JP2012094924A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor using a spacer capable of reducing loss and mitigating uneven distribution of magnetic flux density to improve energy conversion efficiency by reducing a leakage flux generated at a gap peripheral part.SOLUTION: A reactor includes nearly U-shaped core blocks 5 and a pair of I-shaped parts 4 configured by combining two or more rectangular core blocks 4a, 4b, and 4c. An annular core 2 is formed by connecting the above-mentioned nearly U-shaped core blocks to both ends of the pair of I-shaped parts. A coil 3 is provided at the outer periphery of the annular core. A spacer 7 configured by dispersing a powdery magnetic material 9 into a base material made of a nonmagnetic material is interposed between at least the above I-shaped parts and nearly U-shaped core blocks.

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 is increased, and the energy conversion efficiency of the reactor is lowered. 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, A spacer formed by dispersing a powdered magnetic material is interposed between at least the I-shaped portion and the substantially U-shaped core block.

  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 permeability of the material constituting the spacer, and the like 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.

  As in the invention described in claim 2, the relative magnetic permeability of the material constituting the spacer inserted between the I-shaped portion and the substantially U-shaped core block is set to the rectangular shape constituting the I-shaped portion. It is preferable to set the relative permeability of the material constituting the spacer interposed between the shape core blocks.

  As the relative permeability of the material constituting the spacer is increased, the leakage magnetic flux from the spacer can be reduced. For this reason, the relative magnetic permeability of the material constituting the spacer inserted between the I-shaped part and the substantially U-shaped core block, in which leakage magnetic flux is likely to be generated, is used as the rectangular core block constituting the I-shaped part. By setting the relative permeability of the material constituting the spacer interposed therebetween, leakage magnetic flux can be efficiently prevented.

Further, when the relative permeability of the material constituting the spacer inserted between the I-shaped portion and the substantially U-shaped core block is set larger than the material constituting the spacer inserted in another part, In order to construct a reactor with a certain performance, it is necessary to change the thickness of other spacers or the relative magnetic permeability of the material constituting these spacers. For this reason, the relative magnetic permeability of the material which comprises the spacer inserted between the said I-shaped part and the said substantially U-shaped core block is inserted between the said rectangular core blocks which comprise the said I-shaped part. The rectangular core which is set larger than the relative magnetic permeability of the material constituting the spacer and the thickness of the spacer inserted between the I-shaped portion and the substantially U-shaped core block is configured as the I-shaped portion. By setting the thickness larger than the thickness of the spacer inserted between the blocks, a spacer having the same magnetic permeability can be configured. That is, the relative permeability 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 of the material constituting the spacer 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 material constituting the spacer to 1.5 to 5, as in the invention described in claim 3.

  If the relative magnetic permeability of the material constituting the spacer is 1.5 or less, leakage flux similar to that of the conventional non-magnetic spacer is likely to be generated, and an effect of reducing leakage 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 made of a material having a relative permeability greater than 1 is provided, to obtain the same magnetic characteristics, the thickness of the spacer must be increased substantially in proportion to the relative permeability. 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 formed of a material having a relative permeability greater than 5, the thickness of the spacer is too large with respect to the length of the core, and the size of the entire apparatus is correspondingly increased. In addition, the loss may increase as the total length of the core increases. Therefore, it is desirable to set the relative permeability of the material constituting the spacer to 5 or less.

  The invention described in claim 4 of the present application is such that the material constituting the spacer is a powder magnetic material having a relative magnetic permeability of 1000 or more in a base material formed from a nonmagnetic material. %.

  The powdered magnetic material having a high relative permeability can easily attract the magnetic flux, and can prevent the magnetic flux from leaking from the spacer. Therefore, it is preferable to employ a magnetic material having as large a relative 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 fifth 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 6, 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 7, a compacted body or a sintered compact can be adopted 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 8, the core block is formed from a powder compact including a powdery magnetic body and a binder resin, and the material constituting the spacer is blended in the binder resin in the core block. Is formed from a green compact with the relative permeability 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 the powdered magnetic material 9 in a base material made of 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.

  Further, in this embodiment, the relative magnetic permeability of the material constituting the spacer is set to about 2 by blending the powdered magnetic material 9 with 17 volume% with respect to the base material. 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 magnetic permeability of the material constituting the spacer 7 is set to 2, the thickness is 2 as compared with the conventional spacer S formed from the material having the relative magnetic permeability 1 shown in FIG. It is set to double. 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.

  FIG. 5 shows an example in which both the spacers 27a and 27d according to the present invention and the conventional spacers 27b and 27c are employed in the annular core 22 having the configuration 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 spacers 27b and 27c made of the conventional ceramic have a relative magnetic permeability of 1, while the spacers 27a and 27d have 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 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 (8)

A substantially U-shaped core block and a pair of I-shaped parts configured by assembling two or more rectangular core blocks;
An annular core is formed by connecting the substantially U-shaped core block to both ends of the pair of I-shaped portions,
A reactor configured by providing a coil on the outer periphery of the annular core,
A spacer made of a material formed by dispersing a powdery magnetic material in a base material made of a non-magnetic material is inserted at least between the I-shaped portion and the substantially U-shaped core block. , Reactor.   The relative magnetic permeability of the material constituting the spacer inserted between the I-shaped portion and the substantially U-shaped core block is configured as the spacer inserted between the rectangular core blocks configuring the I-shaped portion. The reactor according to claim 1, wherein the reactor is set to be larger than a relative permeability of a material to be processed.   The reactor of Claim 1 or Claim 2 whose relative magnetic permeability of the material which comprises the said spacer is 1.5-5.   The material constituting the spacer is formed by including 15% to 25% by volume of a powdery magnetic material having a relative magnetic permeability of 1000 or more in a base material formed of a nonmagnetic material. Or the reactor of Claim 2.   The reactor according to any one of claims 1 to 4, wherein the nonmagnetic material is a resin material.   The reactor according to any one of claims 1 to 5, wherein the nonmagnetic material is a ceramic material.   The reactor according to any one of claims 1 to 6, 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 1-5. The reactor described in.

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