JP2001085249A - Line filter and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a line filter which has a flat shape without increasing a space for board mounting. SOLUTION: This line filter is composed of a closed magnetic circuit magnetic core in which the openings of two U-shaped magnetic cores 1 and 2 having the same size and shape are adhered tightly, a winding bobbin 3 attached to the magnetic leg of either of the magnetic cores 1 and 2, and windings 4 and 5 provided on the winding bobbin 3. In this case, a magnetic leg not attached to the winding bobbin 3 in the magnetic cores 1 and 2 is arranged in the underside of the terminals 6, 7, 8, and 9 of the winding bobbin 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line filter mainly inserted into a power supply circuit of an electronic device and the like, which is suitable for preventing the entry and leakage of noise, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A conventional line filter has a structure in which a winding bobbin is mounted on one magnetic leg of a U-shaped magnetic core, and a pair of windings are formed on the winding bobbin. This line filter was inserted into a power supply line and used to prevent a common mode noise component generated between a pair of lines in the power supply line and the ground.

That is, in a line filter, a pair of windings are generated by a line current so that a magnetic flux generated by a line current does not magnetically saturate two U-shaped magnetic cores constituting a closed magnetic circuit. It is configured to cancel out magnetic flux.

FIG. 4 is an explanatory diagram of a conventional line filter. FIG. 4A shows a front view, and FIG. 4B shows a side view. FIG. 4 shows a line filter of a magnetic core vertical type. The structure is such that U-shaped magnetic cores 14 and 15 are tightly fixed by a spring-like holder 17 to form a closed magnetic path, and one of the U-shaped magnetic cores 14 and 15 has a magnetic leg. Is provided with a winding bobbin 16 and the other magnetic leg is connected to terminals 20, 2
It is located in the direction opposite to the protruding direction of 1, 22, and 23, and has a structure of a magnetic core vertical type. Here, when the winding bobbin 16 is mounted on the board, the terminals 20, 21,
All of 22 and 23 are made to penetrate through the board and are subjected to solder processing.
Here, the winding bobbin 16 radiates heat during the above-described soldering process, secures insulation between the windings 18 and 19 and the board, and furthermore, stabilizes the winding bobbin 16 on the board. In order to secure the terminals, the terminals 20, 21, 22, 23 are provided with protrusions in the direction in which they protrude.

FIG. 5 is an explanatory diagram of another example of the conventional line filter. FIG. 5A is a front view, and FIG.
Shows a side view. FIG. 5 shows a line filter of a magnetic core horizontal type. Its structure is U-shaped magnetic core, 14 and 1
5 are tightly fixed by a spring-like holder 17 to form a closed magnetic circuit. A winding bobbin 16 is disposed on one of the magnetic legs of the U-shaped magnetic cores 14 and 15, and the other is formed. The magnetic legs are located in a direction perpendicular to the direction in which the terminals 20, 21, 22, and 23 project, and have a magnetic core horizontal type structure.
Here, when mounting the winding bobbin 16 on the board, all the terminals 20, 21, 22, and 23 are made to penetrate the board and soldered as in the previous example. Here, the winding bobbin 16
Dissipates heat during the soldering process described above, and
In order to secure insulation between the terminals 8 and 19 and the substrate, and to stably fix the winding bobbin 16 on the substrate, terminals 20 and 2 are provided.
Protrusions are provided in the protruding directions of 1, 22, and 23.

Here, the line filter of the magnetic core horizontal type shown in FIG. 5 has a lower profile than the magnetic core vertical type line filter of FIG.

[0007]

The conventional line filter has the following problems. That is, the mounting height on the substrate is increased by the height of the projecting portion of the winding bobbin, and the line filter of the magnetic core vertical type is replaced with the magnetic core horizontal type line filter, whereby the line filter Although the whole becomes a low profile type, there is a problem that one of the magnetic legs of the U-shaped magnetic cores 14 and 15 protrudes in the lateral direction, so that the space for mounting the substrate is increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a line filter which does not increase the space for mounting a substrate and which has a low profile, and a method of manufacturing the same.

[0009]

According to the line filter of the present invention, when two U-shaped magnetic cores having the same size and shape are mounted inside the winding bobbin, the two U-shaped magnetic cores are used. One of the U-shaped magnetic cores is inserted into a through groove of the winding bobbin, and the other magnetic leg is disposed below a surface on which the terminals of the winding bobbin are located. Are closed to form a closed magnetic circuit core, thereby forming a low-profile line filter. That is,
Conventionally, one magnetic leg of two U-shaped magnetic cores is mounted in such a manner as to effectively utilize an empty space between a winding bobbin and a substrate that has existed.

In this case, a magnetic core cover having a U-shaped cross section is disposed on the magnetic leg of the two U-shaped magnetic cores that is not mounted on the winding bobbin, Fixing the two U-shaped magnetic cores by a spring-like holder;
The fixing of the magnetic core cover is performed at the same time. The magnetic core cover can ensure the insulation distance between the board to be mounted and the two U-shaped magnetic cores.

That is, the present invention provides two U-shaped
And a winding bobbin attached to one magnetic leg of the two U-shaped magnetic cores. A line filter comprising a pair of windings provided on a wire bobbin;
The magnetic legs of the U-shaped magnetic cores that are not mounted on the winding bobbin are line filters arranged on the terminal protruding side of the winding bobbin.

The present invention also provides the line filter, wherein, among the two U-shaped magnetic cores, the magnetic leg not mounted on the winding bobbin has a U-shaped cross section. This is a line filter on which a core cover is arranged.

[0013] In the line filter according to the present invention, the fixing of the two U-shaped magnetic cores and the fixing of the magnetic core cover may be performed simultaneously by a spring holder.

The present invention also relates to two U and U of the same size and shape.
The cores of the two U-shaped cores are attached to a winding bobbin to form a closed magnetic circuit core by bringing the openings into close contact with each other. A method of manufacturing a line filter for applying a pair of windings to a winding leg of the two U-shaped magnetic cores, the magnetic legs being not mounted on the winding bobbin, the terminal protruding side of the winding bobbin. The magnetic core cover having a U-shaped cross section is attached to the two magnetic legs which are brought together, and the two U-shaped magnetic cores are fixed and the magnetic core cover is fixed by a spring holder. Is a method of manufacturing a line filter that simultaneously performs

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A line filter according to an embodiment of the present invention and a method for manufacturing the same will be described below.

FIG. 1 is an explanatory diagram of a line filter according to the present invention. FIG. 1A shows a front view, and FIG.
FIG. FIG. 2 is an exploded view of the line filter of the present invention.

In FIG. 1, two U-shaped magnetic cores 1 and 2 are closed to each other with an opening to form a closed magnetic circuit core. Here, one magnetic leg of the two U-shaped magnetic cores 1 and 2 is inserted into the winding bobbin through groove of the winding bobbin 3. The other magnetic legs are connected to terminals 6 of the winding bobbin 3.
7, 8, 9 are disposed on the protruding surface, that is, on the lower side.

Here, the joint portion between the two U-shaped magnetic cores 1 and 2 is flattened by polishing or the like in order to minimize the gap and secure a magnetic contact area. ing. The winding bobbin 3 is made of a resin molded body, and winding bobbin terminals 6 and 7 and winding bobbin terminals 8 and 9 are obtained at both ends by simultaneous molding.

At the center of the winding bobbin 3, there is a projection,
The central projection is provided to ensure insulation between the windings 4 and 5. A central projection through groove is provided below the central projection, and the two U-shaped magnetic cores 1 and 2 are provided.
The magnetic legs are penetrating.

In the winding groove of the winding bobbin 3, a winding 4 and a winding 5 are wound in the same manner on an insulating film copper wire. The lead wires at the start and end of winding are wound around the winding bobbin terminals 6 and 7 or the winding bobbin terminals 8 and 9 provided at both ends of the winding bobbin 3 and soldered.

One magnetic leg of each of the two U-shaped magnetic cores 1 and 2 is inserted into the through groove 10 of the winding bobbin 3, and the other magnetic leg is Is inserted into the central projection through groove 11.

A magnetic core cover 1 shown in FIG.
3 shows two U-shaped magnetic cores 1 and 2 with respect to the magnetic legs of FIG.
It is mounted in the direction shown. The holder 12 simultaneously fixes the U-shaped magnetic cores 1 and 2 and the magnetic core cover 13.

Here, the magnetic core cover 13 is made of a resin molded body, and the holder 12 is made of a metal spring material, for example, a spring stainless steel material.

The magnetic core cover 13 is used for the purpose of ensuring insulation between the mounting substrate and the magnetic legs of the U-shaped magnetic cores 1 and 2, and also serves as a guide when fixing the holder 12. Also have. In particular, the holder 12 holds the U-shaped magnetic core 1.
A spring having a predetermined strength is used so that no gap is formed at the joint between the first and second members.

As described above, according to the line filter of the present invention, the other magnetic legs of the two U-shaped magnetic cores 1 and 2 are connected to the terminals 6, 7, 8, 9 of the winding bobbin 3. Since it was placed on the side,
The board mounting space can be reduced as compared with the conventional magnetic core horizontal type line fill.

FIG. 2 is an exploded view of the line filter of the present invention. As shown in FIG.
And a U-shaped magnetic core 2 are closely adhered to the opening, a magnetic core cover 13 is mounted on the magnetic legs of each of the U-shaped magnetic cores 1 and 2, and a metallic holder 12 is mounted thereon. Thus, a line filter is manufactured.

[0027]

As described above, according to the present invention, a low-profile shape is maintained without increasing the space for mounting the substrate.
A line filter and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a line filter according to an embodiment of the present invention. 1A is a front view, and FIG. 1B is a side view.

FIG. 2 is an assembled development view of the line filter of the present invention.

FIG. 3 is a perspective view of a magnetic core holder of the line filter of the present invention.

FIG. 4 is an explanatory view of a conventional core vertical type line filter. 4A is a front view, and FIG. 4B is a side view.

FIG. 5 is an explanatory view of a conventional core horizontal type line filter. 5A is a front view, and FIG. 5B is a side view.

[Explanation of symbols]

 1,2,14,15 U-shaped magnetic core 3,16 Winding bobbin 4,5,18,19 Winding 10 Winding bobbin through groove 11 Center projection through groove 12,17 Holder 13 Magnetic core cover 6 , 7,8,9,20,21,22,23 terminals

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 41/00 H01F 27/24 E

Claims (4)

[Claims] 1. Two U-shaped magnetic cores having the same dimensions and shape are
A closed magnetic circuit core formed by closely contacting the openings with each other,
A line filter comprising: a winding bobbin mounted on one magnetic leg of the two U-shaped magnetic cores; and a pair of windings applied to the winding bobbin. A line filter characterized in that a magnetic leg of the U-shaped magnetic core, which is not mounted on the winding bobbin, is arranged on a terminal protruding side of the winding bobbin. 2. The line filter according to claim 1, wherein, of the two magnetic legs of the U-shaped magnetic core, the magnetic leg not mounted on the winding bobbin has a U-shaped cross section. A line filter having a core cover disposed thereon. 3. The line filter according to claim 1, wherein the fixing of the two U-shaped magnetic cores and the fixing of the magnetic core cover are performed simultaneously by a spring-like holder. And a line filter. 4. Two U-shaped magnetic cores having the same dimensions and shape,
The openings are brought into close contact with each other to form a closed magnetic circuit core, and one magnetic leg of the two U-shaped magnetic cores is attached to a winding bobbin, and a pair of windings is attached to the winding bobbin. A method of manufacturing a line filter to be applied, wherein magnetic legs of the two U-shaped magnetic cores, which are not mounted on a winding bobbin, are arranged on terminal protruding sides of the winding bobbin, and have a cross section The two U-shaped magnetic cores are fixed to the two magnetic legs attached to each other, and the two U-shaped magnetic cores and the magnetic core cover are simultaneously fixed by a spring-like holder. A method for manufacturing a line filter.