JPH10294221A - Inductance element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate generation of an eddy current of a metal plate terminal and reduce magnetic loss to improve the energy conversion efficiency, by arranging a metal plate terminal on a cylindrical magnetic material core located with a spacing on the periphery of a drum core of a magnetic material, and thus forming an inductance element. SOLUTION: A metal plate terminal 16 made of a band-shaped metal piece is formed in a U-shape so as to extend on the bottom, lateral and top sides along the outer surface of a magnetic material core 12. A pair of metal plate terminals 16 are cut so that these metal plate terminals are located within the thickness of the magnetic material core 12, with the distal ends thereof not protruding inward, and then, metal plate terminals are fitted in the magnetic material core 12 and fixed on the outer surface. The end of the metal plate terminal 16 on the top side of the magnetic material core 12 is divided into three parts. A center part extends on the surface of a deep portion of a recess 17, and both lateral parts extend on the surface of a shallow portion of the recess 17. An adhesive or the like is filled in a void between the inner surface of the magnetic material core 12 and the lateral surfaces of brims 14A, 14B of a drum core 11, thus fixing the magnetic material core 12 and the drum core 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an inductance element used for a DC / DC converter circuit, a power supply circuit and the like.

[0002]

2. Description of the Related Art FIG. 6 is a top view of a conventional inductance element, and FIG. 7 is a sectional view of FIG. The conventional inductance element includes a drum core 61 on which a ferrite is formed and fired to form a winding 63 on a resin base 67 having a metal plate terminal 66, and a so-called ring core 62 is provided around the drum core 61 at intervals. Place. Thus, a magnetic path is formed by the drum core 61 and the ring core 62. FIG. 8 is a bottom view of another conventional inductance element.
FIG. 9 is a sectional view of FIG. This inductance element does not use a resin base, unlike the above-described one. A metal plate terminal 86 is fixed to the bottom surface of a drum core 81 formed and fired with ferrite.
1, a winding 83 is applied, and a ring core 82 is arranged around the drum core at intervals. Thereby, a magnetic path is formed by the drum core 81 and the ring core 82.

[0003]

These conventional inductance elements are composed of a drum core 61, 81 and a ring core 6.
Since the metal plate terminals 66, 86 extend across the gap between the metal plate terminals 2, 82, an eddy current is generated in the metal plate terminals 66, 86 by magnetic flux leaking from the drum cores 61, 81. Therefore, there is a problem that magnetic loss occurs due to the eddy current and energy conversion efficiency between input and output deteriorates. Also, as shown in FIGS. 8 and 9, the inductance element having the metal plate terminal 86 fixed to the bottom surface of the drum core 81 has the metal plate terminal 86 exposed on the bottom surface of the drum core 81. When mounted, there is a risk of short-circuiting with the wiring pattern provided at the bottom position of the inductance element. Therefore, the printed circuit board of the electronic device cannot provide a wiring pattern at the position of the bottom surface of the inductance element, and there is a problem that the position of the bottom surface of the inductance element becomes a dead space and the size of the electronic device becomes large. An object of the present invention is to provide an inductance element that can reduce the magnetic loss of the inductance element to improve the energy conversion efficiency between input and output, and can eliminate dead space on a printed circuit board of an electronic device on which the inductance element is mounted. With the goal.

[0004]

The inductance element according to the present invention solves the above-mentioned problem by forming a metal plate terminal on a cylindrical magnetic core disposed at a distance around a drum core. is there. That is, the metal plate terminal extends from the bottom surface to the surface along the outer surface of the magnetic core, and is fixed to the magnetic core such that its tip is located within the thickness of the magnetic core, or the outer surface of the magnetic core. And is fixed to the magnetic core such that the tip on the bottom side is located within the thickness of the magnetic core.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inductance element of the present invention
Instead of providing a metal plate terminal on the base or the drum core as in the prior art, the magnetic material extends from the bottom surface to the surface along the outer surface of the cylindrical magnetic core arranged at intervals around the drum core. The metal plate terminal is fixed so that the tip is located within the thickness of the core. In addition, the inductance element of the present invention includes a cylindrical magnetic core arranged at intervals around the drum core without providing terminals on the base or the drum core as in the conventional case, and has a bottom surface and side surfaces along the outer surface thereof. And is fixed to the magnetic core so that the tip on the bottom side is located within the thickness of the magnetic core.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an inductance element according to the present invention will be described below with reference to FIGS. FIG. 1 is a top view of a first embodiment of the inductance element of the present invention, FIG. 2 is a bottom view of FIG. 1, and FIG. 3 is a sectional view of FIG. 1 to 3, reference numeral 11 denotes a drum core, 12 denotes a cylindrical magnetic core, and 13 denotes a winding. The drum core 11 is formed by sintering magnetic powder such as ferrite, and is provided with disk-shaped flanges 14A and 14B at both ends of a cylindrical winding shaft. Tsuba 14A, 1
4B is a pair of cuts 15A at opposing positions,
15B are provided. The cylindrical magnetic core 12 is
This is a so-called ring core formed by sintering magnetic powder such as ferrite into a cylindrical shape. A pair of recesses 17 is formed on the upper surface, and a pair of metal plate terminals 16 as described later are formed along the outer surface. Provided. The recess 17 is provided with a step to form a shallow portion and a deep portion. The metal plate terminal 16
A strip-shaped metal piece is used, and is formed in a U-shape so as to extend along the outer surface of the magnetic core 12 to the bottom surface, the side surface, and the upper surface. The pair of metal plate terminals 16 formed in the U-shape are
The magnetic core 12 can be formed without its tip protruding to the inner surface.
It is cut so as to be located within the thickness of the magnetic core 12, is fitted into the magnetic core 12, and is fixed to the outer surface. In addition, this metal plate terminal 1
The upper end of the magnetic core of No. 6 is divided into three portions, the middle portion of which extends to the surface of the deep portion of the recess 17, and the portions on both sides are shallow of the recess 17. Extending to the surface of the part. Inside the magnetic core 12, a drum core 11 provided with a winding 13 is concentric and has a flange 14A,
4B and the inner surface of the magnetic core 12 are arranged so as to have a gap. The magnetic core 12 and the drum core 11
Are the inner surface of the magnetic core 12 and the flange 14 of the drum core 11
A and 14B are fixed to each other by filling the gap between the side surfaces with an adhesive or the like. Then, the lead of the winding 13 is pulled out from the recesses 15A and 15B of the flange 14A, inserted into the recess 17 of the magnetic core 12, and connected to one end of the terminal 16 by solder or the like. The inductance element formed in this manner is mounted on a printed circuit board of an electronic device such that one end of the metal plate terminal 16 to which the lead of the winding 13 is connected faces upward, and the other end of the metal plate terminal 16 is printed. Connected to the wiring pattern on the board.

FIG. 4 is a top view of a second embodiment of the inductance element according to the present invention. The pair of metal plate terminals 46 fixed to the cylindrical magnetic core 42 are formed in a U-shape, and are cut so that their tips are located within the thickness of the magnetic core 42. An erection 46A is provided at one end located on the upper surface of 42. The magnetic core 42 provided with the pair of metal plate terminals 46 has the drum core 41 disposed concentrically inside and fixed to each other. The winding leads 43A and 43B (partially omitted in the drawing) of the winding wound around the drum core 41 are connected to the connecting portions 46A of the metal plate terminals 46.
And connected by solder. The inductance element formed in this manner is mounted on a printed circuit board of an electronic device such that one end of a metal plate terminal 46 provided with a barb 46A faces upward, and the other end of the metal plate terminal 46 is connected to a wiring pattern. Connected to

FIG. 5 is a sectional view of a third embodiment of the inductance element according to the present invention. A pair of metal plate terminals 56 fixed to the cylindrical magnetic core 52 are formed in an L-shape so as to extend to the bottom surface and the side surface of the magnetic core 52, and a tip on the bottom surface side of the magnetic core 52. Is cut so as to fit within the thickness without protruding from the inner surface of the magnetic core 52. And
The lead of the winding 53 wound around the drum core 51 is drawn out to the bottom side of the magnetic core 52 and connected to the metal plate terminal 56.

Although the embodiments of the inductance element of the present invention have been described above, the present invention is not limited to these embodiments. For example, the cylindrical magnetic core may have various shapes as long as the inside is hollow. Also,
In the first embodiment, the recess on the upper surface of the cylindrical magnetic core may not have a step. In that case, the end of the metal plate terminal on the upper surface side of the magnetic core is divided into three parts, the middle part extends to the concave surface, and both side parts extend to the upper surface of the magnetic core. . Further, in the first embodiment, the lead of the winding may be connected to the other end of the metal plate terminal connected to the wiring pattern of the printed circuit board of the electronic device. Further, in the first embodiment, a stepless recess is provided on the bottom surface of the cylindrical magnetic core, and the end of the metal plate terminal on the bottom surface side of the magnetic core is divided into three portions to form a middle portion. Is extended to the surface of the recess, both sides are extended to the upper surface of the magnetic core, the lead of the winding is connected to the middle part, and both sides are connected to the wiring pattern of the printed circuit board of the electronic device. You may make it. Further, in the second embodiment, the metal plate terminal may be provided with a barb on the other end side connected to the wiring pattern of the printed circuit board of the electronic device.

[0010]

As described above, in the inductance element of the present invention, the metal plate terminal is provided on the cylindrical magnetic core disposed at intervals around the magnetic drum core. The metal plate terminal extends from the bottom surface to the surface along the outer surface of the magnetic core, and is fixed such that its tip is located within the thickness without protruding toward the inner surface of the magnetic core. Extending along the outer surface along the bottom surface and the side surface, and is fixed so that the tip on the bottom surface side is located within the thickness without protruding toward the inner surface side of the magnetic core, so that the tip of the magnetic core has escaped from the conventional drum core. No eddy current is generated in the metal plate terminal by the magnetic flux. Therefore, the inductance element of the present invention can reduce the magnetic loss and improve the energy conversion efficiency. Further, according to the present invention, since the area of the portion of the metal plate terminal located on the bottom surface of the inductance element can be made smaller than that of the conventional one, a wiring pattern is provided at the position of the bottom surface of the inductance element on the printed circuit board of the electronic device. To eliminate dead space.

[Brief description of the drawings]

FIG. 1 is a top view of a first embodiment of the inductance element of the present invention.

FIG. 2 is a bottom view of FIG.

FIG. 3 is a sectional view of FIG. 1;

FIG. 4 is a top view of a second embodiment of the inductance element of the present invention.

FIG. 5 is a sectional view of a third embodiment of the inductance element of the present invention.

FIG. 6 is a top view of a conventional inductance element.

FIG. 7 is a sectional view of FIG. 6;

FIG. 8 is a bottom view of another conventional inductance element.

FIG. 9 is a sectional view of FIG.

[Explanation of symbols]

 11 Drum core 12 Cylindrical magnetic core 13 Winding

Claims (8)

[Claims] 1. A magnetic drum core to which a winding is applied, a cylindrical magnetic core which is spaced around the drum core, and a metal plate terminal to which a lead of the winding is connected, The metal plate terminal extends from the bottom surface to the surface along the outer surface of the magnetic core, and is fixed to the cylindrical magnetic core such that the tip is located within the thickness of the magnetic core. An inductance element characterized by the above-mentioned. 2. A magnetic drum core to which a winding is applied, a cylindrical magnetic core arranged at intervals around the drum core, and a metal plate terminal to which a lead of the winding is connected, The metal plate terminal extends to the bottom surface and the side surface along the outer surface of the magnetic core, and is fixed to the cylindrical magnetic core such that the tip on the bottom surface is located within the thickness of the magnetic core. An inductance element characterized in that: 3. A magnetic drum core to which a winding is applied, a cylindrical magnetic core disposed at intervals around the drum core, and a metal plate terminal to which a lead of the winding is connected, The metal plate terminal is formed in a U-shape so as to extend from the bottom surface to the surface along the outer surface of the magnetic core, and the cylindrical shape is formed such that the tip is located within the thickness of the magnetic core. An inductance element fixed to a magnetic core. 4. A magnetic drum core to which a winding is applied, a cylindrical magnetic core spaced around the drum core, and a metal plate terminal to which a lead of the winding is connected, The metal plate terminal is formed in an L shape so as to extend from the bottom surface to the side surface along the outer surface of the magnetic core, and the cylindrical shape is such that the tip is located within the thickness of the magnetic core. An inductance element fixed to a magnetic core. 5. A magnetic drum core to which a winding is applied, a cylindrical magnetic core forming a magnetic path close to a flange of the drum core, and a metal plate terminal to which a lead of the winding is connected. The metal plate terminal is formed in an L-shape so as to extend from the bottom surface to the surface along the outer surface of the magnetic core, and the metal plate terminal is so formed that its tip is located within the thickness of the magnetic core. An inductance element fixed to a magnetic core in a shape of a circle. 6. A magnetic drum core to which a winding is applied, a cylindrical magnetic core forming a magnetic path close to a flange of the drum core, and a metal plate terminal to which a lead of the winding is connected. The metal plate terminal is formed in an L shape so as to extend to the bottom surface and the side surface along the outer surface of the magnetic core, and the tip on the bottom surface is positioned within the thickness of the magnetic core. An inductance element fixed to the cylindrical magnetic core. 7. The metal terminal according to claim 1, wherein the metal terminal is formed at the end located on the upper surface of the cylindrical magnetic core with an elongate portion for elongating a winding lead. An inductance element described in any one of the above. 8. The metal terminal according to claim 1, wherein an end portion located at a bottom surface of the cylindrical magnetic core is provided with an elongate portion for elongating a lead of a winding. An inductance element described in any one of the above.