JP6956484B2 - Coil device and power converter - Google Patents

Description

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

For example, a power conversion device such as a DC / DC converter is equipped with a coil device such as a smoothing coil or a transformer. When the power conversion device 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 the divided gap is filled with a heat radiating resin to improve the efficiency of heat radiating.

Japanese Unexamined Patent Publication No. 2014-93404

In recent years, wide bandgap semiconductors such as SiC and GaN have been applied to switching elements mounted on power conversion devices, and the switching elements can operate at high temperatures of, for example, 200 ° C. or higher. Along with this, the coil device mounted on the power conversion device is also required to have further improved heat dissipation in order to cope with high temperature operation.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a coil device and a power conversion device capable of more efficiently dissipating heat of a core.

The coil device according to the present invention includes a core containing a magnetic material, a support to which the core is fixed, at least one heat transfer member fixed to the support, and a wall member fixed to the support. The core comprises a first outer leg, a second outer leg, and at least one middle leg located between the first outer leg and the second outer leg. A coil member wound around a first outer leg, a second outer leg or at least one middle leg is further provided, and at least one heat transfer member is disposed inside the at least one middle leg. , The material of at least one heat transfer member is the same as the material of the support, at least one heat transfer member and the support are integrated, the wall members are arranged so as to surround the core in a plan view, and the wall members. The inside of the heat-dissipating resin is filled with high heat-dissipating resin , and at least one heat transfer member contacts the inside of at least one middle leg via the high-heat-dissipating resin, and the heat conductivity of the high-heat-dissipating resin is 0. Ru der 1W / (m · K) or more.

In the coil device according to the present invention, the heat transfer member is arranged inside the middle leg portion of the core. This makes it possible to efficiently dissipate the heat of the core from the middle leg portion to the support via the heat transfer member. Further, by arranging the heat transfer member inside the middle leg portion of the core, it is possible to reduce the temperature difference between the upper surface and the lower surface of the core. Further, since the heat dissipation path from the core to the support is increased, it is possible to suppress the temperature rise of the core. Therefore, it is possible to mount the coil device 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 conversion apparatus which concerns on Embodiment 1. FIG. It is a perspective view of the power conversion apparatus which concerns on Embodiment 1. FIG. It is a perspective view of the coil device which concerns on Embodiment 1. FIG. It is sectional drawing of the coil apparatus which concerns on Embodiment 1. FIG. It is a top view of the coil device which concerns on Embodiment 1. FIG. It is sectional drawing of the coil apparatus which concerns on 1st modification of Embodiment 1. FIG. It is sectional drawing of the coil apparatus which concerns on the 2nd modification of Embodiment 1. FIG. It is a perspective view of the coil device which concerns on Embodiment 2. FIG. It is a top view of the coil device which concerns on Embodiment 2. FIG. It is sectional drawing of the coil apparatus which concerns on Embodiment 3. FIG. It is a top view of the coil device which concerns on the modification of Embodiment 3. It is sectional drawing of the coil apparatus which concerns on the modification of Embodiment 3. It is sectional drawing of the coil apparatus which concerns on Embodiment 4. FIG. It is a side view of the coil device which concerns on the modification of Embodiment 4. It is a perspective view of the coil device which concerns on Embodiment 5. It is sectional drawing of the coil apparatus which concerns on Embodiment 5. FIG.

<Embodiment 1>
FIG. 1 is a circuit configuration diagram of the power conversion device according to the first embodiment. Further, FIG. 2 is a perspective view of the power conversion device. Note that FIG. 2 does not show some parts such as the control circuit 5 and wiring. 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 it. 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, 91D. Each of the switching elements 91A, 91B, 91C, and 91D is, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or the like. Each of the switching elements 91A, 91B, 91C, and 91D is formed of Si, SiC, GaN, or the like as a material.

Further, the transformer circuit 2 includes a coil device 101 as a transformer. The coil device 101 magnetically couples the primary side coil conductor (high voltage side winding) connected to the inverter circuit 1 and the primary side coil conductor, and connects to the rectifying circuit 3 secondary side coil conductor. (Low voltage side winding) is provided.

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

Further, 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 front stage of the inverter circuit 1. Further, a coil device 103 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 for inputting high-voltage DC power, an output terminal 71 for extracting a flat DC voltage, switching elements 91A, 91B, 91C, 91D, diodes 91E, 91F, 91G, 91H, and a capacitor. 60, 61 and the like are mounted on the printed circuit board 80. The printed circuit board 80 is attached to the support 40. The support 40 is a housing of a power conversion device. The housing is made of metal and also serves as a cooler. 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 penetrate the printed circuit board 80 and are attached to the support 40. In FIG. 2, the description of the capacitor 61 and the coil devices 102 and 103 is omitted. Further, the printed circuit board 80 may be equipped with other electronic components in addition to the power conversion device.

In the power conversion device of the first embodiment, for example, a DC voltage of about 100V to about 600V is input to the input terminal 70. Further, a DC voltage of about 12V to about 16V is output from the output terminal 71. Specifically, the high DC voltage input to the input terminal 70 is converted into the first AC voltage by the inverter circuit 1. The first AC voltage is converted by the transformer circuit 2 into a second AC voltage 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.

<Coil device configuration>
FIG. 3 is a perspective view of the coil device 100 as a smoothing coil. Further, FIG. 4 is a cross-sectional view of the coil device 100 along the line segment AA in FIG. Further, 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 material, a coil member 20, a support 40, and a heat transfer member 50. The core 10 includes a first outer leg portion 11, a second outer leg portion 12, and a middle leg portion 13. The middle leg portion 13 is arranged between the first outer leg portion 11 and the second outer leg portion 12. Further, 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. Further, the core 10 is not limited to the EI type, and may be, for example, an EE type, an ER 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 wiring on the printed circuit board 80. In addition, in FIGS. 3 to 5, the description of the printed circuit board 80 other than the coil member 20 is omitted for the sake of easy viewing of the figure.

The arrangement and shape of the coil member 20 are not limited to FIGS. 3 to 5, and the coil member 20 is any of the first outer leg portion 11, the second outer leg portion 12, and the middle leg portion 13. It suffices if it is 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-type core portion 10E is divided into a first E-type core portion 101E and a second E-type core portion 102E in the middle leg portion 13. Further, the I-type core portion 10I is divided into a first type core portion 101I and a second type I core portion 102I at a portion facing the middle leg portion 13. The 1st type core portion 101E and the 1st type I type core portion 101I may be integrally formed. Similarly, the second E-type core portion 102E and the second I-type core portion 102I may be integrally formed.

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

The core 10 containing a magnetic material is, for example, a ferrite core such as Mn—Zn-based ferrite or Ni—Zn-based ferrite. Further, 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, and silver (Ag) alloy. The coil member 20 is formed on the printed circuit board 80 as a wiring pattern. The thickness of the wiring pattern is, for example, 100 μm. Further, 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 40 made of a rigid material. The support 40 to which the core 10 is fixed is a housing of the power conversion device. That is, the lower surface of the core 10, that is, the surface of the I-type core portion 10I opposite to the E-type core portion 10E is fixed to the support 40.

The heat transfer member 50 is formed integrally with the support 40 which is a cooler. The heat transfer member 50 includes an iron (Fe) alloy such as copper (Cu), aluminum (Al), iron (Fe), and SUS304, a copper (Cu) alloy such as phosphor bronze, and an aluminum (Al) alloy such as ADC12. It is made of metal material.

Further, the heat transfer member 50 may be formed of a resin material containing a heat conductive filler. Here, the resin material is polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), or the like.

The thermal conductivity of the heat transfer member 50 is preferably 0.1 W / (m · K) or more, preferably 1 W / (m · K) or more, and 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, for example, cutting, die casting, forging, or molding.

The heat transfer member 50 is arranged so as to come into contact with 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 portion 101E and the second E type core portion 102E, and thermally heats the first E type core portion 101E and the second E type core portion 102E. Is connected to. Further, the heat transfer member 50 is in contact with the dividing surface between the 1st type core portion 101I and the 2nd type core portion 102I, and thermally heats the 1st type core portion 101I and the 2nd type core portion 102I. Is connected to.

The support 40 is made of a material having high thermal conductivity. Materials with high thermal conductivity include, for example, iron (Fe) alloys such as copper (Cu), aluminum (Al), iron (Fe), and SUS304, copper (Cu) alloys such as phosphor bronze, and aluminum (Al) such as ADC12. ) It is a metal material such as an alloy.

Further, the support 40 may be formed of a resin material containing a heat conductive filler. Here, the resin material is polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), or the like. The thermal conductivity of the support 40 is preferably 0.1 W / (m · K) or more, preferably 1 W / (m · K) or more, and 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, heat is generated from energy loss in the core 10. The heat generated by the E-type core portion 10E is transmitted to the I-type core portion 10I via the first outer leg portion 11, the second outer leg portion 12, and the middle leg portion 13. Then, the heat of the I-type core portion 10I is dissipated to the support 40.

Further, in the first embodiment, the heat transfer member 50 is arranged inside the middle leg portion 13 of the core 10. As a result, the heat of the core 10 can be dissipated from the middle leg portion 13 to the support 40 via the heat transfer member 50. In particular, in the first embodiment, the heat transfer member 50 is arranged so as to be sandwiched between the divided portions of the middle leg portion 13 of the core 10. As a result, the heat of the core 10 can be dissipated from the divided surface of the core 10 to the support 40 via the heat transfer member 50. Further, 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 arranging 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 40 of the I-type core portion 10I The temperature difference between the contact surfaces can be reduced. Further, since the heat dissipation path from the core 10 to the support 40 is increased, the temperature rise of the core 10 can be suppressed.

It is assumed that the thermal conductivity of the heat transfer member 50 is equal to or higher than the thermal conductivity of the core 10. It is assumed that the thermal conductivity of the heat transfer member 50 is, 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 40 is reduced in proportion to the cross-sectional area of the heat transfer member 50. Compared to 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. Generally, when a magnetic flux penetrates a conductor, an eddy current is generated in the conductor, and the conductor generates Joule heat due to the eddy current. However, when the specific magnetic permeability of the heat transfer member 50 is smaller than that of the core 10, for example, when the specific magnetic permeability of the heat transfer member 50 is 1 and the specific magnetic permeability of the core 10 is about 1500 to 4000, it occurs inside the core 10. The generated magnetic flux flows inside the core 10, but 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 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 have a surface roughness of 100 μm or less by, for example, milling, 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, it is possible to suppress the temperature rise of the core 10 by improving the heat dissipation of the core 10. That is, in the coil device 100, it is possible to reduce the size of the core 10 while maintaining the heat dissipation of the core 10 to the same level as compared with the coil device in which the middle leg portion 13 is not divided. By miniaturizing the coil device 100 as a smoothing coil, the power conversion device can be miniaturized.

Efficient heat dissipation from the core 10 to the support 40 reduces the amount of heat radiated from the core 10 to the surrounding air. Further, when the lower surface of the support 40 is cooled, it has the 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. be.

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

Further, in the first embodiment, the core 10 is divided into four parts, a first type core part 101E, a second type core part 102E, a first type core part 101I, and a second type core part 102I. Each core becomes smaller. When each core portion is formed by compacting with a mold and then firing, the heat capacity of each core portion is reduced, so that the time required for firing is shortened. In addition, since the mold for each core portion becomes smaller, it is possible to fire a plurality of core portions at the same time. Therefore, it is possible to reduce the manufacturing cost of the core 10. Further, as each core portion is miniaturized, the dimensional accuracy is improved.

Further, in the first embodiment, the heat transfer member 50 and the support 40 are integrated. Therefore, in the manufacturing process of the coil device 100, the first E-type core portion 101E, the second E-type core portion 102E, the first I-type core portion 101I, and the second I-type core portion 102I can be easily positioned with respect to the support 40. It becomes possible and easy to assemble.

Although the configuration of the coil device 100 has been described above, the coil devices 101, 102, and 103 provided in the power conversion device may have the same configuration as the coil device 100.

<Effect>
In the coil device 100 according to the first embodiment, the support 40 to which the core 10 is fixed and at least one heat transfer member 50 fixed to the support 40 are provided, and the core 10 is a first outer leg. A first outer portion comprising a portion 11, a second outer leg portion 12, and at least one middle leg portion 13 arranged between the first outer leg portion 11 and the second outer leg portion 12. Further comprising a leg 11, a second outer leg 12, or a coil member 20 wound around at least one middle leg 13, at least one heat transfer member 50 is inside at least one middle leg 13. Be placed.

In the coil device 100 of the first embodiment, the heat transfer member 50 is arranged inside the middle leg portion 13 of the core 10. As a result, the heat of the core 10 can be efficiently dissipated from the middle leg portion 13 to the support 40 via the heat transfer member 50. Further, by arranging the heat transfer member 50, it is possible to reduce the temperature difference between the upper surface and the lower surface of the core 10. Further, since the heat dissipation path from the core 10 to the support 40 increases, it is possible to suppress the temperature rise of the core 10. Therefore, the coil device 100 can be mounted in a power conversion device or the like that operates at a high temperature.

Further, 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 the divided portions of at least one middle leg portion 13. Arranged like this.

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 40 via the heat transfer member 50. It is possible to dissipate heat.

Further, 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, it is possible to reduce the contact thermal resistance between the heat transfer member 50 and the support 40. Therefore, the heat of the core 10 can be more efficiently dissipated from the middle leg portion 13 to the support 40 via the heat transfer member 50.

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

Further, in the coil device 100 according to the first embodiment, the specific magnetic conductivity of at least one heat transfer member 50 is smaller than the specific magnetic conductivity of the core 10, and the thermal conductivity of at least one heat transfer member 50 is the core. It has a thermal conductivity of 10 or more. Therefore, since the specific magnetic permeability of the heat transfer member 50 is smaller than the specific magnetic permeability of the core 10, it is possible to suppress Joule heat generation of the heat transfer member 50. Further, 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 dissipated.

Further, the power conversion device according to the first embodiment includes a main conversion circuit that converts the input power and outputs it, 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 dissipated. 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, it is possible to suppress the temperature rise of the coil device 100.

Further, 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.

Further, 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. Therefore, the coil device 100 can be applied to the transformer circuit 2 of the main conversion circuit.

<First Modification Example of Embodiment 1>
FIG. 6 is a cross-sectional view of the coil device 100A in the first modification of the first embodiment. In the coil device 100 according to the first embodiment, it is assumed that the heat transfer member 50 and the support 40 are integrally formed. On the other hand, in the coil device 100A in this modification, the heat transfer member 50 is formed as a member separate from the support 40 and then fixed to the support 40.

As shown in FIG. 6, in the coil device 100A, the recess 40a is formed in the support 40. One end of the heat transfer member 50 is fitted and fixed to the recess 40a. The method of fixing the heat transfer member 50 to the support 40 as shown in FIG. 6 is an example. For example, the heat transfer member 50 may be fixed to the support 40 by adhesion or welding. Further, the heat transfer member 50 may be fixed to the support 40 by caulking. In this case, for example, a part of the heat transfer member 50 penetrates the support 40, and the penetrating portion is crushed to fix the heat transfer member 50 to the support 40.

By separating the heat transfer member 51 and the support 40 from each other, it is not necessary to redesign and manufacture the support 40 due to the change in the shape of the heat transfer member 50. Therefore, the shape of the heat transfer member 50 has a resistance cost. It is possible to change with.

<Second variant of Embodiment 1>
FIG. 7 is a cross-sectional view of the coil device 100B in the second modification of the first embodiment. In the coil device 100 according to the first embodiment, the heat transfer member 50 was in direct contact with the core 10. On the other hand, in the coil device 100B in this modification, the heat transfer member 50 is in contact with the core 10 via the high heat radiating resins 31a and 31b, respectively. The high heat dissipation resins 31a and 31b are resins containing a thermally 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.

Generally, the surfaces of the heat transfer member 50 and the core are not uniformly flat but uneven. Therefore, there is a contact thermal resistance at the contact interface. In this modification, the contact thermal resistance can be reduced by filling the unevenness of the interface between the heat transfer member 50 and the core 10 with the high heat radiating resins 31a and 31b.

Further, in the manufacturing process, the highly heat-dissipating resins 31a and 31b act as an adhesive, which facilitates positioning when the core 10 is attached to the heat transfer member 50.

In this modification, the core 10 may be brought into contact with the support 40 via a highly heat-dissipating resin. It is possible to reduce the contact thermal resistance by filling the unevenness at the contact interface between the core 10 and the support 40 with the highly heat-dissipating resin.

<Effect>
In the coil device 100B in the second modification of the first embodiment, at least one heat transfer member 50 contacts the inside of at least one middle leg portion 13 via the high heat dissipation resins 31a and 31b, and has high heat dissipation. The thermal conductivity of the sex resins 31a and 31b is 0.1 W / (m · K) or more. Therefore, the contact thermal resistance can be reduced by filling the unevenness of the interface between the heat transfer member 50 and the middle leg portion 13 of the core 10 with the high heat radiating resins 31a and 31b.

<Embodiment 2>
FIG. 8 is a perspective view of the coil device 200 according to the second embodiment. Further, 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, the description thereof will be omitted.

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

The inside of the wall member 41 is filled with the highly heat-dissipating 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-shaped 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). It is about the same. When the interference between the printed circuit board 80 and the coil member 20 is not a problem, such as when the coil member 20 is formed of windings, the wall member 41 may be made higher to be as high as the core 10.

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

In this modification, the heat of the core 10 and the coil member 20 can be dissipated to the wall member 41 and the support 40 via the highly heat-dissipating resin 30. Therefore, since the heat dissipation path of the core 10 is increased, the heat of the core 10 can be radiated more efficiently.

Further, when the high heat radiating resin 30 has rigidity, the core 10 is held by the high heat radiating resin 30 in addition to the support 40, so that the vibration resistance of the coil device 200 is improved. Further, in the manufacturing process, for example, by integrally molding the support 40 and the wall member 41 and then arranging the core 10 inside the wall member 41, the positioning of the core 10 becomes easy.

<Embodiment 3>
FIG. 10 is a cross-sectional view of the 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 the 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, the description thereof will be 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 made of a resin material containing a thermally conductive filler. Here, the resin material is polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), or the like. Further, the insulating member 22 may be made of 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 preferably 0.1 W / (m · K) or more, preferably 1 W / (m · K) or more, and 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 each of the both end portions of the coil member 20 is connected to the external wiring, the heat of the coil member 20 is dissipated from each of the both end portions to the external wiring. Further, in the third embodiment, since the coil member 20 and the core 10 are in contact with each other via the insulating member 22, the heat of the wound portion of the coil member 20 can be dissipated to the core 10. Therefore, since the heat dissipation distance of the coil member 20 can be shortened, it is possible to suppress the temperature rise of the coil member 20.

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 dissipated to the core 10 via the insulating member 22, and the heat of the core 10 is dissipated to the support 40 via the heat transfer member 50. And heat is dissipated. When the temperature of the coil member 20 is lower than the temperature of the core 10, the heat of the core 10 is dissipated to the coil member 20 via the insulating member 22. Therefore, since the coil member 20 and the core 10 are in contact with each other via the insulating member 22, it is possible to suppress the temperature rise of the coil device 300. Further, the temperature can be made uniform in the entire coil device 300.

In the coil device 300 of the third embodiment, as shown in FIG. 7, the heat transfer member 50 may be configured to come into contact with the core 10 via the high heat radiating resins 31a and 31b, respectively.

<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 with each other via the insulating member 22. Therefore, the heat of the coil member 20 can be dissipated to the core 10 via the insulating member 22, so that the temperature rise of the coil member 20 can be suppressed.

<Modified Example of Embodiment 3>
FIG. 11 is a top view of the coil device 300A in the modified example of the third embodiment. Further, FIG. 12 is a cross-sectional view of the coil device 300A along the line segment BB of FIG. In the coil device 300A 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 will be omitted.

Similar to the coil device 300 of the third embodiment, the heat transfer member 50 of the coil device 300A 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 300A, the heat transfer member 50 penetrates the surface of the core 10 on the folded side (that is, the surface of the core 10 on the −x direction side). The penetrating portion 50a is provided. The penetrating portion 50a of the heat transfer member 50 is in contact with the insulating member 22 that covers the coil member 20.

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

<Effect>
In the coil device 300A in the modified example of the third embodiment, the heat transfer member 50 arranged inside at least one middle leg portion 13 is a surface other than the surface fixed to the support 40 of the core 10. It penetrates either of them and comes into direct or indirect contact with the coil member 20. Therefore, since the heat of the coil member 20 can be dissipated to the heat transfer member 50, it is possible to suppress the temperature rise of the coil member 20.

<Embodiment 4>
FIG. 13 is a cross-sectional view of the coil device 400 according to the fourth embodiment. The coil device 400 according to the fourth embodiment further includes a heat radiating 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, the description thereof will be 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 arranged 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 40 of the core 10).

As shown in FIG. 13, the heat transfer member 50 extends over 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 via the high heat radiating resin. Similarly, the heat radiating member 53 and the heat transfer member 50 may be in contact with each other via the high heat radiating resin.

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

Further, as described in the first embodiment, the support 40 is a housing of the power conversion device. The heat radiating member 53 may be configured as a lid of the housing. Further, the heat radiating member 53 may be configured to cover a part or all of the power conversion device. When the heat radiating member 53 as the lid of the housing presses the core 10 against the support 40 (that is, the housing), the core 10 stably holds the core 10 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. Further, 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, it is possible to further suppress the temperature rise of the core 10. Further, since the heat dissipation path of the core 10 is increased, the temperature can be made uniform in the entire coil device 400.

<Effect>
The coil device 400 according to the fourth embodiment further includes a heat radiating member 53 arranged on any surface 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 arranged inside extends to any of the surfaces other than the surface fixed to the support 40 of the core 10 and comes into contact with the heat dissipation member 53. Therefore, in addition to the heat radiation from the support 40, the heat of the core 10 can be dissipated from the heat dissipation member 53, so that the temperature rise of the core 10 can be further suppressed.

<Modified Example of Embodiment 4>
FIG. 14 is a side view of the coil device 400A in the modified example of the fourth embodiment. In the first to third embodiments, it is assumed that the coil member 20 is formed as wiring on, for example, the printed circuit board 80 (see FIG. 2).

As shown in FIG. 14, in this modification, the coil member 20 is arranged outside the printed circuit board 80. Further, the printed circuit board 80 is arranged above the coil device 400A. The printed circuit board 80 is fixed to the housing of the power conversion device in an area (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 the bent portion is connected to the wiring pattern on the printed circuit board 80. The wiring pattern includes switching elements 91E, 91F, 91G, 91H, a capacitor 60, and the like.

In general, when electronic components such as switching elements and capacitors are exposed to the magnetic flux leaked from the coil device, they may malfunction. In this modification, the heat radiating member 53 is arranged on the upper surface of the core 10 so as to cover the upper surface of the core 10. By covering the upper surface of the core 10 with the heat radiating member 53, it is possible to reduce the magnetic flux leaking from the core 10. Therefore, it is possible to suppress the influence of the magnetic flux on the electronic components mounted on the printed circuit board 80 arranged above the core 10. Further, by increasing the area of the heat radiating member 53, it is possible to further enhance the effect of preventing the leakage of magnetic flux.

<Embodiment 5>
FIG. 15 is a perspective view of the coil device 500 according to the fifth embodiment. Further, FIG. 16 is a cross-sectional view of the coil device 500 in the line segment CC of FIG. As shown in FIGS. 15 and 16, the coil device 500 includes a core 10A, a plurality of coil members 20, 21, a support 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, 133. The three middle leg portions 131, 132, and 133 are arranged 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. Further, 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 wiring on the printed circuit board 80. In addition, in FIGS. 15 and 16, the description of the printed circuit board 80 other than the coil members 20 and 21 is omitted for the sake of easy viewing of the drawings.

The arrangement and shape of the coil members 20 and 21 are not limited to FIGS. 15 and 16, and the coil members 20 and 21 are each of the first outer leg portion 11, the second outer leg portion 12, or the second outer leg portion 12, respectively. It suffices if it is wound around any of the middle legs 131, 132, and 133.

In the fifth embodiment, the middle leg 131 of the core 10A is divided as in the first embodiment. The heat transfer member 50 is arranged 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 arranged 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 arranged so as to be sandwiched between the divided portions of the middle leg portion 133 of the core 10A.

Further, as shown in FIGS. 15 and 16, in the coil device 500 according to the fifth embodiment, two coil devices 100 sharing the support 40 are arranged side by side, and a heat transfer member is provided between the two coil devices 100. It can be expressed as a configuration in which 50 are arranged. 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. In addition, any one of coil devices 100A, 100B, 200, 300, 400, 400A may be arranged instead of the coil device 100.

<Effect>
In the coil device 500 according to the fifth embodiment, at least one middle leg portion 131, 132, 133 is a plurality, and at least one heat transfer member 50, 51, 52 is a plurality, and a plurality of heat transfer members 50, Each of 51 and 52 is arranged inside each of the plurality of middle legs 131, 132 and 133.

Therefore, even if the core 10A of the coil device 500 includes a plurality of middle leg portions 131, 132, 133, the heat transfer members 50, 51, 52 are arranged in the plurality of middle leg portions 131, 132, 133, respectively. By doing so, the heat of the core 10A can be efficiently dissipated from the middle legs 131, 132, 133 to the support 40 via the heat transfer members 50, 51, 52.

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

In the present invention, each embodiment can be freely combined, and each embodiment can be appropriately modified or omitted within the scope of the invention.

1 Inverter circuit, 2 Transformer circuit, 3 rectifying circuit, 4 smoothing circuit, 5 control circuit, 10,10A core, 11 1st outer leg, 12 2nd outer leg, 13,131,132,133 middle leg Parts, 20, 21 coil members, 22 insulating members, 30, 31a, 31b high heat dissipation resin, 40 supports, 50, 51, 52 heat transfer members, 53 heat dissipation members, 60 capacitors, 70 input terminals, 71 outputs Terminals, 80 printed circuit boards, 91A, 91B, 91C, 91D switching elements, 91E, 91F, 91G, 91H diodes, 100, 100A, 100B, 200, 300, 400, 400A, 500 coil devices.

Claims (11)

A core containing a magnetic material and
With the support to which the core is fixed,
With at least one heat transfer member fixed to the support,
The wall member fixed to the support and
With
The core is
The first outer leg and
The second outer leg and
With at least one middle leg arranged between the first outer leg and the second outer leg,
With
A coil member wound around the first outer leg portion, the second outer leg portion, or the at least one middle leg portion is further provided.
The at least one heat transfer member is arranged inside the at least one middle leg portion.
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 wall member is arranged so as to surround the core in a plan view.
The inside of the wall member is filled with a highly heat-dissipating resin .
The at least one heat transfer member comes into contact with the inside of the at least one middle leg portion via the highly heat-dissipating resin.
The thermal conductivity of the high heat dissipation resin Ru der 0.1W / (m · K) or more,
Coil device. The at least one middle leg is divided and
The at least one heat transfer member is arranged so as to be sandwiched between the divided portions of the at least one middle leg portion.
The coil device according to claim 1. The core is directly fixed to the support,
The coil device according to claim 1 or 2. The coil member is covered with an insulating member.
The core and the coil member are in contact with each other via the insulating member.
The coil device according to any one of claims 1 to 3. The heat transfer member disposed inside the at least one middle leg penetrates any of the surfaces of the core other than the surface fixed to the support, and directly or indirectly to the coil member. Contact,
The coil device according to any one of claims 1 to 4. Further comprising a heat radiating member arranged on any of the surfaces of the core other than the surface fixed to the support.
The heat transfer member arranged inside the at least one middle leg portion extends to any of the surfaces other than the surface fixed to the support of the core to form the heat radiation member. Contact,
The coil device according to any one of claims 1 to 5. The relative magnetic permeability of the at least one heat transfer member is smaller than the relative magnetic 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 6. The at least one middle leg is plural,
The at least one heat transfer member is plural, and there are a plurality of them.
Each of the plurality of heat transfer members is arranged inside each of the plurality of the middle legs.
The coil device according to any one of claims 1 to 7. The main conversion circuit that converts the input power and outputs it,
A control circuit that outputs a control signal that controls the main conversion circuit to the main conversion circuit, and a control circuit that outputs the control signal to the main conversion circuit.
With
The main conversion circuit includes at least one coil device according to any one of claims 1 to 8.
Power converter. In the main conversion circuit, the coil device is a smoothing coil that smoothes a voltage.
The power conversion device according to claim 9. In the main conversion circuit, the coil device is a transformer that converts an AC voltage.
The power conversion device according to claim 9.

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