JP6409706B2 - Reactor - Google Patents

Description

  The present invention relates to a reactor.

  More specifically, a reactor is applied as a component of a power conversion device such as an in-vehicle DC-DC converter, as a circuit component that performs voltage step-up or step-down control in the power conversion device.

  As a general configuration form of the reactor, a coil is formed around a U-shaped core or an I-shaped core, and this is accommodated in the case, and a sealing resin body having heat dissipation is provided between the core and the coil and the bottom surface of the case. A form in which a cooler is disposed below the case can be given.

  This configuration will be described with reference to FIG. In the illustrated reactor RT, a core Co in which a coil Ci is disposed is fastened to a case Ca with a bolt B via a stay S, and a sealing material that is a heat dissipation material is interposed between the core Co, the coil Ci, and the bottom surface of the case Ca. A stop resin body Re is molded, and a cooler Cl through which the refrigerant R circulates is disposed below the case Ca to constitute the whole. Patent Document 1 also discloses a reactor in which the lower surface of a coil is fixed to a case via a heat dissipation material.

JP 2009-231495 A

  As shown in FIG. 10, the reactor RT normally cools the heat generated from the coil Ci by transferring it to the cooler Cl below the case Ca through the sealing resin body Re that is a heat radiating material. However, since the cooler Cl exists only in the reactor RT, the heat dissipation path is only the downward route.

  Therefore, a temperature difference occurs between the lower side (cooler Cl side) and the upper side (open side) of the case Ca. The temperature difference increases as the reactor RT is used at a high temperature, and the surrounding air is heated due to the temperature rise in the upper portion of the reactor RT, and the heat receiving effect (heat damage) is generated on the capacitor and the like that are adjacent to the reactor RT. Resulting in. For example, the temperature rise at the time when the reactor RT suddenly overheats cannot respond to the upper portion of the reactor RT, and as a result of instantaneous heat generation, the surrounding air is heated together.

  Further, as shown in FIG. 10, since the core Co is fixed to the case Ca via a relatively rigid stay S, vibrations generated during the operation of the reactor RT are easily transmitted to the case Ca. This is one of the causes of low vibration and low noise performance (so-called NV performance).

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a reactor in which air in the vicinity of the upper portion of the reactor is suppressed from being heated and has little noise and vibration during operation.

  In order to achieve the above object, a reactor according to the present invention is a reactor including a case including a bottom surface, a side surface, and an upper lid, and a core including a coil disposed in the case. A heat dissipating sheet is disposed between the bottom surface, the side surface, the top cover, and the coil.

  The reactor according to the present invention is characterized in that the core and the coil are housed in a case provided with an upper lid, not the case where the upper part is opened, and the structure in which a heat radiation sheet is interposed between the coil and the case constituent member. Is.

  The rectangular parallelepiped case has a total of six surfaces, that is, a bottom surface, four side surfaces, and an upper lid, but the coil formed in the periphery of the rectangular core has a rectangular outer peripheral surface. Therefore, it has four outer peripheral surfaces.

  Therefore, for example, in the form in which one coil is formed with respect to the core, a total of 4 are provided in the gaps between the four outer peripheral surfaces of the coil, the bottom surface constituting the case, the two left and right side surfaces, and the four inner surfaces of the upper lid. Two heat dissipating sheets are provided. In addition, a heat radiating sheet may be further disposed in a gap between the remaining two side surfaces of the case and the core.

  In the form in which two coils are formed on the annular core, a total of six heat dissipating sheets are arranged between the upper and lower surfaces of the two coils, the right side surface of the right coil, the left side surface of the left coil, and the case. Established. In this embodiment, a heat radiating sheet may be disposed between the two coils, and a total of seven heat radiating sheets may be disposed.

  Moreover, in addition to the heat dissipation sheet being interposed between the coil and the constituent members of the case, a heat dissipation sealing resin material may be molded into the case to form a sealing resin body. In this form, two types of heat dissipation members, that is, a heat dissipation sheet and a heat dissipation sealing resin body, are present in the case.

  Also in the reactor of this invention, the form by which the cooler which a refrigerant | coolant recirculates | circulates below the bottom face of a case is desirable.

  According to the reactor of the present invention, not only the route for the heat dissipation path to the cooler below the case, but also the upper route for radiating heat from the upper surface of the coil via the heat dissipation sheet and the upper lid of the case, and the left and right side surfaces of the coil Since it has a route from the right and left heat dissipation sheets and the side where heat is radiated through the side surfaces of the case, the reactor has excellent heat dissipation performance.

  In addition, since the temperature of the upper part of the reactor is raised and the surrounding air is heated, the influence of heat reception (heat damage) on the capacitor and the like adjacent to the reactor cannot occur.

  In addition, the coil (and core) is fixed to the inner surface of the case via a relatively soft heat dissipation sheet, that is, the core is not bolted to the case via the stay as in the case of a conventional reactor. The vibration at the time is absorbed by the heat-dissipating sheet and is not easily transmitted to the case, and as a result, the generation of noise is also suppressed. Therefore, the reactor has a high noise / vibration suppressing effect.

  As can be understood from the above description, according to the reactor of the present invention, the core and the coil are accommodated in the case having the upper lid, and the heat dissipation sheet is interposed between the outer peripheral surface of the coil and the case constituent member. As a result, the heat dissipation route from the heat source such as the coil and the core is secured not only to the lower cooler side, but also to the upper route and the left and right side routes, and the reactor has excellent heat dissipation performance. And the air of the upper part of a reactor is no longer heated, and the heat damage with respect to an adjacent component does not generate | occur | produce. Furthermore, since the coil (and the core) are fixed to the case via the heat dissipation sheet, the effect of suppressing noise and vibration during the operation of the reactor is increased, and the reactor has excellent NV performance.

It is a longitudinal cross-sectional view of Embodiment 1 of the reactor of this invention. It is an II-II arrow line view of FIG. It is the figure explaining the manufacturing method of the reactor of Embodiment 1 in order of (a) and (b). It is a longitudinal cross-sectional view of Embodiment 2 of the reactor of this invention. It is a longitudinal cross-sectional view of Embodiment 3 of the reactor of this invention. It is a longitudinal cross-sectional view of Embodiment 4 of the reactor of this invention. It is a longitudinal cross-sectional view of Embodiment 5 of the reactor of this invention. It is a longitudinal cross-sectional view of Embodiment 6 of the reactor of this invention. It is the figure which showed the experimental result which verified NV performance. It is a longitudinal cross-sectional view of embodiment of the conventional reactor.

  Hereinafter, the first to sixth embodiments of the reactor of the present invention will be described with reference to the drawings.

(Embodiment 1 of the reactor)
1 is a longitudinal sectional view of a reactor according to a first embodiment of the present invention, and FIG. 2 is a view taken in the direction of arrows II-II in FIG. The illustrated reactor 10 is generally configured by a case 4, a core 1 in which a coil 2 is disposed via an insulating resin bobbin 3, and a cooler 7 that is disposed below the case 4 and in which a refrigerant recirculates. Has been.

The core 1 has a U-shaped core and an I-shaped core formed in a substantially ring shape via a gap plate (not shown), and is made of a resin, soft magnetic powder, and the like. Here, as the soft magnetic powder, iron group metals such as Fe, Co, and Ni, alloy powders containing iron as a main component, and the like can be applied. In particular, Fe-Si alloys, Fe-Ni alloys, Fe-Al alloys, Fe-Co alloys, Fe-Cr alloys, Fe-Si-Al alloys, rare earth metals, ferrites, and the like can be applied. On the other hand, the resin may be either a thermosetting resin or a thermoplastic resin, but it is preferable to apply a thermoplastic resin that can eliminate the need for a curing furnace and can be injection-molded to reduce manufacturing time. . Examples of the thermoplastic resin to be applied include polyamide, polyester, polyphenylene sulfide, polyether ether ketone, polyethylene, polypropylene, methacryl, and polyimide resin. The gap plate can be formed of ceramics such as alumina (AL ₂ O ₃ ) or zirconia (ZrO ₂ ). If the electromagnetic characteristics of the reactor, that is, the inductance can be ensured with the structure without the gap plate, the interposition of the gap plate between the cores is unnecessary.

  The coil 2 is composed of a copper conducting wire and an insulating coating such as an enamel coating formed around the conducting wire, and a rectangular wire with a high space factor is suitable.

  The cooler 7 has a flow path formed therein, and cools the heat transferred by the refrigerant flowing back through the flow path. Here, as the refrigerant, cooling water or cooling air from a radiator or the like can be applied.

  The case 4 is made of aluminum or an alloy thereof, and in the cross-section of FIG. 1, is composed of a bottom surface 4a, left and right side surfaces 4b and 4c, and an upper lid 4d, and further includes side surfaces 4e and 4f as shown in FIG. doing.

  In FIG. 1, the outer shape of the coil 2 is substantially rectangular, and the four outer peripheral surfaces thereof face the bottom surface 4a, the left and right side surfaces 4b, 4c, and the upper lid 4d of the case 4, respectively.

  In the reactor 10, heat radiation sheets 5 a, 5 b, 5 c, and 5 d are disposed at positions opposite to the four coils 2 and the case 4, and the coil 2 (and the core 1) are fixed to the case 4 by the heat radiation sheets 5 a and the like. Has been. That is, unlike the conventional reactor RT shown in FIG. 10, the core Co and the coil Ci are not fixed to the case Ca by fastening with the bolt B through the stay S.

  Here, if the heat radiation sheet 5a, 5b, 5c, 5d is a moisture curable type or a room temperature curable type (which may be either a one-component type or a two-component mixed type), a silicone resin, an epoxy resin, or a urethane resin. It is formed from the material which used the resin etc. as a base resin.

  Here, the silicone resin will be further described. This silicone resin (silicone polymer) has a siloxane bond structure in which a polymer is formed by alternately bonding silicon and oxygen as a main skeleton. Depending on the presence or absence and type of additives, there are sheet-like, paste-like, and liquid-type ones, and sheet-like silicone can be used as the silicone forming the heat-dissipating sheets 5a, 5b, 5c, 5d. . In addition, although the thermal conductivity of the silicone polymer itself is as small as 0.16 W / mK, it can be mixed by mixing thermal conductive fillers such as silica, alumina, boron nitride, silicon nitride, silicon carbide, and magnesium oxide. Since it becomes silicone which has high heat dissipation according to quantity (mixing ratio), it is preferable to use the resin material containing the appropriate filler so that desired heat dissipation may be satisfied.

For example, heat dissipation sheets 5a, 5b, 5c, 5d having physical properties of thermal conductivity λ ≧ 0.5 W / mK, insulation (volume resistivity) ≧ 10 ¹² Ωcm, initial hardness (durometer Type A) ≦ 50 can be applied. .

  According to the reactor 10 shown in FIGS. 1 and 2, the core 1 and the coil 2 are accommodated in the case 4 having the upper lid 4d, and the heat radiation sheets 5a, 5b, and 5c are respectively provided between the outer peripheral surface of the coil 2 and the case constituent members. , 5d, the heat dissipation route from the heat source such as the coil 2 and the core 1 is secured not only to the lower cooler 7 side but also to the upper route and the left and right side routes. The reactor 10 has excellent heat dissipation performance. And the air of the upper part of the reactor 10 is no longer heated, and the heat damage with respect to an adjacent component cannot also arise. Furthermore, since the coil 2 (and the core 1) are fixed to the case 4 via the heat radiation sheets 5a, 5b, 5c, and 5d, the effect of suppressing noise and vibration during the operation of the reactor 10 is increased, and NV performance is improved. Excellent reactor 10 is obtained.

  Next, a method for manufacturing the reactor 10 will be outlined with reference to FIG.

  First, as shown in FIG. 3A, in the case 4 in which the upper lid 4d is opened, the heat radiation sheets 5a, 5b, and 5c are attached to the inside of the bottom surface 4a and the insides of the left and right side surfaces 4b and 4c. The core 1 provided with the coil 2 is accommodated in the case 4 via (X1 direction).

  Next, as shown in FIG. 3B, after the heat dissipation sheet 5d is attached to the upper surface of the coil 2, the reactor 10 shown in FIGS. 1 and 2 is manufactured by assembling the upper lid 4d. In addition, the method of sticking the heat radiating sheet 5d on the inner surface of the upper lid 4d and installing this on the upper surface of the coil 2 may be used.

  Thus, in the illustrated reactor 10, the core and the coil are not bolted and fixed to the case via the stay, so there is no need to provide a bolt fastening hole in the case, and no fastening bolt is required. It becomes. And, since the case 4 and the coil 2 (and the core 1) are fixed by simply attaching the heat radiation sheets 5a, 5b, 5c and 5d to the predetermined positions and attaching the coil 2 to them, the assembly is extremely easy. It is.

(Embodiment 2 of the reactor)
FIG. 4 is a longitudinal sectional view of a reactor according to a second embodiment of the present invention. A reactor 10A shown in the figure is configured by disposing heat-dissipating sheets 5e, 5f between two end surfaces of the core 1 and side surfaces 4e, 4f of the case 4 with respect to the reactor 10 shown in FIGS.

  That is, the case 4 is a hexahedron including the upper lid 4d, and the heat radiating sheets 5a, 5b, 5c, 5d, 5e, and 5f are disposed on the inner surfaces of all the six surfaces.

  Thus, by disposing the heat radiation sheets 5a, 5b, 5c, 5d, 5e, and 5f on the inner surfaces of all the six surfaces of the case 4 and fixing the core 1 and the coil 2 through these, the reactor 10A is activated. The effect of suppressing noise and vibration is further enhanced, and the reactor 10A is further excellent in NV performance.

(Embodiment 3 of the reactor)
FIG. 5 is a longitudinal sectional view of a reactor according to a third embodiment of the present invention. The illustrated reactor 10B is obtained by molding a sealing resin material in the case 4 with respect to the reactor 10 shown in FIGS. 1 and 2 and forming a sealing resin body 6 in addition to the heat radiation sheets 5a, 5b, 5c, and 5d. It is.

  Here, the sealing resin body 6 is also formed of a material having a base resin made of a silicone resin, an epoxy resin, a urethane resin, or the like, like the heat radiation sheets 5a, 5b, 5c, and 5d.

  In this way, in the form in which the heat radiation sheets 5a, 5b, 5c, and 5d and the sealing resin body 6 are mixed, the heat conductivity of the heat radiation sheets 5a, 5b, 5c, and 5d is the heat conductivity of the sealing resin body 6. It is preferable to select both materials so as to be higher.

  According to the reactor 10B, since the heat radiation sheets 5a, 5b, 5c, and 5d and the sealing resin body 6 are disposed in the case 4, the reactor 10B is further excellent in heat radiation performance.

  Although illustration is omitted, in the manufacturing process of the reactor 10B, when the sealing resin material is molded in the case and the upper lid is closed, a part of the sealing resin material leaks between the upper lid and the side surface, By fixing this, the upper lid can be fixed. That is, a sealing process or an adhesion process is not required when fixing the upper lid.

(Reactor embodiments 4, 5, 6)
FIG. 6 is a longitudinal sectional view of a reactor according to a fourth embodiment of the present invention. The illustrated reactor 10 </ b> C has two coils 2, 2 disposed in an annular core 1 in a case 4.

  Therefore, in the reactor 10C, in FIG. 6, the heat radiation sheet 5b is interposed between the left side surface of the left coil 2 and the side surface 4b of the case 4, and the heat radiation sheet is interposed between the right side surface of the right coil 2 and the side surface 4c of the case 4. 5c is interposed between the upper and lower surfaces of each coil 2 and the upper lid 4d and bottom surface 4a of the case 4, respectively.

  On the other hand, FIG. 7 is a longitudinal sectional view of a reactor according to a fifth embodiment of the present invention. In the illustrated reactor 10D, a heat dissipation sheet 5g is interposed between the two coils 2 and 2 with respect to the reactor 10C.

  FIG. 8 is a longitudinal sectional view of a reactor according to a sixth embodiment of the present invention. The illustrated reactor 10E is obtained by forming a sealing resin body 6 in the case 4 with respect to the reactor 10D.

  In any of the reactors 10C, 10D, and 10E, similarly to the reactors 10, 10A, and 10B, the reactor is excellent in heat dissipation performance and excellent in NV performance.

(Experiment and results of NV performance verification)
The present inventors conducted experiments to verify NV performance. In this experiment, the reactor of the present invention shown in FIGS. 1 and 2 (example, in which the four outer peripheral surfaces of the coil are fixed to the case) and the conventional reactor shown in FIG. 10 (comparative example) The core was bolted to the case via the stay), and both reactors were operated to measure vibration.

  FIG. 9 shows the experimental results. Here, in FIG. 9, the maximum value of the vibration of the comparative example is set to 100, and the maximum value of the vibration of the example is shown as a ratio to 100.

  Compared to 100 of the comparative example, the example is 44, and it has been demonstrated that the vibration can be reduced by 56%.

  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 ... Core, 2 ... Coil, 3 ... Bobbin, 3a ... Bolt, 4 ... Case, 4a ... Bottom surface, 4b, 4c, 4e, 4f ... Side surface, 4d ... Top cover, 5a, 5b, 5c, 5d, 5e, 5f, 5g ... heat dissipation sheet, 6 ... sealing resin body, 7 ... cooler, 10, 10A, 10B, 10C, 10D, 10E ... reactor

Claims (3)

A case composed of a bottom surface, a side surface and an upper lid;
A core comprising a coil disposed in a case, and a reactor,
A heat dissipating sheet is arranged between the bottom, side, upper lid and coil constituting the case ,
A reactor in which the coil and the core are fixed to the case through only the heat dissipation sheet . The reactor of Claim 1 by which the thermal radiation sheet | seat which consists of a separate member is each arrange | positioned between the bottom face, side surface, upper cover, and coil which comprise a case. The reactor of Claim 1 or 2 with which the thermal radiation sheet is arrange | positioned also between the separate side surface and core which comprise a case.

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