JP2013143454A - Reactor, core component, manufacturing method of reactor, converter, and electric power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor which achieves excellent assembly workability while ensuring electrical insulation between a coil and a magnetic core.SOLUTION: A reactor 1A includes: a coil 2 formed by winding a winding wire 2w; and a magnetic core 3 disposed at the interior and the exterior of the coil 2 and forming a closed magnetic path. At least a part of the magnetic core 3 is formed by a composite material including magnetic powder and a resin. The reactor 1A further includes a resin case 4. The resin case 4 houses the magnetic core 3 and electrically insulates the magnetic core 3 from the coil 2. The magnetic core 3 and the resin case 4 are integrally joined by the composite material forming the magnetic core 3.

Description

  The present invention relates to a reactor used as a component of a power conversion device such as an in-vehicle DC-DC converter mounted on a vehicle such as a hybrid vehicle, a core component suitable for the component of the reactor, a method of manufacturing the reactor, The present invention relates to a converter including a reactor and a power conversion device including the converter. In particular, the present invention relates to a reactor excellent in assembling workability and a manufacturing method thereof.

  A reactor is one of the parts of a circuit that performs a voltage step-up operation or a voltage step-down operation. This reactor is used for a converter mounted on a vehicle such as a hybrid vehicle. As the reactor, for example, there is one shown in Patent Document 1.

  The reactor of patent document 1 is provided with the cyclic | annular core (magnetic core), the coil arrange | positioned on the outer periphery of this core, and the insulator for ensuring the insulation between a core and a coil. The core includes an intermediate core (inner core portion) and an end core (outer core portion). The intermediate core is configured by alternately laminating core pieces and gap portions at locations where coils are disposed on the outer periphery thereof. The end core connects the end faces of the intermediate core. The insulator includes a cylindrical portion that covers the outer periphery of the intermediate core, and a pair of flange portions that are in contact with the end face of the coil. The tubular portion covers the outer periphery of the intermediate core by joining the half-cut square tube pieces together. A collar part is a rectangular frame arrange | positioned at the both ends of a cylindrical part.

JP 2010-272772 A

  By disposing the insulator as described above, the distance between the coil and the magnetic core can be maintained so that the coil and the magnetic core do not come into contact with each other, and insulation between the coil and the magnetic core can be ensured. In the case of the above-described reactor, it is necessary to arrange a tubular insulator on the outer periphery of the inner core portion, and to arrange the reactor integrally with the outer core portion and the coil between the outer core portion and the coil. Assembling workability tends to be complicated.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a reactor excellent in assembly workability while ensuring insulation between a coil and a magnetic core.

  Another object of the present invention is to provide a core component that can be suitably used for the reactor.

  Another object of the present invention is to provide a reactor manufacturing method for manufacturing the reactor.

  Another object of the present invention is to provide a converter including the reactor and a power converter including the converter.

  A reactor according to the present invention includes a coil formed by winding a winding and a magnetic core that is disposed inside and outside the coil to form a closed magnetic circuit, and at least a part of the magnetic core includes magnetic powder and resin. Consists of composite materials. A resin case for housing the magnetic core and insulating the magnetic core and the coil is provided. And the magnetic core and the resin case are integrally joined by the constituent resin of the composite material.

  By providing the resin case, the reactor according to the present invention functions as an insulating member that insulates the magnetic core from the coil, so that the insulation between the coil and the magnetic core can be ensured. Further, since the resin case and the magnetic core are integrally joined with the constituent material of the magnetic core, the number of parts is small and the assembly workability is excellent.

  As one form of this invention reactor, it is mentioned that a magnetic core contains a compacting body.

  According to said structure, it can be set as the magnetic core from which magnetic permeability differs partially by including the compacting body which is easy to generally make high permeability.

  As one form of this invention reactor, it is mentioned that a magnetic core is provided with the inner core part arrange | positioned inside a coil, and the outer core part which is arrange | positioned on the outer side of a coil and forms a closed magnetic circuit with an inner core part. It is done. Either one of the inner core portion and the outer core portion has a composite material having a higher magnetic permeability than the other.

  According to said structure, when the magnetic permeability of the inner core part is higher than an outer core part, the magnetic flux density of an inner core part can be raised and an inner core part can be made compact. When the magnetic permeability of the outer core portion is higher than that of the inner core portion, the leakage magnetic flux from the outer core portion can be reduced.

  As one form of this invention reactor, it is mentioned that content of the magnetic body powder in a composite material is 30 volume% or more and 70 volume% or less.

  According to said structure, since the ratio of the magnetic component which occupies for a magnetic core is sufficiently high because content of magnetic body powder shall be 30 volume% or more, the saturation magnetic flux density of the core can be raised. By setting the content of the magnetic powder to 70% by volume or less, the fluidity is excellent and the productivity of the composite material is excellent.

  As one form of this invention reactor, it is mentioned that the inner core part arrange | positioned inside a coil among magnetic cores is comprised with the compacting body.

  According to said structure, since an inner core part can be made into a high magnetic permeability by comprising an inner core part with the compacting body which is generally easy to make it high magnetic permeability, a magnetic flux can be passed more through a coil. As a result, when obtaining the same magnetic flux as a reactor in which the inner core portion is not formed of a compacted body, the inner core portion can be reduced in size, and the reactor as a whole can be reduced in size.

  As one form of the reactor of the present invention, a coil formed by connecting a pair of coil elements wound with windings in parallel with each other, a pair of inner core portions disposed inside each coil element, and exposed from the coil And a magnetic core having a pair of outer core portions that are connected to each inner core portion to form an inner core portion and an annular core. The shape of the resin case is composed of any one of an L shape, a J shape, a] shape, and a U shape that integrally store at least a part of one outer core portion and the inner core portion. It is mentioned.

  According to the above configuration, since the shape of the resin case is any of the above, at least a part of the one outer core portion and the inner core portion can be integrally stored in the resin case, and the reactor is configured. The number of parts to be reduced can be reduced.

  The core component of the present invention is a component for constituting a reactor including a coil formed by winding a winding and a magnetic core that is disposed inside and outside of the coil to form a closed magnetic circuit, and a magnetic core and a resin case. With The magnetic core has a composite material including a magnetic powder and a resin. The resin case houses the magnetic core and insulates the magnetic core from the coil when the coil is arranged on the outer periphery of the magnetic core. And the magnetic core and the resin case are integrally joined by the constituent resin of the composite material.

  The core component of the present invention is easy to handle because the magnetic core is housed in the resin case and the magnetic core and the resin case can be integrated, and can be suitably used for the construction of the reactor.

  The reactor manufacturing method of the present invention includes a magnetic core that forms a closed magnetic path inside and outside a coil formed by winding a winding, and at least a part of the magnetic core is composed of a composite material including magnetic powder and resin. The reactor manufacturing method includes a case preparation process and a core part molding process. The case preparing step prepares a resin case that houses the magnetic core and insulates the magnetic core from the coil. In the core part molding step, at least a part of the resin case is filled with the composite material, the constituent resin of the composite material is cured, and the composite material and the resin case are joined together.

  The reactor manufacturing method of the present invention can manufacture a reactor that can insulate a magnetic core and a coil when combined with a coil and is excellent in assembly workability.

  The reactor of the present invention can be suitably used as a component part of a converter. The converter of the present invention comprises a switching element, a drive circuit that controls the operation of the switching element, and a reactor that smoothes the switching operation, and converts the input voltage by the operation of the switching element. The form whose reactor is this invention reactor is mentioned. This converter of the present invention can be suitably used as a component part of a power converter. The power converter of the present invention includes a converter that converts an input voltage and an inverter that is connected to the converter and converts between direct current and alternating current, and drives a load with the power converted by the inverter. And the converter is a converter according to the present invention.

  The converter and the power conversion device of the present invention are excellent in assembly workability as a whole of the converter and the power conversion device by providing the reactor of the present invention that is excellent in assembly workability while ensuring insulation between the coil and the magnetic core. It can be suitably used for in-vehicle components.

  The reactor of the present invention is excellent in assembly workability while ensuring insulation between the coil and the magnetic core.

  Since the core component of the present invention is easy to handle, it can be suitably used to construct a reactor.

  The reactor manufacturing method of the present invention can manufacture a reactor excellent in assembly workability.

  The converter and power converter of the present invention can be suitably used for in-vehicle components.

(A) is a schematic perspective view which shows the reactor which concerns on Embodiment 1, (B) is (B)-(B) sectional drawing taken along (A). 1 is a schematic exploded perspective view of a reactor according to Embodiment 1. FIG. 5 is a schematic exploded perspective view of a reactor according to Embodiment 2. FIG. 1 is a schematic configuration diagram schematically showing a power supply system of a hybrid vehicle. It is a schematic circuit diagram which shows an example of this invention power converter device which provides this invention converter.

  Hereinafter, an embodiment of a reactor of the present invention will be described with reference to the drawings. The same reference numerals in the figure indicate the same names.

Embodiment 1
[Reactor]
A reactor 1A according to the first embodiment will be described with reference to FIG. 1 and FIG. The reactor 1A includes a coil 2 and a magnetic core 3. The magnetic core 3 is composed of a plurality of divided pieces, and each divided piece is housed in a resin case 4 to constitute a core component 10. The feature of the reactor 1A is that at least a part of the magnetic core 3 is composed of a composite material including magnetic powder and resin, and the magnetic core 3 and the resin case 4 are integrally joined with the resin. . In this example, a coil 2 having a pair of coil elements 2a and 2b formed by spirally winding the winding 2w, and a pair of inner core portions 31 (31a and 31b respectively) disposed in the coil elements 2a and 2b, respectively. ) And the magnetic core 3 having the outer core portion 32 (32a, 32b) that connects these inner core portions 31 (31a, 31b) to form a closed magnetic circuit. Hereinafter, each configuration will be described in detail. In the description, the core component 10 including the resin case 4 which is a feature of the present invention will be described.

[Core parts]
Here, there is a pair of core components 10, each including a part of the magnetic core 3 and resin cases 4a and 4b. The magnetic core 3 and the resin cases 4a and 4b constitute at least a part of the magnetic core 3. They are joined together with a composite material. When the coil 2 is combined with the pair of core components 10a and 10b to excite the coil 2, the magnetic core 3 forms a closed magnetic circuit.

(Resin case)
The resin cases 4a and 4b each house a part of the magnetic core 3, ensure insulation between the coil 2 and the magnetic core 3, and protect the magnetic core 3 from the external environment.

  The material of the resin case 4 is insulative enough to insulate the coil 2 from the magnetic core 3, and heat when the reactor 1A is used and heat when filling a composite material of the magnetic core 3 described later. And a resin having a heat resistance enough to withstand. As the material, for example, epoxy resin, silicone resin, polybutylene terephthalate (PBT) resin, urethane resin, polyphenylene sulfide (PPS) resin, acrylonitrile-butadiene-styrene (ABS) resin and the like can be used. Alternatively, it is preferable that the resin case 4 is made of the same resin as that of the composite material constituting the magnetic core 3 because the adhesion to the magnetic core 3 can be improved.

  The shape of at least one of the two resin cases 4a and 4b is preferably a shape that can accommodate one outer core portion 32 and at least a part of the inner core portion 31 integrally. Then, since the outer core portion 32 and the inner core portion 31 can be handled as an integrated object, the number of parts constituting the reactor 1A can be reduced. In particular, it is preferable that the inner core portion storage region for storing the inner core portion 31 in the resin case 4 and the outer core portion storage region for storing the outer core portion 32 communicate with each other. The inner core portion 31 and the outer core portion 32 can be directly connected. A portion corresponding to the inner core portion storage area is disposed inside the coil 2.

  Examples of combinations of the outer core portion 32 and the inner core portion 31 that are accommodated in the resin case 4 include, for example, “one inner core portion 31 and one outer core portion 32”, “part of one inner core portion 31 and the other. Inner core portion 31 and one outer core portion 32 ”,“ both inner core portions 31 and one outer core portion 32 ”, and“ a part of both inner core portions 31 and one outer core portion 32 ”. Can be mentioned. It is preferable that the resin case 4 can accommodate these combinations.

  Specific shapes of the resin case 4 include a rectangular shape, an L shape, a J shape, a U shape, and a] shape. That is, the resin case 4 is composed of a bottom portion formed of any one of a rectangular shape, an L shape, a J shape, a U shape, and a] shape, and a plurality of side wall portions erected from each side of the bottom portion. A box-shaped body in which the bottom and the side wall are integrally formed can be used. The L-shaped resin case 4 can accommodate, for example, “one inner core portion 31 and one outer core portion 32” integrally. In the case of the J-shape, for example, “a part of one inner core portion 31, the other inner core portion 31, and one outer core portion 32” can be accommodated integrally. In the case of a U-shape, for example, “both inner core portions 31 and one outer core portion 32” can be accommodated integrally. ], For example, “a part of one inner core part 31, a part of the other inner core part 31, and one outer core part 32” can be accommodated integrally. Each side wall part may be comprised only by the plane, and may be comprised by the plane and the curved surface. For example, at least one of the surface facing the inner end surface 32e of the outer core portion and the surface facing the outer end surface 32o of the side wall portion of the resin case 4 is formed of a curved surface, and the outer core portion 32 is accommodated in the resin case 4. The region may be formed in an arc shape. The side facing the bottom surface of the resin case 4 is open. The magnetic core 3 can be stored from this opening.

  When the core parts 10a and 10b are configured using the two resin cases 4a and 4b, it is preferable that the resin cases 4a and 4b have the same shape. Then, the manufacturability of the core component 10 is more excellent. The combination of the shapes of the pair of resin cases 4a and 4b is typically "L-shaped-L-shaped", "J-shaped-J-shaped", or "] -shaped-]-shaped". Can be mentioned. By making the pair of resin cases 4 L-shaped, when connecting the pair of core parts 10 in an annular shape, the connecting part between the core parts 10a and 10b can be arranged outside the coil 2, and the core parts 10a and 10b It is easy to connect each other. The shapes of the pair of resin cases 4a and 4b may be different from each other. Examples of combinations in which the shapes of the pair of resin cases 4a and 4b are different from each other include “U-shaped-I-shaped”. The I-shaped resin case is composed of an I-shaped (rectangular) bottom portion and a plurality of side walls erected from each piece of the bottom portion. Even in that case, the number of parts can be reduced, so that the assembly workability of the reactor 1A can be improved.

  Here, the shape of the pair of resin cases 4a and 4b is the same. The pair of resin cases 4a and 4b is an L-shaped box formed by an L-shaped bottom and six side walls standing on the bottom, and the bottom and side walls are both flat. Is done. The resin case 4 accommodates one outer core portion 32 and one inner core portion 31 integrally. The inner core portion 31 and the outer core portion 32 housed in the resin case 4 are prismatic bodies, and an integrated body of both the core portions 31 and 32 is an L-shaped prismatic body.

  The end surface 4e of one resin case 4 (4a) and the opposing surface of the other resin case 4 (4b) facing the end surface 4e function as a gap between the inner core portion 31 and the outer core portion 32. The magnetic core 3 may be exposed by providing an opening in at least one of the end surface 4e of the resin case 4 (4a) and the facing surface of the resin case 4 (4b) facing the end surface 4e. When the magnetic core 3 is exposed from both the opposing surfaces, the end surface 31e of the inner core portion 31 (31a) in one core component 10 (10a) and the outer core portion 32 (32b) in the other core component 10 (10b) This inner end face (32e) can be directly connected without going through the resin case 4 (4a, 4b), and the magnetic core 3 without a gap can be formed throughout. When the core component 10 is manufactured, a sealing plate is disposed in the opening so that the composite material does not leak from the opening, so that the magnetic core 3 is accommodated in the resin case 4, and the opening A core component 10 having a portion can be produced. The sealing plate may be removed after the composite material is cured.

  The resin case 4 may further include a lid 40. If the opening of the resin case 4 is closed with the lid 40, the insulation between the magnetic core 3 and the coil 2 can be ensured more reliably. The shape of the lid 40 may be a shape along the shape of the bottom (opening) of the resin case 4. Here, the lid portions 40a and 40b are formed of L-shaped flat plates. The same material as the resin case 4 can be used as the material of the lid 40. The lid 40 may also be integrally joined to the magnetic core 3 by a composite material constituting the magnetic core 3, or may be separately fixed to the resin case 4 with an adhesive or a tape.

  Injection molding can be suitably used for molding the resin case 4.

(Magnetic core)
The magnetic core 3 is disposed outside the coil elements 2a and 2b and connected to the inner core parts 31a and 31b, and a pair of inner core parts 31a and 31b disposed inside the coil elements 2a and 2b. Inner core portions 31a and 31b and outer core portions 32a and 32b forming an annular core are provided.

  At least a part of the magnetic core 3 is composed of a composite material containing magnetic powder and resin. The entire magnetic core 3 may be composed of a composite material. In this case, it is preferable that the magnetic permeability is different between the inner core portion 31 and the outer core portion 32. For example, the inner core portion 31 may be made of a composite material having a higher permeability (lower) than the outer core portion 32, or the outer core portion 32 may be made of a composite material having a higher permeability (lower) than the inner core portion 31. You may comprise. The magnetic permeability of each of the core portions 31 and 32 can be changed by appropriately adjusting the content of the magnetic powder contained in the composite material. In addition to the composite material, the magnetic core 3 may include a green compact or a laminate of electromagnetic steel sheets. A part with a high magnetic permeability can be made partially by including a green compact or a laminate of electromagnetic steel sheets in part. The inner core portion 31 may include a green compact or a laminate of electromagnetic steel plates, and the outer core portion 32 may include a green compact or a laminate of electromagnetic steel plates. By making the magnetic permeability of the inner core portion 31 higher than the magnetic permeability of the outer core 32, it is possible to pass more magnetic flux. Leakage magnetic flux can be reduced by making the magnetic permeability of the outer core portion 32 higher than the magnetic permeability of the inner core portion 31.

  The green compact is typically manufactured by subjecting raw material powder to pressure treatment and then appropriately heat treatment, and can be molded relatively easily even if it has a complicated three-dimensional shape. The raw material powder includes a coating powder or a ferrite powder having an insulating coating made of silicone resin or phosphate on the surface of particles made of a soft magnetic material such as an iron-based material (iron group metal or iron alloy) or a rare earth metal, Furthermore, a mixed powder in which an additive such as a resin such as a thermoplastic resin and an additive such as a higher fatty acid (typically one that disappears by heat treatment or changes into an insulator) is appropriately mixed. By the above manufacturing method, a green compact with an insulating material interposed between soft magnetic particles is obtained. Since this green compact has excellent insulation, eddy current loss can be reduced. The green compact can increase the saturation magnetic flux density by adjusting the raw materials and manufacturing conditions such as increasing the amount of soft magnetic powder of the raw materials and increasing the molding pressure. A well-known thing can be utilized for a compacting body.

  The composite material can typically be manufactured by cast molding. In cast molding, a composite material is obtained by injecting a mixture containing magnetic powder and resin into a mold (resin case 4) without applying pressure and molding and curing.

  The magnetic substance powder in the composite material may be, for example, the same composition as the soft magnetic powder constituting the green compact or a different composition. Even in the case of the same composition, since the composite material contains a resin that is a nonmagnetic material, the saturation magnetic flux density is lower than that of the green compact and the magnetic permeability is also lower.

  The magnetic powder in the composite material may contain a single type or a plurality of types of powders having different materials. That is, it includes at least one kind of the above-mentioned soft magnetic powder. In any case, even in the case of a composite material, if it is a coating powder as in the case of a green compact, the insulation between soft magnetic particles can be improved and eddy current loss can be reduced.

  The average particle diameter of the magnetic powder in the composite material is 1 μm or more and 1000 μm or less, and particularly 10 μm or more and 500 μm or less. When the magnetic powder includes a plurality of types of powders (coarse powder and fine powder) having different particle diameters, it is easy to obtain a reactor having a high saturation magnetic flux density and a low loss. The average particle size of the magnetic powder in the composite material is substantially the same (maintained) as that of the raw material powder. When a powder having an average particle diameter satisfying the above range is used as a raw material, the composite material can be manufactured with good productivity and excellent productivity.

  The content of the magnetic powder in the composite material is 30% by volume or more and 70% by volume or less in terms of volume ratio when the composite material is 100%. When the magnetic substance powder is 30% by volume or more, since the ratio of the magnetic component is sufficiently high, it is easy to improve the magnetic characteristics such as the saturation magnetic flux density of the entire magnetic core 3. When the magnetic powder is 70% by volume or less, the productivity of the composite material is excellent.

  Typically, the resin used as the binder in the composite material includes a thermosetting resin such as an epoxy resin, a phenol resin, a silicone resin, and a urethane resin. In addition, thermoplastic resins such as PPS resin, polyimide resin, and fluorine resin, room temperature curable resin, or low temperature curable resin can be used.

  In addition to the magnetic powder and the resin, a composite material containing a powder (filler) made of a nonmagnetic material such as ceramics such as alumina or silica can be obtained. The filler contributes to suppression (uniform dispersion) of uneven distribution of the magnetic powder. If the filler is fine, intervening between the magnetic particles can suppress a decrease in the ratio of the magnetic powder due to the inclusion of the filler. When the composite material is 100% by mass, the filler content is 0.2% by mass or more and 20% by mass or less, further 0.3% by mass or more and 15% by mass or less, particularly 0.5% by mass or more and 10% by mass or less. The effect of suppressing the uneven distribution of the powder and the effect of suppressing the decrease in the content of the magnetic powder can be sufficiently obtained.

  When the outer core portion 32 (inner core portion 31) has a higher magnetic permeability than the inner core portion 31 (outer core portion 32), the relative permeability of the outer core portion 32 (inner core portion 31) is 15 to 500. The relative permeability of the inner core portion 31 (outer core portion 32) is 5 to 15, and the relative permeability of the entire magnetic core 3 is 10 to 50.

  When the magnetic core 3 includes a green compact, the ratio of the green compact and the composite material may be appropriately selected so as to satisfy the above-described relative permeability. When the total of the green compact and the composite material is 100%, for example, when the outer core portion 32 (inner core portion 31) includes the green compact, the volume ratio of the green compact is 30% by volume or more 70 It is mentioned that it is made into volume% or less.

  The magnetic core 3 can be formed of a uniform material as a whole, but here the material is partially different. Specifically, the inner core portion 31 is composed of a composite material, and the outer core portion 32 is composed of the same composite material as that of the inner core portion 31 and a green compact. Thus, the magnetic core 3 is partially different in magnetic characteristics due to different constituent materials.

  The inner core portion 31 is composed of a composite material of a coating powder and an epoxy resin having an insulating coating on the surface of particles made of an iron-based material (pure iron) having an average particle size of 75 μm or less (pure components in the composite material). Iron powder content: 45% by volume). The inner core portion 31 does not include a gap material or an air gap. By configuring the inner core portion 31 with the composite material, the magnetic permeability can be made lower than that of the outer core portion 32 formed of the powder compact. In addition, the inner core portion 31 and the resin case 4 can be joined together.

  By configuring the outer core portion 32 with the same composite material and powder compact as the inner core portion 31, the magnetic permeability can be made higher than that of the inner core portion 31 composed of only the composite material. By including the composite material, the outer core portion 32 and the inner core portion 31 are easily joined together, and the outer core portion 32 and the resin case 4 are easily joined together.

  In one resin case 4 of this example, no gap is interposed between the outer core portion 32 and the inner core portion 31. That is, in the resin case 4, the inner core part 31 and the outer core part 32 having no gap can be integrated. Therefore, as described above, the end surface 4e of one resin case 4 and the opposite surface of the one resin case 4 to the end surface 4e of the other case 4 are opened, and the core components 10 including the case 4 are connected to each other. When combined in an annular shape, the magnetic core 3 without a gap can be formed throughout. By not having a gap, (1) downsizing, (2) reduction in loss, and (3) reduction in inductance reduction when energizing a large current can be achieved. Note that the magnetic core 3 can also have a form in which a gap material made of a nonmagnetic material such as an alumina plate or an air gap is interposed.

[coil]
The coil 2 includes a pair of coil elements 2a and 2b formed by spirally winding a single continuous winding 2w having no joint part, and a coil connecting part 2r for connecting both the coil elements 2a and 2b. . The coil elements 2a and 2b are hollow cylindrical bodies having the same number of turns, and are arranged in parallel (side by side) so that the axial directions are parallel to each other. The inside of both coil elements 2a and 2b is a place where a part of the core parts 10a and 10b is respectively arranged (FIG. 1 (A)). Thereby, the core parts 10a and 10b are combined in a ring shape to form the reactor 1A. On the other end side of the coil 2 (right side in FIG. 2), a part of the winding 2w is bent into a U shape to form a coil coupling portion 2r. With this configuration, the winding directions of both coil elements 2a and 2b are the same.

  Each coil element can be produced by separate windings, and one end of each coil element winding can be made into a coil joined by welding, soldering, crimping or the like.

  As the winding 2w, a coated wire having an insulating coating made of an insulating material can be suitably used on the outer periphery of a conductor made of a conductive material such as copper, aluminum, or an alloy thereof. The conductor is typically a rectangular wire, and various other cross-sectional shapes such as a circular shape, an elliptical shape, and a polygonal shape can be used. The flat wire (1) has a high space factor, (2) it is easy to ensure a wide contact area with the bonding layer 42 provided on the bottom plate portion 40 described later, and (3) the contact area with the terminal fitting 8 described later. There is an advantage that it is easy to ensure widely. Here, the conductor is made of a copper rectangular wire, and the insulation coating is made of a coated rectangular wire made of enamel (typically polyamide imide) .Each coil element 2a, 2b turns this covered rectangular wire into edgewise winding. Edgewise coil. The end face shape (FIG. 1 (B)) of each coil element 2a, 2b is a shape obtained by rounding a rectangular corner, but it can be appropriately changed such as a circular shape.

  Both ends of the winding 2w forming the coil 2 are appropriately extended from the turn forming portion on one end side of the coil 2 and pulled out to the outside. Both ends of the winding 2w are exposed on the exposed conductor part of the insulation coating, and one end of a terminal fitting (not shown) made of a conductive material such as copper, aluminum or an alloy thereof is soldered, welded, or crimped. Connected. An external device (not shown) such as a power source for supplying power to the coil 2 is connected to the coil 2 via the terminal fitting.

[Use]
Reactor 1A having the above-described configuration has applications such as maximum current (DC): about 100A to 1000A, average voltage: about 100V to 1000V, operating frequency: about 5kHz to 100kHz, typically electric It can be suitably used as a component part of an in-vehicle power converter such as an automobile or a hybrid automobile.

[Reactor manufacturing method]
The manufacturing method of the reactor 1A includes a case preparation process and a core part molding process, and can be manufactured as follows. First, a resin case 4 and a green compact forming part of the outer core portion 32 are prepared. The resin case 4 may be prepared by molding into a desired shape by injection molding or the like, or may be prepared by purchasing a resin case 4 molded in advance in the same manner. The green compact is disposed in the storage area of the outer core portion 32 in the prepared resin case 4. Next, the composite material constituting the inner core portion 31 is filled into the resin case 4. At this time, filling is performed so that the compacted body disposed in the storage region of the outer core portion 32 is covered with the composite material. The filled composite material is cured to produce the inner core portion 31, and the inner core portion 31 and the outer core portion 32 are integrally connected. With this composite material, the core component 10 in which the inner core portion 31, the outer core portion 32, the resin case 4, and the lid portion 40 are integrated is manufactured. At this time, the lid 40 is arranged on the resin case 4 before the resin of the composite material is cured, and the lid 40 is also combined with the resin and fixed integrally with the resin case 4. In this way, a pair of core components 10 is produced. Then, a part of the core components 10a and 10b is inserted inside the coil elements 2a and 2b, respectively, and the core components 10a and 10b are connected to each other. The core parts 10a and 10b can be integrally connected with an adhesive or the like. By this step, reactor 1A can be manufactured.

[Function and effect]
According to the reactor 1A described above, by providing the resin case 4 that houses the inner core portion 31 and the outer core portion 32, the core portion 31, 32, and the coil 2 can be insulated. Therefore, for example, since an insulating member such as an insulator constituted by a plurality of members is unnecessary, the number of parts can be reduced, and the work of assembling the magnetic core 3 and the insulator becomes unnecessary. In addition, the inner core portion 31 and the outer core portion 32 are accommodated in the resin case 4, and the core portions 31, 32 and the resin case 4 are integrally formed by a composite material constituting the core portions 31, 32. By joining, it can be set as the core component 10 which comprises the inner core part 31, the outer core part 32, and the resin case 4 integrally, and it can be handled easily while the number of parts can be reduced. Since the reactor 1A can be manufactured by assembling the core component 10 to the coil 2, the assembly workability of the reactor 1A is excellent. A magnetic core having a partially different permeability can be obtained by simply placing a compacted body constituting the outer core portion 32 in the resin case 4 and filling the composite material constituting the inner core portion 31 and the outer core portion 32. Can be easily formed.

<Modification 1>
In the first embodiment, in the magnetic core 3 housed in the resin case 4, the outer core portion 32 is formed of a green compact and a composite material, and the inner core portion 31 is formed of a composite material. In Modification 1, in the magnetic core, the relative permeability of the outer core portion is 15 to 50, the relative permeability of the inner core portion is 5 to 15, and the relative permeability of the entire magnetic core is 10 to 40. . Specifically, the outer core portion is a high permeability composite material (content of pure iron powder in the composite material: 65% by volume), and the inner core portion is a low permeability composite material (pure iron powder in the composite material). Content: 40% by volume). Thus, the magnetic core 3 is partially different in magnetic characteristics due to different constituent materials.

  When both core parts of the inner core part and the outer core part are formed of composite materials having different magnetic powder contents, a partition plate is interposed between the respective storage areas of both core parts in the resin case during manufacturing. It is preferable to make it. In that case, after filling and curing the constituent material of one core part, the constituent material of the other core part may be filled and cured, or the constituent materials of both core parts may be filled and cured simultaneously in each storage area. May be. In the former case, it may be removed after the constituent material of one core part is cured. In the latter case, the partition plate may be removed after filling the constituent materials of the core portions into the case. In the latter case, a part of the constituent resins of each core part is mixed at the boundary between both core parts, and one core part and the other core part can be integrally connected with good adhesion. In addition, a magnetic core in which the content of the magnetic powder is inclined from one core part to the other core part in the vicinity of the boundary between both core parts can be obtained. If it does so, it can suppress that the magnetic permeability changes rapidly between both core parts. In any case, the gap plate may be used with the partition plate interposed.

<Modification 2>
In the modified example 2, in the magnetic core, the outer core portion can be composed of only the composite material, and the inner core portion can be composed of the same composite material as that of the outer core portion and the green compact. The magnetic core 3 has partially different magnetic properties due to different constituent materials. Specifically, the inner core portion 31 has a higher saturation magnetic flux density than the outer core portion 32, and the outer core portion 32 has a lower magnetic permeability than the inner core portion 31. More specifically, the inner core portion has a saturation magnetic flux density of 1.6 T or more and exceeds the saturation magnetic flux density of the outer core portion, preferably 1.2 times or more of the outer core portion, and a relative permeability of 100 to 500, the outer core. Part, saturation magnetic flux density: 0.5 T or more, less than saturation magnetic flux density of the inner core part 31, relative magnetic permeability: 5-30, relative magnetic permeability of the entire magnetic core composed of the inner core part and the outer core part is 10-100. . The saturation magnetic flux density of the inner core portion 31 is preferably 1.8 T or more, more preferably 2 T or more, and more preferably 1.5 times or more, more preferably 1.8 times or more of the saturation magnetic flux density of the outer core portion 32.

<Modification 3>
As a third modification, a coil molded body including a resin mold portion that covers at least a part of the outer periphery of the coil and maintains the shape of the coil can be obtained.

  As the constituent resin of the resin mold portion, for example, a thermosetting resin such as an epoxy resin, a silicone resin, or an unsaturated polyester, or a thermoplastic resin such as a polyphenylene sulfide (PPS) resin or a liquid crystal polymer (LCP) can be suitably used. In addition to using a resin mold part that is a mixture of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, and silicon carbide mixed with the above resin, the insulation can be improved. Heat dissipation is also improved. In particular, it is preferable that a resin having a thermal conductivity of 1 W / m · K or more, more preferably 2 W / m · K or more, is used for the resin mold part because of excellent heat dissipation.

  The coil and the core component may be integrally held by the resin mold portion. In that case, the resin case does not have to include the lid. When producing a coil molded body, a core component including a magnetic core and a resin case (without a lid) and a coil are combined and housed in a mold. When filling the constituent resin of the resin mold part into the mold and covering the outer periphery of the coil, the opening of the resin case may be covered with the constituent resin of the resin mold part. At this time, the bottom and side walls of the resin case are brought into contact with the inner peripheral surface of the coil, and the resin of the resin mold portion is filled with a gap formed between the opening of the resin case and the inner peripheral surface of the coil. It is preferable to do. Thereby, the magnetic core can be arranged coaxially with the coil. By filling this constituent resin, a coil molded body can be produced, a lid portion can be formed from the constituent resin of the resin mold portion, and the opening of the resin case can be sealed. Therefore, it is not necessary to use a separate lid. In addition, the coil molded body and the core component can be molded integrally.

Embodiment 2
A reactor 1B according to the second embodiment will be described with reference to FIG. The reactor 1B of the second embodiment has a point that the coil 2 is one, the combination of the shape of the resin case 4 is “E-shaped”, and the magnetic core 3 accommodated in the resin case 4 is transparent. It is different from the first embodiment in that it is composed of two types of composite materials having different magnetic susceptibility. Hereinafter, the points different from the first embodiment will be mainly described.

[Core parts]
(Resin case)
The resin case 4a is an E-shaped box-shaped body formed of an E-shaped bottom portion and 12 side wall portions erected on the bottom portion, and both the bottom portion and the side wall portion are configured as a flat surface. ing. The resin case 4b is an I-shaped box composed of an I-shaped (rectangular) bottom and four side walls standing from each side of the bottom. The bottom and side walls are both It consists of a plane. That is, the resin case 4a accommodates the inner core portion 31 and a part of the outer core portion 32 (outer core portion 32a), and the resin case 4b accommodates a portion of the outer core portion 32 (outer core portion 32b). To do. The inner core portion 31 accommodated in the resin case 4a is a rectangular parallelepiped prismatic body, the outer core portion 32a is a U-shaped prismatic body, and an integral part of the core portions 31 and 32a is an E-shape. It becomes a prismatic body. On the other hand, the outer core portion 32 housed in the resin case 4b is an I-shaped (cuboid) columnar body. The resin cases 4a and 4b include lid portions 40a and 40b made of flat plates, respectively. The shapes of the lid portions 40a and 40b are the same as the bottom portions, the shape of the lid portion 40a is E-shaped, and the lid portion 40b is rectangular. Further, the combination of the shapes of the pair of resin cases 4a and 4b may be “E-shaped”.

(Magnetic core)
In the magnetic core 3, both the inner core portion 31 and the outer core portion 32 are made of a composite material, and the outer core portion 32 is made of a composite material having a higher magnetic permeability than the inner core portion 31.

  As described above, when the magnetic core 3 is manufactured, it is preferable to provide a partition plate in the resin case 4a. Then, each core part 31 and 32a can be formed in a desired storage area within the resin case 4a. The resin case 4a may be filled with the constituent materials of the core portions 31 and 32a individually or at the same time.

[coil]
The coil 2 is a cylindrical body formed by spirally winding one continuous winding 2w. A portion of the core part 10a in which the inner core portion 31 is stored is inserted inside the cylindrical body. The end face shape of the coil 2 (cross-sectional shape in a direction perpendicular to the axis of the coil 2) is a shape obtained by rounding each corner of the rectangle. Other examples of the shape of the end face of the coil 2 include a shape made up of only a curve, such as an ellipse, and a shape made up of a combination of a straight line and a curve, such as a racetrack shape made up of a combination of a straight line and an arc.

  Both ends of the winding 2w formed by spirally winding the winding 2w may be arranged on one end side of the coil 2, and each end of the winding 2w is in a different direction in the axial direction of the coil 2. You may arrange in. Here, both end portions of the winding 2 w are arranged on one end side of the coil 2. Specifically, one end of the winding 2w is folded back from the other end side of the coil 2 to one end side so as to be parallel to the axial direction of the coil 2, and the other end of the winding 2w is extended in the radial direction of the coil 2, It is bent toward one end side of 2 to be parallel to the axial direction. Thus, since both ends of the winding 2w are arranged on one end side of the coil 2, it is easy to attach a terminal member or the like.

<< Embodiment 3 >>
The reactors of Embodiments 1 and 2 and Modifications 1 to 3 can be used, for example, as a component part of a converter mounted on a vehicle or the like, or a component part of a power conversion device including the converter.

  For example, a vehicle 1200 such as a hybrid vehicle or an electric vehicle is used for traveling by being driven by a main battery 1210, a power converter 1100 connected to the main battery 1210, and power supplied from the main battery 1210 as shown in FIG. Motor (load) 1220. The motor 1220 is typically a three-phase AC motor, which drives the wheel 1250 when traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 includes an engine in addition to the motor 1220. In FIG. 4, an inlet is shown as a charging point of the vehicle 1200, but a form including a plug may be adopted.

  The power conversion device 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110 and performing mutual conversion between direct current and alternating current. Converter 1110 shown in this example boosts the DC voltage (input voltage) of main battery 1210 of about 200 V to 300 V to about 400 V to 700 V and feeds power to inverter 1120 when vehicle 1200 is traveling. In addition, converter 1110 steps down a DC voltage (input voltage) output from motor 1220 via inverter 1120 to a DC voltage suitable for main battery 1210 during regeneration, and charges main battery 1210. The inverter 1120 converts the direct current boosted by the converter 1110 into a predetermined alternating current when the vehicle 1200 is running and supplies power to the motor 1220. During regeneration, the alternating current output from the motor 1220 is converted into direct current and output to the converter 1110. doing.

  As shown in FIG. 5, the converter 1110 includes a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor L, and converts input voltage by ON / OFF repetition (switching operation). (In this case, step-up / down pressure) is performed. For the switching element 1111, a power device such as FET or IGBT is used. The reactor L has the function of smoothing the change when the current is going to increase or decrease by the switching operation by utilizing the property of the coil that tends to prevent the change of the current to flow through the circuit. As this reactor L, the reactor of the said Embodiments 1-3 and the modifications 1-3 is provided. By providing the reactor 1A having excellent assembly workability, the productivity of the power conversion device 1100 and the converter 1110 is excellent.

  Vehicle 1200 is connected to converter 1110, power supply converter 1150 connected to main battery 1210, sub-battery 1230 as a power source for auxiliary devices 1240, and main battery 1210. Auxiliary power converter 1160 for converting high voltage to low voltage is provided. The converter 1110 typically performs DC-DC conversion, while the power supply device converter 1150 and the auxiliary power supply converter 1160 perform AC-DC conversion. Some converters 1150 for power feeding devices perform DC-DC conversion. The reactor of power supply device converter 1150 and auxiliary power supply converter 1160 has the same configuration as the reactors of Embodiments 1 to 3 and Modifications 1 to 3 above, and uses reactors whose sizes and shapes are appropriately changed. can do. In addition, the reactors according to the first and second embodiments and the first to third modifications may be used for a converter that performs input power conversion and that only performs step-up or converters that perform only step-down.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.

  The reactor of the present invention can be used for components of power conversion devices such as DC-DC converters and air conditioner converters mounted on vehicles such as hybrid vehicles, plug-in hybrid vehicles, electric vehicles, and fuel cell vehicles. The core component of the present invention can be used as a constituent component of a reactor used in the above power converter.

1A, 1B reactor 10,10a, 10b Core parts
2 Coil 2a, 2b Coil element 2r Coil connection part 2w Winding
3 Magnetic core 31,31a, 31b Inner core 31e End face
32,32a, 32b Outer core 32e Inner end face 32o Outer end face
4,4a, 4b Resin case 4e End face 40,40a, 40b Lid
1100 Power converter 1110 Converter 1111 Switching element
1112 Drive circuit L Reactor 1120 Inverter
1150 Power supply converter 1160 Auxiliary power converter
1200 Vehicle 1210 Main battery 1220 Motor 1230 Sub battery
1240 Auxiliary 1250 Wheel

Claims (10)

A coil formed by winding a winding and a magnetic core that is disposed inside and outside of the coil to form a closed magnetic circuit, and at least a part of the magnetic core is made of a composite material including magnetic powder and resin. A reactor,
A resin case that houses the magnetic core and insulates the magnetic core from the coil;
The reactor, wherein the magnetic core and the resin case are integrally joined by a constituent resin of the composite material.   The reactor according to claim 1, wherein the magnetic core includes a green compact. The magnetic core is
An inner core disposed inside the coil;
An outer core part disposed outside the coil and forming a closed magnetic path together with the inner core part,
3. The reactor according to claim 1, wherein any one of the inner core portion and the outer core portion includes the composite material having a higher magnetic permeability than the other.   Content of the said magnetic body powder in the said composite material is 30 volume% or more and 70 volume% or less, The reactor of Claims 1-3 characterized by the above-mentioned.   The reactor according to any one of claims 1 to 4, wherein, of the magnetic core, an inner core portion disposed inside the coil is configured by a compacted body. The coil is formed by connecting a pair of coil elements wound with the winding in parallel with each other,
The magnetic core is
A pair of inner core portions disposed inside each of the coil elements;
A pair of outer core portions that are exposed from the coil and connected to the inner core portions to form the inner core portion and an annular core;
The shape of the resin case is configured by any one of an L shape, a J shape, a] shape, and a U shape that integrally accommodates the one outer core portion and at least a part of the inner core portion. The reactor of any one of Claims 1-5 characterized by the above-mentioned. A core component for configuring a reactor comprising a coil formed by winding a winding and a magnetic core that is disposed inside and outside of the coil to form a closed magnetic path,
A magnetic core having a composite material including magnetic powder and resin;
When the magnetic core is housed and a coil is arranged on the outer periphery of the magnetic core, the magnetic core and the resin case for insulating the coil are provided,
The core part, wherein the magnetic core and the resin case are integrally joined by a constituent resin of the composite material. A method of manufacturing a reactor in which a magnetic core that forms a closed magnetic path is formed inside and outside of a coil formed by winding a winding, and at least a part of the magnetic core is formed of a composite material including magnetic powder and resin,
A case preparing step of housing the magnetic core and preparing a resin case for insulating the magnetic core and the coil;
A core part molding step of filling at least a part of the resin case with the composite material, curing the constituent resin of the composite material, and integrally joining the composite material and the resin case. A method for manufacturing a reactor. A converter comprising a switching element, a drive circuit that controls the operation of the switching element, and a reactor that smoothes the switching operation, and converts the input voltage by the operation of the switching element,
The said reactor is a reactor of any one of Claims 1-6, The converter characterized by the above-mentioned. A converter for converting an input voltage, and an inverter connected to the converter for converting between direct current and alternating current, and for driving a load with electric power converted by the inverter,
The power converter according to claim 9, wherein the converter is the converter according to claim 9.

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