JPH05243061A - Flat coil - Google Patents

Abstract

PURPOSE:To inexpensively provide a flat transformer capable of satisfactorily maintaining isolation among coils by uniting a pair of flat lattice shaped bobbin element pieces while holding a flat core therebetween, and winding a coil on the external surface of the linked pieces of the bobbin element pieces. CONSTITUTION:Between opposite ribs 2, 2 of a pair of bobbin element pieces 1, 1, each piece being yielded by molding plastic into a substantially lattice shape, there are formed a plurality of bridging pieces 3, 3 for coupling the external surfaces of those ribs and further there are formed left and right side plates 4, 4. Final ends 2a, 2a of the opposite ribs 2, 2 are protruded from the internal surfaces of the respective side plates 4, 4. Further, another bobbin element piece 1 is fitted to the upper half of a one character shaped flat core 5 in the thickness direction for coverage over the latter, said core 5 being fitted at the lower half thereof in the thickness direction to the final ends 2a, 2a and the opposite ribs 2, 2 in contact with the outer edges of the final ends and with the inner edges of the opposite ribs 2, 2. Finally, a coil is wound on the external surfaces of the opposite ribs 2, 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat coil suitable for a high frequency transformer in an inverter power source or the like in which a flat core is covered with two ladder-shaped flat bobbins and a coil is wound on the flat bobbin.

[0002]

2. Description of the Related Art As an example in which a coil is wound around a bobbin having a frame-shaped window hole, there is a conventional one described in Japanese Utility Model Laid-Open No. 57-138304.

This prior art is a coil in which a window is provided in a coil winding portion of a bobbin, and a part of a core installed in the bobbin is fitted in the window hole.

[0004]

The prior art described above is a coil in which a core whose cross section is close to a square is inserted into a bobbin of a cage frame with a collar, so that the length, width, and height are equal to each other. However, only a so-called three-dimensional coil is obtained, which is a cause of greatly obstructing flattening of the circuit board.

As a mere flat coil, there have been spider coils and loop antenna coils used for Natsukashi's ore radio for a long time, but these flat coils are air-core and have low efficiency, and the winding is troublesome and automatic winding is possible. There was a problem that it was impossible.

According to the present invention, in order to eliminate the above-mentioned problems, a pair of flat ladder-shaped bobbin pieces are attached with a flat core sandwiched between them, and a coil is wound around the outer surface between the bridging pieces. Then, it aims at providing the flat transformer which can maintain the isolation between each coil favorably at low cost.

[0007]

DISCLOSURE OF THE INVENTION The above-mentioned object of the present invention is to provide a plurality of bridging pieces for connecting the outer surfaces of the respective ribs between opposing ribs of a pair of bobbin pieces formed of plastic in a substantially ladder shape. Forming the left and right side plates and fitting the lower half in the thickness direction between the inner edges of the facing ribs, and placing the other half on the upper half in the thickness direction of the one-character flat core This can be achieved by fitting and covering in the same manner as above and winding the coil around the outer surface of the facing rib.

The outer magnetic path core may be fixed between the wide side edges of the flat core, and the terminal plate may be sandwiched between the facing gaps of the left and right side plates of the pair of bobbin pieces.

[0009]

[Function] A pair of bobbin pieces formed by molding plastic into a substantially ladder shape is fitted with the lower half in the thickness direction between the opposing ribs, and the upper half of the one-character flat core in the thickness direction has another bobbin in the upper half. Since the element piece was fitted and covered in the same manner as the above, when winding the coil on the outer surface of the facing rib, the bobbin element piece did not unnecessarily sway or come off with respect to the flat core. It can be wrapped beautifully, neatly and quickly.

Further, since each bridging piece is an insulator made of plastic, good insulation can be maintained between the coils wound between them.

Further, if the outer magnetic circuit core is fixed between the outer edges of both ends of the flat core in the lengthwise direction, a closed magnetic circuit type coil with a core is formed, and its inductance can be increased.

Further, by sandwiching the terminal plates in the facing gaps of the left and right side plates of the pair of bobbin pieces, the lead wire of the coil can be surely processed and mounted on the external circuit member such as the printed circuit board easily. And surely it can be realized.

[0013]

EXAMPLES Examples will be described with reference to the drawings. First, as shown in FIGS. 1 and 2, the basic structure of the present invention is such that a pair of bobbin pieces 1,1 formed by molding a heat-resistant plastic such as a phenol resin into a substantially ladder shape are provided between opposing ribs 2,2 of each of these. Forming a plurality of bridging pieces 3,3 that connect the outer surfaces of the ribs and forming left and right side plates 4,4,
The end portions 2a, 2a of the facing ribs 2, 2 are projected from the inner surface of 4.

The lower half of the flat rib 5 in the thickness direction is fitted and stored between the inner edges of the facing ribs 2, 2 as shown in FIG. Similarly to the above, 1 is fitted and covered as shown in the drawings, and the coil L is wound on the outer surface of the opposed ribs 2, 2 as shown in FIG. 4 to form the flat coil according to the present invention.

If the flat core 5 having an insulating coating is used, it can be used as a coil for high voltage.

Also, the outer edges 5 of both ends of the flat core 5 in the length direction
If the outer magnetic circuit core 6 is fixed between a and 5a as shown in FIG. 7, it becomes a closed magnetic circuit type and the inductance of the coil L can be increased.

Further, if the terminal plate 7 having the terminal pin 7a is sandwiched in the facing gap g between the left and right side plates 4, 4 of the pair of bobbin pieces 1, 1 as shown in FIGS. , L lead wires can be easily and surely executed, and solder mounting on the circuit board P can be easily realized as shown in FIG.

As the bobbin piece 1, a simple ladder-shaped piece as shown in FIG. 8 may be used. If the bobbin element 1 is made symmetrical in the vertical and horizontal directions, the degree of freedom in the joining direction is expanded.

The flat coil of the present invention is constructed as described above, and its operation will be specifically described below. A pair of bobbin pieces made of plastic molded into a ladder shape 1,1
As shown in Fig. 2, the other half of the bobbin element 1 is inserted into the upper half of the flat core 5 in the shape of a letter in which the lower half in the thickness direction is fitted between the facing ribs 2 and Since they are fitted and covered as shown in each figure, when the coil L is wound on the outer surface of the opposing ribs 2,2, the bobbin element 1,1 does not unnecessarily sway or come off with respect to the flat core 5. Therefore, the coil L can be wound beautifully, orderly and quickly.

Further, the insulation between the coils L, L wound between the bridging pieces 3, 3 as shown in FIG. 4 can be maintained well.

Furthermore, the outer edges of both ends of the flat core 5 in the longitudinal direction
If the outer magnetic path core 6 is fixed between 5a and 5a as shown in FIG. 7,
It becomes a coil with a closed magnetic circuit type core, and its inductance can be increased.

If the terminal plate 7 having the terminal pin 7a is sandwiched in the facing gap g of the left and right side plates 4,4 of the pair of bobbin pieces 1,1 as shown in FIG. The lead wire processing can be reliably performed, and mounting on the external circuit member P such as a printed circuit board can be easily and reliably realized.

[0023]

Since the present invention is configured as described above, it has the following effects. The flat coil according to claim 1 has the first effect that a flat coil can be realized as a whole, and since the two ladder-shaped bobbin pieces are fitted to the flat letter-shaped core, the bridging piece of the bobbin is used. The coil can be wound in an orderly and quick manner, and since the two bobbin pieces 1 and 1 are put together, the thickness variation of the flat core 5 can be absorbed well, and there are second and third effects that the mass productivity is excellent.

According to the second aspect, the outer magnetic path core 6 firmly fixed between the outer edges 5a, 5a at both ends of the flat core 5 in the longitudinal direction.
By this, a closed magnetic circuit can be formed together with the flat core 5 with a single letter,
Since the inductance of the flat coil can be increased and the U-shaped outer magnetic circuit core 6 can be supported by the terminal ends 2a, 2a of the opposing ribs 2, 2, the effect of preventing the displacement of each core can be added.

In the third aspect, since the terminal plate 7 having the terminal pins 7a and the like is sandwiched in the facing gap g between the left and right side plates 4,4 of the pair of bobbin pieces 1,1, the leads of the coils L, L are attached. It is possible to add the effect that the line processing can be reliably performed and the mounting on an external circuit member such as a printed circuit board can be easily and surely realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a combination of a bobbin piece and a flat core before winding a coil.

FIG. 2 is a perspective view showing a state immediately before combining the above.

FIG. 3 is a side view of what is shown in FIG.

FIG. 4 is a sectional view taken along the line AA of FIG.

5 is a cross-sectional view taken along line BB of FIG. 3 with the coil wound.

FIG. 6 is a cross-sectional view taken along the disconnection line in FIG.

FIG. 7 is a cross-sectional plan view showing another embodiment of the present invention.

FIG. 8 is a perspective view showing another example of the bobbin piece.

[Explanation of symbols]

 1 Bobbin element 2 Opposing rib 2a Termination 3 Bridging piece 4 Side plate 5 Flat core 5a Wide side edge 6 Outer magnetic path core 7 Terminal plate g Opposing gap L coil

Claims (3)

[Claims] 1. A plurality of bridging pieces (3, 3) connecting the outer surfaces of these ribs (2, 2) of a pair of bobbin pieces (1, 1) formed by molding plastic into a substantially ladder shape are formed between opposing ribs (2, 2). Together with the left and right side plates 4,4, the lower half of the flat rib 5 in the thickness direction is fitted between the inner edges of the facing ribs 2,2. The element piece 1 is fitted and covered in the same manner as described above, and the coil L is attached to the outer surface of the opposing ribs 2, 2.
A flat coil made by winding. 2. The outer edges 5 of both ends of the flat core 5 in the longitudinal direction.
The flat coil according to claim 1, wherein a U-shaped outer magnetic path core 6 is fixed between a and 5a. 3. The left and right side plates 4, 4 of the pair of bobbin pieces 1, 1.
The flat coil according to claim 1 or 2, wherein the terminal plate 7 is sandwiched in the facing gap g of 4.