JP2015201542A - reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor capable of reducing DC resistance of an entire coil and also suppressing an increase in eddy loss in a conductor.SOLUTION: A reactor includes a core portion 1 and a coil 2. The coil 2 includes a first and second coil portions 2a, 2b which are laminated in an axial direction. In the first coil portion 2a, one end 21a of a first conductor 21 is arranged at an outermost in a radial direction, and one end 22a of a second conductor 22 is arranged at an outermost in the radial direction in the second coil portion 2b. The one end 21a of the first conductor of the first coil portion 2a is electrically connected to the one end 21a of the first conductor 21 of the second coil portion 2b, and one end 22a of the second conductor 22 of the first coil portion 2a is electrically connected to the one end 22a of the second conductor 22 of the second coil portion 2a.

Description

  The present invention relates to a reactor suitably used for, for example, an electric circuit or an electronic circuit.

  A reactor is a passive element that uses a winding, for example, various electric currents such as prevention of harmonic current in a power factor correction circuit, smoothing of current pulsation in a current type inverter or chopper control, and boosting of a DC voltage in a converter. Used in circuits and electronic circuits.

  Also, in recent years, from the viewpoint of reducing environmental load, etc., the introduction of solar cells that can directly convert light energy into electric power without discharging carbon dioxide by using the photovoltaic effect has been promoted. For example, a solar power generation system is being introduced for residential use. Such a solar cell power generation system includes, for example, a solar cell module that converts solar light energy into electric power, and a power conditioner that converts DC power generated by the solar cell module into AC power in order to perform system linkage. And a distribution board that distributes the AC power converted by the power conditioner to various places in the house and to the electric power company. A reactor is usually used for the power conditioner.

  In addition, from the viewpoint of reducing the environmental load, etc., hybrid vehicles and electric vehicles (hereinafter collectively referred to as “environment-friendly vehicles”) capable of reducing carbon dioxide emissions have been researched and developed. Its spread is also being promoted. In such an environment-friendly vehicle, a booster circuit is used in the drive control system of the drive motor in order to improve the driving efficiency of the drive motor, and a reactor is usually incorporated in this booster circuit.

  For example, in Patent Document 1, an eddy current generated in a conductor is effectively suppressed by wrapping a coil obtained by flatly winding a strip-shaped conductor having a thickness equal to or less than the skin depth corresponding to the driving frequency in a pancake shape. Such a reactor is disclosed.

Japanese Patent No. 4654317

  However, in the above-mentioned patent document 1, since a conductor having a thickness equal to or less than the skin depth of the driving frequency is used, there is a problem that the direct current resistance of the entire coil is increased.

  In this case, for example, as shown in FIG. 8A, two strip-like first and second conductors 121 and 122 that are electrically connected in parallel to each other are arranged so as to overlap each other in the thickness direction. In this state, the first conductor 121 and the second conductor 122 may be wound and formed into a pancake shape. Thereby, compared with the thing of the said patent document 1 and a conductor cross-sectional area increases, the direct current | flow resistance of the whole coil part can be made small.

  However, as shown in FIG. 8B, the first conductor 121 and the second conductor 122 form a loop, and the magnetic flux line q3 penetrating therethrough in the axial direction generates the induced electromotive force p3, resulting in an excessive eddy current. May flow, resulting in an increase in eddy loss.

  An object of the present invention is to provide a reactor that can reduce the direct current resistance of the entire coil and can suppress an increase in vortex loss in a conductor.

  The reactor of the present invention is a reactor including a core portion and a coil included in the core portion, and the coil includes a plurality of coil portions stacked in an axial direction, and each of the coil portions includes: In a state where two strip-shaped first and second conductors electrically connected in parallel with each other are arranged so as to overlap each other across the insulating layer, the first conductor and the second conductor are The two coil portions that are formed in a pancake shape by being wound and are adjacent to each other in the axial direction penetrate through each coil portion as the first and second conductors of each coil portion are energized. One end of the first conductor in one of the two coil portions and one end of the first conductor in the other coil so that the directions of the magnetic flux lines formed are opposite to each other. When the part is electrically connected Further, one end portion of the second conductor in the one coil portion and one end portion of the second conductor in the other coil portion are electrically connected to each other. .

  According to this, the first conductor and the second conductor are overlapped in parallel, for example, compared with a so-called single-winding coil portion in which one conductor is wound into one pancake shape having the same diameter, for example. Although the number of turns is halved, a plurality of coil portions stacked in the axial direction are doubled in series, the number of turns of the entire coil can be the same or increased, and the inductance can be the same or increased. On the other hand, the conductor cross-sectional area is larger than that of the one pancake-shaped coil part, and the DC resistance of the entire coil part can be reduced.

  Also, the two coil portions adjacent to each other in the axial direction are formed so that the directions of the magnetic flux lines formed so as to penetrate each coil portion are opposite to each other. The induced electromotive force generated in each conductor of the section is canceled out, thereby effectively suppressing the eddy current.

  In another aspect, in the reactor, the one coil portion is arranged such that one end portion of the first conductor is disposed on the outermost side in the radial direction, and one end portion of the second conductor is the first conductor portion. The first and second conductors are formed by being sequentially wound in one direction from the radially inner side to the radially outer side so as to be disposed on the radially inner side of the one end, and the other coil The portion is arranged such that one end portion of the second conductor is arranged on the most radially outer side, and one end portion of the first conductor is arranged on the radially inner side of the one end portion of the second conductor, The first and second conductors are formed by being sequentially wound in the one direction from the radially inner side to the radially outer side, and the one end portion of the first conductor and the other of the one coil portion are formed. One end of the first conductor in the coil portion is electrically Is connected to the one end portion of the second conductor at one end and the other coil portion of the second conductor in the one coil portion is characterized by being electrically connected.

  According to this, the first conductor and the second conductor can be formed by using two coils formed by winding in the same winding direction, and can be manufactured easily.

  In another aspect, in the reactor, the core portion is formed of a green compact that is an insulating film-coated metal powder and is formed by pressing and hardening a ferromagnetic metal powder.

  According to this, since the green compact is isotropic and has a large specific resistance, eddy current loss generated in the core portion and the magnetic member is suppressed.

  In another aspect, the reactor further includes a cylindrical pole piece disposed at a substantially central portion of the core portion, and the core portion has a hole for receiving the pole piece at the substantially central portion. The pole piece is arranged in the hole so that a gap can be formed between the inner periphery of the hole in the core portion and the outer periphery of the pole piece.

  According to this, the air gap of the magnetic circuit becomes a circle surrounding the pole piece. At this time, depending on the assembly error of the pole piece, a portion where the gap is narrowed and a portion where the gap is widened are formed. However, since the contribution to the inductance cancels out, the inductance value is stabilized even if the assembly error varies. In addition, since the change in inductance causes the magnetic attraction force as it is, the vibration accompanying the change in the air gap due to the AC excitation does not essentially occur.

  In another aspect, in the reactor, the core part and the pole piece are formed of a green compact that is an insulating film-coated metal powder and hardened by pressing a ferromagnetic metal powder, and the density of the pole piece is It is characterized by being higher than the density of the core part.

  According to this, the pole piece in which the magnetic flux lines are concentrated and the magnetic flux density is higher than that of the core portion is made of a material having a higher magnetic permeability than the core portion, that is, a material having a higher density. The amount of magnetic flux leakage to the coil can be reduced, and eddy current loss in the coil conductor can be suppressed.

  The reactor of the present invention can reduce the direct current resistance of the entire coil, and can suppress an increase in vortex loss in the conductor.

It is sectional drawing of the reactor of one embodiment of this invention. It is a schematic diagram of the coil used for the reactor of FIG. It is the graph which represented the skin depth (skin thickness) of various metal materials as a function of frequency. It is a figure which shows the equivalent circuit of the coil used for the reactor of FIG. It is a schematic diagram of the modification of a coil. It is sectional drawing of the reactor of other embodiment. It is sectional drawing of the reactor of other embodiment. (A) is sectional drawing of the reactor of a comparative example, (b) is a figure which shows the equivalent circuit of the coil of the reactor of the comparative example of Fig.8 (a).

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a reactor according to an embodiment of the present invention.

  A reactor 10 according to this embodiment includes a core portion 1 and a coil 2 included in the core portion 1.

  The core portion 1 is a member that passes a magnetic flux generated by a magnetic field generated in the coil 2 when the coil 2 is energized. In this embodiment, as shown in FIG. 1, the core portion 1 includes a first core 1a stacked in the axial direction and a second core 1b made of a separate body separated from the first core 1a. It consists of two.

  The first core 1a is a so-called pot type including a first coil portion 2a of a coil 2 to be described later, and the first core 1a includes two core members 10a and 10b opposed in the axial direction. .

  In this embodiment, these core members 10a and 10b have the same shape from the viewpoint of improving productivity, and the core members 10a and 10b each have a disk shape that covers the end portion of the coil 2 in the axial direction. The disc part 11 and the cylindrical part 12 extending substantially perpendicularly from the outer peripheral edge of the disc part 11 are provided.

  These core members 10a and 10b are made of a material having predetermined magnetic properties. In this embodiment, the core members 10a and 10b are made of a green compact (compact core) obtained by pressurizing and solidifying the insulating film-coated iron powder. The soft magnetic powder used for the green compact is a ferromagnetic metal powder, for example, pure iron powder, iron-based alloy powder (for example, Fe-Al alloy, Fe-Si alloy, Sendust, Permalloy, etc.), or amorphous A powder is mentioned. Furthermore, as an insulating film covering the surface of the soft magnetic powder, a film made of an inorganic material such as an oxide, a film made of an organic material such as a silicone resin, or a two-layered structure of an inorganic material and an organic material is combined. A film is formed.

  The core members 10a and 10b can control the magnetic properties by the particle size and particle size distribution of the powder, and also the density of the molded body. For example, by increasing the density of the molded body, the magnetic permeability is increased and the particle size of the powder is decreased. By doing so, it is possible to suppress eddy current loss. Therefore, in order to realize the electromagnetic characteristics required for the reactor, the particle size of the powder used for the green compact and the density of the compact are adjusted. In the case of pure iron powder, the density of the compact can be adjusted by adding the nonmagnetic powder material in the range of about 3.0 g / cc to about 5.0 g / cc, and about 5.0 g / cc to about 7 In the range of 0.7 g / cc, the pressure can be adjusted by molding.

  Then, the cylindrical portions 12 and 12 of the two core members 10a and 10b are combined so as to contact each other, thereby forming the first core 1a having the coil storage portion 13 therein.

  Further, the cylindrical portions 12 that are combined with each other are provided with connection holes 14 that are opened from the end surface of the cylindrical portion 12 to the outside at a predetermined depth in the axial direction so as to penetrate from the coil storage portion 13 to the outside.

  In addition, a first outlet hole 15 is provided in the disk portion 11 of the core member 10a on one axial side (the upper side in FIG. 1) so as to penetrate from the coil housing portion 13 to the outside.

  Instead of the first lead hole 15, the second core 1b is opened in the disk portion 11 of the core member 10b on the other axial side (the lower side in FIG. 1) so as to penetrate from the coil housing portion 13 to the outside. The second outlet hole 16 is provided, and the other configuration is substantially the same as that of the first core 1a.

  The coil 2 includes a first coil part 2a housed in the first core 1a and a second coil housed in the second core 1b and stacked on the other axial side of the first coil part 2a (lower side in FIG. 1). The coil part 2b is provided.

  The first coil portion 2a includes a coil body portion 20a, a first coil connection portion 20c, and a first lead portion 20b. The first coil portion 2 a is formed by a strip-shaped first conductor 21 and a second conductor 22.

In this embodiment, the first conductor 21 and the second conductor 22 have substantially the same configuration, and are made of aluminum having a predetermined thickness that is insulatively coated with an insulating material except for both ends. This thickness is less than or equal to the skin depth (skin thickness) with respect to the drive frequency supplied to the reactor 10, and the eddy current loss can be further reduced. In general, the current flowing through the coil flows only in the range up to the skin depth, and the current does not flow uniformly throughout the conductor cross section. Therefore, eddy current loss can be reduced by setting the thickness of the conductors 21 and 22 to be equal to or less than the skin depth. The skin depth δ is generally δ = (ρ / πfμ) ^1/2 (where f: frequency, μ: magnetic permeability of the conductor member, ρ: electrical conductivity of the conductor member). FIG. 3 is a graph showing skin depth δ of various metal materials as a function of frequency.

  The coil body portion 20a is formed on the cylindrical winding frame 3 in a state where the first conductor 21 and the second conductor 22 are overlapped with each other in the thickness direction, sequentially from the radially inner side to the radially outer side. It is formed in a pancake shape by being wound in the clockwise direction (one direction). Further, in this state, the one end portion 21a of the first conductor 22 is disposed on the most radially outer side, and the one end portion 22a of the second conductor 22 is disposed on the radially inner side of the one end portion 21a of the first conductor 21. The first conductor 21 is disposed adjacent to one end 21a.

  The first coil connecting portion 20c is formed on the radially outer side of the coil body portion 20a, and a part of each of the one end portion 21a of the first conductor 21 and the one end portion 22a of the second conductor 22 is the first. One coil connecting portion 20c is formed.

  The first lead portion 20b is formed on the radially inner side of the coil body portion 20a, and a part of each of the other end portion 21b of the first conductor 21 and the other end portion 22b of the second conductor 22 is the first. The lead portion 20b is formed.

  As shown in FIG. 1, the first coil portion 2a formed in this way has the coil main body portion 20a housed in the coil housing portion 13 of the first core portion 1a and the first lead portion 20b first. The first coil connecting portion 20c is extended from the connecting hole 14 to the outside in the radial direction.

  Similar to the first coil portion 2a, the second coil portion 2b includes a coil main body portion 19a, a second coil connection portion 19c, and a second lead-out portion 19b. The second coil portion 2b is also shaped like a belt. The first conductor 21 and the second conductor 22 are formed. The first conductor 21 and the second conductor 22 have the same configuration as that of the first coil portion 2a.

  Then, in a state where the first conductor 21 and the second conductor 22 are overlapped with each other in the thickness direction, the winding frame 3 sequentially from the radially inner side to the radially outer side in the same winding direction as the first coil portion 2a, That is, it is formed in a pancake shape by being wound in the counterclockwise direction (one direction) in FIG.

  However, the coil body portion 19a of the second coil portion 2b is different from the first coil portion 2a in that the one end portion 22a of the second conductor 22 is arranged on the outermost radial direction as shown in FIG. One end 21 a of one conductor 21 is disposed radially inward of one end 22 a of second conductor 22 and adjacent to one end 22 a of second conductor 22.

  The second coil connecting portion 19c of the second coil portion 2b is formed on the radially outer side of the coil body portion 20a, and is formed between the one end portion 21a of the first conductor 22 and the one end portion 22a of the second conductor 22. Each part forms the second coil connection portion 19c.

  The second lead portion 19b is formed on the radially inner side of the coil body portion 19a, and a part of each of the other end portion 21b of the first conductor 21 and the other end portion 22b of the second conductor 22 is the second. The lead portion 19b is formed.

  As shown in FIG. 1, the second coil portion 2b formed in this way has the coil main body portion 19a housed in the coil housing portion 13 of the second core portion 1b and the second lead portion 19b second. The second coil connecting portion 19c is extended from the connecting hole 14 to the outside in the radial direction.

  Further, the first coil connection portion 20c and the second coil connection portion 19c that are extended from the connection hole 14 are electrically connected by a lead wire or the like. Specifically, the one end portion 21a of the first conductor 21 in the first coil portion 2a and the one end portion 21a of the first conductor 21 in the second coil portion 2b are electrically connected, and the first coil portion 2a One end 22a of the second conductor 22 and one end 21a of the second conductor 21 in the second coil portion 2b are electrically connected by a lead wire or the like.

  As a result, a first coil portion 2a and a pancake-like second coil portion 2b are formed on one axial side (the lower side in FIG. 1) of the first coil portion 2a, and are laminated in the axial direction. The coil part 2 which has the two coil parts 2a and 2b is obtained.

  The reactor 10 of the present invention configured as described above is formed by winding one conductor into two pancakes having the same diameter by overlapping two first conductors 21 and two second conductors 22 in parallel. The number of turns is halved compared to the coil, but the number of turns in the entire coil is unchanged by doubling in two stages in series in the axial direction. On the other hand, the conductor cross-sectional area is also doubled by the parallel two-layer stacking and remains unchanged.

  In this embodiment, the first coil portion 2 a is arranged such that one end portion of the first conductor 21 is arranged on the outermost side in the radial direction, and one end portion of the second conductor 22 is one end portion of the first conductor 21. The second coil portion 2b is arranged such that one end portion of the second conductor 22 is arranged on the outermost radial direction, and one end portion of the first conductor 21 is one end portion of the first conductor. It is arrange | positioned at the radial inside. In other words, the first coil portion 2a and the second coil portion 2b are arranged such that the radial positions of the respective one end portions of the first conductor 21 and the second conductor 22 are reversed. The one end portion 21a of the first conductor 21 in the first coil portion 2a and the one end portion 21a of the first conductor 21 in the second coil portion 2b are electrically connected, and the first end portion 21a in the first coil portion 2a is electrically connected. One end 22a of the two conductors 22 and one end 21a of the second conductor 21 in the second coil portion 2b are electrically connected.

  As a result, as shown in FIG. 4, the first conductor 21 and the second conductor 22 in the first coil portion 2a are energized to the first conductor 21 and the second conductor 22 of the first and second coil portions 2a, respectively. Direction of the magnetic flux line q1 penetrating in the axial direction through the loop formed by and the magnetic flux line q2 penetrating in the axial direction through the loop formed by the first conductor 21 and the second conductor 22 in the second coil portion 2b Are opposite to each other. Therefore, the induced electromotive force generated in the conductors 21 and 22 of the first coil portion 2a and the second coil portion 2b adjacent to each other in the axial direction is canceled, thereby effectively suppressing the eddy current and suppressing the eddy loss. be able to.

  Further, in the above embodiment, the first conductor 21 and the second conductor 22 can be formed by using the two first coil portions 2a and the second coil portion 2b formed by winding in the same winding direction, and can be easily manufactured. Can be.

  In the above-described embodiment, the first conductor 21 and the second conductor 22 are arranged so that the radial positions of the respective one end portions are reversed between the first coil portion 2a and the second coil portion 2b. However, it is not limited to this form, and can be changed as appropriate.

  For example, as shown in FIG. 5, in the first coil portion 2a and the second coil portion 2b, the winding directions of the first and second conductors 22 are reversed (in FIG. 5, the first coil portion 2a is radially inward). The second coil portion 2b is wound in the clockwise direction from the radially inner side to the outer side), and the first conductors 21 of the first coil portion 2a and the second coil portion 2b, respectively. The one end portion 21 a of the second conductor 22 is arranged on the radially inner side of the one end portion of the first conductor 21. The one end portion 21a of the first conductor 21 in the first coil portion 2a and the one end portion 21a of the first conductor 21 in the second coil portion 2b are electrically connected, and the first end portion 21a in the first coil portion 2a is electrically connected. It is assumed that one end 22a of the two conductors 22 and one end 22a of the second conductor 22 in the second coil portion 2b are electrically connected.

  Even if it does in this way, it forms with the 1st conductor 21 and the 2nd conductor 22 in the 1st coil part 2a with energization to the 1st conductor 21 and the 2nd conductor 22 of each of the 1st and 2nd coil parts 2a. A magnetic flux line q1 (see FIG. 2) penetrating the loop in the axial direction, and a magnetic flux line q2 penetrating the loop formed by the first conductor 21 and the second conductor 22 in the second coil portion 2b in the axial direction. Can be opposite to each other. As a result, the induced electromotive force generated in each of the conductors 21 and 22 of the first coil portion 2a and the second coil portion 2b adjacent to each other in the axial direction is canceled, thereby effectively suppressing the eddy current and reducing the eddy loss. Can be suppressed.

  That is, in FIG. 5, one coil portion of the two coil portions is arranged such that one end portion of the first conductor is arranged on the outermost side in the radial direction, and one end portion of the second conductor is one end portion of the first conductor. The first and second conductors are formed by being wound in one direction sequentially from the radially inner side to the radially outer side so as to be disposed on the radially inner side of the two coil portions. The coil portion includes a first conductor such that one end of the first conductor is disposed on the outermost side in the radial direction, and one end of the second conductor is disposed on the inner side in the radial direction of the one end of the first conductor. And the second conductor is formed by being wound in the other direction in which the winding direction is opposite to the one coil part sequentially from the radially inner side to the radially outer side, and the first conductor of the one coil part is formed. One end and one end of the first conductor of the other coil are electrically connected. With a first end of the second conductor of one end and the other coil portion of the second conductor of one coil portion are electrically connected.

  Moreover, in the said embodiment, although the core part 1 was comprised from the cylindrical thing which does not have a hole in center part, it is not restricted to this form, It can change suitably. For example, as shown in FIG. 6, each of the first and second cores 201a and 201b is formed of a cylindrical shape having a hole 211a at the center thereof, and a columnar pole piece 206 is arranged in the hole 211a. It may be provided.

  Specifically, the pole piece 206 is a cylindrical body made of a green compact obtained by pressurizing and hardening an insulating film-coated iron powder, for example. The soft magnetic powder used for the green compact is a ferromagnetic metal powder, for example, pure iron powder, iron-based alloy powder (for example, Fe-Al alloy, Fe-Si alloy, Sendust, Permalloy, etc.), or amorphous A powder is mentioned.

  The pole piece 206 has an outer diameter smaller than the inner diameter of the hole 211a of the first and second cores 201a and 201b, and the outer peripheral surface of the pole piece 206 and the hole 211a of the first and second core parts 201a and 201b. A gap 207 is formed between the inner peripheral surface and the inner peripheral surface.

  In this way, when the coaxial structure in which the pole piece 206 is disposed at the center of the first and second cores 201 a and 201 b is used, the magnetic circuit gap 207 has a circular shape surrounding the pole piece 206. At this time, depending on the assembly error of the pole piece 206, the gap 207 is narrowed and widened, but the contribution to the inductance cancels out, so that the variation in inductance becomes much more tolerant of the assembly accuracy. Since the change in inductance causes a magnetic attraction force as it is, the vibration accompanying the change in the air gap due to the AC excitation can be essentially eliminated.

  Further, in this case, the pole piece 206 in which the magnetic flux lines are concentrated and the magnetic flux density is higher than that of the core part 201 is made of a material having a higher magnetic permeability than the first and second cores 201a and 201b, that is, having a higher density. It is preferable to keep it. Thereby, the leakage magnetic flux line to the coil 2 can be reduced, and the eddy current loss in the coil 2 can be suppressed.

  Moreover, in the said embodiment, although the core part 1 was comprised from two with the 2nd core 1b which consists of the 1st core 1a and the 1st core 1a which was separate, the thing of this form However, it can be changed as appropriate.

  For example, it may be composed of one integrally formed. In detail, as shown in FIG. 7, the core part 301 is comprised from the core main body 310a by which both surfaces of the axial direction were opened, and the two 1st and 2nd core member pieces 310b and 310c.

  The core main body 310a includes connection holes 314a in the upper and lower portions of the circumferential surface.

  The first core member piece 310b includes a first lead hole 315 penetrating in the axial direction, and includes a connection hole 314b on the peripheral surface. And the 1st core member piece 310b is united with the core main body 310a from the one side (upper side of FIG. 6) of an axial direction. Thereby, between the 1st core member piece 310b and the core main body 310a, the 1st coil accommodating part 313a which accommodates the 1st coil part 2a by the 1st core member piece 310b and the core main body 310a is partition-formed. . Further, the connection hole 314a of the core body 310a and the connection hole 314b of the first core member piece 310b are combined to form one connection hole.

  The second core member piece 310c includes a second lead hole 316 penetrating in the axial direction, and a connection hole 314b on the peripheral surface. And the 2nd core member piece 310c is united with the core main body 310a from the other side (lower side of FIG. 6) of an axial direction. Thus, a second coil storage portion 313b for storing the second coil portion 2b is defined by the second core member piece 310c and the core body 310a between the second core member piece 310c and the core body 310a. . The connection hole 314a of the core body 310a and the connection hole 314b of the second core member piece 310c are combined to form one connection hole.

  Moreover, in the said embodiment, although the coil 2 was comprised from two of the 1st coil part 2a and the 2nd coil part 2b, it is not restricted to the thing of this form, Three or more coil parts are made to an axial direction. It may be laminated. Preferably, an even number of coil portions are stacked in the axial direction.

DESCRIPTION OF SYMBOLS 1 Core part 1a 1st core 1b 2nd core 2 Coil 2a 1st coil part 2b 2nd coil part 21 1st conductor 22 2nd conductor

Claims (5)

A reactor including a core part and a coil included in the core part,
The coil includes a plurality of coil portions stacked in an axial direction,
Each of the coil portions is arranged such that two strip-shaped first and second conductors electrically connected in parallel with each other are arranged so as to overlap each other in the thickness direction with an insulating layer interposed therebetween. And the second conductor are formed into a pancake shape by being wound,
The two coil portions adjacent to each other in the axial direction are arranged such that the directions of the magnetic flux lines formed so as to penetrate each coil portion are energized with energization of the first and second conductors of each coil portion. The one end portion of the first conductor in one coil portion of the two coil portions and the one end portion of the first conductor in the other coil portion are electrically connected, and the one A reactor configured such that one end of the second conductor in the coil portion and one end of the second conductor in the other coil portion are electrically connected. In the one coil portion, one end portion of the first conductor is arranged on the outermost side in the radial direction, and one end portion of the second conductor is arranged on the inner side in the radial direction of the one end portion of the first conductor. As described above, the first and second conductors are formed by being sequentially wound in one direction from the radially inner side to the radially outer side,
In the other coil portion, one end portion of the second conductor is arranged on the outermost side in the radial direction, and one end portion of the first conductor is arranged on the inner side in the radial direction of the one end portion of the second conductor. As described above, the first and second conductors are formed by being wound in the one direction sequentially from the radially inner side to the radially outer side,
The one end portion of the first conductor in the one coil portion and the one end portion of the first conductor in the other coil portion are electrically connected, and the second conductor in the one coil portion is electrically connected. The reactor according to claim 1, wherein one end portion and one end portion of the second conductor in the other coil portion are electrically connected.   3. The reactor according to claim 1, wherein the core portion is made of a green compact that is an insulating film-coated metal powder and is formed by pressing and solidifying a ferromagnetic metal powder. A cylindrical pole piece disposed substantially in the center of the core part, further comprising:
The core portion includes a hole for receiving the pole piece in the substantially central portion;
The said pole piece is arrange | positioned in the said hole so that a clearance gap can be formed between the inner periphery of the hole in the said core part, and the outer periphery of the said pole piece. The reactor as described in any one. The core part and the pole piece are formed of a green compact obtained by pressurizing and solidifying a ferromagnetic metal powder, which is an insulating film-coated metal powder,
The reactor according to claim 4, wherein a density of the pole piece is higher than a density of the core portion.