Patent Application
20240029930
The present disclosure relates to a reactor, a converter and a power conversion device.
This application claims a priority based on Japanese Patent Application No. 2019-229734 filed on Dec. 19, 2019, all the contents of which are hereby incorporated by reference.
Patent Document 1 discloses a reactor including a coil, a magnetic core, a case for an assembly of the coil and the magnetic core and a sealing resin for covering the outer periphery of the assembly by being filled into the case. The coil includes two coil elements formed by winding a winding wire. Hereinafter, the coil elements are called winding portions. The magnetic core includes a pair of inner core portions to be covered by the respective winding portions and a pair of outer core portions to be arranged outside the winding portions to sandwich the pair of inner core portions. Patent Document 1 discloses to provide a resin introduction path for filling the sealing resin from a bottom side toward an opening side of the case in a side wall portion of the case.
Patent Document 2 discloses an assembly including a coil having one winding portion and a magnetic core having two E-shaped core pieces as one form of the assembly. The core piece includes a plate-like coupling portion arranged on an end surface of the coil, an inner core protrusion projecting from a central part of the coupling portion, and outer peripheral portions respectively projecting from parts near both edges of the coupling portion, and has an E-shaped outer appearance. The inner core protrusion is arranged in the winding portion. The outer peripheral portions are arranged to partially cover the outer peripheral surface of the coil.
A reactor of the present disclosure is provided with a coil including one winding portion, a magnetic core having parts to be arranged inside and outside the winding portion, a resin member for specifying mutual positions of the coil and the magnetic core, a case for accommodating an assembly including the coil, the magnetic core and the resin member, and a sealing resin portion to be filled into the case, wherein the magnetic core includes a middle core portion to be arranged inside the winding portion, two side core portions to be arranged in parallel to the middle core portion outside the winding portion, and two end core portions connecting the middle core portion and the side core portions on both end parts of the winding portion, the case includes a bottom plate portion, the assembly being placed on the bottom plate portion, a side wall portion in the form of a rectangular frame for surrounding the assembly, and an opening facing the bottom plate portion, the side wall portion includes a pair of long side parts and a pair of short side parts, the assembly is so arranged that exposed surfaces not facing the respective side core portions, out of an outer peripheral surface of the winding portion, face toward the long side parts, the resin member includes a protruding portion projecting toward one of the short side parts, and a gap is formed by an inner surface of the side wall portion including the one short side part and the protruding portion when the case is viewed from above.
A converter of the present disclosure includes the reactor of the present disclosure.
A power conversion device of the present disclosure includes the converter of the present disclosure.
It is considered to obtain a reactor by accommodating an assembly including a coil having one winding portion and two E-shaped core pieces in a case and filling a sealing resin into the case. If a resin introduction path is provided in a side wall portion of the case as disclosed in Patent Document 1 in filling the sealing resin into the case, a special processing is necessary to form the resin introduction path. Further, a thickness of the side wall portion of the case needs to be increased due to a necessity to form the resin introduction path.
Further, the size reduction of the reactor is desired. Here, the size reduction of the reactor means that an installation area of the reactor is small and an interval between the assembly and the case is small. Accordingly, a structure capable of satisfactorily filling the sealing resin into the case while realizing the size reduction of the reactor is desired in the assembly including the coil having one winding portion.
One object of the present disclosure is to provide a reactor small in size and excellent in productivity. Another object of the present disclosure is to provide a converter including the above reactor. Still another object of the present disclosure is to provide a power conversion device including the above converter.
The reactor of the present disclosure is small in size and excellent in productivity. The converter of the present disclosure and the power conversion device of the present disclosure are small in size and excellent in productivity.
[Description of Embodiments of Present Disclosure]
First, embodiments of the present disclosure are listed and described.
In the reactor of the present disclosure, the assembly is so arranged in the case that the exposed surfaces not facing the respective side core portions, out of the outer peripheral surface of the winding portion, face toward the long side parts. This arrangement mode is a called an upright type below. The upright types include a horizontal type and a vertical type. In the horizontal type, the assembly is so accommodated in the case that the exposed surfaces of the winding portion face toward the long side parts of the side wall portion and an axial direction of the winding portion is parallel to the bottom plate portion of the case. In the vertical type, the assembly is so accommodated in the case that the exposed surfaces of the winding portion face toward the long side parts of the side wall portion and the axial direction of the winding portion is perpendicular to the bottom plate portion of the case. On the other hand, in the reactor described in Patent Document 2, the assembly is so accommodated in the case that the exposed surfaces of the winding portion face toward the bottom plate portion and the opening of the case. That is, in the reactor described in Patent Document 2, the assembly is so accommodated in the case that the respective side core portions face the side wall portion of the case. The arrangement mode of the assembly in the reactor described in Patent Document 2 is called a flat type.
Since the exposed surfaces of the winding portion are facing the side wall portion in the reactor of the present disclosure, heat of the coil is easily dissipated to the case. Thus, heat dissipation is better when the arrangement mode of the assembly is the upright type than when the arrangement mode of the assembly is the flat type. In improving heat dissipation, an area of the exposed surfaces of the winding portion is, for example, made larger than an area of surfaces of the winding portion facing the respective side core portions. If the area of the exposed surfaces of the winding portion is larger than the area of the surfaces facing the respective side core portions, an installation area of the assembly with respect to the bottom plate portion of the case can be made smaller when the arrangement mode of the assembly is the upright type than when the arrangement mode of the assembly is the flat type. Such a reactor of the present disclosure is thin and small in size in addition to being excellent in heat dissipation.
In the reactor of the present disclosure, the resin member, which is a constituent member of the assembly, includes the protruding portion projecting toward the one short side part of the side wall portion. The reactor of the present disclosure includes the gap formed by the inner surface of the side wall portion including the one short side part, toward which the protruding portion is facing, and the protruding portion when the case is viewed from above. Since the reactor of the present disclosure includes the gap, a resin, which will become the sealing resin portion, can be filled into the case through the gap with the assembly accommodated in the case in forming the sealing resin portion. For example, the resin can be filled into the case by inserting a nozzle for injecting the resin into the gap and injecting the resin from the bottom plate portion side of the case through the nozzle. The size of the gap can be adjusted according to the size of the protruding portion, and the gap, into which a nozzle of a large diameter is insertable, can be easily formed. If the diameter of the nozzle is large, an operation of filling the resin, which will become the sealing resin portion, can be efficiently performed. Therefore, the reactor of the present disclosure is excellent in productivity.
In the reactor of the present disclosure, the resin can be injected by inserting the nozzle into the gap in forming the sealing resin portion. Thus, in the reactor of the present disclosure, a resin introduction path needs not be provided in the side wall portion of the case and no special processing is necessary for the case. Thus, the reactor of the present disclosure is excellent in the manufacturability of the case and, consequently, excellent in productivity. Further, the resin introduction path needs not be provided in the side wall portion of the case and a thickness of the side wall portion needs not be increased. In the reactor of the present disclosure, the resin can be injected by inserting the nozzle into the gap provided on the side of the one short side part. Thus, in the reactor of the present disclosure, an interval between the side wall portion excluding the one short side part and the assembly can be reduced as compared to the case where the other short side part and the long side parts are provided with protruding portions. Therefore, the reactor of the present disclosure can be reduced in size.
Besides, the following effects can be expected for the reactor of the present disclosure. If the resin is injected by inserting the nozzle into the gap, the resin is injected from the side of the one short side part and flows toward the other short side part. Specifically, the resin injected from the nozzle flows between the assembly and the long side parts from the side of the one short side part and merges on the side of the other short side part. Thus, a merging point of the resin is created at a location distant from a location where the resin was injected. In this case, air bubbles mixed into the resin float up while the resin is flowing from the side of the one short side part toward the side of the other short side part, and the air bubbles in the resin are easily removed. Thus, the remaining of the air bubbles in the sealing resin portion can be reduced by injecting the resin from the side of the one short side part. Further, if the resin is injected from the side of the one short side part, the merging point of the resin is one location on the side of the other short side part. Since the entrainment of air bubbles easily occurs at the merging point of the resin, less merging points are preferable. Since the resin merges at one location by injecting the resin from the side of the one short side part, the remaining of air bubbles is easily reduced.
In the above aspect, the magnetic core can be integrally held and, consequently, the assembly can be integrally held by the molded resin portion. The assembly is obtained by fabricating a set by assembling the coil and the magnetic core and forming the molded resin portion for this set. If the protruding portion is provided on the molded resin portion, the protruding portion can be formed together by the resin, which will become the molded resin portion, in forming the molded resin portion for the set. Therefore, the above aspect is excellent in productivity.
In the above aspect, the winding portion and the magnetic core can be held in a positioned state by the frame-like members. The assembly is obtained by assembling the coil, the magnetic core and the frame-like members. If the protruding portion is provided on the frame-like member, the protruding portion can be formed at a predetermined position of the assembly only by assembling the coil, the magnetic core and the frame-like members. The second frame piece is not arranged between the middle core portion and the side core portions and is located outside the magnetic core. Thus, if the protruding portion is provided on the second frame piece, the protruding portion is easily caused to project toward the one short side part and the shape of the protruding portion is easily simplified.
In the above aspect, an arrangement mode of the assembly is a horizontal type. If the arrangement mode of the assembly is the horizontal type, the both end parts of the winding portion are easily pulled out to the opening side of the case on the sides of the respective short side parts of the case. Further, if the arrangement mode of the assembly is the horizontal type, the assembly is easily reduced in height as compared to the case where the arrangement mode is a vertical type. This is because the exposed surfaces not facing the respective side core portions, out of the outer peripheral surface of the winding portion, are generally longer along the axial direction of the winding portion than along a direction orthogonal to the axial direction of the winding portion.
In the above aspect, the assembly is easily stably supported in the case. Further, in the above aspect, the assembly is easily held at a predetermined position in the case when the resin, which will become the sealing resin portion, is filled into the case.
In the above aspect, the assembly can be positioned with respect to the case by providing the protruding portion on the resin member, which is a constituent member of the assembly. Particularly, a positional deviation of the assembly caused by a flow of the resin can be suppressed by the contact of the protruding portion with the inner surface of the short side part when the resin, which will become the sealing resin portion, is filled into the case. Thus, the above aspect is more excellent in productivity due to the contact of the protruding portion with the inner surface of the short side part.
In the above aspect, the protruding portion includes the hole, and the protruding portion and the sealing resin portion can be firmly joined and, consequently, the assembly and the sealing resin portion can be firmly joined by filling a part of the sealing resin portion in the hole. This is because the first resin portion filled in the hole and the second resin portion provided in contact with the first and second surfaces are caught by the protruding portion. Besides, in the above aspect, a resin filled state on the side of the one short side part can be confirmed through the hole in forming the sealing resin portion by including the hole in the protruding portion. Further, in the above aspect, air bubbles mixed into the resin being filled on the side of the one short side part can be removed through the hole in forming the sealing resin portion by including the hole in the protruding portion. That is, the hole provided in the protruding portion fulfills a function as a confirmation hole for confirming the resin filled state and a function as a deaeration hole for removing air bubbles mixed into the resin when the sealing resin portion is formed. After the sealing resin portion is formed, the hole provided in the protruding portion fulfills a function as a hooking structure for joining the assembly and the sealing resin portion.
In the above aspect, the assembly can be firmly fixed to the case by fastening the protruding portion to the mounting seat. In the above aspect, the detachment of the assembly from the case, for example, due to an impact or vibration can be avoided.
The converter of the present disclosure is small in size and excellent in productivity since including the reactor of the present disclosure.
The power conversion device of the present disclosure is small in size and excellent in productivity since including the converter of the present disclosure.
Specific examples of reactors according to embodiments of the present disclosure are described below with reference to the drawings. In figures, the same reference signs denote the same components. In each figure, some of components may be shown in an exaggerated or simplified manner for the convenience of description. A dimension ratio of each part in figures may be different from an actual one. Note that the present invention is not limited to these illustrations and is intended to be represented by claims and include all changes in the scope of claims and in the meaning and scope of equivalents.
A reactor 1A according to a first embodiment is described with reference to
The sealing resin portion 9 is not shown in
The configuration of the reactor 1A is described in detail below.
[Coil]
As shown in
A coated wire including a conductor wire and an insulation coating can be cited as the winding wire. Copper and the like can be cited as a constituent material of the conductor wire. Resins such as polyamide imide can be cited as a constituent material of the insulation coating. A coated rectangular wire having a rectangular cross-sectional shape, a coated round wire having a circular cross-sectional shape and the like can be cited as the coated wire.
The winding portion 20 of this example is an edgewise coil in the form of a rectangular tube formed by winding a coated rectangular wire in an edgewise manner. Thus, an end surface shape of the winding portion 20 when viewed from the axial direction is a rectangular shape. That is, the winding portion 20 has four flat surfaces and four corners. The corners of the winding portion 20 are rounded. Surfaces of the winding portion 20 other than the corners are substantially constituted by flat surfaces. Thus, as shown in
[Magnetic Core]
As shown in
The shape of the middle core portion 31 substantially corresponds to the inner peripheral shape of the winding portion 20. A gap is present between the inner peripheral surface of the winding portion 20 and the outer peripheral surface of the middle core portion 31. A resin for constituting the molded resin portion 5 to be described later is filled into this gap. In this example, the middle core portion 31 has a square column shape, more specifically a rectangular column shape, and the end surface shape of the middle core portion 31 when viewed from the axial direction is a rectangular shape. Corners of the middle core portion 31 are rounded to extend along the corners of the winding portion 20.
The shapes of the side core portions 32, 33 are not particularly limited if the side core portions 32, 33 are shaped to extend in the axial direction of the winding portion 20 outside the winding portion 20. In this example, the side core portions 32, 33 are in the form of rectangular parallelepipeds extending in the axial direction of the winding portion 20. The side core portions 32, 33 are arranged to face two surfaces located at positions opposite to each other across an axis of the winding portion 20, out of four surfaces constituting the outer peripheral surface of the winding portion 20. That is, the side core portions 32, 33 are arranged to sandwich the two surfaces located at the positions opposite to each other across the axis of the winding portion 20, out of the four surfaces constituting the outer peripheral surface of the winding portion 20, from outer sides. The side core portions 32, 33 are arranged to face the respective upper and lower surfaces of the winding portion 20 in
The shapes of the end core portions 34, 35 are not particularly limited if the end core portions 34, 35 are shaped to connect the end parts of the one middle core portion 31 and the two side core portions 32, 33. In this example, the end core portions 34, 35 are in the form of rectangular parallelepipeds long in an arrangement direction of the one middle core portion 31 and the two side core portions 32, 33.
In the middle core portion 31 and the side core portions 32, 33, surfaces facing in directions orthogonal to both the arrangement direction of the respective core portions 31, 32 and 33 and longitudinal directions of the respective core portions 31, 32 and 33 are flush with each other. In
The magnetic core 3 of this example includes two E-shaped core pieces 3a, 3b as shown in
<Constituent Material>
The magnetic core 3 is constituted by a compact containing a soft magnetic material. Examples of the soft magnetic material include metals such as iron and iron alloy and non-metals such as ferrite. Examples of the iron alloy include a Fe—Si alloy and a Fe—Ni alloy. Powder compacts and compacts of composite materials can be cited as the compact containing the soft magnetic material.
The powder compact is obtained by compression-forming a powder made of a soft magnetic material, i.e. a soft magnetic powder. The powder compact has a higher ratio of the soft magnetic powder occupying the core piece as compared to composite materials. A content of the soft magnetic powder in the powder compact is, for example, more than 80% by volume and, further, 85% by volume if the powder compact is 100% by volume.
In a compact of a composite material, a soft magnetic powder is dispersed in a resin. The compact of the composite material is obtained by filling a raw material, in which the soft magnetic powder is mixed and dispersed in the uncured resin, and solidifying the resin. Magnetic properties such as a relative magnetic permeability and a saturated magnetic flux density of the composite material are easily controlled by adjusting a content of the soft magnetic powder in the resin. A content of the soft magnetic powder in the compact of the composite material is, for example, 30% by volume or more and 80% by volume or less if the composite material is 100% by volume.
The soft magnetic powder is an aggregate of soft magnetic particles. The soft magnetic particles may be coated particles having insulation coatings on the surfaces thereof. Phosphates and the like can be cited as a constituent material of the insulation coating. The resin of the composite material is, for example, a thermosetting resin or thermoplastic resin. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a silicone resin and a urethane resin. Examples of the thermoplastic resin include a polyphenylene sulfide (PPS) resin, a polyamide (PA) resin (e.g. nylon 6, nylon 66 and nylon 9T), a liquid crystal polymer (LCP), a polyimide (PI) resin and a fluororesin. The composite material may contain a filler in addition to the resin. By containing the filler, the heat dissipation of the composite material can be improved. A powder made of a nonmagnetic material such as ceramics and carbon nanotubes can be, for example, utilized as the filler. Examples of the ceramics include oxides, nitrides and carbides of metals or non-metals. Examples of the oxides include alumina, silica and magnesium oxide. Examples of the nitrides include silicon nitride, aluminum nitride and boron nitride. Examples of the carbides include silicon carbide.
[Frame-Like Members]
The reactor 1A of this example includes two frame-like members 4a, 4b. As shown in
The both frame-like members 4a, 4b have the same basic configuration. The frame-like member 4a, 4b includes a pair of first frame pieces 41 and a pair of second frame pieces 42. The first frame pieces 41 are arranged between the middle core portion 31 and the side core portions 32, 33. Further, the first frame pieces 41 are arranged between the end surface of the winding portion 20 and the end core portion 34, 35. That is, the first frame pieces 41 are arranged in spaces constituted by the middle core portion 31, the side core portions 32 and the end core portion 34, 35. The second frame pieces 42 connect the pair of first frame pieces 41 to extend along the exposed surfaces of the winding portion 20. The outer surfaces of the second frame pieces 42 are substantially flush with the exposed surfaces of the winding portion 20. Thus, with the molded resin portion 5 to be described later provided for the set of the coil 2, the magnetic core 3 and the frame-like members 4a, 4b, surfaces of the second frame pieces 42 facing in the same directions as the exposed surfaces are exposed from the middle core portion 5. The outer peripheral surfaces of the frame-like members 4a, 4b are substantially constituted by flat surfaces. Out of the outer peripheral surface of the frame-like member 4a, 4b, the outer surfaces of the pair of second frame pieces 42 are facing the long side parts 823, 824 (
A through hole 40 is constituted by the pair of first frame pieces 41 and the pair of second frame pieces 42. The middle core portion 31 is inserted in the through hole 40. The through hole 40 has a shape substantially corresponding to the outer peripheral shape of the middle core portion 31. The inner peripheral surface of the through hole 40 is provided with cuts partially constituting a gap between the outer peripheral surface of the middle core portion 31 and the inner peripheral surface of the through hole 40 with the middle core portion 31 inserted. The resin for constituting the middle core portion 5 to be described later is filled into the gap constituted by the cuts.
The frame-like member 4a, 4b of this example includes a recess 43 on the side of the end core portion 34, 35. Specifically, surfaces of the first frame pieces 41 on the side of the end core portion 34, 35 are recessed from surfaces of the second frame pieces 42 on the side of the end core portion 34, 35. Edge parts of the end core portion 34, 35 on the side of the winding portion 20 are fit into the recess 43. The end core portion 34, 35 is held in the frame-like member 4a, 4b by this recess 43. The second frame piece 42 is provided with a cut 47 (
Further, the frame-like member 4a, 4b of this example includes an inner projecting piece 45 and outer projecting pieces 46. The inner projecting piece 45 projects toward the winding portion 20 from four corners of the through hole 40. In this example, projecting pieces projecting from two specific adjacent corners, out of the four corners of the through hole 40, are connected. That is, the inner projecting piece 45 of this example is composed of three projecting pieces. The inner projecting piece 45 is formed along the outer peripheral surface of the middle core portion 31. The middle core portion 31 is held in the frame-like member 4a, 4b and an interval between the winding portion 20 and the middle core portion 31 is held by this inner projecting piece 45. The outer projecting pieces 46 are constituted by plate-like pieces projecting toward the winding portion 20 from the outer edges of the first frame pieces 41. The outer projecting pieces 46 are interposed between the winding portion 20 and the side core portions 32, 33. The outer projecting pieces 46 extend up to a central part in the axial direction of the winding portion 20. Insulation between the winding portion 20 and the side core portions 32, 33 is ensured by these outer projecting pieces 46.
<Constituent Material>
Examples of a constituent material of the frame-like members 4a, 4b include electrically insulating materials. Resins are typical examples of the electrically insulating materials. Specific examples of resins include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include an epoxy resin, a phenol resin, a silicone resin, a urethane resin and an unsaturated polyester resin. Examples of thermoplastic resins include a PPS resin, a PA resin, an LCP, a PI resin, a fluororesin, a polytetrafluoroethylene (PTFE) resin, a polybutylene terephthalate (PBT) resin and an acrylonitrile-butadiene-styrene (ABS) resin. The constituent material of the frame-like members 4a, 4b may contain a filler in addition to the resin. By containing the filler, the heat dissipation of the frame-like members 4a, 4b can be improved. A filler similar to the one used in the aforementioned composite material can be utilized as this filler. In this example, the constituent material of the frame-like members 4a, 4b is the PPS resin.
[Molded Resin Portion]
The reactor 1A of this example includes the molded resin portion 5. As shown in
<Constituent Material>
A resin similar to the aforementioned one for constituting the frame-like members 4a, 4b can be utilized as a resin for constituting the molded resin portion 5. The constituent material of the molded resin portion 5 may contain the aforementioned filler in addition to the resin. In this example, the molded resin portion 5 is made of PPS resin.
[Protruding Portion]
As shown in
The position and number of the protruding portion 6 are not particularly limited. The position of the protruding portion 6 along the depth direction of the case 8 is preferably on the side of the opening 83 of the case 8. By locating the protruding portion 6 on the side of the opening 83 of the case 8, the gaps 7 are easily formed. For example, the inner surface of the side wall portion 82 of the case 8 may be inclined to expand from the side of the bottom plate portion 81 toward the side of the opening 83. If the inner surface of the side wall portion 82 is inclined, the interval between the case 8 and the assembly 10 is larger on the side of the opening 83. Thus, the gaps 7 are easily stably formed by locating the protruding portion 6 on the side of the opening 83. Further, the position of the protruding portion 6 along the width direction of the case 8 is preferably a widthwise center of the short side part 821. By providing one protruding portion 6 in the widthwise center of the short side part 821, the protruding portion 6 is easily formed. Further, by providing one protruding portion 6 in the widthwise center of the short side part 821, the gaps 7 are easily stably formed. The position of the protruding portion 6 may be deviated from the center of the short side part 821. It is sufficient to provide at least one protruding portion 6, but a plurality of protruding portions 6 may be provided.
The shape of the protruding portion 6 is not particularly limited. In this example, the protruding portion 6 has a triangular shape in a plan view as shown in
The protruding portion 6 has such a thickness as not to be easily deformed or broken. The thickness here is a dimension in the height direction, i.e. a vertical dimension on the plane of
The protruding portion 6 functions to restrict the position of the assembly 10 in the length direction with respect to the case 8. For example, the tip of the protruding portion 6 in a projecting direction thereof contacts the inner surface of the short side part 821. By the contact of the protruding portion 6 with the inner surface of the short side part 821, the assembly 10 can be satisfactorily positioned with respect to the case 8. Particularly, a positional deviation of the assembly 10 caused by a flow of the resin can be suppressed in forming the sealing resin portion 9.
[Case]
By accommodating the assembly 10 as shown in
The case 8 includes the bottom plate portion 81, the side wall portion 82 and the opening 83. The bottom plate portion 81 is a flat plate member, on which the assembly 10 is placed. The side wall portion 82 is a rectangular frame body for surrounding the assembly 10. The case 8 is a bottomed tubular container in which an accommodation space for the assembly 10 is formed by the bottom plate portion 81 and the side wall portion 82 and the opening 83 is formed on a side facing the bottom plate portion 81. In this example, the bottom plate portion 81 and the side wall portion 82 are integrally formed. The side wall portion 82 has a height equal to or more than that of the assembly 10.
The bottom plate portion 81 of this example is in the form of a rectangular plate. In the bottom plate portion 81, an inner bottom surface on which the assembly 10 is placed is substantially constituted by a flat surface. The side wall portion 82 includes the pair of short side parts 821, 822 and the pair of long side parts 823, 824. The inner surfaces of the short side parts 821, 822 and the long side parts 823, 824 of this example are substantially constituted by flat surfaces. The respective corners formed by the short side parts 821, 822 and the long side parts 823, 824 are constituted by curved surfaces.
A rectangular frame shape of the side wall portion 82 of this example means that the inner peripheral surface of the side wall portion 82 defines a substantially rectangular shape when the case 8 is viewed from above. The rectangular shape here may not be rectangular in a geometrically strict sense and may be included in a range regarded as substantially rectangular including rectangular shapes with rounded corners or chamfered corners. For example, this range includes a rectangular shape with corners formed by curved surfaces having a relatively large radius of curvature as in the side wall portion 82 of this example.
The inner surface of the side wall portion 82 may be inclined to expand from the side of the bottom plate portion 81 toward the side of the opening 83. More specifically, at least either the inner surfaces of the long side parts 821, 822 or the inner surfaces of the long side parts 823, 824 of the side wall portion 82 may be inclined to be more spaced apart from each other from the side of the bottom plate portion 81 toward the side of the opening 83. That is, at least one of the inner surfaces of the short side parts 821, 822 and the long side parts 823, 824 may be inclined outwardly of the case 8 with respect to a perpendicular direction to the inner bottom surface of the bottom plate portion 81. Note that the above perpendicular direction is equivalent to the height direction of the case 8.
If the respective inner surfaces of the short side parts 821, 822 and the long side parts 823, 824 are inclined to be more spaced apart from each other from the side of the bottom plate portion 81 toward the side of the opening 83, an operation of the accommodating the assembly 10 into the case 8 is easily performed in a manufacturing process of the reactor 1A. Further, in the case of manufacturing the case 8 made of metal by die casting, an operation of removing the case 8 from a mold is easily performed since at least one of the respective inner surfaces of the short side parts 821, 822 and the long side parts 823, 824 is inclined. In this example, all the inner surfaces of the short side parts 821, 822 and the long side parts 823, 824 are inclined to expand the inner surface of the side wall portion 82 from the side of the bottom plate portion 81 toward the side of the opening 83 as shown in
Angles of inclination between the respective inner surfaces of the short side parts 821, 822 and the long side parts 823, 824 and a perpendicular to the inner bottom surface of the bottom plate portion 81 can be appropriately selected. The angles of inclination are, for example, 0.5° or more and 5° or less and, further, 1° or more and 2° or less. If the angles of inclination are too large, the interval between the outer peripheral surface of the assembly 10 and the inner peripheral surface of the side wall portion 82 becomes larger on the side of the opening 83. If the above interval is too large, heat of the assembly 10 on the side of the opening 83 is unlikely to be efficiently dissipated to the case 8. Thus, too large angles of inclination are not preferable also in terms of heat dissipation. Therefore, an upper limit of the angles of inclination is set to be 5° or less and, further, 2° or less.
A length of the case 8 is, for example, 80 mm or more and 120 mm or less and, further, 90 mm or more and 115 mm or less. A width of the case 8 is, for example, 30 mm or more and 80 mm or less and, further, 35 mm or more and 70 mm or less. A height of the case 8 is, for example, 70 mm or more and 140 mm or less and, further, 80 mm or more and 130 mm or less. The length of the case 8 is a length in the lateral direction on the planes of
<Constituent Material>
The case 8 is made of nonmagnetic metal. Examples of nonmagnetic metal include aluminum, alloys thereof, magnesium and alloys thereof, copper and alloys thereof, silver and alloys thereof and austenite-based stainless steels. These metals are relatively high in thermal conductivity. Thus, the case 8 can be used as a heat dissipation path, and the heat of the assembly 10 is efficiently dissipated to outside via the case 8. Therefore, the heat dissipation of the assembly 10 is improved. Besides metals, resins and the like can be used as the material for constituting the case 8.
The case 8 made of metal can be, for example, manufactured by die casting. The case 8 of this example is constituted by a die cast product made of aluminum.
[Arrangement Mode of Assembly]
An arrangement mode of the assembly 10 with respect to the case 8 is a horizontal type. In this case, as shown in
Further, if the outer peripheral surface of the winding portion 20 are substantially constituted by flat surfaces as in this example, a facing area of the winding portion 20 and the side wall portion 82 can be increased. Thus, the reactor 1A can efficiently utilize the case 8 as a heat dissipation path. Therefore, the reactor 1A easily dissipates the heat of the coil 2 to the case 8 and is excellent in the heat dissipation of the assembly 10.
An interval between the inner surface of the side wall portion 82 excluding the one short side part 821 and the outer surface of the assembly 10 is, for example, 0.5 m or more and 1.5 mm or less and, further, 0.5 mm or more and 1 mm or less. This interval is an interval between a part of the assembly 10 closest to the side wall portion 82 and the short side part 822 and the long side parts 823, 824 of the side wall portion 82. As described later, if the respective inner surfaces of the short side part 822 and the long side parts 823, 824 of the side wall portion 82 are inclined, a minimum value may be adopted as the above interval. Since this interval is 0.5 mm or more, the resin, which will become the sealing resin portion 9, flows between the assembly 10 and the side wall portion 82. On the other hand, since the interval is 1.5 mm or less and, further, 1 mm or less, the case 8 is easily reduced in size. Further, since interval is 1.5 mm or less and, further, 1 mm or less, the interval between the outer surface of the winding portion 20 and the inner surface of the side wall portion 82 is reduced, wherefore the heat dissipation of the assembly 10 can be improved.
[Gaps]
As shown in
In forming the sealing resin portion 9, a nozzle 100 for injecting the resin, which will become the sealing resin portion 9, is inserted into the gap 7 as shown in
[Sealing Resin Portion]
The sealing resin portion 9 is filled into the case 8 and seals at least a part of the assembly 10. The assembly 10 can be mechanically protected and protected from an external environment by the sealing resin portion 9. Protection from the external environment aims to improve corrosion resistance and the like.
In this example, the sealing resin portion 9 is filled up to an opening end of the case 8 and the entire assembly 10 is embedded in the sealing resin portion 9. Only a part of the assembly 10 may be sealed by the sealing resin portion 9. For example, out of the assembly 10, the entire winding portion 20 may be embedded in the sealing resin portion 9 and a member located closer to the opening 83 than the winding portion 20, i.e. a part of the molded resin portion 5, may be exposed from the sealing resin portion 9. The sealing resin portion 9 is interposed between the winding portion 20 and the side wall portion 82 of the case 8. In this way, the heat of the coil 2 can be transferred to the case 8 via the sealing resin portion 9. Thus, the heat dissipation of the assembly 10 is improved.
<Constituent Material>
Examples of the resin of the sealing resin portion 9 include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include an epoxy resin, a urethane resin, a silicone resin and an unsaturated polyester resin. Examples of thermoplastic resins include a PPS resin. The sealing resin portion 9 of this example is made of silicone resin, more specifically, silicone gel. The higher the thermal conductivity of the sealing resin portion 9, the more preferable. The reason for this is that the heat of the coil 2 is easily transferred to the case 8. Thus, the material for constituting the sealing resin portion 9 may contain, for example, a filler as described above in addition to the above resin. Components of the above material may be adjusted to enhance the thermal conductivity of the sealing resin portion 9. The thermal conductivity of the sealing resin portion 9 is, for example, preferably 1 W/m·K or more and, further, 1.5 W/m·K or more.
Besides, an unillustrated adhesive layer may be provided between the assembly and the bottom plate portion 81. The adhesive layer can firmly fix the assembly 10 to the case 8. The adhesive layer is, for example, made of electrically insulating resin. Examples of the electrically insulating resin for constituting the adhesive layer include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include an epoxy resin, a silicone resin and an unsaturated polyester resin. Examples of thermoplastic resins include a PPS resin and LCP. The material for constituting the adhesive layer may contain the above filler in addition to the resin. The adhesive layer may be formed by using a commercially available adhesive sheet or commercially available adhesive.
<<Manufacturing Method>>
Mainly with reference to
In the first step, the assembly 10 and the case 8 are prepared.
In the second step, the assembly 10 is accommodated into the case 8.
In the third step, the sealing resin portion 9 is formed in the case 8.
[First Step]
In the first step, the assembly 10 and the case 8 are prepared. As shown in FIG. 3, the assembly 10 is obtained by fabricating a set by assembling the coil 2, the magnetic core 3 and the frame-like portions 4a, 4b and forming the molded resin portion 5 (
The prepared case 8 is, for example, made of nonmagnetic metal. The case 8 of this example is a die-cast product made of aluminum.
[Second Step]
In the second step, the assembly 10 is accommodated into the case 8 through the opening 83 of the case 8. The assembly 10 is so accommodated in the case 8 that the arrangement mode of the assembly 10 is the horizontal type described above. Specifically, as shown in
[Third Step]
In the third step, the resin is filled into the case 8 to form the sealing resin portion 9 shown in
The resin is filled by inserting the nozzle 100 into the gap 7 formed by the inner surface of the short side part 821 of the side wall portion 82, the inner surface of the long side part 823 and the protruding portion 6 as shown in
If the resin is poured from the side of the opening 83 of the case 8, air bubbles are easily mixed into the resin and tend to remain in the sealing resin portion 9. Particularly, the air bubbles tend to remain in the sealing resin portion 9 on the side of the bottom plate portion 81. If the nozzle 100 is inserted into the gap 7 and the resin is injected from the side of the bottom plate portion 81 to the side of the opening 85, air bubbles are hardly mixed into the resin and hardly remain in the sealing resin portion 9. Particularly, it can be avoided that the air bubbles remain in the sealing resin portion 9 on the side of the bottom plate portion 81. Thus, the sealing resin portion 9 can be satisfactorily filled into the case 8.
In the case of this example, the protruding portion 6 provided on the molded resin portion 5 contacts the short side part 821 of the side wall portion 82, whereby a state where the assembly 10 is positioned with respect to the case 8 can be maintained. Thus, a positional deviation of the assembly 10 an be effectively suppressed at the time of filling the resin, which will become the sealing resin portion 9.
If the nozzle 100 is inserted into the gap 7 provided on the side of the one short side part 821 and the resin is injected as shown in
Although the case where the nozzle 100 is inserted into one gap 7 on the side of the long side part 823 and the resin is injected is illustrated in the example of
The resin is preferably injected by placing the case 8 accommodating the assembly 10 in a vacuum tank and injecting the resin in a vacuum state. The generation of air bubbles in the sealing resin portion 9 can be suppressed by injecting the resin in the vacuum state.
By solidifying the resin after the resin is filled into the case 8, the sealing resin portion 9 shown in
<<Effects>>
The reactor 1A of the first embodiment achieves the following effects.
The reactor 1A includes the protruding portion 6 provided on the molded resin portion 5 and the gaps 7 formed by the one short side part 821, the long side parts 823, 824 and the protruding portion 6. Thus, in forming the sealing resin portion 9, the resin, which will become the sealing resin portion 9, can be filled by inserting the nozzle 100 into the gap 7. The size of the gap 7 can be adjusted according to the size of the protruding portion 6. Thus, even if the diameter of the nozzle 100 is large, the gap 7 corresponding to the diameter of the nozzle 100 can be easily formed. If the diameter of the nozzle 100 is large, a resin filling operation can be efficiently performed. Therefore, the productivity of the reactor 1A is excellent.
In forming the sealing resin portion 9, the resin can be injected by inserting the nozzle 100 into the gap 7. Thus, a resin introduction path needs not be provided in the side wall portion 82 of the case 8 and no special processing is necessary for the case 8. Therefore, the reactor 1A can reduce the manufacturing cost of the case 8.
The protruding portion 6 is integrally molded to the molded resin portion 5. The assembly 10 is obtained by fabricating the set by assembling the coil 2, the magnetic core 3 and the frame-like members 4a, 4b and forming the molded resin portion 5 for this set. If the protruding portion 6 is provided on the molded resin portion 5, the protruding portion 6 can be formed together by the resin, which will become the molded resin portion 5, in forming the molded resin portion 5 for the set. Therefore, the reactor 1A in which the protruding portion 6 is constituted by the molded resin portion 5 is excellent in productivity.
The protruding portion 6 and the gaps 7 are provided only on the side of the one short side part 821. Thus, the interval between the side wall portion 82 excluding the one short side part 821 and the assembly 10 can be reduced. Therefore, the reactor 1A can be reduced in size.
A reactor 1B according to a second embodiment is described with reference to
[Arrangement Mode of Assembly]
The arrangement mode of the assembly 10 with respect to the case 8 is the vertical type. In this case, as shown in
If the arrangement mode of the assembly 10 is the vertical type, a protruding portion 6 extends in a direction orthogonal to the axial direction of the winding portion 20 as shown in
A reactor 1C according to a third embodiment is described with reference to
A sealing resin portion 9 is not shown in
[Protruding Portion]
Second frame pieces 42 in the one frame-like member 4a include the protruding portions 6 projecting toward one short side part 821. The protruding portion 6 is an integrated component integrally molded to the frame-like member 4a. The protruding portion 6 is provided on a surface of the second frame pieces 42 on the side of an end core portion 34. The frame-like member 4a includes a pair of second frame pieces 42 (
In the reactor 1C including the protruding portions 6 on the frame-like member 4a, the gap 7 (
A reactor 1D according to a fourth embodiment is described with reference to
[Protruding Portion]
Second frame pieces 42 in the one frame-like member 4a include the protruding portions 6 projecting toward one short side part 821. The protruding portion 6 is an integrated component integrally molded to the frame-like member 4a. The protruding portion 6 is provided on a surface of the second frame pieces 42 on the side of a side core portion 32. The frame-like member 4a includes a pair of second frame pieces 42 (
In the reactor 1D including the protruding portions 6 on the frame-like member 4a, the gap 7 (
A reactor 1E according to a fifth embodiment is described with reference to
[Protruding Portion]
As shown in
The through hole 63 of this example is constituted by a circular hole having a uniform diameter. The through hole 63 may be formed into a tapered shape having a diameter gradually decreasing from the side of the first surface 61 toward the side of the second surface 62. A part of the sealing resin portion 9 is filled into the through hole 63. Thus, by forming the through hole 63 into a tapered shape, a larger contact area of the protruding portion 6 and the sealing resin portion 9 is easily secured as compared to a circular hole uniformly formed to have a diameter on a small side. Further, by forming the through hole 63 into a tapered shape, the sealing resin portion 9 is easily caught in a region leading to the first surface 61 from the tapered surface. A cross-sectional shape of the through hole 63 is not limited to a circular shape and may be a polygonal shape.
[Sealing Resin Portion]
The sealing resin portion 9 includes a first resin portion 91 filled in the through hole 63 provided in the protruding portion 6 and a second resin portion 92 provided in contact with the first and second surfaces 61, 62. The first and second resin portions 91, 92 constitute an integrated object by being continuously provided.
The reactor 1E of the fifth embodiment includes the through hole 63 in the protruding portion 6, and the protruding portion 6 and the sealing resin portion 6 can be firmly joined and, consequently, the assembly 10 and the sealing resin portion 9 can be firmly joined by filling a part of the sealing resin portion 9 in the through hole 63. This is because the first resin portion 91 filled in the through hole 63 and the second resin portion 92 provided in contact with the first and second surfaces 61, 62 are caught by the protruding portion 6.
Besides, in the reactor 1E of the fifth embodiment, a resin filled state on the side of one short side part 821 can be confirmed through the through hole 63 in forming the sealing resin portion 9 by including the through hole 63 in the protruding portion 6. Further, in the reactor 1E of the fifth embodiment, air bubbles mixed into the resin being filled on the side of the one short side part 821 can be removed through the through hole 63 in forming the sealing resin portion 9 by including the through hole 63 in the protruding portion 6.
A reactor 1F according to a sixth embodiment is described with reference to
[Mounting Seat]
As shown in
[Protruding Portion]
As shown in
The protruding portion 6 may further include another unillustrated through hole in addition to the through hole 64 overlapping the screw hole 85 of the mounting seat 84. A part of a sealing resin portion 9 is filled into the other through hole. The other through hole, into which the part of the sealing resin portion 9 is filled, has a function of the through hole 63 described in the fifth embodiment.
In this example, as shown in
In the reactor 1F of the sixth embodiment, the assembly 10 can be firmly fixed to the case 8 by fastening the protruding portion 6 to the mounting seat 84. Thus, the reactor 1F can avoid the detachment of the assembly 10 from the case 8, for example, due to an impact, vibration or the like. Further, in this example, the mounting seat 84 is formed to extend from the base plate portion 81 toward the opening 83 along the inner surface of the short side part 821. In the reactor 1F, since the mounting seat 84 is present in the case 8, a volume of the case 8 is reduced as compared to the reactor 1A of the first embodiment. Thus, a used amount of a resin, which will become the sealing resin portion 9, is reduced in the reactor 1F as compared to the reactor 1A. Thus, the reactor 1F can reduce manufacturing cost since the used amount of the expensive resin, which will become the sealing resin portion 9, is reduced.
A reactor 1G according to a seventh embodiment is described with reference to
[Projections]
As shown in
The numbers, positions and shapes of the projections 68, 69 are not particularly limited and can be appropriately selected. For example, one projection 68 may be provided or a plurality of the projections 68 may be provided. In this example, two first projections 68 are provided at an interval in a length direction on each of the surfaces of the molded resin portion 5 facing the both long side parts 823, 824. Further, one projection 69 is provided in a widthwise center on the surface of the molded resin portion 5 facing the short side part 822. The positions of the projections 68, 69 along a depth direction of the case 8 are preferably on the side of an opening 83 of the case 8. If the projections 68, 69 are located on the side of the opening 83, the assembly 10 is easily stably supported in the case 8. The projection 68, 69 has a hemispherical shape. A projecting amount of the projection 68, 69 can be appropriately set according to an interval between the outer peripheral surface of the molded resin portion 5 and the long side parts 823, 824 and the short side part 822 of a side wall portion 82. The projecting amount of the projection 68, 69 is, for example, 0.5 mm or more and 1.5 mm or less.
In the reactor 1G of the seventh embodiment, the interval between the outer peripheral surface of the assembly 10 and the inner peripheral surface of the side wall portion 82 is easily properly maintained by including the projections 68, 69 on the outer peripheral surface of the molded resin portion 5. The projections 68, 69 may be in contact with the inner peripheral surface of the side wall portion 82. By the contact of the projections 68 with the respective inner surfaces of the long side parts 823, 824, the assembly 10 is easily positioned in the width direction with respect to the case 8. Further, by the contact of the projection 69 with the inner surface of the short side part 822, the assembly 10 is easily positioned in the length direction with respect to the case 8. Particularly, if the inner peripheral surface of the side wall portion 82 is inclined to expand from the side of a bottom plate portion 81 toward the side of the opening 83, the projections 68, 69 respectively contact the inner surfaces of the long side parts 823, 824 and the inner surface of the short side part 822, whereby excessive inclination of the assembly 10 in the case 8 can be suppressed.
The respective reactors according to the first to seventh embodiments can be utilized in an application satisfying the following energization conditions. The energization conditions are, for example, a maximum direct current of about 100A or more 1000A or less, an average voltage of about 100 V or more and 1000 V or less, and a use frequency of about 5 kHz or more and 100 kHz or less. The respective reactors according to the first to seventh embodiments can be utilized as a constituent component of a converter to be placed in a vehicle such as an electric or hybrid vehicle and as a constituent component of a power conversion device including this converter.
A vehicle 1200 such as an electric or hybrid vehicle includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210 and a motor 1220 utilized for running by being driven by power supplied from the main battery 1210 as shown in
The power conversion device 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110 for mutual conversion of a direct current and an alternating current. The converter 1110 shown in this example feeds power to the inverter 1120 by stepping up an input voltage of the main battery 1210 of about 200 V to 300 V to about 400 V to 700 V. The converter 1110 charges the main battery 1210 by stepping down the input voltage output from the motor 1220 via the inverter 1120 at the time of regeneration to a direct-current voltage compatible with the main battery 1210. The input voltage is a direct-current voltage. The inverter 1120 feeds power to the motor 1220 by converting a direct current stepped up by the converter 1110 into a predetermined alternating current during the running of the vehicle 1220, and converts the alternating current output from the motor 1220 into a direct current and outputs the converted direct current to the converter 1110 at the time of regeneration.
The converter 1110 includes a plurality of switching elements 1111, a driving circuit 1112 for controlling the operation of the switching elements 1111 and a reactor 1115, and converts an input voltage by being repeatedly turned on and off as shown in
The vehicle 1200 includes a power feeder converter 1150 connected to the main battery 1120 and an auxiliary equipment power supply converter 1160 connected to a sub-battery 1230 serving as a power supply for auxiliary equipment 1240 and the main battery 1210 and configured to convert a high voltage of the main battery 1210 into a low voltage. The converter 1110 typically performs a DC-DC conversion, but the power feeder converter 1150 and the auxiliary equipment power supply converter 1160 perform an AC-DC conversion. Some of the power feeder converters 1150 may perform a DC-DC conversion. Reactors configured similarly to the reactor of any one of the first to seventh embodiments and having the sizes, shapes and the like thereof changed as appropriate can be utilized as reactors of the power feeder converter 1150 and the auxiliary equipment power supply converter 1160. Further, the reactor of any one of the first to seventh embodiments can also be utilized in a converter for converting an input voltage and only stepping up or stepping down the voltage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-229734 | Dec 2019 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/046172 | 12/10/2020 | WO |
