JP2013143453A - Housing structure of reactor and electric power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a housing structure of a reactor which is more lightweight than conventional housing structures.SOLUTION: A reactor 1 comprises: a cylindrical coil; and a magnetic core disposed at the interior and the exterior of the coil and forming a closed magnetic path. In a housing structure 10 of the reactor, the reactor 1 is housed in a structure case 4 with a circuit component 5 functioning in cooperation with the reactor 1. At least a part of the magnetic core of the reactor 1 included in the housing structure 10 of the reactor, which is disposed at the outer peripheral side of the coil, is formed by a resin core material including magnetic material powder and a resin. The structure case 4 is provided between the reactor 1 and the circuit component 5 and includes an electromagnetic shield part (a partition part 42) shielding magnetic flux leaking from the reactor 1 to the circuit component 5.

Description

  The present invention relates to a reactor storage structure in which a reactor including a coil and a magnetic core is stored in a structure case together with a circuit component that cooperates with the reactor, and a power converter including a converter to which the reactor storage structure is applied. About.

  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 Literature 1 discloses a reactor that is used as one component of a converter of a power conversion device that is mounted on a vehicle such as a hybrid vehicle. The magnetic core of the reactor of Patent Document 1 includes an inner core portion disposed inside the coil and an outer core portion disposed on the outer periphery of the coil, and the outer core portion includes a magnetic powder such as pure iron powder. And a composite material containing a resin in which the powder is dispersed (hereinafter referred to as a resin core material). Hereinafter, this type of reactor is referred to as a resin core type reactor.

  The reactor is housed in a large case (hereinafter, the case in which the reactor and the circuit parts are housed together is referred to as a structure case) together with circuit parts (for example, a switching element in the case of a converter) cooperating with the reactor. And mounted on the vehicle. Here, in the resin core type reactor, the magnetic flux easily leaks from the magnetic core provided in the reactor, and this leakage magnetic flux may adversely affect the circuit component. Therefore, the resin core type reactor is housed in the structure case in a state of being housed in a reactor case made of a nonmagnetic metal such as aluminum (see FIG. 1 of Patent Document 1).

JP 2011-1992257 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. Therefore, it is considered how to reduce the weight of the reactor, or how to reduce the weight of the reactor storage structure in which the reactor is stored in a structure case together with other circuit components.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a reactor storage structure that is lighter than conventional ones.

  Another object of the present invention is to provide a power conversion device including the reactor storage structure of the present invention that functions as a converter.

  As a result of reviewing the configuration of the converter, which is a typical example of a conventional reactor storage structure, the present inventors have focused on the fact that the reactor is double-covered by the reactor case and the structure case. The reactor storage structure was completed. Hereinafter, the storage structure of the reactor of the present invention is defined.

  The reactor storage structure of the present invention stores a reactor including a cylindrical coil and a magnetic core that is disposed inside and outside of the coil to form a closed magnetic path in a structure case together with circuit components that cooperate with the reactor. This is a reactor storage structure. In the reactor storage structure, at least a part of the magnetic core of the reactor that is disposed on the outer peripheral side of the coil is formed of a resin core material including magnetic powder and resin. And the structure case with which the storage structure of this invention reactor is provided is equipped with an electromagnetic shielding part between a reactor and a circuit component, It is characterized by the above-mentioned.

  According to the configuration of the reactor storage structure of the present invention, since the reactor case can be omitted, the reactor storage structure can be made lighter than before. Here, if the reactor case is simply omitted, circuit components may be adversely affected by leakage magnetic flux leaking from a portion made of the resin core material of the reactor. On the other hand, in the storage structure of the reactor of the present invention, the leakage magnetic flux is shielded by the electromagnetic shielding portion, thereby avoiding adverse effects on the circuit components due to the leakage magnetic flux.

  As one form of the reactor storage structure of the present invention, the structure case is erected from the bottom plate portion on which the reactor is placed and the edge of the bottom plate portion, and the bottom plate portion constitutes a bottomed cylindrical case body Side walls, a lid that closes the opening of the case body, and a partition that protrudes from the bottom plate and functions as an electromagnetic shielding part. In that case, the reactor is accommodated in one space sandwiching the partition portion of the space in the case surrounded by the bottom plate portion, the side wall portion, and the lid portion, and the circuit component is accommodated in the other space.

  According to the said structure, since the inside of a structure case is closed, it can prevent effectively that the leakage magnetic flux of a reactor leaks out of a structure case. Therefore, it is possible to avoid the adverse effect of the leakage magnetic flux of the reactor on the electrical equipment disposed in the vicinity of the reactor storage structure.

  As one form of the storage structure of the reactor of the present invention, a form in which one space and the other space are closed without communicating with each other can be exemplified. In order to achieve such a configuration, the partition portion may be connected to all of the bottom plate portion, the side wall portion, and the lid portion.

  If it is the said structure, it can prevent effectively that the leakage magnetic flux of a reactor penetrate | invades into the other space where a circuit component is arrange | positioned from one space where a reactor is arrange | positioned, and malfunction of the circuit component by leakage magnetic flux is prevented. It can be avoided.

  As one form of the storage structure of the reactor of the present invention, a predetermined gap is provided between the partition part and the lid part, and one space and the other space communicate with each other via the gap. It can be.

  According to the above configuration, the space near the gap between the partition portion and the lid portion can be used as a part of the magnetic path while preventing leakage magnetic flux of the reactor from leaking out of the structure case. Details will be described in an embodiment described later.

  As one form of the storage structure of the reactor of the present invention, the space between the inner surface and the reactor in one space is separated in a range of 2 to 10 mm, and the space outside the core used for adjusting the inductance of the reactor is between them. It can be set as the form currently formed.

  By using the space outside the core for adjusting the inductance of the reactor, the magnetic core of the reactor can be reduced in size and weight, that is, the reactor can be reduced in size and weight. As a result, it is possible to reduce the weight of the reactor storage structure.

  As one form of the storage structure of the reactor of the present invention, the conductivity of the electromagnetic shielding part is preferably 1 MS / m (mega siemens per meter) or more.

  If the conductivity of the electromagnetic shielding portion is 1 MS / m or more, the leakage magnetic flux can be reliably shielded. Examples of the material that achieves such conductivity include iron-based alloys, aluminum (including the alloys thereof), magnesium (including the alloys thereof), and the like.

  As one form of the storage structure of the reactor according to the present invention, it is preferable that a heat sink is provided between the reactor and the mounting surface of the reactor in the structure case.

  By providing the heat sink, the heat generated in the reactor during the operation of the reactor can be efficiently radiated from the reactor.

  The form which applies the reactor storage structure to a converter as one form of the storage structure of this invention reactor is mentioned. In this case, the reactor storage structure (= converter) includes a switching element as a circuit component and a drive circuit that controls the operation of the switching element. The reactor is connected to the switching element so as to smooth the switching operation of the switching element. The reactor storage structure having such a configuration functions as a converter that converts the input voltage by the operation of the switching element.

  The reactor storage structure may be applied to at least a part (or all) of the power converter. For example, it is a power conversion device that 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. Thus, the power conversion device of the present invention in which the storage structure of the reactor of the present invention is applied to a part (or all) of the power conversion device can be cited.

  The power converter of the present invention using the lightweight reactor storage structure of the present invention contributes to weight reduction of equipment (for example, a vehicle such as a hybrid car) provided with these.

  In the reactor storage structure of the present invention, the reactor case that contains the leakage magnetic flux of the reactor is omitted. Therefore, the reactor storage structure of the present invention is lighter than the conventional structure.

(A) The schematic longitudinal cross-sectional view of the storage structure of the reactor of this invention which accommodated the reactor and the circuit component which cooperates with this reactor in the structure case, (B) this invention which abbreviate | omitted the cover part of the structure case It is a schematic top view of the reactor storage structure. It is a schematic top view of the storage structure of this invention reactor provided with two partition parts. (A) is a schematic perspective view of the horizontal type reactor used for the storage structure of this invention reactor, (B) is BB sectional drawing of (A). (A) is a schematic perspective view of the vertical installation type reactor used for the storage structure of this invention reactor, (B) is BB sectional drawing of (A). 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.

  Embodiments of the present invention will be specifically described below with reference to the drawings. The same reference numerals in the figure indicate the same names.

<Embodiment 1>
≪Overall structure≫
As shown in FIG. 1, the reactor storage structure 10 of the present invention includes a reactor 1, a circuit component 5 that cooperates with the reactor 1, and a structure case 4 that stores them. There are two features of the reactor storage structure 10. The first is that the reactor 1 to be used is a pot type reactor without a reactor case, and the second is an electromagnetic shielding part that shields the leakage magnetic flux of the reactor 1 between the reactor 1 and the circuit component 5. That is, a partition portion 42 is provided. Hereinafter, each structure of the reactor storage structure 10 will be described in detail.

≪Reactor≫
The pot type reactor in the present invention includes a horizontal type and a vertical type, and the difference between them is that the direction of the axis of the coil with respect to the storage case is different. First, with reference to FIG. 3, the configuration and arrangement of the horizontal reactor 1 will be described in detail. Next, the vertical reactor 1 ′ will be briefly described with reference to FIG.

  A horizontal reactor 1 shown in FIG. 3 includes one coil 2 and a magnetic core 3 that is disposed inside and outside the coil 2 to form a closed magnetic path, and a part of the magnetic core 3 (specifically, The outer core portion 32 or a part of the outer core portion 32 is a pot type reactor made of a resin core material containing magnetic powder and resin. Although a pot type reactor is normally provided with the reactor case which contains a leakage magnetic flux, the reactor 1 in this invention is characterized by not having the reactor case.

[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)
3B is a cross-sectional view of the reactor 1 cut along a plane orthogonal to the axial direction of the coil 2 (cross section BB in FIG. 3A). 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 such that a part of the magnetic core 3 (inner core portion 31) is inserted in the inner periphery thereof, and the axial direction of the coil 2 is parallel to the bottom plate portion 40 of the structure case 4 described later. (Refer to FIG. 1 together. The bottom of FIG. 3 is the bottom plate portion 40). That is, this arrangement in which the axial direction of the coil 2 is parallel to the bottom plate portion 40 is a horizontal type arrangement. In addition, when the end surface shape of the coil 2 is a race track shape, the coil is arranged so that the planar space formed by the straight line portion on the outer peripheral surface thereof is parallel to the bottom plate portion 40 of the structure case 4. In short, the coil 2 may be stored horizontally with respect to the structure case 4.

  The coil 2 is covered with the magnetic core 3 (outer core portion 32) on almost the entire outer peripheral surface thereof. However, a part of the coil 2 in the circumferential direction that is not covered with the magnetic core 3 may be provided such that a part of the outer peripheral surface of the coil 2 is in contact with the bottom plate portion 40 of the structure case 4.

(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. 3, 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]
As shown in FIG. 3A, 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 a cylindrical outer peripheral surface of the coil 2. And an outer core portion 32 formed so as to cover at least a part thereof, and forms a closed magnetic circuit 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 1 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 part)
The inner core portion 31 is a cylindrical body having an outer shape along the inner peripheral shape of the coil 2. The whole inner core part 31 is comprised from the compacting body, and can be made into the solid body which a gap material and an air gap do not interpose. 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 be configured such that a gap material or an air gap having a permeability lower than that of the core piece is interposed between a plurality of core pieces made of a green compact or an electromagnetic steel plate.

  The green compact forming the inner core portion 31 is typically made of a soft magnetic powder having an insulating coating made of 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. After molding, it is obtained by firing at a temperature lower than the heat resistance temperature of the insulating coating. 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 FIG. 3A, the axial length of the coil 2 in the inner core portion 31 (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 portion 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 space where the coil 2 exists in the reactor 1, a longitudinal section, a transverse section (FIG. 3B), and a horizontal section (a section cut through a plane parallel to the bottom plate portion 40 of the structure case 4 through the axis of the coil 2. ), 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 form a closed magnetic path, and the shape (coating space 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 space of the structure case 4 was not covered with the outer core part 32 in the outer peripheral surface of the coil 2, but was exposed is mentioned, for example. Alternatively, a pedestal (not shown) for supporting the coil 2 from the outer periphery is provided on the bottom plate portion 40 of the structure case 4, and the outer core portion 32 is not interposed between the pedestal and the coil 2, or the outer peripheral surface of the coil 2. Is in contact with at least one side wall 41 of the structure case 4, and the outer core 32 is not interposed at the contact location.

  Here, the outer core portion 32 is entirely formed of a resin core material (molded and cured body) containing magnetic powder and resin, and the inner core portion 31 and the outer core portion 32 do not intervene with an adhesive. The outer core portion 32 is joined by a constituent resin. 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 resin core material containing magnetic powder and resin, the outer core portion 32 having an arbitrary shape can be easily manufactured, and the magnetic characteristics of the outer core portion 32 can be easily changed. There are advantages. In addition, the outer core portion 32 may be a pressure-molded body obtained by pressure-molding magnetic powder and resin powder.

  Further, since the outer core portion 32 covers the entire coil 2 and the inner core portion 31, it also functions as a sealing material for the coil 2 and the inner core portion 31. Therefore, the reactor 1 can protect the coil 2 and the inner core portion 31 from the external environment by the outer core portion 32 and can enhance mechanical protection.

  The outer core portion 32 made of a molded hardened body can typically be formed by injection molding or cast molding. In the injection molding, usually, a powder made of a magnetic material and a fluid resin are mixed, the mixed fluid is poured into a molding die by applying a predetermined pressure, and then the resin 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. On the other hand, the outer core portion 32 made of a pressure-molded body is formed by mixing a powder made of a magnetic material and a powder made of a resin material, filling the mixed powder in a mold, and then pressure-molding.

  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

  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.

  In addition to the horizontal type reactor 1 described above, as shown in FIG. 4, a vertical type reactor 1 'may be used. Except for the orientation with respect to the storage case 4, the basic configuration of the vertical reactor 1 ′ is the same as that of the horizontal reactor 1 described above. Hereinafter, only the direction of the reactor 1 ′ with respect to the structure case 4 will be described.

  In the vertically placed reactor 1 ′, the coil 2 provided in the reactor 1 ′ is housed in the structure case 4 so that the axis of the coil 2 is perpendicular to the bottom plate portion 40 (see FIG. 1). Further, the inner core portion 31 inserted through the coil 2 is also housed in the structure case 4 so that its axis is perpendicular to the bottom plate portion 40, and one end surface 31 e of the inner core portion 31 is the bottom plate portion of the structure case 4. 40 (the lower side in the drawing in FIG. 4). On the other hand, the outer core portion 32 provided in the reactor 1 ′ includes an outer peripheral surface of the coil 2 housed in the structure case 4, an outer peripheral surface in the vicinity of one end surface 31 e of the inner core portion 31, and the other of the inner core portion 31. The end face 31e and the outer peripheral surface in the vicinity thereof are covered.

  Reactors 1 and 1 ′ having the above-described configuration typically have applications in which energization conditions are, for example, maximum current (direct current): about 100 A to 1000 A, average voltage: about 100 V to 1000 V, and operating frequency: about 5 kHz to 100 kHz. Can be suitably used for components of an in-vehicle power converter such as an electric vehicle or 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.

≪Structure case 4≫
[Overall structure of structure case]
As shown in FIG. 1, the structure case 4 is typically a bottomed cylindrical case composed of a rectangular bottom plate portion 40 and four side wall portions 41 erected from the bottom plate portion 40. It is a rectangular parallelepiped box provided with a main body and a lid portion 43 that closes an opening of the case main body. The structure case 4 further includes a partition portion 42 protruding from the bottom plate portion 40. In the structure case 4, the essential components are the bottom plate part 40, the side wall part 41, and the partition part 42, and the lid part 43 is optional. However, if the lid portion 43 is provided, it is possible to avoid the leakage magnetic flux of the reactor 1 from affecting the electrical equipment disposed outside the structure case 4.

  The bottom plate part 40, the side wall part 41, and the partition part 42, which are essential components of the structure case 4, can be formed integrally. Of course, the three members 40, 41, and 42 may be separate members, or any two of them may be integrally formed. In addition, the partition part 42 is not necessarily limited to one, and may be two or more as described later with reference to FIG.

(Partition section)
The partition portion 42 is arranged between the part made of the resin core material and the circuit component 5 so that the leakage magnetic flux leaking from the part made of the resin core material of the reactor 1 does not adversely affect the circuit component 5. It is an electromagnetic shielding part which shields magnetic flux. In the example shown in FIG. 1, the partition portion 42 is connected to all of the bottom plate portion 40, the side wall portion 41, and the lid portion 43, and completely partitions the internal space of the structure case 4 into two spaces. Therefore, the magnetic flux generated in one space 11 (the other space 12) sandwiching the partition portion 42 is shielded by the partition portion 42 and cannot enter the other space 12 (the one space 11). Therefore, in the reactor storage structure 10 of the present embodiment, the reactor 1 is disposed in one space 11 partitioned by the partition portion 42, and the circuit component 5 that cooperates with the reactor 1 is disposed in the other space 12. Thus, the leakage magnetic flux of the reactor 1 is prevented from adversely affecting the circuit component 5. Needless to say, the cooperating reactor 1 and circuit component 5 are connected by a wiring (not shown), and a portion through which the wiring passes is provided in the partition portion 42.

  Next, a case where there are a plurality of partition portions (that is, a case where the reactor structure includes a plurality of reactors) will be described with reference to FIG. The reactor storage structure 10 ′ illustrated in FIG. 2 includes two partition portions 42 </ b> A and 42 </ b> B. In this case, when viewed from the partition portion 42A, the space is divided into a space (one space 11A) on the right side of the drawing with respect to the partition portion 42A and another space (the other space 12A). Therefore, the reactor 1A is disposed in one space 11A on the right side of the partition 42A. Next, when viewed from the partition portion 42B, the space is divided into a space (one space 11B) on the left side of the paper with respect to the partition portion 42 and a space other than that (the other space 12B). Therefore, the reactor 1B is arranged in one space 11B on the left side of the partition 42B. And the circuit component 5 is arrange | positioned in the space of the paper surface center shared by the other space 12A in the partition part 42A, and the other space 12B in the partition part 42B. Even when there are three or more partitions, circuit components may be arranged in a portion shared by the other spaces of the partitions based on the same concept.

  Here, the partition part 42 may be disposed so that the leakage magnetic flux from the reactor 1 does not reach the circuit component 5 in terms of its function, and is completely connected to the bottom plate part 40, the side wall part 41, and the lid part 43. There is no need to be. For example, there may be a gap between the partition portion 42 and the lid portion 43 (the portion indicated by the white arrow in FIG. 1A). By setting it as such a structure, not only the one space 11 in which the reactor 1 is arrange | positioned but the other space 12 in which the circuit component 5 is arrange | positioned can be utilized for adjustment of the inductance of the reactor 1. FIG. However, in this case, the position of the upper end of the partition part 42 needs to be higher than the circuit component 5 by 10 mm or more. Otherwise, the adverse effect on the circuit component 5 due to the leakage magnetic flux from the reactor 1 cannot be avoided, and the meaning of providing the partition portion 42 may be lost.

  Further, a gap may be formed between the partition portion 42 and the side wall portion 41 in order to adjust the inductance of the reactor 1. For example, the partition portion 42 is connected to the bottom plate portion 40 and the lid portion 43 but not connected to the side wall portion 41, and the partition portion 42 is connected to the bottom plate portion 40, but is connected to the lid portion 43 and the side wall portion 41. Can be in an unconnected form. Of course, also in that case, it is necessary to adjust the size of the gap so that the adverse effect on the circuit component 5 due to the leakage magnetic flux from the reactor 1 can be avoided.

[Reactor arrangement in the structure case]
A space is provided between the reactor 1 arranged in one space 11 and the inner peripheral surface of the structure case 4 as shown in the figure. Specifically, the bottom surface of the reactor 1 is in contact with the bottom plate portion 40, but the top surface and the side surface of the reactor 1 are separated from the lid portion 43, the partition portion 42, and the side wall portion 41. That is, the core outer space is formed between the outer peripheral surface of the reactor 1 and the inner peripheral surface of the structure case 4. This space outside the core can be used for adjusting the inductance of the reactor 1. In this case, since the size of the magnetic core 3 (outer core portion 32) of the reactor 1 can be reduced by the amount of adjustment of the inductance by the space outside the core, the weight of the reactor 1, that is, the weight of the reactor storage structure 10 can be reduced. Can do. Unlike the illustrated configuration, the reactor 1 may be arranged in the space 11 of the structure case 4 with almost no gap. For example, if the structure case 4 itself is used as a mold for producing the reactor 1, the reactor 1 is arranged in one space 11 without a gap.

  The space between the inner peripheral surface of the structure case 4 and the reactor 1 for securing the space outside the core used for adjusting the inductance of the reactor 1 is preferably 2 to 10 mm. Although this space | interval changes with the use conditions of the reactor 1, and the value of the target inductance, the balance of the merit and demerit of providing a space outside a core is good by setting it as the said range, and it is preferable. The merit is that the magnetic core 3 can be downsized as described above. The demerit is that one space 11 tends to be large in order to secure the space outside the core.

[Constituent materials]
The structure case 4 is preferably made of a nonmagnetic metal having a conductivity of 1 MS / m or more, such as aluminum or an alloy thereof, magnesium or an alloy thereof. By doing so, the leakage magnetic flux from the reactor 1 can be enclosed in the structure case 4. Here, the material of each part 40-43 which comprises the structure case 4 may be the same, and may differ.

  In addition, the structure case 4 may be composed of a composite material including an insulating resin and a nonmagnetic metal. For example, a composite material in which an insulating resin is disposed in pores of a porous body made of a nonmagnetic metal, or a composite material in which a powder made of a nonmagnetic metal is dispersed in an insulating resin can be used. By using such a composite material, the weight of the structure case 4, that is, the weight of the reactor storage structure 10 can be reduced. Here, the entire structure case 4 may be composed of a composite material, or only a part of the structure case 4 may be composed of a composite material. In the latter case, for example, the bottom plate portion 40 that is desirable to have high strength because the reactor 1 is placed is made of a nonmagnetic metal plate material such as aluminum, and the portions other than the bottom plate portion 40 are made of the composite material. Can be mentioned.

≪Reactor fixing to structure case≫
The reactor 1 can be bonded to the bottom plate portion 40 of the structure case 4 with an adhesive or the like. In that case, the adhesive preferably has excellent electrical insulation. By using an insulating adhesive, insulation between the reactor 1 and the structure case 4 can be ensured. Furthermore, the adhesive preferably has excellent thermal conductivity. For example, a silicone resin, an acrylic resin, an epoxy resin, or the like containing a filler having excellent thermal conductivity and electrical insulating properties such as alumina can be suitably used. 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.

[Heatsink]
In the present embodiment shown in FIG. 1 (A), a heat radiating plate 6 is interposed between the reactor 1 and the bottom plate portion 40 of the structural body case 4, and both 1 and 4 are joined. By providing the heat radiating plate 6, the heat generated in the reactor 1 can be efficiently radiated to the structural body case 4, and the reactor 1 can be operated stably. It is preferable to use the above-described insulating adhesive for bonding the heat radiating plate 6 and the bottom plate portion 40 and bonding the heat radiating plate 6 and the reactor 1.

As a material for the heat radiating plate 6, for example, an amide imide resin, a polyimide resin, a polyester resin, or an epoxy resin can be used. Such a material has excellent thermal conductivity and electrical insulation, so that insulation between the coil 2 and the structure case 4 can be ensured. The heat sink 6 made of the resin includes ceramic fillers such as silicon nitride (Si ₃ N ₄ ), alumina (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), and silicon carbide (SiC). May be included. By making the heat sink 6 contain a ceramic filler, the heat conductivity and electrical insulation of the heat sink 6 can be enhanced.

[Others]
In order to improve the insulation between the coil 2 and the structure case 4, an insulating material such as an insulating paper, an insulating sheet, or an insulating tape may be interposed between the coil 2 and the structure case 4. . 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 the extent that the minimum insulation required between the coil 2 and the structure case 4 can be ensured. By reducing the thickness as much as possible, the thermal conductivity is reduced due to the interposition of the insulating material. In addition to being able to suppress, downsizing can be achieved.

≪Effect of reactor storage structure≫
Since the reactor storage structure 10 is not provided with a reactor case, the reactor storage structure 10 is lighter and easier to handle than the conventional configuration. Therefore, it is possible to reduce the weight of a device that employs such a reactor storage structure 10. Further, omitting the reactor case is advantageous in terms of cost.

<Modified Embodiment>
In the first embodiment, the coil 2 is embedded in the outer core portion 32. However, a coil molded body (not shown) in which the coil is molded in advance with the inner resin portion is used, and this coil molded body is embedded in the outer core portion. Also good.

  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 space where the inner resin portion covers the coil may be at least a part of both end faces and the outer peripheral face 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.

  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.

<Embodiment 2>
The reactor storage structure 10 described in the first embodiment can be applied to a converter used in a power conversion device mounted on a vehicle such as a hybrid vehicle or an electric vehicle.

  As a vehicle provided with a power converter, the vehicle 1200 illustrated in FIG. 5 can be mentioned, for example. A vehicle 1200 shown in FIG. 5 includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and a motor (load) 1220 that is driven by power supplied from the main battery 1210 and used for traveling. . 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. 5, 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. 6, 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.

  The configuration of the reactor storage structure 10 described in the first embodiment is applied to the entire power conversion apparatus 1100 described with reference to FIG. Specifically, the reactor L of FIG. 6 is arranged in one space 11 of the structure case 10 having the partition portion 42 as shown in FIG. 1, and the switching elements 1111 and 1111 of FIG. The circuit 1112 and the inverter 1120 are arranged as the circuit component 5. Of course, the reactor L does not include a reactor case. By doing so, weight reduction of the power converter device 1100 of FIG. 6 can be achieved.

  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 reactor storage structures shown in the above-described embodiments and modifications may be applied to the reactors of the power supply device converter 1150 and the auxiliary power supply converter 1160. Further, the reactor storage structure of the above-described embodiment can also be used for a converter that performs conversion of input power, that is, a converter that performs only step-up or a 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.

  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.

10, 10 'Reactor storage structure 11, 11A, 11B One space 12, 12A, 12B The other space 1, 1', 1A, 1B Reactor 2 Coil 2w Winding 3 Magnetic core 31 Inner core portion 31e End face 32 Outside Core part 4 Structure case 40 Bottom plate part 41 Side wall part 43 Lid part 42, 42A, 42B Partition part (electromagnetic shielding part)
DESCRIPTION OF SYMBOLS 5 Circuit component 6 Heat sink 1100 Power converter 1110 Converter 1111 Switching element 1112 Drive circuit L Reactor 1120 Inverter 1150 Power supply converter 1160 Auxiliary power supply converter 1200 Vehicle 1210 Main battery 1220 Motor 1230 Sub battery 1240 Auxiliary equipment 1250 Wheel

Claims (9)

A reactor storage structure in which a reactor including a cylindrical coil and a magnetic core disposed inside and outside the coil to form a closed magnetic path is stored in a structure case together with circuit components that cooperate with the reactor. ,
Of the magnetic core, at least a part of the portion disposed on the outer peripheral side of the coil is made of a resin core material containing magnetic powder and resin,
The structure case is
A reactor storage structure comprising an electromagnetic shielding portion between the reactor and the circuit component. The structure case is
A bottom plate portion on which the reactor is placed;
A side wall portion standing from an edge of the bottom plate portion and constituting a bottomed cylindrical case body with the bottom plate portion;
A lid for closing the opening of the case body;
A partition portion protruding from the bottom plate portion and functioning as an electromagnetic shielding portion,
Of the space in the case surrounded by the bottom plate portion, the side wall portion, and the lid portion, the reactor is housed in one space sandwiching the partition portion, and the circuit component is housed in the other space. The reactor storage structure according to claim 1.   The reactor storage structure according to claim 2, wherein the one space and the other space are closed without communicating with each other.   3. A predetermined gap is provided between the partition part and the lid part, and the one space and the other space communicate with each other through the gap. The reactor storage structure described.   The inner peripheral surface of the structure case in the one space and the reactor are separated in a range of 2 to 10 mm, and an outer space for the core used for adjusting the inductance of the reactor is formed therebetween. The reactor storage structure according to any one of claims 2 to 4, wherein the reactor storage structure is provided.   The reactor storage structure according to any one of claims 1 to 5, wherein the electromagnetic shielding portion has a conductivity of 1 MS / m or more.   The reactor storage structure according to any one of claims 1 to 6, further comprising a radiator plate between the reactor and a mounting surface of the reactor in the structure case. A switching element as the circuit component and a drive circuit for controlling the operation of the switching element;
The reactor is connected to the switching element so as to smooth the switching operation of the switching element,
The reactor storage structure according to any one of claims 1 to 7, wherein the reactor storage structure functions as a converter that converts an input voltage by an operation of the switching element. 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 power converter according to claim 8, wherein at least a part of the power converter is configured with the reactor storage structure according to claim 8.

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