JP2012084773A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor which allows easy inductance adjustment.SOLUTION: A reactor 1α comprises: a coil 2α; and a magnetic core 3 which is arranged in the inside and outside of the coil 2α to form a closed magnetic circuit. The magnetic core 3 comprises: a plurality of magnetic core pieces 31m which form at least part of the magnetic core 3; and gap materials 31g which are arranged between the magnetic core pieces 31m. The reactor 1α further comprises adhesive tape 4 which integrally fixes an assembly 100 of the magnetic core pieces 31m and the gap materials 31g. The adhesive tape 4 is provided with openings 40. Because the assembly is fixed into an integrated state with the adhesive tape 4 having openings 40, it is unnecessary to use adhesive to thereby eliminate the complexity in operation caused by the use of adhesive. Furthermore, the assembly 100 can be fixed with its gap length kept constant, thus making it possible to obtain desired inductance.

Description

  The present invention relates to a reactor used for a component of a power conversion device such as a vehicle-mounted DC-DC converter. In particular, the present invention relates to a reactor including a reactor core that allows easy adjustment of inductance and is excellent in assembling workability.

  A reactor is one of the parts of a circuit that performs a voltage step-up operation or a voltage step-down operation. This reactor is used for a converter mounted on a vehicle such as a hybrid vehicle. The main constituent members of the reactor are a core made of a magnetic material and a coil wound around a part of the outer periphery of the core. As the core, for example, there is a core as shown in Patent Document 1.

  The core described in Patent Document 1 is configured by combining a plurality of magnetic core pieces. This core has an annular shape, and has two linear portions facing each other and two curved portions facing each other, and a gap of a predetermined interval is formed between each of the magnetic core pieces forming the linear portion and the curved portion. Has been. A gap material is disposed in each gap, and the gap material is fixed to an adjacent magnetic core piece with an adhesive.

JP 2006-351679 A

  However, when an adhesive is used for joining the magnetic core piece and the gap material as described above, there are the following problems.

(1) Complexity of assembly work associated with use of adhesive When the core is composed of a plurality of core pieces and a gap material, it is necessary to apply and cure the adhesive at each contact point between the core piece and the gap material. Further, depending on the amount of the adhesive, the adhesive may protrude from between the core piece and the gap material, and post-treatment such as wiping off the protruding adhesive is also necessary. For this reason, the assembly work of the reactor using the adhesive becomes complicated.

(2) Difficulty in adjusting inductance It is difficult to apply an adhesive while reducing variations in thickness in one coating layer and variations in thickness between multiple coating layers. Even if these variations can be reduced and the adhesive can be applied, the adhesive before curing is fluid, so the thickness of the adhesive after curing is uniform depending on the pressure contact between the core piece and the gap material. Difficult to make. Therefore, the variation in the thickness of the adhesive tends to increase, and when the reactors are mass-produced, it is difficult to uniformly adjust the inductance of each reactor.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a reactor that does not require an adhesive for joining the core piece and the gap member, and that allows easy adjustment of the inductance. is there.

  The reactor of the present invention includes a coil and a magnetic core that is disposed inside and outside the coil to form a closed magnetic circuit. The magnetic core includes a plurality of magnetic core pieces and a gap member disposed at least at a part between the magnetic core pieces. Furthermore, an adhesive tape for integrally fixing the assembly of the magnetic core piece and the gap material is provided. The adhesive tape has an opening.

  According to said structure, it is not necessary to use an adhesive agent by fixing the assembly of a magnetic core piece and a gap material integrally with an adhesive tape, and the assembly operation | work of a reactor can be simplified. Moreover, with the non-use of the adhesive, it is possible to eliminate variation in gap length, which is the interval between adjacent core pieces.

  By fixing the assembly in an integrated manner with an adhesive tape having an opening, air can be discharged from between the assembly and the adhesive tape through the opening. If air remains between the assembly and the adhesive tape, the air may expand due to heat generated during the manufacture or operation of the reactor, leading to peeling of the adhesive tape, and developing a misalignment between the magnetic core piece and the gap material. There is. In addition, air may function as a heat insulating layer to prevent heat dissipation of the magnetic core, or may interfere with the close arrangement of the coil and the magnetic core piece. Therefore, if air can be discharged from between the assembly and the adhesive tape through the opening, all of these disadvantages can be eliminated.

  As one form of this invention, it is mentioned that the said opening part is arrange | positioned between the magnetic core pieces which pinch | interpose at least a gap material among the outer peripheral surfaces of the said assembly.

  According to the above configuration, when the assembly is integrally fixed with the adhesive tape, at least a portion where the air tends to remain on the outer peripheral surface of the assembly, for example, between the two magnetic core pieces sandwiching the gap material By arranging the opening, it becomes easier to discharge air.

  As one form of this invention, the shape of the said opening part is mentioned as a hole shape.

  According to said structure, since the shape of the said opening part is a hole shape, when sticking an adhesive tape on the said assembly, it becomes easier to discharge | emit the air between the said assembly and an adhesive tape from the opening part. .

  As one form of this invention, it is mentioned that the shape of the said opening part is slit shape.

  According to the above configuration, the air can be discharged from the opening provided in the slit shape, and the shape of the opening is a slit shape. Therefore, as in the case where a hole is provided in the adhesive tape, The adhesive tape is not removed, and the braid can be fixed using a large surface area.

  As one form of this invention, it is mentioned that the said opening part is disperse | distributed uniformly over the whole surface of the said adhesive tape.

  According to said structure, the said air can be discharged | emitted from almost anywhere of an adhesive tape.

  As one mode of the present invention, the area of the opposing surfaces of the gap material and the magnetic core piece may be such that the opposing surfaces of the gap material are smaller than the opposing surfaces of the magnetic core pieces.

  According to said structure, since the area of the opposing surface of a gap material is smaller than the area of the opposing surface of a magnetic core piece, since the gap material does not protrude from the outer peripheral surface of the said magnetic core piece, a magnetic core The piece can be in close proximity to the coil. Therefore, the heat from the coil can be effectively radiated.

  As one form of this invention, it is mentioned that the said assembly is being fixed with the adhesive tape of 1 sheet along the circumferential direction.

  According to said structure, in order to fix the said assembly integrally, it is sufficient to stick an adhesive tape to an assembly once, and it is excellent in working efficiency.

  As one form of this invention, it fixes with the said adhesive tape along the circumferential direction for every area | region straddling both magnetic core pieces which pinch | interpose a gap material in the said assembly, and the said adhesive tape is affixed except the said area | region. Not to mention.

  According to said structure, since the location which sticks the said adhesive tape is every area | region straddling both magnetic core pieces which pinch | interpose a gap material in the said assembly, the usage-amount of an adhesive tape can be reduced. That is, since the contact area between the adhesive tape and the magnetic core piece can be reduced, it is possible to reduce the area where air may remain.

  Further, since the adhesive tape is exposed without being attached except for the region in the assembly, the heat generated from the coil can be effectively conducted to the magnetic core piece, and the heat dissipation can be improved. it can.

  As one form of this invention, fixing at least two places which oppose the outer peripheral surface of the said assembly with the said adhesive tape along a longitudinal direction is mentioned.

  According to said structure, the usage-amount of the adhesive tape for fixing to the said assembly integral can be reduced. That is, since the contact area between the adhesive tape and the magnetic core piece can be reduced, it is possible to reduce the area where air may remain.

  Since the reactor of the present invention uses an adhesive tape without using an adhesive when fixing the assembly of the magnetic core piece and the gap material together, it eliminates the troublesome work caused by using the adhesive. be able to. In addition, since the assembly is fixed by the adhesive tape having the opening, it is possible to eliminate all inconveniences caused by the air remaining between the assembly and the adhesive tape. Adjustment can be facilitated.

1 is a schematic perspective view showing a reactor according to Embodiment 1. FIG. FIG. 3 is an exploded perspective view illustrating an outline of each configuration of the reactor according to the first embodiment. It is a figure which shows the form which affixed the adhesive tape which concerns on Embodiment 1 on a part of magnetic core, Comprising: It is a schematic perspective view for demonstrating the opening part provided in the adhesive tape. It is explanatory drawing which shows the positional relationship of the both ends of the adhesive tape which concerns on Embodiment 1, Comprising: (A) is a front view which shows a butting type, (B) is a front view which shows a clearance gap type, (C) is a duplication type. It is a front view showing It is a figure which shows the form which affixed the adhesive tape which concerns on Embodiment 2 on a part of magnetic core, Comprising: It is a schematic perspective view for demonstrating the opening part provided in the adhesive tape. It is a figure which shows the reactor which concerns on Embodiment 3, Comprising: (A) is a perspective view, (B) is sectional drawing cut | disconnected by the BB line in (A) of FIG. It is a perspective view which shows the outline of the form which affixed the adhesive tape which concerns on the modification 1 to a part of magnetic core. It is a figure which shows the outline of the form which affixed the adhesive tape which concerns on the modification 2 to a part of magnetic core, Comprising: (A) is a perspective view, (B) is a front view. It is a figure which shows the outline of the formation which affixed the adhesive tape which concerns on the modification 3 to a part of magnetic core, Comprising: (A) is a perspective view, (B) is a front view.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol in a figure shows the same name thing.

<< Embodiment 1 >>
≪Overall structure≫
As shown in FIGS. 1 and 2, the reactor 1α includes a coil 2α and a magnetic core 3 on which the coil 2α is disposed. The magnetic core 3 includes an inner core portion 31 inserted through the coil 2α and a connecting core portion 32 disposed on the outer periphery of the coil 2α and connected to the inner core portion 31. The magnetic core 3 is closed by both the core portions 31 and 32. Form a road. As shown in FIGS. 2 and 3, the inner core portion 31 includes a set 100 of a plurality of magnetic core pieces 31 m and a gap material 31 g disposed therebetween. The reactor 1α is characterized in that the adhesive tape 4 for fixing the assembly 100 integrally is provided and an opening 40 for allowing air to pass through the adhesive tape 4 is provided. Hereinafter, each configuration will be described in detail.

[coil]
The coil 2α includes a pair of coil elements 2a and 2b formed by spirally winding a single continuous winding 2w having no joint part, and a coil connecting part 2r for connecting both the coil elements 2a and 2b. . Each coil element 2a, 2b has the same number of turns, and the shape (end face shape) seen from the axial direction is substantially rectangular. These two coil elements 2a and 2b are arranged side by side so that their axial directions are parallel to each other, and a part of the winding 2w is bent in a U-shape on the other end side of the coil 2α so that the coil connecting portion 2r is formed. Is formed. With this configuration, the winding directions of both coil elements 2a and 2b are the same.

  The winding 2w is preferably a covered wire having an insulating coating made of an insulating material on the outer periphery of a conductor made of a conductive material such as copper or aluminum. Here, a coated rectangular wire is used in which the conductor is made of a rectangular copper wire and the insulating coating is made of enamel (typically polyamideimide). The thickness of the insulating coating is preferably 20 μm or more and 100 μm or less, and the thicker the pinholes can be reduced, the higher the electrical insulation. Both coil elements 2a, 2b are formed in a hollow rectangular tube shape by winding the above-mentioned covered rectangular wire edgewise. The winding 2w can be used in various shapes such as a circular shape, an elliptical shape, a polygonal shape, etc., in addition to the conductor made of a rectangular wire. A flat wire is easier to form a coil having a higher space factor than when a round wire having a circular cross section is used. In addition, it can be set as the form which produced each coil element by a separate coil | winding, and joined the end part of the coil | winding which forms each coil element by welding etc. to make it an integral coil.

  Both end portions of the winding forming the coil are appropriately extended from the turn forming portion on one end side of the coil and pulled out of the case. A terminal member (not shown) made of a conductive material is connected to the exposed conductor portion of the both ends of the drawn winding wire after the insulation coating is peeled off. An external device (not shown) such as a power source for supplying power is connected to the coil 2α via this terminal member.

[Magnetic core]
The magnetic core 3 has a pair of inner core portions 31 in which the coil elements 2a and 2b are respectively disposed, and a pair of connecting core portions 32 that are not disposed in the coil 2α and are exposed from the coil 2α. Here, each inner core part 31 is a rectangular parallelepiped shape, and each connection core part 32 is a prismatic body having a pair of trapezoidal surfaces. In the magnetic core 3, the connecting core portions 32 are disposed so as to sandwich the inner core portions 31 that are spaced apart from each other, and the end surfaces 31 e of the inner core portions 31 and the inner end surfaces 32 e of the connecting core portions 32 are brought into contact with each other. It is formed in an annular shape (FIG. 2). The inner core portion 31 and the connecting core portion 32 form a closed magnetic circuit when the coil 2α is excited.

  The inner core portion 31 is a laminate configured by alternately laminating magnetic core pieces 31m made of a magnetic material and gap members 31g typically made of a non-magnetic material, and the connecting core portion 32 is made of a magnetic material. A magnetic core piece made of a material. Further, a plurality of magnetic core pieces 31m may be formed between the gap members 31g. For example, the magnetic core pieces 31m may be divided in the axial direction of the coil 2α, and the divided pieces may be arranged in parallel. The magnetic core piece 31m may be divided in a direction orthogonal to the axial direction of the coil 2α, and the divided pieces may be stacked. Each magnetic core piece 31m includes a green compact formed using a soft magnetic powder having an insulating coating, a laminated steel plate in which a plurality of electromagnetic steel plates having an insulating coating are laminated, or magnetic powder and a resin. It can be comprised from the shaping | molding hardening body comprised from a mixture.

(Green compact)
The green compact is typically formed of soft magnetic powder having an insulating coating on the surface or mixed powder in which a binder is appropriately mixed in addition to soft magnetic powder, and then fired at a temperature lower than the heat resistance temperature of the insulating coating. Can be obtained. The green compact can easily form a three-dimensional shape, and for example, can easily form an inner core portion having an outer shape adapted to the shape of the inner peripheral surface of the coil. In addition, the compacted body has an insulator between the magnetic powders, so that the magnetic powders are insulated from each other, eddy current loss can be reduced, and even when high-frequency power is applied to the coil, The loss can be reduced.

  The above soft magnetic powder includes Fe-based alloy powders such as Fe-Si, Fe-Ni, Fe-Al, Fe-Co, Fe-Cr, Fe-Si-Al as well as iron group metal powders such as Fe, Co and Ni. Alternatively, rare earth metal powder, ferrite powder or the like can be used. In particular, the Fe-based alloy powder is easy to obtain a compacted body having a higher saturation magnetic flux density than a magnetic material such as ferrite. Examples of the insulating coating formed on the soft magnetic powder include a phosphoric acid compound, a silicon compound, a zirconium compound, an aluminum compound, or a boron compound. Examples of the binder include thermoplastic resins, non-thermoplastic resins, and higher fatty acids. This binder disappears by the above baking, or changes to an insulator such as silica. A well-known thing may be utilized for a compacting body.

  The saturation magnetic flux density of the green compact can be changed by adjusting the material of the soft magnetic powder, the mixing ratio of the soft magnetic powder and the binder, the amount of various coatings, and the like. For example, a powder compact with a high saturation magnetic flux density can be obtained by using a soft magnetic powder with a high saturation magnetic flux density or by increasing the proportion of the soft magnetic material by reducing the blending amount of the binder. In addition, the saturation magnetic flux density tends to be increased by changing the molding pressure, specifically, by increasing the molding pressure. It is advisable to select the material of the soft magnetic powder and adjust the molding pressure so as to obtain a desired saturation magnetic flux density.

(Laminated steel sheet)
The laminated steel sheet is composed of a laminate in which a plurality of electromagnetic steel sheets having an insulating coating are laminated. For example, when an electromagnetic steel plate is used for the inner core portion, it is easy to obtain a magnetic core having a high saturation magnetic flux density as compared with the case where a green compact is used.

(Molded cured body)
The molded and hardened body is composed of a mixture containing magnetic powder and resin. This molded cured body can typically be formed by injection molding or cast molding. In the injection molding, a magnetic powder made of a magnetic material and a fluid resin are mixed, the mixture is poured into a mold by applying a predetermined pressure, and then the resin is cured. In cast molding, after obtaining a mixture similar to that of injection molding, the mixture is injected into a mold without applying pressure to be molded and cured.

  In any of the above molding methods, the same magnetic powder as that described above can be used as the magnetic powder. In particular, as the soft magnetic powder, a powder made of an iron-based material such as pure iron powder or Fe-based alloy powder can be suitably used. Since the iron-based material is a material having a higher saturation magnetic flux density and magnetic permeability than ferrite and the like, a core having a certain saturation magnetic flux density and magnetic permeability can be obtained even when the resin content is high. A coating powder having a coating made of iron phosphate or the like on the surface of particles made of a soft magnetic material may be used. As these magnetic powders, powders having an average particle diameter of 1 μm or more and 1000 μm or less, and more preferably 10 μm or more and 500 μm or less can be easily used.

  In any of the above-described molding methods, a thermosetting resin such as an epoxy resin, a phenol resin, or a silicone resin can be suitably used as the binder resin. When a thermosetting resin is used, the molded body is heated to thermally cure the resin. A room temperature curable resin or a low temperature curable resin may be used. In this case, the molded body is allowed to stand at a room temperature to a relatively low temperature to be cured. The molded and hardened body has a relatively large amount of non-magnetic resin as compared with the green compact and the electromagnetic steel sheet.

  In addition to the magnetic powder and the resin serving as the binder, a filler made of ceramics such as alumina or silica may be mixed into the constituent material of the molded cured body. By mixing the filler having a specific gravity smaller than that of the magnetic powder, uneven distribution of the magnetic powder is suppressed, and an inner core portion in which the magnetic powder is uniformly dispersed can be easily obtained. Moreover, when the said filler is comprised from the material excellent in thermal conductivity, it can contribute to the improvement of heat dissipation. In the case of mixing the filler, the total content of the magnetic powder and the filler is 20% by volume to 70% by volume when the inner core part is 100% by volume.

  The permeability and saturation magnetic flux density of the molded cured body can be adjusted by changing the blending of the magnetic powder and the resin serving as the binder. For example, when the blending amount of the magnetic powder is reduced, a molded and hardened body having a low magnetic permeability can be obtained.

  Since each core part 31 and 32 can be selected from the constituent material mentioned above, it can be set as the form which made the material of the inner core part 31 and the material of the connection core part 32 differ. For example, when the inner core portion 31 is the above-mentioned green compact or the above-mentioned laminated body and the connecting core portion 32 is the above-mentioned molded and hardened body, the saturation magnetic flux density of the inner core portion 31 is easier to increase than the connecting core portion 32. Here, 31 m of magnetic core pieces and the connection core part 32 are made into the compacting body of the soft magnetic powder containing iron, such as iron and steel.

  The gap material 31g is a plate-like body disposed between the magnetic core pieces 31m for adjusting the inductance. The outer shape of the gap material 31g can be selected as appropriate, and the area (outer dimensions) between the opposing surfaces of the magnetic core piece 31m and the gap material 31g may be equivalent to the magnetic core piece 31m. In particular, it is preferable that the outer dimension of the gap material 31g is smaller than the outer dimension of the magnetic core 31m. By doing so, since the gap material 31g does not protrude from the outer peripheral surface of the magnetic core piece 31m to the outer periphery, the magnetic core piece 31m can be brought close to the coil 2α, and heat from the coil 2α passes through the magnetic core piece 31m. Effectively dissipates heat. Here, the outer shape of the gap material 31g is a shape along the shape of the inner peripheral surface of the cylindrical coil 2α, similar to the outer shape of the magnetic core piece 31m. It is slightly smaller than the outer dimension of the piece 31m.

  The material constituting the gap material 31g is preferably a material having a lower magnetic permeability than the magnetic core piece 31m. Specifically, the material is preferably made of a material having a relative permeability of 1.1 or more and less than 1.5. Such a material is typically made of a non-magnetic material, and examples thereof include alumina, glass epoxy resin, and unsaturated polyester. In particular, a hard and highly rigid material is preferable because variations in gap length hardly occur. In addition to the above constituent materials, a mixed material in which a powdered magnetic material is dispersed in a nonmagnetic material may be used. Examples of the nonmagnetic material include ceramics and phenol resin, and examples of the powdery magnetic material include ferrite, Fe, Fe-Si, and sendust.

  The number of the magnetic core pieces 31m and the gap members 31g described above may be appropriately selected so that the reactor 1α has a desired inductance.

  The assembly 100 of the magnetic core piece 31m and the gap material 31g described above is integrally fixed by the adhesive tape 4 described later.

  In the magnetic core 3, the installation side surface of the inner core portion 31 and the installation side surface of the connecting core portion 32 are not flush with each other. Specifically, when the reactor 1α is installed on a fixed object, the surface on the connection core portion 32 that is the installation side (hereinafter referred to as the core installation surface; the lower surface in FIG. 2) is the surface that is the installation side of the inner core portion 31. Than protruding. In addition, the core installation surface of the connection core portion 32 is flush with the surface on the installation side of the coil 2α (hereinafter referred to as the coil installation surface; the lower surface in FIG. 2). In the state where the reactor 1 is installed on the fixed object, the length in the direction perpendicular to the surface of the fixed object (here, the length perpendicular to the axial direction of the coil 2α and the vertical direction in FIG. 2)) is adjusted is doing. Therefore, the magnetic core 3 is H-shaped when seen through from the side in a state where the reactor 1α is installed. Further, in a state where the magnetic core 3 is assembled in an annular shape, the side surface (the front side and the back surface in FIG. 2) of the connecting core portion 32 protrudes outward from the side surface of the inner core portion 31. Therefore, the magnetic core 3 is H-shaped even when seen through the upper surface or the lower surface in a state where the reactor is installed (in a state where the lower side is the installation side in FIG. 2). Such a three-dimensional magnetic core 3 can be easily formed by forming a compacted body, and a portion protruding from the inner core portion 31 in the connecting core portion 32 can also be used as a magnetic path.

[Adhesive tape]
The adhesive tape 4 is used to integrally fix the assembly 100 of the magnetic core piece 31m and the gap material 31g described above. The adhesive tape 4 is composed of a base material and an adhesive, and the opening 40 is used to allow air to pass therethrough. It is provided so as to communicate with the front and back of the tape 4.

  The adhesive tape 4 is preferably made of a material that has excellent heat resistance, a tensile strength of 20 N / 10 mm or more, an elongation of 95% or less, and an adhesive strength of at least one of 2.0 N / 10 mm or more. It is even more preferable if it is satisfied. As such a material, for example, polyester, polyimide (PI), polytetrafluoroethylene (PTFE) film, glass cloth, silicone, acrylic, or the like can be used as the base material of the adhesive tape 4. In particular, when the base material is made of silicone or acrylic, vibration due to magnetostriction of the magnetic core 3 can be reduced, which is preferable. An acrylic or silicone adhesive can be used as the adhesive. By satisfying at least one of the above ranges, it is possible to prevent the positional relationship between the magnetic core piece and the gap material from shifting when the assembly 100 is fixed integrally. The tensile strength, elongation, and adhesive strength are values measured by the test method defined in “Adhesive Tape / Adhesive Sheet Test Method JIS Z 0237 (2009)”. In this example, a polyester film is used for the substrate, and a silicone-based adhesive is used for the adhesive. The characteristic values of the adhesive tape 4 measured by the test method described above were 35 N / 10 mm in tensile strength, 70% elongation at break, and 3.5 N / 10 mm in adhesive strength.

  The magnitude | size of the adhesive tape 4 is good to select suitably with the sticking location of the adhesive tape 4 mentioned later. The thickness of the adhesive tape 4 may be a thickness that can sufficiently fix the assembly 100 and can insulate the coil 2α and the inner core portion 31. Specifically, the thickness of the adhesive tape 4 is 0.08. What is necessary is just 0.13 mm. Here, the thickness of the base material is 0.110 mm.

(Aperture)
As shown in FIG. 2, the adhesive tape 4 is provided with an opening 40 for allowing air to pass therethrough so as to communicate with the front and back of the adhesive tape 4. When the assembly 100 is fixed integrally with the adhesive tape 4 by the opening 40, the air between the assembly 100 and the adhesive tape 4 is discharged from the opening 40, and between the assembly 100 and the adhesive tape 4. It is possible to prevent air from remaining on the surface.

  The shape of the opening 40 provided in the pressure-sensitive adhesive tape 4 is a hole shape formed by partially punching the pressure-sensitive adhesive tape 4, a slit shape formed by cutting that does not partially remove the pressure-sensitive adhesive tape 4, or the hole It is mentioned that both the shape and the slit shape are provided. In the case of a hole shape, specifically, all circles including a perfect circle or an ellipse, a polygonal shape, or a combination thereof, and in the case of a slit shape, specifically, a straight line, a curve, or a combination thereof Various lines can be selected. Further, the hole shape and the slit shape may be partially combined. The size of the opening may be appropriately selected so that air is discharged between the assembly 100 and the adhesive tape 4. For example, when a plurality of the openings are provided, the sizes of all the openings may be the same or different.

  And the position where this opening part 40 is provided should just be selected suitably, and when the opening part 40 is provided with two or more, it is good to also select the space | interval of opening parts 40 each suitably. In particular, when the adhesive tape 4 is affixed to the assembly 100, at least the gap between the magnetic core pieces 31 m sandwiching the gap material 31 g in which air tends to remain on the outer peripheral surface of the assembly 100, or the vicinity thereof. It is preferable that By doing so, when the assembly 100 is fixed integrally with the adhesive tape 4, the air between the assembly 100 and the adhesive tape 4 can be more effectively discharged from the opening 40. And air hardly remain between the adhesive tape 4 and the adhesive tape 4. In particular, it is more preferable that the openings 40 are uniformly distributed over the entire surface of the adhesive tape 4 because a plurality of openings 40 can be easily provided between the magnetic core pieces 31m sandwiching the gap 31g. In that case, air can be discharged from almost anywhere on the adhesive tape 4.

Here, uniformly dispersed over the entire surface means that, for example, when the shape of the opening 40 is a hole, 3 to 7 pieces / cm ^{2 are} provided. And when the opening part 40 is slit shape, 3-14 piece / cm < ² > is mentioned.

  In this example, as an example of the opening 40, as shown in FIG. 3, the circular holes 40c formed by partially punching the adhesive tape 4 are uniformly distributed over the entire surface of the adhesive tape 4. Has been. The diameter of the circular holes 40c is 2 mm, and the pitches (distances between the centers of the holes) between the adjacent circular holes 40c are provided at intervals of 5 mm. By providing the opening 40 of the circular hole 40c as described above, as described above, the opening 40 can be arranged between the magnetic core pieces 31m sandwiching the gap material 31g in the outer peripheral surface of the assembly 100. In addition, air can be prevented from remaining between the assembly 100 and the adhesive tape 4, and the assembly 100 can be fixed integrally.

  When the assembly 100 is fixed integrally with the pressure-sensitive adhesive tape 4, the magnetic core piece 31 m and the gap material 31 g are displaced from each other at the position where the pressure-sensitive adhesive tape 4 is pasted, and the gap length does not vary. As long as it is on the outer peripheral surface of the assembly 100 that can be fixed in this manner, the number of sheets to be pasted may be appropriately selected. For example, you may affix along the circumferential direction of the said assembly 100, and you may affix an adhesive tape along a longitudinal direction (axial direction), and may fix the said assembly 100. FIG. When pasting along the circumferential direction, it may be fixed along the circumferential direction of the assembly 100 with a single adhesive tape 4 as in this example, or both magnetic core pieces sandwiching the gap material 31g in the assembly 100 You may fix with the adhesive tape 4 of several sheets for every area | region over 31 m. In the former case, since the number of times the adhesive tape 4 is applied is only once, it is difficult to take time. In the latter case, the gap is fixed for each region straddling the magnetic core pieces 31m sandwiching the gap material 31g. It is necessary to stick the adhesive tape 4 only, but the contact area between the adhesive tape 4 and the magnetic core piece 31m can be reduced, and the area where air may remain can be reduced. On the other hand, when affixing the adhesive tape 4 along the longitudinal direction (axial direction) of the assembly 100, it is preferable to affix at least two locations on the outer peripheral surface facing each other. By doing so, the assembly 100 can be fixed integrally, and the contact area between the adhesive tape 4 and the magnetic core piece 31m can be reduced, and the area where air can remain is reduced. it can. In addition, when two or more adhesive tapes 4 are pasted, the braid 100 may be fixed by pasting so that the intervals between the adhesive tapes 4 are equal.

  And when sticking this adhesive tape 4 along the circumferential direction of the braid 100, the position of the both ends of the adhesive tape 4 can be selected suitably. For example, both ends of the adhesive tape 4 may be abutted as in the butting type in FIG. 4A, or the gap between both ends of the adhesive tape 4 is open as in the gap type in FIG. Alternatively, both ends of the adhesive tape 4 may be overlapped as in the overlapping type (C). In the case of the butt type, the assembly 100 can be firmly fixed, and when inserted into the coil 2α, the distance from the coil 2α can be made constant at any point in the circumferential direction. This is preferable in that the insulation with the magnetic core piece 31m can be ensured uniformly. Moreover, in the case of a clearance type, it is preferable at the point which can discharge | emit air easily from the location opened, and can reduce the usage-amount of an adhesive tape. And in the case of a duplication type, it is preferable at the point which can fix the said assembly 100 reliably.

[Insulator]
Furthermore, an insulator 5 may be provided between the coil 2α and the magnetic core 3 in order to increase the insulation between the coil 2α and the magnetic core 3 and the certainty of positioning thereof. The insulator 5 has a configuration including a bobbin disposed on the outer periphery of the inner core portion 31 and a pair of frame-like portions 52 that are in contact with the end surface of the coil 2α (the surface where the turn of the coil element appears to be annular). It is done.

  Here, the bobbin is configured by a pair of cross-sectioned bobbin pieces 51, and the bobbin pieces do not contact each other, and the bobbin is disposed only on a part of the outer peripheral surface of the inner core portion 31. The bobbin can be a cylindrical body arranged along the entire circumference of the outer peripheral surface of the inner core portion 31, but if the insulation distance between the coil 2α and the inner core portion 31 can be secured, As shown in FIG. 2, a part of the inner core portion 31 may not be covered with the bobbin piece 51. In FIG. 2, for convenience of explanation, the bobbin piece 51 is shown only for the inner core portion 31 on the front side of the paper, but it is also provided on the inner core portion 31 on the back side of the paper in FIG. In addition, here, the bobbin piece 51 is provided with a window portion penetrating the front and back.

  Since a part of the inner core portion 31 to which the adhesive tape 4 is attached is exposed from the bobbin, the bobbin material can be reduced. Moreover, when setting it as the form which provides sealing resin, it is set as the bobbin piece 51 which has the said window part, or it is set as the structure where the perimeter of the inner core part 31 is not covered with the bobbin piece 51. And the contact area between the sealing resin and the sealing resin can be increased.

  The frame-shaped part 52 has a flat plate shape and has a pair of openings through which the respective inner core parts 31 are inserted, and protrudes toward the inner core part 31 so that the inner core part 31 can be easily introduced. It has a short cylindrical part. The one frame-like portion 52 is provided with a coil connecting portion 2r and a flange portion 52f for insulating between the coil connecting portion 2r and the connecting core portion 32.

  As the constituent material of the insulator, an insulating material such as polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin, liquid crystal polymer (LCP) can be used.

[Case]
A case (not shown) for housing the coil 2α and the magnetic core 3 may be provided. The shape and size of the case can be selected as appropriate. Moreover, the material of the case is a nonmagnetic material such as aluminum, aluminum alloy, magnesium, or magnesium alloy, and a conductive material can be suitably used. A case made of a nonmagnetic material having conductivity can effectively prevent leakage magnetic flux to the outside of the case. A case made of a lightweight metal such as aluminum, magnesium, or an alloy thereof is superior in strength to a resin and is lightweight, and thus is suitable for an automobile part that is desired to be reduced in weight.

[Sealing resin]
The case described above may be filled with a sealing resin (not shown) made of an insulating resin. When the sealing resin is filled in the case, the coil 2α is embedded in the sealing resin. In this case, the end of the winding 2w is drawn out of the case and exposed from the sealing resin. Examples of the sealing resin include an epoxy resin, a urethane resin, and a silicone resin. In addition, the sealing resin contains a filler excellent in insulation and thermal conductivity, for example, a filler made of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, mullite, and silicon carbide. Then, the heat dissipation can be further enhanced.

{Manufacture of reactors}
Reactor 1α having the above-described configuration can be manufactured as follows.

  First, as shown in FIG. 2, the assembly 100 in which the magnetic core pieces 31m and the gap material 31g are laminated is fixed integrally with the adhesive tape 4 described above to form the inner core portion 31, and the bobbin piece of the insulator 5 is formed on the outer periphery thereof. In a state where 51 is arranged, the coil elements 2a and 2b are inserted. The frame-like portion 52 and the connecting core portion 32 are arranged in the coil 2α so that the end faces of both the coil elements 2a, 2b and the end face 31e of the inner core portion 31 are sandwiched between the frame-like portion 52 and the connecting core portion 32 of the insulator 5. The end surface 31 e of the inner core portion 31 is exposed from the opening of the frame-shaped portion 52 and contacts the inner end surface 32 e of the connecting core portion 32. And the reactor 1 (alpha) can be manufactured by fixing the end surface 31e of the inner core part 31 and the inner end surface 32e of the connection core part 32 with an adhesive agent.

  In addition, the pair of bobbin pieces 51 are not configured to engage with each other, but are inserted into the coil elements 2a and 2b together with the inner core part 31 and further provided with the connecting core part 32, whereby the coil elements 2a and 2b are arranged. The state arrange | positioned between the inner peripheral surface and the inner core part 31 is maintained, and it does not drop out.

  Furthermore, a reactor including the sealing resin is formed by appropriately filling and curing the sealing resin in the case. In this case, the sealing resin to be filled enters the concave portion formed in the assembly 100 described above from the opening 40 of the adhesive tape 4 and can directly hold the magnetic core piece 31m and the gap material 31g. That is, the assembly 100 can be fixed integrally with the adhesive tape 4 and further fixed with the sealing resin, so that the gap length can be kept more firmly and constant. Therefore, since the core is held against the vibration caused by the magnetostriction of the magnetic core 3 and the magnetic attractive repulsion force between the magnetic core pieces 31m, vibration noise can be reduced. And the inner core part 31, the connection core part 32, and the coil 2 (alpha) can be hold | maintained integrally by sealing resin. Further, the end surface 31e of the inner core portion 31 and the inner end surface 32e of the connecting core portion 32 are not fixed with an adhesive, and the inner core portion 31, the connecting core portion 32, and the coil 2α are all held together by a sealing resin. In this case, an adhesive-less reactor that does not use any adhesive can be used.

[Usage]
Reactor 1α has applications in which energization conditions are, for example, maximum current (direct current): about 100 A to 1000 A, average voltage: about 100 V to 1000 V, operating frequency: about 5 kHz to 100 kHz, typically an electric vehicle, a hybrid vehicle, etc. It can utilize suitably for the component of the vehicle-mounted power converter device.

[Function and effect]
According to embodiment mentioned above, there exist the following effects.

  (1) Since the adhesive tape is used to fix the assembly of the magnetic core piece and the gap material together, it is not necessary to use an adhesive. Therefore, since the troublesome work caused by using the adhesive can be eliminated, the assembly work of the reactor can be simplified.

  (2) When fixing a braid with an adhesive tape, it is easy to obtain a desired inductance because variations in gap length can be eliminated with the non-use of an adhesive.

  (3) By fixing the assembly of the magnetic core piece and the gap material integrally with an adhesive tape having an opening, air can be discharged from between the assembly and the adhesive tape through the opening. . That is, all inconveniences caused by air remaining between the adhesive tape and the assembly can be eliminated.

<< Embodiment 2 >>
Next, Embodiment 2 will be described based on FIG. The second embodiment is different from the first embodiment in the shape of the opening 40 provided in the adhesive tape 4 for fixing the assembly 100 of the magnetic core piece 31m and the gap material 31g. Hereinafter, differences from the first embodiment will be described.

  Similarly, in this example, the assembly 100 of the magnetic core piece 31m and the gap material 31g is stuck and fixed along the circumferential direction of the assembly 100 with a single adhesive tape 4. And the opening part 40 connected to the front and back for letting air pass through in the adhesive tape 4 is provided, The shape is a slit shape formed by the notch | incision which does not remove the adhesive tape 4 partially. The trajectory and length of the cut and the interval between the cuts can of course be selected as appropriate. Here, as an example, the straight slit 40s having a length of 2 mm is provided in one direction (in this example, the width of the adhesive tape 4). Are arranged in a straight line at intervals of 5 mm with respect to (direction), and at intervals of 20 mm with respect to the other direction (in the longitudinal direction of the adhesive tape 4 in this example) so as to be arranged in parallel. By fixing with the adhesive tape 4 in which such slits 40s are formed, air does not remain between the assembly 100 and the adhesive tape 4, and the adhesive tape is partially adhered as in the case where a hole is provided in the adhesive tape. Since the tape 100 is not removed and the braid 100 can be fixed by using more surface area of the adhesive tape 4, the braid 100 can be fixed more firmly.

<< Embodiment 3 >>
Furthermore, Embodiment 3 is demonstrated based on FIG. The third embodiment is different from the first and second embodiments in that there is one coil element 2c and the connecting core portion 32 is formed of a molded and hardened body. Hereinafter, differences from the first and second embodiments will be described.

  Here, the reactor 1β includes a coil 2β and a magnetic core 3 on which the coil 2β is disposed. The coil 2β is composed of one coil element 2c formed by winding the winding 2w. The magnetic core 3 includes one inner core portion 31 inserted into the coil 2β and a connecting core portion 32 disposed on the outer periphery of the coil 2β and connected to the inner core portion 31. 31 and 32 form a closed magnetic circuit. The reactor 1β has a configuration in which the coil 2β and the inner core portion 31 are substantially covered by the connecting core portion 32. The inner core part 31 is comprised from the same thing as Embodiment 1 mentioned above, and the connection core part 32 is comprised from the shaping | molding hardening body containing the magnetic powder mentioned above and resin. And this connection core part 32 and the said inner core part 31 are joined by the constituent resin of the connection core part 32, without interposing an adhesive agent. Therefore, the magnetic core 3 is a member that is integrated throughout the whole without using an adhesive.

  Also in this example, a member that improves the insulation between the coil 2β and the magnetic core 3, such as the bobbin shown in the first embodiment, may be provided on the outer periphery of the inner core portion 31. In addition, in order to improve the insulation between the coil 2β and the magnetic core 3, an insulating tube is disposed on a part of the winding 2w forming the coil 2β, or an insulating tape is provided on the inner and outer peripheral surfaces of the coil 2β. Or an insulating paper or an insulating sheet may be disposed.

{Manufacture of reactors}
The reactor 1β can be manufactured, for example, as follows. First, a plurality of magnetic core pieces 31m and a gap material 31g are prepared, and the assembled material 100 is produced by arranging the gap material 31g between the magnetic core pieces 31m. Next, a piece of adhesive tape 4 is attached to the outer peripheral surface of the assembly 100, and the assembly 100 is fixed integrally to form the inner core portion 31. And this inner core part 31 is penetrated in the coil 2 (beta), and is accommodated in the case (not shown) mentioned above. Thereafter, a mixture of a magnetic material and a resin constituting the connecting core portion 32 is appropriately poured into the case to form the connecting core portion 32 having a predetermined shape, and then the resin is cured. Through the above, reactor 1β is obtained.

[Function and effect]
According to the reactor of this example, since the coil and the inner core part are integrally formed by the connecting core part, an adhesive-less structure that does not use any adhesive can be obtained.

  Moreover, since the inner core part is formed of a compacted molded body and the connecting core part is formed of a molded cured body, the inner core part has a higher saturation magnetic flux density than the connecting core part, and the connecting core part is more than the inner core part. Also, the magnetic permeability can be lowered. That is, when a constant magnetic flux is obtained by the saturation magnetic flux density of the inner core portion being high, for example, the entire magnetic core is made of a single type of material, and the saturation magnetic flux of both the inner core portion and the connecting core portion is used. The cross-sectional area of the inner core portion can be reduced compared to reactors having the same density. Therefore, the outer diameter of the coil provided on the outer periphery of the inner core portion can be reduced, and the reactor can be further reduced in size. And since the coil | winding which comprises a coil can be shortened because the outer diameter of a coil can be made small, the resistance of a coil can be lowered | hung. Therefore, loss can be reduced. Furthermore, since the magnetic permeability of the connecting core portion is lower than that of the inner core portion, the predetermined inductance can be sufficiently satisfied.

<Modification>
Hereinafter, a modification is demonstrated based on FIGS. In any of the modifications, the position where the adhesive tape 4 is applied to fix the assembly 100 of the magnetic core piece 31m and the gap material 31g is different from those of the first and second embodiments. Therefore, although the opening part provided in the adhesive tape 4 is abbreviate | omitted in FIGS. 7-9, in any modification, the opening part is provided similarly to embodiment mentioned above. Hereinafter, differences from the embodiment will be described.

[Modification 1]
In the first modification, as shown in FIG. 7, each region straddling both magnetic core pieces 31m sandwiching the gap material 31g is fixed with the adhesive tape 4 along the circumferential direction. It was configured to be exposed. And also in this modification 1, like FIG. 4 shown by embodiment mentioned above, the both ends of the adhesive tape 4 may be faced | matched, a space | interval may be provided, and you may make it overlap. As such, since the location where the adhesive tape 4 is applied is in each region straddling both magnetic core pieces 31m sandwiching the gap material 31g in the assembly 100, the contact area between the adhesive tape 4 and the magnetic core pieces 31m is reduced, and the air Areas that may remain can be reduced. Moreover, since the area | region other than the said area | region in the said assembly 100 is exposed, the heat | fever which generate | occur | produced from the coil can be effectively conducted to the magnetic core piece 31m, and heat dissipation can be improved.

[Modification 2]
In the modified example 2, as shown in FIG. 8, in the assembly 100 of the magnetic core piece 31m and the gap material 31g, the adhesive is adhered along the longitudinal direction so as to cover the four corners of the outer peripheral surface and the vicinity thereof. It was set as the structure which affixes a tape and fixes it integrally. That is, the corners and the vicinity thereof are exposed. By doing so, the contact area between the pressure-sensitive adhesive tape 4 and the magnetic core piece 31m can be reduced, the area where air can remain is reduced, and the braid can be sufficiently fixed. Further, since the exposed surface area of the assembly 100 is large, heat can be effectively radiated from the coil to the magnetic core piece 31m.

[Modification 3]
In the modification 3, as shown in FIG. 9, in the assembly 100 of the magnetic core piece 31m and the gap material 31g, the adhesive tape 4 along the longitudinal direction (axial direction) is formed in the central portion of the plane of the outer peripheral surface. It was set as the structure fixed by. By fixing in this way, the contact area between the adhesive tape 4 and the magnetic core piece 31m can be reduced, the area where air can remain is reduced, and the assembly can be sufficiently fixed. it can. Further, since the exposed surface area of the assembly 100 is large, heat can be effectively radiated from the coil to the magnetic core piece 31m.

<Test example>
As a test example, an assembly fixed integrally with the same adhesive tape as in FIGS. 3, 5, and 7 to 9, and as a comparative example, a single adhesive tape without an opening is provided as shown in FIG. 3. Assemblies fixed on the entire circumference of the outer peripheral surface are prepared, and these are designated as test pieces 1 to 6 in order. Here, each adhesive tape uses a polyester film as a base material and a silicone adhesive as an adhesive. And the heat test shown below to these test pieces 1-6 is performed.

[Heat resistance test]
The test pieces 1 to 6 were left in an atmosphere at 250 ° C. for 10 minutes. Then, after 10 minutes, it was confirmed whether or not the adhesive tape substrate and the adhesive, and the adhesive and the braid were separated.

[Results of heat test]
As a result of the heat resistance test, even when left in an atmosphere at 250 ° C. for 10 minutes, in test pieces 1 to 5, peeling occurs between the adhesive tape substrate and the adhesive, and between the adhesive and the assembly. There wasn't. On the other hand, peeling of the adhesive tape was observed on the test piece 6 of the comparative example. This is because, in test pieces 1 to 5, air does not remain between the adhesive tape and the assembly due to the openings provided in each adhesive tape, and the adhesive tape is not spaced between the assemblies. It is thought that it was because it was able to be pasted. On the contrary, since the test piece 6 was not provided with an opening, air remained between the adhesive tape and the assembly, and it was estimated that the adhesive tape was peeled off because the air expanded by heat.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration.

  The reactor of the present invention can be used as a component of a power conversion device such as a bidirectional DC-DC converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle.

DESCRIPTION OF SYMBOLS 1 (alpha), 1 (beta) Reactor 100 Assembly 2 (alpha), 2 (beta) Coil 2a, 2b, 2c Coil element 2r Coil connection part 2w Winding 3 Magnetic core 31 Inner core part 31e End surface 31m Magnetic core piece 31g Gap material 32 Connection core part 32e Inner end surface 4 Adhesive Tape 40 Opening 40c Circular hole 40s Straight slit 5 Insulator 51 Bobbin piece 52 Frame-like part 52f Flange part

Claims (9)

A reactor comprising a coil and a magnetic core disposed inside and outside the coil to form a closed magnetic path;
The magnetic core is
A plurality of magnetic core pieces;
A gap material arranged at least in part between the magnetic core pieces,
Furthermore, comprising an adhesive tape that integrally fixes the assembly of the magnetic core piece and the gap material,
The said adhesive tape is provided with the opening part, The reactor characterized by the above-mentioned.   2. The reactor according to claim 1, wherein the opening is disposed between both magnetic core pieces sandwiching at least a gap material on an outer peripheral surface of the assembly.   The reactor according to claim 1, wherein the opening has a hole shape.   The reactor according to claim 1, wherein the opening has a slit shape.   The reactor according to any one of claims 1 to 4, wherein the openings are uniformly distributed over the entire surface of the adhesive tape.   The area of each opposing surface of the said gap material and a magnetic core piece is smaller than the opposing surface of each magnetic core piece, The opposing surface of a gap material is any one of Claims 1-5 characterized by the above-mentioned. Reactor.   The reactor according to any one of claims 1 to 6, wherein the assembly is fixed by a single piece of the adhesive tape along a circumferential direction thereof.   It is fixed with the adhesive tape along the circumferential direction for each region straddling both magnetic core pieces sandwiching the gap material in the assembly, and the adhesive tape is not pasted except for the region. Item 7. The reactor according to any one of Items 1 to 6.   The reactor according to any one of claims 1 to 6, wherein at least two opposing portions of the outer peripheral surface of the assembly are fixed with the adhesive tape along a longitudinal direction.

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