Abstract: A reactor includes a coil formed by connecting a pair of coil elements configured by a wound wire, and magnetic core. The reactor for an on-vehicle converter converts an input voltage. Electricity applying conditions include a maximum DC current of 100 A or higher and 1000 A or lower, an average voltage of 100 V or higher and 1000 V or smaller, and a usable frequency of 5 kHz or higher and 100 kHz or smaller. The magnetic core is obtained by combining a plurality of divided core pieces without a gap provided. All the divided core pieces are made of hardened compact obtained by hardening resin of composite material containing magnetic powder and the resin. A distance between an inner peripheral surface of the coil element and an outer peripheral surface of the magnetic core opposite to the inner peripheral surface is 0.1 mm or more and 2 mm or less.

Abstract: A reactor 1 of the present invention includes a coil 2 and a magnetic core 3 disposed inside and outside the coil 2 to form a closed magnetic path. At least part of the magnetic core 3 is made of a composite material containing a magnetic substance powder and a resin containing the powder being dispersed therein. The magnetic substance powder contains powders respectively made of a plurality of materials differing in the relative permeability, representatively, a pure iron powder and an iron alloy powder. Thanks to provision of the magnetic core 3 made of the composite material containing magnetic substance powders made of different types of materials, the reactor 1 achieves both a high saturation magnetic flux density and a low-loss characteristic.

Abstract: A reactor includes a coil formed by connecting a pair of coil elements configured by a wound wire, and magnetic core. The reactor for an on-vehicle converter converts an input voltage. Electricity applying conditions include a maximum DC current of 100 A or higher and 1000 A or lower, an average voltage of 100 V or higher and 1000 V or smaller, and a usable frequency of 5 kHz or higher and 100 kHz or smaller. The magnetic core is obtained by combining a plurality of divided core pieces without a gap provided. All the divided core pieces are made of hardened compact obtained by hardening resin of composite material containing magnetic powder and the resin. A distance between an inner peripheral surface of the coil element and an outer peripheral surface of the magnetic core opposite to the inner peripheral surface is 0.1 mm or more and 2 mm or less.

Abstract: There is provided a composite material containing magnetic powder and a polymeric material including the powder in a dispersion state, wherein a content of the magnetic powder with respect to the whole composite material is more than 50% by volume and 75% by volume or less, a saturation magnetic flux density of the composite material is 0.6 T or more, and a relative magnetic permeability of the composite material is more than 20 and is 35 or less. It is preferable that a density ratio of the magnetic powder should be 0.38 or more and 0.65 or less. The density ratio is set to be an apparent density/a true density. Moreover, it is preferable that the magnetic powder should include a plurality of particles constituted of the same material.

Abstract: A reactor 1? includes one coil 2, a magnetic core 3 to which the coil 2 is arranged, and a case 4 containing an assembly 10 of the coil 2 and the magnetic core 3. The magnetic core 3 includes an inner core portion 31 inserted into the coil 2, and a coupling core portion 32 disposed around the coil 2. The coupling core portion 32 is made of a mixture of magnetic powder and resin. The coil 2 is covered with the coupling core portion 32 and is enclosed within the case 4 in a sealed state. The reactor 1? includes, in an outermost surface region exposed at an opening of the case 4, a magnetic shield layer 5 made of non-magnetic powder, having smaller specific gravity than the magnetic powder and having electrical conductivity, and the resin. A small reactor capable of reducing magnetic flux leaked to the outside is thereby provided.

Abstract: A reactor 1? includes a coil 2 formed by winding a wire 2w, a magnetic core 3 that is disposed inside and outside of the coil 2 and forms a closed magnetic circuit, and a case 4 that has an opening portion and a bottom surface 40 that opposes the opening portion and that houses an assembly 10 of the coil 2 and the magnetic core 3. At least the opening portion of the case 4 side of the magnetic core 3 is formed of a molded solid body that contains magnetic powder and resin. A surface layer 5, which prevents the magnetic powder from rusting, is provided on a surface of the magnetic core 3 on the opening portion of the case 4 side. The surface layer 5 has a resin portion formed of resin similar to the resin contained in the magnetic core 3. The resin portion is formed so as to be continuous with the resin contained in the magnetic core 3 without an interface formed therebetween.

Abstract: A reactor 1A of the present invention includes one coil 2 and a magnetic core 3. The coil 2 includes a turn portion 2t formed by a spirally wound wire 2w whose conductor is a rectangular wire, and draw-out portions 2d of the wire 2w drawn out from the turn portion 2t. The magnetic core 3 is disposed inside and outside the coil 2 to form a closed magnetic path. At least part of the outer circumference of each draw-out portion 2d is formed by a composite material containing magnetic substance powder and resin. The reactor 1A further includes a mold resin portion 21 that covers the outer circumference of the turn portion 2t and at least part of the draw-out portions 2d to retain the shape of the coil 2. In each corner portion region of the mold resin portion 21 covering corresponding corner portion of the wire 2w at each draw-out portion 2d, the outer circumferential face being brought into contact with the outer core portion 32 is formed by a curved surface.

Abstract: Provided are a coil component capable of contributing to improving productivity of a reactor, and a reactor exhibiting good productivity. A reactor 1A includes one coil 2 formed by spirally winding a wire 2w, and a magnetic core 3, which is disposed inside and outside the coil 2 and which forms a closed magnetic circuit. The magnetic core 3 includes an inner core portion 31 disposed inside the coil 2, and an outer core portion 32 disposed around the coil 2. The coil 2 and the inner core portion 31 constitute a coil component 2A held as an integral unit by a resin molded portion 20. A shape of the coil 2 is maintained by the resin molded portion 20. Since the coil component 2A includes a portion of the magnetic core 3, the number of components can be reduced, and the coil 2 and the inner core portion 31 can be easily placed into a case 4A when they are housed therein. The coil 2 is easier to handle because the coil shape is constantly maintained without expanding or contracting.

Abstract: A reactor 1A of the present invention includes a sleeve-like coil 2, a magnetic core 3A having an inner core portion 31 disposed inside the coil 2 and an outer core portion 32A disposed outside the coil 2 to form a closed magnetic path with the inner core portion 31, and a case 4 storing the coil 2 and the magnetic core 3A. The case 4 is made of non-magnetic metal such as aluminum, and structured by a pair of bottomed sleeve-like bottomed case pieces 41 and 42. The outer core portion 32A is a mold product (a hardened mold product) of a mixture of magnetic powder and resin, and integrally molded with the bottomed case pieces 41 and 42. Since the case 4 and the outer core portion 32A are integrally molded, they exhibit excellent adhesion, and consequently, the heat dissipating characteristic of the reactor 1A can be enhanced. Further, since the case 4 and the outer core portion 32A are integrally molded, excellent assemblability is exhibited, and consequently, excellent productivity is also achieved.

Abstract: Provided is a reactor including a core; and a case housing the coil and the core, the core including an inner core portion arranged inside the coil and an outer core portion partly or entirely covering the outside of the coil, the outer core portion being formed of a mixture of a magnetic material and a resin. The coil is arranged such that the axial direction of the coil is substantially parallel to a bottom surface of the case. The difference in concentration of the magnetic material in the outer core portion in the axial direction of the coil is smaller than the difference in concentration of the magnetic material in the outer core portion in a direction along a side wall of the case. With the reactor, even if the outer core portion covering the outside of the coil is formed of the mixture of the magnetic material and the resin, a desirable inductance value can be easily achieved and the reactor can have good heat radiation performance.

Abstract: A reactor 1A of the present invention includes a sleeve-like coil 2, a magnetic core 3 that is disposed inside and outside the coil 2 to form a closed magnetic path, and a case 4A that stores the coil 2 and the magnetic core 3. At least part of the magnetic core 3 (herein an outer core portion 32 provided on the outer circumference side of the coil 2) is formed by a composite material that contains magnetic substance powder and resin. At least part of the outer circumference of the coil 2 is covered by a resin mold portion 21 that is formed by an insulating resin, whereby the shape of the coil 2 is retained. A heat dissipating pedestal portion 5A that forms at least part of the case 4A and that is formed by a non-magnetic metal material is integrally retained with the coil 2 by the resin forming the resin mold portion 21.

Abstract: A reactor 1A of the present invention includes a sleeve-like coil 2, a magnetic core 3 disposed inside and outside the sleeve-like coil 2 to form a closed magnetic path, and a case 4A storing the coil 2 and the magnetic core 3. At least part of the magnetic core 3 (herein, an outer core portion 32 provided on the outer circumferential side of the coil 2) is formed by a composite material containing magnetic substance powder and resin. The case 4A is formed by a bottom plate portion 40 and a wall portion 41 each being an independent member. In the reactor 1A, the coil 2 and the bottom plate portion 40 that is made of a non-magnetic metal material are integrally retained by a resin mold portion 21 formed by an insulating resin. Since the resin mold portion 21 fixes the coil 2 and the bottom plate portion 40, the heat of the coil 2 can be efficiently transferred to the installation target. Accordingly, the reactor 1A has an excellent heat dissipating characteristic.

Abstract: A reactor having a good heat dissipation effect is provided. The reactor includes one coil formed by winding a wire, a magnetic core arranged inside and outside the coil and forming a closed magnetic circuit, and a case for housing an assembly of the coil and the magnetic core. An end surface of the coil has a race track shape, and the coil is housed in the case such that the axial direction of the coil is parallel to an outer bottom surface of the case. A part of an outer peripheral surface of the coil is covered with the magnetic core (outer core portion), and a remaining part thereof not covered with the magnetic core is contacted with an inner bottom surface of the case. Since a part (mainly a linear portion) of the outer peripheral surface of the coil is directly contacted with the inner bottom surface of the case, heat of the coil can be directly dissipated such that the heat is released through the case to an installation target, e.g., a water cooling base, on which the case is installed.

Abstract: A reactor 1A of the present invention includes a sleeve-like coil 2, a magnetic core 3A having an inner core portion 31 disposed inside the coil 2 and an outer core portion 32A disposed outside the coil 2 to form a closed magnetic path with the inner core portion 31. The outer core portion 32A is a mold product (a hardened mold product) of a mixture of magnetic powder and resin, and structured by a combination of two radially divided pieces 321 and 322 that can be separated in the radial direction of the coil 2. Since the outer core portion 32A is structured by a plurality of divided pieces, the manufacturing time per divided piece can be shortened and excellent productivity of the reactor 1A is exhibited. When the hardened mold product is formed by injection molding, further excellent productivity is exhibited. Since the seam portion of the radially divided pieces 321 and 322 does not break the magnetic flux, no gaps that divide the magnetic flux occur between the divided pieces 321 and 322.

Abstract: A reactor includes a coil formed by winding a wire, and a magnetic core in which a closed magnetic path is formed by both an inner core portion inserted in the coil and an outer core portion covering outer peripheral surfaces of the inner core portion and the coil. The outer core portion is formed of a mixture containing a magnetic material and resin. One of the coil and the inner core portion has an exposed portion where a part of the outer peripheral surface is not covered with the outer core portion, and at least a part of the exposed portion is in contact with a heat dissipation layer provided in a heat dissipation plate.

Abstract: Provided is a reactor having a small size with consideration of loss reduction. A reactor 1A includes a coil 10 and a magnetic core 20. The coil 10 is formed by winding a wire. The magnetic core 20 includes an internal core portion 21 that is inserted through the coil 10 and a couple core portion 23 that is coupled to an end of the internal core portion 21 and that covers an outer periphery of the coil 10. The core portions 21 and 23 form a closed magnetic path. An interposed core portion 25 is disposed between the coil 10 and the internal core portion 21. The reactor 1A satisfies 0<S2/S1<0.15, where S1 is an inner cross-sectional area of the coil 10 and S2 is a cross-sectional area of the interposed core portion 25; and satisfies B1>B2 and B1>B3, where B1 is a saturation magnetic flux density of the internal core portion 21, B2 is a saturation magnetic flux density of the couple core portion 23, and B3 is a saturation magnetic flux density of the interposed core portion 25.

Abstract: A reactor 1A includes a single coil 2 formed by spirally winding a wire 2w and a magnetic core 3 that is disposed inside and outside the coil 2 and forms a closed magnetic circuit. The magnetic core 3 includes an inner core portion 31 disposed inside the coil 2 and an outer core portion 32 disposed so as to cover the outer periphery of the coil 2. The outer core portion 32 is formed of a composite material containing a magnetic powder and a resin. In a section of this composite material, the maximum bubble diameter is 300 ?m or less. In the reactor 1A, the outer core portion 32 has a maximum bubble diameter of 300 ?m or less and, as a result, the loss is low and magnetic characteristics are less likely to be decreased.

Abstract: A converter including a reactor as one of a component for the converter, the reactor comprising: a coil; a core having an inner core portion arranged inside the coil and an outer core portion covering the outside of the coil; and a case housing the coil and the core, wherein the case has a heat-radiation structure at an inner wall surface, the heat-radiation structure being provided for at least one of the coil and the inner core portion, wherein the heat-radiation structure is non-similar to an outer wall surface of the case, and is formed of the inner wall surface that is formed to correspond to an external shape of the at least one of the coil and the inner core portion.

Abstract: A converter including a reactor as one of a component for the converter, the reactor comprising: a coil; a core having an inner core portion arranged inside the coil and an outer core portion covering the outside of the coil; and a case housing the coil and the core, wherein the case has a heat-radiation structure at an inner wall surface, the heat-radiation structure being provided for at least one of the coil and the inner core portion, wherein the heat-radiation structure is non-similar to an outer wall surface of the case, and is formed of the inner wall surface that is formed to correspond to an external shape of the at least one of the coil and the inner core portion.

Abstract: A reactor 1 of the present invention includes a coil 2 and a magnetic core 3 disposed inside and outside the coil 2 to form a closed magnetic path. At least part of the magnetic core 3 is made of a composite material containing a magnetic substance powder made of an identical material and a resin containing the powder being dispersed therein. In the particle size distribution of the magnetic substance powder, a plurality of peaks are present. That is, the magnetic substance powder contains both a fine powder and a coarse powder at high frequencies. Since the composite material contains the fine powder, it can reduce the eddy current loss, and hence achieves to be a low-loss material. Thanks to the mixed powder including the fine powder and the coarse powder, the packing density of the magnetic substance powder is increased. Thus, the composite material exhibits a high saturation magnetic flux density.