JP5023601B2 - Reactor - Google Patents

Description

  The present invention relates to a reactor and a reactor spacer mounted on an electric vehicle such as a hybrid vehicle or a fuel cell vehicle.

  In recent years, automobiles that run by driving a motor with a DC power source such as a hybrid vehicle and a fuel cell vehicle have been developed due to environmental problems. These automobiles are equipped with a boost converter that boosts the voltage of a battery that is a DC power supply, and a reactor is a main component of the boost converter.

  As described in Patent Document 1, the reactor includes an annular core and a coil wound around a predetermined portion of the core. In a vehicle-mounted reactor, a pair of parallel I-shaped parts are formed by assembling two or more core blocks, respectively, due to restrictions on mounting space and manufacturing method, and substantially U-shaped at both ends of these I-shaped parts In many cases, a substantially oval annular core formed by connecting core blocks is employed. A gap is provided between the core blocks in order to adjust the inductance of the magnetic circuit, and a spacer made of a nonmagnetic material is inserted in the gap. By passing a current through the coil, an annular magnetic circuit is formed in the core.

JP2004-241475

  Since the spacer is made of a nonmagnetic material, leakage magnetic flux is likely to be generated from the peripheral edge of the gap. When the leakage magnetic flux is generated, eddy current is generated in the coil and the core block, the loss increases, and the energy conversion efficiency of the reactor decreases. Moreover, the magnetic flux density in the core is unevenly distributed due to the leakage magnetic flux, and the vibration and noise of the core are induced.

  FIG. 6 schematically shows the state of leakage magnetic flux when a conventional spacer S is inserted in a gap G provided between the core blocks C and C. As shown in this figure, at the peripheral edge of the gap G, it can be seen that the magnetic flux LF leaks from the edges of the cores C and C so as to draw a substantially circular arc. It can also be seen that the magnetic flux density is unevenly distributed in the spacer or in the vicinity of the core.

  On the other hand, the gap is provided to adjust the inductance of the reactor. In order to obtain a required performance, a gap having a predetermined length must be provided with respect to the entire length of the core.

  The present invention provides a reactor using a spacer that can reduce energy loss by reducing the leakage magnetic flux generated in the peripheral edge of the gap and improve the energy conversion efficiency by mitigating the uneven distribution of magnetic flux density. It is.

The invention described in claim 1 includes a substantially U-shaped core block and a pair of I-shaped parts configured by assembling two or more rectangular core blocks, and at both ends of the pair of I-shaped parts. An annular core is formed by connecting the substantially U-shaped core block, and a reactor configured by providing a coil on the outer periphery of the annular core, and in a base material made of a non-magnetic material, The ratio of the spacer material inserted between the I-shaped part and the substantially U-shaped core block, with a spacer made of a material formed by dispersing the powdered magnetic material interposed between the core blocks. The magnetic permeability is set to be larger than the relative magnetic permeability of the spacer material interposed between the rectangular core blocks constituting the I-shaped portion, and is inserted between the I-shaped portion and the substantially U-shaped core block. The thickness of the spacer Serial is constructed by setting larger than the thickness of the spacer interposed between the rectangular core blocks constituting the I-section.

  Since the core is made of a magnetic material, the magnetic flux flows in a direction orthogonal to the core cross section. On the other hand, since the conventional spacer is made of a nonmagnetic material such as ceramic, leakage magnetic flux is likely to occur around the periphery of the spacer facing the outer space.

  In the present invention, since the powdery magnetic material is dispersed inside the spacer, the magnetic flux easily passes through the spacer as compared with the spacer formed from the conventional non-magnetic material. For this reason, the leakage magnetic flux to the outside of the spacer can be reduced.

  The form of the spacer, the relative magnetic permeability, etc. can be set according to the performance required for the reactor. Moreover, the spacer which concerns on this invention can also be selectively provided in the gap part which a leak magnetic flux tends to produce.

In the present invention, the permeability of the spacer material interposed between the I-shaped section and the generally U-shaped core block, a spacer material interposed between said rectangular core blocks constituting the I-shaped portion Is set to be larger than the magnetic permeability .

As the magnetic permeability of the spacer material is increased, the leakage magnetic flux from the spacer can be reduced. For this reason, the magnetic permeability of the spacer material inserted between the I-shaped portion and the substantially U-shaped core block where leakage magnetic flux is likely to be generated is inserted between the rectangular core blocks constituting the I-shaped portion. By setting it larger than the magnetic permeability of the spacer material , leakage flux can be efficiently prevented.

In addition, when the relative permeability of the spacer material inserted between the I-shaped portion and the substantially U-shaped core block is set larger than the relative permeability of the spacer material inserted in another part, it is constant. In order to construct a performance reactor, it is necessary to change the thickness of other spacers or the relative permeability of the spacer material . For this reason, the relative magnetic permeability of the spacer material inserted between the I-shaped portion and the substantially U-shaped core block is determined by the spacer material inserted between the rectangular core blocks constituting the I-shaped portion . It is set larger than the relative magnetic permeability, and the thickness of the spacer inserted between the I-shaped portion and the substantially U-shaped core block is inserted between the rectangular core blocks constituting the I-shaped portion. By setting it larger than the thickness of the spacer, a spacer having the same magnetic permeability can be configured. That is, the relative permeability of the spacer material is set large and the thickness is set large so that the performance of the spacer is the same.

In the spacer according to the present invention, the relative magnetic permeability is set to be larger than 1 by dispersing the powdered magnetic material. In order to exert the effect of reducing the leakage magnetic flux, it is preferable to set the relative permeability of the spacer material to 1.5 to 5 as in the invention described in claim 2 .

If the relative permeability of the spacer material is 1.5 or less, the same leakage magnetic flux as that of the conventional nonmagnetic spacer is likely to be generated, and the effect of reducing the leakage magnetic flux cannot be expected.

On the other hand, in order to regulate the performance of the reactor, it is necessary to provide a gap of a predetermined length in terms of relative permeability 1 with respect to the entire length of the annular core. Therefore, when a spacer having a relative permeability of the spacer material greater than 1 is provided, the thickness of the spacer must be increased almost in proportion to the relative permeability of the spacer material . For example, when a spacer having a relative magnetic permeability of 2 is employed, the thickness of the spacer must be set to about twice. For this reason, when the spacer is made of a material having a relative permeability greater than 5, the thickness of the spacer becomes too large with respect to the length of the core, and the size of the entire device is increased accordingly. In addition, the loss may increase as the total length of the core increases. Accordingly, it is desirable to set the relative permeability of the spacer material to 5 or less.

The invention described in claim 3 of the present application is formed by including 15% to 25% by volume of the above-described spacer material in a powder magnetic material having a relative permeability of 1000 or more.

  A powdery magnetic material having a high magnetic permeability can easily attract a magnetic flux and prevent the magnetic flux from leaking out of the spacer. Therefore, it is preferable to employ a magnetic material having as large a permeability as possible. Further, by dispersing the powdered magnetic material evenly in the base material made of a nonmagnetic material, it is possible to prevent the magnetic flux from being disturbed inside the spacer.

  The particle size of the powdery magnetic material is not particularly limited, but it is preferable to employ a powdery magnetic material of 1 μm to 250 μm.

  The kind of the powdery magnetic material is not limited. Further, not only one kind of powdery magnetic material but also a mixture of a plurality of kinds of magnetic materials can be adopted. For example, one containing one or more components selected from ferrite and metal magnetic particles (Fe, FeSi, Sendust, etc.) can be adopted.

According to a fourth aspect of the present invention, the nonmagnetic material is formed from a resin material. The kind of the resin material is not limited, and various resin materials can be used as long as they have magnetic characteristics, hardness, and moldability that can function as a spacer. For example, a phenol resin can be adopted. Further, as in the invention described in claim 5 , a ceramic material can be adopted as the non-magnetic material.

The method of forming the spacer is not particularly limited. That is, as in the invention described in claim 6 , a compacted body or a sintered compact can be employed as the spacer. Further, when a resin is used as a base material, an injection molded body or an extruded molded body can be employed.

In the invention described in claim 7, the core block is formed from a powder compact including a powdered magnetic material and a binder resin, and the spacer is changed in the amount of the binder resin in the core block. Is formed from a green compact in which the relative permeability of the spacer material is set to a predetermined value.

  By using the same materials and techniques for manufacturing the core, a common manufacturing facility can be used. This can also reduce the cost.

To provide a reactor spacer and a reactor using this spacer which can improve energy conversion efficiency by reducing leakage magnetic flux generated in the peripheral portion of the gap and reducing loss and mitigating uneven magnetic flux density. Can do.

  As shown in FIG. 1, the reactor 1 includes an annular core 2 and a coil 3 mounted around the core 2. Between the core 2 and the coil 3, a bobbin for holding the coil 3 on the outer periphery of the core 2 with a predetermined interval is inserted, and the whole is accommodated in a box-shaped case (not shown). ing.

  FIG. 2 is an overall perspective view of the annular core 2. In the present embodiment, a pair of parallel I-shaped parts 4 and 4 are formed by assembling three rectangular core blocks 4a, 4b and 4c, respectively, and substantially U-shaped at both ends of these I-shaped parts. A substantially oval annular core 2 is formed by connecting the core blocks 5 and 5. Plate-like spacers 7 are inserted in the gaps 6 provided between the core blocks 5, 4a, 4b, 4c.

  FIG. 3 schematically shows the internal structure of the spacer according to the present embodiment.

  The spacer 7 is formed by uniformly dispersing a powdered magnetic material 9 on a base material 7 made of a phenol resin. In this embodiment, a powdery phenol resin is employed as the resin material, and an Fe-6.5% Si powder having an average particle size of 150 μm is employed as the powder magnetic material, and these mixtures are compacted. Thus, the spacer 7 having a rectangular plate shape is formed. The kind of said powdery resin material is not specifically limited, An epoxy resin etc. can be employ | adopted besides the said phenol resin.

In this embodiment, the magnetic permeability of the spacer material is set to about 2 by blending the powdered magnetic material 9 with 17 volume% of the spacer 7. In addition, the compounding quantity of the said magnetic material and a relative magnetic permeability can be set according to the performance of a reactor.

FIG. 4 schematically shows the state of magnetic flux when the reactor is operated with the spacer 7 having the above-described configuration interposed in the gap 6 formed between the core blocks 4a and 4b. In this embodiment, since the relative permeability of the spacer material constituting the spacer 7 is set to 2, the thickness is set to be twice that of the conventional spacer S having the relative permeability 1 shown in FIG. ing. Thereby, the function equivalent to the conventional spacer can be exhibited.

  As is clear from comparison between FIG. 4 and FIG. 6, in the spacer 7 according to this embodiment, the leakage magnetic flux LF at the edge of the spacer is reduced. In addition, the magnetic flux is less disturbed inside the spacer or the core in the vicinity thereof. For this reason, generation | occurrence | production of an eddy current etc. decreases, loss can reduce and it can improve the efficiency of a reactor.

5, the spacer 27a according to the present invention, 27d and conventional spacer 27b, both 27c, an example of a case of adopting the annular core 22 of the embodiment shown in FIG. In this embodiment, spacers 27b and 27c made of a conventional ceramic material are employed in the gaps provided between the rectangular core blocks 24a, 24b, and 24c, while the substantially U-shaped core block 25 that easily generates leakage magnetic flux The spacers 27a and 27d according to the present invention are employed in the gap provided between the rectangular core blocks 24a and 24c.

The conventional spacers 27b and 27c made of ceramic are made of a material having a relative magnetic permeability of 1, while the spacers 27a and 27d are made of a material of a relative magnetic permeability of 2. In the embodiment, in order to make the performance in these magnetic circuits the same, the thickness of the spacers 27a and 27d is set to about twice that of the spacers 27b and 27c.

  In the gap provided between the substantially U-shaped core block 25 and the rectangular core blocks 24a and 24c, leakage magnetic flux was likely to occur, but by adopting the above configuration, the leakage magnetic flux in this portion was reduced, The efficiency of the reactor can be improved.

  In the embodiment, the spacer is formed in a rectangular plate shape, but the dimensional form can be set according to the form of the reactor.

  In addition, the types and blending amounts of the nonmagnetic material and the powdered magnetic material constituting the base material are not limited to the examples, and a desired relative magnetic permeability and form can be obtained using various materials as necessary. The spacer can be formed.

  The present invention is not limited to the above-described embodiments. The embodiments disclosed herein are illustrative in all respects and should not be construed as being restrictive. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

It is a perspective view which shows the external appearance of the reactor which concerns on this invention. It is a perspective view which shows the external appearance of the core of the reactor shown in FIG. It is a figure which shows typically the internal structure of the spacer which concerns on a 1st Example. It is sectional drawing which represented typically the state of the magnetic flux at the time of operating the reactor by inserting the spacer which concerns on this invention into the gap in an annular core. It is a top view at the time of using the conventional spacer and the spacer of this invention for a cyclic | annular core block. It is sectional drawing which represented typically the state of the magnetic flux at the time of operating a reactor by inserting the conventional spacer in the gap provided in an annular core.

4a core block 4b core block 7 spacer

Claims (7)

A substantially U-shaped core block; and a pair of I-shaped parts configured by assembling two or more rectangular core blocks. The substantially U-shaped core block is provided at both ends of the pair of I-shaped parts. An annular core is formed by connecting, and a reactor configured by providing a coil on the outer periphery of the annular core,
While interposing a spacer made of a material formed by dispersing a powdered magnetic material in a base material made of a non-magnetic material , between each core block,
The relative permeability of the spacer material inserted between the I-shaped portion and the substantially U-shaped core block is the relative permeability of the spacer material inserted between the rectangular core blocks constituting the I-shaped portion. Set larger,
A reactor in which a thickness of a spacer inserted between the I-shaped portion and the substantially U-shaped core block is set larger than a thickness of a spacer inserted between the rectangular core blocks constituting the I-shaped portion. . The reactor of Claim 1 whose relative magnetic permeability of the said spacer material is 1.5-5. The reactor according to claim 1, wherein the spacer material is formed so as to include 15% by volume to 25% by volume of a powdered magnetic material having a relative permeability of 1000 or more. The reactor according to any one of claims 1 to 3 , wherein the nonmagnetic material is a resin material. The reactor according to any one of claims 1 to 4 , wherein the nonmagnetic material is a ceramic material. The reactor according to any one of claims 1 to 5 , wherein the spacer is a green compact or a sintered compact. While forming the core block from a powder compact including a powdery magnetic material and a binder resin,
The said spacer is formed from the compacting body which set the relative permeability to the predetermined value by changing the compounding quantity of the binder resin of the said core block, The any one of Claims 1-6. The reactor described in .

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