JP2011254042A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor with excellent manufacturing efficiency while ensuring desired inductance performance by eliminating use of a gap plate and an adhesive layer.SOLUTION: A reactor 100 includes non-magnetic and substantially annular core materials 10 (10A, 10B) that penetrate a plurality of magnetic cores 20, 30 and position and fixe the magnetic cores 20, 30, and the whole reactor is formed into a substantially annular shape.

Description

  The present invention relates to a reactor constituting a power conversion circuit.

  The reactor of the power conversion circuit is generally accommodated in, for example, a housing in a posture in which coils are formed in two longitudinal portions of a reactor core that is generally annular in plan view. A typical reactor core is made up of a magnetic core material consisting of a stack of magnetic steel sheets or a dust core, and a non-magnetic gap plate or spacer is interposed between each core material. A reactor is formed by adhering and fixing a plate and the core material with an adhesive. Since the magnetic cores are attracted to each other by a magnetic attractive force, a gap length having a desired thickness can be ensured by interposing this gap plate or spacer between the magnetic cores.

  The general structure of a conventional reactor will be described with reference to FIG. 8. A core plate a having a substantially U shape in plan view (U type core) and a core b having a rectangular shape in plan view (I type core) are gap plates. An insulating bobbin (not shown) or the like is formed on the longitudinal part of the adhesive layer d via c, and a coil (not shown) is formed around the bobbin. As a conventional published technique related to the reactor core having such a configuration, for example, a reactor core disclosed in Patent Document 1 can be cited.

  By the way, when the core material and the gap plate are bonded, the durability of the reactor is lowered due to the deterioration of the adhesiveness. Furthermore, due to the manufacturing tolerance of both the core material and the gap plate and the manufacturing tolerance of the adhesive layer, the average magnetic path length of the reactor in which these members are assembled changes, and a desired inductance cannot be obtained. Problems can arise.

  In other words, the conventional reactor has a structure in which the magnetic core material and the gap plate are bonded and fixed via an adhesive layer. The manufacturing tolerance of this adhesive layer is the same as the manufacturing tolerance of other core materials. This is extremely difficult to eliminate, and as described above, the deterioration of the adhesive layer is significant compared to other members, so that this adhesive layer determines the durability of the reactor. It was a cause. In addition, in the reactor of the said patent document 1, it adds that it is difficult to ensure predetermined | prescribed magnetic path length easily in the state in which the electric current is not supplied with the manufactured reactor.

  In addition, it is necessary to fix the magnetic core before the adhesive layer is cured, and there is a problem that a jig for that purpose is required, and that the core fixing operation until curing is required. More specifically, in addition to the magnetic core, the gap plate is also fixed with a jig, and the adhesive layer is formed in a posture that secures a space for the adhesive layer so that a desired thickness is formed. It is necessary to

  Furthermore, in the case where the reactor is mounted in an engine room such as a hybrid vehicle, there is a possibility that it will be placed in a cold cycle environment within a range of about −40 ° C. to 150 ° C. due to a change in its use environment. In the reactor in which the gap plate is interposed, there may be a problem that peeling is likely to occur at the bonding portion between the core material and the gap plate. This is because the core material, gap plate, and adhesive layer have different linear expansion coefficients, resulting in a difference in thermal expansion between the members. The structurally weak adhesive layer is caused by this thermal expansion difference and repeated thermal stress. It is because it becomes easy to peel.

JP 2004-241475 A

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a reactor excellent in manufacturing efficiency while eliminating a gap plate and an adhesive layer and ensuring desired inductance performance.

  In order to achieve the above object, a reactor according to the present invention is a non-magnetic, substantially annular core material that penetrates a plurality of magnetic cores to position and fix the magnetic core, and is formed in a generally annular shape. .

  The reactor of the present invention eliminates the hard gap plate and the adhesive layer arranged between the reactor cores that constitute the conventional reactor, and instead, each magnetic core is used as a positioning fixing means for a plurality of magnetic cores. A substantially annular non-magnetic core material that penetrates is applied.

  Here, the magnetic core refers to a U-shaped core or an I-shaped core having magnetism, and a reactor can be constituted by two U-shaped cores. A reactor can also be formed by interposing an I-type core. Further, the magnetic core may be formed from a laminate formed by laminating silicon steel plates, or a pressure formed by pressing a soft magnetic metal powder or a magnetic powder coated with a soft magnetic metal powder with a resin binder. Although it may be formed from a powder magnetic core, it is preferable that the magnetic core is formed from a powder magnetic core in consideration of manufacturing efficiency when forming the magnetic core around a substantially annular core material.

  The non-magnetic, substantially annular core material defines the shape of a substantially annular reactor core by the alignment of its axial center, and further has a posture in which the above-mentioned U-shaped core and I-shaped core are provided with a desired thickness gap. Positioning and fixing with.

  This nonmagnetic core material can be formed of a thermosetting or thermoplastic resin material, a ceramic material such as alumina or zirconia, a nonmagnetic metal such as aluminum or stainless steel, or the like.

  According to the reactor of the present invention described above, a structure in which a magnetic core is fixed while securing a gap of a desired thickness around a substantially annular and non-magnetic core material, a gap plate in a conventional reactor, An adhesive layer can be dispensed with, and the above-described problems of a reactor including these members can be solved at a stretch.

  Further, the number of components can be reduced by eliminating the gap plate and the adhesive layer, and the manufacturing cost can be greatly reduced by reducing the material cost and improving the manufacturing efficiency.

  Also, in a preferred embodiment of the reactor according to the present invention, the core member is formed with a protrusion protruding in a direction perpendicular to the axis, and the protrusion guarantees a gap between adjacent magnetic cores. Is.

  In arranging a plurality of magnetic cores while securing a gap of a desired thickness around the core material, the reactor according to the present embodiment is a core material part where the gap is formed in order to precisely guarantee the thickness of the gaps. A protrusion projecting in a direction orthogonal to the axis of the core member (a direction extending in a substantially annular shape) is provided. And since this protrusion has the thickness of the desired gap, the magnetic path length of the reactor can be secured, thereby ensuring the inductance performance of the reactor.

  Protrusions corresponding to each gap are provided at a plurality of gap positions to be formed, and the thickness of the gap (the total thickness of all the gaps) that satisfies the desired inductance performance is the thickness of this protrusion (the thickness of all the protrusions) ).

  Here, the core material described above may be integrally formed as a whole, or may be formed in a substantially annular shape by connecting a plurality of divided bodies.

  In a form in which the core material is integrally formed in a substantially annular shape, the core material is placed in a molding die, filled with magnetic powder in the molding die, and pressed, so that a plurality of magnetic materials are secured while securing a gap around the core material. The core can be molded at once.

  In addition, when the core material is composed of a plurality of divided bodies, the core materials adjacent to each other are assembled by fitting, screwing, pinning, etc. A substantially annular reactor can be formed by previously forming a magnetic core and assembling the core members in a substantially annular shape.

  In a preferred embodiment of the reactor according to the present invention, the core member has a flow path therein so that a cooling medium flows therethrough.

  A conventional reactor radiates heat generated in the coil to the outside through a sealing resin body having heat dissipation potted around the reactor core, more specifically, around the coil formed around the reactor core. The form is common. However, in this heat radiation mode, since the generated heat is expected only from the heat flow that radiates from the inside of the core to the outside through the sealing resin body, the heat transferred to the reactor core is sufficiently Since heat could not be dissipated, it was easy to go inside the core, and therefore there was room for improvement in heat dissipation.

  On the other hand, in the reactor according to the present embodiment, the non-magnetic core material described above has a pipe structure, and a cooling medium such as water or air can flow freely in the inside thereof. The heat generated and transferred to the reactor core can be cooled from the inside of the core, and it is possible to effectively eliminate the heat generated in the core.

  In other words, the reactor of this form can guarantee a gap with a desired thickness precisely while eliminating the need for a gap plate or an adhesive layer with a non-magnetic core material, and in addition, a cooling medium circulates inside the core material. The heat dissipation performance can be greatly improved.

  Moreover, in the reactor mentioned above, the insulating resin mold body may be formed around the substantially annular magnetic core as in a conventional reactor.

  The insulating resin mold body ensures insulation between the magnetic core and the coil formed on the outer periphery thereof.

  Further, a part of the formed resin mold body is interposed in the gap between the adjacent magnetic cores, so that a gap made of the resin mold body is formed.

  By interposing the resin mold body in the gap, it is possible to further ensure the gap thickness, and further, the rigidity of the reactor (the gap area around the core material is made of only air) ( Strength) can be remarkably increased.

  Further, after forming a resin mold body that guarantees insulation between the coil and the magnetic core on the outer periphery of the magnetic core and forming the coil around the periphery, a sealing resin body having excellent heat dissipation may be formed on the outer periphery. Of course.

  As can be understood from the above description, according to the reactor of the present invention, it is possible to precisely secure a gap having a desired thickness while eliminating the adhesive layer and gap plate of the reactor having the conventional structure, and manufacturing. Manufacturing costs can be greatly reduced by improving efficiency and reducing the number of parts.

It is a perspective view of one embodiment of the core material which constitutes the reactor of the present invention. (A) is a perspective view of other embodiment of a core material, (b) is the figure explaining the fitting structure of the core material. (A) is a perspective view of further another embodiment of a core material, (b) is a bb arrow line view of Drawing 3a, and (c) explains a fitting structure of a core material. FIG. It is a top view of one embodiment of the reactor of the present invention comprising the core shown in FIG. It is a top view of other embodiments of the reactor of the present invention. (A) is the schematic diagram explaining the width | variety of the magnetic core, the width | variety, and thickness of a core material, (b) is a bb arrow line view of FIG. 6a. It is the graph which showed the relationship between the magnetic core cross-sectional area and the thickness of a gap, and the relationship between the width | variety of the core material in a gap, and the thickness of a gap. It is the perspective view explaining the general structure of the conventional reactor.

  Embodiments of the present invention will be described below with reference to the drawings. In the illustrated example, the illustration of the coils constituting the reactor is omitted. Moreover, although the reactor which comprises the core material shown in FIG. 2 is illustrated as a typical example of the reactor of the present invention, it is needless to say that the reactor having the core material shown in FIGS. is there. Furthermore, the number and form of the magnetic core constituting the reactor are not limited to the illustrated example, the form consisting of only two U-type cores, two or four I-type cores, and eight or more I-type cores Of course, it may be a form.

  1 to 3 both show an embodiment of a core material constituting the reactor of the present invention.

  A core member 10 shown in FIG. 1 includes a main body 11 having a substantially annular shape in plan view (a shaft center is substantially annular), and protrusions 12 and 12 projecting in the left-right direction perpendicular to the axial direction of the main body 11. Has been.

  The thickness t of the protrusion 12 is a thickness of a gap between magnetic cores constituting a reactor described later, and is adjusted to a thickness that satisfies a desired inductance performance. The core material 10 is integrally molded from a nonmagnetic material, and is molded from a thermosetting or thermoplastic resin material, a ceramic material such as alumina or zirconia, a nonmagnetic metal such as aluminum or stainless steel, or the like. it can.

  On the other hand, the outer appearance of the core material 10A shown in FIG. 2a is the same as that of the core material 10 shown in FIG. 1, but the entire core material 10A is not integrally molded, and the divided bodies 11a, 11b, and 11c are assembled. It was found and constructed.

  An example of the assembled form is shown in FIG. 2b. For example, when the divided body 11c is taken up and described, a fitting projection 14 is provided at one end, and a fitting groove 13 is provided at the other end. The substantially annular core member 10A is configured by fitting one fitting protrusion 14 of the divided bodies 11c, 11c (or divided bodies 11a, 11c, divided bodies 11b, 11c) into the other fitting groove 13. Is done.

  Furthermore, the core material 10B shown in FIG. 3a is formed by assembling the divided bodies in the same manner as the core material 10A shown in FIG. 2a, and the divided bodies 11a ′, 11b ′, and 11c ′ are in the assembled posture. It has a flow path in fluid communication.

  That is, as shown in the cross-sectional view of FIG. 3b and the perspective view of FIG. 3c, a flow path 15 is defined at the center thereof, and a coolant such as water or air circulates in the flow path. The heat generated sometimes can be cooled from the inside of the reactor tank.

  In FIG. 3a, a pipe for providing a cooling medium, a pipe for discharging the medium heated by generated heat, and a structure in which these pipes are in fluid communication with a part of the flow path 15 are shown. Illustration is omitted.

  In the illustrated example, as shown in FIG. 3 c, a fitting protrusion 17 or a fitting groove 16 is provided around the flow path 15 provided in the divided body 11 c ′.

  Next, a reactor including the core material 10A shown in FIG. 2 will be described with reference to FIGS.

  In the reactor 100 shown in FIG. 4, an I-type magnetic core 30 is disposed between the protrusions 12 and 12 of the core 10A to form a straight portion, and the two straight portions are connected to the U-shaped magnetic cores 20 and 20. The whole is composed of.

  Each of the magnetic cores 20 and 30 is formed around the core divided bodies 11a, 11b, and 11c, and the manufacturing method thereof accommodates each of the divided bodies 11a, 11b, and 11c in a molding die. The magnetic cores 20 and 30 made of powder magnetic cores having the cores 11a, 11b and 11c therein are individually manufactured by filling the magnetic powder therein and applying pressure.

  Here, the magnetic powder forming the magnetic cores 20 and 30 is a soft magnetic metal powder or a magnetic powder in which a soft magnetic metal powder is coated with a resin binder. Examples of the soft magnetic metal powder include iron, iron-silicon-based powders. Alloys, iron-nitrogen alloys, iron-nickel alloys, iron-carbon alloys, iron-boron alloys, iron-cobalt alloys, iron-phosphorus alloys, iron-nickel-cobalt alloys and iron-aluminum- A silicon-based alloy or the like can be used. Soft magnetic metal oxide powders may be used, and examples thereof include manganese-based, nickel-based, and magnesium-based ferrites.

  In the reactor 100 shown in FIG. 4, the magnetic cores 20 and 30 are fixed by a substantially annular core material 10 </ b> A, and the thickness of the gap G between adjacent magnetic cores is guaranteed by the thickness t of the protrusion 12. .

  That is, by positioning the magnetic cores 20 and 30 with the core material 10A, a gap plate and an adhesive layer can be eliminated, and further, the thickness of the gap G is precisely guaranteed by the protrusions 12 of the core material 10A. Can do.

  Insulating resin mold body 40 is formed on the outer periphery of reactor 100 shown in FIG. 4, and a coil (not shown) is formed on the outer periphery, thereby ensuring insulation between the coil and magnetic core 30. Furthermore, you may form the sealing resin body not shown excellent in heat dissipation in the outer periphery of the coil formed in the circumference | surroundings of the resin mold body 40. FIG.

  Moreover, although illustration is abbreviate | omitted, the heat which produced in the coil can be cooled from the inside of a reactor core by manufacturing the reactor which comprises the core material 10B shown in FIG. By doing this, heat generated in the coil can be radiated to the outside through the sealing resin body while cooling from the inside of the reactor core. As a result, heat dissipation in the reactor core is eliminated, and extremely high heat dissipation performance can be expected as compared with a conventional reactor.

[Verification of the relationship between the cross-sectional area of the magnetic core and the thickness of the gap, and the relationship between the width of the core material in the gap and the thickness of the gap, and results]
The inventors of the present invention relate to a reactor having a non-magnetic core material as shown in the figure, and the magnetic core cross-sectional area and gap thickness for making the reactor have the same inductance performance as a conventional reactor without the core material. The relationship and the relationship between the width of the core material in the gap and the thickness of the gap were verified.

  In the reactor structure of the present invention, the cross-sectional area of the magnetic core is reduced compared to the case where the core material is not provided by embedding a non-magnetic core material inside the magnetic core, and therefore the cross-sectional area of the magnetic core is reduced. However, since the volume of the gap G that determines the inductance performance varies with an increase in the cross-sectional area, the relationship between the cross-sectional area of the magnetic core and the thickness of the gap in the gap, and the core in the gap The relationship between the width of the material and the thickness of the gap is specified.

  In this verification, as shown in FIGS. 6A and 6B, the width of the core material 10A is s1, the width considering the protrusion 12 in the gap G is s2, the thickness of the magnetic core 30 in which the core material 10A is embedded is q, and the core material 10A. The height of the magnetic core 30 is p, and the cross-sectional area of the magnetic core can be expressed as Ac = qp. The verification result is shown in FIG.

  In the figure, when the thickness of the gap is four thicknesses in the range of 1.95 to 2 mm, the core cross-sectional area where a predetermined inductance performance is obtained and the width of the core material in the gap are verified, and the solid line indicates the core Correlation lines specified from the results relating to the cross-sectional area are shown, and dotted lines indicate correlation lines obtained from the results relating to the width of the core material.

  Both show a linear correlation, and it can be seen that a reactor having a certain inductance performance can be manufactured by increasing the cross-sectional area of the magnetic core and the width of the core material in the gap as the thickness of the gap increases.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 10, 10A, 10B ... Core material, 11 ... Main body, 12 ... Protrusion, 11a, 11a ', 11b', 11b ', 11c, 11c' ... Divided body of core material, 13, 16 ... Fitting groove, 14, 17 ... Fitting protrusion, 15 ... Flow path, 20 ... Magnetic core (U-type core), 30 ... Magnetic core (I-type core), 40 ... Resin molded body, 100, 100A ... Reactor, G ... Gap

Claims (7)

  A reactor in which a non-magnetic, substantially annular core material passes through a plurality of magnetic cores to position and fix the magnetic core, and is formed in a generally annular shape.   The reactor according to claim 1, wherein the core member has a protrusion protruding in a direction perpendicular to the axis thereof, and the protrusion guarantees a gap between adjacent magnetic cores.   The reactor according to claim 1, wherein the core material is integrally formed as a whole.   The reactor according to claim 1, wherein the core material is formed by connecting a plurality of divided bodies and forming an overall ring shape.   The reactor according to any one of claims 1 to 4, wherein the core member has a flow path therein so that a cooling medium flows therethrough.   The reactor according to claim 1, wherein an insulating resin mold body is formed around the substantially annular magnetic core.   The reactor according to claim 6, wherein the resin mold body forms a gap between adjacent magnetic cores.

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