JPH04109607A - U-shaped core - Google Patents

Abstract

PURPOSE:To obtain a shorter and lighter coil by dividing the U-shaped face of a U-shaped core into a plurality of pieces at the side magnetic leg and a groove between the central magnetic leg and the side magnetic leg. CONSTITUTION:The U-shaped face of a U-shaped core 51, which consists of a central magnetic leg 52, a side magnetic foot 53 parallel thereto, and a yoke 55 to connect one end of the central magnetic leg 52 and one end of the side magnetic leg 53, is divided into a plurality of pieces at the side magnetic foot 53 and a groove 54 between the central magnetic leg 52 and the side magnetic leg 53. Therefore, one winding part of a coil bobbin fitted on the central magnetic leg 52 can be prevented from projecting by the difference between the heights of the side magnetic leg 53 and the yoke 55 and the height of the central magnetic leg 52. Thereby a shorter coil including the U-shaped core can be made and the coil can be lightened by the weight of the magnetic material cut out by division.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a U-shaped core made of a magnetic material used for the magnetic core of choke coils, noise filters, etc. This invention relates to a U-shaped core that has been designed to be smaller and lighter.

(Prior Art) In recent years, there has been an increasing demand for smaller electronic devices, and there is a demand for electronic devices that are thin and lightweight and can be carried and used, especially outdoors or indoors.

Therefore, there is a strong demand for choke coils, noise filters, and the like that are components of these electronic devices to be smaller and lighter.

Therefore, cores made of magnetic materials used as the magnetic cores of choke coils, noise filters, etc. are strongly required to be thinner and lighter, and various proposals have been made to date.

As the core, a U-shaped core having a U-shape is known, and a conventional example of the U-shaped core will be described with reference to FIG. 7.

In FIG. 7, a U-shaped core 1 made of a magnetic material such as ferrite has a longitudinally elongated central magnetic leg 2, and a shape between the central magnetic leg 2 and the path (cross-sectional area of the central magnetic leg 2). , and a side magnetic leg 3 having a cross-sectional area of -) are arranged in parallel through a groove 4, and one end of each is connected by a yoke portion 5. There is.

At this time, the surface opposite to the connection surface where the central magnetic leg 2 and the side magnetic leg 3 are connected to the yoke portion 5 is generally configured to form a coil etc. by combining the U-shaped core 1 into a set.
formed on the same surface.

Furthermore, the upper and lower U-shaped surfaces formed by the central magnetic leg 2, side magnetic legs 3, and yoke portion 5 of the U-shaped core I are also generally formed on the same plane.

Further, a coil bobbin 6 wound with enameled wire or the like is fitted into the central magnetic leg 2 of the U-shaped core 1, as shown by imaginary lines in the figure.

Therefore, in the U-shaped core l, the coil bobbin 6 is
At the same time as being fitted into the ta leg 2, another U-shaped core or 1
When combined with a mold core, a coil or the like is constructed.

When the coil bobbin 6 is fitted into the U-shaped core 1 as described above, the upper and lower windings of the coil bobbin 6 are
The U-shaped core 1 projects from the upper and lower surfaces of the central magnetic leg 2 by widths Za and zb, respectively.

This cannot be said to mean that the mounting height when mounting the coil etc. made up of the U-shaped core 1 on an electronic circuit board etc. is made low, and that the stability of the said IT is poor. There was a problem.

For this reason, another U-shaped core has been devised, and this U-shaped core will be described with reference to FIG.

The U-shaped core 11 includes a central magnetic leg 12 that is elongated in the horizontal direction;
It has a shape between the center magnetic leg 12 and the path (the cross-sectional area of the center magnetic leg 12 and the cross-sectional area of the side magnetic legs 13 are between the paths),
The side magnetic legs 13, which are elongated in the vertical direction, are arranged in parallel with each other via the legs 14, and one end of each leg is connected by a yoke portion 5.

At this time, the center magnetic leg 12 and the side magnetic legs 13 are the yoke portion]
The opposite surface of the connection surface connected to 5 is formed on the same plane, and the upper diamond-shaped surface formed by the side magnetic leg 13 and the yoke part 15, and the side magnetic leg 13 and the yoke part 12, the side magnetic leg 13, and the yoke part. The lower U-shaped surfaces formed by 15 are also formed on the same surface.

The U-shaped core 11 has a space 1 that is the height of the side magnetic legs 13 and the yoke portion 15 minus the height of the central magnetic field l111.2.
7, so that when a coil bobbin (not shown) is fitted, the upper part of the winding of the coil bobbin does not protrude by the space 17.

The U-shaped core 11 is formed by press-molding a powdered magnetic material using, for example, a double-acting press device (not shown) having a plurality of pressure surfaces.

According to the above-mentioned double-acting press device, each pressurizing surface works in a double-acting manner to press the magnetic material, so it is difficult to mold the magnetic material so that it has uniform pressure. There was a risk that microcracks or the like would occur in the U-shaped core 11, which is a molded body, due to internal stress or the like during the double-action pressurization.

Furthermore, it is of the nt7] type breathless device type, and is not suitable for mass production because the operation control is complicated and the molding speed is slow.

(Problem to be Solved by the Invention) However, the cross-sectional area of the above-mentioned conventional center magnetic leg and (!ll m leg is between the paths), and the upper and lower U-shaped surfaces of the center magnetic leg, 1ltl ff1 leg, and the yoke portion are the same. U formed in a planar shape
According to the type core, when a coil bobbin is fitted to the central magnetic leg, the upper and lower portions of the winding of the coil bobbin protrude from the U-shaped surface, and the coil etc. formed by assembling the U-shaped core is There is a problem in that the coil is taller than other electronic components, and the protrusion becomes an obstacle, making it impossible to stably mount the coil on an electronic circuit board or the like.

Furthermore, the center magnetic leg is extended from the side magnetic leg with a space above the upper surface of the side magnetic leg and the yoke part so that the coil bobbin can be efficiently accommodated and the coil etc. can be made low in profile. In the pole-shaped core, in order to make the cross-sectional area of the central magnetic leg and the cross-sectional area of the side magnetic legs into a gap, the central magnetic leg is elongated in the lateral direction. There was a problem in that the shaped core itself became elongated in the lateral direction, making it impossible to downsize the coil etc. made up of the U-shaped core.

The present invention has been made in view of the above circumstances, and has a structural design that effectively utilizes the dimensions of each part, resulting in a compact, lightweight,
Moreover, it provides a U-shaped core with excellent magnetic properties.

(Means for solving problem f!) In order to achieve the above object, the present invention provides a central magnetic leg,
In the U-shaped core, the U-shaped core includes a side magnetic leg arranged parallel to the magnetic core, and a yoke portion that connects one end side of the center magnetic leg and one end side of the side magnetic leg to each other. The above object is achieved by processing the surface so as to be divided into a plurality of parts along the side stone legs and the grooves provided between the center magnetic leg and the side magnetic legs.

Further, the present invention achieves the above object by making the cross-sectional area of the center magnetic leg smaller than the cross-sectional area of the side magnetic legs.

(Function) The present invention includes a central magnetic leg, side magnetic legs arranged parallel to the central magnetic leg, and a yoke portion that connects one end side of the central magnetic leg and one end side of the side magnetic leg to each other. The U-shaped surface of the U-shaped core is divided into a plurality of parts along the side stone leg and the groove provided between the center magnetic leg and the side magnetic leg. It is possible to prevent one winding part of the coil bobbin fitted to the leg from protruding by an amount equal to the height of the center magnetic leg subtracted from the height of the side magnetic legs and yoke part, and therefore the U-shaped core It is possible to reduce the height of the coil or the like to be constructed, and also to reduce the weight of the coil or the like by the amount of the magnetic material particles removed by the dividing process.

Further, the U-shaped core is arranged on the side lif! Since one winding part of the coil bobbin can be configured so as not to protrude beyond the surface consisting of the legs and the yoke part, when mounting the coil etc. on an electronic circuit board, etc., it is possible to avoid the problem of direct contact with the board. By using the abutment surface, the coil etc. can be stably mounted on the board.

Furthermore, since the U-shaped core has a dividing surface formed on the side magnetic leg by dividing the side magnetic leg into a plurality of parts,
The dividing surface and the locking protrusion formed on the coil bobbin can be brought into contact and locked, and the locking part can relieve the internal stress etc. received when fitting the coil bobbin to the center magnetic leg. It is possible to protect the legs and the coil bobbin from damage, etc., and it is also possible to reliably and robustly manufacture the coil etc. formed by the U-shaped core.

Furthermore, by dividing the U-shaped surface of the U-shaped core into a plurality of parts along the side stone legs and the grooves provided between the center magnetic leg and the side magnetic legs, the side magnetic Since the cross-sectional area of the center magnetic leg can be made smaller than the cross-sectional area of the leg, the amount of winding wire wound around the coil bobbin fitted to the center magnetic leg can be increased, and the coil etc. The inductance value of can be increased.

(Example) Embodiments of the present invention will be described in detail based on two drawings.

FIG. 1 is a perspective view showing an embodiment of a U-shaped core according to the present invention, FIG. 2(a) is a plan view showing a diamond-shaped core of the same embodiment, and FIG. FIG. 3 is a plan view showing a coil constructed by combining a set of U-shaped cores according to the same embodiment, and FIG. 4 is a cross-sectional view showing the cross section of the U-shaped core according to the same embodiment. FIG. 5 is a perspective view showing a coil bobbin fitted to the central magnetic leg of the U-shaped core, and FIG. ) is a perspective view showing another U-shaped core according to the present invention, and FIG. 6(b) is a side view showing the side surface of the square-shaped core of the same embodiment.

The U-shaped core 51 shown in FIG. 1 is manufactured by the following steps.

A powdered magnetic material is connected to the center magnetic leg, side magnetic legs arranged parallel to the center magnetic leg, and one end side of the center magnetic leg and one end of the side magnetic leg by using a star motion type brace device or the like. It is molded into a U-shaped molded member having a yoke portion.

The single-acting type press device is different from the double-acting type press device in which a plurality of pressurizing surfaces work together to apply pressure to the magnetic material, and is configured to apply pressure using a single opposing surface.2.The device is small and Operation control is easy and suitable for device production.

At this time, since the press surface of the single-acting press device is processed into a flat surface, the upper and lower mold surfaces formed by the center magnetic leg, side magnetic legs, and yoke portion of the U-shaped molded member are each flat. is doing.

Next, the U-shaped molded member is attached to the center magnetic leg, the side magnetic leg, and the yoke portion along the groove provided between the side magnetic leg and the center 1i1111Il and the side magnetic leg. The portion is cut using a grinder device equipped with a disk-shaped grinder made of an abrasive material or the like.

A tapered portion is formed in the disk type grinder equipped in the grinder device, and the tapered portion is formed in a portion of the side magnetic leg and the yoke portion.

At this time, the width of the cut by the cutting process reaches the other area where a part of the side magnetic leg remains, and the depth depends on the installation height of the rotating shaft on which the disc-shaped grinder is mounted.

As shown in FIG. 1, the U-shaped core 51 manufactured as described above has a center magnetic leg 52 formed into a substantially square shape by the cutting process, and a side magnetic leg 53 elongated in the vertical direction. groove 5
4 are arranged in parallel, and one end of each is connected by a yoke portion 55.

At this time, the upper surface of the central magnetic leg 52 is partially horizontally notched by the cutting process to form a notch 57, and the yoke portion 55 from the connecting portion of the central magnetic leg 52 to the approximate center of the groove 54 A portion of the upper surface is horizontally notched to form a full notch 56, and furthermore, a portion of the yoke portion 55 and side M1wJ53 following the full notch 56 are obliquely notched, respectively, to form a yoke tapered portion 58b and a side magnetic leg. A tapered portion 58a is formed to become a tapered portion 58.

As can be seen from FIG. 2(a), the U-shaped core 51 has a U-shaped upper and lower surface.

Furthermore, as shown in FIG. 2(b), the central magnetic leg 52
By forming the cutout portion 57 and the entire cutout portion 56 in a part of the yoke portion 55, the center magnetic leg 5
2 is formed low in height by the height width obtained by subtracting the height Hl of the center magnetic leg 52 from the height H2 of the side FB leg 53.

Therefore, the coil bobbin 65 (
(represented by imaginary lines) is fitted into the central magnetic leg 52,
The upper winding portion of the coil bobbin 65 can be made not to protrude beyond the height H2 of the side magnetic leg 53 and the yoke portion 55.

Further, referring to the same figure, by forming the cutout portion 57 and the entire cutout portion 56 in the U-shaped core 51, approximately twice the center magnetic leg cross-sectional area 62 of the center magnetic leg 52 becomes larger than the side magnetic leg. 53, the side magnetic leg cross-sectional area is 63.

As shown in FIG. 3, the coil bobbin 65 is fitted into the center 1if [052], and the core 51 is combined with another U-shaped core 61 having a line-symmetrical shape to form a choke coil, a noise filter, etc. A coil 60 is configured.

Here, an example of the shape of the coil bobbin 65 will be described with reference to FIG. 4. A substantially square-shaped insertion hole 69a and a substantially square insertion hole 69b into which the central magnetic leg 52 is inserted are respectively formed in the center. Fitting frame 68a and fitting frame 68
b are arranged in parallel, and the insertion holes 69a, 6
The fitting frames 68a, 6 are supported by the support plate 64 at the lower part of the fitting frame 9b.
8b are connected.

Furthermore, on the upper right side of the fitting frames 68a, 68b,
A locking protrusion 67 is provided that protrudes with the same inclination as the side magnetic leg tapered portion 58a of the tapered portion 58.

A winding frame (not shown) is provided at a portion of the coil bobbin 65 sandwiched between the fitting frame 68a and the fitting frame 68b, and an enameled wire or the like is wound around the winding frame. A portion 66 is formed.

A coil 60 formed by mounting the U-shaped core 51 and other U-shaped cores 61 on the coil bobbin 65 will be described with reference to FIG. 5.

The central magnetic leg 52 of the U-shaped core 51 is inserted into the insertion holes 69a and 69b of the coil bobbin 65 to which the winding portion 66 is attached.
and the center magnetic legs of the other U-shaped cores 61 are fitted into each other.

At this time, the locking protrusion 67 abuts and locks on the side magnetic leg tapered portion 58a.

In this state, the U-shaped core 51 and the other U-shaped cores 61 are fixed by a fixture (not shown) to form a coil 60.

According to the U-shaped core 51 according to this embodiment, the U-shaped core 51
On one U-shaped surface of the center magnetic leg 52 and the yoke part 5
The notch 57 and extra notch 56 are formed by cutting a part of the 1IlII M1 leg 5.
When the height Hl of the central magnetic leg 52 is formed to be lower than the height H2 of 3, and the coil bobbin 65 is fitted to the central magnetic leg 52, the height Hl is reduced by the height H2 minus the height Hl. It is possible to prevent the upper part of the winding of the coil bobbin 65 from protruding, and therefore, the height of the coil formed by the U-shaped core can be made low.

Further, the izv-type core 5I is cut by the cutting process to remove the upper surface of the yoke part 55 from the connecting part of the center magnetic leg 52 and the center taltl 152 to the approximate center of the groove 54, and from the center to the part of the side magnetic leg 53. A portion of the U-shaped core 51 is cut out to form a cutout portion 57, an extra cutout portion 56, and a tapered portion S8. It can be made lighter.

Further, since the U-shaped core 51 can be configured so that one winding portion of the coil bobbin 65 does not protrude beyond the surface formed by the side magnetic legs 53 and the yoke portion 55, the U-shaped core 51
When a coil or the like in which the mold core 51 is incorporated is mounted on an electronic circuit board or the like (not shown), the coil 60 is stably mounted on the board by using the ventral surface as the contact surface with the board. be able to.

Furthermore, since the center magnetic leg cross-sectional area 62 is approximately half of the side magnetic leg cross-sectional area 63 of the U-shaped core 51 due to the formation of the notch 57, The amount of winding of enamelled wire or the like wound around the coil bobbin 65 can be increased, and therefore the inductance value of the coil 60 can be increased.

In addition, the U-shaped core 51 has a tapered portion 58 which is cut out in a tapered shape from the yoke portion 55 at the rear of the substantially central portion of the holder 54 to a part of the side magnetic leg 53, and includes a side magnetic leg tapered portion 58a and a yoke tapered portion 58b. As a result, the side magnetic leg tapered portion 58a and the locking protrusion 67 formed on the coil bobbin 65 can be brought into contact and locked, thereby allowing the coil bobbin 65 to be fitted onto the center magnetic leg 52. Since the internal stress etc. that are received during the process can be alleviated, the central magnetic leg 52 and the coil bobbin 65 can be protected from damage, etc., and the coil etc. made up of the U-shaped core can be manufactured reliably and robustly. can.

In this embodiment, approximately 2 of the central magnetic leg cross-sectional area 62
Although the notch 57 and the extra notch 56 are formed by cutting so that the cross-sectional area of the side magnetic leg is double the cross-sectional area of the side magnetic leg 63, the present invention is not limited to this. 6
By making 2 smaller, the magnification is increased (not limited to an integral multiple), and the amount of winding that can be wound around the coil bobbin 65 can be further increased.

At this time, by enlarging the notch 57 and the extra notch 56, the center magnetic leg cross-sectional area 62 becomes smaller, but the U-shaped core manufactured in this way is used for choke coils, noise filters, etc. is common, so even if the center magnetic leg cross-sectional area 62 and the side magnetic leg cross-sectional area 63 are not the same, there is no problem with the magnetic properties of the U-shaped core.

Furthermore, in the present embodiment, the central magnetic leg 52 has been described as having a substantially square shape; however, it is not limited to this (for example, it may be elongated in the vertical direction, or may have a horizontal shape). It may have an elongated shape in the direction, or it may have a substantially elliptical shape.

Next, other embodiments according to the present invention are shown in FIGS. 6(a) and 6(b).
This will be explained with reference to.

In this embodiment, the same parts as in the previous embodiment are given the same reference numerals, and the description thereof will be omitted.

The grinder device used for cutting in this embodiment has, for example, a disk-type grinder, and the side FaIlIII 53 of the disk-type grinder is tapered, and the center magnetic leg 52 and the center A cutout portion 57 and an extra cutout portion 56 are formed by horizontally cutting out a portion of the upper portion from the magnetic leg 52 to approximately the center of the ll54, and
A tapered portion 78 consisting of a side magnetic leg tapered portion 78a and a yoke tapered portion 78b is formed by cutting out a portion of the side magnetic leg 53 obliquely from approximately the center of the groove 54 to a portion of the side magnetic leg 53.

At this time, the width of the tapered portion formed on the disk type grinder is not longer than that in the previous embodiment, and this allows the side magnetic leg 53 to have the side M! A vertical portion 74 that continues vertically from the leg tapered portion 78a is formed.

The U-shaped core 71 manufactured as described above has a central magnetic leg 5.
A coil bobbin 75 having a winding portion 66 is fitted into the coil bobbin 75. At this time, a locking protrusion 77 formed on the coil bobbin 75 and the side magnetic leg tapered portion 78a abut and lock. It has become.

This embodiment also provides the same effects as the previous embodiment.

In addition, if the ridge of the disc type grinder in the grinder device used for the above-mentioned cutting process is subjected to curved surface processing,
By cutting with the grinder device, it is possible to manufacture a U-shaped core in which a cutting curved portion is formed in the extra notch 86, which makes it possible to manufacture a U-shaped core with a cutting curve formed in the extra notch 86. It is possible to prevent microcracks from occurring in the mold core.

Note that when iron powder is used as the magnetic material, a powder magnetic core is formed by pressure molding, and when ferrite powder is used, a binder is added to the ferrite powder and granulated. A ferrite core is formed by pressure molding and further firing.

(Effects of the Invention) Since the U-shaped core according to the present invention is configured as described above, it has the following effects.

(1) A central magnetic leg, side magnetic legs arranged parallel to this,
A U-shaped surface of a U-shaped core consisting of a yoke portion that connects one end side of the center magnetic leg and one end side of the side magnetic leg to each other is provided between the center magnetic leg and the side magnetic leg. Since the groove is divided into multiple parts along the center part or the side magnetic leg side, one winding part of the coil bobbin that is fitted to the central magnetic leg is
It is possible to prevent the side magnetic legs and the yoke from protruding by subtracting the height of the center magnetic leg from the height of the side magnetic legs and the yoke portion, thereby making it possible to reduce the height and size of the coil etc. formed by the U-shaped core. Has excellent effects.

(2) Furthermore, the U-shaped core has the advantage of being able to reduce the weight of the U-shaped core and the coil, etc. in which the U-shaped core is incorporated, by the amount of the magnetic material particles removed by the dividing process. have an effect.

(3) Furthermore, the U-shaped core can be configured so that one winding part of the coil bobbin fitted to the center magnetic leg does not protrude beyond the surface formed by the side magnetic legs and the yoke part. , when mounting the coil etc. on an electronic circuit board etc.
By using the ventral surface as the contact surface with the substrate, the coil, etc. can be stably mounted on the substrate, and the electronic equipment etc. on which the coil, etc. are mounted can be miniaturized. It has a great effect.

(4) Furthermore, the front 20 type surface is aligned along the center part of the groove provided between the center magnetic leg and the side magnetic leg or along the side magnetic leg side,
Since the center magnetic leg is divided into a plurality of parts so that the cross-sectional area of the center magnetic leg is smaller than the cross-sectional area of the side magnetic leg, the winding wire wound on the coil bobbin fitted to the center magnetic leg is Since the amount of winding can be increased, the inductance value of the coil etc. can be increased, and therefore, even with coils having the same shape, there is an excellent effect that the inductance value can be obtained more efficiently.

(5) Furthermore, since the U-shaped core has a dividing surface formed on the side magnetic leg by dividing the side magnetic leg into a plurality of parts, the dividing surface and the locking protrusion formed on the coil bobbin and,
can be abutted and locked, and the internal stress received when fitting the coil bobbin to the center magnetic leg can be alleviated by the corresponding contact part.
This has an excellent effect in that the central magnetic leg and the coil bobbin can be protected, and the coil etc. constituted by the U-shaped core can be manufactured reliably and robustly.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the U-shaped core according to the present invention, and FIG. 2(a) is a second plan view showing the U-shaped core of the same embodiment.
b) is a sectional view showing the X-x cross section of the U-shaped core of the same embodiment; FIG. 3 is a plan view showing a coil constructed by combining a set of U-shaped cores according to the same embodiment; The figure is a perspective view showing a coil bobbin fitted to the 16Fa leg inside the U-shaped core according to the same embodiment. Figure 5 is a perspective view showing a coil constructed by combining a set of U-shaped cores according to the same embodiment. 6(a) is a perspective view showing another U-shaped core according to the present invention, FIG. 6(b) is a side view showing the side surface of the U-shaped core of the same embodiment, and FIG. 7 is a conventional U-shaped core. Section 8 of the perspective view showing the type core is a perspective view showing another conventional U-type core. 51... U-shaped core, 52... Center m leg 53...
- Side magnetic leg, 55...Yoke part, 56...Full notch part, 57...Notch part, 58...Taber part 58. 62...Central magnetic leg cross-sectional area, 63...Side magnetic leg cross-sectional area. Diagram

Claims (2)

[Claims] (1) A central magnetic leg, side magnetic legs arranged parallel to this,
A U-shaped core comprising a yoke portion that connects one end side of the center magnetic leg and one end side of the side magnetic leg to each other, the U-shaped surface of the U-shaped core is connected to the side magnetic leg portion and the center. A U-shaped core characterized in that it is processed so as to be divided into a plurality of parts along a groove provided between a magnetic leg and a side magnetic leg. (2) The U-shaped core according to claim 1, characterized in that the cross-sectional area of the central magnetic leg is smaller than the cross-sectional area of the side magnetic legs.