JP2006100513A - Reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reactor employing the iron core of a low manufacturing cost which remarkably reduces an eddy current loss due to leakage flux and which is reduced in man-hours thereby permitting easy manufacturing. <P>SOLUTION: The reactor is constituted of a yoke core consisting of a wound core formed by winding a magnetic thin belt, a leg core consisting of a laminated core formed by punching the magnetic thin belt and worked by laminating the punched thin sheets, and a coil. The leg core is arranged so that the laminating surface of the same is orthogonal to the laminated surface of the yoke core. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reactor. More specifically, the present invention relates to a reactor that is configured by arranging a separator, that is, a gap, in a wound iron core and is used in an inverter circuit, a converter circuit, or the like in order to remove noise.

  In a reactor using a wound core with a gap, the gap of the wound core tends to be increased in recent years as the switching circuit has a higher frequency and higher harmonic components. However, as the gap increases, the leakage magnetic flux from the gap also increases, leading to an increase in copper eddy current loss that occurs between the gap and the windings in the vicinity thereof.

  In this case, the gap division number is increased, the gap per gap is decreased, the distance between the gap and the surrounding coil is increased, the leakage magnetic flux is reduced, or copper foil or litz wire is used as a copper wire. Is used to cope with an increase in copper eddy current loss.

  However, it has been confirmed that even if such measures are taken, the iron loss will be larger than expected, and as a countermeasure against this, the thickness of the magnetic ribbon may be further reduced, or another low iron loss may be achieved. It can be dealt with by changing to a magnetic ribbon, but both have led to an increase in the price of the iron core.

The following are proposed as examples of the prior art.
Patent Document 1 discloses a core leg with a gap by stacking a plurality of block cores having a circular cross section formed by radially laminating directional silicon steel sheets via a magnetic gap. Winding is wound around the gap core leg, and a yoke iron core having a rectangular cross section formed by laminating silicon steel plates is arranged above and below the gap core leg, and the yoke core and gap are formed by tightening studs. In the cored reactor with a gap, which is designed to tighten the attached core legs integrally, the direction of the outermost and innermost punches of the block core is made perpendicular to the direction in which the main magnetic flux flows, that is, they are stacked radially. An iron core reactor with a gap having a circular cross-sectional structure has been proposed.

  In Patent Document 2, four laminated cores made up of four I-type sheet cores, and a reactor made up of a gap and a coil, two laminated cores positioned inside the coil and arranged orthogonal to this There is disclosed a reactor in which the sheet cores constituting the two laminated cores located on the outer sides have different plate thicknesses.

  In Patent Document 3, in a power transformer used for a switchboard or the like, a plurality of winding elements are passed through each of two or three core legs in parallel with a four-legged magnetic core or a five-legged magnetic core. A configuration has been proposed in which a single-phase or three-phase power transformer is formed by forming a primary winding and a secondary winding by wiring connection. This is because the electrostatic capacitance between the primary winding and the secondary winding is small, the winding length of the winding is shortened, the high frequency noise is cut off, the loss is small, and the efficiency is high.

  In Patent Document 4, in a core reactor with a cap, a core unit is formed of a wound core, and a strip-shaped iron plate having a width of twice or less the gap length is provided on at least one of an inner peripheral side and an outer peripheral side of the wound core. A radially arranged configuration is disclosed.

  Patent Document 5 discloses a reactor in which a main leg iron core disposed in a reactor coil is composed of a plurality of laminated and bonded partial iron cores disposed with a gap interposed in a magnetic flux passing direction. An iron core, in which the partial cores are laminated such that thin steel plates of the same width are laminated in a rectangular cross section, the stacking directions thereof are orthogonal to each other, and the core mass is within a predetermined outer contour line of the partial cores. And the steel plate surface in the stacking direction is arranged to form an angle of 45 degrees or less with the normal spring with respect to the outer contour line.

  Patent Document 6 discloses an iron core for forming a magnetic circuit, in which a rectangular parallelepiped laminated core piece is provided between cut surfaces of a pair of C-shaped split core pieces obtained by dividing an annular wound core member. An iron core in which a looped magnetic path is formed by interposing is disclosed.

Japanese Patent Laid-Open No. 4-116812 JP-A-11-238630 JP 2003-197437 A Japanese Utility Model Publication No.57-83723 Japanese Utility Model Publication No.59-11430 JP 2004-87668 A

  In the configuration disclosed in Patent Document 1, the flow of the fringing magnetic flux matches the directivity of the silicon steel sheet at the outermost and innermost sides of the iron core, so that the magnetic flux easily flows, thus reducing the iron loss of that portion. can do. On the other hand, there is a problem that it takes time and labor to manufacture the iron core by radially stacking the punched plates, and the manufacturing cost is high.

  In the configuration disclosed in Patent Document 2, by using a low-cost material for a portion having a low magnetic flux density in the core forming the magnetic path of the reactor, the characteristics of the reactor are not significantly impaired, that is, loss or A low-cost reactor can be manufactured without increasing the temperature rise too much. On the other hand, there are only four gaps formed by the configuration of the laminated core, and there is a problem that the gaps cannot be dispersed, and since the gap is arranged outside the coil, the leakage magnetic flux is large, There is a problem that the vortex loss of the core and the coil is large.

  In the configuration disclosed in Patent Document 3, the capacitance between the primary winding and the secondary winding is small, the winding length of the winding is shortened, the high frequency noise cutoff characteristics are good, and the loss is low. Small and efficient. However, this power transformer has a small eddy current loss due to leakage magnetic flux due to the current-carrying condition at commercial frequencies, and has no effect of orthogonal arrangement. On the other hand, the high frequency noise blocking performance is obtained by the shield between the primary and secondary winding elements, and is not due to the orthogonality of the laminated surfaces.

  In the configuration disclosed in Patent Document 4, it takes time and effort to increase the number of man-hours for manufacturing the iron core by radially stacking the punched plates.

  In the configuration disclosed in Patent Document 5, since punched plates having different dimensions are stacked, there is a problem that it takes time and man-hours are increased.

  In the configuration disclosed in Patent Document 6, since the laminated surfaces of the yoke core and the leg iron core are not orthogonal to each other, there is a problem that eddy current iron loss due to leakage magnetic flux from the gap is large.

(Object of invention)
The present invention has been made in view of the above-described problems associated with conventional reactors, and an object thereof is to provide a reactor in which eddy current loss due to leakage magnetic flux is significantly reduced.
Another object of the present invention is to provide a reactor that uses a low-cost core that can be easily manufactured with a reduced number of steps.

  The present invention provides a reactor consisting of a yoke core made of a wound core formed by winding a magnetic ribbon, a leg iron core made of a stacked iron core punched and laminated, and a coil. It is a reactor characterized by having arrangement | positioning orthogonal to the lamination surface of a yoke core.

Embodiments of the present invention are as follows.
The leg iron core has a structure in which a magnetic ribbon that is punched and striped is laminated in a resin case having a separator.
The leg iron core is formed by integrally forming a laminate of magnetic strips that have been punched into strips by an insert mold.
The leg iron core includes a separator.
The reactor has a non-metallic band for fastening and fixing the iron core.

  In the case of the conventional wound core structure, since the surface of the ribbon is located on the inner side surface and the outer side surface of the core leg in the vicinity of the gap, it is difficult to prevent eddy current loss due to magnetic flux leaking from the portion. Therefore, the present invention provides an inner side surface or an outer side surface of the core leg so that the laminated surface of the ribbon is located on the inner side surface and the outer side surface of the core leg, that is, by making the structure perpendicular to the laminated surface of the yoke core. Even if a leakage magnetic flux penetrating through is generated, an increase in eddy current loss can be significantly reduced. Specifically, it has a laminated core structure in which magnetic ribbons are formed in a laminated structure, and the yoke core is a wound iron core obtained by winding a magnetic ribbon as usual, and the laminated surface of the leg iron core is the lamination of the yoke core Arrange so as to be orthogonal to the surface.

  Since the leg iron cores according to the present invention have to be laminated in a strip shape with a thin plate thickness, it is desirable that the leg iron cores can be easily laminated. As this method, a resin case having a separator is prepared, and magnetic strips punched into strips are laminated and then fixed by taping or the like, and further vacuum impregnated and cured with varnish resin or the like. . Alternatively, a stack of punched strips of magnetic ribbons can be formed by integral molding with an isolator provided by an insert mold.

  As for the conventional fixing method of a wound core with a separator, the outer periphery of the core is fastened and fixed with a nonmagnetic metal band such as stainless steel. Therefore, when this conventional wound iron core with a separator is used in the present invention, the metal surface of the band is located on the outer laminated surface of the leg iron core, and the leakage magnetic flux leaking through the outer surface of the iron core leg. Considering the influence, it is considered that the generation of eddy current loss due to this band cannot be ignored. By using a band made of a nonmetallic insulator instead of a conventional metal band, the above object can be achieved more efficiently.

The reactor of this invention has the effect which can comprise the reactor which reduced the eddy current loss by leakage magnetic flux significantly.
According to the reactor of the present invention, there is also an effect that it is possible to configure a reactor that uses an iron core with a low production cost that can be easily manufactured with less man-hours.

The reactor of embodiment of this invention is demonstrated based on the following figures.
(First embodiment)
As shown in FIG. 1, the reactor 1 of the first embodiment includes a pair of yoke cores (winding cores) 10 and 12 in which directional electromagnetic steel sheets having a thickness of 0.1 mm are stacked, and a directionality having a thickness of 0.1 mm. Two pairs of leg iron cores (stacked iron cores) 14, 16, 18, 20 laminated with electromagnetic steel plates, a pair of first separators 22, 24 with a thickness of 2.0 mm laminated with epoxy glass, and an epoxy resin impregnated tape And four second separators 30, 32, 34, and 36 having a thickness of 0.08 mm. The first separators 22 and 24 are sandwiched between the leg iron cores (stacked iron cores) 14, 16, 18, and 20 without a gap. The second separators 30, 32, 34, 36 are sandwiched between the yoke cores (winding cores) 10, 12 and the leg iron cores (stacked iron cores) 14, 16, 18, 20 without any gaps. The laminated surface of the yoke cores (winding iron cores) 10 and 12 and the laminated surface of the leg iron cores (stacked iron cores) 14, 16, 18 and 20 are orthogonal to each other.

  The leg portions of the yoke cores (winding iron cores) 10 and 12 and the leg iron cores (stacked iron cores) 14, 16, 18 and 20 are formed by a pair of resin cases 40 made of an epoxy glass laminate for positioning the two mutually. Covered. The assembled yoke cores (winding cores) 10 and 12, leg iron cores (stacked iron cores) 14, 16, 18, and 20, the first separators 22 and 24, and the second separators 30, 32, 34, and 36 are The periphery is fastened by a belt 38 made of SUS304 stainless steel. A coil 44 wound with a litz wire is disposed outside each resin case 40. FIG. 1 shows schematic dimensions in mm.

  The loss of the reactor is measured from a wattmeter connected by applying a 12 KHz sine wave voltage 115 V between the coils of the reactor. In order to improve measurement accuracy, a capacitor is connected and the power factor is adjusted to 1. The loss of the first embodiment was 11.3W.

(Second Embodiment)
Although the reactor 100 of 2nd Embodiment is shown by FIG. 2, about the structure same as the reactor 1 of 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. The assembled yoke cores (winding iron cores) 10 and 12, leg iron cores (stacked iron cores) 14, 16, 18, and 20, the first separators 22 and 24, and the second separators 30, 32, 34, and 36 are The periphery is fastened by a resin band 138. FIG. 2 shows schematic dimensions in mm. The loss of the reactor of 2nd Embodiment was 10.5W.

(First comparative example)
A reactor 200 of a first comparative example corresponding to the first embodiment is for comparison with the reactor 1 of the first embodiment, and is shown in FIG. 3, but is the same as the reactor 1 of the first embodiment. The components are denoted by the same reference numerals, and the description thereof is omitted. The laminated surface of the yoke cores (rolled iron cores) 10 and 12 and the laminated surface of the leg iron cores (stacked iron cores) 14, 16, 18 and 20 are parallel to each other. Resin cases or the like that cover the leg portions of the yoke cores (winding iron cores) 10 and 12 and the leg iron cores (stacked iron cores) 14, 16, 18, and 20 are not provided. FIG. 3 shows schematic dimensions in mm. The loss of the reactor of the first comparative example was 12.4W.

(Second comparative example)
A reactor 300 of a second comparative example corresponding to the second embodiment is for comparison with the reactor 100 of the second embodiment, and is shown in FIG. 4, but is the same as the reactor 100 of the second embodiment. The components are denoted by the same reference numerals, and the description thereof is omitted. The laminated surface of the yoke cores (rolled iron cores) 10 and 12 and the laminated surface of the leg iron cores (stacked iron cores) 14, 16, 18 and 20 are parallel to each other. Resin cases or the like that cover the leg portions of the yoke cores (winding iron cores) 10 and 12 and the leg iron cores (stacked iron cores) 14, 16, 18, and 20 are not provided. FIG. 4 shows schematic dimensions in mm. The loss of the reactor of the second comparative example was 12.8W.

In order to compare the performance of the reactor of the present invention with the performance of the conventional example, a prior art reactor corresponding to the embodiment of the present invention was created and measured.
(Conventional technology)
Although the reactor 400 of a prior art is shown by FIG. 5, a yoke core (winding iron core) is divided into one part.

  A conventional reactor 400 includes a pair of wound cores 410 and 412 in which directional electromagnetic steel sheets having a thickness of 0.1 mm are laminated, and a pair of third separators 422 and 424 in which a thickness of 2.5 mm is laminated with epoxy glass. Have The third separators 422 and 424 are sandwiched between the wound iron cores 410 and 412 without a gap. The laminated surfaces of the wound cores 410 and 412 are parallel to each other.

  The leg portions of the wound cores 410 and 412 are not covered with a resin case or the like. The pair of wound cores 410 and 412 that are assembled are tightened around a belt 438 made of SUS304 stainless steel. A coil 444 wound with a litz wire is disposed around the legs of the wound cores 410 and 412. FIG. 5 shows schematic dimensions in mm. The loss of the prior art reactor was 15.9W.

  In the embodiment of the present invention, the first separator is provided at two places. However, when the first separator is provided at two places or more, for example, four places without changing the total separation distance, the loss is further reduced. Therefore, the present invention does not limit the first separator to two places.

FIG. 1 is an explanatory plan view of a reactor according to a first embodiment of the present invention. FIG. 2 is an explanatory plan view of the reactor according to the second embodiment of the present invention. FIG. 3 is an explanatory plan view of the reactor of the first comparative example of the present invention. FIG. 4 is an explanatory plan view of the reactor of the second comparative example of the present invention. FIG. 5 is an explanatory plan view of a conventional reactor of the present invention.

Explanation of symbols

1 Reactor 10, 12 Junction core (winding iron core)
14, 16, 18, 20 Leg iron core
22, 24 First separator 30, 32, 34, 36 Second separator 38 Band 40 Resin case 44 Coil

Claims (5)

  In a reactor consisting of a wound iron core formed by winding a magnetic ribbon, a leg iron core consisting of a magnetic iron core punched and laminated, and a coil, the laminated surface of the leg iron core is a lamination of the yoke core A reactor having an arrangement perpendicular to a surface.   The reactor according to claim 1, wherein the leg iron core has a structure in which a magnetic ribbon obtained by punching and striping is laminated in a resin case having a separator.   The reactor according to claim 1, wherein the leg iron core is formed by integrally molding a laminate of magnetic ribbons that have been punched into strips.   The reactor according to claim 3, wherein the leg iron core includes a separator.   The reactor according to claim 1, wherein the reactor has a nonmetallic band for fastening and fixing the iron core.

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