JP6655209B2 - Reactor - Google Patents

Description

  The present invention relates to a reactor having an improved structure for fixing a coil.

  For example, as a reactor used for a booster circuit for a vehicle, a reactor in which an annular magnetic core is covered with a resin cover (also called a bobbin) and a coil is provided on the outer periphery of the resin cover is known. I have.

  Conventionally, as described in Patent Literature 1 and Patent Literature 2, in this type of reactor, the entire reactor is housed in a case, and a filler is injected between the reactor and the case to be solidified.

  However, for reactors that generate a large amount of heat when energized, such as those used in vehicles, the surface of the coil is exposed and coolant, such as cooling oil or air, comes into direct contact with the coil due to the need to improve its cooling efficiency. It has been proposed to do so. For example, in Patent Literature 3 and Patent Literature 4, cooling is performed by applying oil to a reactor. In this type of reactor, it is better to use no filler to improve the cooling efficiency.

JP 2014-199872 A JP 2012-049269 A U.S. Patent Publication 2014-266527 JP-A-2005-046481

  Reactors using conventional fillers fill the gap between the conductors that make up the coil and the gap between the coil and the resin cover around the core with the filler, so that when power is supplied to the reactor, The generation of noise due to the vibration of the resin cover was prevented. However, such an effect cannot be obtained with a reactor that does not use a filler, and vibration and noise may be generated.

  Usually, in the reactor, in order to connect the coil to an external electric circuit, a lead portion of the coil end is connected to a terminal on the electric circuit side by means such as welding. However, in a reactor having a structure that does not use a filler, stress is applied to the connection between the coil and the terminal due to vibration of the coil, and there is a possibility that the reactor will be damaged during long-term use.

  An object of the present invention is to reduce the generation of vibration and noise by bonding the coil to a resin cover while bringing the coils constituting the coil into close contact with each other to integrate the coil, and to reduce the generation of vibration between the coil and the electric circuit. An object of the present invention is to provide a reactor in which stress is not applied to a connection portion.

The reactor of the present invention has the following configuration.
(1) A core, a resin cover provided around the core, and a coil arranged around the core outside the resin cover.
(2) The coil includes a conductor having a self-fusing layer formed on a surface thereof, and adjacent conductors are bonded to each other by the self-fusing layer.
(3) The resin cover includes a bonding portion provided on a part thereof and facing an end of the coil, and the end of the coil is bonded to the resin cover with an adhesive at the bonding portion. Have been.
(4) The bonding portion is a flat surface formed on the surface of the resin cover, and the end of the coil is bonded to the flat surface.

The reactor of the present invention preferably has the following configuration.
(1) The conducting wire is a flat wire, and the flat surface of the flat wire is bonded to the bonding surface of the resin cover.
(2) The end of the coil and the resin cover are adhered to each other by a self-bonding layer of the coil.
(3) At least a part of the core is embedded in the resin cover.

  In the present invention, the end of the coil refers to the last turn of the conductor and / or the lead of the conductor. When a plurality of coils are formed by winding a single conductor as in the illustrated embodiment, the turns of the conductor exposed at the ends of the coils are also included in the ends of the coils. It is.

  According to the present invention, since the entire coil is integrated by the self-fusing layer and the end of the coil is fixed to the resin cover by the self-fusing layer, vibration and noise of the coil are prevented, and the coil is pulled out. The stress applied to the connection between the part and the terminal is reduced, and a highly reliable reactor can be obtained.

FIG. 2 is an exploded perspective view showing the first embodiment of the reactor of the present invention. FIG. 2 is a perspective view of the first embodiment. The perspective view seen from the coil side of a 1st embodiment. FIG. 2 is an exploded perspective view of the first embodiment as viewed from a coil side. The perspective view of a 2nd embodiment. The perspective view of a 3rd embodiment. The perspective view of a 4th embodiment. The top view of a 5th embodiment.

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

[1. First Embodiment]
(1) Configuration The reactor of the present embodiment includes an annular core 1, first and second resin covers 21 and 22 covering the periphery thereof, and a coil 3 mounted on a leg of the core 1. I have. The annular core 1 is made of a powder magnetic core such as pure iron, sendust, or Fe—Si alloy, a ferrite core, or a magnetic material such as a laminated steel sheet.

  The annular core 1 has two thick I-shaped cores 11a and 11b forming left and right legs, four thin I-shaped cores 12a, 13a, 12b and 13b bonded to both sides thereof, and a yoke portion 2 The two block-shaped cores 14c and 14d are bonded in a rectangular shape. In the present embodiment, spacers 15a, 15b forming magnetic gaps are provided at the bonding portions of two thick I-shaped cores 11a, 11b and four thin I-shaped cores 12a, 13a, 12b, 13b bonded to both sides thereof. The spacers 15a and 15b are appropriately used depending on the presence or absence of a magnetic gap, and the present invention can be applied to an annular core without a spacer.

  It is preferable to use, for example, an epoxy adhesive for bonding the cores or the core and the spacer. In particular, when a vehicle cooling oil, for example, ATF (Automatic Transmission Fluid) which is a transmission lubricating oil is used as a refrigerant, an epoxy-based adhesive is preferable from the viewpoint of oil resistance, but when another refrigerant is used. For example, it is also possible to use other adhesives such as a silicone-based, acrylic-based, polyurethane-based adhesive, or a mixed adhesive of two or more of these.

  The coil 3 has two winding portions 3a, 3b mounted on the outer periphery of the left and right legs 11a, 11b of the annular core 1. The two winding portions 3a and 3b are connected by a connecting portion 3c formed at one end thereof. In the present embodiment, the last turn portions of the two winding portions 3a and 3b are located on the same direction side of the coil, and lead portions 3d and 3e for connecting to an external electric circuit are drawn from the last turn portions. ing. In this case, the first drawer 3d is drawn in the same direction as the axial direction of the coil, and the second drawer 3e is drawn in a direction perpendicular to the axial direction of the coil.

  As the coil 3, a "self-fusing coil" in which a self-fusing layer such as a thermosetting resin in a semi-cured state is formed on the surface of a conductive wire having an insulating film formed around an electric wire. "Self-fusing coil" means that by heating a conductor, the resin formed on the surface of the conductor itself is melted and bonded to the adjacent conductor without the need for any other adhesive or mold resin. , And the conductor is integrated. As the resin forming the self-fusion layer, a phenol resin, an epoxy resin, a polyimide resin, a resin obtained by modifying a part of the epoxy resin into a phenol resin, or the like can be used. The one in which the fusion film made of the agent is in a semi-cured state is used.

  Although the conductor is not particularly limited, an edgewise coil formed of a flat wire is used in the present embodiment. The edgewise coil is a coil wound vertically with the short side of the flat wire as the inner diameter surface. Compared to a coil wound with a round wire, the cross section is square and the winding cross-sectional area is large and the space factor is high. In addition, since the winding is not wound in a multilayer like a round wire but is made of a single layer, the temperature difference between the inside and outside of the winding is small, the heat radiation performance is excellent and the temperature rise is small. From such advantages, it is suitable as a coil for a highly efficient reactor.

  Such a self-fusing type edgewise coil uses a flat wire having a self-fusing layer compared to a conventional technology in which a coil formed by winding a flat wire is integrated by impregnation or resin molding. In addition, it is possible to eliminate the complexity of the impregnation process and the possibility that the insulating coating of the conductor is damaged during the molding of the mold. In addition, since the self-fusing type edgewise coil can be brought into direct contact with the refrigerant, there is also an advantage that the cooling effect is higher than those obtained by impregnating the periphery of the conductor with resin or resin-molding.

  The first and second resin covers 21 and 22 are made of a heat-resistant material such as PPS (polyphenylene sulfide) resin, which has a higher bonding temperature than the self-bonding layer. In addition, if it has heat resistance, a saturated polyester resin, urethane resin, epoxy resin, BMC (bulk molding compound), PBT (polybutylene terephthalate), or the like can be used.

  The first and second resin covers 21 and 22 each include a covering portion 2c having block-shaped cores 14c and 14d embedded therein, and left and right bobbins 2a and 2b formed as a pair with the covering portion 2c. Have. The first resin cover 21 is similarly annularly combined with a second resin cover 22 having a yoke portion and left and right legs, and the winding portions 3a, 3b of the coil 3 are provided on the outer periphery of the bobbins 2a, 2b. Are attached to form a reactor.

  The left and right bobbins 2a and 2b have a cylindrical shape, and form the legs of the annular core 1 inside the left and right bobbins 2a and 2b when the first and second resin covers 21 and 22 are combined. The thick I-shaped cores 11a and 11b, the thin I-shaped cores 12a, 13a, 12b and 13b and the spacers 15a and 15b are inserted. As described above, the thick I-shaped cores 11a, 11b, the thin I-shaped cores 12a, 13a, 12b, 13b and the spacers 15a, 15b are bonded by an adhesive.

  At the upper part of the first resin cover 21, the flat wall portions 2d and 2e are opposed to the final turn portions of the conductor exposed at the ends of the winding portions 3a and 3b of the coil. It is formed in a direction perpendicular to the axial direction. The last turn of the conductor is adhered to the walls 2d and 2e with an adhesive. In this case, in this embodiment, since the conducting wire is formed of a rectangular wire, the flat surface of the rectangular wire is bonded to the bonding surface of the first resin cover 21 in a state of being overlapped.

  As the adhesive for bonding the walls 2d and 2e and the final turn of the conductor, the same epoxy adhesive as that for bonding the core and the spacer can be used, but other adhesives may be used. I do not care. Further, the adhesive in the present invention also includes a self-fusion layer. The self-fusion layer covering the surface of the conductor is used as it is, and the walls 2d and 2e and the last turn of the conductor are provided on the conductor. It is also possible to adhere by a fusion layer.

  Openings 2f are formed in the walls 2d and 2e so that a part of the bonded wire is exposed from a surface opposite to a surface bonded to the wire. That is, in the present embodiment, the outer periphery of the resin cover and the coil can be brought into contact with the refrigerant that cools the reactor without the presence of a filler that fixes them. The surface of the conductor can be contacted through the portion 2f. Reinforcing ribs 2g are provided between the walls 2d and 2e and the surface of the resin cover 21, avoiding the opening 2f.

(2) Manufacturing Method The reactor of the present embodiment is manufactured as follows.
First, a rectangular wire having a self-fusion layer formed on its surface is edgewise wound to form a coil 3 having left and right winding portions 3a and 3b and a connection portion 3c. In this case, the winding operation of the flat wire is performed at normal temperature so that the self-fused layer on the surface does not melt and the adjacent flat wire does not adhere.

  After the coil 3 is formed, the coil 3 is combined with the first and second resin covers 21 and 22 so that the annular core 1 and the bobbins 2a and 2b are inserted into the winding portions 3a and 3b. . That is, when the first and second resin covers 21 and 22 are molded, the block-shaped cores 14c and 14d are molded therein, so that the yoke portion of the annular core 1 is embedded.

  In this state, the spacers 15a, 15b and the I-shaped cores 11a, 11b, 13a, 13b are fitted and bonded to the bobbins 2a, 2b of one of the resin covers (for example, the second resin cover 22). After that, the two winding portions 3a and 3b of the coil 3 are mounted outside the bobbins 2a and 2b. Furthermore, the bobbins 2a and 2b of the first resin cover 21 are inserted into the inside of the winding portions 3a and 3b, and the first resin cover 21 and the second resin cover 22 are combined with each other. The I-shaped core 14c embedded inside the one resin cover 21 is bonded to the I-shaped cores 12a and 12b. Further, the I-shaped cores 12a and 12b are bonded to the I-shaped cores 11a and 11b via the spacers 15a and 15b.

  In this case, for bonding the cores and the spacer, for example, an adhesive made of a thermosetting resin is applied, and the core is heated and cured simultaneously with the adhesive of the self-fusion layer for bonding the conductive wires of the coil. The curing of the adhesive and the curing of the self-fusion layer may be performed separately, or the adhesive between each core and the spacer may be cured before the self-fusion layer.

  At this time, an adhesive is applied to the walls 2d and 2e, and the end of the coil 3 and the resin cover 21 are bonded. Thereafter, the coil 3 and the resin cover 2 are pressed from the axial direction in a heating atmosphere of 140 to 200 ° C. in a state where the end surfaces of the winding portions 3a and 3b are in contact with the walls 2d and 2e. In this case, a pressing jig such as a mold is brought into contact with the coil-side molded product 2 so that the coil 3 does not come into contact with the pressing jig. The curing of the adhesive applied to the walls 2d and 2e may be performed simultaneously with the curing of the adhesive of each core and spacer or the adhesive of the self-fusion layer, or may be performed separately.

  When the coil 3 is pressurized in a heating atmosphere, the resin constituting the self-fusion layer is melted, and the adjacent rectangular wires are bonded to each other by the melted resin, so that the entire coil is integrated. At the same time, the end of the coil 3 is fixed to the walls 2d and 2e of the first resin cover 21 by curing the adhesive applied to the walls 2d and 2e. When a self-fusion layer is used as the adhesive, the self-fusion layer of the coil 3 is melted, so that the end of the coil 3 is attached to the walls 2d and 2e of the first resin cover 21. Fixed.

  Although not shown, the second resin cover 22 mounted on the opposite side of the coil 3 can also be combined with the coil 3 at the same time and integrated by heating and pressing. Of course, the second resin cover 22 may be performed in a step different from the heating / pressurizing process of the first resin cover 21 and the coil 3 shown in the drawing.

  In this embodiment, the resin covers 21 and 22 are made of PPS resin, and since this PPS resin has a high melting point of about 280 ° C. and high heat resistance, it is not affected by the melting temperature of the self-bonding layer. There is no. Therefore, the pressing jigs in contact with the resin covers 21 and 22 easily separate from the surfaces of the resin covers 21 and 22 after pressing despite the melting of the self-fusion layer of the coil 3. be able to. it can.

(3) Function / Effect According to the present embodiment, the following function / effect is exhibited.

(A) Adjacent conductors of the coil 3 are fixed to each other by an adhesive layer having a self-fusion function, and the entire coil 3 is formed into one lump, so that the resonance point (frequency) of the coil 3 is increased, At the same time as the vibration of the coil 3 itself is suppressed, the ends of the coil 3 are fixed to the walls 2d and 2e provided on the resin cover 21 by bonding with an adhesive. Is more reliably fixed, and the vibration of the coil 3 is suppressed. As a result, the generation of vibration and noise when the reactor is energized is effectively prevented, and the vibration of the lead portions 3d and 3e of the coil 3 is also suppressed, so that the stress applied to the connection between the coil 3 and the terminal is reduced. And the possibility of breakage of the connection part even during long-term use is eliminated.

(B) In the present embodiment, a rectangular wire is used as the conductor of the coil 3, and the resin cover 21 side is provided with the wall portions 2 d and 2 e overlapping with the plane of the rectangular wire. Can secure a large bonding area, and the coil 3 and the resin cover 21 can be firmly bonded.

(C) When the coil 3 and the resin cover 21 are bonded using the self-fusion layer formed on the surface of the conductor, no separate adhesive is required and the bonding operation is simple. It is. In addition, the coil 3 is bonded to the wound portion of the coil 3 and the resin cover 21 is bonded to the end of the coil 3, and the coil 3 is mounted on the wall 2 d of the resin cover 21 in a state where the coil 3 is mounted outside the resin cover 21. , 2e, so that they can be performed at the same time, and there is an advantage that the bonding operation of the two can be performed more easily.

(D) In the edgewise coil 3 formed by winding a rectangular wire, a step is generated between the lead wire at the start or end of the winding and the lead wire of the next winding which overlaps the winding, so that the end face of the coil 3 is flat. Not be. Therefore, when the resin cover 21 and the end of the coil 3 are bonded, a sufficient contact area between them cannot be obtained, and the bonding strength may be weakened. On the other hand, in the present embodiment, by providing the resin cover 21 with the walls 2d and 2e for bonding to the conductor, the bonding area between the end of the coil 3 and the resin cover 21 is increased, and sufficient strength is obtained. Can be secured.

(E) In the present embodiment, since the vibration of the coil 3 and the lead portion thereof is suppressed, it is not necessary to fix the coil 3 and the resin cover 21 with a filler, and even if the coil 3 is exposed, the vibration can be suppressed. Since the durability is ensured, it is possible to bring a coolant such as a cooling oil into direct contact with the coil 3, thereby improving the cooling efficiency of the reactor.

(F) In the present embodiment, the opening 2f is formed in the walls 2d and 2e, so that the coolant can be brought into contact with the surface of the conductor opposite to the bonding surface. It can be performed more effectively.

[2. Second Embodiment]
In the present embodiment, as shown in FIG. 5, the wall portions 2d and 2e provided on the resin covers 21 and 22 are extended in accordance with the positions of the lead portions 3d and 3e of the conductor together with the final turn of the conductor constituting the coil 3. It was done. In this manner, not only the final turn of the conductor, but also the lead portions 3d and 3e protruding from the coil 3 can be adhered to the walls 2d and 2e, and the conductor can be fixed more firmly. As a result, even if the connecting portions between the drawers 3d and 3e and the terminals are separated, the vibration of the drawers can be effectively suppressed.
As described above, in the present invention, the positions and shapes of the wall portions 2d and 2e serving as the adhesive portions can be changed according to the directions of the lead portions 3d and 3e and the positions of the connection portions with the terminals.

[3. Third Embodiment]
In the present embodiment, as shown in FIG. 6, in addition to the walls 2d and 2e on the upper surface of the resin cover 21, a wall 2h supporting the lead portions 3d and 3e of the conductor on the side surface of the reactor is provided as the bonding portion. It is provided. In other words, the positions of the lead portions 3d and 3e of the conductor can be variously adjusted in accordance with the positions of the terminals connected to the external electric circuit, and accordingly, the position of the wall 2h is also changed as in the present embodiment. It can be changed as appropriate.

[4. Fourth embodiment]
In the present embodiment, as shown in FIG. 7, flat surfaces 2i and 2j on which the lead portions 3d and 3e of the conductive wire overlap are formed on the upper surface of the resin cover 21, and the flat surfaces 2i and 2j are connected to the lead portions 3d and 3d. 3e. In this case, the flat surfaces 2i and 2j are provided along the extending direction of the lead portions 3d and 3e, and may be provided along the axial direction of the coil, or may be provided in a direction perpendicular to the axial direction of the coil. Is also good. Further, as shown in the figure, the flat surfaces 2i and 2j may be the bottom surfaces of the grooves one step lower than the upper surface of the resin cover 21. Thus, by arranging the drawers on the groove-shaped flat surfaces 2i, 2j, the adhesive strength between the drawers 3d, 3e and the resin cover 21 can be further improved.

[5. Fifth Embodiment]
In the present embodiment, as shown in FIG. 8, the surface of the resin covers 21 and 22 facing the coil end faces is filled with resin so as to fill a step formed between them, thereby increasing the bonding area. Things. That is, since the final turn portion of the coil 3 is formed by winding a conductive wire, it is inclined with respect to the surfaces of the resin covers 21 and 22. Therefore, a gap is created simply by overlapping the two. Therefore, in the present embodiment, an inclined portion 2k corresponding to the angle of the conducting wire of the coil 3 is formed as an adhesive portion on the surface of the resin covers 21 and 22 facing the coil end surface.

  As shown in the plan view of the right winding part 3b in FIG. 8, the inclined part 2k is formed in a ring shape in accordance with the last turn part of the coil 3, and is a cross-sectional view of the left winding part 3a in FIG. As shown in (1), the amount of protrusion from the surfaces of the resin covers 21 and 22 is determined according to the distance between the end surfaces of the coil 3 and the end surfaces of the resin covers 21 and 22. According to the present embodiment, the gap between the end of the coil 3 and the opposing surfaces of the resin covers 21 and 22 can be filled by the inclined portion 2k, so that a high adhesive strength between them can be obtained.

[6. Other Embodiments]
The present invention is not limited to the above-described embodiment, but includes the following other embodiments.
(1) The conductive wire forming the coil 3 is not limited to a rectangular wire, but may be a round wire or a square wire. The winding method of the coil 3 is not limited to the edgewise winding, and other methods such as α winding can be adopted.

(2) Grooves and recesses are formed in the walls 2d, 2e, 2h and the flat surfaces 2i, 2j serving as adhesion portions, and a conductor such as a flat wire or a round wire is fitted into these grooves and recesses, and self-fusion is performed. The resin cover 21 and the drawers 3d and 3e are adhered by a layer.

(3) The openings 2f provided in the walls 2d, 2e, 2h are not limited to the illustrated embodiment. The shape and number thereof such as rectangles and grooves can be freely selected, and if the bonding strength is secured, the opening 2f is made as large as possible to increase the contact area between the refrigerant and the lead portions 3d and 3e of the conductor. Is preferable for improving the cooling performance. For example, the position of the opening 2f is not limited to the portion of the walls 2d, 2e, 2h overlapping with the rectangular wire, but is provided at the flange 2m provided at the edge of the walls 2d, 2e, 2h. It is also possible.

(4) The shape of the annular core 1 is not limited to a rounded square as shown in the figure, but may be applied to a track-like, annular, figure-eight, or a core having three or more legs. When a core is formed, a desired annular core 1 can be formed by appropriately selecting a U-shaped, T-shaped, or E-shaped core in addition to combining the cores of the illustrated embodiment. The shape and number of the coils 3 can be appropriately changed according to the shape of the core 1 and the like.

(5) The combination of the resin cover and the core may be prepared separately, and the core may be simply inserted into the resin cover. Alternatively, as shown in the illustrated embodiment, a molding method or an insert may be used. A part of the core may be integrally embedded in the resin cover by a molding method. When the core is embedded in the resin cover, the fixing strength of both can be improved.

(6) In the illustrated embodiment, the first resin cover 21 is provided with an adhesive portion such as a wall, a flat surface, and an inclined portion, but the second resin cover 22 is provided with a similar adhesive portion. Alternatively, the coil 3 may be bonded so as to be sandwiched between the two resin covers 21 and 22 from both sides. In this case, the adhesion between the coil 3 and the resin covers 21 and 22 becomes more reliable, so that noise and vibration of the reactor can be reduced and strength can be improved.

DESCRIPTION OF SYMBOLS 1 ... Annular core 11a, 11b, 12a, 12b13a, 13b ... I-shaped core 14c, 14d ... Block-shaped core 15a, 15b ... Spacer 21, 22 ... Resin cover 2a, 2b ... Bobbin 2c ... Covering part 2d, 2e, 2h ... Wall 2f ... Opening 2g ... Ribs 2i and 2j ... Flat surface 2k ... Inclination 2m ... Flange 3 ... Coil 3a, 3b ... Wound 3C ... Connection 3d, 3e ... Drawer

Claims (4)

Core, a resin cover provided around the core, and a coil disposed around the core outside the resin cover,
The coil includes a conductive wire having a self-fusing layer formed on a surface thereof, and adjacent conductive wires are bonded to each other by the self-fusing layer,
The resin cover includes an adhesive portion provided on a part thereof and facing an end of the coil, and in the adhesive portion, an end of the coil is adhered to the resin cover by an adhesive,
The reactor, wherein the bonding portion is a flat surface formed on a surface of the resin cover, and an end of the coil is bonded to the flat surface.   The reactor according to claim 1, wherein the conductive wire is a flat wire, and a flat surface of the flat wire is bonded to a bonding surface of the resin cover.   3. The reactor according to claim 1, wherein the end of the coil and the resin cover are bonded by a self-fusion layer of the coil. 4.   4. The reactor according to claim 1, wherein at least a part of the core is embedded inside the resin cover. 5.

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