JP2013106003A - Reactor, converter and electric power conversion system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor having a case for housing an assembly of a coil and magnetic core, and being lighter than a conventional reactor.SOLUTION: A reactor 1A comprises: an assembly 10 of a coil 2 and a magnetic core 3; and a case 4A for housing the assembly 10. At least of a part of the case 4A provided in the reactor 1A contains a porous body consisting of non-magnetic metal. Thereby a ratio of the non-magnetic metal per unit volume of the case 4A can be lower than that of a conventional structure, and the weight of the case 4A, in fact, that of the reactor 1A can be reduced.

Description

  The present invention relates to a reactor in which a combination of a coil and a core is housed in a case, a converter using the reactor, and a power converter using the converter.

  Magnetic components such as reactors and motors that include a coil and a magnetic core on which the coil is disposed are used in various fields. For example, Patent Document 1 discloses a reactor used for a circuit component of a converter that is mounted on a vehicle such as a hybrid vehicle. The reactor of this patent document 1 is equipped with the structure which accommodated the assembly of the coil and the magnetic core in the case. The magnetic core includes a cylindrical inner core portion disposed inside the coil, and an outer core portion (referred to as a connecting core portion in Patent Document 1) disposed on the outer periphery of the coil. The outer core portion is composed of a magnetic powder such as pure iron powder and a resin (binder resin) that encloses the powder.

JP 2011-124310 A

  In recent years, it has been desired to reduce the weight of vehicles such as hybrid cars in consideration of the global environment, and the weight of each part of the vehicle can be reduced by gram units to achieve a total weight reduction of the vehicle. It is hoped that.

  This invention is made | formed in view of the said situation, and one of the objectives is providing the reactor lighter than before in the reactor provided with the case which accommodates the assembly of a coil and a magnetic core. Another object of the present invention is to provide a converter using the reactor of the present invention and a power converter using the converter.

  As a result of reviewing the configuration of the conventional reactor, the present inventors have focused on the fact that the case is made of a nonmagnetic metal such as aluminum. The case is made of a non-magnetic metal because the case shields the leakage magnetic flux from the magnetic core that is generated when the reactor is operated. Therefore, it is not preferable to ignore the problem of leakage magnetic flux, such as omitting the case or configuring the case from a lightweight insulating resin. Thus, as a result of studying a configuration that can shield leakage magnetic flux by the case and reduce the weight of the case, the present inventors have completed the reactor of the present invention. Below, this invention reactor is prescribed | regulated.

  The reactor of the present invention is a reactor including a coil and magnetic core combination and a case for storing the combination, and at least a part of the case includes a porous body made of a nonmagnetic metal. And Of course, in order to maximize the shielding effect of the leakage magnetic flux by the case, it is preferable that a porous body is included throughout the case.

  According to the reactor of the present invention, the case can be reduced in weight, that is, the reactor can be reduced in weight. This is because a part of the case is a porous body having voids, so that the ratio of the nonmagnetic metal per unit volume is lower than that of the conventional case, and the case can be reduced in weight accordingly.

  As one form of this invention reactor, it is preferable that at least one part of a case is comprised from the composite material containing insulating resin and a porous body.

  A composite material in which an insulating resin is further combined with a porous body is superior in strength to a porous body alone. Therefore, the strength of the porous body portion in the case can be ensured.

  As one form of this invention reactor, it is preferable that the hole of a porous body is filled with insulating resin.

  By filling the pores of the porous body with the insulating resin, the strength of the porous body, that is, the strength of the case can be improved.

  As one form of this invention reactor, it is preferable that a case uses a porous body as frame | skeleton, and the volume ratio of the porous body which occupies for the said case is 10-70 volume%. Here, if the entire case is made of a porous body, 10 to 70% by volume is a porous body, and the remainder is a void. If the entire case is made of a composite material, 10 to 70% by volume is a porous body, and the remainder is an insulating resin, or an insulating resin and a gap.

  Since the porous body is structurally excellent in strength, the ratio of the porous body in the case, that is, the ratio of the nonmagnetic metal in the case can be kept low. As a result, the case can be effectively reduced in weight, and thus the reactor can be effectively reduced in weight. Moreover, if the volume ratio of the porous body in a case exists in the said range, the shielding effect of the leakage magnetic flux by a case can fully be ensured.

  As one form of this invention reactor, it is preferable that the material of a porous body is a nickel-chromium alloy.

  Since nickel-chromium alloy is excellent in strength, the strength of the porous body, that is, the strength of the case can be effectively improved when the nickel-chromium alloy is used as the material of the porous body.

  As one form of this invention reactor, it is preferable that the material of a porous body is aluminum.

  Aluminum is suitable for weight reduction of the case because it is nonmagnetic, excellent in strength, and lightweight.

  As one form of this invention reactor, a coil is cylindrical and a magnetic core is arrange | positioned from the outer side of a coil to the inner surface of a case from the inner side of a coil, and forms a closed magnetic circuit with an inner core part. Preferably, the outer core portion is made of a mixture containing magnetic powder and resin.

  The above-described configuration is a so-called pot type reactor. Of course, the reactor of the present invention is not limited to a pot type reactor, and as shown in a fourth embodiment described later, an annular magnetic core that penetrates the inside of two coil elements is attached to the case via a sealing resin. A stored reactor may be used.

  As one form of this invention reactor, it is preferable that a case is a bottomed cylindrical shape.

  According to the said structure, it is easy to accommodate an assembly in a case. The case may have a cylindrical shape with no bottom.

  As one form of this invention reactor, it is preferable that the inner surface of a case has uneven | corrugated shape.

  When the concave and convex shape is formed on the inner surface of the case, the adhesion between the inner surface of the case and a member in contact with the inner surface can be improved. Specifically, in the case of a pot type reactor, the adhesion between the inner surface of the case and the outer core portion can be improved, and in the case of a reactor having an annular magnetic core that penetrates the inside of two coil elements, The adhesion between the inner surface of the resin and the sealing resin can be improved. In order to form a concavo-convex shape on the inner surface of the case, after the case is made, the inner surface of the case is roughened, or a concavo-convex shape is formed on the mold for producing the case, and the concavo-convex shape of the mold is formed on the case. Transfer it.

  Here, in the reactor of the present invention, at least a part of the case includes a non-magnetic metal porous body, and the uneven shape due to the presence of the complicated three-dimensional network shape of the porous body is formed on the inner surface of the case. Easy to form. Therefore, the uneven shape on the inner surface of the case may be formed of a nonmagnetic metal porous body.

  The reactor of the present invention can be suitably used as a component part of a converter. The converter of the present invention includes 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. As a power converter of the present invention, a converter for converting an input voltage and an inverter connected to the converter for converting direct current and alternating current to each other and driving a load with the power converted by the inverter And the converter is a converter according to the present invention.

  The converter of the present invention using the light reactor of the present invention and the power converter of the present invention contribute to reducing the weight of equipment (for example, a vehicle such as a hybrid car) provided with these.

  The reactor of the present invention is lightweight while having a case for containing leakage magnetic flux from the magnetic core.

1 is a perspective view of a reactor of the present invention according to Embodiment 1. FIG. (A) is AA sectional drawing of FIG. 1, (B) is BB sectional drawing. (A) is a longitudinal cross-sectional view of this invention reactor which concerns on Embodiment 2, (B) is a cross-sectional view of the reactor. (A) is a see-through | perspective perspective view of this invention reactor which concerns on Embodiment 3, (B) is BB sectional drawing of the perspective view. It is a disassembled perspective view of the combination body of the reactor of this invention which concerns on Embodiment 4. FIG. 1 is a schematic configuration diagram schematically showing a power supply system of a hybrid vehicle. It is a schematic circuit which shows an example of this invention power converter device provided with this invention converter.

  Hereinafter, embodiments of the present invention will be described more specifically. The same reference numerals in the figure indicate the same names.

<Embodiment 1>
A reactor 1A according to the first embodiment will be described with reference to FIGS. Reactor 1A is a so-called pot that includes one coil 2, a magnetic core 3 that is arranged inside and outside of coil 2 to form a closed magnetic path, and a case 4A that houses a combination 10 of coil 2 and magnetic core 3. It is a type reactor. This reactor 1A is characterized in that a part of the magnetic core 3 is formed of a molded hardened body obtained by curing a resin in which magnetic powder is dispersed, and the case 4A is a composite material of an insulating resin and a nonmagnetic metal. It is in the configuration. Hereinafter, each configuration will be described in detail.

[Coil 2]
The coil 2 is a cylindrical body formed by spirally winding one continuous winding 2w. As the winding 2w, a coated wire having an insulating coating made of an insulating material on the outer periphery of a conductor made of a conductive material such as copper, aluminum, or an alloy thereof can be suitably used. As the conductor, a round wire having a circular shape, a deformed wire having a polygonal shape, or the like can be used in addition to a rectangular wire having a rectangular cross section as illustrated. The insulating material constituting the insulating coating is typically an enamel material such as polyamideimide. The thickness of the insulating coating is preferably 20 μm or more and 100 μm or less, and the thicker the pinholes can be reduced, the higher the insulation. The number of turns (number of turns) of the coil 2 can be selected as appropriate, and those of about 30 to 70 can be suitably used for in-vehicle components.

《End face shape》
FIG. 2B is a cross-sectional view (cross section BB in FIG. 1) in which the reactor 1 </ b> A is cut along a plane orthogonal to the axial direction of the coil 2. The coil 2 has a uniform cross-sectional shape in the axial direction and is equal to the end face shape. The end face shape of the coil 2 is circular as shown in FIG. In addition, the end surface shape of the coil 2 may be a racetrack shape including a pair of linear portions arranged in parallel and a pair of semicircular arc portions arranged so as to connect the ends of both linear portions. good.

《Arrangement》
The coil 2 is housed in the case 4A in a state where a part of the magnetic core 3 (inner core portion 31) is inserted on the inner periphery thereof. In particular, in the reactor 1A of the present invention, when the reactor 1A is installed on an installation target (not shown) such as a cooling stand, the horizontal type housed in the case 4A so that the axial direction of the coil 2 is parallel to the surface of the installation target. Arrangement. Here, in the reactor 1A, the installation surface that contacts the installation object is the outer bottom surface 40o (FIG. 2) of the case 4A configured as a flat surface, and therefore the coil 2 is accommodated in the case 4A in parallel with the outer bottom surface 40o. ing. Further, when the end surface shape of the coil 2 is a racetrack shape, the coil is arranged so that the planar region formed by the straight line portion on the outer peripheral surface thereof is parallel to the outer bottom surface 40o of the case 4A. In short, the coil 2 may be stored horizontally with respect to the case 4A.

  In addition, the coil 2 is covered with the magnetic core 3 (outer core portion 32) almost entirely on the outer peripheral surface thereof. However, a part of the outer peripheral surface of the coil 2 is in contact with the inner bottom surface of the case 4 </ b> A or a surface of the outer core portion 32, and a part of the coil 2 in the circumferential direction is not covered with the magnetic core 3. You may have a place.

《Treatment of winding end》
The winding 2w forming the coil 2 has a lead portion that is appropriately extended from the turn forming portion and drawn to the outside of the outer core portion 32, and is exposed by peeling off the insulating coating at both ends. A terminal member (not shown) made of a conductive material such as copper or aluminum is connected to the portion. An external device (not shown) such as a power source for supplying power is connected to the coil 2 via the terminal member. Here, in the example shown in FIG. 1, both ends of the winding 2 w are drawn upward so as to be orthogonal to the axial direction of the coil 2, but the drawing direction of both ends can be appropriately selected. For example, both ends of the winding 2w may be drawn out so as to be parallel to the axial direction of the coil 2, or the drawing directions of the ends can be made different from each other. Of the above-mentioned lead-out locations, at least a portion that may come into contact with the magnetic core 3 (especially the outer core portion 32) includes an insulating paper, an insulating tape (for example, a polyimide tape), an insulating film (for example, a polyimide film). It is preferable to dispose an insulating material such as), dip-coat the insulating material, or cover with an insulating tube (such as a heat-shrinkable tube or a room temperature shrinkable tube).

[Magnetic core 3]
As shown in FIG. 1, the magnetic core 3 includes a columnar inner core portion 31 inserted into the coil 2, at least one end surface 31 e of the inner core portion 31, and at least a part of the cylindrical outer peripheral surface of the coil 2. And a closed magnetic circuit is formed when the coil 2 is excited. In this example, the magnetic properties of the inner core portion 31 and the outer core portion 32 are different, specifically, the saturation magnetic flux density of the inner core portion 31 is higher than that of the outer core portion 32, and A configuration in which the magnetic permeability is lower than that of the inner core portion 31 will be described. By adopting such a configuration, the cross-sectional area (surface through which the magnetic flux passes) of the inner core portion 31 can be reduced when compared with a magnetic core made of a single material and having a uniform saturation magnetic flux density. Thus, the reactor 1A can be reduced in size and weight. Note that the inner core portion 31 and the outer core portion 32 may be formed of the same constituent material and have the same magnetic characteristics.

<Inner core 31>
The inner core portion 31 is a cylindrical body having an outer shape along the inner peripheral shape of the coil 2. The inner core portion 31 is entirely formed of a compacted body, and here is a solid body without any gap material or air gap. Since the gap does not exist, it is possible to suppress the leakage magnetic flux at the gap portion from affecting the coil 2. However, the inner core portion 31 may have a form in which a gap material made of a nonmagnetic material such as an alumina plate or an air gap is interposed.

  The green compact is typically formed of a soft magnetic powder having an insulating coating made of a silicone resin or the like on the surface, or a mixed powder in which a binder is appropriately mixed in addition to the soft magnetic powder, and then the insulating coating. It can be obtained by firing at a temperature lower than the heat resistant temperature. In the production of green compacts, by adjusting the material of the soft magnetic powder, the mixing ratio of the soft magnetic powder and the binder, the amount of various coatings including the insulating coating, etc., and adjusting the molding pressure The saturation magnetic flux density can be changed. For example, by using soft magnetic powder with a high saturation magnetic flux density, increasing the proportion of soft magnetic material by reducing the amount of binder, or increasing the molding pressure, compacting with high saturation magnetic flux density The body is obtained.

  Examples of the soft magnetic powder include iron group metals such as Fe, Co, and Ni, and Fe-based alloys containing Fe as a main component, such as Fe—Si, Fe—Ni, Fe—Al, Fe—Co, Fe—Cr, and Fe—. Examples thereof include powders made of iron-based materials such as Si—Al, rare earth metal powders, and ferrite powders. In particular, the iron-based material is easy to obtain a magnetic core having a saturation magnetic flux density higher than that of ferrite. Examples of the insulating coating formed on the soft magnetic powder include a phosphoric acid compound, a silicon compound, a zirconium compound, an aluminum compound, or a boron compound. This insulating coating can effectively reduce eddy current loss, especially when the magnetic particles constituting the magnetic powder are made of a metal such as an iron group metal or an Fe-based alloy. Examples of the binder include thermoplastic resins, non-thermoplastic resins, and higher fatty acids. This binder disappears by the above baking, or changes to an insulator such as silica. The compacted body is a case where an insulating material such as an insulating coating exists between the magnetic particles so that the magnetic particles are insulated from each other to reduce eddy current loss, and high-frequency power is supplied to the coil 2. Also, the loss can be reduced. A well-known thing can be utilized for a compacting body.

  Here, the inner core part 31 is comprised from the compacting body which consists of a soft-magnetic material provided with an insulating film, a saturation magnetic flux density is 1.6 T or more, and 1.2 of the saturation magnetic flux density of the outer core part 32. It is more than double. Moreover, the relative magnetic permeability of the inner core portion 31 is, for example, 100 to 500, and the relative magnetic permeability of the entire magnetic core 3 including the inner core portion 31 and the outer core portion 32 is, for example, 10 to 100. When obtaining a constant magnetic flux, the higher the absolute value of the saturation magnetic flux density of the inner core portion 31 is, and the higher the saturation magnetic flux density of the inner core portion 31 is relative to the outer core portion 32, the more the inner core portion 31 has. The cross-sectional area can be reduced. Therefore, the form with the high saturation magnetic flux density of the inner core part 31 can contribute to size reduction of a reactor. 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 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, both of which have an upper limit Absent. In addition, if it replaces with a compacting body and the laminated body of the electromagnetic steel plate represented by the silicon steel plate is utilized, it will be easy to raise the saturation magnetic flux density of the inner core part 31 further.

  In the example shown in FIGS. 1 and 2, the length of the inner core portion 31 in the axial direction of the coil 2 (hereinafter simply referred to as the length) is longer than the length of the coil 2. In the state of being inserted and arranged in the coil 2, both end surfaces 31 e and 31 e of the inner core portion 31 and the vicinity thereof protrude from each end surface of the coil 2. The protruding length of the inner core portion 31 can be selected as appropriate. Here, in the inner core portion 31, the protruding lengths protruding from the end faces of the coil 2 are made equal, but may be different, and the protruding portion may exist only from one of the end faces of the coil 2. The inner core portion 31 can be disposed on the inside. The length of the inner core portion 31 and the length of the coil 2 may be equal, and the length of the inner core portion 31 may be shorter than the length of the coil 2.

  Further, in order to further improve the insulation between the coil 2 and the inner core portion 31, an insulating material (not shown) may be interposed between the inner core portion 31 and the coil 2. Examples of the insulating material include attaching an insulating tape to the inner peripheral surface of the coil 2 and the outer peripheral surface of the inner core portion 31, and disposing insulating paper or an insulating sheet. Further, a bobbin (not shown) made of an insulating material may be disposed on the outer periphery of the inner core portion 31. As the bobbin constituent material, an insulating resin such as polyphenylene sulfide (PPS) resin, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE) resin can be suitably used. Further, when the bobbin is formed into a cylindrical shape by combining the divided pieces, it is easy to arrange the bobbin on the outer periphery of the inner core portion 31.

<< Outer core part 32 >>
The outer core portion 32 is combined with the inner core portion 31 to constitute a closed magnetic circuit. In this example, it is formed so as to cover both end faces of the coil 2, substantially all of the outer peripheral face of the coil 2, and both end faces 31e, 31e of the inner core portion 31 and the vicinity thereof, and has the following cross-sectional shape. Have About the area | region where the coil 2 exists in reactor 1A, a longitudinal cross-section (FIG. 2 (A)), a horizontal cross section (FIG. 2 (B)), and a horizontal cross section (through the axis | shaft of the coil 2 and parallel to the outer bottom face 40o of case 4A). When a cross section taken along a plane is taken, each cross-sectional shape is annular. The magnetic core 3 forms a closed magnetic path by providing a part of the outer core portion 32 so as to connect both end faces 31e, 31e of the inner core portion 31.

  The outer core portion 32 only needs to be able to form a closed magnetic path, and the shape (coating region of the coil 2) is not particularly limited. For example, a configuration in which a part of the outer periphery of the coil 2 is not covered by the outer core portion 32 is allowed. As this form, the form by which the opening side area | region of case 4A was not covered with the outer core part 32 in the outer peripheral surface of the coil 2, for example was mentioned. Alternatively, a base (not shown) for supporting the coil from the outer periphery is provided on the inner bottom surface 40i of the case 4A, and the outer core portion 32 is not interposed between the base and the coil, or the outer peripheral surface of the coil 2 is the case 4A. The form which touches at least one side wall part 41, and the outer core part 32 is not interposed in the contact location is mentioned.

  Here, the entire outer core portion 32 is formed of a mixture (molded and hardened body) containing magnetic powder and resin, and the inner core portion 31 and the outer core portion 32 do not intervene with an outer core. It is joined by the constituent resin of the portion 32. The outer core portion 32 is also configured such that no gap material or air gap is interposed. Therefore, the magnetic core 3 is an integrated product that is integrated without any gap material. By configuring the outer core portion 32 from a mixture containing magnetic powder and resin, the magnetic properties of the outer core portion 32 that can easily manufacture the outer core portion 32 of any shape can be easily changed. There are advantages such as.

  Further, since the outer core portion 32 seals the coil 2 and the inner core portion 31 in the case 4 </ b> A, it also functions as a sealing material for the coil 2 and the inner core portion 31. Therefore, the reactor 1 </ b> A can protect the coil 2 and the inner core portion 31 from the external environment by using the outer core portion 32 and can enhance mechanical protection.

  The molded cured body can typically be formed by injection molding or cast molding. In injection molding, usually, a powder made of a magnetic material and a fluid resin are mixed, and this mixed fluid is molded by pouring it into a molding die (here, case 4A) under a predetermined pressure. Is cured. In cast molding, a mixed fluid similar to that of injection molding is obtained, and then the mixed fluid is injected into a molding die without applying pressure to be molded and cured.

  In any of the molding methods, the same magnetic powder as that used for the inner core portion 31 described above can be used as the magnetic powder. In particular, the soft magnetic powder used for the outer core portion 32 can be suitably made of an iron-based material such as pure iron powder or Fe-based alloy powder. You may mix and use the multiple types of magnetic powder from which a material differs. You may utilize the coating powder provided with the insulating film which consists of phosphate etc. on the surface of the magnetic particle which consists of a soft magnetic material (especially metal material). When coating powder is used, eddy current loss can be reduced. As the magnetic powder, it is easy to use a powder having an average particle diameter of 1 μm to 1000 μm, and more preferably 10 μm to 500 μm. When a plurality of types of powders having different particle sizes are used, a reactor having a high saturation magnetic flux density and a low loss is easily obtained.

  In any of the above-described molding methods, a thermosetting resin such as an epoxy resin, a phenol resin, a silicone resin, or a urethane resin can be suitably used as the resin serving as the binder. When a thermosetting resin is used, the molded body is heated to thermally cure the resin. A normal temperature curable resin or a low temperature curable resin may be used as the binder resin. In this case, the molded body is allowed to stand at a normal temperature to a relatively low temperature to be cured. Since the molded hardened body has a relatively large amount of resin that is a non-magnetic material, even when the same soft magnetic powder as that of the green compact forming the inner core portion 31 is used, the saturation magnetic flux density is higher than that of the green compact. And a core with low magnetic permeability is easily formed.

  In addition to the magnetic powder and the resin serving as the binder, a filler made of ceramics such as alumina or silica may be mixed into the constituent material of the molded cured body. By mixing the filler having a specific gravity smaller than that of the magnetic powder, uneven distribution of the magnetic powder is suppressed, and an outer core portion in which the magnetic powder is uniformly dispersed can be easily obtained. Moreover, when the said filler is comprised from the material excellent in thermal conductivity, it can contribute to the improvement of heat dissipation. When the filler is mixed, the filler content may be 0.3% by mass or more and 30% by mass or less when the molded hardened body is 100% by mass, and the total content of the magnetic powder and the filler is outside. When a core part is 100 volume%, 20 volume%-70 volume% are mentioned. In addition, if the filler is made finer than the magnetic powder, the filler is interposed between the magnetic particles to effectively prevent uneven distribution, and the magnetic powder can be uniformly dispersed, and the ratio of the magnetic powder due to the inclusion of the filler It is easy to suppress the decrease of

  Note that when the coil 2 is housed in the case 4A in a horizontal arrangement like the reactor 1A and in the state where the coil 2 is close to the inner bottom surface 40i of the case 4A, the magnetic powder is placed on the bottom surface 40 of the case 4A during the production of the molded cured body. It may settle to the side and become the outer core part in which the magnetic powder is unevenly distributed on the bottom surface 40 side. However, even in this case, a region having a high density of magnetic powder in the outer core portion can be easily brought into contact with the inner core portion 31, so that a closed magnetic circuit can be sufficiently formed.

  Here, the outer core portion 32 is composed of a molded hardened body of a coating powder and an epoxy resin, each of which is provided with the above coating on the surface of particles made of an iron-based material having an average particle diameter of 100 μm or less, and has a relative magnetic permeability of 5 to 30, Saturation magnetic flux density: 0.5 T or more and less than the saturation magnetic flux density of the inner core portion 31. By making the magnetic permeability of the outer core portion 32 lower than that of the inner core portion 31, the leakage magnetic flux of the magnetic core 3 can be reduced, or the magnetic core 3 having a gapless structure can be obtained. The permeability and saturation magnetic flux density of the molded cured body can be adjusted by changing the blending of the magnetic powder and the resin serving as the binder. For example, when the blending amount of the magnetic powder is reduced, a molded and hardened body having a low magnetic permeability can be obtained. For the saturation magnetic flux density and relative permeability of each of the core portions 31, 32, a test piece prepared from each of the core portions 31, 32 is prepared, and a commercially available BH curve tracer, VSM (sample vibration type magnetometer), or the like is used. Can be measured.

[Case 4A]
As shown in FIGS. 1 and 2, the case 4 </ b> A is typically a rectangular parallelepiped box composed of a rectangular bottom plate portion 40 and four side wall portions 41 erected from the bottom plate portion 40. Yes, there may be one in which the surface facing the bottom plate portion 40 is opened. The case 4A includes a mold for molding the outer core portion 32 of the molded and hardened body, a container for housing the combined body 10 of the coil 2 and the magnetic core 3, a member for containing leakage magnetic flux from the magnetic core 3, and heat dissipation. Used as a route. Note that the case 4 </ b> A may be configured by only the side wall portion 41.

  Case 4A of this embodiment is comprised from the composite material containing insulating resin and the porous body which consists of a nonmagnetic metal. However, only a part of the case 4A may be made of a composite material. In that case, portions other than the composite material may be made of a nonmagnetic metal to enhance the shielding effect of leakage magnetic flux by the case 4A, or may be made of an insulating resin to further reduce the weight of the case 4A. .

<Composite material: porous body of insulating resin and non-magnetic metal>
The composite material has a configuration in which an insulating resin is disposed in a gap (a portion other than the porous body including pores of the porous body, as will be described later) between the porous bodies made of a nonmagnetic metal. When forming case 4A using the composite material provided with a porous body, it is preferable that the volume ratio of the porous body to case 4A shall be 10-70 volume%.

  As the nonmagnetic metal powder, for example, a metal such as aluminum, aluminum alloy, magnesium, magnesium alloy, nickel-chromium alloy such as Inconel, or austenitic stainless steel can be preferably used. In particular, since aluminum, magnesium, and alloys thereof are lightweight, they are also suitable as a component material for automobile parts that are desired to be lightweight.

  On the other hand, as the insulating resin, a thermosetting resin, a delayed curable resin, a thermoplastic resin, or the like can be used. For example, epoxy, silicone, PPS, BMC (Bulk molding compound), etc. can be used as the insulating resin. These resins may be mixed with a filler made of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, and silicon carbide, thereby improving the heat dissipation of the case 4A. .

  The arrangement form of the insulating resin with respect to the gap of the porous body can be roughly classified into three. Since the arrangement form of the insulating resin is related to the manufacturing method of the nonmagnetic metal porous body, the manufacturing method of the porous body will be described first.

  In general, a porous body is a three-dimensional network substrate made of an insulating resin such as foamed urethane, and the surface of the substrate (including the surface of the pores of the network) is coated with a nonmagnetic metal (such as electroless plating). For example, an intermediate porous body coated with nickel-chromium alloy or aluminum is prepared, and the intermediate porous body is heat-treated to disappear the substrate (for example, patent 2628600 filed by the present applicant). No. gazette and International Publication No. 2011/118460).

  Here, the intermediate porous body is a member made of an insulating resin and a nonmagnetic metal member coated on the surface thereof. In other words, in the nonmagnetic metal porous body made of a hollow skeleton, It can be said that it is a composite material in which the substrate is disposed in the hollow portion (gap). A form in which this intermediate porous body is directly used as a composite material is the first form of the composite material using the porous body. Since the composite material of this form has a simple manufacturing process, it is excellent in productivity.

  The intermediate porous body has a form in which a non-magnetic metal is plated on the surface of a three-dimensional mesh-shaped insulating resin base and still has three-dimensional holes (gap). May be filled. A form in which the intermediate porous body in which the pores are filled with the insulating resin is used as the composite material is the second form of the composite material using the porous body. The composite material in this form is superior in strength to the form using the intermediate porous body as it is. Filling the pores of the intermediate porous body with the insulating resin can be performed, for example, by immersing (pressurizing) the intermediate porous body in a pool of insulating resin and curing the insulating resin. Needless to say, the curing factor varies depending on the type of insulating resin (for example, time, temperature increase, or temperature decrease).

  The third form of the composite material is a form in which the pores of the porous body from which the substrate has disappeared and the hollow portion of the skeleton (the portion where the substrate was present) are filled with an insulating resin. Here, when producing a substrate having pores, the substrate is often produced from a soft material such as urethane. This is because a soft material is easier to form pores. Therefore, instead of a soft substrate such as urethane, an insulating resin excellent in strength, such as epoxy, is filled in the hollow portion of the skeleton, so that the strength is higher than the form in which the insulating resin is filled in the intermediate porous body where the substrate remains. It can be set as the composite material provided. In addition, the composite material of this third form has an advantage that it can be produced simply by purchasing a commercially available porous body and filling the porous body with an insulating resin. Filling the gap between the porous bodies in this form with the insulating resin may be performed in the same manner as the composite material of the second form.

  In order to fabricate the composite case 4A including the porous body described above, for example, a base to be prepared when the porous body is fabricated is prepared in advance in the shape of the case 4A, and a nonmagnetic metal is applied to the base. It is preferable to produce an intermediate porous body by plating. When the intermediate porous body is used as it is as the composite material in the present invention, the case 4A is completed at this point. In order to further increase the strength of the case 4A, the pores of the intermediate porous body are filled with insulating resin, or the base body of the intermediate porous body is removed by heat treatment, and then the gap between the porous bodies is filled with insulating resin. Just do it.

  In addition, the case 4A may be manufactured by preparing a plurality of plate-like composite materials including a porous body, combining them in a box shape, and integrating them with an insulating resin. For example, a plate-shaped composite material is laid on the bottom of a bottomed cylindrical first mold, a second mold serving as a core is placed inside the first mold, and the inner wall surface of the first mold A plate-shaped composite material is inserted into the gap with the outer peripheral surface of the second mold. Then, an insulating resin is poured into the gap between the first mold and the second mold to cure the insulating resin.

<< Inner shape of case >>
It is preferable that a large number of fine irregularities be formed on the inner surface of the case 4A (see the enlarged portion in the circle of the alternate long and short dash line in FIG. 2A). By increasing the contact area between the inner surface of the case 4 </ b> A and the molded cured body (outer core portion 32) due to the unevenness, the adhesion between them can be increased.

  The unevenness on the inner surface is preferably a size and shape that does not cause cracks in the molded cured body (outer core portion 32). Specifically, the maximum height (maximum height difference between the concave portion and the convex portion) is 1 mm or less, preferably 0.5 mm or less. By setting it as such a size, even if resin shrinks when resin of mixed fluid hardens | cures, it can suppress that it is hard to peel from a case, and it can suppress that a shaping | molding hardening body produces a crack. As a lower limit of the size of the unevenness, it is preferable to have an unevenness with a minimum height of 0.05 mm or more in order to ensure adhesion between the case inner surface and the molded cured body.

  On the other hand, the shape of the unevenness is preferably a shape in which the surface of the fine unevenness is a curved surface and has substantially no corners. By making the surface uneven by a curved surface having no corners, it is possible to effectively suppress the occurrence of cracks in the molded cured body.

  In order to form a concavo-convex shape on the inner surface of the case 4A, after producing the case 4A, the inner surface of the case 4A is roughened, or a concavo-convex shape is formed on the mold for producing the case 4A. The shape may be transferred to the case 4A. In addition, the uneven shape may be caused by the presence of a nonmagnetic metal porous body included in the case 4A.

  As shown in FIG. 2 (B), the bottom plate portion 40 of the case 4A includes an outer bottom surface 40o that serves as an installation surface for an installation target such as a cooling table, and an inner bottom surface 40i that faces a combined body of a coil and a magnetic core. Is provided. A pedestal (not shown) that supports a part of the outer peripheral surface of the coil 2 may be provided on the inner bottom surface 40i. For example, the pedestal part may be formed integrally with the inner bottom surface 40i with a concave curved surface that conforms to the outer peripheral surface of the coil. Such a curved surface also functions as a positioning portion for the coil 2 in the case. The surface of the curved surface may not have the fine irregularities described above. Thereby, damage to the insulation coating of the coil 2 can be suppressed.

  When the inner bottom surface 40i of the case 4A does not have a curved surface, a positioning member (not shown) may be separately arranged so that the coil 2 can be easily positioned in the case 4A. For example, if the positioning member is a molded and hardened body made of the same material as the constituent material of the outer core portion 32, the positioning member can be easily integrated when the outer core portion 32 is formed, and the separate member is used as a magnetic path. be able to. Alternatively, if the positioning member is made of a material having excellent heat dissipation, the heat dissipation can be improved.

[Other configurations]
In the example shown in FIG. 1, the case 4 </ b> A includes a mounting portion 45 having a bolt hole 45 h for fixing the reactor 1 </ b> A to the installation target with a fixing member such as a bolt. By having the attachment portion 45, the reactor 1A can be easily fixed to the installation target by a fixing member such as a bolt.

  In order to enhance the insulation between the coil 2 and the case 4A, an insulating material such as the insulating paper, the insulating sheet, or the insulating tape described above may be interposed between the coil 2 and the case 4A. For example, by winding the insulating tape or the like around the surface of the coil 2, the insulating material is present on both the inner peripheral surface and the outer peripheral surface of the coil 2 (which may include the end surface of the coil 2). can do. This insulating material only needs to be present to such an extent that the minimum insulation required between the coil 2 and the case 4A can be ensured. By making the insulating material as thin as possible, it is possible to suppress a decrease in thermal conductivity due to the inclusion of the insulating material. In addition, downsizing can be achieved.

  Alternatively, an insulating adhesive can be used as the insulating material. That is, the coil 2 and the case 4A can be fixed with an adhesive. In this configuration, the insulation between the coil 2 and the case 4A can be improved, and the coil 2 can be adhered to the case 4A with an adhesive regardless of the resin component of the outer core portion 32. In particular, the adhesive can be suitably used that has excellent thermal conductivity, for example, an adhesive containing a filler having excellent thermal conductivity and electrical insulation, such as alumina. When the thickness of the adhesive layer is reduced and a multilayer structure is used, electrical insulation can be improved even if the total thickness is small. Further, when this adhesive is in the form of a sheet, it is excellent in workability. As such an adhesive, a commercially available product can be used.

  In addition, it can be set as the form provided with physical quantity measuring sensors (not shown), such as a temperature sensor and a current sensor. In this embodiment, the wiring connected to the sensor is pulled out from the opening of the case.

[Use]
Reactor 1A having the above-described configuration is, for example, an electric vehicle in which energization conditions are, for example, maximum current (direct current): about 100 A to 1000 A, average voltage: about 100 V to about 1000 V, and operating frequency: about 5 kHz to 100 kHz. It can be suitably used as a component part of a vehicle-mounted power conversion device such as a hybrid vehicle. In this application, it is expected that an inductance satisfying 10 μH or more and 2 mH or less of the inductance when the DC current is 0 A and 10% or more of the inductance when the maximum current is applied is 10% or more can be suitably used.

[Reactor manufacturing method]
Reactor 1A can be manufactured as follows, for example. First, the inner core part 31 which consists of the coil 2 and a compacting body is prepared, the inner core part 31 is inserted in the coil 2, and the assembly of the coil 2 and the inner core part 31 is produced. As described above, an insulating material (not shown) may be appropriately disposed between the coil 2 and the inner core portion 31. Moreover, you may arrange | position insulating materials, such as an insulating tube, as mentioned above in the extraction | drawer location of the coil | winding 2w.

  Next, the assembly is stored in the case 4A. In the case 4A, a mixed fluid of magnetic powder and resin constituting the outer core portion 32 is appropriately poured and molded into a predetermined shape, and then the outer core portion 32 can be formed by curing the resin. The reactor 1A (FIG. 1) is obtained.

〔effect〕
Reactor 1A is lighter and easier to handle than a reactor having a conventional structure including a case. Therefore, when an electric circuit is produced using reactor 1A, the productivity of the electric circuit can be improved. Moreover, the weight reduction of the apparatus which mounts the electric circuit provided with the reactor 1A can be achieved by using the reactor 1A lighter than before.

<Embodiment 2>
Next, the reactor of Embodiment 2 is demonstrated with reference to FIG. This reactor 1B is different from the first embodiment in that a lid 5 is further provided. Since other configurations are the same as those in the first embodiment, the following description will be mainly made on this difference. The case 4B has the same configuration as the case 4A of the first embodiment, although the reference numeral is different.

〔Constitution〕
The lid 5 covers at least a part of the opening of the case 4B. In this example, the lid 5 is provided so as to cover almost the entire surface of the case opening. If the area covering the opening of the case 4B is large, (1) the outer core portion 32 can be protected, (2) dropout of the stored items in the case 4B can be suppressed, and (3) leakage magnetic flux from the magnetic core 3 can be prevented. There exists an effect that it can be effectively contained in 4B. In order to suppress the falling off of the stored item in the case 4B, it is preferable to provide the lid 5 so as to straddle at least the location where the opening is opposed.

  The lid 5 is preferably composed of the same configuration as the case 4B (that is, the case 4A of the first embodiment), that is, a composite material including an insulating resin and a nonmagnetic metal. In this case, the case 5B including the lid 5 may be regarded as the case 4B. If it is such a structure, the weight increase of the reactor 1B by having added the lid | cover 5 can be suppressed. The lid 5 may be a simple non-magnetic metal plate, and even in that case, the effects (1) to (3) can be obtained.

  When the end of the winding 2w constituting the coil 2 is pulled out to the opening side of the case 4B, the lid 5 is provided with an outlet at the end of the winding 2w. This outlet may be a through hole or a notch formed inward from the outer peripheral edge of the lid 5. In addition, when a physical quantity measurement sensor such as a temperature sensor or a current sensor is provided in the reactor 1B and a wiring connected to the sensor is pulled out from the opening of the case, an outlet for the wiring is provided in the lid 5. This outlet may also be a through hole or a notch.

  In order to fix the lid 5 to the opening of the case 4B, welding, tightening using a bolt, or the like can be used. In the latter case, it is preferable to provide a mounting portion (not shown) that is screwed into or penetrates the bolt so as to protrude inside or outside the case 4B. In addition, the lid 5 may be fixed by integrating the lid 5 with the outer core portion 32 by using a resin constituting the molded cured body.

<Embodiment 3>
With reference to FIG. 4, the reactor 1C of Embodiment 3 is demonstrated. The basic configuration of the reactor 1C is the same as that of the reactor 1A of the first embodiment described above, and the coil 2, the magnetic core 3, and the case 4C that houses the coil 2 and the magnetic core 3 (the same as the case 4A of the first embodiment). Configuration). The difference between the reactor 1 </ b> C and the reactor 1 </ b> A is that the coil 2 is stored. Hereinafter, this difference and its effects will be mainly described, and detailed description of other configurations and effects common to the first embodiment will be omitted.

  The case 4 </ b> C includes a rectangular plate-shaped bottom plate portion 40 and a rectangular frame-shaped side wall 41 erected from the bottom plate portion 40. Of course, the case 4C of the third embodiment may be provided with a lid similar to that of the second embodiment. The coil 2 is housed in the case 4C with respect to the inner bottom surface 40i of the case 4C so that the axis of the coil 2 is perpendicular to the bottom plate portion 40 (outer bottom surface 40o). Called). Further, the inner core portion 31 inserted through the coil 2 is also stored so that its axis is perpendicular to the bottom plate portion 40, and one end surface 31e of the inner core portion 31 is in contact with the inner bottom surface 40i of the case 4C. The outer core portion 32 includes an outer peripheral surface of the coil 2 housed in the case 4C, an outer peripheral surface in the vicinity of one end surface 31e of the inner core portion 31, and the other end surface 31e of the inner core portion 31 and an outer peripheral surface in the vicinity thereof. And cover.

Irregularities similar to those of the first embodiment are also formed on the inner surface of the case 4C.
However, in this example, the above-mentioned unevenness is not provided in a part of the bottom surface of the case that comes into contact with one end surface of the inner core portion.

  In the case 4C, as shown in FIG. 4B, a positioning member (not shown) for the coil 2 is provided in order to place the coil 2 in an intermediate portion of the case 4C. The positioning member may be formed integrally with the side wall 41 of the case 4C or the like, or may be a separate member formed of a composite material or the like constituting the outer core portion 32. In addition, the case 4C may be configured to include a positioning member (not shown, for example, a protrusion protruding from the inner bottom surface 40i) of the inner core portion 31 therein.

  The vertical type reactor 1 </ b> C can reduce the bottom plate portion 40 of the case 4 </ b> C, so that the installation area can be reduced as compared with the horizontal type reactor 1 </ b> A. Moreover, the inner core part 31 is excellent in stability with respect to the case 4C by using the end surface 31e as a contact surface with respect to the case 4C.

<Modification>
In the first to third embodiments, the coil 2 is embedded in the outer core portion 32 made of a molded and hardened body. However, a coil molded body (not shown) in which the coil is previously molded with the inner resin portion is used, and this coil molded body is used as the outer side. It is good also as a structure embed | buried in a core part. Since the point that the coil is a coil molded body is a difference from the other embodiments, the following description will be mainly given of this difference.

  The coil molded body has a configuration in which the axial length of the coil is held by the inner resin portion. In particular, it is possible to reduce the size by forming a coil molded body in which the length of the coil in the axial direction is held in a state compressed more than the free length. The region where the inner resin portion covers the coil may be at least a part of both end surfaces and the outer peripheral surface of the coil. Furthermore, you may cover at least one part of an inner peripheral surface of a coil with an inner side resin part. By adjusting the thickness of the inner resin part that covers the inner peripheral surface of the coil, the resin part can be used for positioning the inner core part. However, the end portion of the winding wire constituting the coil is exposed from the inner resin portion.

  The coil molded body may have a configuration in which a hollow hole for fitting the inner core portion is formed on the inner peripheral side of the coil, or may be a configuration in which the coil and the inner core portion are integrally molded with the inner resin portion. In this case, it is easy to store the integrated body of the coil and the inner core portion in the case. Thus, the coil molded body can easily handle the coil and can shorten the length of the coil in the axial direction. As for the thickness of the inner side resin part in a coil molded object, about 1 mm-10 mm are mentioned, for example.

  For the production of the coil molded body, for example, a production method described in JP-A-2009-218293 can be used. Examples of the molding include injection molding, transfer molding, and cast molding.

  As the resin of the inner resin portion, a thermosetting resin such as an epoxy resin, or a thermoplastic resin such as a PPS resin or LCP can be suitably used. When these resins are mixed with a filler made of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, and silicon carbide, heat dissipation can be improved.

  By using the coil molded body, the coil can be handled as a component in which expansion and contraction is suppressed, and the productivity of the reactor is excellent. In particular, if it is a coil molded body in which the inner core part and the coil are integrated, the number of parts handled at the time of manufacture can be reduced, and the productivity of the reactor is further improved.

<Embodiment 4>
The combination provided in the reactor of the present invention may be a combination of a type in which an annular magnetic core is arranged in a coil in which two coil elements are connected on one end side. Even in that case, the configuration of the case can use the same configuration as in the first to third embodiments. Therefore, in the following description, only the configuration of the combination will be described with reference to FIG.

[Coil 2 ']
Coil 2 'which comprises union 10' is provided with a pair of coil elements 2a and 2b, and coil connection part 2r which connects both coil elements 2a and 2b. The coil elements 2a and 2b are formed in a hollow rectangular tube shape with the same number of turns and the same winding direction, and are arranged side by side so that the axial directions are parallel to each other. The connecting portion 2r is a portion bent in a U shape that connects the coil elements 2a and 2b on the other end side of the coil 2 '(the right side in FIG. 5).

[Magnetic core 3 ']
The magnetic core 3 ′ includes a pair of inner core portions 31 ′ and 31 ′ disposed inside the coil elements 2a and 2b, and a pair of outer core portions 32 ′ and 32 ′ exposed from the coil 2 ′. Have. Each inner core portion 31 ′, 31 ′ is configured by alternately laminating divided cores (core pieces) 31m made of a substantially rectangular parallelepiped magnetic material and gap plates 31g having a lower magnetic permeability than the divided core 31m. It is a laminate. On the other hand, each outer core part 32 ', 32' is a columnar core piece which has a dome-shaped surface, for example. One end (the left side of the drawing) of the inner core portions 31 ′ and 31 ′ that are spaced apart is connected via one outer core portion 32 ′, and the other ends (the right side of the drawing) of the core portions 31 ′ and 31 ′ are connected to each other. Are connected via the other outer core portion 32 '. As a result, an annular magnetic core 3 ′ is formed by the inner core portions 31 ′, 31 ′ and the outer core portions 32 ′, 32 ′.

  For each of the core pieces, a molded body using magnetic powder or a laminated body in which a plurality of magnetic thin plates (for example, electromagnetic steel plates) having an insulating coating are laminated can be used. The split core 31m constituting the inner core portions 31 'and 31' and the outer core portions 32 'and 32' may have different magnetic characteristics by using different magnetic materials.

[Bobbin]
The combined body 10 ′ of this embodiment includes a bobbin 6 ′ for enhancing the insulation between the coil 2 ′ and the magnetic core 3 ′. The bobbin 6 ′ has a pair of inner bobbins 61 ′ disposed on the outer periphery of the inner core portion 31 ′ and a pair of frame-shaped bobbins 62 that are in contact with the end surfaces of the coil 2 ′ (surfaces in which the turns of the coil appear to be annular). 'And the configuration with. As a constituent material of the bobbin 6 ′, an insulating material such as polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin, liquid crystal polymer (LCP) can be used.

[Sealing resin]
Sealing resin is filled between the above-described combination 10 'and a case (not shown). By doing so, it can prevent union 10 'from dropping out of a case. As the sealing resin, for example, an epoxy resin, a urethane resin, a silicone resin, or the like can be used. Moreover, the heat dissipation of sealing resin can also be improved by containing the filler excellent in insulation and heat conductivity in sealing resin.

<Embodiment 5>
The reactor of Embodiments 1-4 can be utilized for the component of the converter mounted in a vehicle etc., and the component of a power converter device provided with this converter, for example.

  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. The motor (load) 1220 is provided. The motor 1220 is typically a three-phase AC motor, which drives the wheel 1250 during traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, vehicle 1200 includes an engine in addition to motor 1220. In addition, in FIG. 6, although an inlet is shown as a charge location of the vehicle 1200, it is good also as a form provided with a plug.

  Power conversion device 1100 includes converter 1110 connected to main battery 1210 and inverter 1120 connected to 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 200V to 300V to about 400V to 700V and supplies power to inverter 1120 when vehicle 1200 is traveling. In addition, converter 1110 steps down DC voltage (input voltage) output from motor 1220 via inverter 1120 to DC voltage suitable for main battery 1210 during regeneration, and causes main battery 1210 to be charged. 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 the motor 1220 with electric power. 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. 7, 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). 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 prevents the change of the current to flow through the circuit. As this reactor L, the reactor as described in the said embodiment and modification is used. By using these lightweight and easy-to-handle reactors, the power converter 1100 (including the converter 1110) can be reduced in weight.

  Vehicle 1200 is connected to converter 1110, power supply converter 1150 connected to main battery 1210, sub-battery 1230 serving as a power source for auxiliary machinery 1240, and main battery 1210. Auxiliary power supply 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 power supply device converters 1150 perform DC-DC conversion. The reactors of the power supply device converter 1150 and the auxiliary power supply converter 1160 have the same configuration as the reactors of the above-described embodiments and modifications, and a reactor whose size and shape are appropriately changed can be used. In addition, the reactor of the above-described embodiment can be used for a converter that performs conversion of input power and that only performs step-up or converter that performs only step-down.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, you may comprise the case in embodiment only with a porous body. In that case, it is desirable to ensure insulation between the case and the combination by interposing an insulating member between the case and the combination.

  The reactor of the present invention can be used as a component of a power conversion device such as a bidirectional DC-DC converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle.

1A, 1B, 1C reactor 10, 10 'combination 2, 2' coil 2w winding 2a, 2b coil element 2r coil connecting part 3, 3 'magnetic core 31, 31' inner core part 31e end face 31m divided core 31g gap plate 32, 32 'outer core part 4A, 4B, 4C case 40 bottom plate part 40i inner bottom face 40o outer bottom face 41 side wall part 45 mounting part 45h bolt hole 5 lid 6' bobbin 61 'inner bobbin 62' frame-shaped bobbin 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 equipment 1250 Wheels

Claims (11)

A reactor comprising a coil and magnetic core combination, and a case for storing the combination,
At least a part of the case includes a porous body made of a nonmagnetic metal.   The reactor according to claim 1, wherein at least a part of the case is made of a composite material including an insulating resin and the porous body.   The reactor according to claim 2, wherein the pores of the porous body are filled with the insulating resin. The case has the porous body as a skeleton,
The reactor according to any one of claims 1 to 3, wherein a volume ratio of the porous body in the case is 10 to 70% by volume.   The reactor according to any one of claims 1 to 4, wherein a material of the porous body is a nickel-chromium alloy.   The reactor according to any one of claims 1 to 4, wherein a material of the porous body is aluminum. The coil is cylindrical,
The magnetic core has an inner core portion disposed inside the coil, and an outer core portion that is disposed from the outside of the coil to the inner surface of the case and forms a closed magnetic path together with the inner core portion,
The reactor according to any one of claims 1 to 6, wherein the outer core portion is made of a mixture containing magnetic powder and resin.   The reactor according to claim 1, wherein the case has a bottomed cylindrical shape.   The reactor according to claim 1, wherein an inner surface of the case has an uneven shape. A converter that includes 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 as described in any one of Claims 1-9, The converter characterized by the above-mentioned. A converter for converting an input voltage, and an inverter connected to the converter and converting between direct current and alternating current, and for driving a load with electric power converted by the inverter,
The said converter is a converter of Claim 10, The power converter device characterized by the above-mentioned.

Images