JP2004111754A - Inductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inductor which can reduce the number of components of a multi-phase type converter. <P>SOLUTION: The inductor comprises one upper-side ER-type core 11, one lower-side I-type core 12, and two coils 13. Central legs 11c and 11c of the ER-type core 11 are fit by insertion into the coils 13 and 13 respectively, and at the same time the coils 13 and 13 are stored in recessed portions 11b and 11b of the ER-type core 11 respectively, and then the ER-type core 11 and the I-type core are bought faced to face with each other, forming a closed magnetic path. Terminals 13a and 13a of one of the coils 13 are fit in notches 12a and 12b formed in one side 12a of the I-type core 12, while terminals 13a and 13a of the other coil 13 are fit in cutouts 12b and 12b formed in another side 12c of the I-type core 12. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inductor used for various electronic devices, and in particular, an inductor in which a closed magnetic circuit is configured by an upper first core (for example, an ER type core) and a lower second core (for example, an I type core). About.
[0002]
[Prior art]
A member that supplies power to a CPU (Central Processing Unit) used in a personal computer is a DC-DC converter including a metal-oxide semiconductor-field effect transistor (MOS-FET), an inductor, a capacitor, and a control circuit. There are various types of inductors used in DC-DC converters. As the speed of the CPU increases, increasing the current to cope with the increase in current consumption and reducing the loss in the high-frequency region are required for inductors. Is required.
[0003]
FIG. 4 is an exploded perspective view of a conventional inductor capable of achieving such a large current and low loss (for example, see Patent Document 1). This conventional inductor includes an upper ER core 41, a lower I core 42, a coil 43, and an auxiliary terminal 44.
[0004]
[Patent Document 1]
JP-A-10-223450
The ER-type core 41 shown in FIG. 4A has a column-shaped central leg 41c erected at the center of a concave portion 41b surrounded by outer legs 41a provided on each of a pair of opposing sides. Two sides on the side where 41a, 41a are not provided are openings 41d, 41d. The coil 43 shown in FIG. 4 (b) is an edgewise coil formed by winding a rectangular conductor which has been subjected to insulation coating treatment. The winding start and end of the coil 43 are stripped of the insulation coating, plated with solder, and further L-shaped. To form terminals 43a. The I-shaped core 42 shown in FIG. 4 (c) is provided with cutouts 42b, 42b for fitting the terminals 43a, 43a of the coil 43 projecting in parallel on one side 42a, and the other side 42c facing the side 42a. A notch 42d for attaching an auxiliary terminal 44 having a U-shaped cross section is provided at the center of the notch.
[0006]
The edgewise coil 43 is accommodated in the recess 41b of the ER core 41, the recess 41b of the ER core 41 is closed by the I-core 42, and the auxiliary terminal 44 is attached to the I-core 42. The coil 43 is housed in the concave portion 41b in such a manner that the coil 43 is fitted into the central leg 41c of the ER core 41, and the ER core 41 and the I core 42 are abutted to form a closed magnetic circuit. At this time, the terminals 43a, 43a of the coil 43 are fitted into the notches 42b, 42b of the I-shaped core 42. Note that the auxiliary terminal 44 is used in order to obtain mounting strength when mounting the inductor on the printed circuit board.
[0007]
[Problems to be solved by the invention]
By using the inductor having the above-described configuration, it was possible to supply power to a high-power CPU with one DC-DC converter. However, recently, the power to be supplied to the CPU has been further increased with the further improvement of the processing speed of the CPU. In the case of a high-end CPU, a plurality of DC-DC converters are connected in parallel. A multi-phase system for supplying power is employed.
[0008]
In the case of this multi-phase system, a plurality of components are required in accordance with the number of DC-DC converters, and inductors are also required for the number of DC-DC converters. As a result, there is a problem that an increase in mounting space and cost is inevitable. Specifically, when an inductor having a configuration as shown in FIG. 4 is used, one inductor is composed of four parts (ER-type core 41, I-type core 42, coil 43, and auxiliary terminal 44). Therefore, a two-phase DC-DC converter requires two (= 4 × 2) parts using two inductors.
[0009]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inductor that can greatly reduce the number of components configured in a multi-phase converter as compared with the related art.
[0010]
[Means for Solving the Problems]
An inductor according to a first aspect of the present invention is an inductor that includes a first core and a second core each made of a magnetic material, and a plurality of coils each formed by winding a rectangular conductor. A plurality of pillar-shaped legs are provided, each of the plurality of coils is fitted into each of the plurality of legs, and the first core and the second core are abutted.
[0011]
In the inductor according to the first aspect of the present invention, a plurality of coils are respectively fitted into a plurality of columnar legs provided on one first core (for example, an ER type core). It has a configuration in which one second core (for example, an I-type core) is abutted. As described above, a plurality of inductors are integrated by a pair of cores. In a multi-phase converter, the number of components is reduced as compared with a conventional example in which a plurality of inductors are simply configured in parallel. Also, the mounting density is improved as compared with the case where a plurality of inductors are individually mounted. Further, assembling workability is improved and production cost is reduced.
[0012]
In the inductor according to a second aspect of the present invention, in the first aspect, the first core has an opening on both sides, and both terminals of each of the plurality of coils project from the opening on the same side of the first core. And wherein both terminals of at least one set of coils among the plurality of coils protrude from the openings on different sides of the first core.
[0013]
In the inductor according to the second aspect of the present invention, both terminals of each of the plurality of coils protrude from the opening on the same side of the first core, and both terminals of at least one of the plurality of coils are connected to other terminals. It comes out of the opening on the side different from both terminals of the coil. Therefore, the terminals are arranged so that the mounting balance is good and sufficient mounting strength is obtained, so that auxiliary terminals for obtaining the mounting strength are unnecessary, further reducing the number of parts, reducing the number of assembly steps, and Production costs can be reduced.
[0014]
In the inductor according to a third aspect, in the first aspect, the first core has an opening on both sides, and both terminals of each of the plurality of coils are connected to the opening on a different side of the first core. It is characterized in that each comes out.
[0015]
In the inductor according to the third aspect, both terminals of each of the plurality of coils protrude from openings on different sides of the first core. Therefore, the terminals are arranged so that the mounting balance is good and sufficient mounting strength is obtained, so that auxiliary terminals for obtaining the mounting strength are unnecessary, further reducing the number of parts, reducing the number of assembly steps, and Production costs can be reduced.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments.
(1st Embodiment)
FIG. 1 is an exploded perspective view showing the configuration of the inductor according to the first embodiment of the present invention. The inductor according to the first embodiment includes one upper ER core 1, one lower I core 2, two coils 3, 3, and one auxiliary terminal 4. I have.
[0017]
The ER-type core 1 as a first core shown in FIG. 1A has a pair of short sides facing each other and three side legs 1a, 1a, 1a provided therebetween, and adjacent side legs 1a, 1a. At the center of each of two concave portions 1b, 1b surrounded by 1a, column-shaped central legs 1c, 1c are erected. In addition, a pair of long sides facing each other where the side legs 1a are not provided are four openings 1d, 1d, 1d, 1d.
[0018]
Each of the two coils 3 and 3 shown in FIG. 1 (b) is an edgewise coil formed by winding a rectangular conductor having been subjected to insulation coating treatment. The terminals 3a, 3a are formed by plating and further deformed into an L shape. The I-shaped core 2 as a second core shown in FIG. 1C has cutouts 2b, 2b, 2b into which the terminals 3a, 3a, 3a, 3a of the coils 3, 3 projecting in parallel on one side 2a are fitted. , 2b, and a notch 2d for mounting the auxiliary terminal 4 having a U-shaped cross section is provided at the center of the other side 2c facing the one side 2a.
[0019]
Edge-wise wound coils 3 and 3 are accommodated in the recesses 1 b and 1 b of the ER core 1, and the recesses 1 b and 1 b of the ER core 1 are closed with the I-shaped core 2. The auxiliary terminal 4 is attached to the portion 2d. The coils 3, 3 are housed in the recesses 1b, 1b, respectively, in such a manner that the coils 3, 3 are fitted into the respective center legs 1c, 1c of the ER core 1, and the ER core 1 and the I-core 2 The closed magnetic circuit is formed by abutting. At this time, the terminals 3a, 3a, 3a, 3a of the coils 3, 3 are fitted into the notches 2b, 2b, 2b, 2b of the I-shaped core 2. Note that the auxiliary terminal 4 is used in order to obtain a mounting strength when mounting the inductor on the printed circuit board.
[0020]
The inductor according to the first embodiment includes one ER-type core 1, one I-type core 2, two coils 3, 3, and one auxiliary terminal 4. Are 5 in total, and the number of components can constitute an inductor used in a two-phase DC-DC converter, compared to the conventional example that required 8 components. The number of parts can be reduced.
[0021]
(2nd Embodiment)
FIG. 2 is an exploded perspective view showing the configuration of the inductor according to the second embodiment of the present invention. The inductor according to the second embodiment includes one upper ER core 11, one lower I core 12, and two coils 13 and 13.
[0022]
The ER-type core 11 as the first core shown in FIG. 2A is provided with a pair of opposing short sides and three side legs 11a, 11a, 11a in the middle between the short sides. At the center of each of the two concave portions 11b, 11b surrounded by 11a, columnar central legs 11c, 11c are erected. Further, a pair of long sides facing each other where the side legs 11a are not provided are four openings 11d, 11d, 11d, 11d.
[0023]
Each of the two coils 13, 13 shown in FIG. 2 (b) is an edgewise coil formed by winding a rectangular wire which has been subjected to an insulating coating treatment. The terminals 13a are formed by plating and further deformed into an L-shape. The I-shaped core 12 as a second core shown in FIG. 2C has cutouts 12b, 12b into which the terminals 13a, 13a of one coil 13 projecting in parallel are fitted on one side 12a. Notches 12b, 12b are provided in the other side 12c opposite to 12a to fit the terminals 13a, 13a of the other coil 13 projecting in parallel.
[0024]
Edge-wise wound coils 13, 13 are accommodated in the recesses 11 b, 11 b of the ER core 11, and the recesses 11 b, 11 b of the ER core 11 are closed by the I-shaped core 12. The coils 13, 13 are housed in the recesses 11 b, 11 b in such a manner that the coils 13, 13 are fitted into the respective center legs 11 c, 11 c of the ER core 11, and the ER core 11 and the I-type core 12 are joined together. The closed magnetic circuit is formed by abutting. At this time, the terminals 13a, 13a, 13a, 13a of the coils 13, 13 are fitted into the notches 12b, 12b, 12b, 12b of the I-shaped core 12.
[0025]
In the second embodiment, unlike the first embodiment in which all four terminals 3a of the two coils 3 and 3 come out from the same side of the ER type core 1, both terminals of one coil 13 are different. Since the terminals 13a and 13a and both terminals 13a and 13a of the other coil 13 are taken out from different sides of the ER-type core 11, two terminals 13a are arranged on both sides of the I-type core 12 so that the mounting balance is good. Therefore, the auxiliary terminal 4 provided in the first embodiment for obtaining the mounting strength is unnecessary. The inductor according to the second embodiment includes one ER type core 11, one I type core 12, and two coils 13, 13, so that the number of parts is four in total. Thus, the inductor used in the two-phase DC-DC converter can be configured with four parts, and the number of parts is halved as compared with the conventional example that required eight parts. Can be reduced.
[0026]
(Third embodiment)
FIG. 3 is an exploded perspective view showing the configuration of the inductor according to the third embodiment of the present invention. The inductor according to the third embodiment includes an upper ER core 21, a lower I-core 22, and two coils 23.
[0027]
The ER-type core 21 as the first core shown in FIG. 3A has a pair of opposing short sides and three side legs 21a, 21a, 21a provided therebetween, and the adjacent side legs 21a, 21a. At the center of each of the two concave portions 21b, 21b surrounded by 21a, column-shaped central legs 21c, 21c are erected. A pair of long sides facing each other where the side legs 21a are not provided are four openings 21d, 21d, 21d, 21d.
[0028]
Each of the two coils 23, 23 shown in FIG. 3 (b) is an edgewise coil formed by winding a rectangular conductor having been subjected to an insulation coating treatment. The terminals 23a, 23a which are plated and further deformed into an L-shape to be drawn out in different directions are formed. The I-shaped core 22 as the second core shown in FIG. 3 (c) has cutouts 22b, 22b on one side 22a for fitting the terminals 23a, 23a protruding in one direction of the coils 23, 23, respectively. Notches 22b, 22b for fitting terminals 23a, 23a projecting in the other direction of both coils 23, 23 are provided on the other side 22c facing one side 22a.
[0029]
Edge-wise wound coils 23, 23 are accommodated in the recesses 21b, 21b of the ER core 21, and the recesses 21b, 21b of the ER core 21 are closed by the I-shaped core 22. The coils 23, 23 are accommodated in the recesses 21b, 21b, respectively, in such a manner that the coils 23, 23 are fitted into the respective center legs 21c, 21c of the ER core 21, and the ER core 21 and the I-type core 22 are joined together. The closed magnetic circuit is formed by abutting. At this time, the terminals 23a, 23a, 23a, 23a of the coils 23, 23 are fitted into the notches 22b, 22b, 22b, 22b of the I-shaped core 22.
[0030]
In the third embodiment, unlike the first embodiment in which all four terminals 3a of the two coils 3 and 3 come out from the same side of the ER type core 1, one end of each coil 23 is provided. Terminal 23a and the other terminal 23a are put out from different sides of the ER-type core 21. Therefore, two terminals 23a are arranged on both sides of the I-type core 22 and the mounting balance is good. As in the embodiment, the auxiliary terminal 4 in the first embodiment is unnecessary. Further, since the inductor according to the third embodiment also includes one ER-type core 21, one I-type core 22, and two coils 23, 23 as in the second embodiment, The number of components is four in total, and the inductors used in the two-phase DC-DC converter can be configured with four components, and the conventional example requires eight components. In comparison, the number of parts can be reduced by half.
[0031]
In the above-described example, an inductor used in a two-phase DC-DC converter has been described, but an inductor used in a three-phase or more DC-DC converter can of course be similarly configured.
[0032]
Generally, when an inductor used in a DC-DC converter of the n-type (n is an integer of 2 or more) phase method is configured, if the conventional inductor shown in FIG. Since four parts are required, 4n parts are required as a whole. On the other hand, in the present invention, in the case of the first embodiment, one ER type core 1, one I type core 2, n coils 3 and one auxiliary terminal 4 are connected. This is necessary, and (n + 3) parts are required as a whole. In the case of the second and third embodiments, one ER-type core 11 and 21 and one I-type core 12 and 22 And n coils 13 and 23 are required, and a total of (n + 2) parts are required. As described above, in the present invention, the number of components constituting the inductor in the multi-phase DC-DC converter can be reduced, and the effect of reducing the number of components increases as the number of phases increases.
[0033]
Although the coil in each of the above-described embodiments is an edgewise wound coil, it goes without saying that a similar effect can be obtained even with a flat edge wound coil. The ER-type core and the I-type core are made of MnZn ferrite, NiZn ferrite or metal dust-based material, and the material may be different between the ER-type core and the I-type core. Furthermore, an air gap may be provided in a part of the core to improve the DC superimposition characteristics.
[0034]
【The invention's effect】
As described in detail above, in the present invention, a plurality of coils are respectively inserted into a plurality of columnar legs (center legs) provided on one first core (ER type core). Since the configuration is such that the core and one second core (I-type core) abut each other, the number of components of the inductor in the multi-phase converter can be significantly reduced. As a result, member costs are reduced, and workability in assembling is improved, so that production costs can be reduced. Further, since the integrated configuration is adopted, the mounting efficiency and the mounting density can be improved as compared with the case where a plurality of inductors are individually mounted.
[0035]
Further, in the present invention, both terminals of each of the plurality of coils protrude from the opening on the same side of the first core (ER type core), and both terminals of at least one of the plurality of coils are connected to other terminals. The coil is configured so that it comes out of the opening on the side different from the two terminals of the coil.Therefore, there is no need for an auxiliary terminal for assisting the mounting strength, further reducing the number of parts, assembling man-hours, and lowering the production cost. Can be planned.
[0036]
Further, in the present invention, since both terminals of each of the plurality of coils are configured to protrude from the openings on the different side of the first core (ER type core), auxiliary terminals for assisting the mounting strength are unnecessary. Furthermore, the number of parts can be further reduced, the number of assembling steps can be reduced, and the production cost can be reduced.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a configuration of an inductor according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a configuration of an inductor according to a second embodiment of the present invention.
FIG. 3 is an exploded perspective view showing a configuration of an inductor according to a third embodiment of the present invention.
FIG. 4 is an exploded perspective view showing a configuration of a conventional inductor.
[Explanation of symbols]
1,11,21 ER type core (first core)
2,12,22 I-type core (second core)
3, 13, 23 Coil 4 Auxiliary terminals 1a, 11a, 21a Side legs 1b, 11b, 21b Recesses 1c, 11c, 21c Central legs 1d, 11d, 21d Openings 2a, 12a, 22a Sides 2b, 2d, 12b, 22b Notch Parts 2c, 12c, 22c Other sides 3a, 13a, 23a Terminal

Claims (3)

An inductor comprising a first core and a second core each made of a magnetic material, and a plurality of coils each formed by winding a rectangular wire, wherein a plurality of pillar-shaped legs are provided on the first core. An inductor, wherein each of the plurality of coils is fitted into each of the plurality of legs, and the first core and the second core abut each other. The first core has openings on both sides, and both terminals of each of the plurality of coils project from the openings on the same side of the first core, and at least one set of the plurality of coils is provided. 2. The inductor according to claim 1, wherein both terminals of said coil project from said openings on different sides of said first core. 2. The first core has openings on both sides, and both terminals of each of the plurality of coils respectively protrude from the openings on different sides of the first core. Inductor.

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