JP2010027946A - Magnetic core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress crossing of magnetic flux, leaking out of an air gap, with winding while suppressing a decrease of a winding area. <P>SOLUTION: A center gap G11 is provided between a center magnetic leg 13a provided on an upper core 11a and a center magnetic leg 13b provided on a lower core 11b, and the width W11 of the center magnetic leg 13a is set to be smaller than the width W12 of the center magnetic leg 13b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic core, and is particularly suitable for application to a method of reducing leakage magnetic flux leaking out of a magnetic core from an air gap.

  In a coil component used for a power supply device or the like, in order to prevent the magnetic core included in the coil component from becoming saturated when a large current flows through the coil component, the center magnetic leg or side of the magnetic core is used. An air gap is provided in the magnetic leg.

  Here, if an air gap is provided in the center magnetic leg or the side magnetic leg of the magnetic core, the magnetic flux leaks out of the magnetic core from the air gap, and the leaked magnetic flux is linked to the winding. Eddy current is generated in the wire. For this reason, in the conventional coil parts, the eddy current loss becomes large, the power conversion efficiency is deteriorated, the heat generation of the winding is increased, the insulation film of the winding is dissolved, and the dielectric breakdown is caused. there were.

  For this reason, for example, in Patent Document 1, a separator having a substantially triangular cross section is provided on the outer periphery of a bobbin winding frame corresponding to the air gap of the center magnetic leg of the magnetic core, and the winding frame is divided into two parts. A method is disclosed in which both heat generation due to leakage magnetic flux from the gap and securing of a winding region are achieved.

JP 2005-340487 A

  However, in the method disclosed in Patent Document 1, the winding is applied to the magnetic core so as to avoid the periphery of the air gap in order to reduce the heat generation of the winding due to the leakage magnetic flux from the air gap. There is a problem in that the number of coil parts decreases and the size of the coil component increases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic core capable of suppressing magnetic flux leaking from an air gap from interlinking with a winding while suppressing a decrease in the winding area.

  In order to solve the above-described problem, according to the magnetic core according to claim 1, the magnetic path of the magnetic flux generated from the winding is provided by providing a winding region around which the winding is wound and being disposed opposite to each other. In the magnetic core including the first core and the second core that form the magnetic core, the first core and the second core are each provided with a magnetic leg disposed to face each other through an air gap. At least one of them is configured to converge the magnetic flux flowing through the air gap.

  According to the magnetic core of claim 2, the area of the cross section where the magnetic flux of the magnetic leg of the first core is linked is smaller than the area of the cross section where the magnetic flux of the magnetic leg of the second core is linked. It is characterized by that.

  The magnetic core according to claim 3 is characterized in that a convex portion is formed at a tip end of at least one of the first core and the second core.

  The magnetic core according to claim 4 is characterized in that a recess is formed at the tip of at least one of the first core and the second core.

  As described above, according to the present invention, by converging the magnetic flux leaking into the air gap between the cores, even when the winding is arranged so as to surround the air gap, the air gap is outside the magnetic core. It is possible to suppress the leaked leakage magnetic flux from interlinking with the winding. For this reason, it is possible to reduce the eddy current loss without arranging the windings so as to avoid the periphery of the air gap, and it is possible to increase the power conversion efficiency while suppressing the enlargement of the coil parts. At the same time, the heat generation of the windings can be reduced, and the reliability of the coil components can be improved.

Hereinafter, a magnetic core according to an embodiment of the present invention will be described with reference to the drawings.
1-1 is a perspective view showing a schematic configuration of the magnetic core according to the first embodiment of the present invention, and FIG. 1-2 is a cross-sectional view showing the magnetic core of FIG.
1-1 and 1-2, the magnetic core 11 is provided with an upper core 11a and a lower core 11b. In addition, as a material of the upper core 11a and the lower core 11b, for example, a magnetic material such as pure iron, ferrite, or permalloy can be used. Here, the upper core 11a is provided with a center magnetic leg 13a and side magnetic legs 12a and 14a, and the center magnetic leg 13a is disposed between the side magnetic legs 12a and 14a. The lower core 11b is provided with a center magnetic leg 13b and side magnetic legs 12b, 14b, and the center magnetic leg 13b is disposed between the side magnetic legs 12b, 14b.

  The upper core 11a and the lower core 11b are opposed to each other while the center magnetic legs 13a and 13b, the side magnetic legs 12a and 12b, and the side magnetic legs 14a and 14b are arranged to face each other. Here, the lengths of the center magnetic legs 13a, 13b are set shorter than the lengths of the side magnetic legs 12a, 12b, 14a, 14b, and the center magnetic legs 13a, 13b are arranged to face each other via the center gap G11. Yes.

  Further, the area of the cross section where the magnetic flux H11 of the center magnetic leg 13a of the upper core 11a is linked is set to be smaller than the area of the cross section of the magnetic flux H11 of the center magnetic leg 13b of the lower core 11b. . Specifically, the width W11 of the center magnetic leg 13a is set to be smaller than the width W12 of the center magnetic leg 13b. The width W11 of the center magnetic leg 13a is preferably set so that the magnetic flux H11 flowing out from the center magnetic leg 13a to the center gap G11 does not diverge around the center gap G11.

  In the gap between the center magnetic legs 13a, 13b and the side magnetic legs 12a, 12b and the gap between the center magnetic legs 13a, 13b and the side magnetic legs 14a, 14b, the winding around which the winding M11 is wound is wound. The winding M11 can be arranged so that a region is formed and the center magnetic legs 13a and 13b are surrounded.

  When a current is passed through the winding M11, a magnetic flux H11 is generated around the winding M11. The magnetic flux H11 generated around the winding M11 flows through the magnetic path in the magnetic core 11 via the center magnetic legs 13a, 13b and the side magnetic legs 12a, 12b, 14a, 14b. Here, when the magnetic flux H11 flows into the center magnetic leg 13a, it flows through the center magnetic leg 13a and then flows out into the center gap G11. Then, the magnetic flux H11 that has flowed out to the center gap G11 flows into the center magnetic leg 13b and flows back through the magnetic path in the magnetic core 11.

  Here, by making the width W11 of the center magnetic leg 13a smaller than the width W12 of the center magnetic leg 13b, the magnetic flux H11 flowing through the magnetic core 11 is converged by the center magnetic leg 13a and then flows out to the center gap G11. It becomes possible. Therefore, even when the winding M11 is arranged in the magnetic core 11 so as to surround the center gap G11, the leakage magnetic flux leaking out of the magnetic core 11 from the center gap G11 is linked with the winding M11. It becomes possible to suppress. As a result, the eddy current loss can be reduced without arranging the winding M11 so as to avoid the periphery of the center gap G11, and the power conversion efficiency can be increased while suppressing an increase in the size of the coil component. In addition, the heat generation of the winding M11 can be reduced, and the reliability of the coil component can be improved.

  In the first embodiment described above, the method of setting the width W11 of the center magnetic leg 13a to be smaller than the width W12 of the center magnetic leg 13b has been described. However, the width W12 of the center magnetic leg 13b You may set so that it may become smaller than the width W11 of the magnetic leg 13a.

FIGS. 2-1 to 2-3 are sectional views showing the relationship between the width W11 of the center magnetic leg 13a of the upper core 11a of FIG.
In FIG. 2-1, when the width W11 of the center magnetic leg 13a is equal to the width W12 of the center magnetic leg 13b, since the magnetic resistance is large in the center gap G11, the magnetic flux H11 flowing out from the center magnetic leg 13a to the center gap G11 is It diverges around the center gap G11. Then, the magnetic flux H11 flowing out to the center gap G11 flows into the center magnetic leg 13b while being converged by the center magnetic leg 13b.

  For this reason, when the magnetic flux H11 flows out from the center magnetic leg 13a to the center gap G11, the magnetic flux H11 leaks out of the magnetic core 11 from the air gap G11, and the leaked leakage magnetic flux H12 is linked to the winding M11.

  On the other hand, as shown in FIGS. 2-2 and 2-3, when the width W11 of the center magnetic leg 13a is decreased, the magnetic flux H11 is flown from the center magnetic leg 13a to the center gap G11. The magnetic flux H11 that is converged by the center magnetic leg 13a and flows out from the center magnetic leg 13a to the center gap G11 can be caused to flow into the center magnetic leg 13b without diverging around the center gap G11.

  For this reason, it becomes possible to prevent the leakage magnetic flux H12 leaking out of the magnetic core 11 from the center gap G11 from interlinking with the winding M11, and the winding M11 is arranged so as to avoid the periphery of the center gap G11. Without this, eddy current loss can be reduced.

FIG. 3A is a perspective view illustrating a schematic configuration of a magnetic core according to the second embodiment of the present invention, and FIG. 3B is a cross-sectional view illustrating the magnetic core of FIG.
3A and 3B, the magnetic core 31 is provided with an upper core 31a and a lower core 31b. Here, the upper core 31a is provided with a center magnetic leg 33a and side magnetic legs 32a, 34a, and the center magnetic leg 33a is disposed between the side magnetic legs 32a, 34a. The lower core 31b is provided with a center magnetic leg 33b and side magnetic legs 32b and 34b, and the center magnetic leg 33b is disposed between the side magnetic legs 32b and 34b.

  The upper core 31a and the lower core 31b are opposed to each other while the center magnetic legs 33a and 33b, the side magnetic legs 32a and 32b, and the side magnetic legs 34a and 34b are arranged to face each other. Here, the lengths of the center magnetic legs 33a, 33b are set shorter than the lengths of the side magnetic legs 32a, 32b, 34a, 34b, and the center magnetic legs 33a, 33b are arranged to face each other via the center gap G31. Yes.

  Further, a convex portion is formed on the center magnetic leg 33a of the upper core 31a, and a concave portion is formed on the center magnetic leg 33b of the lower core 31b. When the round surfaces are formed in the convex and concave portions, the curvature of the round surfaces is preferably set so that the magnetic flux H31 flowing out from the center magnetic leg 33a to the center gap G31 does not diverge around the center gap G31. .

  In the gap between the center magnetic legs 33a and 33b and the side magnetic legs 32a and 32b and the gap between the center magnetic legs 33a and 33b and the side magnetic legs 34a and 34b, the winding around which the winding M31 is wound is wound. The winding M31 can be arranged so that a region is formed and the center magnetic legs 33a and 33b are surrounded.

  Here, by forming convex portions and concave portions in the center magnetic legs 33a and 33b, the magnetic flux H31 flowing through the magnetic core 31 can be converged by the center magnetic legs 33a and then flowed out to the center gap G31. In addition, the magnetic flux H31 that has flowed out to the center gap G31 can flow into the center magnetic leg 33b before it diverges around the center gap G31. Therefore, it is possible to suppress the leakage magnetic flux leaking around the center gap G31 from interlinking with the winding M31 without arranging the winding M31 so as to avoid the circumference of the center gap G31. It is possible to reduce eddy current loss while suppressing a decrease in the line area.

In the second embodiment described above, the method of forming the convex portion on the center magnetic leg 33a and forming the concave portion on the center magnetic leg 33b has been described. However, the concave portion is formed on the center magnetic leg 33a and the center magnetic leg 33b is formed. A convex portion may be formed on the surface.
Alternatively, a convex portion may be formed on the remaining one end face of the center magnetic legs 33a, 33b while the front end face of either one of the center magnetic legs 33a, 33b is kept flat.

FIG. 4-1 is a perspective view illustrating a schematic configuration of a magnetic core according to a third embodiment of the present invention, and FIG. 4-2 is a cross-sectional view illustrating the magnetic core of FIG.
4A and 4B, the magnetic core 41 is provided with an upper core 41a and a lower core 41b. Here, the upper core 41a is provided with a center magnetic leg 43a and side magnetic legs 42a, 44a, and the center magnetic leg 43a is disposed between the side magnetic legs 42a, 44a. The lower core 41b is provided with a center magnetic leg 43b and side magnetic legs 42b, 44b, and the center magnetic leg 43b is disposed between the side magnetic legs 42b, 44b.

  The upper core 41a and the lower core 41b are opposed to each other while the center magnetic legs 43a and 43b, the side magnetic legs 42a and 42b, and the side magnetic legs 44a and 44b are arranged to face each other. Here, the lengths of the center magnetic legs 43a and 43b are set shorter than the lengths of the side magnetic legs 42a, 42b, 44a and 44b, and the center magnetic legs 43a and 43b are arranged to face each other via the center gap G41. Yes.

  Further, convex portions are formed on the center magnetic legs 43a and 43b of the upper cores 41a and 41b. When the rounded surface is formed on the convex portion, the curvature of the rounded surface is preferably set so that the magnetic flux H41 flowing out from the center magnetic leg 43a to the center gap G41 does not diverge around the center gap G41.

  In the gap between the center magnetic legs 43a, 43b and the side magnetic legs 42a, 42b and the gap between the center magnetic legs 43a, 43b and the side magnetic legs 44a, 44b, the winding M41 is wound. The winding M41 can be arranged so that a region is formed and the center magnetic legs 43a and 43b are surrounded.

  Here, by forming convex portions on the center magnetic legs 43a and 43b, the magnetic flux H41 flowing in the magnetic core 41 can be converged by the center magnetic legs 43a and then flowed out to the center gap G41. The magnetic flux H41 flowing out to the center gap G41 can be caused to flow into the center magnetic leg 43b while being converged. For this reason, it is possible to suppress the leakage magnetic flux leaking around the center gap G41 from interlinking with the winding M41 without arranging the winding M41 so as to avoid the circumference of the center gap G41. It is possible to reduce eddy current loss while suppressing a decrease in the line area.

FIG. 5-1 is a perspective view illustrating a schematic configuration of a magnetic core according to the fourth embodiment of the present invention, and FIG. 5-2 is a cross-sectional view illustrating the magnetic core of FIG.
5A and 5B, the magnetic core 51 is provided with an upper core 51a and a lower core 51b. Here, the upper core 51a is provided with a center magnetic leg 53a and side magnetic legs 52a and 54a, and the center magnetic leg 53a is disposed between the side magnetic legs 52a and 54a. The lower core 51b is provided with a center magnetic leg 53b and side magnetic legs 52b and 54b, and the center magnetic leg 53b is disposed between the side magnetic legs 52b and 54b.

  The upper core 51a and the lower core 51b are opposed to each other while the center magnetic legs 53a and 53b, the side magnetic legs 52a and 52b, and the side magnetic legs 54a and 54b are arranged to face each other. Here, the center magnetic legs 53a and 53b are arranged to face each other via the center gap G51, the side magnetic legs 52a and 52b are arranged to face each other via the side gap G52, and the side magnetic legs 54a and 54b are arranged to the side gap G53. Are arranged opposite to each other.

  Further, the area of the cross section where the magnetic flux H51 of the center magnetic leg 53a of the upper core 51a is linked is set to be smaller than the area of the cross section of the magnetic flux H51 of the center magnetic leg 53b of the lower core 51b. . Further, the cross-sectional area where the magnetic flux H51 of the side magnetic legs 52a and 54a of the upper core 51a is linked is smaller than the area of the cross-section where the magnetic flux H51 of the side magnetic legs 52b and 54b of the lower core 51b is linked. Is set to

Specifically, the width of the center magnetic leg 53a is set to be smaller than the width of the center magnetic leg 53b, and the width of the side magnetic legs 52a and 54a is smaller than the width of the side magnetic legs 52b and 54b, respectively. It is set to be.
The width of the center magnetic leg 53a is preferably set so that the magnetic flux H51 flowing from the center magnetic leg 53a to the center gap G51 does not diverge around the center gap G51. The widths of the side magnetic legs 52a and 54a are preferably set so that the magnetic flux H51 flowing out from the side magnetic legs 52b and 54b to the side gaps G52 and G53 does not diverge around the side gaps G52 and G53.

  In the gap between the center magnetic legs 53a, 53b and the side magnetic legs 52a, 52b and the gap between the center magnetic legs 53a, 53b and the side magnetic legs 54a, 54b, a winding around which the winding M51 is wound. The winding M51 can be arranged so that a region is formed and the center magnetic legs 53a and 53b are surrounded.

  Here, the width of the center magnetic leg 53a is made smaller than the width of the center magnetic leg 53b, and the widths of the side magnetic legs 52a and 54a are made smaller than the widths of the side magnetic legs 52b and 54b, respectively. The magnetic flux H51 flowing through the center magnetic leg 53a is converged by the center magnetic leg 53a and then allowed to flow out into the center gap G51, while the magnetic flux H51 flowing out into the side gaps G52 and G53 is converged while the side magnetic leg 52a, It becomes possible to flow into each of 54a.

  For this reason, even when the winding M51 is arranged beside the center gap G51 and the side gaps G52 and G53, the leakage magnetic flux leaking out of the magnetic core 51 from the center gap G51 and the side gaps G52 and G53 is caused by the winding M51. It is possible to suppress interlinkage with. As a result, the eddy current loss can be reduced without arranging the winding M51 so as to avoid the periphery of the center gap G51 and the side gaps G52 and G53, and the power conversion efficiency can be reduced while suppressing the enlargement of the coil parts. Can be increased, and the heat generation of the winding M51 can be reduced, so that the reliability of the coil component can be improved.

  In the fourth embodiment described above, a method for setting the width of the center magnetic leg 53a and the side magnetic legs 52a and 54a to be smaller than the width of the center magnetic leg 53b and the side magnetic legs 52b and 54b will be described. However, the width of the center magnetic leg 53b and the side magnetic legs 52b, 54b may be set to be smaller than the width of the center magnetic leg 53a and the side magnetic legs 52a, 54a, respectively.

  Alternatively, the width of the center magnetic leg 53a may be smaller than the width of the center magnetic leg 53b, and the width of the side magnetic legs 52a and 54a may be larger than the width of the side magnetic legs 52b and 54b. The width of the leg 53b may be smaller than the width of the center magnetic leg 53a, and the width of the side magnetic legs 52b and 54b may be larger than the width of the side magnetic legs 52a and 54a.

  Further, a convex portion may be formed at the tip of the side magnetic legs 52a and 54a, and a concave portion may be formed at the tip of the side magnetic legs 52b and 54b, or a concave portion may be formed at the tip of the side magnetic legs 52a and 54a. The convex portions may be formed at the tips of the side magnetic legs 52b, 54b, or the convex portions may be formed at the tips of the side magnetic legs 52a, 54a, 52b, 54b.

FIG. 6 is a perspective view showing a schematic configuration of a magnetic core according to the fifth embodiment of the present invention.
In FIG. 6, the magnetic core 61 is provided with an upper core 61a and a lower core 61b. Here, the upper core 61a is provided with a center magnetic leg 63a and side magnetic legs 62a and 64a, and the center magnetic leg 63a is disposed between the side magnetic legs 62a and 64a. The lower core 61b is provided with a center magnetic leg 63b and side magnetic legs 62b and 64b, and the center magnetic leg 63b is disposed between the side magnetic legs 62b and 64b. Here, the center magnetic legs 63a and 63b are formed in a cylindrical shape. The center magnetic leg 63a is held by a portion protruding laterally from the side magnetic legs 62a, 64a, and the center magnetic leg 63b is held by a portion protruding laterally from the side magnetic legs 62b, 64b.

  The upper core 61a and the lower core 61b are opposed to each other while the center magnetic legs 63a and 63b, the side magnetic legs 62a and 62b, and the side magnetic legs 64a and 64b are arranged to face each other. Here, the lengths of the center magnetic legs 63a, 63b are set shorter than the lengths of the side magnetic legs 62a, 62b, 64a, 64b, and the center magnetic legs 63a, 63b are arranged to face each other via the center gap G61. Yes.

  Further, the area of the cross section where the magnetic flux of the center magnetic leg 63a of the upper core 61a is linked is set to be smaller than the area of the cross section of the magnetic flux of the center magnetic leg 63b of the lower core 61b. Specifically, the diameter of the center magnetic leg 63a is set to be smaller than the diameter of the center magnetic leg 63b. The diameter of the center magnetic leg 63a is preferably set so that the magnetic flux flowing out from the center magnetic leg 63a to the center gap G61 does not diverge around the center gap G61.

  In the gap between the center magnetic legs 63a and 63b and the side magnetic legs 62a and 62b and the gap between the center magnetic legs 63a and 63b and the side magnetic legs 64a and 64b, a winding region in which the winding is wound. And the windings can be arranged so that the center magnetic legs 63a and 63b are surrounded.

  Thereby, even when the EER core is used, the magnetic flux flowing through the center gap G61 between the center magnetic legs 63a and 63b can be converged. For this reason, it becomes possible to suppress the leakage magnetic flux leaking around the center gap G61 from interlinking with the winding without arranging the winding so as to avoid the circumference of the center gap G61. It is possible to reduce the eddy current loss while suppressing the decrease of the eddy current.

In the fifth embodiment described above, the method of setting the diameter of the center magnetic leg 63a to be smaller than the diameter of the center magnetic leg 63b has been described. However, the diameter of the center magnetic leg 63b is set to be smaller than the center magnetic leg 63a. You may set so that it may become smaller than the diameter of this.
Further, a convex portion may be formed at the tip of the center magnetic leg 63a, and a concave portion may be formed at the tip of the center magnetic leg 63b. A concave portion may be formed at the tip of the center magnetic leg 63a, and the center magnetic leg 63b A convex portion may be formed at the tip, or a convex portion may be formed at the tip of the center magnetic legs 63a and 63b.

In the above-described fifth embodiment, the configuration in which the side gaps are not provided between the side magnetic legs 62a and 62b and between the side magnetic legs 64a and 64b has been described as an example. When side gaps are provided between the side magnetic legs 64a and 64b, the cross-sectional areas of the side magnetic legs 62a and 64a are set to be smaller than the cross-sectional areas of the side magnetic legs 62b and 64b, respectively. Alternatively, the cross-sectional areas of the side magnetic legs 62b and 64b may be set to be smaller than the cross-sectional areas of the side magnetic legs 62a and 64a, respectively.
When side gaps are provided between the side magnetic legs 62a and 62b and between the side magnetic legs 64a and 64b, convex portions are formed at the ends of the side magnetic legs 62a and 64a, and the side magnetic legs 62b and 64b A concave portion may be formed at the tip, a concave portion may be formed at the tip of the side magnetic legs 62b and 64b, and a convex portion may be formed at the tip of the side magnetic legs 62a and 64a. You may make it form a convex part in the front-end | tip of leg 62a, 64a, 62b, 64b.

FIG. 7 is a perspective view showing a schematic configuration of a magnetic core according to the sixth embodiment of the present invention.
In FIG. 7, the magnetic core 71 is provided with an upper core 71a and a lower core 71b. Here, the upper core 71a is provided with a center magnetic leg 73a and side magnetic legs 72a and 74a, and the center magnetic leg 73a is disposed between the side magnetic legs 72a and 74a. The lower core 71b is provided with a center magnetic leg 73b and side magnetic legs 72b and 74b. The center magnetic leg 73b is disposed between the side magnetic legs 72b and 74b. Here, the center magnetic legs 73b, 73b are formed in a cylindrical shape, and the inner surfaces of the side magnetic legs 72a, 74a, 72b, 74b are formed in an arc shape. The center magnetic leg 73a is held at the center of the plate-like portion stretched between the side magnetic legs 72a and 74a, and the center magnetic leg 73b is stretched between the side magnetic legs 72b and 74b. Is held in the center of the shaped part.

  The upper core 71a and the lower core 71b are opposed to each other while the center magnetic legs 73a and 73b, the side magnetic legs 72a and 72b, and the side magnetic legs 74a and 74b are arranged to face each other. Here, the lengths of the center magnetic legs 73a, 73b are set shorter than the lengths of the side magnetic legs 72a, 72b, 74a, 74b, and the center magnetic legs 73a, 73b are arranged to face each other via the center gap G71. Yes.

  Further, the area of the cross section where the magnetic flux H71 of the center magnetic leg 73a of the upper core 71a is linked is set to be smaller than the area of the cross section of the magnetic flux H71 of the center magnetic leg 73b of the lower core 71b. . Specifically, the diameter of the center magnetic leg 73a is set to be smaller than the diameter of the center magnetic leg 73b. The diameter of the center magnetic leg 73a is preferably set so that the magnetic flux flowing out from the center magnetic leg 73a to the center gap G71 does not diverge around the center gap G71.

  In the gap between the center magnetic legs 73a and 73b and the side magnetic legs 72a and 72b and the gap between the center magnetic legs 73a and 73b and the side magnetic legs 74a and 74b, a winding region in which the winding is wound. And the windings can be arranged so that the center magnetic legs 73a and 73b are surrounded.

  Thereby, even when the PQ core is used, the magnetic flux flowing through the center gap G71 between the center magnetic legs 73a and 73b can be converged. For this reason, it is possible to suppress the leakage magnetic flux leaking around the center gap G71 from interlinking with the windings without arranging the windings so as to avoid the periphery of the center gap G71. It is possible to reduce the eddy current loss while suppressing the decrease of the eddy current.

In the sixth embodiment described above, the method of setting the diameter of the center magnetic leg 73a to be smaller than the diameter of the center magnetic leg 73b has been described. However, the diameter of the center magnetic leg 73b is set to be smaller than the center magnetic leg 73a. You may set so that it may become smaller than the diameter of this.
Further, a convex portion may be formed at the tip of the center magnetic leg 73a, and a concave portion may be formed at the tip of the center magnetic leg 73b. A concave portion may be formed at the tip of the center magnetic leg 73a, and the center magnetic leg 73b A convex portion may be formed at the tip, or a convex portion may be formed at the tip of the center magnetic legs 73a and 73b.

  In the above-described sixth embodiment, the configuration in which the side gaps are not provided between the side magnetic legs 72a and 72b and between the side magnetic legs 74a and 74b has been described as an example, but between the side magnetic legs 72a and 72b and When side gaps are provided between the side magnetic legs 74a and 74b, the cross-sectional areas of the side magnetic legs 72a and 74a are set to be smaller than the cross-sectional areas of the side magnetic legs 72b and 74b, respectively. Alternatively, the cross-sectional areas of the side magnetic legs 72b and 74b may be set to be smaller than the cross-sectional areas of the side magnetic legs 72a and 74a, respectively.

  When side gaps are provided between the side magnetic legs 72a and 72b and between the side magnetic legs 74a and 74b, a convex portion is formed at the tip of the side magnetic legs 72a and 74a, and the side magnetic legs 72b and 74b A recess may be formed at the tip, a recess may be formed at the tip of the side magnetic legs 72b and 74b, and a protrusion may be formed at the tip of the side magnetic legs 72a and 74a. You may make it form a convex part in the front-end | tip of leg 72a, 74a, 72b, 74b.

  In the above-described embodiment, the EE core, the EER core, and the PQ core have been described as examples. However, as long as the core is provided with an air gap, the core may be applied to other types of cores.

  The magnetic core of the present invention can suppress the leakage of the magnetic flux from the air gap while suppressing a decrease in the winding area, and can be used for coil parts such as a switching power supply and an uninterruptible power supply. Can be used.

It is a perspective view showing a schematic structure of a magnetic core concerning a 1st embodiment of the present invention. It is sectional drawing which shows the magnetic core of FIGS. 1-1 with a coil | winding. It is sectional drawing which shows the relationship between the width W11 of the center magnetic leg 13a of the upper core 11a of FIGS. 1-1, and leakage magnetic flux. It is sectional drawing which shows the relationship between the width W11 of the center magnetic leg 13a of the upper core 11a of FIGS. 1-1, and leakage magnetic flux. It is sectional drawing which shows the relationship between the width W11 of the center magnetic leg 13a of the upper core 11a of FIGS. 1-1, and leakage magnetic flux. It is a perspective view which shows schematic structure of the magnetic core which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the magnetic core of FIGS. 3-1 with a coil | winding. It is a perspective view which shows schematic structure of the magnetic core which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the magnetic core of FIG. 4-1 with a coil | winding. It is a perspective view which shows schematic structure of the magnetic core which concerns on 4th Embodiment of this invention. It is sectional drawing which shows the magnetic core of FIGS. 5-1 with a coil | winding. It is a perspective view which shows schematic structure of the magnetic core which concerns on 5th Embodiment of this invention. It is a perspective view which shows schematic structure of the magnetic core which concerns on 6th Embodiment of this invention.

Explanation of symbols

11, 31, 41, 51, 61, 71 Magnetic core 11a, 31a, 41a, 51a, 61a, 71a Upper core 11b, 31b, 41b, 51b, 61b, 71b Lower core 12a, 12b, 14a, 14b, 32a, 32b 34a, 34b, 42a, 42b, 44a, 44b, 52a, 52b, 54a, 54b, 62a, 62b, 64a, 64b, 72a, 72b, 74a, 74b Side magnetic legs 13a, 13b, 33a, 33b, 43a, 43b 53a, 53b, 63a, 63b, 73a, 73b Center magnetic legs G11, G31, G41, G51, G61, G71 Center gap M11, M31, M41, M51 Winding G52, G53 Side gap

Claims (4)

In a magnetic core comprising a first core and a second core that are provided with a winding region in which a winding is wound and are arranged opposite to each other to form a magnetic path of a magnetic flux generated from the winding,
The first core and the second core are each provided with a magnetic leg disposed opposite to each other through an air gap,
At least one of the magnetic legs is configured to converge a magnetic flux flowing through the air gap.   2. The magnetic core according to claim 1, wherein an area of a cross section where magnetic fluxes of the magnetic legs of the first core are linked is smaller than an area of a cross section where magnetic fluxes of the magnetic legs of the second core are linked. .   The magnetic core according to claim 1, wherein a convex portion is formed at a tip of at least one of the first core and the second core.   4. The magnetic core according to claim 1, wherein a concave portion is formed at a tip end of at least one of the first core and the second core. 5.

Images