JP2006344867A - Reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reactor core which can eliminate or lessen various problems resulting from a gap. <P>SOLUTION: The reactor 1 comprises a substantially troidal core 3, and coils 5 and 7 arranged on the periphery of the core 3 and it is used in the driving power supply system of a hybrid car or an electric automobile. The core 3 is constituted by bonding two magnetic bodies 11 and 13 of substantially U-shaped plan view through no gap. In order to achieve low permeability and low coercive force and from viewpoint of moldability, a powder magnetic material using a high anisotropy nanocrystal material is employed as a material of the magnetic bodies 11 and 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reactor that has a substantially toroidal core and is used in a power supply system for driving a hybrid vehicle or an electric vehicle (including a fuel cell vehicle in the present application).

  As a conventional reactor, there is one in which a silicon steel plate is used as a core material and a plurality of ceramic gaps for permeability adjustment are inserted (for example, Patent Document 1). In such a reactor, in order to cope with the high output of a drive power supply system such as a hybrid vehicle, it is necessary to reduce the magnetic permeability of a core made of a silicon steel plate having a high magnetic permeability and make the core difficult to be magnetically saturated. The gaps (for example, 6 locations) are dispersed and inserted in the core.

JP 2004-95570 A

  However, in the configuration in which a large number of gaps are inserted in the core as described above, there is a problem that leakage magnetic flux due to the gaps increases. The leakage magnetic flux becomes a noise source for the peripheral circuit and induces an eddy current in the peripheral conductor and increases iron loss.

  Further, in the configuration in which a large number of gaps are provided, it is necessary to divide the core into a large number of parts, so that the cost of assembling the core increases, and noise is generated due to collision and separation between the gap and the magnetic body in each gap part during driving. There is also a problem that is likely to occur.

  Therefore, the problem to be solved by the present invention is to provide a reactor that can solve or alleviate problems caused by the gap.

  In order to solve the above problems, in the invention of claim 1, a reactor used in a power supply system for driving a hybrid vehicle or an electric vehicle, which is formed of a dust magnetic material and has no gap interposed therebetween. A toroidal core and a coil provided on the outer periphery of the core are provided.

  According to a second aspect of the present invention, there is provided a reactor used in a power supply system for driving a hybrid vehicle or an electric vehicle, wherein the magnetic part is formed of dust magnetic material and the gap is inserted at one or two places. A substantially toroidal core, and a coil provided on the outer periphery of the core.

  According to a third aspect of the present invention, in the reactor according to the second aspect of the present invention, the gap is interposed in a portion of the core covered by the coil.

  According to a fourth aspect of the present invention, in the reactor according to any one of the first to third aspects, a nanocrystalline material is used as the dust magnetic material.

  According to the first aspect of the present invention, since the core is formed by using the dust magnetic material whose permeability is relatively easy to adjust by selecting the material, the gap-free core is formed. Various problems (leakage magnetic flux, high cost, noise, etc.) caused by the problem can be solved.

  According to the second aspect of the present invention, by forming the magnetic body portion of the core using the dust magnetic material whose permeability can be adjusted relatively easily by selecting the material, one or two gap insertion portions are formed. Therefore, various problems caused by the gap (leakage magnetic flux, cost increase, noise, etc.) can be reduced.

  According to invention of Claim 3, since the gap is inserted in the part covered with the coil of a core, the leakage magnetic flux in a gap can be suppressed effectively.

  According to the invention described in claim 4, since the nanocrystalline material is used as the dust magnetic material, a core having a low magnetic permeability and a low coercive force can be easily formed.

<First Embodiment>
FIG.1 and FIG.2 is the top view and side view of the reactor which concern on 1st Embodiment of this invention. As shown in FIGS. 1 and 2, the reactor 1 includes a core 3 having a substantially toroidal shape (for example, a substantially rectangular toroidal shape), and coils 5 and 7 provided on the outer periphery of the core 3. And used for a power supply system for driving a hybrid vehicle or an electric vehicle.

  The core 3 is configured by joining (for example, joining with an adhesive or the like) two magnetic bodies 11 and 13 that are substantially U-shaped in plan view, and is configured not to interpose a gap.

As a material of the magnetic bodies 11 and 13, a dust magnetic material is used in order to realize a low magnetic permeability and a low coercive force and from the viewpoint of ease of forming. Here, the low magnetic permeability is a characteristic necessary for preventing the core 3 from being magnetically saturated due to a high output of a drive power supply system such as a hybrid vehicle. Further, the low coercive force is a characteristic necessary for suppressing the core loss (hysteresis loss) of the core 3. For example, from the viewpoint of magnetic permeability, the material and the number of inserted gaps (in this embodiment, no gap is inserted) are determined so that the relative permeability μ _r satisfies the following relational expression (1). The In Equation (1), l is the magnetic path length of the core 3, L is the inductance of the reactor 1, μ ₀ is the vacuum magnetic permeability, N is the number of turns of the coils 5 and 7, and S Is the cross-sectional area of the core 3.

  The dust magnetic material is a metal magnetic powder or a metal magnetic powder covered with a predetermined insulating coating, which is bonded with a resin, filled with a powder magnetic material in a predetermined mold, and pressed and compressed. Then, the shape is formed by heat treatment. For this reason, the dust magnetic body has the advantage that it is easy to mold and the advantage that the magnetic properties (such as permeability and coercive force) can be easily controlled by the degree of freedom of material selection.

  In addition, specific examples of the dust magnetic material that realizes low magnetic permeability and low coercive force include a metal magnetic powder using a nanocrystalline material (especially an anisotropic nanocrystalline material), a metal in a dust magnetic body. The film thickness of the insulating film (or insulating layer) between the particles is a very thin film (for example, the film thickness is set to 10 nm to 1 μm) that maintains the distance at which the interaction between the magnetic moments in adjacent particles does not work. And what increased the ratio of the resin material for coupling | bonding etc. can be considered. Insulating materials include non-crystalline materials (glass, phosphate, borate, silicate, etc.) that exhibit high electrical resistance and good deformation followability.

  Nanocrystalline material is a metal magnetic powder with a crystal size of nanosize, and compositionally, ferromagnetic elements (Fe, Co, Ni, etc.) and amorphization promoting elements (O, N, B, Nb) Etc.) and an element (Si, Al, rare earth, etc.) that can be easily combined with an amorphization-promoting element. In order to increase the anisotropy and lower the magnetic permeability, it is possible to increase the ratio of Co to Fe in the combination of (Fe—Co) — (Si, B). In general, the nanocrystalline material is produced by adjusting the crystal size to be nano-sized when heat-treating an amorphous powder or ribbon produced by a rapid cooling method (atomization, melt span). As a specific material example, for example, Hitachi Metals' fine met (Fe-Si-B-Nb-Cu) (trade name) can be cited.

  About the point (principle etc.) which can form the magnetic bodies 11 and 13 of low magnetic permeability by using an anisotropic nanocrystal material for dust magnetic material, magnetic anisotropy is increased like a normal magnetic material. This realizes low magnetic permeability. However, the coercive force increases as the magnetic anisotropy increases in the normal magnetic material, but the nanocrystalline material can realize a high anisotropy and a low coercive force due to the special crystal grain size. It has become. More specifically, since a nanocrystal has a crystal structure different from an amorphous material, it exhibits magnetic anisotropy, and a low magnetic permeability can be realized by increasing the magnetic anisotropy. In addition, the coercive force usually increases as the crystal grain size becomes smaller. However, when the crystal grain size becomes smaller than 100 nanometers, the smaller the grain size, the smaller the coercive force tends to become smaller. Low coercivity is achieved by setting the crystal grain size in the region.

  In addition, regarding the point (principle etc.) that can achieve low magnetic permeability and low coercive force by making the film thickness of the insulating film (or insulating layer) between the metal particles in the dust magnetic material extremely thin, Reduced film thickness by reducing the contact point between metal particles while suppressing the contact point (insulation breakdown point) between metal particles (thinning is made thin enough to ignore the effect of demagnetizing field), and reducing the contact point between metal particles. The magnetic susceptibility is realized, and a low coercive force can be realized by suppressing the influence of the demagnetizing field.

  The coils 5 and 7 are configured using rectangular wires or round wires, and are respectively mounted on the outer circumferences of two opposing sides of the core 3 so as to surround the joint portions of the magnetic bodies 11 and 13. .

  As described above, according to the present embodiment, by forming the magnetic bodies 11 and 13 of the core 3 using the dust magnetic material whose permeability can be adjusted relatively easily by selecting the material, there is no gap. 3 is formed, various problems (leakage magnetic flux, cost increase, noise, etc.) due to the gap can be solved.

  Further, by using an anisotropic nanocrystalline material or the like as the dust magnetic material, the core 3 having a low magnetic permeability and a low coercive force can be easily formed.

Second Embodiment
FIG. 3 is a plan view of the reactor according to the second embodiment of the present invention, and FIG. 4 is an exploded view of the core of the reactor of FIG. The reactor 21 according to the present embodiment is substantially different from the reactor 1 according to the first embodiment described above only in that the gaps 25 and 26 are inserted into the core 23 and related points, and corresponding portions. Are denoted by the same reference numerals, and description thereof is omitted.

  In the reactor 21 according to the present embodiment, as shown in FIGS. 3 and 4, one gap 25, 27 is inserted in each of the joint portions of the magnetic bodies 11, 13 of the core 23. 27, the magnetic permeability of the core 23 is finely adjusted. That is, in this embodiment, the number of insertions of the gaps 25 and 27 is minimized by roughly adjusting the magnetic permeability of the core 23 by selecting the dust magnetic material of the magnetic bodies 11 and 13. . As a modification, the gaps 25 and 27 may be inserted in one place (in this case, it is necessary to adjust the length of one arm of the magnetic bodies 11 and 13 asymmetrically).

  As the dust magnetic material used for the magnetic bodies 11 and 13, the same material as in the first embodiment is used.

  For example, the gaps 25 and 27 are set to about 1 mm (or about 1 mm or less) in thickness, and are formed of ceramic or the like. The joints between the magnetic bodies 11 and 13 and the gaps 25 and 27 are bonded by, for example, an adhesive.

  The coils 5 and 7 are mounted on the outer circumferences of the two opposite sides of the core 23 so as to surround a portion where the gaps 25 and 27 of the core 23 are inserted.

  As described above, according to the present embodiment, by forming the magnetic bodies 11 and 13 of the core 23 using the dust magnetic material whose permeability can be adjusted relatively easily by selecting the material, the gap insertion point can be determined. Since the core 23 suppressed in two places is formed, various problems (leakage magnetic flux, cost increase, noise, etc.) due to the gaps 25 and 27 can be reduced.

  Moreover, since the gaps 25 and 27 are inserted in the portions covered by the coils 5 and 7 of the core 23, the leakage magnetic flux in the gaps 25 and 27 can be effectively suppressed.

  Further, by using an anisotropic nanocrystalline material or the like as the dust magnetic material, the core 23 having a low magnetic permeability and a low coercive force can be easily formed.

It is a top view of the reactor which concerns on 1st Embodiment of this invention. It is a side view of the reactor of FIG. It is a top view of the reactor which concerns on 2nd Embodiment of this invention. It is the figure which decomposed | disassembled the core of the reactor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor 3 Core 5, 7 Coil 11, 13 Magnetic body 21 Reactor 23 Core 25, 27 Gap

Claims (4)

A reactor used in a power supply system for driving a hybrid vehicle or an electric vehicle,
A substantially toroidal core that is formed of a dusting magnetic material and has no gap interposed therebetween;
A coil provided on the outer periphery of the core;
The reactor characterized by providing. A reactor used in a power supply system for driving a hybrid vehicle or an electric vehicle,
A substantially toroidal core in which a magnetic part is formed of a dust magnetic material and a gap is inserted in one or two places;
A coil provided on the outer periphery of the core;
The reactor characterized by providing. The reactor according to claim 2,
The reactor, wherein the gap is inserted in a portion of the core covered by the coil. In the reactor according to any one of claims 1 to 3,
A reactor in which a nanocrystalline material is used as the dust magnetic material.

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