JP2000012341A - Choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a choke coil ensuring lower production costs by reducing the number of production processes. SOLUTION: This choke coil is equipped with a pot-type core 10 incorporating a bottom wall 12 supporting a magnetic core 13 and side walls in a body, wherein two facing steps 14 are formed on the top part of the two facing side walls 11, so that the steps 14 are placed lower in height than the top part of adjacent side walls of the side walls 11. The choke coil is also equipped with a plate core 19, a coil 2, and a U-shaped terminal 30 consisting of a fitting part 301 and connections 302. The U-shaped terminal 30 is fitted and fixed on two facing side ends 191 of the plate core 19 by the fitting part 301. At the same time, the tip of the winding 21 of the coil 2 is wound and soldered on the connections 302. The two facing side ends 191 of the plate core 19 are arranged to correspond to the stop 14 of the two facing side walls 11 of the pot-type core 10. In this situation, the plate core 19 is connected and fixed by fitting of the coil 2 to the magnetic core 13. Thus, the choke coil is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a choke coil, and more particularly, to an SMD choke coil mounted on a substrate surface.

[0002]

2. Description of the Related Art A conventional example of a choke coil will be described with reference to FIGS. FIG. 4 is an exploded perspective view of a conventional example, in which (a) is a perspective view of a pot-type core viewed from above,
(B) is a perspective view of the pot type core viewed from below, (c) is a perspective view of a plate core, and (d) is a perspective view of a coil.
FIG. 5 shows the assembled choke coil.
(A) is a perspective view thereof, and (b) is a line A- in (a).
It is a figure which shows the longitudinal cross section along A '.

[0003] In Figs. 4 and 5, reference numeral 10 denotes an entire pot type core. Reference numeral 11 denotes a pair of side walls facing each other among four side walls of the pot-shaped core 10, reference numeral 12 denotes a bottom wall, and reference numeral 13 denotes a magnetic core. Reference numeral 3 denotes a terminal, and a through hole indicated by 31 is formed in the terminal 3 so as to penetrate the bottom wall 12 as well.
Reference numeral 2 denotes a coil, which comprises a winding 21 and a winding 22
It consists of windings. 19 is a plate core.

[0004] The pot type core 10 is made of ferrite.
The mold is filled with the ferrite fine powder and pressurized, and the four side walls including the opposed two side walls 11, which are the main body of the core, the bottom wall 12, and the magnetic core 13 standing upright from the bottom wall 12 are integrally formed. The pot-shaped core press-formed body made of the ferrite fine powder is then fired at a high temperature to form a ferrite pot-shaped core 10. Similarly, the plate core 19 is formed by press-molding and firing ferrite fine powder.

[0005] At four corners below the pot-shaped core 10, side walls 1 are provided.
The terminal 3 is formed from 1 to the bottom wall 12. The terminal 3 is formed by applying a metal powder paste from the side wall 11 to the bottom wall 12 of the ferrite pot type core 10 and baking. As described above, the through hole 31 is formed in the terminal 3 so as to pass through the bottom wall 12 as well. The coil 2 is a common mode choke coil in which two windings 21 and 22 are fitted to the magnetic core 13 to form a four-terminal two-circuit coil.

To assemble a choke coil using the above components, first, a pot-shaped core 10 and a coil 2 are prepared, and the coil 2 is fitted to a magnetic core 13 standing upright on a bottom wall 12 of the pot-shaped core 10. Combine. In a state where the coil 2 is fitted to the magnetic core 13, a total of four ends of the two windings 21 and 22 of the coil 2 are slightly protruded from the bottom wall 12 to the outside through the through holes 31. The portion where the leading end of the winding 22 is projected from the bottom wall 12 to the outside is a fired region of the terminal 3, where the soldering between the terminal 3 and the leading end of the winding 22 is performed. Finally, the plate core 19 is bonded and fixed to the open end of the pot-shaped core 10 by applying a thermosetting adhesive.

[0007]

In the above choke coil, a metal powder paste is applied from the side walls 11 to the bottom wall 12 at the lower four corners of the pot-shaped core 10, and then the terminals are attached to the surface of the bottom wall 12 by baking. Form 3 The step of forming the terminal 3 includes a step of applying a metal powder paste to the bottom wall 12 of the pot-shaped core 10, a step of firing the pot-shaped core 10 coated with the metal powder paste, cooling after firing, and other steps. Including, it accounts for a large proportion of the whole choke coil in the manufacturing process, and has a great influence on the manufacturing cost.

The actual outer dimensions of the pot-shaped core 10 are approximately 14 × 14 × 4 mm. A pot-shaped core 10 having such an external dimension that is not necessarily large
When the distal end of the winding 22 is projected through the through hole 31 of the terminal 3 formed at this point, and the terminal 3 and the distal end of the winding 22 are soldered here, the unsoldered state of incomplete soldering There is a great possibility that a solder connection will be made. in this case,
Since the area to be soldered and the members to be soldered are minute, it is extremely difficult to visually check whether or not the terminal 3 and the end of the winding 22 are securely soldered.

The present invention provides a choke coil that solves the above-mentioned problems.

[0010]

Means for Solving the Problems Claim 1 is provided with a pot type core 10 in which a bottom wall 12 and a side wall 11 on which a magnetic core 13 is erected are integrally formed, and upper ends of two side walls 11 facing each other are adjacent. A step portion 14 which is extremely slightly lower than the upper end portions of both side walls is formed, and a plate core 19 is provided;
A terminal 30 having a coil 2 and comprising a fitting portion 301 and a connecting portion 302 formed integrally with the fitting portion 301;
The terminal 30 having a U-shaped cross section is fitted and fixed to two opposing side edges 191 of the plate core 19 via a fitting portion 301, and a winding portion 21 of the coil 2 is connected to the connection portion 302. The two side edges 191 of the plate core 19 facing each other, into which the U-shaped terminals 30 are fitted and fixed, are connected to the stepped portions 14 of the two opposite side walls 11 of the pot-shaped core 10. In this state, the coil 2 was fitted to the magnetic core 13 to form a choke coil in which the plate core 19 was fixedly joined to the open end of the pot-shaped core 10.

Claim 2: In the choke coil described in claim 1, the coil 2 comprises a four-terminal two-circuit composed of a magnetic core 13 fitted with two windings 21 and 22. A choke coil, which is a common mode coil, was configured. Claim 3: In the choke coil described in claim 1, the coil 2 is a magnetic core 13
A choke coil, which is a two-terminal one-circuit normal mode coil composed of a single winding 21 fitted to the coil, is formed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view of an embodiment, in which (a) is a perspective view of a pot-type core viewed from above,
(B) is a perspective view of the pot type core viewed from below, (c) is a perspective view of a plate core, (d) is a perspective view of a coil,
(E) is a figure which shows the cross section of a terminal and its fitting fixed part. 2A and 2B are views showing the assembled choke coil, FIG. 2A is a perspective view thereof, and FIG. 2B is a line A in FIG.
It is a figure which shows the longitudinal cross section along -A '.

1 and 2, FIG. 4 and FIG.
The same reference numerals are given to the members common to the members in. Here, reference numeral 30 denotes a U-shaped terminal, and a fitting portion 301 and a connecting portion 3 formed integrally with the fitting portion 301.
02. The U-shaped terminal 30 is formed by cutting and plastically processing a thin sheet metal. In this embodiment, the coil 2 includes two windings 21 fitted to the magnetic core 13.
And a four-terminal two-circuit coil constituted by a winding 22 and a common mode choke coil.

The pot type core 10 is made of ferrite.
The mold is filled with ferrite fine powder and pressurized, and four side walls including two side walls 11 facing each other as a main body of the core and a bottom wall 1 are formed.
2 and a magnetic core 13 standing upright from the bottom wall 12 are integrally molded. The pot-shaped core press-formed body made of the ferrite fine powder is then fired at a high temperature to form a ferrite pot-shaped core 10. In this example,
The upper end of the two opposing side walls 11 is slightly lower in height than the upper ends of the adjacent side walls by an amount corresponding to the thickness of the sheet metal forming the U-shaped terminal 30. It has been. Similarly, the plate core 19 is formed by press-molding and firing ferrite fine powder.

In this embodiment, a U-shaped terminal 3
0 denotes two opposite side edges 19 of the plate core 19.
1 are fitted and fixed to each other through the fitting portions 301 near both ends. In order to assemble a choke coil using the above components, first, the plate core 19 and the U-shaped terminal 30 are prepared, and the U-shaped terminal 30 is connected to the two side edges 191 of the plate core 19 facing each other. Are fitted and fixed via fitting portions 301 in the vicinity of both ends. Then, the coil 2 is prepared, and a total of four ends of the winding 21 and the winding 22 of the coil 2 are wound around the connecting portion 302 of the U-shaped terminal 30 fitted and fixed to the plate core 19 and soldered. . Next, the pot-shaped core 10 is prepared, and the opposing two side edges 191 of the plate core 19 to which the U-shaped terminals 30 are fitted and fixed are connected to the step 14 of the opposing two side walls 11 of the pot-shaped core 10. In the state corresponding to
The coil 2 attached to the plate core 19 is fitted to the magnetic core 13 erected on the pot core 10 via the U-shaped terminal 30 so that the plate 2 The core 19 is bonded and fixed by applying a thermosetting adhesive.

Referring to FIG. 3, another embodiment will be described.
In this embodiment, the coil 2 is attached to the magnetic core 13 by one winding 21.
Are fitted to form a two-terminal one-circuit normal mode choke coil. The embodiment of FIG. 3 differs from the embodiment of FIG. 2 using a common mode choke coil in this respect. Correspondingly, the U-shaped cross-section terminals 30 are fitted and fixed one by one to two opposing side edges 191 of the plate core 19 via the fitting portions 301.

[0017]

As described above, according to the present invention, the U-shaped cross-section terminal is formed by cutting and plastically processing a thin sheet metal so that the fitting portion and the connecting portion can be integrally and extremely easily and inexpensively. It can be easily assembled by fitting this to the plate core via the fitting portion.
The connection between the U-shaped terminal and the end of the winding of the coil is performed by winding the end of the winding around the connection portion and soldering, so that the connection is performed electro-mechanically firmly, and the solder is securely inserted. Confirmation as to whether or not it is attached can be easily performed visually.

Further, by changing the number of the coils and the corresponding number of the U-shaped terminals 30 corresponding thereto, a common mode choke coil and a normal mode choke coil can be formed using the pot type core and the plate core in common. Therefore, the number of manufacturing steps of the common mode choke coil and the normal mode choke coil can be reduced by the amount that the core can be commonly used, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating an embodiment.

FIG. 2 shows the assembled version of the embodiment of FIG. 1;

FIG. 3 is an exploded perspective view illustrating another embodiment.

FIG. 4 is an exploded perspective view illustrating a conventional example.

FIG. 5 shows an assembled version of the embodiment of FIG.

DESCRIPTION OF SYMBOLS 10 Pot-type core 11 Side wall 12 Bottom wall 13 Magnetic core 14 Stepped portion 19 Plate core 191 Side edge 2 Coil 21 Winding 22 Winding 3 Terminal 30 U-shaped terminal 31 Through hole 301 Fitting portion 302 Connection Department

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[Procedure amendment]

[Submission date] June 11, 1999 (1999.6.1
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010]

Means for Solving the Problem A rectangular port type core 10 integrally formed with a bottom wall 12 and a side wall 11 on which a magnetic core 13 is erected is provided. the upper end surface of the side wall 11 is recessed portion 14 which is only slightly lower compared to the upper end face of the adjacent side walls are formed, comprises a rectangular plate core 19, comprises a coil 2, a U-shaped fitting portion 301 and its
On the other hand provided with a U-shaped cross section type terminal 30 made of connecting portion 302 formed integrally at a right angle therewith a free end of the leg portion, the cross-sectional <br/> face shape type terminal 30 is the rectangular plate core The fitting portion 301 is fitted on the two side edges 191 facing each other.
To the connection portion 302 is fixed in the distal end portion of the winding 21 of the coil 2 is solderability, the U-shaped cross section
The thickness of the mold terminal 30 and the depth of the concave portion 14 are substantially equal.
And each of the U-shaped terminals 30 is connected to the square pot.
It is located in the concave portion 14 of the two side walls of the mold core 10 and
In a state in which the inner surface and brought close correspondence of the serial connecting portions 302 and the second side wall 11, the <br/> the coil 2 to the opening end face of the rectangular pot core 10 by fitting to the magnetic core 13 A choke coil in which the plate core 19 was fixed was constructed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 15/10 F

Claims (3)

[Claims] 1. A pot-type core having a bottom wall and a side wall on which a magnetic core is erected is integrally formed, and upper ends of two side walls opposed to each other are slightly smaller than upper ends of adjacent side walls. A plate-shaped core, a coil, a fitting portion and a connecting portion integrally formed with the fitting portion, a U-shaped cross-section terminal, and a U-shaped cross section. The terminals are fitted and fixed to the two opposing side edges of the plate core via the fitting portions, and the connecting portions are wound with the ends of the coil windings and soldered. The coil is fitted to the magnetic core in a state where the two opposing side edges where the mold terminals are fitted and fixed correspond to the two opposing side walls of the pot type core, and the open end of the pot type core. The plate core is fixed to the Kukoiru. 2. The choke coil according to claim 1, wherein the coil is a common mode coil composed of a four-terminal two-circuit formed by fitting two windings to a magnetic core. And choke coil. 3. The choke coil according to claim 1, wherein the coil is a two-terminal one-circuit normal mode coil comprising a magnetic core and one winding fitted thereto. .