JP2022170059A - Reactor and method for manufacturing reactor - Google Patents

Abstract

To provide a reactor which is reduced in the size while reducing separation of a split core, and a method for manufacturing the reactor.SOLUTION: A reactor 1 includes a coil 2, a core 3, and a mold resin 5. The coil 2 is formed by winding a conductive wire 21, the core 3 is mounted with the coil 2 and is formed by connecting a plurality of split cores 41, and a mold resin 5 coats and is integrated with the coil 2 and the core 3. Each of the mold resin 5 and the split cores 41 has a recess 6 and a projection 7 for connecting the split cores 41 through the mold resin 5 by fitting. The recess 6 is deep in a direction orthogonal to arrangement of the split cores 41, and the projection 7 projects in a direction orthogonal to arrangement of the split cores 41, and is distributed and fit into the mold resin 5 side and the split cores 41 side.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a reactor having a coil and a core and a manufacturing method for manufacturing the reactor.

A reactor mainly consists of a coil and a core. When energized, the coil generates magnetic flux according to the number of turns. The core forms a closed magnetic circuit through which the magnetic flux generated by the coil passes according to a magnetic permeability higher than that of a vacuum. In other words, a reactor is an electromagnetic component that converts electrical energy into magnetic energy for storage and release.

Such reactors are used in a wide variety of applications. Typical reactors include step-up reactors, series reactors, parallel reactors, current limiting reactors, starting reactors, shunt reactors, neutral point reactors and arc extinguishing reactors.

A boost reactor is incorporated in a vehicle booster circuit such as a drive system for a hybrid vehicle or an electric vehicle. A series reactor is connected in series with the motor circuit to limit the current during a short circuit. A parallel reactor stabilizes current sharing between parallel circuits. A current limiting reactor is connected to limit the current during a short circuit. The starting reactor is connected in series with the motor circuit protecting the machine to limit the starting current. The shunt reactor is connected in parallel to the transmission line to compensate for phase-advancing reactive power and suppress abnormal voltage. A neutral point reactor is connected between the neutral point and the ground and used to limit the ground fault current that flows in the event of a ground fault in the power system. The arc extinguishing reactor automatically extinguishes an arc that occurs when a single-line ground fault occurs in a three-phase power system.

This reactor includes a mold resin that simultaneously coats and integrates the coil and the core. By integrating the coil and the core, the mold resin suppresses the vibration of the reactor and further protects the insulating coating that protects the conductive wires of the coil.

In addition, the core is divided into a plurality of pieces, and the divided cores are sometimes formed in a row (see, for example, Patent Document 1). Split cores are joined by adhesive or the like at their split surfaces, but this requires time and effort to apply and dry the adhesive, which has been a factor in increasing the number of man-hours and manufacturing time.

Therefore, the mold resin extends to the back surface of the split core region, which is farthest from the adjacent split core along the direction in which the split cores are arranged, and holds the core so as to sandwich it from the direction in which the split cores are arranged. As a result, even if the split cores are not bonded to each other, the split cores do not separate from each other or vibrate individually, and the number of manufacturing steps and manufacturing time can be reduced.

JP 2019-110232 A

In recent years, the integration of circuit components has progressed remarkably, for example, in in-vehicle applications, and further miniaturization of reactors is expected. Mold resin constitutes the outermost shell of the reactor. Therefore, if it is possible to limit the areas of the coil and the core covered with the mold resin, it contributes to the miniaturization of the reactor.

However, if the split cores are not bonded, if the cores cannot be sandwiched by the molding resin in the direction in which the split cores are arranged, the split cores will collide with each other due to vibration and become a source of noise. The core separates and the magnetic permeability of the core changes. Even if the split cores are joined, if the mold resin cannot hold the cores in the direction in which the split cores are arranged, the adhesive will peel off, and the split cores will collide with each other due to vibration, causing noise, and in the worst case. In the case of (2), the split core separates and the magnetic permeability of the core changes.

The present invention has been proposed to solve the above problems, and an object of the present invention is to provide a reactor that is downsized while suppressing the risk of split core separation, and a method for manufacturing this reactor.

In order to achieve the above object, a reactor according to an embodiment of the present invention includes a coil formed by winding a conductive wire, a core on which the coil is mounted and formed by connecting a plurality of split cores, and the coil. a mold resin that coats and integrates with the core, and the mold resin and the split cores each have recesses and protrusions that connect the split cores to each other through the mold resin by fitting. The recess is deep in a direction orthogonal to the arrangement of the split cores, the protrusion protrudes in a direction orthogonal to the arrangement of the split cores, and the recess and the protrusion are located on the mold resin side and the split core. Distributed and fitted on the core side.

The split core has a rear surface farthest from the adjacent split core along the direction in which the adjacent split cores are arranged, and the mold resin exposes the entire rear surface of the split core. can be

The core has a ring shape formed by connecting the split cores, and the mold resin covers a boundary region including the boundary of the split cores on the ring inner peripheral surface of the core, and the recess and the recess. The convex portion may be formed on the outer peripheral surface covering the boundary region on the side of the split core and the boundary region on the side of the mold resin.

The mold resin may have a flange that covers an edge of the ring-shaped surface of the core that is in contact with the ring inner peripheral surface of the core.

The mold resin may expose the outer peripheral surface of the core.

The split cores may be connected in a non-bonded manner.

The split core has a split core main body through which the magnetic flux passes, and a split core coating resin that covers the split core main body. It may be formed on the surface of resin.

A method for manufacturing a reactor is also an aspect according to an embodiment of the present invention. In order to achieve the above object, a method for manufacturing a reactor according to an embodiment of the present invention includes a split core main body through which a magnetic flux passes, which is coated with a split core coating resin. a core molding step of forming a split core by coating, and a secondary molding step of forming a mold resin on the core in which the split cores are connected and the coil attached to the core, wherein the core molding step Then, deep recesses are formed in the split core coating resin in a direction orthogonal to the arrangement of the split cores, and in the secondary molding step, a mold having a gate hole at a position facing the recesses or in the vicinity of the recesses is used. 2. The molding resin is characterized by forming a convex portion that fits into the concave portion.

ADVANTAGE OF THE INVENTION According to this invention, even if it limits the area|region of a coil and a core covered with mold resin, the possibility that a split core may separate can be suppressed and a reactor can be reduced in size.

FIG. 2 is a perspective view of a reactor omitting mold resin; 3 is an exploded perspective view of the core; FIG. FIG. 4 is a perspective view showing a reactor containing mold resin; FIG. 4 is a top view showing a reactor containing mold resin; It is a perspective view showing a core. FIG. 4 is a cross-sectional view of the core cut along the direction in which split cores are arranged; It is a perspective view of mold resin, (a) is a perspective view seen from one direction, and (b) is a perspective view seen from a direction rotated 90 degrees with respect to the perspective view of (a). FIG. 3 is a cross-sectional view of the reactor cut along the direction in which split cores are arranged; It is a perspective view which shows the formation process of mold resin.

A reactor according to an embodiment of the present invention will be described below with reference to the drawings. In each drawing, the thickness, size, positional relationship, ratio, shape, etc. may be emphasized for easy understanding, and the present invention is not limited to such emphasis.

FIG. 1 is a perspective view showing the main configuration of the reactor of the present embodiment, and for convenience of explanation, the mold resin 5 (see FIG. 3, etc.) is omitted. Reactor 1 includes coil 2 and core 3 . Coil 2 is fitted on core 3 . This coil 2 generates magnetic flux according to the number of turns when energized. The core 3 is a closed magnetic circuit through which the magnetic flux generated by the coil 2 passes according to a magnetic permeability higher than that of a vacuum. That is, the reactor 1 is an electromagnetic component that converts electrical energy into magnetic energy, stores and releases the magnetic energy. The core 3 has a plurality of fixing portions 49 through which bolts can be inserted.

The coil 2 is a wound body in which a conductive wire 21 such as a copper wire is wound in a cylindrical shape. The conductive wire 21 is coated with an insulating coating such as enamel coating. The coil 2 is formed by spirally winding the conductive wire 21 along the winding axis while shifting the winding position for each turn. Conductive wires 21 are pulled out from the winding start and winding end of the coil 2 . A conductive wire 21 drawn out from the coil 2 is welded to a bus bar 22 which is a conductive member. The busbar 22 is, for example, a long plate of copper or the like, and a terminal block 23 connected to an external circuit is formed at the tip of the busbar 22 . The coil 2 is supplied with current from the outside through the busbar 22 and generates a magnetic flux penetrating along the winding axis.

The core 3 is formed by connecting two split cores 41 with their end faces 44 facing each other. The two split cores 41 are non-bonded. That is, the end faces 44 are butted against each other without being coated with an adhesive, the end faces 44 are only in contact with each other, and the two split cores 41 are not joined. For non-bonding, the end faces 44 of the split cores 41 are butted against each other without an adhesive, and an air gap is formed between the split core main bodies 42 so that the split core coating resins 43 are in contact with each other without being joined. Aspects are also included.

FIG. 2 is an exploded perspective view of the core 3. FIG. As shown in FIG. 2 , the core 3 has a middle leg 31 , two outer legs 32 and a pair of yokes 33 . The middle leg 31 has a smaller diameter than the inner diameter of the coil 2, extends the same as or slightly longer than the entire length of the coil 2, and the coil 2 is fitted therein. The outer legs 32 extend on both sides of the middle leg 31 and are parallel to the middle leg 31 on the same plane as the middle leg 31 . The yoke 33 is arranged separately at both ends of the middle leg 31 and both outer legs 32 , is perpendicular to the middle leg 31 and both outer legs 32 , and connects the middle leg 31 and both outer legs 32 . Such a core 3 has an approximate θ shape in which two annular shapes having a common center leg 31 are connected.

Both split cores 41 are formed by dividing the center of the middle leg 31 and both outer legs 32 of the core 3 so that the middle leg 31 and both outer legs 32 are perpendicular to each other, and have an approximate E shape. The core 3 is formed by arranging the split cores 41 with the end surfaces 44 of the split cores 41 facing each other, separating the rear surfaces 48 of the split cores 41 , and connecting the two split cores 41 . Each split core 41 comprises a split core main body 42 and a split core coating resin 43 .

The split core main body 42 includes a magnetic material such as a powder magnetic core, a ferrite magnetic core, a metal composite core, or a laminated steel plate. A powder magnetic core is obtained by annealing a powder compact formed by compacting magnetic powder. The magnetic powder is mainly composed of iron, and includes pure iron powder, iron-based permalloy (Fe--Ni alloy), Si-containing iron alloy (Fe--Si alloy), sendust alloy (Fe--Si--Al alloy), Amorphous alloys, nanocrystalline alloy powders, mixed powders of two or more of these powders, and the like are included. A metal composite core is a core formed by kneading and molding magnetic powder and resin.

The split core main body 42 also has an E-shape to match the shape of the split core 41 . The split core main body 42 may have an E-shape as a seamless one-piece unit, or may be subdivided into a plurality of blocks, and each block may be connected to match the shape of the split core 41 . It may be made to form an E shape.

The split core coating resin 43 covers the split core body 42 except for the end face 44 of the split core body 42 , and the split core coating resin 43 has an E shape corresponding to the shape of the split core 41 . there is The split core coating resin 43 has insulating properties and heat resistance, and the split core coating resin 43 may be mixed with a thermally conductive filler.

Examples of the material of the split core coating resin 43 include epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or a combination thereof.

3 is a perspective view showing the reactor 1 containing the mold resin 5, and FIG. 4 is a top view showing the reactor 1 containing the mold resin 5. As shown in FIG. As shown in FIGS. 3 and 4, the reactor 1 further includes a mold resin 5 that coats and integrates the coil 2 and the core 3 . The mold resin 5 has insulating properties and heat resistance, and the mold resin 5 may be mixed with a thermally conductive filler.

The material of the molding resin 5 includes epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or a combination thereof.

The mold resin 5 is formed by injection molding with the coil 2 and the core 3 accommodated in a mold. This mold resin 5 flows around the coil 2 and covers the entire surface of the coil 2 including the inner and outer peripheries. However, it is not necessary to cover the entire surface of the coil 2 with the mold resin 5, and a flat plate 53 may be placed on a partial surface of the coil 2 and covered with the flat plate 53. The mold resin 5 adheres to the entire peripheral edge of the flat plate 53 and covers the entire other surface of the coil 2 .

In addition, the mold resin 5 covers the inner peripheral surface 45 (see FIG. 2) of the core 3 which does not affect the size increase of the reactor 1 . The inner peripheral surface 45 of the core 3 is defined by one surface of the outer leg 32 facing the middle leg 31, two surfaces of the middle leg 31 facing the outer leg 32, and one surface of the yoke 33 sandwiched between these surfaces. be done. Among them, the mold resin 5 covers at least one surface of the outer leg 32 facing the middle leg 31 .

Further, the mold resin 5 is in contact with the inner peripheral surface 45 of the core 3 among the annular surfaces 46 (see FIG. 2) of the core 3 in order to prevent vibration that oscillates in the direction orthogonal to the middle leg 31 and both outer legs 32. It has a flange 51 overlying the edge region. The annular surface 46 of the core 3 is parallel to the plane on which the middle leg 31 and the outer leg 32 are arranged.

However, the mold resin 5 does not expose and cover the entire area of the rear surface 48 (see FIG. 2) of the split core 41 in order to reduce the size of the reactor 1 . The back surface 48 is the surface farthest from the other split cores 41 along the alignment direction 9 of the split cores 41 . Preferably, the mold resin 5 does not cover the entire area of the outer peripheral surface 47 (see FIG. 2) of the core 3 to expose it so as to further reduce the size of the reactor 1 . An outer peripheral surface 47 of the core 3 is a surface located opposite to the inner peripheral surface 45 .

Here, FIG. 5 is a perspective view showing the core 3, and FIG. 6 is a cross-sectional view of the core 3 taken along the direction 9 in which the split cores 41 are arranged. As shown in FIGS. 5 and 6 , the split core 41 has recesses 6 . The recesses 6 are formed in the vicinity of the end surfaces 44 of the outer legs 32 on the inner peripheral surface 45 of each split core 41 , and extend in a groove shape so as to connect the two annular surfaces 46 . . As for the core 3 as a whole, two cores are formed on each of the outer legs 32 with the end face 44 interposed therebetween, so that a total of four cores 3 are formed. The recess 6 is deep in a direction perpendicular to the alignment direction 9 of the split cores 41 . That is, the recess 6 has an inner wall surface perpendicular to the alignment direction 9 of the split cores 41 .

On the other hand, FIG. 7 is a perspective view of the mold resin, (a) is a perspective view seen from one direction, and (b) is a view seen from a direction rotated 90 degrees with respect to the perspective view of (a). It is a perspective view. As shown in FIG. 7 , the mold resin 5 has projections 7 . The convex portion 7 protrudes in a direction perpendicular to the alignment direction 9 of the split cores 41 . The convex portion 7 is formed on the outer peripheral surface 52 covering the inner peripheral surface 45 of the outer leg 32 of the split core 41 and protrudes toward the inner peripheral surface 45 .

As shown in FIG. 8, which is a cross-sectional view of the reactor 1 cut along the direction 9 in which the split cores 41 are arranged, the protrusions 7 of the mold resin 5 are fitted with the recesses 6 of the split cores 41. there is Therefore, each split core 41 is positionally fixed with the mold resin 5 as a reference in the alignment direction 9 of the split cores 41 . Therefore, even if the split cores 41 are not bonded to each other and the mold resin 5 does not extend so as to embrace both back surfaces 48 of the core 3, the split cores 41 approach or separate from each other along the alignment direction 9. The fear of change is contained.

In this way, the concave portion 6 and the convex portion 7 can be formed on any surface of the core 3 covered with the mold resin 5 in order to maintain the state in which the split cores 41 are connected via the mold resin 5 . For example, the recesses 6 are formed on the annular surface 46 and the outer peripheral surface 47 of the core 3 , and the mold resin 5 covers the annular surface 46 and the outer peripheral surface 47 and has the protrusions 7 at locations corresponding to the recesses 6 . You may have This also makes it possible to make the reactor more compact than a reactor in which the mold resin 5 extends so as to hold both rear surfaces 48 of the core 3 .

However, it is particularly preferable to cover the inner peripheral surface 45 of the core 3 with the molding resin 5 and provide the recesses 6 and the protrusions 7 on the inner peripheral surface 45 of the core 3 and the outer peripheral surface 52 of the molding resin 5 . This is because even if the inner peripheral surface 45 of the core 3 is covered with the mold resin 5 , the reactor 1 does not become large, and the reactor 1 can be further miniaturized.

The above-described reactor 1 undergoes a core molding process for manufacturing the split cores 41 and a secondary molding process for forming the core 3 by connecting the split cores 41 and integrating the coil 2 and the core 3 with the mold resin 5. manufactured.

In the core molding step, if metal collars or the like are inserted into the split core body 42 or the fixing portion 49 in addition to the split core body 42 in the mold for the split core coating resin 43, the metal collars or the like are accommodated. Then, the resin material of the split core covering resin 43 is injected into the mold. As a result, the split core 41 is produced by coating the split core main body 42 with the split core coating resin 43 in which the recess 6 is formed.

If the split core main body 42 is, for example, a powder magnetic core, the split core main body 42 is pressed into the shape of the split core main body 42 after forming a single layer or a multi-layer insulating coating on the soft magnetic powder. It is produced by molding and firing the pressure-molded body.

In the secondary molding process, the busbars 22 are welded to the coils 2 , the coils 2 and the busbars 22 are fitted into the split cores 41 , and the split cores 41 are accommodated side by side in the mold for the molding resin 5 . A flat plate 53 is put on the coil 2 . The mold for the mold resin 5 consists of an upper mold and a lower mold, and the flat plate 53 is interposed between the coil 2 and the upper mold as a cushioning material so that the surface of the coil 2 is not damaged by the upper mold. is doing. When the mold is closed, the coil 2 is pressed by the mold through the flat plate 53 and is supported so as to suppress positional displacement within the mold, and the unevenness and twist of the surface of the coil 2 are corrected. be.

FIG. 9 is a perspective view showing the coil 2 and the core 3 accommodated in the mold of the mold resin 5 and showing the process of forming the mold resin 5. As shown in FIG. As shown in FIG. 9, when the mold is closed, the resin material of the mold resin 5 is injected into the mold. The gate hole 8 for injecting the resin material of the mold resin 5 can be arranged at various positions, but at least it can be arranged corresponding to the recess 6 formed in the split core 41 .

The gate hole 8 faces the annular surface 46 side opening of the recess 6 , and the resin material of the mold resin 5 is efficiently poured into the recess 6 . Therefore, the mold resin 5 is formed with the protrusions 7 in close contact with the recesses 6 without gaps. Therefore, the split cores 41 are precisely fitted and fixed without rattling. The gate hole 8 may be formed so that the resin material of the mold resin 5 can be efficiently poured into the concave portion 6, and the gate hole 8 should be located near the concave portion 6 even if there is no precision in facing the opening of the concave portion 6 on the side of the annular surface 46. Just do it.

Due to the presence of the gate holes 8, dome-shaped gate traces 54 are generated at both ends of each protrusion 7 so as to be caught on the annular surface 46 of the core 3 (see, for example, FIGS. 3 and 7). . The gate mark 54 makes it difficult for the protrusion 7 to crack due to vibration, and prevents the protrusion 7 from being damaged and detached from the recess 6 . The gate mark 54 may be formed in a dome shape, or in a mortar shape with a recessed center portion.

Thus, the reactor 1 of this embodiment includes the coil 2 , the core 3 and the mold resin 5 . The coil 2 is formed by winding a conductive wire 21, the core 3 is formed by connecting the coil 2 and a plurality of split cores 41 in a row, and the mold resin 5 covers the coil 2 and the core 3 and integrates them. become At this time, each of the mold resin 5 and the split core 41 has a concave portion 6 and a convex portion 7 that connect the split cores 41 to each other through the mold resin 5 by fitting. The concave portion 6 is deep in the direction perpendicular to the row of the split cores 41, and the convex portion 7 protrudes in the direction perpendicular to the row of the split cores 41. The mold resin 5 side and the split core 41 side are distributed and fitted together. there is

Thus, even if the rear surface 48 farthest from the adjacent split cores 41 along the alignment direction 9 with the split cores 41 is completely exposed without being held by the mold resin 5, the split cores 41 may be separated. can be suppressed, and the reactor 1 can be miniaturized.

In the present embodiment, the two E-shaped split cores 41 are connected to form the core 3 having a substantially θ shape, but the shape and division manner of the core 3 are not limited to this. For example, the core 3 may be formed by a split core 41 that serves as the middle leg 31 , a split core 41 that serves as the outer leg 32 , and a split core 41 that serves as the yoke 33 . The alignment direction 9 is determined for each set of two adjacent split cores 41 .

For example, a concave portion 6 is provided in each of the middle leg 31 and the yoke 33 so as to be orthogonal to the alignment direction 9 of the divided core 41 of the middle leg 31 and the divided core 41 of one yoke 33, and covers the middle leg 31 and the yoke 33. Protrusions 7 to be fitted with these recesses 6 may be formed on the mold resin 5 . Further, the mold resin 5 may be provided with the concave portion 6 of the outer leg 32 and the convex portion 7 that fits with the concave portion 6 of the yoke 33 on the other side.

Further, the core 3 is composed of, for example, a total of three split cores 41 of first to third, and the third split core 41 is continuous from the direction perpendicular to the alignment direction 9 of the first and second split cores 41 . may be In this case, deep concave portions 6 and convex portions 7 in a direction perpendicular to the alignment direction 9 of the first and second split cores 41 may be distributed to the first and second split cores 41 and the mold resin 5. good. Further, another concave portion 6 and a convex portion 7 deep in a direction perpendicular to the arrangement direction 9 in which the third split core 41 and the first or second split core 41 are arranged are formed in the third split core 41 and the first split core 41 . Alternatively, it may be provided separately to the second split core 41 and the mold resin 5 .

Further, in the present embodiment, the recess 6 is formed in the split core 41 and the protrusion 7 is provided in the mold resin 5, but the present invention is not limited to this. That is, the split core 41 may be provided with the protrusions 7 and the mold resin 5 may be provided with the recesses 6 . Further, one split core 41 is provided with a concave portion 6, a mold resin 5 is provided with a convex portion 7 for fitting with this split core 41, and the other split core 41 is provided with a convex portion 7, and this split core 41 is provided with a convex portion 7. A concave portion 6 may be provided in the mold resin 5 for fitting with the mold resin 5 .

The core 3 has an annular shape formed by connecting the split cores 41 , and the concave portion 6 and the convex portion 7 are formed on the inner peripheral surface 45 of the split core 41 and the outer peripheral surface 52 of the mold resin 5 . made it Even if the inner peripheral surface 45 of the core 3 is covered with the mold resin 5, the reactor 1 does not become large, and both the downsizing of the reactor 1 and the separation prevention of the split core 41 can be satisfactorily achieved. That is, for example, the mold resin 5 exposes the rear surface 48 of the split core 41 and also exposes the outer peripheral surface 47 of the core 3 , thereby further miniaturizing the reactor 1 .

In order to prevent the separation of the split cores 41, at least the mold resin 5 should be applied only to the areas of the inner peripheral surface 45 of the core 3 where the fitting structure with the concave portions 6 and the convex portions 7 is to be formed. should be covered. Among the inner peripheral surfaces 45 of the split cores 41, the boundary regions of the separation of the split cores 41 are preferable among the inner peripheral surfaces 45 of the core 3 as the regions where the fitting structure is formed by the concave portions 6 and the convex portions 7. The possibility of separation of the split core 41 can be further suppressed.

The separation boundary of the split cores 41 is the portion where the end faces 44 face each other. The boundary region is a region extending to both sides along the outer leg 32 across the boundary of this separation, and does not have to extend over the entire length of the outer leg 32 . In other words, it is not essential that the mold resin 5 covers the entire outer leg 32 portion of the inner peripheral surface 45, and it is not essential that the yoke 33 region of the inner peripheral surface 45 is covered. Furthermore, it is not essential to cover the area of the middle leg 31 of the inner peripheral surface 45 .

Further, the mold resin 5 has a flange 51 that covers the edge of the annular surface 46 of the core 3 that is in contact with the inner peripheral surface 45 of the core 3 . As a result, even if the area of the mold resin 5 is reduced to downsize the reactor 1, the vibration amplitude in the direction orthogonal to the annular surface 46 of the core 3 can be suppressed.

In this embodiment, the split cores 41 are arranged in a row without joining. The non-bonded split cores 41 are easy to separate and are particularly useful for the reactor 1 provided with the concave portion 6 and the convex portion 7, but the split cores 41 may be bonded. Even if the end faces 44 of the split cores 41 are bonded to each other with an adhesive, there is a risk that the adhesive will come off due to vibration and the split cores 41 will separate. Therefore, even in the reactor 1 to which the split cores 41 are joined, it is possible to reduce the size of the reactor 1 while suppressing the separation of the split cores 41 .

Here, non-joining includes a mode in which the end faces 44 of the split cores 41 are butted against each other without an adhesive, and an air gap is formed between the split core main bodies 42 and the split core coating resins 43 are butted against each other. It is something that can be done.

Moreover, the method for manufacturing such a reactor 1 includes a core molding process and a secondary molding process. In the core molding step, split core bodies 42 through which magnetic flux passes are coated with split core coating resin 43 to fabricate split cores 41 . In the secondary molding process, the mold resin 5 is formed on the core 3 in which the split cores 41 are connected and the coil 2 attached to the core 3 . In this core molding step, deep recesses 6 are formed in the split core coating resin 43 in a direction perpendicular to the arrangement of the split cores 41. A mold having a gate hole 8 is used to form a convex portion 7 fitted with a concave portion 6 in a mold resin 5 .

Thereby, the resin material of the mold resin 5 is sufficiently filled in the concave portion 6, and the convex portion 7 can be formed in close contact with the concave portion 6 without a gap. Therefore, it is possible to reduce the risk that the split core 41 will rattle and that the reactor 1 will generate noise.

The above embodiments of the present invention are presented as examples, and are not limited to the above embodiments. The above embodiment can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. The embodiments and modifications thereof are included in the scope of the present invention.

1 Reactor 2 Coil 21 Conductive wire 22 Bus bar 23 Terminal block 3 Core 31 Middle leg 32 Outer leg 33 Yoke 41 Split core 42 Split core main body 43 Split core covering resin 44 End surface 45 Inner peripheral surface 46 Annular surface 47 Outer peripheral surface 48 Rear surface 49 Fixed Part 5 Mold resin 51 Flange 52 Peripheral surface 53 Flat plate 54 Gate mark 6 Concave part 7 Protruding part 8 Gate hole 9 Alignment direction

Claims (8)

a coil formed by winding a conductive wire;
a core on which the coil is mounted and which is formed by connecting a plurality of split cores;
a molding resin that coats and integrates the coil and the core;
with
each of the mold resin and the split core has a concave portion and a convex portion that connect the split cores to each other through the mold resin by fitting;
The recess is deep in a direction perpendicular to the arrangement of the split cores, and the protrusion protrudes in a direction perpendicular to the arrangement of the split cores,
The concave portion and the convex portion are distributed and fitted to the mold resin side and the split core side,
A reactor characterized by each of the split cores has a back surface that is farthest from the adjacent split cores along the direction in which the adjacent split cores are arranged;
The mold resin exposes the entire back surface of the split core;
The reactor according to claim 1, characterized by: The core has a ring shape formed by connecting the split cores,
The mold resin covers a boundary region including a boundary between the split cores on the ring inner peripheral surface of the core,
The concave portion and the convex portion are formed on an outer peripheral surface covering the boundary region on the side of the split core and the boundary region on the side of the mold resin;
The reactor according to claim 2, characterized by: The mold resin has a flange that covers an edge of the ring-shaped surface of the core that is in contact with the ring inner peripheral surface of the core,
The reactor according to claim 3, characterized by: the mold resin exposing the outer peripheral surface of the core;
The reactor according to claim 3 or 4, characterized by: the split cores are connected in a non-bonded manner;
The reactor according to any one of claims 1 to 5, characterized by: The split core has a split core main body through which the magnetic flux passes, and a split core covering resin covering the split core main body,
The concave portion or the convex portion distributed to the split core side is formed on the surface of the split core coating resin;
The reactor according to any one of claims 1 to 6, characterized by: a core molding step of manufacturing a split core by coating a split core main body through which magnetic flux passes with a split core coating resin;
a secondary molding step of forming molding resin on the core in which the split cores are connected and the coil attached to the core;
including
In the core molding step, deep recesses are formed in the split core coating resin in a direction orthogonal to the arrangement of the split cores,
In the secondary molding step, a mold having a gate hole at a position facing the recess or in the vicinity of the recess is used to form, in the mold resin, a protrusion that fits into the recess;
A method for manufacturing a reactor, characterized by:

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