JP2017011117A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component in which a magnetic flux exerting influences upon a coil is reduced, the coil component including a coil that is formed by combining components of different relative permeability values.SOLUTION: A coil component 100 comprises: a pair of first core parts 210 and 220 which are disposed at a predetermined interval and in parallel with each other; a pair of second core parts 230 and 240 which are connected to end faces of the first core parts 210 and 220 and form a closed magnetic path by coupling end portions of the first core parts 210 and 220 with each other; and a coil that is wound around the first core parts 210 and 220. Each of the first core parts 210 and 220 includes at least one first core material part 211, 221 having first permeability in a zero magnetic field. Each of the second core parts 230 and 240 includes at least one second core material part 231, 241 having second permeability, higher than the first permeability, in the zero magnetic field. The second core material parts 230 and 240 are disposed at least in a boundary between the first core parts 210 and 220 and the second core parts 230 and 240. A ratio of a height H of the first core material parts 211 and 221 and a length D in a first direction is 3 or less.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a coil component.

  Patent Document 1 discloses a reactor including a core and a coil wound around a part of the core as one of coil components.

  The core for reactor used for the reactor of patent document 1 is a cyclic | annular core provided with the coil arrangement | positioning part covered with a coil, and the exposed part which is not covered with a coil.

  The coil arrangement part and the exposed part in the core of Patent Document 1 have different relative magnetic permeability. Specifically, the relative magnetic permeability of the exposed portion is at least twice the relative magnetic permeability of the coil placement portion.

JP 2012-89899 A

  In the reactor shown in FIG. 1 of Patent Document 1, the ratio of the height and thickness of the coil arrangement portion constituting the core is about four times. According to the inventor's investigation, when such a core with a high aspect ratio is used, the distribution of magnetic flux is biased (converged) in the coil arrangement portion, and magnetic flux leakage occurs. The leaked magnetic flux causes copper loss in the coil.

  Therefore, an object of the present invention is to provide a coil component having a core in which components having different magnetic permeability in a zero magnetic field are combined and having reduced leakage magnetic flux.

  According to the present invention, the first coil component is connected to a pair of first core portions arranged in parallel to each other at a predetermined interval in the first direction, and to the end face of the first core portion, and the first core Each of the first core portions includes a pair of second core portions that form a closed magnetic path by connecting the ends of the portions, and coils that are respectively wound around the first core portions. At least one first core material portion having a first permeability, and each of the second core portions has a second core material portion having a second permeability higher than the first permeability in a zero magnetic field. Including at least one, wherein the second core material portion is disposed at a boundary between at least the first core portion and the second core portion, and a ratio of the height of the first core material portion to the length in the first direction is A coil component of 3 or less is obtained.

  Further, according to the present invention, as the second coil component, a coil component which is a first coil component and the ratio of the height of the first core material portion to the length in the first direction is 2 or less is obtained. .

  In addition, according to the present invention, as the third coil component, a coil component that is a second coil component and the ratio of the height and thickness of the first core material portion is 1 or less is obtained.

  Further, according to the present invention, as the fourth coil component, any one of the first to third coil components, wherein a cross-sectional area of the first core portion is larger than a cross-sectional area of the second core portion. Large coil parts are obtained.

  Further, according to the present invention, the fifth coil component is a fourth coil component, wherein a cross-sectional area of the first core portion is 1.2 times or more twice a cross-sectional area of the second core portion. The following coil parts are obtained.

  Further, according to the present invention, the sixth coil component is a fifth coil component, wherein the cross-sectional area of the first core portion is 1.3 times the cross-sectional area of the second core portion. Parts are obtained.

  According to the present invention, as the seventh coil component, any one of the first to sixth coil components, wherein each of the first core portions is configured by the first core material portion, As for each of the second core parts, a coil component composed of the second core material part is obtained.

  According to the present invention, as the eighth coil component, any one of the first to sixth coil components, wherein each of the first core portions includes a pair of the first core material portions and the first core material portions. And a third core material portion having a magnetic permeability equal to the second magnetic permeability, and each of the second core portions is a coil component made up of the second core material portion. can get.

  Furthermore, according to the present invention, as the ninth coil component, any one of the first to seventh coil components, wherein a gap is formed in a part of a boundary between the first core portion and the second core portion. A coil component characterized in that a material is provided is obtained.

  INDUSTRIAL APPLICABILITY The present invention can provide a coil component that has a core having a combination of members having different magnetic permeability in a zero magnetic field and has reduced leakage magnetic flux.

It is a perspective view which shows the reactor which is a coil components by the 1st Embodiment of this invention. It is a disassembled perspective view which shows the core contained in the reactor of FIG. It is a disassembled perspective view which shows the reactor of FIG. It is a figure for demonstrating the core contained in the reactor of FIG. It is a graph which shows a simulation result. It is a figure for demonstrating the structure of the core contained in the reactor by the 2nd Embodiment of this invention. It is a figure for demonstrating the modification of the core contained in the coil components of this invention.

(First embodiment)
With reference to FIG. 1 thru | or FIG. 4, the reactor 100 which is a coil components by the 1st Embodiment of this invention is demonstrated. Reactor 100 according to the present embodiment is used for, for example, an inverter or a voltage converter of an electric vehicle. However, the coil component of the present invention is not limited to these applications.

  As shown in FIG. 1, the reactor 100 includes a resin molded body 110 that wraps a core (200 in FIG. 2) and a coil 120 that is wound around a part of the resin molded body 110. Usually, the coil 120 is covered with a coil cover made of an insulating resin (not shown).

  As can be understood from FIG. 3, the resin molded body 110 is configured by combining a pair of resin molded portions 111 and 112 made of an insulating resin. Each of the pair of resin molding portions 111 and 112 includes two parallel coil winding portions 113 and 114 and a connection portion 115 that connects one end portions of the two coil winding portions 113 and 114. ing. Further, in each of the resin molding portions 111 and 112, a flange 116 is provided at the boundary between the coil winding portions 113 and 114 and the connection portion 115. The overall shape of the resin molded body 110 is generally annular or frame-shaped.

  As can be understood from FIGS. 1 and 3, the coil 120 has two toroidal portions provided between a pair of flanges 116. The coil 120 is formed of a single insulated conductive wire, for example, a flat wire, and the two toroidal portions are electrically connected to each other. In other words, the coil 120 is formed so that one conductive wire is continuously wound around two coil winding portions (113 and 114 in FIG. 3). The coil 120 may be further covered with an insulator (not shown). In that case, the insulator is located between the coil 120 and a coil cover (not shown).

  As shown in FIG. 2, the core 200 used in the reactor 100 includes a pair of first core portions 210 and 220 and a pair of second core portions 230 and 240. In the present embodiment, the first core portions 210 and 220 are respectively configured by first core members 211 and 221, and the second core portions 230 and 240 are respectively configured by second core members 231 and 241. The first core members 211 and 221 are formed in the same size and shape using the same material. The first core members 211 and 221 are formed so as to have a first magnetic permeability in a zero magnetic field. In other words, in the present embodiment, each of the first core portions 210 and 220 includes a single first core material portion having a first magnetic permeability. Similarly to the first core members 211 and 221, the second core members 231 and 241 are formed in the same size and shape using the same material. The second core members 231 and 241 are formed to have a second magnetic permeability higher than the first magnetic permeability in a zero magnetic field. In other words, in the present embodiment, each of the second core portions 230 and 240 includes a single second core material portion having a second magnetic permeability.

  As the first core material portion (first core members 211 and 221), a casting core obtained by curing a slurry obtained by mixing magnetic powder with resin can be used. Further, as the second core material portion (second core members 231 and 241), a dust core obtained by press-molding magnetic powder coated with an insulating film can be used. However, the first core material portion and the second core material portion are not limited to this, and can be manufactured by an arbitrary manufacturing method.

  As understood from FIG. 3, the first core members 211 and 221 are disposed in the coil winding portions 113 and 114 of the resin molded body 110. Specifically, one of the first core members 211 is disposed inside a cylindrical body constituted by the coil winding portion 113 of the resin molding portion 111 and the coil winding portion 114 of the resin molding portion 112. The other first core member 221 is disposed inside a cylindrical body constituted by the coil winding portion 114 of the resin molding portion 111 and the coil winding portion 113 of the resin molding portion 112. That is, the first core members 211 and 221 are arranged in parallel at a predetermined interval in the first direction A. On the other hand, the second core members 231 and 241 are respectively disposed in the connecting portions 115 of the resin molding portions 111 and 112. The second core members 231 and 241 are connected to the end surfaces of the first core members 211 and 221. Thus, the second core members 231 and 241 connect the ends of the first core members 211 and 221 to form an annular or frame-shaped closed magnetic path. As will be described later, the ratio H / D between the height of the first core members 211 and 221 (H in FIG. 2 or 4) and the length in the first direction (D in FIG. 2 or 4) is 3 or less. (H / D ≦ 3) is desirable.

  Hereinafter, the structure of each part of the reactor 100 is further demonstrated with the manufacturing method. Referring to FIG. 3, the resin molded portions 111 and 112 are separated from each other in a state before the reactor 100 is assembled. The resin molding parts 111 and 112 accommodate the second core members 231 and 241 (see FIG. 2), respectively. In other words, the second core members 231 and 241 are covered with the resin molding portions 111 and 112, respectively. The resin molding parts 111 and 112 are formed by primary insert molding so as to enclose the second core members 231 and 241. Specifically, after the second core member 231 (or 241) is placed in a mold for forming a resin molding part, an insulating resin is injected into the mold and cured. Thereby, the resin molding part 111 (or 112) is formed around the second core member 231 (or 241). This molding is performed such that a part of the second core member 231 (or 241) is exposed in the coil winding portions 113 and 114.

  As can be understood from FIG. 3, the resin molding portions 111 and 112 are combined with each other so that the coil winding portions 113 and 114 abut each other. Convex portions 117 and concave portions 118 corresponding to each other are formed on end surfaces of the coil winding portions 113 and 114. When an adhesive is applied to the end surfaces of the coil winding portions 113 and 114 and they are abutted with each other, the resin molding portions 111 and 112 are joined to each other. At this time, the corresponding convex portions 117 and concave portions 118 determine the relative positions of the resin molding portions 111 and 112.

  When the resin molding portions 111 and 112 are combined with each other, the first core members 211 and 221 are accommodated in the coil winding portions 113 and 114. At this time, the coil 120 is mounted on the outer peripheral side of the coil winding portions 113 and 114.

  In a state where the resin molding parts 111 and 112 are combined with each other, both end surfaces of the first core members 211 and 221 face side surfaces of the pair of second core members 231 and 241. At this time, the end surfaces of the first core members 211 and 221 may or may not be in contact with the side surfaces of the opposing second core members 231 and 241. In order to control the positions of the first core members 211 and 221 in the coil winding portions 113 and 114, protrusions and the like may be formed in advance in the coil winding portions 113 and 114.

  The first core members 211 and 221 are bonded to the second core members 231 and 241 with an adhesive or the like. Alternatively, these are bonded by a resin used for forming the coil cover during secondary insert molding for forming a coil cover (not shown). When secondary insert molding is used, it is necessary to previously form grooves, slits, or the like through which resin passes on the side surfaces and end surfaces of the coil winding portions 113 and 114. In any case, both end surfaces of the first core members 211 and 221 are bonded to the second core members 231 and 241. Accordingly, both end portions of the first core members 211 and 221 are connected by the second core members 231 and 241.

  The coil 120 is wound in advance in a toroidal shape before the resin molding portions 111 and 112 are combined with each other. When the coil 120 is mounted on the coil winding portions 113 and 114, the end portions 121 and 122 of the coil 120 are pulled out through the slit 119 formed in the flange 116, as understood from FIGS. .

  By performing secondary insert molding on the reactor 100 shown in FIG. 1, a coil cover (not shown) is formed. Specifically, a coil cover forming die is attached to the reactor 100 so as to cover the coil 120, and an insulating resin is injected into the attached die and cured. Thereby, the coil cover which covers the coil 120 is formed. The coil cover may be formed to expose a part of the coil 120 for heat dissipation. When the resin is also allowed to flow inside the coil winding portions 113 and 114, the resin flow passages and exhaust holes are formed in the resin molding portions 111 and 112 in advance as described above. These flow paths and exhaust holes can be formed when the resin molding parts 111 and 112 are manufactured, that is, in the primary insert molding. As described above, the coil cover (not shown) is attached to the reactor 100 of FIG.

  As described above, the first core members 211 and 221 have a relatively low first magnetic permeability, and the second core members 231 and 241 have a relatively high second magnetic permeability. Here, as shown in FIG. 4, the height of the first core members 211 and 221 is H, and the length in the first direction is D. The inventor has noticed that the performance of the reactor 100 decreases as the ratio H / D of the height H to the length D increases. Therefore, the inventor repeated various simulations to obtain an appropriate range of the ratio H / D. One of the simulation results was as shown in Table 1.

  This simulation was performed by changing the cross-sectional areas of the first core members 211 and 221 without changing the configuration of the second core members 231 and 241. Here, the coil 120 assumed what wound the flat wire of a cross section of 5 mm x 1 mm for 60 turns. The thickness T of the second core members 231 and 141 was 10 mm. Furthermore, the distance (thickness of the insulating material) between the coil 120 and the first core members 211 and 221 was 1 mm. Under the above conditions, the inductance L of the coil 120 and the resistance component Rac of the impedance were calculated.

  FIG. 5 is a graph showing a simulation result. As understood from the graph, when the ratio H / D is 3 or less (H / D ≦ 3), the resistance component Rac is significantly reduced. Therefore, the ratio H / D of the first core members 211 and 221 is preferably 3 or less (H / D ≦ 3), more preferably 2 or less (H / D ≦ 2), and 1 or less ( It is further desirable that H / D ≦ 1). Thus, in the present embodiment, by setting the ratio H / D to 3 or less, leakage of magnetic flux to the coil 120 can be suppressed, and loss can be reduced.

  In addition, the area (cross-sectional area) S1 of the surface perpendicular to the height direction of the first core members 211 and 221 (up and down direction in FIG. 4) and the width direction of the second core members 231 and 241 (left and right direction in FIG. 4). When the area (cross-sectional area) S <b> 2 of the vertical surface is equal, the first core members 211 and 221 are more likely to be magnetically saturated than the second core members 231 and 241. Therefore, the cross-sectional area S1 of the first core members 211 and 221 is set to the cross-sectional area of the second core members 231 and 241 so that the magnetic saturation characteristics of the first core members 211 and 221 and the second core members 231 and 241 are balanced. It may be larger than S2 (S1 / S2> 1). According to a simulation result different from the above, the ratio S1 / S2 is desirably 1.2 or more and 2 or less (2 ≧ S1 / S2 ≧ 1.2), and more desirably about 1.3 (S1 / S1). S2≈1.3).

  As described above, the coil component according to the present embodiment is connected to the pair of first core portions 210 and 220 arranged in parallel with each other at a predetermined interval and the end faces of the first core portions 210 and 220, and the first A pair of second core portions 230 and 240 that connect ends of the first core portions 210 and 220 to form a closed magnetic circuit, and a coil 120 wound around the first core portions 210 and 220, respectively. . Each of the first core portions 210 and 220 includes first core members 211 and 221 that are first core material portions having a first relative permeability in a zero magnetic field. Each of the second core portions 230 and 240 includes second core members 231 and 241 that are second core material portions having a second relative permeability higher than the first relative permeability in a zero magnetic field. The side surfaces of the second core members 231 and 241 are arranged at the boundary between the first core portions 210 and 220 and the second core portions 230 and 240. The ratio H / D between the height H and the thickness D of the first core members 211 and 221 that are the first core material portions is 3 or less. With this configuration, the coil component according to the present embodiment can suppress performance degradation due to leakage of magnetic flux.

(Second Embodiment)
In 1st Embodiment mentioned above, the 1st core parts 210 and 220 are comprised by the single 1st core members 211 and 221 respectively. However, the present invention is not limited to this configuration. In the core included in the reactor according to the second embodiment of the present invention, as shown in FIG. 6, the first core portions 210 and 220 are configured by three core members 261 to 263 and 264 to 266, respectively. Yes. That is, the first core portion 210 (220) includes a pair of first core material portions 261 and 262 (264 and 265) having a first relative permeability and a second ratio sandwiched between them. It is comprised with the core member 263 (266) which is the 3rd core material part which has a magnetic permeability.

  One end surface of the core member 261 is bonded to the side surface of one second core member 231, and the other end surface is bonded to one end surface of the core member 263. One end surface of the core member 262 is bonded to the side surface of the other second core member 241, and the other end surface is bonded to the other end surface of the core member 263. Similarly, one end surface of the core member 264 is bonded to the side surface of one second core member 231, and the other end surface is bonded to one end surface of the core member 266. Further, one end surface of the core member 265 is bonded to the side surface of the other second core member 241, and the other end surface is bonded to the other end surface of the core member 266. In FIG. 6, the core member 263 (266) is disposed at the center of the first core portion 210 (220) in the height direction (vertical direction in FIG. 6). Therefore, the heights of the core members 261, 262, 264, and 265 are all equal (= H / 2).

  According to the present embodiment, the height of the first core portions 210 and 220 can be made longer than that of the first embodiment while maintaining the ratio H / D at 3 or less. Thereby, the length of the coil 120 can be lengthened (the number of turns is increased). That is, the degree of freedom in design increases.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made. For example, both the core member having the first magnetic permeability and the core member having the second magnetic permeability may be cast cores, or both may be dust cores. In addition, as shown in FIG. 7, a gap material 300 having a high magnetic resistance may be provided at a part of the boundary between the first core portions 210 and 220 and the second core portions 230 and 240 as necessary. . Moreover, in the said embodiment, although the cross section of the 1st core parts 210 and 220 and the 2nd core parts 230 and 240 is a rectangle, circular and a polygon may be sufficient. Furthermore, the level | step difference (concave or convex part) corresponding to the 1st core part 210,220 may be formed in the surface where the 1st core part 210,220 of the 2nd core part 230,240 is connected. . Furthermore, although the said embodiment has what is called a UU core, this invention is applicable also to EE core, for example.

DESCRIPTION OF SYMBOLS 100 Reactor 110 Resin molding 111,112 Resin molding part 113,114 Coil winding part 115 Connection part 116 Flange 117 Convex part 118 Concave part 120 Coil 121,122 End part 131,132 Opening part 200 Core 210,220 1st core part 211,221 1st core member 230,240 2nd core part 231,241 2nd core member 261-266 Core member

Claims (9)

A pair of first core portions arranged in parallel to each other at a predetermined interval in the first direction;
A pair of second core parts connected to the end surfaces of the first core part and connecting the ends of the first core parts to form a closed magnetic path;
A coil wound around each of the first core parts,
Each of the first core parts includes at least one first core material part having a first permeability in a zero magnetic field,
Each of the second core parts includes at least one second core material part having a second magnetic permeability higher than the first magnetic permeability in a zero magnetic field,
The second core material part is disposed at a boundary between at least the first core part and the second core part,
The coil component in which the ratio of the height of the first core member to the length in the first direction is 3 or less.   2. The coil component according to claim 1, wherein a ratio of the height of the first core member to the length in the first direction is 2 or less.   The coil component according to claim 2, wherein a ratio of the height of the first core member to the length in the first direction is 1 or less.   The coil component according to any one of claims 1 to 3, wherein a cross-sectional area of the first core portion is larger than a cross-sectional area of the second core portion.   5. The coil component according to claim 4, wherein a cross-sectional area of the first core portion is not less than 1.2 times and not more than twice a cross-sectional area of the second core portion.   The coil component according to claim 5, wherein a cross-sectional area of the first core portion is 1.3 times a cross-sectional area of the second core portion.   Each of the said 1st core part is comprised with the said 1st core material part, and each of the said 2nd core part is comprised with the said 2nd core material part in any one of Claim 1 thru | or 6. The coil component described.   Each of the first core portions includes a pair of first core material portions and a third core material portion having a permeability equal to the second permeability sandwiched between the first core material portions and the second core material portions. Each of the core parts is a coil component in any one of Claims 1 thru | or 6 comprised by the said 2nd core material part.   The coil component according to any one of claims 1 to 8, wherein a gap member is provided at a part of a boundary between the first core portion and the second core portion.

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