and fixing the core 6 in a.

When the transformer 1 thus constructed is mounted on the printed board 7, the pins 5 are inserted into the mounting holes 7a provided in the printed board 7 and the transformer 1 is mounted by soldering or the like. It is fixed on the printed board 7 and is electrically connected to a conductive pattern or the like formed on the printed board 7.

[0004]

However, in the transformer 1 configured as described above, the primary coil 3 and the secondary coil 4 are formed by winding the winding around the groove portion of the coil bobbin 2, and the coil is further formed. It is necessary to work the winding lead terminals 3 and 4 to the pin 5. For this reason, the number of parts is large, the assembling work becomes complicated, and the coil bobbin having the pins is mounted on the printed circuit board at the time of mounting on the printed circuit board, so that the mounting dimension becomes relatively high. There was a problem.

Further, since the primary coil 3 and the secondary coil 4 are wound in the same groove portion, there is a problem that they are not suitable for a high voltage type or an insulation type transformer. .

[0006]

In view of the above points, according to the present invention, a coil formed in a spiral shape on a surface of a printed circuit board and an insertion hole provided in a coil region of the printed circuit board are inserted. A coil bobbin wound around a coil bobbin having a brim at both ends, and a core attached to the printed circuit board so as to face each other from both sides of the printed circuit board in a region of the coil. An elastic piece is provided on at least one of the collars, the elastic piece is deformed to insert the coil bobbin into the insertion hole of the printed board, and after the insertion, the elastic piece returns to fix the coil bobbin to the printed board. It has been configured.

[0007]

According to the above construction, since a part of the coil can be formed on the printed circuit board, a coil bobbin for this coil is unnecessary, so that the number of parts can be reduced and the winding groove of the coil bobbin can be reduced. Since the work of winding the winding wire to the coil is reduced, the component cost and the assembly cost can be significantly reduced.

Further, since it is not necessary to provide a pin on the coil bobbin, the height of the entire coil bobbin can be small, and the coil bobbin is inserted into an insertion hole provided on the printed circuit board so as to project onto the printed circuit board. The height is significantly reduced, and the entire structure can be made thin.

Further, since the coil on the printed circuit board and the coil wound around the coil bobbin are separated from each other, they can be surely insulated from each other, and the high voltage type or the insulation type coil can be easily obtained. Can be configured.

When the coil bobbin is inserted into the insertion hole, one of the collars formed on the coil bobbin elastically deforms to pass through the insertion hole, and after the insertion, the collar returns to its original state. Returning to this, the coil bobbin can be fixed to the printed circuit board by sandwiching the printed circuit board together with the other collar, so that the coil bobbin can be easily attached to the insertion hole of the printed circuit board.

[0011]

Embodiments of the transformer according to the present invention will be described below. FIG. 1 shows a first embodiment of a transformer according to the present invention. The transformer 10 includes a coil having a conductive pattern spirally formed on a lower surface of a printed circuit board 11, for example, a primary coil 12 and the printed circuit board. Winding 13a of the coil bobbin 13 inserted into the insertion hole 11a provided near the center of the area of the primary coil 12 of FIG.
The winding coil wound around, for example, the secondary coil 14 and the printed circuit board 11 and the coil bobbin 13 are attached to the printed circuit board 11 so as to face each other in the area of the coils 12 and 14 from above and below. It is composed of cores 15 and 16.

As shown in FIG. 2, the primary coil 12 has two connecting lead patterns 1 extending leftward in the drawing.
Ends 12 on one side (outer side of the spiral) with respect to 7, 18
a is directly and integrally connected to one of the lead patterns 17, and the other end (spiral inner side) of the end portion 12
b is connected to the other lead pattern 18 so as to intersect the spirally formed primary coil 12.

Regarding this intersection, the primary coil 1
Jumper 2 which crosses under the insulating layer 19 placed under
It can be connected to the lead pattern 18 via 0.

Of the cores 15 and 16, the core 15 is
As shown in FIG. 1, a disc-shaped main body 15 a and the main body 15 a
a central core portion 15b extending upward from the central portion of a,
It is composed of an annular core portion 15c extending upward from the peripheral portion of the main body 15a, and the annular core portion 15c is
Portions that are diametrically opposed to each other are notched.

In the core 15 thus constructed, the central core portion 15b is located below the coil bobbin 13 in the area including the coil 12 of the printed board 11, and the annular core portion is formed in the insertion hole 13c at the center of the coil bobbin 13. 15c is inserted into the insertion hole 11b of the printed circuit board 11, and the central core portion 15b and the annular core portion 15c projecting on the upper surface of the printed circuit board can be fixed to the lower surface of the core 16. As a result, the cores 15 and 16 are attached so as to face each other from both sides of the printed circuit board 11.

As shown in FIG. 1, the coil bobbin 13 has flanges 13d and 13e integrally formed on the upper and lower ends thereof, and is wound from the inside to the outside in the winding groove between the flanges 13d and 13e. By doing so, the secondary coil 14 is configured. The winding lead end of the secondary coil 14 is connected to the lead patterns 21 and 22 formed on the upper surface of the printed board. Further, the coil bobbin 13 is formed with an insertion hole 13c at the center thereof so that the central core portion 15b of the lower core 15 can penetrate therethrough.

Further, the coil bobbin 13 has a collar 13d.
Is composed of a plurality of elastic pieces. As a result, as shown in FIG. 3, the coil bobbin 13 is inserted into the insertion hole 11a of the printed board 11 from the direction of the arrow A, and the collar 13d is deformed at the intermediate portion of the insertion hole 11a as illustrated. When the collar 13d is further inserted and the collar 13d reaches the upper surface of the printed circuit board 11, the collar 13d elastically returns to the original state as shown in FIG. 1, and the printed circuit board 11 is sandwiched between the collar 13d and the collar 13e. By doing so, the coil bobbin 13 can be fixed to the printed circuit board 11.

The transformer 10 according to the present invention is configured as described above, and the coil bobbin 13 around which the coil 14 is wound can be easily inserted and fixed to the printed circuit board 11 on which the coil 12 is formed. . Then core 1
By mounting the components 5 and 16, the assembly of the transformer 10 is completed. Therefore, the number of parts is small, and the assembly can be easily performed.

Moreover, the coil 12 is the printed circuit board 11
Coil bobbin 1 which is formed flat on the surface of
Since 3 is inserted into the printed circuit board 11, the height of the core 15 and 16 protruding above the printed circuit board 11 can be remarkably reduced, and the thinning is promoted. It

FIGS. 4 and 5 show a second transformer according to the present invention.
An example is shown. Here, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

In the transformer 30 shown in FIGS. 4 and 5, the collar of the coil bobbin 13 has an elastic piece 13d and a positioning piece 13.
It is composed of f. The elastic piece 13d functions as described above, but the positioning piece 13f has
The tip portion is formed shorter than the elastic piece 13d so as to contact the inner wall of the insertion hole 11a when the coil bobbin 13 is inserted into the insertion hole 11a of the printed board 11. As a result, the coil bobbin 13 can be attached to the printed board 11 without being eccentric with respect to the insertion hole 11a. Further, the positioning piece 13f has a coil 14 with a brim 1.
Since it is regulated between 3e and 3e, the winding work of the coil 14 becomes easy and the variation of the inductance value is eliminated.

As described above, in addition to the effects of the first embodiment described above, this embodiment has the coil bobbin 13 inserted into the printed circuit board 11 without eccentricity, and the winding coil 12 is provided.
This has the effect of facilitating winding work and reducing the variation in inductance.

In the above description, it was described that the primary coil 12 is formed by the conductive pattern of the printed board 11. However, instead of the conductive pattern, a flat winding coil may be fixed on the printed board. Good.

[0024]

As described above, according to the present invention, the coil is directly formed on the printed circuit board, so that the number of parts is reduced and the structure is made thin. Can be preferably used, and an extremely excellent transformer can be provided which allows the coil bobbin to be easily attached to the printed circuit board.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a transformer according to the present invention.

2 is a schematic cross-sectional view of the transformer of FIG.

FIG. 3 is a schematic sectional view showing how a coil bobbin is inserted into an insertion hole of a printed board.

FIG. 4 is a schematic sectional view showing a second embodiment of the transformer according to the present invention.

5 is a schematic cross-sectional view of the transformer of FIG.

FIG. 6 is a schematic diagram showing an example of a conventional transformer.

[Explanation of symbols]

 11 Printed Circuit Board 11a Insertion Hole 12 Coil (Coil Made of Conductive Pattern) 13 Coil Bobbin 13d Collar (Elastic Piece) 13e Collar 14 Winding Coil 15, 16 Core

Claims (1)

[Claims] 1. A coil formed in a spiral shape on a surface of a printed circuit board, and a winding wound around a coil bobbin having a collar at both ends, which is inserted into an insertion hole provided in a coil region of the printed circuit board. In the coil and the area of the coil,
A core attached to the printed circuit board so as to face each other from both sides of the printed circuit board, an elastic piece is provided on at least one flange of the coil bobbin, and the elastic piece is deformed to move the coil bobbin to the printed circuit board. A transformer configured to be inserted into an insertion hole, and after insertion, the elastic piece returns to fix the coil bobbin to the printed circuit board.