Reactor

Abstract

A reactor is provided that can fix a coil while eliminating the need for bonding a core member and improving productivity. [Solution] The core 1 has a plurality of core members 11 with end faces 113, and is formed by butting the end faces 113 together; a first resin member 2 has a plurality of resin bodies 21, 22 that cover the periphery of the core members 11, and covers the periphery of the core 1 by combining the resin bodies 21, 22; coils 5a, 5b that are attached to a part of the core 1 via the first resin member 2; and a second resin member 3 that extends in a direction intersecting the end faces 113, covers the periphery of the coils 5a, 5b, and covers the yoke portion of the core 1 where the coils 5a, 5b are not attached via the first resin member 2.

Description

Technical Field

[0001] The present invention relates to a reactor including a core and a coil.

Background Art

[0002] Reactors are used in various applications, including drive systems for hybrid vehicles, electric vehicles, and fuel cell vehicles. For example, as a reactor used in an in-vehicle boost circuit, a coil is wound around a resin bobbin disposed around an annular core, and then these are housed in a metal case, and a filler is poured into the case and solidified. Many such reactors are used (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, insulation between a core and a coil has been achieved by interposing a resin between the two. As one method, it is conceivable to put the core and the coil together in a mold and fix them, and integrally mold both of them at the same time. However, it is difficult to integrally mold the core and the coil at the same time. The coil has an irregular shape such as springback, and it is difficult to fix it in the mold because gaps are generated between the wire rods. Further, even if the core and the coil are fixed in the mold, the core or the coil is blown and moved by the injection pressure of the resin injected into the mold, making it difficult to maintain the insulation distance between the core and the coil, and it is difficult to fix the core and the coil together in the mold and mold them.

[0005] Therefore, conventionally, a method of dividing and constructing a reactor has been adopted. That is, first, the divided core members are resin-molded to form mold cores, and then coils are fitted into the mold cores, and the end faces of the respective mold cores are adhered to each other with an adhesive or the like to produce a reactor. However, this adhesion work requires time and labor for the application and drying of the adhesive, which has been a factor increasing the manufacturing man-hours and manufacturing time.

[0006] On the other hand, when the coil receives external vibration or the magnetic attraction force during the operation of the reactor, the electric wires constituting the coil vibrate. Therefore, the electric wires may rub against each other, and scratches may occur on the coating of the electric wires. In particular, when dust gets into the space between the electric wires, the damage becomes significant. In addition, the coil is electrically connected to external devices and components by welding or the like. Therefore, when the coil moves due to vibration or the like, stress is applied to the connection part with the external devices and components, and there is a risk that poor contact or disconnection may occur and the electrical connection cannot be maintained.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a reactor capable of fixing a coil while improving productivity by eliminating the adhesion work of the core members.

Means for Solving the Problems

[0008] The reactor of the present invention has a plurality of core members having end faces that serve as joint surfaces. An annular core is formed by butting the end faces against each other, and there are a plurality of resin bodies that cover the periphery of the core members. A first resin member is formed by combining the resin bodies to cover the periphery of the core. A coil is mounted on a part of the core via the first resin member. A second resin member covers the periphery of the coil and extends in a direction intersecting the end face, covering the yoke portion of the core where the coil is not mounted via the first resin member. The first resin member covers the back surface of the yoke portion on the side opposite to the end face, and the second resin member covers the back surface of the yoke portion via the first resin member so as to sandwich the end face of the core member. The end face of the core member is joined without using an adhesive due to the heat shrinkage of the second resin member. The coil has an end portion drawn out to the outside from above the yoke portion, and the second resin member has an end covering portion that covers the end portion above the yoke portion, and the end covering portion covers the yoke portion via the first resin member. It is characterized by this.

[0009] The first resin member is provided with an opening that exposes the back surface of the yoke portion on the side opposite to the end face, and a part of the second resin member provided parallel to the end face may cover the opening.

[0010] The second resin member may be provided with an opening through which the bottom surface of the coil is exposed.

[0011] The core member is a U-shaped core. The first resin member has a first resin body and a second resin body in a U-shaped configuration that cover the U-shaped core. The second resin member may have 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 the yoke connecting the legs of the U-shaped core.

[0012] The first resin member is provided with two injection marks of the resin constituting the first resin member in the portion covering the yoke portion, and the second resin member may cover the space between the injection marks.

[0013] The end of the coil is drawn out from above the yoke portion to the outside, and the second resin member may have an end covering portion that covers the end portion above the yoke portion, and the end covering portion may cover the yoke portion via the first resin member.

Effect of the Invention

[0014] According to the present invention, it is possible to obtain a reactor that can fix the coil while improving productivity by eliminating the need for the bonding operation of the core member.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0016] Hereinafter, with reference to the drawings, a reactor according to an embodiment of the present invention will be described.

[0017] [1. Embodiment] [1-1. Configuration] The reactor of this embodiment is a large-capacity reactor used, for example, in drive systems of hybrid vehicles, electric vehicles, fuel cell vehicles, etc. The reactor is a main component of the electric circuit mounted on these vehicles. This electric circuit has semiconductor switching elements such as IGBTs in addition to the reactor. When the on / off of the semiconductor switching element is performed at high speed, the reactor converts the electric energy supplied from an external power source into magnetic energy, repeatedly accumulates and releases the energy, and suppresses current and voltage.

[0018] FIG. 1 is a perspective view of the reactor according to this embodiment. FIG. 2 is an exploded perspective view of the upper surface side of the reactor according to this embodiment. FIG. 3 is an exploded perspective view of the bottom surface side of the reactor according to this embodiment. FIG. 4 is a sectional view taken along line A-A of FIG. 1. FIG. 5 is a sectional view taken along line B-B of FIG. 1.

[0019] In this specification, the z-axis direction shown in the drawings is the "upper" side, and the opposite direction is the "lower" side. To explain the configuration of each member, "lower" is also referred to as "bottom". "Upper" and "lower" refer to the positional relationship of each component of the reactor, and do not refer to the positional relationship and direction when the reactor is mounted on the actual machine to be installed. The z-axis direction may also be referred to as the height direction.

[0020] 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.

[0021] The core 1 has a pair of leg portions on which the coil 5 is mounted and a pair of yoke portions connecting the ends of the leg portions, and is formed in a ring shape by a magnetic material such as a compacted powder core, a ferrite core, or a laminated steel plate. The inside of the core 1 serves as a path for the magnetic flux generated by the coil 5 to form a magnetic circuit.

[0022] Specifically, as shown in FIGS. 2 and 3, the core 1 has a plurality of core members 11, and the end faces of the core members 11 are abutted against each other to form an annular shape. Here, the core members 11 are U-shaped cores 11a and 11b, which are composed of powder cores. The U-shaped cores 11a and 11b are composed of a pair of legs 111 and a yoke 112 that connects one ends of the legs 111, and form a U-shaped shape as a whole. The end faces 113 of the legs 111 of the U-shaped cores 11a and 11b that are not connected by the yoke 112 serve as the joint surfaces with the other U-shaped cores 11a and 11b. That is, the core 1 forms an annular shape by abutting the end face 113 of the leg 111 of the U-shaped core 11a and the end face 113 of the leg 111 of the U-shaped core 11b against each other.

[0023] The leg portion of the core 1 is formed by abutting the legs 111 of two core members 11. The yoke portion of the core 1 is the yoke 112, which is the portion of the core 1 where the coil 5 is not mounted.

[0024] 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 is a member made of resin that combines the resin bodies 21 and 22 to cover the periphery of the core 1. As the resin, for example, epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), etc. can be used.

[0025] The resin bodies 21 and 22 have shapes following the U-shaped cores 11a and 11b. Specifically, the resin bodies 21 and 22 have a core covering portion 201 that covers the core member 11 and a fixing portion 202.

[0026] The core covering portion 201 is a portion that covers the core member 11, and here it is U-shaped as a whole to cover the U-shaped cores 11a and 11b. The core covering portion 201 has cylindrical bobbins 20a and 20b that cover the legs 111 and a yoke covering portion 20c that connects the bobbins 20a and 20b.

[0027] The bobbins 20a and 20b are interposed between the core 1 and the coil 5 to provide insulation for both. One end of each of the bobbins 20a and 20b is open, and the end faces 113 of the internal U-shaped cores 11a and 11b are exposed through the opening. Here, the ends of the bobbins 20a and 20b are flush with the end faces 113. A plurality of spacers 207 extending in the direction in which the cylinder extends (y-axis direction) are provided on the outer peripheries of the bobbins 20a and 20b. As shown in FIG. 5, the spacers 207 bulge from the outer peripheral surfaces of the bobbins 20a and 20b to maintain the distance from the inner peripheries of the coils 5a and 5b. The yoke covering portion 20c is a cylindrical portion that covers the yoke 112.

[0028] The yoke covering portion 20c is provided with a recess 203. The recess 203 is a portion recessed across the upper surface and the back surface of the yoke covering portion 20c. Specifically, the recess 203 extends in a direction intersecting the end face 113 on the upper surface of the yoke covering portion 20c, and extends in the vertical direction on the back surface of the yoke covering portion 20c. Here, the extending direction on the upper surface is the same as the extending direction of the bobbins 20a and 20b, and the recess 203 is provided across the upper surface of the yoke covering portion 20c in this direction.

[0029] An opening 204 for exposing the bottom surface of the core member 11 (i.e., the bottom surface of the yoke 112) is provided on the bottom surface of the yoke covering portion 20c. Here, the opening 204 is substantially trapezoidal in shape, but its shape is not particularly limited. Further, an opening 205 for exposing the back surface of the yoke 112 is provided on the side surface on the back side of the yoke covering portion 20c. The "back surface" referred to here means the side surface opposite to the end face 113. Here, the opening 205 is rectangular in shape and two are provided. However, its shape and number are not particularly limited.

[0030] The fixing portion 202 is a part for fixing the reactor to the object to be installed, and is provided to protrude on both sides of the core covering portion 201. Therefore, the fixing portion 202 is located at the four corners when the first resin member 2 is formed. A screw hole 202a is provided in the fixing portion 202, and a screw is inserted into the screw hole 202a, and the reactor is fixed to the object to be installed by screwing. A ring-shaped or cylindrical collar (not shown) may be embedded in the fixing portion 202 so that the screw hole 202a is formed.

[0031] In addition, the resin bodies 21 and 22 are provided with injection marks 206 of the resin constituting the resin bodies 21 and 22. The injection mark 206 is a mark formed when the resin is injected into the mold for forming the resin bodies 21 and 22 and the resin solidifies, and is formed by unevenness or 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 is not limited to the upper surface of the yoke covering portion 20c, and may be provided 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 thin line generated at a location where the resins that have merged in the mold are fused together. Here, it is assumed that a weld line W is provided between the injection marks 206 of the yoke covering portion 20c.

[0032] The coil 5 is formed by winding a conductor having an insulating coating. Here, the coil 5 has a pair of coils 5a and 5b. In the present embodiment, the coils 5a and 5b are edgewise coils of flat wires. However, the wire material and winding method of the coils 5a and 5b are not limited to edgewise coils of flat wires, and other forms may be used.

[0033] The ends of the coils 5a and 5b are drawn out to the outside of the reactor and connected to the wiring of external devices such as an external power supply. When power is supplied from the external power supply, an electric current flows through the coils 5a and 5b, generating a magnetic flux that penetrates the coils 5a and 5b, and an annular closed magnetic circuit is formed in the core 1.

[0034] The second resin member 3 is a member made of resin that covers the periphery of the coils 5a and 5b, extends in a direction (here, the y-axis direction) intersecting the end face 113, and covers the yoke portion (yoke 112) of the core 1 where the coils 5a and 5b are not mounted via the first resin member 2. As the resin, for example, epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), etc. can be used. The second resin member 3 and the first resin member 2 may use the same type of resin or different types of resins. 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 second resin member 3 can be prevented from peeling off from the first resin member 2 and the coils 5a and 5b due to the vibration of the coils 5a and 5b. That is, it is possible to suppress 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 and the deterioration of heat dissipation.

[0035] Specifically, the second resin member 3 has a coil covering portion 31 that covers the periphery of the coils 5a and 5b and a yoke covering portion 32 that covers the yoke portion (yoke 112) of the core 1.

[0036] The coil covering portion 31 is a portion that covers the periphery of the coils 5a and 5b. In the present 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.

[0037] As shown in FIGS. 4 and 5, the coil covering portions 31a and 31b have a double cylinder structure, that is, an outer cylinder 311, an inner cylinder 312, and a connecting portion 313. The outer cylinder 311 covers the outer peripheries of the coils 5a and 5b. However, openings 311a and 311b are provided on the upper and lower surfaces of the outer cylinder 311 to expose the upper and bottom surfaces of the coils 5a and 5b. The inner cylinder 312 covers the inner peripheries of the coils 5a and 5b and also covers the outer periphery of the first resin member 2. The outer cylinder 311 and the inner cylinder 312 are arranged with a common central axis extending in the y-axis direction, with the inner cylinder 312 on the inner side and the outer cylinder 311 on the outer side. 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, continuously connecting the coil covering portions 31a and 31b and the yoke covering portion 32 without a gap. In this embodiment, in order to avoid the influence of thermal shrinkage after the production of the second resin member 3, a cavity is provided between the outer cylinders 311. However, it may be continuously formed with resin so as to fill the cavity.

[0038] 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 covers a part of the yoke covering portion 20c.

[0039] The yoke covering portion 32 is fixed to a part of the yoke covering portion 20c. Here, the yoke covering portion 32 is connected to one end of the coil covering portions 31a and 31b and is provided to extend in a direction intersecting the end face 113. Here, the direction intersecting the end face 113 is the direction perpendicular to the end face 113 (y-axis direction), which is the extending direction of the leg portion of the core 1 or the winding axis direction of the coils 5a and 5b.

[0040] Specifically, the yoke covering portion 32 has an L shape and includes a plate-like body 321 that covers the upper surface of the yoke covering portion 20c and a plate-like body 322 that covers the back surface of the yoke covering portion 20c. The plate-like body 321 is a part of the yoke covering portion 32 that extends in a direction intersecting the end face 113. Here, it extends on the xy plane. One end of the plate-like body 322 is 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.

[0041] The plate-like bodies 321 and 322 are fitted into the concave portion 203. The upper surface of the yoke covering portion 20c and the plate-like body 321 are located on the same plane (xy plane) and are flat. The back surface of the yoke covering portion 20c and the plate-like body 322 are located on the same plane (xz plane) and are flat. The plate-like bodies 321 and 322 are fixed to the surface of the concave portion 203.

[0042] 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 straight portion of the yoke 112. This is to prevent the stress caused by the shrinkage of the resin described later from concentrating on the upper side of the end face 113. Here, the "width" refers to the length in the x-axis direction.

[0043] The plate-like body 322 covers the opening 205 provided on the back surface of the yoke covering portion 20c, and the back surface of the yoke 112 is not exposed to the outside. Here, the plate-like body 322 is provided with bulging portions 322a having a shape (here, a rectangular shape) following the shape of the opening 205 on the surface closer to the back surface of the yoke 112 according to the number of the openings 205. The bulging portions 322a are fitted into the openings 205 to prevent the back surface of the yoke 112 from being exposed to the outside.

[0044] [1-2. Manufacturing method] The manufacturing method of this reactor will be described with reference to FIGS. 6 to 8. This reactor is manufactured using a mold. However, the mold is not shown in FIGS. 6 to 8.

[0045] The manufacturing method of this reactor includes (1) a core member molding step, (2) a reactor body assembly step, and (3) a reactor body molding step. FIG. 6 is a diagram for explaining the core molding step. FIG. 7 is a diagram for explaining the assembly step. FIG. 8 is a diagram for explaining the reactor body molding step.

[0046] (1) Core member molding step The core member molding process is a process of resin-molding the core member 11. Here, the core member 11 is the U-shaped cores 11a and 11b. As shown in FIG. 6, resin molding is performed on the U-shaped cores 11a and 11b to form core units 1a and 1b in which the peripheries of the U-shaped cores 11a and 11b are covered with resin bodies 21 and 22. Since the basic configurations of the core units 1a and 1b are the same, the manufacturing method of the core unit 1a will be described, and the description of the core unit 1b will be omitted.

[0047] For manufacturing the core unit 1a, a mold divided into an upper mold and a lower mold is used. First, the U-shaped core 11a is placed in the lower mold. At this time, as indicated by the white arrow in FIG. 6, a substantially trapezoidal protrusion bulging upward from the inside of the lower mold supports the bottom surface of the yoke 112. When placing, a collar (not shown) to be embedded in the fixing portion 202 may be placed beside the U-shaped core 11a. Next, the upper mold is set, and as indicated by the white arrow in FIG. 6, the U-shaped core 11a is clamped from both sides by a jig. That is, the back surface (the back surface of the yoke 112) of the U-shaped core 11a on one side is pushed in the direction of the end surface 113, and the end surface 113 on the other side is pushed in the direction of the back surface of the U-shaped core 11a. In this state, the mold is filled with resin through a gate, which is a resin injection through-hole provided in the upper mold, and solidified, thereby manufacturing the core unit 1a in which the U-shaped core 11a and the resin body 21 are integrated.

[0048] At this time, by adjusting the injection direction and speed of the resin filled into the mold, and by utilizing the self-weight of the U-shaped core 11a, the position variation of the U-shaped core 11a in the mold can be suppressed. For example, as indicated by the black arrow in FIG. 6, the gates are located at two positions on the upper surface of the yoke 112. By filling the resin into the mold from the upper surface side of the yoke 112 downward, the injection pressure from above by the resin and the clamping between the protrusion bulging from the inner bottom surface of the lower mold can hold it in the vertical direction. Also, by holding the extending direction of the leg 111 by the jig and the inner wall of the mold, the U-shaped core 11a can be held from the extending direction of the leg 111 orthogonal to the vertical direction.

[0049] After the filled resin is solidified, the produced core units 1a and 1b are taken out of 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 without being coated with resin because the U-shaped core 11a is pressed by a jig or a protrusion in the mold. Also, in the mold, protrusions that bulge toward both sides but do not contact the upper and back surfaces of the yoke 112 are provided, and the recess 203 is formed by these protrusions. Further, the resins injected from the two gates meet near the intermediate position, and a weld line W is formed at the central portion of the recess 203. The weld line W does not necessarily have to be at the central portion of the recess 203, and it may be between the two gates, that is, between the injection marks 206. Also, the weld line W does not have to be straight and may be, for example, a wavy line.

[0050] As described above, since the resin bodies 21 and 22 are formed by the resin molding method, the configuration of each part of the resin bodies 21 and 22 is continuously formed without joints with the same resin.

[0051] (2) Reactor main body assembly process The reactor main body assembly process is a process of assembling the core units 1a and 1b and the coils 5a and 5b to form the reactor main body 10. That is, as shown in FIG. 7, the bobbins 20a and 20b of the core units 1a and 1b are fitted into the hollow portions of the coils 5a and 5b with the ends (not shown) pulled out upward from both sides, and the end faces 113 of the core units 1a and 1b are butted against each other to form the reactor main body 10. At this time, the end faces 113 are not adhered with an adhesive.

[0052] (3) Reactor main body molding process The reactor body molding process is a process of forming the second resin member 3 on the reactor body 10 to constitute the reactor. To form the second resin member 3, an upper mold and a lower mold are used. Here, as shown in FIG. 8, the reactor body 10 is placed in the lower mold so that it is upside down. That is, the ends of the coils 5a and 5b are respectively inserted into four holes dug and provided in the lower mold. The holes are of 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.

[0053] 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 mold. Further, the upper mold is set so as to press 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 on the inner wall surface of the upper mold. That is, as shown by the 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 that covers the periphery of the coils 5a and 5b is formed, and a yoke covering portion 32 that is connected to the coil covering portion 31 so as to fill the recess 203 is formed, constituting the reactor.

[0054] Thus, 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 configurations of the respective portions 31 and 32 are continuously formed seamlessly with the same resin.

[0055] In addition, the position of the gate for injecting the resin into the mold is set to a position that does not overlap with 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, they can be located on the back side or the bottom side of each yoke 112, and when one gate is provided, it can be located between the coils 5a and 5b. Further, a plurality of projections smaller than the wall thickness of the second resin member 3 may be provided on the surface of the first resin member 2 such as the bobbins 20a and 20b of the second resin member 3 in a zigzag pattern. Thereby, when forming the second resin member 3, the flow of the resin injected into the mold can be disturbed, and the formation of the weld line can be prevented.

[0056] [1-3. Function and Effect] (1) The reactor of the present embodiment includes a plurality of core members 11 having end faces 113, an annular core 1 formed by butting the end faces 113 against each other, a plurality of resin bodies 21 and 22 covering the periphery of the core members 11, a first resin member 2 formed by combining the resin bodies 21 and 22 to cover the periphery of the core 1, coils 5a and 5b mounted on a part of the core 1 via the first resin member 2, and a second resin member 3 that covers the periphery of the coils 5a and 5b, extends in a direction intersecting the end face 113, and covers the yoke portion of the core 1 where the coils 5a and 5b are not mounted via the first resin member 2.

[0057] 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 the bonding operation of the core member 11. That is, the second resin member 3 extends in a direction intersecting the end face 113 and covers up to the yoke portion of the core 1. Therefore, the thermal shrinkage of the second resin member 3 that occurs after the reactor body molding process occurs from the back side of the yoke portion toward the end face 113 side. For this reason, the second resin member 3 pulls the core unit 1a toward the core unit 1b side and the core unit 1b toward the core unit 1a side, and the end faces 113 are abutted against each other without using an adhesive. Therefore, since it is not necessary to apply an adhesive to the end face 113 or provide a drying time therefor, the productivity can be improved. Moreover, since the coils 5a and 5b are covered by the second resin member 3 (here, the coil covering portion 31), the coils 5a and 5b can be fixed. Conventionally, the coils have been fixed by housing the reactor in a case and filling and solidifying a filler in the case. However, according to the present embodiment, neither the case nor the filler is required, and the productivity can be improved and the size can be reduced.

[0058] Note that the second resin member 3 only needs to cover a part of the upper surface of the yoke 112 (the upper surface of the yoke covering portion 20c) to obtain the thermal shrinkage effect of sandwiching the end face 113, and it is not necessary to cover up to the back surface of the yoke 112. Further, by the resin molding method, the inner surfaces of the bobbins 20a and 20b and the surfaces of the U-shaped cores 11a and 11b are fixed, and the inner cylinders 312 of the coil covering portions 31a and 31b are fixed to the first resin member 2 (specifically, the bobbins 20a and 20b). Also with this configuration, the end faces 113 can be abutted against each other without using an adhesive due to the thermal shrinkage of the inner cylinder 312.

[0059] (2) The second resin member 3 is configured to cover up to the back surface of the yoke portion (yoke 112) of the core 1 on the side opposite to the end face 113 so as to sandwich the end face 113 of the core member 11. As a result, due to the thermal shrinkage that occurs after the reactor body molding process, the back surfaces of the pair of yokes 112 are pushed so as to approach each other, so that the butting of the end faces 113 can be made stronger.

[0060] (3) The first resin member 2 is provided with a recess 203 in a portion covering the yoke portion. The second resin member 3 is provided with a plate-like body 321, which is a part extending in a direction intersecting the end face 113, in the recess 203, so that the surfaces of the first resin member 2 and the second resin member 3 in the yoke portion are located on the same plane and made flat. Thus, since the second resin member 3 does not cover the entire first resin member 2, miniaturization can be achieved. Also, in the present embodiment, the plate-like body 321 is provided in the recess 203 so that the surfaces of the first resin member 2 and the second resin member 3 in the yoke portion are located on the same plane and made flat. Also by this, miniaturization of the reactor can be achieved.

[0061] (4) The first resin member 2 is provided with an opening 205 that exposes the back surface of the yoke portion on the side opposite to the end face 113. The second resin member 3 is provided with a plate-like body 322, which is a part provided parallel to the end face 113, so as to cover the opening 205. Thus, since the back surface of the yoke 112 of the core 1 is not exposed, rust of the core 1 can be prevented, and malfunctions of peripheral devices that may occur due to the spread of the rust by vibrations or the like of the reactor can be prevented.

[0062] (5) The second resin member 3 is provided with an opening 311b through which the bottom surfaces of the coils 5a and 5b are exposed. Thus, the cooling efficiency of the reactor can be improved. For example, by disposing the reactor on a heat radiating member such as a heat radiating sheet, heat generated by driving the reactor can be released to the outside through the coils 5a and 5b. Also, since an opening 204 is provided in the bottom surface 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 radiating member, and the cooling efficiency of the reactor can be improved. Further, in the present embodiment, the second resin member 3 is provided with an opening 311a through which the upper surfaces of the coils 5a and 5b are exposed. Thus, heat generated in the atmosphere or the like can be released, and the cooling efficiency of the reactor can be improved.

[0063] (6) In the first resin member 2, two injection marks 206 of the resin constituting the first resin member 2 are provided in the portion covering the yoke portion, and the second resin member 3 covers between the injection marks 206. Specifically, it is covered by the yoke covering portion 32. Thereby, the weld line W formed in the first resin member 2 can be covered by the second resin member 3.

[0064] That is, between the injection marks 206, the resins injected from the respective gates merge, and a weld line W is formed on the surface of the yoke covering portion 20c. This 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 harsh environment where low-temperature environments and high-temperature environments 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 as the first resin member 2 repeatedly expands and contracts thermally, and cracks may occur in the portion of the weld line W where the strength is relatively weak. Also, when the impacts received by the reactor are repeated, cracks may occur in the portion of the weld line W. When cracks occur, the insulation distance between the core 1 and the coil 5 cannot be maintained, and insulation breakdown occurs.

[0065] In contrast, in the present embodiment, since the yoke covering portion 32 covers between the injection marks 206 of the yoke covering portion 20c where the weld line W may occur, even if cracks occur in the portion of the weld line W, the insulation distance can be maintained and the reliability can be improved. Note that the occurrence of cracks is less likely to occur as the resin thickness is thicker. Therefore, from common technical knowledge, the portion where the weld line W of the yoke covering portion 20c may occur is made thicker. On the contrary, in the present embodiment, a concave portion 203 that is recessed one step from the surroundings is provided in the yoke covering portion 20c where the weld line W can be formed, making it thinner. The reason is that by the yoke covering portion 32 filling the concave portion 203, the weld line W can be covered to ensure insulation, and miniaturization can be achieved, and both advantages can be enjoyed.

[0066] As described above, the present invention has two independent objectives. That is, the first objective is to provide a reactor that can fix a coil while improving productivity by eliminating the need for the bonding operation of the core member. The second objective is to provide a reactor that ensures an insulation distance and improves reliability even when a weld line is formed. Therefore, achieving only the second objective is also within the scope of the present invention.

[0067] [2. Second Embodiment] [2-1. Configuration] The reactor according to the second embodiment will be described with reference to FIGS. 9 to 11. The basic configuration of the second embodiment is the same as that of the first embodiment. Therefore, only the differences from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and detailed descriptions thereof will be omitted.

[0068] FIG. 9 is a perspective view of the 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. FIG. 11 is a cross-sectional view taken along the line C-C of FIG. 9.

[0069] As shown in FIG. 10, the recess 203 of the present embodiment is a recessed portion provided on the back surface of the yoke covering portion 20c and faces the end surface 113 through the core member 11. This recess 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 in the back 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 formed. Spacers 207 are provided on each surface of each of the bobbins 20a and 20b, and cutout portions 208 are provided on both sides of the spacers 207.

[0070] 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 to the outside. Here, the ends 51 to 54 are portions that protrude in the y-axis direction from the winding portions of the conductors of the coils 5a and 5b.

[0071] The second resin member 3 has an end covering portion 33, and the end covering portion 33 covers the upper ends 51 to 54 of the yoke 112. However, the terminal covering portion 33 does not cover the tips of the ends 51 to 54, and the wire material with the insulating film peeled off is exposed.

[0072] 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 upper surface of the yoke 112 is covered from the end face 113 side to the edge on the back side of the yoke 112 through the yoke covering portion 20c on the lower surface of the end covering portion 33, and the covered portion is fixed to the surface of the yoke covering portion 20c. The end covering portion 33 does not necessarily cover between the injection marks 206.

[0073] The plate-like body 322 is connected to the tip portion on the back side of the yoke 112 of the end covering portion 33 and is fitted into the recess 203. That is, the second resin member 3 (here, the plate-like body 322) covers the back portion of the yoke portion facing the end face 113 via the core member 11. Further, the bulge portion 322a provided on the plate-like body 322 is fitted into the opening 205 to prevent the exposure of the back of the yoke 112 to the outside.

[0074] Further, the second resin member 3 is provided with a sensor unit covering portion 34 that covers the sensor unit 9 described later. Here, the sensor unit covering portion 34 extends in the y-axis direction from the middle of the winding portions of the coils 5a and 5b to cover the upper surface of the yoke 112 between the coil covering portions 31a and 31b, and is provided so as to connect the two portions 31a and 31b. Further, the sensor unit covering portion 34 intersects with the connecting portion 313 that connects between the coil covering portions 31a and 31b on the resin body 22 side. In other words, the connecting portion 313 connects between the coil covering portions 31a and 31b via the sensor unit covering portion 34.

[0075] The reactor of the present embodiment is provided with a sensor unit 9, and the first resin member 2 is provided with a mounting portion 209 for mounting the sensor unit 9.

[0076] The sensor unit 9 includes a temperature sensor 91 that detects the temperature inside the reactor, and a connector 92 that is coated with resin around the temperature sensor 91 and is connected to the attachment portion 209.

[0077] When the connector 92 is attached to the attachment portion 209, the temperature sensor 91 is disposed between the coils 5a and 5b. The temperature sensor 91 includes a temperature detection portion 91a that detects the temperature inside the reactor, and a lead wire 91b that is connected to the temperature detection portion 91a and transmits the temperature information detected by the temperature detection portion 91a to the outside of the reactor. As the temperature detection portion 91a, for example, a thermistor whose electrical resistance changes with temperature change can be used, but it is not limited thereto. The lead wire 91b outputs the temperature information detected by the temperature detection portion 9a, for example, to a control circuit that turns on and off the current flowing through the coils 5a and 5b.

[0078] The connector 92 is, for example, in a cylindrical shape with one end closed, and in the middle thereof, an overhanging portion 92a that protrudes outward for connection to the attachment portion 209 is provided. The attachment 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 bodies 209a are provided in parallel with a distance approximately equal to the thickness of the overhanging portion 92a. The plate-like body 209a is provided with a notch 209b. By fitting the connector 92 into the notch 209b and inserting the overhanging portion 92a into the gap between the plate-like bodies 209a, the temperature sensor 91 is fixed to the reactor main body 10.

[0079] The manufacturing method of the reactor of the present 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 manufactured by a resin molding method. Therefore, the attachment portion 209 is integrally formed without a joint with the same resin as the configuration of each part of the resin body 22. Further, 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 integrally formed without a joint with the same resin.

[0080] The differences between the manufacturing method of this embodiment and the first embodiment are as follows: firstly, in the core member molding process, the mounting portion 209 is provided on the resin body 22; secondly, in the assembly process of the reactor main body 10, a step of attaching a separately manufactured temperature sensor 91 to the mounting portion 209 is added; thirdly, in the reactor main body molding process, the terminal covering portion 33 is provided.

[0081] [2-2. Function and Effect] The second resin member 3 of this embodiment covers the back portion of the yoke portion facing the end face 113 via the core member 11. In this way, since the yoke covering portion 32 (plate-like body 322) is arranged to face the end face 113, the thermal contraction force can be more efficiently applied in the direction of pressing the end faces 113 against each other, and the butting of the end faces 113 can be made stronger.

[0082] Moreover, due to the efficient action of this thermal contraction force, the amount of resin covering the upper part of the yoke portion of the yoke covering portion 32 can be reduced. As a result, during thermal contraction, the resin on the upper part of the yoke portion fixed to the upper surface of the yoke covering portion 20c pulls the upper surface of the yoke covering portion 20c towards the end face 113, preventing stress concentration on the upper part of the end face 113 and improving the reliability of the reactor.

[0083] In other words, the resin covering the upper part of the yoke portion of the yoke covering portion 32 can be made thinner in the x-axis direction compared to the first embodiment. Specifically, in the reactor of this embodiment, the ends 51 to 54 of the coils 5a and 5b are drawn out from above the yoke portion to the outside, and the second resin member 2 has an end covering portion 33 that covers the ends 51 to 54 above the yoke portion, and the end covering portion 33 covers the yoke portion via the first resin member 2.

[0084] Thus, since the terminal covering portion 33 covers the yoke portion via the first resin member 2, the terminal covering portion 33 has the function of covering the terminals 51 to 54 and also serves as the yoke covering portion 32. Therefore, it is possible to prevent stress concentration on the upper part of the end face 113, reduce the amount of resin for providing the yoke covering portion 32, and reduce the manufacturing cost.

[0085] (Modification example) In this embodiment, the lower surface of the terminal covering portion 33 also serves as the yoke covering portion 32. However, the present invention is not limited to this, and the terminal covering portion 33 may be provided independently of the yoke covering portion 32. For example, instead of the terminals 51 to 54 being drawn out to the outside via the upper part of the yoke portion, they may be drawn out directly upward from the ends of the winding portions of the coils 5a and 5b. In this case, since the terminal covering portion 33 is not located above the yoke portion, it is independent of the yoke covering portion 32.

[0086] [3. Other embodiments] The present invention is not limited to the above-described embodiment, and also includes other embodiments shown below. Further, the present invention also includes a form in which at least any two of the above-described embodiment and the following other embodiments are combined.

[0087] (1) In the above-described embodiment, the core member 11 is formed as the U-shaped cores 11a and 11b. However, the present invention is not limited to this, and as long as the annular core 1 can be configured, it may be an I-shaped core, an E-shaped core, a T-shaped core, a C-shaped core, or a J-shaped core, and any combination of the core members 11 may be used.

[0088] (2) In the above-described embodiment, the injection mark 206 is exposed to the outside, but it may be covered with the second resin member 3.

[0089] (3) In the above embodiment, the weld line W is provided on the surface of the yoke covering portion 20c. However, the weld line W does not necessarily have to be provided. For example, by setting the number of gates provided in the mold used when forming the resin bodies 21 and 22 to one and setting the injection mark 206 to one, it is possible to prevent the resin injected from the gate from merging.

[0090] (4) In the above embodiment, the injection mark 206 is provided on the yoke covering portion 20c, but it may be provided on the surfaces of the bobbins 20a and 20b.

Explanation of Reference Numerals

[0091] 1 Core 10 Reactor Body 11 Core Member 11a, 11b U-shaped Core 111 Leg 112 Yoke 113 End Face 2 First Resin Member 21, 22 Resin Body 201 Core Covering Portion 20a, 20b Bobbin 20c Yoke Covering Portion 202 Fixing Portion 202a Screw Hole 203 Recess 204 Opening 205 Opening 206 Injection Mark 207 Spacer 208 Cutout Portion 209 Mounting Portion W Weld Line 5 Coil 5a, 5b Coil 3 Second Resin Member 31 Coil Covering Portion 31a, 31b Coil Covering Portion 311 Outer Cylinder 311a Opening 311b Opening 312 Inner Cylinder 313 Connecting Portion 32 Yoke covering part 321, 322 Plate-like bodies 322a Bulging part 33 End covering part 34 Sensor unit covering part 9 Sensor unit 91 Temperature sensor 91a Temperature detection part 91b Lead wire 92 Connector 92a Protruding part

Claims

1. Having a plurality of core members each having an end face that serves as a joint surface, and an annular core formed by butting the end faces against each other, Having a plurality of resin bodies that cover the periphery of the core member, and a first resin member that combines the resin bodies to cover the periphery of the core, A coil mounted on a part of the core via the first resin member, A second resin member that covers the periphery of the coil and extends in a direction intersecting the end face, and covers the yoke portion of the core where the coil is not mounted via the first resin member, Comprising, The first resin member covers the back surface of the yoke portion on the side opposite to the end face, The second resin member covers the back surface of the yoke portion via the first resin member so as to sandwich the end face of the core member, The end face of the core member is joined without using an adhesive due to thermal shrinkage of the second resin member, The end of the coil is drawn out to the outside from above the yoke portion, The second resin member has an end covering portion that covers the end portion above the yoke portion, The end covering portion covers the yoke portion via the first resin member, A reactor characterized by the above.

2. The first resin member is provided with an opening that exposes the back surface of the yoke portion on the side opposite to the end face, 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 above.

3. 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 above.

4. The core member is a U-shaped core, The first resin member has a first resin body and a second resin body having a U-shaped configuration that covers 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 the yoke connecting the legs of the U-shaped core, The reactor according to any one of claims 1 to 3, characterized by the above.

5. The first resin member is provided with two injection marks of the resin constituting the first resin member at a portion covering the yoke portion, The second resin member covers between the injection marks, The reactor according to any one of claims 1 to 4, characterized by the above.

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