JPH04109610A - Manufacture of u-shaped core - Google Patents

Abstract

PURPOSE:To simplify the process of manufacture of a U-shaped core by molding a magnetic material into a U-shape, which has a pair of side pillars and a common pillar to connect one end of each of the side pillars, and cutting the material to divide its U-shaped face into a plurality of sections. CONSTITUTION:A magnetic material is molded by single-acting press into a U-shape having a pair of side pillars 62 and 63 and a common pillar 65 to connect one end of each of the side pillars 62 and 63 and cut divide its U-shaped face into a plurality of sections. A U-shaped core, which consists of a central magnetic foot 82, a side magnetic leg 83 parallel thereto, and a yoke 85 to connect the central magnetic leg 82 and the side magnetic leg 83, is made. Thereby a U-shaped core of structure with effectively used dimensions is obtained by a simple process of manufacture without using a large-scale mold.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a U-air core made of a magnetic material used for a magnetic core of a choke coil, a noise filter, etc. The present invention relates to a method for manufacturing a U-shaped core by performing molding and cutting.

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

Therefore, there is a strong demand for choke coils, noise filters, and the like used in 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.

A U-shaped core is known as a magnetic core incorporated in the choke coil or the like, and a conventional example of the U-shaped core will be described with reference to FIGS. 6 and 7.

In FIG. 6, a U-shaped core 1 made of a magnetic material such as ferrite has a central magnetic leg 2 that is elongated upward, and side magnetic legs 3 that have the same shape as the central magnetic leg 2. The yoke portions 5 are disposed through the yoke portion 5, and each end is connected by a yoke portion 5.

At this time, the surfaces opposite to the connecting surfaces where the central magnetic leg 2 and the side magnetic legs 3 are connected to the yoke part 5 are formed on the same plane, and the central magnetic leg 2, the III magnetic leg 3 and the yoke part The upper and lower rectangular surfaces constituted by 5 are also formed on the same plane.

A coil bobbin 6 made of a fill material wound with enameled wire or the like is fitted into the central magnetic leg 2 of the U-shaped core 1, as shown by the imaginary line in the figure. By combining the U-shaped core 1 with another U-shaped core, the choke coil or the like can be 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
It protrudes 7 widths from the upper and lower surfaces of the central magnetic leg 2 of the U-shaped core 1, so it cannot be said that the dimensions of each part are effectively utilized in the structural design of the U-shaped core 1, and the transformer etc. There were problems such as poor stability when mounting on a printing board, etc.

For this reason, a U-shaped core has been devised with a structural design that makes effective use of the dimensions of each part, and this U-shaped core will be explained with reference to FIG. 7.

In the U-shaped core 11, a laterally elongated central magnetic leg 12 extends from approximately the center of the right front side of the yoke portion 15, and a side magnetic leg 13 extends from the central magnetic leg 12 through a groove 14. is arranged, and one end of the side magnetic leg 13 is connected to the yoke portion 15.

At this time, the center magnetic leg 12 and the side magnetic legs 13 are connected to the yoke portion 1.
5 are formed on the same plane, and the upper and lower diamond-shaped surfaces constituted by the side stones 1113 and the yoke portion 15 are also formed on the same plane.

Further, since the central magnetic leg 12 is connected to the substantially central portion of the right front surface of the yoke portion 15, there are spaces 17a, 1.7
b is provided.

A coil bobbin 16 is fitted into the central magnetic leg 12 of the U-shaped core 11, as shown by the imaginary line in the same figure, and further, by combining the U-shaped core 11 with another diamond-shaped core, , choke coils, etc. are formed.

According to the U-shaped core 11, the central magnetic leg 12 is elongated in the lateral direction, and spaces 17a, 17b are formed at the upper and lower portions of the central magnetic leg 12 compared to the height of the side 1ifllllII13 and the yoke portion 15. Since the coil bobbin 16 fitted to the central magnetic leg 12 does not substantially protrude beyond the upper and lower surfaces of the side magnetic legs 13 and the yoke portion 15, the U-shaped core 11 can be made smaller. This means that a structural design corresponding to the above has been made.

Next, a manufacturing method for manufacturing the U-shaped core I using a dry single-acting press device 25 will be described in FIGS. 8(a) and (
This will be explained with reference to b).

FIG. 8(a) is a plan view showing a state in which the lower mold 23 is fitted into the formwork 21 of the single-acting press device 25, and FIG.
), the granulated powder 24 made of a magnetic material filled in the U plastic molding hole 21a of the same mold 21 is transferred to the upper mold 22 and the lower mold 23.
FIG. 3 is a cross-sectional view taken along line AA, showing a state in which pressure is applied.

The lower mold 23 is inserted from below into the U plastic molding hole 21a formed in the formwork 21, and the granulated powder 24 made of a magnetic material is filled into the U plastic molding hole 21a, and the upper mold 2 is inserted from above.
2 is inserted and pressurized to mold the U-shaped core 1.

At this time, the pressure surface of the upper mold 22 and the pressure surface of the lower mold 23 are
In order to uniformly pressurize the granulated powder 24, the central magnetic legs 2. The upper and lower surfaces of each of the side magnetic legs 3 and the yoke portion 5 are formed on the same plane.

According to the above-mentioned single-acting type brace device 25, the U-shaped core l has a uniform density in each part, and the molding process is performed by a simple operation, so the single-acting type brace device 25 has a small size and a simple configuration. It had the characteristics of fast molding speed and suitable for mass production.

Next, the double-acting brace device 35 causes the U-shaped core 11 to
A manufacturing method for manufacturing the same will be explained with reference to FIGS. 9(a) and (b).

FIG. 9(a) is a plan view showing a state in which the lower mold 33 is fitted into the formwork 31 of the double-acting brake device 35, and FIG.
), the granulated powder 34 made of a magnetic material filled in the rectangular molding hole 31a of the mold frame 31 is inserted into the upper mold 32 and the lower mold 3.
FIG. 3 is a cross-sectional view taken along line B-B showing a state in which pressure is applied.

The lower mold 33 is inserted from below into the rectangular molding hole 31a formed in the formwork 31, and the rectangular molding hole 31. a
A granulated powder 34 made of a magnetic material is filled inside, and an upper mold 32 is inserted from above to apply pressure, thereby molding the U-shaped core 11.

At this time, the first lower mold pressing surface 33a and the second lower mold pressing surface 33b of the lower mold 33 are opposite to the upper mold pressing surface 32a of the upper mold 32.
is configured to double-act and operate, and the center magnetic leg 12 is molded approximately at the center of the right front side of the yoke portion 15, and the side magnetic legs 13 are molded.

(Problems to be Solved by the Invention) However, according to the above-mentioned conventional method for manufacturing a U-shaped core, it is difficult to form a U-shaped core in which a coil bobbin is efficiently accommodated and configured to have a low profile using a pressurizing press. In this case, a double-acting press device must be used as the pressure press device, and due to the characteristics of the double-acting press device, it is difficult to mold the magnetic material to a uniform density, and the molding process is difficult. There was a problem in that microcracks etc. were generated during the process.

Further, the double-acting press device is large and has complicated operation control, so the molding speed is slow, making it unsuitable for mass production.

The present invention has been made in view of the above circumstances, and has a U-shaped structure designed to effectively utilize the dimensions of each part through a simple manufacturing process without using large-scale molding equipment that is difficult to control. The present invention provides a method for manufacturing a U-shaped core.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a central magnetic leg,
In a method for manufacturing a U-shaped core, the U-shaped core includes a side magnetic leg arranged parallel to the side magnetic leg, 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. and a common column connecting one end of each of the pair of side columns, by molding a magnetic material into a U-shape, and cutting the U-shaped surface of the molded body so as to divide it into a plurality of parts. By manufacturing the U-shaped core by forming the center magnetic leg on one side column and using the other side column as the side magnetic leg,
This aims to achieve the above objectives.

(Operation) A material is molded into a U-shape having a pair of side pillars and a common pillar that connects one end of each of the pair of side pillars, and the molded surface of the molded body is cut into a plurality of parts. A central magnetic leg, side magnetic legs arranged parallel to the central magnetic leg, and a yoke portion that connects one end of the central magnetic leg and one end of the side magnetic leg to each other by processing.

It is possible to manufacture a U-shaped core consisting of:

In addition, a U-shaped core is manufactured by molding a magnetic material into a U-shape using a small and simple device such as a single-acting press, and cutting the shaped surface of the molded body. For,
There is no need to use large and complicated control devices such as double-acting braces.

Furthermore, in the U-shaped core manufactured by the above manufacturing process, the height of the central magnetic leg is formed to be lower than the height of the side magnetic legs, so that when the coil bobbin is fitted into the central magnetic leg, , it is possible to prevent the winding width of one of the coil bobbins from substantially protruding from the height of the side magnetic legs.

In the present invention, magnetic properties using a single-acting press or the like (Example) Examples of the present invention will be described in detail with reference to the drawings.

FIG. 1(a) is a perspective view showing an example of the molding process according to the method for manufacturing a U-shaped core of the present invention, and FIG. 1(b) is a U-shaped molded member formed by the molding process according to the same example. FIG. 1(c) is a perspective view showing an example of the cutting process according to the same example, and FIG. 1(d) shows a U-shaped core formed by the manufacturing method according to the same example. A perspective view, FIG. 2(a) is a U manufactured by the manufacturing method according to the same example.
FIG. 2(b) is a plan view showing the mold core, FIG. 2(b) is a sectional view showing the XX cross section of the U-shaped core manufactured by the manufacturing method according to the same example, and FIG. 3 is the U-shaped core according to the same example. FIG. 4 is a perspective view showing the shape of a U-shaped core produced by another manufacturing method according to the present invention, and FIG.
The figure is a perspective view showing the shape of a U-shaped core produced by another manufacturing method according to the present invention.

As shown in FIG. 1(a), approximately in the center of the formwork 51,
A concave U-shaped hole 51a is formed by molding or the like, and the U-shaped hole 51a has a female shape.

From below the U-shaped hole 51a of the formwork 51, the U-shaped hole 51
A lower mold 53 having the same shape as a is used as a male mold, and its upper part is inserted as shown by arrow I in the figure.

The U-shaped hole 51a is filled with granulated powder 54 made of a magnetic material.

From above the U-shaped hole 518 filled with the granulated powder 54,
An upper mold 52 having the same shape as the U-shaped hole 51a and the lower mold 53 serves as a male mold, and its lower part is inserted as shown by arrow I in the figure.

Therefore, the single-acting breath device 55 configured as described above
The granulated powder 54 filled in the U-shaped hole 51a of the upper die 5
2 upper mold pressure surface 52a and lower mold pressure surface 53a of the lower mold 53
The U-shaped molded member 6 shown in FIG. 1(b) is pressurized by
It is molded into 1.

The U-shaped molded member 61 has a first side post 62 and a second side post 63 disposed through a groove 64 on both sides, and one end of each of the first side post 62 and the second side post 63 is in common. The first side of the U-shaped molded member 61 is connected by a pillar 65, and the upper mold pressing surface 52a of the upper mold 52 and the lower mold pressing surface 53a of the lower mold 53 are flat-processed. Pillar 6
2. The upper and lower surfaces of each of the second side pillar 63 and the common pillar 65 are formed on the same plane.

Next, as shown in FIG. 1(c), a disc type grinder 71 made of an abrasive material or the like and a grinder device 73, which is rotatably attached to a rotating shaft 74, are driven by a drive device (not shown) as indicated by the arrow in the figure. The U-shaped molded member 61 is rotated in the direction of (2), and is moved in the direction of the arrow (2) in the figure by a moving mechanism (not shown).

Therefore, the first side post 62 of the U-shaped molded member 61
Along the longitudinal direction of the side column 62, the grinder device 73
The U-shaped core 81 is formed by cutting to a depth determined by the cutting width of the cutting surface 71a of the disc-shaped grinder 71 and the installation height of the rotary shaft 74, as shown in FIG. 1(d).

The U-shaped core 81 is formed into the first side column 62 by the cutting process.
A part of the common column 65 is cut to form a cutting groove 86.

Here, as shown in the figure, the U-shaped core 81 has a first
The side pillar 62 becomes the central magnetic leg 82, the second side pillar 63 becomes the side magnetic leg 83, the common pillar 65 becomes the yoke part 85, and the full part 64 becomes the groove 84.

The U-shaped core 81 has a U-shape when observed from above, as shown in FIG. 2(a).

Further, as shown in FIG. 2(b), the U-shaped core 81 has a cutting groove 86 cut into it, so that the height HI of the center magnetic leg 82 is higher than the height H2 of the side magnetic leg 83. It also has a low profile.

That is, as shown by the imaginary line in FIG. 1(d), when the coil bobbin 88 constituted by a coil or the like wound with enameled wire or the like is fitted into the central magnetic leg 82, the coil bobbin 88 The upper part of the winding can be prevented from substantially protruding above the height H2 of the side magnetic leg 83.

FIG. 3 shows a choke coil 91 constructed by combining the U-shaped cores manufactured by the manufacturing method of this embodiment and fitting the coil bobbin 88 into each central magnetic leg.

According to this embodiment, the small and simple single-acting breath device 5
5, the magnetic material is molded into a U-shaped molded member 61, and the U-shaped core is manufactured by cutting the U-shaped molded member 61 along the first common column 62. Manufacturing process becomes unnecessary.

In addition, in manufacturing the U-shaped core 81 that efficiently accommodates the coil bobbin and has a low profile that can be mounted on an electronic circuit board, etc., there is no need for a double-acting brace device that is large and has complicated operation control. The magnetic material is press-molded to have a uniform density, the molding speed is improved, mass production is possible, and microcracks etc. occurring in the U-shaped core can be prevented.

Further, in the U-shaped core 81 manufactured by the above manufacturing process, the height Hl of the central magnetic leg 82 is formed to be lower than the height H2 of the side magnetic leg 83, so that the coil bobbin 88 is 82, one coil winding width of the coil bobbin 88 can be prevented from protruding beyond the side magnetic leg 83. Therefore, it is possible to prevent the coil winding width of one side of the coil bobbin 88 from protruding beyond the side magnetic leg 83. Can be stably mounted.

Next, another embodiment of the present invention will be described with reference to FIG. 4.

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

When the ridge of the cutting surface 71a of the disc type grinder 71 of the grinder device 73 is curved, the U-shaped molded member 61 has a curved portion 102 in the cutting groove 86 cut by the grinder device 73. Formed U-shaped core1.
Ol can be produced, which further prevents microcracks from occurring in the U-shaped core 81.

Next, another embodiment of the present invention will be described with reference to FIG.

In this embodiment as well, the same parts as in the previous embodiment are denoted by the same reference numerals and the explanation thereof will be omitted.

If the ridge of the disk-type grinder 71 of the grinder device 73 is subjected to a tapering process, it is possible to manufacture a U-shaped core 111 in which a tapered part 112 is formed on the yoke part 85, and the cutting process is performed by the tapered part 112. Since the amount can be increased, the weight of the U-shaped core 1.11 can be further reduced.

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, followed by pressure molding. A ferrite core is formed by molding and firing.

In addition, in this example, in order to pressurize the granulated powder,
Although a single-acting type breather was used, the present invention is not limited to this, and a type 5 extrusion molding machine or the like may also be used.

Further, in this embodiment, a rotating disc-shaped grinder device is used for cutting, but the present invention is not limited to this, and for example, a rotating belt-shaped sander or the like may be used.

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

(1) Manufacture a U-shaped core by molding magnetic material into a U-shaped molded member using a small and simple single-acting press, etc., and cutting the U-shaped surface of the molded body into multiple parts. Therefore, it has the excellent effect of simplifying the manufacturing process of the U-shaped fan to be incorporated into a choke coil or the like.

(2) In addition, the U-shaped core is formed to efficiently accommodate the coil bobbin and has a low profile so that it can be mounted on an electronic circuit board, etc.
The U-shaped core is manufactured by molding the magnetic material into a U-shaped molded member using a single-acting press device, without the need for molding using a large double-acting press device with complicated operation control. It has the advantage of being pressure molded with uniform density, improving molding speed, enabling mass production, and preventing microcracks that occur due to pressurization with a double-acting press machine. have an effect.

(3) In addition, in the U-shaped core manufactured by the above manufacturing process, the height of the central magnetic leg is formed to be lower than the height of the side magnetic legs, so that the coil bobbin is fitted into the central magnetic leg. When the winding width of one coil of the coil bobbin is lower than the height of the side magnetic leg, it is possible to prevent the coil winding width of one side of the coil bobbin from protruding beyond the height of the side magnetic leg, thereby stably mounting a choke coil or the like in which the U-shaped core is incorporated on an electronic circuit board or the like. It has the excellent effect of being able to

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing an example of the molding process according to the method for manufacturing a U-shaped core of the present invention, and FIG. 1(b) is a U-shaped molded member formed by the molding process according to the same example. FIG. 1(c) is a perspective view showing an example of the cutting process according to the same example, and FIG. 1(d) shows a U-shaped core formed by the manufacturing method according to the same example. A perspective view, FIG. 2(a) is a plan view showing a U-shaped core manufactured by the manufacturing method according to the same example, and FIG. 2(b) is a U-shaped core manufactured by the manufacturing method according to the same example. FIG. 3 is an explanatory diagram illustrating a state in which U-shaped cores according to the same embodiment are combined, and FIG. 4 is a U-shaped core according to another manufacturing method according to the present invention. FIG. 5 is a perspective view showing the shape of a U-shaped core according to another manufacturing method according to the present invention. FIGS. 6 and 7 are perspective views showing a conventional diamond-shaped core. Figure (a) is an explanatory diagram illustrating a method of manufacturing a U-shaped core using a conventional single-acting type brace, Figure 8 (b) is a sectional view showing the A-A cross section of the single-acting type brace, Figure 9 (a) ) is an explanatory diagram illustrating a method of manufacturing a U-shaped core using a conventional double-acting type brace, and FIG. 9(b) is a sectional view showing a BB cross section of the double-acting type press. 55 ・ ・ 61 ・ ・ 62 ・ 65 ・ 71 ・ 73 ・ 81 ・ 82 ・ 85 ・ ・Single acting type brace! - U-shaped molded member, - First side column, 63... - Common column, disk type grinder, - Grinder device, - U-shaped core, - Center magnetic leg, 83... - Yoke part, 86... Second (lIll pillar/side magnetic leg, cutting groove. Fig. 1

Claims (1)

[Claims] (1) A central magnetic leg, side magnetic legs arranged parallel to this,
A method for manufacturing 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 central magnetic leg is formed on one side column by molding a magnetic material into a U-shape having a common column and cutting the U-shaped surface of the molded body into a plurality of parts. A method for manufacturing a U-shaped core, characterized in that the U-shaped core is manufactured by using the other side pillar as the side magnetic leg.