Reactor manufacturing method

Abstract

To provide a reactor and a manufacturing method thereof in which burr generation is inhibited even when a connecting coil is adopted.SOLUTION: A connecting coil 1 is obtained by winding a plurality of separated points in one conductive wire 10 by edgewise winding, and includes at least a first coil 11, a second coil 12, and a connecting portion 2 connecting the coils. The first coil 11 and the second coil 12 have respective winding axes 13A parallel to each other, and are arranged in a direction orthogonal to the winding axes 13A. The connecting portion 2 is bent such that a wide face 26a falls in the direction parallel to the winding axes 13A.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a reactor and a method for manufacturing the reactor.

Background Art

[0002] A reactor has a coil and a core, and is a passive element that converts electrical energy into magnetic energy for storage and release. Reactors are used in a wide variety of applications. Representative reactors include step-up reactors, series reactors, parallel reactors, current-limiting reactors, starting reactors, shunt reactors, neutral point reactors, and arc-extinguishing reactors.

[0003] Step-up reactors are incorporated into in-vehicle boost circuits such as the drive systems of hybrid vehicles and electric vehicles. Series reactors are connected in series to motor circuits to limit the current during a short circuit. Parallel reactors stabilize the current sharing between parallel circuits. Current-limiting reactors limit the current during a short circuit and are connected thereto. Starting reactors are connected in series to motor circuits that protect machinery to limit the starting current. Shunt reactors are connected in parallel to transmission lines to compensate for leading reactive power and suppress abnormal voltages. Neutral point reactors are connected between the neutral point and the ground and are used to limit the ground fault current flowing during a ground fault accident in the power system. Arc-extinguishing reactors automatically extinguish the arc generated during a single-phase ground fault in a three-phase power system.

[0004] In this reactor, the core is coated with a core coating resin, and the coil is attached to the core via the core coating resin. Also, the reactor body including the core and the coil is at least coated with a molding resin. The core coating resin and the molding resin provide insulation between the core and the coil and between the coil and external members, and protect the core and the coil from direct physical contact, for example, so that the enamel coating of the coil does not break.

[0005] For molded resins, injection molding is frequently used, in which the reactor body is housed in a mold and resin is injected into the mold. For example, there are reactors in which a portion of the coil is not covered with resin, leaving a portion of the coil exposed. By exposing a portion of the coil, the condition of the coil can be visually inspected, and the heat dissipation of the coil can be ensured. In such reactors, the mold is pressed against the surface of the coil, or a frame is pressed against the surface of the coil, to prevent resin from entering the area to be exposed (see, for example, Patent Documents 1 to 3).

[0006] The coil is created by spirally winding conductive wire along a winding shaft, shifting the winding position with each turn, to form a cylindrical shape. It has an external shape with four flat surfaces and four curved surfaces arranged alternately. Due to manufacturing precision reasons, the surface of the coil is not always perfectly smooth, and twists occur on the surface of the coil. Therefore, even if the mold or frame is made to be tightly fitted to the coil, there is a risk that a gap will occur between the mold or frame and the surface of the coil. If this occurs, resin may penetrate through this gap, potentially causing burrs to form on the surface that is to be exposed.

[0007] To address this problem, the mold or frame is pressed firmly against the surface of the coil to correct any unevenness or twisting. The reason for pressing the coil through the frame is that if the coil were pressed too hard with the mold to correct the unevenness or twisting, it would damage the coil, for example, causing the enamel coating to break.

[0008] In this configuration, a connecting coil may be provided in the reactor. To obtain a high inductance value in the high-current region, the connecting coil is formed by connecting two coils in parallel, with the direction of the current flowing through each coil being opposite to that of the other coil. This connecting coil may be formed from a single conductive wire. That is, the first coil is formed using one region of a single conductive wire, and the second coil is formed using the other region of the same conductive wire. The remaining portion of the conductive wire between the regions used to form the two coils becomes the connecting portion that links the two coils (see, for example, Patent Document 4).

[0009] When two separate coils are mounted on a reactor, four terminals are required, increasing the material cost of the reactor. Also, when two separate coils are joined together, the ends of the two coils must be welded, increasing the labor costs. On the other hand, a joined coil only requires two terminals and does not require welding of the ends of the two coils. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 5869518 [Patent Document 2] Japanese Patent Publication No. 2015-130410 [Patent Document 3] Japanese Patent Publication No. 2018-011019 [Patent Document 4] Patent No. 4812641 [Overview of the project] [Problems that the invention aims to solve]

[0011] One type of conductive wire used for coils is flat wire. One method of winding coils is edgewise winding, where the wire is wound so that its wide surface extends perpendicular to the coil's winding axis. Compared to flatwise winding, edgewise winding has the advantage of shortening the winding axis direction for the same number of turns.

[0012] In a connected coil, if flat rectangular wire is used for the conductive wire and edgewise winding is employed as the winding method, the wire extends perpendicular to the winding axis, and the connecting portion between two coils, when stretched straight from the end of each coil to the end of the other coil, expands to a wide surface perpendicular to the winding axis. On the other hand, when forming molded resin, in order to suppress resin leakage, the surface of the coil is strongly pressed with a mold or frame to correct any irregularities or twists on the coil surface, and the direction in which the mold or frame presses the coil is also perpendicular to the winding axis.

[0013] If the connecting portion of the connecting coils is not flexible enough in the direction in which the mold or frame presses against the surface of the coil, the force will not be transmitted to the coil, and the unevenness and twisting of the coil surface cannot be corrected. However, the connecting portion has a wide surface aligned with the direction in which the mold or frame presses against the surface of the coil. When considering the force pressing on one coil, the connecting portion can be considered as a cantilever beam with the end of that coil as the point of application of force. The second moment of area of ​​this connecting portion is proportional to the product of the cube of the width of the wide surface and the width of the narrow surface.

[0014] Therefore, in reactors employing connected coils made by edgewise winding a single conductive wire, the connecting section acts as a rigid beam, reducing the effect of correcting surface irregularities and twists in the coil. As a result, during the molding of the molded resin, it becomes impossible to eliminate the risk of resin leaking between the coil and the mold or frame, and of burrs forming on the surface that was intended to be exposed.

[0015] The present invention was made to solve the above-mentioned problems, and its objective is to provide a reactor and a method for manufacturing the same in which burr generation is suppressed even when a connected coil is used. [Means for solving the problem]

[0016] In order to solve the above problems, the method for manufacturing a reactor according to the present invention includes a coil creating step of creating a connection coil by winding a plurality of spaced locations in a single conductive wire by edgewise winding, and a molding step of coating at least the connection coil with resin after mounting the connection coil on a core. In the coil creating step, a first coil and a second coil are created in the connection coil, the first coil and the second coil are arranged with their winding axes parallel to each other, a connecting portion connecting the first coil and the second coil is extended between the first coil and the second coil, and the connecting portion is bent so as to fall in a direction in which the wide surface of the connecting portion is parallel to the winding axis. The connecting portion has a first surplus length portion extending with an end portion of the first coil as a base end, a second surplus length portion extending with an end portion of the second coil as a base end, and a wire connecting portion connecting the first surplus length portion and the second surplus length portion. In the molding step, while correcting the twist of the first coil and the second coil, at least the connection coil is coated with resin Furthermore, after the bending process is completed, the overhead wire section has the same length as the end-to-end distance, which is the straight-line distance between the end of the first coil and the end of the second coil. and that is a feature of the present invention.

Advantages of the Invention

[0017] According to the present invention, when molding the mold resin, it becomes easy to correct the unevenness and twist of the coils in the connection coil, and the generation of burrs is suppressed.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view of a reactor body. [Figure 2] It is a perspective view showing a core portion, (a) shows a core inside the core portion, and (b) shows a core coating resin outside the core portion. [Figure 3] It is a first perspective view of a connection coil. [Figure 4] It is a second perspective view of a connection coil. [Figure 5] It is a perspective view showing a state in which the first coil and the second coil are pressed by a first plate body and a second plate body, (a) shows the first plate body side, and (b) shows the second plate body side. [Figure 6]It is a cross-sectional view showing the state in which the first coil and the second coil are held by the first plate and the second plate, and is cut along the direction orthogonal to the reel. [Figure 7] It is a perspective view showing a reactor in which the reactor body is coated with a mold resin. [Figure 8] It is an enlarged side perspective view of the connecting portion and the yoke covering portion. [Figure 9] It is a partially enlarged view of the first plate.

Embodiments for Carrying out the Invention

[0019] The reactor and its manufacturing method according to an embodiment of the present invention will be described while referring to the drawings. FIG. 1 is a perspective view showing the configuration of the reactor body 6. The reactor body 6 is used as a step-up reactor incorporated in an in-vehicle boost circuit, and is also used for series reactors, parallel reactors, current-limiting reactors, starting reactors, shunt reactors, neutral point reactors, arc extinguishing reactors, and the like. This reactor body 6 includes a mold core 3 and a connecting coil 1.

[0020] The connecting coil 1 is mounted on the mold core 3. This mold core 3 is an annular body that forms a closed magnetic circuit and passes the magnetic flux generated by the connecting coil 1 according to a magnetic permeability higher than that of vacuum. The mold core 3 includes a core 31 shown in FIG. 2(a). The core 31 is a magnetic material such as a ferrite core, a laminated steel sheet, a dust core, or a metal composite. The metal composite core is a core formed by kneading and molding magnetic powder and resin.

[0021] This core 31 has an annular shape including two leg portions 311 on which the connecting coil 1 is mounted and a yoke portion 312 connecting the two leg portions 311. This core 31 is formed, for example, by abutting and joining the ends of U-shaped blocks to form an annular shape. The U-shaped blocks may be adhered to each other with an adhesive on the joining end faces, or may be wound and fixed with a tape. A gap for increasing the magnetic resistance of the core 31 may be arranged inside the U-shaped blocks.

[0022] Furthermore, as shown in Figure 2(b), the molded core 3 is equipped with a core coating resin 32. The core coating resin 32 is a molded product that maintains a certain shape and covers the core 31. The connecting coil 1 is wound around the core 31 via the core coating resin 32. This core coating resin 32 insulates the connecting coil 1, which is fitted into the core 31, from the core 31. The core coating resin 32 is made of materials such as epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or a composite thereof.

[0023] The core coating resin 32 follows the shape of the core 31 and has an annular shape comprising a leg coating portion 321 that covers the two leg portions 311 and a yoke coating portion 322 that covers the yoke portion 312. The core coating resin 32 covers the core 31 by injection molding the resin into the two U-shaped blocks of the core 31 placed in a mold. In addition to the annular shape with two leg portions 311, the molded core 3 may also have a θ shape with three leg portions 311, or even a shape with four or more leg portions 311, consisting of a series of annular shapes.

[0024] Returning to Figure 1, the connecting coil 1 is a cylindrical winding made of conductive wire 10 such as enamel-coated copper wire, through which current flows and generates magnetic flux according to the number of turns. In order to obtain a high inductance value in the high current region, this connecting coil 1 is formed by arranging multiple coils in parallel and connecting them so that the direction of the current flowing through both coils is opposite to that of the other. For example, the connecting coil 1 comprises a first coil 11 and a second coil 12. The first coil 11 and the second coil 12 are arranged with their respective winding axes 13A parallel and along the alignment direction 13B perpendicular to the winding axes 13A. The first coil 11 and the second coil 12 are then fitted into the two legs 311 of the molded core 3 via the leg covering portion 321 of the core covering resin 32.

[0025] The first coil 11 and the second coil 12 are connected by a connecting portion 2 that extends from one end face of each coil, and lead wires 11b and 12b are drawn from the other end faces of each coil for current input and output to the outside. When current flows through the lead wires 11b and 12b to such a connecting coil 1, the connecting coil 1 generates magnetic flux according to the number of turns. The molded core 3 becomes a closed magnetic path and allows the magnetic flux generated by the connecting coil 1 to pass through with a permeability higher than that of a vacuum. Therefore, the reactor body 6 becomes an electromagnetic component that converts electrical energy into magnetic energy and stores and releases it.

[0026] Here, the connecting portion 2 extends between the first coil 11 and the second coil 12 and is bent so as to collapse toward the surface 323 of the yoke covering portion 322 of the core covering resin 32. The detailed configuration of such a connecting coil 1 is shown in Figures 3 and 4.

[0027] Figures 3 and 4 are perspective views of the connecting coil 1 from various directions. As shown in Figures 3 and 4, the bodies 11a and 12a of the connecting coil 1 are wound bodies formed by winding the conductive wire 10 spirally along the winding shaft 13A, shifting the winding position by one turn at a time. The first coil 11 and the second coil 12 are spiral edgewise coils. The spiral edgewise coil is formed by winding the conductive wire 10 such that the wide side 26a of the flat rectangular conductive wire 10 expands in a direction perpendicular to the winding shaft 13A, and the narrow side 26b expands along the winding shaft 13A.

[0028] The first coil 11, the second coil 12, and the connecting portion 2 are formed by shaping a single conductive wire 10. The first coil 11 is formed by winding the first winding range 10a of the single conductive wire 10. The second coil 12 is formed by winding the second winding range 10b, which is opposite to the first winding range 10a of the single conductive wire 10. Furthermore, a third connecting range 10c between the first winding range 10a and the second winding range 10b of the single conductive wire 10 is formed into the connecting portion 2.

[0029] The connecting section 2 comprises an excess length 22 extending from the end 11c of the first coil 11 as its base, an excess length 22 extending from the end 12c of the second coil 12 as its base, and an overhead wire section 21 connecting both excess length sections 22. The overhead wire section 21 extends across the first coil 11 and the second coil 12, connecting both excess length sections 22. This overhead wire section 21 has the same length as the end-to-end distance 13C, which is the straight-line distance between the end 11c of the first coil 11 and the end 12c of the second coil 12.

[0030] The base end of the excess length 22 extending from the first coil 11 is pulled out in a direction perpendicular to the winding shaft 13A and different from the direction of the end 12c of the second coil 12. The excess length 22 has a bend 23 in the middle, and the part of the excess length 22 that is on the overhead wire section 21 side is bent in the direction of the yoke section 312 (hereinafter referred to as the yoke direction 24), which is on the opposite side from the body 11a of the first coil 11 and the body 12a of the second coil 12. The tip of the extended end of the excess length 22 extending from the first coil 11 is connected to the overhead wire section 21 at a right angle.

[0031] Similarly, the base end of the excess length 22 extending from the second coil 12 is pulled out in a direction perpendicular to the winding shaft 13A and different from the direction of the end 11c of the first coil 11. This excess length 22 has a bend 23 in the middle, and from the middle of the excess length 22 toward the overhead wire section 21, it is bent toward the yoke 24 opposite to the body 11a of the first coil 11 and the body 12a of the second coil 12, along the winding shaft 13A. The tip of the extended end of the excess length 22 extending from the second coil 12 is connected perpendicularly to the overhead wire section 21.

[0032] In general, starting from the first coil 11 and following the connecting section 2, the excess length 22 is first pulled out from the end 11c of the first coil 11 in a direction perpendicular to the winding shaft 13A and different from the direction of the end 12c of the second coil 12. The excess length 22 bends at the bending section 23 along the winding shaft 13A toward the yoke 24. The extended tip of the excess length 22 then connects perpendicularly to the end of the overhead wire section 21.

[0033] The overhead wire section 21 extends from the body 11a of the first coil 11 and the body 12a of the second coil 12 at a distance along the winding shaft 13A. The overhead wire section 21 extends toward the second coil 12 perpendicular to the winding shaft 13A by the distance between the ends 13C, which is the straight-line distance between the end 11c of the first coil 11 and the end 12c of the second coil 12. The end of the overhead wire section 21 reaches a position where it overlaps with the end 12c of the second coil 12 in the direction of the winding shaft 13A.

[0034] The excess length 22 connected to the second coil 12 extends from the end of the overhead wire section 21 along the winding shaft 13A in a direction approaching the body 12a of the second coil 12. This excess length 22 bends at the bending section 23 in a direction perpendicular to the winding shaft 13A, reaching the end 12c of the second coil 12 from a direction different from the direction of the end 11c of the first coil 11.

[0035] As shown in Figure 1, such a connecting coil 1 is attached to the molded core 3. When this is done, the connecting portion 2 is bent so that it collapses toward the surface 323 of the yoke covering portion 322 of the core covering resin 32. The connecting coil 1 is made by winding a flat rectangular conductive wire 10 using edgewise winding. Therefore, the overhead wire portion 21 of the bent connecting portion 2 has a wide surface 26a that spreads parallel to the winding axis 13A, and a narrow surface 26b that is perpendicular to the winding axis 13A. That is, when the connecting coil 1 is covered with resin, the narrow surface 26b of the overhead wire portion 21 of the connecting portion 2 follows the direction in which the first coil 11 and the second coil 12 are pushed in order to correct the twisting and unevenness of the first coil 11 and the second coil 12 of the connecting coil 1. The wide surface 26a of the overhead wire portion 21 spreads in a direction perpendicular to the direction of pushing.

[0036] Figure 5 is a perspective view showing the state in which the first coil 11 and the second coil 12 are held in place by the first plate 41 and the second plate 42, where (a) shows the side of the first plate 41 and (b) shows the side of the second plate 42. As shown in Figure 5, after assembling the connecting coil 1 and the molded core 3, the first coil 11 and the second coil 12 are sandwiched between the first plate 41 and the second plate 42, which are made of insulating resin. In addition, a sensor 5 such as a thermistor that detects physical quantities such as the temperature of the reactor body 6 is placed in the gap between the first coil 11 and the second coil 12.

[0037] The first plate 41 is placed on the upper surface 14a, and the second plate 42 is laid beneath the first coil 11 and the second coil 12 so as to be in contact with the lower surface 14b. The first coil 11 and the second coil 12 have an external shape formed by alternately connecting four curved surfaces and four flat surfaces parallel to the winding shaft 13A. Of the four flat surfaces, the one parallel to the alignment direction 13B of the first coil 11 and the second coil 12 is called the upper surface 14a, and the back surface of this upper surface 14a is called the lower surface 14b.

[0038] The first plate 41 is a solid flat plate with its entire surface filled. The second plate 42, on the other hand, is a frame with an exposed window 42a inside. This second plate 42 is suitable for heat dissipation of the first coil 11 and the second coil 12 by opening a portion of the lower surface 14b of the first coil 11 and the second coil 12 through the exposed window 42a. In addition, the state of the first coil 11 and the second coil 12 can be visually observed through the exposed window 42a of the second plate 42.

[0039] As shown in Figure 6, a force is applied to the first coil 11 and the second coil 12 via the first plate 41 in the direction from the upper surface 14a to the lower surface 14b. The first coil 11 and the second coil 12 are pressed against the second plate 42. At this time, the direction of the force applied to the first coil 11 and the second coil 12 is such that the narrow surface 26b of the overhead wire section 21 of the connecting section 2 expands. The direction in which the wide surface 26a of the overhead wire section 21 of the connecting section 2 expands is perpendicular to the direction of this force.

[0040] In this case, the second moment of area of ​​the overhead wire section 21 is proportional to the product of the cube of the width of the narrow surface 26b and the width of the wide surface 26a. In contrast, the second moment of area of ​​the overhead wire section 21 before it is bent with respect to the bending section 23 is proportional to the product of the cube of the width of the wide surface 26a and the width of the narrow surface 26b. That is, in this reactor body 6, the connecting section 2 is bent in such a way that the wide surface 26a of the connecting section 2 tilts in a direction parallel to the winding shaft 13A, making it easier to apply force to the first coil 11 and the second coil 12.

[0041] Therefore, it is easier to eliminate the unevenness and twisting of the first coil 11 and the second coil 12. In other words, the first coil 11 and the second coil 12 can be easily pressed against the second plate 42, and the gap between the first coil 11 and the second coil 12 and the second plate 42 can be eliminated.

[0042] Furthermore, since the first plate 41 is a solid flat plate, it has higher rigidity than the second plate 42 and is suitable as a pressing plate to eliminate unevenness and twisting of the first coil 11 and the second coil 12. This first plate 41 can apply a greater force to the first coil and the second coil 12. In this reactor body 6, the first plate 41 can apply a greater force to the first coil 11 and the second coil 12, and the bending of the connecting part 2 can transmit a greater force to the first coil 11 and the second coil 12.

[0043] As shown in Figure 7, resin is injected into the mold, and the connecting coil 1, including the connecting portion 2, is covered with mold resin 43. When the resin is injected into the mold, the first coil 11 and the second coil 12 are pressed against the second plate 42 by the first plate 41. As a result, the gap between the second plate 42 and the first coil 11 and the second coil 12 is eliminated by correcting the unevenness and twisting of the first coil 11 and the second coil 12, and the generation of burrs on the exposed window 42a is suppressed.

[0044] Furthermore, the first plate 41, the second plate 42, and the molding resin 43 are made of materials such as epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or composites thereof.

[0045] Here, Figure 8 is an enlarged side perspective view of the connecting portion 2 and the yoke covering portion 322, with the molded resin 43 removed in the drawing. As shown in Figure 8, the bent portion 23 of the connecting portion 2 is bent at a 90-degree angle, and the overhead wire portion 21 and the surface 323 of the yoke covering portion 322 are parallel. However, the bent portion 23 is positioned at a height distance from the surface 323 of the yoke covering portion 322, and the overhead wire portion 21 and the yoke covering portion 322 have a distance 33D between their opposing surfaces of 0.5 mm to 5.0 mm.

[0046] The gap between the overhead wire section 21 and the yoke covering section 322 provides room for the overhead wire section 21 to flex when the first plate 41 presses against the first coil 11 and the second coil 12. However, if the distance between opposing surfaces 33D exceeds 5.0 mm, shrinkage and voids will occur in the molded resin 43 filled between the overhead wire section 21 and the yoke covering section 322. However, if the distance between opposing surfaces 33D is 5.0 mm or less, the occurrence of shrinkage and voids can be suppressed. Therefore, it is possible to suppress the peeling of the enamel coating and loss of insulation at the locations of shrinkage and voids where the overhead wire section 21 is exposed.

[0047] Furthermore, if a distance 33D between opposing surfaces exceeds 5.0 mm, there is a risk that the overhead wire section 21 may be buffeted by the resin that forcefully enters the gap between the overhead wire section 21 and the yoke covering section 322. However, if the distance 33D between opposing surfaces is 5.0 mm or less, the force that buffets the overhead wire section 21 is weakened, and the exposure of the connecting section 2 from the molded resin 43 can be suppressed.

[0048] Returning to Figure 7, the molded resin 43 covering the connecting portion 2 has one hole 431a and two holes 431b, exposing the connecting portion 2. These holes 431a and 431b are marks left by an unshown pin used to press down on the connecting portion 2 when forming the molded resin 43. Hole 431a is the mark left by pressing down on the overhead wire portion 21, and hole 431b is the mark left by pressing down on the excess length portion 22. Even when a distance 33D between opposing surfaces of 0.5 mm to 5.0 mm is formed, by pressing down on the connecting portion 2, the risk of the resin that has seeped between the overhead wire portion 21 and the yoke covering portion 322 causing the overhead wire portion 21 to be pushed up and the connecting portion 2 to be exposed from the molded resin 43 can be further reduced, and damage to the enamel coating of the connecting portion 2 can be further suppressed.

[0049] As described above, this reactor is manufactured by including a coil creation process and a molding process. In the coil creation process, a connected coil 1 is created by winding multiple spaced-apart points in a single conductive wire 10 using edgewise winding. The connected coil 1 is created in detail as follows: A first coil 11 and a second coil 12 adjacent to the first coil 11 are created. The first coil 11 and the second coil 12 are placed side by side with their winding axes 13A parallel to each other. A connecting portion 2 that connects the first coil 11 and the second coil 12 is extended between the first coil 11 and the second coil 12.

[0050] Furthermore, the coil manufacturing process includes a bending step in which the connecting portion 2 is bent so that the wide surface 26a of the connecting portion 2 is parallel to the winding shaft 13A. After the connecting coil 1 is mounted on the core 31, in the subsequent molding step, the twist of the first coil 11 and the second coil 12 is corrected while at least the connecting coil 1 is covered with resin.

[0051] As a result, the connecting coil 1 of the reactor body 6 extends between the first coil 11 and the second coil 12, and the connecting portion 2 is bent so that its wide surface 26a is parallel to the winding shaft 13A. This shortens the projected length of the connecting portion 2 along the direction perpendicular to the winding shaft 13A, making it easier to apply force to the first coil 11 and the second coil 12 from the direction perpendicular to the winding shaft 13A. Therefore, it becomes easier to correct any irregularities or twists in the first coil 11 and the second coil 12, and burrs are less likely to occur when molding the molded resin 43.

[0052] Furthermore, since the connecting portion 2 is bent in a direction parallel to the winding shaft 13A, the connecting portion 2 does not protrude from the upper surfaces 14a of the first coil 11 and the second coil 12. As a result, the connecting portion 2 does not interfere with the mold, and the entire upper surfaces 14a of the first coil 11 and the second coil 12 can be pressed by the mold. Therefore, in this respect as well, it becomes easier to apply force to the first coil 11 and the second coil 12.

[0053] This connecting section 2 is bent 90 degrees until the wide surface 26a of the overhead wire section 21 is parallel to the winding shaft 13A, and brought closer to the surface 323 of the yoke covering section 322, but is not limited to this. If the projected length of the connecting section 2 along the direction perpendicular to the winding shaft 13A is shortened, it becomes easier to apply force to the first coil 11 and the second coil by the amount of the shortening. However, if the wide surface 26a of the overhead wire section 21 is bent 90 degrees until it is parallel to the winding shaft 13A, the second moment of area is minimized, and the effect of correcting irregularities and twists in the first coil 11 and the second coil 12 is improved. It is preferable to bend it at least 45 degrees or more.

[0054] Furthermore, although the connecting portion 2 is bent toward the yoke 24, it may also be bent in a direction that overlaps the body 11a of the first coil 11 and the body 12a of the second coil 12, from the viewpoint of making it easier to apply force to the first coil 11 and the second coil 12. However, by bending the connecting portion 2 toward the yoke 24, the reactor body 6 can be made lower in the height direction perpendicular to the winding shaft 13A. Also, compared to the case where the connecting portion 2 is bent toward the body 11a or body 12a, the bending jig does not interfere with the sides of the body 11a of the first coil 11 and the body 12a of the second coil 12. Therefore, the position of the bending jig can be freely set, and the accuracy of the bending is improved. In addition, the jig does not scratch or damage the first coil 11 and the second coil 12.

[0055] Furthermore, in the bending process of the connecting portion 2, the connecting portion 2 is bent toward the yoke covering portion 322 so as not to come into contact with the surface 323 of the yoke covering portion 322. This prevents the connecting portion 2 from being supported by the yoke covering portion 322 and becoming unable to flex when force is applied to the first coil 11 and the second coil 12 to correct unevenness or twisting.

[0056] However, the distance 33D between the opposing surfaces of the connecting portion 2 and the yoke covering portion 322 is set to be between 0.5 mm and 5.0 mm. This reduces the risk of shrinkage or voids occurring in the molded resin 43 filled between the overhead wire portion 21 and the yoke covering portion 322. Therefore, physical contact with the overhead wire portion 21 through shrinkage or voids can be prevented, thus suppressing damage such as peeling of the enamel coating.

[0057] Furthermore, the molded resin 43 has multiple holes 431a, 431b through which the wide surface 26a of the connecting portion 2 is exposed. This allows the wide surface 26a of the connecting portion 2 to be held down with a pin before being molded with resin during the molding process. Therefore, even if there is a gap between the overhead wire portion 21 and the yoke covering portion 322 of the connecting portion 2, the risk of the connecting portion 2 being blown around and deformed, and exposed from the molded resin 43, is reduced. Consequently, the connecting portion 2 is protected by the molded resin 43, and the risk of damage to the enamel coating, for example, is reduced.

[0058] Furthermore, the first plate body 41, which acts as a pressing body for the first coil 11 and the second coil 12 in the molding process, is a solid flat plate with its entire surface filled. This first plate body 41 is highly rigid and can strongly press the first coil 11 and the second coil 12. Therefore, it becomes even easier to correct any unevenness or twisting in the first coil 11 and the second coil 12. If the correction of unevenness or twisting is to be facilitated solely by the bending action of the connecting part 2, the first plate body 41 may be a frame, just like the second plate body 42.

[0059] In the molding process, the first coil 11 and the second coil 12 are pressed together via the first plate 41, but this is not the only method. The mold may be pressed against the first coil 11 and the second coil 12 to correct any irregularities or twists in the coil, and this correction is facilitated by bending the connecting portion 2.

[0060] Furthermore, this reactor is equipped with a second plate body 42 having an exposed window 42a, and the example illustrates the generation of burrs inside the exposed window 42a due to a gap between the first coil 11 and the second coil 12 and the second plate body 42. However, the bending of the connecting portion 2 can address situations where gaps occur at the areas on the surfaces of the first coil 11 and the second coil 12 where burrs are to be trimmed.

[0061] In this reactor, the connecting section 2 is composed of an overhead wire section 21 and an excess length section 22. This connecting section 2 not only electrically connects the first coil 11 and the second coil 12, but also serves as an offset section that absorbs wire feeding errors during the formation of the first coil 11 and the second coil 12. The excess length section 22 is made longer in advance to absorb wire feeding errors during the formation of the first coil 11 and the second coil 12, and the juxtaposition position of the first coil 11 and the second coil 12 is adjusted using the length of the excess length section 22. In other words, the excess length section 22 is the surplus after absorbing wire feeding errors during the formation of the first coil 11 and the second coil 12.

[0062] The connecting section 2 is not limited to this, and since the excess length 22 is not made longer in advance, it does not function as an offset section and may only electrically connect the first coil 11 and the second coil 12. That is, the connecting section 2 may include an overhead line section 21 that starts at the end 11c of the first coil 11 and ends at the end 12c of the second coil 12.

[0063] Even with a connecting section 2 that merely electrically connects the first coil 11 and the second coil 12, if the wide surface 26a is positioned perpendicular to the winding shaft 13A, it becomes difficult to apply force to correct any unevenness or twisting in the first coil 11 and the second coil 12. On the other hand, even with such a connecting section 2, bending the wide surface 26a of the connecting section 2 so that it tilts in a direction parallel to the winding shaft 13A makes it easier to apply force to the first coil 11 and the second coil 12.

[0064] Furthermore, the bent portion 23 that bends the connecting portion 2 toward the yoke covering portion 322 is not limited to the excess length portion 22. The connecting portion 2 may be bent along the length direction of the overhead wire portion 21, or bent at the boundary portion 25 (see Figures 3 and 4) where it bends from the excess length portion 22 toward the overhead wire portion 21. However, if the overhead wire portion 21 is bent along the length direction, the area requiring bending becomes long, and the boundary portion 25 has already been deformed by edgewise bending in order to extend the overhead wire portion 21 from the end of the excess length portion 22. For this reason, it is preferable to create the bent portion 23 in the excess length portion 22 in that it is easier to perform high-precision bending.

[0065] The embodiments of the present invention described above are merely examples and are not limited to those embodiments. 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. The embodiments and their variations are included within the scope of the present invention.

[0066] For example, the first plate 41 functioned as a cover for the first coil 11 and the second coil 12, and as a pressing body for the first coil 11 and the second coil 12. In addition, the first plate 41 can also function as a positioning member for the lead wires 11b and 12b. Figure 9 is a partially enlarged view of the first plate 41 placed in the second coil 12. The first plate 41 placed in the first coil 11 has the same shape and function as the first plate 41 placed in the second coil 12, so its description is omitted.

[0067] As shown in Figure 9, the first plate 41 is positioned to overlap each of the leader lines 12b. The first plate 41 has a clamping portion 411 formed at a position that overlaps with the leader lines 12b. The clamping portion 411 is shaped like a hoe and clamps the leader lines 12b, correcting the extension of the leader lines 12b.

[0068] Furthermore, a space 412 is formed at a position that overlaps with the lead wire 12b's lead base end 121b. When the lead wire 12b is drawn out from the second coil 12, the lead base end 121b is bent in the direction of drawing. As a result, the lead base end 121b curves, and precision errors occur in the size of the lead base end 121b. The space 412 is made large to prevent the first plate body 41 from being placed or being unable to be clamped by the clamping portion 411 due to contact with the lead base end 121b which has precision errors. [Explanation of symbols]

[0069] 1. Connecting coil 10 Conductive wires 10a First winding range 10b Second winding range 10c Third linkage range 11. First coil 11a Torso 11b Leader line 11c end 12. Second coil 12a Fuselage 12b Leader line 121b Drawer base end 12c end 13A winding shaft 13B Alignment direction 13C End-to-end distance 14a Top side 14b Bottom side 2 Connecting part 21 Overhead line section 22 Extra length 23. Bending section 24 Towards York 25 Boundary part 26a Wide surface 26b narrow side 3 mold core 31 cores 311 Legs 312 York section 32 Core coating resin 321 Leg covering part 322 Yoke covering 323 Surface 33D Distance between opposing surfaces 41 First plate 411 Clamping part 412 Space section 42 Second plate 42a Exposed window 43. Mold resin 431a Hole 431b Hole 5 sensors 6. Reactor body

Claims

1. The coil manufacturing process involves creating a connected coil by winding multiple spaced points within a single conductive wire using edgewise winding, and After attaching the connecting coil to the core, a molding step is performed in which the connecting coil is coated with resin, Includes, In the coil fabrication process, A first coil and a second coil are created within the aforementioned connecting coil. The first coil and the second coil are arranged with their winding axes parallel to each other. The connecting portion that connects the first coil and the second coil is extended between the first coil and the second coil, The process includes bending the connecting portion such that the wider surface of the connecting portion is bent in a direction parallel to the winding shaft, The connecting portion has a first excess length portion extending from the end of the first coil as its base, a second excess length portion extending from the end of the second coil as its base, and an overhead wire portion connecting the first excess length portion and the second excess length portion. In the molding process, at least the connecting coil is coated with resin while correcting the twist of the first coil and the second coil. The overhead wire section, after the bending process is completed, has the same length as the end-to-end distance, which is the straight-line distance between the end of the first coil and the end of the second coil. A method for manufacturing a reactor characterized by the following.

2. Before attaching the connecting coil to the core, the process includes a core coating step in which a core coating resin, including a yoke coating portion that covers the yoke portion of the ring-shaped core, is applied to the ring-shaped core. In the bending process, the connecting portion is bent toward the yoke covering portion so as not to come into contact with the surface of the yoke covering portion. A method for manufacturing a reactor according to claim 1, characterized by the above.

3. The distance between the opposing surfaces of the connecting portion and the yoke covering portion shall be 0.5 mm or more and 5.0 mm or less. A method for manufacturing a reactor according to claim 2, characterized by the above.

4. In the molding process, The first coil and the second coil are respectively sandwiched between the first and second plates, The twist is corrected by pressing the first coil and the second coil through one of the first plate and the second plate. A method for manufacturing a reactor according to any one of claims 1 to 3, characterized by the above.

5. During the molding process, one of the first plate body and the second plate body that are pressed is a solid plate with its entire surface filled. A method for manufacturing a reactor according to claim 4, characterized by the above.

6. During the molding process, the other of the first plate and the second plate, against which the first coil and the second coil are pressed, is a frame. A method for manufacturing a reactor according to claim 4 or 5, characterized by the above.

7. In the molding process, the wide surface of the connecting portion is held in place with a pin before being molded with resin. A method for manufacturing a reactor according to any one of claims 1 to 6, characterized by the above.

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