JP2018093009A - Coil device and power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil device and a power converter, capable of more efficiently radiating heat from a core.SOLUTION: A coil device 100 includes: a supporter 40 having a fixed core 10; at least one heat transfer member 50 fixed on the supporter 40. The core 10 includes a first outer leg part 11, a second outer leg part 12 and at least one middle leg part 13 disposed between the first leg part 11 and the second outer leg part 12 and further includes a coil member 20 wound around the first outer leg part 11, the second outer leg part 12 or at least one middle leg part 13. At least one heat transfer member 50 is disposed inside at least one middle leg part 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil device and a power converter.

  For example, a coil device such as a smooth coil or a transformer is mounted on a power converter such as a DC / DC converter. When the power converter operates, the coil device generates heat. Since the power loss increases as the temperature of the coil device rises, the coil device requires a heat dissipation structure.

  For example, in Patent Document 1, the middle leg portion of the core is divided, and heat radiation efficiency is improved by filling the divided gaps with a heat radiation resin.

JP 2014-93404 A

  In recent years, wide band gap semiconductors such as SiC and GaN have been applied to switching elements mounted on power conversion devices, and switching elements can operate at a high temperature of, for example, 200 ° C. or higher. In connection with this, also in the coil apparatus mounted in a power converter device, in order to respond | correspond to high temperature operation | movement, the further heat dissipation improvement is calculated | required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a coil device and a power converter that can more efficiently dissipate the heat of the core.

  A coil device according to the present invention includes a core including a magnetic body, a support body to which the core is fixed, and at least one heat transfer member fixed to the support body. The core includes a first outer leg portion. And a second outer leg, and at least one middle leg disposed between the first outer leg and the second outer leg, the first outer leg, the second outer leg, A coil member wound around the outer leg portion or at least one middle leg portion is further provided, and the at least one heat transfer member is disposed inside the at least one middle leg portion.

  In the coil device according to the present invention, the heat transfer member is disposed inside the middle leg portion of the core. Thereby, it becomes possible to efficiently radiate the heat of the core from the middle leg portion to the support via the heat transfer member. Furthermore, the temperature difference between the upper surface and the lower surface of the core can be reduced by arranging the heat transfer member inside the middle leg portion of the core. Moreover, since the heat dissipation path from the core to the support body increases, it is possible to suppress the temperature rise of the core. Accordingly, the coil device can be mounted on a power conversion device or the like that operates at a high temperature.

It is a figure which shows the circuit structure of the power converter device which concerns on Embodiment 1. FIG. 1 is a perspective view of a power conversion device according to a first embodiment. 1 is a perspective view of a coil device according to Embodiment 1. FIG. 2 is a cross-sectional view of the coil device according to Embodiment 1. FIG. 3 is a top view of the coil device according to Embodiment 1. FIG. FIG. 6 is a cross-sectional view of a coil device according to a first modification of the first embodiment. FIG. 6 is a cross-sectional view of a coil device according to a second modification of the first embodiment. 6 is a perspective view of a coil device according to Embodiment 2. FIG. 6 is a top view of a coil device according to Embodiment 2. FIG. 6 is a cross-sectional view of a coil device according to Embodiment 3. FIG. FIG. 10 is a top view of a coil device according to a modification of the third embodiment. FIG. 10 is a cross-sectional view of a coil device according to a modification of the third embodiment. It is sectional drawing of the coil apparatus which concerns on Embodiment 4. FIG. 10 is a side view of a coil device according to a modification of the fourth embodiment. FIG. 10 is a perspective view of a coil device according to a fifth embodiment. FIG. 6 is a cross-sectional view of a coil device according to a fifth embodiment.

<Embodiment 1>
FIG. 1 is a circuit configuration diagram of the power conversion device according to the first embodiment. FIG. 2 is a perspective view of the power converter. In FIG. 2, some components such as the control circuit 5 and wiring are not shown. In the first embodiment, the power conversion device is, for example, a DC / DC converter.

  As shown in FIG. 1, the power conversion device includes a main conversion circuit and a control circuit 5. The main conversion circuit converts the input DC voltage Vin into a DC voltage Vout and outputs the converted voltage. The control circuit 5 outputs a control signal for controlling the main conversion circuit to the main conversion circuit. The main conversion circuit includes an inverter circuit 1, a transformer circuit 2, a rectifier circuit 3, and a smoothing circuit 4.

  As shown in FIG. 1, the inverter circuit 1 includes switching elements 91A, 91B, 91C, and 91D. Each of the switching elements 91 </ b> A, 91 </ b> B, 91 </ b> C, 91 </ b> D is, for example, a MOSFET (Metal Oxide Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or the like. Each of the switching elements 91A, 91B, 91C, and 91D is formed using Si, SiC, GaN, or the like as a material.

  The transformer circuit 2 includes a coil device 101 as a transformer. The coil device 101 includes a primary side coil conductor (high voltage side winding) connected to the inverter circuit 1 and a secondary side coil conductor that is magnetically coupled to the primary side coil conductor and connected to the rectifier circuit 3. (Low voltage side winding).

  The rectifier circuit 3 includes diodes 91E, 91F, 91G, and 91H. Each of the diodes 91E, 91F, 91G, and 91H is formed using Si, SiC, GaN, or the like as a material.

  The smoothing circuit 4 includes a coil device 100 as a smoothing coil and a capacitor 60. Further, a coil device 102 as a resonance coil and a capacitor 61 are connected to the previous stage of the inverter circuit 1. A coil device 103 serving as a filter coil is connected between the inverter circuit 1 and the transformer circuit 2.

  As shown in FIG. 2, an input terminal 70 to which high-voltage DC power is input, an output terminal 71 for taking out a flat DC voltage, switching elements 91A, 91B, 91C and 91D, diodes 91E, 91F, 91G and 91H, a capacitor 60 and 61 are mounted on the printed circuit board 80. The printed circuit board 80 is attached to the support body 40. The support body 40 is a housing of the power conversion device. The housing is made of metal and also serves as a cooler. Note that the ground potential of the power conversion circuit is connected to the support 40.

  Further, as shown in FIG. 2, the cores of the coil devices 100 and 101 are attached to the support body 40 through the printed circuit board 80. In FIG. 2, the description of the capacitor 61 and the coil devices 102 and 103 is omitted. In addition to the power converter, other electronic components may be mounted on the printed circuit board 80.

  In the power conversion device according to the first embodiment, for example, a DC voltage of about 100 V to about 600 V is input to the input terminal 70. The output terminal 71 outputs a DC voltage of about 12V to about 16V. Specifically, a DC high voltage input to the input terminal 70 is converted into a first AC voltage by the inverter circuit 1. The first AC voltage is converted by the transformer circuit 2 into a second AC voltage that is lower than the first AC voltage. The second AC voltage is rectified by the rectifier circuit 3. The smoothing circuit 4 including the coil device 100 as a smoothing coil smoothes the voltage output from the rectifier circuit 3 and outputs a low DC voltage to the output terminal 71.

<Configuration of coil device>
FIG. 3 is a perspective view of the coil device 100 as a smooth coil. FIG. 4 is a cross-sectional view of the coil device 100 taken along line AA in FIG. FIG. 5 is a top view of the coil device 100.

  As shown in FIGS. 3 to 4, the coil device 100 includes a core 10 including a magnetic body, a coil member 20, a support body 40, and a heat transfer member 50. The core 10 includes a first outer leg part 11, a second outer leg part 12, and a middle leg part 13. The middle leg portion 13 is disposed between the first outer leg portion 11 and the second outer leg portion 12. The core 10 is an EI type core, and is divided into an E type core portion 10E and an I type core portion 10I. The core 10 is not limited to the EI type, and may be, for example, an EE type, an EER type, an ER type, or the like.

  The coil member 20 is wound around the middle leg portion 13 for one turn. The coil member 20 is formed as a wiring on the printed circuit board 80. Note that in FIGS. 3 to 5, the printed board 80 other than the coil member 20 is not shown for easy viewing.

  The arrangement and shape of the coil member 20 are not limited to those shown in FIGS. 3 to 5, and the coil member 20 may be any one of the first outer leg portion 11, the second outer leg portion 12, and the middle leg portion 13. It only has to be wound around the crab.

  In the first embodiment, the middle leg portion 13 of the core 10 is divided. That is, as shown in FIGS. 3 to 5, the E-shaped core portion 10E is divided at the middle leg portion 13 into the first E-shaped core portion 101E and the second E-shaped core portion 102E. The I-type core portion 10I is divided into a first I-type core portion 101I and a second I-type core portion 102I at a portion facing the middle leg portion 13. Note that the first E-type core part 101E and the first I-type core part 101I may be formed integrally. Similarly, the second E-type core part 102E and the second I-type core part 102I may be integrally formed.

  In the first embodiment, the heat transfer member 50 is disposed inside the middle leg portion 13 of the core 10. That is, the heat transfer member 50 is disposed so as to be sandwiched between the divided portions of the middle leg portion 13 of the core 10. In the E-type core part 10E, the heat transfer member 50 is disposed so as to be sandwiched between the divided first E-type core part 101E and second E-type core part 102E. Further, in the I-type core portion 10I, the heat transfer member 50 is disposed so as to be sandwiched between the divided first I-type core portion 101I and second I-type core portion 102I.

  The core 10 including a magnetic material is a ferrite core such as Mn—Zn ferrite or Ni—Zn ferrite. The core 10 may be an amorphous core or an iron dust core.

  The coil member 20 is formed of a conductive metal such as copper (Cu), gold (Au), copper (Cu) alloy, nickel (Ni) alloy, gold (Au) alloy, silver (Ag) alloy, or the like. The coil member 20 is formed as a wiring pattern on the printed board 80. The thickness of the wiring pattern is, for example, 100 μm. The coil member 20 may be a winding instead of a wiring pattern. One end of the coil member 20 is connected to the rectifier circuit 3, and the other end is connected to the capacitor 60 and the output terminal 71.

  The core 10 is fixed to a support body 40 made of a rigid material. The support body 40 to which the core 10 is fixed is a casing of the power conversion device. That is, the lower surface of the core 10, that is, the surface of the I-type core portion 10 </ b> I opposite to the E-type core portion 10 </ b> E is fixed to the support body 40.

  The heat transfer member 50 is formed integrally with the support body 40 that is a cooler. The heat transfer member 50 is made of copper (Cu), aluminum (Al), iron (Fe), iron (Fe) alloys such as SUS304, copper (Cu) alloys such as phosphor bronze, aluminum (Al) alloys such as ADC12, etc. It is made of a metal material.

  Further, the heat transfer member 50 may be formed of a resin material containing a heat conductive filler. Here, the resin material includes polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and the like.

  The heat conductivity of the heat transfer member 50 is 0.1 W / (m · K) or more, preferably 1 W / (m · K) or more, more preferably 10 W / (m · K) or more. Further, the heat transfer member 50 is preferably made of a non-magnetic material. The heat transfer member 50 and the support 40 are integrally formed by cutting, die casting, forging, molding, or the like.

  The heat transfer member 50 is disposed so as to contact the inside of the divided middle leg portion 13 of the core 10. That is, the heat transfer member 50 is in contact with the dividing surface between the first E-type core part 101E and the second E-type core part 102E, and thermally connects the first E-type core part 101E and the second E-type core part 102E. Connected to. Further, the heat transfer member 50 is in contact with the dividing surface between the first I-type core portion 101I and the second I-type core portion 102I, and thermally connects the first I-type core portion 101I and the second I-type core portion 102I. Connected to.

  The support body 40 is formed of a material having high thermal conductivity. Examples of the material having high thermal conductivity include copper (Cu), aluminum (Al), iron (Fe), iron (Fe) alloys such as SUS304, copper (Cu) alloys such as phosphor bronze, and aluminum (Al) such as ADC12. ) Metal materials such as alloys.

  Moreover, the support body 40 may be formed with the resin material containing a heat conductive filler. Here, the resin material includes polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and the like. The thermal conductivity of the support 40 is 0.1 W / (m · K) or more, preferably 1 W / (m · K) or more, more preferably 10 W / (m · K) or more.

<Heat dissipation of coil device>
When a current flows through the coil member 20 and the coil device 100 operates, the core 10 generates heat from energy loss. The heat generated by the E-type core portion 10E is transmitted to the I-type core portion 10I through the first outer leg portion 11, the second outer leg portion 12, and the middle leg portion 13. The heat of the I-type core portion 10I is radiated to the support body 40.

  Furthermore, in the first embodiment, the heat transfer member 50 is disposed inside the middle leg portion 13 of the core 10. Thereby, the heat of the core 10 can be radiated from the middle leg portion 13 to the support body 40 via the heat transfer member 50. In particular, in the first embodiment, the heat transfer member 50 is disposed so as to be sandwiched between the divided portions of the middle leg portion 13 of the core 10. Thereby, the heat of the core 10 can be radiated from the split surface of the core 10 to the support body 40 via the heat transfer member 50. In the first embodiment, since the heat transfer member 50 and the support 40 are integrally formed, the contact thermal resistance can be reduced, and the heat dissipation of the core 10 is further improved.

  In the first embodiment, by disposing the heat transfer member 50, the temperature difference between the upper surface and the lower surface of the core 10, that is, the upper surface of the E-type core portion 10E and the support body 40 of the I-type core portion 10I. The temperature difference between the contact surfaces can be reduced. Moreover, since the heat radiation path from the core 10 to the support body 40 increases, the temperature rise of the core 10 can be suppressed.

  A case is assumed in which the thermal conductivity of the heat transfer member 50 is equal to or higher than the thermal conductivity of the core 10. The heat conductivity of the heat transfer member 50 is assumed to be, for example, 3.0 W / (m · K) or more. In this case, the thermal resistance from the upper surface of the core 10 to the support body 40 decreases in proportion to the cross-sectional area of the heat transfer member 50. Compared with the coil device in which the core 10 is not divided in the middle leg portion 13 and does not include the heat transfer member 50, the coil device 100 in the first embodiment has a thermal resistance from the upper surface of the core 10 to the support 40. It can be reduced by 5% or more.

  When a current flows through the coil member 20 and the coil device 100 operates, a magnetic flux is generated inside the core 10. In general, when magnetic flux passes through a conductor, an eddy current is generated in the conductor, and the eddy current generates Joule heat. However, when the relative permeability of the heat transfer member 50 is smaller than that of the core 10, for example, when the relative permeability of the heat transfer member 50 is 1 and the relative permeability of the core 10 is about 1500 to 4000, the heat transfer member 50 is generated inside the core 10. The magnetic flux that has flowed through the core 10 does not penetrate the heat transfer member 50. Therefore, the heat transfer member 50 does not generate heat due to the eddy current, and the temperature of the heat transfer member 50 is lower than that of the core 10 that generates heat. Therefore, the heat transfer member 50 can contribute to heat dissipation as a heat transfer member of the core 10.

  When each of the surface where the core 10 and the support 40 contact and the surface where the core 10 and the heat transfer member 50 contact each other has a surface roughness of 100 μm or less by milling, for example, the contact thermal resistance is reduced, and the core The heat dissipation effect of 10 is further improved.

  As described above, in the coil device 100 according to the first embodiment, the heat dissipation of the core 10 is improved, so that the temperature increase of the core 10 can be suppressed. That is, in the coil device 100, it is possible to reduce the size of the core 10 while maintaining the same heat dissipation of the core 10 as compared with the coil device in which the middle leg portion 13 is not divided. By downsizing the coil device 100 as a smooth coil, the power converter can be downsized.

  By efficiently radiating heat from the core 10 to the support body 40, the amount of heat radiated from the core 10 to the surrounding air is reduced. Furthermore, when the lower surface of the support 40 is cooled, there is an effect of lowering the temperature of the air around the coil device 100, and it is possible to suppress the temperature rise of other electronic components arranged around the coil device 100. is there.

  For example, when the coil member 20 is a pattern formed on the printed circuit board 80 and the coil device 100 is directly incorporated into the support body 40, the first E-type core unit 101E, the second E-type core unit 102E, the first I-type core unit 101I, The second I-type core portion 102I and the coil member 20 can be individually incorporated into the support body 40. Therefore, since it is not necessary to assemble the coil device 100 in advance before attaching it to the support body 40, the manufacturing cost can be reduced. In the first embodiment, since the coil device 100 can be directly incorporated into the support body 40, the casing of the coil device 100 itself is not necessary, and the coil device 100 can be downsized.

  Furthermore, in the first embodiment, the core 10 is divided into four parts, that is, a first E type core unit 101E, a second E type core unit 102E, a first I type core unit 101I, and a second I type core unit 102I. Each core part becomes smaller. When each core part is baked after being compacted by a mold, the heat capacity of each core part is reduced, so that the time required for firing is shortened. Moreover, since the metal mold | die of each core part becomes small, it becomes possible to bake a several core part simultaneously. Therefore, the manufacturing cost of the core 10 can be reduced. Furthermore, the dimensional accuracy is increased by reducing the size of each core.

  Moreover, in this Embodiment 1, the heat-transfer member 50 and the support body 40 are integrated. Therefore, in the manufacturing process of the coil device 100, the first E-type core part 101E, the second E-type core part 102E, the first I-type core part 101I, and the second I-type core part 102I can be easily positioned with respect to the support body 40. It becomes possible and assembly becomes easy.

  In addition, although the structure of the coil apparatus 100 was demonstrated above, it is good also as a structure similar to the coil apparatus 100 also in the coil apparatuses 101,102,103 with which a power converter device is equipped.

<Effect>
The coil device 100 according to the first embodiment includes a support body 40 to which the core 10 is fixed, and at least one heat transfer member 50 fixed to the support body 40, and the core 10 has a first outer leg. Part 11, a second outer leg part 12, and at least one middle leg part 13 arranged between the first outer leg part 11 and the second outer leg part 12, and the first outer leg part The coil member 20 wound around the leg 11, the second outer leg 12, or the at least one middle leg 13 is further provided, and the at least one heat transfer member 50 is disposed inside the at least one middle leg 13. Be placed.

  In the coil device 100 according to the first embodiment, the heat transfer member 50 is disposed inside the middle leg portion 13 of the core 10. Thereby, the heat of the core 10 can be efficiently radiated from the middle leg portion 13 to the support body 40 via the heat transfer member 50. Furthermore, the temperature difference between the upper surface and the lower surface of the core 10 can be reduced by arranging the heat transfer member 50. Moreover, since the heat radiation path from the core 10 to the support body 40 increases, the temperature rise of the core 10 can be suppressed. Therefore, the coil device 100 can be mounted in a power conversion device or the like that operates at a high temperature.

  In the coil device 100 according to the first embodiment, at least one middle leg portion 13 is divided, and at least one heat transfer member 50 is sandwiched between divided portions of at least one middle leg portion 13. Are arranged as follows.

  Therefore, by sandwiching the heat transfer member 50 between the divided middle leg portions 13 of the core 10, the heat of the core 10 is more efficiently transferred from the middle leg portion 13 to the support body 40 via the heat transfer member 50. It is possible to dissipate heat.

  In the coil device 100 according to the first embodiment, the material of the heat transfer member 50 is the same as the material of the support 40, and the heat transfer member 50 and the support 40 are integrated. Thereby, the contact thermal resistance between the heat transfer member 50 and the support 40 can be reduced. Therefore, the heat of the core 10 can be further efficiently radiated from the middle leg portion 13 to the support body 40 via the heat transfer member 50.

  In the coil device 100 according to the first embodiment, the core 10 is directly fixed to the support body 40. Therefore, it is possible to reduce the thermal resistance between the core 10 and the support body 40 as compared with the case where another member is interposed between the core 10 and the support body 40.

  In the coil device 100 according to the first embodiment, the relative magnetic permeability of at least one heat transfer member 50 is smaller than the relative magnetic permeability of the core 10, and the thermal conductivity of at least one heat transfer member 50 is It is 10 or more thermal conductivity. Therefore, the Joule heat generation of the heat transfer member 50 can be suppressed when the relative permeability of the heat transfer member 50 is smaller than the relative permeability of the core 10. Moreover, when the thermal conductivity of the heat transfer member 50 is equal to or higher than the thermal conductivity of the core 10, the heat of the core 10 can be efficiently radiated.

  Further, the power conversion device according to the first embodiment includes a main conversion circuit that converts and outputs input power, and a control circuit 5 that outputs a control signal for controlling the main conversion circuit to the main conversion circuit. The main conversion circuit includes at least one coil device 100. In the first embodiment, the heat of the coil device 100 can be efficiently radiated. Therefore, even when the power conversion device on which the coil device 100 is mounted operates at a high temperature of, for example, 200 ° C. or higher, the temperature increase of the coil device 100 can be suppressed.

  In the main conversion circuit of the power conversion device according to the first embodiment, the coil device 100 is a smoothing coil that smoothes the voltage. Therefore, the coil device 100 can be applied to the smoothing circuit 4 of the main conversion circuit.

  In the main conversion circuit of the power conversion device according to the first embodiment, the coil device 100 may be a transformer that converts an AC voltage. Accordingly, the coil device 100 can be applied to the transformer circuit 2 of the main conversion circuit.

<First Modification of First Embodiment>
FIG. 6 is a cross-sectional view of coil device 100A according to the first modification of the first embodiment. In the coil device 100 according to the first embodiment, the heat transfer member 50 and the support body 40 are integrally formed. On the other hand, in the coil device 100 </ b> A according to this modification, the heat transfer member 50 is formed as a separate member from the support body 40 and then fixed to the support body 40.

  As shown in FIG. 6, in the coil device 100 </ b> A, the support 40 has a recess 40 a. One end of the heat transfer member 50 is fitted and fixed to the recess 40a. Note that the method of fixing the heat transfer member 50 to the support 40 shown in FIG. 6 is an example, and the heat transfer member 50 may be fixed to the support 40 by adhesion or welding, for example. Further, the heat transfer member 50 may be fixed to the support body 40 by caulking. In this case, for example, a part of the heat transfer member 50 penetrates the support body 40 and the heat transfer member 50 is fixed to the support body 40 by crushing the penetrated portion.

  Since the heat transfer member 51 and the support 40 are separate members, it is not necessary to design and manufacture the support 40 again in accordance with the change in the shape of the heat transfer member 50. Can be changed.

<Second Modification of First Embodiment>
FIG. 7 is a cross-sectional view of coil device 100B according to the second modification of the first embodiment. In the coil device 100 according to the first embodiment, the heat transfer member 50 is in direct contact with the core 10. On the other hand, in the coil device 100B according to this modification, the heat transfer member 50 is in contact with the core 10 via the high heat dissipation resins 31a and 31b. High heat dissipation resin 31a, 31b is resin containing a heat conductive filler. Here, the resin is silicone, urethane, epoxy or the like. The high heat dissipation resins 31a and 31b preferably have a thermal conductivity of 0.1 W / (m · K) or more.

  In general, the surfaces of the heat transfer member 50 and the core are not uniformly flat but uneven. Therefore, contact thermal resistance exists at the contact interface. In this modification, the contact heat resistance can be reduced by filling the unevenness of the interface where the heat transfer member 50 and the core 10 are in contact with the high heat dissipation resins 31a and 31b.

  Further, in the manufacturing process, the high heat dissipation resins 31 a and 31 b act as adhesives, so that positioning is facilitated when the core 10 is attached to the heat transfer member 50.

  In the present modification, the core 10 may be brought into contact with the support body 40 via a high heat dissipation resin. The contact heat resistance can be reduced by filling the unevenness at the contact interface between the core 10 and the support 40 with the high heat dissipation resin.

<Effect>
In the coil device 100B according to the second modified example of the first embodiment, at least one heat transfer member 50 is in contact with the inside of at least one middle leg portion 13 via the high heat dissipation resins 31a and 31b, thereby achieving high heat dissipation. The thermal conductivities of the conductive resins 31a and 31b are 0.1 W / (m · K) or more. Therefore, the contact heat resistance can be reduced by filling the unevenness of the interface where the heat transfer member 50 and the middle leg portion 13 of the core 10 are in contact with each other with the high heat radiation resins 31a and 31b.

<Embodiment 2>
FIG. 8 is a perspective view of the coil device 200 according to the second embodiment. FIG. 9 is a top view of the coil device 200. The coil device 200 according to the second embodiment further includes a wall member 41 and a high heat dissipation resin 30 with respect to the coil device 100 according to the first embodiment. Since other configurations are the same as those of the coil device 100, description thereof is omitted.

  As shown in FIG. 8, in the coil device 200, a wall member 41 is joined to the support body 40. The wall member 41 is disposed so as to surround the core 10 in plan view. The material of the wall member 41 is the same as that of the support body 40. The wall member 41 may be formed integrally with the support body 40.

  The inside of the wall member 41 is filled with a high heat dissipation resin 30. The high heat dissipation resin 30 is a resin containing a heat conductive filler. Here, the resin is silicone, urethane, epoxy or the like. The high heat dissipation resin 30 preferably has a thermal conductivity of 0.1 W / (m · K) or more.

  As shown in FIG. 8, the height of the wall member 41 is the same as the height of the I-type core portion 10I so that the wall member 41 does not interfere with the coil member 20 formed on the printed circuit board 80 (not shown). The same level. When interference between the printed circuit board 80 and the coil member 20 does not become a problem, such as when the coil member 20 is formed of a winding, the wall member 41 may be made higher to have the same height as the core 10.

<Effect>
The coil device 200 according to the second embodiment further includes a wall member 41 fixed to the support body 40. The wall member 41 is disposed so as to surround the core 10 in a plan view, and a high heat dissipation is provided inside the wall member 41. The functional resin 30 is filled.

  In this modification, the heat of the core 10 and the coil member 20 can be radiated to the wall member 41 and the support body 40 via the high heat dissipation resin 30. Therefore, since the heat dissipation path of the core 10 increases, the heat of the core 10 can be radiated more efficiently.

  In addition, when the high heat dissipation resin 30 has rigidity, the core 10 is held by the high heat dissipation resin 30 in addition to the support body 40, so that the vibration resistance of the coil device 200 is improved. Further, in the manufacturing process, for example, after the support body 40 and the wall member 41 are integrally molded, the core 10 is disposed inside the wall member 41, thereby facilitating the positioning of the core 10.

<Embodiment 3>
FIG. 10 is a cross-sectional view of coil device 300 according to the third embodiment. In the coil device 300 according to the third embodiment, the coil member 20 is covered with an insulating member 22 with respect to the coil device 100 according to the first embodiment. Since other configurations are the same as those of the coil device 100, description thereof is omitted.

  As shown in FIG. 10, the coil member 20 covered with the insulating member 22 is in contact with the core 10 via the insulating member 22. The insulating member 22 is formed of a resin material containing a heat conductive filler. Here, the resin material includes polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and the like. The insulating member 22 may be a rubber material such as silicone or urethane. Further, the insulating member 22 may be a paint or a thin film such as enamel or solder resist. The thermal conductivity of the insulating member 22 is 0.1 W / (m · K) or more, preferably 1 W / (m · K) or more, more preferably 10 W / (m · K) or more.

  When a current flows through the coil member 20 and the coil device 300 operates, a current flows through the coil member 20 and the temperature of the coil member 20 rises due to Joule heat generation. Since both end portions of the coil member 20 are connected to external wiring, the heat of the coil member 20 is radiated from the both end portions to the external wiring. Furthermore, in the third embodiment, since the coil member 20 and the core 10 are in contact with each other via the insulating member 22, it is possible to radiate the heat of the winding portion of the coil member 20 to the core 10. Therefore, since the heat radiation distance of the coil member 20 can be shortened, the temperature rise of the coil member 20 can be suppressed.

  When the temperature of the coil member 20 is higher than the temperature of the core 10, the heat of the coil member 20 is radiated to the core 10 via the insulating member 22, and the heat of the core 10 is transferred to the support body 40 via the heat transfer member 50. And dissipate heat. Further, when the temperature of the coil member 20 is lower than the temperature of the core 10, the heat of the core 10 is radiated to the coil member 20 through the insulating member 22. Therefore, the coil member 20 and the core 10 are in contact with each other via the insulating member 22, whereby the temperature rise of the coil device 300 can be suppressed. Further, the temperature can be made uniform throughout the coil device 300.

  In addition, in the coil apparatus 300 of this Embodiment 3, as shown in FIG. 7, it is good also as a structure which the heat-transfer member 50 contacts with the core 10 via each of the high heat dissipation resin 31a, 31b.

<Effect>
In the coil device 300 according to the third embodiment, the coil member 20 is covered with the insulating member 22, and the core 10 and the coil member 20 are in contact via the insulating member 22. Therefore, since the heat of the coil member 20 can be radiated to the core 10 via the insulating member 22, the temperature rise of the coil member 20 can be suppressed.

<Modification of Embodiment 3>
FIG. 11 is a top view of a coil device 300A according to a modification of the third embodiment. FIG. 12 is a cross-sectional view of the coil device 300A along the line BB in FIG. In the coil device 300 </ b> A in this modification, the shape of the heat transfer member 50 is different from that of the coil device 300 of the third embodiment. Since other configurations are the same as those of the coil device 300, the description thereof is omitted.

  Similar to the coil device 300 of the third embodiment, the heat transfer member 50 of the coil device 300 </ b> A is arranged so as to be sandwiched between the divided portions of the middle leg portion 13 of the core 10. As shown in FIGS. 11 and 12, in the coil device 300 </ b> A, the heat transfer member 50 penetrates the surface of the core 10 on which the coil member 20 is folded (that is, the surface of the core 10 on the −x direction side). The penetrating part 50a is provided. The through portion 50 a of the heat transfer member 50 is in contact with the insulating member 22 that covers the coil member 20.

  In the present modification, the heat of the coil member 20 is radiated to the through portion 50 a via the insulating member 22 in addition to being radiated to the core 10 via the insulating member 22. Therefore, the heat of the coil member 20 can be radiated more efficiently, and the temperature rise of the coil member 20 can be suppressed. The penetrating portion 50 a may penetrate the surface on the x direction side of the core 10, and may be thermally connected to the coil member 20 and the insulating member 22 on the surface on the x direction side of the core 10.

<Effect>
In the coil device 300 </ b> A according to the modification of the third embodiment, the heat transfer member 50 disposed inside the at least one middle leg portion 13 is a surface other than the surface fixed to the support body 40 of the core 10. The coil member 20 is directly or indirectly contacted through either of them. Therefore, since the heat of the coil member 20 can be radiated to the heat transfer member 50, the temperature rise of the coil member 20 can be suppressed.

<Embodiment 4>
FIG. 13 is a cross-sectional view of coil device 400 in the fourth embodiment. The coil device 400 according to the fourth embodiment further includes a heat dissipation member 53 with respect to the coil device 100 according to the first embodiment. Since other configurations are the same as those of the coil device 100, description thereof is omitted.

  Similar to the coil device 100 of the first embodiment, the heat transfer member 50 of the coil device 400 is arranged so as to be sandwiched between the divided portions of the middle leg portion 13 of the core 10. As shown in FIG. 13, a heat radiating member 53 is disposed on the upper surface of the core 10 of the coil device 400 (that is, the surface opposite to the surface fixed to the support body 40 of the core 10).

  As shown in FIG. 13, the heat transfer member 50 extends to the upper surface of the core 10 and is in contact with the heat dissipation member 53. The heat radiating member 53 and the core 10 may be in contact with each other through a high heat radiating resin. Similarly, the heat dissipation member 53 and the heat transfer member 50 may be in contact with each other via a high heat dissipation resin.

  The heat dissipation member 53 may be made of the same material as the heat transfer member 50. The heat radiating member 53 may be formed integrally with the heat transfer member 50. A heat sink provided with fins or the like may be disposed on the upper surface of the heat dissipation member 53. The heat dissipation member 53 itself may be a heat sink.

  Further, as described in the first embodiment, the support body 40 is a casing of the power conversion device. The heat radiating member 53 may be configured as a lid of the housing. Moreover, the heat radiating member 53 may be configured to cover part or all of the power converter. When the heat radiating member 53 as a lid of the casing presses the core 10 against the support 40 (that is, the casing), the core 10 is stably held between the heat radiating member 53 and the support 40. Therefore, the vibration resistance of the coil device 400 is improved.

  Since the heat radiating member 53 is in contact with the upper surface of the core 10, the heat of the core 10 can be radiated. Furthermore, since the heat radiating member 53 is in contact with the heat transfer member 50, the heat of the core 10 can be efficiently radiated from the middle leg portion 13 to the heat radiating member 53 via the heat transfer member 50. Become. Therefore, the temperature rise of the core 10 can be further suppressed. Further, since the heat dissipation path of the core 10 is increased, the temperature can be made uniform throughout the coil device 400.

<Effect>
The coil device 400 according to the fourth embodiment further includes a heat dissipating member 53 disposed on any one of the surfaces other than the surface fixed to the support 40 of the core 10, and includes at least one middle leg portion 13. The heat transfer member 50 disposed inside extends to any one of the surfaces other than the surface fixed to the support body 40 of the core 10 and contacts the heat radiating member 53. Accordingly, in addition to the heat radiation from the support body 40, the heat of the core 10 can be radiated from the heat radiation member 53, so that the temperature rise of the core 10 can be further suppressed.

<Modification of Embodiment 4>
FIG. 14 is a side view of a coil device 400A according to a modification of the fourth embodiment. In the first to third embodiments, the coil member 20 is formed as a wiring on, for example, the printed board 80 (see FIG. 2).

  As shown in FIG. 14, in this modification, the coil member 20 is disposed outside the printed circuit board 80. Further, the printed board 80 is disposed on the upper part of the coil device 400A. The printed circuit board 80 is fixed to the casing of the power conversion device in a region not shown.

  As shown in FIG. 14, the coil member 20 has one or more bent portions. The end of the coil member 20 having a bent portion is connected to the wiring pattern on the printed circuit board 80. Switching elements 91E, 91F, 91G, 91H, a capacitor 60, and the like are mounted on the wiring pattern.

  In general, when electronic components such as switching elements and capacitors are exposed to magnetic flux leaking from the coil device, malfunction may occur. In this modification, the heat dissipation member 53 is disposed on the upper surface of the core 10 so as to cover the upper surface of the core 10. Since the heat dissipation member 53 covers the upper surface of the core 10, the magnetic flux leaking from the core 10 can be reduced. Therefore, it is possible to suppress the electronic component mounted on the printed circuit board 80 disposed on the upper part of the core 10 from being affected by the magnetic flux. Further, by increasing the area of the heat dissipation member 53, it is possible to further enhance the effect of preventing magnetic flux leakage.

<Embodiment 5>
FIG. 15 is a perspective view of coil device 500 according to the fifth embodiment. FIG. 16 is a cross-sectional view of the coil device 500 taken along line CC in FIG. As shown in FIGS. 15 and 16, the coil device 500 includes a core 10 </ b> A, a plurality of coil members 20, 21, a support body 40, and a plurality of heat transfer members 50, 51, 52.

  The core 10A includes a first outer leg portion 11, a second outer leg portion 12, and three middle leg portions 131, 132, and 133. The three middle leg portions 131, 132, and 133 are disposed between the first outer leg portion 11 and the second outer leg portion 12.

  The coil member 20 is wound around the middle leg 131 for one turn. The coil member 21 is wound around the middle leg portion 133 for one turn. Each of the coil members 20 and 21 is formed as a wiring on the printed circuit board 80. In FIGS. 15 and 16, the printed circuit board 80 other than the coil members 20 and 21 is not shown for easy viewing.

  The arrangement and shape of the coil members 20 and 21 are not limited to those shown in FIGS. 15 and 16, and each of the coil members 20 and 21 includes the first outer leg portion 11, the second outer leg portion 12, or the like. What is necessary is just to wind around any of the middle leg parts 131,132,133.

  In the fifth embodiment, as in the first embodiment, the middle leg 131 of the core 10A is divided. The heat transfer member 50 is disposed so as to be sandwiched between the divided portions of the middle leg portion 131 of the core 10A.

  Further, the middle leg portion 132 of the core 10A is divided. The heat transfer member 51 is disposed so as to be sandwiched between the divided portions of the middle leg portion 132 of the core 10A. Further, the middle leg portion 133 of the core 10A is divided. The heat transfer member 52 is disposed so as to be sandwiched between the divided portions of the middle leg portion 133 of the core 10A.

  As shown in FIGS. 15 and 16, the coil device 500 according to the fifth embodiment has two coil devices 100 that share the support 40 arranged side by side, and a heat transfer member between the two coil devices 100. 50 can be expressed as a configuration. In this case, one coil device 100 can be used as a smoothing coil, and the other coil device 100 can be used as a transformer, a resonance coil, a filter coil, or the like. Instead of the coil device 100, any of the coil devices 100A, 100B, 200, 300, 400, and 400A may be arranged.

<Effect>
In the coil device 500 according to the fifth embodiment, there are a plurality of at least one middle leg portions 131, 132, 133, a plurality of at least one heat transfer members 50, 51, 52, and a plurality of heat transfer members 50, Each of 51 and 52 is arrange | positioned inside each of the some middle leg part 131,132,133.

  Therefore, even if the core 10A of the coil device 500 includes a plurality of middle leg portions 131, 132, and 133, the heat transfer members 50, 51, and 52 are disposed on the plurality of middle leg portions 131, 132, and 133, respectively. As a result, the heat of the core 10A can be efficiently radiated from the middle leg portions 131, 132, 133 to the support body 40 through the heat transfer members 50, 51, 52.

  Further, for example, the coil device 500 described in the first embodiment may be configured by arranging two coil devices 100 side by side via the heat transfer member 51. In this case, the heat of the cores adjacent to each other of the two coil devices 100 can be efficiently radiated through the heat transfer member 51. Therefore, it is possible to suppress the temperature rise of the coil device 500 as a whole.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Inverter circuit, 2 transformer circuit, 3 rectifier circuit, 4 smoothing circuit, 5 control circuit, 10, 10A core, 11 1st outer leg part, 12 2nd outer leg part, 13, 131, 132, 133 middle leg Part, 20, 21 coil member, 22 insulating member, 30, 31a, 31b high heat dissipation resin, 40 support, 50, 51, 52 heat transfer member, 53 heat dissipation member, 60 capacitor, 70 input terminal, 71 output Terminal, 80 Printed circuit board, 91A, 91B, 91C, 91D Switching element, 91E, 91F, 91G, 91H Diode, 100, 100A, 100B, 200, 300, 400, 400A, 500 Coil device.

Claims (14)

A core containing a magnetic material;
A support to which the core is fixed;
At least one heat transfer member fixed to the support;
With
The core is
A first outer leg;
A second outer leg;
At least one middle leg disposed between the first outer leg and the second outer leg;
With
A coil member wound around the first outer leg, the second outer leg, or the at least one middle leg;
The at least one heat transfer member is disposed inside the at least one middle leg.
Coil device. The at least one middle leg is divided;
The at least one heat transfer member is disposed so as to be sandwiched between divided portions of the at least one middle leg.
The coil device according to claim 1. The material of the at least one heat transfer member is the same as the material of the support,
The at least one heat transfer member and the support are integrated;
The coil device according to claim 1 or 2. The core is directly fixed to the support;
The coil device according to any one of claims 1 to 3. A wall member fixed to the support;
The wall member is disposed so as to surround the core in a plan view;
The inside of the wall member is filled with a high heat dissipation resin,
The coil apparatus as described in any one of Claims 1-4. The coil member is covered with an insulating member,
The core and the coil member are in contact via the insulating member;
The coil device according to any one of claims 1 to 5. The heat transfer member disposed inside the at least one middle leg portion penetrates any one of surfaces other than the surface fixed to the support body of the core, and directly or indirectly to the coil member. In contact with the
The coil device according to any one of claims 1 to 6. A heat dissipating member disposed on any one of the surfaces other than the surface fixed to the support of the core;
The heat transfer member disposed inside the at least one middle leg extends to any one of the surfaces other than the surface fixed to the support of the core, and serves as the heat dissipation member. Contact,
The coil device according to any one of claims 1 to 7. The at least one heat transfer member is in contact with the inside of the at least one middle leg through a high heat dissipation resin,
The thermal conductivity of the high heat dissipation resin is 0.1 W / (m · K) or more.
The coil device according to any one of claims 1 to 8. The relative permeability of the at least one heat transfer member is smaller than the relative permeability of the core,
The thermal conductivity of the at least one heat transfer member is equal to or higher than the thermal conductivity of the core.
The coil device according to any one of claims 1 to 9. The at least one middle leg is plural,
The at least one heat transfer member is plural,
Each of the plurality of heat transfer members is disposed inside each of the plurality of middle legs.
The coil apparatus as described in any one of Claims 1-10. A main conversion circuit that converts and outputs input power; and
A control circuit for outputting a control signal for controlling the main conversion circuit to the main conversion circuit;
With
The main conversion circuit includes at least one coil device according to any one of claims 1 to 11.
Power conversion device. In the main conversion circuit, the coil device is a smoothing coil for smoothing a voltage.
The power conversion device according to claim 12. In the main conversion circuit, the coil device is a transformer for converting an AC voltage.
The power conversion device according to claim 12.

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