JP6651592B1 - Reactor cooling structure and power converter - Google Patents

Abstract

A reactor cooling structure and a power conversion device capable of cooling a reactor more efficiently. A cooling structure of a reactor includes a bottom wall (2n) provided with a first opening (2a) and a side wall (2m) provided with a second opening (2b). A case (2) in which a first recess (2o) for accommodating a toroidal reactor (1) in which a coil (12) is wound around (11) is formed, and the reactor is accommodated in the first recess. A housing (3) provided with a second recess (3a) for housing the case as a module, and a second recess housing the module, a bottom wall, at least a part of the reactor, and a side wall. A resin (4) filled as a filler in the second recess, which is present up to a position including at least a part of the provided second opening. [Selection diagram] Fig. 1

Description

  The present invention relates to a reactor cooling structure and a power converter.

  An electric vehicle such as an electric vehicle or a hybrid vehicle is equipped with a power conversion device. As a power conversion device mounted on an electric vehicle, specifically, a charger that converts commercial AC power to DC power and charges a high-voltage battery, and converts DC power of a high-voltage battery to DC power of a different voltage Examples include a DC (Direct Current) / DC converter and an inverter that converts DC power from a high-voltage battery into AC power to a motor.

  Some power converters include a reactor for noise removal, current control, and the like. When a relatively large inductance is required, a toroidal reactor using a hollow cylindrical core having no space in the magnetic path due to air or other members is suitable as the reactor. Specifically, a hollow cylindrical core has a larger area in which a coil can be wound with respect to the projected area of the entire core than a U-shaped core or the like. Therefore, when a relatively large inductance is required, a toroidal reactor is often used.

  In the reactor, the calorific value increases as the flowing power increases. In a power converter mounted on an electric vehicle, the power flowing through the reactor is relatively large. Therefore, a reactor cooling structure is required. As a conventional reactor cooling structure, the reactor is housed in a case with a through hole on the bottom surface, the case is brought into contact with the housing, and the resin filled in the through hole makes the space between the reactor and the housing Some are thermally connected (for example, see Patent Document 1).

JP 2015-89179 A

  For example, in the field of electrified vehicles, there is a demand for improved fuel efficiency and an expanded cabin space. Therefore, there is a demand for a power conversion device mounted on an electric vehicle to be reduced in weight, size, cost, and power efficiency.

  As a miniaturization measure when applying a toroidal-shaped reactor to the power converter, the diameter of the conductor is made smaller, thereby increasing the winding of the coil, and reducing the winding layer of the coil, thereby reducing the diameter of the reactor. It is mentioned. If the diameter of the conductor can be reduced, the number of turns of the coil can be increased and the volume of the core can be reduced, so that the entire reactor can be significantly reduced in size. However, when such a miniaturization measure is adopted, the resistance value of the coil increases, and the heat generation density increases due to the decrease in the surface area of the coil. Therefore, a reactor cooling structure that cools the reactor more efficiently is required.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a reactor cooling structure for efficiently cooling a reactor, and a power conversion device.

The cooling structure for a reactor according to the present invention accommodates a toroidal reactor in which a coil is wound around a core by a bottom wall provided with a first opening and a side wall provided with a second opening. A case in which a first concave portion is formed, a case in which a case in which the reactor is stored in the first concave portion is provided with a second concave portion, and a second concave portion in which the module is stored. And a resin filled as a filler in the second recess, which is present up to a position including at least a part of the bottom wall, at least a part of the reactor, and the second opening provided in the side wall. And an insulating member disposed between a portion of the coil not covered with the resin and a side surface of the second concave portion .

  According to the present invention, the reactor can be cooled more efficiently.

FIG. 2 is a side sectional view showing the power conversion device according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing a core constituting the reactor employed in the power converter according to Embodiment 1 of the present invention. FIG. 2 is a perspective view illustrating a configuration of a reactor employed in the power converter according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing a module including a reactor employed in the power converter according to Embodiment 1 of the present invention. FIG. 2 is a bottom view showing a module including a reactor employed in the power conversion device according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing a housing for housing a module including a reactor employed in the power converter according to Embodiment 1 of the present invention. It is the figure which expanded the A section shown in FIG. It is the figure which expanded the B section shown in FIG. FIG. 3 is a side cross-sectional view illustrating a power conversion device according to a first modification of the first embodiment of the present invention. FIG. 9 is a bottom view showing a module including a reactor employed in a power converter according to Modification 2 of Embodiment 1 of the present invention. FIG. 5 is a side cross-sectional view illustrating a power conversion device according to a second modification of the first embodiment of the present invention. FIG. 7 is a side sectional view showing a power converter according to Embodiment 2 of the present invention. FIG. 7 is a perspective view showing a module including a reactor employed in a power converter according to Embodiment 2 of the present invention. FIG. 10 is a side cross-sectional view showing a resin plate and a radiator plate employed in a power converter according to Modification 1 of Embodiment 2 of the present invention. FIG. 13 is a top view showing a resin plate and a heat sink used in a power converter according to Modification 1 of Embodiment 2 of the present invention. FIG. 13 is a side cross-sectional view showing a resin plate and a radiator plate employed in a power converter according to Modification 2 of Embodiment 2 of the present invention. FIG. 13 is a side cross-sectional view showing a resin plate and a radiator plate employed in a power converter according to Modification 3 of Embodiment 2 of the present invention. FIG. 13 is a side cross-sectional view showing a resin plate and a radiator plate employed in a power converter according to Modification 4 of Embodiment 2 of the present invention. FIG. 15 is a side cross-sectional view showing a resin plate and a heat sink adopted in a power converter according to Modification 5 of Embodiment 2 of the present invention. FIG. 15 is a side sectional view showing a power converter according to Modification 6 of Embodiment 2 of the present invention. FIG. 13 is a side sectional view showing a power conversion device according to Embodiment 3 of the present invention.

  Hereinafter, embodiments of a power conversion device according to the present invention will be described with reference to the drawings. The power conversion device according to the present invention includes the reactor cooling structure according to the present invention. In the drawings, the same or corresponding elements are denoted by the same reference numerals.

Embodiment 1 FIG.
FIG. 1 is a side sectional view showing a power converter according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view showing a core constituting a reactor employed in the power converter according to Embodiment 1 of the present invention. FIGS. 3 and 4 are perspective views showing the configuration of a reactor employed in the power converter according to Embodiment 1 of the present invention, and FIG. 4 is employed in the power converter according to Embodiment 1 of the present invention. FIG. 5 is a perspective view showing a module including a reactor, FIG. 5 is a bottom view showing a module including a reactor employed in the power converter according to Embodiment 1 of the present invention, and FIG. 6 is a view showing Embodiment 1 of the present invention. It is a perspective view which shows the housing | casing which accommodates the module containing the reactor employ | adopted in such a power converter.

  In the perspective views shown in FIGS. 2 and 3, one part of one component is removed, and the inside of one part is shown. As shown in FIG. 1, the positional relationship in the following description is expressed assuming that the horizontal direction toward FIG. 1 is a plane direction and the vertical direction toward FIG. 1 is a vertical direction.

  As shown in FIG. 2, the core 11, which is a component of the reactor 1, has a hollow cylindrical shape, and is entirely covered by a bobbin 13. The core 11 is formed of a metal such as ferrite or nanocrystalline magnetic material having high magnetic permeability. The core 11 is manufactured by, for example, a step of crystallizing a molten alloy into a metal ribbon by rapid cooling such as a single roll method, forming the core into a magnetic core shape, and heat-treating.

  The bobbin 13 is made of an insulating resin material having excellent electrical insulation such as PBT (PolyButylene Terephthalate), and is composed of an upper bobbin 13b and a lower bobbin 13c. The upper bobbin 13b and the lower bobbin 13c are manufactured by a manufacturing method such as injection molding. By mounting the upper bobbin 13b and the lower bobbin 13c so as to sandwich the core 11, the core 11 and the bobbin 13 are integrated. Then, insulation between the core 11 and each coil 12 is secured by the bobbin 13, and insulation between the two coils 12 is secured by the insulating wall 13 a provided at the center of the bobbin 13.

  As shown in FIG. 3, around the bobbin 13 attached to the core 11, two coils 12 made of a conductor such as a copper wire subjected to an enamel coating are wound while securing an insulation distance. Has been. The winding directions of the two coils 12 are opposite to each other. By energizing both coils 12, a large inductance is obtained. The energization generates Joule heat from the coil 12. Four terminals 12 a to 12 d are provided for energizing each coil 12. For example, the terminals 12a and 12d are for energizing one of the two coils 12, and the terminals 12b and 12c are for energizing the other of the two coils 12.

  The insulation distance includes a space distance and a creepage distance. In order to secure electrical insulation, it is necessary to secure both a spatial distance and a creepage distance. Here, unless otherwise specified, the term “insulation distance” is used to refer to a space distance and a creepage distance that are more important for ensuring electrical insulation.

  The reactor 1 has a structure in which a coil 12 is wound around a bobbin 13 mounted on a core 11, as shown in FIG. The step of winding each coil 12 is basically performed by a person. Since the adjustment is performed manually, the dimensional variation of the coil 12 is relatively large.

  As shown in FIG. 1, the resin case 2 that houses the reactor 1 has a U-shaped cross section when cut along a plane parallel to the up-down direction. The resin case 2 has a circular bottom wall 2n and a hollow cylindrical side wall 2m. As a result, the resin case 2 has a recess 2o that is a space in which the reactor 1 can be stored. The diameter of the side wall 2m, that is, the width in the plane direction is a length exceeding the maximum radial dimension of the reactor 1.

  An opening 2b is provided in the side wall 2m, as shown in FIG. An opening 2a is provided in the bottom wall 2n as shown in FIG. The opening 2a corresponds to the first opening in the first embodiment, and the opening 2b corresponds to the second opening in the first embodiment. The recess 2o corresponds to the first recess in the first embodiment.

  The resin case 2 is manufactured by injection molding using an electrically insulating resin material such as PBT. The resin case 2 contacts the at least one or more coils 12 on the bottom wall 2n to position the reactor 1 in the vertical direction. The reactor 1 is housed in the resin case 2 such that the central axis 11g of the column 11 of the core 11 shown in FIG. 2 and the central axis 2g of the resin case 2 shown in FIG. These center axes 2g and 11g are parallel or substantially parallel to the up-down direction.

  As shown in FIG. 3, a resin plate 15, which is a plate-like member, is fixed to the coil 12 of the reactor 1 stored in the resin case 2 with an adhesive 14. The resin plate 15 is made of an insulating resin material having excellent electric insulation such as PBT. The adhesive 14 uses an insulating resin material having excellent electrical insulation properties, such as a silicone resin.

As shown in FIG. 4, the resin case 2 is provided with a protrusion 2c that protrudes upward, in other words, protrudes in a direction opposite to the bottom wall 2n. The resin plate 15 is provided with an opening 15a large enough to allow the protrusion 2c to pass therethrough. The opening 15a corresponds to the third opening in the first embodiment, and the protrusion 2c corresponds to the second protrusion in the first embodiment.

  By penetrating the projection 2c through the opening 15a, positioning in the planar direction between the reactor 1 and the resin case 2 can be performed. By fixing the reactor 1 inserted into the resin case 2 with an adhesive or the like, a module in which the reactor 1, the resin case 2, and the resin plate 15 fixed by the adhesive 14 are integrated is completed. When the module is stored in the recess 3a of the housing 3, the resin plate 15 is placed on the side opposite to the bottom wall 2n side of the module, as shown in FIG.

  As shown in FIG. 4, four terminals 12 a to 12 d for energizing each coil 12 are drawn upward toward the resin plate 15. The positions of the terminal portions 12a to 12d with respect to the resin plate 15 are determined by being inserted into the four holes 15b provided in the resin plate 15, respectively. Therefore, insulation between the terminal portions 12a to 12d is ensured. The resin plate 15 is fixed to the coil 12 by the adhesive 14 with the terminal portions 12a to 12d inserted into the four holes 15b, respectively. The resin plate 15 also secures insulation between the coil 12 and other parts other than the terminal portions 12a to 12d. Hole 15b corresponds to the first hole in the first embodiment.

  The housing 3 is made of an aluminum-based metal formed by, for example, aluminum die-casting, and is used for removing heat generated in the reactor 1. As shown in FIG. 6, the housing 3 has, as a recess capable of housing the resin case 2, a recess 3 a having a length that exceeds, for example, the maximum diameter of the resin case 2 in the radial direction. A radiation fin 3b for cooling is provided below the concave portion 3a. By flowing a fluid between the radiation fins 3b, the amount of heat transmitted to the housing 3 can be efficiently removed. The fluid is, for example, an antifreeze such as LLC (Long Life Coolant), water, or air. In addition, at least one or more holes 3c are provided in the edge 3f of the concave portion 3a for positioning the resin case 2. The recess 3a corresponds to the second recess in the first embodiment, and the hole 3c corresponds to the sixth hole in the first embodiment.

  The resin 4 exists in the concave portion 3a. In the first embodiment, the resin 4 is obtained by curing the filler. For this reason, in the first embodiment, for example, a filler that becomes the resin 4 is injected into the recess 3a, and the module illustrated in FIG. 4 is inserted into the recess 3a before the filler hardens. As a result, the space inside the concave portion 3a, that is, the space where neither the reactor 1 nor the resin case 2 exists, is filled with the filler material that becomes the resin 4. As a result, the module is fixed by the resin 4 and heat can be transmitted from the reactor 1 to the housing 3 via the resin 4. The bottom wall 2n including the opening 2a and the side wall 2m including the opening 2b are paths for heat transfer. Examples of the filler that becomes the resin 4 include a silicone-based potting resin material having excellent fluidity, insulating properties, and thermal conductivity.

  The resin case 2 is accommodated in the concave portion 3a such that the central axis 2g of the cylinder shown in FIG. 4 and the central axis 3g of the concave portion 3a shown in FIG. The vertical position of the resin case 2 in the concave portion 3a is determined by one or more protrusions 2d provided on the bottom wall 2n of the resin case 2 as shown in FIGS. That is, when the protrusion 2 d comes into contact with the bottom surface 3 d of the concave portion 3 a of the housing 3, the relative position in the vertical direction within the concave portion 3 a of the resin case 2 is determined. The height of the projection 2d, that is, the width in the up-down direction is a length that secures a necessary insulation distance between the reactor 1 and the housing 3. The protrusion 2d corresponds to the first protrusion in the first embodiment.

  By providing the protrusion 2d on the resin case 2, the number of parts can be reduced as compared with the case where the protrusion 2d is formed as another part. Therefore, providing the protrusion 2d on the resin case 2 is effective in terms of suppressing manufacturing costs, shortening the time required for manufacturing the power conversion device 10, and the like. However, in order to secure a necessary insulation distance between the reactor 1 and the housing 3, the protrusion 2d may be a separate component from the resin case 2, and the protrusion 2d itself is prepared as one component. Is also conceivable. As a component different from the resin case 2, a housing 3 can be cited.

  As shown in FIG. 4, two positioning protrusions 2 f are provided on the upper side of the resin case 2. The protrusion 2f is provided on the connection portion 2e, and the connection portion 2e is provided on the resin wall 2h, which is the plate-like portion in the first embodiment. On the other hand, two holes 3c are provided in the edge 3f of the recess 3a of the housing 3 as shown in FIG. The hole 3c allows the protrusion 2f to be inserted. For this reason, by inserting each projection 2f into the corresponding hole 3c, relative positioning in the planar direction between the resin case 2 and the housing 3 can be performed. In order for such positioning to be possible, the vertical position of the protrusion 2f, its height, and the depth of the hole 3c are such that when the protrusion 2d is brought into contact with the bottom surface 3d, the connecting portion 2e is brought into contact with the edge 3f. It is determined so as not to make contact and the tip of the projection 2f does not contact the bottom of the hole 3c. The protrusion 2f corresponds to the third protrusion in the first embodiment.

  As shown in FIG. 4, the resin wall 2h has a width in the circumferential direction of the reactor 1 and is provided for each hole 15b. Thereby, each resin wall 2h is arranged between terminal portions 12a to 12d and side surface 3e of concave portion 3a. Therefore, insulation between the terminal portions 12a to 12d and the housing 3 can be more reliably ensured by the resin walls 2h. The details of the resin wall 2h will be described later with reference to FIG.

  As shown in FIGS. 1 and 4, the resin case 2 is provided with a resin wall 2 i at a position on the radial end side over the entire circumferential direction. The resin 4 is filled up to a position in contact with a part of the resin wall 2i. Therefore, the resin 4 is filled in a part of the opening 2 b provided in the side wall 2 m of the resin case 2. Resin wall 2i corresponds to the insulating member in the first embodiment. The details regarding the resin wall 2i will be described later with reference to FIG.

  As shown in FIG. 1, the printed wiring board 5 located above the reactor 1 is electrically connected to the reactor 1 through a through hole 5a. That is, the terminal portions 12a to 12d of the reactor 1 are electrically connected to the corresponding through holes 5a. The electrical connection is made, for example, by soldering or welding. The printed wiring board 5 is fixed to at least one or more bosses (not shown) provided on the housing 3 by screws, for example.

  Next, the effect on cooling of reactor 1 in the first embodiment will be specifically described. In the first embodiment, as described above, the openings 2a and 2b are provided in the bottom wall 2n and the side wall 2m of the resin case 2, respectively, and the resin 4 is injected into the recess 3a as a filler and cured. Fix the module. For this reason, the main heat radiation path from the reactor 1 to the housing 3 has a configuration in which only the resin 4 is interposed. There are two interfaces on the heat dissipation path between the reactor 1 and the resin 4 and between the resin 4 and the housing 3.

  The thickness of the resin 4 in the vertical direction below the reactor 1 is determined by the height of the protrusion 2d provided on the bottom wall 2n. Therefore, the influence of the dimensional variation of the coil 12 manually wound by a person on the insulating property is reduced. As a result, the thickness of the resin 4 as an intermediate member on the heat radiation path can be controlled within an error range corresponding to the dimensional tolerance of each thickness of the protrusion 2d and the bottom wall 2n of the resin case 2.

  By reducing the number of intermediate members and the number of layers at the interface, the thermal resistance of the heat radiation path can be further reduced. The smaller the thermal resistance, the better the heat radiation performance. In the first embodiment, as shown in FIG. 1, the resin 4 is an intermediate member of a first heat radiation path formed between the reactor 1 and the bottom surface 3 d of the recess 3 a of the housing 3. At the same time, it is an intermediate member of a second heat radiation path formed between the reactor 1 and the side surface 3e of the recess 3a of the housing 3. Therefore, compared to the cooling structure disclosed in Patent Literature 1 in which only the first heat dissipation path is formed, in the first embodiment, the entire heat dissipation area can be made larger and the heat resistance can be made smaller. Can be. As a result, higher heat dissipation performance, in other words, higher cooling performance can be realized.

  In the first embodiment, the protrusion 2d separates the bottom wall 2n from the bottom 3d. As a result, the structure is such that the resin 4 also exists between the bottom wall 3d and the portion of the bottom wall 2n where the opening 2a does not exist. With such a structure, the heat conductivity of the resin 4 is better than that of the resin case 2, so that the amount of heat conducted from the opening 2a to the bottom surface 3d is diffused to a larger area and conducted. become. Such diffusion results in lower thermal resistance. For this reason, providing an interval between the bottom wall portion 2n and the bottom surface 3d has an effect of improving heat radiation performance.

  By realizing higher cooling performance, temperature rise of reactor 1 due to energization is suppressed. By suppressing the temperature rise, the increase in the resistance value of the coil 12 is also suppressed. Therefore, high efficiency of power conversion by the power conversion device 10 can also be realized.

  By increasing the efficiency of power conversion, power energy consumption can be reduced. With higher efficiency and improved heat dissipation performance, it is possible to use a conductor having a smaller diameter for the coil 12. By using a conductor having a smaller diameter, the size of the reactor 1 can be further reduced. Specifically, by using a conductor having a smaller diameter, the number of turns of the coil 12 can be increased, and the volume of the core 11 can be further reduced. Therefore, the entire reactor 1 can be significantly reduced in size. As a result, it is possible to reduce the size and weight of the entire power conversion device 10 and to suppress the manufacturing cost due to the size reduction.

  As described above, the projections 2f provided on the resin case 2 and the holes 3c provided on the housing 3 allow the resin case 2 and the reactor 1 housed in the resin case 2 to be relative to the plane direction of the housing 3. Positioning is performed. By housing the reactor 1 in the resin case 2, it is possible to reduce the amount of positional deviation between the central axis 11 g of the core 11 and the central axis 3 g of the housing 3 due to dimensional variations of the coil 12. That is, it is possible to suppress the reactor 1 from being largely displaced from the center of the recess 3 a of the housing 3. Accordingly, the thickness of the resin 4 around the reactor 1 in the planar direction can be made more uniform. As a result, the deviation of the cooling capacity depending on the position can be reduced, and the reduction of the deviation enables more efficient cooling of the reactor 1.

  When the reactor 1 is fixed without using the resin case 2, the reactor 1 is positioned by, for example, the printed wiring board 5 located above the reactor 1. In that case, the thickness of the resin 4 changes according to the dimensional variation of the coil 12. In particular, the thickness of the resin 4 in the vertical direction changes. However, in the first embodiment, the thickness of the resin 4 in the vertical direction from the bottom surface 3d of the housing 3 to the resin case 2 is determined by the protrusion 2d provided on the resin case 2. The thickness usually corresponds to the shortest distance between the coil 12 and the bottom surface 3d. On the other hand, the reactor 1 and the side surface 3e are appropriately separated from each other by the protrusion 2f provided on the resin case 2, the hole 3c provided on the housing 3, and the side wall 2m of the resin case 2. From these facts, it is possible to reliably ensure the insulation between the reactor 1, particularly the coil 12 and the housing 3.

  FIG. 7 is an enlarged view of the portion A shown in FIG. 1, and FIG. 8 is an enlarged view of the portion B shown in FIG. Next, with reference to FIG. 7 and FIG. 8, a specific description will be given of the improvement in insulation performance realized by the two types of resin walls 2 h and 2 i.

  As shown in FIG. 7, the resin wall 2h is located between the terminal portion 12d of the coil 12 and the side surface 3e of the housing 3. If the resin wall 2h does not exist, the insulation distance between the terminal portion 12d and the housing 3 is a linear distance a + b from the terminal portion 12d to the side surface 3e. However, by providing the resin wall 2h, the insulation distance between the terminal portion 12 and the housing 3 becomes the linear distance c from the terminal portion 12d to the resin wall 2h and the linear distance c from the end of the resin wall 2h to the side surface 3e. This is the distance c + d obtained by adding the distance d. The magnitude relationship between these insulation distances is a + b <c + d. In this way, by providing the resin wall 2h, the insulation distance can be made longer, so that the insulation performance is improved, and the insulation between the terminal portion 12d and the housing 3 can be more reliably ensured. .

  As shown in FIG. 8, the resin wall 2i is located between the coil 12 and the side surface 3e of the housing 3. If the resin wall 2i does not exist, the insulation distance between the coil 12 and the housing 3 is a linear distance e + f from the coil 12 to the side surface 3e. However, by providing the resin wall 2i, the insulation distance between the coil 12 and the housing 3 becomes equal to the linear distance g from the coil 12 to the end of the resin wall 2i and the linear distance h from the resin wall 2i to the side surface 3e. And g + h. The magnitude relationship between these insulation distances is e + f <g + h. Therefore, by providing the resin wall 2i, the insulation performance is improved, as in the case of providing the resin wall 2h, and the insulation between the coil 12 and the housing 3 can be more reliably ensured.

  In the first embodiment, as shown in FIG. 1, the resin 4 is present in a void portion in which neither the reactor 1 nor the resin case 2 exists in the recess 3 a, and the reactor 1 and the resin case 2 Is fixed in the concave portion 3a. Therefore, for example, when the power conversion device 10 is mounted on an electric vehicle, even if vibration or impact is applied to the power conversion device 10 from the outside due to running of the vehicle or the like, the power conversion device 10 remains in the recess 3 a of the reactor 1 and the resin case 2. The positional relationship can be stably maintained. The printed wiring board 5 is fixed to the housing 3 with screws. Thus, the positional relationship between the housing 3 and the printed wiring board 5 can be stably maintained. For this reason, even when the weight of the reactor 1 is relatively heavy, high earthquake resistance can be realized. Due to this earthquake resistance, stress applied to the connection portion of the through hole 5a connecting the printed wiring board 5 and each of the terminal portions 12a to 12d is suppressed to an extremely small range. As a result, the possibility that the connection portion is broken can be suppressed. Therefore, the occurrence of a failure in the power conversion device 10 can be greatly suppressed.

  In the first embodiment, the core 11 is manufactured by forming a ribbon-shaped metal into a magnetic core shape and then crystallizing the same by a heat treatment. Not limited. The core 11 may be manufactured by casting, punching by a press, cutting, or the like. When these manufacturing methods are adopted, the manufacturing cost of the core 11 can be further reduced. Further, it is possible to easily cope with a complicated core shape such as a U-shape and the like, and the production cost can be kept low. The first embodiment can be applied to a reactor other than a toroidal shape, and other electromagnetic induction devices, because it can easily cope with a complicated core shape.

  In the first embodiment, the two coils 12 are wound around the bobbin 13 while securing the insulation distance. However, the number of the coils 12 may be one, or three or more. That is, the number of coils 12 is not particularly limited. The coil 12 may be formed by bundling two or more conductive wires. When two or more conductive wires are used, it is possible to further reduce the resistance value of the coil 12 while increasing the cross-sectional area of the coil 12 in the radial direction of the core 11. Therefore, it is possible to further improve the power efficiency of power conversion device 10 while suppressing the temperature rise of reactor 1.

  In the first embodiment, the bobbin 13 has an upper bobbin 13b and a lower bobbin 13c both formed by injection molding or the like, and the upper bobbin 13b and the lower bobbin 13c are mounted with the core 11 therebetween. However, the bobbin 13 may be manufactured by insert-molding the core 11. By manufacturing by insert molding, it is possible to reduce a boundary layer due to air or the like existing between the core 11 and the bobbin 13. By reducing the boundary layer, the thermal resistance of the core 11 can be further reduced.

  In addition, since the adhesive used for fixing the core 11 and the bobbin 13 generally has a lower heat-resistant temperature than the material of the core 11 and the resin constituting the bobbin 13, the adhesive has a large influence on the heat-resistant temperature of the reactor 1. There are many. However, the adhesive for fixing the core 11 can be made unnecessary by the insert molding. Therefore, by adopting insert molding, the heat-resistant temperature of reactor 1 can be further increased.

  The reactor 1 and the resin case 2 housed as a module in the recess 3 a are fixed by the resin 4. Therefore, when the reactor 1 is stored in the resin case 2, the reactor 1 does not necessarily have to be fixed to the resin case 2. However, when the reactor 1 is not stable in the resin case 2, the reactor 1 may be fixed to the resin case 2 with an adhesive or the like.

  In the first embodiment, an interval is provided between the bottom wall 2n of the resin case 2 and the bottom 3d of the recess 3a by the protrusion 2d. However, as shown in FIG. 9, a space is provided between the bottom wall 2n of the resin case 2 and the bottom 3d of the recess 3a by the protrusion 2f provided on the resin case 2 and the hole 3c provided on the housing 3. You may do it. In such a case, the projection 2d may not be provided.

  When the structure as shown in FIG. 9 is adopted, the distance between the bottom wall 2n and the bottom 3d is determined by the protrusion 2f, the connection 2e, and the hole 3c. For this reason, similarly to the case where the protrusion 2d is provided, it is possible to suppress the influence on the insulating property due to the dimensional variation of the coil 12. Therefore, insulation can be ensured more reliably.

  As shown in FIG. 10, the opening 2 a provided in the bottom wall 2 n of the resin case 2 may include a hole 2 j having a size smaller than the maximum outer diameter of the core 11 of the reactor 1. The position of the hole 2j is preferably set to a position that matches the center of the core 11 within an allowable range. This is because the toroidal reactor 1 usually has a higher heat density at an inner portion than the inner diameter of the core 11 and has a maximum temperature at the inner portion. Therefore, by providing the hole 2j as one of the openings 2a in the bottom wall 2n of the resin case 2, the ratio of the resin 4 in contact with the region where the heat density of the reactor 1 is highest can be maximized. In other words, the thermal resistance from the reactor 1 to the bottom surface 3d of the housing 3 can be further reduced. Therefore, the heat radiation performance can be further improved. Hole 2j corresponds to a through-hole in the modification of the first embodiment.

  In the case where the hole 2j as shown in FIG. 10 is provided, as shown in FIG. 11, one or more convex portions 3h having a height capable of ensuring insulation with the coil 12 are provided on the bottom surface 3d in accordance with the position of the hole 2j. , May be provided. By providing the convex portion 3h at a position facing the hole 2j, the thickness of the resin 4 from the reactor 1 to the bottom surface 3d of the housing 3 becomes smaller, so that the thermal resistance can be made smaller. Therefore, the heat radiation performance can be further improved. The convex portion 3h corresponds to a second convex portion in the modification of the first embodiment.

  In the first embodiment, after completing a module in which the reactor 1, the resin case 2, and the resin plate 15 are integrated, the module is housed in the concave portion 3a, and is fixed by the resin 4 as a cured filler. I have to. By housing the reactor 1 in the resin case 2, higher heat dissipation performance is realized while ensuring insulation and vibration resistance between the coil 12 and the housing 3. When the reactor 1 is housed in the resin case 2 to form a module, the module can be easily assembled, and the module can be easily housed in the recess 3a. This contributes to a reduction in the manufacturing cost of the power conversion device 10.

  In the first embodiment, the resin wall 2i and the resin wall 2h for enabling more reliable insulation are provided in the resin case 2. By providing the resin wall 2i and the resin wall 2h in the resin case 2, an increase in the number of parts is suppressed, and the assembly of the power conversion device 10 becomes easier. However, at least one of the resin walls 2h and 2i may be provided on a component different from the resin case 2. For example, the resin wall 2h may be provided on the resin plate 15. Even if the resin wall 2 h is provided on the resin plate 15, an increase in the number of parts can be suppressed, which is effective in suppressing the manufacturing cost of the power converter 10. Even if the resin wall 2i is provided on the resin wall 15, the increase in the number of components can be suppressed, and thus the production cost of the power conversion device 10 can be reduced.

  Alternatively, one of the resin walls 2h and 2i may be one or more components. For example, an insulating sheet may be used as the resin wall 2i. When an insulating sheet is used as the resin wall 2i, the thickness of the resin 4 existing between the coil 12 and the side surface 3e of the housing 3 can be further reduced while securing insulation between the coil 12 and the side surface 3e. For this reason, it contributes to downsizing of the power converter 10.

Embodiment 2 FIG.
FIG. 12 is a side sectional view showing a power converter according to Embodiment 2 of the present invention, and FIG. 13 is a perspective view showing a module including a reactor employed in the power converter according to Embodiment 2 of the present invention. It is. In the second embodiment, the shapes of the resin case 2 and the resin plate 15, the filling amount of the resin 4, and the upper portion of the resin plate 15 are different from those of the first embodiment. Therefore, the following description focuses on the differences from the first embodiment.

  In the second embodiment, as shown in FIGS. 12 and 13, the heat radiation plate 6 is added to the upper part of the resin plate 15, that is, the side opposite to the module side of the resin plate 15. The heat radiating plate 6 has an outer diameter that can be inserted into the recess 3 a of the housing 3. The heat radiating plate 6 is provided with an opening 6a for passing the terminal portions 12a to 12d and an opening 6b for passing the projection 2c. Therefore, as shown in FIG. 12, the heat radiating plate 6 can be stacked on the resin plate 15 in the recess 3a, that is, on the side of the resin plate 15 opposite to the reactor 1 side. By passing the protrusion 2c through the opening 6b, the plane direction of the heat sink 6 is positioned. The opening 6a corresponds to the fourth opening in the second embodiment, and the opening 6b corresponds to the fifth opening in the second embodiment.

  The resin 4 is filled in the concave portion 3 a up to the heat radiating plate 6. The resin 4 realizes reliable insulation between the coil 12 and the housing 3, between the heat sink 6 and the housing 3, and between the heat sink 6 and peripheral components (not shown). Therefore, in the second embodiment, the resin wall 2i is omitted.

  The heat radiating plate 6 is manufactured, for example, by stamping a metal flat plate with a press die or the like. According to this manufacturing method, the heat sink 6 can be manufactured at low cost. Further, the heat radiating plate 6 can also be manufactured by cutting a flat metal plate. The method for manufacturing the heat sink 6 is not particularly limited. The heat radiating plate 6 is made of metal and therefore has high thermal conductivity. The resin 4 or the resin plate 15 exists between the heat sink 6 and the coil 12. Therefore, insulation between the heat sink 6 and the reactor 1 is ensured. The heat radiating plate 6 and the resin plate 15 are thermally connected by, for example, a gap filler.

  Next, the effect on cooling of reactor 1 in the second embodiment will be specifically described.

  As described above, the portion inside the inner diameter of the core 11 is the portion where the temperature rise is the largest. In the first embodiment, the amount of heat in a portion inside the inner diameter of the core 11 mainly flows to the bottom surface 3d. However, in the second embodiment, as shown in FIG. 12, the heat radiating plate 6 is added to the upper portion of the resin plate 15, and the resin 4 exists up to the upper portion of the heat radiating plate 6. Therefore, as a heat radiation path for flowing the amount of heat inside the inner part of the core 11 to the housing 3, a heat radiation path formed by the inside part → the resin 4 → the resin plate 15 → the resin 4 → the side surface 3e, the inside part → the resin 4 → the resin A heat radiation path formed by the plate 15 → the heat radiation plate 6 → the resin 4 → the side surface 3e and a heat radiation path formed by the inner part → the resin 4 → the side surface 3e are added. With the addition of such a heat radiation path, the thermal resistance between the portion inside the inner diameter of the core 11 and the housing 3 becomes smaller. Therefore, in the second embodiment, higher heat dissipation performance is realized as compared with the first embodiment. By realizing higher heat dissipation performance, it is possible to reduce the size, increase the efficiency, reduce the weight, and reduce the cost of the power conversion device 10 as compared with the first embodiment. Since the amount of heat of the resin plate 15 can be radiated to the side surface 3e of the housing 3 via the heat radiating plate 6 and the resin 4, the low temperature of the printed wiring board 5 installed on the upper part is also realized.

  The heat radiating plate 6 is integrated with the reactor 1, the resin case 2, and the resin plate 15, and is housed in the concave portion 3a of the housing 3 as a module. Therefore, as in the first embodiment, high assemblability is realized. Since the heat radiating plate 6 is covered with the resin 4, insulation between the heat radiating plate 6 and the terminal portions 12a to 12d can be reliably ensured.

  The resin plate 15 may be provided with a hole 15c at the center, for example, as shown in FIGS. The hole 15c is for removing air existing below the resin plate 15 when the module is inserted into the concave portion 3a filled with the filler material to be the resin 4. Therefore, when the hole 15c is provided, the heat radiating plate 6 is arranged away from the resin plate 15 as shown in FIG. In the example shown in FIG. 14, two columnar portions 7 protruding above and below the heat radiating plate 6 are provided, and the heat radiating plate 6 is separated upward from the resin plate 15. As described above, the columnar portion 7 is used for the relative positioning of the heat sink 6 in the vertical direction.

  As shown in FIG. 14, by separating the resin plate 15 and the heat radiating plate 6, air existing below the resin plate 15 can be efficiently removed. By eliminating the air, the thermal resistance between the portion inside the inner diameter of the core 11 and the housing 3 can be further reduced. Further, by filling the inside of the hole 15c with the resin 4, the inner part → the resin 4 → the heat radiating plate 6 → the resin 4 → the side surface 3e is provided as a heat radiating path for flowing the amount of heat inside the core 11 to the housing 3. In addition, the thermal resistance between the portion inside the core 11 and the housing 3 can be further reduced. That is, by providing the holes 15c in the resin plate 15, higher heat radiation performance can be realized more reliably.

  The columnar part 7 is an electrically insulating resin such as PBT, for example, and can be provided on the heat sink 6 by insert molding. When the columnar portion 7 is made of resin, the filler that becomes the resin 4 does not have to be filled so as to cover the columnar portion 7. That is, as shown in FIG. 12, the filler to be the resin 4 may be filled so as to cover the heat sink 6.

  As shown in FIG. 16, the heat radiating plate 6 may be provided with a convex portion 6 c having an outer diameter smaller than the hole 15 c on the resin plate 15 side in accordance with the position of the hole 15 b of the resin plate 15. By providing such a convex portion 6c, the thickness of the resin 4 existing between the heat radiating plate 6 and a portion inside the inner diameter of the core 11 can be further reduced. For this reason, the thermal resistance between the inside of the inner diameter of the core 11 and the housing 3 can be further reduced, and higher heat dissipation performance is realized. The protrusion 6c corresponds to the first protrusion in the second modification of the second embodiment.

  The height of the protrusion 6c in the vertical direction is preferably such that the tip of the protrusion 6c is present in the hole 15c and does not protrude to the reactor 1 side of the resin plate 15. This is to ensure the insulation between the heat radiating plate 6 and the reactor 1 while enabling the elimination of air.

  As shown in FIG. 17, the heat sink 6 may further be provided with one or more holes 6d. The holes 6d make it possible to more reliably eliminate air existing below the heat sink 6. Therefore, as compared with the case where the hole 6d is not provided in the heat radiating plate 6, the thermal resistance between the inner part of the core 11 and the housing 3 can be reduced more reliably, and the high heat radiating performance is also improved. Realized more reliably. The hole 6d corresponds to a fifth hole in the third modification of the second embodiment.

  When the holes 6d are provided, the protrusions 6c may be provided on the heat sink 6 as shown in FIG. By providing the protruding portion 6c, the thermal resistance between the inner portion of the core 11 and the housing 3 can be reduced more reliably, and high heat dissipation performance is more reliably realized.

  As shown in FIG. 19, a hole 6e may be provided at the tip of the convex portion 6c. This hole 6e becomes a passage for passing air to be eliminated. When the module including the heat radiating plate 6 is inserted into the concave portion 3a, the module serves as a passage for the resin 4 as well as the air. For this reason, the hole 6e makes it possible to reliably realize high heat dissipation performance and to quickly store the module in the recess 3a. Hole 6e corresponds to a third hole in Modification 5 of Embodiment 2.

  The hole 15c corresponds to the second hole in the second embodiment in each of the examples shown in FIGS. 14 and 17, and in each of the examples shown in FIGS. 16, 18, and 19, the second hole in the second embodiment. 4 holes. In the examples shown in FIGS. 16, 18 and 19, holes corresponding to the second and fourth holes may be provided separately from the hole 15c. When a hole corresponding to the fourth hole is provided, it is possible to provide a protrusion different from the protrusion 6c corresponding to the provided hole. The more the number of convex portions is increased, the more efficiently heat radiation can be performed.

  As shown in FIG. 20, a wall 6 f whose tip projects between the resin plate 15 and the side surface 3 e of the housing 3 may be provided at the radial end of the heat radiating plate 6. The wall 6f has higher thermal conductivity than the resin 4. Therefore, by providing the wall 6f, the thermal resistance between the resin plate 15 and the side surface 3e of the housing 3 can be further reduced, and the heat radiation performance is improved. The wall 6f corresponds to a plate-shaped protrusion in the sixth modification of the second embodiment.

  When the wall 6f does not exist, between the resin plate 15 and the side surface 3e of the housing 3, the resin plate 15 → the resin 4 existing between the heat radiation plate 6 and the resin plate 15 → the side surface 3e of the housing 3, And a heat radiation path formed by the resin plate 15 → the resin 4 → the side surface 3 e of the housing 3. By providing the wall 6f, these two heat dissipation paths are formed by the resin plate 15 → the resin 4 existing between the heat dissipation plate 6 and the resin plate 15 → the wall 6f → the resin 4 → the side surface 3e of the housing 3. The heat radiation path formed by the resin plate 15 → the resin 4 → the wall 6f → the resin 4 → the side surface 3e of the housing 3. As a result, the length of the resin 4 to which heat is transmitted is shortened, and the shortened portion makes the wall 6f a heat transmission path. Therefore, by providing the wall 6f, the thermal resistance between the resin plate 15 and the side surface 3e of the housing 3 can be further reduced.

  The protrusion 6c including the protrusion 6c and the hole 6e can be provided on the heat sink 6 by, for example, press working. The protrusion 6c including the hole 6e can be provided on the heat sink 6 by cutting. The wall 6f can be formed by bending a sheet metal. The wall 6f may be formed by cutting. The cutting can be performed with higher precision than the press. Therefore, when high accuracy is required, it is preferable to use cutting rather than pressing for forming the wall 6f.

Embodiment 3 FIG.
FIG. 21 is a side sectional view showing a power converter according to Embodiment 3 of the present invention. The third embodiment is different from the first embodiment in a method of providing an interval between the bottom wall 2n of the resin case 2 and the bottom 3d of the housing 3. Therefore, the following description focuses on the differences from the first embodiment.

  In the third embodiment, as shown in FIG. 21, an insulating sheet 8 is provided on the entire bottom surface 3d of the housing 3, and the insulating sheet 8 is provided between the bottom wall 2n of the resin case 2 and the bottom surface 3d of the housing 3. 8 is sandwiched. Thereby, the space between the bottom wall 2n of the resin case 2 and the bottom surface 3d of the housing 3 is kept apart, and the insulation between the reactor 1 and the housing 3 is ensured. As the insulating sheet 8, for example, a sheet using silicone rubber and having excellent electrical insulation is preferable.

  The resin case 2 may be damaged, bent, or the like. The reactor 1 is relatively heavy and generates heat, and the resin case 2 and the resin 4 deteriorate with time. For this reason, there is a high possibility that the bottom wall 2n is particularly damaged or bent. Damage, curvature, and the like of the bottom wall 2n are likely to adversely affect the resin 4 existing between the bottom wall 2n and the bottom surface 3d. For these reasons, if the bottom wall 2n is damaged or bent, insulation between the reactor 1 and the housing 3 may not be ensured.

  However, as shown in FIG. 21, when the insulating sheet 8 is arranged between the bottom wall 2n of the resin case 2 and the bottom 3d of the housing 3, it is assumed that the bottom wall 2n is damaged, bent, or the like. Also, insulation between the reactor 1 and the housing 3 can be ensured. Therefore, higher durability can be realized and reliability can be improved as compared with the first embodiment. The heat radiation performance can be realized at the same level as in the first embodiment.

  1 reactor, 2 resin case, 2a opening (first opening), 2b opening (second opening), 2c projection (second projection), 2d projection (first projection), 2f projection ( 3h resin wall (plate-like portion), 2i resin wall (insulating member), 2j hole (through hole), 2m side wall portion, 2n bottom wall portion, 2o concave portion (first concave portion), 3 Housing, 3a concave portion (second concave portion), 3c hole (sixth hole), 3f edge, 3h convex portion (second convex portion), 4 resin, 6 heat sink, 6a opening (4th opening) Part), 6b opening (fifth opening), 6c protrusion (first protrusion), 6d hole (fifth hole), 6e hole (third hole), 6f wall (plate-like protrusion) Part), 8 insulating sheets, 10 power converters, 11 cores, 12 coils, 12a to 12d terminal parts, 13 bobbins, 15 resin plate (plate-like part) ), 15a opening (third opening), 15b hole (first hole), 15c hole (second bore, the fourth hole in).

Claims (23)

A case in which a first concave portion for accommodating a toroidal reactor in which a coil is wound around a core is formed by a bottom wall portion provided with a first opening portion and a side wall portion provided with a second opening portion. When,
A housing provided with a second recess for housing the case in which the reactor is housed in the first recess as a module;
In the second recess in which the module is housed, the module is present up to a position including the bottom wall, at least a part of the reactor, and at least a part of the second opening provided in the side wall. A resin filled in the second recess as a filler ,
An insulating member disposed between a portion of the coil that is not covered with the resin and a side surface of the second recess;
Reactor cooling structure equipped with. A first projection is provided for securing a space between the bottom wall of the case and a bottom surface of the housing.
The reactor cooling structure according to claim 1. The first protrusion is provided on the case and is in contact with the bottom surface;
The reactor cooling structure according to claim 2. A plate provided on the side opposite to the bottom wall side of the module housed in the second concave portion and provided with at least one first hole through which a terminal portion of a coil wound on the core penetrates Shaped member,
The reactor cooling structure according to any one of claims 1 to 3 , further comprising: In the second concave portion, a heat radiating plate housed on the opposite side of the plate-shaped member from the module side is further provided,
The resin exists up to a position covering the heat sink.
The reactor cooling structure according to claim 4 . The case is provided with a second protrusion protruding on a side opposite to the bottom wall side,
The plate-shaped member is provided with a third opening through which the second protrusion passes.
The reactor cooling structure according to claim 5 . The heat sink has a fifth opening through which the second protrusion passes.
A reactor cooling structure according to claim 6 . An insulating plate portion disposed between the terminal portion and a side surface of the second concave portion,
The reactor cooling structure according to any one of claims 5 to 7 , further comprising: The plate-shaped member is provided with at least one or more second holes,
Cooling structure of the reactor according to any one of claims 5 8. The radiator plate is provided with a fourth opening through which the terminal portion passes.
The reactor cooling structure according to claim 5 . A first protrusion protruding toward the module is provided on the heat sink;
The reactor cooling structure according to any one of claims 5 to 10 . A third hole is formed in the first protrusion;
Cooling structure of a reactor according to claim 1 1. The plate-shaped member is provided with a fourth hole into which the first protrusion can be inserted.
Cooling structure of a reactor according to claim 1 1 or 1 2. The radiator plate is provided with a plate-like protrusion that projects between the plate-like member and a side surface of the second recess.
Cooling structure of the reactor according to any one of claims 5 1 3. The heat sink has at least one or more fifth holes,
Cooling structure of the reactor according to any one of claims 5 1 4. The case is made of an insulating member,
The insulating member is provided in the case,
The reactor cooling structure according to claim 1 . The reactor cooling structure according to claim 8 , wherein the plate portion is provided in the case. The plate-shaped portion is provided on the plate-shaped member,
A reactor cooling structure according to claim 8 . The first opening provided in the bottom wall portion includes a through hole formed in an outer diameter less than a maximum outer diameter of the core constituting the reactor,
The reactor cooling structure according to any one of claims 1 to 18 . On the bottom surface of the second concave portion, a second convex portion is provided at a position facing the through hole.
The reactor cooling structure according to claim 19 . An insulating sheet provided on a bottom surface of the second concave portion;
The casing and the reactor are thermally connected via the insulating sheet.
Cooling structure of the reactor according to any one of claims 1 2 0. A sixth hole is provided at an edge of the second concave portion of the housing,
The case is provided with a third protrusion inserted into the sixth hole when the module is housed in the second recess.
The reactor cooling structure according to any one of claims 1 to 21. Cooling structure of the reactor according to any one of claims 1 2 2,
A power converter having:

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