JP2016032012A - Reactor and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor capable of securing a desired fastening performance while maintaining the physical constitution and performance of the reactor itself, and also to provide a method of manufacturing the same.SOLUTION: In a reactor, a core 11 is formed around linear parts 10b of a coil 10, connection parts 12 are formed around curved parts 10a of the coil 10, and the connection parts 12 are constituted from a raw material having lower magnetic permeability than a magnetic powder mixed material constituting the core 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reactor mounted on an electric vehicle, a hybrid vehicle, and the like, and a manufacturing method thereof.

  A reactor of a power conversion circuit is generally formed on a case in a posture in which a coil is formed at two longitudinal portions of a substantially circular annular reactor in plan view, and the reactor and the coil are molded with a molding resin body for sealing. It is placed and configured. This reactor core is composed of a laminate of a plurality of magnetic steel sheets or a split core consisting of dust cores, and a gap plate made of a non-magnetic material is interposed between each split core. A reactor core is formed by being bonded and fixed with an adhesive.

  For example, a heat radiating plate (heat sink) is provided on the lower surface (bottom surface) of this case, and a cooler that circulates cooling water and air may be provided below the heat sink. Joule heat generated when the coil is energized Is radiated from the coil or reactor via a mold resin body or a heat sink, for example, via a cooler.

  As a form of fixing the reactor composed of the reactor core and the coil as described above, a form in which the reactor is adhered and fixed to the case through an adhesive or the like, a connection provided in the case (through a fastening screw, a fastening pin, etc.) The form etc. which are fastened and fixed to the location) are known.

  In recent years, for the purpose of reducing the size and weight, the reactor core and the molded resin body are formed of the same material, that is, a soft magnetic metal powder is coated with a resin binder around a coil in a wound state. Development of a reactor in which the magnetic powder mixed material is integrally molded and the coil is mounted on the case in a posture in which the coil is molded with the magnetic powder mixed material as a molded resin body is also in progress (for example, Patent Document 1). .

JP 2012-199580 A

  By the way, when a reactor in which a core made of a magnetic powder mixed material is integrally formed in a coil is fastened and fixed to a case or the like, a form in which a connecting portion in which a through hole for passing a fastening screw or the like is passed through the core constituting the reactor is provided. Or the form etc. which provide the connection part which formed the through-hole for letting a fastening screw etc. pass to the member different from the said core formed in the outer side of the core can be considered.

  However, when the connection portion is provided on the core itself, the connection portion is filled with a lot of soft magnetic powder, so that the impact resistance, strength, and the like are lowered, and there is a problem that sufficient fastening performance cannot be secured. . In addition, if the core itself is made of a non-magnetic material or if the filling amount of the soft magnetic powder in the core itself is lowered in order to ensure impact resistance, strength, etc. at the connection part, the flow of magnetic flux is hindered and the reactor performance (inductance And loss).

  On the other hand, when the connection part is provided on a member separate from the core formed on the outside of the core, impact resistance and strength can be ensured according to the material constituting the connection part, but the size of the reactor itself is increased. Problems may occur.

  This invention is made | formed in view of the subject mentioned above, and it aims at providing the reactor which can ensure desired fastening performance, and its manufacturing method, maintaining the physique and performance of the reactor itself.

  In order to achieve the above object, a reactor according to the present invention includes a coil formed by winding so as to have a straight portion and a curved portion, a core made of a magnetic powder mixed material including magnetic powder and a resin binder, And a connecting portion for connecting the coil and the core to another part, wherein the core is formed around a straight portion of the coil, and the connecting portion is formed around a curved portion of the coil In addition, the connecting portion is made of a material having a lower magnetic permeability than the magnetic powder mixed material constituting the core.

  The core constituting the reactor is formed, for example, by pressing a magnetic powder mixed material in which a soft magnetic metal powder is coated with a resin binder. Examples of the soft magnetic metal powder include iron, nickel, cobalt, and iron-silicone. Alloy, iron-nitrogen alloy, iron-nickel alloy, iron-carbon alloy, iron-boron alloy, iron-cobalt alloy, iron-chromium alloy, iron-phosphorus alloy, iron-aluminum alloy Iron-nickel-cobalt alloys, iron-aluminum-silicone alloys, rare earth metals, etc., and soft magnetic metal oxide powders such as manganese-based, nickel-based, and magnesium-based ferrites You can also. The resin binder may be either a thermosetting resin or a thermoplastic resin. Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a melamine resin. As, for example, any one of polypropylene (PP), polyethylene (PE), methacrylic resin, polyimide (PI), polyamide (PA), polyester, polyphenylene sulfide, polyetheretherketone, polyamideimide, thermoplastic epoxy resin, etc. Alternatively, two or more kinds of mixed materials can be mentioned, but a thermoplastic resin is preferable in consideration of production efficiency.

  In addition, the connection part constituting the reactor is formed of, for example, the same material (thermosetting resin or thermoplastic resin) as the resin binder forming the core, and in order to increase toughness, for example, glass fiber And fillers made of fibers such as carbon fiber, fillers made of inorganic substances such as silica, talc, and alumina, and thermosetting elastomers and thermoplastic elastomers.

  According to the above-described embodiment, the core made of the magnetic powder mixed material including the magnetic powder and the resin binder around the linear portion of the coil having a relatively low magnetic resistance and a high magnetic flux density (that is, a large flow of magnetic flux). And a magnetic material having a lower magnetic permeability than the magnetic powder mixture constituting the core around the curved portion of the coil having a relatively high magnetic resistance and a low magnetic flux density (that is, a low magnetic flux flow). By forming the connecting portion, the impact resistance and strength at the connecting portion can be increased while maintaining the physique and performance of the reactor itself, and desired fastening performance can be ensured.

  In addition, the method of manufacturing a reactor according to the present invention includes a coil formed by winding so as to have a straight portion and a curved portion, a core made of a magnetic powder mixed material including magnetic powder and a resin binder, the coil, A reactor for connecting the core to another component, a core forming step of forming the core around a straight portion of the coil, and a curved portion of the coil A connection part forming step of forming the connection part made of a material having a lower magnetic permeability than the magnetic powder mixed material constituting the core.

  Preferably, the core forming step includes a step of gripping the curved portion and arranging the coil in a molding die, and a step of injecting the magnetic powder mixed material into the molding die, and the connection portion The forming step includes a step of placing the preliminary body produced in the core forming step in a mold, and a step of injecting a material having a lower magnetic permeability than the magnetic powder mixture into the mold. Is the method.

  According to the above-described method, the core made of the magnetic powder mixed material including the magnetic powder and the resin binder around the linear portion of the coil having a relatively low magnetic resistance and a high magnetic flux density (ie, a high magnetic flux flow). A connection made of a material having a magnetic permeability lower than that of the magnetic powder mixed material constituting the core around the curved portion of the coil having a relatively high magnetic resistance and a low magnetic flux density (that is, a low magnetic flux flow) By forming the portion, the impact resistance and strength at the connection portion can be increased with a simple method while maintaining the physique and performance of the reactor itself, and desired fastening performance can be ensured.

  As can be understood from the above description, according to the present invention, a core made of a magnetic powder mixed material containing magnetic powder and a resin binder is formed around the linear portion of the coil, and around the curved portion of the coil. By forming the connecting portion made of a material having a lower magnetic permeability than the magnetic powder mixture constituting the core, desired fastening performance can be ensured while maintaining the physique and performance of the reactor itself.

It is a perspective view showing an embodiment of a reactor of the present invention typically. It is a cross-sectional view of the reactor shown in FIG. It is explanatory drawing explaining the core formation process of the manufacturing method of the reactor shown in FIG. 1, Comprising: (a) is the cross-sectional view, (b) is BI-BI arrow sectional drawing of Fig.3 (a). Yes, (c) is a cross-sectional view taken along the line CI-CI in FIG. It is a perspective view which shows typically the preliminary body of a reactor after a core formation process. It is explanatory drawing explaining the connection part formation process of the manufacturing method of the reactor shown in FIG. 1, Comprising: (a) is the cross-sectional view, (b) is BII-BII arrow sectional drawing of Fig.5 (a). (C) is a cross-sectional view taken along arrow CII-CII in FIG. It is a transverse cross section of other examples of an embodiment of a reactor of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, with reference to FIG. 1 and FIG. 2, the whole structure of the reactor of this invention is demonstrated. FIG. 1 is a perspective view schematically showing an embodiment of the reactor of the present invention, and FIG. 2 is a cross-sectional view of the reactor shown in FIG.

  The illustrated reactor 1 mainly includes a coil 10 formed by winding around a predetermined winding axis L (in the illustrated example, an axis extending in the longitudinal direction), magnetic powder, and a resin binder. A core 11 made of a magnetic powder mixed material and a connecting portion 12 for connecting and fixing the reactor 1 to another component (for example, a case) are provided.

  The coil 10 is formed by winding a long flat plate-like winding having a substantially rectangular cross section into a spiral shape so as to exhibit a substantially rectangular shape (square shape or rectangular shape) in plan view. A curved portion 10a having a predetermined curvature is formed at one corner, and a straight portion 10b having a predetermined length is formed between the curved portions 10a.

  The straight line portion 10b is a portion where the center line C in the thickness direction of the coil 10 exhibits a straight line shape when viewed in a plan view (in the winding axis L direction). A center line C in the thickness direction of the coil 10 is a curved portion.

  One end 10d of the coil 10 (winding thereof) extends outward from a predetermined curved portion 10a and in the normal direction of the outer shape of the coil 10, and The other end 10e of the winding) is directed outward from the curved portion 10a at a position symmetrical to the predetermined curved portion 10a with respect to the center of the reactor 1 through the connecting member 13, for example. The coil 10 extends in the normal direction of the outer shape.

  The core 11 made of the magnetic powder mixed material is formed integrally with the coil 10 around the four straight portions 10b of the coil 10 or inside the coil 10 so as to have a predetermined thickness.

  The core 11 is formed, for example, by pressing a magnetic powder mixed material in which a soft magnetic metal powder is coated with a resin binder. Examples of the soft magnetic metal powder include iron, nickel, cobalt, and iron-silicone alloys. , Iron-nitrogen alloy, iron-nickel alloy, iron-carbon alloy, iron-boron alloy, iron-cobalt alloy, iron-chromium alloy, iron-phosphorus alloy, iron-aluminum alloy, iron -Nickel-cobalt alloys, iron-aluminum-silicone alloys, rare earth metals, and the like, and soft magnetic metal oxide powders such as manganese-based, nickel-based, and magnesium-based ferrites can also be used. . The resin binder may be either a thermosetting resin or a thermoplastic resin. Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a melamine resin. As, for example, any one of polypropylene (PP), polyethylene (PE), methacrylic resin, polyimide (PI), polyamide (PA), polyester, polyphenylene sulfide, polyetheretherketone, polyamideimide, thermoplastic epoxy resin, etc. Alternatively, two or more kinds of mixed materials can be mentioned, but a thermoplastic resin is preferable in consideration of production efficiency. In order to secure the desired reactor performance, the ratio of the soft magnetic metal powder in the magnetic powder mixed material is preferably 30% by volume or more, and more preferably 50% by volume or more.

  On the other hand, the connection portion 12 is formed around the four curved portions 10 a of the coil 10 integrally with the coil 10 and adjacent to the core 11, and each connection portion 12 is a magnetic powder constituting the core 11. It is made of a material having a lower magnetic permeability than the mixed material.

  Each connecting portion 12 is formed of, for example, the same kind of material as the resin binder forming the core 11 (a thermosetting resin or a thermoplastic resin, but a thermoplastic resin is preferable) and enhances toughness. Therefore, for example, fillers made of fibers such as glass fibers and carbon fibers, fillers made of inorganic substances such as silica, talc, and alumina, and thermosetting elastomers and thermoplastic elastomers can also be included. Furthermore, in order to suppress the magnetic flux leakage of the core 11, the same kind of soft magnetic metal powder as the soft magnetic metal powder forming the core 11 may be added. The proportion of the powder is preferably 50% by volume or less, and more preferably 30% by volume or less.

  Further, of the four connecting portions 12, both ends 10 d and 10 e of the coil 10 protrude from the connecting portion 12 that is symmetrical with respect to the center of the reactor 1, and the coil of each connecting portion 12 is provided. For example, a through-hole 12a extending in the vertical direction for passing the fastening pin P is formed in a portion outside the ten curved portions 10a.

  As shown in FIG. 1, the reactor 1 having such a configuration is disposed on a case H as a fixing member provided with an insertion hole Ha at a position corresponding to the through hole 12 a of the connection part 12. The fastening pin P having the large-diameter head Pa is inserted through the through-hole 12a of 12 and the insertion hole Ha of the case H, and the large-diameter head Pa (the lower surface) of the fastening pin P is connected to the connecting portion 12 (the upper surface). In the pressed state, the lower end of the fastening pin P is caulked, bent, or welded on the lower surface side of the case H, so that it is connected and fixed to the case H as one component such as a power control unit (PCU).

  Next, with reference to FIGS. 3-5, the manufacturing method (reactor manufacturing method of this invention) of the reactor 1 shown in FIG. 1 is demonstrated. FIG. 3 is an explanatory view for explaining a core forming step of the method for manufacturing the reactor shown in FIG. 1, FIG. 3 (a) is a cross-sectional view thereof, and FIG. 3 (b) is a cross-sectional view of FIG. FIG. 3C is a cross-sectional view taken along the arrow line BI-BI, and FIG. 3C is a cross-sectional view taken along the line CI-CI in FIG. FIG. 4 is a perspective view schematically showing a reactor preliminary body after the core forming step. FIG. 5 is an explanatory view for explaining the connecting portion forming step of the manufacturing method of the reactor shown in FIG. 1, wherein FIG. 5 (a) is a cross-sectional view thereof, and FIG. It is BII-BII arrow sectional drawing of a), FIG.5 (c) is CII-CII arrow sectional drawing of Fig.5 (a).

  First, after preparing the wound coil 10 having the above-described configuration, in the core forming step, as shown in FIG. 3, the outer surface of the curved portion 10 a at the four corners of the coil 10 is covered so as to cover the outer surface. The curved portion 10a is held by the inner peripheral surface of the mold K1, and the coil 10 is placed in the mold K1. Specifically, the upper and lower surfaces and side surfaces of the curved portion 10a are brought into contact with the inner peripheral surfaces of the upper die K1a and the lower die K1b constituting the forming die K1, and the surface of the straight portion 10b is constituted by the upper die constituting the forming die K1. K1a and the lower mold K1b are separated from the inner peripheral surfaces, and only the four curved portions 10a of the coil 10 are sandwiched between the upper mold K1a and the lower mold K1b constituting the mold K1, and the coil 10 is placed in the mold K1. To place.

  Next, for example, a magnetic powder mixed material in which soft magnetic powder and a resin binder are kneaded is injected and injected into the molding die K1 through the gate G1 provided in the approximate center of the upper die K1a of the molding die K1, The magnetic powder mixture is cured and demolded. As a result, the core 11 made of the magnetic powder mixed material is integrally formed around the four linear portions 10b of the coil 10 and in the interior 10c (see FIG. 4). The reactor after the core formation process in which the core 11 is formed around the linear portion 10b of the coil 10 and in the interior 10c and the four curved portions 10a of the coil 10 are exposed is referred to as a reactor preliminary body 2.

  Next, in the connecting portion forming step, a forming die K2 different from the forming die K1 in which the four through-hole forming pins K2c are arranged at predetermined positions is prepared, and as shown in FIG. The core 11 of the preliminary body 2 is held by the inner peripheral surface of the molding die K2, and the preliminary body 2 is arranged in the molding die K2. Specifically, the upper and lower surfaces of the core 11 are brought into contact with the inner peripheral surfaces of the upper mold K2a and the lower mold K2b constituting the molding die K2, and the surfaces of the curved portion 10a are arranged on the upper die K2a and the lower die constituting the molding die K2. Separated from the inner peripheral surface of the mold K2b, only the core 11 of the preliminary body 2 is sandwiched between the upper mold K2a and the lower mold K2b constituting the molding mold K2, and the preliminary body 2 is placed at a predetermined position in the molding mold K2. To place.

  For example, a material (for example, thermoplasticity) having a lower magnetic permeability than the magnetic powder mixture constituting the core 11 is provided via a gate G2 provided at a position corresponding to each curved portion 10a of the upper mold K2a of the mold K2. A material obtained by kneading a resin binder made of resin and a reinforcing filler is injected into the mold K2 and injected, and the material is cured and demolded. Thereby, the connection part 12 in which the through-hole 12a extended in the vertical direction for letting the fastening pin P pass is formed around the four curved parts 10a of the coil 10, and the coil 10 in the wound state is integrally formed. It molds with the material which comprises the core 11 and the four connection parts 12 so that the both ends 10d and 10e may be exposed (refer FIG. 1).

  Thus, according to the reactor 1 of the present embodiment, the magnetic powder and the resin binder are disposed around the straight portion 10b of the coil 10 that has a relatively low magnetic resistance and a high magnetic flux density (that is, a high magnetic flux flow). And the core 11 is formed around the curved portion 10a of the coil 10 having a relatively high magnetic resistance and a low magnetic flux density (that is, a low magnetic flux flow). By forming the connecting portion 12 made of a material having lower magnetic permeability and higher toughness than the magnetic powder mixed material constituting, the impact resistance and strength at the connecting portion 12 are maintained while maintaining the physique and performance of the reactor itself. The desired fastening performance can be ensured.

  Further, the connecting portion 12 described above may be non-magnetic or may have a predetermined magnetic permeability lower than that of the core 11, but may have a predetermined magnetic permeability by adding soft magnetic metal powder. By making it, the magnetic flux leakage of the core 11 can also be suppressed.

  In the above-described embodiment, the core 11 is integrally formed around the linear portion 10b of the coil 10 or the inside 10c, and the connecting portion 12 is integrated only around the curved portion 10a of the coil 10 so as to be adjacent to the core 11. Although the form to form was demonstrated, of course, the material which comprises the connection part 12 may be formed in the circumference | surroundings so that the core 11 formed in the circumference | surroundings of the linear part 10b of the coil 10 and the inside 10c may be covered. is there.

  In the above-described embodiment, the through hole 12a is formed in the connecting portion 12 made of a material having a lower magnetic permeability than the magnetic powder mixture constituting the core 11, and the fastening pin P is passed through the through hole 12a by caulking or the like. Although the form fixed to the case H has been described, for example, a male screw may be screwed to the lower end side of the fastening pin P, and the reactor 1 may be screwed to the case H and fixed. Further, for example, the reactor 1 may be fixed to the case H by holding the connection portion 12 while pressing the connection portion 12 with a predetermined gripping means and the case H without forming the through hole 12 a in the connection portion 12.

  In the above-described embodiment, the coil 10 constituting the reactor 1 has been wound in a spiral shape so as to have a substantially rectangular shape in plan view. However, the outer shape and winding method of the coil 10 are as follows. Needless to say, it can be changed as appropriate. For example, as shown in FIG. 6, a coil 10 </ b> A constituting the reactor 1 </ b> A includes two semicircular or substantially U-shaped curved portions 10 a </ i> A and two straight portions 10 b </ i> A connecting the ends of the two curved portions 10 a </ i> A. The core 11A made of a magnetic powder mixed material is integrally formed around the two straight portions 10bA and the inside 10cA, and extends in the longitudinal direction around the two curved portions 10aA, for example, for passing fastening pins. The connecting portion 12A made of a material having a lower magnetic permeability than the magnetic powder mixed material constituting the core 11A in which the through hole 12aA is formed may be integrally formed.

  Further, the reactor 1 described above may be in a housingless form that is not accommodated in the housing, or may be accommodated in the housing, and in any of these forms, a form having a heat sink plate further below it. The final form, such as a form in which a refrigerant reflux or the like is further provided below the heat sink plate, a form in which the case on which the coil is placed and fixed itself has a refrigerant reflux or the like, can be selected as appropriate.

  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 1 ... Reactor, 2 ... Reactor spare body, 10 ... Coil, 10a ... Coiled part of coil, 10b ... Linear part of coil, 10c ... Inside of coil, 10d, 10e ... End part of coil, 11 ... Core, 12 ... Connection portion, 12a ... through hole, H ... case, Ha ... insertion hole, K1, K2 ... molding die, K1a, K2a ... upper die, K1b, K2b ... lower die, K2c ... through hole forming pin, L ... winding shaft Heart, P ... Fastening pin

Claims (4)

A coil formed by winding so as to have a straight portion and a curved portion, a core made of a magnetic powder mixed material containing magnetic powder and a resin binder, and a connection for connecting the coil and the core to other components And a reactor comprising:
The core is formed around the straight portion of the coil, the connecting portion is formed around the curved portion of the coil, and the connecting portion has a lower magnetic permeability than the magnetic powder mixture constituting the core. Reactor made of materials. A coil formed by winding so as to have a straight portion and a curved portion, a core made of a magnetic powder mixed material containing magnetic powder and a resin binder, and a connection for connecting the coil and the core to other components And a reactor manufacturing method comprising:
Forming a core around a straight portion of the coil; and
And a connecting portion forming step of forming the connecting portion made of a material having a lower magnetic permeability than the magnetic powder mixture constituting the core around the curved portion of the coil.   The said core formation process includes the process of hold | gripping the said curve part, arrange | positioning the said coil in a shaping | molding die, and the process of inject | pouring the said magnetic powder mixed material in the said shaping | molding die. Reactor manufacturing method.   The connecting portion forming step includes a step of placing the preliminary body produced in the core forming step in a mold, and a step of injecting a material having a lower magnetic permeability than the magnetic powder mixture into the mold. The manufacturing method of the reactor of Claim 2 or 3 containing these.

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