Method for manufacturing a reactor and reactor
The method secures the reactor components by adhesive bonding with X, Y, and Z-direction restricting portions, addressing vibration-induced stress and preventing welded joint damage, while improving heat dissipation.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TAMURA KK
- Filing Date
- 2024-11-25
- Publication Date
- 2026-06-04
AI Technical Summary
Reactor components experience excessive stress and potential damage at the welded joint due to vibrations, resulting from dimensional tolerances and clearance between convex and concave parts, which can lead to failure in environments subject to vibration.
A method involving the use of adhesive to join molded core and coil components, with specific adhesive application and curing processes to create X, Y, and Z-direction restricting portions, ensuring secure bonding and restricting movement in three axes, thereby preventing stress on the welded joint.
The method effectively prevents damage to the welded joint between the busbar and lead wire by securely joining the molded core and coil, even in vibrating environments, while maintaining productivity and enhancing heat dissipation.
Smart Images
Figure 2026091383000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing a reactor including a mold core and a mold coil, and a reactor.
Background Art
[0002] Reactors are used in various applications such as OA equipment, solar power generation systems, automobiles, and uninterruptible power supplies. A reactor is an electromagnetic component that converts electrical energy into magnetic energy for storage and release.
[0003] A reactor includes a core and a coil. The core is a magnetic body and has an annular shape. The coil is attached to the core. A lead wire is drawn out from the coil, and the lead wire is connected to a bus bar for electrically connecting to an external device by welding. Power is supplied from the external device to the coil through the bus bar, and the coil generates a magnetic flux. The core serves as a magnetic path for the magnetic flux generated by the coil.
[0004] In order to insulate the core and the coil, the core and the coil may be respectively injection molded and combined to form a mold core and a mold coil to produce a reactor. For example, a convex portion is provided on the mold core, while a concave portion corresponding to the convex portion is provided on the mold coil, and the reactor is produced by fitting the convex portion of the mold core into the concave portion of the mold coil.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0006] Due to dimensional tolerances and other reasons, there is a certain clearance between the convex and concave parts even when they are fitted together. On the other hand, reactors are sometimes installed in environments that vibrate, such as automobiles. Therefore, when reactors are installed in environments where vibrations occur, the molded core and molded coil may move by the amount of the clearance, and excessive stress may be placed on the welded joint connecting the busbar and lead wire due to the vibration, potentially causing damage.
[0007] The present invention was made to solve the above problems, and its objective is to provide a method for manufacturing a reactor and a reactor that firmly joins the molded core and molded coil and prevents damage to the welded joint between the busbar and the lead wire. [Means for solving the problem]
[0008] The present invention provides a method for manufacturing a reactor, comprising: a molded core manufacturing step of producing a pair of molded cores by molding at least a portion of a core member with core mold resin; a molded coil manufacturing step of producing a molded coil by molding at least a portion of a coil with coil mold resin; an bonding step of joining the molded core and the molded coil with an adhesive; and a welding step of connecting the lead wires of the coil and a busbar fixed to the molded core by welding, wherein the core member has a plurality of leg portions and a yoke portion connecting the leg portions, and the coil is mounted on the leg portions, and The bonding process includes an application step of applying the adhesive to the joint surface of the leg portion of the core member and the inner circumferential surface of the yoke portion of the core member or the molded coil facing the inner circumferential surface of the yoke portion; a pressing step of spreading the applied adhesive; and a curing step of curing the adhesive, wherein the pressing step is characterized by spreading the adhesive applied to the joint surface so that it overflows onto at least one of the upper and lower surfaces of the leg portion, and at least one of the inner side surface of the leg portion which is the surface where the leg portions face each other, and the outer side surface which is the surface opposite the inner side surface, and adheres to the molded coil.
[0009] The reactor of the present invention comprises a pair of molded cores covering at least a portion of a core member with core mold resin, a molded coil covering at least a portion of a coil with coil mold resin, an adhesive for joining the molded cores and the molded coil, and a busbar fixed to the molded core and connected to the lead wires of the coil by welding, wherein the core member has a plurality of legs and a yoke portion connecting the legs, the coil is mounted on the legs, and the adhesive is positioned between the joining surfaces of the legs and forms a core joining portion for joining the core member. The device is characterized by having: an X-direction restricting portion disposed between the inner circumferential surface of the yoke portion and the molded coil, and joining the inner circumferential surface and the molded coil; a Y-direction restricting portion disposed between at least one of the inner side surface of the leg portion, which is the surface on which the leg portions face each other, and the outer side surface, which is the surface opposite to the inner side surface, and the molded coil, and joining the inner side surface or the outer side surface to the molded coil; and a Z-direction restricting portion disposed between at least one of the upper surface and the lower surface of the leg portion and the molded coil, and joining the upper surface or the lower surface to the molded coil. [Effects of the Invention]
[0010] According to the present invention, a method for manufacturing a reactor and a reactor can be obtained that firmly joins the molded core and molded coil and prevents damage to the welded joint between the busbar and the lead wire. [Brief explanation of the drawing]
[0011] [Figure 1] This is a perspective view showing the overall structure of the reactor. [Figure 2] This is a perspective view showing the overall structure of the mold core. [Figure 3] This is a perspective view of the core component. [Figure 4] This is a perspective view of a molded coil. [Figure 5] This is a perspective view of the coil. [Figure 6] This is a magnified view of the protruding part. [Figure 7] This is a schematic diagram showing the location where adhesive is formed. [Figure 8] This diagram shows how to apply adhesive to the joining surfaces. [Modes for carrying out the invention]
[0012] [Embodiment] A reactor according to an embodiment will be described with reference to the drawings. Figure 1 is a perspective view showing the overall configuration of reactor 10. In each drawing, thickness, dimensions, positional relationships, ratios, or shape may be emphasized for ease of understanding, and the present invention is not limited to such emphasis.
[0013] The winding axis direction of coil 6 is the X direction shown in Figure 1, the direction in which the legs of the core member are aligned is the Y direction shown in Figure 1, also referred to as the width direction, and the direction perpendicular to the winding axis direction and the width direction is the Z direction shown in Figure 1, also referred to as the height direction.
[0014] The reactor 10 is an electromagnetic component that converts electrical energy into magnetic energy for storage and release, and is used in various applications such as office automation equipment, solar power generation systems, and automobiles. The reactor 10 comprises a pair of molded cores 1a and 1b and a molded coil 5.
[0015] Figure 2 is a perspective view showing the overall configuration of molded cores 1a and 1b. Molded cores 1a and 1b are manufactured by molding core members 21 and 22 that constitute core 2 with core mold resin 3.
[0016] Core 2 can be made of a compacted magnetic core, a ferrite core, laminated steel sheet, or a metal composite core. A metal composite core is a magnetic material formed by mixing magnetic powder and resin, and then hardening the resin.
[0017] The core 2 consists of a pair of core members 21 and 22. The core members 21 and 22 are of the same shape and size. FIG. 3 is a perspective view of the core member 21. The core member 21 has a U-shaped configuration having a pair of leg portions 23 extending in the winding axis direction and a yoke portion 24 connecting the pair of leg portions 23. A coil 6 is mounted on the leg portion 23.
[0018] The tip surface of the leg portion 23 has a joint surface 231, an inner curved surface 232, and an outer curved surface 233. The tip surface of the leg portion 23 is an end surface orthogonal to the winding axis direction and is the end surface on the opposite side connected to the yoke portion 24. The joint surface 231 is a flat surface. The joint surface 231 is disposed closer to the inner curved surface 232 side than the central position in the width direction (Y direction) of the leg portion 23. That is, the central position in the width direction of the joint surface 231 is disposed closer to the inner curved surface 232 side than the central position in the width direction of the leg portion 23. By joining the joint surfaces 231 of the core members 21 and 22, the core 2 becomes an annular shape. The core 2 forms a closed magnetic path through which the magnetic flux generated by the coil 6 passes.
[0019] In this embodiment, a spacer 25 is provided between the joint surfaces 231 of the core members 21 and 22 (see FIG. 2). As the spacer 25, a non-magnetic material, ceramic, non-metal, resin, carbon fiber, or a composite material of two or more of these or gap paper can be used. By joining the core members 21 and 22 via the spacer 25 in this way, a magnetic gap having a predetermined width is provided to prevent a decrease in the inductance of the reactor 10. Alternatively, the core members 21 and 22 may be directly joined with an adhesive without providing a gap.
[0020] The inner curved surface 232 is located at the inner corner of the tip surface of the leg portion 23. The inner curved surface 232 is positioned between the joint surface 231 and the inner side surface 236 (described later), connecting the joint surface 231 and the inner side surface 236. The inner curved surface 232 is curved. The outer curved surface 233 is located at the outer corner of the tip surface of the leg portion 23. The outer curved surface 233 is positioned between the joint surface 231 and the outer side surface 237 (described later), connecting the joint surface 231 and the outer side surface 237. In other words, the joint surface 231 is located between the inner curved surface 232 and the outer curved surface 233. The bending radius of the inner curved surface 232 is smaller than the bending radius of the outer curved surface. That is, the outer curved surface 233 is more gently curved than the inner curved surface 232. Also, the surface area of the inner curved surface 232 is smaller than the surface area of the outer curved surface 233. The inner side indicates the direction toward the center of the reactor 10, while the outer side indicates the direction away from the center of the reactor 10.
[0021] The leg portion 23 has an upper surface 234 and a lower surface 235 perpendicular to the height direction. The upper surface 234 and the lower surface 235 are flat surfaces. The upper surface 234 and the lower surface 235 are each connected to the joint surface 231. The leg portion 23 also has an inner side surface 236 and an outer side surface 237 perpendicular to the width direction. The inner side surface 236 is the surface on which the pair of leg portions 23 face each other, and the outer side surface 237 is the surface on the opposite side of the inner side surface 236. The inner side surface 236 and the outer side surface 237 are flat surfaces. The inner side surface 236 is connected to the inner curved surface 232. The outer side surface 237 is connected to the outer curved surface 233.
[0022] The yoke portion 24 connects the pair of leg portions 23. The yoke portion 24 is covered with core mold resin 3. However, the inner circumferential surface 241 of the yoke portion 24 is not covered with core mold resin 3 and is exposed. The inner circumferential surface 241 of the yoke portion 24 is the surface perpendicular to the winding shaft and is the surface (formed between the leg portions 23) that faces the annular surface 61 of the coil 6, which will be described later.
[0023] Returning to Figure 2, the core mold resin 3 is formed by molding the core members 21 and 22, respectively. The core mold resin 3 is integrated with the core members 21 and 22. As shown in Figure 2, it covers a portion of the core members 21 and 22. In this embodiment, the core mold resin 3 covers only the yoke portion 24 of the core member 2. In other words, the leg portion 23 of the core member 2 is not covered by the core mold resin 3 and is exposed. Also, the core mold resin 3 does not cover the inner circumferential surface 241 of the yoke portion 24, and the inner circumferential surface 241 is exposed.
[0024] The core mold resin 3 is made of resin. Examples of the resins used for the core mold resin 3 include epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or composites thereof. A thermally conductive filler may also be mixed into the resin. In this embodiment, PPS is used for the core mold resin 3.
[0025] The molded core 1a has busbars 4a. The busbars 4a are, for example, plate-shaped conductive members such as copper or aluminum. The busbars 4a are covered with core mold resin 3 and fixed to the molded core 1a. The busbars 4a are connected to the lead wires 62 of the coil 6 by welding. The busbars 4a are also connected to the connection terminals of external equipment. The reactor 10 is electrically connected to the external equipment via the busbars 4a.
[0026] Figure 4 is a perspective view of the molded coil 5. Figure 5 is a perspective view of the coil 6. The molded coil 5 has a coil 6 and a coil molding resin 7. The molded coil 5 is manufactured by molding the coil 6 with the coil molding resin 7.
[0027] Coil 6 is composed of a single flat, rectangular conductive member insulated with enamel or the like. Coil 6 is formed by winding the conductive member in a cylindrical shape while shifting the winding position in the direction of the winding axis. In this embodiment, it is an edgewise coil made of a flat rectangular copper wire. However, the type of wire and winding method of coil 6 are not limited to this and may be of other forms.
[0028] Two coils 6 are provided. The two coils 6 are arranged side by side so that their outer surfaces, which extend along the winding axis, face each other. Each coil 6 has an annular surface 61 perpendicular to the winding axis. From each coil 6, a lead wire 62, which forms the end of a conductive member, is drawn out from one of the annular surfaces 61. Each lead wire 62 is connected to the busbars 4a and 4b by welding. The coils 6 are energized via the busbars 4a and 4b and generate magnetic flux.
[0029] The coil 6 is surrounded by an upper cover 63, an inner circumferential cover 64, and a lower cover 65. The upper cover 63, inner circumferential cover 64, and lower cover 65 are made of resin. The upper cover 63 covers the upper surface of the coil 3. The inner circumferential cover 64 covers the inner circumferential surface and one annular surface 61 of the coil 6. In this embodiment, the portion of the inner circumferential cover 64 that covers the inner circumferential surface of the coil 6 is not covered by the coil mold resin 8. That is, the inner circumference of the molded coil 5 is formed by the inner circumferential cover 64. The lower cover 65 covers the lower surface and the other annular surface 61 of the coil 6. By covering the coil 6 with the upper cover 63, inner circumferential cover 64, and lower cover 65, direct contact between the coil 6 and the mold, pressing member, jig, or injected resin is prevented during molding.
[0030] The coil molding resin 7 coats the coil 6 either directly or via various covers 63, 64, and 65. The coil molding resin 7 is made of resin. Examples of the resin used for the coil molding resin 7 include epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or composites thereof. A thermally conductive filler may also be mixed into the resin.
[0031] As shown in Figure 4, the coil mold resin 7 has protrusions 71. There are two protrusions 71. Each protrusion 71 is provided on the end face of the coil mold resin 7 perpendicular to the winding shaft. More specifically, the protrusions 71 are provided between the annular surfaces 61 of a pair of coils 6. The protrusions 71 are provided in the central part of the height direction of the reactor 10. The protrusions 71 extend from the end face of the coil mold resin 7 perpendicular to the winding shaft toward the inner circumferential surface 241 of the yoke portion 24. That is, the protrusions 71 face the inner circumferential surface 241 of the yoke portion 24.
[0032] Figure 6 is an enlarged view of the protrusion 71. The protrusion 71 is a rectangular flat plate shape, although it is not limited to this. However, the protrusion 71 has multiple grooves 72 formed in it. The grooves 72 cut out the protrusion 71. The depth of the grooves 72 is shorter than the protruding length of the protrusion 71. In other words, the grooves 72 do not cut out to the bottom surface of the protrusion 71, that is, to the end surface of the coil mold resin 7 where the protrusion 71 is not formed.
[0033] The groove 72 has a plurality of vertical grooves 721 and a plurality of horizontal grooves 722. The vertical grooves 721 extend in the height direction. The plurality of vertical grooves 721 are arranged at equal intervals. In this embodiment, three vertical grooves 721 are formed. The horizontal grooves 722 extend in the width direction. That is, the horizontal grooves 722 extend perpendicularly to and intersect with the vertical grooves 721. The plurality of horizontal grooves 722 are arranged at equal intervals. In this embodiment, six horizontal grooves 722 are formed. In this way, the projection 71 is formed in a grid pattern by the vertical grooves 721 and horizontal grooves 722.
[0034] The molded coil 5 has a busbar 4b. The busbar 4b is covered with coil molding resin 7 and fixed to the molded coil 5. The busbar 4b is connected to the lead wires 62 of the coil 6 by welding. The busbar 4b is also connected to the connection terminals of external equipment.
[0035] The molded cores 1a, 1b and molded coil 5 are fixed together by adhesive 8. In this embodiment, epoxy resin is used as the adhesive 8, but other adhesives may be used. Figure 7 is a schematic diagram showing the formation locations of the adhesive 8. As shown in Figure 7, the adhesive 8 has a core joint portion 81, an X-direction restricting portion 82, a Y-direction restricting portion 83, and a Z-direction restricting portion 84. The core joint portion 81, the X-direction restricting portion 82, the Y-direction restricting portion 83, and the Z-direction restricting portion 84 are formed when the adhesive 8 hardens during the curing process described later.
[0036] The core joint portion 81 is formed between the joint surfaces 231 of the leg portions 23 of the core members 21 and 22. The core joint portion 81 abuts against each joint surface 231 and joins the core members 21 and 22. In this embodiment, since a spacer 25 is interposed between each joint surface 231, the core joint portion 81 is formed between the joint surface 231 of the core member 21 and the spacer 25, and between the joint surface 231 of the core member 22 and the spacer 25. Therefore, the core joint portion 81 abuts against each joint surface 231 and the spacer 25, and the core members 21 and 22 are joined via the spacer 25.
[0037] The X-direction restricting portion 82 is formed between the inner circumferential surface 241 of the yoke portion 24 of the core members 21 and 22 and the protruding portion 71 of the coil mold resin 7. The X-direction restricting portion 82 is in contact with the inner circumferential surface 241 and the protruding portion 71. The X-direction restricting portion 82 is also formed inside the vertical groove 721 and horizontal groove 722 of the protruding portion 71. The X-direction restricting portion 82 joins and fixes the inner circumferential surface 241 of the mold cores 1a and 1b and the protruding portion 71 of the mold coil 5. The X-direction restricting portion 82 may be formed to extend beyond the size of the protruding portion 71.
[0038] The Y-direction restricting portion 83 is formed between at least one of the inner side surface 236 and outer side surface 237 of the core members 21 and 22 and the inner circumferential surface of the molded coil 5 (the inner circumferential surface cover 64 that covers the inner circumferential surface of the coil 6). In this embodiment, the Y-direction restricting portion 83 is formed only on the inner side surface 236. The Y-direction restricting portion 83 is in contact with the inner side surface 236 and the inner circumferential surface cover 64 of the core members 21 and 22. The Y-direction restricting portion 83 extends across the inner side surfaces of both core members 21 and 22. That is, the Y-direction restricting portion 83 is also in contact with the inner curved surface 232 and the spacer 25 of the core members 21 and 22, and is also formed in the space defined by the inner curved surface 232 of the core members 21 and 22, the spacer 25 and the inner circumferential surface cover 64. The Y-direction restricting portion 83 joins and fixes the inner side surface 236 of the molded cores 1a and 1b and the inner circumferential surface cover 64 of the molded coil 5. The Y-direction restricting section 83 is connected to the core joint section 81.
[0039] The Z-direction restricting portion 84 is formed between at least one of the upper surface 234 and lower surface 235 of the core members 21 and 22 and the inner circumferential surface cover 64 that covers the inner circumferential surface of the coil 6. In this embodiment, the Z-direction restricting portion 84 is formed on the surfaces of both the upper surface 234 and lower surface 235 of the core members 21 and 22. The Z-direction restricting portion 84 is in contact with the upper surface 234 and lower surface 235 of the core members 21 and 22 and the inner circumferential surface cover 64. The Z-direction restricting portion 84 extends across the upper surface 234 and lower surface 235 of the core members 21 and 22, respectively. That is, the Z-direction restricting portion 84 is also in contact with the upper and lower surfaces of the core joint portion 81 and the spacer 25. The Z-direction restricting portion 84 joins and fixes the upper surface 234 and lower surface 235 of the molded cores 1a and 1b to the inner circumferential surface cover 64 of the molded coil 5.
[0040] In this embodiment, the reactor 10 is further equipped with a sensor 9. The sensor 9 measures a physical quantity of the reactor 10. For example, the sensor 9 can be a thermistor whose electrical resistance changes with temperature. However, the sensor 9 is not limited to a thermistor and may be a magnetic sensor, current sensor, thermal fuse, or other type of sensor.
[0041] [Manufacturing method] Next, the method for manufacturing the reactor 10 in this embodiment will be described. The method for manufacturing the reactor 10 includes a mold core manufacturing step, a mold coil manufacturing step, an adhesion step, and a welding step.
[0042] The mold core manufacturing process involves creating mold cores 1a and 1b by mold molding. A core member 21 is placed in a mold, and core mold resin 3 is injected into the mold. Molded core 1a is then manufactured by curing the core mold resin 3. Similarly, molded core 1b is manufactured by placing a core member 22 in a mold, injecting core mold resin 3 into the mold, and curing the core mold resin 3. When manufacturing molded core 1a, the busbar 4a is also placed in the mold and molded together with the core member 21, thereby fixing the busbar 4a to molded core 1a.
[0043] The molded coil manufacturing process is the process of manufacturing a molded coil 5 by molding. The coil 6 and busbar 4b are placed in a mold, and coil mold resin 7 is injected into the mold. The molded coil 5 is then manufactured by curing the coil mold resin 7.
[0044] Furthermore, the mold core manufacturing process and the mold coil manufacturing process can be performed in either order. Also, the mold core manufacturing process and the mold coil manufacturing process can be performed simultaneously.
[0045] The bonding process involves joining and fixing the mold cores 1a and 1b and the mold coil 5 with adhesive 8. The bonding process includes a coating step, a pressing step, and a curing step.
[0046] The coating process involves applying adhesive 8 to the mold cores 1a and 1b and the mold coil. First, adhesive 8 is applied to the inner circumferential surface 241 of the yoke portion 24 of the mold core 1a and the joint surface 231 of the leg portion 23. Figure 8 shows how to apply adhesive 8 to the joint surface 231. As shown in Figure 8, adhesive 8 is applied to the central part of the joint surface 231, near the edge on the upper surface 234 side of the leg portion 23, near the edge on the lower surface 235 side, and near the edge on the inner side surface 236 side. The amount of adhesive 8 applied to the joint surface 231 is such that, by the pressing process, the adhesive 8 applied to the joint surface 231 will overflow onto the upper surface 234, lower surface 235, and inner side surface 236 of the leg portion 23, and fill the gap between the upper surface 234, lower surface 235, and inner side surface 236 of the leg portion 23 and the inner circumferential surface of the mold coil 5.
[0047] Next, the molded coil 5 is inserted into the leg portion 23 of the molded core 1a. At this time, the adhesive 8 applied to the inner circumferential surface 241 of the molded core 1a adheres to the protruding portion 71 of the molded coil 5. After inserting the molded coil 5 to the predetermined position, the spacer 25 is inserted into the inner circumference of the molded coil 5 so that it adheres to the adhesive 8 applied to the joint surface 231.
[0048] Finally, adhesive 8 is applied to the inner circumferential surface 241 of the yoke portion 24 of the mold core 1b and the joint surface 231 of the leg portion 23. As with the mold core 1a, adhesive 8 is applied to the central part of the joint surface 231, near the edge on the upper surface 234 side of the leg portion 23, near the edge on the lower surface 235 side, and near the edge on the inner side surface 236 side, as shown in Figure 8. Then, the mold core 1b is inserted into the mold coil 5. The mold core 1b is inserted until the adhesive 8 applied to the inner circumferential surface 241 of the mold core 1b adheres to the protruding portion 71 of the mold coil 5.
[0049] Once the mold core 1b has been inserted into the mold coil 5, the process moves to the pressing step. The pressing step involves pressing the mold cores 1a and 1b to spread the adhesive 8. The mold cores 1a and 1b are pressed along the winding axis direction against the back surface (the side opposite to the inner circumferential surface 241) of the yoke portion 24 of the mold cores 1a and 1b. By pressing, the adhesive 8 applied to the joint surface is spread so that it adheres to the entire joint surface 231.
[0050] Further pressure causes the adhesive 8 applied to the joint surface 231 to ooze out from the joint surface 231 toward the upper surface 234, lower surface 235, and inner side surface 236 of the leg portion 23. The oozing adhesive 8 spreads into the space between the upper surface 234 or lower surface 235 and the inner circumferential surface of the molded coil 5, and adheres to the upper surface 234, lower surface 235, and the inner circumferential surface of the molded coil 5. The oozing adhesive 8 also fills the space between the inner curved surface 232 and the inner circumferential surface of the molded coil 5, spreads into the space between the inner side surface 236 and the molded coil 5, and adheres to the inner side surface 236 and the inner circumferential surface of the molded coil 5. In addition, the adhesive 8 applied to the inner circumferential surface 241 of the yoke portion 24 is pushed out onto the inner circumferential surface 241 when pressed, and also enters the vertical groove 721 and horizontal groove 722 of the protruding portion 71.
[0051] After the pressing process, the process moves to the curing process. The curing process is a process of drying and curing the adhesive 8. For example, the adhesive 8 is cured by exposing it to heat. The temperature and time of exposure to heat should be selected to be optimal depending on the material of the adhesive. As a result, the adhesive 8 is cured, and the core joint portion 81, the X-direction restricting portion 82, the Y-direction restricting portion 83, and the Z-direction restricting portion 84 are formed. The core members 21 and 22 are joined by the core joint portion 81, forming an annular core 2. In addition, the molded cores 1a and 1b and the molded coil 5 are joined and fixed by the X-direction restricting portion 82, the Y-direction restricting portion 83, and the Z-direction restricting portion 84.
[0052] The welding process involves joining the lead wires 62 and busbars 4a and 4b of the coil 6 by welding. Through the welding process, the lead wires 62 and busbars 4a and 4b are fixed in a connected state.
[0053] [Effects and Effects] As described above, the reactor 10 of this embodiment comprises a pair of molded cores 1a and 1b that cover at least a portion of the core members 21 and 22 with core mold resin 3, a molded coil 5 that covers at least a portion of the coil 6 with coil mold resin 7, an adhesive 8 that joins the molded cores 1a and 1b and the molded coil 5, and a busbar 4a fixed to the molded core 1a that is connected to the lead wires 62 of the coil 6 by welding. The core members 21 and 22 have a plurality of leg portions 23 and a yoke portion 24 that connects the leg portions 23, and the coil 6 is mounted on the leg portions 23. The adhesive 8 includes a core joint portion 81 positioned between the joint surfaces 231 of the leg portion 23 to join the core members 21 and 22, an X-direction restricting portion 82 positioned between the inner circumferential surface 241 of the yoke portion 24 and the molded coil 5 to join the inner circumferential surface 241 and the molded coil 5, a Y-direction restricting portion 83 positioned between the inner side surface 236 of the leg portion 23 and the molded coil 5 to join the inner side surface 236 and the molded coil 5, and a Z-direction restricting portion 84 positioned between the upper surface 234 and the lower surface 235 of the leg portion 23 and the molded coil 5 to join the upper surface 234 or the lower surface 235 and the molded coil 5.
[0054] Thus, the molded cores 1a, 1b and molded coil 5 are restricted from moving in the X direction (winding axis direction) by the X direction restricting section 82, from moving in the Y direction (width direction) by the Y direction restricting section 83, and from moving in the Z direction (height direction) by the Z direction restricting section 84. In other words, the molded cores 1a, 1b and molded coil 5 are joined in all three axes by the X direction restricting section 82, the Y direction restricting section 83, and the Z direction restricting section 84, and their movement is restricted. Therefore, even if the reactor 10 is mounted in an environment where vibration occurs, the movement of the molded cores 1a, 1b and molded coil 5 can be suppressed, and excessive stress can be applied to the welded joint of the lead wire 62 and the busbar 4a fixed to the molded core 1a, preventing damage. Although the molded core 1b does not have busbars, it is joined to the molded core 1a by the core joint 81. If the molded core 1b moves due to vibration, it may affect the molded core 1a. Therefore, it is preferable that the molded core 1b is also joined to the molded coil 5 in three axial directions to restrict its movement.
[0055] If the coil 6 is not molded with coil molding resin 8, even if vibration is applied to the reactor, the coil 6 itself can absorb the vibration as a spring because it is wound in a spiral shape, thus mitigating the stress on the weld to a certain extent. On the other hand, as in this embodiment, if the coil 6 is molded with coil molding resin 8, the springiness of the coil 6 is lost, so the coil 6 itself cannot absorb vibration, and stress is easily applied to the weld. In addition, since the coil 6 itself becomes a single heavy mass due to the coil molding resin 8, the stress on the weld increases even more. However, as in this embodiment, all three axial directions are joined with adhesive 8, and the movement of the mold cores 1a, 1b and mold coil 5 is restricted, so it is possible to suppress excessive stress on the weld due to vibration.
[0056] Furthermore, the Y-direction restricting portion 83 is positioned between the inner side surface 236 and the molded coil 5. That is, since the Y-direction restricting portion 83 is formed closer to the center of gravity of the reactor 10, its rigidity is increased, effectively preventing excessive stress on the welded portion due to vibration and damage. In addition, since the center of the coil 6 becomes hot, the Y-direction restricting portion 83 also functions as a heat dissipation path, improving the heat dissipation of the reactor 10.
[0057] The manufacturing method for the reactor 10 of this embodiment includes a mold core manufacturing step of molding a core member 21 with core mold resin 3 to produce a pair of mold cores 1a and 1b, a mold coil manufacturing step of molding a coil 6 with coil mold resin 7 to produce a mold coil 5, an bonding step of joining the mold cores 1a and 1b and the mold coil 5 with adhesive 8, and a welding step of connecting the lead wires 62 of the coil 6 and the busbar 4a fixed to the mold core 1a by welding. The core members 21 and 22 have a plurality of leg portions 23 and a yoke portion 24 connecting the leg portions 23, and the coil 6 is mounted on the leg portions 23. The bonding step includes an application step of applying adhesive 8 to the joining surfaces 231 of the leg portions 23 of the core members 21 and 22 and the inner circumferential surfaces 241 of the yoke portion 24 of the core members 21 and 22, a pressing step of spreading the applied adhesive 8, and a curing step of curing the adhesive 8. In the pressing process, the adhesive 8 applied to the joint surface 231 is spread out, causing it to overflow onto both the upper surface 234 and the lower surface 235 of the leg portion, as well as the inner side surface 236 of the leg portion 23, and adhere to the molded coil 5.
[0058] In this way, by pressing the adhesive 8 applied to the joint surface 231, it is made to overflow onto the upper surface 234, lower surface 235, and inner side surface 236 of the leg portion 23, thus increasing productivity compared to applying it to each location individually. In this embodiment, the adhesive 8 is made to overflow onto both the upper surface 234 and the lower surface 235 of the leg portion 23, but it is sufficient to overflow it onto at least one of the upper surface 234 or the lower surface 235. Even with this configuration, the molded cores 1a, 1b and the molded coil 5 can be fixed, and the effect of suppressing excessive stress on the welded joint between the lead wire 62 and the busbar 4a fixed to the molded core 1a due to vibration can be obtained.
[0059] The coil mold resin 7 has a projection 71 that faces the inner circumferential surface 241 of the yoke portion 24 and protrudes toward the inner circumferential surface 241. The projection 71 has a groove 72, and the X-direction restricting portion 82 is in contact with the projection 71 and is formed inside the groove 72.
[0060] As a result, the surface area of the X-direction restricting portion 82 in contact with the coil mold resin 7 increases. Therefore, the bonding strength between the mold cores 1a and 1b and the mold coil 5 is increased. Thus, the stress on the welded joint between the lead wire 62 and the busbar 4a due to vibration can be effectively suppressed.
[0061] The coil mold resin 7 is made of PPS (Polyphenylene Sulfide), and the adhesive 8 is an epoxy resin. PPS and epoxy resin do not mix well, and the adhesive strength tends to be weak. However, in this embodiment, a groove 72 is provided in the protruding portion 71, the adhesive 8 is allowed to penetrate into the groove 72, and the X-direction restricting portion 82 is formed inside the groove 72. Therefore, even with materials that do not mix well, the inner circumferential surface 241 of the yoke portion 24 and the protruding portion 71 of the coil mold resin 7 firmly bond the mold cores 1a and 1b and the mold coil 5, restricting movement in the X direction.
[0062] In particular, in this embodiment, the groove 72 is formed by a plurality of vertical grooves 721 and a plurality of horizontal grooves 722, and the protruding portion 71 is lattice-shaped. Therefore, the X-direction restricting portion 82 can further increase the bonding strength between the molded cores 1a, 1b and the molded coil 5.
[0063] [Other embodiments] While embodiments of the present invention have been described herein, these embodiments are presented as examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. Embodiments and their variations are included in the scope and essence of the invention, as well as in the claims and their equivalents.
[0064] In the above embodiment, the Y-direction restricting portion 83 is formed between the inner side surface 236 and the molded coil 5, but it may also be formed between the outer side surface 237 and the molded coil 5. Even with this configuration, the outer side surfaces 237 of the molded coils 1a and 1b and the molded coil 5 can be joined by the Y-direction restricting portion 83, so that the movement of the molded cores 1a and 1b and the molded coil 5 in the Y direction (width direction) can be restricted. Furthermore, by providing the Y-direction restricting portion 83 on the outer side surface 237 side, during the pressing process, when viewing the coil 6 from the annular surface 61 of the coil 6 in the winding axis direction, it is possible to check whether the adhesive 8 is protruding into the gap between the outer side surface 237 and the inner circumferential surface (inner circumferential surface cover 64) of the molded coil 5.
[0065] Furthermore, the Y-direction restricting portion 83 may be formed on both the inner side surface 236 and the outer side surface 237. This allows the molded coil 5 to be joined to both the inner side surface 236 and the outer side surface 237, thereby increasing the joining strength.
[0066] In the above embodiment, when forming the X-direction restricting portion 82, the adhesive 8 was applied to the inner circumferential surface 241 of the yoke portion 24. However, it may also be applied to the molded coil 5 facing the inner circumferential surface 241 instead of the inner circumferential surface 241. That is, the adhesive may be applied to the protruding portion 71 of the molded coil 5.
[0067] Furthermore, the protrusions 71 may be provided on the molded coils 1a and 1b. For example, the inner circumferential surface 241 of the yoke portion 24 may be covered with the core mold resin 3. Then, the core mold resin 3 may be provided with protrusions 71 that project toward the annular surface 61 of the coil 6.
[0068] In the above embodiment, the adhesive 8 was applied not only to the central portion of the joining surface 231, but also to the vicinity of the edge on the upper surface 234 side, the vicinity of the edge on the lower surface 235 side, and the vicinity of the edge on the inner side surface 236 side of the joining surface 231. However, if the adhesive 8 extends onto the upper surface 234, lower surface 235, and inner side surface 236 of the leg portion 23, it may be applied only to the central portion.
[0069] In the above embodiment, the busbar 4a was covered with core mold resin 3 by molding, but the method of fixing the busbar 4a to the mold core 1a is not limited to this. For example, a terminal block having the busbar 4a may be manufactured separately from the mold core 1a, and this terminal block may be fixed to the mold core 1a with fasteners such as bolts. Even with such a configuration, movement of the mold cores 1a, 1b and the mold coil 5 can be suppressed, and excessive stress on the welded joint between the lead wire 62 and the busbar 4a can be prevented from causing damage. [Explanation of symbols]
[0070] 10 Reactors 1a, 1b mold core 2 cores 21 Core members 22 Core members 23 Legs 231 Joint surface 232 Inner curved surface 233 Outer curved surface 234 Top surface 235 Bottom surface 236 Medial side 237 Outer side 24 York section 241 Inner surface 25 Spacers 3 Core mold resin 4a, 4b busbar 5 Molded Coils 6 coils 61 Annular surface 62 Lead Line 63 Top cover 64 Inner surface cover 65 Bottom cover 7. Coil mold resin 71 Protrusion 72 Groove 721 Vertical groove 722 Yokomizo 8. Adhesive 81 Core joint 82 X direction regulation part 83 Y-direction restriction section 84 Z direction regulation part 9 sensors
Claims
1. A molded core manufacturing process involves molding at least a portion of a core member with core mold resin to produce a pair of molded cores, A molded coil manufacturing process involves molding at least a portion of a coil with coil molding resin to produce a molded coil, A bonding step in which the mold core and the mold coil are joined together with an adhesive, A welding process in which the lead wires of the coil and the busbar fixed to the molded core are connected by welding, Includes, The core member has a plurality of legs and a yoke portion connecting the legs, The coil is attached to the leg portion, The bonding process described above is: A coating step of applying the adhesive to the joint surface of the leg portion of the core member, and to the inner circumferential surface of the yoke portion of the core member or to the molded coil facing the inner circumferential surface of the yoke portion, A pressing step to spread the applied adhesive, A curing step for curing the adhesive, Includes, In the pressing step, the adhesive applied to the joining surface is spread so that it protrudes onto at least one of the upper and lower surfaces of the leg portion, and onto at least one of the inner side surface of the leg portion that faces the other leg portion, and the outer side surface that is the opposite side of the inner side surface, and adheres to the molded coil. A method for manufacturing a reactor characterized by the following.
2. In the pressing step, the adhesive applied to the joint surface is spread out so that it protrudes onto the inner side surface of the leg. A method for manufacturing a reactor according to claim 1, characterized by the above.
3. In the pressing step, the adhesive applied to the joint surface is spread out so that it spills out onto the outer side surface of the leg. A method for manufacturing a reactor according to claim 1, characterized by the above.
4. The coil mold resin has a protruding portion that faces the inner circumferential surface of the yoke portion and protrudes toward the inner circumferential surface, The aforementioned protrusion has a groove, In the pressing step, the adhesive applied to the inner circumferential surface of the yoke portion or the molded coil facing the inner circumferential surface of the yoke portion is pressed so as to enter the groove. A method for manufacturing a reactor according to any one of claims 1 to 3, characterized by the above.
5. The coil mold resin is made of PPS (Polyphenylene Sulfide), The adhesive is made of epoxy resin. A method for manufacturing a reactor according to claim 4, characterized by the above.
6. A pair of molded cores, in which at least a portion of the core member is covered with core mold resin, A molded coil in which at least a portion of the coil is covered with a coil molding resin, An adhesive for joining the mold core and the mold coil, A busbar fixed to the mold core and connected to the lead wires of the coil by welding, Equipped with, The core member has a plurality of legs and a yoke portion connecting the legs, The coil is attached to the leg portion, The aforementioned adhesive A core joint portion is positioned between the joint surfaces of the leg portions and joins the core member, An X-direction restricting portion is positioned between the inner circumferential surface of the yoke portion and the molded coil, and joins the inner circumferential surface and the molded coil. A Y-direction restricting portion is positioned between the inner side surface of the leg, which is the surface where the leg portions face each other, and the outer side surface, which is the surface opposite to the inner side surface, and the molded coil, and joins the inner side surface or the outer side surface with the molded coil. A Z-direction restricting portion is provided, which is positioned between at least one of the upper and lower surfaces of the leg portion and the molded coil, and which joins the upper surface or the lower surface with the molded coil. Having A reactor characterized by the following.
7. The Y-direction restricting portion is positioned between the inner side surface of the leg portion and the molded coil. The reactor according to claim 6, characterized by the following:
8. The Y-direction restricting portion is positioned between the outer side surface of the leg portion and the molded coil. The reactor according to claim 6, characterized by the following:
9. The coil mold resin has a protruding portion that faces the inner circumferential surface of the yoke portion and protrudes toward the inner circumferential surface, The aforementioned protrusion has a groove, The X-direction restricting portion is in contact with the protruding portion and is formed inside the groove. A reactor according to any one of claims 6 to 8, characterized by the following:
10. The coil mold resin is made of PPS (Polyphenylene Sulfide), The adhesive is an epoxy resin. The reactor according to claim 9, characterized by the following: