JPH0766890B2 - U-shaped core - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a U-shaped core made of a magnetic material used for a magnetic core such as a choke coil and a noise filter, and more specifically, reduced in size and weight. At the same time, the present invention relates to a U-shaped core in which a coil bobbin fitted to a magnetic core is securely locked and a coil component or the like can be manufactured robustly.

(Prior Art) In recent years, there has been an increasing demand for miniaturization of electronic devices, and in particular, there has been a demand for thin and lightweight electronic devices that can be carried and used outdoors or indoors.

Therefore, the choke coil, the noise filter, and the like, which are components of these electronic devices, are also desired to be small and lightweight.

Therefore, even for the core made of a magnetic material used as a magnetic core such as the choke coil and the noise filter, thinning and weight reduction are strongly demanded, and various proposals have been made so far.

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.

In FIG. 9, U made of a magnetic material such as ferrite
The mold core 1 includes a central magnetic leg 2 that is elongated in the longitudinal direction, and a shape that is substantially the same as the central magnetic leg 2 (the cross-sectional area of the central magnetic leg 2 and the side magnetic legs 3).
And a side magnetic leg 3 having a cross-sectional area of substantially the same) and a side magnetic leg 3 are arranged in parallel through a groove 4, and one end of each of them is a yoke portion 5.
It is configured by being connected by.

At this time, since the central magnetic leg 2 and the side magnetic leg 3 are connected to the yoke portion 5 on the opposite side to each other, the U-shaped cores 1 are generally combined to form a coil or the like.
It is formed on the same surface.

Further, the upper and lower U-shaped surfaces formed by the central magnetic leg 2, the side magnetic legs 3 and the yoke portion 5 of the U-shaped core 1 are generally formed on the same plane.

A coil bobbin 6 around which an enamel wire or the like is wound is fitted to the central magnetic leg 2 of the U-shaped core 1 as shown by a virtual line in the figure.

Therefore, the U-shaped core 1 constitutes a coil by fitting the coil bobbin 6 to the central magnetic leg 2 and combining it with another U-shaped core or I-shaped core. .

When the coil bobbin 6 is fitted to the U-shaped core 1 as described above, the upper and lower windings of the coil bobbin 6 are
From the upper and lower surfaces of the central magnetic leg 2 of the U-shaped core 1, Za and
Zb width will be projected.

This does not mean that the mounting height when mounting the coil or the like composed of the U-shaped core 1 on the electronic circuit board or the like is low, and the mounting is not stable. was there.

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

The U-shaped core 11 has a laterally elongated central magnetic leg 12 and a substantially same shape as the central magnetic leg 12 (a cross-sectional area of the central magnetic leg 12 and a side magnetic leg).
The cross-sectional area of 13 is approximately the same), and the side magnetic legs 13 that are elongated in the longitudinal direction are arranged in parallel through the groove 14, and one end of each is connected by the yoke portion 5. It is composed by.

At this time, the opposite surface of the connecting surface where the central magnetic leg 12 and the side magnetic leg 13 are connected to the yoke portion 15 is formed on the same surface and is formed by the side magnetic leg 13 and the yoke portion 15. The upper L-shaped surface and the lower U-shaped surface formed by the central magnetic leg 12, the side magnetic legs 13 and the yoke portion 15 are also formed on the same plane.

Since the U-shaped core 11 has a space 17 obtained by subtracting the height of the central magnetic leg 12 from the height of the side magnetic leg 13 and the yoke portion 15, 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 molded by pressing a powdery magnetic material with a double-action pressing machine (not shown) having a plurality of pressing surfaces.

(Problems to be Solved by the Invention) However, the above-described conventional central magnetic leg and side magnetic legs have substantially the same cross-sectional area, and the upper and lower U-shaped surfaces of the central magnetic leg, the side magnetic legs, and the yoke portion are in the same plane. According to the formed U-shaped core, when the coil bobbin is fitted to the central magnetic leg, the upper and lower winding portions of the coil bobbin protrude from the U-shaped surface, and the coil is formed by assembling the U-shaped core. However, there is a problem that they are taller than other electronic parts and the like, and the protrusions become obstacles, so that the coil cannot be stably mounted on an electronic circuit board or the like.

Further, the central magnetic leg is extended from the side magnetic leg with a space from the upper surface of the side magnetic leg and the yoke portion so that the coil bobbin can be accommodated efficiently and the height of the coil etc. can be made low. In the U-shaped core, since the central magnetic leg is elongated in the lateral direction (horizontal direction), the strength of the magnetic core is weakened, and it is easily damaged by internal stress received when the coil bobbin is fitted on the central magnetic leg. Further, there is a problem that the strength of the completed coil component becomes weak because the coil bobbin after fitting is not securely locked to the magnetic core against wobbling.

The present invention has been made in view of the above circumstances, and is a U-shape that is compact and lightweight, and is capable of reliably manufacturing a coil component and the like while securely engaging with a coil bobbin fitted to a magnetic core. It provides the core.

(Means for Solving the Problems) According to the present invention, a central magnetic leg, a side magnetic leg arranged in parallel with the central magnetic leg, and one end side of the central magnetic leg and one end side of the side magnetic leg are connected to each other. In a U-shaped core composed of a yoke portion, a magnetic core is provided, a portion extending from the central magnetic leg connection side of the yoke portion to the side magnetic leg connection portion, and a part of the side magnetic leg on the central magnetic leg side. A part of the U-shaped upper surface of the U-shaped core is cut along the leg direction so as to be horizontally cut so as to be lower than the height of the remaining side of the side magnetic leg and the yoke portion, and a step portion is formed on the side magnetic leg. The above object is achieved by providing a U-shaped core characterized by being formed.

(Operation) In the present invention, the central magnetic leg, the side magnetic legs arranged in parallel with the central magnetic leg, and the yoke portion connecting the one end side of the central magnetic leg and the one end side of the side magnetic leg to each other. In the U-shaped core, the central magnetic leg, the portion from the central magnetic leg connecting side of the yoke portion to the side magnetic leg connecting portion, and the part of the side magnetic leg on the central magnetic leg side are extended along the magnetic leg direction. Since a part of the U-shaped upper surface of the U-shaped core is cut horizontally so as to be lower than the height of the rest of the side magnetic leg and the yoke portion, the step portion is formed in the side magnetic leg. Since the winding portion can be made low in height, and the central magnetic leg, the yoke portion, and a part of the side magnetic leg are cut off, a significant weight reduction of the core can be achieved and the coil component can be reduced in weight.

Further, the stepped portion of the side magnetic leg and the locking projection formed on the coil bobbin can be abutted and locked, and the internal stress and the like received when the coil bobbin is fitted to the central magnetic leg can be relaxed by the locking portion. Therefore, the central magnetic leg, the coil bobbin, and the like can be protected from damage and the like, and the coil and the like configured by the U-shaped core can be reliably and robustly manufactured.

(Example) The Example of this invention is described in detail based on drawing.

1 is a perspective view showing an embodiment of a U-shaped core according to the present invention, and FIG. 2 (a) is a plan view showing the U-shaped core of the same embodiment.
2 (b) is a cross-sectional view showing an X-X cross section of the U-shaped core of the same embodiment, and FIG. 3 is a plan view showing a coil formed by combining one set of U-shaped cores according to the same embodiment. FIG. 4 is a perspective view showing a coil bobbin fitted to the central magnetic leg of the U-shaped core according to the same embodiment, and FIG. 5 is a coil constructed by combining one set of U-shaped cores according to the same embodiment. FIG. 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. Is a perspective view showing another U-shaped core according to the present invention, and FIG. 8 is a perspective view showing another U-shaped core according to the present invention.

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

The magnetic material in powder form is connected to the central magnetic leg, the side magnetic leg arranged in parallel with the central magnetic leg, and one end side of the central magnetic leg and one end side of the side magnetic leg by a single-acting press device or the like. Forming a U-shaped molded member having a yoke portion to be processed.

The single-acting type press machine is different from the double-acting type press machine in which a plurality of pressurizing surfaces are interlocked with each other to process a magnetic material. Easy operation control and suitable for mass production.

At this time, since the pressing surface of the single-acting type press machine is flattened, the upper and lower U-shaped surfaces formed by the central magnetic leg, the side magnetic legs and the yoke portion of the U-shaped molding member are flat. Is doing.

Next, the U-shaped molded member was equipped with a disk-type grinder in which the central magnetic leg, the yoke portion and a part of the side magnetic leg were formed along with the side magnetic leg by an abrasive material or the like. It is cut by a grinder device.

At this time, the cutting width by the cutting process reaches another region where a part of the side magnetic leg remains, and the depth depends on the installation height of the rotary shaft on which the disc grinder is mounted.

As shown in FIG. 1, the U-shaped core 51 manufactured as described above includes a central magnetic leg 52 having a substantially square shape by the cutting, a side magnetic leg 53 having an elongated shape in the longitudinal direction, Are arranged in parallel through the groove 54, and one ends thereof are connected by the yoke portion 55, respectively.

At this time, the upper surface of the central magnetic leg 52 is horizontally cut by the cutting process to form a notch 57, and the yoke 55 extending from the connecting portion of the central magnetic leg 52 to the connecting portion of the side magnetic leg 53 is formed. An upper surface is partially cut out horizontally to form a notch portion 56, and further, the yoke portion 55 and a part of the side magnetic leg 53 following the excessive notch portion 56 are partially notched horizontally along the magnetic leg direction. A side magnetic leg notch 58 is formed by being cut.

Therefore, the side magnetic leg 53 is formed with a stepped portion constituted by the side magnetic leg cutout portion 58, the vertical surface portion 59, and the upper surface of the cutout remaining portion by cutting.

The U-shaped core 51 has a U-shaped upper surface and a lower surface as can be seen by referring to FIG.

Further, as shown in FIG. 2 (b), the central magnetic leg 52 and the yoke portion 55 are partially formed with the cutout portion 57 and the extra cutout portion 56, so that the central magnetic leg 52 is The height of the side magnetic leg 53 is reduced by the height H1 of the central magnetic leg 52 from the height H2 of the side magnetic leg 53 to form a low profile.

Therefore, when the coil bobbin 65 (indicated by phantom lines) on which the enamel wire or the like is wound is fitted to the central magnetic leg 52, the winding portion 66 above the coil bobbin 65 has the side magnetic leg 53 and the yoke. It is possible to prevent the portion 55 from protruding beyond the height H2.

Further, referring to the figure, the U-shaped core 51 is provided with the cutout portion 57.
By forming the and the notch 56, approximately twice the central magnetic leg cross-sectional area 62 of the central magnetic leg 52 is equal to the side magnetic leg cross-sectional area of the side magnetic leg 53.
It is 63.

U-shaped core in which the coil bobbin 65 is fitted to the central magnetic leg 52.
51 is another U having a line-symmetrical shape as shown in FIG.
By being combined with the mold core 61, the coil 60 such as a choke coil or a noise filter is configured.

Here, an example of the shape of the coil bobbin 65 will be described with reference to FIG. 4. A substantially square insertion hole 69a and an insertion hole 69b into which the central magnetic leg 52 is inserted are formed in the center. The fitting frames 68a and 68b are arranged in parallel with each other, and the fitting frames 68a and 68b are connected to each other by the support plate 64 below the insertion holes 69a and 69b.

Further, on the upper right side of the fitting frames 68a, 68b, a locking projection that is locked by being brought into contact with the side magnetic leg notch 58.
67 is projected.

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

The U-shaped core 51 and another U-shaped core 61 are connected to the coil bobbin.
The structure of the coil 60 mounted on the coil 65 will be described with reference to FIG.

Insertion hole 69a of the coil bobbin 65 in which the winding portion 66 is mounted,
The central magnetic leg 52 of the U-shaped core 51 and the central magnetic leg of another U-shaped core 61 are fitted and inserted in 69b.

At this time, the locking projection 67 is brought into abutment engagement with the side magnetic leg notch 58.

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

According to the U-shaped core 51 of this embodiment, the notch 57 is formed by cutting the central magnetic leg 52, the yoke portion 55, and a part of the side magnetic leg 53 on one U-shaped surface of the U-shaped core 51. Since the excess cutout 56 and the side magnetic leg cutout 58 are formed, the height H1 of the central magnetic leg 52 is formed to be lower than the height H2 of the side magnetic leg 53, and the central magnetic leg 52 is formed. When the coil bobbin 65 is fitted to
The coil bobbin 65 is subtracted from the height H2 by the height H1.
It is possible to prevent the upper part of the winding of the coil from protruding, and thus the coil and the like formed by the U-shaped core can be made low in height.

Further, the U-shaped core 51 is cut into the central magnetic leg 52, the yoke portion 55 from the connecting portion of the central magnetic leg 52 to a portion of the groove 54, and a part of the side magnetic leg 53 by the cutting process, and is cut out respectively. Since the portion 57, the extra cutout portion 56, and the side magnetic leg cutout portion 58 are cut out, the weight of the U-shaped core 51 and the coil 60 can be reduced by the amount of the magnetic material cut out by the cutout.

Further, the U-shaped core 51 has a side magnetic leg notch 58, since the side magnetic leg notch 58, the vertical surface portion 59, and the step portion constituted by the upper surface of the notch remaining portion are notched in the side magnetic leg 53. And the locking protrusion 67 formed on the coil bobbin 65 can be abutted and locked, and thereby the internal stress or the like received when the coil bobbin 65 is fitted to the central magnetic leg 52 can be alleviated. Magnetic leg 52
In addition, the coil bobbin 65 and the like can be protected from damage and the like, and the coil and the like configured by the U-shaped core can be reliably and robustly manufactured.

Further, in the present embodiment, the case where the central magnetic leg 52 has a substantially square shape has been described, but the present invention is not limited to this. For example, the central magnetic leg 52 may have a long shape in the vertical direction, and the horizontal direction. May have an oblong shape, or may have a substantially elliptical shape.

Next, another embodiment according to the present invention is shown in FIG.
Description will be given with reference to (b).

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

The grinder device used for cutting in the present embodiment has, for example, a disc type grinder, and the side magnetic leg 53 side of the disc type grinder is tapered, and the central magnetic leg 52 and The upper part from the central magnetic leg 52 to the groove 54 is partially cut out horizontally to form a cutout portion 57 and a surplus cutout portion 56, and a part of the side magnetic leg 53 is cut out obliquely to form a side magnetic leg taper. The part 78 is formed.

At this time, the taper portion formed on the disc grinder is not so large that the side magnetic leg taper portion 78 reaches the upper surface of the side magnetic leg 53. A vertical portion 74 which is vertical to the taper portion 78 is formed.

The coil bobbin 75 having the winding portion 66 on the central magnetic leg 52 is fitted to the U-shaped core 71 manufactured as described above. At this time, the locking protrusion 77 formed on the coil bobbin 75 and the The side magnetic leg taper portion 78 and the side magnetic leg taper portion 78 are abutted and locked.

Also in this embodiment, the same effect as the previous embodiment is obtained.

Further, by making the taper portion formed in the disk type grinder provided in the grinder device wider than that in the previous embodiment, the taper is tapered to the upper surface of the side magnetic leg 53 as shown in FIG. U-shaped core with machined side magnetic leg taper 88
81 can also be formed.

Further, when the ridge portion of the disk type grinder in the grinder device used for the above-mentioned cutting is subjected to the curved surface processing, as shown in FIG. 8, the side magnetic leg taper portion 98 and the vertical portion are formed.
It is possible to form the U-shaped core 91 having 99, which can prevent generation of microcracks or the like in each part of the U-shaped core in the step of combining the U-shaped cores or the like.

When iron powder is applied to the magnetic material, a dust core is formed by pressure molding, and when ferrite powder is applied, a binder is added to the ferrite powder to granulate and add. 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 effects described below.

(1) Since the central magnetic leg of the U-shaped core and the yoke and part of the side magnetic leg are machined, a significant weight reduction of the core is achieved, and a coil or the like incorporating the U-shaped core is provided. It has an excellent effect of reducing the weight.

(2) In addition, the U-shaped core is capable of abutting and locking the side magnetic leg notch portion of the side magnetic leg formed by cutting and the locking protrusion formed on the coil bobbin, and the coil bobbin by the corresponding contact portion. Since it is possible to relieve the internal stress and the like received when fitting the core to the central magnetic leg, the central magnetic leg and the coil bobbin, etc. can be protected, and the coil etc. composed of the U-shaped core can be manufactured reliably and robustly It has an excellent effect of being able to.

[Brief description of drawings]

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 the U-shaped core of the same embodiment, and FIG. 2 (b) is a U of the same embodiment. FIG. 3 is a plan view showing a coil formed by combining a set of U-shaped cores according to the same embodiment, and FIG. 4 is a U-shaped structure according to the same embodiment. FIG. 6 is a perspective view showing a coil bobbin fitted to the central magnetic leg of the die core, FIG. 5 is a perspective view showing a coil formed by combining a set of U-shaped cores according to the same embodiment, and FIG. ) Is a perspective view showing another U-shaped core according to the present invention, FIG. 6B is a side view showing a side surface of the U-shaped core of the same embodiment, and FIG. 7 is another U-shaped core according to the present invention. FIG. 8 is a perspective view showing another U-shaped core according to the present invention, FIG. 9 is a perspective view showing a conventional U-shaped core, and FIG. 10 is another. It is a perspective view which shows the conventional U-shaped core. 51 …… U-shaped core, 52 …… Central magnetic leg, 53 …… Side magnetic leg, 55 …… Yoke part, 56 …… Excessive notch, 57 …… Notch, 58 …… Side magnetic leg notch, 62 …… Central magnetic leg cross-sectional area, 63 …… Side magnetic leg cross-sectional area.

Claims (1)

[Claims] 1. A U-shaped structure comprising a central magnetic leg, a side magnetic leg arranged parallel to the central magnetic leg, and a yoke portion connecting one end side of the central magnetic leg and one end side of the side magnetic leg to each other. In the core, the central magnetic leg, the portion from the central magnetic leg connecting side of the yoke portion to the side magnetic leg connecting portion, and the part of the side magnetic leg on the central magnetic leg side are extended along the magnetic leg direction along the magnetic leg direction. A step is formed in the side magnetic leg by processing a part of the U-shaped upper surface of the core so as to be horizontally cut so as to be lower than the height of the side magnetic leg and the rest of the yoke portion. Type core.