JP2024148614A - Reactor - Google Patents

Abstract

To provide a reactor capable of being down-sized while securing insulation at a welding point.SOLUTION: A reactor includes: a plurality of leg parts horizontally arranged; a coil 4 wound around the leg parts; and a bus bar 41 connected to leader wires 43, 44 of the coil 4 by welding. The coil 4 has the leader wire 43 which is wound around each of the adjacent leg parts, and wound around the same legs two times or more and led out from an inner end face 45 opposite the coil 4 wound around the same leg part. The leader wire 43 includes: an inner extension part 431 extending from a curved part 42 of the coil 4 toward an upper flat part 411 of the coil but not reaching the center of the upper flat part 411; a refracting part 432 connected to the inner extension part 431 and refracting toward the coil 4 wound around the same leg part; and a straight line part 433 connected to the refracting part 432, extending above the coil 4 wound around the same leg, and connected at its tip part to the bus bar.SELECTED DRAWING: Figure 4

Description

The present invention relates to a reactor in which the coil lead wire and bus bar are welded.

Reactors are used in a variety of applications, including office equipment, solar power generation systems, automobiles, and uninterruptible power supplies. A reactor is an electromagnetic component that converts electrical energy into magnetic energy and stores and releases it. A reactor primarily comprises a core, a coil, a resin member, and a bus bar.

The core contains a magnetic material and is ring-shaped with multiple legs and a pair of yokes connecting the legs. The coil is made of a single conductive member covered with an insulating coating such as enamel. The coil is attached to the legs of the core. A resin member is provided between the core and coil to insulate them from each other.

A wire is drawn out from the coil. The wire is connected to the bus bar by welding. The bus bar is also connected to the terminals of the external device. In this way, power is supplied from the external device to the reactor via the bus bar. When current is passed through the coil, it generates magnetic flux according to the number of turns, and the core becomes a magnetic path through which the magnetic flux generated by the coil passes.

JP 2015-065345 A

The coil may be wound around each of the multiple legs, and may also be wound around one leg multiple times. For example, as shown in FIG. 9, the core has two legs 210a, 210b, and two coils 400 are wound around each of the legs 210a, 210b. The coil 400 has lead wires 410, 420 drawn out from the end faces of the coil that are perpendicular to the winding axis and that face the coil 400 wound around the same legs 210a, 210b. The lead wires 410, 420 extend upward, and their tip faces become the welding surface 80 that is welded to the bus bar 510.

The lead wire 420 of the coil 400 wound around the leg 210a and the lead wire 410 of the coil 4 wound around the leg 210b are positioned close to each other (circled with dotted lines in FIG. 9). When welding, the insulating coating covering the conductive member that constitutes the coil 400 is peeled off, so the required insulation distance is large. Therefore, the distance between the coil 400 wound around the leg 210a and the coil 400 wound around the leg 210b is increased to ensure the insulation distance between the lead wires 410 and 420. This leads to an increase in the size of the reactor.

The present invention was made to solve the above problems, and its purpose is to provide a reactor that can be made smaller while ensuring insulation at the welded points.

The reactor of the present invention comprises a core with multiple legs arranged side by side, a coil consisting of four alternately formed flat parts and four curved parts wound around the legs, and a bus bar connected to the lead wire of the coil by welding, wherein a plurality of the coils are provided, each wound around adjacent legs, and two or more are wound around the same leg, and the lead wire of the coil has a first lead wire drawn out from an inner end face facing the coil wound around the same leg, and the first lead wire has an inner extension portion that extends from the curved part of the coil toward the flat part of the upper surface of the coil and does not reach the center of the flat part of the upper surface, a bent part that is connected to the inner extension portion and bent toward the coil wound around the same leg, and a straight part that is connected to the bent part, extends above the coil wound around the same leg, and has a tip that connects to the bus bar.

The present invention makes it possible to obtain a reactor that can be made compact while still ensuring insulation at the welded points.

FIG. 2 is a perspective view showing the overall configuration of a reactor. FIG. 2 is a perspective view showing a state in which a coil is wound around a core. FIG. 2 is a perspective view showing the overall configuration of a reactor body. FIG. 1 is a perspective view of coils wound around the same leg. FIG. FIG. FIG. 4 is a perspective view showing a welding point between a bus bar and a lead wire of a coil. FIG. 11 is a perspective view showing an overall configuration of a reactor according to another embodiment. 1 is a diagram showing welding points between coil lead wires and bus bars in a conventional reactor. FIG.

The reactor according to the embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of the reactor. Note that in each drawing, for ease of understanding, dimensions, positional relationships, ratios, shapes, etc. may be emphasized or components may be omitted, but the present invention is not limited to such emphasis.

The reactor 10 is an electromagnetic component that converts electrical energy into magnetic energy and stores and releases it, and is used in a variety of fields, including drive systems for hybrid cars, electric cars, and fuel cell cars, as well as office equipment, solar power generation systems, and uninterruptible power supplies. As shown in FIG. 1, the reactor 10 comprises a reactor body 1, a terminal block 5, a case 6, and a filling molding section 7. The reactor body 1 is housed in the case 6. The filling molding section 7, which is made of solidified filling material, is formed within the case 6.

Figure 2 is a perspective view showing the state in which the coil is wound around the core. Figure 3 is a perspective view showing the overall configuration of the reactor body. As shown in Figures 2 and 3, the reactor body 1 has a core 2, a resin member 3, and a coil 4.

The core 2 is made of a magnetic material. The core 2 becomes a magnetic path through which the magnetic flux generated by the coil 4 flows. The core 2 can be a powder magnetic core, a ferrite magnetic core, a laminated steel plate, a metal composite core, or the like. A metal composite core is a magnetic material formed by kneading magnetic powder and resin and hardening the resin.

The core 2 has multiple legs 21 and a yoke portion 22 connecting the multiple legs. In this embodiment, a pair of legs 21 are provided, and are arranged side by side so that their extension directions are parallel. Each leg 21 is formed by joining multiple core members. A pair of yoke portions 22 are provided. The wide surface of the yoke portion 22 is joined to the end of each leg 21. In this way, the core 2 is formed into a ring shape by the pair of legs 21 and the pair of yoke portions 22.

Spacers may be inserted between the core members constituting the leg 21 or between the leg 21 and the yoke 22. The spacers may be made of non-magnetic material, ceramic, non-metal, resin, carbon fiber, or a composite material of two or more of these, or gap paper. The inclusion of a spacer provides a magnetic gap of a predetermined width, preventing a decrease in inductance of the reactor 10. Alternatively, an air gap may be provided without using a spacer.

As shown in FIG. 3, the resin member 3 covers the periphery of the core 2. The resin member 3 insulates the core 2 from the coil 4. The resin member 3 is formed by molding the core 2 and is integrated with the core 2. However, the resin member 3 may be molded separately from the core 2 and then assembled to the core 2, or the coil 4 may be molded to form the resin member 3 integrated with the coil 4.

The resin member 3 has a leg covering portion 31 and a yoke covering portion 32. The leg covering portion 31 covers the leg portion 21 of the core 2. The yoke covering portion 32 covers the yoke portion 22 of the core 2. The resin member 3 can be disassembled into two parts at the center of the leg covering portion 31. By dividing the resin member 3 into two parts, the wound coil 4 can be inserted into the leg portion 21.

The resin member 3 is made of resin, and examples of the resin include epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenyl Sulfide), PBT (Polybutylene Terephthalate), and a combination of these. The resin of the resin member 3 may be a thermosetting resin such as a phenolic resin. A thermally conductive filler may be mixed into the resin.

The coil 4 is composed of a single conductive member that is insulated with enamel or the like. The coil 4 is formed by winding the conductive member into a cylindrical shape while shifting the winding position in the winding axis direction. The conductive member is a rectangular wire, and the coil 4 is an edgewise coil in which the wide surface of the conductive member extends in a direction perpendicular to the winding axis of the coil 4. The coil 4 has four flat portions 41, namely a top flat portion 411, two side flat portions 412, and a bottom flat portion 413, and four curved portions 42. The curved portions 42 are arranged between the four flat portions 41, and the coil 4 is formed into a square cylindrical shape.

The up-down direction refers to the direction perpendicular to the bottom surface of the case 6 described below, with the direction away from the bottom surface of the case 6 being referred to as "up" and the direction approaching the bottom surface of the case 6 being referred to as "down." In other words, the bottom flat portion 413 is the end surface of the coil 4 that faces the bottom surface of the case 6, and the top flat portion 411 is the end surface of the coil 4 opposite the bottom flat portion 413. In addition, the side surface of the coil 4 refers to the end surface of the coil 4 that is perpendicular to the lateral arrangement direction of the legs 21 of the core 2.

The coils 4 are wound around the legs 21 of the core 2. The coils 4 are wound around adjacent legs 21. Two coils 4 are wound around each leg 21. That is, four coils 4 are provided. The four coils 4 have the same shape and size. Note that one coil 4 wound around the same leg 21 may be referred to as coil 4a, and the other coil 4 as coil 4b.

Figure 4 is a perspective view of the coil wound around the same leg of the core. The leg and the resin member are omitted in Figure 4. The coil 4 has lead wires 43, 44 which are the ends of the conductive member. The lead wire 43 is drawn from the inner end surface 45 of the coil 4. The lead wire 44 is drawn from the outer end surface 46 of the coil 4. The inner end surface 45 is the end surface of the coil 4 which is perpendicular to the winding axis and faces the coil 4 wound around the same leg 21. The outer end surface 46 is the end surface of the coil 4 which is perpendicular to the winding axis and faces the opposite side of the inner end surface 45. The lead wire 43 is drawn through above the coil 4 wound around the same leg 21 and the lead wire 44 of the coil 4.

The configuration of the lead wires 43a and 44a will be described based on the coil 4a. The lead wires 43b and 44b of the coil 4b have the same configuration as the lead wires 43a and 44a of the coil 4a. Figure 5 is an enlarged view of the lead wire 43. The lead wire 43a has an inner extension portion 431, a bent portion 432, and a straight portion 433.

The inner extension 431 is connected to the rectangular wire that constitutes the side flat portion 412, which is the side of the coil 4. The inner extension 431 extends upward so that the wide surface of the rectangular wire is perpendicular to the winding axis. The inner extension 431 extends so that the lower surface of the lead wire 43 is higher than the upper surface of the lead wire 44. More specifically, the inner extension 431 extends so that the lower surface of the straight portion 433 of the lead wire 43 is higher than the upper surface of the extension portion 441 of the lead wire 44 described later. The lower surface of the straight portion 433 of the lead wire 43 is the end surface where the straight portion 433 faces the upper flat portion 411. The upper surface of the extension portion 441 of the lead wire 44 is the end surface opposite to the end surface where the extension portion 441 faces the lower flat portion 413.

The inner extension 431 is curved toward the top flat portion 411 of the coil 4a. The inner extension 431 does not reach the center C of the top flat portion 411. The center C refers to a position halfway along the length of the top flat portion 411 in the lateral direction of the legs 21, in other words, the position of the center of the length of the coil 4 in the lateral direction of the legs 21.

The bent portion 432 is connected to the inner extension portion 431. The bent portion 432 is bent 90 degrees toward the coil 4b wound around the same leg portion 21. When bent 90 degrees, the wide surface of the rectangular wire is perpendicular to the lateral arrangement direction of the legs 21. The bent portion 432 bent 90 degrees does not reach the center C of the upper surface flat portion 411. More specifically, there is a gap of distance L between the bent portion 432 of the coil 4a and the bent portion 432 of the coil 4b, which is sufficient for insulation. In other words, the bent portion 432 of the coil 4a can be positioned as long as the closest point to the bent portion 432 of the coil 4b is up to a position L/2 away from the center C.

The straight portion 433 is connected to the bent portion 432. The straight portion 433 extends parallel to the winding axis. The narrow side of the rectangular wire is the upper surface of the straight portion 433. In other words, the wide side of the rectangular wire is perpendicular to the lateral arrangement direction of the legs 21, and the short side of the rectangular wire is parallel to the lateral arrangement direction of the legs 21. The straight portion 433 passes above the upper flat portion 411 of the coil 4b. It is sufficient that the straight portion 433 passes above the upper flat portion 411 to an extent that insulation between the straight portion 433 and the coil 4b can be achieved.

The straight portion 433 extends toward the outside of the reactor body 1 so as to intersect with the extension portion 441 of the lead wire 44 of the coil 4b. The straight portion 433 extends so that its tip is formed outside the yoke covering portion 32. The straight portion 433 extends above the lead wire 44. There is a gap between the bottom surface of the straight portion 433 and the top surface of the lead wire 44. This gap is large enough to insulate the straight portion 433 from the lead wire 44. The tip of the straight portion 433 is connected to the bus bar 51 by welding. The tip of the straight portion 433 is positioned outside the reactor 10 with respect to the side wall of the case 6.

Figure 6 is an enlarged view of the lead wire 44. The lead wire 44a has an extension portion 441, a bent portion 442, and a straight portion 443. The extension portion 441 extends so that its wide surface is perpendicular to the winding axis. The extension portion 441 extends from one curved portion 42 that sandwiches the upper flat portion 411 to the other curved portion 42. The extension portion 441 passes below the lead wire 43b of the coil 4b.

The bent portion 442 is connected to the extending portion 441. The bent portion 442 is bent 90 degrees toward the outside of the reactor body 1. In other words, the bent portion 442 is bent 90 degrees toward the opposite side of the coil 4a. When bent 90 degrees, the wide surface of the rectangular wire is perpendicular to the lateral arrangement direction of the legs 21.

The straight portion 443 is connected to the bent portion 442. The straight portion 443 extends in a direction parallel to the winding axis and away from the coil 4a. The tip of the straight portion 443 is connected to the bus bar 51 by welding. The tip of the straight portion 443 is positioned outside the reactor 10 relative to the side wall of the case 6.

The terminal block 5 is a member that holds the bus bar 51. The terminal block 5 is formed by molding. As shown in FIG. 1, two terminal blocks 5 are provided. The two terminal blocks 5 have the same shape and size. Each terminal block 5 is disposed on the outside of the side wall of the case 6 so as to face the side wall of the case 6 that is perpendicular to the winding axis. Each terminal block 5 has a bus bar 51 and a fixing portion 52.

Figure 7 is a perspective view showing the welding points of the busbar and the coil lead wire. The busbar 51 is made of a conductive material such as copper. Two busbars 51 are provided on each terminal block 5. The busbars 51 are the same shape and size. The busbar 51 has a bolt hole 511 and two connection parts 512, 513. The bolt hole 511 is used to fasten a terminal (not shown) of an external device.

The connection part 512 connects to the straight part 433 of the lead wire 43. The connection part 512 extends upward toward the tip of the straight part 433 of the lead wire 43. The tip surface of the connection part 512 and the upper surface of the straight part 433 are flush with each other. The flush tip surface of the connection part 512 and the upper surface of the straight part 433 become the welding surface 8.

The connection portion 513 connects to the straight portion 443 of the lead wire 44. The connection portion 513 extends upward toward the tip of the straight portion 443 of the lead wire 44. The tip surface of the connection portion 513 and the upper surface of the straight portion 443 are flush with each other. The flush tip surface of the connection portion 513 and the upper surface of the straight portion 443 become the welding surface 8.

The fixing parts 52 are members that fix the terminal block 5 to the case 6. Two fixing parts 52 are provided on the terminal block 5. The fixing parts 52 are provided on the ends of the terminal block 5 that are aligned in the lateral direction of the legs 21. A collar is embedded in the fixing parts 52.

As shown in FIG. 1, the case 6 houses the reactor body 1. The case 6 has a roughly rectangular bottom surface and four side walls rising from the edges of the bottom surface, with the surface facing the bottom surface being open. In other words, the case 6 is box-shaped with an open top surface, and the space enclosed by the bottom surface and the four side walls is the space for housing the reactor body 1. The case 6 is made of a lightweight metal with high thermal conductivity, such as an aluminum alloy, and has heat dissipation properties.

The case 6 has fixing parts for fixing the terminal block 5. The fixing parts are provided at positions corresponding to the fixing parts of the terminal block 5. There are four fixing parts. Each fixing part is provided at one of the four corners of the case 6.

The filling molding portion 7 is a member formed by solidifying a filling material. The filling molding portion 7 is formed inside the case 6. The filling molding portion 7 is formed in the gaps between the core 2, the resin member 3, the coil 4, and the case 6. A relatively soft, highly thermally conductive resin is suitable for the filling material that constitutes the filling molding portion 7 in order to ensure the heat dissipation performance of the reactor 10 and reduce the transmission of vibration from the reactor body 1 to the case 6. It is also preferable that the filling material has insulating properties.

(Action and Effect)
As described above, the reactor 10 of the present embodiment includes the core 2 having the multiple legs 21 arranged side by side, the coils 4a, 4b each having four flat portions 41 and four curved portions 42 formed alternately and wound around the legs 21, and the bus bar 51 connected to the lead wires 43, 44 of the coils 4a, 4b by welding. A plurality of coils 4 are provided, each wound around adjacent legs 21, and two or more coils are wound around the same leg 21, with lead wires 43a, 43b drawn out from the inner end surface 45 facing the coils 4a, 4b wound around the same leg 21. The lead wires 43a, 43b have an inner extension portion 431 that extends from the curved portion 42 of the coils 4a, 4b toward the upper flat portion 411 of the coils 4a, 4b and does not reach the central portion C of the upper flat portion 411, a bent portion 432 that connects to the inner extension portion 431 and bent toward the coils 4a, 4b wound around the same leg portion 21, and a straight portion 433 that connects to the bent portion 432, extends above the coils 4a, 4b wound around the same leg portion 21, and has a tip that connects to the bus bar 51.

This allows the reactor 10 to be made smaller while ensuring insulation at the welded points. Specifically, as shown in FIG. 9, when the lead wires 410, 420 rise straight up and are welded to the bus bar 510, the coils 400 need to be spaced apart to insulate the adjacent welded surfaces (see the dotted circle areas in FIG. 9).

However, in this embodiment, the inner extension portion 431 extends toward the inside of the coil 4a. Therefore, the lead wires 43 of the coils 4 wound around adjacent legs 21 extend in directions away from each other.

When welding the tip of the inner extension 431, i.e., the boundary between the inner extension 431 and the bent portion 432, to the connection portion 512 of the busbar 51, a welding surface 8 is formed in a close position on the lead wires 43a, 43b of the coils 4a, 4b wound around the same leg 21. Therefore, insulation cannot be achieved.

Therefore, the bent portion 432 and the straight portion 433 are used to extend the lead wires 43a and 43b to the outside of the reactor body 1, and the tip of the straight portion 433 extending to the outside of the side wall of the case 6 becomes the welding surface 8. By arranging the lead wires 43 in this way, insulation is ensured at each welding surface 8, and the distance between the coils 4 can be reduced, so the reactor 10 can be made smaller. Note that the bent portions 432 wound on the same leg 21 are close to each other, but since the conductive member that constitutes the bent portion 432 is coated with an insulating film, the insulation distance is ensured even if they are arranged closer to the welding surface 8 where the insulating film is peeled off and welding is performed.

The coil 4 is made of a conductive member of rectangular wire. The straight section 433 extends so that the wide surface of the rectangular wire is perpendicular to the lateral arrangement direction of the legs 21. This means that all of the welding surfaces 8 face upward. In other words, the welding direction is one direction. This improves the workability of the welding.

The straight portion 433 extends above the lead wires 44a, 44b of the coils 4a, 4b wound around the same leg 21. This allows the vertical dimension of the reactor 10 to be reduced.

If the straight portion 433 extends below the lead wire 44, the straight portion 433 needs to be spaced a certain distance from the upper flat portion 411 of the coil 4 to insulate it from the upper flat portion 411. The lead wire 44 needs to be located further above the straight portion 433, so the reactor 10 becomes larger in the vertical direction. On the other hand, if the straight portion 433 is located above the lead wire 44 as in this embodiment, the straight portion 433 is located above the lead wire 44 by the insulation distance from the upper flat portion 411 of the coil 4, and the lead wire 44 is located below the straight portion 433, so the vertical dimension of the reactor 10 can be further reduced.

The multiple coils 4 provided are of the same shape and size. This improves the productivity of the coils 4. In addition, because the coils 4 are of the same shape and size, the bus bars 51 and the terminal blocks 5 that hold the bus bars 51 can also be of the same shape and size. This improves the productivity of the bus bars 51 and the terminal blocks 5. In addition, because only one type of mold can be used to mold the terminal blocks 5, production costs can be reduced.

Other Embodiments
In this specification, an embodiment of the present invention has been described, but this embodiment is presented as an example and is not intended to limit the scope of the invention. The above-mentioned embodiment 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 embodiment and its modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and gist of the invention.

In the above embodiment, the straight portion 433 of the lead wire 43 is configured so that the wide surface is perpendicular to the lateral arrangement direction of the leg portions 21, but this is not limited thereto. As shown in FIG. 8, the straight portion 433 may extend so that the wide surface is perpendicular to the vertical direction. In this case, the end face of the bus bar 51 perpendicular to the winding shaft and the end faces of the lead wires 43 and 44 become the welding surface 8. That is, the welding direction is opposite between the welding to the bus bar 51 of the terminal block 5a and the welding to the bus bar 51 of the terminal block 5b, resulting in two directions. Therefore, the configuration of the embodiment in which welding work can be performed in one direction is more efficient at welding.

In the above embodiment, the straight portion 433 of the lead wire 43 extends above the lead wire 44, but it may also pass below it. However, if the straight portion 433 passes above the lead wire 44, the reactor 10 can be made smaller in the vertical direction. The straight portion 433 needs to be spaced a certain distance from the upper flat portion 411 of the coil 4 to insulate it from the upper flat portion 411. Therefore, the lead wire 44 needs to be positioned further above the straight portion 433, so the reactor 10 becomes larger in the vertical direction. On the other hand, if the straight portion 433 is positioned above the lead wire 44, the straight portion 433 is positioned above the insulation distance from the upper flat portion 411 of the coil 4, and the lead wire 44 is positioned below the straight portion 433, so the vertical dimension of the reactor 10 can be made smaller.

In the above embodiment, the core 2 has a pair of legs 21, but three or more legs may be provided. In this case, the legs 21 have a middle leg located in the middle and a pair of outer legs located on either side of the middle leg. Two coils 4 are wound around the middle leg and two around at least one of the outer legs.

REFERENCE SIGNS LIST 1 Reactor 1 Reactor body 2 Core 21 Leg 22 Yoke 3 Resin member 31 Leg covering portion 32 Yoke covering portion 4, 4a, 4b Coil 41 Flat portion 411 Upper surface flat portion 412 Side surface flat portion 413 Lower surface flat portion 42 Curved portion 43, 43a, 43b Lead wire 431 Inner extension portion 432 Bend portion 433 Straight portion 44, 44a, 44b Lead wire 441 Extension portion 442 Bend portion 443 Straight portion 45 Inner end surface 46 Outer end surface 5 Terminal block 51 Bus bar 511 Bolt hole 512 Connection portion 513 Connection portion 52 Fixing portion 6 Case 7 Filling molding portion 8 Welding surface C Center portion 210a, 210b Leg 400 Coil 410, 420 Lead wire 510 Busbar 80 Welding surface

Claims (4)

A core having a plurality of legs arranged side by side;
a coil having four alternately flat portions and four alternately curved portions, the coil being wound around the leg;
a bus bar connected to the lead wire of the coil by welding;
Equipped with
The coil is provided in plurality, and is wound around each of the adjacent legs, and two or more coils are wound around the same leg,
the coil lead wire includes a first lead wire led from an inner end surface facing the coil wound around the same leg;
The first lead wire is
an inner extension portion that extends from the curved portion of the coil toward the flat portion of the upper surface of the coil but does not reach a center of the flat portion of the upper surface;
a bending portion connected to the inner extension portion and bending toward a coil wound around the same leg;
a straight portion connected to the bent portion, extending above the coil wound around the same leg, and having a tip portion connected to the bus bar;
having
A reactor characterized by the above. The coil is made of a conductive member made of rectangular wire,
The straight portion extends so that a wide surface of the rectangular wire is perpendicular to the lateral arrangement direction of the leg portions;
The reactor according to claim 1 . the coil has a second lead wire drawn from an outer end surface opposite to the inner end surface,
the straight portion extends above the second lead of the coil wound around the same leg;
The reactor according to claim 1 or 2, The coils provided in plurality are of the same shape and size;
The reactor according to claim 1 or 2,

Images