JP2023073439A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor capable of fixing a coil while improving productivity, by eliminating the need for bonding work of a core member.

SOLUTION: A reactor includes an annular core 1 having multiple core members 11 having an end face 113, and formed by butting the end faces 113, a first resin member 2 having multiple resin bodies 21, 22 covering around the core members 11, and covering around the core 1 by combining the bodies 21, 22, coils 5a, 5b attached to a part of the core 1 via the first resin member 2, and a second resin member 3 extending in a direction intersecting the end faces 113, and covering the circumference of the coils 5a, 5b, and covering the yoke part of the core 1 to which the coils 5a, 5b are not attached via the first resin member 2.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a reactor having a core and coils.

Reactors are used in a variety of applications, including drive systems for hybrid vehicles, electric vehicles, and fuel cell vehicles. For example, as a reactor used in a booster circuit for a vehicle, after winding a coil around a resin bobbin arranged around an annular core, these are housed in a metal case, and a filler is poured into the case. Hardened ones are often used (see Patent Document 1, for example).

JP 2011-124267 A

Conventionally, the insulation between the core and the coil has been achieved by interposing a resin between them. One possible method is to put the core and the coil together in a mold and fix them together, and then integrally mold them both at the same time. However, it is difficult to integrally mold both the core and the coil at the same time. It is difficult to fix the coil in the mold because the shape is not constant due to springback, and there are gaps between the wires. In addition, even if the core and coil are fixed in the mold, the injection pressure of the resin injected into the mold will cause the core or coil to move, making it difficult to maintain the insulation distance between the core and coil. It is difficult to fix and mold the core and coil in the mold at the same time.

Therefore, conventionally, a method of constructing the reactor by dividing it has been adopted. That is, first, a mold core is formed by resin-molding a divided core member, then a coil is fitted into the mold core, and the end surfaces of the mold cores are adhered to each other with an adhesive or the like to produce a reactor. . However, this bonding operation requires time and labor for applying and drying the adhesive, which has been a factor in increasing manufacturing man-hours and manufacturing time.

On the other hand, the electric wire constituting the coil vibrates when the coil receives vibration from the outside or receives magnetic attraction force during the operation of the reactor. As a result, the wires may rub against each other and the coating of the wires may be damaged. In particular, if dust gets into between electric wires, the damage becomes remarkable. Also, the coil is electrically connected to an external device or part by welding or the like. Therefore, when the coil moves due to vibration or the like, stress is applied to the connection portion with an external device or component, and there is a risk of contact failure or disconnection resulting in failure to maintain electrical connection.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and an object thereof is to provide a reactor capable of fixing a coil while improving productivity by eliminating the adhesion work of a core member. That's what it is.

A reactor of the present invention has a plurality of core members having end faces serving as joint surfaces, and has a plurality of annular cores formed by abutting the end faces, and a plurality of resin bodies covering the core members, wherein the resin body a first resin member that covers the periphery of the core by combining the first resin member, a coil attached to a part of the core through the first resin member, and a coil that covers the periphery of the coil and intersects the end face a second resin member that extends in a direction and covers the yoke portion of the core to which the coil is not attached via the first resin member, wherein the first resin member is separated from the end face The second resin member covers the back surface of the yoke portion on the opposite side, and the second resin member covers the back surface of the yoke portion via the first resin member so as to sandwich the end surface of the core member. and

The first resin member is provided with an opening that exposes the back surface of the yoke portion opposite to the end surface, and the second resin member has a part parallel to the end surface. You may make it cover an opening part.

The second resin member may be provided with an opening through which the bottom surface of the coil is exposed.

The core member is a U-shaped core, the first resin member has a U-shaped first resin body and a second resin body covering the U-shaped core, and the second The resin member has a coil covering portion that covers the coil, and a yoke covering portion that protrudes from the coil covering portion in a direction crossing the end face and covers a yoke that connects the legs of the U-shaped core. Also good.

The first resin member is provided with two injection traces of the resin constituting the first resin member in a portion covering the yoke portion, and the second resin member is provided so as to cover between the injection traces. You can do it.

An end of the coil is pulled out from above the yoke portion, and the second resin member has an end covering portion covering the end above the yoke portion. A covering portion may cover the yoke portion via the first resin member.

ADVANTAGE OF THE INVENTION According to this invention, the reactor which can fix a coil can be obtained, improving productivity by making the adhesion|attachment work of a core member unnecessary.

1 is a perspective view of a reactor according to an embodiment; FIG. It is an upper surface side exploded perspective view of a reactor concerning an embodiment. It is a bottom side exploded perspective view of a reactor concerning an embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along the line BB of FIG. 1; It is a figure for demonstrating a core molding process. It is a figure for demonstrating the assembly process of a reactor main body. It is a figure for demonstrating a reactor main body molding process. It is a perspective view of a reactor according to a second embodiment. FIG. 7 is an exploded perspective view of a reactor according to a second embodiment; FIG. 10 is a sectional view taken along line CC of FIG. 9;

Hereinafter, reactors according to embodiments of the present invention will be described with reference to the drawings.

[1. embodiment]
[1-1. composition]
The reactor of this embodiment is a large-capacity reactor that is used, for example, in drive systems of hybrid vehicles, electric vehicles, and fuel cell vehicles. Reactors are a major part of the electrical circuits installed in these automobiles. This electric circuit has semiconductor switching elements such as IGBTs in addition to reactors. As the semiconductor switching element is turned on and off at high speed, the reactor converts electrical energy supplied from an external power source into magnetic energy, repeats storage and release of the energy, and suppresses current and voltage.

FIG. 1 is a perspective view of a reactor according to this embodiment. FIG. 2 is an upper exploded perspective view of the reactor according to the present embodiment. FIG. 3 is a bottom side exploded perspective view of the reactor according to the present embodiment. FIG. 4 is a cross-sectional view taken along line AA of FIG. FIG. 5 is a cross-sectional view along BB in FIG.

In this specification, the z-axis direction shown in the drawings is the "upper" side, and the opposite direction is the "lower" side. "Bottom" is also referred to as "bottom" in describing the configuration of each member. "Upper" and "lower" refer to the positional relationship of each component of the reactor, and do not refer to the positional relationship or direction when the reactor is mounted on the actual device to be installed. The z-axis direction may also be referred to as the height direction.

As shown in FIGS. 1 to 3, this reactor includes a core 1, a first resin member 2, a coil 5, and a second resin member 3. As shown in FIGS.

The core 1 has a pair of legs to which the coil 5 is attached and a pair of yokes that connect the ends of the legs, and is annularly formed of a magnetic material such as a dust core, a ferrite core, or a laminated steel plate. It is The inside of the core 1 serves as a path for the magnetic flux generated by the coil 5 to form a magnetic circuit.

Specifically, as shown in FIGS. 2 and 3, the core 1 has a plurality of core members 11, and end surfaces of the core members 11 are butted together to form an annular shape. Here, the core members 11 are U-shaped cores 11a and 11b, and are composed of dust cores. The U-shaped cores 11a and 11b are composed of a pair of legs 111 and a yoke 112 connecting ends of the legs 111, and form a U-shape as a whole. The end faces 113 of the legs 111 of the U-shaped cores 11a and 11b, which are not connected by the yoke 112, form joint surfaces with the other U-shaped cores 11a and 11b. That is, the core 1 forms an annular shape by abutting the end faces 113 of the legs 111 of the U-shaped core 11a and the end faces 113 of the legs 111 of the U-shaped core 11b.

The legs of the core 1 are formed by abutting the legs 111 of the two core members 11 . The yoke portion of the core 1 is the yoke 112, which is the portion of the core 1 to which the coil 5 is not attached.

The first resin member 2 has a plurality of (here, two) resin bodies 21 and 22 that cover the periphery of the core member 11, and the resin bodies 21 and 22 are combined to form a member made of resin that covers the periphery of the core 1. is. Examples of resins that can be used include epoxy resins, unsaturated polyester resins, urethane resins, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), and the like.

The resin bodies 21 and 22 have shapes that follow the U-shaped cores 11a and 11b. Specifically, the resin bodies 21 and 22 have a core covering portion 201 covering the core member 11 and a fixing portion 202 .

The core covering portion 201 is a portion that covers the core member 11, and has a U-shape as a whole in order to cover the U-shaped cores 11a and 11b here. The core covering portion 201 has tubular bobbins 20a and 20b that cover the legs 111, and a yoke covering portion 20c that connects the bobbins 20a and 20b.

The bobbins 20a and 20b are interposed between the core 1 and the coil 5 to insulate them. One ends of the bobbins 20a and 20b are open, and end surfaces 113 of the internal U-shaped cores 11a and 11b are exposed from the opening. Here, the end portions of the bobbins 20a and 20b and the end surface 113 are flush with each other. A plurality of spacers 207 are provided on the outer circumferences of the bobbins 20a and 20b so as to extend in the direction in which the cylinder extends (the y-axis direction). As shown in FIG. 5, the spacer 207 protrudes from the outer peripheral surfaces of the bobbins 20a and 20b to keep the distance from the inner periphery of the coils 5a and 5b. The yoke covering portion 20c is a cylindrical portion that covers the yoke 112. As shown in FIG.

A concave portion 203 is provided in the yoke covering portion 20c. The concave portion 203 is a concave portion extending over the upper surface and the rear surface of the yoke covering portion 20c. Specifically, the concave portion 203 extends in a direction crossing the end surface 113 on the upper surface of the yoke covering portion 20c, and extends vertically on the rear surface of the yoke covering portion 20c. Here, the extending direction of the upper surface is the same as the extending direction of the bobbins 20a and 20b, and the recess 203 is provided over the upper surface of the yoke covering portion 20c in this direction.

An opening 204 that exposes the bottom surface of the core member 11 (that is, the bottom surface of the yoke 112) is provided in the bottom surface of the yoke covering portion 20c. Here, the opening 204 has a substantially trapezoidal shape, but the shape is not particularly limited. An opening 205 that exposes the back surface of the yoke 112 is provided on the side surface of the yoke covering portion 20c on the back surface side. As used herein, the term “back surface” refers to the side surface opposite to the end surface 113 . Here, the openings 205 are rectangular and two are provided. However, the shape and number are not particularly limited.

The fixing part 202 is a part for fixing the reactor to an installation object, and is provided so as to protrude from both sides of the core covering part 201 . Therefore, the fixing portions 202 are positioned at the four corners when the first resin member 2 is constructed. A screw hole 202a is provided in the fixing portion 202, a screw is inserted into the screw hole 202a, and the reactor is fixed to the installation object by fastening with the screw. A ring-shaped or cylindrical collar (not shown) may be embedded in the fixed portion 202 so as to form a screw hole 202a.

Further, the resin bodies 21 and 22 are provided with injection traces 206 of the resin forming the resin bodies 21 and 22 . The injection traces 206 are traces formed when the resin is injected into the molds for forming the resin bodies 21 and 22 and the resin is solidified, and is made up of unevenness and the like. Here, two injection marks 206 are provided on the upper surface of the yoke covering portion 20c and are exposed to the outside. However, the injection mark 206 may be provided not only on the upper surface of the yoke covering portion 20c but also on the bottom surface or the side surface of the yoke covering portion 20c. A weld line W may be provided between the injection marks 206 of the yoke covering portion 20c (see FIG. 6). The weld line W is a fine line generated at a location where the resins that have merged in the mold are fused together. Here, it is assumed that the weld line W is provided between the injection marks 206 of the yoke covering portion 20c.

The coil 5 is formed by winding a conductive wire having an insulating coating. Here, the coil 5 has a pair of coils 5a, 5b. In this embodiment, the coils 5a and 5b are rectangular wire edgewise coils. However, the wire material and winding method of the coils 5a and 5b are not limited to edgewise coils of rectangular wires, and other forms may be used.

Ends of the coils 5a and 5b are pulled out of the reactor and connected to wiring of an external device such as an external power supply. When power is supplied from an external power supply, a current flows through the coils 5a and 5b to generate a magnetic flux penetrating through the coils 5a and 5b, forming an annular closed magnetic circuit within the core 1. FIG.

The second resin member 3 covers the periphery of the coils 5a and 5b, extends in a direction intersecting the end surface 113 (here, the y-axis direction), and is a yoke portion (yoke portion) of the core 1 to which the coils 5a and 5b are not attached. 112) is covered with the first resin member 2 interposed therebetween. Examples of resins that can be used include epoxy resins, unsaturated polyester resins, urethane resins, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), and the like. The same kind of resin may be used for the second resin member 3 and the first resin member 2, or different kinds of resin may be used. As the resin used for the second resin member 3, a soft material that follows the vibration of the coils 5a and 5b is preferable. This is because the separation of the second resin member 3 from the first resin member 2 and the coils 5a and 5b due to the vibration of the coils 5a and 5b can be suppressed. In other words, it is possible to suppress deterioration in heat dissipation due to the formation of an air layer between the second resin member 3 and the first resin member 2 or the coils 5a and 5b due to peeling.

Specifically, the second resin member 3 has a coil covering portion 31 that covers the coils 5 a and 5 b and a yoke covering portion 32 that covers the yoke portion (yoke 112 ) of the core 1 .

The coil covering portion 31 is a portion that covers the coils 5a and 5b. In this embodiment, since two coils 5a and 5b are provided, the coil covering portions 31 for the respective coils 5a and 5b are referred to as coil covering portions 31a and 31b.

The coil covering portions 31a and 31b have a double tube structure, that is, an outer tube 311, an inner tube 312 and a connecting portion 313, as shown in FIGS. The outer cylinder 311 covers the outer circumferences of the coils 5a and 5b. However, openings 311a and 311b are provided in the upper and lower surfaces of the outer cylinder 311 to expose the upper and lower surfaces of the coils 5a and 5b. The inner cylinder 312 covers the inner periphery of the coils 5 a and 5 b and the outer periphery of the first resin member 2 . The outer cylinder 311 and the inner cylinder 312 share a central axis extending in the y-axis direction, and the inner cylinder 312 is arranged inside and the outer cylinder 311 is arranged outside. The connecting portion 313 connects the ends of the outer cylinder 311 and the inner cylinder 312 . Further, the connecting portion 313 is connected to the yoke covering portion 32 and seamlessly connects the coil covering portions 31a and 31b and the yoke covering portion 32 continuously. In addition, in this embodiment, a cavity is provided between the outer cylinders 311 in order to avoid the influence of heat shrinkage after the second resin member 3 is manufactured. However, the resin may be made continuous so as to fill the cavity.

The yoke covering portion 32 covers the yoke portion (yoke 112) of the core 1 with the yoke covering portion 20c interposed therebetween. In other words, the yoke covering portion 32 partially covers the yoke covering portion 20c.

The yoke covering portion 32 is fixed to a portion of the yoke covering portion 20c. Here, the yoke covering portion 32 is connected to one end of the coil covering portions 31 a and 31 b and extends in a direction intersecting the end surface 113 . Here, the direction intersecting with the end face 113 is the direction (y-axis direction) perpendicular to the end face 113, which is the extending direction of the legs of the core 1 or the winding axis direction of the coils 5a and 5b.

Specifically, the yoke covering portion 32 is L-shaped and has a plate-like body 321 covering the upper surface of the yoke covering portion 20c and a plate-like body 322 covering the rear surface of the yoke covering portion 20c. Plate-like body 321 is part of yoke covering portion 32 extending in a direction intersecting end surface 113 . Here, it spreads out on the xy plane. The plate-like body 322 has one end connected to the plate-like body 321 and extends in the height direction. Here, the plate-like body 322 extends on the xz plane and is provided parallel to the end face 113 so as to sandwich the end face 113 .

The plates 321 and 322 are fitted in the recess 203, the upper surface of the yoke covering portion 20c and the plate 321 are flat on the same plane (xy plane), and the rear surface of the yoke covering portion 20c is flat. and the plate-like body 322 are located on the same plane (xz plane) and are flat. Plate-like bodies 321 and 322 are fixed to the surface of recess 203 .

The width of the plate-like body 321 is preferably smaller than the width of the yoke 112 and more preferably smaller than the width of the linear portion of the yoke 112 . This is to prevent stress due to shrinkage of resin, which will be described later, from being concentrated on the upper side of the end surface 113 . Note that the "width" here refers to the length in the x-axis direction.

The plate-like body 322 covers the opening 205 provided on the rear surface of the yoke covering portion 20c, and the rear surface of the yoke 112 is not exposed to the outside. Here, the plate-like body 322 is provided with bulging portions 322 a having a shape (rectangular shape in this case) following the shape of the openings 205 on the surface closer to the rear surface of the yoke 112 in accordance with the number of the openings 205 . The bulging portion 322a is fitted in the opening 205 to prevent the rear surface of the yoke 112 from being exposed to the outside.

[1-2. Production method]
A method of manufacturing this reactor will be described with reference to FIGS. 6 to 8. FIG. This reactor is manufactured using a mold. However, the mold is not illustrated in FIGS.

This reactor manufacturing method includes (1) a core member molding process, (2) a reactor body assembly process, and (3) a reactor body molding process. FIG. 6 is a diagram for explaining the core molding process. FIG. 7 is a diagram for explaining the assembly process. FIG. 8 is a diagram for explaining the reactor body molding process.

(1) Core Member Molding Process The core member molding process is a process of resin-molding the core member 11 . The core members 11 are U-shaped cores 11a and 11b here. As shown in FIG. 6, resin molding is performed on U-shaped cores 11a and 11b to form core units 1a and 1b in which resin bodies 21 and 22 cover the periphery of U-shaped cores 11a and 11b. Since the core units 1a and 1b have the same basic configuration, the manufacturing method of the core unit 1a will be described, and the description of the core unit 1b will be omitted.

A mold that is divided into an upper mold and a lower mold is used to manufacture the core unit 1a. First, the U-shaped core 11a is placed in the lower mold. At this time, as indicated by white arrows in FIG. 6, a substantially trapezoidal projection protruding upward from the lower die supports the bottom surface of the yoke 112 . During this placement, a collar (not shown) embedded in the fixing portion 202 may be placed on the side of the U-shaped core 11a. Next, the upper die is set, and the U-shaped core 11a is sandwiched from both sides by jigs as indicated by white arrows in FIG. That is, one side of the back surface of the U-shaped core 11a (the back surface of the yoke 112) is pushed toward the end surface 113, and the other side of the end surface 113 is pushed toward the back surface of the U-shaped core 11a. In this state, resin is filled into the mold through a gate, which is a through-hole for resin injection provided in the upper mold, and solidified to form a core unit in which the U-shaped core 11a and the resin body 21 are integrated. 1a is produced.

At this time, positional fluctuation of the U-shaped core 11a in the mold can be suppressed by adjusting the injection direction and speed of the resin filled into the mold and by utilizing the weight of the U-shaped core 11a. . For example, the gates are located at two locations on the upper surface of the yoke 112, as indicated by black arrows in FIG. The injection pressure from above and the protrusion protruding from the inner bottom surface of the lower mold can hold it in the vertical direction. The U-shaped core 11a can also be held down from the extending direction of the legs 111 perpendicular to each other.

After solidifying the filled resin, the manufactured core units 1a and 1b are removed from the mold. The openings 204 and 205 formed in the resin bodies 21 and 22 and the openings exposing the end faces 113 of the bobbins 20a and 20b are formed by pressing the U-shaped core 11a by a jig or a projection in the mold. It is formed without being covered. Further, the mold is provided with protrusions that do not contact the upper surface and the back surface of the yoke 112 but protrude toward both sides, and the recesses 203 are formed by these protrusions. Also, the resins injected from the two gates meet near the middle position to form a weld line W in the central portion of the recess 203 . The weld line W does not necessarily have to be provided at the central portion of the recess 203, and may be provided at the location 206 between the two gates, that is, between the injection marks. Also, the weld line W may not be linear, and may be a wavy line, for example.

As described above, since the resin bodies 21 and 22 are formed by the resin molding method, the respective parts of the resin bodies 21 and 22 are seamlessly formed from the same resin.

(2) Assembly Process of Reactor Body The assembly process of the reactor body is a process of assembling the core units 1a and 1b and the coils 5a and 5b to form the reactor body 10 . That is, as shown in FIG. 7, the bobbins 20a and 20b of the core units 1a and 1b are fitted from both sides into the air-core portions of the coils 5a and 5b with their ends (not shown) pulled out upward, and the core units 1a and 1b are assembled. The reactor body 10 is configured by abutting the end faces 113 . At this time, the end surfaces 113 are not adhered to each other with an adhesive.

(3) Reactor Body Molding Process The reactor body molding process is a process of forming the second resin member 3 on the reactor body 10 to configure the reactor. An upper mold and a lower mold are used to form the second resin member 3 . Here, as shown in FIG. 8, the reactor main body 10 is arranged in the lower die so as to be upside down. That is, the ends of the coils 5a and 5b are respectively inserted into four holes dug in the lower die. The holes are approximately the same size as the coils 5a and 5b, and the ends of the coils 5a and 5b are press-fitted into the holes. Therefore, the reactor body 10 is fixed within the mold.

By inserting the ends of the coils 5a and 5b deep into the holes, the upper surfaces of the coils 5a and 5b and the surface of the yoke covering portion 20c excluding the recess 203 come into contact with the bottom surface of the lower die. Further, the upper mold is set so that the inner wall surface of the upper mold presses the bottom surfaces of the coils 5a and 5b, the bottom surface of the yoke 112 exposed from the opening 204, and the surface of the yoke covering portion 20c. That is, as indicated by white arrows in FIG. 8, the reactor body 10 is fixed vertically and horizontally within the mold. In this state, the mold is filled with resin and solidified. As a result, a coil covering portion 31 covering the coils 5a and 5b is formed, and a yoke covering portion 32 connected to the coil covering portion 31 is formed so as to fill the recess 203, thereby forming a reactor.

As described above, since the second resin member 3 is formed by the resin molding method, the coil covering portion 31, the yoke covering portion 32, and the respective portions 31 and 32 are seamlessly formed by the same resin. It is configured.

The position of the gate for injecting the resin into the mold is set so as not to overlap the weld line W of the first resin member 2 even if the weld line is formed in the second resin member 3 . For example, when two gates are provided, it can be on the back side or bottom side of each yoke 112, and when one gate is provided, it can be between the coils 5a and 5b. Alternatively, the second resin member 3 may be provided with a plurality of projections smaller than the thickness of the second resin member 3 such as the bobbins 20a and 20b on the surface of the first resin member 2, such as by arranging them in a zigzag pattern. . Thereby, when the second resin member 3 is formed, the flow of the resin injected into the mold is disturbed, and the formation of the weld line can be prevented.

[1-3. Action/effect]
(1) The reactor of the present embodiment has a plurality of core members 11 having end faces 113, and includes a plurality of annular cores 1 formed by abutting the end faces 113 and a plurality of resin bodies 21 and 22 surrounding the core members 11. a first resin member 2 covering the circumference of the core 1 by combining resin bodies 21 and 22; coils 5a and 5b attached to a part of the core 1 via the first resin member 2; A second resin member 3 that covers the periphery of 5a and 5b, extends in a direction intersecting with the end surface 113, and covers the yoke portion of the core 1 to which the coils 5a and 5b are not attached via the first resin member 2. and prepared.

As a result, it is possible to obtain a reactor capable of fixing the coils 5a and 5b while improving productivity by eliminating the need for bonding the core member 11 . That is, since the second resin member 3 extends in a direction intersecting with the end surface 113 and covers up to the yoke portion of the core 1, the heat shrinkage of the second resin member 3 occurring after the reactor body molding process is It occurs from the back side of the yoke portion toward the end face 113 side. Therefore, the second resin member 3 attracts the core unit 1a to the core unit 1b side and the core unit 1b to the core unit 1a side, and the end faces 113 are butted against each other without using an adhesive. Therefore, it is not necessary to apply an adhesive to the end face 113 or provide a drying time, so that productivity can be improved. Moreover, since the coils 5a and 5b are covered with the second resin member 3 (here, the coil covering portion 31), the coils 5a and 5b can be fixed. Conventionally, the coil is fixed by housing the reactor in a case and filling and solidifying the filler in the case. Productivity can be improved and miniaturization can be achieved.

If the second resin member 3 partially covers the upper surface of the yoke 112 (the upper surface of the yoke covering portion 20c), the heat contraction effect of sandwiching the end surface 113 can be obtained. do not have. In addition, the inner surfaces of the bobbins 20a and 20b and the surfaces of the U-shaped cores 11a and 11b are fixed by the resin molding method, and the inner cylinders 312 of the coil covering portions 31a and 31b are attached to the first resin member 2 (specifically, are fixed to the bobbins 20a and 20b), and also with this configuration, the end surfaces 113 can be abutted against each other by heat shrinkage of the inner cylinder 312 without using an adhesive.

(2) The second resin member 3 covers up to the rear surface of the yoke portion (yoke 112 ) of the core 1 opposite to the end face 113 so as to sandwich the end face 113 of the core member 11 . As a result, the rear surfaces of the pair of yokes 112 are pushed closer together due to thermal contraction that occurs after the reactor body molding process, so that the end surfaces 113 can be abutted more firmly.

(3) The first resin member 2 is provided with a recess 203 in a portion covering the yoke portion, and the second resin member 3 has a plate-like body 321 extending in a direction intersecting the end face 113 . Provided in the recess 203, the surfaces of the first resin member 2 and the second resin member 3 in the yoke portion are positioned on the same plane and made flat. As a result, the second resin member 3 does not cover the entire first resin member 2, so that the size can be reduced. Further, in this embodiment, the plate-like body 321 is provided in the concave portion 203 so that the surfaces of the first resin member 2 and the second resin member 3 in the yoke portion are positioned on the same plane and flattened. . Also by this, size reduction of a reactor can be achieved.

(4) The first resin member 2 is provided with an opening 205 that exposes the back surface of the yoke portion opposite to the end surface 113 , and the second resin member 3 is provided parallel to the end surface 113 . The opening 205 is covered with a plate-like body 322 which is a part. As a result, since the back surface of the yoke 112 of the core 1 is not exposed, it is possible to prevent the core 1 from rusting, and to prevent malfunctions of the peripheral devices that may occur due to the diffusion of the rust due to the vibration of the reactor or the like. .

(5) The second resin member 3 is provided with openings 311b through which the bottom surfaces of the coils 5a and 5b are exposed. Thereby, the cooling efficiency of the reactor can be improved. For example, by arranging the reactor on a heat dissipation member such as a heat dissipation sheet, the heat generated by driving the reactor can be released to the outside via the coils 5a and 5b. In addition, since the opening 204 is provided in the bottom portion of the yoke 112 of the first resin member 2, the bottom surface of the yoke 112 can be directly pressed against the heat dissipation member, and the cooling efficiency of the reactor can be improved. can. Furthermore, in the present embodiment, the second resin member 3 is provided with openings 311a through which the upper surfaces of the coils 5a and 5b are exposed. As a result, the heat generated in the atmosphere can be released, and the cooling efficiency of the reactor can be improved.

(6) The first resin member 2 is provided with two injection traces 206 of the resin constituting the first resin member 2 in the portion covering the yoke portion, and the second resin member 3 is provided between the injection traces 206. was covered. Specifically, it is covered with the yoke covering portion 32 . Thereby, the weld line W formed in the first resin member 2 can be covered with the second resin member 3 .

That is, between the injection marks 206, the resin injected from each gate joins to form a weld line W on the surface of the yoke covering portion 20c. The weld line W is a portion with relatively weak strength, and cracks are likely to occur in this portion. In particular, the reactor may be used in a severe environment in which a low temperature environment and a high temperature environment are repeated, for example, in the range of -40°C to 170°C. In such a case, stress is applied to the first resin member 2 due to repeated thermal expansion and contraction of the first resin member 2, and cracks may occur in the weld line W portion where the strength is relatively weak. be. Further, if the reactor receives repeated impacts, cracks may occur in the weld line W portion. If cracks occur, the insulation distance between the core 1 and the coil 5 cannot be maintained, resulting in dielectric breakdown.

In contrast, in the present embodiment, the yoke covering portion 32 covers the injection marks 206 of the yoke covering portion 20c where the weld line W may occur. , the insulation distance can be kept and the reliability can be improved. It should be noted that cracks are less likely to occur as the resin thickness increases. Therefore, according to common technical knowledge, the portion of the yoke covering portion 20c where the weld line W may occur is made thicker. On the contrary, in the present embodiment, the yoke covering portion 20c where the weld line W can be formed is intentionally provided with a recess 203 recessed one step from the periphery to make it thinner. The reason for this is that the yoke covering portion 32 filling the concave portion 203 can cover the weld line W to ensure insulation, and the size can be reduced, so that both advantages can be enjoyed.

Thus, the present invention has two independent objectives. That is, as described above, the first object is to provide a reactor capable of fixing a coil while improving productivity by eliminating the need for a core member bonding operation. A second object is to provide a reactor that secures an insulation distance even if a weld line is formed and improves reliability. It is therefore within the scope of the invention to achieve only the second objective.

[2. Second Embodiment]
[2-1. composition]
A reactor according to the second embodiment will be described with reference to FIGS. 9 to 11. FIG. The second embodiment has the same basic configuration as the first embodiment. Therefore, only the points different from the first embodiment will be described, and the same parts as in the first embodiment will be assigned the same reference numerals, and detailed description thereof will be omitted.

FIG. 9 is a perspective view of a reactor according to the second embodiment. FIG. 10 is an exploded perspective view of the reactor according to the second embodiment. However, the core units 1a and 1b are in an assembled state. 11 is a cross-sectional view taken along line CC of FIG. 9. FIG.

As shown in FIG. 10, the recessed portion 203 of this embodiment is a recessed portion provided on the back surface of the yoke covering portion 20c, and faces the end face 113 with the core member 11 interposed therebetween. This recessed portion 203 extends to the edge of the upper surface of the yoke covering portion 20c. An opening 205 for exposing the back surface of the yoke 112 is provided on the bottom surface of the recess 203 at the back surface portion of the yoke portion. One of the fixing portions 202 is provided closer to the bobbin 20b than the corner when the first resin member 2 is constructed. A spacer 207 is provided on each surface of each of the bobbins 20a and 20b, and lightening portions 208 are provided on both sides of the spacer 207. As shown in FIG.

As shown in FIGS. 9 and 10, both ends 51 to 54 of the coils 5a and 5b are drawn out from above the yoke 112. As shown in FIGS. Here, the end portions 51 to 54 are portions protruding in the y-axis direction from the wound portions of the conductive wires of the coils 5a and 5b.

The second resin member 3 has an end covering portion 33 that covers the upper ends 51 to 54 of the yoke 112 . However, the terminal covering portion 33 does not cover the tips of the end portions 51 to 54, and the wires from which the insulating coating is stripped are exposed.

The end covering portion 33 is connected to the coil covering portion 31 and the plate-like body 322, and covers the yoke 112 via the first resin member 2 (here, the yoke covering portion 20c). Specifically, the lower surface of the end covering portion 33 covers the upper surface of the yoke 112 through the yoke covering portion 20c from the end surface 113 side to the rear edge of the yoke 112, and the covered portion is the yoke covering portion 20c. adheres to the surface of The end covering portion 33 does not necessarily have to cover between the injection marks 206 .

The plate-like body 322 is connected to the tip of the end covering portion 33 on the back side of the yoke 112 and is fitted in the recess 203 . That is, the second resin member 3 (here, the plate-like body 322 ) covers the rear portion of the yoke facing the end surface 113 with the core member 11 interposed therebetween. Also, the protrusion 322a provided on the plate-like body 322 is fitted into the opening 205 to prevent the rear surface of the yoke 112 from being exposed to the outside.

Further, the second resin member 3 is provided with a sensor unit covering portion 34 for covering the sensor unit 9 which will be described later. Here, the sensor unit covering portion 34 extends in the y-axis direction between the coil covering portions 31a and 31b from the middle of the winding portions of the coils 5a and 5b to the extent to cover the upper surface of the yoke 112. It is provided to connect Further, the sensor unit covering portion 34 crosses the connecting portion 313 that connects the coil covering portions 31a and 31b on the resin body 22 side. In other words, the connecting portion 313 connects the coil covering portions 31 a and 31 b via the sensor unit covering portion 34 .

The reactor of this embodiment is provided with the sensor unit 9 , and the first resin member 2 is provided with a mounting portion 209 for mounting the sensor unit 9 .

The sensor unit 9 has a temperature sensor 91 that detects the temperature inside the reactor, and a connector 92 that is formed by coating the periphery of the temperature sensor 91 with resin and is connected to the mounting portion 209 .

The temperature sensor 91 is arranged between the coils 5 a and 5 b by attaching the connector 92 to the attachment portion 209 . The temperature sensor 91 includes a temperature detecting portion 91a that detects the temperature inside the reactor, and a lead wire 91b that is connected to the temperature detecting portion 91a and transmits temperature information detected by the temperature detecting portion 91a to the outside of the reactor. As the temperature detection unit 91a, for example, a thermistor whose electrical resistance changes with temperature change can be used, but the temperature detection unit 91a is not limited to this. The lead wire 91b outputs, for example, temperature information detected by the temperature detector 9a to a control circuit that turns on and off currents that flow through the coils 5a and 5b.

The connector 92 has, for example, a cylindrical shape with one end closed, and a projecting portion 92a projecting outward for connection with the mounting portion 209 is provided in the middle thereof. The mounting portion 209 is erected between the coils 5a and 5b of the yoke covering portion 20c of the resin body 22. Here, two plate-like members 209a are provided parallel to each other and spaced apart by the thickness of the projecting portion 92a. . A notch 209b is provided in the plate-like body 209a, and the connector 92 is fitted in the notch 209b, and the protrusion 92a is inserted into the gap of the plate-like body 209a, whereby the temperature sensor 91 is attached to the reactor main body 10. Fixed.

The manufacturing method of the reactor of this embodiment is basically the same as that of the first embodiment. That is, the first resin member 2 and the second resin member 3 can be produced by a resin molding method. Therefore, the mounting portion 209 is seamlessly formed of the same resin as the structure of each portion of the resin body 22 . In addition, the coil covering portion 31, the connecting portion 313, the terminal covering portion 33, the sensor unit covering portion 34, and the plate-like body 322 are seamlessly formed of the same resin.

The manufacturing method of this embodiment differs from that of the first embodiment in that, firstly, in the core member molding step, the resin body 22 is provided with the mounting portion 209, and secondly, in the reactor body 10 assembling step. First, a step of attaching the separately manufactured temperature sensor 91 to the attachment portion 209 is added. Third, the terminal covering portion 33 is provided in the reactor body molding step.

[2-2. Action/effect]
The second resin member 3 of the present embodiment covers the rear portion of the yoke facing the end face 113 with the core member 11 interposed therebetween. Since the yoke covering portion 32 (the plate-like body 322) is arranged so as to face the end faces 113 in this way, the heat shrinkage force can be applied more efficiently in the direction of pressing the end faces 113 together. 113 matching can be made more robust.

In addition, due to the efficient action of this heat shrinkage force, the amount of resin covering the upper portion of the yoke covering portion 32 can be reduced. The resin on the upper portion of the yoke portion can prevent stress concentration on the upper portion of the end surface 113 caused by pulling the upper surface of the yoke covering portion 20c toward the end surface 113, thereby improving the reliability of the reactor.

In other words, the resin covering the upper portion of the yoke portion of the yoke covering portion 32 can be thinner in the x-axis direction than in the first embodiment. Specifically, in the reactor of this embodiment, the ends 51 to 54 of the coils 5a and 5b are pulled out from above the yoke portion, and the second resin member 2 extends the ends 51 to 54 above the yoke portion. It has an end covering portion 33 for covering, and the end covering portion 33 covers the yoke portion with the first resin member 2 interposed therebetween.

Since the terminal covering portion 33 covers the yoke portion through the first resin member 2 in this way, the terminal covering portion 33 has the function of the yoke covering portion 32 in addition to the function of covering the terminals 51 to 54 . Therefore, it is possible to prevent stress concentration on the upper portion of the end face 113, reduce the amount of resin for providing the yoke covering portion 32, and reduce the manufacturing cost.

(Modification)
In the present embodiment, the lower surface of the terminal covering portion 33 has the function of the yoke covering portion 32 , but the terminal covering portion 33 may be provided independently of the yoke covering portion 32 . For example, the terminals 51 to 54 may be drawn directly upward from the ends of the winding portions of the coils 5a and 5b instead of being drawn out through the upper portion of the yoke portion. In this case, the terminal covering portion 33 is not located above the yoke portion, and thus is independent of the yoke covering portion 32 .

[3. Other embodiments]
The present invention is not limited to the above embodiments, but also includes other embodiments shown below. Moreover, the present invention also includes a form in which at least any two of the above embodiment and other embodiments described below are combined.

(1) In the above embodiment, the core members 11 are U-shaped cores 11a and 11b. A core, a C-shaped core, or a J-shaped core may be used, and any combination of core members 11 may be used.

(2) Although the injection mark 206 is exposed to the outside in the above embodiment, it may be covered with the second resin member 3 .

(3) In the above embodiment, the weld line W is provided on the surface of the yoke covering portion 20c, but the weld line W may not necessarily be provided. For example, by setting the number of gates provided on the mold used for forming the resin bodies 21 and 22 to one and the number of injection marks 206 to be one, the resin injected from the gates is prevented from joining. can be done.

(4) In the above embodiment, the injection marks 206 are provided on the yoke covering portion 20c, but they may be provided on the surfaces of the bobbins 20a and 20b.

1 core 10 reactor main body 11 core members 11a, 11b U-shaped core 111 leg 112 yoke 113 end surface 2 first resin members 21, 22 resin body 201 core covering portions 20a, 20b bobbin 20c yoke covering portion 202 fixing portion 202a screw hole 203 recessed portion 204 opening 205 opening 206 injection mark 207 spacer 208 lightening portion 209 mounting portion W weld line 5 coils 5a and 5b coil 3 second resin member 31 coil covering portions 31a and 31b coil covering portion 311 outer cylinder 311a opening Portion 311b Opening 312 Inner cylinder 313 Connecting portion 32 Yoke covering portions 321, 322 Plate-like body 322a Swelling portion 33 End covering portion 34 Sensor unit covering portion 9 Sensor unit 91 Temperature sensor 91a Temperature detecting portion 91b Lead wire 92 Connector 92a overhang

Claims (6)

an annular core having a plurality of core members having end surfaces serving as joint surfaces, the end surfaces being butted against each other;
a first resin member having a plurality of resin bodies covering the periphery of the core member, wherein the resin bodies are combined to cover the periphery of the core;
a coil attached to a portion of the core via the first resin member;
a second resin member that covers the circumference of the coil, extends in a direction that intersects with the end surface, and covers, via the first resin member, a yoke portion of the core to which the coil is not attached;
with
The first resin member covers the rear surface of the yoke portion opposite to the end surface,
wherein the second resin member covers the rear surface of the yoke portion via the first resin member so as to sandwich the end face of the core member;
A reactor characterized by The first resin member is provided with an opening that exposes the rear surface of the yoke portion opposite to the end surface,
a part of the second resin member provided parallel to the end face covers the opening;
The reactor according to claim 1, characterized by: the second resin member is provided with an opening through which the bottom surface of the coil is exposed;
The reactor according to claim 1 or 2, characterized by: The core member is a U-shaped core,
The first resin member has a U-shaped first resin body and a second resin body covering the U-shaped core,
The second resin member has a coil covering portion that covers the coil, and a yoke covering portion that protrudes from the coil covering portion in a direction intersecting the end face and covers a yoke that connects the legs of the U-shaped core. matter,
The reactor according to any one of claims 1 to 3, characterized by: The first resin member is provided with two injection traces of the resin constituting the first resin member in a portion covering the yoke portion,
the second resin member covering between the injection marks;
The reactor according to any one of claims 1 to 4, characterized by: An end of the coil is pulled out from above the yoke portion,
the second resin member has an end covering portion covering the end above the yoke portion;
the end covering portion covering the yoke portion via the first resin member;
The reactor according to any one of claims 1 to 5, characterized by:

Images