Patent Description:
There is known a coil component including a rod-shaped core and a coil wound around the core (for example, document <CIT>).

Document <CIT> shows an inductive component having a winding and a core which comprises a plurality of core areas which contain different magnetic materials. All the parts of the core are held together and guided by a screw which passes through a hole.

Document <CIT> shows a reactor which includes a core, a bobbin, a coil, and a case. The core is fixed to the case by a bolt via the middle leg section. The middle leg section includes a through-hole. A post projects inside a bottom wall of the case, and a screw hole is formed at the tip of the post. While a boss section of the bobbin is being fitted to the through-hole, the coil is provided in the bobbin, with the center leg section as a center. The post is fitted into a hole of the boss section from a lower portion, and the tip of the post is extended to a middle position of the middle leg section. The bolt is inserted from an upper side to the hole of the boss section, and the tip of the bolt is screwed to a screw hole of the post, thus fixing the bobbin and the coil to the case via the core, and supporting the core without any contact via a gap by the case, at a part which is other than the post.

Document <CIT> shows one of a reactor and a transformer including two facing yoke cores, and a plurality of magnetic leg cores around which coils are wound and gap adjustment means are disposed. The two facing yoke cores are connected with the plurality of magnetic leg cores, and are provided with isotropic magnetic bodies on at least one of the connection parts. The isotropic magnetic bodies are formed from an isotropic magnetic material.

According to document <CIT>, a core reactor is provided with gaps. This reactor has a structure, wherein a plurality of pieces of block cores, which are formed by laminating radially blanks consisting of a silicon steel plate and have a section formed into a circular form, are stacked via magnetic gaps to constitute a core leg with gaps, a winding is wound on the periphery of this leg. This leg with a circular section and yoke cores with a rectangular section are combined integrally with each other.

In document <CIT>, a core for a reactor is described. The core consists of an inner core, an outer core, end cores, and a gap is attached on the core. The gap is formed by distributing and disposing a plurality of gap materials in the inner core, and the inner core is divided into a plurality of core pieces by the gap materials.

Document <CIT> discloses a choke coil with at least one iron core, circular in cross-section, made of iron discs stacked one on top of the other in the axial direction with non-magnetic intermediate spaces and formed by lamellae made of transformer sheet metal. The lamellae being in axially parallel planes radially to segments of the circular cross-section are layered in that each segment contains a first packet of a few lamellae of the same length and a further packet of lamellae that are shorter from lamella to lamella. The number of slats in the further package is an even number. The slats of this further package, starting with the longest and the shortest, each pair in pairs to the length of the slat in the first package. Only every second lamella from the further package rests against the outermost lamella from the first package of the adjacent segment.

In document <CIT>, a reactor device is shown, the reactor device being provided with a plurality of leg portion iron cores, and yoke section iron cores which are arranged at both ends of the leg portion iron cores. Herein, the leg portion iron core is formed of an amorphous metal wound iron core which has an insertion hole that penetrates through the center, and a slit formed along a radial direction, and the yoke section iron core is formed of a wound iron core which has a substantially oval shape and a long hole communicated with the insertion hole of the leg portion iron core.

According to document <CIT>, a block iron core is known. The block iron core is stacked via a magnetic gap to form an iron core leg, a winding is wound around the iron core leg, a yoke iron core is arranged above and below the iron core leg, and a yoke iron core and an iron core. In a core type reactor with a gap interposed with a wound core block for magnetic flux diversion formed by winding a silicon steel band in a ring shape with a leg, the diameter of the wound core block is made larger than the width of the yoke core.

Document <CIT> shows a cylindrical iron core which comprises a plurality of core blocks formed by concentrically laminating cylindrical core elements which are formed by laminating a plurality of magnetic steel plates, each of which is provided with a curved portion having a curved section in the width direction, while shifting from each other in the width direction.

According to the present invention, a coil component unit in accordance with independent claim <NUM> is provided. Furthermore, a more advantageous embodiment is defined in dependent claim <NUM>.

According to the present invention, it is possible to reduce alternating-current resistance and achieve sufficient quality factors.

As a result of studies made by the present inventor, there is a possibility that, with the coil component having the structure as described in Patent Document <NUM>, a large loss of electric power resulting from alternating-current resistance happens, and adequate quality factors cannot be obtained.

The present invention has been made in view of the problem described above, and is to provide a coil component having a structure that can reduce alternating-current resistance and achieve sufficient quality factors.

The above and other objects, advantages and features of this invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings.

Hereinbelow, exemplary embodiments according to the present invention will be described with reference to the drawings. Note that, in all the drawings, the same reference characters are attached to similar constituent components, and detailed explanation thereof will not be repeated as appropriate.

First, a coil component <NUM> according to this exemplary embodiment will be described with reference to <FIG>.

The coil component <NUM> according to this exemplary embodiment includes a core <NUM> and a coil <NUM> wound around the core <NUM>. The core <NUM> is configured to include a plurality of split cores <NUM> arranged linearly alongside each other in the axial-center direction of the coil <NUM>. An intervening layer made out of a non-magnetic material (for example, comprised of an insulating coating <NUM> illustrated in <FIG>) is disposed between split cores <NUM> adjacent to each other of the plurality of split cores <NUM>.

The "plurality of split cores <NUM> forming the core <NUM> is arranged linearly alongside each other in the axial-center direction of the coil <NUM>" means, in other words, that the coil <NUM> is wound along the axial direction of the core <NUM>.

With the coil component <NUM> according to this exemplary embodiment, the intervening layer made out of a non-magnetic material is disposed between individual split cores <NUM> forming the core <NUM> to reduce the leakage magnetic flux, and hence, it is possible to reduce alternating-current resistance of the coil <NUM>.

The coil component <NUM> according to this exemplary embodiment can be favorably used as a resonance coil for a field coupling non-contact power supply system, can be used at high frequencies (for example, a band of MHz) and with large electric power (the order of kw or higher), and has a structure that achieves a low loss. In such a resonance coil, the alternating-current resistance due to stray capacity, proximity effect and core loss causes a large loss. However, in the case of this exemplary embodiment, the leakage magnetic flux can be reduced and the skin effect of magnetic flux can be reduced, so that the core loss can be reduced. Thus, it is possible to achieve a resonance coil exhibiting excellent quality factors.

Below, detailed description will be given.

As illustrated in any of <FIG>, in the case of this exemplary embodiment, the split cores <NUM> forming the core <NUM> are each formed into an annular shape (for example, a circular ring shape).

In addition, the coil <NUM> is disposed around the core <NUM> in a manner such that the axial directions of the split cores <NUM> align with the axial-center direction of the coil <NUM> (see <FIG> and <FIG>).

The core <NUM>, which is an assembly of circular ring-shaped split cores <NUM>, is formed into a hollow cylindrical shape.

That is, in the case of this exemplary embodiment, the core <NUM> is comprised of a tubular core body 30a, and has a cylindrical hollow portion 30b formed inside of the core body 30a.

As illustrated in <FIG>, a coating (for example, an insulating coating <NUM>) made out of a non-magnetic material is formed on the entire surface of each of the split cores <NUM>. A portion of this coating that faces an adjacent split core <NUM> forms the above-described intervening layer.

That is, each of the split cores <NUM> is configured to include a split core body <NUM> made out of a magnetic material and formed into an annular shape (for example, a circular ring shape), and the insulating coating <NUM> formed on the entire surface of the split core body <NUM>.

The insulating coating <NUM> is made out of an insulating material such as a resin.

Furthermore, for example, in each of the split cores <NUM> (each of the split core bodies <NUM>), peripheral edge portions on both end surfaces of a split core <NUM> in the axial direction thereof (a peripheral edge portion on the outer peripheral side and a peripheral edge portion on the inner peripheral side) are formed into a chamfering shape. Thus, the outer peripheral surface of the core body 30a (the side circumferential surface of the core body 30a) is constricted at regular intervals in the axial direction of the core <NUM>. On the other hand, the inner peripheral surface of the core body 30a is expanded toward the outer side in the radial direction at regular intervals in the axial direction of the core <NUM>.

However, the present invention is not limited to this example. The outer peripheral surface and the inner peripheral surface of the core body 30a may have a cylindrical shape having the same diameter throughout the entire axial direction of the core <NUM> (shape without constricted or expanded portion).

As illustrated in <FIG>, the bobbin <NUM> is comprised of a hollow cylindrical bobbin body 20a. A cylindrical hollow portion 20b is formed inside of the bobbin body 20a.

In the bobbin body 20a, for example, one or a plurality of openings 20c penetrating the inside and the outside of the bobbin main body 20a are formed. That is, the hollow portion 20b, which is the inside space of the bobbing body 20a, and the external space of the bobbin body 20a are communicated with each other through each of the opening 20c.

The bobbin <NUM> is made out of a resin or other insulating, non-magnetic material.

As illustrated in <FIG>, the coil <NUM> is formed by spirally winding a metal wire 10a. The coil <NUM> has an outwardly extending piece <NUM> at both ends thereof.

The example illustrated in <FIG> gives an example in which the wire 10a is a rectangular wire and the coil <NUM> is an edgewise coil. However, the wire 10a may be other wire. In addition, the coil <NUM> may have a structure other than the edgewise coil,.

The outer diameter of the core <NUM> (the outer diameter of the core body 30a) is smaller than the inner diameter of the bobbin <NUM> (the inner diameter of the bobbin body 20a).

The inner diameter of the coil <NUM> is larger than the outer diameter of the bobbin <NUM> (the outer diameter of the bobbin body 20a).

As illustrated in <FIG>, the coil component <NUM> is configured by disposing the coil <NUM> around the bobbin body 20a, and inserting the core <NUM> into the hollow portion 20b of the bobbin <NUM>.

<FIG> and <FIG> are diagrams each illustrating a coil component unit <NUM> formed by making plural (for example, two) coil components <NUM> into a unit. <FIG> is a perspective view of the unit, and <FIG> is a sectional plan view of the unit. The coil component according to the present invention includes the coil component unit <NUM>.

As for the positional relationship of the coil component unit <NUM> in each of <FIG> and <FIG>, the directions of forward, backward, left, and right are shown in each drawing. These directions are used only to illustrate the structure of the coil component unit <NUM>, and do not necessarily correspond to the positional relationships of the coil component unit <NUM> during manufacturing or when in use.

Although any flange portion <NUM> (see <FIG> and <FIG>) of the bobbin <NUM> is not illustrated in <FIG> and <FIG>, the bobbin <NUM> includes a pair of flange portions <NUM> each provided on both ends of the bobbin body 20a in the axial direction of the bobbin body 20a. These flange portions <NUM> are each formed into, for example, a square shape or other rectangular shapes.

In addition, as illustrated in <FIG> and <FIG>, in the axial direction of the bobbin body 20a, the longitudinal dimension of the core <NUM> is longer than that of the bobbin <NUM>, and the end portion of the core <NUM> protrudes from each of both ends of the bobbin <NUM>.

Here, the two coil components <NUM> of the coil component unit <NUM> are arranged in parallel so that the axial directions of bobbin bodies 20a of these coil components <NUM> extend in parallel to each other.

In addition, a flat plate-like partitioning plate <NUM> is disposed between the two coil components <NUM>.

In the axial direction of the bobbin body 20a, both ends of the partitioning plate <NUM> are each provided with a cutout-shaped portion 80a having a shape obtained by cutting out a rectangular-shaped portion from the partitioning plate <NUM>.

As illustrated in <FIG>, a flat plate-like spacer <NUM> is disposed at both ends of the coil component <NUM> in the axial direction of the bobbin body 20a.

In addition, a holding member <NUM> is disposed at positions located outside of the spacer <NUM> in the axial direction of the bobbin body 20a (at a position located in front of the forward-side spacer <NUM> in <FIG> and at a position located behind the backward-side spacer <NUM> in <FIG>).

That is, the coil component unit <NUM> includes a pair of spacers <NUM> and a pair of holding members <NUM>.

Each of the holding members <NUM> and the spacers <NUM> is used to fix both of the two coil components <NUM> that the coil component unit <NUM> includes.

The spacers <NUM> and the holding members <NUM> each have an insertion hole 50a and an insertion hole 60a, respectively, formed therein. A bolt <NUM> is inserted into the insertion hole 50a and the insertion hole 60a of each of the spacer <NUM> and the holding member <NUM>, respectively, located at both ends of the coil component <NUM> and is also inserted into the hollow portion 30b of the core <NUM>. A nut <NUM> is tightened at the tip end side of the bolt <NUM>. With this configuration, a pair of holding members <NUM>, a pair of spacers <NUM>, and the coil components <NUM> are fixed to each other with a fastening member <NUM> including the bolt <NUM> and the nut <NUM>.

That is, by fastening the bolt <NUM> and the nut <NUM> together, both ends of the core <NUM> are sandwiched by the pair of holding members <NUM> via the spacers <NUM>, respectively.

This configuration creates a state where the plurality of split cores <NUM> forming the core <NUM> are in pressure contact with each other, reducing positional shift of the plurality of split cores <NUM>.

As described above, the coil component unit <NUM> (coil component) includes the holding member <NUM> that makes the plurality of split cores <NUM> in pressure contact with each other by sandwiching both ends of the core <NUM>.

The spacer <NUM> on one side and a holding member <NUM> adjacent to this spacer <NUM> are disposed so as to penetrate through a plate surface of the partitioning plate <NUM> through the cutout-shaped portion 80a on one side (penetrate in the right and left direction in <FIG> and <FIG>).

Similarly, the spacer <NUM> on the other side and a holding member <NUM> adjacent to this spacer <NUM> are disposed so as to penetrate through a plate surface of the partitioning plate <NUM> through the cutout-shaped portion 80a on the other side (penetrate in the right and left direction in <FIG> and <FIG>).

In addition, the outwardly extending pieces <NUM> located at both ends of the coil <NUM> of each of the coil components <NUM> are provided with a terminal portion <NUM> for external connection.

According to the first exemplary embodiment as described above, the intervening layer made out of a non-magnetic material is disposed between the plurality of split cores <NUM> forming the core <NUM>, and hence, it is possible to reduce alternating-current resistance of the coil <NUM>.

That is, since the core <NUM> includes plural separating magnetic gaps (magnetic gaps existing between split cores <NUM>), the leakage magnetic flux from the core <NUM> reduces, which makes it possible to reduce the alternating-current resistance of the coil <NUM> in a high frequency band.

In the case of this exemplary embodiment, each of the split cores <NUM> has an annular shape, and the core <NUM> has a hollow cylindrical shape. Thus, the high-frequency magnetic flux not only passes through the outer peripheral surface of the core <NUM> but also passes through the inner peripheral surface, which reduces an influence of the skin effect, and hence, it is possible to further reduce the alternating-current resistance.

Claim 1:
A coil component unit (<NUM>), comprising:
a pair of cores (<NUM>) being arranged in parallel so that the axial directions of the pair of cores (<NUM>) extend in parallel to each other; and
a pair of coils (<NUM>) wound around each of the pair of cores (<NUM>),
wherein each of the pair of cores (<NUM>) is configured to include a plurality of split cores (<NUM>) arranged linearly alongside each other in an axial-center direction of the coil (<NUM>) wound around the core (<NUM>),
wherein the split cores (<NUM>) are each formed into an annular shape,
wherein an axial direction of each of the split cores (<NUM>) aligns with the axial-center direction of the coil (<NUM>), so as to form the core (<NUM>) into a hollow cylindrical shape having a hollow portion (30b),
wherein an intervening layer made out of a non-magnetic material is disposed between split cores (<NUM>) adjacent to each other of the plurality of split cores (<NUM>), the coil component unit (<NUM>) further comprising:
a pair of holding members (<NUM>) arranged one on each side in the axial-center direction of the pair of cores (<NUM>), wherein each of the holding members (<NUM>) comprises respective insertion holes (60a), and
a pair of fastening members (<NUM>) fastening the pair of holding members (<NUM>) to each other,
wherein the pair of fastening members (<NUM>) comprises each a bolt (<NUM>), each bolt (<NUM>) being inserted into a respective insertion hole (60a) of said holding members (<NUM>) and passing through said hollow portions (30b) of a respective one of the pair of cores (<NUM>),
wherein a respective nut (<NUM>) is tightened at the tip end side of a respective one of the bolts (<NUM>) so as to sandwich both ends of the pair of cores (<NUM>) by the pair of holding members (<NUM>) such that the plurality of split cores (<NUM>) have been made in a state in pressure contact with each other, characterized in that
a flat plate-like partitioning plate (<NUM>) is disposed between the pair of cores (<NUM>), both ends of the partitioning plate (<NUM>) each being provided with a cutout-shaped portion (80a), and
wherein said pair of holding members (<NUM>) are disposed so as to penetrate through a plate surface of the partitioning plate (<NUM>) through the respective cutout-shaped portions (80a).