JP2015076478A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently secure electrical insulation properties between a coil and a case.SOLUTION: A reactor includes: a case 1; a coil 3; a bottom core part 5 which is a powder-compact radiation magnetic core having a radiation path to the case 1; and an insulator 8. At least the coil 3, the bottom core part 5 and the insulator 8 are housed in the case 1. The insulator 8 is disposed in a portion having a path from at least a surface of the coil 3 out of a surface of the bottom core part 5, the path is provided which radiates heat generated in the coil 3 to the case 1 via the bottom core part 5, and a magnetic flux generated by energization to the coil 3 and circulating around the periphery of the coil 3 of the bottom core part 5 penetrates through at least a part of the insulator 8.

Description

  The present invention relates to a reactor using an inductance used for boosting applications and the like.

  Investigations have been made on a reactor using a powder compact core obtained by compacting a metal soft magnetic powder or a magnetic powder mixed resin core mixed with a resin and cured.

  In Patent Document 1, by providing a T-shaped core section integrally formed from the inside to the outside of the coil, heat generated during operation of the reactor is radiated to the inner bottom surface of the case via the T-shaped core. This proposal is described in paragraph 0028 and the like.

  Moreover, the structure which electrically insulates a coil and a core by covering a coil with insulating resin is disclosed.

JP 2013-162069 A

  In the configuration of Patent Document 1, there is a problem that it is difficult to increase electrical insulation because a sufficient consideration is not given to the conductive path from the coil to the case through the core.

  That is, an object of the present invention is to provide a reactor having high electrical insulation between a coil and a case.

  The present invention provides a case, a coil, a dust-radiating magnetic core having a heat radiation path to the case, and an insulator, and the case includes at least the coil, the dust-radiating magnetic core, and the insulator. And the insulator is disposed at least in a portion of the surface of the dust radiating magnetic core having a path from the coil surface, and heat generated in the coil is passed through the dust radiating magnetic core. The magnetic flux that has a path for radiating heat to the case and that circulates around the coil of the dust radiating magnetic core generated by energization of the coil is solved by a reactor that penetrates at least a part of the insulator.

  Here, the path is a path starting from the coil surface and ending with the dust radiating magnetic core via a dust core or a fixed resin other than the dust radiating core in the case.

  In addition, the insulator here refers to an entire portion having a path from the coil surface that does not have a seam or a cut that can be a conductive path.

  In addition, it is desirable that the entire surface of the dust radiating magnetic core is covered with the insulator.

  Further, the composite soft body mainly includes a binder and a soft metal magnetic powder, the soft metal powder has an insulating film on the surface, and the composite magnetic body fills a gap inside the case. It is desirable that

  Further, the thickness of the insulator is 0.3 mm or more, the thickness of the composite magnetic body between the coil surface and the case is 2 mm or more, and the relative permeability of the dust radiating magnetic core is Preferably, the relative magnetic permeability of the composite magnetic body is less than 50.

  It is desirable to inject an uncured composite magnetic body into the case, and then house the coil, the dust radiating magnetic core, and the insulator in the case to cure the insulating resin or the composite magnetic body.

  By this invention, since an insulator is distribute | arranged to all the conductive paths from the coil surface to a case via a dust core, the insulation between a coil and a case can be improved.

  Furthermore, since the magnetic flux around the coil penetrates the insulator, the insulator functions as a magnetic gap, and the initial permeability of the reactor can be lowered and the DC superimposition characteristics can be improved.

  In addition, since the dust core is fixed by the composite magnetic body filled around, the dust core can be protected from impact force and the like.

  In addition, by filling the surface of the metal soft magnetic powder with an insulating coating, the gap is filled with an insulating composite magnetic material, thereby improving the DC superposition characteristics and permeability without affecting the insulating properties. Can do.

It is a perspective view of the reactor in Embodiment 1 of this invention. It is sectional drawing of the reactor in Embodiment 1 of this invention, and respond | corresponds to the cross section of the A surface in FIG. 2A is a cross-sectional view that does not include the protrusion on the inner surface of the case, and FIG. 2B is a cross-sectional view that includes the protrusion on the inner surface of the case. It is sectional drawing which shows the creation process of the reactor in Embodiment 1 of this invention, Fig.3 (a) shows after the composite magnetic body casting, FIG.3 (b) shows the state after bottom core part and a core part installation. ing. It is sectional drawing of the reactor in Embodiment 2 of this invention, and respond | corresponds to the modification of FIG. It is sectional drawing of the reactor in Embodiment 3 of this invention, and respond | corresponds to the modification of FIG. It is a top view of the reactor in Embodiment 4 of this invention. It is a perspective view of the reactor in Embodiment 4 of this invention. It is a perspective view which shows the manufacturing method of the reactor in Embodiment 4 of this invention, and has shown the manufacture procedure in order from FIG. 8 (a) to FIG.8 (d). It is sectional drawing of the reactor in Embodiment 2 of this invention, and respond | corresponds to the modification of FIG. It is a perspective view which shows the manufacturing method of the reactor in Embodiment 5 of this invention, and has shown the manufacture procedure in order of Fig.10 (a) to FIG.10 (e).

(Embodiment 1)
FIG. 1 is a perspective view of a reactor according to Embodiment 1 of the present invention.

  The reactor body is accommodated in the case 1.

  Since the case 1 is provided with the attachment portion 11, it can be fixed to the installation destination by bolting or the like.

  The opening of the case 1 is sealed by the lid 2, and the terminals 31 and 32 are drawn from the coil accommodated in the case 1.

  FIG. 2 is a cross-sectional view of the reactor according to the first embodiment of the present invention, and corresponds to the cross section of plane A in FIG. 2A is a cross-sectional view that does not include the protrusion on the inner surface of the case, and FIG. 2B is a cross-sectional view that includes the protrusion on the inner surface of the case.

  As shown in FIG. 2A, the composite magnetic body is also filled between the inner peripheral surface of the case 1 and the bottom core portion 5 and the upper core portion 6. The thickness of the composite magnetic material to be filled is preferably 1 mm or more in order to ensure fillability, and is preferably 3 mm or less in order to ensure heat dissipation and inductance.

  As shown in FIG. 2B, such filling is performed by supporting a part of the bottom core portion 5 and the upper core portion 6 by the protrusion 10 on the inner surface of the case 1 so that a gap is formed between the inner surface of the case 1. It becomes possible by making it.

  A core 4 is disposed inside a coil 3 in which a conducting wire is wound in a cylindrical shape, a bottom core 5 is disposed outside the bottom of the case 1, and an upper core 6 is disposed on the opening of the case 1.

  Here, the center core portion 4, the bottom core portion 5, and the upper core portion 6 are dust cores, and the bottom core portion 5 and the upper core portion 6 are covered with an insulator 8 on the surface.

  In the case where an insulator is coated on the dust core, a configuration in which the entire surface is insulated and coated can be relatively easily taken.

  Here, this invention does not deny that the core part 4 is insulation-coated. What is necessary is just to select the necessity of covering suitably according to the required inductance value.

  In addition, the conductive path from the coil 3 to the case 1 can be cut off without providing the insulator 8 at the portion of the bottom core portion 5 facing the case 1 and the protrusion 10 described later, thereby improving the insulation.

  In this case, the heat dissipation from the bottom core part 5 to the case 1 is further improved.

  The outer peripheral surface, the bottom core portion 5 and the upper core portion 6 of the coil 3 are covered with a composite magnetic body 7.

  Here, examples of the composite magnetic body 7 include Fe-Si-based metal soft magnetic powder whose surface is coated with an oxide film or a film containing silicon oxide, and a thermosetting resin such as an epoxy resin. It is mainly composed of a binder, is liquid when uncured, and can be cured by heating or the like.

  Although it is necessary to ensure insulation between the coil 3 and the inner surface of the case 1, sufficient electrical insulation can be ensured if the thickness of the composite magnetic body 7 filled in between is 3 mm or more.

  Of the surfaces of the bottom core portion 5 and the upper core portion 6 that are in contact with the case 1, a portion having a path P from the surface of the coil 3 through the composite magnetic body 7 is covered with an insulator 8.

  Further, the magnetic flux B generated by the energization current to the coil 3 circulates around the coil 3 and penetrates the insulator 8 on the surface of the bottom core portion 5.

  That is, the insulator 8 has both a function of ensuring insulation between the coil 3 and the case 1 and a magnetic gap function.

  In the present embodiment, the core 4 inside the coil 3 is composed of a dust core and the outer periphery of the coil 3 is composed of a composite magnetic body 7. However, in order to ensure sufficient DC superposition characteristics, such a coil is used. It is desirable that the inner part is made of a magnetic material having a higher magnetic permeability and saturation magnetic flux density than the outer periphery.

  FIG. 3 is a cross-sectional view illustrating a process of creating a reactor according to the first embodiment of the present invention. FIG. 3 (a) is after composite magnetic material casting, and FIG. 3 (b) is after the bottom core portion and the center core portion are installed. Shows the state.

  The reactor according to the present invention fills the gap with the composite magnetic material.

  If the composite magnetic body is poured after the dust core or coil is accommodated in the case, the composite magnetic body may not be filled between the dust core and the coil.

  Therefore, as shown in FIG. 3 (a), an uncured composite magnetic body 7 is poured into the case 1 in advance, and the bottom core portion 5 and the middle core portion 4 are arranged in this order as shown in FIG. 3 (b). The components are assembled in the case 1 from the top to the top.

  Degassing may be performed by appropriately evacuating during assembly.

  Thereby, the composite magnetic body 7 is easily filled in the gaps between the components in the case, and the reactor is completed by curing the composite magnetic body 7 by heating or the like.

  That is, the present invention includes a case 1, a coil 3, a bottom core portion 5 that is a dust-radiating magnetic core having a heat dissipation path to the case 1, and an insulator 8, and the case 1 includes at least the coil 3 and the bottom core portion. 5 and the insulator 8 are accommodated, and the insulator 8 is disposed in at least a portion of the surface of the bottom core portion 5 having a path from the surface of the coil 3, and heat generated in the coil 3 is transmitted via the bottom core portion 5. The magnetic flux that circulates around the coil 3 of the bottom core portion 5 that has a path for radiating heat to the case 1 and that is generated by energization of the coil 3 can take an embodiment of a reactor that penetrates at least a part of the insulator 8.

(Embodiment 2)
FIG. 4 is a cross-sectional view of the reactor according to the second embodiment of the present invention, and corresponds to the modification of FIG.

  The difference from FIG. 2 in the first embodiment is that the bottom core portion and the upper core portion are not provided.

  Moreover, the center core part 4 is provided so that the cover part 2 may be contact | connected from the case 1 bottom part, and the point which has the magnetic gap which consists of an insulator in the middle is also different.

  In the present embodiment, since there is a sufficient gap between the inner peripheral surface of the case 1 and the coil 3 and the core part 4, it is not necessary to provide a protrusion on the case 1.

  In the case of such a configuration, since the path P from the surface of the coil 3 attached to the core portion 4 reaches the outer peripheral surface of the core portion 4, the outer peripheral surface of the core portion 4 is covered with the insulator 8. Yes.

  Thereby, the magnetic flux B generated by energizing the coil 3 penetrates the insulator 8, and the insulator 8 has a function of ensuring insulation between the case 1 and the lid 2 and serving as a magnetic gap.

(Embodiment 3)
FIG. 5 is a cross-sectional view of a reactor according to Embodiment 3 of the present invention, and corresponds to the modification of FIG.

  2 is different from FIG. 2 in Embodiment 1 in that an upper core portion is not provided, and an intermediate bottom core portion 40 serving as both a middle core portion and a bottom core portion is provided.

(Embodiment 4)
FIG. 6 is a top view of a reactor according to the fourth embodiment of the present invention.

  6 is the same as that of FIG. 5 in the third embodiment, except that the coil is a double pancake winding described in paragraph 0075 of JP2013-161892A. . In the double pancake winding, since it is necessary to take out the terminal in the coil radial direction, the terminals 31 and 32 are drawn out from the side surface of the case 1.

  FIG. 7 is a perspective view of a reactor according to Embodiment 4 of the present invention.

  A space between the coil 3 and the midsole core portion 40 and the inner peripheral surface of the case 1 and the lid portion 2 is filled with a composite magnetic material (not shown).

  Here, since it is necessary to provide the opening 100 in order to pull out the terminals 31 and 32, the manufacturing method of the first embodiment is used as it is unless the opening 100 is a sealing lid having a lead-out port for the terminals 31 and 32. It cannot be applied.

  FIG. 8 is a perspective view showing a method for manufacturing a reactor according to Embodiment 4 of the present invention, and shows the manufacturing procedure in the order of FIG. 8 (a) to FIG. 8 (d).

  First, as shown in FIG. 8A, a protrusion 12 for positioning is provided in advance at the center of the inner bottom surface of the case 1.

  Next, as shown in FIG. 8B, an adhesive is applied to the protrusion 12 and its periphery using a dispenser 101 or the like, and as shown in FIG. 8C, the midsole core portion 40 is bonded. Then, an adhesive is also applied to the surface of the midsole core portion 40, a coil (not shown) is adhered, and a lid portion (not shown) is attached.

  Finally, as shown in FIG. 8D, an uncured composite magnetic body in the beaker 1001 is poured from the opening 100, and the composite magnetic body is cured to complete the reactor.

  Here, since a sufficiently large gap is opened between the coil 3 and the midsole core portion 40 and the inner surface of the case 1, the composite magnetic body is poured after the midsole core portion 40 and the coil 3 are assembled in the case 1. But it can be filled.

(Embodiment 5)
FIG. 9 is a cross-sectional view of the reactor according to the second embodiment of the present invention, and corresponds to the modification of FIG.

  2 in the first embodiment, the bottom core portion 5 is in contact with the bottom surface of the inner surface of the case 1, the upper core portion 6 is in contact with the lid portion 2, and the outer peripheral ends of the bottom core portion 5 and the upper core portion 6 are inside the coil 3. The difference exists between the peripheral surface and the outer peripheral surface.

  Moreover, although the point which the core part 4 is divided by the magnetic gap is also different, such a structure should just be adjusted suitably according to a required DC superimposition characteristic.

  The point that the support column 13 is provided is also different. Although details will be described later, the support column 13 is used to position the center core portion 4, the bottom core portion 5, and the upper core portion 6.

  The support column 13 may be made of the same metal such as aluminum as the case 1, and in this case, the support column 13 forms a heat dissipation path to the case 1.

  FIG. 10 is a perspective view showing a method for manufacturing a reactor according to the fifth embodiment of the present invention, and shows the manufacturing procedure in the order of FIG. 10 (a) to FIG. 10 (e).

  First, as shown in FIG. 10A, a support column 13 for positioning is provided in advance at the center of the inner bottom surface of the case 1.

  Next, as shown in FIG. 10B, the bottom core portion 5 and the center core portion 4 having a through hole at the center portion are attached to the support column 13.

  Next, as shown in FIG. 10 (c), the coil 3 is attached, as shown in FIG. 10 (d), the upper core portion 6 is attached, and further the lid portion 2 (not shown) is attached.

  Finally, the uncured composite magnetic body in the beaker 1001 is poured from the opening 100, and the composite magnetic body is cured to complete the reactor.

DESCRIPTION OF SYMBOLS 1 Case 2 Cover part 3 Coil 4 Middle core part 5 Bottom core part 6 Upper core part 7 Composite magnetic body 8 Insulator 10, 12 Protrusion part 11 Attachment part 13 Support | pillar 31, 32 Terminal 40 Middle bottom core part 100 Opening part 101 Dispenser 1001 Beaker B Magnetic flux P Path

Claims (5)

Case and
Coils,
A dust-radiating magnetic core having a heat dissipation path to the case;
With an insulator,
The case contains at least the coil, the dust radiating magnetic core and the insulator,
Of the surface of the dust radiating magnetic core, the insulator is disposed on at least a portion having a path from the coil surface,
A path for radiating heat generated in the coil to the case through the dust radiating magnetic core;
A magnetic flux that circulates around the coil of the dust radiating magnetic core generated by energization of the coil penetrates at least a part of the insulator.   The reactor according to claim 1, wherein a surface of the dust radiating magnetic core is entirely covered with the insulator. Furthermore, it has a composite magnetic body mainly containing a binder and a metal soft magnetic powder,
The metal soft magnetic powder has an insulating film on the surface,
The reactor according to claim 1, wherein the composite magnetic body fills a gap inside the case. The insulator has a thickness of 0.3 mm or more,
The thickness of the composite magnetic body between the coil surface and the case is 2 mm or more,
The powder magnetic core has a relative magnetic permeability of 50 or more,
The reactor according to claim 3, wherein a relative magnetic permeability of the composite magnetic body is less than 50.   An uncured composite magnetic material is injected into the case, and then the coil, the dust radiating magnetic core, and the insulator are accommodated in the case, and the insulating resin or the composite magnetic material is cured. The reactor in any one of Claims 1-3.

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