JPH10163029A - Common mode choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high coupling factor, small size and high mass productivity by providing a soft-magnetic material-made return magnetic path member for magnetically connecting flanges at both ends of a drum coil. SOLUTION: A common choke coil has a square columnar winding and flanges 2, 3 at both ends of the winding with positioning protrusions disposed between the flanges 2, 3 and winding. A soft-magnetic ferrite-made drum core 4 having electrode protrusions 12, 13 on the top faces of the flanges 2, 3 is combined with two coil windings at the winding of the drum core 4 and U-shaped soft-magnetic ferrite-made return magnetic path 7 fitted to the positioning protrusions. Leads 8, 9 at the ends of the first coil winding and leads 10, 11 at the ends of the second coil windings are led out to the electrode protrusions 12, 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a surface mount type common mode choke coil mainly used for noise prevention.

[0002]

2. Description of the Related Art Conventional surface mount type common mode choke coils include those manufactured by a lamination technique,
There is a magnetic core having a square or circular closed magnetic path on which a winding is applied, in particular, a magnetic core formed of a ferrite magnetic core.

FIG. 6 shows an example of a conventional common mode choke coil in which a winding is applied to a conventional closed magnetic circuit core. As shown in FIG. 6, a conventional wound-type common mode choke coil connects the terminal of a toroidal coil 30 having a closed magnetic path core wound to an electrode 32 provided on a case 31, and then connects the toroidal coil 30. Are stored in the case 31. The electrode 32 is an integral part having one end inside the case and the other end outside the case.

[0004]

The common mode choke coil manufactured by the lamination technique is small in size, has high productivity, and is suitable for surface mounting, but has a drawback that the coupling coefficient is low. On the other hand, a wound-type common mode choke coil in which a winding is applied to a closed magnetic circuit core has a high coupling coefficient, but has a disadvantage that it is larger than a common mode choke coil formed by lamination technology and has low mass productivity. Was.

That is, although the winding type common mode choke coil has a high coupling coefficient due to the effect of the closed magnetic circuit core, the toroidal coil 30 is housed in the case 31, so that it has no functionally unnecessary space. Because it was not obtained, the size became large and the mass productivity was poor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small, high-productivity common mode choke coil having a high coupling coefficient.

[0007]

Conventionally, a coil formed by winding a drum core 22 made of a soft magnetic material having flanges 2 and 3 at both ends of a winding part 1 as shown in FIG. It was used as an inductor and the like.

Therefore, in order to solve the above-mentioned problems, the present invention relates to a winding part of a drum core made of a soft magnetic material and having a winding part and flanges formed at both ends of the winding part. By applying a winding and magnetically connecting the collar,
A closed magnetic circuit is formed to increase the coupling coefficient.

That is, a return path body made of a soft magnetic material for magnetically connecting the flanges at both ends of the drum coil is provided. Furthermore,
The outer shape of the return path body is formed in a U-shape in order to minimize the gap between the junction between the return path body and the flange and to simplify the joining operation.

[0010] Further, in order to facilitate the joining operation of the drum core and the return path body, that is, the assembling work, a positioning projection is provided so that the drum core and the return path body are fitted to each other. And between the winding part.

[0011] In addition, a side surface of each of the flanges at both ends of the drum core is provided with two windings wound around a winding portion of the drum core.
By forming the electrodes connecting the lead wires of one or more windings, the electrode attaching process can be minimized and the size can be reduced. Further, by providing the electrode protrusion on the flange of the drum core, the work of attaching the electrodes is further facilitated. Thereby, it is possible to improve mass productivity and reduce costs.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIG. 1 is an external perspective view of a common mode choke coil according to the present invention. FIG. 2 is an external perspective view of a return path body made of a soft magnetic material used for the common mode choke coil of the present invention. FIG. 3 is an external perspective view of a drum core made of a soft magnetic material used for the common mode choke coil of the present invention.

[0014] The common mode choke coil of the present invention comprises:
It has a prismatic winding winding portion 1 and flanges 2 and 3 formed at both ends of the winding portion, and a positioning projection 5 is provided between the flanges 2 and 3 and the winding portion 1. Also, a drum core 4 (FIG. 3) made of soft magnetic ferrite provided with electrode projections 12 and 13 on the upper surfaces of the flanges 2 and 3, and two drums wound around the winding part 1 of the drum core 4. It comprises a coil winding and a return path body 7 (FIG. 2) made of a U-shaped soft magnetic ferrite which fits into the positioning projection.

More specifically, two windings are applied to the winding winding portion 1 of the drum core 4, and furthermore, lead leads 8, 9 at both ends of the first coil winding and the second coil winding. The lead-out leads 10 and 11 at both ends are drawn out to the electrode protrusions 12 and 13, respectively, and are soldered to the electrodes made of conductive coating or plating applied to the end surfaces of the protrusions.

Next, the drum core 4 is fitted to the return magnetic path body 7, and the drum core 4 and the return magnetic path 7 are bonded to each other with an adhesive and joined to complete the common mode choke coil of the present invention (FIG. 1).

According to this embodiment, since the drum core and the U-shaped return path form a closed magnetic path,
Leakage magnetic flux is reduced. Therefore, the first coil and the second coil
The coil has a coupling coefficient comparable to that of a common mode choke coil using a toroidal coil, and can easily realize 0.9 or more (FIG. 4). Also, it was easy to assemble, and the size was reduced to a size almost equal to that of the laminated type.

Although the present embodiment has been described assuming that the number of coils is two, the present invention is effective even if the number of coils is three or more.

[0019]

According to the present invention, a common mode choke coil having a high coupling coefficient, small size and high productivity can be obtained.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a common mode choke coil of the present invention.

FIG. 2 is an external perspective view of a return path body made of a soft magnetic material used for the common mode choke coil of the present invention.

FIG. 3 is an external perspective view of a drum core used in the common mode choke coil of the present invention.

FIG. 4 is a diagram showing a relationship between a frequency and a coupling coefficient of a common mode choke coil having a U-shaped outer shape of a soft magnetic return path body of the present invention.

FIG. 5 is an external perspective view of a drum core used in a conventional common mode choke coil.

FIG. 6 is an explanatory diagram of a configuration of a conventional wound common mode choke coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Winding winding part 2, 3 Flange 4 Drum core (of this invention) 5 Positioning convex part 7 Return path body 8, 9 Lead-out lead part of 1st coil winding 10, 11 2nd coil winding Lead lead portion 12, 13 Electrode convex portion 22 (conventional) drum core 30 Toroidal coil 31 Case 32 Electrode K Coupling coefficient f Frequency

Claims (5)

[Claims] 1. A coil formed by winding a drum core made of a soft magnetic material, and a return path body made of a soft magnetic material for magnetically connecting flanges at both ends of the drum core. Common mode choke coil. 2. A drum core made of a soft magnetic material, a coil wound around a winding part of the drum core, and a return magnetic path body made of a soft magnetic material whose outer shape fitted with the drum core has a U-shape. A common mode choke coil characterized by comprising: 3. The common mode choke coil according to claim 2, wherein the drum core is provided with a convex portion that fits with the return path body. 4. The common mode choke coil according to claim 1, wherein an electrode for connecting a lead wire of the coil is formed on a flange of the drum core. 5. The common mode choke coil according to claim 4, wherein a protrusion for providing an electrode is provided on a flange of the drum core.