JPH07211547A - Line filter - Google Patents

Abstract

PURPOSE:To provide a small-size and high-performance line filter which is inserted into a power circuit of various kinds of electronic apparatuses and prevents the incoming and leakage of noise. CONSTITUTION:A two-piece dividable coil bobbin 4 which has a projection 2 formed on its collar is assembled into a monoblock letter-shaped closed magnetic circuit magnetic core 1 and then a pair of coils 5 are wound around the bobbin 4. This is fixed with a core band 8 which has a plurality of engagement teeth. Due to this structure, a stable and small-size line filter which hardly has the deterioration in inductance with the passage of time without using an adhesive can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line filter which is inserted in a power supply circuit of electronic equipment to prevent noise from entering and leaking.

[0002]

2. Description of the Related Art Generally, a line filter is mainly used to prevent a common mode noise component generated between a pair of lines in a power supply line and ground, and its electric circuit diagram is shown in FIG. That is, the line filter includes the pair of windings 11 so that the magnetic flux generated by the line current does not magnetically saturate the magnetic core 12 forming the closed magnetic circuit.
Are configured so that the magnetic fluxes generated by the line currents cancel each other out.

As an example of a concrete structure of the line filter, as shown in FIGS. 11 and 12, one of the square-shaped closed magnetic circuit magnetic cores 13 made of a magnetic material having a high magnetic permeability such as ferrite or the like is provided on one magnetic leg. 2 on the center magnetic leg of the closed magnetic circuit core 14
Winding bobbin 15 made of resin molded body divided
And a pair of windings 11 are formed on the winding bobbin 15 by rotating the winding bobbin 15 using the gear portion 16 provided on the end surface or the central portion of the winding bobbin 15.

Next, the metal terminal 17 is inserted into the insertion hole provided in the flange portion of the winding bobbin 15 or the metal terminal 17 is inserted.
The terminal plate 18 made of the resin molded body is attached to the constituent body made of the magnetic cores 13 and 14 and the winding bobbin 15, and the winding lead is wound around the metal terminal 17 and connected by soldering or the like. Finally, in order to prevent the magnetic cores 13 and 14, the winding bobbin 15, and the terminal plate 18 from rattling, an adhesive 19 is used to fix them to form a line filter.

[0005]

In the line filter having the above structure, the terminal plate 18 is attached, so that the bottom area and the volume are large, and since the adhesive 19 is used for fixing, the adhesive curing is performed. The stress in is magnetic core 1
3 and 14, magnetic strain was generated in the magnetic cores 13 and 14, and deterioration of the inductance with time of about 5 to 30% occurred.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide a compact and high-performance line filter.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is provided on one magnetic leg of a closed-type closed magnetic circuit magnetic core with an integrated mouth or on a central magnetic leg of a closed closed magnetic circuit magnetic core of an integrated type. A pair of windings are attached to a two-division winding bobbin that is mounted and has protrusions on the flanges at both ends, and the closed magnetic circuit core and the gear portion provided at the center of the winding bobbin are provided with a plurality of engaging teeth. It is configured to be fixed by the core band that it has.

Alternatively, it is mounted on one magnetic leg of the closed-ended closed magnetic circuit core of the integral type or on the central magnetic leg of the closed closed magnetic circuit core of the integrated Japanese letter-shaped, the protrusions on both ends of the flange and the flanges on both ends. A pair of windings are formed on a two-divided winding bobbin having a plurality of grooves on the outer side surface of the core, and a core holder is inserted into the plurality of grooves on the outer side surface of the flange part at both ends of the closed magnetic circuit core and the winding bobbin. It is fixedly configured.

[0009]

With the above construction, the bottom area and volume of the line filter can be made small, and the closed magnetic circuit core and the winding bobbin can be fixed without using an adhesive, so that the deterioration of inductance due to adhesion over time can be prevented. It is possible to provide a high-performance line filter that does not have this.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIGS. 1 and 2 are perspective views of vertical and horizontal line filters according to a first embodiment of the present invention.
3 (a) is a front view of the core band, FIG. 3 (b) is a sectional view taken along the line AA 'of the core band, and FIG. 3 (c) is a bottom view of the core band.

As shown in FIG. 1, on one magnetic leg of a closed magnetic circuit core 1 having a square shape of an integral type and made of a high magnetic permeability material such as ferrite, two to six protrusions 2 are provided on the flanges at both ends. Two semicircular winding bobbins 4 made of a resin molded body having a gear portion 3 provided at the center or the end face are fitted and fixed by sandwiching two magnetic bobbins 4 with one magnetic leg in between.

Next, by rotating the gear part 3 of the winding bobbin 4 from the outside, the winding bobbin 4 is rotated, and the insulating coating copper wire is provided in the two winding grooves of the winding bobbin 4. A pair of windings 5 are wound in the direction. The winding start and winding end lead wires 6 are wound around metal terminals 7 which are inserted and fixed after winding in through holes provided in the flanges of both ends of the winding bobbin 4, and are connected by soldering or the like. Alternatively, before winding, the metal terminal 7 is inserted into the winding bobbin 4 for winding, and after winding, the metal terminal 7 is moved by a required length to be a printed circuit board insertion terminal, and the winding start and winding are performed. The end lead wire 6 may be connected to the metal terminal 7.

Next, the core band 8 for fixing the assembly structure of the integral mouth-shaped closed magnetic circuit magnetic core 1, the winding bobbin 4, and the winding 5 will be described with reference to FIGS. 3 (a) to 3 (c). .

The core band 8 is composed of a U-shaped magnetic core fixing portion 8a and a ring-shaped bobbin fixing portion 8b made of an elastic synthetic resin, and the magnetic core fixing portion 8a of the bobbin fixing portion 8b.
The separation portion 8c is formed in a portion facing
Has a plurality of engaging teeth 8d in the vicinity of the
c has an engaging claw 8e that can be engaged.

The closed magnetic circuit core 1 and the winding bobbin 4 are engaged along the outside of a gear portion 3 provided in the central portion along a core band 8, and the engaging teeth 8d of the core band 8 are attached to the gear portion 3. The core band 8 is fixed by engaging the engaging claws 8e with each other. The direction of the core band 8 can also be used in a structure in which the closed magnetic circuit magnetic core 1 is horizontally incorporated as shown in FIG.

(Embodiment 2) FIGS. 4 and 5 are perspective views of vertical and horizontal line filters according to a second embodiment of the present invention.
FIG. 6 is a perspective view of the core band.

The core band 9 has a U-shaped magnetic core fixing portion 9a engaged with the closed magnetic circuit magnetic core 1 and an arcuate bobbin fixing portion 9b.
And a plurality of engaging teeth 9d on the inner peripheral surface of the arc of the bobbin fixing portion 9b, and the core band 9 is made of an elastic resin molding.

A core band 9 is inserted between the closed magnetic circuit magnetic core 1 and a gear portion 3 provided in the central portion of the winding bobbin 4, and engaging teeth 9d of a bobbin fixing portion 9b are engaged with the gear portion 3 to engage them. Then, the winding bobbin 4 is fixed to the closed magnetic circuit core 1.

The direction of the core band 9 can be applied to a horizontal line filter as shown in FIG.

(Embodiment 3) FIGS. 7 and 8 are perspective views of vertical and horizontal line filters according to a third embodiment of the present invention.
FIG. 9 is a perspective view of the core fixture.

The core fixture 10 is assembled so as to cover the closed magnetic circuit magnetic core 1, and the open end face 10a thereof is inserted into the groove portions 4a provided on the outer side surfaces of the flange portions at both ends of the winding bobbin 4 to form the winding bobbin. 4 is fixed to the closed magnetic circuit magnetic core 1.

The core fixture 10 can be applied to a horizontal line filter as shown in FIG.

In each of the above-mentioned embodiments, the closed magnetic circuit core 1 is shown as an integral type V-shaped magnetic core, but an integrated type Japanese closed magnetic circuit magnetic core is used, and the central magnetic leg of this closed magnetic circuit core is used. Two
It is also possible to incorporate a split type winding bobbin.

[0025]

With the above-mentioned structure, the present invention provides
A closed magnetic circuit core and a winding bobbin are provided by a core band or a core fixing tool by using the gear part provided on the closed magnetic circuit core and the winding bobbin or the grooves provided on the outer side surfaces of the collar at both ends of the magnetic core and the winding bobbin. By fixing, the stress applied to the closed magnetic circuit core due to hardening of the adhesive agent can be removed, the inductance hardly changes over time, and both can be securely fixed without any rattling, improving quality and improving the performance of the line filter. It will be possible. Further, the workability of assembling is good, and it can contribute to downsizing of the line filter, which is of great industrial value.

[Brief description of drawings]

FIG. 1 is a perspective view of a vertical line filter according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the horizontal line filter.

3A is a front view of the core band in the same embodiment, FIG. 3B is a sectional view of the core band, and FIG.

FIG. 4 is a perspective view of a vertical line filter according to a second embodiment of the present invention.

FIG. 5 is a perspective view of the horizontal line filter.

FIG. 6 is a perspective view of a core band in the same embodiment.

FIG. 7 is a perspective view of a vertical line filter according to a third embodiment of the present invention.

FIG. 8 is a perspective view of the horizontal line filter.

FIG. 9 is a perspective view of a core holder according to the embodiment.

FIG. 10 is a circuit diagram of a general line filter.

FIG. 11 is a perspective view of a conventional line filter.

FIG. 12 is a perspective view of a conventional line filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed magnetic circuit magnetic core 2 Projection part 3 Gear part 4 Winding bobbin 4a Groove part of winding bobbin 5 Winding 6 Lead wire 7 Metal terminal 8 Core band 8a Magnetic core fixing part 8b Bobbin fixing part 8c Separation part 8d Engaging tooth 8e engagement Synthetic claw 9 Core band 9a Magnetic core fixing part 9b Bobbin fixing part 9d Engaging tooth 10 Core fixing tool 10a Open end surface

Continued Front Page (72) Inventor Shunpachi Inoue 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A two-divided type, which is mounted on one magnetic leg of a closed-ended magnetic circuit core with an integrated mouth or on a central magnetic leg of a closed closed-circuit magnetic core with an integrated Japanese character, and is provided with protrusions at both end flanges. A line filter comprising a winding bobbin provided with a pair of windings, and a closed magnetic circuit core and a gear portion provided in a central portion of the winding bobbin fixed by a core band having a plurality of engaging teeth. 2. The integral type V-shaped closed magnetic circuit magnetic core is mounted on one magnetic leg or on the central magnetic leg of the integrated Japanese V-shaped closed magnetic circuit magnetic core, and the flanges at both ends are provided with protrusions and the flanges at both ends. A pair of windings are formed on a two-divided winding bobbin having a plurality of grooves on the outer side surface of the core, and a core holder is inserted into the plurality of grooves on the outer side surface of the flange part at both ends of the closed magnetic circuit core and the winding bobbin. A fixed line filter.