JP2011077217A - Choke coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve DC superposition characteristics of a toroidal core by making a shape of a gap flexible. <P>SOLUTION: A toroidal type choke coil includes the toroidal core 200 formed by annularly winding a belt-like magnetic body 210 and an interconnect 400 wound around the toroidal core 200, wherein the belt-like magnetic body 210 is formed by sticking together a magnetic thin belt 220 made of a magnetic material and an insulating thin belt made of an insulating material, and provided with a plurality of gaps 240 at prescribed intervals. The plurality of gaps 240 are formed, for example, at equal intervals or at random intervals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a structure of a toroidal core of a choke coil.

  2. Description of the Related Art Conventionally, a toroidal choke coil having a toroidal core and a winding wound around the toroidal core is known as a choke coil used for a noise filter or an inverter circuit of an air conditioner. In general, this toroidal core is formed by winding a belt-shaped magnetic steel sheet into a donut shape, heat-treating and impregnating with varnish, curing, and then cutting a part using a grinding machine such as a grindstone to create a gap with a predetermined width. Is formed.

  Magnetic saturation characteristics can be improved by providing a gap in the toroidal core, but the formation of the gap by cutting requires high equipment investment and maintenance costs for the grinding machine, and increases processing accuracy. In addition, there is a problem that burrs are generated on the cut surface of the gap, eddy current loss due to a short circuit increases between the layers of the belt-shaped magnetic steel sheet, and heat generation is increased.

  Therefore, as shown in FIGS. 5A to 5D, as a toroidal choke coil 12, a winding 15 is wound around a core case 14 in which a toroidal core 13 is housed, and a strip-shaped magnetic steel sheet. When a plurality of slit holes 17 are sequentially provided at 16 (a <b <c) and the belt-shaped magnetic steel sheet 16 is wound, the plurality of slit holes 17 are gathered on the toroidal core 13. Thus, there has been proposed one in which a gap 18 is formed in one place (see, for example, Patent Document 1). According to the toroidal core 13, the gap 18 is formed regardless of the cutting process by the grinding machine, and thus the above-described problem can be solved.

  However, in Patent Document 1, since the toroidal core 13 is formed by winding the belt-shaped magnetic steel plate 16, the gap 18 is formed as a part of the strip-shaped magnetic steel plate 16 like the slit hole 17 in FIG. Must be connected. For this reason, compared to the case where the gap is formed by completely cutting the strip-shaped magnetic steel plate 16, the DC superposition characteristics are deteriorated, and the toroidal core 13 is magnetically saturated even when the current value flowing through the winding 15 is low. there were.

JP-A-2005-303001 (pages 8 to 9, FIGS. 1 and 2)

  In view of the above problems, an object of the present invention is to provide a choke coil that can improve the direct current superposition characteristics of a toroidal core by giving the gap shape flexibility.

  In order to solve the above problems, the present invention provides a choke coil comprising a toroidal core in which a band-shaped magnetic body is wound in an annular shape, and a winding wound around the toroidal core. The strip-shaped magnetic body is formed by bonding a magnetic ribbon made of a magnetic material and an insulating ribbon made of an insulating material, and the magnetic ribbon is provided with a plurality of gaps. ing.

  According to a second aspect of the present invention, in the choke coil according to the first aspect, the plurality of gaps are formed at the same interval.

  According to a third aspect of the present invention, in the choke coil according to the first aspect, the plurality of gaps are formed at random intervals.

  According to a fourth aspect of the present invention, in the choke coil according to the first aspect, the plurality of gaps are formed at intervals that are sequentially enlarged.

  According to a fifth aspect of the present invention, in the choke coil according to the first aspect, the band-shaped magnetic body is wound to form a gap set in which the gaps are partially concentrated in the radial direction of the toroidal core. The configuration is characterized in that a plurality of components are distributed in the circumferential direction.

  According to the present invention, since the toroidal core can be manufactured even when the gap is formed by completely cutting the magnetic ribbon, the gap can be easily provided, and the DC superposition characteristics of the toroidal core can be improved. Can do.

It is explanatory drawing which shows the choke coil by this invention, (A) is a top view, (B) is a side view, (C) is DD sectional drawing of (B). It is explanatory drawing of the strip | belt-shaped magnetic body by this invention, (A) is a schematic front view of the strip | belt-shaped magnetic body of 1st Example, (B) is a schematic front view of the strip | belt-shaped magnetic body of 2nd Example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of an arrangement of a gap according to the present invention, in which (A) is an enlarged view of a main part of a cross section of a toroidal core in a first embodiment, It is a schematic diagram which shows the toroidal core manufacturing apparatus for forming the toroidal core by this invention. It is explanatory drawing which shows the conventional choke coil, (A) is an external appearance perspective view of a choke coil, (B) is a schematic front view of the strip | belt-shaped magnetic steel plate reduced in the elongate direction, (C) is an external perspective view of a toroidal core, (D) is principal part sectional drawing equivalent to the AA line of (C).

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The toroidal type choke coil according to the present invention is an electronic component used for a noise filter, an inverter circuit, etc. of an air conditioner. As shown in FIG. 1, the toroidal choke coil 100 includes a toroidal core 200, a core case 300, a winding 400 made of an insulated wire wound around the core case 300, a lead wire 500, a relay terminal. The heat-resistant tube 600 is provided so as to partially cover the winding 400 and the lead wire 500 connected via the connector, and the connector 700 is connected to one end of the lead wire 500.

  As shown in FIG. 2, the toroidal core 200 includes a magnetic ribbon 220 having a predetermined magnetic permeability and formed of a magnetic material such as amorphous metal, and an insulating ribbon 230 formed of an insulating material having heat resistance. The belt-like magnetic body 210 having two layers is formed, and the belt-like magnetic body 210 is wound in an annular shape, and then heat treated and impregnated with varnish to be cured and formed into a donut shape.

  The core case 300 is composed of an upper case 310 and a lower case 320 formed of a heat-resistant resin material in order to protect the toroidal core 200 from impact and the insulation with the winding 400, The upper case 310 and the lower case 320 have a substantially cylindrical outer shape, a donut-shaped cavity in the inner diameter portion, and are formed so that the toroidal core 200 can be stored therein. Further, the lower case 320 is provided with three through holes 330 for fixing the toroidal choke coil 100 to the casing of the air conditioner (not shown) with screws.

  As the winding 400, an insulated wire satisfying desired electrical characteristics such as a rated current and a DC superimposed inductance is selected, and is wound spirally around a substantially cylindrical core case 300 with a predetermined number of turns.

  Lead wire 500 is made of a conductor and a resin coating, and one end is electrically connected to winding 400 via a relay terminal, and the other end is electrically connected to connector 700 having a female terminal. Note that the female terminal of the connector 700 is electrically connected to a male terminal provided on a control board (not shown).

  The heat-resistant tube 600 is formed of a heat-resistant material, and the heat-resistant tube 600 covers the lead 400 from the lead portion of the winding 400 drawn out from the donut-shaped cavity of the core case 300 to the middle of the lead wire 500. In addition, the lead wire 500 and the relay terminal are protected from the heat generated by the toroidal choke coil 100 itself and the heat generated by other electric devices installed in the vicinity, and the insulation of the relay terminal is ensured.

  Next, of the configurations of the toroidal choke coil 100 described above, the toroidal core 200 that is a feature of the present invention will be described. As shown in FIG. 1C, the toroidal core 200 is provided with a gap 240 for preventing magnetic saturation even when the current flowing through the winding 400 increases due to load fluctuation. A plurality of gaps 240 are arranged in the circumferential direction and the radial direction of the toroidal core 200 formed in a donut shape.

  Thus, the structure of the strip-shaped magnetic body 210 for disposing a plurality of gaps 240 in the toroidal core 200 is as shown in FIG. As an embodiment of the present invention, a band-like magnetic body 210 in which a plurality of gaps 240 are randomly distributed in the circumferential direction and the radial direction of the toroidal core 200 and a plurality of gaps 240 are arranged in the radial direction of the toroidal core 200. Two embodiments of the belt-like magnetic body 210 in which a plurality of gap groups partially gathered in the circle are distributed in the circumferential direction will be described.

  First, the band-shaped magnetic body 210 in which a plurality of gaps 240 are randomly distributed in the circumferential direction and the radial direction of the toroidal core 200 will be described. As shown in FIG. 2A, the belt-like magnetic body 210 includes a magnetic ribbon 220 made of a magnetic material having a thickness T1 of 25 μm and an insulating ribbon 230 made of an insulating material having a thickness T2 of about 1 μm. The magnetic ribbon 220 has a plurality of slits 241 that intersect in the longitudinal direction, and each slit 241 functions as a gap 240. Yes.

  Each gap 240 has a gap width G of 100 μm, and the magnetic ribbon 220 as a whole at the same intervals a, b, c (a = b = c) preset in the longitudinal direction of the magnetic ribbon 220. Is formed. The toroidal core 200 completed by molding the strip-shaped magnetic body 210 as described above has a gap 240 formed in each toroidal core as shown in FIG. 3A in which the portion E in FIG. 1C is enlarged. A plurality of 200 are arranged in a randomly dispersed manner in the circumferential direction and the radial direction.

  Next, a description will be given of the belt-like magnetic body 210 in which a plurality of gap sets in which the gaps 240 are partially gathered in the radial direction of the toroidal core 200 are arranged in the circumferential direction. Note that description of parts common to the above-described embodiments is omitted. As shown in FIG. 2B, the band-shaped magnetic body 210 has gaps d, e, and f (d <e <f) where the gaps 240 are sequentially enlarged in the longitudinal direction of the magnetic ribbon 220. A plurality of gap sets are formed on the entire magnetic ribbon 220, such as a gap set by (1)) and a gap set by previously set gaps g, h, i (g <h <i) which are different from the above. Since the circumferential length of the plurality of gap sets increases from the inner diameter side of the toroidal core 200 to the outer diameter side, the gaps that are sequentially expanded as the gap groups are arranged on the outer diameter side. It is set to be large. The toroidal core 200 completed by molding the band-shaped magnetic body 210 as described above has a gap 240 as shown in FIG. 3B, in which the E portion of FIG. 1C is enlarged. A plurality of gap sets in which four gaps 240 are gathered partially in the radial direction of the core 200 are arranged in the circumferential direction.

  In the former embodiment, each gap 240 is formed at the same intervals a, b, and c preset in the longitudinal direction of the magnetic ribbon 220, but the present invention is not limited to this, and the gap 240 is not limited thereto. May be formed at random intervals a, b, c (a ≠ b ≠ c) set in advance in the longitudinal direction of the magnetic ribbon 220. In this embodiment, the gap width G of each gap 240 is 100 μm. However, the present invention is not limited to this, and the gap width G can be set as appropriate in order to obtain necessary DC superposition characteristics. Furthermore, in the latter embodiment, each gap 240 is a gap set in which four gaps 240 are partially gathered in the radial direction of the toroidal core 200. However, the present invention is not limited to this, and the diameter of the toroidal core 200 is not limited thereto. It may be a gap set in which two or more parts are gathered partially in the direction. In addition, as shown in FIG. 3B, each gap 240 is arranged such that a plurality of gap sets are dispersed in the radial direction and the circumferential direction of the toroidal core 200. Not limited to this, the gap 240 may be formed at intervals that are sequentially enlarged in the longitudinal direction of the magnetic ribbon 220 so that the gap pair is formed at one location in the radial direction of the toroidal core 200.

  Next, a manufacturing process for forming the toroidal core 200 described above will be described. As shown in FIG. 4, the toroidal core manufacturing apparatus 800 includes an insulating ribbon drum 810 wound with an insulating ribbon 230, a magnetic ribbon drum 820 wound with a magnetic ribbon 220, and an insulating ribbon drum 810. The feeding roller 830 that transfers the insulating ribbon 230 pulled out and the magnetic ribbon 220 pulled out from the magnetic ribbon drum 820 to the cutting device 840 and the insulating ribbon 230 transferred from the feeding roller 830 and the magnetic Of the strip-shaped magnetic body 210 bonded with the thin strip 220, a cutting device 840 that cuts only the magnetic strip 220, and the strip-shaped magnetic body 210 that has been cut only the magnetic strip 220 by the cutting device 840 are wound. It is comprised with the strip | belt-shaped magnetic body winding reel 850. FIG.

  In order to mold the toroidal core 200 using this toroidal core manufacturing apparatus 800, first, although not shown in the drawing, the surface of the insulating ribbon 230 drawn from the insulating ribbon drum 810 is bonded to the magnetic ribbon 220. An adhesive is applied in advance. Subsequently, the insulating ribbon 230 to which the adhesive is applied and the magnetic ribbon 220 pulled out from the magnetic ribbon drum 810 are bonded together by the feed roller 830, and two layers of the insulating ribbon 230 and the magnetic ribbon 220 are bonded. A belt-like magnetic body 210 having a structure is formed.

  The belt-like magnetic body 210 is sequentially transferred to the position of the cutting device 840 at a predetermined interval by the feed roller 830, and only the magnetic ribbon 220 is cut by the cutter of the cutting device 840. By cutting the magnetic ribbon 220, a plurality of slits 241 are formed at the intervals described above. These slits 241 form a plurality of gaps 240. At this time, the feed roller 830 and the cutting device 840 are controlled in conjunction with a drive control signal corresponding to the above-described interval from a controller (not shown). In addition, although the slit 241 was formed in the cutting device 840, it is not restricted to this, You may make it change the specification of the cutter of the cutting device 840, and may form a slit hole.

  Thereafter, the toroidal core 200 is formed by winding the band-shaped magnetic body 210 from which only the magnetic ribbon 220 is cut, in an annular shape by the band-shaped magnetic body winding reel 850 a predetermined number of times. Although not shown, the toroidal core 200 is completed by removing it from the belt-shaped magnetic winding reel 850, applying heat treatment and varnish impregnation, and curing to form a donut shape.

  In the present embodiment described above, the slit 241 is formed after the magnetic ribbon 220 and the insulating ribbon 230 are bonded together in the toroidal core manufacturing apparatus 800. However, the present invention is not limited to this. After cutting the magnetic ribbons 220 at predetermined intervals and sequentially aligning the plurality of magnetic ribbons 220, the magnetic ribbons 220 are pasted on the insulating ribbon 230 so as to have a predetermined gap width G. A plurality of gaps 240 may be provided without forming the slit 241 by combining them.

  According to the embodiment described above, in the toroidal choke coil 100 including the toroidal core 200 in which the belt-shaped magnetic body 210 is wound in an annular shape and the winding 400 wound around the toroidal core 200, The belt-like magnetic body 210 is formed by bonding a magnetic ribbon 220 made of a magnetic material and an insulating ribbon 230 made of an insulating material so that a plurality of gaps 240 are provided in the magnetic ribbon 220.

  As a result, even if the gap 240 is provided by completely cutting the magnetic ribbon 220, the belt-like magnetic body 210 is connected by the insulating ribbon 230, so that the toroidal core 200 can be manufactured by winding the belt-like magnetic body 210. . Thereby, the direct current superimposition characteristic required for the toroidal core 200 can be improved.

  Further, a plurality of gaps 240 are formed at the same interval or at random intervals, or a band set is formed by winding the belt-like magnetic body 210 to partially gather the gaps 240 in the radial direction of the toroidal core 200. A plurality of sets are arranged in a distributed manner in the circumferential direction.

  As a result, the magnetic flux leakage is dispersed by winding the belt-shaped magnetic body 210 and dispersing the plurality of gaps 240 in the circumferential direction and the radial direction of the toroidal core 200, so that heat generation and vibration caused by the leakage magnetic flux are also dispersed. The toroidal core 200 can suppress heat generation and vibration due to leakage magnetic flux.

DESCRIPTION OF SYMBOLS 100 Toroidal type choke coil 200 Toroidal core 210 Strip | belt-shaped magnetic body 220 Magnetic thin strip 230 Insulating thin strip 240 Gap 241 Slit 300 Core case 310 Upper case 320 Lower case 330 Through-hole 400 Winding 500 Lead wire 600 Heat-resistant tube 700 Connector 800 Toroidal core Manufacturing device 810 Insulating ribbon drum 820 Magnetic ribbon drum 830 Feed roller 840 Cutting device 850 Strip-like magnetic winding reel

Claims (5)

  In a choke coil comprising a toroidal core in which a band-shaped magnetic body is wound in an annular shape and a winding wound around the toroidal core, the band-shaped magnetic body is composed of a magnetic ribbon made of a magnetic material and an insulating material. A choke coil comprising a plurality of gaps provided in the magnetic ribbon.   The choke coil according to claim 1, wherein the plurality of gaps are formed at the same interval.   The choke coil according to claim 1, wherein the plurality of gaps are formed at random intervals.   The choke coil according to claim 1, wherein the plurality of gaps are formed at intervals that sequentially increase.   The band-shaped magnetic body is wound to form a gap set in which the gaps are partially gathered in the radial direction of the toroidal core, and a plurality of the gap sets are arranged in a circumferential direction. The choke coil according to claim 1.

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