JP2016157890A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component which can be assembled easily because deviation of stacking of annular magnetic cores is small, while reducing the impact of leakage flux on the DC superposition characteristics.SOLUTION: A coil component has a first annular magnetic core, and a second annular magnetic core having an effective permeability larger than that of the first annular magnetic core, a composite magnetic core consisting of the first and second annular magnetic cores has a race track shape, a first reel where a first coil is laid is disposed on one of opposite straight line part, a second reel where a second coil of different winding direction from the first coil is laid on the other straight line part, the first and second coils are connected so that the magnetic flux generated in each coil has the same direction in the magnetic path, the first and second reels are composed of an insulating resin, and have partitions for determining the intervals of the first and second annular magnetic cores, respectively.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil component such as a reactor or a choke used in various power supply devices, electronic devices, and the like.

  Inductors such as choke coils are used in power factor correction (PFC) circuits and smoothing circuits of power supply devices installed in home appliances such as air conditioners, motor-driven vehicles such as hybrid vehicles and electric vehicles, and solar power generation devices. It is used. The appropriate inductance value of the inductance element for the power supply device varies depending on the specifications such as the output rating of the circuit and the state of the load. Therefore, in order to configure a power supply device that is efficient over a wide range from a small current to a large current with consideration for power conversion efficiency, load fluctuation response characteristics, etc., an inductance value according to the magnitude of the load current A non-linear inductance element (coil component) that changes is used.

  For example, Patent Document 1 proposes a coil component that changes non-linearly so as to increase the inductance at a small current in order to improve the efficiency at a small current. FIG. 14 is an external perspective view thereof. In this coil component, a second annular magnetic core 93 having an annular shape without a gap and a first annular magnetic core 91 having a gap 92 are concentrically stacked to form a composite magnetic core, and a plurality of annular magnetic cores having different magnetic resistances are formed. It has a coil wound in common. In the drawing, the coil is omitted. As the magnetic material constituting each of the annular magnetic cores, either a metal magnetic material such as an amorphous alloy, permalloy, silicon steel plate, or soft ferrite is used.

  Patent Document 2 discloses a coil component in which an electromagnetic shielding plate is sandwiched and integrated between a plurality of annular annular magnetic cores having different magnetic resistances. FIG. 15 is an external perspective view thereof. An electromagnetic shielding plate 104 is sandwiched and integrated between the first annular magnetic core 101 and the second annular magnetic core 102 provided with a gap 103, and a coil 105 common to the first annular magnetic core 101 and the second annular magnetic core 102 is provided. Prepare. Amorphous or nanocrystalline alloy is used for each annular magnetic core. The electromagnetic shielding plate 104 is made of aluminum, copper, SUS304, or the like, and prevents eddy current loss from occurring due to the magnetic field leaking from the gap 103 provided in the second annular magnetic core 102 to the first annular magnetic core 101. Yes.

JP 59-182514 A JP 2003-272937 A

  FIG. 16 is a diagram for explaining leakage magnetic flux in the coil component of Patent Document 1. In FIG. Since the first annular magnetic core 91 and the second annular magnetic core 93 are closely and concentrically stacked, the magnetic flux 95 leaking from the gap 92 provided in the first annular magnetic core 91 tends to enter the second annular magnetic core 93. It has a configuration. The second annular magnetic core 93 has a problem that eddy current loss occurs due to leakage magnetic flux 95 when a magnetic metal material such as an amorphous alloy having a small specific resistance or a silicon steel plate is used.

  Moreover, it is preferable that the coil components used in the power factor correction (PFC) circuit and the smoothing circuit have a steep transition from the high inductance operation to the low inductance operation with respect to the DC superimposed current. However, when the leakage magnetic flux 95 is routed through the second annular magnetic core 93, the change in inductance is slowed down, and there are cases where the value is larger than the inductance required for the coil component at a predetermined DC superimposed current.

  In Patent Document 2, since the electromagnetic shielding plate 104 itself is made of a conductor such as aluminum or copper, heat is generated by an eddy current flowing through the electromagnetic shielding plate 104. The electromagnetic shielding plate 104 also functions as a mounting bracket and contributes to heat radiation to the attachment target by using the bracket portion as a path, but the structural design of the electromagnetic shielding plate 104 with sufficient consideration for heat transfer is required. Further, if the heat transfer to the object to be attached is insufficient, the temperature of the annular magnetic core may rise and the magnetic characteristics may fluctuate.

  The coil component of the cited document 1 is configured by simply stacking annular magnetic cores. In the coil component of the cited document 2, a coil is commonly wound around an annular magnetic core arranged concentrically with an electromagnetic shielding plate interposed therebetween. In any case, when stacking and fixing a plurality of annular magnetic cores, no consideration is given to the point of constituting with a small deviation, and it is difficult to obtain a coil component with little deviation between the annular magnetic cores, The positional deviation of the annular magnetic cores arranged side by side has a problem of causing variation (variation) in the inductance of the coil components. Moreover, in the coil components of the cited document 1 and the cited document 2, the structure for insulating and protecting the coil is not shown. In the coil component of the cited document 2, the coil is wound in contact with the edge portions of the annular magnetic cores 101 and 102 and the electromagnetic shielding plate 104, and the insulation clothing is easily damaged.

  Therefore, the present invention suppresses the stacking deviation of the annular magnetic cores and is easy to assemble while being regulated to a predetermined overlapping interval. Magnetic flux leaking from the gap provided in one annular magnetic core An object of the present invention is to provide a coil component that does not easily wrap around a magnetic core.

The coil component of the present invention is a coil component in which a plurality of annular magnetic cores having different effective magnetic permeability are arranged concentrically with intervals to form a composite magnetic core, and a common coil is laid on each annular magnetic core,
A composite magnetic core having a first annular magnetic core and a second annular magnetic core having an effective permeability larger than that of the first annular magnetic core, and comprising the first annular magnetic core and the second annular magnetic core has a racetrack shape. The first winding frame in which the first coil is laid on one of the opposing linear portions in the composite magnetic core, and the second winding frame on which the second coil having a different winding direction from the first coil is laid on the other. The first coil and the second coil are connected so that the magnetic flux generated in each coil is in the same direction in the magnetic path, and the first winding frame and the second winding frame are made of an insulating resin. Each of the coil parts has a partition portion for determining an interval between the first annular magnetic core and the second annular magnetic core.

  In the coil component of the present invention, it is preferable that the first annular magnetic core is constituted by a metal powder core and the second annular magnetic core is constituted by a ferrite core or an amorphous core.

  In the coil component of the present invention, it is preferable that the second annular magnetic core is constituted by individual magnetic cores arranged annularly at intervals.

  According to the present invention, the variation in inductance can be suppressed by suppressing the deviation of the stacking of the annular magnetic cores, and the magnetic flux leaks from the gap provided in one annular magnetic core by restricting to the overlapping interval of the annular magnetic cores. However, it is possible to provide a coil component that is difficult to go around the other annular magnetic core.

It is a front view which shows the external appearance of the coil component of one embodiment of this invention. It is a top view which shows the external appearance of the coil component of one embodiment of this invention. It is a side view which shows the external appearance of the coil component of one embodiment of this invention. It is a connection diagram of the coil in the coil component of one embodiment of the present invention. It is a top view which shows the external appearance of the 1st annular magnetic core used for the coil components of one embodiment of this invention. It is a perspective view which shows the external appearance of the individual piece magnetic core which comprises the 1st annular magnetic core shown in FIG. It is a top view which shows the external appearance of the 2nd annular magnetic core used for the coil components of one embodiment of this invention. It is a perspective view which shows the external appearance of the individual piece magnetic core which comprises the 2nd annular magnetic core shown in FIG. It is a front view which shows the external appearance of the winding frame of the coil used for the coil component of one embodiment of this invention. It is a top view which shows the external appearance of the winding frame of the coil used for the coil component of one embodiment of this invention. It is a side view which shows the external appearance of the winding frame of the coil used for the coil component of one embodiment of this invention. It is a perspective view which shows the external appearance of the composite magnetic core which consists of a 1st annular magnetic core and a 2nd annular magnetic core. It is a figure which shows the direct current | flow superimposition characteristic of the coil components of one embodiment of this invention. It is an external appearance perspective view of the conventional coil components. It is an external appearance perspective view of other conventional coil components. It is a figure for demonstrating the leakage magnetic flux in the conventional coil components.

  Hereinafter, although embodiment of the coil component which concerns on this invention is described concretely using figures, this invention is not limited to this. Moreover, the structure demonstrated in each embodiment is applicable also in other embodiment, unless the meaning of other embodiment is impaired, In that case, the overlapping description is abbreviate | omitted suitably.

  FIG. 1 is a front view showing an embodiment of the coil component of the present invention, FIG. 2 is a top view of the coil component shown in FIG. 1, and FIG. 3 is a side view of the coil component shown in FIG. FIG. 4 is a connection diagram of coils in a coil component according to an embodiment of the present invention. FIG. 5 is a top view showing the appearance of the first annular magnetic core used in the coil component according to one embodiment of the present invention. FIG. 6 is a perspective view showing the external appearance of the individual magnetic core constituting the first annular magnetic core shown in FIG. FIG. 7 is a top view showing the appearance of the second annular magnetic core used in the coil component according to one embodiment of the present invention. FIG. 8 is a perspective view showing the appearance of an individual magnetic core constituting the second annular magnetic core shown in FIG. FIG. 9 is a front view showing an appearance of a coil winding frame used in the coil component according to one embodiment of the present invention. 10 is a top view of the reel shown in FIG. FIG. 11 is a side view of the reel shown in FIG.

  The coil component 1 shown in FIGS. 1 to 3 includes a first winding frame 50a and a second winding frame in which a first annular magnetic core 10 and a second annular magnetic core 20 and the first and second annular magnetic cores 10 and 20 are arranged. 50b, and a first coil 60a and a second coil 60b laid on the first and second winding frames 50a and 50b. The ends 100a and 100b of the first coil 60a and the second coil 60b having different winding directions are connected by connection means 200 such as crimp terminals, and the magnetic flux generated in each coil is the same direction in the magnetic path as shown in FIG. Connect so that

  The first annular magnetic core 10 is required not to be magnetically saturated with respect to a large load current flowing through the coil. Therefore, it is preferable to use a metal powder core that can be configured to have a low effective permeability and a high saturation magnetic flux density. The metal powder core is a magnetic core using metal magnetic powder whose surface is covered with an insulating film, and is formed by mixing, molding, and heat-treating metal magnetic powder and a resin or glass to be an insulating film, for example. It is preferable to use a metal magnetic material having a high saturation magnetic flux density of 1T or more as the magnetic material. For example, pure iron, Fe—Si magnetic powder, Fe—Si—Al magnetic powder, Fe—Si—Cr magnetic powder, Fe base An amorphous alloy magnetic powder such as Co base can be used.

  The second annular magnetic core 20 has a high inductance at a relatively small load current, and a magnetic material that is magnetically saturated when a predetermined load current is exceeded is selected based on the saturation magnetic flux density and the magnetic permeability. The second annular magnetic core 20 is provided with a magnetic gap according to a required inductance value and operating current. The first annular magnetic core 10 may also be provided with a magnetic gap according to the required inductance value and operating current.

  As a magnetic material to be used, it is preferable to use Ni-based, Mn-based soft ferrite, Fe-based, and Co-based amorphous alloys. For example, when the load current at which the magnetic saturation is relatively small, soft ferrite having a low saturation magnetic flux density may be used, and when maintaining a high inductance value up to a load current larger than soft ferrite, an amorphous alloy is used. Use it. When it is desired to rapidly decrease the inductance value at a predetermined load current, it is preferable to use soft ferrite having a saturation magnetization smaller than that of the amorphous alloy. The amorphous alloy used for the second annular magnetic core 20 is usually provided in a ribbon shape. It can be wound and cut to form a cut core, or a ribbon can be punched into a predetermined shape and laminated to form a laminated core.

  The first annular magnetic core 10 and the second annular magnetic core 20 are combined with individual U-shaped, L-shaped, J-shaped, or I-shaped individual magnetic cores so that they can be arranged on a winding frame described later. Configured. FIG. 5 is a configuration example of the annular magnetic core using the L-shaped individual core shown in FIG. 6, and FIG. 7 is a configuration example of the annular magnetic core using the U-shaped individual core shown in FIG. is there. The first annular magnetic core 10 and the second annular magnetic core 20 are combined with individual magnetic cores to form a racetrack shape having straight portions of short sides and long sides, respectively. Hereinafter, the case where the L-shaped individual magnetic core is used as the first annular magnetic core and the U-shaped individual magnetic core is used as the second annular magnetic core will be described.

  The first annular magnetic core 10 shown in FIG. 5 is composed of L-shaped individual magnetic cores 10a, 10b, 10c, and 10d. When a metal powder core that requires high pressure for molding is used as the first annular magnetic core 10, it is preferable that the individual cores have simple shapes so that the molding can be easily performed. It may be a letter shape or an I shape. On the other hand, many individual cores are required to make an annular magnetic core, and there is a drawback that the number of man-hours to be assembled increases, and the shape of the individual core may be determined in consideration of the ease of molding and the assembly man-hours. .

  The L-shaped individual cores 10a, 10b, 10c, and 10d shown in FIG. 6 are formed in the same shape. The first annular magnetic core 10 is configured such that the end faces 18 are abutted and abutted with no gap therebetween to be bonded and fixed. The first annular magnetic core 10 has a rectangular shape having two short side portions and two long side portions facing each other. If a J-shaped individual magnetic core is used, the short side portion has an arc shape. In the illustrated example, the individual magnetic cores are configured without a gap, but a gap is provided between the end faces 18 of the individual magnetic cores to form a magnetic gap, and the inductance value of the coil component at high load current is adjusted to be small. Also good.

  The second annular magnetic core 20 shown in FIG. 7 is composed of a plurality of magnetic cores arranged with gaps serving as magnetic gaps in the magnetic path. The second annular magnetic core 20 is configured by opposing a ferrite core or amorphous core 20a, 20b, which is a substantially U-shaped individual magnetic core shown in FIG. 8, with a gap 16 serving as a magnetic gap. The air gap 1 can adjust the inductance value of the coil component at the time of a low load current and the load current at which the second annular magnetic core 20 is magnetically saturated. The effective magnetic permeability of the second annular magnetic core 20 is larger than that of the first annular magnetic core 10. The second annular magnetic core 20 is also a rectangle having two short side portions and two long side portions facing each other.

  Both the first annular magnetic core 10 and the second annular magnetic core 20 are configured in a racetrack shape, and a first winding frame 50a and a second winding frame 50b formed of a heat-resistant resin are arranged on the straight portion thereof. 9 to 11 show the structure of the winding frame. In the illustrated example, the respective winding frames are formed in the same shape, and a pair of flange portions 51 are provided, and a cylinder in which coils 60a and 60b each wound with a conducting wire are laid in a portion partitioned by the flange portions 51. A part 52 is provided. Each flange 51 is provided with a notch for drawing out the ends of the coils 60a and 60b. Two openings formed as through holes 56 a and 56 b are juxtaposed through the partition portion 55 in the region inside the body portion 52. Each of the winding frames is preferably formed of a resin having insulating properties, heat resistance, and moldability. Specifically, polyphenylene sulfide, liquid crystal polymer, polyethylene terephthalate, polybutylene terephthalate, and the like are preferable. An injection molding method can be used for these moldings.

  The individual cores constituting the first annular magnetic core 10 and the second annular magnetic core 20 are passed through the through-holes 56a and 56b, respectively, and fixed with an adhesive for each annular magnetic core. It is restrained and fixed by a band. A simple structure in which a first annular magnetic core 10 and a second annular magnetic core 20 configured in a racetrack shape are juxtaposed using a coil winding frame, and the first annular magnetic core 10 and the second annular magnetic core 20 are arranged. Since the straight portion is passed through the winding frame, the coil parts can be easily assembled.

  Further, the distance between the first annular magnetic core 10 and the second annular magnetic core 20 can be determined by the thickness of the partition portion 55. The partition portion according to the illustrated example has a resin formed on one side without a gap so as to completely separate the first annular magnetic core 10 and the second annular magnetic core 20, but the opening side is formed by removing a part of the resin. It is good also as a hook-like shape and protrusion shape which protrudes. Further, the partition portion may be provided only in a part in the winding axis direction of the coil as long as the function is not hindered.

  FIG. 12 shows an external perspective view of the composite magnetic core of the coil component with the winding frame and coil omitted. The first annular magnetic core 10 and the second annular magnetic core 20 are stacked to constitute a composite magnetic core. In the stacking, when the first annular magnetic core 10 and the second annular magnetic core 20 are brought into contact with each other, the magnetic flux leaking from the magnetic gap (gap 16) of the second annular magnetic core 20 wraps around the first annular magnetic core 10 and enters the magnetic path. This causes a problem that the inductance value is not sufficiently lowered even at a high load current. Therefore, the first annular magnetic core 10 and the second annular magnetic core 20 are overlapped with each other by the partition part 55 of the winding frame. The thickness of the partition portion 55 is preferably equal to or greater than the interval between the gaps 16 provided in the second annular magnetic core 20, and is preferably about 0.3 mm to 2.0 mm.

  In the composite magnetic core, a first coil 60a and a second coil 60b having a winding direction different from that of the first coil 60a are laid, and the first magnetic flux 60a and the second magnetic flux generated in the coils 60b have the same direction. The coil 60a and the second coil 60b are connected. The first annular magnetic core 10 and the second annular magnetic core 20 are disposed inside each of the coils 60a and 60b, and the coil component 1 has the first annular magnetic core 10 and the second annular magnetic core 20 in a region where the DC superimposed current is small. Therefore, in the region where the DC superimposed current is large, the first annular magnetic core 10 can maintain the inductance with a low inductance value.

  A coil using a metal powder core of Fe-9.5 mass% Si-5.5 mass% Al alloy (Sendust) as the first annular magnetic core and an Mn ferrite core (MB19D made by Hitachi Metals) as the second annular magnetic core Parts were produced.

  Each of the coils 60a and 60b is formed by winding an enameled wire around the winding frames 50a and 50b. Through the two through holes 56a and 56b provided in the winding frames 50a and 50b, a ferrite core and a metal powder core are passed through an epoxy. After fixing with a system adhesive, the coil parts 1 were obtained by connecting the ends of the coils 60a and 60b. Each of the first annular magnetic core 10 and the second annular magnetic core 20 has an outer dimension of 54 mm × 42 mm, an inner dimension of 33 mm × 11 mm, a thickness of 20 mm, and a thickness of the partition portion 55 of the reels 50a and 50b is 0.6 mm. Yes. The distance between the first annular magnetic core 10 and the second annular magnetic core 20 is substantially the same as the thickness of the partition portion 55. The effective magnetic permeability of the first annular magnetic core 10 was 60, and the effective magnetic permeability of the second annular magnetic core 20 was 180.

  An air gap 16 was provided on the long side of the second annular magnetic core 20 facing each other. The intervals are each 0.3 mm. The number of turns of each coil 60a, 60b is 38 turns. The configuration of the coil component is the same as that shown in FIGS. Since the obtained coil component is assembled on the basis of the winding frame, deviation between the annular magnetic cores can be easily reduced.

  The result of evaluating the DC superposition characteristics of the obtained coil component is shown in FIG. As for the inductance of the coil component, a high inductance value is obtained by the first and second annular magnetic cores until the DC superimposed current Idc is up to 2A, and the influence of magnetic flux leaking from the magnetic gap is reduced. It declined sharply. Furthermore, the second annular magnetic core can maintain the inductance without saturation up to a large region where the DC superimposed current exceeds 30 A with a low inductance value.

DESCRIPTION OF SYMBOLS 1 Coil component 10 1st cyclic | annular magnetic core 10a, 10b, 10c, 10d Metal powder core 20 2nd cyclic | annular magnetic core 20a, 20b Ferrite core, amorphous core 50a, 50b Winding frame 60a, 60b 1st coil, 2nd coil

Claims (3)

A coil component in which a plurality of annular magnetic cores having different effective magnetic permeability are arranged concentrically at intervals to form a composite magnetic core, and a common coil is laid on each annular magnetic core,
A first annular magnetic core, and a second annular magnetic core having an effective permeability larger than that of the first annular magnetic core,
A composite magnetic core composed of the first annular magnetic core and the second annular magnetic core has a racetrack shape, a first winding frame in which a first coil is laid on one of opposing linear portions of the composite magnetic core, and the other And a second winding frame in which a second coil having a winding direction different from that of the first coil is laid,
The first coil and the second coil are connected so that the magnetic flux generated in each coil is in the same direction in the magnetic path,
The coil component, wherein the first winding frame and the second winding frame are made of an insulating resin, and each has a partition portion that determines an interval between the first annular magnetic core and the second annular magnetic core. The coil component according to claim 1,
The coil component, wherein the first annular magnetic core is constituted by a metal powder core, and the second annular magnetic core is constituted by a ferrite core or an amorphous core. The coil component according to claim 1 or 2,
The coil component, wherein the second annular magnetic core is constituted by individual magnetic cores arranged in an annular shape at intervals.

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