JP2003017329A - Inductance element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductance element that achieves simple structure by reducing the number of components, and at the same time prevents leakage flux from leaking to the outside. SOLUTION: An outer core 19 that is rectangular when being seen from a first direction C is composed of two core splits 20 in the same shape where the outer core 19 is divided by a division surface 22 that orthogonally crosses the first direction C. In each core split 20, one surface that orthogonally crosses the first direction C is blocked by a wall 23. Inside space 27 is formed by the wall 23 and projections 24A to 24D being extended along the outer periphery of the wall 23. Both the end sections of a middle leg core 31 where wiring 32 is fitted are fitted to a recess 28 that is formed in a pair of the projections 24A and 24B of each core split 20 that oppose each other and is opened in the inside space 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductance element mainly mounted on a circuit board of various electronic devices in a surface mounting form.

[0002]

2. Description of the Related Art Conventionally, as an inductance element such as a choke coil or a reactor, those shown in FIGS. 6A to 6C are known. In the inductance element of (a), the winding 4 is attached to the core middle foot portion 3 of the E-shaped core 1, and the I-shaped core 2 is combined with the E-shaped core 1 to form two closed magnetic lines. A path is formed, and a gap 7 is provided between the tip surface of the core middle leg portion 3 and the I-shaped core 2. In the inductance element of (b), two E-shaped cores 1 are combined with each other, and a winding wire 4 is attached to each core midfoot portion 3 of each E-shaped core 1 so that the two One closed magnetic circuit is formed, and a gap 8 is formed between the tips of the two core midfoot portions 3.

The inductance element shown in (c) has a core 9 having a core mid-foot 10 at the center of a flat plate, and the bobbin 11 is provided on the core mid-foot 10 of the core 9.
The core 4 is wound with the winding 4, and a box-shaped core 12 having one surface (the lower surface in the figure) opened is combined and joined to the core 10 in the direction indicated by the arrow, and the inner space of both cores 9 and 12 is joined. The winding 4 is housed inside. Further, each of the cores 9 and 12 is provided with a pair of terminal electrodes 13 and 14, and the terminal electrodes 13 and 14 are used to be mounted on a circuit board.

[0004]

[Problems to be Solved by the Invention] However,
In the inductance elements of (a) and (b), since the leakage magnetic flux generated in the gaps 7 and 8 leaks to the outside of the cores 1 and 2, not only the magnetic permeability is lowered, but also this inductance element is mounted on a circuit component. In some cases, noise may be generated by magnetically affecting the peripheral circuit components. In the inductance element of (b), since the leakage magnetic flux 17 generated in the gap 8 interlinks with the winding 4,
The eddy current 18 is generated in the heat generation and the eddy current loss occurs.

On the other hand, in the inductance element of (c),
A gap is formed between the tip surface of the core midfoot portion 10 and the inner surface of the core 12, but since this gap and the winding are confined in the inner space defined by both cores 9 and 12,
It is less likely that leakage magnetic flux due to the gap will leak to the outside and cause noise. On the other hand, this inductance element cannot smoothly dissipate the heat generated by the winding to the outside, and it is not easy to connect the lead wire from the winding and the terminal electrodes 13 and 14. Further, each of the inductance elements (a) and (c) has two cores 1, 9 and 2, 1 having different shapes.
Since 2 are combined, the number of types of parts increases and the productivity is low.

The present invention has been made in view of the above-mentioned conventional problems, and provides an inductance element in which the leakage flux generated in the gap does not leak to the outside while having a simplified structure by reducing the number of parts. The purpose is to do.

[0007]

In order to achieve the above object, an inductance element according to one configuration of the present invention is
When viewed from the direction, the rectangular outer core is composed of two core split bodies of the same shape divided by a split surface orthogonal to the first direction, and each core split body is orthogonal to the first direction. One surface is closed by a wall, and a protrusion that extends along the outer periphery of the wall and forms an inner space with the wall is provided.
Furthermore, on the pair of projecting portions of each of the core divided bodies facing each other,
A recess opening to the inner space is formed, and in the recess,
Both ends of the metatarsal core on which the winding wire is mounted are fitted.

In this inductance element, since the inner leg core and the winding are housed in the inner space of the two core divided bodies constituting the outer core, the leakage of magnetic flux to the outside is small and a high magnetic permeability is secured. be able to. Further, since the outer core is composed of two core divided bodies having the same shape,
Productivity is improved. Further, since the metatarsal core having the winding attached thereto is retained by fitting both ends into a recess opening in the inner space of each core division, a resin for retaining the winding and the metatarsal core is retained. It is possible to reduce the number of parts, simplify the configuration, and reduce the cost without separately requiring a molded product or the like.

In a preferred embodiment of the present invention, a gap is formed between the outer core and the both ends of the metatarsal core in the recess. According to this configuration, the leakage magnetic flux generated in the gap does not interlink with the winding,
No eddy current is generated, and leakage magnetic flux does not leak to the outside. Further, the gap can be easily formed by interposing a spacer or molding the end portion of the metatarsal core with resin.

In another preferred embodiment of the present invention, the pair of protrusions or the other pair of protrusions are formed with through-holes through which lead wires of the windings are drawn out. Accordingly, the lead wire of the winding can be easily led out to the outside through the through hole, and the heat generated by the winding can be smoothly released to the outside through the through hole.

In another preferred embodiment of the present invention, the core division body has a substantially triangular shape when viewed from a direction along the axial center of the metatarsal core. According to this configuration, 2
It is possible to reliably prevent an operation error in which the two divided cores are combined from the regular combination arrangement in the arrangement in which one of them is rotated by, for example, 90 ° in the assembly process while maintaining the productivity improvement by forming the one core divided body into the same shape.

[0012]

Preferred embodiments of the present invention will be described below with reference to the drawings. 1 is an exploded perspective view showing an inductance element according to a first embodiment of the present invention, and FIG. 2 is a perspective view showing a completed assembly state of the inductance element. This inductance element has a first direction C
The outer core 19 having a rectangular shape when viewed from above is composed of two core split bodies 20 of the same shape that are split by the split surface 22 of FIG. 2 orthogonal to the first direction C. The outer core 19 is configured by joining two core divided bodies 20 to each other by a joining means such as an adhesive, and has a flat rectangular parallelepiped shape.

As shown in FIG. 1, each core segment 20 has one surface orthogonal to the first direction C closed by a wall 23, and faces the inner surface of the core segment 20 in the first direction C. Protrusions 2 and extending along the outer periphery of the wall 23
4A to 24D are formed, and the wall 23 and the protrusions 24A to 24D are formed.
A concave inner space 27 is formed. The inner space 27 surrounded by the four protrusions 24A to 24D is formed in the pair of protrusions 24A and 24B facing each other of each core segment 20.
A recess 28 that opens toward the front is formed. Further, notches 30 are formed in the other pair of protrusions 24C and 24D, and both notches 30 are formed by the two core split bodies 20.
As shown in FIG. 2, the through holes 29 having a rectangular cross section are formed in a state where they are abutted against each other.

A winding 32 is wound around the central portion of the flat middle core 31 shown in FIG. This winding 32
Is made up of two round wires 33, 34 stacked in the axial direction to form a spiral 2
It is formed by double winding and its two round wires 3
Both ends of 3, 34 are leader lines 33a, 33b, 34a, 3
It is pulled out as 4b. The middle foot core 31 having the winding 32 wound around the center thereof has its both ends fitted into the respective recesses 28 of the respective core split bodies 20, and has a holding hole formed by the upper and lower recesses 28. Held in place and fixed with an adhesive. At that time, the four leader lines 33a, 33b, 34a,
Two 34b are drawn out from the through holes 29 on both sides.

The protrusions 24C and 24D in which the notches 30 are formed in the core split body 20 on one side (upper side in FIG. 1) are
The four terminal plates 35 are provided by insert molding so as to be exposed on the outer and upper surfaces of the protrusions 24C and 24D, and the four lead lines 33a, 33b, 34a drawn from the above-described through hole 29. , 34b have the ends shown in FIG.
As shown in FIG. 5, each of them is individually soldered to the terminal board 35.

Both ends of the middle foot core 31 are shown in FIG.
As shown in (a), the upper and lower surfaces are fitted in the recess 28 with a thin spacer 38 made of a non-magnetic material interposed. As a result, a gap G is formed by the spacer 38 between the outer core 19 and the metatarsal core 21 in the recess 28.

In this inductance element, since the inner leg core 31 and the winding wire 32 are housed in the inner space 27 of the two core divided bodies 20 constituting the outer core 19 shown in FIG. 1, the leakage of the magnetic flux to the outside. Is low and high magnetic permeability can be secured. Further, since the outer core 19 is composed of the two core divided bodies 20 having the same shape, the productivity is improved with the reduction of the number of parts. In addition, the winding 32
Is sandwiched between the walls 23 of each of the two core divisions 20, and the middle foot core 31 is held by fitting both ends into a recess 28 that opens toward the inner space 27 in each core division 20. Therefore, the winding 32 and the middle foot core 31
In this respect, the number of parts can be further reduced, the configuration can be simplified, and a considerable cost reduction can be achieved.

Since the gap G shown in FIG. 3B is formed by the spacer 38 interposed between the outer core 19 in the recess 28 and both ends of the metatarsal core 31,
Since the leakage magnetic flux generated in the gap G does not interlink with the winding 32, there is no possibility of generating an eddy current, and the leakage magnetic flux does not leak to the outside. Further, the gap G can be set to have a desired magnetic resistance by interposing a spacer 38 having a required thickness. The gap G is formed on the end face of the metatarsal core 31 and the recess 28.
It may be formed by inserting a spacer between the vertical wall surface and the vertical wall surface. Alternatively, when the entire middle foot core 31 and the winding 32 are molded with resin, the gap can be formed by the molding resin around the both ends of the middle foot 31, and in that case, a separate spacer is omitted. it can. The gap does not necessarily have to be formed.

The lead wires 33a, 33b of the winding 32,
34a and 34b are notches 30 of the pair of core split bodies 20.
It can be easily led out to the outside through the through hole 29 formed by combining the two. Moreover, the through hole 29 is connected to the lead wire 3
Since the opening area is larger than the cross-sectional shape of 3a to 34b, it also has a function of smoothly releasing the heat generated by the winding 32 to the outside. Therefore, the inductance element of this embodiment can be surface-mounted on a circuit board and used as an electronic circuit element such as a suitable choke coil, reactor or transformer having the above-mentioned excellent performance.

The cross-sectional shape of the through hole 29 is a square shape in the above embodiment, but it may be a circular shape or an elliptical shape.

FIG. 4 is an exploded perspective view showing an inductance element according to a second embodiment of the present invention, and FIG. 5 is a perspective view showing a completed assembly state of the inductance element. This inductance element has a flat rectangular parallelepiped outer core 3 shown in FIG.
The pair of core split bodies 40 having the same shape forming 9 are substantially triangular when viewed from the second direction D along the axial center of the metatarsal core 41. The winding 42 has a flat cross section with a rectangular cross section.
The two rectangular wires 43 and 44 are formed by overlapping the two rectangular wires 43 and 44 in the axial direction and double winding them in a spiral shape.
Both ends of each of the lead wires 43a, 43b, 44a, 4
4b and the lead wire 43a,
The leading end portions 45 of 43b, 44a and 44b are bent so that they can be joined to the outer surface of the outer core 39 after being led out to the outside of the outer core 39.

Similar to the first embodiment, one surface of each core division body 40 orthogonal to the first direction (FIG. 5) C is closed by a wall 44 so that the inner surface of the core division body 40 has a first surface. Three protrusions 47A to 47C that project in the direction C and extend along the outer periphery of the wall 44 are formed.
A concave inner space 48 is formed by 7C and the wall 44. A pair of protrusions 4 of each core divided body 40 facing each other
A rectangular recess 49 that opens toward the inner space 48 is formed in the center of each of the 7A and 47B, and a lead-out groove is formed at a portion of the pair of protrusions 47A and 47B near the other protrusion 47C. 50 are formed.

This inductance element has a middle foot core 41.
Both ends of the lead wire are fitted into the recesses 49, and the lead wires 43a, 43
b, 44a, 44b are inserted into the lead-out groove 50 and pulled out to the outside of the core divided body 40. In this state, the two core divided bodies 4
It is assembled by abutting 0s with each other and joining them by a joining means such as an adhesive. Finally, as shown in FIG. 5, the leading end portion 45 of each of the lead wires 43a, 43b, 44a, 44b drawn to the outside of the outer core 39 has an adhesive like an adhesive on the outer surface serving as the main surface of the outer core 39. Bonded by bonding means to form a terminal electrode.

Therefore, this inductance element is
In addition to obtaining the same effects as those described in the first embodiment, the core split body 40 has a substantially triangular shape when viewed from the axial center direction D of the metatarsal core 41. Since the combined arrangement of the core divided bodies 40 can be visually recognized at a glance, in the assembly process, one of the divided cores 40 can be changed from the regular combined arrangement to one, for example, 90 around the first direction C.
There is an advantage that work mistakes such as combining by turning arrangement can be surely prevented. In addition, the winding 42 is a rectangular wire 43,
Since it is composed of 44, the contact area between the rectangular wires 43 and 44 is large, so that the thermal conductivity is good and an excellent heat dissipation effect can be obtained. Furthermore, the leader lines 43a, 4
Since the tip ends of 3b, 44a, and 44b are the terminal electrodes 45, it is not necessary to separately provide terminal electrodes, and the number of parts can be reduced.

The core divided body 40 does not have to be a perfect triangle when viewed from the second direction D. For example, as shown by the two-dot chain line, the lower core divided body 40 in FIG. The protrusion 47C may be cut in a horizontal plane, and the protrusion 47D may be formed on the side of the wall 44 facing the protrusion 47C correspondingly.

[0026]

As described above, according to the inductance element of the present invention, since the leakage flux to the outside is small, a high magnetic permeability can be secured, and the outer core is divided into two cores having the same shape. Since it is composed of a body, productivity is improved, and the number of parts can be reduced and the structure can be simplified.
A considerable cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an inductance element according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which the above inductance element is completely assembled.

3A is a sectional view taken along line AA of FIG. 2, and FIG. 3B is FIG.
FIG. 6 is a sectional view taken along line BB of FIG.

FIG. 4 is an exploded perspective view showing an inductance element according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a state in which the above inductance element is completely assembled.

6A to 6C are a side view, a side view, and an exploded perspective view showing a conventional inductance element.

[Explanation of symbols]

19, 39 ... Outer core, 20, 40 ... Core division body, 22 ...
Dividing surfaces, 23, 44 ... Walls, 24A-24D, 47A-4
7C ... Protrusion, 27, 48 ... Inner space, 28, 49 ... Recess, 29, 51 ... Through hole, 31, 41 ... Metatarsal core, 3
2, 42 ... Winding, 33, 43 ... Leader wire, C ... First direction, D ... Second direction.

Continued front page    (72) Inventor Yukitaka Sakamoto             Tabuchi, 4-5 Techno Park, Sanda City, Hyogo Prefecture             Electric Co., Ltd. (72) Inventor Mahei Kotani             Tabuchi, 4-5 Techno Park, Sanda City, Hyogo Prefecture             Electric Co., Ltd. F-term (reference) 5E070 AA01 AB01 BA20

Claims (4)

[Claims] 1. A rectangular outer core as viewed from the first direction, which has the same shape and is divided by a dividing surface orthogonal to the first direction.
Each of the core divided bodies is provided with a protrusion having one surface orthogonal to the first direction closed by a wall and extending along the outer periphery of the wall to form an inner space together with the wall. A recess opening to the inner space is formed in a pair of projecting portions of the core divided bodies facing each other, and both ends of the metatarsal core having the windings fitted therein are fitted into the recess. Inductance element being combined. 2. The inductance element according to claim 1, wherein a gap is formed between the outer core and the both ends of the metatarsal core in the recess. 3. The inductance element according to claim 1, wherein the pair of protrusions or the other pair of protrusions has a through hole for drawing out the lead wire of the winding. 4. The inductance element according to claim 1, wherein the core division body is substantially triangular when viewed from a direction along an axis of the metatarsal core.